Hepatitis C virus infection and lipoproteins

描述（由申请人提供）：丙型肝炎病毒（HCV）感染是一个主要的全球健康问题，在美国感染了大约400万人，在全球感染了1.7亿人。HCV病毒体的性质和生化组成尚未确定，主要是由于缺乏一个强大的培养系统，HCV感染和繁殖。最近，我们已经成功地建立了一个稳定的培养系统，强大的生产感染性HCV。对含HCV RNA颗粒的表征显示，低密度的HCV颗粒具有最高的感染性，与高密度的颗粒形成鲜明对比，高密度的颗粒含有最高水平的HCV RNA基因组但不具有感染性。此外，在HCV颗粒的低密度部分中检测到载脂蛋白B和E，并且HCV感染被人脂蛋白LDL和VLDL强效抑制。因此，我们假设HCV病毒粒子与脂蛋白组装，脂蛋白通过与细胞表面受体/辅助受体的特异性相互作用在介导HCV感染中发挥重要作用。HCV病毒粒子与脂蛋白的组装代表了一个新的概念，值得探索性研究，并有望发现新的抗病毒药物。本申请的总体目标是确定含HCV RNA颗粒的性质和生化组成，并确定脂蛋白在HCV组装和感染中的作用。我们的具体目标是：1）使用结构、细胞生物学、生物化学、免疫学和蛋白质组学方法确定含HCV RNA颗粒的性质和生物化学组成以及HCV感染性的结构决定因素; 2）通过改变稳定的HCV产生细胞中脂蛋白的产生水平以及通过使用针对特异性载脂蛋白的抗体来确定脂蛋白在HCV病毒体产生和感染中的作用。脂蛋白的水平将通过载脂蛋白表达载体和化学诱导剂上调或通过特异性siRNA和小分子抑制剂下调。此外，我们将确定人类脂蛋白抑制HCV感染的潜在机制。这些研究的结果不仅将确定HCV感染的分子基础，还将为抗病毒干预提供新的靶点。此外，从我们的研究中获得的信息将提供一个基础，对HCV病毒粒子组装和感染的分子机制的透彻理解。丙型肝炎病毒（HCV）感染构成了一个重大的全球健康问题，在美国感染了约400万人，在全球感染了1.7亿人。本申请旨在确定HCV颗粒的性质和生化组成，并确定脂蛋白在HCV产生和感染中的作用。这些研究结果将为HCV感染的抗病毒干预提供新的靶点和治疗方法。

DESCRIPTION (provided by applicant): Hepatitis C virus (HCV) infection poses a major global health problem, infecting approximately 4 million people in the United States and 170 million people worldwide. The properties and biochemical composition of HCV virions have not been determined due largely to the lack of a robust culture system for HCV infection and propagation. Recently, we have successfully established a stable culture system for robust production of infectious HCV. The characterization of HCV RNA-containing particles revealed that the low-density HCV particles were of the highest infectivity in sharp contrast to the higher-density particles, which contained the highest level of HCV RNA genome but were not infectious. Additionally, apolipoproteins B and E were detected in the low- density fractions of HCV particles, and HCV infection was potently inhibited by human lipoproteins LDL and VLDL. Therefore, we hypothesize that HCV virion is assembled with lipoproteins, which play important roles in the mediation of HCV infection through specific interactions with cell surface receptors/co-receptors. HCV virion assembly with lipoproteins represents a novel concept that warrants exploratory investigation and holds promise for discovering novel antiviral drugs. The overall goal of this application is to determine the properties and biochemical composition of HCV RNA-containing particles and to define the role of lipoproteins in HCV assembly and infection. Our specific aims are: 1) to determine the nature and biochemical composition of HCV RNA-containing particles and the structural determinants of HCV infectivity using structural, cell biological, biochemical, immunological, and proteomic approaches; 2) to define the role of lipoproteins in HCV virion production and infection by altering the levels of lipoprotein production in stable HCV-producing cells as well as by using antibodies against specific apolipoproteins. The levels of lipoproteins will be either up regulated by apolipoprotein-expression vectors and chemical inducers or down regulated by specific siRNAs and small molecular inhibitors. Additionally, we will determine the underlying mechanisms for the inhibition of HCV infection by human lipoproteins. Findings derived from these studies will not only determine the molecular basis underlying HCV infectivity but also provide novel targets for antiviral intervention. Furthermore, information gained from our studies will provide a foundation towards a thorough understanding of the molecular mechanisms of HCV virion assembly and infection. Hepatitis C virus (HCV) infection poses a major global health problem, infecting about 4 million people in the United States and 170 million people worldwide. This application is to determine the properties and biochemical composition of HCV particles and to define the role of lipoproteins in HCV production and infection. Findings derived from these studies will provide novel targets and therapies for antiviral intervention of HCV infection.