Molecular Aspects of the Antigenic Variation of Swine Vesicular Disease and Coxsackie B5 Viruses

Abstract

The antigenic variation of swine vesicular disease virus (SVDV) and Coxsackie B5 virus (CB5) was examined at the molecular level by analyzing the protein and nucleic acid of the virus particles. The tryptic peptides of carboxymethylated 35S-methionine labeled virus particles were very similar, although some minor differences were apparent. Competition hybridization experiments confirmed that there is variation in the RNA sequence of antigenically distinct SVD viruses and some limited homology of these RNA to the CB5 virus RNA. Competition hybridization using mixtures of 2 RNA as competitors showed that the sequences shared by the CB5 virus RNA were largely the same as those shared by the CB5 virus RNA and the SVDV RNA. Similar experiments with the SVDV RNA established that the homologous regions in these RNA were also shared. Thermal denaturation curves of SVDV RNA-RNA hybrids generally supported the competition hybridization results, but the hybrids between SVDV RNA and CB5 virus RNA were shown to be mismatched. RNase T1 oligonucleotide maps of the virus RNA were also compared to obtain another measure of relatedness. A number of long oligonucleotides were shared by the SVDV RNA, but few of these were found in either of the CB5 RNA. Further ways of investigating the antigenic variation of SVDV at the molecular level are discussed.