Establishment of a novel hepatitis B virus culture system using immortalized human hepatocytes.

Recent development of hepatitis B virus (HBV) culture systems has made it possible to analyze the almost all steps of the viral life cycle. However, the reproducibility of interaction between HBV and host cells seemed inaccurate in those systems because of utilization of cancer cell lines with a difference from hepatocytes in the majority of cases. In this study, in order to resolve this point, a novel HBV culture system using non-cancer-derived immortalized human hepatocytes derived cell lines, producing exogenous human sodium taurocholate cotransporting polypeptide, was developed. One of the cell clones, E/NtG8 cells, was permissive to both blood-borne HBV (HBVbb) and culture-derived recombinant HBV when cultured in the three-dimensional condition. Furthermore, the production of infectious HBV particles, which showed the similar physicochemical properties to HBVbb, was observed for about a month after HBVbb infection in this system, suggesting that it may reproduce whole steps of the HBV lifecycle under the condition analogous to human liver cells infected with HBV. This system seemed to contribute not only to find novel interactions between HBV and host cells but also to understand mechanism of HBV pathogenesis.