Development and characterization of monoclonal antibodies to Ebola virus glycoprotein

Abstract

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