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: 6590953
• 负责人: WILLIAM AUSTIN O'BRIEN
• 金额: $ 33.19万
• 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/6590953
• 关键词: HIV infections; SDS polyacrylamide gel electrophoresis; biological signal transduction; cell membrane; clinical research; confocal scanning microscopy; cytokine; cytokine receptors; endocytosis; flow cytometry; glycoproteins; human immunodeficiency virus 1; human tissue; immunoprecipitation; macrophage; monoclonal antibody; polymerase chain reaction; virion; virus infection mechanism; virus receptors

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CD 4和趋化因子辅助受体（CCR 5或CXCR 4）相互作用。然而，可能还有其他细胞因素参与决定HIV进入的效率，这可能（部分）解释了来自不同供体的原代细胞对HIV感染易感性的显著差异。在鉴定巨噬细胞（Mphi）中H1 V辅因子的研究中，我们发现四种独立产生的针对四跨膜糖蛋白CD 63的单克隆抗体（mAb）可以阻断HIV进入Mphi，但不能阻断T细胞。CD 63的功能尚未完全了解，但另一种四聚糖蛋白CD 81已被提出作为丙型肝炎病毒的受体，CD 9与猫免疫缺陷病毒（FIV）感染有关。CD 63以前被认为是血小板活化标志物，以及恶性黑色素瘤的标志物，两者似乎都与逆转录病毒感染无关。我们的实验将研究CD 63在HIV进入MO中的作用。这些研究可能会导致针对HIV进入的新型抗逆转录病毒疗法的发展。我们将在四年内实现这些目标：具体目标1。为了验证CD 63在促进HIV进入Mphi中具有特定作用的假设，我们将确定CD 63介导的HIV进入的潜在机制。实验将根据初始研究优先进行，这些研究更精确地确定了参与抗CD 63抑制的HIV进入步骤，将初始研究导向晚期进入事件，如CD 63在CD 4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CD 63相互作用，包括结合和CCR 5依赖性进入途径。具体目标2。检验HIV靶细胞之间的细胞特异性差异影响CD 63在促进HIV进入中的作用的假设。我们将控制并检测不同水平的受体/辅助受体/CD 63表达和活化标志物对原代CD 4+细胞中抗CD 63抑制易感性的影响。我们还将检测抗CD 63抑制的细胞系模型，这将有助于这些研究中的细胞操作和抑制作用的一致性。具体目标3。验证抗CD 63单克隆抗体可抑制不同HIV-1原代株感染Mphi的假设。这将包括亚型B和非亚型B毒株，包括一些专门使用CCR 5作为有效感染的辅助受体（R5）的毒株，以及使用CXCR 4或CCR 5的双嗜性毒株（R5 X4），以及能够在Me中复制的X4毒株。实现这些目标将提供对HIV-1进入机制的重要新见解，并可能为抗逆转录病毒治疗提供重要的新靶点。