HIV ENV & MACROPHAGE CHEMOKINE RECEPTOR IONIC SIGNALING

艾滋病毒环境病毒

• 批准号: 6312479
• 负责人: BRUCE D FREEDMAN
• 金额: $ 27.74万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6312479
• 关键词: CD4 molecule; HIV envelope protein gp120; HIV infections; biological signal transduction; calcium flux; clinical research; cytokine receptors; feline immunodeficiency virus; human immunodeficiency virus 1; human tissue; intracellular transport; macrophage; membrane channels; receptor coupling; virus infection mechanism

DESCRIPTION: The chemokine receptors CCR5 & CXCR4 serve as co-receptors for HIV-1 entry. Since their normal function is to transduce signals in response to chemokines, HIV-1 gp12O could also activate intracellular signals, with consequences for pathogenesis by modifying viral entry, post-entry steps or cell functions apart from infection. Ca+2 elevations or protein phosphorylation responses to gp12O through CCR5 or CXCR4 have been reported in lymphoid cells in some but not all studies. While co-receptor signaling domains are dispensable for entry in transfected cell lines, recent studies suggest that signaling may affect entry or post-entry infection steps in some primary cells. Macrophages express CD4, CCR5 & CXCR4, and are important targets of HIV-1 in vivo but gpl2O/chemokine receptor signaling has not been addressed in them. Indeed, relatively little is known in general about mechanisms of chemokine receptor signaling in primary macrophages. In preliminary studies, we have found that gp12O initiates intracellular signals in primary human macrophages through CCR5 & CXCR4, activates K+, Cr, & non-selective cation channels, and elevates intracellular Ca +. R5 and X5 gp12O elicited qualitatively similar but quantitatively different responses and, unexpectedly, the patterns of ion channel signaling elicited by gp120 differed from those elicited by the receptors' natural chemokine ligands. Our hypothesis is that HIV-1 Env initiates intracellular signals in macrophages through the co-receptors that lead to critical alterations in cellular function, virus entry, and/or post-entry steps of infection. To better understand the mechanisms of chemokine receptor signaling & ion channel activation in macrophages by gp120 (as well as chemokines), and consequences of gp120-mediated signals for macrophage function & infection, we will (a) Define the ionic signaling pathways activated in primary macrophages by gp 120 using primary & prototype HIV- 1 & SIV strains and strains that differ in ability to utilize macrophage chemokine receptors, and chemokines; (b) Identify the mechanisms of chemokine receptor ionic signaling in macrophages by defining CCR5 & CXCR4 coupling to K+, Cl- & non-selective cation channels, role of CD4 co-engagement, source & coupling for Ca2 elevations, and structural elements in CCR5 involved; (c) Determine the role of Env signaling in entry, infection & replication in macrophages, including the formation & significance of gp12O-induced capping as well as post-entry events, and; (d) Determine the effects of gp120 signaling on macrophage function such as aberrant secretion of mediators, phagocytosis, and killing.

描述：趋化因子受体CCR5＆CXCR4充当共振子。 HIV-1条目。由于它们的正常功能是响应于 趋化因子，HIV-1 GP12O还可以激活细胞内信号，并具有 通过修改病毒进入，进入后步骤或 细胞功能除了感染外。 CA+2高升高或蛋白质磷酸化 通过CCR5或CXCR4对GP12O的反应已在淋巴样细胞中报道 在某些但不是所有研究中。而共受体信号域是 最近的研究可用于进入转染的细胞系，最近的研究表明 信号传导可能会影响某些主要细胞中的进入或进入后感染步骤。 巨噬细胞表达CD4，CCR5和CXCR4，是HIV-1的重要靶标 体内尚未解决体内GPL2O/趋化因子受体信号传导。 实际上，关于趋化因子机制的一般知名度很少 一级巨噬细胞中的受体信号传导。在初步研究中，我们有 发现GP12O在原发性巨噬细胞中启动细胞内信号 通过CCR5和CXCR4，激活K+，CR和非选择性阳离子通道，并且 提高细胞内Ca +。 R5和X5 GP12O在定性上引起相似的引起 定量不同的响应以及意外的离子模式 GP120引起的通道信号与由 受体的天然趋化因子配体。我们的假设是HIV-1 Env 通过共受体启动巨噬细胞中的细胞内信号 导致细胞功能，病毒进入和/或的严重改变 感染后的步骤。 更好地了解趋化因子受体信号传导和离子的机制 GP120（以及趋化因子）和巨噬细胞中的通道激活 GP120介导的巨噬细胞功能和感染信号的后果，我们 威尔（a）定义在原发性巨噬细胞中激活的离子信号通路 使用gp 120使用主要和原型HIV-1和SIV菌株和菌株 利用巨噬细胞趋化因子受体和趋化因子的能力有所不同。 （b）确定趋化因子受体离子信号传导的机制 通过将CCR5和CXCR4耦合定义为K+，Cl-和非选择性阳离子，巨噬细胞 渠道，CD4共同参与的作用，CA2高程的来源和耦合以及 CCR5中涉及的结构元素； （c）确定ENV信号的作用 在巨噬细胞中的进入，感染和复制中，包括形成和 GP12O诱导的封盖以及进入后事件的重要性，以及； （D） 确定GP120信号传导对巨噬细胞功能的影响，例如 介体，吞噬作用和杀戮的异常分泌。