Characterization of monoclonal antibodies raised against a synthetic peptide capable of inducing a neutralizing response to human rhinovirus type 2

Synthetic peptides incorporating the derived amino acid sequence of VP2 residues 156 to 170 of human rhinovirus type 2 (HRV2) have previously been shown to elicit antibodies that neutralize virus infectivity. The proportion of virus-reactive antibodies present in polyclonal antisera to these peptides is, however, very low. Moreover, neutralization titrations of such antisera correlate poorly with other assays of either anti-virus or anti-peptide activity, suggesting the presence of antibodies with different specificities. To investigate these findings further, we produced a panel of monoclonal antibodies (MAbs) to VP2 peptides of residues 156 to 170 and characterized their reactions with a range of antigens in ELISA, precipitation and neutralization titrations. All the MAbs obtained recognized the homologous peptide, but could be divided into four main reaction groups according to their specificity for viral antigens. Antibodies in the first group recognized and neutralized native virus, apparently by preventing attachment to cells. A second group of MAbs bound to intact particles with similar affinities to the first group, but failed to neutralize infectivity. Antibodies in the third group recognized virus only after capsid distortions incurred by heating or by previous reaction with polyclonal antibodies. The fourth group comprised MAbs that were mainly peptide-specific. Some possible applications of anti-peptide MAbs to improving the design of peptide immunogens are considered.