The Murine Antibody Response to Lactate Dehydrogenase-elevating Virus

Mice infected with lactate dehydrogenase-elevating virus (LDV) were found to produce high titres of IgG anti-LDV antibodies that remained elevated for more than l year. This response, which was T-dependent, showed a striking preponderance of IgG2a with, from one strain to another, variable proportions of IgG2b and IgG3 but always very little IgG1. The binding of these antibodies to viral protein blots showed a major reaction with VP3, the heterogeneous glycosylated material of the viral envelope. A minor reaction was also noted with VPI, the nucleocapsid protein, but no antibodies were detected against VP2, the non-glycosylated nvelope protein of LDV. A similar preponderance of anti-VP3 antibodies was also observed in a large set of anti-LDV hybridomas. Analysis of VP3 with monoclonal antibodies uggested that, despite its heterogeneity, this material has a common polypeptide moiety that apparently carries two major epitopes