Hepatitis C virus and autophagic response

描述（由申请人提供）：丙型肝炎病毒（HCV）是一种重要的人类病原体，可导致严重的肝脏疾病，包括肝硬化和肝细胞癌。最近，我们的实验室发现HCV可以干扰自噬途径，导致自噬体在细胞中的积累。自噬在维持细胞内环境稳定中起重要作用。HCV在慢性感染过程中持续干扰自噬途径的能力在HCV发病机制和肿瘤发生中具有深远的影响。我们的进一步研究揭示了HCV RNA复制复合物与自噬体膜的关联，表明HCV诱导自噬体以促进其RNA合成。HCV通过抑制自噬体与溶酶体的融合而诱导自噬体。有趣的是，我们的初步研究还表明，HCV诱导自噬体的生物合成通过一种新的机制，独立于3类磷脂酰肌醇-3-激酶（PI 3 KC 3）。在本申请中，我们建议继续我们的新发现，研究HCV如何抑制自噬体的成熟。具体来说，我们将测试HCV诱导Rubicon从HOPS复合物中隔离UVRAG以抑制自噬体成熟的假设。此外，我们还将阐明HCV诱导自噬体生物合成的分子途径。最后，我们还将使用我们最近开发的一种新方法来纯化HCV感染细胞中的自噬体，并表征其相关蛋白因子，以了解这些膜囊泡的生物发生以及自噬体与HCV RNA复制复合物之间的关系。我们的研究将为我们了解HCV与其宿主细胞之间的相互作用提供重要信息，并有助于更好地了解HCV的复制和发病机制。

DESCRIPTION (provided by applicant): Hepatitis C virus (HCV) is an important human pathogen that can cause severe liver diseases including liver cirrhosis and hepatocellular carcinoma. Recently, our laboratory discovered that HCV could perturb the autophagic pathway, leading to the accumulation of autophagosomes in cells. Autophagy plays an important role in maintaining cellular homeostasis. The ability of HCV to persistently perturb the autophagic pathway during chronic infection can have profound consequences in HCV pathogenesis and oncogenesis. Our further studies revealed the association of the HCV RNA replication complex with autophagosomal membranes, suggesting that HCV induces autophagosomes to facilitate its RNA synthesis. HCV apparently induces autophagosomes by inhibiting their fusion with lysosomes. Interestingly, our preliminary studies also indicate that HCV induces the biogenesis of autophagosomes via a novel mechanism independent of the class 3 phosphatidylinositol-3-kinase (PI3KC3). In this application, we propose to continue our novel findings to study how HCV inhibits the maturation of autophagosomes. Specifically, we will test the hypothesis that HCV induces Rubicon to sequester UVRAG from the HOPS complex to inhibit the maturation of autophagosomes. In addition, we will also elucidate the molecular pathway of HCV-induced biogenesis of autophagosomes. Finally, we will also use a novel approach that we recently developed to purify autophagosomes from HCV-infected cells and to characterize their associated protein factors to understand the biogenesis of these membrane vesicles and the relationship between autophagosomes and the HCV RNA replication complex. Our proposed research will generate important information for us to understand the interaction between HCV and its host cell and lead to a better understanding of HCV replication and pathogenesis.