ISOLATION OF ESCAPE MUTANTS OF A HYBRID POLIOVIRUS WITH THE AID OF INSERT-SPECIFIC POLYCLONAL ANTIBODIES

We constructed a hybrid type 1/type 3 poliovirus comprising the BC-loo p of capsid protein VP1 of PV3/Finland/60212/84 and the rest derived f rom PV1/Mahoney, and cultured the virus in the presence of diluted rab bit antiserum to PV3/Finland/60212/84. Several strains isolated under this selection showed point mutations in the inserted type 3 polioviru s sequence but only in one case in the flanking PV1/Mahoney-derived RN A. These results indicate that, with the use of recombinant cDNA techn ology, it may be possible to study molecular interactions of defined r egions of virus capsid proteins with neutralizing polyclonal antibodie s.