Roles of Macropinocytosis in HIV-1 infection of CD4+ T Cells

巨胞饮作用在 HIV-1 感染 CD4 T 细胞中的作用

• 批准号: 10652492
• 负责人: PHILIP D KING
• 金额: $ 64.25万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-23 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10652492
• 关键词: Acquired Immunodeficiency Syndrome; Affect; Binding; Biology; CCR5 gene; CD4 Positive T Lymphocytes; CXCR4 gene; Capsid; Cell Line; Cell Nucleus; Cell fusion; Cell membrane; Cell physiology; Cell surface; Cells; Clathrin; Complex; Cytoplasm; Data; Endocytosis; Environment; Event; Genes; Genetic; Goals; HIV; HIV Envelope Protein gp120; HIV Infections; HIV-1; Human; Immunology; Infection; Knowledge; Laboratories; Location; Mediating; Metabolism; Microscopic; Molecular; Molecular Conformation; N-terminal; Nature; Outcome; Pathway interactions; Peptides; Play; Process; Productivity; Property; Reporting; Research; Role; Signal Transduction; Surface; T-Cell Activation; T-Lymphocyte; Testing; Viral; Virion; Virus; Virus Diseases; cell type; env Glycoproteins; experimental study; improved; novel; particle; permissiveness; pharmacologic; receptor; receptor binding; small molecule

Title: Roles of Macropinocytosis in HIV-1 infection of CD4+ T Cells Project Summary: Host cell entry is the first step in the replication cycle of HIV-1, the causative agent of AIDS. Although receptor binding of viral Env glycoprotein and subsequent virus-cell fusion during the virus entry process have been described in detail, subcellular locations of these events remain to be determined. In particular, despite the importance of CD4+ T lymphocytes as a natural host cell type for HIV-1, the contribution of virion endocytosis to HIV-1 infection of CD4+ T cells remains poorly understood. Previous studies of HIV-1 entry into T cells have largely focused on clathrin-mediated endocytosis and cell surface fusion. However, our team recently discovered that primary CD4+ T cells engage in robust macropinocytosis, a large-scale, clathrin-independent form of endocytosis. Importantly, our preliminary data indicate that pharmacological inhibition of macropinocytosis blocks both internalization of HIV-1 particles and productive infection in primary human CD4+ T cells. In contrast, the same treatment does not affect HIV infection of a commonly used CD4+ T cell line. These results suggest that the macropinocytic entry is a hitherto overlooked mode of HIV-1 entry that contributes to infection of primary human CD4+ T cells. Interestingly, our preliminary study also showed that inhibition of macropinocytosis after completion of virus internalization also blocks expression of virus-encoded genes, suggesting that macropinocytosis has another later role in productive HIV infection, which is separable from virus internalization. In the current application, we propose to determine the roles of macropinocytosis in productive infection of primary CD4+ T cells. Our long-term goal is to fully describe cellular mechanisms that promote HIV-1 infection and to use the obtained knowledge for developing antiviral strategies. Our central hypothesis in this application is that macropinocytosis in primary human CD4+ T cells contributes to productive infection as a major HIV-1 entry pathway and as a cellular function necessary for maintaining a permissive environment for the virus. To test this hypothesis, we plan to determine: 1) the extent to which macropinocytic internalization contributes to productive HIV entry into primary human CD4+ T cells; 2) the roles played by Env-receptor interactions in promoting HIV-1 macropinocytosis; 3) the influence of macropinosome environment on HIV-1 entry; and 4) the nature of post-internalization macropinocytosis function that promotes productive infection. The outcomes of the experiments outlined in this proposal will likely fill the knowledge gap in our understanding of HIV-1 entry, a fundamental aspect of the HIV-1 replication cycle, and help us develop or improve antiviral strategies that target virus entry and establishment of productive infection in CD4+ T cells.

标题：巨胞饮作用在 CD4+ T 细胞的 HIV-1 感染中的作用 项目概要： 进入宿主细胞是HIV-1（艾滋病的病原体）复制周期的第一步。虽然受体 病毒进入过程中病毒包膜糖蛋白的结合以及随后的病毒-细胞融合 尽管详细描述，这些事件的亚细胞位置仍有待确定。特别是，尽管 CD4+ T 淋巴细胞作为 HIV-1 天然宿主细胞类型的重要性，病毒颗粒内吞作用的贡献 CD4+ T 细胞与 HIV-1 感染的关系仍知之甚少。先前关于 HIV-1 进入 T 细胞的研究 主要关注网格蛋白介导的内吞作用和细胞表面融合。然而，我们团队最近 发现初级 CD4+ T 细胞参与强大的巨胞饮作用，这是一种大规模的、不依赖于网格蛋白的 内吞作用的形式。重要的是，我们的初步数据表明，药物抑制 巨胞饮作用可阻断 HIV-1 颗粒的内化和原代人类的生产性感染 CD4+ T 细胞。相比之下，相同的治疗不会影响常用 CD4+ T 细胞的 HIV 感染 线。这些结果表明巨胞饮进入是迄今为止被忽视的 HIV-1 进入模式 有助于原代人类 CD4+ T 细胞的感染。有趣的是，我们的初步研究还表明 病毒内化完成后巨胞饮作用的抑制也会阻断病毒编码的表达 基因，表明巨胞饮作用在生产性 HIV 感染中还有另一个后期作用，这是可分离的 来自病毒内化。在当前的应用中，我们建议确定巨胞饮作用在 原代 CD4+ T 细胞的生产性感染。我们的长期目标是充分描述细胞机制 促进 HIV-1 感染并利用获得的知识制定抗病毒策略。我们的中央 本申请中的假设是原代人 CD4+ T 细胞中的巨胞饮作用有助于生产 感染作为主要的 HIV-1 进入途径和维持许可所必需的细胞功能 病毒的生存环境。为了检验这个假设，我们计划确定：1）巨胞饮的程度 内化有助于 HIV 有效地进入原代人类 CD4+ T 细胞； 2）所扮演的角色 环境受体相互作用促进 HIV-1 巨胞饮作用； 3）大胞质体的影响 HIV-1 进入的环境； 4) 促进内化后巨胞饮功能的性质 生产性感染。本提案中概述的实验结果可能会填补知识空白 帮助我们了解 HIV-1 进入（HIV-1 复制周期的一个基本方面），并帮助我们开发 或改进针对病毒进入并在 CD4+ T 细胞中建立有效感染的抗病毒策略。