HIV LTR AND VIRAL GENE EXPRESSION IN THE HUMAN CNS

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。这个 多核巨细胞结构中HIV标志物的鉴定 来源于单核/巨噬细胞系的细胞(包括脑 小胶质细胞)是HIV中枢神经系统的主要指标之一 入侵。然而，由于这些技术的敏感性有限， 用于检测病毒标志物和神经胶质细胞的屈光特性 细胞在体外产生HIV-1感染，仍然有可能 脑神经胶质细胞AMY也可能在体内感染 以低水平病毒基因表达的限制性感染方式发生 导致细胞紊乱和神经胶质功能障碍。这些 研究表明，神经功能障碍涉及到 具有免疫和神经系统来源的靶细胞的HIV-1 包括单核/巨噬细胞、小胶质细胞、星形胶质细胞，以及 少见少突胶质细胞和神经元。在病毒进入之后， HIV-1感染在免疫或免疫系统内特定细胞类型中的结局 神经系统严重依赖于相互作用的细胞因子。 与位于U3、R和U3中的逆转录病毒LTR序列 HIV-1 LTR的U5区，并且表达水平是有效的 不受病毒反式激活蛋白Tat的调控。此外， 研究还表明，细胞因素也可能调节 LTR活动的水平。作为细胞因子介导的后果 LTR活性的调节，可能是细胞类型的特异性 因子可能在调节病毒活性方面发挥关键作用 神经胶质细胞。因此，病毒在大脑中的表达水平 可能不仅受感染细胞类型的影响，而且还受 细胞分化状态和细胞外信号。基座 基于这些观察，我们建议描述神经胶质细胞的特征。 可能参与调节HIV-1 LtR的因素和病毒序列 中枢神经系统的活性和病毒基因的表达。《公约》的具体目标 建议的研究是利用一系列细胞系和原代细胞 免疫和神经系统起源的群体(1)识别顺式- 调控HIV-1 LTR活性利用的作用序列 瞬时表达分析；(2)表征 选定的顺式作用序列对HIV-1 LTR活性的影响 感染性病毒构建物；(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 人中枢神经系统起源的细胞和；(4)鉴定PCR- 衍生HIV-1 Ltr临床分离株，有助于细胞类型- 人类中枢神经系统来源细胞中LTR活性的特异性调节。 神经胶质细胞群体的特征可能直接 关系到我们对相关神经功能障碍的理解 人类感染了HIV-1病毒。

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.