Mapping of linear antibody epitopes of the glycoprotein of VHSV, a salmonid rhabdovirus

Antibody Linear epitopes of the glycoprotein G (gpG) of the viral haemorrha gic septicaemia virus (VHSV), a rhabdovirus of salmonids, were mapped by pe pscan using overlapping 15-mer peptides covering the entire gpG sequence an d ELISA with polyclonal and monoclonal murine and polyclonal trout antibodi es. Among the regions recognized in the pepscan by the polyclonal antibodie s (PAbs) were the previously identified phosphatidylserine binding heptad-r epeats (Estepa & Coll 1996; Virology 216:60-70) and leucocyte stimulating p eptides (Lorenzo et al. 1995; Virology 212:348-355). Among 17 monoclonal an tibodies (MAbs), only 2 non-neutralizing MAbs, I10 (aa 139-153) and IP1H3 ( aa 399-413), could be mapped to specific peptides in the pepscan of the gpG . Mapping of these MAbs was confirmed by immunoblotting with recombinant pr oteins and/or other synthetic peptides covering those sequences. None of th e neutralizing MAbs tested reacted with any of the gpG peptides. Previously mapped MAb resistant mutants in the gpG did not coincide with any of the L inear epitopes defined by the pepscan strategy, suggesting the complementar ity of the 2 methods for the identification of antibody recognition sites.