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。HCV的慢性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。涉及复制的机制还不完全清楚。已经发现HCV非结构蛋白NS 5A对于病毒的复制机制是必需的，并且在感染性病毒颗粒的组装中是关键的，然而其具体作用尚不清楚。最近来自Bohjanen实验室的初步数据表明，HCV NS 5A蛋白与宿主含GRE的转录本结合，并介导它们在肝癌细胞系中的稳定。这些数据表明，HCV可以通过NS 5A介导的含GRE转录物的稳定化来操纵宿主细胞mRNA的衰减。这些转录物的稳定化将防止细胞死亡并促进病毒感染细胞的生长，从而允许病毒在宿主中建立慢性感染。在这项研究中，我们的目的是确定宿主细胞的转录本，结合丙型肝炎病毒的非结构蛋白，并确定是否NS 5A抑制剂BMS 790052块HCV复制通过干扰NS 5A的结合，GRE-含有宿主细胞的转录本。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，它还将暴露至关重要的基因，从而揭示潜在的治疗目标。此外，NS 5A抑制剂下游效应的解剖将暴露HCV复制机制中的其他弱点，扩大我们对病毒的理解，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.