Role of Lipids in Hepatitis C Virus Maturation

 描述(申请人提供)：慢性丙型肝炎病毒感染影响全球约1.7亿人，并构成纤维化、脂肪变性和肝细胞癌(HCC)的重要风险因素。丙型肝炎病毒感染是肝移植的主要指标。在这里，我们建议表征脂质在病毒粒子形态发生中的作用，主要集中在感染肝细胞的成熟和分泌。在之前的资助中，我们已经确定并表征了几种脂类和脂类相互作用蛋白在影响丙型肝炎病毒分泌中的作用。 丙型肝炎病毒通过高尔基体网络的成熟/分泌被认为与极低密度脂蛋白(VLDL)的组装和分泌有关。极低密度脂蛋白的转运发生在专门的极低密度脂蛋白运输小泡(VTV)中。我们建议使用已建立的分离VTV的生化分级程序来表征丙型肝炎病毒相关VTV在高尔基网络中的运输。一种新描述的体外发芽试验后高尔基VTV运输将被检查。丙型肝炎病毒感染细胞中含有丙型肝炎病毒病毒组分的VTV的特征对于低估丙型肝炎病毒分泌过程是至关重要的。我们还建议确定影响大货物高尔基体运输的因素，如VTV在丙型肝炎病毒成熟过程中的功能重要性。在此背景下，几种蛋白质，包括磷脂酰肌醇-4磷酸(PI4P)相互作用蛋白Arfaptin被证明影响跨高尔基网络中的大货物，将表征它们在丙型肝炎病毒-VTV运输中的作用。这些研究将揭示丙型肝炎病毒成熟、分泌和排出的独特机制，并将作为其他RNA病毒的模型。这项研究的结果将为影响丙型肝炎病毒分泌途径的细胞靶点的治疗设计开辟新的途径。

 DESCRIPTION (provided by applicant): Chronic Hepatitis C virus infections affect about 170 million people worldwide and constitute a significant risk factor for fibrosis, steatosis and hepatocellular carcinoma (HCC). HCV infections are a major indicator for liver transplantation. Here, we propose to characterize the role of lipids in virion morphogenesis mostly focusing on maturation and secretion from infected hepatocytes. In the previous grant we had identified and characterized the role of several lipids and lipid interacting proteins in affecting HCV secretion. HCV maturation/secretions through the Golgi network is believed to occur in association with very low-density lipoprotein (VLDL) assembly and secretion. VLDL transport occurs in specialized VLDL transport vesicles (VTVs). We propose to characterize the transport of HCV-associated VTVs across the Golgi network using the established biochemical fractionation procedures for isolating VTVs. A newly described in vitro budding assay for the post- Golgi VTV transport will be examined. Characterization of VTVs in HCV infected cells containing HCV virions components is of fundamental importance to the understating the process of HCV secretion. We also propose to determine the functional importance of factors that affect Golgi transport of large cargos such as VTVs in HCV maturation. In this context, several proteins including a phosphatidylinosito-4 phosphate (PI4P)- interacting protein Arfaptin shown to affect large cargos in the trans-Golgi network will be characterized for their role in HCV-VTV transport. These studies will reveal unique insight into the mechanisms of HCV maturation, secretion and egress and will serve as a model for other RNA viruses. The results of this study will open new avenues for therapeutic design of cellular targets affecting the HCV secretory pathway.