Regulation of HIV Replication by Host Factors

宿主因素对 HIV 复制的调节

• 批准号: 6431629
• 负责人: Audrey Lewis Kinter
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6431629
• 关键词: AIDS therapy; CD4 molecule; HIV infections; antiviral agents; cell line; chemokine; cytokine; drug design /synthesis /production; drug screening /evaluation; gene expression; host organism interaction; human immunodeficiency virus; human tissue; immunopathology; immunoregulation; interleukin 2; leukocyte activation /transformation; leukocyte count; lymphocyte; monocyte; natural killer cells; protease inhibitor; tissue /cell culture; tumor necrosis factor alpha; virus replication; AIDS therapy; CD4 molecule; HIV infections; antiviral agents; cell line; chemokine; cytokine; drug design /synthesis /production; drug screening /evaluation; gene expression; host organism interaction; human immunodeficiency virus; human tissue; immunopathology; immunoregulation; interleukin 2; leukocyte activation /transformation; leukocyte count; lymphocyte; monocyte; natural killer cells; protease inhibitor; tissue /cell culture; tumor necrosis factor alpha; virus replication

This project was designed to investigate the cellular and molecular pathways involved in the HIV regulatory effects of cytokines/chemokines, tissue-associated factors and HIV envelope proteins. We had previously demonstrated that pro-inflammatory cytokines (PIC) and certain C-C-chemokines acted cooperatively to enhance endogenous replication of X4 strains of HIV, whereas these factors acted antagonistically in determining the level of endogenous R5 HIV strain replication. Following previous in vitro observations that IL-2 is a potent inducer of PIC and CCR5 chemokines, as well as CCR5 expression, we have analyzed various parameters in peripheral blood mononuclear cells from HIV-infected individuals receiving IL-2 subcutaneously. We have demonstrated that in vivo IL-2 administration results in significant and sustained increases CCR5 chemokine RNA and protein levels, as well as in transient increases in the expression of CCR5 in the CD4+ T lymphocyte population. Of interest, despite IL-2-associated increases in CCR5 expression, the frequency of isolation of endogenous R5 HIV from PBMC of individuals receiving IL-2 was significantly lower than that from cells of matched HIV-infected subjects not undergoing IL-2 therapy. These data suggest that, in individuals harboring predominantly R5 strains of HIV, the ability of IL-2 to induce HIV-suppressive factors in vivo, particularly CCR5 chemokines, may override HIV-inductive effects of IL-2, such as upregulation of CCR5 expression and the production of PIC. Our studies of potential effects of chemokines on HIV replication are being expanded to include analysis of numerous C-C and CXC chemokines, as well as certain lymphoid tissue (LT)-associated factors, for their effects on HIV replication in CD4+ T cells. Preliminary results suggest that certain LT-associated chemokines, such as SDF and SLC, may stimulate post-entry HIV life cycle events, such as proviral integration. Furthermore, LT-associated extracellular matrix proteins, such as laminin, appear to enhance early HIV entry events. These findings demonstrate that numerous lymphoid tissue-associated host factors are capable of upregulating HIV production from infected CD4+ T cells. The ability of HIV envelope protein (gp160) to modulate HIV expression from cellular reservoirs of HIV, such as resting latently-infected CD4+ T cells isolated from HIV-infected subjects, was investigated. HIV gp160 was found to induce infectious HIV from resting CD4+ T cells and this effect was not associated with expression of cellular activation markers, progression through the cell cycle, interferon-gamma production or apoptosis. These data suggest that the latently HIV-infected resting CD4+ T cell reservoir may serve as a source of infectious HIV while maintaining its long-lived resting T cell phenotype. Finally, the relevance of CCR7, a chemokine receptor that plays an important role in homing of cells to T cell areas of LT and in mounting an appropriate immune response, in HIV pathogenesis is being investigated. We have found that HIV disease is associated with a reduced frequency of CCR7+ cells in both memory and naive T cell compartments. We have confirmed that CCR7+, but not CCR7-, memory CD4+ T cells differentially express the X4 HIV co-receptor, CXCR4, as compared to CCR5. In this regard, we have found that CCR7+ CD4+ T cells may be preferentially depleted in HIV-infected subjects harboring X4 HIV strains. The implications of CD4+ T cells homing to LT, the primary site of HIV replication, via expression of CCR7 and the differential expression of HIV coreceptors on CCR7+ cells are being further studied.

该项目旨在研究细胞因子/趋化因子，组织相关因子和HIV包膜蛋白的HIV调节作用的细胞和分子途径。 我们先前曾证明，促炎性细胞因子（PIC）和某些C-C-化学家合作起作用，以增强HIV X4菌株的内源性复制，而这些因素在确定内源性R5 HIV菌株复制水平时作用拮抗。在先前的体外观察到IL-2是PIC和CCR5趋化因子的有效诱导剂以及CCR5表达的诱导剂后，我们已经分析了来自接受IL-2皮下注射的HIV感染的个体的外周血单核细胞中的各种参数。 我们已经证明，体内IL-2给药会导致CCR5趋化因子RNA和蛋白质水平以及CD4+ T淋巴细胞群中CCR5表达的瞬态增加。有趣的是，尽管CCR5表达与IL-2相关的增加，但接受IL-2的个体内源性R5 HIV的频率显着低于未接受IL-2治疗的匹配的HIV感染受试者的细胞。 这些数据表明，在具有R5 HIV菌株的个体中，IL-2在体内诱导HIV抑制因子的能力，尤其是CCR5趋化因子，尤其是CCR5趋化因子，可能会覆盖IL-2的HIV诱导作用，例如CCR5表达上调和PIC的产生。我们对趋化因子对HIV复制的潜在影响的研究正在扩展，包括分析对许多C-C和CXC趋化因子以及某些淋巴组织（LT）相关因子的分析，以对CD4+ T细胞中的HIV复制作用。初步结果表明，某些与LT相关的趋化因子（例如SDF和SLC）可能会刺激进入后的HIV生命周期事件，例如前病毒整合。此外，与LT相关的细胞外基质蛋白（如层粘连蛋白）似乎增强了早期HIV进入事件。 这些发现表明，许多淋巴组织相关的宿主因子能够上调受感染的CD4+ T细胞的HIV产生。研究了HIV包膜蛋白（GP160）从HIV的细胞库中调节HIV表达的能力，例如从HIV感染的受试者中分离出的静止的静止感染的CD4+ T细胞。 发现HIV GP160引起静息CD4+ T细胞的感染HIV，这种作用与细胞活化标记的表达，通过细胞周期，干扰素 - γ产生或凋亡无关。这些数据表明，潜在的HIV感染的静息CD4+ T细胞库可以作为传染性HIV的来源，同时保持其长寿命的静息T细胞表型。 最后，正在研究HIV发病机理中CCR7的相关性，CCR7是一种在细胞向LT的T细胞区域寄养并安装适当的免疫反应中起重要作用的趋化作用。 我们发现，HIV疾病与记忆和天真T细胞室中CCR7+细胞的频率降低有关。我们已经证实，与CCR5相比，CCR7+（但未CCR7-的记忆CD4+ T细胞）差异地表达了X4 HIV共受体CXCR4。 在这方面，我们发现CCR7+ CD4+ T细胞可能优先耗尽具有X4 HIV菌株的HIV感染受试者。 通过CCR7的表达表达和HIV共受体对CCR7+细胞的差异表达，CD4+ T细胞与LT的hiv复制的主要位点（HIV复制的主要位点）的含义正在进一步研究。