Human anthrax toxin neutralizing monoclonal antibodies and methods of use thereof

Human anthrax toxin neutralizing monoclonal antibodies and methods for their use.

Field of the Invention

This invention relates, in general, to anti-anthrax antibodies, as well as methods for their use.

Background

Bacillus anthracis, the virulent endospore-forming bacteria, well known for its recent use as a bioterrorism weapon, has infested humans and livestock since ancient times (Friedlander, 2000). The bacterium has been associated with the discovery of the sciences of bacteriology and immunology, unleashing Pasteur's famous demonstration of sheep protection with vaccines in Pouilly-le-Fort, France. Since then, the attention that Bacillus anthracis has received has largely revolved around its properties, which make it perfectly suitable as a biological weapon because it forms heat-resistant spores that are easy to produce and transport, and can infect through the pathway Spray

US 2004/009178 A1 refers to some human neutralizing antibodies described as useful as antitoxins or anti-infectives with respect to infectious agents, for example anthrax, botulism, smallpox, Venezuelan equine encephalitis virus (VEEV), West Nile virus ( WNV) and the like.

Cirino, NM et al., Infection and Immunity, June 1999, vol. 67, nº 6, pp. 2957-2963 refers to the disruption of anthrax toxin binding through the use of competitive inhibitors and human antibodies.

Balint, RF and Larrick, JW, Gene, 137 (1993), pp. 109-118 refers to methods for modifying antibodies so that they have a higher affinity contact with protein antigens, called parsimonious mutagenesis.

WO 2005/023177 refers to human monoclonal antibodies against the protective antigen of Bacillus anthracis.

WO 03/037370 describes an antigenic composition comprising a protective antigen and a lethal factor, in which one of the protective antigen and / or lethal factor lacks a functional binding site. Antibodies against these polypeptides are mentioned.

Little, M. et al., Immunology Today (2000), vol. 21, No. 8, pp. 364-370 refers to the production of human monoclonal antibodies and recombinant fragments.

Summary of the invention

The invention is based, in part, on the discovery of totally human anthrax toxin neutralizing monoclonal antibodies. The monoclonal antibody (mAb) of the invention binds to the Bacillus anthracis protective antigen (AP) polypeptide and neutralizes the lethal toxin (TxLe). This description also provides a mAb that binds to the lethal factor (FL) polypeptide of Bacillus anthracis and neutralizes the lethal toxin (TxLe). Examples of monoclonal antibodies include IQNPA and IQNLF described herein.

The present invention provides an isolated fully human monoclonal antibody or a functional fragment thereof, which binds to an epitope in a region of the protective antigen polypeptide and neutralizes the lethal Bacillus anthracis toxin, wherein said antibody or its functional fragment has a heavy chain with three CDRs comprising an amino acid sequence selected from the group consisting of KKPGA (SEQ ID NO: 11), SNAIQWVRQAPGQRLEW (SEQ ID NO: 12) and YMELSSLR (SEQ ID NO: 13), and has a light chain with three CDRs that comprise a sequence an amino acid sequence selected from the group consisting of LTQSPGTLSLS (SEQ ID NO: 14), SYSSLAW (SEQ ID NO: 15) and GPDFTLTIS (SEQ ID NO: 16).

An IQNPA antibody contains a heavy chain polypeptide having the amino acid sequence of SEQ ID NO: 2 or a fragment thereof, and the nucleic acid sequence of SEQ ID NO: 1 or a fragment thereof. Preferably, the IQNPA antibody heavy chain polypeptide has the amino acid sequence of amino acid residues 1-106 of SEQ ID NO: 2, and more preferably amino acid residues 31-106 of SEQ ID NO: 2. An IQNPA antibody contains a light chain polypeptide having the amino acid sequence of SEQ ID NO: 4 or a fragment thereof, and the nucleic acid sequence of SEQ ID NO: 3 or a fragment thereof. Preferably, the IQNPA antibody light chain polypeptide has the amino acid sequence of amino acid residues 1-97 of SEQ ID NO: 2, and more preferably amino acid residues 24-97 of SEQ ID NO: 2.

Also included in the invention is an isolated fully human monoclonal antibody or a fragment thereof, which has a heavy chain with three CDRs containing the amino acid sequence KKPGA (SEQ ID NO: 11); SNAIQWVRQAPGQRLEW (SEQ ID NO: 12); YMELSSLR (SEQ ID NO: 13), or a light chain with three CDRs containing the amino acid sequence LTQSPGTLSLS (SEQ ID NO: 14); SYSSLAW (SEQ ID NO: 15); GPDFTLTIS (SEQ ID NO: 16). The antibody binds to an epitope in a region of the protective antigen polypeptide and neutralizes the Bacillus anthracis lethal toxin polypeptide.

Alternatively, the monoclonal antibody is an antibody that binds to the same epitope as IQNPA. For example, the antibody competes with the binding of the IQNPA monoclonal antibody to domain 4 of a protective antigen polypeptide.

Binding to the protective antigen means that the monoclonal antibody interacts specifically with a portion of the polypeptide of the protective antigen. For example, the monoclonal antibody binds to domain 4 of a protective antigen polypeptide. A specific interaction means that the monoclonal antibody has a binding affinity, said binding affinity being from about 10-6 M to about 10-14 M. Preferably, the binding affinity is from about 10-8 M to about 10-12 M. For example, the binding affinity is about 10-10 M. The binding affinity is measured by methods known in the art.

Neutralization of the lethal toxin is defined by an increase in cell survival after exposure to Bacillus anthracis. For example, the monoclonal antibody decreases the formation of complexes between the protective antigen and the lethal factor (FL) or the edema factor (FE), thereby decreasing the translocation of FL and FE towards the cellular cytosol.

Optionally, the monoclonal antibody inhibits the binding of (i) AP to the target cells, (ii) AP to the anthrax toxin receptor (RTA), or (iii) from the lethal factor to the protective antigen. Alternatively, mAb inhibits the binding of AP to AP, thereby avoiding heptamerization.

The monoclonal antibody is 2, 4, 8, 10, 15, 20, 25 or more times effective to neutralize the lethal toxin of Bacillus anthracis compared to a natural Bacillus anthracis antiserum. A natural Bacillus anthracis antiserum is derived, for example, from subjects immunized with an anthrax vaccine, such as AVA or AVP. Examples of Bacillus anthracis antisera include AVR414.

The invention also includes methods for preventing or reducing the risk of developing a Bacillus anthracis infection in a subject, identifying a subject at risk of developing a Bacillus anthracis infection and administering to the subject a composition containing a human monoclonal antibody of the invention, such as IQNPA, or a combination of IQNPA and IQNLF.

The invention also includes methods for alleviating a symptom of a Bacillus anthracis infection in a subject, identifying a subject suffering from a Bacillus anthracis infection and administering to the subject a composition containing a human monoclonal antibody of the invention, such as IQNPA. Optionally, an antibiotic, such as ciprofloxacin, doxycycline, amoxicillin, or penicillin G procaine, is also administered to the subject.

Also included in the invention is a method for passive immunization of a subject against Bacillus anthracis, by administration to a subject of a composition containing the monoclonal antibody of the invention, such as IQNPA mAb.

The monoclonal antibody is administered before exposure to Bacillus anthracis. For example, the monoclonal antibody is administered at least 1 year before exposure to Bacillus anthracis. The monoclonal antibody is administered 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months

or more before exposure to Bacillus anthracis. Alternatively, the monoclonal antibody is administered after exposure to Bacillus anthracis. For example, the monoclonal antibody is administered at least 1 hour, 2 hours, 3 hours, 4 hours, 8 hours or more after exposure to Bacillus anthracis. The monoclonal antibody is administered 1 day, 2 days, 3 days, 4 days or more after exposure to Bacillus anthracis.

The subject suffers or is at risk of developing a Bacillus anthracis infection. The subject is a mammal, such as a human being, a primate, a mouse, a rat, a dog, a cat, a cow, a horse, a pig.

A subject suffering from or at risk of developing Bacillus anthracis is identified by methods known in the art, for example, by isolating B. anthracis from blood, dermal lesions, or respiratory secretions, or by measuring specific antibodies in the blood. The symptoms of a B infection. Anthracis include fever (a temperature greater than 37.8 ° C), chills or night sweats, flu-like symptoms, cough, usually a non-productive cough, chest discomfort, shortness of breath, fatigue, muscle aches, sore throat , followed by swallowing difficulties, enlarged lymph nodes, headache, nausea, loss of appetite, abdominal pain, vomiting, or diarrhea, or in the case of skin contraction, a sore, especially on the face, the arms or hands, which begins as a bump in relief and develops in a painless ulcer with a black area in the center.

The invention also provides a method for detecting the presence of a Bacillus anthracis bacterium in a sample, by contacting a sample known or suspected to contain a Bacillus anthracis bacterium with the monoclonal antibody according to the invention, and detecting the presence or absence of an antibody-bacterium complex. The presence of an antibody-bacterium complex indicates that the sample contains a Bacillus anthracis bacteria. In contrast, the absence of an antibody-bacterium complex indicates that the sample does not contain a Bacillus anthracis bacteria. The sample is, for example, blood, a dermal lesion, respiratory secretions, vesicular fluid or cerebrospinal fluid. The sample is contacted with the monoclonal antibody in vitro or in vivo. The monoclonal antibody is, for example, IQNPA. Optionally, the monoclonal antibody is labeled.

A composition, and a passive vaccine composition containing the monoclonal antibody according to the invention and a carrier are also provided. The invention also includes a kit containing, in one or more containers, the monoclonal antibody according to the invention.

In another aspect, the invention provides an isolated nucleic acid molecule that includes the sequence of SEQ ID NO: 1 or SEQ ID NO: 3, or a fragment, homologue, analogue or derivative thereof. The nucleic acid may include, for example, a nucleic acid sequence encoding a polypeptide at least 99% identical to a polypeptide that includes the amino acid sequences of SEQ ID NO: 2 or SEQ ID NO: 4, or an acid sequence nucleic encoding a polypeptide at least 95% identical to a polypeptide that includes the amino acid sequences of SEQ ID NO: 2 or SEQ ID NO: 4. The nucleic acid may be, for example, a genomic DNA fragment, or a cDNA molecule. Preferably, the nucleic acid appears in nature. The invention also provides a nucleic acid sequence that is complementary to the nucleic acid sequence of SEQ ID NO: 1 or SEQ ID NO: 3.

Also included in the invention is a vector containing one or more of the nucleic acids described herein, and a cell containing the vectors or nucleic acids described herein.

In another aspect, the invention provides an isolated polypeptide that includes the sequence of SEQ ID NO: 2 or SEQ ID NO: 4, or a fragment, homologue, analogue or derivative thereof. The polypeptide may include, for example, an amino acid sequence at least 99% identical to a polypeptide of SEQ ID NO: 2 or SEQ ID NO: 4, or a polypeptide at least 95% identical to a polypeptide that includes amino acid sequences SEQ ID NO: 2 or SEQ ID NO: 4.

The invention is also directed to host cells transformed with a vector comprising any of the nucleic acid molecules described above.

Summary of one aspect of this description

This description also refers to an IQNLF antibody that contains a heavy chain polypeptide having the amino acid sequence of SEQ ID NO: 6 or a fragment thereof, and the nucleic acid sequence of SEQ ID NO: 5 or a fragment of this. Preferably, the IQNLF antibody heavy chain polypeptide has the amino acid sequence of amino acid residues 1-106 of SEQ ID NO: 6, and more preferably amino acid residues 31-106 of SEQ ID NO: 6. An IQNLF antibody contains a light chain polypeptide having the amino acid sequence of SEQ ID NO: 8 or a fragment thereof, and the nucleic acid sequence of SEQ ID NO: 7 or a fragment thereof. Preferably, the IQNLF antibody light chain polypeptide has the amino acid sequence of amino acid residues 1-97 of SEQ ID NO: 2, and more preferably amino acid residues 24-97 of SEQ ID NO: 2.

In addition, this description provides an isolated fully human monoclonal antibody or a fragment thereof, which has a heavy chain with three CDRs containing the amino acid sequence VQPGG (SEQ ID NO: 17); SYAMSWVRQAPGKGLEW (SEQ ID NO: 18); YMQMNSL (SEQ ID NO: 19), or a light chain with three CDRs containing the amino acid sequence TQSPDFQSVSP (SEQ ID NO: 20); SSLHWYQ (SEQ ID NO: 21); DFTLTINSL (SEQ ID NO: 22). The antibody binds to an epitope in a region of the lethal factor polypeptide and neutralizes the lethal Bacillus anthracis toxin.

Alternatively, the monoclonal antibody is an antibody that binds to the same epitope as IQNLF. For example, the antibody competes with the binding of the IQNLF monoclonal antibody to a FL polypeptide.

FL binding means that the mAb interacts specifically with a portion of the FL polypeptide. A specific interaction means that the monoclonal antibody has a binding affinity, said binding affinity being from about 10-6 M to about 10-14 M. Preferably, the binding affinity is about 10-8 M to about 10-12 M. For example, the binding affinity is approximately 1010 M. Binding affinity is measured by methods known in the art.

Neutralization of the lethal toxin is defined by an increase in cell survival after exposure to Bacillus anthracis. For example, the monoclonal antibody decreases the formation of complexes between the protective antigen and the lethal factor (FL) or the edema factor (FE), thereby decreasing the translocation of FL and FE towards the cellular cytosol.

Optionally, the monoclonal antibody inhibits the binding of (i) AP to the target cells, (ii) AP to the anthrax toxin receptor (RTA), or (iii) from the lethal factor to the protective antigen. Alternatively, mAb inhibits the binding of AP to AP, thereby avoiding heptamerization.

The monoclonal antibody is 2, 4, 8, 10, 15, 20, 25 or more times effective to neutralize the lethal toxin of Bacillus anthracis compared to a natural Bacillus anthracis antiserum. A natural Bacillus anthracis antiserum is derived, for example, from subjects immunized with an anthrax vaccine, such as AVA or AVP. Examples of Bacillus anthracis antisera include AVR414.

The invention also includes methods for preventing or reducing the risk of developing a Bacillus anthracis infection in a subject, identifying a subject at risk of developing a Bacillus anthracis infection and administering to the subject a composition containing a human monoclonal antibody of the invention, such as IQNLF, or a combination of IQNLF and IQNPA.

The invention also includes methods for alleviating a symptom of a Bacillus anthracis infection in a subject, identifying a subject suffering from a Bacillus anthracis infection and administering to the subject a composition containing a human monoclonal antibody of the invention, such as an IQNLF antibody. . Optionally, an antibiotic, such as ciprofloxacin, doxycycline, amoxicillin, or penicillin G procaine, is also administered to the subject.

Also included in the invention is a method for passive immunization of a subject against Bacillus anthracis, by administration to a subject of a composition containing the monoclonal antibody of the invention, such as mAb IQNLF.

The monoclonal antibody is administered before exposure to Bacillus anthracis. For example, the monoclonal antibody is administered at least 1 year before exposure to Bacillus anthracis. The monoclonal antibody is administered 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months

or more before exposure to Bacillus anthracis. Alternatively, the monoclonal antibody is administered after exposure to Bacillus anthracis. For example, the monoclonal antibody is administered at least 1 hour, 2 hours, 3 hours, 4 hours, 8 hours or more after exposure to Bacillus anthracis. The monoclonal antibody is administered 1 day, 2 days, 3 days, 4 days or more after exposure to Bacillus anthracis.

The subject suffers or is at risk of developing a Bacillus anthracis infection. The subject is a mammal, such as a human being, a primate, a mouse, a rat, a dog, a cat, a cow, a horse, a pig.

A subject suffering from or at risk of developing Bacillus anthracis is identified by methods known in the art, for example, by isolating B. anthracis from blood, dermal lesions, or respiratory secretions, or by measuring specific antibodies in the blood. The symptoms of a B infection. Anthracis include fever (a temperature greater than 37.8 ° C), chills or night sweats, flu-like symptoms, cough, usually a non-productive cough, chest discomfort, shortness of breath, fatigue, muscle aches, sore throat , followed by swallowing difficulties, enlarged lymph nodes, headache, nausea, loss of appetite, abdominal pain, vomiting, or diarrhea, or in the case of skin contraction, a sore, especially on the face, the arms or hands, which begins as a bump in relief and develops in a painless ulcer with a black area in the center.

The invention also provides a method for detecting the presence of a Bacillus anthracis bacterium in a sample, by contacting a sample known or suspected to contain a Bacillus anthracis bacterium with the monoclonal antibody according to the invention, and detecting the presence or absence of an antibody-bacterium complex. The presence of an antibody-bacterium complex indicates that the sample contains a Bacillus anthracis bacteria. In contrast, the absence of an antibody-bacterium complex indicates that the sample does not contain a Bacillus anthracis bacteria. The sample is, for example, blood, a dermal lesion, respiratory secretions, vesicular fluid or cerebrospinal fluid. The sample is contacted with the monoclonal antibody in vitro or in vivo. The monoclonal antibody is, for example, IQNLF. Optionally, the monoclonal antibody is labeled.

A composition, and a passive vaccine composition containing the monoclonal antibody according to the invention and a carrier are also provided. The invention also includes a kit containing, in one or more containers, the monoclonal antibody according to the invention.

In another aspect, the invention provides an isolated nucleic acid molecule that includes the sequence of SEQ ID NO: 5 or SEQ ID NO: 7, or a fragment, homologue, analogue or derivative thereof. The nucleic acid may include, for example, a nucleic acid sequence encoding a polypeptide at least 99% identical to a polypeptide that includes the amino acid sequences of SEQ ID NO: 6 or SEQ ID NO: 8, or an acid sequence nucleic encoding a polypeptide at least 95% identical to a polypeptide that includes the amino acid sequences of SEQ ID NO: 6 or SEQ ID NO: 8. The nucleic acid may be, for example, a genomic DNA fragment, or a cDNA molecule. Preferably, the nucleic acid appears in nature. The invention also provides a nucleic acid sequence that is complementary to the nucleic acid sequence of SEQ ID NO: 5 or SEQ ID NO: 7.

Also included in the invention is a vector containing one or more of the nucleic acids described herein, and a cell containing the vectors or nucleic acids described herein.

In another aspect, the invention provides an isolated polypeptide that includes the sequence of SEQ ID NO: 6 or SEQ ID NO: 8, or a fragment, homologue, analogue or derivative thereof. The polypeptide may include, for example, an amino acid sequence at least 99% identical to a polypeptide of SEQ ID NO: 6 or SEQ ID NO: 8, or a polypeptide at least 95% identical to a polypeptide that includes amino acid sequences SEQ ID NO: 6 or SEQ ID NO: 8.

The invention is also directed to host cells transformed with a vector comprising any of the nucleic acid molecules described above.

Unless otherwise indicated, all technical and scientific terms and expressions used herein have the same meaning as those usually understood by those skilled in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein may be used in the practice or test of the present invention, suitable methods and materials are described below. In case of conflict, the present specification will dominate, including the definitions. In addition, the materials, methods and examples are illustrative only and are not intended to be limiting.

Other features and advantages of the invention will be apparent from the following detailed description and claims.

Brief description of the drawings

Figure 1 is a bar chart showing the results of an anthrax toxin neutralization test (first experiment) demonstrating that IQNPA-1 and IQNPA-2 are effective in neutralizing the toxin in vitro.

Figure 2 is a bar chart showing the results of an anthrax toxin neutralization test (second experiment) demonstrating that IQNPA-1 and IQNPA-2 are effective in neutralizing the toxin in vitro.

Figure 3 is a bar chart showing the results of an anthrax toxin neutralization test demonstrating that IQNPA-1 and IQNPA-2 are effective in neutralizing the toxin in vitro after allowing AP to bind to target cells for 2 hours.

Figure 4 is a bar chart showing the results of an anthrax toxin neutralization assay that demonstrates that IQNPA-1 and IQNPA-2 are effective in neutralizing the toxin in vitro after allowing AP to bind to target cells for 3 hours.

Figure 5 is a bar chart showing the results of an in vitro anthrax toxin neutralization test demonstrating that IQNLF-1 and IQNLF-2 are effective in neutralizing the toxin in vitro.

Figure 6 is a bar chart showing the results of an in vivo anthrax toxin neutralization test measured after preincubation of the target cells and the protective antigen, which demonstrates that IQNPA-1 and IQNPA-2 are effective. to neutralize the toxin in vivo.

Figure 7 is a linear graph showing the effect of IQNPA-1 dilution on the survival of passively immunized mice 2.5 hours before exposure to 30 x DLM of anthrax spores.

Figure 8 is a linear graph showing the effect of IQNPA-2 dilution on the survival of passively immunized mice 2.5 hours before exposure to 30 x DLM of anthrax spores.

Figure 9 is a linear graph showing the effect of dilution of a control anthrax serum on the survival of passively immunized mice 2.5 hours before an exposure to 30 x DLM of anthrax spores.

Figure 10 is a linear graph showing the effect of the dose on the survival of passively immunized mice measured up to 10 days after exposure.

Figure 11 is a probit graph for huMab 10 days after exposure.

Figure 12 is a graph showing the survival effect of mice treated once with IQNPA-1, IQNPA-2, or control anthrax serum at different times after exposure.

Figure 13 is a graph showing the survival effect of mice treated once with IQNPA-1, or control anthrax serum at different times after exposure.

Detailed description of the invention

The present invention is based in part on the discovery of fully human monoclonal antibodies, IQNPA-1 and IQNPA-2, which are specific for the protective antigen (AP) of B. anthracis, and IQNLF-1 and IQNLF-2, which are specific for the lethal factor (FL) of B. anthracis. Sequence analysis of IQNPA-1 and IQNPA-2 revealed that the two antibodies have the same nucleic acid sequence and are therefore derived from the same primary clone. Similar results were obtained for IQNLF-1 and IQNLF-2. Accordingly, the terms IQNPA-1 and IQNPA-2, and IQNLF-1 and IQNLF-2 are used interchangeably, and the antibodies are herein referred to respectively, IQNPA and IQNLF antibodies. The hybridoma cell lines that produce the human monoclonal antibodies IQNPA-1 and IQNPA-2, and IQNLF-1 and IQNLF-2 are called hybridomas IQNPA-1 and IQNPA-2, and IQNLF-1 and IQNLF-2, respectively. The IQNPA and IQNLF antibodies are collectively referred to herein as IQN or huMab antibodies.

IQNPA antibodies neutralize the lethal Bacillus anthracis toxin in vivo and in vitro.

Similarly, IQNLF antibodies neutralize the lethal Bacillus anthracis toxin in vitro. In addition, IQNPA antibodies bind to the anthrax toxin receptor (RTA) receptor binding site of the AP polypeptide. In mice exposed to IQNPA antibodies before exposure to B. Anthracis was found that treatment with antibodies protected 50% of animals exposed to dosages as low as 2.7 and 4.8 µg / ml, which correlate approximately with 0.125 and 0.25 mg / kg, respectively . In addition, IQNPA antibodies provide 100% protection when administered up to 36 hours after exposure to 25-40 x DLM of Bacillus anthracis spores. In contrast, in untreated mice, the average time to death after exposure to these spores is approximately 55 hr (2.3 days). These results demonstrate that IQNPA antibodies are useful for post-exposure and prophylactic treatment of anthrax infection.

B. anthracis is an aerobic Gram-positive, spore-forming, bacilliform bacterium. B. anthracis has two main virulence factors, a tripartite toxin and an antifagocytic capsule. The three exotoxin proteins are the edema factor (FE), the lethal factor (FL), and the protective antigen (AP). FE and FL enzymatically modify substrates of mammalian cell cytosol; FE is an adenylate cyclase that causes loss of fluids from affected tissues and inhibition of phagocytosis, and FL is a zinc-dependent protease that breaks down the mitogen-activated protein kinase kinase and causes macrophage lysis. The AP derives its name from the fact that it is the key protective immunogen in current human vaccines. The AP binds to the anthrax toxin receptor (RTA), after which a 20 kDa fragment is cleaved, allowing the remaining 63 kDa of the carboxy-terminal part to form a heptamer inserted into the membrane that joins a to three of the toxic enzymes, FL, to form the lethal toxin (TxLe), or EF, to form the edema toxin (TE), and translocates the toxic enzymes into the cytosol. TxLe is the main contributor to virulence in infected animals, and appears to be the main effector of the shock and death of systemic anthrax.

The human being in general acquires the disease directly, by contact with infected cattle, or indirectly in industrial jobs that are dedicated to the processing of animal products. There are three forms of the disease that are recognized in humans: cutaneous, inhalation and gastrointestinal infection. The inhalation form is the most worrisome in the context of a biological attack. After inhalation, the spores are phagocytosed by alveolar macrophages and transported to the drainage lymph nodes, where the spores germinate and the multiplication of the vegetative bacilli occurs. As a result, fatal bacteremia and toxemia occur, with a mortality rate in untreated individuals> 80%. Early treatment is essential, since animal studies suggest that the disease reaches a point where antibiotics are no longer effective due to the accumulation of a lethal toxin level, even if the body is sensitive to the agent.

Currently, the US authorized human vaccine (AVA) stimulates antibodies that neutralize anthrax toxin activity (Ivins et al., 1998). However, it has been shown that it may take several weeks to organize a significant neutralizing antibody response. Therefore, active immunization is not likely to be effective within the time frame of an infection. An alternative strategy would be to administer preformed lethal toxin neutralizing antibodies. It has been shown in a series of animal studies that preformed antibodies from animals (eg, horses) immunized with anthrax or AP vaccine can passively protect receptors, including humans. However, there are disadvantages to the use of animal derived serum. Access depends on the continuous availability of animals immunized, maintained and controlled correctly. The concentration, efficiency and safety of the material is variable and uncontrollable. In addition, animal derived sera can only be used effectively for a limited period of time, since a neutralizing antibody response will be organized against animal antibodies after prolonged or repeated use. More seriously, there is the fact that human receptors can react adversely to serum, which varies from serum sickness to anaphylactic shock, or can contract one of a series of lethal animal pathogens for humans.

An improvement would be the use of polyclonal antibodies collected from humans that have been immunized with the authorized human anthrax vaccine (AVA). The advantage of using sera derived from humans is that human sera are less immunogenic than animal sera, therefore a lower response of neutralizing antibodies would occur, which allows prolonged and repeated use, and a probable reduction in adverse responses . In addition, human IgG has a serum half-life of 20 days and, in theory, an infusion of human antibodies could protect an exposed individual for several weeks. However, the main disadvantages of this strategy are the risk of disease transmission, the variations between the batches in the concentration of the active ingredients and, therefore, in the effectiveness of the material and the inability to generate sufficient amounts of protective sera ( with qualifications high enough) to protect all people exposed in the case of an attack with biological or bioterrorist weapons.

Alternatively, the best strategy would be to develop neutralizing human anthrax toxin monoclonal antibodies that could be used to treat infected individuals and / or to provide "short-term coverage" to unprotected individuals who are or will be deployed in high environments. risk. Other advantages would be the reduced need to take prophylactic antibiotics, whose long-term use can cause considerable gastrointestinal dysfunctions, as well as the antibodies being effective against antibiotic resistant anthrax strains. Accordingly, human monoclonal antibodies have all the advantages of human polyclonal antibodies but none of the disadvantages mentioned above and, as such, could constitute optimal antitoxins.

Accordingly, the invention provides human monoclonal antibodies that neutralize the lethal Bacillus anthracis toxin that are useful for reducing the risk of B. anthracis infection and for treating a subject infected with B. anthracis. For example, monoclonal antibodies IQNPA-1 and IQNPA-2 have been identified as antibodies capable of neutralizing the lethal Bacillus anthracis toxin in vivo and in vitro.

The IQNPA antibody includes a heavy chain region (SEQ ID NO: 2) encoded by the nucleic acid sequence that follows in SEQ ID NO: 1, and a light chain (SEQ ID NO: 4) encoded by the sequence of nucleic acid shown in SEQ ID NO: 3. The start and end codons, which define the coding region, are underlined in SEQ ID NO: 1 and SEQ ID NO: 3.

> IQNPA Hy nucleotide sequence: (SEQ ID NO: 1)

> IQNPA Hy nucleotide sequence: (SEQ ID NO: 2)

> IKNPA LK nucleotide sequence: (SEQ ID NO: 3)

> IQNPA LK nucleotide sequence: (SEQ ID NO: 4)

The IQNLF antibody includes a heavy chain region (SEQ ID NO: 6) encoded by the nucleic acid sequence that follows in SEQ ID NO: 5, and a light chain (SEQ ID NO: 8) encoded by the sequence of nucleic acid shown in SEQ ID NO: 7. The start and end codons, which define the coding region, are underlined in SEQ ID NO: 5 and SEQ ID NO: 7.

> IQNLF Hy nucleotide sequence: (SEQ ID NO: 5)

> IQNLF Hy nucleotide sequence: (SEQ ID NO: 6)

> IQNLF LK nucleotide sequence: (SEQ ID NO: 7)

> IQNLF LK nucleotide sequence: (SEQ ID NO: 8)

As used herein, the term "antibody" refers to immunoglobulin molecules and immunologically active portions of immunoglobulin (Ig) molecules, that is, molecules that contain a specifically binding antigen binding site ( immunoreacts) to an antigen. "Binds specifically" or "immunoreacts" means that the antibody reacts with one or more antigenic determinants of the desired antigen and does not react (ie binds) with other polypeptides or binds with a much lower affinity (Kd> 10 -6) to other polypeptides.

The term "monoclonal antibody" (MAb) or "monoclonal antibody composition", as used herein, refers to a population of antibody molecules containing only a molecular species of an antibody molecule consisting of a product Exclusive light chain gene and an exclusive heavy chain gene product. In particular, the complementarity determining regions (CDRs) of the monoclonal antibody are identical in all population molecules. MAbs contain an antigen binding site capable of immunoreacting with a particular epitope of the antigen that is characterized by an exclusive binding affinity for it.

In general, antibody molecules obtained from humans are related to any of the classes of IgG, IgM, IgA, IgE and IgD, which differ from each other by the nature of the heavy chain present in the molecule. Certain classes also have subclasses, such as IgG1, IgG2, and others. In addition, in humans, the light chain can be a kappa chain or a lambda chain.

The term "antigen binding site" or "binding portion" refers to the part of the immunoglobulin molecule that participates in antigen binding. The antigen binding site is formed by amino acid residues of the N (terminal) variable regions of the heavy ("H") and light ("L") chains. Three very divergent sections within the V regions of the heavy and light chains, called "hypervariable regions", are interposed between more conserved flanking sections known as "frame regions" or "FR". Therefore, the term "FR" refers to naturally occurring amino acid sequences between hypervariable regions and adjacent to them in immunoglobulins. In an antibody molecule, the three hypervariable regions of a light chain and the three hypervariable regions of a heavy chain are arranged relative to each other in the three-dimensional space to form an antigen binding surface. The antigen-binding surface is complementary to the three-dimensional surface of a bound antigen, and the three hypervariable regions of each of the heavy and light chains are called "complementarity determining regions" or "CDR."

As used herein, the term "epitope" includes any protein determinant capable of specifically binding to an immunoglobulin, a scFv, or a T-cell receptor. Epitopic determinants usually consist of clusters of surface molecules. chemically active, such as amino acids or sugar side chains, and usually have specific three-dimensional structural characteristics, as well as specific loading characteristics. Antibodies against the Nterminales or C-terminal peptides of a polypeptide can be generated. For example, the antibody is generated against the lethal factor, the edema factor or the protective antigen. Optimally, the antibody is generated against domain 4 of a peptide of the protective antigen. For example, the antibody binds to amino acid residues 608-735 of a peptide of the protective antigen. The antibody binds to the amino acid sequence: NNIAVGADES WKEAHREVI NSSTEGLLLN IDKDIRKILS GYIVEIEDTE GLKEVINDRYDMLNISSLRQ DGKTFIDFKK YNDKLPLYIS NPNYKVNVYA VTKENTIINP SENGDTSTNG IKKILIFSKK GYEIG (SEQ ID NO: 9), or TNIYTVLDKI KLNAKMNILI RDKRFHYDRN NIAVGADESV VKEAHREVIN SSTEGLLLNI DKDIRKILSG YIVEIEDTEG LKEVINDRYD MLNISSLRQD GKTFIDFKKY NDKLPLYISNPNYKVNVYAV TKENTIINPS ENGDTSTNGI KKILIFSKKG YEIG (SEQ ID NO: 10).

As used herein, the terms "immunological binding" and "immunological binding properties" refer to non-covalent interactions of the type that occur between an immunoglobulin molecule and an antigen for which the immunoglobulin is specific. The strength or affinity of immunological binding interactions can be expressed in terms of the dissociation constant (Kd) of the interaction, in which a smaller Kd represents a greater affinity. The immunological binding properties of selected polypeptides are quantified using methods known in the art. One of these methods involves measuring the rates of formation and dissociation of the antigen-binding site / antigenic complex, these rates depending on the concentrations of the complex associates, the affinity of the interaction, and the geometric parameters that influence equally in the constant in both directions. Therefore, the "affinity constant" (Kon) and the "dissociation constant (Koff) can be determined by calculating the concentrations and actual rates of association and dissociation (see Nature, 361: 186-87 (1993)) . The Koff / Kon ratio allows the cancellation of all parameters not related to affinity, and is equal to the dissociation constant Kd (see, in general, Davies et al. (1990), Annual Rev. Biochem., 59: 439-473). An antibody of the present invention is said to bind specifically to an anthrax epitope when the equilibrium binding constant (Kd) is: 1 µM, preferably: 100 nM, more preferably: 10 nM, and most preferably from 100 pM to about 1 pM, as measured by assays, such as radioligand binding assays or similar assays known to those skilled in the art.

As used herein, the term "fragment", when used with reference to a nucleic acid encoding IQNLF or IQNPA, is intended to indicate a nucleic acid having substantially the same sequence as a portion of a nucleic acid encoding IQNLP or IQNPA. The nucleic acid fragment is of sufficient length and sequence to selectively hybridize with a nucleic acid encoding an IQNLP or IQNPA antibody, or a nucleotide sequence that is complementary to a nucleic acid encoding an IQNLP or IQNPA antibody. Therefore, the fragment is intended to include primers for sequencing and polymerase chain reaction (PCR), as well as probes for a transfer or hybridization in nucleic acid solution. The meaning of the term is also intended to include regions of nucleotide sequences that do not directly encode IQNLP or IQNPA polypeptides, such as introns, and sequences of untranslated regions of the gene encoding IQNLP or IQNPA.

Those skilled in the art will recognize that it is possible to determine, without undue experimentation, whether a human monoclonal antibody has the same specificity as a human monoclonal antibody of the invention (for example, the IQNLP and IQNPA monoclonal antibody) by determining whether the former prevents the second, it binds to an anthrax protective antigen polypeptide, a lethal factor polypeptide, or an anthrax toxin receptor. If the human monoclonal antibody being tested competes with the human monoclonal antibody IQNLP or IQNPA, as demonstrated by a decrease in the binding of the human monoclonal antibody IQNLP or IQNPA, then the two monoclonal antibodies bind to the same epitope or an epitope very related. Another way to determine if a human monoclonal antibody has the specificity of a human monoclonal antibody of IQNLP or IQNPA is to pre-incubate the human monoclonal antibody of the invention with a protective antigen polypeptide, with which it would normally be reactive, and then add the human monoclonal antibody being tested to determine if the human monoclonal antibody being tested is inhibited its ability to bind to the polypeptide of the protective antigen. If the human monoclonal antibody being tested is inhibited, then it most likely has the same epitopic specificity, or a functionally equivalent epitopic specificity as the monoclonal antibody of the invention. The selection of human monoclonal antibodies of the invention is also carried out using B. anthracis and determining whether the monoclonal test antibody is capable of neutralizing B. anthracis.

Various methods known in the art are used for the production of monoclonal antibodies directed against an anthrax protein, or against derivatives, fragments, analogs, homologs or orthologs thereof (see, for example, Antibodies: A Laboratory Manual, Harlow E. and Lane D., 1988, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, incorporated herein by reference). Fully human antibodies are antibody molecules in which the complete sequence of the light chain and heavy chain, including the CDRs, arise from human genes. These antibodies are referred to as "human antibodies" or "fully human antibodies" herein. Human monoclonal antibodies can be prepared using the trioma technique; the human B cell hybridoma technique (see, Kozbor, et al., 1983, Immunol. Today, 4:72); and the EBV hybridoma technique for producing human monoclonal antibodies (see, Cole, et al., 1985, in: MONOCLONAL ANTIBODIES AND CANCER THERAPY, Alan R. Liss, Inc., pp. 77-96). Human monoclonal antibodies can be used and can be produced using human hybridomas (see, Cote, et al., 1983, Proc. Natl. Acad. Sci. USA, 80: 2026-2030), or transforming human B cells with the Epstein Barr virus in vitro (see, Cole, et al., 1985, in: MONOCLONAL ANTIBODIES AND CANCER THERAPY, Alan R. Liss, Inc., pp. .77-96).

The functional fragments of the IQNLP and IQNPA antibodies are also included in the invention. A functional fragment means an antibody molecule or a functional fragment thereof, which has substantially the same amino acid sequences of the heavy and light chain CDRs, as they appear in IQNLF or IQNPA. The functional fragment still retains part or all of the binding activity to FL or AP. These functional fragments may include, for example, functional fragments of antibodies, such as Fab, F (ab) 2, Fv, single chain Fv (scFv). Other functional fragments may include, for example, heavy chain polypeptides.

or light, variable region polypeptides, or CDR polypeptides or portions thereof, with the proviso that said functional fragments retain binding activity, specificity, FL or AP binding activity, or neutralizing activity. The term is also intended to include polypeptides that include, for example, modified forms of natural amino acids, such as D-stereoisomers, unnatural amino acids, analogs and amino acid mimetics, with the proviso that said polypeptides retain functional activity as defined above. When used with reference to a functional fragment, it is not necessary that all IQNLF or IQNPA CDRs are represented. Instead, only CDRs that would normally be present in the portion of antibody that corresponds to the functional fragment are present. Similarly, the term "functional fragment" when used with reference to a coding nucleic acid is intended to refer to a nucleic acid encoding an antibody or a functional fragment that has no substitutions on the amino acids of IQNLF or IQNPA outside the CDRs, and that it has substantially the same nucleotide sequence

that the nucleotide sequences of the heavy and light chain CDRs, and that it substantially encodes the same amino acid sequences of the CDRs found in IQNLF or IQNPA. The meaning of functional fragment is intended to include less important variations and modifications of the antibody, with the proviso that its function is not compromised. These functional fragments are well known to those skilled in the art. These terms and expressions are described, for example, in Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, New York (1989); Molec Biology and Biotechnology: A Comprehensive Desk Reference (Myers, RA (ed.), New York: VCH Publisher, Inc.); Huston et al., Cell Biophysics, 22: 189-224 (1993); Pluckthun and Skerra, Meth. Enzymol., 178: 497-515 (1989); and in Day, ED, Advanced Immunochemistry, 2nd ed., Wiley-Liss, Inc., New York, NY (1990).

In the case where there are two or more definitions of a term or expression that are used and / or accepted in the art, the definition of the term or expression as used herein is intended to include all these meanings, unless explicitly state otherwise. A specific example is the use of the term "CDR" to describe the non-contiguous antigen combination sites that are within the variable region of both heavy and light chain polypeptides. This specific region has been described by Kabat et al., Supra, and by Chothia et al., J. Mol. Biol., 196: 901-917 (1987), and by MacCallum et al., J. Mol. Biol., 262: 732-745 (1996), in which the definitions include overlaps or subsets of amino acid residues when compared to each other. However, the application of any of the definitions for an IQNLF or IQNPA CDR, or its variants, is intended to be within the scope of the term or expression as defined and used herein. The amino acid residues that include the CDRs, as defined in each of the references cited above, are listed below in Table A for comparison.

TABLE A

<dl><dt>CDR Definitions </dt>&lt;dd /&gt;</dl>

<dl><dt>Kabat1 </dt><dd>Chothia2 MacCallum3 </dd></dl>

<dl><dt>Vh </dt><dd>CDR1 31-35 26-32 30-35 </dd></dl>

<dl><dt>Vh </dt><dd>CDR2 50-65 53-55 47-58 </dd></dl>

<dl><dt>Vh </dt><dd>CDR3 95-102 96-101 93-101 </dd></dl>

<dl><dt>VL </dt><dd>CDR1 24-34 26-32 30-36 </dd></dl>

<dl><dt>VL </dt><dd>CDR2 50-56 50-52 46-55 </dd></dl>

<dl><dt>VL </dt><dd>CDR3 89-97 91-96 89-96 </dd></dl>

<dl><dt>1 The numbering of the remains follows the nomenclature of Kabat et al., Supra. 2 The numbering of the remains follows the nomenclature of Chothia et al., Supra. 3 The numbering of the remains follows the nomenclature of MacCallum et al., Supra.</dt>&lt;dd /&gt;</dl>

Sequences that correspond to the IQNPA CDRs include, for example, the regions defined by Kabat et al., Supra and / or the regions defined by Chothia et al., Supra, as well as those defined by MacCallum et al., Supra. . The fragments of the IQNPA CDRs for each of the above definitions correspond to the nucleotides indicated below in Table B when they are numbered according to SEQ ID NO: 1 and 3. Nucleotide sequence numbering is extracted from the primary sequence shown in SEQ ID NO: 1 and 3, and conforms to the definitions previously indicated in Table A.

TABLE B

<dl><dt>Nucleotide remains of IQNPA CDRs </dt>&lt;dd /&gt;</dl>

<dl><dt>Kabat </dt><dd>Chothia Maccallum </dd></dl>

<dl><dt>Vh </dt><dd>CDR1 104-118 89-109 101-118 </dd></dl>

<dl><dt>Vh </dt><dd>CDR2 161-211 170-181 152-190 </dd></dl>

<dl><dt>Vh </dt><dd>CDR3 308-331 311-328 302-328 </dd></dl>

<dl><dt>VL </dt><dd>CDR1 83-115 89-109 101-121 </dd></dl>

<dl><dt>VL </dt><dd>CDR2 161-181 161-169 149-178 </dd></dl>

<dl><dt>VL </dt><dd>CDR3 278-304 284-301 278-301 </dd></dl>

Similarly, the IQNPA CDR fragments for each of the above definitions correspond to the amino acid residues indicated below in Table C, when they are numbered according to SEQ ID NO: 2 and 4. The amino acid residue number is extracted from the primary sequence shown in SEQ ID NO: 2 and 4, and conforms to the definitions previously indicated in table A.

TABLE C

<dl><dt>Amino acid residues of IQNPA CDRs </dt>&lt;dd /&gt;</dl>

<dl><dt>Kabat </dt><dd>Chothia Maccallum </dd></dl>

<dl><dt>Vh </dt><dd>CDR1 Lys31-Ala35 Ser26-Lys32 Val30-Ala35 </dd></dl>

<dl><dt>Vh </dt><dd>CDR2 Ser50-Trp66 Ile53-Val56 Thr47-Ala59 </dd></dl>

<dl><dt>Vh </dt><dd>CDR3 Tyr99-Arg106 Met100-Leu105 Thr97-Leu105 </dd></dl>

<dl><dt>VL </dt><dd>CDR1 Leu24-Ser34 Gln26-Ser32 Thr30-Gly36 </dd></dl>

<dl><dt>VL </dt><dd>CDR2 Ser50-Trp56 Ser50-Ser52 Ser46-Ala55 </dd></dl>

<dl><dt>VL </dt><dd>CDR3 Gly89-Ser97 Asp91-Ile96 Gly89-Ile96 </dd></dl>

Therefore, the invention also provides nucleic acid fragments encoding substantially the same amino acid sequence as a CDR of a heavy or light chain polypeptide of IQNLF.

5 Sequences that correspond to the IQNLF CDRs include, for example, the regions defined by Kabat et al., Supra and / or the regions defined by Chothia et al., Supra, as well as those defined by MacCallum et al., Supra. . The fragments of the IQNLF CDRs for each of the above definitions correspond to the nucleotides indicated below in Table D when they are numbered according to SEQ ID NO: 5 and 7. Nucleotide sequence numbering is extracted from the primary sequence shown in SEQ ID NO: 5 and 7, and conforms to the

10 definitions previously indicated in table A.

TABLE D

<dl><dt>Nucleotide remains of IQNLF CDRs </dt>&lt;dd /&gt;</dl>

<dl><dt>Kabat </dt><dd>Chothia Maccallum </dd></dl>

<dl><dt>Vh </dt><dd>CDR1 Lys31-Ala35 Ser26-Lys32 Val30-Ala35 </dd></dl>

<dl><dt>Vh </dt><dd>CDR2 Ser50-Trp66 Ile53-Val56 Thr47-Ala59 </dd></dl>

<dl><dt>Vh </dt><dd>CDR3 Tyr99-Arg106 Met100-Leu105 Thr97-Leu105 </dd></dl>

<dl><dt>VL </dt><dd>CDR1 Leu24-Ser34 Gln26-Ser32 Thr30-Gly36 </dd></dl>

<dl><dt>VL </dt><dd>CDR2 Ser50-Trp56 Ser50-Ser52 Ser46-Ala55 </dd></dl>

<dl><dt>VL </dt><dd>CDR3 Gly89-Ser97 Asp91-Ile96 Gly89-Ile96 </dd></dl>

Similarly, the IQNLF CDR fragments for each of the above definitions correspond to nucleotide amino acid residues indicated below in Table D when they are numbered according to SEQ ID NO: 6 and 8. The numbering of amino acid residues It is extracted from the primary sequence shown in SEQ ID NO: 6 and 8, and conforms to the definitions previously indicated in Table A.

TABLE E

<dl><dt>Amino acid residues of IQNPA CDRs </dt>&lt;dd /&gt;</dl>

<dl><dt>Kabat </dt><dd>Chothia Maccallum </dd></dl>

<dl><dt>Vh </dt><dd>CDR1 Val31-Gly35 Ser26-Gln32 Leu30-Gly35 </dd></dl>

<dl><dt>Vh </dt><dd>CDR2 Ser50-Trp65 Met53-Val56 Met47-Ala59 </dd></dl>

<dl><dt>Vh </dt><dd>CDR3 Tyr99-Arg106 Met100-Leu105 Thr97-Leu105 </dd></dl>

<dl><dt>VL </dt><dd>CDR1 Thr24-Pro34 Ser26-Val32 Gln30-Glu36 </dd></dl>

<dl><dt>VL </dt><dd>CDR2 Ser50-Gln56 Ser50-Leu52 Gln46-Tyr55 </dd></dl>

<dl><dt>VL </dt><dd>CDR3 Asp89-Thr97 Thr91-Ser96 Asp89-Ser96 </dd></dl>

Therefore, the invention also provides nucleic acid fragments encoding substantially the same amino acid sequence as a CDR of a heavy or light chain IQNPA polypeptide.

As used herein, the term "substantially" or the term "substantially the same" when

it is used with reference to a sequence of nucleotides or amino acids intended to mean that the

nucleotide or amino acid sequence shows a considerable degree or amount of coincidence of

sequence when compared to a reference sequence. This considerable degree or amount of sequence matching 25 is also considered significant and, therefore, shows characteristics that are decidedly

Recognizable or known. Therefore, a nucleotide sequence that is substantially the same sequence of

nucleotides that a heavy or light chain of IQNLF or IQNPA and its fragments refers to a sequence that

shows characteristics that are decidedly known or recognizable by coding or by being the sequence of

amino acids of IQNLF or IQNPA. Its minor modifications are also included, with the proviso that they are recognizable as a sequence of the IQNLF or IQNPA antibody. Similarly, a sequence of

amino acids that is substantially the same amino acid sequence as the heavy or light chain of IQNLF or

IQNPA or its functional fragments refers to a sequence that shows characteristics that are decidedly known or recognizable by representing the amino acid sequence of IQNLF or IQNPA and its minor modifications.

Besides the conservative amino acid substitutions, minor modifications of the nucleotide sequences encoding IQNLF or IQNPA that allow functional amino acid substitution are also intended to be included within the term definition. The substitution of functionally equivalent amino acids encoded by the nucleotide sequences and IQNLF or IQNPA is routine and can be performed by methods known to those skilled in the art. Briefly, the substitution of functionally equivalent amino acids can be carried out by identifying the amino acids that are desired to be changed, incorporating the changes in the coding nucleic acid, and then determining the function of the modified and expressed recombinant IQNLF or IQNPA polypeptide or polypeptides. Rapid methods for manufacturing and selecting multiple simultaneous changes are known in the art, and can be used to produce a coding nucleic acid bank containing all possible changes or all desired changes, and then expressing and selecting the bank for IQNLF polypeptides. or IQNPA that retain the function. These methods include, for example, codon-based mutagenesis, random oligonucleotide synthesis, and partially degenerated oligonucleotide synthesis.

The identification of the amino acids to be changed can be carried out by those skilled in the art using the current information available regarding the structure and function of the antibodies, as well as the current and available information that includes methods for grafting procedures. of CDR. For example, CDRs can be identified within the donor antibody by any of the criteria specified in Kabat et al., Supra, Chothia et al., Supra and / or MacCallum et al., Supra, and any or all amino acid residues not identical that are outside these CDR sequences can be changed to functionally equivalent amino acids. Using the above described methods known in the art, any or all non-identical amino acids can be changed individually or in combination with amino acids in different positions to incorporate the desired number of amino acid substitutions at each of the desired positions. The IQNLF or IQNPA polypeptides containing the desired substituted amino acids are then produced, and selected for preservation or enhancement of function, compared to unsubstituted IQNLF or IQNPA polypeptides. Production of substituted IQNLF or IQNPA polypeptides can be carried out, for example, by recombinant expression using methods known to those skilled in the art. IQNLF or IQNPA polypeptides that show conservation or increased function, compared to unsubstituted IQNLF or IQNPA, are considered to contain minor modifications of the coding nucleotide sequence, which result in functional substitution of one or more more amino acids

The functional substitution of amino acids is beneficial, since it allows the rapid identification of equivalent amino acid residues without the need for structural information or laborious procedures that are necessary to evaluate and identify the amino acid residues that must be considered for the substitution to transfer so satisfactory donor binding function. In addition, existing discontinuous procedures for changing and testing the amino acids identified for substitution are eliminated. Fundamentally, using the functional substitution strategy described above, all non-identical amino acid residues between the donor and the human framework can be identified, and substituted with any or all other possible amino acid residues in each non-identical position to produce a population of substituted polypeptides. containing all possible permutations and combinations or all desired permutations and combinations. The population of substituted polypeptides can then be selected to detect substituted polypeptides that retain function. Using the codon-based mutagenesis procedures described above, the generation of a bank of substituted amino acid residues and the selection of functionally substituted residues have been used for the rapid production of grafted therapeutic antibodies, as well as for the rapid alteration of the affinity of antibodies Examples of these procedures appear, for example, in Rosok et al., J. Biol. Chem., 271: 22611-22618 (1996), and in Glaser et al., J. Immunol., 149: 3903-3913 ( 1992), respectively.

The antibodies are purified by well known techniques, such as affinity chromatography using protein A or protein G, which mainly provides the IgG fraction of the immune serum. Then, or alternatively, the specific antigen that is the target of the immunoglobulin sought, or an epitope thereof, can be immobilized on a column to purify the specific immunological antibody by immunoaffinity chromatography. Immunoglobulin purification is analyzed, for example, in D. Wilkinson (The Scientist, published by The Scientist, Inc., Philadelphia PA, vol. 14, No. 8 (April 17, 2000), pp. 25-28).

It is desirable to modify the antibody of the invention with respect to the effector function to enhance, for example, the efficacy of the antibody in treating B. anthracis. For example, a cysteine ​​residue or moieties may be introduced into the Fc region, thereby allowing the formation of intercatenary disulfide bonds in this region. The homodimeric antibody generated in this manner may have a better internalization capacity and / or produce greater complement-mediated cell death and greater antibody-dependent cellular cytotoxicity (ADCC) (see, Caron et al., J. Exp Med. , 176: 1191-1195 (1992), and Shopes, J. Immunol., 148: 2918-2922 (1992)). Alternatively, an antibody can be modified to have dual Fc regions and, thereby, may have a greater complement-mediated lysis and higher ADCC capabilities (see, Stevenson et al., Anti-Cancer Drug Design, 3: 219- 230 (1989)).

The invention also relates to immunoconjugates comprising an antibody conjugated to a cytotoxic agent, such as a toxin (for example, an enzymatically active toxin of bacterial, fungal, plant or animal origin, or its fragments), or a radioactive isotope (is say, a radioconjugate).

Enzymatically active toxins and their fragments that can be used include diphtheria A chain, active fragments that do not bind diphtheria toxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain , the A chain of the abrin, the A chain of the modecin, alpha-sarcin, the proteins of Aleurites fordii, the diantine proteins, the proteins of Phytolacca americana (PAPI, PAPII, and PAP-S), the Momordica inhibitor charantia, curcina, Crotine, the inhibitor of Saponaria officinalis, gelonin, mitogelin, restrictocin, fenomycin, enomycin, and trichothecenes. A variety of radionuclides are available for the production of radioconjugated antibodies. Examples include 212Bi, 131I, 131In, 90Y, and 186Re.

Antibody and cytotoxic agent conjugates are manufactured using a variety of bifunctional protein coupling agents, such as N-succinimidyl-3- (2-pyridyldithiol) propionate (SPDP), iminothiolane (IT), bifunctional derivatives of imidoesters (such such as dimethyl adipimidate HCl), active esters (such as disuccinimidyl suberate), aldehydes (such as glutaraldehyde), bis-azido compounds (such as bis- (pazidobenzoyl) hexanediamine), bis-diazonium derivatives (such as bis- (p-diazoniumbenzoyl) ethylenediamine), diisocyanates (such as toliene 2,6-diisocyanate), and bis-active fluorine compounds (such as 1,5-difluoro-2,4-dithitrobenzene) ). For example, a ricin immunotoxin can be prepared as described in Vitetta et al., Science, 238: 1098 (1987). Carbon-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid14 (MX-DTPA) is an example of a chelating agent for the conjugation of the radionuclide to the antibody (see WO 94/11026).

Those skilled in the art will recognize that a wide variety of possible moieties can be coupled to the resulting antibodies or other molecules of the invention (see, for example, "Conjugate Vaccines", Contributions to Microbiology and Immunology, JM Cruse and RE Lewis, Jr. (eds.), Carger Press, New York, (1989), whose total content is incorporated herein by reference).

The coupling is achieved by any chemical reaction that binds the two molecules, with the proviso that the antibody and the other moiety retain their respective activities. This bond can include many chemical mechanisms, for example covalent bonding, affinity binding, intercalation, coordinated bonding and complex formation. However, the preferred link is the covalent bond. Covalent bonding is achieved by direct condensation of existing side chains, or by incorporating external bridge molecules. Many bivalent or polyvalent linkers are useful for coupling protein molecules, such as the antibodies of the present invention, to other molecules. For example, representative coupling agents may include organic compounds, such as thioesters, carbodiimides, succinimide esters, diisocyanates, glutaraldehyde, diazobenzenes, and hexamethylenediamines. This listing is not intended to be exhaustive of the various classes of coupling agents known in the art, but are examples of the most common coupling agents (see, Killen and Lindstrom, Jour. Immun., 133: 1335-2549 (1984); Jansen et al., Immunological Reviews, 62: 185-216 (1982); and Vitetta et al., Science, 238: 1098 (1987). Preferred connectors are described in the literature (see, for example, Ramakrishnan, S. et al., Cancer Res., 44: 201-208 (1984), which describes the use of MBS (M-maleimidobenzoyl-N- ester) hydroxysuccinimide)). See also US Patent No. 5,030,719, which describes the use of a halogenated acetylhydrazide derivative coupled to an antibody through an oligopeptide linker. Particularly preferred connectors include: (i) EDC (1-ethyl-3- (3dimethylaminopropyl) carbodiimide hydrochloride; (ii) SMPT (4-succinimidyloxycarbonyl-alpha-methyl-alpha- (2-pyridyldithio) toluene, Pierce Chem. Co ., cat. no. 21558G); (iii) SPDP (succinimidyl-6- [3- (2-pyridyldithio) propionamido] hexanoate, Pierce Chem. Co., cat. 21651G); (iv) Sulfo-LC-SPDP (sulfosuccinimidyl-6- [3- (2-pyridyldithio) propianamide], Pierce Chem. Co. cat. no. 2165-G); and (v) sulfo-NHS (N-hydroxysulfosuccinimide, Pierce Chem. Co., cat. no. 24510) conjugated to EDC.

The connectors described above contain components that have different attributes, thereby leading to conjugates with different physicochemical properties. For example, sulfo-NHS esters of alkyl carboxylates are more stable than sulfo-NHS esters of aromatic carboxylates. Connectors containing NHSester are less soluble than sulfo-NHS esters. In addition, the SMPT connector contains a sterically hindered disulfide bond, and can form conjugates with greater stability. Disulfide bonds in general are less stable than other bonds, because the disulfide bond is broken in vitro, resulting in less conjugate available. Sulfo-NHS, in particular, can enhance the stability of carbodiimide couplings. Carbodiimide couplings (such as EDC), when used together with sulfo-NHS, form esters that are more resistant to hydrolysis than the carbodiimide coupling reaction alone.

Treatment methods

The invention provides prophylactic, prophylactic after exposure, and therapeutic methods for treating a subject who is at risk (or is susceptible) of contracting a B. anthracis infection. Passive immunization has proven to be an effective and safe strategy for the prevention and treatment of infectious diseases. Passive immunization using a neutralizing human monoclonal antibody provides an immediate treatment strategy for prophylaxis and emergency treatment of a Bacillus anthracis infection. In addition, passive immunization in a subject exposed to anthrax using a neutralizing human monoclonal antibody allows the subject to organize an endogenous protective response against the infectious agent, thereby making active immunization with an anthrax vaccine unnecessary for future protection. . The infectious agent, in all its immunogenic and non-immunogenic components, will be processed and presented to the specific immune system, producing a long-term protective immunity.

By binding to Bacillus anthracis, the IQNPA and IQNLF antibodies modulate the recognition of the antigen by the immune system of a subject, thereby inducing the natural immunity of the subject.

A Bacillus anthracis infection is avoided, or the risk of developing a Bacillus anthracis infection in a subject is reduced, by administering to the subject an IQNPA or IQNLF antibody. A subject who is at risk of contracting a Bacillus anthracis infection includes individuals who have contacted, or suspected of having contacted, or who may contact (i.e. exposed) with spores or vegetative cells. of a strain of Bacillus anthracis in any way. For example, it can be exposed to a cloud of disseminated anthrax spores deliberately or unintentionally, touching soil, infected animals or animal products, or working with spores or vegetative cells in a laboratory. The administration of a prophylactic agent occurs before the manifestation of the characteristic symptoms of Bacillus anthracis, so that a disease or disorder is prevented or, alternatively, its progress or severity is delayed.

Alternatively, the IQNPA or IQNLF antibodies are administered therapeutically. For example, IQN antibodies are administered to a subject after the manifestation of a symptom of a Bacillus anthracis infection. Optionally, IQN antibodies are administered with an antibiotic treatment regimen. Treatment reduces the severity or relieves a symptom of a Bacillus anthracis infection. The effectiveness of the treatment is determined together with any known method to diagnose or treat a Bacillus anthracis infection. Relief of one or more symptoms of Bacillus anthracis infection indicates that the compound confers a clinical benefit.

The symptoms of Bacillus anthracis vary depending on how the disease was contracted (for example, skin, by inhalation or intestinal), but the symptoms usually appear within 7 days. The majority (approximately 95%) of anthrax infections appear when the bacteria enter a cut or abrasion of the skin, such as when wool, skins, leather or contaminated hair products (especially goat hair) of animals are handled infected. The cutaneous infection begins with a raised bump that produces itching that looks like an insect bite, but that develops in a vesicle in 1-2 days and then in a painless ulcer, usually with a diameter of 1-3 cm, with a characteristic black (dead) necrotic area in the center. The lymph glands in the adjacent area may swell. Approximately 20% of untreated cases of cutaneous anthrax end in death. The initial symptom of anthrax inhalation may resemble a common cold. After several days, the symptoms can progress to serious respiratory problems and shock. Anthrax by inhalation is usually fatal. The form of anthrax intestinal disease can occur after consumption of contaminated meat and is characterized by acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting, and fever are followed by abdominal pain, blood vomiting, and severe diarrhea. Intestinal anthrax causes death in 25% to 60% of cases.

Bacillus anthracis infection is diagnosed by isolating B. anthracis from blood, skin lesions, or respiratory secretions, or by measuring specific antibodies in the blood of people with suspected cases.

The IQNPA or IQNLF antibodies are administered before exposure to Bacillus anthracis. For example, the monoclonal antibody is administered at least 1 year before exposure to Bacillus anthracis. For example, the monoclonal antibody is administered 1-7 days, 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months or more before exposure to Bacillus anthracis. Alternatively, the monoclonal antibody is administered after exposure to Bacillus anthracis. For example, the monoclonal antibody is administered at least 1 hour, 2 hours, 3 hours, 4 hours, 8 hours or more after exposure to Bacillus anthracis. The monoclonal antibody is administered 1 day, 2 days, 3 days, 4 days or more after exposure to Bacillus anthracis. IQNPA antibodies

or IQNLF are administered as an individual dose. Alternatively, the IQNPA or IQNLF antibodies are administered in multiple doses. For example, the IQNPA or IQNLF antibodies are administered in two, three, four or five doses. The doses are administered with a range, for example, of 1, 2, 3, 4 or more days.

Optionally, the IQNPA or IQNLF antibodies are co-administered with an antibiotic. Alternatively, the IQNPA or IQNLF antibodies are administered before or after the administration of an antibiotic. Antibiotics include, for example, ciprofloxacin, doxycycline, amoxicillin, and procaine penicillin G.

A therapeutically effective amount of an antibody of the invention generally refers to the amount necessary to achieve a therapeutic objective. As indicated above, this may be a binding interaction between the antibody and its target antigen that, in certain cases, interferes with the functioning of the target. The amount required to be administered further will depend on the binding affinity of the antibody for its specific antigen, and will also depend on the rate at which an administered antibody is destroyed from the free volume of another subject to which it is administered. The usual ranges for a therapeutically effective dosage of an antibody or an antibody fragment of the invention can be, as a non-limiting example, from about 0.1 mg / kg body weight to about 50 mg / kg body weight. The usual dosage frequencies may vary, for example, from twice daily to once weekly.

Drug Compositions

Therapeutic or prophylactic compositions are provided herein, which generally comprise mixtures of one or more IQNPA or IQNLF monoclonal antibodies and combinations thereof. Prophylactic compositions are used to prevent a Bacillus anthracis infection, and the therapeutic compositions are used to treat individuals following a Bacillus anthracis infection. Prophylactic uses include the provision of a major antibody titer to Bacillus anthracis in a treated subject. In this way, subjects with a high risk of contracting Bacillus anthracis are provided with passive immunity against Bacillus anthracis.

Optionally, the composition is administered together with auxiliary immunoregulatory agents, for example cytokines, lymphokines, and chemokines that include, but are not limited to IL-2, modified IL-2 (Cys125-Ser125), GM-CSF, IL-12, y-interferon, IP-10, MIP11, and RANTES.

The antibodies or agents of the invention (also referred to herein as "active compounds"), and their derivatives, fragments, analogs and homologues, are incorporated into pharmaceutical compositions suitable for administration. Such compositions generally comprise the antibody or agent, and a pharmaceutically acceptable carrier. As used herein, the term "pharmaceutically acceptable carrier" is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and delaying absorption agents, and the like, compatible with pharmaceutical administration. . Suitable vehicles are described in the most recent edition of Remington's Pharmaceutical Sciences, a conventional reference text in the field, which is incorporated herein by reference. Preferred examples of such carriers or diluents include, but are not limited to water, saline, Ringer's solutions, dextrose solution, and 5% human serum albumin.

A pharmaceutical composition of the invention is formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral administration, for example intravenous, intradermal, subcutaneous, oral (eg, inhalation), transdermal (ie, topical), transmucosal, and rectal. The solutions or suspensions used for parenteral, intradermal, or subcutaneous application may include the following components: a sterile diluent, such as water for injection, saline solution, nonvolatile oils, polyethylene glycols, glycerin, propylene glycol or other synthetic solvents; antibacterial agents, such as benzyl alcohol or methylparabenos; antioxidants, such as ascorbic acid or sodium bisulfite; chelating agents, such as ethylenediaminetetraacetic acid (EDTA); buffers, such as acetates, citrates or phosphates; and agents for adjusting tonicity, such as sodium chloride or dextrose. The pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. Parenteral preparation can be enclosed in ampoules, disposable syringes, or multi-dose vials made of glass or plastic.

Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions or dispersions (when water soluble), and sterile powders for improvised preparation of sterile injectable solutions or dispersions. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EL ™ (BASF, Parsippany, NJ), or phosphate buffered saline (PBS). In all cases, the composition must be sterile and must be fluid to the extent that it can be easily injected. It must be stable under the conditions of manufacture and conservation, and must be preserved against the contaminating action of microorganisms, such as bacteria and fungi. The carrier may be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by maintaining the required particle size in the case of a dispersion, and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In many cases it will be preferable to include isotonic agents, for example, sugars, polyalcohols, such as mannitol, sorbitol, and sodium chloride in the composition.

Prolonged absorption of the injectable compositions can be achieved by including in the composition an agent that delays absorption, for example aluminum monostearate and gelatin.

Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of the ingredients listed above, as required, followed by sterilization by filtration. In general, dispersions are prepared by incorporating the active compound in a sterile vehicle containing a basic dispersion medium and the other required ingredients from those listed above. In the case of sterile powders for the preparation of sterile injectable solutions, the preparation methods are vacuum drying and lyophilization that produces a powder of the active ingredient plus any other desired ingredient from a solution thereof previously sterilized by filtration.

For administration by inhalation, the compounds are administered in the form of an aerosol spray from a pressurized container or dispenser containing a suitable propellant, for example, a gas, such as carbon dioxide, or a nebulizer.

Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants suitable for the barrier to be permeated are used in the formulation. These penetrants are generally known in the art and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal administration can be achieved through the use of nasal sprays or suppositories. For transdermal administration, the active compounds are formulated in ointments, balms, gels or creams, as is generally known in the art.

In one embodiment, the active compounds are prepared with vehicles that will protect the compound against rapid removal from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biocompatible biodegradable polymers, such as ethylene vinyl acetate, polyanhydrides, poly (glycolic acid), collagen, polyorthoesters, and poly (lactic acid) can be used. The methods for preparing said formulations will be apparent to those skilled in the art. The materials can also be obtained from the market of Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions (including liposomes targeting cells infected with monoclonal antibodies against viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in US Patent No. 4,522,811.

It is especially advantageous to formulate oral or parenteral compositions in a unit dosage form to facilitate administration and to make the dosage more uniform. A unit dosage form, as used herein, refers to physically discrete units suitable as unit dosages for the subject to be treated; Each unit contains a predetermined amount of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical vehicle. The specification for the unit dosage forms of the invention is dictated and depends directly on the exclusive characteristics of the active compound and the specific therapeutic effect to be achieved and the limitations inherent in the technique of composing this type of active compound for treatment. of individuals

The pharmaceutical compositions may be included in a container, a container, a kit, or a dispenser together with instructions for administration.

Bacillus anthracis bacteria selection

Antibodies directed against Bacillus anthracis are useful in methods known in the art related to the location and / or quantification of a Bacillus anthracis bacteria in a sample. A Bacillus anthracis bacterium is detected in a sample by contacting the sample known or suspected of containing the bacterium with an IQPN antibody, and detecting the presence or absence of an antibodybacteria complex. The presence of a complex indicates that the sample contains Bacillus anthracis. Conversely, the absence of a complex indicates that the sample does not contain Bacillus anthracis. The sample is contacted with the IQN antibody in vitro. Alternatively, the sample is contacted with the IQN antibody in vivo.

An IQN antibody is used to isolate, ie detect, a Bacillus anthracis bacteria in a sample by conventional techniques, such as immunoaffinity, chromatography or immunoprecipitation. An IQN antibody is also used diagnosticly to control protein levels in a tissue as part of a clinical trial procedure, for example to determine the efficacy of a particular treatment regimen. Detection can be facilitated by the coupling (ie, physical binding) of the antibody to a detectable label. The term "labeled" with respect to the probe or antibody is intended to include direct labeling of the probe or antibody by coupling (ie, physical binding) of a detectable substance to the probe or antibody, as well as indirect labeling. of the probe or antibody for its reactivity with another reagent that is directly labeled. Examples of detectable substances include various enzymes, prosthetic groups, fluorescent materials, luminescent materials, bioluminescent materials, and radioactive materials. Examples of suitable enzymes include horseradish peroxidase, alkaline phosphatase, 1-galactosidase, or acetylcholinesterase; Examples of suitable prosthetic group complexes include streptavidin / biotin and avidin / biotin; Examples of suitable fluorescent materials include umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansyl chloride or phycoerythrin; An example of a luminescent material includes luminol; Examples of bioluminescent materials include luciferase, luciferin, and aequorin; and examples of suitable radioactive materials include 125I, 131I, 35S or 3H. Indirect labeling includes the detection of a primary antibody using a fluorescently labeled secondary antibody and the terminal labeling of a biotin DNA probe so that it can be detected with fluorescently labeled streptavidin.

The term "biological sample" is intended to include tissues, cells and biological fluids isolated from a subject, as well as tissues, cells and fluids present within a subject. Therefore, the term "biological sample" includes blood and a fraction or component of blood that includes blood serum, blood plasma, or lymph, dermal lesions, respiratory secretions, vesicular fluid or fluid cerebrospinal

A kit for detecting the presence of a Bacillus anthracis bacteria in a sample is also included in the invention. For example, the kit may comprise: a labeled compound or agent capable of detecting Bacillus anthracis (for example, IQNPA-1, IQNPA-2, IQNLF-1 or IQNLF-2) in a sample; a means to determine the amount of Bacillus anthracis in the sample; and a means to compare the amount of Bacillus anthracis in the sample with a pattern. The compound or agent is packaged in a suitable container. The kit also includes instructions for using the kit to detect a Bacillus anthracis bacteria in a sample.

The invention will be further illustrated in the following non-limiting examples:

Example 1: Preparation of human monoclonal antibodies against anthrax

The following general methods were used to prepare human monoclonal antibodies of the invention.

Reagents

HAM DMEM / F12 culture medium (Cambrex Biosciences 12-719F) is prepared with sodium bicarbonate 1300 mg / l (Merck), sodium pyruvate 55 mg / l (Fluka), mercaptoethanol 2.3 mg / l (Merck ), gentamicin 60 mg / l (Sigma), and 8% fetal bovine serum (Wisent). In fusion experiments, the medium is also supplemented with hypoxanthine 13.61 mg / l (Fluka) and thymidine 3.83 mg / l (Fluka). This medium is called DMEM / F12 of HAM / HT.

The hybridoma selection is performed with DMEM / F12 of HAM / HT supplemented with 1% supernatant containing IL-6 of the human bladder carcinoma cell line T24 (T24CM) and 0.4 M aminopterin (Sigma). Melting medium: ready-to-use hypo-osmotic buffer (Eppendorf).

Cell cultures

Thymoma EL-4 mutant cells, EL4 / B5, were routinely cultured in DMEM / F12 of HAM supplemented with 8% FCS at cell concentrations between 1 x 104 and 1 x 106 c / ml. If the cells grow larger than 1 x 10 6 c / ml they can lose their stimulatory activity of B cells. NS-1 murine myeloma cells, or K6HKB5 and PAI-1 xenohybrids are used as fusion partners for murine and human B cells, respectively . The cells were routinely cultured in DMEM / F12 HAM / HT supplemented with 10% FCS at concentrations between 5 x 104 and 15 x 105 cells per ml. One day before the fusion, the cultures were divided 1: 3 to create a logarithmic phase culture on the day of the fusion.

Preparation of a human T-cell / macrophage (TSN) supernatant

Freshly isolated mononuclear cells were centrifuged for 10 min at 2000 N / kg. Subsequently, B and T cells were separated according to a modification of the method described by Gutiérrez et al. (1979). The sediment was resuspended in 5 ml of 100% SIP. A 10 ml layer of 70% SIP was then placed, followed by a 25 ml layer of 50% SIP, over 100% SIP. The gradient was centrifuged for 10 min at 25,000 N / kg. The fraction enriched in T cells that remains at the interface between 70% and 50% SIP is collected and washed twice with HEM DMEM / F12 supplemented with 10% FCS. The washed cells are stimulated for 40-45 h in DMEM / F12 of HAM supplemented with 10% FCS, 5 g / ml PHA (Wellcome), and 10 ng / ml PMA (Sigma). Finally, the supernatant is collected, filtered through a 0.2 m membrane filter and stored in aliquots at -70 ° C.

B / EL-4 cell cultures

B / EL-4 cell cultures are prepared as described in Zubler et al. Briefly, crude or purified B cells are mixed with TSN and 50,000 B5 / EL-4 cells are irradiated (2500 RAD) in a final volume of 2001 DMEM / F12 HAM supplemented with 10% FCS in background tissue culture plates 96-well flat The optimal amount of TNS for each lot is established by titration. Normally 10% TSN is sufficient for optimal stimulation of human B cells, while 20% TSN is normally required for murine B cells. The cultures are incubated at 37 ° C with 5% CO2 and 100% humidity. Supernatants for immunoglobulin production are tested between day 8 and day 12.

Mononuclear cell isolation

Blood is drawn from an anthrax vaccine, 5-10 days after the last booster shot. The blood is diluted 50/50 in v / v with sterile PBS and centrifuged in Isopaque Ficoll (45 min, 400 g). The mononuclear cells resulting from this procedure are used fresh, or frozen in liquid N2.

Enrichment of human B cells

Isolated mononuclear cells (fresh or thawed) were enriched for B lymphocytes with the "intact B cells" protocol of an AutoMACS device (Miltenyi Biotec Inc., Auburn, CA). This B-cell enriched suspension was used fresh, or thawed from liquid N2.

CD40 lymphocyte expansion

Enriched B lymphocytes were expanded using the 3T6CD40L expansion system. Briefly, 3TCD40L cells were collected at a confluence of approximately 80%. The culture medium was rejected and EDTA buffer (6 ml in T75 or 3 ml in T25) was added. The cells were resuspended and irradiated with 100 Gy with a source of Cs137. The cells were washed in linoleum medium and counted. The required concentration in 24 wells: 8 x 10e4 ml; in 96 wells: 2 x 10e5 / ml. A similar amount and volume of B cells was added to the irradiated 3T6CD40L cells (i.e., 1: 1). 10 ng / ml rhIL-4 was added to the culture.

The culture medium was cooled, half volume + IL-4 every 3 days. Freshly irradiated 3T6CD40L cells (2 x 105 in 24 wells; 5 x 10e3 in 96 wells) were added every 7 days, or B cells were collected and transferred to a new plate with freshly irradiated 3T6CD40L (the same concentration as the initial culture ). After approximately 5 to 7 days, the characteristic B cell clusters were visible in the culture. Cultured B cells were harvested between days 5 and 11, carefully resuspending the cells with a Pasteur pipette.

Immunoadsorption procedure

6-well culture plates were incubated overnight with 4 ml per well of a solution containing 1 to 10 ug of antigen in 0.05 M sodium carbonate buffer, pH = 9.6. Then, the wells were washed with PBS and used directly for immunoadsorption experiments or stored at 20 ° C. Immunoadsorption was performed by incubating the enriched B cells in wells coated with the antigen for 1 to 2 hours at 37 ° C, 5% CO2 and 100% humidity. After this incubation, unbound cells were gently removed by three successive washes with PBS. Then the specific B cells bound to the antigen were recovered by incubating each well with 250 ul of PBS containing 1.1 mM EDTA-Na2 and 0.05% trypsin (Flow, cat. No. 16-893-49), pH = 7.5, for 2 minutes. Trypsin treatment was stopped by adding 5 ml of DMEM / F12 HAM supplemented with 10% FCS. Finally, the entire surface of the wells was rinsed with the medium using a Pasteur pipette to remove residual bound B cells mechanically.

Electrofusion

The electrofusion of lymphocytes to myeloma cells K6H6B5 is performed in a proportion ranging from 1: 0.5 to

1:10 in 60 µl of fusion medium in a microcamera. The B cell cultures were mixed with myeloma cells in 2 ml centrifuge tubes. Serum was removed from the cells by washing once with fusion medium. Then the cell suspension was centrifuged and the pellet was resuspended in 60 µl of fusion medium at room temperature. The entire cell suspension was pipetted into the internal space of a fusion chamber. The chamber consists of two stainless steel disc-shaped electrodes inserted in a Perspex box. The electrodes are separated by a Teflon spacer with variable diameter and a thickness of 0.50 mm. The alignment is produced by an alternating electric field of 1 MHz and 150 V / cm for 30 sg, followed immediately by a pulse peak of 1500 V / cm for 15 µs. Then a square pulse of high field of 3 kV / cm and a duration of 10 s was applied immediately, causing the cell membrane to rupture. Again, the alternate field is applied for 30 s to allow intermingling of the cells and to reseal the membranes. The contents of the fusion chamber were transferred to 20 ml of a selection medium (HAT) and were

cultured in 96-well microculture plates. On day 9, the cultures were studied to observe the growth of the hybridoma, and the supernatants were tested for immunoglobulin production.

PEG Fusion

Fusion of PEG with myeloma cells (K6H6 / B5) occurs in a 1: 1 ratio in 1-1.5 ml of a solution of PEG 4000 (50%) for 3 minutes. After two washing steps (stage one with DMEM / F12, and stage two with HT-medium), these fusion products were seeded in microtiter plates and cultured in selection medium (HAT) for 9 days.

Specific monoclonal antibodies to B. anthracis were selected by methods known in the art.

Example 2: In vitro evaluation of the neutralization activity of human monoclonal antibodies against anthrax

The ability of hMab IQNPA-1 and IQNPA-2 to neutralize anthrax toxin in vitro was determined. The target cells were exposed to the B. anthracis (AP) protective antigen that had been pre-incubated with the hMab IQNPA-1 and IQNPA-2 (pre-exposure). Alternatively, the target cells were incubated with AP before exposure to the hMab IQNPA-1 and IQNPA-2 (post-exposure).

Pre-exposure

Briefly, 50,000 RAW cells / well were cultured (target cells). AP and hMab were pre-incubated for 1 hr and then added to the RAW cell culture. The lethal factor (FL) was added and the culture was incubated for 12 to 15 hr at 37 ° C. WST-1 was added and the OD450 was measured at 1 and 2 hours. This experiment was repeated twice. The results are shown in figures 1 and 2.

Post-exposure

RAW264.7 cells (target cells) were incubated with PA for 2 hours or for 3 hours before the addition of hMab IQNPA-1 and IQNPA-2. FL and IQNPA-1 and IQNPA-2 were added, and the culture was incubated for 12 to 15 hours at 37 ° C. WST-1 was added and the OD450 was measured at 1 and 2 hours. This experiment was repeated twice. As shown in Figures 3-4, the IQNPA-1 and IQNPA-2 hMab were able to completely neutralize the lethal toxin after the protective antigen had bound to the target cells.

In other experiments, the target cells were exposed to AP. After one hour, hMab IQNLF-1 and IQNLF-2 recognizing FL were added to the culture and incubated for 15 hours at 37 ° C. WST-1 was added and the OD450 was measured at 1 hour. The results are shown in figure 5.

Example 3: In vitro comparison of the neutralization activity of human monoclonal antibodies against anthrax with the AVR414 serum

The neutralization activity of the hMab toxin IQNPA-1 and IQNPA-2 was compared with the activity of sera from individuals immunized with the human anthrax vaccine (AVA). This serum is called AVA414. The trial was conducted at the Center for Disease Control (Atlanta, Georgia). As shown in Figure 7, both hMab IQNPA-1 and IQNPA-2 were 25 x more effective in neutralizing anthrax toxin in the 99% protection assay.

Example 4: Determination of the affinity of human monoclonal antibodies against anthrax

The kinetics and binding affinity of the neutralizing hMab IQNPA-1 and IQNPA-2 were analyzed by the protective antigen of B. anthracis purified by surface plasmon resonance (BIAcore 3000, Sweden). The B. anthracis protective antigen was covalently immobilized on a CM5 detector chip through an amine group using the amine coupling kit (BIAcore). The kinetic parameters of antibody binding at different molar concentrations were measured, and evaluated with the BIA evaluation software. The results are shown in Table 1.

Table 1. Kinetic speeds and binding affinity of the huMab IQNPA-1 and IQNPA-2

<dl><dt>ka (1 / Ms) </dt><dd>kd (1 / s) Rmax (RU) KA (1 / M) KD (M) Chi2 </dd></dl>

<dl><dt>IQNPA-1 </dt><dd>1.6e5 1.93e-5 939 8.31e9 1,2e-10 89.5 </dd></dl>

<dl><dt>IQNPA-2 </dt><dd>1.78e5 1.81e-5 1090 9.86e9 1.01e-10 211 </dd></dl>

Example 5: Identification of the epitope recognized by monoclonal antibodies against anthrax

To determine the epitopes recognized by huMab, IQNPA-1 and IQNPA-2 were selected against the domains of the recombinant protective antigen. The following AP domains were selected: GST-1; GST1-2; GST1-2-3; GST1-2-3-4; GST3-4; and GST-4. The initial concentration of the huMab was: IQNPA-1, 0.77 mg / ml, and IQNPA-2, 0.65

5 mg / ml

Briefly, a microtiter plate was coated for each domain or combination of domains. The coating concentration was determined for the molar concentration of each domain. Each Mab was analyzed in duplicate at two initial dilutions of 1: 1000 and 1: 10,000. The trial was performed as follows:

1. Plates are coated with domains (50 µl per well) and incubated overnight at 4 ° C.

<dl>&lt;dt /&gt;<dd>10 2. Wash and block with 5% Blotto for 2 hours at 37 ° C. </dd></dl>

<dl><dt>3.</dt><dd> Wash and add diluted mAbs 1: 1000 (2 µl in 1,998 ml) and 1: 10,000 (200 µl of 1: 1000 in 1.8 ml) in 1% Blotto. 100 µl are added in the first two wells and serially diluted through the plate in 50 µl. Incubate overnight at 4 ° C.</dd></dl>

<dl><dt>4.</dt><dd> Wash. Goat anti-human IgG-HRP diluted 1: 6000 is added. Incubate for 1 hour at 37 ° C.</dd></dl>

<dl>&lt;dt /&gt;<dd>fifteen 5. It washes. ABTS is added and a reading is made at intervals of 10, 20 and 30 minutes.</dd></dl>

Plate lining concentrations

The coating of the plate with full length rAP was with 5 µg / ml. As it is an 83 kDa protein, this is equal to 6.02 x 10-11 moles per ml. Therefore, equimolar plate coatings have been calculated from their molecular weight (assuming an insignificant binding of the GST marker).

twenty Table 2

<dl><dt>Domain </dt><dd>PM in Daltons Coating Conc. (! g / ml) for 6.02 x 10-11 moles / ml Conc. Of the master protein domain solution (mg / ml) vol. of the stock solution required to coat a plate</dd></dl>

<dl><dt>GST 1 </dt><dd>57400 3.45 4.4 3.9 µl in 4.9961 ml </dd></dl>

<dl><dt>GST 1 to 2 </dt><dd>82600 4.97 1.6 15.5 µl in 4.9845 ml </dd></dl>

<dl><dt>GST 1 to 3 </dt><dd>94500 5.69 0.9 31.6 µl in 4.9684 ml </dd></dl>

<dl><dt>GST 1 to 4 </dt><dd>109000 6.56 1.3 25.2 µl in 4.9748 ml </dd></dl>

<dl><dt>GST 3 to 4 </dt><dd>53300 3.21 4.4 3.6 µl in 4.9964 ml </dd></dl>

<dl><dt>GST 4 </dt><dd>41400 2.49 4.6 2.7 µl in 4.9973 ml </dd></dl>

As shown in Table 3, both huMab only recognized the AP domain proteins that contained domain 4. Assays against GST-1, 1 to 2, and 1 to 3 were repeated with plaque coating proteins that previously they had not been used, at an initial dilution of the 1: 100 sample and with a control sample

25 positive to determine that there was no problem with the trial. Since the endpoint titers of the three domain proteins that contained domain 4 are approximately equal, this suggests that huMab bind specifically to only portion of domain 4 of the protective antigen proteins.

Table 3

<dl><dt>Domain </dt><dd>Endpoint Title </dd></dl>

<dl><dt>IQNPA-1 </dt><dd>IQNPA-2 </dd></dl>

<dl><dt>GST 1 </dt><dd> &lt;1:100* &lt;1:100* </dd></dl>

<dl><dt>GST 1 to 2 </dt><dd> &lt;1:100* &lt;1:100* </dd></dl>

<dl><dt>GST 1 to 3 </dt><dd> &lt;1:100* &lt;1:100* </dd></dl>

<dl><dt>GST 1 to 4 </dt><dd> 1:256000 1:128000 </dd></dl>

<dl><dt>GST 3 to 4 </dt><dd> 1:256000 1:256000 </dd></dl>

<dl><dt>GST 4 </dt><dd> 1:256000 1:128000 </dd></dl>

<dl><dt>* These tests were repeated with mAb at an initial dilution of 1: 100. </dt>&lt;dd /&gt;</dl>

Example 6: In vivo evaluation of the preexposure protective efficacy of human monoclonal antibodies against anthrax

The huMab IQNPA-1 and IQNPA-2 recognize the protective antigen of Bacillus anthracis. HuMab have been shown to neutralize the lethal toxin-induced cytotoxicity in an eukaryotic cell line in vitro. The objective of this study was to determine whether the inhibition of cytotoxicity observed in vitro correlates with protective efficacy in vivo.

Each of the huMab was administered to groups of 5 A / J mice (Harlan, United Kingdom) intraperitoneally at a standard dose of 200 µg in 0.1 ml of PBS (equal to 10 mg / kg body weight, assuming 20 g per mouse). A reference serum comprising assembled aliquots of macaque rhesus antiserum was administered

10 (references of animals 221 and 224) against rAP to groups of 5 mice at dose levels of 200 µg and 500 µg, each in 0.1 ml of PBS. The exposure was administered 2.5 hours after passive immunization by intraperitoneal injection. The exposure consisted of the B. anthracis STI strain, administered at a dose of 4.18 x104 spores / 0.1 ml.

Initial observation after immunization demonstrates that mice do not react adversely to

fifteen Strange IgG administered. Each of the huMab administered at a dose level of 200 µg totally protected the mice against exposure to injected anthrax (table 4). Macaque reference serum confers a 40% protection to any of the dose levels of 200 µg or 500 µg.

Table 4. Number of A / J mice that survive 10 days after exposure

<dl><dt>Receiving mouse </dt><dd>Element IgG concentration in the treatment groups (! G / mouse) Survivors / exposed number (%) on day 10 </dd></dl>

<dl><dt>1 </dt><dd>IQNPA-1 200 5/5 (100) </dd></dl>

<dl><dt>2 </dt><dd>IQNPA-2 200 5/5 (100) </dd></dl>

<dl><dt>3 </dt><dd>Reference element 200 2/5 (40) </dd></dl>

<dl><dt>4 </dt><dd>Reference element 500 2/5 (40) </dd></dl>

<dl><dt>5 </dt><dd>Without stimulating - 0/5 (0) </dd></dl>

twenty Example 7: Determination of ED50 in vivo of human monoclonal antibodies against anthrax

The objective of this study is to determine the relationship between the dose of huMab administered and the protection conferred by passive transfer in the mouse model, and identify an effective dose at 50% (ED50).

The study was conducted in female A / J mice of the same age (Harlan, United Kingdom). Each huMab was titrated in a dose-response curve to determine the ED50. Each huMab was diluted as described in Table 5, to achieve the required dose levels. Dosage levels of each huMab were administered in the range of 100 µg to 2.5 µg intraperitoneally (ip) to groups of 5 mice, at 2.5 hours before exposure to 4.64 x 104 spores / 0.1 ml (approximately 30 DLM) of the STI strain of B. anthracis. A reference serum comprising assembled aliquots of rhesus macaque antiserum against rAP (animal references 221 and 224) was administered to groups of 5 A / J mice in the same dose range. The survival of the mice was determined at 10

30 days after exposure.

Table 5. Preparation of serial dilutions of test and reference elements to achieve working dilutions

<dl><dt>Element </dt><dd>Concentrations Element (ml) PBS (ml) Dose </dd></dl>

<dl><dt>0.77 mg / ml </dt><dd>1.00 0.54 100 µg / 0.2 ml </dd></dl>

<dl><dt>IQNPA-1 </dt><dd>100 µg / 0.2 ml 0.50 0.50 25 µg / 0.1 ml </dd></dl>

<dl><dt>100 ! g / 0.2 ml </dt><dd>0.20 0.80 10! G / 0.1 ml </dd></dl>

<dl><dt>25 ! g / 0.1 ml </dt><dd>0.10 0.90 2.5 µg / 0.1 ml </dd></dl>

<dl><dt>0.65 mg / ml </dt><dd>1.00 0.30 100 µg / 0.2 ml </dd></dl>

<dl><dt>IQNPA-2 </dt><dd>100 µg / 0.2 ml 0.50 0.50 25 µg / 0.1 ml </dd></dl>

<dl><dt>100 ! g / 0.2 ml </dt><dd>0.20 0.80 100 µg / 0.1 ml </dd></dl>

<dl><dt>25 ! g / 0.1 ml </dt><dd>0.10 0.90 2.5 µg / 0.1 ml </dd></dl>

<dl><dt>Reference -221 </dt><dd>5.92 mg / ml 0.10 0.49 100 µg / 0.1 ml </dd></dl>

<dl><dt>Reference -224 </dt><dd>6.09 mg / ml 0.10 0.51 100 µg / 0.1 ml </dd></dl>

<dl><dt>Element of </dt><dd>100 µg / 0.1 ml 0.20 0.60 25 µg / 0.1 ml </dd></dl>

<dl><dt>reference gathered </dt><dd>100 µg / 0.1 ml 0.10 0.90 10! G / 0.1 ml </dd></dl>

<dl><dt>(221 + 224) </dt><dd>25 µg / 0.1 ml 0.10 0.90 2.5 µg / 0.1 ml </dd></dl>

Initial observation after immunization demonstrates that the mice did not react adversely to the huMab, although there was a transient adverse reaction against the macaque reference serum (attributed to the urea content). All mice recovered before exposure. Both huMab offered 5 protection in the 10-day trial in a dose-related manner. The protection offered was greater than that of the reference serum, which protected 60% of the animals at the higher dose level (Table 6). The effect of dilution of the huMab and the reference serum on survival over ten days is shown in Figures 7-9. The HuMab behaved very similarly, providing dose levels of 100 µg and 25 µg at 80% protection, and providing the dose level of 2.5 µg at 60% protection. Surprisingly, the level of

10 10 µg dose of each huMab provided minimal protection, although the group size was too small for this to be identified as a significant result other than the 2.5 µg dose level. A dose-response curve of the survival rate for huMab and the reference antiserum is shown (Figure 10).

Table 6. Number of A / J mice that survive 10 days after exposure

<dl><dt>Receiving mouse </dt><dd>Element IgG concentration in the treatment groups (! G / mouse) Survivors / exposed number (%) on day 10 </dd></dl>

<dl><dt>1 </dt><dd>IQNPA-1 100 4/5 (80) </dd></dl>

<dl><dt>2 </dt><dd> 25 4/5 (80) </dd></dl>

<dl><dt>3 </dt><dd> 10 1/5 (20) </dd></dl>

<dl><dt>4 </dt><dd> 2,5 3/5 (60) </dd></dl>

<dl><dt>5 </dt><dd>IQNPA-2 100 4/5 (80) </dd></dl>

<dl><dt>6 </dt><dd> 25 4/5 (80) </dd></dl>

<dl><dt>7 </dt><dd> 10 2/5 (40) </dd></dl>

<dl><dt>8 </dt><dd> 2,5 3/5 (60) </dd></dl>

<dl><dt>9 </dt><dd>Reference element 100 3/5 (60) </dd></dl>

<dl><dt>10 </dt><dd> 25 0/5 (0) </dd></dl>

<dl><dt>11 </dt><dd> 10 0/5 (0) </dd></dl>

<dl><dt>12 </dt><dd> 2,5 0/5 (0) </dd></dl>

fifteen There was little difference in time to death for each of the HuMab. At the 25 µg dose level, the huMab IQNPA-1 shows a delayed time to death compared to the huMab IQNPA-2, but an inverse result occurred at the 100 µg dose level.

The test design used in this study is a parallel-line test in which the efficacy of huMab is

twenty compare with the efficacy of the reference antiserum. Since the reference antiserum only protects mice at the higher dose level, the data could not be included in the statistical analyzes. When the huMab data were compared for linearity, the slopes generated by titrating each huMab did not differ significantly (p&gt; 0.05) (table 7). A probit analysis was performed on the slopes for each huMab (figure 11). The ED50 values ​​were derived for each huMab and its relative power was calculated (table 8). TO

25 From this calculation it can be seen that the huMab IQNAP-1 is half as potent as the huMab IQNPA-2.

Table 7. Summary of statistical analyzes of the pending dilution of vaccines with P values

<dl><dt>Statistical test </dt><dd>P value * </dd></dl>

<dl><dt>Constant </dt><dd> 0,476 </dd></dl>

<dl><dt>Dilution </dt><dd> 0,144 </dd></dl>

<dl><dt>1 compared to 2 </dt><dd> 0,741 </dd></dl>

<dl><dt>Equal earrings </dt><dd> 0,932 </dd></dl>

<dl><dt>* P value &lt;0.05 significantly different </dt>&lt;dd /&gt;</dl>

Table 8. Calculation of DE50 values ​​and relative power of huMab

<dl><dt>Element </dt><dd>DE50 (! G / ml) Relative potency of IQNPA-1 vs. IQNPA-2 </dd></dl>

<dl><dt>IQNPA-1 </dt><dd> 4,8511 0,5503 </dd></dl>

<dl><dt>IQNPA-2 </dt><dd> 2,6696 </dd></dl>

In summary, the result of this study demonstrates that both huMab provide protection against anthrax exposure in the mouse model. Probit analysis indicates that IQNPA-2 is twice as potent as IQNPA-1 (Figure 11).

Example 8: In vivo evaluation of protective efficacy after exposure of human monoclonal antibodies against anthrax

The objective of this study is to determine if huMab can be effective when administered by post-exposure therapy and, if so, to determine the therapeutic window of post-exposure.

200 µg of huMab A / J mice were administered intraperitoneally at 4 hours, 8 hours, 12 hours and 24 hours after exposure to the STI strain of B. anthracis, administered at a dose of 5.6 x 104 spores / 0.1 ml, equivalent to approximately 40 mean lethal doses (DLM). As shown in Table 9 and Figure 12, both huMab provided protection against infection. The slight advance that was observed on days 10 and 20 in the groups dosed with IQNPA-2 and IQNPA-1, respectively, at 8 h after exposure was not significant (1 animal of 5).

The huMab IQNPA antibodies tested did not differ significantly from each other in the protection they confer to recipient mice by passive transfer. Both IQNPA-1 and IQNPA-2 are protective in the mouse model when administered up to 24 hours after exposure to the STI strain of B. anthracis, and protection is maintained for 20 days after exposure, when it would be expected that the titers of passively transferred antibodies were decreasing. The reference element offers less protection to mice over time.

In summary, these studies demonstrate that the fully human monoclonal antibodies IQNPA-1 and 2 are useful drugs for the prophylactic treatment and post-exposure of anthrax.

Table 9. Number of surviving A / J mice 20 days after exposure

<dl><dt>No. of receiving mouse cage (n = 5) </dt><dd>Treatment groups Post-exposure treatment time Survivors / exposed number (%) on day 10 Survivors / exposed number (%) on day 20 </dd></dl>

<dl><dt>1 </dt><dd>IQNPA-1 200! G / mouse +4 h 5/5 5/5 </dd></dl>

<dl><dt>2 </dt><dd>+8 h 5/5 4/5 </dd></dl>

<dl><dt>3 </dt><dd>+12 h 5/5 5/5 </dd></dl>

<dl><dt>4 </dt><dd>+24 h 5/5 5/5 </dd></dl>

<dl><dt>5 </dt><dd>IQNPA-2 200! G / mouse +4 h 5/5 5/5 </dd></dl>

<dl><dt>6 </dt><dd>+8 h 4/5 4/5 </dd></dl>

<dl><dt>7 </dt><dd>+12 h 5/5 5/5 </dd></dl>

<dl><dt>8 </dt><dd>+24 h 5/5 5/5 </dd></dl>

<dl><dt>9 </dt><dd>Reference element (samples collected 221 + 224) +4 h 4/5 4/5 </dd></dl>

<dl><dt>10 </dt><dd>+8 h 4/5 3/5 </dd></dl>

<dl><dt>11 </dt><dd>+12 h 3/5 2/5 </dd></dl>

<dl><dt>12 </dt><dd>+24 h 1/5 0/5 </dd></dl>

In a second study, A / J mice were administered 180 µg of huMab intraperitoneally at 24 hours, 36 hours, and 48 hours, or 1000 µg of huMab intraperitoneally at 4 hours, 8 hours, 12 hours and 24 hours after exposure to the STI strain of B. anthracis, administered at a dose of 3.4 x 104 spores / 0.1 ml, equivalent to approximately 25 mean lethal doses (DLM). As shown in Table 10 and Figure 13, IQNPA-2 offered protection against infection for 10 days after exposure. Total protection was observed in mice dosed with 100 µg of the test element at 24 hours after exposure. Total protection was extended at 36 hours after exposure when the mice were dosed with 180 µg of the test element (table 10). Figure 13 shows the effect on the survival of mice when they are vaccinated at different times after exposure. The reference element offers less protection to mice over time.

Table 10. Number of A / J mice that survive 10 days after exposure

<dl><dt>No. of receiving mouse cage (n = 5) </dt><dd>Treatment groups Treatment time after exposure Survivors / exposed number (%) on day 10 </dd></dl>

<dl><dt>1 </dt><dd>IQNPA-1 180! G / mouse +24 h 5/5 </dd></dl>

<dl><dt>2 </dt><dd>+36 h 5/5 </dd></dl>

<dl><dt>3 </dt><dd>+48 h 3/5 </dd></dl>

<dl><dt>4 </dt><dd>IQNPA-2 100! G / mouse +4 h 4/5 </dd></dl>

<dl><dt>5 </dt><dd>+8 h 5/5 </dd></dl>

<dl><dt>6 </dt><dd>+12 h 5/5 </dd></dl>

<dl><dt>7 </dt><dd>+24 h 5/5 </dd></dl>

<dl><dt>8 </dt><dd>+36 h 2/5 </dd></dl>

<dl><dt>9 </dt><dd>+48 h 3/5 </dd></dl>

<dl><dt>10 </dt><dd>Reference element (samples collected 221 + 224) +8 h 3/5 </dd></dl>

<dl><dt>11 </dt><dd>+12 h 2/5 </dd></dl>

<dl><dt>12 </dt><dd>+24 h 1/5 </dd></dl>

Other realizations

Although specific embodiments have been described in detail herein, this has been done as an example only with

5 an illustrative objective and is not intended to be limiting with respect to the scope of the appended claims, which appear below. In particular, the inventors contemplate that various substitutions, alterations and modifications can be made in the invention without departing from the spirit and scope of the invention as defined by the claims. Other aspects, advantages and modifications are considered to be within the scope of the following claims. The claims presented are representative of the inventions

10 described herein.