Adaptation of primate cell-adapted hepatitis A virus strain HM175 to growth in guinea pig cells is independent of mutations in the 5 ' nontranslated region

Previous studies of hepatitis A virus (HAV) genotypes after adaptation of w ild-type virus to growth in cell cultures of primate origin identified dete rminants for growth in cell culture in the viral 2B and 2C protein-coding r egions of the genome and demonstrated that an increased growth efficiency i n a particular cell line was achieved by subsequent mutations in the 5' non translated region (5'NTR). The results reported in this study demonstrate t hat the passage of HAV adapted to primate BS-C-1 cells in guinea pig cells resulted in increased growth efficiency in the rodent cells and decreased g rowth efficiency in BS-C-1 cells. This adaptation occurred without mutation in the 5'NTR, but the viral 2B and 2C proteins seem to play a role during adaptation to the new environment, as one mutation occurred in each protein . Although the data presented here do not clearly identify which region of the viral genome underwent mutations to improve the interaction of the viru ses with guinea pig proteins, they do confirm that the 5'NTR is not the onl y region responsible for providing host cell-specific information.