Reciprocal Interaction of JCV and Host Regulators

JCV 和主机调节器的相互作用

• 批准号: 6919796
• 负责人: Kamel Khalili
• 金额: $ 29.53万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6919796
• 关键词: DNA repair; Polyomavirus hominis 2; astrocytes; cell cycle proteins; gene interaction; genetic promoter element; glia; host organism interaction; immediate early protein; immunocytochemistry; intermolecular interaction; neurotropic virus; regulatory gene; small interfering RNA; transcription factor; transfection /expression vector; viral myelinopathy; virus antigen; virus cytopathogenic effect; virus genetics; virus protein; virus replication

The human polyomavirus, JCV, is the etiologic agent of Progressive Multifocal Leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system (CNS) that usually affects immunosuppressed patients. JCV has an unusually narrow tissue tropism which restricts its productive replication to oligodendrocytes, a subclass of glial cells in the CNS which are responsible for production of the myelin sheath. Earlier studies by us and others have indicated that the cell type-specific tropism of JCV to glial cells is determined at the level of viral early gene transcription, which is responsible for the production of T-antigen. In collaboration with host regulatory proteins, T-antigen orchestrates subsequent events during the viral lytic cycle including viral DNA replication and late gene transcription and leads to the destruction of oligodendrocytes and demyelination of the brain. Histological analysis of PML brains has revealed that in addition to demyelination of white matter, a number of abnormalities are observed in both surviving oligodendrocytes and the other subclass of glial cells, astrocytes, suggesting dyregulation of pathways responsible for host cell homeostasis including control of the cell cycle and DNA repair. In support of this notion, results from immunohistochemical staining of clinical samples revealed the presence of double-strand breaks, indicative of dysfunctionality of DNA repair, an unusual expression of proteins which are in control of cellular proliferation, and apoptosis. Accordingly, results from in vitro cell culture infection revealed that the JCV early protein, T-antigen, and the viral non-structural protein, Agnoprotein, by dysregulating the level of expression and activities of factors involved in cell cycle control and DNA repair may affect a process that leads to the development of some of the pathological features that are seen in oligodendrocytes and astrocytes of PML. In this research project we aim to: (i) investigate the effect of JCV early protein on process involved in genomic stability at the early stage of viral infection by analyzing its interaction with IRS-1, p53, and Rad51, three critical proteins that, by communicating with T-antigen, can influence the process of homologous recombination; (ii) determine the molecular mechanisms by which the JCV late protein, Agnoprotein, through its association with p53 and Ku70 dysregulates non-homologous end joining during the course of infection. Such comprehensive studies of viral -host interaction at the molecular level should enable us to understand the molecular pathogenesis of JCV-CNS disorders and provide us with pivotal information for therapeutic intervention.

人类多瘤病毒 (JCV) 是进行性多灶性白质脑病 (PML) 的病原体，PML 是一种致命的中枢神经系统 (CNS) 脱髓鞘疾病，通常影响免疫抑制患者。 JCV 具有异常狭窄的组织向性，这限制了其对少突胶质细胞的有效复制，少突胶质细胞是中枢神经系统中负责髓鞘生成的神经胶质细胞的一个亚类。我们和其他人的早期研究表明，JCV 对神经胶质细胞的细胞类型特异性趋向性是在病毒早期基因转录水平上决定的，该转录负责 T 抗原的产生。 T 抗原与宿主调节蛋白合作，协调病毒裂解周期中的后续事件，包括病毒 DNA 复制和晚期基因转录，并​​导致破坏 少突胶质细胞和大脑脱髓鞘。 PML大脑的组织学分析表明，除了白质脱髓鞘之外，在存活的少突胶质细胞和胶质细胞的其他亚类星形胶质细胞中都观察到了许多异常，这表明负责宿主细胞稳态的通路失调，包括细胞周期的控制和DNA修复。为了支持这一观点，临床样本的免疫组织化学染色结果显示存在双链断裂，表明 DNA 修复功能障碍，即受控蛋白质的异常表达 细胞增殖和细胞凋亡。因此，体外细胞培养物感染的结果表明，JCV早期蛋白、T抗原和病毒非结构蛋白Agno蛋白通过调节参与细胞周期控制和DNA修复的因子的表达水平和活性，可能影响导致PML少突胶质细胞和星形胶质细胞中所见的一些病理特征发展的过程。在这个研究项目中，我们的目标是：（i）通过分析 JCV 早期蛋白与 IRS-1、p53 和 Rad51 的相互作用，研究 JCV 早期蛋白对病毒感染早期基因组稳定性过程的影响，这三种关键蛋白通过与 T 抗原通讯，可以影响同源重组过程； (ii)确定JCV晚期蛋白Agno蛋白通过其与p53和Ku70的关联在感染过程中失调非同源末端连接的分子机制。这种在分子水平上对病毒与宿主相互作用的全面研究应该使我们能够了解 JCV-CNS 疾病的分子发病机制，并为我们提供治疗干预的关键信息。