Reverse Genetic Analysis of Adaptive Mutations Within the Capsid Proteins of Enterovirus 71 (EV-A71) Strains Necessary for Infection of CHO-K1 Cells

Previous studies had described the adaptation of Enterovirus 71 (EV-A71) strains that enabled entry and viral replication in Chinese Hamster Ovary (CHO) cell line. In this study, we described two EV71 strains, EV71:TLLm and EV71:TLLcho, that productively infect CHO-K1 cells. We evaluated various VP1 and VP2 mutations in these two CHO-adapted EV-A71 strains to assess their contribution to the phenotype of CHO cell adaptation. Our current findings do not fully support previous observations and strongly suggest the need for cooperation of various adaptive mutations in the capsid to enable successful EV-A71 infection of a different host species.