HIV GP120 Desensitization of TCell Receptor Function

HIV GP120 T细胞受体功能脱敏

• 批准号: 6599249
• 负责人: John C Cambier
• 金额: $ 14.96万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-01 至 2002-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6599249
• 关键词: AIDS; CD4 molecule; HIV envelope protein gp120; HIV infections; SCID mouse; SDS polyacrylamide gel electrophoresis; T cell receptor; affinity chromatography; apoptosis; biological signal transduction; cell aggregation; cellular immunity; gene targeting; genetically modified animals; helper T lymphocyte; human tissue; hydrolysis; immunoprecipitation; inositol phosphates; intermolecular interaction; pathologic process; phosphorylation; protein tyrosine kinase; tissue /cell culture; western blottings

DESCRIPTION: (provided by applicant) A major contributing factor in progression of HIV disease to AIDS is the loss of functional CD4+ T cells that provide critical helper activity for humoral and cell-mediated immune responses. It appears that only a small, proportion of T cell loss is attributable to lytic infection. Rather most T cells are stimulated to become antiger irresponsive and/or to undergo apoptosis by a mechanism involving of HIV gp120-induced CD4-mediatec transmembrane signal transduction. This response can apparently be induced by soluble gp120, gpl2( aggregated by endogenous anti-gp 120 antibodies, HTV itself or infected cells expressing cell surface gp120. The molecular mechanisms underlying CD4 transduction of "inhibitory" signals is unknown. Experiments proposed in this application seek to address the molecular basis and functional consequences of gp120 stimulated CD4 signaling. Studies conducted during the previous period of support have led to a quantum leap in our understanding of the inhibitory signaling circuitry activated by gp120. They show that the SH2 domain containing jnositol 5 Phosphatase SHIP and its effector, the adapter Downstream Qf Kiinase (Dok), which were previously implicate in inhibitory FcyRIIB signaling, are associated with CD4fLck complexes and are phosphorylated upon CD4 aggregation by gp 120. Further, findings indicate that linker functions of SHIP and Dok, and enzymatic activity of SHIP are activated by this stimulation. Finally, studies using T cells from SHIP knockout mice demonstrate that SI-HP is required for optimal CD4-mediated inhibition of T cell activation. Towards elucidation of this circuitiy, we propose dissection of intermolecular interactions among CD4/Lck, SHIP and Dok, and the regulatory function of these interactions (aim 1). Further studies wifi define the site within TCR signaling cascades that are the targets of SHIP and Dok (aim 2). In aim 3 we propose use of the SCID-hu thyfliv model to directly analyze the role of SHIP and Dok in HIV- 1 induced immunopathology ir human T cells. Finally, we will address the role of SHIP and Dok in progression of HIV disease to AIDS (aim 4). The studies will employ biochemical assays of signal transduction, in conjunction with gene mutation anc deletion, and human-mouse chimera to define structure-function relationships in the pathway. Finally, HIV infected patients will be employed to assess the possibility that mutations/allotypic differences which rendei this inhibitory circuit inactive may result in long term non-progression. The studies may validate SHIP as target for discovery of therapeutic agents for AIDS.

描述：（由申请人提供）进展的主要因素 艾滋病的HIV疾病是提供提供的功能性CD4+ T细胞的损失 体液和细胞介导的免疫反应的关键助手活性。它 似乎只有一小部分T细胞丢失归因于裂解 感染。相反，大多数T细胞都被刺激为反应变得不重要 和/或通过涉及HIV GP120诱导的机制进行凋亡 CD4-密元跨膜信号转导。这种反应显然可以 由可溶性GP120，GPL2诱导（由内源性抗GP 120汇总 抗体，HTV本身或表达细胞表面GP120的感染细胞。这 “抑制性”信号转导的基于CD4的分子机制为 未知。该应用中提出的实验试图解决分子 GP120的基础和功能后果刺激了CD4信号。 在上一期支持期间进行的研究导致了量子 飞跃我们对被激活的抑制信号传导电路的理解 GP120。他们表明，含有jnositol 5磷酸酶船的SH2域和 它的效应子，下游QF基因酶（DOK），以前是 与抑制性fcyriib信号有关，与CD4FLCK有关 复合物并通过GP 120聚集CD4的磷酸化。此外， 调查结果表明，船和DOK的接头功能以及酶活性 该刺激激活了船的船。最后，使用来自T细胞的T细胞的研究 船舶敲除小鼠证明了最佳CD4介导的Si-HP是必需的 抑制T细胞活化。 为了阐明这种电路，我们提出了分子间的解剖 CD4/LCK，船和DOK之间的相互作用以及这些的调节功能 互动（目标1）。进一步研究WiFi定义了TCR信号中的位点 是船舶和DOK的目标的级联（AIM 2）。在AIM 3中，我们建议使用 Scid-hu Thyfliv模型的直接分析船和Dok的作用 HIV-1诱导人类T细胞的免疫病理学。最后，我们将解决 船和DOK在艾滋病毒疾病向艾滋病发展中的作用（AIM 4）。 研究将采用信号转导的生化测定，在 与基因突变ANC删除和人鼠嵌合体的结合以定义 路径中的结构功能关系。最后，艾滋病毒感染患者 将被用来评估突变/同型差异的可能性 这是这种抑制作用不活跃的归因可能会导致长期 非进展。研究可能会验证船作为发现的目标 艾滋病的治疗剂。