Identification of the Location of Antigenic Sites of Swine Vesicular Disease Virus with Neutralization-resistant Mutants

Neutralization sites on swine vesicular disease virus (SVDV) have been identified by sequence analysis of neutralization-resistant mutants. Eight neutralizing monoclonal antibodies (MAbs) were produced and neutralization-resistant mutants were selected with the MAbs. Resistance of the mutants to neutralization was shown using the stab-neutralization method, and the results indicated the presence of five neutralization sites on the virus. The location of each site was identified from amino acid changes resulting from nucleotide substitutions in the mutants, and designated site 1 (residues 87 and 88 of VP1), 2a (residue 163 of VP2), 2b (residue 154 of VP2), 3a (residue 272 and 275 of VP1, 60 of VP3) and 3b (residues 70 and 233 of VP2, 73 and 76 of VP3). The locations of the amino acids substitutions at each site formed a cluster on a computer-simulated three-dimensional model of SVDV and were exposed to the surface of the virion.