Hepatic differentiation of stem cells and the cellular determinants of hepatitis

描述（由申请人提供）：我们项目的广泛、长期目标是通过表征丙型肝炎病毒（HCV）感染所必需的细胞辅因子来推进病毒与宿主细胞相互作用的知识。丙型肝炎病毒感染全球1.7亿人，是导致肝细胞癌的主要原因。了解这种病毒如何与宿主细胞相互作用（例如，是什么使细胞易受HCV感染）对诊断、抗病毒药物和预防性疫苗的开发至关重要。我们之前对多能干细胞和定向肝分化的研究表明，分化过程中的肝脏特异性与HCV感染的容纳性之间存在相关性。细胞从非允许型向允许型转变的特征揭示了参与调节病毒易感性的候选基因。其中一个细胞因子相互作用

DESCRIPTION (provided by applicant): The broad, long-term goal of our program is to advance knowledge of virus-host cell interactions by characterizing cellular cofactors essential for hepatitis C virus (HCV) infection. HCV infects 170 million people worldwide and is major cause of hepatocellular carcinoma. Understanding how this virus interacts with the host cell (e.g., what makes a cell susceptible to HCV infection) is of critical importance to the development of diagnostics, antiviral drugs, and a prophylactic vaccine. Our previous studies of pluripotent stem cells and directed hepatic differentiation demonstrated a correlation between hepatic specification during the differentiation process and permissiveness to HCV infection. Characterization of the cellular transition from nonpermissive to permissive revealed candidate genes that are involved in regulating viral susceptibility. One of these cellular factors interacts with HCV glycoprotein E1 and plays an essential role in the HCV life cycle. The experiments proposed here will determine the molecular determinants of HCV permissiveness during hepatic development and identify new cellular cofactors and potential drug targets for HCV therapy. The following experiments will be performed: (1) Suppression of putative proviral factors and overexpression of putative antiviral factors in stem cells. These will be followed by hepatic differentiation and HCV infection of the differentiated human hepatocyte-like cells (DHHs). (2) Mechanistic studies of a novel proviral factor whose role has been validated by our preliminary studies. Specific steps of the HCV life cycle will be examined, and the interaction between viral and host protein will be dissected. (3) In vivo experiments designed to assess the potential of genetically modified DHHs to repopulate mouse liver and confer HCV resistance to the chimeric liver. The results of the proposed studies will not only provide significant insights into the properties of the host cells that govern HCV susceptibility but also reveal new therapeutic targets for antiviral intervention.