Detection by monoclonal antibodies of an antigenic determinant critical for poliovirus neutralization present on VP1 and on heat-inactivated virions.

Hybridoma cell lines were established against poliovirus type 1 (Mahoney) heat-denatured virions (C particles). Each anti-C monoclonal antibody (McAb) immunoprecipitated specifically one of the individualized poliovirus capsid polypeptides VP1, VP2, or VP3. One of the anti-C McAb (C-3), reacting with VP1, neutralized homologous virus and immunoprecipitated infectious D particles. Its properties have been compared to those of a neutralizing anti-D McAb (D-Ic). In contrast with the C-3 antigenic site, the D-Ic epitope was not present on C particles nor on individualized structural polypeptide. This demonstrates that C-3 and D-Ic epitopes represent two independent antigenic determinants, both critical for poliovirus neutralization.