Characterization of the antigenic, immunogenic, and pathogenic variation of infectious bursal disease virus due to propagation in different host systems (bursa, embryo, and cell culture). II. Antigenicity at the epitope level.

Antigenic variation of infectious bursal disease virus (IBDV) due to propagation in different host systems (bursa of Fabricius, embryos, or cell cultures) was determined by enzyme-linked immunosorbent assay (indirect and antigen capture) and western blot analysis. To conduct this study, we used 27 non-neutralizing anti-VP(2) monoclonal antibodies, a reference panel of nine neutralizing monoclonal antibodies, and 13 neutralizing anti-IBDV chicken polyclonal antibodies. Changes occurred in neutralizing, cross-reactive, conformation-dependent epitopes on the VP(2) protein of IBDV. Interestingly, non-neutralizing, cross-reactive, conformation-dependent and confirmation-independent epitopes also changed on VP(2). These epitope changes were directly associated with the method used to propagate IBDV. These results demonstrate that different host systems may play an important role in the antigenicity of IBDV.