Gut Cytotoxic CD4 T cells in HIV-1 Pathogenesis

HIV-1 发病机制中的肠道细胞毒性 CD4 T 细胞

• 批准号: 10542815
• 负责人: Mario Luis Santiago
• 金额: $ 44.57万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-07 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10542815
• 关键词: Apoptotic; Archives; Automobile Driving; Biological; Biology; Biopsy; Blood; CCR5 gene; CD3 Antigens; CD4 Positive T Lymphocytes; Cell Death; Cell secretion; Cells; Cessation of life; Chronic; Circulation; Cytotoxic T-Lymphocytes; Data; Development; Disease; Enteral; Enterobacteriaceae; Epithelium; Exposure to; Flow Cytometry; Frequencies; Functional disorder; Gastrointestinal tract structure; Genes; Gram-Negative Bacteria; Granzyme; Growth; Gut Mucosa; HIV-1; Human; Human Biology; Immune; In Vitro; Individual; Infection; Inflammation; Inflammatory; Inflammatory Response; Knowledge; LAMP-1; Lamina Propria; Leaky Gut; Life Cycle Stages; Ligands; Link; Lymphoid; Lymphoid Tissue; Macaca mulatta; Mediating; Mediator; Memory; Microbe; Modeling; Molecular; Molecular Profiling; Mucositis; Mucous Membrane; Outcome; Pathogenesis; Pathogenicity; Pathway interactions; Persons; Phenotype; Plasma; Play; Population; Predisposition; Process; Production; Proliferating; Property; Reporting; Resolution; Role; SIV; Signal Pathway; Signal Transduction; Site; Source; T-Cell Activation; T-Cell Depletion; T-Lymphocyte; Up-Regulation; Viral; Virus Diseases; Work; acute infection; antiretroviral therapy; cell type; cohort; commensal bacteria; comorbidity; cytokine; cytotoxic; dysbiosis; extracellular; gut microbiome; immune activation; in vivo; inhibitor; insight; memory CD4 T lymphocyte; microbial; microbial products; microbiome; mortality; mutant; novel marker; novel therapeutic intervention; perforin; peripheral blood; response; survival prediction; systemic inflammatory response; transcription factor; transcriptome; transcriptomics; transmission process

ABSTRACT HIV-1-associated inflammation and chronic immune activation persist despite suppressive antiretroviral therapy and are strongly linked to the development of comorbidities and increased mortality. The gastrointestinal (GI) tract is likely a major source of chronic inflammation, as early HIV-1 replication and CD4 T cell depletion in the gut results in mucosal inflammation and barrier dysfunction, leading to the translocation of enteric microbes/microbial products into the lamina propria and the systemic circulation. To gain insights into the molecular processes that drive gut-focused chronic immune activation, we profiled the transcriptome of gut CD4+CD8α- T cells exposed to gram-negative enteric bacteria and then infected with HIV-1 ex vivo. Multiple granzyme genes were upregulated following microbe exposure that was further enhanced with HIV-1 infection, suggesting the synergistic induction of CD4 cytotoxic T lymphocyte (CTL) activity. In pilot ex vivo studies, the human gut CD4 CTL phenotype was associated with granzyme (GZ) B expression, TCR signaling, Th1/17 polyfunctionality, reactivity to commensal bacteria and subsets expressing GZA, perforin and/or CD107a. The CD4 CTL phenotype was expressed in CD4 T cells from the gut to a much greater extent than from peripheral blood and lymphoid tissue. Importantly, HIV-1 replicated to a greater extent in gut CD4 CTLs ex vivo. Here, we hypothesize that gut CD4 CTLs are uniquely primed to respond to enteric microbes, are highly susceptible to HIV-1 mediated killing, and play critical roles in mucosal HIV-1 pathogenesis via cytolytic and pro-inflammatory mechanisms. To gain insights on the role of gut CD4 CTLs in HIV-1 pathogenesis, we propose 3 aims. In Aim 1, we will determine if microbiome species and ligands induce gut CD4 CTLs in an MHC-II-dependent manner, obtain insights into gut CD4 CTL origin and function by single-cell transcriptomics, and investigate the stability and fate of these cells ex vivo. In Aim 2, we will determine how HIV-1 infection further augments GZB production in gut CD4 T cells and using our ex vivo lamina propria aggregate culture (LPAC) model, determine if gut CD4 CTLs exacerbate direct and bystander HIV-1-mediated CD4 T cell death via cytolytic mechanisms. In Aim 3, we will evaluate the triggers for GZ secretion and dissect the non-cytolytic, pro-inflammatory properties of GZs secreted by microbe-exposed gut CD4 T cells ex vivo. Importantly, we will explore the in vivo relationship between CD4 CTL frequencies and markers of mucosal and systemic inflammation in archived plasma and gut biopsies from well-characterized cohorts of both untreated and treated persons with chronic HIV-1 infection. Altogether, these studies should provide critical information on this striking gut immune cell subpopulation and its contribution to mucosal inflammation and disease.

抽象的 尽管抑制性抗逆转录病毒治疗，HIV-1相关炎症和慢性免疫激活仍然存在 治疗并与合并症的发生和死亡率增加密切相关。这 胃肠道 (GI) 可能是慢性炎症的主要来源，因为早期 HIV-1 复制和 CD4 T 肠道中的细胞耗竭会导致粘膜炎症和屏障功能障碍，从而导致细胞易位 肠道微生物/微生物产物进入固有层和体循环。深入了解 驱动以肠道为中心的慢性免疫激活的分子过程，我们分析了肠道的转录组 CD4+CD8α- T 细胞暴露于革兰氏阴性肠道细菌，然后离体感染 HIV-1。多种的 接触微生物后，颗粒酶基因上调，HIV-1 感染进一步增强这种情况， 表明 CD4 细胞毒性 T 淋巴细胞 (CTL) 活性的协同诱导。在体外试验研究中， 人肠道 CD4 CTL 表型与颗粒酶 (GZ) B 表达、TCR 信号传导、Th1/17 相关 多功能性、对表达 GZA、穿孔素和/或 CD107a 的共生细菌和亚群的反应性。这 CD4 CTL 表型在肠道 CD4 T 细胞中的表达程度远高于外周血 血液和淋巴组织。重要的是，HIV-1 在离体肠道 CD4 CTL 中复制程度更高。在这里，我们 假设肠道 CD4 CTL 具有独特的能力来响应肠道微生物，并且高度 易受 HIV-1 介导的杀伤作用，并通过粘膜 HIV-1 发病机制发挥关键作用 细胞溶解和促炎机制。深入了解肠道 CD4 CTL 在 HIV-1 中的作用 发病机制，我们提出3个目标。在目标 1 中，我们将确定微生物组物种和配体是否诱导肠道 CD4 CTL 以 MHC-II 依赖性方式，通过单细胞深入了解肠道 CD4 CTL 的起源和功能 转录组学，并研究这些细胞离体的稳定性和命运。在目标 2 中，我们将确定如何 HIV-1 感染进一步增强肠道 CD4 T 细胞中 GZB 的产生，并使用我们的离体固有层 聚合培养 (LPAC) 模型，确定肠道 CD4 CTL 是否加剧直接和旁观者 HIV-1 介导的 CD4 T 细胞通过溶细胞机制死亡。在目标 3 中，我们将评估 GZ 分泌的触发因素并进行剖析 离体微生物暴露的肠道 CD4 T 细胞分泌的 GZ 具有非溶细胞性、促炎特性。 重要的是，我们将探索 CD4 CTL 频率与粘膜和粘膜标记物之间的体内关系。 存档的血浆和肠道活检中的系统性炎症来自未经治疗的特征明确的队列 并治疗慢性 HIV-1 感染者。总而言之，这些研究应该提供关键的 有关这一引人注目的肠道免疫细胞亚群及其对粘膜的贡献的信息 炎症和疾病。