HIV LTR AND VIRAL GENE EXPRESSION IN THE HUMAN CNS

HIV LTR 和人类中枢神经系统中的病毒基因表达

• 批准号: 6112323
• 负责人: Brian Wigdahl
• 金额: $ 20.74万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6112323
• 关键词: AIDS dementia complex; DNA footprinting; HIV infections; astrocytes; brain cell; cell type; embryo /fetus tissue /cell culture; gel mobility shift assay; gene expression; genetic regulatory element; host organism interaction; human fetus tissue; human genetic material tag; human immunodeficiency virus 1; microglia; molecular cloning; nervous system infection; neurotropic virus; nucleic acid repetitive sequence; oligodendroglia; site directed mutagenesis; transcription factor; virus genetics; virus replication

Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) results in progressive neurologic dysfunction in pediatric and adult acquired immunodeficiency syndrome (AIDS) patients. The identification of HIV markers within multinucleated giant cells structure derived from cells of the monocyte/macrophage lineage (including brain microglial cells) represents one of the major indicators of HIV CNS invasion. However, due to the limited sensitivity of the techniques utilized to detect viral markers and the refractile nature of neuroglial cells to productive HIV-1 infection in vitro, it remains possible that brain neuroglial cells amy also be infected in vivo with infection likely to occur as a restricted infection with low level viral gene expression leading to cellular perturbation and neuroglial dysfunction. These studies suggest the neurologic dysfunction involves the interaction of HIV-1 with target cells of both immune and nervous system origin that include monocyte/macrophage, microglial cells, astrocytes, and to a lesser extent, olligodendrocytes and neurons. Subsequent to viral entry, the outcome of HIV-1 infection in a given cell type within the immune or nervous system is critically dependent on cellular factors that interact with retroviral LTR sequences that are localized within the U3, R, and U5 regions of the HIV-1 LTR and that the level of expression is potently unregulated by the viral transactivator protein Tat. Furthermore, studies have also demonstrated that cellular factors may also regulate the level of LTR activity. As a consequences of cellular factor-mediated modulation of LTR activity, it is possible that cell-type specific factors may play a critical role in modulating viral activity in neuroglial cells. Therefore, the level of viral expression in the brain may not only be influenced by the cell type infected but also by the state of cellular differentiation and by extracellular signals. Based on these observations, we propose to characterize the neuroglial cell factors and viral sequences that may be involved in regulating HIV-1 LTR activity and viral gene expression in the CNS. The specific aims of the proposed studies are to utilize a series of cell lines and primary cell populations of immune and nervous system origin to (1) identify cis- acting sequences involved in regulating HIV-1 LTR activity utilizing transient expression assays; (2) characterize the contribution of selected cis-acting sequences to HIV-1 LTR activity in the context of infectious viral constructs; (3) characterize trans-acting factors participating in cell type-specific regulation of HIV-1 LTR activity in cells of human CNS origin and; (4) identify sequence variations in PCR- derived HIV-1 LTR clinical isolates which contribute to cell type- specific regulation of LTR activity in cells of human CNS origin. Characterization of the neuroglial cell populations may have direct bearing on our understanding of the neurologic dysfunction associated with HIV-1 infection in humans.

人类免疫缺陷病毒（HIV）中枢神经系统感染 中枢神经系统（CNS）导致儿童进行性神经功能障碍 和成人获得性免疫缺陷综合征（AIDS）患者。 的 多核巨细胞结构中HIV标志物鉴定 来源于单核细胞/巨噬细胞谱系的细胞（包括脑 小胶质细胞）是HIV CNS的主要指标之一 入侵 然而，由于这些技术的灵敏度有限， 用于检测病毒标志物和神经胶质细胞的增殖活性， 细胞生产的HIV-1感染在体外，它仍然有可能， 脑神经胶质细胞也可能在体内被感染 以低水平病毒基因表达的限制性感染发生 导致细胞扰动和神经胶质功能障碍。 这些 研究表明，神经功能障碍涉及以下因素的相互作用： HIV-1与免疫和神经系统来源的靶细胞， 包括单核细胞/巨噬细胞、小神经胶质细胞、星形胶质细胞，且 少部分为少突胶质细胞和神经元。 病毒进入后， HIV-1感染在免疫系统内特定细胞类型中的结果，或 神经系统严重依赖于细胞因子， 逆转录病毒LTR序列位于U3，R， HIV-1 LTR的U 5区域，并且表达水平是有效的。 不受病毒反式激活蛋白达特的调节。 此外，委员会认为， 研究还表明，细胞因子也可以调节 LTR活性水平。 作为细胞因子介导的 LTR活性的调节，可能是细胞类型特异性的 因子可能在调节病毒活性中起关键作用， 神经胶质细胞 因此，病毒在大脑中的表达水平 不仅受感染细胞类型的影响， 细胞分化状态和细胞外信号。 基于 根据这些观察，我们建议将神经胶质细胞 可能参与调节HIV-1 LTR的因子和病毒序列 活性和病毒基因在CNS中的表达。 的具体目标 提出的研究是利用一系列细胞系和原代细胞 免疫和神经系统来源的群体，以（1）识别顺式- 参与调节HIV-1 LTR活性的作用序列， 瞬时表达测定;（2）表征 选择的顺式作用序列对HIV-1 LTR活性的影响 感染性病毒构建体;（3）表征反式作用因子 参与HIV-1 LTR活性的细胞类型特异性调节， 人CNS来源的细胞;（4）鉴定PCR中的序列变异。 衍生的HIV-1 LTR临床分离株，其导致细胞类型- 在人CNS来源的细胞中特异性调节LTR活性。 神经胶质细胞群的特征可能直接影响 影响了我们对神经功能障碍的理解 人类感染HIV-1病毒。