Location of neutralizing epitopes defined by monoclonal antibodies generated against the outer capsid polypeptide, VP1, of foot-and-mouth disease virus A12.

The epitopes of six monoclonal antibodies generated against type A12 foot-and-mouth disease virus (FMDV) VP1 or its largest cyanogen bromide fragment (13 kd) were characterized. Five of these monoclonal antibodies neutralized viral infectivity. Solid-phase and competitive antigen binding assays using virion-derived antigens or a biosynthetic VP1 polypeptide identified two distinct neutralizing epitopes. One epitope was located between amino acid residues 145-168 of VP1 and the other between amino acids 169-179. The results indicate that antibodies reacting with two distinct areas of the VP1 polypeptide are capable of neutralizing FMD virus.