Analysis of Serotype-specific Neutralization Epitopes on VP7 of Human Rotavirus by the Use of Neutralizing Monoclonal Antibodies and Antigenic Variants

Abstract
Summary We analysed serotype-specific antigens of human rotavirus (HRV) by the use of neutralizing monoclonal antibodies (N-MAbs). The reactivity patterns of 12 serotype-specific N-MAbs against 15 HRV strains in a neutralization test revealed great intraserotypic antigenic variation especially those belonging to serotypes 2, 3 and 4. On the basis of the protein specificity of the antibodies examined, it was suggested that whereas serotype 2-specific neutralization epitopes were present on both VP3 and VP7 outer capsid proteins, serotype 1-, 3- and 4-specific neutralization epitopes were located on VP7. Serotype-specific neutralization epitopes on VP7 of the serotype 1 HRV KU strain were analysed further using mutants of the KU strain resistant to different serotype 1-specific N-MAbs. The result suggested the presence of at least five operationally overlapping neutralization epitopes on VP7 of the KU strain, which collectively constituted a single large neutralization domain.