Developing Murine Models of HCV Replication

描述(申请人提供)：约2%的世界人口感染丙型肝炎病毒(丙型肝炎病毒)，已成为一个重大的公共卫生问题，造成重大的医疗、社会和经济负担。70%-90%的感染者未能清除病毒，继续慢性感染，有可能发展为持续性肝炎、肝硬变和肝细胞癌(HCC)。因此，丙型肝炎病毒相关性肝病是美国肝移植的主要原因。目前，没有预防性疫苗可用，只有20%-30%的慢性感染患者对目前可用的治疗方法有反应。因此，迫切需要一种预防性疫苗和替代治疗选择。不幸的是，缺乏强大的组织培养复制系统和小动物模型，阻碍了理解并因此抗击这种感染的研究努力。虽然最近发展的体外丙型肝炎病毒复制子系统已经克服了这些局限性，但仍需要小动物模型来研究病毒与宿主的相互作用，以评估病毒的病理效应，更好地了解丙型肝炎病毒免疫学(例如，恢复期和持久性的免疫学和病毒学基础)，以及测试生理和药理药物控制丙型肝炎病毒感染的体内潜力。因此，这一探索性建议的目标是创造能够表达并有可能复制丙型肝炎病毒的小鼠模型。最初的努力将集中在使用可选择的丙型肝炎病毒复制体，这已被证明是一种有效的丙型肝炎病毒复制系统。然而，在这些研究中获得的小鼠适应信息可能随后允许开发复制天然丙型肝炎病毒基因组的类似模型。具体的研究目标是：1)确定是否可以通过调整现有的丙型肝炎病毒复制子在小鼠肝细胞中复制来改变丙型肝炎病毒的物种趋向性；2)确定是否可以通过体内瞬时T7驱动的丙型肝炎病毒构建物(S)的表达来建立急性丙型肝炎病毒的小鼠模型；以及3)确定稳定的核糖核酸聚合酶I驱动的丙型肝炎病毒构建物(S)是否可以作为体内丙型肝炎病毒的慢性小鼠模型。

DESCRIPTION (provided by applicant): With approximately 2% of the world population infected, Hepatitis C Virus (HCV) has emerged as a significant public health problem creating a significant medical, social, and economic burden. Between 70- 90% of those infected fail to clear the virus and remain chronically infected with the likelihood of progression to persistent hepatitis, liver cirrhosis, and hepatocellular carcinoma (HCC). As a result, HCV-associated liver disease is the leading cause of liver transplantation in the United States. At this time, no preventative vaccine is available, and only 20-30% of chronically infected patients respond to the currently available therapy. Hence, there is a pressing need for a preventative vaccine and alternative treatment options. Unfortunately, research efforts to understand, and thus combat, this infection have been hindered by the lack of robust tissue culture replication systems and small animal models. While the recent development of the in vitro HCV replicon system has overcome some of these limitations, small animal models are still needed for the study of viral-host interactions to assess the pathological effects of the virus and to better understand HCV immunology (e.g. the immunological and virological basis of recovery versus persistence), as well as for testing the in vivo potential of physiological and pharmacological agents for controlling HCV infection. Therefore, the objective of this exploratory proposal is to create mouse models capable of expressing, and potentially replicating, HCV. Initial efforts will focus on the use of selectable HCV replicons, which have proven to be an efficient HCV replication system. However, the mouse-adaptation information gained in these studies may subsequently allow for the development of analogous models that replicate native HCV genomes. The Specific Aims to be addressed are: 1) determine if HCV species tropism can be altered by adapting currently available HCV replicons to replicate in mouse hepatocytes; 2) determine if a murine model of acute HCV can be established by transient T7-driven expression of HCV construct(s) in vivo; and 3) determine if stable RNA Polymerase I-driven expression of HCV construct(s) can serve as a chronic murine model of HCV in vivo.