Monoclonal antibodies to the ClfA protein and method of use in treating or preventing infections
Monoclonal antibodies which can bind to the ClfA protein and which are generated from binding subdomains or active fragments of the ClfA protein from Staphylococcus aureus , including the active fragments proteins from its fibrinogen binding domain such as Clf40 protein, the Clf33 protein, or ClfA N3, are provided which can be useful in the treatment and protection against infection from staphylococcal bacteria such as Staphylococcus aureus . In addition, medical instruments can be treated using the monoclonal antibodies of the invention in order to reduce or eliminate the possibility of their becoming infected or further spreading the infection. In particular, the antibodies of the present invention are advantageous because they can prevent adherence of the bacteria to host cells by impairing or inhibiting the ability of S. aureus ClfA to bind to fibrinogen or fibrin, and thus can be utilized in methods or treating or preventing staphylococcal inventions.
1. A monoclonal antibody which binds to an epitope that is recognized by a monoclonal antibody selected from the group consisting of monoclonal antibodies 12-9 and 13-2.
2. The antibody according to claim 1 wherein said antibody recognizes a protein selected from the group consisting of S. aureus Clf40 protein, the S. aureus Clf33 protein, and the S. aureus ClfA N3 protein.
3. The antibody according to claim 1 , wherein said antibody treats S. aureus infection in a human or animal.
4. The antibody according to claim 1 , wherein said antibody inhibits binding of staphylococcal bacteria to fibrinogen or fibrin.
5. The antibody according to claim 1 , wherein said antibody is suitable for parenteral, oral, intranasal, subcutaneous, aerosolized or intravenous administration in a human or animal.
6. The antibody according to claim 1 where in the monoclonal antibody is of a type selected from the group consisting of murine, chimeric, humanized and human monoclonal antibodies.
7. The antibody according to claim 1 wherein the antibody is a single chain monoclonal antibody.
8. The antibody according to claim 1 that is raised against a protein having an amino acid sequence selected from the group consisting of SEQ ID NO:2 and SEQ ID NO:4.
9. The antibody according to claim 8 wherein the protein has an amino acid sequence encoded by a nucleic acid sequence according to SEQ ID NO:1 or SEQ ID NO:3, or degenerates thereof.
10. The antibody according to claim 1 having a variable light chain having the amino acid sequence SEQ ID NO: 18 and a variable heavy chain having the amino acid sequence SEQ ID NO: 20.
11. The antibody according to claim 1 having a variable light chain sequence encoded by a nucleic acid having the sequence SEQ ID NO: 17, or degenerates thereof, and a variable heavy chain sequence encoded by a nucleic acid having the sequence of SEQ ID NO: 19, or degenerates thereof.
12. Isolated antisera containing an antibody according to claim 1 .
13. A diagnostic kit comprising an antibody according to claim 1 and means for detecting binding by that antibody.
14. The diagnostic kit according to claim 13 wherein said means for detecting binding comprises a detectable label that is linked to said antibody.
15. A method of diagnosing an infection of S. aureus comprising adding an antibody according to claim 1 to a sample suspected of being infected with S. aureus , and determining if antibodies have bound to the sample.
16. A pharmaceutical composition for treating an infection of S. aureus comprising an effective amount of the antibody of claim 1 and a pharmaceutically acceptable vehicle, carrier or excipient.
17. A method of treating an infection of S. aureus comprising administering to a human or animal patient an effective amount of an antibody according to claim 1 .
18. A method of making the monoclonal antibody of claim 1 comprising raising a hybridoma against an isolated protein selected from the group consisting of S. aureus Clf40, Clf33 and ClfA N3 and screening said hybridoma for reactivity with said epitopes.
19. The antibody according to claim 1 that has the ability to bind to the amino acid sequence of SEQ ID NO:2.
20. The antibody according to claim 1 that has the ability to bind to an amino acid sequence coded by the nucleic acid sequence of SEQ ID NO:1 or degenerates thereof.
21. The antibody according to claim 1 further comprising a physiologically acceptable antibiotic.
22. The antibody according to claim 1 that is cross-reactive to multiple strains of S. aureus.
23. The antibody according to claim 1 which recognizes the A domain of S. aureus ClfA protein.
24. The antibody according to claim 1 having a variable light chain having the amino acid sequence SEQ ID NO:6 and a variable heavy chain having the amino acid sequence SEQ ID NO:8.
25. The antibody according to claim 1 having a variable light sequence encoded by a nucleic acid sequence having the sequence SEQ ID NO:5, or degenerates thereof, and a variable heavy chain encoded by a nucleic acid having the sequence SEQ ID NO:7, or degenerates thereof.
26. The antibody according to claim 1 having a variable light chain having the amino acid sequence SEQ ID NO:10 and a variable heavy chain having the amino acid sequence SEQ ID NO:12.
27. The antibody according to claim 1 having a variable light sequence encoded by a nucleic acid sequence having the sequence SEQ ID NO:9, or degenerates thereof, and a variable heavy chain encoded by a nucleic acid having the sequence SEQ ID NO:11, or degenerates thereof.