Antigenic sites of poliovirus type 3 eliciting IgA monoclonal antibodies in orally immunized mice

A panel of neutralizing IgA monoclonal antibodies was produced from mice or ally inoculated with poliovirus type 3 Sabin and cholera toxin as adjuvant. Low levels of neutralizing antibodies were elicited in mice after several boosts, but only in the presence of cholera toxin. Characterization of IgA MAbs by neutralization-escape virus mutants showed that all but one neutral izing MAbs against type 3 poliovirus were directed to antigenic site N-AgII I, which was previously found by us to be the major target of mucosal immun e response to Sabin 1 in the mouse. Our data indicate that residue 236 of V P3, not previously reported, is also involved in forming site N-AgIII in ad dition to formerly described VP3 (aa 58-59) and VP1 (aa 286-290) residues. Unlike poliovirus type 1 IgA MAbs, all IgA MAbs herein described neutralize d the wild-type parental poliovirus. (C) 2001 Academic Press.