Epitope evolution in poliovirus maturation

Eight monoclonal antibodies specific for native (N) poliovirus antigen all recognized empty capsids extracted from infected HeLa cells; only three of them recognized 14S particles. The facts point to the existence of two different epitopes N1 and N2, only one of which (N1) is present on 14S particles (these observations confirm and extend findings by EMINI et al). Another epitope of 14S particles is recognized by antibodies to heated (H) poliovirus antigen. Infected cell extract-catalyzed polymerization of 14S particles yielded mainly empty capsids carrying the N1 and N2, but no H epitopes.