CROSS-REACTIVE, SEROTYPE-SPECIFIC AND MONOTYPE-SPECIFIC NEUTRALIZATION EPITOPES ON VP7 OF SEROTYPE G3 AND G5 PORCINE ROTAVIRUS STRAINS

VP7 specific monoclonal antibodies raised against serotype G5 porcine rotavirus strains isolated in Venezuela showed either a serotype G5- o r monotype-specific pattern of reactivity by neutralization against a panel of 53 group A rotavirus isolates representative of all establish ed G serotypes. Monoclonal antibodies raised against two G3 porcine st rains were either specific for a subset of porcine G3 strains or react ive with another subset of porcine G3 strains and with most G5 strains . Neither were reactive with G3 strains from other species. Analysis o f neutralization resistant mutants selected with these monoclonal anti bodies indicated that epitopes defined by cross-reactive, serotype- an d monotype-specific monoclonal antibodies overlap functionally and tha t binding and neutralization by these antibodies depended on specific amino acid residues in the region A or C of VP7. Results indicate that a high degree of monotypic variation occurs among G5 and G3 porcine r otavirus strains and the existence of at least one common epitope shar ed by G5 and G3 porcine strains, in the major neutralization domain of these VP7s.