Human monoclonal antibodies against
View Patent ↗Isolated human monoclonal antibodies which bind to Anthrax protective antigen are disclosed. The human antibodies can be produced in a non-human transgenic animal, e.g., a transgenic mouse, capable of producing multiple isotypes of human monoclonal antibodies by undergoing V-D-J recombination and isotype switching. Also disclosed are derivatives of the human antibodies (e.g., bispecific antibodies and immunoconjugates), pharmaceutical compositions comprising the human antibodies, non-human transgenic animals and hybridomas which produce the human antibodies, and therapeutic and diagnostic methods for using the human antibodies.
1. An isolated monoclonal antibody comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO:2, wherein the antibody specifically binds to human B. anthracis protective antigen.
2. An isolated monoclonal antibody comprising a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO:4, wherein the antibody specifically binds to B. anthracis protective antigen.
3. An isolated monoclonal antibody or antigen binding portion thereof comprising:
(a) heavy chain variable regions CDR1, CDR2, and CDR3 comprising the amino acid sequences of SEQ ID NO: 24, 22, and 20, respectively; and
(b) light chain variable regions CDR1, CDR2, and CDR3 comprising the amino acid sequences of SEQ ID NO: 30, 28, and 26, respectively;
wherein the antibody binds to B. anthracis protective antigen.
4. An isolated monoclonal antibody or antigen binding portion thereof, comprising a heavy chain variable region and a light chain variable region, wherein the sequences of the heavy chain variable region and the light chain variable region, respectively, comprise the sequences of SEQ ID NOs: 2 and 4, and wherein the antibody specifically binds to B. anthracis protective antigen.
5. The monoclonal antibody of claims 1 , 2 , 3 , or 4 , wherein the antibody is human.
6. An isolated monoclonal antibody which specifically binds with an affinity of at least 10 7 M −1 to an epitope on B. anthracis protective antigen recognized by the antibody of claim 3 or 4 .
7. The antibody of claim 3 , which neutralizes a Bacillus anthracis toxin in a toxin neutralization assay.
8. The antibody of claim 7 , where the toxin neutralization assay employs a cell from a tissue selected from nervous, heart, lung, and bone marrow.
9. The antibody of claim 8 , where the cell is a macrophage.
10. The antibody of claim 3 , comprising a human IgG heavy chain and a human kappa light chain.
11. The antibody of claim 3 , comprising an IgG1 or IgG3 heavy chain.
12. The antibody of claim 3 , wherein the antibody is a Fab fragment or a single chain antibody (scFv).
13. The antibody of claim 7 wherein the ability of the antibody to neutralize the toxin requires binding to Fc receptor.
14. The antibody of claim 3 , wherein the antibody exhibits higher affinity for PA63 over PA 83 according to standard ELISA.
15. The antibody of claim 3 , wherein the antibody:
(1) does not bind PA 83 at 1 μg/ml, OD 405 nm 0.2 or less according to standard ELISA;
(2) does not block anthrax lethal factor or edema factor binding to PA.
16. The antibody of claim 3 , wherein the antibody does not compete with an anti-PA antibody selected from murine 1G3, murine 2D5 and murine 14B7 in binding to PA 63.
17. A method of inhibiting a physiological activity of B. anthracis protective antigen, comprising contacting B. anthracis protective antigen with an effective amount of the antibody of claim 3 , such that the physiological activity of the protective antigen is inhibited.
18. A method of neutralizing a B. anthracis toxin, comprising contacting B. anthracis protective antigen with an effective amount of the antibody of claim 3 , such that the toxin is neutralized.
19. A method of treating anthrax in a host infected with B. anthracis , comprising administering to the host the antibody of claim 3 in an amount effective to treat anthrax.
20. The method of claim 19 , further comprising administering an additional therapeutic agent.
21. The method of claim 20 , wherein the additional therapeutic agent is selected from an antibiotic and vaccine.
22. A method for detecting the presence of B. anthracis protective antigen in a sample comprising:
contacting the sample with the antibody of claim 3 , under conditions which allow for formation of a complex comprising the antibody and the protective antigen; and
detecting the formation of the complex.
23. A pharmaceutical composition comprising the antibody of claim 3 , and a pharmaceutically acceptable carrier.
24. A method for treating or preventing anthrax in a patient in need of such treatment, comprising the step of administering the antibody of claim 3 in a dosage from 0.1 mg/kg to 100 mg/kg.
25. A method for treating or preventing anthrax in a patient in need of such treatment, comprising the step of administering the antibody of claim 3 in a dosage from 0.3 mg/kg to 50 mg/kg.
26. A method for treating or preventing anthrax in a patient in need of such treatment, comprising the step of administering the antibody of claim 3 in a dosage from 1 mg/kg to 12 mg/kg.
27. The method according to claim 24 , wherein the patient is infected with B. anthracis.
28. The method according to claim 27 , wherein the patient exhibits neutropenia.
29. The method according to claim 27 , wherein the patient exhibits one or more signs and/or symptoms of anthrax infection.
30. The method according to claim 24 , wherein the patient is not infected with B. anthracis.
31. The method according to claim 24 , wherein the dosage is administered subcutaneously or intravenously.
32. The method according to claim 24 , wherein one or more additional dosages is administered.