Regulation of host cell gene expression by the hepatitis C virus protein NS5A

描述（由申请人提供）：丙型肝炎病毒（HCV）是肝脏疾病和死亡的主要原因，影响全球约1.7亿人。慢性丙肝病毒感染可导致肝纤维化、肝硬化和肝细胞癌。HCV必须利用宿主基因表达机制来促进病毒复制。复制过程中涉及的机制尚不完全清楚。研究发现，HCV非结构蛋白NS5A对病毒的复制机制和感染性病毒颗粒的组装至关重要，但其具体作用尚不清楚。Bohjanen实验室最近的初步数据表明，HCV NS5A蛋白与宿主含gre转录物结合，并介导其在肝癌细胞系中的稳定。这些数据表明，HCV可以通过NS5A介导的含有gr的转录物的稳定来操纵宿主细胞mRNA的衰变。这些转录本的稳定可以防止细胞死亡，促进病毒感染细胞的生长，从而使病毒在宿主体内建立慢性感染。在本研究中，我们旨在鉴定与丙型肝炎病毒非结构蛋白结合的宿主细胞转录本，并确定NS5A抑制剂BMS 790052是否通过干扰NS5A与含gre的宿主细胞转录本的结合来阻断HCV复制。进一步了解人类细胞系中参与HCV RNA调控的关键基因，将有助于表征病毒复制周期。此外，它将揭示至关重要的基因，从而揭示潜在的治疗目标。此外，解剖NS5A抑制剂的下游作用将揭示HCV复制机制中的其他薄弱环节，扩大我们对病毒的了解并促进新疗法的创新。

DESCRIPTION (provided by applicant): Hepatitis C virus (HCV) is a major cause of liver disease and mortality, affecting approximately 170 million people worldwide. Chronic infection with HCV leads to liver fibrosis, cirrhosis and hepatocellular carcinoma. HCV must use the host gene expression machinery to facilitate viral replication. The mechanisms involved in the replication are incompletely understood. It has been found that the HCV nonstructural protein NS5A is essential to the replication machinery of the virus and critical in the assembly of infectious viral particles, however its specific role remains unclear. Recent preliminary data from the Bohjanen's laboratory indicates that the HCV NS5A protein binds to host GRE-containing transcripts and mediates their stabilization in hepatoma cell lines. This data suggest that HCV could manipulate host cellular mRNA decay through NS5A- mediated stabilization of GRE-containing transcripts. Stabilization of these transcripts would prevent cell death and promote growth of virus -infected cells allowing the virus to establish chronic infection in the host. In this study, we aim to identify host cellular transcripts that bind to the hepatitis C virus non-structural protein and to determine if the NS5A inhibitor BMS 790052 blocks HCV replication through interference with the binding of NS5A to GRE-containing host cellular transcripts. Further understanding of the critical genes involved in RNA regulation of HCV in human cell lines, will help characterize the virus replication cycle. In addition, it will expose genes of critical importance, thus unveiling potential targets for treatment. Moreover, dissection of the downstream effects of NS5A inhibitors will expose additional weak spots in the HCV replication machinery, expanding our understanding of the virus and facilitating innovation of new therapies.