MICROGLIA, CYTOKINE AND HIV

中枢神经系统（CNS）功能障碍是一个突出的特点， 艾滋病患者。多达70%的艾滋病患者表现出神经系统 疾病过程中的功能障碍，以及神经系统 这些表现对许多人来说是导致临床问题的原因。有 HIV-1直接感染CNS的重要证据， 内存在HlV-1病毒基因组、病毒抗原和病毒颗粒 脑巨噬细胞和小神经胶质细胞已经被很好地记录。我们有 建立并表征了用于研究的人神经胶质细胞培养物， HIV-1感染和发病机制。 我们已经确定， HIV-1在体外可有效感染孕三个月的人小胶质细胞。 此外，小胶质细胞和星形胶质细胞都产生细胞因子， 以相互依存的方式。 在本申请中，我们建议 研究HIV-1作为细胞因子产生的直接调节剂在 小胶质细胞，以及星形胶质细胞作为中间细胞连接 小胶质细胞和靶细胞如神经元和少突胶质细胞的损伤。 本提案的指导目标是通过以下方式确定机制： HIV-1介导的功能和结构病理学与 艾滋病>有四个具体目标：1）确定HIV-1是否诱导 在培养的人胎儿小胶质细胞中产生细胞因子; 2）确定 如果HIV-1诱导培养的人胎儿产生一氧化氮， 小胶质细胞和星形胶质细胞; 3）确定细胞因子或 神经胶质细胞产生的一氧化氮对培养神经元存活和生长的影响; 检测细胞因子和一氧化氮合酶的表达 in the CNS中枢神经系统in vivo体内.有待验证的假设是，在人类中， 星形胶质细胞而不是小胶质细胞是神经毒素的主要来源 一氧化氮和HIV-1直接或间接通过可溶性 HIV感染的小胶质细胞的因子，可能激活星形胶质细胞诱导 一氧化氮合酶（iNOS）途径。各种实验室的能力 HIV-1菌株和临床分离株激活小胶质-星形胶质细胞 细胞因子级联和高输出一氧化氮的产生将是 考察一氧化氮和细胞因子作为HIV-1的结果产生 将测试小胶质细胞的自分泌和旁分泌 在体外对星形胶质细胞和小胶质细胞的影响，因为一氧化氮已被 被证明是细胞生长和免疫功能的重要调节剂。 最后，使用从晚期建立的人胎儿神经元细胞培养物， 中期妊娠流产，我们建议研究这些影响 关于细胞死亡机制的假定神经毒素。

Central nervous system (CNS) dysfunction is a prominent feature in patients with AIDS. As many as 70% of AIDS patients show neurological dysfunctions during the course of the disease, and nervous system manifestations are leading clinical problems for many. There is significant evidence for direct infection of the CNS by HIV-1, and the presence of HlV-1 viral genome, viral antigens and viral particles within brain macrophages and microglia has been well documented. We have established and characterized human glial cell cultures for the study of HIV-1 infection and pathogenesis. We have determined that late second trimester human microglia can be productively infected by HIV-1 in vitro. In addition, both microglia and astrocytes produce cytokines and growth factors in an interdependent manner. In this application, we propose to examine the role of HIV-1 as a direct modulator of cytokine production in microglia, and the role of astrocytes as an intermediary cell linking microglia and injury of target cells such as neurons and oligodendroglia. The guiding objectives of this proposal are to determine the mechanisms by which HIV-1 mediates functional and structural pathology associated with AIDS> There are four specific aims: 1) to determine if HIV-1 induces the production of cytokines in cultured human fetal microglia; 2) to determine if HIV-1 induces the production of nitric oxide in cultured human fetal microglia and astrocytes; 3) to determine the effects of cytokines or nitric oxide produced by glia on neuronal survival and growth in culture; and 4) to determine the expression of cytokines and nitric oxide synthase in the CNS in vivo. The hypothesis to be tested is that in humans, astrocytes rather than microglia are the major source of the neurotoxin nitric oxide and that HIV-1 directly, or indirectly through soluble factors from HIV-infected microglia, may activate the astrocyte inducible nitric oxide synthase (iNOS) pathway. The ability of various laboratory strains and clinical isolates of HIV-1 to activate microglia-astrocyte cytokine cascades and high output nitric oxide generation will be examined. Nitric oxide and cytokines produced as a result of HIV-1 exposure of microglia will be tested for their autocrine and paracrine effects on astrocytes and microglia in vitro, since nitric oxide has been shown to be a profound modulator of cell growth and immune function. Finally, using human fetal neuronal cell cultures established from late second trimester abortuses, we propose to study the effects of these putative neurotoxins with respect to the mechanisms of cell death.