Rsv-specific binding molecules and means for producing them
Abstract
An isolated antibody or functional part thereof that is capable of specifically binding with the respiratory syncytial virus (VSR) F antigen, and in which the antibody or functional part thereof comprises: a. a heavy chain complementarity determining region (CDR) 1 comprising the amino acid sequence NYIIN (SEQ ID NO: 1), a heavy chain CDR2 comprising the amino acid sequence GIIPVLGTVHYAPKFQG (SEQ ID NO: 2), a CDR3 of heavy chain comprising the amino acid sequence ETALVVSTTYLPHYFDN (SEQ ID NO: 3), a light chain CDR1 comprising the amino acid sequence QASQDIVNYLN (SEQ ID NO: 4), a light chain CDR2 comprising the amino acid sequence VASNLET (SEQ ID NO: 5), and a light chain CDR3 comprising the amino acid sequence QQYDNLP (SEQ ID NO: 6); or b. a heavy chain CDR 1 comprising the amino acid sequence GFSFSHYA (SEQ ID NO: 73), a heavy chain CDR2 comprising the amino acid sequence ISYDGENT (SEQ ID NO: 74), a heavy chain CDR3 comprising the sequence of amino acids ARDRIVDDYYYYGMDV (SEQ ID NO: 75), a light chain CDR1 comprising the amino acid sequence QDIKKY (SEQ ID NO: 76), a light chain CDR2 comprising the DAS amino acid sequence and a light chain CDR3 comprising the amino acid sequence QQYDNLPPLT (SEQ ID NO: 77); or c. a heavy chain CDR 1 comprising the amino acid sequence GFTFSSYN (SEQ ID NO: 80), a heavy chain CDR2 comprising the amino acid sequence ISAGSSYI (SEQ ID NO: 81), a heavy chain CDR3 comprising the sequence amino acid AREDYGPGNYYSPNWFDP (SEQ ID NO: 82), a light chain CDR1 comprising the amino acid sequence SSNIGAGYD (SEQ ID NO: 83), a light chain CDR2 comprising the GNT amino acid sequence and a light chain CDR3 comprising the HSYDRSLSG amino acid sequence (SEQ ID NO: 84); or d. a heavy chain CDR 1 comprising the amino acid sequence GFNFHNYG (SEQ ID NO: 87), a heavy chain CDR2 comprising the amino acid sequence VWYDGSKK (SEQ ID NO: 88), a heavy chain CDR3 comprising the sequence of amino acids VRDKVGPTPYFDS (SEQ ID NO: 89), a light chain CDR1 comprising the amino acid sequence NIGSET (SEQ ID NO: 90), a light chain CDR2 comprising the DDD amino acid sequence, and a light chain CDR3 comprising the amino acid sequence QVWDRSNYHQV (SEQ ID NO: 91).

Term
1.7 yearsto projected expiry
Projected expiry 30 May 2028, counted from filing; an application has no term until it is granted.
- Priority
- Filed
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- Today
- Projected expiry
11 claims: 3 independent, 8 dependent
- 1ES 2 575 129 T3 REIVINDICACIONES 1. Un anticuerpo aislado o parte funcional del mismo que es capaz de unirse específicamente con el antígeno F del virus sincitial respiratorio (VSR), y en el que el anticuerpo o parte funcional del mismo comprende:a. una región determinante de complementariedad (CDR) 1 de cadena pesada que comprende la secuencia de aminoácidos NYIIN (SEQ ID NO: 1), una CDR2 de cadena pesada que comprende la secuencia de aminoácidos GIIPVLGTVHYAPKFqG (SEQ ID NO: 2), una CDR3 de cadena pesada que comprende la secuencia de aminoácidos ETALVVSTTYLPHYFDN (SeQ ID NO: 3), una CDR1 de cadena ligera que comprende la secuencia de aminoácidos QASQDIVNYLN (SEQ ID NO: 4), una CDR2 de cadena ligera que comprende la secuencia de aminoácidos VASNLET (SEQ ID NO: 5), y una CDR3 de cadena ligera que comprende la secuencia de aminoácidos QQYDNLP (SEQ ID NO: 6);o b. una CDR 1 de cadena pesada que comprende la secuencia de aminoácidos GFSFSHYA (SEQ ID NO: 73), una CDR2 de cadena pesada que comprende la secuencia de aminoácidos ISYDGENT (SEQ ID NO: 74), una CDR3 de cadena pesada que comprende la secuencia de aminoácidos ARDRIVDDYYYYGMDV (SEQ ID NO: 75), una CDR1 de cadena ligera que comprende la secuencia de aminoácidos QDIKKY (SEQ ID NO: 76), una CDR2 de cadena ligera que comprende la secuencia de aminoácidos DAS y una CDR3 de cadena ligera que comprende la secuencia de aminoácidos QQYDNLPPLT (SEQ ID NO: 77);o c. una CDR 1 de cadena pesada que comprende la secuencia de aminoácidos GFTFSSYN (SEQ ID NO: 80), una CDR2 de cadena pesada que comprende la secuencia de aminoácidos ISAGSSYI (SEQ ID NO: 81), una CDR3 de cadena pesada que comprende la secuencia de aminoácidos AREDYGPGNYYSPNWFDP (SEQ ID NO: 82), una CDR1 de cadena ligera que comprende la secuencia de aminoácidos SSNIGAGYD (SEQ ID NO: 83), una CDR2 de cadena ligera que comprende la secuencia de aminoácidos GNT y una CDR3 de cadena ligera que comprende la secuencia de aminoácidos HSYDRSLSG (SEQ ID NO: 84);o d. una CDR 1 de cadena pesada que comprende la secuencia de aminoácidos GFNFHNYG (SEQ ID NO: 87), una CDR2 de cadena pesada que comprende la secuencia de aminoácidos VWYDGSKK (SEQ ID NO: 88), una CDR3 de cadena pesada que comprende la secuencia de aminoácidos VRDKVGPTPYFDS (SEQ ID NO: 89), una CDR1 de cadena ligera que comprende la secuencia de aminoácidos NIGSET (SEQ ID NO: 90), una CDR2 de cadena ligera que comprende la secuencia de aminoácidos DDD, y una CDR3 de cadena ligera que comprende la secuencia de aminoácidos QVWDRSNYHQV (SEQ ID NO: 91).
- 2El anticuerpo o parte funcional del mismo de la reivindicación 1, en el que el anticuerpo comprende una secuencia de cadena pesada variable que comprende la secuencia de aminoácidos QVQLVQSGAEVKKPGSSVMVSCQASGGPLRNYIINWLRQAPGQGPEWMGGIIPVLG TVHYAPKFQGRVTITADESTDTAYIHLISLRSEDTAMYYCATETA LVVSTTYLPHYFDN WGQGTLVTVSS (SEQ ID NO:7) y/o una secuencia de cadena ligera variable que comprende la secuencia de aminoácidos DIQMTQSPSSLSAAVGDRVTITCQASQDIVNYLNWYQQKPGKAPKLLIYVASNLETG VPSRFSGSGSGTDFSLTISSLQPEDVATYYCQQYDNLPLTFGGGT KVEIKRTV (SEQ ID NO: 8).
- 3El anticuerpo o parte funcional del mismo de la reivindicación 1, en el que la parte funcional del mismo es un anticuerpo de un único dominio, un anticuerpo monocatenario, un fragmento variable monocatenario (scFv), un fragmento Fab o un fragmento F(ab')2.
- 4Un ácido nucleico aislado que codifica el anticuerpo o parte funcional del mismo de una cualquiera de las reivindicaciones 1 a 3.
- 5La secuencia de ácido nucleico aislada de la reivindicación 4, en la que la secuencia de ácido nucleico comprende secuencias de nucleótidos de cadena pesada y ligera seleccionadas del grupo que consiste en:(i) SEQ ID NO: 9 y SEQ ID NO: 10;(ii) SEQ ID NO: 139 y SEQ ID NO: 141;y (iii) SEQ ID NO: 140 y SEQ ID NO: 142.
- 6Una célula que expresa la secuencia de ácido nucleico de la reivindicación 4 o 5.
- 7Un método para producir un anticuerpo o una parte funcional del mismo de una cualquiera de las reivindicaciones 1 a 3, comprendiendo los métodos cultivar en la célula de la reivindicación 6 in vitro, y obtener anticuerpos o partes funcionales de los mismos producidos por las células.
- 8Una composición que comprende el anticuerpo o parte funcional de una cualquiera de las reivindicaciones 1 a 6, y un vehículo, diluyente y/o excipiente farmacéuticamente aceptable.
- 9El anticuerpo o una parte funcional de una cualquiera de las reivindicaciones 1 a 3, o la composición de la reivindicación 8, o la secuencia de ácido nucleico de la reivindicación 4 o 5 para uso en el tratamiento o prevención de un trastorno relacionado con VSR, o para prevenir o contrarrestar los efectos adversos de una infección por VSR en un sujeto humano. ES 2 575 129 T3
- 10Uso del anticuerpo o una parte funcional de una cualquiera de las reivindicaciones 1 a 3, o la composición de la reivindicación 8, o la secuencia de ácido nucleico de la reivindicación 4 o 5 en la preparación de un medicamento para tratar o prevenir un trastorno relacionado con VSR, o prevenir o contrarrestar los efectos adversos de una infección por VSR en un sujeto humano.
- 11El anticuerpo o una parte funcional, composición o la secuencia de ácido nucleico de la reivindicación 9 para uso de la reivindicación 9, o el uso de la reivindicación 10, en el que el sujeto humano tiene una enfermedad pulmonar crónica, enfermedad cardíaca congénita o inmunidad comprometida, o el sujeto humano es un niño de menos de 6 semanas de edad o un sujeto anciano, opcionalmente en el que el anticuerpo o parte funcional del mismo se formula 10 para la administración a una dosificación de 0,1 a 10 mg/kg del peso corporal del sujeto humano.
Independent claims11
436 paragraphs in 53 sections, as filed
IS 2 575 129 T3
DESCRIPTION
RSV-specific binding molecules and means of producing them
The invention relates to the fields of biology and medicine.
Respiratory Syncytial Virus (RSV) is a common cold virus that belongs to the paramyxovirus family. RSV is virulent, easily transmissible, and the most common cause of lower respiratory tract disease in children less than 2 years of age. Up to 98% of children attending daycare will become infected in a single RSV season. Between 0.5% and 3.2% of children with RSV infection require hospitalization. There have been approximately 90,000 hospital admissions and 4,500 deaths annually in the United States. Important risk factors for hospitalization due to RSV are premature birth, chronic lung disease, congenital heart disease, compromised immunity, and age less than 6 weeks in otherwise healthy children. No effective treatment for RSV positive bronchiolitis is available other than palliative care in the form of adequate nutrition and oxygen therapy. Antiviral therapies such as ribavirin have not been shown to be effective in RSV infection. A monoclonal antibody, palivizumab (also called Synagis), is registered for prophylaxis against RSV infection. Palivizumab is an engineered (humanized) monoclonal antibody to the RSV fusion protein. However, palivizumab is not always effective. Therefore, there is a need for alternative antibodies and therapies against RSV in the art.
It is an object of the present invention to provide means and methods to counteract and / or prevent RSV-related disease. It is a further object of the invention to provide alternative and / or improved antibodies against RSV and to provide stable cells capable of producing antibodies against RSV.
Therefore the present invention provides the isolated antibodies of claims 1-3, the isolated nucleic acid sequences of claims 4-5, the cell of claim 6, the method of claim 7, the composition of claim 8 and the antibodies, nucleic acids or compositions of claims 911, for use of claim 9-11.
The present invention provides antibodies that are capable of specifically binding RSV. Such antibodies also referred to herein as "anti RSV antibodies" or "RSV specific antibodies", are capable of specifically binding with at least one RSV component, such as for example an epitope of a RSV protein. Non-specific binding is not encompassed by the term "specific binding". Anti RSV antibodies according to the present invention are particularly suitable for counteracting and / or at least in part preventing RSV infection and / or adverse effects of RSV infection. A particularly preferred anti RSV antibody according to the present invention is the antibody designated "D25", which has a heavy chain region and a light chain region as depicted in Figures 11A-D. The CDR sequences of D25, which in particular contribute to the antigen-binding properties of D25, are depicted in Figure HD. The D25 antibody appears to have superior characteristics compared to the registered anti RSV antibody Palivizumab (Figure 8). For example, D25 has an IC50 value of approximately 0.4-1.5 ng / ml in an in vitro neutralization assay in which HEp-2 cells are infected with RSV, whereas Palivizumab has an IC50 value of approximately 453 ng / ml.
A functional equivalent of an antibody is defined herein as a functional part, derivative, or analog of an antibody.
A functional part of an antibody is defined as a part that has at least one property the same as said antibody in type, not necessarily in quantity. Said functional part is capable of binding with the same antigen as said antibody, although not necessarily to the same degree. A functional part of an antibody preferably comprises a single domain antibody, a single chain antibody, a single chain variable fragment (scFv), an Fab fragment or an F (ab ') 2 fragment.
A functional derivative of an antibody is defined as an antibody that has been altered so that at least one property, preferably an antigen-binding property, of the resulting compound is essentially of the same type, not necessarily of the same amount. A derivative is provided in many ways, for example by conservative amino acid substitution, whereby one amino acid residue is substituted for another residue with generally similar properties (size, hydrophobicity, etc.), so that overall operation is probably not it is severely affected.
One skilled in the art is also capable of generating antibody analogs. This is done for example by scanning a peptide library or phage display library. Said analog has essentially at least one property the same as said antibody in type, not necessarily in quantity.
As is well known to one of ordinary skill in the art, an antibody heavy chain is the larger of the two types of chains that make up an immunoglobulin molecule. A heavy chain comprises constant domains
ES 2 575 129 T3 and a variable domain, said variable domain being involved in antigen binding. An antibody light chain is the smaller of the two types of chains that make up an immunoglobulin molecule. A light chain comprises a constant domain and a variable domain. The variable domain is, together with the heavy chain variable domain, involved in antigen binding.
Complementarity determining regions (CDRs) are the hypervariable regions present in heavy chain variable domains and light chain variable domains. The CDRs of a heavy chain and the linked light chain of an antibody together form the antigen-binding site.
Now that the present invention provides the information that the CDR sequences depicted in Figure 11 provide desired RSV binding characteristics, the variants may comprise at least one altered CDR sequence. For example, conservative amino acid substitution is applied. Conservative amino acid substitution involves substitution of one amino acid with another with generally similar properties (size, hydrophobicity, etc.), so that overall function is probably not seriously affected.
It is also possible to change at least one CDR sequence depicted in Figure 11 to generate a variant antibody, or a functional equivalent thereof, with at least one altered property compared to D25. An antibody or functional equivalent may comprise a CDR sequence that is at least 70% identical to a CDR sequence as depicted in Figure 11, such that the favorable binding characteristics of D25 are at least partially or even maintained. improve. A CDR sequence as depicted in Figure 11 can be altered so that the resulting antibody or functional equivalent comprises at least one improved property, such as for example improved binding affinity, selectivity and / or stability, compared to D25. Various methods of altering an amino acid sequence are available in the art. For example, a heavy chain or light chain sequence is artificially synthesized with a desired CDR sequence. Preferably, a nucleic acid sequence encoding a CDR sequence is mutated, for example using random, or directed mutagenesis.
Disclosed herein is an isolated, synthetic or recombinant antibody or a functional equivalent thereof that is capable of specifically binding respiratory syncytial virus and comprising:
- a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the NYIIN sequence and / or
- a heavy chain CDR2 sequence comprising a sequence that is at least 75% identical to the sequence GIIPVLGTVHYAPKFQG and / or
- a heavy chain CDR3 sequence comprising of a sequence that is at least 70% identical to the sequence ETALWSTTYLPH YFDN and / or
- a light chain CDR1 sequence comprising a sequence that is at least 85% identical to the QASQDIVNYLN sequence and / or
- a light chain CDR2 sequence comprising a sequence that is at least 70% identical to the VASNLET sequence.
Said antibody also comprises a light chain CDR3 sequence comprising a sequence that is at least 70% identical to the QQYDNLP sequence.
An antibody or a functional equivalent may comprise a CDR sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90% identical to at least one of the represented CDR sequences. in Figure HD. More preferably, an antibody or a functional equivalent may comprise a CDR sequence that is at least 95% identical to at least one of the CDR sequences depicted in Figure HD. The particularly preferred antibody D25, described above, comprises CDR sequences consisting of the CDR sequences depicted in Figure HD. A particularly preferred embodiment according to the invention therefore provides an isolated, synthetic or recombinant antibody or a functional equivalent thereof which is capable of specifically binding respiratory syncytial virus and which comprises:
- a heavy chain CDR1 sequence comprising the sequence NYIIN,
- a heavy chain CDR2 sequence comprising the GIIPVLGTVHYAPKFQG sequence, a heavy chain CDR3 sequence comprising the ETALWSTTYLPHYFDN sequence,
- a light chain CDR1 sequence comprising the QAS QD IVNYLN sequence,
- a light chain CDR2 sequence comprising the VASNLET sequence and a light chain CDR3 sequence comprising the QQYDNLP sequence.
An antibody is disclosed herein or a functional equivalent is provided comprising all three heavy chain CDR sequences and all three light chain CDR sequences as depicted in Figure HD, or sequences that are at least 70 %, preferably at least 80%, more preferably at least 85% identical thereto. Further disclosed is an isolated, synthetic or recombinant antibody or a
ES 2 575 129 T3 functional equivalent thereof comprising a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the NYIIN sequence and a heavy chain CDR2 sequence comprising a sequence that is at least 70 % identical to the GIIPVLGTVHYAPKFQG sequence and a heavy chain CDR3 sequence comprising a sequence that is at least 70% identical to the ETALWSTTYLPHYFDN sequence and a light chain CDR1 sequence comprising a sequence that is at least 70% identical to the QASQDIVNYLN sequence and a light chain CDR2 sequence that comprises a sequence that is at least 70% identical to the VASNLET sequence, and a light chain CDR3 sequence that comprises a sequence that it is at least 70% identical to the QQYDNLP sequence. Said antibody or functional equivalent preferably comprises CDR sequences that are at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% identical to the CDR sequences heavy chain and light chain CDR sequences as depicted in Figure HD. Also disclosed is an antibody or functional equivalent comprising the aforementioned CDR1, CDR2 and CDR3 heavy chain sequences as well as the aforementioned light chain CDR1, CDR2 and CDR3 sequences.
Also disclosed are antibodies or functional equivalents thereof that comprise a variable heavy chain amino acid sequence that is at least 70% identical to the heavy chain sequence as depicted in Figure 11. Such heavy chain sequences provide binding properties. at desired RSV, as demonstrated by the D25 antibody. An antibody or a functional equivalent thereof is therefore further disclosed, having a heavy chain sequence comprising a sequence that is at least 70% identical to the sequence.
QVQLVQSGAEVKKPGSSVMVSCQASGGPLRNYIINWLRQAPGQGPEWMGGIIPVLGTVHYAPKFQGRVTITADESTD TAYIHLISLRSEDTAMYYCATETALWSTTYLPHYFDNWGQGTLVTVSSS. In addition, variable light chain amino acid sequences that are at least 70% identical to the light chain sequence as depicted in Figure 11 also provide desired RSV binding properties, as demonstrated by the D25 antibody. Also disclosed is therefore an antibody, or a functional equivalent thereof having a light chain sequence that is at least 70% identical to the sequence, DIQMTQSPSSLSAAVGDRVTITCQASQDIVNYLNWYQQKPGKAPKLLIYVASN LETGVNPSLLLIYVASN LETGVNPSRFSGSGSGTYQFSLTIGVSGSGSGTDFSLDVPSLFGSGSGTDFSLIKTVPEDQTVPDLFGSGSGTQFSLIKTIPDFKTISGSGSGTDFSLQDVPSRFSGSGSGTDFSLTQVPKTLLIYVASNLETGVNPSRFSGSGSGTQDFSL. An antibody or a functional part may comprise a variable heavy chain sequence and / or a variable light chain sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90% , more preferably at least 95% identical to the heavy chain sequence and / or the light chain sequence as depicted in Figure 11. The higher the homology, the more closely said antibody or functional part will resemble the D25 antibody. An antibody or functional part may comprise a heavy chain as well as a light chain that resembles the heavy and light chain of D25. Thus further disclosed is an antibody or functional part comprising a heavy chain sequence and a light chain sequence which are at least 70%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%. %, more preferably at least 95% identical to the heavy chain sequence and the light chain sequence as depicted in Figure 11.
One embodiment provides an antibody comprising a heavy chain sequence consisting of the heavy chain sequence as depicted in Figure 11, and a light chain sequence consisting of the light chain sequence as depicted in Figure 11. Alternatively, as is well known to those skilled in the art, it is possible to generate a shortened heavy chain or light chain sequence while maintaining a binding property of interest. Preferably, said shortened heavy chain or light chain having a shorter constant region, compared to the original heavy or light chain, is generated. The variable domain preferably remains. For example, a Fab fragment or F (ab ') 2 fragment is produced based on a heavy chain sequence or light chain sequence depicted in Figure 11. Also disclosed is therefore a functional equivalent of an antibody comprising at least a functional part of a sequence as depicted in Figure 11. A functional part can be at least 20 amino acids long and can comprise a sequence that is at least 70% identical to the heavy chain CDRI sequence depicted in Figure HD, and / or a sequence that is at least 75% identical. to the heavy chain CDR2 sequence depicted in Figure HD and / or a sequence that is at least 70% identical to the heavy chain CDR3 sequence depicted in Figure HD, and / or a sequence that is at least 85% identical to the light chain CDR1 sequence depicted in Figure HD and / or a sequence that is at least 70% identical to the light chain CDR2 sequence depicted in Figure HD . Preferably, said functional part may also comprise a sequence that is at least 70% identical to the light chain CDR3 sequence depicted in Figure HD.
Another particularly preferred anti RSV antibody according to the present invention is the antibody designated "AM 14", which has a heavy chain region and a light chain region as depicted in Figure 14A. The CDR sequences of AM14, which in particular contribute to the antigen-binding properties of AM14, are also depicted in Figure 14A.
Now that the present invention provides the information that the CDR sequences depicted in Figure 14A provide desired RSV binding characteristics the variants may comprise at least one
ES 2 575 129 T3 CDR sequence altered. For example, conservative amino acid substitution is applied. Conservative amino acid substitution involves substitution of one amino acid with another with generally similar properties (size, hydrophobicity, etc.), so that overall function is probably not severely affected. It is also possible to change at least one CDR sequence depicted in Figure 14A to generate a variant antibody, or a functional equivalent thereof, with at least one altered property compared to AM14. An antibody or functional equivalent may comprise a CDR sequence that is at least 70% identical to a CDR sequence as depicted in Figure 14A, such that the favorable binding characteristics of AM14 are at least partially or even maintained. improve. A CDR sequence as depicted in Figure 14A can be altered so that the resulting antibody or functional equivalent comprises at least one improved property, such as for example improved binding affinity, selectivity and / or stability, compared to AM14.
Various methods of altering an amino acid sequence are available in the art. For example, a heavy chain or light chain sequence is artificially synthesized with a desired CDR sequence. Preferably, a nucleic acid sequence encoding a CDR sequence is mutated, for example using random, or directed mutagenesis.
Disclosed herein is an isolated, synthetic, or recombinant antibody or a portion, derivative, and / or functional analog thereof that is capable of specifically binding respiratory syncytial virus and comprising:
- a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the GFSFSHYA sequence, and / or
- a heavy chain CDR2 sequence comprising a sequence that is at least 70% identical to the ISYDGENT sequence, and / or
- a heavy chain CDR3 sequence comprising a sequence that is at least 70% identical to the ARDRIVDDYYYYGMDV sequence, and / or
- a light chain CDR1 sequence comprising a sequence that is at least 70% identical to the QDIKKY sequence, and / or
- a light chain CDR2 sequence comprising a sequence that is at least 70% identical to the DAS sequence, and / or
- a light chain CDR3 sequence comprising a sequence that is at least 70% identical to the sequence of NLPPLT QQYD.
An antibody or functional equivalent may comprise a CDR sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90% identical to at least one of the represented CDR sequences. in Figure 14A. More preferably, an antibody or a functional equivalent may comprise a CDR sequence that is at least 95% identical to at least one of the CDR sequences depicted in Figure 14A. The particularly preferred antibody AM14, described above, comprises CDR sequences consisting of the CDR sequences depicted in Figure 14A. A particularly preferred embodiment according to the invention therefore provides an isolated, synthetic or recombinant antibody which is capable of specifically binding with respiratory syncytial virus and which comprises:
a heavy chain CDR1 sequence comprising the GFSFSHYA sequence, a heavy chain CDR2 sequence comprising the ISYDGENT sequence, a heavy chain CDR3 sequence comprising the ARDRIVDDYYYYGMDV sequence, a light chain CDR1 sequence comprises the QDIKKY sequence, a light chain CDR2 sequence comprising the DAS sequence and a light chain CDR3 sequence comprising the QQYD NLPPLT sequence.
Disclosed herein is an antibody or functional equivalent comprising all three heavy chain CDR sequences and all three light chain CDR sequences as depicted in Figure 14A, or sequences that are at least 70% identical thereto. . An isolated antibody is therefore further disclosed, synthetic or recombinant or a functional equivalent thereof comprising a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the GFSFSHYA sequence and a heavy chain CDR2 sequence comprising a sequence that is at least 70 % identical to the ISYDGENT sequence and a heavy chain CDR3 sequence comprising a sequence that is at least 70% identical to the ARDRIVDDYYYYGMDV sequence and a light chain CDR1 sequence that comprises a sequence that is at least 70% identical to the QDIKKY sequence and a light chain CDR2 sequence that comprises a sequence that is at least 70% identical to the DAS sequence, and a light chain CDR3 sequence that comprises a sequence that is at least 70% identical to the QQYDNLPPLT sequence. Said antibody or functional equivalent preferably comprises CDR sequences that are at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% identical to the CDR sequences heavy chain and light chain CDR sequences as depicted in Figure 14A. Also disclosed is an antibody or functional equivalent that
ES 2 575 129 T3 comprises the aforementioned heavy chain CDR1, CDR2 and CDR3 sequences from Figure 14A as well as the above mentioned light chain CDR1, CDR2 and CDR3 sequences from Figure 14A.
Also disclosed are antibodies or functional equivalents thereof that comprise a heavy chain amino acid sequence that is at least 70% identical to a heavy chain sequence as depicted in Figure 14A. Such heavy chain sequences provide desired RSV binding properties, as demonstrated by the AM14 antibody. Also further disclosed is an antibody or a functional equivalent thereof, which has a heavy chain sequence comprising a sequence that is at least 70% identical to the sequence EVQLVESGGGWQPGRSLRLSCAASGFSFSHYAMHWVRQAPGKGLEWVAVIS YDGENTYYADSVKGRFSISRDNSKNYARDVSEDLQMVKGRFSISRDNSATTVSEDLQMVKGRFSISRDNSLTVSEDLQMVKGRFSISRDNSLTVSEDLQMVKGRFSISRDNSLTVSEDLQMVKGRFSISRDNSLTVSEDLQMDVKGRFSISRDNSLTVSEDLQMVKGRFSISRDNSLTVSEDLQMVKGRFSISRDNSLTVSEDLQMVKGRFSISDNS
In addition, light chain amino acid sequences that are at least 70% identical to a light chain sequence as depicted in Figure 14A also provide desired RSV binding properties, as demonstrated by the AM14 antibody. Therefore, an antibody, or a functional equivalent thereof, is also disclosed that has a light chain sequence that is at least 70% identical to the sequence DIQMTQS PS SLSASVGDRVT I TCQASQDIKKYLNWYHQKPGKVPELLMHDASNLETGVPSRF SGRGSGTKEDQVELTIGGPIKTDFTLTY SSLQPIKTGTLTYGPIKTDFTLTIGGTVPIKTDFTLTYGSGPIKTDFTLTY sequence. An antibody or functional part may preferably comprise a variable heavy chain sequence and / or a variable light chain sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%. , more preferably at least 95% identical to a heavy chain sequence and / or a light chain sequence as depicted in Figure 14A. The higher the homology, the more closely said antibody or functional part will resemble the AM14 antibody. An antibody or corresponding functional part may comprise a heavy chain as well as a light chain that resembles the heavy and light chain of AM14. Thus further disclosed is an antibody or functional part comprising a heavy chain sequence and a light chain sequence which are at least 70%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%. %, more preferably at least 95% identical to the heavy chain sequence and the light chain sequence as depicted in Figure 14A.
One embodiment provides an antibody comprising a heavy chain sequence consisting of the heavy chain sequence as depicted in Figure 14A, and a light chain sequence consisting of the light chain sequence as depicted in Figure 14a. Alternatively, as is well known to those of skill in the art, it is possible to generate a shortened heavy chain or light chain sequence while maintaining a binding property of interest. Preferably, said shortened heavy chain or light chain having a shorter constant region, compared to the original heavy or light chain, is generated. The variable domain preferably remains. For example, a Fab fragment or F (ab ') 2 fragment is produced based on a heavy chain sequence or light chain sequence depicted in Figure 14A. Therefore also disclosed is a functional equivalent of an antibody comprising at least a functional part of a sequence as depicted in Figure 14A. A functional part can be at least 20 amino acids in length and can comprise a sequence that is at least 70% identical to at least one of the CDR sequences depicted in Figure 14A.
Another particularly preferred anti RSV antibody according to the present invention is the antibody designated "AM16", which has a heavy chain region and a light chain region as depicted in Figure 14B. The CDR sequences of AM16, which in particular contribute to the antigen-binding properties of AM16, are also depicted in Figure 14B.
Now that the present invention provides the information that the CDR sequences depicted in Figure 14B provide desired RSV binding characteristics, the variants may comprise at least one altered CDR sequence. For example, conservative amino acid substitution is applied. Conservative amino acid substitution involves substitution of one amino acid with another with generally similar properties (size, hydrophobicity, etc.), so that overall function is probably not severely affected.
It is also possible to change at least one CDR sequence depicted in Figure 14B to generate a variant antibody, or a functional equivalent thereof, with at least one altered property compared to AM16. An antibody or functional equivalent may comprise a CDR sequence that is at least 70% identical to a CDR sequence as depicted in Figure 14B, such that the favorable binding characteristics of AM16 are at least partially or even preserved. improve. A CDR sequence as depicted in Figure 14B can be altered so that the resulting antibody or functional equivalent comprises at least one improved property, such as for example improved binding affinity, selectivity and / or stability, compared to AM16. Various methods of altering an amino acid sequence are available in the art. For example, a heavy chain or light chain sequence with a desired CDR sequence is artificially synthesized. Preferably, a nucleic acid sequence encoding a CDR sequence is mutated, for example using random or site-directed mutagenesis.
IS 2 575 129 T3
Disclosed herein is an isolated, synthetic, or recombinant antibody or a portion, derivative, and / or functional analog thereof that is capable of specifically binding respiratory syncytial virus and comprising:
- a heavy chain CDR1 sequence comprising a sequence that is at least 70% GFTFSSYN sequence, and / or
- a heavy chain CDR2 sequence comprising a sequence that is at least 70% ISAGSSYI sequence, and / or
- a heavy chain CDR3 sequence comprising a sequence that is at least 70% AREDYGPGNYYSPNWFDP sequence, and / or
- a light chain CDR1 sequence comprising a sequence that is at least 70% SSNIGAGYD sequence, and / or
- a light chain CDR2 sequence comprising a sequence that is at least 70% GNT sequence, and / or
- a light chain CDR3 sequence comprising a sequence that is at least 70% HSYDRSLSG sequence.
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An antibody or a functional equivalent may comprise a CDR sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90% identical to at least one of the represented CDR sequences. in Figure 14B. More preferably, an antibody or a functional equivalent may comprise a CDR sequence that is at least 95% identical to at least one of the CDR sequences depicted in Figure 14B. The particularly preferred antibody AM16, described above, comprises CDR sequences consisting of the CDR sequences depicted in Figure 14B. A particularly preferred embodiment according to the invention therefore provides an isolated, synthetic or recombinant antibody which is capable of specifically binding with respiratory syncytial virus and which comprises:
a heavy chain CDR1 sequence comprising the GFTFSSYN sequence and / or a heavy chain CDR2 sequence comprising the ISAGSSYI sequence, a heavy chain CDR3 sequence comprising the AREDYGPGNYYSPNWFDP sequence, a light chain CDR1 sequence comprising the SSNIGAGYD sequence, a light chain CDR2 sequence comprising the GNT sequence and a light chain CDR3 sequence comprising the HSYDRSLSG sequence.
Disclosed herein is an antibody or functional equivalent comprising all three heavy chain CDR sequences and all three light chain CDR sequences as depicted in Figure 14B, or sequences that are at least 70% identical thereto. . An isolated antibody is therefore further disclosed, synthetic or recombinant or a functional equivalent thereof comprising a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the GFTFSSYN sequence and a heavy chain CDR2 sequence comprising a sequence that is at least 70 % identical to the ISAGSSYI sequence and a heavy chain CDR3 sequence comprising a sequence that is at least 70% identical to the AREDYGPGNYYSPNWFDP sequence and a light chain CDR1 sequence that comprises a sequence that is at least 70% identical to SSNIGAGYD and a light chain CDR2 sequence that comprises a sequence that is at least 70% identical to the GNT sequence, and a light chain CDR3 sequence that comprises a sequence that it is at least 70% identical to the HSYDRSLSG. Said antibody or functional equivalent preferably comprises CDR sequences that are at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% identical to the CDR sequences aforementioned heavy chain CDR sequences and the aforementioned light chain CDR sequences as depicted in Figure 14B. Also disclosed is an antibody or functional equivalent comprising the aforementioned heavy chain CDR1, CDR2 and CDR3 sequences of Figure 14B as well as the aforementioned light chain CDR1, CDR2 and CDR3 sequences of Figure 14B.
Also disclosed are antibodies or functional equivalents thereof that comprise a heavy chain amino acid sequence that is at least 70% identical to a heavy chain sequence as depicted in Figure 14B. Such heavy chain sequences provide desired RSV binding properties, as demonstrated by the AM16 antibody. An antibody, or functional equivalent thereof, is further disclosed, having a heavy chain sequence comprising a sequence that is at least 70% identical to the sequence.
EVQLVETGGGLAQPGGSLRLSCAASGFTFSSYNMNWVRQAPGKGLEWVSHISAGSSYIYYSD
SVKGRFTVSRDNVRNSVYLQMNSLRAADTAVYYCAREDYGPGNYYSPNWFDPWGQGTLVTVS S. In addition, light chain amino acid sequences that are at least 70% identical to a light chain sequence as depicted in Figure 14B also provide desired RSV binding properties, as demonstrated by the AM16 antibody. An antibody, or a functional equivalent thereof, is therefore also disclosed having a light chain sequence that is at least 70% identical to the sequence QSWTQPPSVSGAPGQRVT I SCTGS SSNI GAGYDVHWYQQLPGTAPKLLIYGNTNRPSGVS D
IS 2 575 129 T3
RFSGSKSGTSASLAI TGLQAEDEADYYCHSYDRSLSGS-VFGGGTKLTV. An antibody or functional part may comprise a variable heavy chain sequence and / or a variable light chain sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% identical to the heavy chain sequence and / or the light chain sequence as depicted in Figure 14B. The higher the homology, the more closely said antibody or functional part will resemble the AM16 antibody. An antibody or functional part can comprise a heavy chain as well as a light chain that resembles the heavy and light chain of AM16. Thus further disclosed is an antibody or functional part comprising a heavy chain sequence and a light chain sequence which are at least 70%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%. %, more preferably at least 95% identical to the heavy chain sequence and the light chain sequence as depicted in Figure 14B.
One embodiment provides an antibody comprising a heavy chain sequence consisting of the heavy chain sequence as depicted in Figure 14B, and a light chain sequence consisting of the light chain sequence as depicted in Figure 14b. Alternatively, as is well known to those of skill in the art, it is possible to generate a shortened long chain or heavy chain sequence while maintaining a binding property of interest. Preferably, said shortened heavy chain or light chain having a shorter constant region, compared to the original heavy or light chain, is generated. The variable domain preferably remains. For example, a Fab fragment or F (ab ') 2 fragment is produced based on a heavy chain sequence or light chain sequence depicted in Figure 14B. A functional equivalent of an antibody is therefore also disclosed which comprises at least a functional part of a sequence as depicted in Figure 14B. A functional part can be at least 20 amino acids long and can comprise a sequence that is at least 70% identical to at least one of the CDR sequences depicted in Figure 14B.
Another particularly preferred anti RSV antibody according to the present invention is the antibody designated "AM23", which has a heavy chain region and a light chain region as depicted in Figure 14C. The CDR sequences of AM23, which in particular contribute to the antigen-binding properties of AM23, are also depicted in Figure 14C.
Now that the present invention provides the information that the CDR sequences depicted in Figure 14C provide desired RSV binding characteristics, the variants may comprise at least one altered CDR sequence. For example, conservative amino acid substitution is applied. Conservative amino acid substitution involves substitution of one amino acid with another with generally similar properties (size, hydrophobicity, etc.), so that overall performance is unlikely to be seriously affected.
It is also possible to change at least one CDR sequence depicted in Figure 14C to generate a variant antibody, or a functional equivalent thereof, with at least one altered property compared to AM23. An antibody or functional equivalent may comprise a CDR sequence that is at least 70% identical to a CDR sequence as depicted in Figure 14C, such that the favorable binding characteristics of AM23 are at least partially maintained or even maintained. improve. A CDR sequence as depicted in Figure 14C can be altered so that the resulting antibody or functional equivalent comprises at least one improved property, such as for example improved binding affinity, selectivity and / or stability, compared to AM23. Various methods of altering an amino acid sequence are available in the art. For example, a heavy chain or light chain sequence with a desired CDR sequence is artificially synthesized. Preferably, a nucleic acid sequence encoding a CDR sequence is mutated, for example using random, or directed mutagenesis.
Disclosed herein is an isolated, synthetic, or recombinant antibody or a portion, derivative, and / or functional analog thereof that is capable of specifically binding respiratory syncytial virus and comprising:
- a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the GFNFHNYG sequence, and / or
- a heavy chain CDR2 sequence comprising a sequence that is at least 70% identical to the VWYDGSKK sequence, and / or
- a heavy chain CDR3 sequence comprising a sequence that is at least 70% identical to the VRD KVGPTPYFD S sequence, and / or
- a light chain CDR1 sequence comprising a sequence that is at least 70% identical to the NIGSET Y sequence, and / or
- a light chain CDR2 sequence comprising a sequence that is at least 70% identical to the DDD sequence, and / or
- a light chain CDR3 sequence comprising a sequence that is at least 70% identical to the sequence of QVWDRSNYH QV.
IS 2 575 129 T3
An antibody or a functional equivalent may comprise a CDR sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90% identical to at least one of the represented CDR sequences. in Figure 14C. More preferably, an antibody or a functional equivalent may comprise a CDR sequence that is at least 95% identical to at least one of the CDR sequences depicted in Figure 14C. The particularly preferred antibody AM23, described above, comprises CDR sequences consisting of the CDR sequences depicted in Figure 14C. A particularly preferred embodiment according to the invention therefore provides an isolated, synthetic or recombinant antibody which is capable of specifically binding with respiratory syncytial virus and which comprises:
a heavy chain CDR1 sequence comprising the GFNFHNYG sequence, a heavy chain CDR2 sequence comprising the VWYDGSKK sequence, a heavy chain CDR3 sequence comprising the VRDKVGPTPYFDS sequence, a light chain CDR1 sequence comprises the NIGSET sequence, a light chain CDR2 sequence comprising the DDD sequence and a light chain CDR3 sequence comprising the QVWDRSNYH QV sequence.
An antibody or functional equivalent comprising the three heavy chain CDR sequences and the three light chain CDR sequences as depicted in Figure 14C is disclosed herein. An isolated antibody is further disclosed, synthetic or recombinant or a functional equivalent thereof comprising a heavy chain CDR1 sequence comprising a sequence that is at least 70% identical to the GFNFHNYG sequence and a heavy chain CDR2 sequence comprising a sequence that is at least 70 % identical to the VWYDGSKK sequence and a heavy chain CDR3 sequence comprising a sequence that is at least 70% identical to the VRDKVGPTPYFDS sequence and a light chain CDR1 sequence that comprises a sequence that is at least 70% identical to the NIGSET sequence and a light chain CDR2 sequence that comprises a sequence that is at least 70% identical to the DDD sequence and a light chain CDR3 sequence that comprises a sequence which is at least 70% identical to the QVWDRSNYH QV sequence. Said antibody or functional equivalent preferably comprises CDR sequences that are at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% identical to the CDR sequences aforementioned heavy chain CDR sequences and the aforementioned light chain CDR sequences as depicted in Figure 14C. Also disclosed is an antibody or functional equivalent comprising the aforementioned heavy chain CDR1, CDR2 and CDR3 sequences of Figure 14C as well as the aforementioned light chain CDR1, CDR2 and CDR3 sequences of Figure 14C.
Also disclosed are antibodies or functional equivalents thereof that comprise a heavy chain amino acid sequence that is at least 70% identical to a heavy chain sequence as depicted in Figure 14C. Such heavy chain sequences provide desired RSV binding properties, as demonstrated by the AM23 antibody. An antibody or a functional equivalent thereof is further disclosed, having a heavy chain sequence comprising a sequence that is at least 70% identical to the sequence.
EVQLVESGGNVVKPGTSLRLSCAATGFNFHNYGMNWVRQAPGKGLEWVAWWYDGSKKYYAD SVTGRFAI
SRDNSKNTLYLQMNSLRVEDTAVYYCVRDKVGPTPYFDSWGQGTLVTVS S. In addition, light chain amino acid sequences that are at least 70% identical to a light chain sequence as depicted in Figure 14C also provide desired RSV binding properties, as demonstrated by the AM23 antibody. An antibody, or a functional equivalent thereof, is therefore disclosed that has a light chain sequence that is at least 70% identical to the sequence SYVLTQPPSVSLAPGGTAAI TCGRNNIGSETVHWYQQK-PGQAPVLWYDDDDRPSGI PERFS GSNSGNTATLT I
SRVEAGDEADYYCQVWDRSNYHQVFGGGTKLTV. An antibody or functional part may comprise a variable heavy chain sequence or a variable light chain sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% identical to the heavy chain sequence and / or the light chain sequence as depicted in Figure 14C. The higher the homology, the more closely said antibody or functional part will resemble the AM23 antibody. An antibody or functional part can comprise a heavy chain as well as a light chain that resembles the heavy and light chain of AM23. An antibody or functional part is therefore further disclosed comprising a heavy chain sequence and a light chain sequence which are at least 70%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%. %, more preferably at least 95% identical to the heavy chain sequence and the light chain sequence as depicted in Figure 14C.
One embodiment provides an antibody comprising a heavy chain sequence consisting of the heavy chain sequence as depicted in Figure 14C, and a light chain sequence consisting of the light chain sequence as depicted in Figure 14C. Alternatively, as is well known to those skilled in the art, it is possible to generate a shortened heavy chain or light chain sequence while maintaining a binding property of interest. Preferably, said shortened heavy chain or light chain is generated having a shorter constant region, compared to heavy or light chain
ES 2 575 129 T3 original. The variable domain preferably remains. For example, an Fab fragment or F (ab ') 2 fragment is produced based on a heavy chain sequence or light chain sequence depicted in Figure 14C. Also disclosed therefore is a functional equivalent of an antibody comprising at least a functional part of a sequence as depicted in Figure 14C. A functional part can be at least 20 amino acids long and can comprise a sequence that is at least 70% identical to at least one of the CDR sequences depicted in Figure 14C.
The present invention provides RSV-specific antibodies as defined in the claims that have improved properties compared to prior art antibodies. The inventors have succeeded in generating RSV-specific antibodies with low IC50 values. Said antibodies have a particularly high or strong affinity for RSV and are therefore particularly suitable for counteracting and / or at least in part preventing RSV infection and / or adverse effects of RSV infection. One disclosure provides an antibody having an IC50 value of less than 10 ng / ml in an in vitro neutralization assay in which HEp-2 cells are infected with RSV, and a functional equivalent of said antibody. Said antibody or functional equivalent preferably has an IC50 value of less than 5 ng / ml, more preferably less than 2 ng / ml. The preferred antibody D25 has an IC50 value of about 0.5-1.5 ng / ml in the in vitro neutralization assay described in the examples (see Figure 8).
An antibody according to the invention is preferably a human antibody. The use of human antibodies for human therapy reduces the likelihood of side effects due to an immune reaction in a human individual against non-human sequences. In another preferred embodiment an antibody or functional part, derivative or analog according to the invention is a chimeric antibody. In this way, sequences of interest, such as for example a binding site of interest, can be included in an antibody or functional equivalent according to the invention.
The invention further provides an isolated synthetic or recombinant nucleic acid sequence encoding an antibody according to the invention. Said nucleic acid is isolated for example from a B lymphocyte which is capable of producing an antibody according to the invention, as outlined in more detail below. A nucleic acid sequence disclosed herein may comprise a sequence that is at least 70% homologous to at least one functional part of a nucleic acid sequence as depicted in Figure 11, Figure 12, Figure 14A, Figure 14B and / or Figure 14B. Said nucleic acid sequence may comprise a sequence that is at least 75%, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% homologous to at least one functional part. of a nucleic acid sequence as depicted in Figure 11, Figure 12, Figure 14A, Figure 14B and / or Figure 14B. Said functional part has a length of at least 30 nucleotides, preferably at least 50 nucleotides, more preferably at least 75 nucleotides. Said functional part can encode at least one nucleic acid sequence as represented in Figure HD, Figure 12, Figure 14A, Figure 14B and / or Figure 14B. Said sequence is preferably a CDR sequence.
An antibody according to the invention is particularly suitable for use as a medicine or prophylactic agent. An antibody according to the invention is therefore also provided herein, for use as a medicament and / or prophylactic agent. In a particularly preferred embodiment said antibody comprises D25, AM14, AM16 and / or AM23 antibody. Said drug or prophylactic agent is preferably used to counteract or at least partially prevent RSV infection or to counteract or at least partially prevent adverse effects of RSV infection. Therefore also disclosed is a use of an antibody, functional part, derivative or analog according to the invention for the preparation of a medicament and / or a prophylactic agent for at least in part treating and / or preventing an RSV-related disorder as well as a method of at least in part treating or preventing an RSV-related disorder, the method comprising administering to an individual in need thereof a therapeutically effective amount of an antibody or functional equivalent according to the invention. Said antibody preferably comprises the D25, AM14, AM16 and / or AM23 antibody.
To counteract RSV, an antibody according to the invention can be administered to an individual before an RSV infection has taken place. Alternatively, an antibody according to the invention can be administered when an individual is already infected with RSV. Said antibody can be administered to individuals with an increased risk of RSV-related disorders, such as for example children with premature birth, individuals with chronic lung disease, congenital heart disease and / or compromised immunity, and children with an age less than 6 weeks. In addition, the elderly are at increased risk for RSV-related disorders. The antibodies according to the invention can be administered orally or by one or more injections. Antibody dose ranges according to the invention for use in therapeutic applications as described hereinbefore are designed based on increasing dose studies in the clinic in clinical trials for which there are stringent protocol requirements. Typical doses are between 0.1 and 10 mg per kg of body weight. For therapeutic application, the antibodies according to the invention are typically combined with a pharmaceutically acceptable carrier, adjuvant, diluent and / or excipient. Examples of suitable carriers include for example keyhole limpet hemocyanin (KLH), serum albumin (for example BSA or RSA) and ovalbumin. Many suitable adjuvants, oil-based and
ES 2 575 129 T3 based on water are known to those skilled in the art. In one embodiment, said adjuvant comprises Specol. In another embodiment, said suitable vehicle comprises a solution such as saline.
In yet another embodiment a nucleic acid encoding an antibody is used according to the invention. Upon administration of said nucleic acid, antibodies or functional equivalents are produced by the host machinery. The antibodies or functional equivalents produced are capable of preventing and / or counteracting RSV infection and / or the adverse effects of RSV infection. Also provided herewith is therefore a nucleic acid sequence, according to the invention for use as a medicament and / or prophylactic agent. Said nucleic acid is preferably used to counteract RSV. Therefore further disclosed is a use of a nucleic acid sequence, part, derivative and / or functional analog according to the invention for the preparation of a medicament and / or prophylactic agent for at least in part treating and / or preventing a RSV-related disorder.
By at least a functional part of a nucleic acid is meant a part of said nucleic acid, at least 30 base pairs in length, preferably less 50 base pairs in length, more preferably at least 100 base pairs in length, which it comprises at least one expression characteristic (in type not necessarily in quantity) as a nucleic acid of the invention. Said functional part encodes at least one amino acid sequence comprising a sequence that is at least 70% identical to a CDR sequence as represented in Figure HD, Figure 14A, Figure 14B and / or Figure 14C.
The invention further provides an isolated antibody-producing cell capable of producing an antibody, according to the invention. Possible (but not limiting) ways of obtaining such antibody-producing cells are outlined in detail in the examples. The inventors have developed and used a new method to improve the stability of cells producing RSV-specific antibodies. Using this method, RSV-specific antibody-producing cells are generated that are stable for at least six months. Also hereby disclosed is a RSV-specific antibody producing cell according to the invention, which is stable for at least nine weeks, preferably for at least three months, more preferably for at least six months.
The present inventors have used their information that the stability of a RSV-specific antibody-producing cell is influenced by the amount of BCL6 and / or Blimp-1 expression product within said antibody-producing cell. The amount of BCL6 and / or Blimp-1 expression product is influenced directly or indirectly. Preferably the amounts of both BCL6 and Blimp-1 expression products within said antibody-producing cell are regulated, since both expression products are involved in the stability of an antibody-producing cell. The stability of an antibody-producing cell is defined as the ability of said antibody-producing cell to remain at a certain stage of development (preferably after said cell has been brought to that stage). The different developmental stages of a cell imply at least one different characteristic of that cell. For example, a memory B lymphocyte is known to differentiate upon stimulation into an antibody-secreting plasma cell through a stage that some researchers refer to as a plasmablast. A memory B lymphocyte, a plasmablast, and a plasma cell are different developmental stages of a B lymphocyte, in which the B lymphocyte has different characteristics. A memory B lymphocyte shows low proliferation and secretion of antibodies. A plasmablast shows both higher levels of proliferation and higher levels of antibody secretion compared to a memory B lymphocyte, whereas a plasma cell secretes high levels of antibody but is unable to proliferate. With the methods disclosed herein it has been possible to regulate the replicative lifespan of an antibody-producing cell. A replicative lifespan of an antibody-producing cell is defined herein as the period of time in which a B lymphocyte and its descendant cells are capable of replicating while maintaining their ability to produce antibodies and / or develop to a antibody-producing cell. Preferably the replicative life of an antibody-producing cell is prolonged, which means that said antibody-producing cell will not differentiate terminally, or only after a longer period compared to the same type of antibody-producing cells that are used today, and they continue to proliferate in vitro. According to the inventors it is possible to regulate the amount of BCL6 and / or Blimp-1 expression product in an antibody-producing cell to such an extent that the antibody-producing cell is brought to and / or maintained in a predetermined developmental stage in which cells continue to proliferate. With the inventors' disclosed method it has therefore been possible to increase the replicative lifespan of an antibody-producing cell since it is possible to maintain a B lymphocyte at a certain stage of development where replication occurs. Reference is made to document PCT / NL2006 / 000625, submitted by the same applicant. Means and methods for producing stable RSV-specific antibody producing cells are disclosed herein.
An antibody-producing cell is defined as a cell that is capable of producing and / or secreting antibody or a functional equivalent thereof, and / or said cell being capable of developing into a cell that is capable of producing and / or secreting antibody or a functional equivalent of it. An RSV-specific antibody producing cell is defined herein as a cell capable of producing and / or secreting antibodies or functional equivalents thereof that are capable of specifically binding RSV and / or a RSV component, such as by For example, an epitope of RSV F (fusion) protein, RSV G (binding) protein, or RSV
ES 2 575 129 T3 SH protein (small hydrophobic) from RSV. Preferably, said RSV-specific antibody-producing cell comprises a B lymphocyte and / or a plasma cell derived from B lymphocytes. A B lymphocyte is referred to herein as an antibody-producing cell, even when the B lymphocyte is in a stage where antibody production is low or not present at all, such as a previously untreated B lymphocyte or a memory B lymphocyte, which is activated or not, because said cells are capable of developing into antibody-producing cells, such as a plasmablast and / or a plasma cell.
A cell producing RSV-specific antibodies preferably comprises a mammalian cell. Non-limiting examples include antibody-producing cells derived from an individual human, rodent, rabbit, llama, pig, cow, goat, horse, ape, gorilla. Preferably, said antibody-producing cell comprises a human cell, a murine cell, a rabbit cell and / or a flame cell.
BCL6 encodes a transcriptional repressor that is required for the development and maturation of normal B lymphocytes and T lymphocytes and required for the formation of germinal centers. (Ye, 1997). BCL6 is highly expressed in germinal center B lymphocytes while it is barely expressed in plasma cells. BCL6 inhibits the differentiation of activated B lymphocytes into plasma cells. The transcriptional repressor B lymphocyte-induced maturation protein 1 (Blimp-1) is required for the development of a B lymphocyte in a plasma cell. The human variant of Blimp-1 is called Prdml. As used herein, any reference to Blimp-1 includes a reference to Prdml. Blimp-1 drives the differentiation of plasma cells. BCL6 and Blimp-1 repress each other's expression; therefore, in a natural situation in which one reaches a higher level of expression than the other, the stage of differentiation is imposed. In the human body, differentiation of plasma cells from treatment-naïve or activated memory B lymphocytes involves down-regulation of BCL6 and up-regulation of Blimp-1. In germinal cells the expression of BCL6 is high and the expression of Blimp-1 is low. In resting memory cells the expression of BCL6 and Blimp-1 are low. The signals that trigger differentiation cause upregulation of Blimp-1, and this Blimp-1 counteracts the expression of BCL6. The stage in which both BCL6 and Blimp-1 are expressed is short-lived and is called a plasmablast. With progressively increasing levels of Blimp-1, the expression of BCL6 dies down, resulting in a plasma cell.
A RSV-specific antibody-producing cell can be provided in which BCL6 and Blimp-1 are co-expressed (meaning that both BCL6 and Blimp-1 are expressed in said antibody-producing cell for at least 1 day, preferably at least one week , more preferably at least six weeks, more preferably at least three months Said RSV-specific antibody producing cell is capable of proliferating when an appropriate signal is provided. The co-expression of BCL6 and Blimp-1 has been found to result in an antibody-producing cell that is capable of proliferating and producing antibody. BCL6 and Blimp-1 are preferentially co-expressed in a B lymphocyte, preferably a human B lymphocyte. Co-expression of BCL6 and Blimp-1 in a B lymphocyte results in stabilization of said B lymphocyte in a plasmablast-like stage. Plasmablasts, like plasma cells, are capable of secreting antibody. However, plasmablasts are still capable of proliferating, whereas plasma cells have lost their ability to proliferate. Plasma cells are therefore unsuitable for culturing antibody-producing cell lines.
A cell producing RSV-specific antibodies may comprise an exogenous nucleic acid sequence encoding BCL6 or a part, derivative and / or functional analog thereof. An exogenous nucleic acid is defined herein as a nucleic acid sequence that does not naturally belong to the genome of a cell. With such an exogenous nucleic acid molecule it is possible to regulate a concentration of BCL6 in an antibody-producing cell independently of the expression of endogenous BCL6. Therefore, even if endogenous BCL6 expression is low or absent, for example caused by Blimp-1, an exogenous nucleic acid sequence encoding BCL6 or a functional part, derivative and / or analog thereof is still capable of produce a concentration of BCL6 that is sufficient to influence the stability of an antibody-producing cell. Preferably, said nucleic acid sequence encoding BCL6 or a part, derivative and / or functional analog thereof is constitutively active, so that the expression of BCL6 is maintained even when the expression of endogenous BCL6 of said cell is inhibited by a repressor endogenous such as Blimp-1. More preferably, the expression of said nucleic acid sequence encoding BCL6 or a functional part, derivative and / or analog thereof is regulated by an exogenous inducer of repressor, so that the extent of BCL6 expression is regulated ad libitum.
Preferably, as outlined in more detail below, a RSV-specific antibody producing cell may comprise an exogenous nucleic acid sequence encoding Bcl-xL or a functional part, derivative and / or analog thereof. If Bcl-xL or a functional part, derivative and / or analog thereof is present, it is possible to grow plasmablasts under conditions of low cell density. The expression of said nucleic acid sequence encoding Bcl-xL or a part, derivative and / or functional analog thereof is preferentially regulated by an exogenous repressor inducer, so that the extent of Bcl-xL expression is regulated by Will. Disclosed herein is a RSV-specific antibody producing cell comprising: - an exogenous nucleic acid sequence encoding BCL6 or a part, derivative and / or functional analog thereof and / or an exogenous nucleic acid sequence encoding Bcl-xL or a part, derivative and / or functional analog thereof.
IS 2 575 129 T3
Said cell that produces RSV-specific antibodies preferably comprises both an exogenous nucleic acid sequence encoding BCL6 or a part, derivative and / or functional analog thereof, and an exogenous nucleic acid sequence encoding Bcl-xL, or a part, derivative and / or functional analog thereof. Preferably, the expression of said nucleic acid sequence encoding BCL6, Bcl-xL or a part, derivative and / or functional analog of BCL6 or Bcl-xL is regulated by an activator and / or repressor that is inducible by an exogenous compound. For example, an inducible promoter system such as Tet-on or Tet-off system is used.
A stable RSV-specific antibody-producing cell can be generated by co-expressing BCL6 and Blimp-1 in a RSV-specific antibody-producing cell. A RSV-specific antibody producing cell is preferably obtained from an individual who has been exposed to RSV. Methods for isolating antibody-producing cells are well known in the art. For example, RSV-derived compounds that are labeled with a marker and / or a tag are incubated with a sample from an individual who has been exposed to RSV, said sample comprising antibody-producing cells. RSV-specific antibody producing cells that recognize the labeled RSV-derived compounds are isolated while unbound cells are washed away. The resulting RSV-specific antibody-producing cells are subsequently stabilized by co-expressing BCL6 as well as Blimp-1.
Total antibody-producing cells from a RSV-exposed donor can first be stabilized and then cells that recognize the labeled RSV-derived compound isolated. Alternatively, the antibody-producing cells are equipped with a (fluorescent) marker downstream of their B-lymphocyte receptor (BCR, membrane-expressed form of the antibody) that signals when the antibody-producing cell binds with an unlabeled / unlabeled antigen. tagged using the BCR. Antibody-producing cells in which the marker is activated are selected and subsequently stabilized by co-expressing BCL6 as well as Blimp-1. When antigen derived compounds are not available but when assays are available to screen for single antibodies, whole / ensemble antibody producing cells can be stabilized by co-expressing BCL6 as well as Blimp-1 and optionally also Bcl-XL. Consequently, cells are grown at low densities, preferably between 10 and 100 cells per 96 wells, in the presence of L cells (mini volume cultures, MBC). Culture supernatants can be used directly in screening assays, such as ELISA, Western blot, or functional assays such as ELISPOT, neutralization assays, or cell migration assays. MBC can be selected and, to obtain monoclonal cell lines of the antibody producing cell of interest, limiting dilution cultures are pre-formed and, preferably 2-3 weeks later, supernatants from those cultures are screened again in the preferred assay.
As is well known to those of skill in the art, many alternative methods are available in the art. The methods mentioned above are non-limiting.
A method is therefore further disclosed for producing an antibody-producing cell, which is stable for at least three months and which is capable of producing RSV-specific antibodies or functional equivalents thereof, the method comprising:
- increasing an expression level of Blimp-1 in a cell that is capable of producing RSV-specific antibodies or functional equivalents thereof; Y
- increasing and / or maintaining a level of expression of BCL6 in said cell.
It has become possible to convert a RSV-specific B lymphocyte into a plasmablast-like cell and stabilize such a cell so that rapid differentiation into a plasma cell does not occur. This is contrary to the natural development of plasma cells, in which the expression of Blimp-1 in a memory B lymphocyte results in rapid development in a plasma cell, thereby inhibiting the expression of BCL6 so that the resulting plasma cell just express BCL6. One embodiment of the disclosure therefore involves the co-expression of both BCL6 and Blimp-1 in a RSV-specific B lymphocyte, resulting in a cell that is capable of both proliferating and producing antibodies. The level of expression of BCL6 in said RSV-specific B lymphocyte is preferably brought up, and is maintained at essentially the same level or a higher level compared to a plasmablast. In this way, a stable culture of RSV-specific B lymphocytes is generated, said cells remaining capable of producing RSV-specific antibodies. These RSV-specific B cells that co-express BCL6 and Blimp-1 are further stabilized, preferably by addition of the anti-apoptotic gene Bcl-xL. With the introduction of Bcl-xL it is now possible to grow plasmablasts under conditions of low cell density. Therefore, the invention also provides a method for culturing plasmablasts under conditions of low cell density which comprises generating a cell that produces RSV-specific antibodies with expression levels of BCL6, Blimp-1 and Bcl-xL with any of the methods described. in the present document.
The amount of BCL6 expression product (preferably a BCL6 protein) in a RSV-specific antibody-producing cell is regulated in various ways.
An antibody-producing cell can be uncovered with a compound capable of directly or indirectly influencing the expression of BCL6. An antibody-producing cell is preferentially uncovered with a compound
ES 2 575 129 T3 capable of enhancing the expression of BCL6, to counteract the negative regulation of BCL6 during the expression of Blimp-1. Said compound preferably comprises an activation and transcription signal transducer protein 5 (STAT5) or a part, derivative and / or functional analog thereof, and / or a nucleic acid sequence encoding it. STAT5 is a signal transducer capable of enhancing the expression of BCL6. There are two known forms of STAT5, STAT5a and STAT5b, which are encoded by two different genes, linked in tandem. Administration and / or activation of STAT5 results in enhanced BCL6 levels. Therefore, the down-regulation of BCL6 by Blimp-1 is at least partially offset by the up-regulation expression of BCL6 by STAT5 or a functional derivative and / or analogue thereof. Therefore, STAT5 or a functional part, derivative and / or analog thereof is capable of directly influencing the expression of BCL6. It is also possible to indirectly influence the expression of BCL6. This is done for example by regulating the amount of a compound which in turn is capable of directly or indirectly activating STAT5 and / or regulating the expression of STAT5. Therefore the expression and / or activity of endogenous and / or exogenous STAT5 increases. It is therefore possible to indirectly enhance the expression of BCL6 by culturing an antibody-producing cell in the presence of interleukin (IL) 2 and / or IL 4 that are capable of activating STAT5.
A cell producing RSV-specific antibodies can comprise a nucleic acid sequence encoding STAT5 or a part, derivative and / or functional analog thereof, in which said nucleic acid sequence is constitutively active, meaning that STAT5 is expressed continuously, regardless of the presence of regulators (endogenous). In the event that endogenous STAT5 expression is low, or absent, an exogenous constitutively active nucleic acid sequence encoding STAT5 or a functional part, derivative and / or analog thereof is preferably applied resulting in a concentration of STAT5 or a part, derivative and / or functional analog thereof that is sufficient to enhance the expression of BCL6. More preferably, a cell producing RSV-specific antibodies may comprise a nucleic acid sequence encoding a compound comprising STAT5 or a functional part, derivative and / or analog thereof, preferably a fusion protein, the activity of which is regulated by a exogenous repressor inducer, so that the extent of BCL6 expression activation is regulated ad libitum. Another system that allows the induction of BCL-6 is provided by a Tet-on system in which the addition of tetracycline and / or tetracycline derivatives induces the activity of a transactivator that induces transcription of the BCL6 gene followed by protein synthesis. BCL. In a preferred embodiment of the disclosure, an antibody-producing cell may comprise a nucleic acid sequence encoding an estrogen receptor (ER) and STAT5 as an ER-STAT5 fusion protein. This fusion protein is inactive because it forms a complex with heat shock proteins in the cytosol. Thus, STAT5 is unable to reach the nucleus and the expression of BCL6 is not enhanced. After administration of the exogenous inducer 4-hydroxy-tamoxifen (4HT), the ER-STAT5 fusion protein dissociates from the heat shock proteins, so that STAT5 is able to enter the nucleus and activate the expression of BCL6.
Additionally, or alternatively, the expression of BCL6 in a RSV-specific antibody-producing cell is enhanced by culturing said antibody-producing cell in the presence of a compound capable of directly or indirectly enhancing the expression of BCL6.
Disclosed herein is a method for producing a RSV-specific antibody producing cell comprising:
- providing a cell producing RSV-specific antibodies with a compound capable of directly or indirectly enhancing the expression of BCL6; me
- culturing a cell that produces RSV-specific antibodies in the presence of a compound capable of directly or indirectly enhancing the expression of BCL6. Said compound capable of directly or indirectly enhancing the expression of BCL6 preferably comprises STAT5 or a part, derivative and / or functional analog thereof.
A method is therefore disclosed which comprises providing said RSV-specific antibody producing cell with STAT5 or a part, derivative and / or functional analog thereof, or with a nucleic acid sequence encoding STAT5 or a part, derivative and / or or functional analog thereof. Said antibody-producing cell can be cultured after introduction of a nucleic acid sequence encoding STAT5 or a part, derivative and / or functional analog thereof into said cell. Said nucleic acid sequence is for example introduced into said cell by virus-mediated gene transfection and / or transfer. Many alternative methods of introducing a nucleic acid sequence into a cell are available in the art and need no further explanation here.
With a compound capable of directly or indirectly enhancing the expression of BCL6 it is possible to enhance the expression of endogenous BCL6. However an antibody producing cell may comprise a nucleic acid sequence encoding BCL6 or a part, derivative and / or functional analog thereof. As explained hereinbefore, an exogenous nucleic acid encoding BCL6 is preferred because this allows regulation of a concentration of BCL6 within a cell independent of endogenous BCL6 expression. Thus, even if endogenous BCL6 expression is low or absent, for example caused by Blimp-1, an exogenous nucleic acid sequence encoding BCL6 or a part, derivative and / or analog
ES 2 575 129 T3 functional thereof is still capable of producing a concentration of BCL6 that is sufficient to influence the stability of an antibody-producing cell. Also disclosed is therefore a method comprising providing a RSV-specific antibody producing cell with a nucleic acid sequence encoding BCL6 or a functional part, derivative and / or analog thereof. Preferably, said antibody-producing cell is provided with a constitutively active nucleic acid sequence encoding BCL6 or a functional part, derivative and / or analog thereof, so that the expression of BCL6 is maintained even when the expression of endogenous BCL6 from said cell is inhibited by an endogenous repressor such as Blimp-1. More preferably, the expression of said nucleic acid sequence encoding BCL6 or a functional part, derivative and / or analog thereof is regulated by an exogenous inducer of repressor, so that the extent of BCL6 expression is regulated at will. For example, an inducible promoter system is used such as a Tet-on or Tet-off system, as already described.
Also disclosed is a method in which the amount of BCL6 is indirectly regulated by the provision of a RSV-specific antibody-producing cell with a nucleic acid sequence encoding E47 or a functional part, derivative and / or analog thereof. E47 encodes a transcription factor that belongs to a family of helix-loop-helix proteins, specifically E. There are four proteins E, E12, E47, E2-2, and HEB, which are involved in lymphocyte development. E12 and E47 are encoded by a gene, called E2A, that is spliced differently. Proteins E can be inhibited by the protein E inhibitor ld2 and Id3, and by ABF-I (Mathas S., 2006). E proteins have been described as tumor suppressors and overexpression has been shown to induce apoptosis. One of the specific targets of E47 are the Socsl and Socs3 genes. These Socs genes are known as negative regulators of STAT [delta] b and therefore indirectly of BCL6. In other words, the expression of E47 within a B lymphocyte enhances the expression of Blimp-1 which results in differentiation of B lymphocytes to an antibody-producing phenotype (plasma cell).
The amount of Blimp-1 expression in a RSV-specific antibody-producing cell is also regulated in various ways. A RSV-specific antibody producing cell is provided with a compound capable of directly or indirectly influencing the expression of Blimp-1. Additionally, or alternatively, an antibody-producing cell is cultured in the presence of a compound capable of directly or indirectly influencing the expression of Blimp-1. A method is therefore further disclosed which comprises providing a RSV-specific antibody producing cell with a compound capable of directly or indirectly influencing the expression of Blimp-1. A method is further disclosed which comprises culturing said antibody-producing cell in the presence of a compound capable of directly or indirectly influencing the expression of Blimp-1. A compound that is capable of enhancing the expression of Blimp-1 can be used to counteract the down-regulation of Blimp-1 during the expression of BCL6. Said compound more preferably comprises IL-21.
Said compound capable of directly or indirectly influencing the expression of Blimp-1 may comprise an activation and transcription signal transducer protein 3 (STAT3) or a part, derivative and / or functional analog thereof, and / or a sequence of nucleic acid that encodes it. STAT3 is a signal transducer that is involved in the development and differentiation of B lymphocytes. STAT3 is capable of positively regulating the expression of Blimp-1. A method is therefore further disclosed in which said compound capable of directly or indirectly influencing the expression of Blimp-1 comprises STAT3 or a part, derivative and / or functional analog thereof, or a nucleic acid sequence encoding STAT3 or a part, derivative and / or functional analog thereof. More preferably, the expression of said nucleic acid sequence encoding STAT3 or a part, derivative and / or functional analog thereof is up-regulated by an exogenous inducer of repressor, so that the extent of expression of STAT3 is regulated at will. . For example, an inducible promoter system is used such as for example a Tet-on or Tet-off system. A fusion product comprising STAT3, a derivative or analog, and ER can be introduced into said cell allowing regulation of STAT3 expression by hydroxy tamoxifen.
Since STAT3 is capable of influencing the expression of Blimp-1, it is also possible to indirectly regulate the expression of Blimp-1 by administering a compound capable of directly or indirectly regulating the activity and / or expression of STAT3. An antibody-producing cell can be provided with a compound that is capable of enhancing STAT3 activity, so that the expression of Blimp-1 is also indirectly enhanced. A method is therefore further provided in which an antibody-producing cell is provided with a compound capable of directly or indirectly enhancing the activity of STAT3.
An antibody-producing cell can be provided with a compound capable of directly or indirectly activating STAT3, to enhance the expression of Blimp-1.
STAT3 is activated in various ways. Preferably, STAT3 is activated by providing an antibody-producing cell with a cytokine. Cytokines, which are naturally involved in B lymphocyte differentiation, are very effective in regulating STAT proteins. They are very effective activators of STAT3 IL-21 and IL-6, but IL-2, IL-7, IL-10, IL-15 and IL-27 are also known to activate STAT3. Furthermore, Toll-like receptors (TLRs) that are involved in innate immunity are also capable of activating STAT3. An embodiment of the present disclosure therefore provides a method in which said compound capable of directly or indirectly influencing the expression of Blimp-1 comprises IL-21, IL-2, IL-6, IL-7, IL-10 , IL-15 and / or IL -27. More preferably IL15 is used
IS 2 575 129 T3
21, as IL-21 is particularly suitable for influencing the stability of an antibody-producing cell. IL-21 is able to positively regulate the expression of Blimp-1 even when the expression of Blimp-1 is counteracted by BCL6.
Additionally or alternatively a mutated Janus kinase (JAK) is used to activate STAT3. Naturally, a JAK is capable of phosphorylating STAT3 after having itself activated by at least one cytokine. A Janus kinase capable of activating STAT3, independent of the presence of cytokines, is particularly suitable in a method disclosed herein.
As already explained above, a compound capable of enhancing the expression of Blimp-1 may comprise a nucleic acid sequence encoding STAT3 or a functional part, derivative and / or analog thereof. The functional presence of an exogenous nucleic acid sequence encoding STAT3 or a functional part, derivative and / or analog thereof allows a continuous presence of STAT3 or a functional part, derivative and / or analog thereof even when expression of endogenous STAT3 it is very low or absent.
It is also possible to reduce the expression and / or activity of STAT5 to positively regulate Blimp-1. If the amount and / or activity of STAT5 is reduced, the activation of BCL6 expression is also reduced, resulting in a reduced amount of BCL6 expression product. Since BCL6 and Blimp-1 each counteract the expression of the other, a reduced amount of BCL6 expression product results in an increased amount of Blimp-1 expression product. Compounds capable of negatively regulating STAT5 activity are therefore capable of indirectly upregulating Blimp-1. Such compounds comprise for example members of the cytokine signaling suppressor proteins (SOCS). The amount of Blimp-1 expression product in a RSV-specific antibody producing cell can therefore be up-regulated by providing said cell with a SOCS protein, and / or by activating a SOCS protein within said cell.
The expression and / or activity of STAT5 can be reduced when a RSV-specific antibody producing cell is provided with a nucleic acid sequence encoding E47 or a functional part, derivative and / or analog thereof. The expression of E47 within B lymphocytes expressing high levels of STAT [delta] b intervenes in differentiation and proliferation, ie blocking of STAT5 by E47 and SOCS results in increased BCL6 levels and subsequently increased Blimp-1 levels. The upregulated levels of Blimp-1 result in reduced proliferation and differentiation of the involved cell towards an antibody-producing cell. In other words, the expression of E47 within a B lymphocyte enhances the expression of Blimp-1 resulting in a differentiation of B lymphocytes towards an antibody-producing phenotype (plasma cell).
By at least one functional part of a STAT5 protein, a STAT3, Bcl-xL and / or BCL6 protein is meant a protein molecule that has the same capacity, in type, not necessarily in quantity, to influence the stability of a producer cell of antibodies compared to a STAT5 protein, a STAT3 protein, Bcl-xL and / or BCL6, respectively. A functional part of a STAT5 protein or a STAT3 protein is, for example, devoid of amino acids that are not involved, or are very little involved, in said capacity. A derivative of a STAT5 protein, a STAT3 protein, Bcl-xL and / or BCL6 is defined as a protein that has been altered such that the ability of said protein to influence the stability of an antibody-producing cell is essentially the same in type, not necessarily quantity. A derivative is provided in many ways, for example by conservative amino acid substitution in which one amino acid is substituted for another amino acid with generally similar properties (size, hydrophobicity, etc.), so that overall performance is probably not affected. seriously. A derivative comprises for example a fusion protein, such as a STAT5-ER or STAT3-ER fusion protein whose activity depends on the presence of 4-hydroxy-tamoxifen (4HT). An analog of a STAT5 protein, a STAT3 protein, Bcl-xL and / or BCL6 is defined as a molecule that has the same ability to influence the stability of an antibody-producing cell in type, not necessarily in quantity. Said analog is not necessarily derived from said STAT5 protein, STAT3 protein, Bcl-xL and / or BCL6.
Said RSV-specific antibody-producing cell can be cultured in the presence of IL-21 before said antibody-producing cell is provided with a nucleic acid sequence encoding BCL6 or a functional part, derivative and / or analog thereof. It is preferred to cultivate cells that produce RSV-specific antibodies, preferably B lymphocytes, in the presence of IL-21 before said cell is provided with a nucleic acid sequence encoding BCL6 or a part, derivative and / or functional analog thereof, because the stability, proliferation and / or production of antibodies is particularly well improved.
The disclosure provides a method of influencing the stability of a RSV-specific antibody-producing cell as described herein, further comprising directly or indirectly increasing the amount of Bcl-xL expression product within said RSV-producing cell. antibodies. This is achieved for example by providing said antibody-producing cell with a nucleic acid sequence encoding Bcl-xL or a functional part, derivative and / or analog thereof or with nucleic acid sequences encoding other anti-apoptotic agents including but not limited to Bcl -two. In another embodiment more than
ES 2 575 129 T3 the present disclosure this is achieved by providing said antibody-producing cell with a compound capable of directly or indirectly enhancing the expression of Bcl-xL, preferably said compound comprises APRIL, BAFF, CD40, BCR stimulation, cytokines, factors growth agents or downstream effectors such as JNK and AKT (PKB).
Bcl-XL is a member of the antiapoptotic Bcl-2 family, Bcl2 proteins interact with and counteract members of the Bcl-2 3 (BH3) homology-only domain family such as Bax, Bak, Bim, and Bad, which they induce the release of cytochrome c after intrinsic death stimuli (Boise, L. H, 1993). Therefore, protection of the integrity of the mitochondrial membrane by proteins such as Bcl-xL is critical for cell survival.
Activation of STAT5 has been shown to protect cells from cell death. STAT5 has been shown to regulate Bcl-xL expression, supporting an antiapoptotic role for STAT5. STAT5 positively regulates Bcl-xL expression via STAT binding elements within the Bcl-xL promoter. In vivo, Bcl-xL expression is absent in bone marrow of mice doubly deficient for STAT5A / B. Furthermore, STAT5-mediated erythroblast survival is dependent on up-regulation of Bcl-xL. Recently, transgenic overexpression of Bcl-xL in mouse B lymphocytes has been shown to promote the survival of B lymphocytes and non-malignant plasma cell foci.
A method of the present disclosure is particularly suitable for producing a cell culture comprising RSV-specific antibody producing cells that can be used to produce a culture of B lymphocytes ex vivo. Said memory B lymphocyte is preferably human so that human antibodies are produced. Said B lymphocyte preferably originates from an individual, said individual having previously been exposed to respiratory syncytial virus. RSV-specific B lymphocytes can be isolated from a peripheral blood sample and / or a tonsil sample, using methods known in the art. Memory B lymphocytes are isolated for example by selection (sorting with magnetic beads) for the B cell marker CD19 and / or CD22 and (subsequent) selection for cell surface IgG and / or CD27 and / or by selection negative with respect to IgM, IgD and / or IgA. In a germinal center B lymphocyte, the expression of BCL6 is high while the expression of Blimp-1 is low. Natural development to an antibody-secreting cell involves up-regulation of Blimp-1 expression. Since Blimp-1 represses the expression of BCL6, up-regulation of Blimp-1 results in down-regulation of BCL6 in a natural setting. However, the expression of Blimp-1 is up-regulated while the expression of BCL6 is maintained at least in part. This results in a RSV-specific antibody producing cell in which BCL6 and Blimp-1 are coexpressed. Said RSV-specific antibody-producing cell is capable of proliferating and secreting anti-RSV antibodies and is therefore suitable for use in ex vivo B-lymphocyte culture. Said antibody-producing cell can be protected by apoptosis by Bcl-xL. A cell producing RSV-specific antibodies provides the advantage that it is stable and does not undergo terminal differentiation for a prolonged period. Said antibody-producing cell is stable for at least one week, preferably for at least one month, more preferably for at least three months, more preferably for at least six months. A B lymphocyte is preferentially cultured in the presence of CD40L since the replication of most B lymphocytes is favored by CD40L.
Expression of BCL6 can be maintained at essentially the same level, or at a higher level, compared to a germ-center B lymphocyte since significant BCL6 expression, in conjunction with Blimp-1 expression, results in an antibody-producing cell with preferred proliferation and antibody-producing properties and / or stability. Such BCL6 expression and / or Blimp-1 expression may be accompanied by Bcl-xL expression, resulting in even more preferred proliferation and antibody-producing properties and / or stability.
Disclosed herein is a method for producing a RSV-specific antibody producing cell that is stable for at least one week, preferably for at least one month, more preferably for at least three months, more preferably for at least six months, understanding the method:
- providing a RSV-specific memory B lymphocyte;
- increasing an expression level of Blimp-1 in said cell; Y
- increasing and / or maintaining a level of expression of BCL6 in said cell. Also provided is an ex vivo method for producing a RSV-specific antibody-producing cell comprising increasing a level of expression of Blimp-1 in a RSV-specific memory B lymphocyte and increasing and / or maintaining an expression level of BCL6 in said cell. Said levels of expression of BCL6 and Blimp-1 are preferably brought and / or maintained essentially at the same level, or at a higher level, compared to a plasmablast. Said B lymphocyte can be transduced with BCL6 and Bcl-xL. Further provided therefore is a method for producing a RSV-specific antibody producing cell that is stable for at least three months, comprising:
IS 2 575 129 T3
- providing a B lymphocyte capable of producing RSV-specific antibodies with BCL6, or a part, derivative and / or functional analog thereof; Y
- providing said B lymphocyte with Bcl-xL or a part, derivative and / or functional analog thereof; Y
- culturing said B lymphocyte.
Said B lymphocyte is preferably provided with a nucleic acid sequence encoding BCL6, or a part, derivative and / or functional analog thereof, and with a Bcl-xL nucleic acid sequence or a part, derivative and / or functional analog of the same.
Said B lymphocyte is preferably cultured in the presence of a compound capable of enhancing the expression of Blimp-1, such as for example IL-21, IL-2, iL-6, 11-7, IL-10, IL-15, IL -27 or a mutated Janus kinase. Preferably, IL-21 is used because this cytokine is particularly suitable for enhancing the expression of Blimp-1 and stabilizing an antibody-producing cell with a method disclosed herein. Furthermore, to enhance the efficiency of transduction, said B lymphocyte is preferably cultured in the presence of IL21 before said B lymphocyte is transduced with a nucleic acid sequence encoding BCL6 and / or Bcl-xL, or a part, derivative and / or functional analog thereof.
Said B lymphocyte is provided with a SOCS protein or a part, derivative and / or functional analog thereof, or a nucleic acid encoding it, since a SOCS protein or a part, derivative and / or functional analog thereof is capable of indirectly enhancing the expression of Blimp-1. In another alternative or additional embodiment of the present disclosure, said B lymphocyte is provided with E47 or a part, derivative and / or functional analog thereof, or a nucleic acid that encodes it. As already outlined above, as a result of an increased level of E47 or a part, derivative and / or functional analog thereof, the function of the Socs protein is enhanced and the expression of Blimp-1 is indirectly increased.
Particularly preferred embodiments of the disclosure are shown in the examples. According to a particularly preferred embodiment of the disclosure, RSV-specific B cells are first cultured in the presence of IL-21. Subsequently, the B lymphocytes undergo a transduction reaction using a nucleic acid encoding BCL6 and a nucleic acid encoding Bcl-xL. Spin transduction is preferably used. More preferably, the B lymphocytes and viruses comprising at least one nucleic acid of interest are mixed, when the mixture is then centrifuged to achieve high transduction efficiency. After transduction, B lymphocytes are cultured in the absence of 11-21 and in the presence of 11-4 and L cells for 3-5 days to allow expression of BCL6. Subsequently, the B lymphocytes can again undergo a transduction reaction using a nucleic acid encoding BCL6 and a nucleic acid encoding Bcl-xL. The B lymphocytes are then cultured again in the absence of 11-21 and in the presence of 11-4 and L cells for 3-5 days to allow expression of BCL6. Subsequently, cells expressing BCL6 and Bcl-xL are isolated and IL-21 is administered back to the culture to enhance replication and antibody production. Antibodies that are secreted by cells expressing Bcl-6, Blimp 1 and Bcl-xL in the culture supernatant are preferably screened for an in vitro neutralizing capacity / activity / reactivity to RSV. Antibody-producing cells that produce those antibodies are further preferably selected, for example by limiting dilution culture. Stable RSV-specific B lymphocytes are therefore obtained in which BCL6 and Blimp-1 are co-expressed. Said B lymphocytes are capable of replicating and producing antibodies in in vitro culture for at least six months.
A method is disclosed herein which further comprises selecting and / or isolating a RSV-specific antibody or functional equivalent thereof. IgM-producing cells and IgG-producing cells can be selected and / or isolated. Preferably, an IgG producing cell is selected and / or isolated.
RSV-specific antibody-producing cells generated by a method disclosed herein are suitable for producing RSV antibodies. However, the genes encoding Ig heavy and / or light chains are isolated from said cell and expressed in a second cell, such as for example cells of a Chinese hamster ovary (CHO) cell line or 293 cells ( T). Said second cell, also referred to herein as a producer cell, is preferably adapted to the production of commercial antibodies. The proliferation of such a producer cell results in a producer cell line capable of producing RSV-specific antibodies. Preferably, said producer cell line is suitable for producing compounds for use in humans. Therefore, said producer cell line is preferably free of pathogens such as pathogenic microorganisms.
A method disclosed herein is preferably used to generate an antibody producing cell that is stable for at least one week, preferably at least one month, more preferably at least three months, more preferably at least six months so that it has been made possible commercial antibody production Most preferably a stable cell line capable of producing monoclonal antibodies is produced. This is preferably done using memory B lymphocytes which have been isolated for example from a sample by selection for CD19 and / or CD22 (marker of B lymphocytes) and cell surface IgG and / or CD27 (to mark memory cells). and / or by negative selection for IgM, IgD and / or IgA. Furthermore, a cell producing RSV-specific antibodies is selected for example in a binding assay using
IS 2 575 129 T3
RSV or a component derived from RSV, such as for example the F protein, G protein and / or the SH protein of RSV. Subsequently, Blimp-1 and BCL6 can be co-expressed in said RSV-specific antibody-producing cell, resulting in a culture of cells capable of specifically binding to (a component of) RSV. In yet another preferred embodiment of the disclosure, said B lymphocyte is additionally provided with Bcl-xL or a part, derivative and / or functional analog thereof.
If you only use a memory cell, you get a cell line that produces monoclonal antibodies. It is also possible to generate a monoclonal antibody-producing cell line that begins with B lymphocytes capable of producing antibodies against RSV. After a stable B lymphocyte culture has been produced with a method disclosed herein, a B lymphocyte capable of producing antibodies against a RSV-specific antigen and at least one functional part of a gene encoding the heavy chain and / or or Ig light chain of said B lymphocyte is preferentially expressed in a second cell line. Preferably at least one functional part of the gene encoding the Ig heavy chain and at least one functional part of the gene encoding the Ig light chain of said B lymphocyte are expressed in a second cell line.
An antibody producing cell, preferably but not necessarily a memory B lymphocyte, that has been obtained from an individual who has been previously exposed to RSV can be used in a method of the present disclosure. In this way, it has been possible to produce human antibodies of interest ex vivo.
A method for producing antibodies that are capable of specifically binding and / or neutralizing respiratory syncytial virus is therefore further disclosed, the method comprising:
- producing an antibody-producing cell capable of producing RSV-specific antibodies with a method according to the invention; Y
- obtaining antibodies produced by said antibody-producing cell.
Also provided is an isolated or recombinant antibody, as defined in the claims as well as an isolated or recombinant antibody-producing cell, as defined in the claims, obtainable by a method according to the invention, as defined in the claims . Said antibody preferably comprises D25, AM14, AM16 and / or AM23 antibody.
Once a RSV-specific antibody-producing cell has been obtained according to the invention as defined in the claims, preferably a functional part of a gene encoding the heavy chain and light chain is isolated and / or artificially generated. Ig of said cell. A nucleic acid sequence is provided that comprises at least a functional part of a nucleic acid sequence as depicted in Figure 11, Figure 12, Figure 14A, Figure 14B or Figure 14C. Said functional part comprises at least one nucleic acid sequence as represented in Figure 11D, Figure 12, Figure 14A, Figure 14B and / or Figure 14C. Said functional part encodes the CDRs as represented in Figure HD, Figure 12, Figure 14A, Figure 14B or Figure 14C.
An isolated, synthetic or recombinant nucleic acid sequence is further disclosed which comprises a heavy chain sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to at least part of the sequence CAGGTGCAGCTGGTACAGTCTGGGGCTGAAGTGAAGAAGCCTGGTCTCGCCGCCTGATGCCGCCGTCTCGCCGTGATGCCGCCGTCTCGCCGTGATGCCGCCGTCTCGCCGTGATG ACTATATTATCAAC,
TGGCTACGACAGGCCCCTGGACAAGGCCCTGAGTGGATGGGA, GGGATCATTCCTGTCTTGGGTACAGTACACTACGCACCGAAGTTCCAGGGC, AGAGTCACGATTACCGCGGACGAATCCACAGACACACGCCTACATCCATGACTGATCAGCCACGCCTACATCCATGACTA
GAAACAGCTCTGGTTGTATCTACTACCTACCTACCACACTACTTTGACAAC, TGGGGCCAGGGAACCCTGGTCACCGTCTCCTCAG, and / or
CAGGTGCAGCTGGTACAGTCTGGGGCTGAAGTGAAGAAGCCTGGGTCCTCGGTGATGGTCTC CTGCCAGGCCTCTGGAGGCCCCCTCAGAAACTATATTATCAACTGGCTACGACAGGCCCCTG GACAAGGCCCTGAGTGGATGGGAGGGATCATTCCTGTCTTGGGTACAGTACACTACGCACCG AAGTTCCAGGGCAGAGTCACGATTACCGCGGACGAATCCACAGACACAGCCTACATCCATCT GATCAGCCTGAGATCTGAGGACACGGCCATGTATTACTGTGCGACGGAAACAGCTCTGGTTG TATCTACTACCTACCTACCACACTACTTTGACAACTGGGGCCAGGGAACCCTGGTCACCGTC TCCTCAG, said part having at the least 15 nucleotides. Said heavy chain sequence is preferably derived from the D25 antibody. Said heavy chain sequence may preferably comprise a sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to a sequence as depicted in Figure HD. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the aforementioned heavy chain sequences.
Also disclosed is an isolated, synthetic or recombinant nucleic acid sequence comprising a light chain sequence that is at least 70%, preferably at least 80%, more preferably at least
ES 2 575 129 T3% homologous to at least part of the sequence
GACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCAGCTGTAGGAGACAGAGTCACCAT CACTTGC,
CAGGCGAGTCAGGACATTGTCAACTATTTAAAT, TGGTATCAACAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTAC, GTTGCATCCAATTTGGAGACA,
GGGGTCCCATCAAGGTTCAGTGGAAGTGGATCTGGGACAGATTTTAGTCTCACCATCAGCAG CCTGCAGCCTGAAGATGTTGCAACATATTATTGT, CAACAATATGATAATCTCCCA,
CTCACATTCGGCGGAGGGACCAAGGTTGAGATCAAAAGA and / or
GACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCAGCTGTAGGAGACAGAGTCACCAT CACTTGCCAGGCGAGTCAGGACATTGTCAACTATTTAAATTGGTATCAACAGAAACCAGGGA AAGCCCCTAAGCTCCTGATCTACGTTGCATCCAATTTGGAGACAGGGGTCCCATCAAGGTTC AGTGGAAGTGGATCTGGGACAGATTTTAGTCTCACCATCAGCAGCCTGCAGCCTGAAGATGT TGCAACATATTATTGTCAACAATATGATAATCTCCCACTCACATTCGGCGGAGGGACCAAGG
TTGAGATCAAAAGA, said part having at least 15 nucleotides. Said light chain sequence is preferably derived from the D25 antibody.
Said light chain sequence preferably comprises a sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to a sequence as depicted in Figure HD. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the light chain sequences mentioned above.
An isolated, synthetic or recombinant nucleic acid sequence is further disclosed which comprises a heavy chain sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to at least part of the sequence GAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTCCGTCCAGTCGTCGCGAGGTCTCCGTCCAGTCGTCGCAGGTCTCT GGATTCAGCTTCAGTCACTATGCC,
ATGCACTGGGTCCGCCAGGCTCCAGGCAAGGGACTGGAGTGGGTGGCAGTT, ATATCTTATGATGGAGAAAATACA, TATTACGCAGACTCCGTGAAGGGCCGATTCTCCATCTCCAGAGACAATTCCAAGAACACAGT GTCTCTGCAAATGAACAGCCTGAGACCTGAGGACACGGCTCTATATTACTGT, GCGAGAGACCGCATAGTGGACGACTACTACTACTACGGTATGGACGTC,
TGGGGCCAAGGGGCCACGGTCACCGTCTCCTCAG and / or
GAGGTGCAGCTGGTGGAGTCTGGGGGAGGCGTGGTCCAGCCTGGGAGGTCCCTGAGACTCTC
CTGTGCGGCCTCTGGATTCAGCTTCAGTCACTATGCCATGCACTGGGTCCGCCAGGCTCCAG GCAAGGGACTGGAGTGGGTGGCAGTTATATCTTATGATGGAGAAAATACATATTACGCAGAC TCCGTGAAGGGCCGATTCTCCATCTCCAGAGACAATTCCAAGAACACAGTGTCTCTGCAAAT GAACAGCCTGAGACCTGAGGACACGGCTCTATATTACTGTGCGAGAGACCGCATAGTGGACG ACTACTACTACTACGGTATGGACGTCTGGGGCCAAGGGGCCACGGTCACCGTCTCCTCA, said part having at the least 15 nucleotides. Said heavy chain sequence is preferably derived from the AM14 antibody. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the aforementioned heavy chain sequences.
Also disclosed is an isolated, synthetic or recombinant nucleic acid sequence comprising a light chain sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to at least a part of the sequence.
GACATCCAGATGACCCAGTCTCCATCTTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCAT
CACTTGCCAGGCGAGT, CAGGACATTAAGAAGTAT,
TTAAATTGGTATCATCAGAAACCAGGGAAAGTCCCTGAGCTCCTGATGCAC, GATGCATCC,
AATTTGGAAACAGGGGTCCCATCAAGGTTCAGTGGCAGGGGATCTGGGACAGATTTTACTCT
CACCATTAGCAGCCTGCAGCCTGAAGATATTGGAACATATTACTGT, CAACAGTATGATAATCTGCCTCCGCTCACT, TTCGGCGGAGGGACCAAGGTGGAGATCAAAC and / or
GACATCCAGATGACCCAGTCTCCATCTTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCAT CACTTGCCAGGCGAGTCAGGACATTAAGAAGTATTTAAATTGGTATCATCAGAAACCAGGGA
AAGTCCCTGAGCTCCTGATGCACGATGCATCCAATTTGGAAACAGGGGTCCCATCAAGGTTC AGTGGCAGGGGATCTGGGACAGATTTTACTCTCACCATTAGCAGCCTGCAGCCTGAAGATAT TGGAACATATTACTGTCAACAGCCTATGATAGCCGACTGACTGACTGACCACGATAGGATGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACTGACT Said light chain sequence is preferably derived from the AM14 antibody.
Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the light chain sequences mentioned above.
An isolated, synthetic or recombinant nucleic acid sequence is further disclosed comprising a heavy chain sequence that is at least 70%, preferably at least 80%, more preferably at least 70%.
ES 2 575 129 T3 minus 90% homologous to at least part of the sequence GAGGTGCAGCTGGTGGAGACCGGGGAGGCCTGGCCCAGCCTGGGGGTCCCTGAGACTCTC
CTGTGCAGCCTCT, GGATTCACATTCAGTAGTTATAAC,
ATGAACTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCACAC,
ATTAGTGCGGGTAGTAGTTACATA, TACTACTCAGACTCAGTGAAGGGCCGATTCACCGTCTCCAGAGACAACGTCAGGAACTCAGT ATATCTGCAAATGAACAGCCTGAGAGCCGCTGACACGGCTGTGTATTACTGT, GCGCCAACATTCGTGATG
TGGGGCCAGGGAACCCTGGTCACCGTCTCCTCAG and / or
GAGGTGCAGCTGGTGGAGACCGGGGGAGGCCTGGCCCAGCCTGGGGGGTCCCTGAGACTCTC
CTGTGCAGCCTCTGGATTCACATTCAGTAGTTATAACATGAACTGGGTCCGCCAGGCTCCAG GGAAGGGGCTGGAGTGGGTCTCACACATTAGTGCGGGTAGTAGTTACATATACTACTCAGAC TCAGTGAAGGGCCGATTCACCGTCTCCAGAGACAACGTCAGGAACTCAGTATATCTGCAAAT GAACAGCCTGAGAGCCGCTGACACGGCTGTGTATTACTGTGCGAGAGAGGATTATGGTCCGG GAAATTATTATAGTCCTAACTGGTTCGACCCCTGGGGCCAGGGAACCCTGGTCACCGTCTCC TCA, said part having at the least 15 nucleotides. Said heavy chain sequence is preferably derived from the AM16 antibody. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the aforementioned heavy chain sequences.
Also disclosed is an isolated, synthetic or recombinant nucleic acid sequence comprising a light chain sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to at least part of the sequence of
CAGTCTGTCGTGACGCAGCCGCCCTCAGTGTCTGGGGCCCCAGGGCAGAGAGTCACCATCTC CTGCACTGGGAGC, AGCTCCAACATCGGGGCAGGTTATGAT,
GTACACTGGTACCAGCAGCTTCCAGGAACAGCCCCCAAACTCCTCATCTAT, GGCAACACT,
AATCGGCCCTCAGGGGTCTCCGACCGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCT GGCCATCACTGGACTCCAGGCTGAGGATGAGGCTGATTATTACTGC, CACTCCTATGACAGAAGCCTGAGTGGT, or TCCCGTAAGTCGGC
CAGTCTGTCGTGACGCAGCCGCCCTCAGTGTCTGGGGCCCCAGGGCAGAGAGTCACCATCTC CTGCACTGGGAGCAGCTCCAACATCGGGGCAGGTTATGATGTACACTGGTACCAGCAGCTTC CAGGAACAGCCCCCAAACTCCTCATCTATGGCAACACTAATCGGCCCTCAGGGGTCTCCGAC CGATTCTCTGGCTCCAAGTCTGGCACCTCAGCCTCCCTGGCCATCACTGGACTCCAGGCTGA GGATGAGGCTGATTATTACTGCCACTCCTATGACAGAAGCCTGAGTGGTTCAGTATTCGGCG
GAGGGACCAAGCTGACCGTC, said part having at least 15 nucleotides. Said light chain sequence is preferably derived from the AM16 antibody. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the light chain sequences mentioned above.
An isolated, synthetic or recombinant nucleic acid sequence is further disclosed comprising a heavy chain sequence that is at least 70%, preferably at least 80%, more preferably at least 90% homologous to at least part of the sequence CAGGTGCAACTGGTGGAGTCTGGGGGAAATGTGGTCAAGCCTGGGACGTCCCTGAGACTCCTGGGACGTCCCTGAGACTCCTGGGACGTCCCTGAGACT
CTGTGCAGCGACT, GGATTCAACTTCCATAACTACGGC,
ATGAACTGGGTCCGCCAGGCTCCAGGCAAGGGGCTGGAGTGGGTGGCGGTT,
GTTTGGTATGATGGAAGTAAGAAA, TACTATGCAGACTCCGTGACGGGCCGATTCGCCATCTCCAGAGACAATTCCAAGAACACTCT GTATCTGCAAATGAACAGCCTGAGAGTCGAGGACACGGCTGTTTATTATTGT, GTGCCGACCTACTGTGACTGTCATGTCGCCAGACATAAAGTGACTGTC and GTGCCGACCTACTAAAGTGACTGTC
GAGGTGCAGCTGGTGGAGTCTGGGGGAAATGTGGTCAAGCCTGGGACGTCCCTGAGACTGTC CTGTGCAGCGACTGGATTCAACTTCCATAACTACGGCATGAACTGGGTCCGCCAGGCTCCAG GCAAGGGGCTGGATAGTAGTGGTAG
TCCGTGACGGGCCGATTCGCCATCTCCAGAGACAATTCCAAGAACACTCTGTATCTGCAAAT GAACAGCCTGAGAGTCGAGGACACGGCTGTTTATTATTGTGTGAGAGATAAAGTGGGACCGA CTCCCTACTTTGACTCCTGGAACGotCCAGGGT having at least 15 nucleides, TCTCTGGAACGotCCAGGGT having at least 15 nucleides. Said heavy chain sequence is preferably derived from the AM23 antibody. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the aforementioned heavy chain sequences.
Also disclosed is an isolated, synthetic or recombinant nucleic acid sequence comprising a light chain sequence that is at least 70%, preferably at least 80%, preferably at least 90% homologous to at least part of the sequence.
TCCTATGTGCTGACTCAGCCACCCTCGGTGTCACTGGCCCCAGGAGGGACGGCCGCGATCAC
CTGTGGAAGAAAC, AACATTGGAAGTGAAACT,
GTGCACTGGTACCAGCAGAAGCCAGGCCAGGCCCCTGTGCTGGTCGTCTAT, GATGATGAC,
GACCGGCCCTCAGGGATCCCTGAGCGATTCTCTGGCTCCAACTCTGGGAACACGGCCACCCT
IS 2 575 129 T3
GACCATCAGCAGGGTCGAGGCCGGGGATGAGGCCGACTATTACTGT, CAGGTGTGGGATAGGAGTAATTATCATCAGGTA, TTCGGCGGAGGGACCAAGTTGACCGTCCTAG and / or TCCTATGTGCTGACTCAGCCCCCCTCGGTGTCACTGGCCCCAGGAGGGACGGCCGCGATCAC CTGTGGAAGAAACAACATTGGAAGTGAAACTGTGCACTGGTACCAGCAGAAGCCAGGCCAGG CCCCTGTGCTGGTCGTCTATGATGATGACGACCGGCCCTCAGGGATCCCTGAGCGATTCTCT GGCTCCAACTCTGGGAACACGGCCACCCTGACCATCAGCAGGGTCGAGGCCGGGGATGAGGC
CGACTATTACTGTCAGGTGTGGGATAGGAGTAATTATCATCAGGTATTCGGCGGAGGGACCA AGCTGACCGTC, said part having at least 15 nucleotides. Said light chain sequence is preferably derived from the AM23 antibody. Also disclosed herein is an isolated, synthetic or recombinant nucleic acid sequence comprising a heavy chain sequence consisting of any of the aforementioned heavy chain sequences.
Also disclosed is a nucleic acid sequence encoding an amino acid sequence that is at least 70%, preferably at least 80%, more preferably at least 90% identical to at least a functional part of an amino acid sequence as depicted in the Figure 11, Figure 14A, Figure 14B and / or Figure 14C, said part having at least 5 amino acid residues. Said nucleic acid sequence can encode an amino acid sequence that is at least 80% identical to the CDR sequence of heavy chain 1, 2 and / or 3 and / or CDR sequence of light chain 1 or 2 represented in Figure 11D . Said nucleic acid sequence can encode an amino acid sequence that is at least 80% identical to at least one of the CDR sequences depicted in Figure 14A, in Figure 14B and / or in Figure 14C. Said nucleic acid sequence can encode an amino acid sequence that is at least 70% identical to a heavy chain sequence represented in Figure 11A, to a heavy chain sequence represented in Figure 14A, to a heavy chain sequence represented in Figure 11B, to a heavy chain sequence depicted in Figure 14C, to a light chain sequence depicted in Figure 11A, to a light chain sequence depicted in Figure 14A, to a light chain sequence depicted in Figure 14B and / or to a light chain sequence depicted in Figure 14C.
An isolated, synthetic or recombinant nucleic acid sequence is thus further disclosed comprising a sequence encoding an amino acid sequence that is at least 70%, preferably at least 80%, more preferably at least 85% identical to a sequence of amino acids as depicted in Figure 11A-D. Said nucleic acid sequence may encode an amino acid sequence that is at least 80% identical to the CDR sequence of heavy chain 1, 2 and / or 3 and / or the sequence of CDR light chain 1 or 2 as represented in Figure 11A-D. One embodiment discloses an isolated, synthetic or recombinant nucleic acid sequence comprising a sequence encoding an amino acid sequence that is at least 70% identical to the NYIIN amino acid sequence, and / or at least 75% identical to the GIIPVLGTVHYAPKFQG sequence and / or at least 70% identical to the ETAl WSTTYLPH YFD N sequence, and / or at least 85% identical to the QASQDIVNYLN sequence, and / or at least 70% identical to the VASNLET sequence, and / or at the least 70% identical to the sequence QVQLVQSGAEVKKPGSSVMVSCQASGGPLRNYIINWLRQAPGQGPEWMGGII PVLGTVHYAPKFQGRVTITADESTDTAYIHLISLRSEDTAMYYCATETALWST TYLPHYFDN WGQGTLVTVSS, and / or at the least 70% identical to the sequence DIQMTQSPSSLSAAVGDRVTITCQASQDIVNYLNWYQQKPGKAPKLLIYVASN
LETGVPSRFSGSGSGTDFSLTISSLQPEDVATYYCQQYDNLPLTFGGGTKVEIK RTV. A nucleic acid sequence disclosed herein may be at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% homologous to any of the sequences listed above.
An isolated, synthetic or recombinant nucleic acid sequence is further disclosed comprising a sequence encoding an amino acid sequence that is at least 70%, preferably at least 80%, more preferably at least 85% identical to an amino acid sequence as described. depicted in Figure 14A-C. Said nucleic acid sequence can encode an amino acid sequence that is at least 70% identical to a CDR sequence as depicted in Figure 14A, 14B and / or 14C. An isolated, synthetic or recombinant nucleic acid sequence may comprise a sequence encoding an amino acid sequence that is at least 70% identical to an amino acid sequence selected from the group consisting of: GFSFSHYA, ISYDGENT, ARDRIVDDYYYYGMDV, QDIKKY, DAS, QQYDNLPPLT ,
EVQLVESGGGWQPGRSLRLSCAASGFSFSHYAMHWVRQAPGKGLEWVAVIS
YDGENTYYADSVKGRFSISRDNSKNTVSLQMNSLRPEDTALYYCARDRIVDD YYYYGMDVWGQGATVTVSS,
DIQMTQSPSSLSASVGDRVTITCQASQDIKKYLNWYHQKPGKVPELLMHDASNLETGVPSRF
SGRGSGTDFTLTISSLQPEDIGTYYCQQYDNLPPLTFGGGTKVEIKRTV, GFTFSSYN, ISAGSSYI,
AREDYGPGNYYSPNWFDP, SSNIGAGYD, GNT, HSYDRSLSG,
EVQLVETGGGLAQPGGSLRLSCAASGFTFSSYNMNWVRQAPGKGLEWVSHI SAGS SYIYYS D SVKGRFTVSRDNVRNSVYLQMNSLRAADTAVYYCAREDYGPGNYYSPN-WFDPWGQGTLVTVS s,
QSVVTQPPSVSGAPGQRVTISCTGSSSNIGAGYDVHWYQQLPGTAPKLLIYGNTNRPSGVSD
RFSGSKSGTSASLAITGLQAEDEADYYCHSYDRSLSGSVFGGGTKLTV, GFNFHNYG, VWYDGSKK,
VRDKVGPTPYFDS, NIGSET, DDD, QVWDRSNYHQV, EVQ LVESGGNWKPGTSLRLSCAATGFNFHNY GMNWVRQAPGKGLEWVA WWYDGSKKYYAD SVTGRFAI
SRDNSKNTLYLQMNSLRVEDTAVYYCVRDKVGPTPYFDSWGQGTLVTVSS, and S YVLTQPPSVS LAPGGTAAI TCGRNNI GSETVHWYQQKPGQAPVL WYDDDDRPSGI PERFST GSNS IGNTATAT
IS 2 575 129 T3
SRVEAGDEADYYCQVWDRSNYHQVFGGGTKLTV. A nucleic acid sequence disclosed herein may be at least 80%, more preferably at least 85%, more preferably at least 90%, more preferably at least 95% homologous to any of the sequences listed above.
As already explained herein above, the nucleic acid sequences according to the present invention as defined in the claims are particularly suitable for expressing an antibody according to the invention, preferably D25, AM14, AM16, AM23 in a nucleic acid expression system. A nucleic acid sequence according to the present invention as defined in the claims is preferentially expressed in a cell, more preferably in a producer cell adapted for the production of antibodies.
The invention is further explained in the following examples. These examples do not limit the scope of the invention, but serve only to clarify the invention.
Examples
Materials and methods
Maintenance and isolation of human B lymphocytes
Using standard procedures, CD19 positive human B lymphocytes were isolated from blood bank derived buffy coat (other sources may be fresh blood with an anticoagulation factor, or a lymphoid organ eg tonsil or spleen). Briefly, total peripheral blood mononuclear cells (PBMC) were isolated using Ficoll density separation (Amersham, Buckinghamshire, UK). CD22-labeled beads were used to positively select for B lymphocytes by MACS cell sorting technique as described by the manufacturer (Miltenyi, Utrecht, The Netherlands). The cells were subsequently stained with appropriate combinations of monoclonal antibodies (mAbs) for CD19, CD27, IgD, IgM and IgA (Becton Dickinson (BD), Franklin Lakes, NJ, USA). Memory B cells that are positive for CD19 and CD27 and negative for IgM, IgA and IgD were then sorted using the FACSAria (BD) (Figure 1). In addition to memory B lymphocytes, other subsets of B lymphocytes can be isolated, such as treatment-naïve, follicular, memory, antibody-producing, centroblast, centrocyte, germinal-core, plasmablast, plasma, germ-zone, perisinusoidal, or transitional (many of these subsets have only been determined in mice) using appropriate markers.
Cell culture
Sorted cells were washed and cultured in 24-well plates (1.5 to 2x10<sup>5</sup> cells / ml) into 80 Gray-irradiated CD40L expressing L cells (5x10<sup>4</sup> cells / ml; provided by Dr. J. Banchereau, Schering Plow France, Dardilly France), in complete medium (Iscove Modified D Minimum Essential Medium containing 8% Fetal Calf Serum (FCS) and Penicillin / Streptomycin). Unless otherwise mentioned, these CD40L expressing L cells are always present in cultures in combination with 8% FCS. To prepare the B lymphocyte for retroviral transduction, cells were cultured for 36 hours in the presence of mouse IL-21 (50 ng / ml, R&D, Minneapolis, MN, USA). After transduction the cells are preferably cultured in the presence of IL-21, however the cells respond to IL-4, IL-15 and IL-10 (without excluding other cytokines). For example, IL-4 induced B lymphocyte expansion is less compared to IL-21 and lower levels of cell division may be required in some experiments.
Retroviral constructs and recombinant retrovirus production
Constitutive active mutants of STAT5a and b have been previously described. DNA encoding these mutants and wild-type STAT5b was obtained from T. Kitamura (IMSUT, Tokyo, Japan). Bcl-6 was identified in a senescence rescue scan in murine fibroblasts as an inhibitor of antiproliferative p19ARF-p53 signaling. Bcl-XL was identified as an antiapoptosis factor, kindly provided by Dr. Korsmeyer (Howard Hughes Medical Institute, Boston, USA). These DNAs were ligated to the LZRS-linker-IRES-GFP (or IRES-YFP or IRES-NGFR) vector that had been previously described (Heemskerk et al., 1997; Heemskerk et al., 1999). Instead of the IRES-GFP (Green Fluorescent Protein) marker an IRES-YFP (Yellow Fluorescent Protein) or an IRES-NGFR (nerve growth factor receptor) was also used. NGFR is an incompetent mutant for NGFR signaling, kindly provided by Dr. C. Bonini. A monoclonal antibody against NGFR (Chromaprobe, Mountain View, CA, USA or Miltenyi) was used to visualize cells expressing NGFR.
For recombinant retrovirus production, retroviral plasmids were transfected into an amphotropic producer cell line without helper virus Phoenix-A, a derivative of the 293 human embryonic kidney cell line (Kinsella and Nolan, 1996) (a kind gift from Dr. G. Nolan, Stanford University, Palo Alto, CA), using Fugene-6 (Roche Diagnostics The Netherlands, Almere, The Netherlands) according to manufacturer's protocols. Two days later, the selection of transfected cells was started by adding puromycin 2 pg / ml (Becton
IS 2 575 129 T3
Dickinson Clontech Laboratories, Palo Alto, CA). Ten to 14 days after transfection, 6 x 10 were seeded.<sup>6 </sup>cells per 10 cm Petri dish (Becton Dickinson Discovery Labware, Bedford, MA) in 10 ml complete medium without puromycin. The following day the medium was renewed and the next day the retroviral supernatant was collected, centrifuged and frozen in cell-free aliquots at -70 ° C. This approach provides rapid, large-scale, high-titer reproducible retroviral production of greater than 3 x 10<sup>6</sup> infectious virus particles / ml.
Retroviral transduction
The CH-296 recombinant human fibronectin fragment transduction procedure (RetroNectin ™; Takara, Otsu, Japan) was analyzed as previously described (Heemskerk et al., 1997; Heemskerk et al., 1999). Non-tissue culture treated 24-well plates (Costar, Badhoevedorp, The Netherlands) were coated with 0.3 ml CH-296 recombinant human fibronectin fragment 30 pg / ml at room temperature for 2 hours or overnight at 4 ° C. When non-tissue culture plates of different sizes were used, the reagents were used proportionally. The CH-296 solution was removed, followed by incubation with 2% human serum albumin (HSA) in phosphate buffered saline (PBS) for 30 minutes at room temperature, followed by washing once with PBS. They were seeded in 5x10 plates<sup>5</sup> B lymphocytes, which were prepared for retroviral transduction in 0.25 ml RPMI without FCS and L cells and mixed with 0.25 ml of thawed retroviral supernatant. For the double transduction of Bcl-6 Bcl-XL, 125 µl of Bcl-6-IRES-NGFR (or IRES-YFP) (Shvarts A. et al. Genes Dev., 2002) and 125 µl of Bcl-XL- IRES-GFP (provided by S. Korsmeyer, Howard Hughes Medical Institute, Children's Hospital, Boston, USA) and added to cells. The culture was subsequently centrifuged at 1800 rpm at 25 ° C for 60 minutes and incubated for 6 hours at 37 ° C. Then 0.25 ml of supernatant was removed and 0.25 ml of fresh retroviral supernatant was added. The culture was centrifuged again at 1800 rpm at 25 ° C for 60 minutes and incubated at 37 ° C overnight. The next day cells were transferred to a 24-well tissue culture treated plate (Costar) and cultured for 3-5 days under normal conditions in the presence of human IL-4 (50 ng / ml) or mouse IL-21 ( 50 ng / ml, R&D, Minneapolis, MN, United States). Transduction efficiency was determined by antibody staining of a truncated signaling-incompetent mutant of the nerve growth factor receptor (ANGFR, provided by C. Bonini, Hospital de San Rafael, Milan, Italy) or (co) expression of GFP and / or YFP. Cells containing the transgene (s) of interest are then selected for further experiments.
Flow cytometry
Antibodies against human molecules IgD, IgG, CD3, CD19, CD20, CD27, CD38, CD40, CD45, CD56, CD70, CD80, CD86, HLA-DR (BD) directly labeled with FITC, PE, PERCP, PE- were used. Cy5, APC or APC-Cy7 and IgM, kappa light chain, lambda light chain, CD138, directly PE-labeled (DAKO) for flow cytometric analysis. The stained cells were analyzed using an LSRII (BD) and the FACS data was processed with FlowJo computer software (Tree Star, Inc).
Proliferation experiment
Treatment-naïve and memory B lymphocytes were isolated from new PBMC in FACSAria: naïve B lymphocytes: CD19-PE-Cy7 pos, CD27-APC neg, IgD-PE pos Memory B lymphocytes: CD19-PE- Cy7 pos, CD27 APC pos, IgD-PE neg, IgA-FITC neg. Cells were washed in PBS and resuspended in 0.5 ml RPMI (37 ° C) without FCS. An equal amount of IMDM containing 2 pM carboxyfluorescein succinimidyl ester (CFSE) was added to the cell mix and incubated for 7 minutes at 37 ° C. Positive labeling of cells was stopped by washing the cell with cold FCS. The cells were resuspended in 500 µl of 8% iMdM-FCS and cultured with L cells and in the absence or presence of IL-21. Unlabeled cells were used as a control. After 36 hours (immediately before transduction), a ratio of cells was analyzed for their CFSE content. The remaining cells were spin transduced with Bcl-6-IRES-NGFR, cultured for 3 days, and analyzed for their CFSE content using the LSRII. Data was analyzed using FlowJo software (Treestar)
Isolation of Antigen-Specific Human B Lymphocytes Using High-Speed Single Cell Sorting
In addition to the above-described memory B cell isolation method that begins with MBC (i.e. 100 cell / well cultures), human memory B cells can also be incubated with a fluorescently labeled antigen and sorted based on antigen recognition. . An example is the isolation of B lymphocytes that bind with phycoerythrin (PE) -labeled tetanus toxoid (provided by A. Radbruch, Berlin, Germany) (Figure 4). Cells were grown at 1 cell / well and checked for TT binding. Despite this, any other labeled antigen can be used.
Determination of B-lymphocyte receptor (BCR) expression after long-term culture of cells transduced with Bcl-6 and Bcl-XL
B lymphocytes that differentiate during in vitro culture are known to lose their membrane expression of BCR, which is also seen in EBV transformed B lymphocytes. Therefore B-lymphocytes transduced with Bcl-6 and
IS 2 575 129 T3
Bcl-XL and cultured in the presence of IL-21 were stained for GFP, NGFR, CD19, Kappa and / or Lambda or IgG or with labeled tetanus toxoid. To show the utility of BCR expression, TT-PE binding cells (Radbruch) were sorted using the FACSAria (BD) at 1 cell / well in 96-well plates, which were seeded with L cells and culture medium containing IL-21. After three weeks the tetanus toxoid binding of growing clones was checked using the Canto FACS (BD). Therefore cells were harvested and stained in 96-well plates with GFP, NGFR, CD19 and TT-PE.
Development of double positive B-lymphocyte lines for Bcl-6 and Bcl-XL that secrete antibodies
B lymphocyte lines were created that produce monoclonal antibodies and are 100% double positive for Bcl-6 and Bcl-XL. First of all this was achieved by inducing proliferation and differentiation using IL-21. Meanwhile these cells are transduced with the retroviruses Bcl-6-IRES-NGFR and Bcl-XL-IRES-GFP. Cells are kept in IL-4 for 3-4 days. Cells that are transduced with one or both of the retroviruses then express the transgene and will therefore express the NGFR or GFP protein. The expression of NGFR and / or GFP can be visualized using the LSRII (BD). If necessary, cells can be transduced again to obtain larger numbers of cells expressing both transgenes. Regardless of a second transduction, cells expressing both transgenes are sorted using the Aria FACS (BD) and cultured at a cell density ranging from 10-500 cells / well in 96-well plates in the presence of IL-21 and 2500 at 5000 L cells / well. These mini volume cultures (MBC) secrete relatively large amounts of antibody into the culture supernatant as early as day 5, which can then be used for screening purposes. Screening can be based on available techniques for the antigen of interest for example ELISA / EIA / RIA, Western blotting, or direct functional assays such as cytokine blocking neutralization experiments. After screening and selection for MBC that recognize the antigen of interest (TT and RSV in our experiments), cells are subcloned at 0.5-1 cell / well into 96 wells in the presence of IL-21. Subcloning typically takes 2-3 weeks and can be performed by limiting dilution (DL) culture or single cell sorting using flow cytometry (FACSAria).
RSV A-2 virus stock and HEp2 cell line
The RSV A-2 virus (kindly provided by G. van Bleek, WKZ, Utrecht) and the HEp2 cell line (Clinical Laboratory, AMC, Amsterdam), were grown in large quantities and frozen in liquid nitrogen.
The adherent HEp2 cell line was grown in normal medium in Falcon T175 flasks before the aliquots were frozen.
To obtain a high titer RSV stock, HEp2 cells were seeded and cultured to 50-60% confluence. It was added to the original RSV stock (1/20 dilution of the total volume 5 ml) for 45 minutes at RT in the HEp2 cells. 15 ml of fresh medium was added and the cells were left overnight at 37 ° C, 5% CO2 with the lid open. The next day the culture supernatant was carefully removed and 15 ml of medium containing 1% FCS was added. Cells were left for 24 to 36 hours at 37 ° C, 5% CO2 with the lid closed. When RSV-induced syncytia were clearly visible and most syncytia were still intact, the medium was collected, filtered (0.22 pm), and centrifuged at 1450 rpm at RT before the samples were flash frozen and stored in liquid nitrogen. . A second harvest can be obtained by immediately adding new medium containing 1% FCS and freezing this batch 4-6 hours later.
RSV lysate for ELISA
HEp2 cells that had been infected with RSV A-2 to obtain virus stocks were used to isolate RSV proteins. Cells were first carefully washed with PBS and trypsinized. Trypsin (Gibco) was washed away and the cell pellet was lysed with 1% octylglycoside (cell pellet from a T175 flask was treated with 2 ml octylglycoside). The suspension was homogenized with a syringe and needle (10 times up and down), incubated for 1 hour on ice and then dialyzed against 2 l of TBS buffer pH 7.4, overnight at 4 ° C. Supernatant was obtained after pelleting the cell debris by centrifugation. Protein content was determined at 3.6 mg / ml and used at 20 pg / ml (50 µl) in ELISA.
Determination of DICT50 and UFP of RSV reserves
To determine the TCID50, 10<sup>4</sup> HEp2 in 96-well plates and infected with a serial dilution of 2 or 10 stages of RSV virus at 4-plo. 2-3 days later the culture supernatant was removed and the cells were fixed with 80% acetone for 10 minutes at RT. After removing the acetone, the fixed cell layer was dried and kept at 4 ° C or frozen at -20 ° C. To stain HEp2 cells with RSV the plates were first blocked with 5% milk powder in PBS 0.1% Tween 20. The plates were then washed 3 times before being incubated for 3-5 hours at 37 ° C with polyclonal goat anti RSVR-HRP (1: 500, Biodesign, Saco, ME, USA) and washed thoroughly. The wells were then incubated with AEC substrate for 30 minutes at RT. Infected foci stain red and can be seen with the eye using a light microscope and can be counted. Standard Excel software was used to determine the TCID50.
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To determine the amount of plaque-forming units (PFU) of the virus, 1x10 were incubated<sup>5</sup>/ ml HEp2 cells in 24-well plates with 10-fold serial dilutions (10<sup>-3</sup> - 10<sup>-7</sup>) Stock RSV virus in medium with 1% FCS at 37 ° C for 45 minutes (200 µl) before covering cells and virus with 0.5 ml of hand-warmed 0.25% seaplaque agar (Biozyme). The agarose layer prevents the spread of the virus to uninfected cells through the culture medium. Thus the virus can only infect adjacent cells, which are eventually destroyed by the virus that creates plaques in the HEp2 cell monolayer. These plates can best be visualized by staining the fixed cells (96% ethanol - 100% acetic acid - 10% formalin 6: 2: 1) with 1% crystal violet solution. The plates are counted (by at least two different people) and the UFP value can be determined.
Selection of neutralizing antibodies to respiratory syncytial virus (RSV)
To obtain anti respiratory syncytial virus (RSV) B lymphocyte clones, peripheral blood cells (PBMC) were isolated from two blood bank-derived buffy coat donors (donor B62 and B63). Before sorting CD19 cells<sup>pos</sup>IgM<sup>neg</sup>IgD<sup>neg</sup>IgA<sup>neg</sup>CD27<sup>pos</sup> Using the FACSAria (BD) (Figure 1), CD22 + cells were isolated using MACS beads and columns (Miltenyi). Only if mentioned otherwise, cells were cultured with L cells. Cells were cultured for 36 hours in the presence of IL-21 before being transduced with Bcl-6-IRESNGFR only. After 12 hours the cells were harvested and cultured for 3 days in the presence of IL-4 before cells expressing NGFR were sorted using MACS beads (Miltenyi) and immediately transduced with Bcl-XL-IRES-GFP. The B cells that did not bind to the MACS beads were washed and transduced with Bcl-6 and Bcl-XL at the same time. After 12 hours the cells were harvested, pooled, and cultured for 3 days in the presence of IL-4 before sorting for GFP and NGFR expression in the FACSAria. Cells were washed and cultured at a density of 100 cells / well in 96-well plates (Costar) in the presence of IL-21.
Cell cultures doubly transduced with Bcl-6 and Bcl-XL were screened for RSV binding using a RSV-infected HEp2 cell lysate ELISA and tested in parallel using a RSV microneutralization experiment. Briefly, 10<sup>4</sup> HEp2 cells in flat bottom 96-well plates (Costar) in complete medium. The following day the medium was replaced for 1 hour at RT with the mixture of RSV virus and cell culture supernatant that had been pre-incubated for 30 minutes at 37 ° C. The total volume is 25 µl and the final RSV concentration is 0.1 MOI. After 1 hour the virus supernatant mixture is diluted 9 times with PBS and replaced with 100 µl of IMDM / 5% FCS. After 2 days the cells are fixed with 80% acetone and stained with polyclonal anti RSV-HRP (Biodesign). Using H2O2 and AEC RSV infected cells develop a red stain. Using light microscopy infected cells can be observed and counted if necessary. As a control for RSV neutralization a polyclonal goat anti RSV (Abcam, Cambridge, MA) is used.
RT-PCR and cloning of VH and VL regions
~ 5x10 total RNA was isolated<sup>5</sup> B lymphocytes with the RNeasy® mini kit (Qiagen, Venlo, The Netherlands). 250 ng of total RNA was reverse transcribed in a 20 µl volume containing 1X first strand buffer, 500 pM dNTP, 250 ng of random hexamers, 5 mM DTT, 40 U of RNasin (Promega) and 200 U of SuperScript III RT (Invitrogen). The cDNA was diluted 10X in Ultrapure water and 2.5 µl of cDNA was subjected to PCR in a 50 µl solution containing 20 mM Tris-HCl, 50 mM KCl, 2.5 mM MgCl2, 250 pM dNTP, 1 U of AmpliTaq Gold DNA polymerase (Applied Biosystems Inc.) and 25 pmol of each primer. The PCR conditions were as follows: 8 minutes of denaturation step at 96 ° C followed by 35 cycles of 30 seconds at 96 ° C, 30 seconds at 60 ° C, 1 min at 72 ° C and a final extension of 10 minutes at 72 ° C.
PCR products were run on agarose gels, purified and cloned into the cloning vector pCR2.1 TA according to the manufacturer's recommendations. Sequence analysis was performed using BigDye Terminator chemistry (Applied Biosystems Inc.) and Vector-NTI software (Invitrogen).
To rule out reverse transcriptase and / or DNA polymerase induced mutations, several cDNA conversions and PCR reactions were performed and individually cloned and sequence analyzed. Consensus sequences were determined with Vector-NTI Contig Express software.
For expression of recombinant protein antibodies in 293T cells, full length heavy and light chain constructs were generated in pcDNA3.1 (+) Zeo (Invitrogen). The heavy chain expression vector was constructed by PCR amplification of the heavy chain leader sequence and VH region of clone D25 introducing a 5'-NheI site and a 3'-XhoI site. The IgG1 constant region (CH1-hinge-CH2-CH3) was amplified from the same cDNA introducing at the same time a 5'-XhoI and a 3'-NotI site. The full length heavy chain expression vector was obtained by three point ligation into NheI / NotI digested pcDNA3.1 (+) Zeo. The full-length light chain expression construct was generated by PCR amplification of the light chain leader sequence, VL region, and light chain constant region with primers introducing a 5'-NheI and 3'-NotI site. This latter product was cloned into NheI / NotI digested pcDNA3.1 (+) Zeo to obtain a full length light chain expression vector.
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Sequence analysis was performed to confirm the correctness of the expression constructs.
Transient double transfection (Fugene-6, Roche, Germany or Lipofectamine LTX, Invitrogen) of 293T cells was performed with both heavy and light chain expression vectors to produce recombinant monoclonal antibody. FACS staining was performed with the resulting culture supernatant (48 hours) in RSV infected Hep2 cells to show functional binding of the antibody to RSV F protein.
The oligonucleotides used for PCR amplifications were: VH regions:
VH1-Dir
VH1B-Dir
VH2A-Dir
VH2B-Dir
VH3-Dir
VH3B-Dir
VH4-Dir
VH5-Dir
VH6- Dir
Cgamma-Inv
AAATCGATACCACCATGGACTGGACCTGGAGG-3 'AAATCGATACCACCATGGACTGGACCTGGAGM-3' AAATCGATACCACCATGGACACACTTTGCTMCAC-3 'AAATCGATACCACCATGGACATACTTTGTTCCAAC-3' AAATCGATACCACCATGGAGTTTGGGCTGAGC-3 'AAATCGATACCACCATGGARYTKKGRCTBHGC-3' AAATCGATACCACCATGAAACACCTGTGGTTCTT-3 'AAATCGATACCACCATGGGGTCAACCGCCATC-3' AAATCGATACCACCATGTCTGTCTCCTTCCTC-3 'GGGTCTAGACAGGCAGCCCAGGGCCGCTGTGC-3' Vkappa regions:
Vk1-Dir 5'-AAATCGATACCACCATGGACATGAGGGTCCCY-3 '
Vk1B-Dir 5'-AAATCGATACCACCATGGACATGAGRGTCCYY-3 '
Vk2-Dir 5'-AAATCGATACCACCATGAGGCTCCCTGCTCAG-3 '
Vk3-Dir 5'-AAATCGATACCACCATGGAARCCCCAGCGCA-3 '
Vk4-Dir 5'-AAATCGATACCACCATGGTGTTGCAGACCCAG-3 '
Ck-Inv 5'-GATCGCGGCCGCTTATCAACACTCTCCCCTGTTGAAGCTCTT-3 'Vlambda regions:
Vllaecb 5'-AAATCGATACCACCATGGCCTGGTCCCCTCTCCTCC-3 '
Vl1g 5'-AAATCGATACCACCATGGCCGGCTTCCCTCTCCTCC-3 '
Vl2 / 10 5'-AAATCGATACCACCATGGCCTGGGCTCTGCTCCTCC-3 '
Vl3jpah 5'-AAATCGATACCACCATGGCCTGGACCGCTCTCCTGC-3 '
V15 / 7 5'-AAATCGATACCACCATGGCCTGGACTCCTCTCCTTC-3 '
V16 / 9 5'-AAATCGATACCACCATGGCCTGGGCTCCTCTCCTTC-3 '
Vl3rm 5'-AAATCGATACCACCATGGCCTGGATCCCTCTCCTCC-3 '
Vl3l 5'-AAATCGATACCACCATGGCCTGGACCCCTCTCTGGC-3 '
Vl3e 5'-AAATCGATACCACCATGGCCTGGGCCACACTCCTGC-3 '
Vl4c 5'-AAATCGATACCACCATGGCCTGGGTCTCCTTCTACC-3 '
Vl8a 5'-AAATCGATACCACCATGGCCTGGATGATGCTTCTCC-3 '
C12 / 7 5'-GATCGCGGCCGCTTATCAWGARCATTCTGYAGGGGCCACTG-3 '
The oligonucleotides used for expression vector constructs were:
Heavy chain expression vector:
<td>VH1-L-Nhel:</td><td>5'-GCGGCTAGCCACCATGGACTGGACCTGGAGG-3 '</td>
<td>JH4 / 5-XhoI:</td><td>5'-GCGCTCGAGACGGTGACCAGGGTTCCCTG-3 '</td>
<td>CHfw-Xhol:</td><td>5'-CGCGCTCGAGTGCCTCCACCAAGGGCCCATCGGTC-3 '</td>
<td>CHrev-Notl:</td><td>5'-GATCGCGGCCGCTTATCATTTACCCGGRGACAGGGAGAGGC-3 '</td>
Light chain expression vector:
VK1 -L-Nhel: 5'-GCGGCTAGCCACCATGGACATGAGGGTCCCY-3 '
CK-Notl: 5'-GATCGCGGCCGCTTATCAACACTCTCCCCTGTTGAAGCTCTT-3 '
EBV RT-PCR
To test whether the strong proliferative response was related to the presence of EBV, an EBV RT-PCR was performed. The RT procedure has been described above. The PCR conditions were as follows: a denaturation step of 7 minutes at 94 ° C followed by 30 cycles of 30 s at 94 ° C, 30 s at 62 ° C (HPRT1), 52 ° C (LMP-1) and 58 ° C (EBNA1 / 2) and 30 s at 72 ° C, and a final extension of 7 minutes at 72 ° C. The oligonucleotides used
ES 2 575 129 T3 for RT-PCR were the following: forward HPRT1 (5'-TATGGACAGGACTGAACGTCTTGC-3 ') and reverse HPRT1 (5'-GACACAAACATGATTCAAATCCCTGA-3'); Forward LMP-1: (5'-GCGACTCTGCTGGAAATGAT-3 ') and reverse LMP-1 (5'-GACATGGTAATGCCTAGAAG-3'); Forward EBNA1 / 2 (5'-AGCAAGAAGAGGAGGTGGTAAG-3 ') and reverse EBNA1 / 2 (5'-GGCTCAAAGTGGTCTCTAATGC-3').
In addition to RT-PCR, PCR was performed directly on cell pellets and supernatant DNA that was isolated using the QIAmp isolation kit (Qiagen).
EXAMPLE 1
Results
B lymphocyte phenotype
The use of human memory B lymphocytes as the platform for isolating therapeutic drugs relies on the ability to grow and test these cells over a relatively long period of time. Human B lymphocytes can be cultured and maintained in a laboratory setting however not long enough to expand, select and clone individual B lymphocyte lines against an antigen of interest. Immortalization techniques based on genetic modifications of human B lymphocytes were developed. Targets downstream of STAT5 were studied. Among others a target is Bcl-6. Bcl-6 inhibits the differentiation of B lymphocytes into plasma cells that stop proliferating. The overexpression of Bcl-6 maintains Blimp1 in equilibrium, a transcription factor whose expression is strongly enhanced by the stimulation of B lymphocytes with IL-21 (it acts through STAT3). Blimp1 is necessary to induce the development of Ig-producing cells (CD20-CD38 +) while Bcl-6 can avoid this (the cells maintain the expression of CD20, the so-called germinal center phenotype).
To study the possible bias of certain cell populations within the B cell compartment, CFSE labeling prior to stimulation of new memory and naive human B cells revealed that all cells begin to divide and all lymphocyte populations B are equally transduced (Figure 2). Memory B lymphocytes transduced with Bcl-6 are shown and cultured in the presence of IL21 and IL-4. Treatment-naïve B lymphocytes were transduced at a lower level and the rates of division were less than 36 hours but were identical to memory B lymphocytes after another 3 days of culture (data not shown).
It was then shown that Bcl-6, together with Bcl-XL (antiapoptotic downstream target of STAT5), CD40L signaling and in the presence of IL-21, maintain human IgG memory B cells in the CD20 + CD38dull phenotype for periods of time. long periods of time (> 3 months) (Figure 3). Furthermore, Bcl-6 Bcl-XL B lymphocytes have a phenotype corresponding to activated B lymphocytes (see Table 1, exemplified by FACS staining of 3 TT + B lymphocyte clones), since these cells have high expression of CD80, CD86 and HLA-DR, determined in three different Bcl-6 Bcl-XL B lymphocyte clones cultured with IL-21 and CD40L signaling.
<td>staining</td><td>Outcome</td><td>staining</td><td>Outcome</td>
<td>CD2</td><td>neg</td><td>CD69</td><td>neg</td>
<td>CD5</td><td>neg</td><td>CD70</td><td>pos</td>
<td>CD7</td><td>neg</td><td>CD71</td><td>pos</td>
<td>CD10</td><td>pos</td><td>CD73</td><td>neg</td>
<td>CD20</td><td>pos</td><td>CD80</td><td>pos / height</td>
<td>CD21</td><td>pos</td><td>CD86</td><td>pos</td>
<td>CD22</td><td>pos</td><td>CD95</td><td>pos / height</td>
<td>CD23</td><td>neg / 5% pos</td><td>CD126</td><td>neg</td>
<td>CD24</td><td>neg</td><td>CD132 (common gamma)</td><td>pos</td>
<td>CD25</td><td>pos</td><td>CD138</td><td>neg / 2% pos</td>
<td>CD27</td><td>neg / low</td><td>CD154 (CD40L)</td><td>8% pos</td>
<td>CD28</td><td>neg</td><td>ICOSL</td><td>pos</td>
<td>CD30</td><td>pos (56-74%)</td><td>IgM</td><td>neg</td>
<td>CD38</td><td>pos / intermediate</td><td>IgG</td><td>pos</td>
<td>CD40</td><td>pos</td><td>HLA-DR</td><td>pos (high)</td>
<td>CD44</td><td>pos</td><td>Kappa</td><td>pos / neg</td>
<td>CD45</td><td>pos</td><td>Lambda</td><td>pos / neg</td>
<td>CD45RA</td><td>pos / height</td><td>IL21-R</td><td>pos</td>
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Membrane expression of antibodies
EBV negative cells transduced with Bcl-6 Bcl-XL remained positive for BCR expression as determined by antigen binding or Kappa or Lambda staining (Figure 3 and 4). Therefore, such cells are particularly suitable for isolating and / or screening after a long culture period for a desired specificity, for example using labeled antigen, because such cells will bind with said antigen labeled with their BCR. This was confirmed by single cell sorting of double transduced B lymphocytes with Bcl-6 and Bcl-XL that bind with PE-labeled TT using the FACSAria. After three weeks, single cell sorted clones were stained with appropriate markers and TT-PE in 96-well plates and measured for binding on the Canto FACS (BD) (Figure 4). In conclusion, in cases where the presence of a B lymphocyte receptor on B lymphocytes is desired, such as for example in screening assays, B lymphocytes are preferentially transduced with Bcl-6 and Bcl-XL and not infected with VEB.
Cell division and growth curves
B-lymphocytes transduced with Bcl-6 Bcl-XL divide on average 0.6 times per day. The speed of division varies between donors and the cell density of the cultures (Figure 5a). The anti RSV clone D25 has a cleavage rate of 0.47 times a day (Figure 5b). Cells can be grown at densities below 1 cell / 96 wells for cloning purposes.
Secretion of B lymphocyte antibodies Bcl-6 Bcl-XL
The B lymphocytes transduced with Bcl-6 Bcl-XL secrete on average one pg / ml of antibodies, which is enough to grow the quantities necessary for preclinical tests (Figure 6). Surprisingly, the anti RSV clone D25 produced three times more antibodies compared to the other cell lines tested.
Determination of EBV content
EBV RT-PCR in mRNA from Bcl-6 Bcl-XL cell lines that were cultured with IL-21 and CD40L signaling. An EBV gene transcript has never been detected in the cell lines obtained with this immortalization technique (data not shown).
Selection procedure
Due to the stability in the growth and expression of BCR, these cells are suitable for isolating antigen-specific B lymphocytes. It provided the inventors with the opportunity to use several different selection and cloning procedures. One is to obtain antigen-specific cells immediately after introduction of Bcl-6 and Bcl-XL by FACS or magnetic bead sorting using labeled antigen of interest thereby enhancing the likelihood of generating multiple antigen-specific B-cell clones. Another option is to grow transduced memory B cells, bulk, purified Bcl-6 Bcl-XL (or any other) at low cell densities (eg 100 cells / well). Supernatants from these 100c / p cultures can be collected and tested for specificity. Cultures of 100 cells / well that are found to be positive for antigen recognition are then subcloned by limiting dilution cultures to obtain monoclonal cell lines. Using both methods, more than 40 B lymphocyte clones that recognized tetanus toxoid (TT) could be isolated. Thus these clones were selected for binding of TT to BCR in the FACSAria or selected by ELISA screening of a series of cultures until the individual monoclonal anti TT cell line (not shown) was isolated.
Selection of RSV Neutralizing Antibodies
From donor B63, 25 cultures of 100 cells / well completely blocked RSV infection and replication. D10, one of the neutralizing 100 cell / well cultures produced a strong anti-RSV antibody which was cloned by limiting dilution culture. One of the monoclonal antibodies, D25 was used to continue the studies. D25, a monoclonal antibody with an IgG1 heavy chain, as determined by commercial ELISA (Sanquin, Amsterdam, not shown) and a Kappa light chain (Figure 7), very effectively blocked RSV infection with an IC50 value between 0.5 and 1.5 ng / ml (± 10 pM) while the IC50 of the conventional anti-RSV antibody used in the clinic (palivizumab developed by MedImmune) is 0.453 mg / ml (3.02 nM) (H. Wu et al. 2005 J.Mol.Biol. And A. Mejias et al. 2005 Antimicrob. Agents Chemother.) (Figure 8).
Antigen recognition
In addition to neutralization experiments, binding of D25 to RSV-infected HEp2 cells was determined. HEp2 cells were infected using the regular virus production protocol. RSV-infected HEp2 cells were trypsinized and incubated with 25-50 ml of culture supernatant. The cells were washed and stained with mouse anti-human IgG-PE (BD or Jackson) to detect the binding of the D25 antibody to the infected cells.
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ELISA control antibody r-Biopharm was used as an internal control. The binding of D25 with intact RSV-infected HEp2 cells is shown in Figure 9a.
Since the envelope (membrane) protein of RSV exists of two proteins, namely protein G and F, the binding of D25 was tested against cells infected with the RSV virus pseudotyped without protein or with the protein F of RSV or G of VSR (kindly provided by John K Rose). As shown in Figure 9b, D25 bound strongly to EL-4 cells infected with VSV F protein. In an attempt to study the epitope recognized by D25 against palivizumab, VSV F protein infected EL-4 cells were incubated with increasing amounts of D25 or palivizumab. Cells were washed and stained with a mixture of 3 mouse anti-F-RSV antibodies (Dako). Unlike Palivizumab which showed competition for binding with VSV-F cells infected with the mouse anti-F-RSV antibody, D25 binding was not affected (data not shown).
Figure 9c shows the binding of Palivizumab (Synagis) and D25 in a concentration-dependent manner with infected HEp2 cells. Since both antibodies bind 1 to 1 with their target protein there is no difference in binding with infected HEp2 cells.
Frequency of binding to RSV antigen versus neutralizing controls
The frequency of antigen-specific memory B cells that bind RSV was calculated to be 17% and the frequency of antigen-specific cells that neutralized RSV was 6%, as determined for donor B63. D25 binds with a conformational epitope that is different from the epitope recognized by palivizumab. This is illustrated in Figure 10 where D25 does not bind to denatured linear epitopes presented by RSV-infected cell lysate applied on ELISA plates whereas palivizumab does bind denatured protein (F).
Isolation and Purification of Antibody Fragments
From various B lymphocyte lines including the highly neutralizing RSV clone D25 we were able to grow volumes up to 500 ml. These culture supernatants contain at least 2 ml / ml, therefore the inventors should be able to obtain enough purified antibody to perform preclinical (animal) studies. Purification is performed using Mounting Antigen Purification Kit (Millipore, Billerica, MA, USA) and HiTrap Protein A HP columns (GE Healthcare, Diegem, Belgium).
In addition, 293T cells were transfected with the D25 heavy and light chain which was subcloned into pCDA3.1 protein expression vectors using lipofectamine LTX (Invitrogen). The amount of IgG that was present in the supernatant was approximately 22 mg / ml (total volume 50 ml). This antibody derived from the cloned nucleotide sequence of the antibody expressed by the B lymphocyte line D25 also recognized infected HEp2 cells (data not shown).
Antibody sequence
Figure 11a shows the nucleotide and light chain amino acid and heavy chain sequence of clone B63D10-D25. Using standard RT-PCR and antibody specific primers, the heavy (Vh1-69) and light (Vkl O8 / 018) chain sequences were determined. The entire antibody sequence was cloned using TOPO vectors and after sequence control, subcloned into the mammalian protein expression vector pCDNA3.1 (Invitrogen). Figures 11b and 11c depict the VH and VL4 chain of the clone, Astricks indicates mutations compared to the germline sequence of Vh1-69 that must have occurred during affinity maturation and additional B-cell selection.
Briefly, the isolation, characterization and long-term culture of human memory B lymphocytes using the Bcl-6 and Bcl-XL transgenes are shown here. They provide the necessary tool to isolate antibodies with unique properties, such as the anti-RSV monoclonal antibody B63D10-B25. Since B lymphocytes are of human origin, they can easily be used as a therapeutic medicine.
EXAMPLE 2
The D25 heavy and light chains were cloned into standard expression vectors as described above ("antibody sequence" p44). To create an expression construct that allows maximum protein expression the D25 heavy and light chain sequences were optimized with respect to their codons by GENEART (Regensburg, Germany). Additional restriction sites were created in this procedure to simplify future cloning procedures but more importantly the nucleotide codons that are translated into amino acid sequences were optimized for maximum protein translation. Therefore the nucleotide sequence was optimized but the amino acid sequence remained unchanged. The neutralizing capacity of D25 derived from purified B cell supernatant, recombinant D25 and GENEART optimized D25 is shown in EXAMPLE 4. All effectively neutralize RSV.
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GENEART modifications compared to the original D25 sequence are depicted in Figure 12. EXAMPLE 3
Following in vitro RSV neutralization experiments, monoclonal antibody D25 was tested in in vivo models. The models that have been described for in vivo anti-RSV assays are BALB / c mice and cotton rats (Sigmodon hispidus) (Mejias A et al., Antimicrobial Agents and chemotherapy 2004; p1811, Johnson S et al., JID 1997; p1215 and Wu H et al., JMB 2007: p652). The BALB / c mouse model is clearly the weakest model but since cotton rats are difficult to obtain and maintain, D25 assays were established in BALB / c mice first.
Protocol: RSV-specific antibodies in BALB / c, Day 5
Experimental design:
Day 1. 100 ml IP injection of antibodies
Day 0. IN infection: 1x10<sup>7</sup> pfu of RSV A2 in 50 ml
Days 1 to 5, general and heavy well-being check of mice
Day 5, autopsy, BAL collection, blood and lungs
Blood collection by venipuncture
Collection of 2.0 ml of BAL via tracheal cannula
Collection of the lungs
Immediately start TCID50 in BAL material (1 ml)
Freeze 1 ml of BAL material (Cytokine ELISA / RT-PCR) -80 ° C
Perform TCID50 on long prepared material (1 ml)
Freeze 1 ml of long material (cytokine ELISA / RT-PCR) -80 ° C
Collect / centrifuge blood for serum hIgG ELISA in storage at -80 ° C
The results are shown in Figure 13:
(A) One day before exposure to RSV (1x10<sup>7</sup> RSV-A2 particles) by nasal spray, animals were injected IP with different amounts of Synagis (MedImmune), purified D25 or a control antibody IgG1 (Eureka) (Table 3). (Figure 13B) Human IgG levels were determined in mouse sera from day 5 and the decrease in serum antibody levels by 5 days; Table 4 shows an overview of the half-life values. Figure 13D represents virus titers found in lung washes (BAL) on day 5 in treated and untreated animals while Figure 13E represents numbers of T and B lymphocytes in peripheral blood of treated and untreated mice. Figure 13F shows the histology of lungs with bronchi and infiltration of (usually mainly eosinophils) untreated and treated animals.
Conclusion / results:
An estimate of the half-life of D25 is 5 to 9 days based on the calculation (linear) that 60 and 30 mg of antibody were injected on day 0 (2 and 1 mg / kg respectively) and on day 5 33 or 16 mg (total volume of mice 1.5). When the injection of 0.5 mg / kg per animal was started on d0 then Ig levels decreased from 15 mg to 11 mg on day 5, which would indicate a half-life of 9 days (Table 4).
Table 4
<td>mg / kg</td><td>total administered d0 (mg)</td><td>detected on d5 (mg)</td><td>half-life (days)</td>
<td> 2,0</td><td> 60</td><td> 33</td><td> 5,6</td>
<td> 1,0</td><td> 30</td><td> 16</td><td> 5,4</td>
<td> 0,5</td><td> 15</td><td> 11</td><td> 9,4</td>
The virus titer as determined by the TCID50 assay shows that 1x10 can be detected in control animals<sup>4</sup> PFU while no virus was detected in animals treated with Synagis (2 mg / kg) or D25 (2, 1 and 0.5 mg / kg).
Animals treated with Synagis or D25 maintained a higher% of peripheral CD4 T lymphocytes and B220 B lymphocytes. Animals treated with Synagis (2 mg / kg) have lower% CD4 T lymphocytes compared to animals treated with D25. Although this may not be significant it is important to note that animals treated with a low dose of D25 (1 and 0.5 mg / kg) maintain high levels of B and T lymphocytes compared to control treated animals.
Although the histology data (Figure 13F) are not quantitative it is clear that Synagis and D25 reduce the influx of immune cells into the lungs and around the bronchi compared to the control. When
ES 2 575 129 T3 D25 and Synagis are compared, then the animals treated with D25 appear to have less cellular infiltration to the lungs and around the bronchi.
To test D25 in cotton rats, experiments are set up to compare animals pretreated with Synagis and D25 before challenge with RSV-X virus at the NVI (Bilthoven, The Netherlands).
EXAMPLE 4
In addition to B63-D10-D25, three new potent RSV neutralizing antibodies (AM14, AM16 and AM23) were isolated from the same donor (B63). 100 cells per well of bulk B-lymphocyte cultures that were originally selected for RSV neutralization and frozen and stored in liquid nitrogen were thawed, and the culture supernatant was assayed for binding with RSV-infected HEp2 cells. It was tested for binding to infected Hep2 cells as it is a marker for antibody recognition of oligomeric, native RSV membrane proteins such as protein F and G and can act as a good predictor of neutralization. When binding was detected, cells were grown into single cells and screened for binding to obtain clones. All three antibodies were cloned into the GENEARt vector that was originally constructed for D25. Also as D25 all recognize the RSV F protein (not shown). After cloning and expression in 293T cells, recombinant protein was purified (nucleotide and amino acid sequences are depicted in Figure 14A, B and C). Antibodies were tested for neutralization against various primary RSV isolates in Vero and Hep2 cells (Figure 15). All three antibodies are of the IgG1 isotype. AM14 has a Kappa light chain, while AM16 and AM23 have a Lambda light chain. All three antibodies, such as D25, contain somatic hypermutations in their antibody variable domains suggesting that they have undergone in vivo affinity maturation during a germinal core reaction, a process that creates unique antibody sequences.
The results are shown in Figures 15-I and 15-II: RS virus neutralization assay with D25 derived from purified B-lymphocyte line supernatant (sD25), recombinant purified d25 (rD25), D25 with codons optimized by recombinant GENEART (rD25 GA), AM14, AM16, AM23 (all purified recombinant proteins) and Synagis. Neutralization by virus antibodies was tested in two different cell lines (Figure 15-I) Vero and (Figure 15-II) Hep2 cells with different antibodies: A2 (A), X (B) and 2006/1 (C) are RSV subtype A while virus Z (D) and 2007-2 (E) are subtype B. 100DICTsü of each virus was added to serial antibody dilutions in DMEM / 1% FCS and incubated for 1 hour at 37 degrees before adding 100 ml of Vero or Hep2 cells (1x10<sup>6</sup>/ ml). The virus antibody mixture was not washed away. After three days the supernatant was removed and the cells were fixed with 80% acetone for 10 minutes at RT. After removal of the acetone, the fixed cell layer was dried and kept at 4 ° C or frozen at -20 ° C. To stain RSV-infected HEp2 cells, the plates were first blocked with 5% milk powder in PBS 0.1% Tween 20, then the plates were washed 3 times before being incubated for 3-5 hours at 37 ° C. with polyclonal goat anti-RSV-HRP (1: 500, Biodesign, Saco, ME, USA) and washed thoroughly. Subsequently all wells were incubated with AEC substrate for 30 minutes at RT. Infected foci stain red and can be seen with the eye using a light microscope and can be counted.
Result / conclusion
All antibodies neutralize RSV strains A and B (Table 5). In general the different D25 antibodies neutralize RSV viruses effectively, although variations can be seen between minor experiments. AM14 is as powerful as D25 while AM16 is as powerful as Synagis. AM23 however neutralizes RSV A strains very effectively, while it is less potent in neutralizing RSV B strains, although it is still comparable to Synagis.
Table 5 IC50 values (ng / ml)
<td>Cell line used</td><td>VSR subtype</td><td>sD25</td><td>rD25</td><td>rD25 GA</td><td>AM14</td><td>AM16</td><td>AM23</td>
<td>Vero</td><td>TO</td><td> 3,4</td><td> 1,6</td><td> 3,2</td><td> 15,2</td><td> 304,3</td><td> 19,4</td>
<td>Vero</td><td>B</td><td> 9,0</td><td> 0,3</td><td> 1,2</td><td> 1,1</td><td> 126,4</td><td> 168,8</td>
<td>HEp2</td><td>TO</td><td> 3,3</td><td> 2,1</td><td> 5,3</td><td> 21,5</td><td> 285,6</td><td> 25,0</td>
<td>HEp2</td><td>B</td><td> 14,3</td><td> 1,9</td><td> 1,3</td><td> 6,7</td><td> 124,8</td><td> 190,7</td>
The IC50 value for each antibody in RS virus subtype A in Vero or HEp2 cells was calculated as the average 50% neutralization in three virus strains (A2, X and 2006-1). The IC50 value for each antibody in RS virus subtype B in Vero or HEp2 cells was calculated as the average 50% neutralization in two virus strains (2007-2 and Z). Each of the neutralization tests was performed in triplicate and repeated twice (also shown in Figure 15A and B).
sD25 = purified B cell-derived culture supernatant rD25 = purified recombinant D25 rD25 GA = GENEART codon optimized recombinant D25 293T cell supernatant
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EXAMPLE 5
Synergistic and blocking effects of anti-RSV antibodies.
To test whether D25, Synagis, or the new set of AM antibodies interfere with each other for RSV F protein recognition, RSV-infected HEp2 cells were pre-incubated with increasing concentrations of unlabeled antibodies until they reached the maximum binding plateau. . The plateau phase in which no increase in binding was detected when the amount of Ig was increased was determined for each antibody (not shown). After washing, the samples were incubated with a standard dose (3 pmol) of PE-labeled D25 or APC-labeled Synagis. This dose also provides maximum binding.
Outcome
As shown in Figure 16 Synagis and labeled D25 show reduced binding to RSV-infected HEp2 cells, when these cells were pre-incubated with Synagis or unlabeled D25. Synagis also shows a slight reduction in AM16-induced binding. The binding of D25 is strongly blocked by AM23 but conversely the binding of D25 is strongly enhanced after pre-incubation with AM14. This indicates that the epitope recognized by D25 is normally not even fully exposed but that the exposure is enhanced after the binding of AM14 to its native epitope. This shows that these two antibodies can work together and enhance neutralization.
Brief description of the drawings
Figure 1.
Isolation of IgG-positive human memory B lymphocytes. Isolated buffy coat PBMCs were incubated using Ficoll density separation (Amersham) with anti-CD22 magnetic beads before being isolated using MACS columns (Miltenyi). CD22 positive cells were then incubated with antibodies against human CD19, CD27, IgM, IgD and IgA (BD). Cells negative for IgM, IgD and IgA and positive for CD19 and CD27 were sorted using high speed single cell sorting (FACSAria, BD).
Figure 2
CFSE staining. New human memory B lymphocytes were isolated, labeled with CSFE, and stimulated for 36 h with IL-21 before being transduced with Bcl-6-IRES-NGFR. Cells were maintained for an additional 3 days in IL-21 before CFSE content was determined. The CFSE stain is diluted with each cell division.
Figure 3
An example of human B lymphocytes transduced with Bcl-6 and Bcl-XL or Bcl-XL only. Cells were maintained with irradiated L cells expressing CD40L and the cytokine IL-21. BCR expression as determined by kappa and lambda staining is shown on the left (93% of cells positive for kappa lambda are of the IgG isotype, not shown). To the right is shown the expression of CD38 on the X axes and the expression of CD20 on the Y axes. CD38 staining<sup>dull</sup>CD20 + indicates germinal or memory center B lymphocytes; CD38 staining<sup>+</sup>CD20<sup>-</sup> indicates plasmablasts.
Figure 4
Isolation of antigen-specific, immortalized human B lymphocytes. Human memory B lymphocytes were isolated as described in Figure 1 and subsequently transduced with Bcl-6-IRES-NGFR and Bcl-XLIRES-GFP. Cells expressing nGfR, GFP were isolated and bound with PE-labeled Tetanus Toxin using the FACSAria. Cells were cultured by single cells in 96-well flat bottom plates in the presence of irradiated L cells and IL-21 before being selected based on binding of TT-PE using the Canto FACS (BD).
Figure 5
Cumulative cell division and growth rate of 6XL B lymphocyte clones. B lymphocytes from (A) two anti-TT clones (B) and one anti-RSV clone (B63D10-D25) were cultured in the presence of IL-21 and irradiated L cells.
Figure 6
Fresh cultures were started with 200,000 cells / 24 wells in 1.0 ml IMDM with 8% FCS and pen / strep. The FCS used was normal (HyClone) or Ultralow Bovine IgG FCS (Gibco). After 3 days the culture supernatant was replaced and the cell numbers were adjusted to 200,000 cells / ml. The 3-day average IgG production measured at 3 consecutive time points is shown. The difference was not significant (p value 0.2).
Figure 7
IS 2 575 129 T3
To determine the light chain phenotype of the anti-RSV clone D25, the D25 B lymphocyte line was stained with kappa-phycoerythrin or lambda-phycoerythrin (BD) antibodies. Only kappa-phycoerythrin antibodies bound with the cell line, showing that this antibody has a kappa light chain.
Figure 8
From donor B63, 100 cell / well cultures were grown using Bcl-6 Bcl-XL positive human memory B cells. One of those cultures, D10 showed strong neutralization. LD-derived monoclonal cell lines were prepared, a D25 effectively neutralized RSV A-2 virus. Shown here D25 compared to palivizumab (synagis) and polyclonal goat anti-RSV. Relevant culture supernatants of Bcl6 transduced Bcl-XL clones cultured with IL-21 and CD40L signaling that produce high levels of antibodies but do not block RSV infection are not shown. Clone D25 was used for further characterization.
Figure 9
In figure 9a: HEp2 cells were seeded at 10-12x10<sup>6</sup> cells per T175 flask (Nunc) in IMDM / 5% FCS. The following day the medium was replaced with 5 ml of RSV virus medium (1.0 MOI) and incubated for 45 minutes at RT before adding 20 ml of fresh medium and the cells were cultured overnight at 37 ° C. The following day the medium was replaced with IMDM / 1% FCS and cultured overnight with a closed lid at 37 ° C. The next day cells were washed with PBS and trypsinized. Primary incubation with culture supernatant was performed to stain infected cells. Secondary incubation was carried out with anti-human IgG-PE (BD). Cells were analyzed using LSRII (BD). The positive control of the r-Biopharm commercial ELISA KIT was used as a positive control.
In Figure 9b: EL-4 cells were infected with VSV virus pseudotyped with RSV F or G protein (kindly provided by John Rose) and incubated with D25 culture supernatant. Cells were washed and incubated with anti-human IgG-PE (Jackson) to detect D25 binding to infected cells. D25 binding was only detected with VSV virus infected cells pseudotyped with RSV F protein. Figure 9c shows the binding of Palivizumab (Synagis) and D25 in a concentration-dependent manner with infected HEp2 cells. Mean fluorescence intensity (MFI) is shown.
Figure 10
Binding of polyclonal goat anti-RSV (positive control), palivizumab (synagis) and D25 with coated infected HEp2 cell lysate.
Figure 11
Sequence analysis of clone D25. 11a shows the nucleotide and predicted amino acid sequence of the variable heavy and light chain domains. 11b / c show the D25 heavy and light chain sequence compared to the predicted germline. Asterisks indicate mutations likely to occur during selection and affinity maturation of the B lymphocyte clone in vivo.
Figure 12
Cloning and expression of recombinant human antibodies from B-lymphocyte lines transduced with BCL6 BCL-xL. This has already been described for the D25 antibody (Figure 11). The nucleotide modifications of GENEART are depicted here compared to the original D25 sequence, note that these mutations do not change the amino acid composition of the D25 antibody.
Figure 13
Challenge BALB / c mice with D25 and Synagis derived from purified B lymphocyte supernatant. (A) One day before exposure to RSV (1x10<sup>7</sup> RSV-A2 particles) by nasal spray, animals were injected IP with different amounts of Synagis (MedImmune), purified D25 or a control antibody IgG1 (Eureka) (Table 3). (B) Human IgG levels were determined in mouse sera from day 5 and the decrease in serum antibody levels at 5 days (C); Table 4 shows an overview of the half-life values. Figure 13D represents virus titers found in lung washes (BAL) on day 5 in treated and untreated animals while Figure 13E represents the numbers of T and B lymphocytes in peripheral blood of treated and untreated mice. (F) shows the histology of lungs with bronchi and infiltration of (usually mainly eosinophils) treated and untreated animals.
Figure 14
Nucleotide and amino acid sequences of three new potent RSV neutralizing antibodies (A) AM14, (B) AM16, and (C) AM23.
Figure 15
SR virus neutralization assay with D25 derived from purified B lymphocyte line supernatant (D25), recombinant purified D25 (rD25), recombinant GENEART codon-optimized D25 (rD25 GA), AM14, AM16, AM23 (all purified proteins recombinants) and Synagis. Neutralization of virus antibodies was tested in two different cell lines (Figure 15-I) Vero and (Figure 15-II) HEp2 cells with different antibodies A2 (A), X (B) and 2006/1 (C) are RSV of subtype A while virus Z (D) 2007-2 (E) are
ES 2 575 129 T3 subtype B. 100 DICT50 of each virus was added to serial antibody dilutions in DMEM / 1% FCS and incubated for 1 hour at 37 degrees before adding 100 ml of Vero or HEp2 cells (1x10<sup>6</sup>/ ml).
Figure 16
Relative binding of a fixed amount (3 pmol) of APC-labeled Synagis and PE-labeled rD25 to RSV-infected HEp2 cells that were pre-incubated with increasing concentrations of the indicated unlabeled antibodies.
References
Banchereau, J., de Paoli, P., Valle, A., Garcia, E., Rousset, F., (1991). Long term human B cell lines dependent on interleukin-4 and antibody to CD40, Science 251, 70-2.
Boise, LH, M. Gonzalez-Garcia, CE Postema, L. Ding, T. Lindsten, LA Turka, X. Mao, G. Nunez, and CB Thompson. (1993). Bcl-x, a bcl-2-related gene that functions as a dominant regulator of apoptotic cell death. Cell 74: 597.
Dadgostar, H., Zarnegar, B., Hoffmann, A., Qin, XF, Truong, U., Rao, G., Baltimore, D., and Cheng, G. (2002). Cooperation of multiple signaling pathways in CD40-regulated gene expression in B lymphocytes. Proc.Natl.Acad.Sci USA 99, 1497-1502.
Heemskerk et al, 1997: J. Exp.Med. Vol 186, pages 1597-1602
Heemskerk et al, 1999: Cell Immunol. Vol 195, pages 10-17
Kinsella and Nolan, 1996: Hum. Gene Ther. Vol 7 pages 1405-1413
Malisan, F., Briere, F., Bridon, JM, Harindranath, N., Mills, FC, Max, EE, Banchereau, J., Martinez-Valdez, H. (1996). Interleukin-10 induces immunoglobulin G isotype switch recombination in human CD40-activated naive B lymphocytes, J. Exp.Med. 183, 937-47.
Mathas S, Janz M, Hummel F, Hummel M, Wollert-Wulf B, Lusatis S, Anagnostopoulos I, Lietz A, Sigvardsson M, Jundt F, Johrens K, Bommert K, Stein H, Dorken B (2006). Intrinsic inhibition of transcription factor E2A by HLH proteins ABF-1 and Id2 mediates reprogramming of neoplastic B cells in Hodgkin lymphoma. Nat Immunol. 7, 207215.
Mejias A et al., Antimicrobial Agents and chemotherapy 2004; p1811, Johnson S et al., JID 1997; p1215 Wu H et al., JMB 2007: p652
Shvarts A. et al, 2002: Genes Dev. Vol 16, pages 681-686
Traggiai, E., Becker, S., Subbarao, K., Kolesnikova, L., Uematsu, Y., Gismondo, MR, Murphy, BR, Rappuoli, R., Lanzavecchia, A. (2004). An efficient method to make human monoclonal antibodies from memory B cells: potent neutralization of SARS coronavirus. Nature Medicine Volume 10, No. 8, 871-875.
Ye, BH, Cattoretti, G., Shen, Q., Zhang, J., Hawe, N., de Waard, R., Leung, C., Nouri-Shirazi, M., Orazi, A., Chaganti, RS , et al. (1997). The BCL-6 proto-oncogene controls germinal-center formation and Th2-type inflammation. Nat Genet 16, 161-170.
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- Moléculas de unión específicas de VSR y medios para producirlas
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- VSR specific binding molecules and means to produce them
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- C07K16/11
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