Project description:Hepatitis C virus (HCV) infection is tightly connected to the lipid metabolism with lipid droplets (LDs) serving as assembly sites for progeny virions. A previous LD proteome analysis identified annexin A3 (ANXA3) as an important HCV host factor that is enriched at LDs in infected cells and required for HCV morphogenesis. To further characterize ANXA3 function in HCV, we performed proximity labeling using ANXA3-BioID2 as bait in HCV-infected cells. Two of the top proteins identified proximal to ANXA3 during HCV infection were the La-related protein 1 (LARP1) and the ADP ribosylation factor-like protein 8B (ARL8B), both of which have been previously described to act in HCV particle production. In follow-up experiments ARL8B functioned as a pro-viral HCV host factor without localizing to LDs und thus likely independent of ANXA3. In contrast, LARP1 interacts with HCV core protein in an RNA-dependent manner and is translocated to LDs by core. Knockdown of LARP1 decreased HCV spreading without altering HCV RNA replication or viral titers. Unexpectedly, entry of HCV particles and E1/E2-pseudotyped lentiviral particles was reduced by LARP1 depletion, whereas particle production was not altered. Using a recombinant vesicular stomatitis virus (VSV)ΔG entry assay, we showed that LARP1 depletion also decreased entry of VSV with VSV, MERS, and CHIKV glycoproteins. Therefore, our data expand the role of LARP1 as an HCV host factor that is most prominently involved in the early steps of infection, likely contributing to endocytosis of viral particles through the pleiotropic effect LARP1 has on the cellular translatome.
Project description:Hepatitis C virus (HCV), a major causative agent of acute and chronic liver disease, belongs to the Flaviviridæ family and contains a single-strand positive-sense RNA genome, which upon virus entry and uncoating, functions as mRNAs and thus can be directly translated into proteins by host cell machinery. To date the HCV origin remains unclear and HCV life cycle and pathogenesis are not enlightened processes due to the absence of HCV efficient cell cultures systems or animals models. Here we show that rabbit and hare HCV-like viruses, RHCV and HHCV respectively, are formed after the inoculation of genomic DNA in Madin-Darby bovine kidney cell line cultures. RHCV is closely related to the HCV-1a/HCV-1b genotypes and HHCV is more closely related to the HCV-1b genotype. These findings could contribute to the understanding of HCV origin as well as clarify the virus life cycle, pathogenesis, evolution and diversity.
Project description:Chronic hepatitis B, C and D virus (HBV, HCV, HDV) infections are leading causes of liver disease and cancer worldwide. Although these viruses differ markedly in their life cycle and genomic organization, they exclusively infect hepatocytes. Recently, the sodium taurocholate cotransporting polypeptide (NTCP) was identified as the first functional receptor for HBV and HDV. Here, we report that NTCP also facilitates HCV entry into human hepatocytes, by augmenting the bile acids-mediated repression of IFN-stimulated genes (ISGs), including IFITM2 and IFITM3, to increase the susceptibility of cells to HCV entry. Furthermore, an HBV-derived preS1 peptide, known to bind NTCP and to inhibit bile acids uptake and HBV infection, inhibits HCV entry by enhancing the expression of ISGs. Our study highlights NTCP as a novel player linking bile acids metabolism to the interferon response in hepatocytes and establishes a role for NTCP in the entry process of multiple hepatotropic viruses, via distinct mechanisms. Collectively, these findings enhance our understanding of hepatitis virus-host interactions and suggest NTCP as an attractive antiviral target for HBV/HCV co-infection.
Project description:Chronic hepatitis B, C and D virus (HBV, HCV, HDV) infections are leading causes of liver disease and cancer worldwide. Although these viruses differ markedly in their life cycle and genomic organization, they exclusively infect hepatocytes. Recently, the sodium taurocholate cotransporting polypeptide (NTCP) was identified as the first functional receptor for HBV and HDV. Here, we report that NTCP also facilitates HCV entry into human hepatocytes, by augmenting the bile acid-mediated repression of IFN-stimulated genes (ISGs), including IFITM2 and IFITM3, to increase the susceptibility of cells to HCV entry. Furthermore, an HBV-derived preS1 peptide, known to bind NTCP and to inhibit bile acid uptake and HBV infection, inhibits HCV entry by enhancing the expression of ISGs. Our study highlights NTCP as a novel player linking bile acid metabolism to the interferon response in hepatocytes and establishes a role for NTCP in the entry process of multiple hepatotropic viruses, via distinct mechanisms. Collectively, these findings enhance our understanding of hepatitis virus-host interactions and suggest NTCP as an attractive antiviral target for HBV/HCV co-infection.
Project description:Laminins are large heterotrimeric cross-shaped extracellular matrix (ECM) glycoproteins with terminal globular domains and a coiled-coil region. We have produced for the first time a recombinant laminin coiled-coil domain and studied the transcriptional profile of cells incubated in coiled-coil-coated wells.
Project description:Chronic hepatitis B, C and D virus (HBV, HCV, HDV) infections are leading causes of liver disease and cancer worldwide. Although these viruses differ markedly in their life cycle and genomic organization, they exclusively infect hepatocytes. Recently, the sodium taurocholate cotransporting polypeptide (NTCP) was identified as the first functional receptor for HBV and HDV. Here, we report that NTCP also facilitates HCV entry into human hepatocytes, by augmenting the bile acid-mediated repression of IFN-stimulated genes (ISGs), including IFITM2 and IFITM3, to increase the susceptibility of cells to HCV entry. Furthermore, an HBV-derived preS1 peptide, known to bind NTCP and to inhibit bile acid uptake and HBV infection, inhibits HCV entry by enhancing the expression of ISGs. Our study highlights NTCP as a novel player linking bile acid metabolism to the interferon response in hepatocytes and establishes a role for NTCP in the entry process of multiple hepatotropic viruses, via distinct mechanisms. Collectively, these findings enhance our understanding of hepatitis virus-host interactions and suggest NTCP as an attractive antiviral target for HBV/HCV co-infection. Transcriptome profiling by DNA microarray of Huh7.5.1 cells transduced to express NTCP.