Immune Mechanisms of HCV Persistence and Pathogenesis

目前有近400万美国人感染丙型肝炎病毒（HCV）。HCV感染是导致 每年约有8，000 - 10，000人死亡，是美国肝脏移植的主要原因。 美国的目前还没有控制丙型肝炎的疫苗。少数人感染了.HCV 在最初的感染过程中克服病毒并将其从血液中清除。剩余的75%-85% 发展成慢性感染这种疾病的严重程度因人而异。分子 病毒持续存在、疾病进展和新疗法的潜在病毒/宿主靶点的基础并不 很好理解。我们假设实质HCV抗原呈递导致不适当的T细胞 功能有助于免疫介导的肝脏炎症， 蛋白质是HCV存活的综合策略的组成部分。三个互补的方法将是 用于检验这些假设：1）为了检验免疫共刺激分子（例如CD 40）在小鼠中的功能， HCV相关的肝损伤，我们将建立一个小鼠谱系，有条件地表达HCV结构 蛋白质和CD 40分子。肝脏的病理变化、肝T细胞引发和 这些小鼠中的效应子功能将通过FACS、ELISPOT和免疫组织学分析来测量。（二） 研究HCV非结构蛋白（NS），特别是NS 3，是否干扰宿主的抗病毒活性。 导致病毒持续存在的反应，我们将产生条件性表达HCV-NS基因的小鼠， 其由新的他莫昔芬诱导系统控制。我们将检测这些动物的干扰素 （IFN）-α/β和适应性免疫应答，以响应肝脏中的病毒攻击。肝损伤 这些动物中的病毒持久性将通过生物化学、组织病理学和 免疫化学和实时PCR分析。3)最后，我们将研究HCV-S的协同作用， 和NS基因对疾病发病机制和病毒在动物中的持续存在的影响 肝脏中的HCV基因。将检测总补体HCV蛋白的免疫抑制作用 在病毒挑战之后。这些研究将提供重要的信息， 在体内负责病毒持久性和疾病进展的机制，并可能有助于设计 未来的战略目标是阻止特定的候选人。

Nearly 4 million Americans are currently infected with hepatitis C virus (HCV). HCV infection is responsible for approximately 8,000-10,000 deaths annually and is the leading reason for liver transplantation in the United States. There is no vaccine for the control of hepatitis C. A small number of people infected with.HCV overcome the virus during the initial infection and clear it from the bloodstream. The remaining 75%-85% develop a chronic infection. The severity of the disease varies greatly from person to person. The molecular basis for viral persistence, disease progression and potential virus/host targets for novel therapeutics is not well understood. We hypothesize that parenchymal HCV antigen presentation leading to inappropriate T cell function contributes to immune-mediated liver inflammation and that direct immunosuppression by viral proteins is a component of an integrated strategy of HCV survival. Three complementary approaches will be used to test these hypotheses: 1) To test the function of immune costimulatory molecules (e.g. CD40) in HCV-related liver injuries, we will establish a lineage of mice that conditionally express HCV structural proteins and CD40 molecules in the liver. Pathological changes in the liver, hepatic T cell priming and effector functions in these mice will be measured by FACS, ELISPOT and immunohistological analyses. 2) To examine whether HCV nonstructural (NS) proteins, especially NS3, interfere with the host antiviral responses leading to viral persistence, we will generate mice conditionally expressing HCV-NS genes, which are controlled by a novel tamoxifen-inducible system. We will examine these animals' interferon (IFN)-alpha/beta and adaptive immune responses in response to a viral challenge in the liver. Hepatic injury and viral persistence in these animals will be determined by biochemical, histopathological and immunochemical, and real-time PCR analyses. 3) Finally, we will examine the synergistic effects of HCV-S and-NS genes on disease pathogenesis and viral persistence in animals conditionally expressing the entire HCV genes in the liver. The immunosuppressive effect of the total complement HCV proteins will be tested following a viral challenge. These studies would provide important information concerning molecular mechanisms responsible for viral persistence and disease progression in vivo, and may aid in devising future strategies targeted at blocking specific candidates.