Genetic and antigenic variance of foot-and-mouth disease virus type Asia1.

The capsid protein encoding genes of five recent type Asia1 foot-and-mouth disease virus isolates, representative of three genotypes, were sequenced. The deduced amino acid sequences were aligned to each other and to two published sequences. The sequence differences suggested different antigenic properties of the isolates. One isolate was used to generate monoclonal antibodies (mAbs) which were analyzed for neutralizing activity and reactivity with trypsinized virus. Trypsin removes the major antigenic sites located at VP1. The five virus isolates formed three reaction patterns with the mAbs, irrespective of their genotype. Combination of all data allowed to suggest the location of the epitope of each antibody: the VP1 G-H and the VP2 B-C loop, the VP3 B-B knob, and the N-terminus of VP2, respectively, were involved.