Antigenic comparison of the polypeptides of foot-and-mouth disease virus serotypes and other picornaviruses

Abstract

The cross-reactivity of proteins coded for by the seven serotypes of foot-and-mouth disease virus (FMDV) was assessed by reaction of infected cell lysates with polyclonal and monospecific antisera against the structural and nonstructural proteins of FMDV type Al 2 strain 119ab. It was shown that the homologous polypeptides from most serotypes are antigenically related. The least cross-reactivity occurred between VP1, VP3, and the protease (3C) of type Al 2 and South African Territories types 1 and 3. There was also a reduced degree of reactivity of Al 2 VP1 serum with VP1 from some A subtypes and the other serotypes. Comparison of FMDV proteins with polypeptides from other picornaviruses by a radioimmune binding assay revealed a low level of reactivity of antisera against some Al 2 poly-peptides with encephalomyocarditis virus (EMCV) infected cell lysates but no reactivity with bovine enterovirus type 1 and swine vesicular disease virus infected cells. The same EMCV proteins were immunoprecipitated by the various reactive Al 2 antisera, but the reaction was abolished if the lysate from EMCV infected cells was denatured prior to immunoprecipitation.