HIV ENV & MACROPHAGE CHEMOKINE RECEPTOR IONIC SIGNALING

描述：趋化因子受体CCR5和CXCR4是 HIV-1进入。因为它们正常功能是转换信号以响应 趋化因子，HIV-1 gp120也可以激活细胞内信号， 通过修改病毒进入、进入后步骤或 细胞的功能不受感染的影响。钙离子升高或蛋白质磷酸化 据报道，淋巴细胞通过CCR5或CXCR4对gp120O产生反应 在一些但不是所有的研究中。而共受体信号域是 对于进入转基因细胞系来说是可有可无的，最近的研究表明 信号转导可能会影响某些原代细胞的进入或进入后感染步骤。 巨噬细胞表达CD4、CCR5和CXCR4，是HIV-1感染的重要靶点 体内，但gpl2O/趋化因子受体信号转导尚未在它们中得到解决。 事实上，人们对趋化因子的作用机制知之甚少。 原代巨噬细胞中的受体信号。在初步研究中，我们有 发现gp120在原代人巨噬细胞中启动细胞内信号 通过CCR5和CXCR4，激活钾、铬和非选择性阳离子通道，以及 升高细胞内钙。R5和X5 gp120在性质上相似，但 数量上不同的反应，以及出乎意料的离子模式 由gp120引发的通道信号与由 受体的天然趋化因子配体。我们的假设是HIV-1环境 通过共同受体在巨噬细胞中启动细胞内信号 导致细胞功能严重改变、病毒入侵和/或 进入后的感染步骤。 为了更好地了解趋化因子受体信号转导机制&离子 巨噬细胞中gp120(以及趋化因子)激活的通道，以及 Gp120介导的信号对巨噬细胞功能和感染的影响 将(A)定义在原代巨噬细胞中激活的离子信号通路 由GP 120使用原代和原型HIV-1和SIV毒株以及 利用巨噬细胞趋化因子受体和趋化因子的能力不同； (B)确定趋化因子受体离子信号转导机制 巨噬细胞通过确定CCR5和CXCR4与K，Cl-和非选择性阳离子偶联 渠道，CD4共同参与的作用，钙升高的来源和耦合，以及 CCR5中的结构元件参与；(C)决定环境信号的作用 巨噬细胞的进入、感染和复制，包括形成和 Gp120诱导的封顶以及进入后事件的意义，以及；(D) 确定gp120信号对巨噬细胞功能的影响，如 介质的异常分泌、吞噬和杀戮。

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.