Identification of an antigenic site in the neutralization of type 3 poliovirus.

Antigenic mutants of type 3 poliovirus were obtained by picking plaques formed in the presence of neutralizing monoclonal antibodies. All the mutants were clustered into a single operationally defined antigenic site based on their reactions with a panel of antibodies. Most of the mutations were shown to be located in the virion protein VP1 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and oligonucleotide mapping, and 15 of 16 mutants had single-point mutations in a region of VP1 encompassing only eight amino acids, a finding suggesting that this is a major target for the neutralization of the virus. Whereas other areas may also be required, it is likely that this region is a necessary component of a vaccine of any kind.