Epitopes on glycoprotein C of bovine herpesvirus-1 (BHV-1) that allow differentiation between BHV-1.1 and BHV-1.2 strains.

In cattle, bovine herpesvirus-1 (BHV-1) can cause a mild genital disease known as infectious pustular vulvovaginitis (IPV) and a more severe respiratory disease known as infectious bovine rhinotracheitis (IBR). On the basis of epidemiological data, it has been proposed that these diseases are caused by strains with different genotypes (IBR by BHV-1.1 and IPV by BHV-1.2 strains). By using a panel of 237 BHV-1 isolates, a monoclonal antibody (MAb 71) was found that failed to react with all 54 putative IPV strains in the panel, and another MAb (77) was found that did not react with 16 of these 54 IPV strains. Because MAbs 71 and 77 also failed to react with a BHV-1.1 glycoprotein C (gC)-deletion mutant, it was hypothesized that both MAbs recognize BHV-1.1 gC. By marker-rescue experiments and by expressing fragments of the BHV-1.1 gC gene in recombinant baculoviruses, it was shown that both MAbs indeed recognize BHV-1.1 gC. MAb 71 recognizes the N-terminal half and MAb 77 recognizes the C-terminal half of BHV-1.1 gC. In a PEPSCAN analysis with 12-mer oligopeptides, MAb 71 reacted with overlapping peptides containing gC amino acid residues 75-80 and MAb 77 did not react in this analysis. The differences in gC found in this study may contribute to the biological differences between BHV-1.1 and BHV-1.2.