We have previously reported that immortalized human hepatocytes (IHH) support the generation of infectious hepatitis C virus (HCV) genotype 1a (clone H77). In the present study, we have investigated the growth of HCV genotype 1a (clone H77) through serial passages and accompanying changes in IHH in response to infection. Eleven serial passages of HCV genotype 1a (clone H77) in IHH were completed. Virus replication was ascertained from the presence of HCV-specific sequences, the detection of core antigen, the virus genome copy number, and the virus titer in IHH culture fluid. Electron microscopy suggested that HCV infection induces autophagic vacuole formation in IHH. Fluorescence microscopy displayed localization of autophagic markers, microtubule-associated protein-1 light chain-3 and Apg5, on the vacuoles of HCV-infected hepatocytes. Taken together, our results suggested that HCV genotype 1a (clone H77) can be serially passaged in IHH and that HCV infection induces an autophagic response in hepatocytes.

Our data provide strong evidence that HBV viral particles themselves can readily inhibit host innate immune responses upon virion/cell interactions, and may explain, at least partially, the "stealthy" character of HBV.

Chronic hepatitis C virus (HCV) infection has a significantly increased prevalence of type 2 diabetes mellitus (T2DM).

Current therapies for chronic hepatitis B virus (HBV) infections are effective at decreasing the viral load in serum, but do not lead to viral eradication. Recent studies highlighted the therapeutic or “adjuvant” potential of immune-modulators. Our aim was to explore the direct anti-HBV effect of Toll-Like-Receptors (TLR) agonists in hepatocytes. HBV-infected primary human hepatocytes (PHH) or differentiated HepaRG cells (dHepaRG) were treated with various TLR agonists. Amongst all TLR ligands tested, Pam3CSK4 (TLR1/2-ligand) and poly(I:C)-(HMW) (TLR3/MDA5-ligand) were the best at reducing all HBV parameters. No or little viral rebound was observed after treatment arrest, implying a long-lasting effect on cccDNA. We also tested Riboxxol that features improved TLR3 specificity compared to poly(I:C)-(HMW). This agonist demonstrated a potent antiviral effect in HBV-infected PHH. Whereas, poly(I:C)-(HMW) and Pam3CSK4 mainly induced the expression of classical genes from the interferon or NF-κB pathway respectively, Riboxxol had a mixed phenotype. Moreover, TLR2 and TLR3 ligands can activate hepatocytes and immune cells, as demonstrated by antiviral cytokines produced by stimulated hepatocytes and peripheral blood mononuclear cells. In conclusion, our data highlight the potential of innate immunity activation in the direct control of HBV replication in hepatocytes, and support the development of TLR-based antiviral strategies.

Our results indicate that HepaRG cells express a similar pattern of functional TLR/RLR as compared to PHH, thus qualifying HepaRG cells as a surrogate model to study pathogen interactions within a hepatocyte innate system.

In the absence of a hepatitis C virus (HCV) culture system, the use of a Semliki Forest virus replicon expressing genes encoding HCV structural proteins that assemble into HCV-like particles provides an opportunity to study HCV morphogenesis. Using this system, we showed that the HCV core protein constitutes the budding apparatus of the virus and that its targeting to the endoplasmic reticulum by means of the signal sequence of E1 protein is essential for budding. In addition, the aspartic acid at position 111 in the HCV core protein sequence was found to be crucial for virus assembly, demonstrating the usefulness of this system for mapping amino acids critical to HCV morphogenesis.Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis and may lead to liver cirrhosis and hepatocellular carcinoma. With an estimated 170 million people worldwide chronically infected with HCV, this disease has emerged as a serious global health problem since the cloning of the viral genome in 1989 (8). Indeed, it has been predicted that chronic HCV infection will lead to an increase in the prevalence of hepatocellular carcinoma in the United States over the next 2 to 3 decades (39). HCV is a small, enveloped, positivestrand RNA virus belonging to the genus Hepacivirus of the Flaviviridae family. Its genome of approximately 9,600 nucleotides contains, at both the 5Ј and 3Ј ends, untranslated regions (UTRs) which flank a single open reading frame encoding a single polyprotein precursor of about 3,000 amino acids (aa) (13). The viral polyprotein can be broadly divided into two regions: the N-terminal one-third encodes the structural components of the virion, including the putative nucleocapsid or core protein and two envelope proteins (E1 and E2), and the remaining two-thirds encode the nonstructural proteins (22). These nonstructural proteins (NS2 through NS5B) have various functions, particularly in HCV genome replication, during the life cycle of the virus. They form a cytoplasmic membraneassociated complex similar to that formed by related positivestrand RNA viruses. The nonstructural proteins are separated from the structural proteins by the short hydrophobic polypeptide p7, the function of which is unknown (22). Translation to generate HCV polyprotein is initiated via an internal ribosome entry site located within the 5Ј UTR. During translation, the mature viral products are generated from the polyprotein by a series of cleavage events. The structural components are produced by cellular protease-mediated cleavages, whereas processing of the nonstructural proteins requires virus-encoded proteases (41). The core protein is produced at the N-terminal end of the polyprotein and is followed by the signal sequence of the E1 envelope glycoprotein. The signal sequence targets the nascent polypeptide chain to the endoplasmic reticulum (ER), allowing the translocation of E1 into the ER lumen, which is essential for the membrane-dependent processing of the core protein (23, 36). In the ER lumen, cleavage by a signal peptida...

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Hepatitis C virus (HCV) chronic infection is