Mechanisms of Hepadnavirus Assembly and Replication

嗜肝DNA病毒组装和复制机制

• 批准号: 8299669
• 负责人: Jianming Hu
• 金额: $ 38.78万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8299669
• 关键词: American; Antiviral Agents; Binding; Biochemical; Biological Assay; Capsid Proteins; Cell Culture System; Cell Extracts; Cells; Characteristics; Charge; Chronic; Chronic viral hepatitis; Circular DNA; Cirrhosis; Complex; DNA; Data; Development; Duck Hepatitis B Virus; Ducks; Family; Funding; Genetic; Genome; Goals; Heat-Shock Proteins 90; Hepadnaviridae; Hepatitis B Virus; In Vitro; Integration Host Factors; Intervention; Liver; Liver Cirrhosis; Liver diseases; Malignant neoplasm of liver; Mediating; Membrane Proteins; Modeling; Modification; Molecular; Molecular Chaperones; Nature; Nucleic Acids; Nucleocapsid; Pathway interactions; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Play; Process; Protein Dephosphorylation; Protein Dynamics; Proteins; RNA; RNA-Directed DNA Polymerase; Recovery; Retroviridae; Reverse Transcription; Ribonucleoproteins; Risk; Role; Signal Transduction; Single-Stranded DNA; Staging; Structure; System; Testing; Time; Viral; Viral Proteins; Virion; Virus; Virus Assembly; Virus Diseases; Virus Replication; anti-hepatitis B; base; follow-up; in vivo; insight; novel; pgRNA; prevent; reconstitution; research study; sound; virus host interaction

Hepatitis B virus (HBV) is a major cause of chronic viral hepatitis that increases dramatically the risk of liver cancer and other end-stage liver diseases such as cirrhosis. HBV belongs to the Hepadnaviridae, a family of para-retroviruses that have a small DNA genome and replicate through an RNA intermediate (the pregenomic RNA, or pgRNA), by a unique reverse transcription pathway. Hepadnaviruses initially assemble an immature nucleocapsid (NC) composed of multiple copies of the capsid protein, and the packaged pgRNA and the virally encQded reverse transcriptase (RT). The immature NC undergoes a process of maturation whereby pgRNA is converted to the characteristic, partially double stranded (OS), relaxed circular (RC) DNA by RT-mediated reverse transcription. The RC DNA-containing, mature NC is then selectively enveloped with the viral envelope (surface) proteins and secreted extracellularly as virions. Using recently established cell-free and cell culture systems and newly developed approaches and models, we propose (1) to determine the nature of nucleic acid within NC that blocks or triggers NC envelopment; (2) to determine the maturation-associated NC structural changes and their role in NC envelopment; and (3) to determine the role of host factors in regulating selective NC envelopment. These Revised Specific Aims are derived from the three sUb-aims of Specific Aim 3 as proposed in the original application. These stUdies are selected because of their likelihood for successful completion within the two year time-frame supported by the the American Recovery and Reinvestment Act of 2009 funding. Also, they still constitute a coherent and sound project separate from Specific Aims 1 and 2 of the original application. The elucidation of the molecular basis of, and viral and host factors involved in, selective NC envelopment will not only provide important insights into the mechanisms of hepadnavirus replication and virus-host interactions but may also facilitate the development of novel and effective anti-HBV strategies targeted at these factors.

乙型肝炎病毒 (HBV) 是慢性病毒性肝炎的主要原因，可显着增加肝病风险 癌症和其他终末期肝脏疾病，例如肝硬化。乙型肝炎病毒属于嗜肝DNA病毒科， 副逆转录病毒具有较小的 DNA 基因组并通过 RNA 中间体（即 前基因组 RNA（或 pgRNA），通过独特的逆转录途径。肝炎病毒最初组装 由衣壳蛋白的多个拷贝组成的未成熟核衣壳（NC），以及包装的 pgRNA 和病毒编码的逆转录酶 (RT)。不成熟的NC经历了一个过程 成熟，其中 pgRNA 转化为特征性的、部分双链 (OS) 的松弛环状 (RC) RT 介导的逆转录 DNA。然后选择性地含有 RC DNA 的成熟 NC 被病毒包膜（表面）蛋白包裹并作为病毒粒子分泌到细胞外。最近使用 建立了无细胞和细胞培养系统以及新开发的方法和模型，我们建议（1） 确定 NC 内阻断或触发 NC 包络的核酸的性质； (2)确定 与成熟相关的 NC 结构变化及其在 NC 包络中的作用； (3) 确定 宿主因子在调节选择性 NC 包络中的作用。这些修订后的具体目标源自 原申请中提出的具体目标 3 的三个子目标。这些研究被选中 因为它们有可能在两年的时间框架内成功完成 2009 年美国复苏和再投资法案资助。而且，它们仍然构成了一个连贯和健全的 项目与原始申请的具体目标 1 和 2 分开。分子的阐明 选择性 NC 包封的基础以及参与的病毒和宿主因素不仅将提供重要的 深入了解嗜肝DNA病毒复制和病毒-宿主相互作用的机制，但也可能促进 针对这些因素开发新颖有效的抗乙肝病毒策略。