Molecular and cellular mechanisms of dendritic cell trans-infection in vitro and

树突状细胞体外转染的分子和细胞机制

• 批准号: 8074064
• 负责人: DAVID J MCDONALD
• 金额: $ 31.09万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8074064
• 关键词: Antigen Presentation; Antigens; Area; Binding; CCR5 gene; CD4 Positive T Lymphocytes; CXCR4 gene; Cell surface; Cells; Chemicals; Chronic; Coculture Techniques; Complex; Conflict (Psychology); Data; Dendritic Cells; Disease; Drug Delivery Systems; Endocytosis; Equilibrium; Family; Goals; Green Fluorescent Proteins; HIV; HIV Antigens; HIV Infections; HIV Receptors; Image Analysis; Immune; Immune response; Immune system; Immunity; In Vitro; Individual; Infection; Intervention; Knowledge; Life; Lipopolysaccharides; Lymphoid; Lymphoid Tissue; Mediating; Membrane; Microscopy; Modeling; Molecular; Myelogenous; Pathway interactions; Phase; Population; Prevention; Process; Reporting; Resolution; Role; Site; Source; Structure; Subcellular structure; Surface; Synapses; System; T cell response; T-Lymphocyte; Testing; Therapeutic; Time; Tissues; Viral; Viral Antigens; Virion; Virus; antigen processing; cell type; design; human disease; in vivo; inhibitor/antagonist; novel; novel therapeutics; novel vaccines; particle; pathogen; public health relevance; research study; synaptogenesis; trafficking; transmission process

DESCRIPTION (provided by applicant): Dendritic cells (DCs) comprise a diverse family of cell types whose primary function is to initiate and drive immune responses. Myeloid dendritic cells patrol areas of the body that are susceptible to invasion by pathogens and engulf antigens for later processing and presentation to T lymphocytes. HIV has appropriated this feature of the immune system to better establish and maintain infection of its primary target--CD4 positive T cells. DCs can efficiently bind and transfer HIV infection without themselves becoming infected, a process called trans-infection, and can in fact greatly enhance the infection of CD4 T cells. DCs are therefore potentially important in initiating HIV infections and in the persistence of viral reservoirs in infected individuals, making them an attractive target for new therapies aimed at prevention and treatment of HIV infection. Using high resolution live-cell microscopy, my lab tracks the trafficking of green fluorescent protein (GFP) tagged HIV within and between DCs and T- cells during trans-infection. We have previously reported that DCs enhance HIV infection by concentrating the virus to sites of contact with CD4 T cells at the same time that the HIV receptors (CD4 and CXCR4/CCR5) are concentrated on the surface of the T cell, forming a structure we called the infectious synapse. More recently, we have discovered that HIV is routed through a unique, pocket- like intracellular structure within DCs prior to transmission to the T cell, and that individual particles are delivered from the pocket and efficiently fuse into the T cell at the infectious synapse. The experiments proposed here will define the molecular machinery involved in the formation of this pocket structure in DCs and how HIV escapes from the pocket at the infectious synapse. We will test the role of DC trans- infection in cultured lymphoid tissue explants using novel fluorescently tagged HIV strains that allow us to track HIV dissemination among infected cell populations. Using specific chemical and molecular inhibitors, we will identify key regulators of trans-infection and explore the relationship between antigen presentation and trans-infection with the goal of tipping the balance away from trans-infection and toward degradation and immune presentation of the virus. We will apply the knowledge gained in the second phase of this study to intervene in trans-infection in the tissue explant model, with the goal of developing therapeutic strategies that reduce DC mediated HIV dissemination and enhance immune control. PUBLIC HEALTH RELEVANCE: During the course of HIV disease, the human immune system engages in a pitched battle with the virus, however the potent CD4 T cell responses that are elicited are the very thing that provides the fuel for HIV infection. Dendritic cells initiate protective immunity by presenting viral antigens to CD4 T cells, however they also elicit destructive infection of T cells through trans-infection. Our studies will define the pathways that distinguish immune presentation and viral dissemination by DCs and provide a framework for understanding these interactions in living tissues. The long-term goal of this study is to discover new drug targets to intervene in the transmission of HIV by DCs, shifting the balance away from trans-infection in favor of immune presentation and control of HIV disease.

描述（由申请人提供）：树突状细胞（DC）构成了一种多样化的细胞类型家族，其主要功能是启动和驱动免疫反应。骨髓的树突状细胞巡逻体内容易受到病原体和吞噬抗原侵袭的侵袭的人体，以便以后的加工和表现为T淋巴细胞。 HIV已将免疫系统的这一特征赋予了更好的建立和维持其主要靶标-CD4阳性T细胞的感染。 DC可以有效地结合和转移HIV感染而不会自身感染，这是一种称为trans侵的过程，实际上可以大大增强CD4 T细胞的感染。因此，DC在启动HIV感染和感染个体的病毒储存库的持续性方面可能很重要，这使其成为旨在预防和治疗HIV感染的新疗法的有吸引力的靶标。我的实验室使用高分辨率的活细胞显微镜跟踪了在转染期间DC和T细胞之间标记的HIV的绿色荧光蛋白（GFP）的运输。我们先前已经报道说，DC通过将病毒浓缩到与CD4 T细胞接触的部位的同时，同时将HIV受体（CD4和CXCR4/CCR5）集中在T细胞表面上，从而增强了HIV感染，从而形成了一种结构，我们称为感染性突触。最近，我们发现HIV是通过传输到T细胞之前DC内独特的，类似的袋中的细胞内结构的路线，并且单个颗粒是从口袋中传递的，并有效地将感染性突触的T细胞融合到T细胞中。这里提出的实验将定义与DC中这种口袋结构形成的分子机械以及HIV如何从传染性突触中的口袋中逃脱。我们将使用新型的荧光标记的HIV菌株来测试直流感染在培养的淋巴组织外植体中的作用，从而使我们能够跟踪感染细胞群体中的HIV传播。使用特定的化学和分子抑制剂，我们将确定转染的关键调节剂，并探索抗原呈递和转染之间的关系，以使平衡从转染，降解和免疫表现降解。我们将应用本研究第二阶段获得的知识来干预组织外植体模型中的转染，目的是制定治疗策略，以减少DC介导的HIV传播并增强免疫控制。 公共卫生相关性：在艾滋病毒疾病过程中，人类免疫系统与病毒进行了激烈的斗争，但是引起的有效的CD4 T细胞反应是为HIV感染提供燃料的原因。树突状细胞通过向CD4 T细胞呈现病毒抗原来启动保护性免疫，但是它们也通过转染引起T细胞的破坏性感染。我们的研究将定义区分DC的免疫表现和病毒传播的途径，并提供一个框架，以理解生物组织中的这些相互作用。这项研究的长期目标是发现新的药物靶标，以干预DC的艾滋病毒传播，将平衡从转染转移，而转化，而转移了艾滋病毒疾病的免疫表现和控制。