Characterization of homotypic and heterotypic VP7 neutralization sites of rhesus rotavirus.

The gene 9 nucleotide sequence was determined for rhesus rotavirus and each of 14 viral variants selected for their resistance to neutralizing monoclonal antibodies. Each variant contains a single gene 9, VP7, mutation which permits viral growth in the presence of the antibody. Variant mutations were identified in two distinct neutralization regions. Region A was identified by monoclonal antibodies that are involved in both serotype-specific and serotype cross-reactive neutralization. Region C was identified by serotype-specific neutralizing monoclonal antibodies. Heterotypic neutralizing monoclonal antibody 57-8 selected variants with a mutation at amino acid 94 in the A region, the same amino acid location selected by serotype-specific monoclonal antibodies. Monoclonal antibody 3 selected a VP7 mutation at amino acid 99 resulting in additional N-linked glycosylation of the VP7 protein. Despite the added VP7 glycosylation, variant v3 was not broadly resistant to additional VP7-specific neutralizing monoclonal antibodies.