IMMUNE REGULATION OF HEPATITIS B VIRUS GENE EXPRESSION

B型肝炎病毒（HBV）引起急性和慢性肝炎，是一种主要的 肝癌的病因 HBV的清除被认为是由 MHC I类限制性细胞毒性T淋巴细胞（CTL）应答。 全身给予HBsAg CTL以及IL-2和TNF α， 可以非细胞病变性下调HBV RNA在肝脏中的表达， HBsAg阳性小鼠在转录后水平。 这个目标 该项目的目的是确定这种抗病毒作用的分子基础， 验证HBV特异性CTL的可溶性产物激活 一种或多种肝细胞效应蛋白，其引起特异性 HBV转录物的不稳定和/或活性降解。 的 本项目的具体目标是：1）确定细胞因子或CTL是否 诱导的下调影响所有的HBV转录后， 转录水平：2）定义HBV上的靶序列 S转录本，对于不稳定/降解很重要 在HBV转基因小鼠中给予细胞因子或CTL后;和，3） 以确定引起特异性免疫应答的细胞内效应分子 减少HBV RNA。 将通过检测HBV来确定靶序列 通过体外衰变产生负调控效应的缺失突变体 测定和使用腺病毒载体的体内试验。 我们会搜查 识别并结合靶序列的肝细胞蛋白， RNA-蛋白质结合试验和通过筛选cDNA表达 图书馆 阐明负调控HBV RNA的机制 表达可能有助于我们理解 病毒清除和/或持久性，并可能有助于 开发抗病毒 毒品

Hepatitis B virus (HBV) caused acute and chronic hepatitis and is a major cause of liver cancer. Clearance of HBV is thought to be mediated by the MHC Class I restricted cytotoxic T lymphocyte (CTL) response. Systematically administered HBsAg CTL, as well as IL-2 and TNF alpha, can noncytopathically downregulate HBV RNA expression in the liver of HBsAg positive mice at the post-transcriptional level. The goal of this project is to determine the molecular basis for this antiviral effect by testing the hypothesis that soluble products of HBV specific CTL activate one or more hepatocellular effector protein(s) that cause the specific destabilization and/or the active degradation of HBV transcripts. The specific aims of this project are: 1) to determine if the cytokine or CTL induced downregulation affects all of the HBV transcripts at the post- transcriptional level: 2) to define the target sequence(s) on the HBV S transcript that is (are) important for destabilization/degradation following cytokine or CTL administration in HBV transgenic mice; and, 3) to define the intracellular effector molecules that cause the specific reduction in HBV RNA. The target sequence will be defined by testing HBV deletion mutants for the negative regulatory effect by in vitro decay assays and in vivo using adenovirus vectors. A search will be made for hepatocellular proteins that recognize and bind the target sequence using RNA-protein binding assays and by screening of a cDNA expression library. Elucidation of the mechanisms that negatively regulate HBV RNA expression may contribute to our understanding of the pathways that lead to viral clearance and/or persistence and may be helpful in the development of antiviral drugs.