Role of Lipids in Hepatitis C Virus Maturation

描述（由申请人提供）：约3%的世界人口感染丙型肝炎病毒（HCV）。HCV感染通常导致慢性肝炎，约三分之一的患者发展为肝硬化，少数患者发展为肝细胞癌。这种感染也与脂肪肝有关。HCV在由病毒和宿主细胞因子组成的核糖核蛋白复合物（RNP）内复制其RNA基因组。其中一种宿主因子，称为氧固醇结合蛋白（OSBP），是我们通过基于亲和力的方法鉴定的。随后的研究表明，OSBP是HCV分泌/释放所必需的，对细胞内RNA复制没有明显影响。属于磷脂酰肌醇-4磷酸（PI 4P）相互作用蛋白质组。在本申请中，我们专注于OSBP和其他两个PI 4 P相互作用蛋白，CERT和GOLPH 3在HCV成熟/分泌途径中的研究。高尔基体激酶PKD在HCV成熟中的作用也将被研究。HCV成熟/分泌，可能发生在高尔基体区室，被广泛认为与极低密度脂蛋白（VLDL）颗粒相关。我们建议通过共聚焦激光显微镜和免疫荧光的背景下，OSBP和VLDL分泌途径的高尔基室的HCV成熟过程的特点。VLDL颗粒通过专门的VLDL转运囊泡（VTV）分泌。使用一个既定的生化分离程序的VTV的隔离，我们建议，以确定与VTV的HCV组件的关联。HCV感染细胞中VTV的特征对理解HCV的形态发生具有重要意义。鉴定参与这种组装/分泌过程的宿主因子也将为设计新的抗病毒策略开辟新的途径。这些研究将揭示HCV成熟、分泌和出芽过程机制的独特见解，并为其他RNA病毒提供独特的模型。 公共卫生相关性：HCV感染进展为肝硬化、脂肪变性和肝癌，并且是肝移植的主要指征，因此代表了主要的公共卫生负担。世界上约有3%的人口感染HCV。

DESCRIPTION (provided by applicant): About 3% of world population is infected with Hepatitis C virus (HCV). HCV infection often leads to chronic hepatitis and about one third of patients develop cirrhosis and a minority of those develops hepatocellular carcinoma. The infection is also associated with fatty liver disease. HCV replicates its RNA genome within ribonucleoprotein complexes (RNP) consisting of viral and host cellular factors. One such host factor, termed oxysterol binding protein (OSBP) was identified by an affinity based approach by us. Subsequent studies revealed that OSBP was necessary for HCV secretion/release with no obvious effect on intracellular RNA replication. It belongs to group of proteins referred to as phosphatidyinosito-4 phosphate (PI4P)-interacting proteins. In this application, we focus on the investigation of OSBP and two other PI4P-interacting proteins, CERT and GOLPH3 in HCV maturation/secretion pathway. Role of Golgi kinase PKD in HCV maturation will also investigated. HCV maturation/secretion, which likely occurs in the Golgi compartment, is widely believed to occur in association with very low density lipoprotein (VLDL) particles. We propose to characterize the HCV maturation process through Golgi compartments by confocal laser microscopy and immunofluorescence in the context of OSBP and VLDL secretory pathway. VLDL particles are secreted via specialized VLDL transport vesicles (VTVs). Using an established biochemical fractionation procedure of isolation of VTVs, we propose to determine the association of HCV components with VTVs. Characterization of VTVs in HCV infected cells containing HCV virion components is of fundamental importance in understanding the HCV morphogenesis. Identification of host factors involved in this assembly/secretion process will also open new avenues for designing novel antiviral strategies. These studies will reveal unique insights into the mechanisms of HCV maturation, secretion and budding processes and provide a unique model for other RNA viruses. PUBLIC HEALTH RELEVANCE: HCV infections progresses to cirrhosis, steatosis, and liver cancer and are the leading indications for liver transplants thus representing a major public health burden. About 3% of world population is infected with HCV.