DEVELOPMENT AND CHARACTERIZATION OF MONOCLONAL ANTIBODIES TO EBOLA VIRUS GLYCOPROTEIN

BALB/с mice were immunized with recombinant Ebola virus glycoprotein. Following selection, screening and cloning of murine hybridomas we obtained 5 genetically stable clones of monoclonal antibodies GPE118 (IgG), GPE274 (IgM), GPE325 (IgM), GPE463 (IgM), and GPE534 (IgG). These antibodies were isolated and purified from ascitic fluid of BALB/с mice using Protein G affinity chromatography (IgG) and euglobulin precipitation method (IgM). For the selection of at least 3 candidate antibodies to be tested in biological assays as components of an antibody cocktail for the prophylaxis and treatment of hemorrhagic fever, we carried out an immunochemical analysis of epitope specificity of isolated antibodies. Based on immunoblotting and sandwich ELISA data, it became evident that the epitope recognized by GPE 534 is different from GPE 118 and GPE 325 epitopes. The latter two antibodies also have different epitope specificity. It is evidenced from immunoblotting data as well as from binding data of these antibodies with intact and oxidized (partly deglycosylated) recombinant glycoprotein. For the studies of biological activity and the development of recombinant counterparts, we isolated 3 candidate high-affinity monoclonal antibodies GPE 534, GPE 118, and GPE 325.

1. Baize S., Pannetier D., Oestereich L. et al. Emergence of Zaire Ebola virus disease in Guinea // N. Engl. J. Med. 2014. Vol. 371. N 15. P. 1418–1425.

2. Geisbert T.W., Young H.A., Jahrling P.B., Davis K.J., Kagan E., Hensley L.E. Mechanisms underlying coagulation abnormalities in ebola hemorrhagic fever: overexpression of tissue factor in primate monocytes/macrophages is a key event // J. Infect. Dis. 2003. Vol. 188. N 11. P. 1618–1629.

3. Geisbert T.W., Hensley L.E., Jahrling P.B., Larsen T., Geisbert J.B., Paragas J., Young H.A., Fredeking T.M., Rote W.E., Vlasuk G.P. Treatment of Ebola virus infection with a recombinant inhibitor of factor VIIa/tissue factor: a study in rhesus monkeys // Lancet. 2003. Vol. 362. N 9400. P. 1953–1958.

4. Warren T.K., Warfield K.L., Wells J., Swenson D.L., Donner K.S., Van Tongeren S.A., Garza N.L., Dong L., Mourich D.V., Crumley S., Nichols D.K., Iversen P.L., Bavari S. Advanced antisense therapies for postexposure protection against lethal filovirus infections // Nat. Med. 2010. Vol. 16. N 9. P. 991–994.

5. Volchkov V.E., Feldmann H., Volchkova V.A., Klenk H.D. Processing of the Ebola virus glycoprotein by the proprotein convertase furin // Proc. Natl. Acad. Sci. USA. 1998. Vol. 95. N 10. P. 5762–5767.

6. Lee J.E, Saphire E.O. Ebolavirus glycoprotein structure and mechanism of entry // Future Virol. 2009. Vol. 4. N 6. P. 621–635.

7. Jahrling P.B., Geisbert J.B., Swearengen J.R., Larsen T., Geisbert T.W. Ebola hemorrhagic fever: evaluation of passive immunotherapy in nonhuman primates // J. Infect. Dis. 2007. Vol. 196. Suppl. 2. P. S400–S403.

8. Parren P.W., Geisbert T.W., Maruyama T., Jahrling P.B., Burton D.R. Pre- and postexposure prophylaxis of Ebola virus infection in an animal model by passive transfer of a neutralizing human antibody // J. Virol. 2002. Vol. 76. N 12. P. 6408–6412

9. Oswald W.B., Geisbert T.W., Davis K.J., Geisbert J.B., Sullivan N.J., Jahrling P.B., Parren P.W., Burton D.R. Neutralizing antibody fails to impact the course of Ebola virus infection in monkeys // PLoS Pathog. 2007. Vol. 3. N 1. e9.

10. Olinger G.G., Pettitt J., Kim D. et al. Delayed treatment of Ebola virus infection with plant-derived monoclonal antibodies provides protection in rhesus macaques // Proc. Natl. Acad. Sci. USA. 2012. Vol. 109. N 44. P. 18030–18035.

11. Qiu X., Audet J., Wong G. et al. Successful treatment of Ebola virus-infected cynomolgus macaques with monoclonal antibodies // Sci. Transl. Med. 2012. Vol. 4. N 138. P. 138–181.

12. Qiu X., Wong G., Audet J. et al. Reversion of advanced Ebola virus disease in nonhuman primates with Zmapp // Nature. 2014. Vol. 514. N 7520. P. 47–53.

13. Sveshnikov P., Kiselev V. Methods, kits and compositions for the development and use of monoclonal antibodies specific to antigens of low immunogenicity. PCT/RU2004/ 000373, Filing date : 24.09.2004.

14. Kohler G., Milstein C. Continuous cultures of fused cells secreting antibody of predefined specificity // Nature. 1975. Vol. 256. N 5517. P. 495–497.

15. García-González M., Bettinger S., Ott S., Olivier P., Kadouche J., Pouletty P. Purification of murine IgG3 and IgM monoclonal antibodies by euglobulin precipitation // J. Immunol. Methods. 1988. Vol. 111. N 1. P. 17–23.

16. Westwood J, Thomas P. Studies on the structure and immunological activity of carcinoembryonic antigen — the role of disulphide bonds // Br. J. Cancer. 1975. Vol. 32. N 6. P. 708.

17. Nakane P.K., Kawaoi A. Peroxidase-labeled antibody. A new method of conjugation // J. Histochem. Cytochem. 1974. Vol. 22. N 12. P. 1084–1091.

18. Ponomarenko J., Vaughan K., Sette A., Maurer-Stroh S. Conservancy of mAb epitopes in Ebolavirus glycoproteins of previous and 2014 outbreaks // PloS Curr. 2014. Vol. 6.