Tree shrew bone marrow-derived mesenchymal stem cells express CD81, OCLN, and miR-122, facilitating the entire...

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and associated cirrhosis, and hepatocellular carcinoma worldwide. At present, there is no prophylactic vaccine against HCV due to the lack of in vivo and in vitro model systems. Although most recombinants of all major HCV genotypes replicate in Huh-7 cell line and derivatives, these cells are human hepatoma-derived cell line. Therefore, the development of un-tumor-derived cell systems facilitating the entire HCV life cycle is urgently needed. In this study, we aimed to establish a novel tree shrew-derived bone marrow-derived mesenchymal stem cell (BM-MSC) system to reconstruct the HCV life cycle. We transduction cluster of differentiation 81 (CD81), occludin (OCLN), and microRNA-122 (miR-122) into BM-MSCs, then used a well-established HCV, produced from the J6/JFH1-Huh7.5.1 culture system, to infect the cells. We observed that BM-MSCs transduction with CD81/OCLN or CD81/OCLN/miR-122 support HCV RNA replication and infectious virus production. We also found that the addition of exogenous vascular endothelial growth factor (VEGF) can enhance HCV infectivity in BM-MSCs, with HCV virus load up to 10⁵ copies/mL. In conclusion, we identified the minimum essential factors required for HCV replication in tree shrew-derived nonhuman nonhepatic BM-MSCs. Further, we identified that exogenous addition of VEGF, and exogenous expression of CD81, OCLN, and miR-122, facilitates efficient viral replication and production of infectious particles. Our results describe a novel cell system capable of supporting the entire HCV life cycle, which may provide an essential tool for anti-HCV drug discovery, vaccine development, and study of pathogenesis.