Abstract
We have selected neutralization escape mutants by using a monoclonal antibody (nt-MAb) against a sequential epitope between amino acids 93 through 104 (neutralization antigenic site I) of poliovirus type 1 Mahoney. The majority of mutants were also resistant against five strain-specific nt-MAbs which recognized conformation-dependent epitopes, suggesting that the neutralization antigenic site I must be involved in the formation of such epitopes. An analysis of all mutants by the binding of nt-MAbs and by isoelectric focusing of VP1 allowed discrimination of five classes of mutants. Sequence analysis of mutant RNAs revealed point mutations and deletions in the antibody-binding site.