Genetic viral and host adaptations to breach species barriers of HCV

描述（由申请人提供）：丙型肝炎仍然是全球流行病。至少有1.3亿人患有慢性丙型肝炎，这是由丙型肝炎病毒（HCV）引起的- a 黄病毒科的正义单链RNA病毒。HCV具有建立慢性感染的高倾向。如果未经治疗，慢性HCV携带者可发展为严重的肝脏疾病，包括纤维化、肝硬化和肝细胞癌（HCC）。抗病毒治疗只是部分有效，昂贵，而且往往耐受性差。目前还不存在HCV的预防性或治疗性疫苗。由于缺乏合适的小动物模型，更有效的治疗方法和疫苗的开发受到阻碍。基于我们先前的观察，即CD 81和闭合蛋白（OCLN）包含使小鼠细胞允许HCV体外进入所需的最小人类因素集，我们尝试通过遗传方法进行鼠人源化。我们证明，这两个人类基因的表达是足够的，使HCV感染的完全免疫能力的近交系小鼠。我们提供了全面的初步数据表明，先天性和适应性免疫反应的组合限制了这些小鼠中持续的HCV复制。我们证明，表达人CD 81和OCLN的小鼠的抗病毒免疫减弱会导致几周内出现低水平的病毒血症。这一观察结果为HCV在条件近交系小鼠中有效复制的可行性提供了关键证据。我们现在建议系统地克服额外的块HCV的种间生长，利用HCV的显着的遗传可塑性。我们的研究将最终导致一个完全免疫活性的HCV感染小鼠模型，我们将使用它来研究HCV相关的肝脏疾病。支持整个HCV生命周期的近交系小鼠模型为体内基因解剖HCV感染提供了前所未有的机会，并为测试和优先考虑候选药物和疫苗提供了重要的临床前平台。!

DESCRIPTION (provided by applicant): Hepatitis C remains a global epidemic. At least 130 million individuals suffer from chronic hepatitis C, which is caused by hepatitis C virus (HCV) - a positive sense, single-stranded RNA virus of the Flaviviridae family. HCV has a high propensity for establishing chronic infection. If untreated chronic HCV carriers can develop severe liver disease including fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Antiviral treatment is only partially effective, costly and often poorly tolerated. A prophylactic or therapeutic vaccine for HCV does not exist. Development of more effective therapies and vaccines has been hampered by the lack of a suitable small animal model.! Building on our previous observation that CD81 and occludin (OCLN) comprise the minimal set of human factors required to render mouse cells permissive for HCV entry in vitro, we attempted murine humanization via a genetic approach. We demonstrated that expression of the two human genes is sufficient to allow HCV infection of fully immunocompetent inbred mice. We provide comprehensive preliminary data demonstrating that a combination of innate and adaptive immune responses restricts persistent HCV replication in these mice. We demonstrate that blunting antiviral immunity in mice expressing human CD81 and OCLN results in low level, viremia over several weeks. This observation provides critical evidence for the feasibility of adapting HCV to replicate efficientlyin conditioned inbred mouse strain. We now propose to systematically overcome additional blocks to interspecies growth of the HCV by exploiting HCV's remarkable genetic plasticity. Our studies will ultimately lead to a fully immunocompetent mouse model for HCV infection, which we will use to study HCV-associated liver disease. An inbred mouse model that supports the entire HCV life-cycle opens unprecedented opportunities to genetically dissect HCV infection in vivo and provides an important preclinical platform for testing and prioritizing drug and vaccine candidates. !