CA2108147C

Heterodimeric receptor libraries, using phagemids

Abstract

The invention comprises filamentous phage encapsulating a genome encoding first and second polypeptides of an autogenously assembling heterodimeric receptor, such as an antibody, anchored to a filamentous phage coat protein membrane anchor domain. Such a phage may be used for expressing a recombinant gene product on the surface of the phage.

CA2108147C, drawing sheet 1
Sheet 1 of 30

Term

Term ended

Expired 10 April 2012, 14.5 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

80 claims: 27 independent, 53 dependent

  1. 1
    CLAIMS :1. A filamentous phage encapsulating a genome encoding first and second polypeptides capable of autogenous assembly to form a ligand-binding heterodimeric receptor, wherein said first polypeptide is fused to a carboxyterminal filamentous phage cpIII or cpVIII membrane anchor domain.
  2. 8
    The filamentous phage of any one of claims 1-7 wherein the phage expresses the heterodimeric receptor and wherein the heterodimeric receptor is accessible for binding to the ligand.
  3. 9
    The filamentous phage of any one of claims 1-8 wherein said first and second polypeptides are individually fused to an amino-terminal prokaryotic secretion signal domain.
  4. 10
    The filamentous phage of any one of claims 1-9 wherein said first polypeptide is fused to the carboxyterminal filamentous phage cpIII membrane anchor domain.
  5. 12
    The filamentous phage of any one of claims 1-9 wherein said first polypeptide is fused to the carboxyterminal filamentous phage cpVIII membrane anchor domain.
  6. 15
    The filamentous phage of any one of claims 1-14 wherein said phage is detectably labeled. CA 02108147 2008-07-04 28395-19 257
  7. 16
    A ligand-binding heterodimeric receptor autogenously assembled from first and second polypeptides, said first polypeptide being fused to a carboxy-terminal filamentous phage cpIII or cpVIII membrane anchor domain.
  8. 22
    The heterodimeric receptor of any one of claims 16-21 wherein said first and second polypeptides are individually fused to an amino-terminal prokaryotic secretion signal domain.
  9. 23
    The heterodimeric receptor of any one of claims 16 to 22 wherein said first polypeptide is fused to the CA 02108147 2008-07-04 28395-19 258 carboxy-terminal filamentous phage cpIII membrane anchor domain.
  10. 26
    The heterodimeric receptor of any one of claims 16 to 22 wherein said first polypeptide is fused to the carboxy-terminal filamentous phage cpVIII membrane anchor domain.
  11. 29
    DNA encoding the heterodimeric receptor of any one of claims 16-28.
  12. 30
    A ligand-binding heterodimeric antibody comprising first and second polypeptides, said first polypeptide being fused to a carboxy-terminal filamentous phage cpIII or cpVIII membrane anchor domain. CA 02108147 2008-07-04 28395-19 259
  13. 36
    DNA encoding the heterodimeric antibody of any one of claims 30-35.
  14. 37
    A polypeptide consisting of a ligand-binding antibody operatively linked to a carboxy-terminal filamentous phage cpIII or cpVIII membrane anchor domain.
  15. 44
    The polypeptide of any one of claims 37-43 wherein the antibody is an antibody variable chain polypeptide.
  16. 46
    DNA encoding the polypeptide of any one of claims 37-45.
  17. 47
    A vector for expressing a fusion polypeptide, said vector comprising upstream and downstream translatable DNA sequences operatively linked via a sequence of nucleotides adapted for directional ligation of an insert DNA, said upstream sequence encoding a prokaryotic secretion signal, said downstream sequence encoding a filamentous phage cpIII CA 02108147 2008-07-04 28395-19 261 or cpVIII membrane anchor, said translatable DNA sequences operatively linked to a set of DNA expression signals for expression of said translatable DNA sequences as portions of said fusion polypeptide, and said vector further comprising a second upstream translatable DNA sequence encoding a prokaryotic secretion signal operatively linked via a sequence of nucleotides adapted for directional ligation of a second insert DNA, said second translatable DNA sequence operatively linked to a set of DNA expression signals for expression of said translatable DNA sequences as a portion of a second fusion polypeptide.
  18. 51
    55. The vector of any one of claims 47-54 further comprising a filamentous phage origin of replication.
  19. 52
    56. The vector of any one of claims 47-55 wherein said set of DNA expression signals includes a promoter, a ribosome binding site, and at least one stop codon in frame with said downstream translatable DNA sequence.
  20. 53
    57. The vector of any one of claims 47-56 wherein said vector comprises the nucleotide sequence shown in SEQ ID NO 116 from base 1 to base 259.
  21. 54
    58. The vector of any one of claims 47-56 wherein said vector comprises the nucleotide sequence shown in SEQ ID NO 3 from base 36 to base 118.
  22. 56
    60. A method of producing a library of dicistronic DNA molecules, each dicistronic DNA molecule comprising first and second cistrons for expressing first and second polypeptides, wherein the first and second polypeptides are capable of autogenous assembly to form a ligand-binding heterodimeric receptor on the surface of a filamentous phage, which method comprises:(a) forming a first ligation admixture by combining in a ligation buffer: (i) a repertoire of first polypeptide genes in the form of linear dsDNA, each having cohesive termini adapted for directional ligation, and CA 02108147 2008-07-04 28395-19 263 (ii) a plurality of DNA expression vectors in linear form, each vector having upstream and downstream first cohesive termini that are (a) adapted for directionally receiving one of said first polypeptide genes in a common reading frame, and (b) operatively linked to respective upstream and downstream translatable DNA sequences, said upstream translatable DNA sequence encoding a prokaryotic secretion signal, said downstream translatable DNA sequence encoding a filamentous phage cpIII or cpVIII membrane anchor, and said translatable DNA sequences operatively linked to respective upstream and downstream DNA expression control sequences;and (b) subjecting said admixture to ligation conditions for a time period sufficient to operatively link said first polypeptide genes to said vectors and produce a plurality of circular DNA molecules each having said first cistron for expressing said first polypeptide;(c) producing a second plurality of DNA expression vectors in linear form, each linear vector having second upstream and downstream cohesive termini (i) adapted for directionally receiving one of a repertoire of second polypeptide genes in a common reading frame, and (ii) operatively linked to respective upstream and downstream DNA sequences, said upstream DNA sequence being a translatable sequence encoding a prokaryotic secretion signal, said downstream DNA sequence having at least one stop codon in said reading frame, and said translatable DNA sequence operatively linked to a DNA expression control sequence, by treating said plurality of circular DNA molecules to restriction endonucleolytic conditions sufficient to cleave said circular DNA molecules and form said second cohesive termini ;CA 02108147 2008-07-04 28395-19 264 (d) forming a second ligation admixture by combining in a ligation buffer: (i) said second plurality of DNA expression vectors formed in step (c), and (ii) said repertoire of second polypeptide genes in the form of dsDNA, each having cohesive termini adapted for directional ligation to said plurality of linear DNA vectors;and (e) subjecting said second admixture to ligation conditions for a time period sufficient to operatively link said second polypeptide genes to said vectors and produce a plurality of circular DNA molecules each having said second cistron for expressing said second polypeptide, thereby forming said library.
  23. 63
    67. The method of any one of claims 60-66 wherein the filamentous phage membrane anchor is a cpIII membrane anchor.
  24. 66
    70. The method of any one of claims 60-66 wherein said filamentous phage membrane anchor is a cpVIII membrane anchor. each phage particle contains the vector according to any one of claims 47-59.
  25. 68
    75. A library of filamentous phage particles wherein each phage particle contains a genome encoding at least one ligand-binding heterodimeric receptor according to any one of claims 16-28, at least one ligand-binding heterodimeric antibody according to any one of claims 30-35, or at least one polypeptide according to any one of claims 37-45.
  26. 69
    76. A library of dicistronic DNA molecules each comprising first and second cistrons of expressing first and second polypeptides of a heterodimeric antibody on the surface of a filamentous phage, said library produced according to the method according to any one of claims 60-72.
  27. 70
    77. A method for changing the diversity of a library of filamentous phage particles comprising the steps of:a) providing the library of filamentous phage particles according to any one of claims 73-75, or the library of dicistronic DNA molecules of claim 76;b) contacting the provided library with a preselected ligand under conditions sufficient for members of the library to bind to the ligand and form a ligand-phage particle complex;and c) isolating phage particles in said complex away from nonbound library members to form a ligand-enriched library comprising phage particles having binding specificity for said preselected ligand.
  28. 74
    81. A method for increasing the diversity of a library of filamentous phage particles comprising the steps of:a) providing the library of filamentous phage particles according to claim 75 wherein the genome encodes an immunoglobulin variable domain-coding nucleotide sequence;and b) mutating the immunoglobulin variable domain-coding nucleotide sequence present in each phage particle in the library to form a library of phage particles each containing a mutated immunoglobulin variable domain nucleotide sequence .
  29. 75
    82. A method for maturing the affinity of an epitope-binding complex, the method comprising the steps of :a) providing the genome of the filamentous phage according to any one of claims 1-15 wherein the first and second polypeptides form an immunoglobulin varible domain;b) mutating the nucleotide sequence encoding the immunoglobulin variable domain in the provided genome to form a library of phage particles containing a mutated immunoglobulin variable domain nucleotide sequence;CA 02108147 2008-07-04 28395-19 268 c) contacting the library formed in step (b) with a preselected ligand under conditions sufficient for members of the library to bind to the ligand and form a ligand-phage particle complex;and d) isolating phage particles in said complex away from non-bound library members to form a ligand-enriched library comprising phage particles having binding specificity for said preselected ligand.
  30. 78
    85. A method for detecting the presence of a preselected ligand in a sample comprising the steps of:a) admixing a sample suspected to contain a preselected ligand with the ligand-binding heterodimeric receptor according to any one of claims 16-28 that binds to said preselected ligand under binding conditions sufficient for said ligand-binding heterodimeric receptor to bind said ligand and form a ligand-receptor complex;and b) detecting the presence of said ligand-receptor complex.
Independent claims30