Role of Tetraspan Glycoproteins (CD63) in HIV Entry

四跨糖蛋白 (CD63) 在 HIV 进入中的作用

• 批准号: 6688454
• 负责人: WILLIAM AUSTIN O'BRIEN
• 金额: $ 33.53万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-12-15 至 2005-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6688454
• 关键词: Role; Tetraspan; Glycoproteins; CD63; HIV

DESCRIPTION (provided by applicant): HIV infection of primary human cells typically requires interaction with both the primary receptor CD4 and a chemokine coreceptor, either CCR5 or CXCR4. There may be additional cellular factors involved in determining the efficiency of HIV entry, however, which may explain (in part) the marked differences in susceptibility to HIV infection among primary cells from different donors. During studies to identify H1V cofactors in macrophages (Mphi), we found that four independently generated monoclonal antibodies (mAb) to a tetraspan membrane glycoprotein, CD63, could block HIV entry into Mphi, but not T-cells. The function of CD63 is not well understood, but another tetraspan protein, CD81, has been proposed as a receptor for Hepatitis C virus, and CD9 has been implicated in infection by feline immunodeficiency virus (FIV). CD63 has previously been recognized as a platelet activation marker, as well as a marker for malignant melanoma, both seemingly unrelated to retroviral infection. Our experiments will investigate the role of CD63 in HIV entry into MO). These studies may lead to development of novel antiretroviral therapies targeting HIV entry. We will pursue these Aims over four years: Specific Aim 1. To test the hypothesis that CD63 has a specific role in facilitating HIV entry into Mphi, we will identify potential mechanisms of CD63-mediated HIV entry. Experiments will be prioritized based on initial studies that more precisely identify the step of HIV entry involved in anti-CD63 inhibition, directing initial studies toward late entry events, such as the role of CD63 in CD4 turnover or virus/receptor endocytosis and signal transduction, or early events, such as anti-CD63 interactions at the cell surface including binding and CCR5-dependent entry pathways. Specific Aim 2. To test the hypothesis that cell-specific differences between HIV target cells affect the role of CD63 in facilitating HIV entry. We will control for and test effects of various levels of receptor/coreceptor/CD63 expression and activation markers on susceptibility to anti-CD63 inhibition in primary CD4+ cells. We will also test cell line models of anti-CD63 inhibition, which would facilitate cell manipulation and the consistency of inhibitory effects in these studies. Specific Aim 3. To test the hypothesis that infection of Mphi by diverse primary HIV-1 strains can be inhibited by anti- CD63 mAb. This will include both subtype B and non-subtype B strains, including some that exclusively use CCR5 as a coreceptor for efficient infection (R5), as well as dual-tropic strains that use either CXCR4 or CCR5 (R5X4), and X4 strains able to replicate in Me. Achieving these Aims will provide important new insights into the mechanism of HIV-1 entry, and may well provide important new targets for antiretroviraI therapy.

描述(由申请人提供)： HIV感染原代人类细胞通常需要与主要受体CD4和趋化因子辅助受体CCR5或CXCR4相互作用。然而，可能还有其他细胞因素参与决定艾滋病毒进入的效率，这可能在一定程度上解释了不同捐赠者的初级细胞对艾滋病毒感染的明显差异。在鉴定巨噬细胞(Mphi)中H1V辅助因子的研究中，我们发现四种独立产生的抗四环素膜糖蛋白CD63的单抗可以阻止HIV进入Mphi，但不能阻止T细胞。CD63的功能还不是很清楚，但另一种蛋白CD81被认为是丙型肝炎病毒的受体，CD9与猫免疫缺陷病毒(FIV)的感染有关。CD63此前被认为是一种血小板激活标志，也是恶性黑色素瘤的标志，两者似乎都与逆转录病毒感染无关。我们的实验将探讨CD63在HIV进入MO中的作用。这些研究可能导致针对艾滋病毒进入的新型抗逆转录病毒疗法的开发。我们将在四年内实现这些目标：具体目标1.为了验证CD63在促进HIV进入MPHI方面具有特定作用的假设，我们将确定CD63介导的HIV进入MPHI的潜在机制。实验将基于更准确地确定HIV进入参与抗CD63抑制的步骤的初步研究，将初步研究引向较晚的进入事件，如CD63在CD4周转或病毒/受体内吞和信号转导中的作用，或早期事件，如细胞表面的抗CD63相互作用，包括结合和CCR5依赖的进入途径。具体目的2.检验HIV靶细胞之间的细胞特异性差异影响CD63促进HIV进入的作用的假设。我们将控制和测试不同水平的受体/辅受体/CD63表达和激活标记对原代CD4+细胞抗CD63抑制敏感性的影响。我们还将测试抗CD63抑制的细胞系模型，这将有助于细胞操作和抑制效果的一致性在这些研究中。具体目的3.验证抗CD63单抗可抑制不同HIV-1原代毒株感染Mphi的假设。这将包括B亚型和非B亚型菌株，包括一些专门使用CCR5作为有效感染的辅助受体(R5)的菌株，以及使用CXCR4或CCR5(R5X4)的双嗜性菌株，以及能够在Me中复制的X4菌株。实现这些目标将为了解HIV-1进入的机制提供重要的新见解，并很可能为抗逆转录病毒治疗提供重要的新靶点。