Hepatitis C virus (HCV) could induce chronic
liver diseases and
hepatocellular carcinoma in human. The use of primary human hepatocyte as a viral host is restrained with the scarcity of tissue supply. A culture model restricted to HCV genotype 2a (JFH-1) has been established using Huh7-derived hepatocyte. Other genotypes including the wild-type virus could not propagate in Huh7, Huh7.5 and Huh7.5.1 cells.
METHODS: Functional hepatocyte-like cells (HLCs) were developed from normal human iPS cells as a host for HCV
infection. Mature HLCs were identified for selective hepatocyte markers, CYP450s, HCV associated receptors and HCV essential host factors. HLCs were either transfected with JFH-1 HCV
RNA or infected with HCV particles derived from patient serum. The enhancing effect of α-
tocopherol and the inhibitory effects of INF-α,
ribavirin and
sofosbuvir to HCV
infection were studied. The HCV viral load and HCV
RNA were assayed for the
infection efficiency.
RESULTS: The fully-developed HLCs expressed phase I, II, and III
drug-metabolizing
enzymes, HCV associated receptors (
claudin-1,
occludin, CD81,
ApoE,
ApoB,
LDL-R) and HCV essential host factors (miR-122 and SEC14L2) comparable to the primary human hepatocyte. SEC14L2, an α-
tocopherol transfer
protein, was expressed in HLCs, but not in Huh7 cell, had been implicated in effective HCVser
infection. The HLCs permitted not only the replication of HCV
RNA, but also the production of HCV particles (HCVcc) released to the
culture media. HLCs drove higher propagation of HCVcc derived from JFH-1 than did the classical host Huh7 cells. HLCs infected with either JFH-1 or wild-type HCV expressed HCV core
antigen, NS5A, NS5B, NS3 and HCV negative-stand
RNA. HLCs allowed entire HCV life cycle derived from either JFH-1, HCVcc or wild-type HCV (genotype 1a, 1b, 3a, 3b, 6f and 6n). Further increasing the HCVser
infection in HLCs was achieved by incubating cell with α-
tocopherol. The supernatant from infected HLCs could infect both naïve HLC and Huh7 cell. Treating infected HLC with INF-α and
ribavirin decreased HCV
RNA in both the cellular fraction and the culture medium. The HLCs reacted to HCVcc or wild-type HCV
infection by upregulating TNF-α, IL-28B and IL-29.
CONCLUSIONS: This robust cell culture model for serum-derived HCV using HLCs as host cells provides a remarkable system for investigating HCV life cycle, HCV-associated
hepatocellular carcinoma development and the screening for new anti HCV drugs.