REGULATION OF HEPATITIS B VIRUS TRANSCRIPTION

据估计，慢性HBV感染仍然是一个主要的临床问题， 全世界有5亿慢性乙肝病毒携带者， 迄今为止，还没有可靠的治疗方法。 慢性病的后果 HBV感染可包括使人衰弱的慢性活动性肝炎、肝硬化、肝硬化和肝硬化。 肝硬化和原发性肝细胞癌是主要原因 死亡率。HBV通过逆转录病毒复制 HBV DNA基因组编码的前基因组RNA。 因此，委员会认为， 病毒基因组的转录是病毒复制的重要步骤。 复制的因此，长期目标是了解 控制HBV协调和差异调节的机制 转录及其对体内病毒生物合成的影响， 病毒转录过程中的关键步骤 被抗病毒药物识别并靶向破坏。 基于 转录因子的知识，这是重要的， 在瞬时转染分析中调节HBV转录 报告基因构建体，从大的转录水平， 主要表面抗原启动子将在本发明的背景下改变， 完整的病毒基因组和对病毒转录物、抗原 生产，复制和病毒的生物合成将被检查。 具体来说，为了重现肝脏的作用， 在HBV转基因小鼠中观察到的病毒复制再生， 消除HNF 1与大表面抗原结合的作用 将检查启动子的2.4kb RNA合成减少， 出现特定的复制中间体，特别是非复制中间体， 纯化的无蛋白RC和CCC HBV DNA。 将检查小鼠的 这些HBV DNA复制中间体整合到宿主中 染色体DNA，一个与原发性 肝细胞癌在男人。建议，肝脏特异性 在体内观察到HBV 2.1kb转录物的表达，但在 细胞培养是由于HNF3与HNF3结合位点相互作用 将检查位于主要表面抗原启动子中的基因。 的 解释这种差异的有利机制假设HNF 3是 在体内改变启动子的局部染色质结构 为了允许近端启动子区域被普遍存在的 转录因子，其随后激活从 启动子 这一机制将直接由职能部门和 体内足迹分析。

Chronic HBV infection remains a major clinical problem with estimates of as many as 500 million HBV chronic carriers in the world for whom, to date, there is no reliable treatment. The consequences of chronic HBV infection can include debilitating chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma which are major causes of mortality. HBV replicates by reverse transcription of the viral pregenomic RNA encoded by the HBV DNA genome. Consequently, transcription of the viral genome is an essential step in virus replication. Therefore, the long term objective is to understand the mechanisms controlling the coordinate and differential regulation of HBV transcription, and their influence on viral biosynthesis in vivo, so that critical steps in the viral transcription process might be identified and targeted for disruption by antiviral agents. Based on the knowledge of the transcription factors which are important in regulating HBV transcription in transient transfection analysis using reporter gene constructs, the levels of transcription from the large and major surface antigen promoters will be altered in the context of the complete viral genome and the effects on viral transcripts, antigen production, replication, and viral biosynthesis will be examined. Specifically, in an attempt to reproduce the effect of liver regeneration on viral replication observed in HBV transgenic mice, the effect of eliminating the binding of HNF1 to the large surface antigen promoter will be examined for reduced 2.4kb RNA synthesis and the appearance of specific replication intermediates, in particular non- encapsidated protein-free RC and CCC HBV DNA. Mice will be examined for the integration of these HBV DNA replication intermediates into the host chromosomal DNA, an event associated with the development of primary hepatocellular carcinoma in man. The suggestion that the liver-specific expression of the HBV 2.1kb transcript observed in vivo but absent in cell culture is due to HNF3 interacting with the HNF3 binding site located in the major surface antigen promoter will be examined. The favored mechanism accounting for this difference assumes that HNF3 is required to alter the local chromatin structure of the promoter in vivo to permit the proximal promoter region to be occupied by ubiquitous transcription factors which subsequently activate transcription from the promoter. This mechanism will be tested directly by functional and in vivo footprinting analysis.