Immunometabolic regulation of CD8+ T cell mediated intestinal epithelial cell death in people with HIV (PWH)

人类免疫缺陷病毒(HIV)感染的一个特征是肠道炎症和 肠道上皮屏障功能。这些缺陷被认为是通过允许 腔微生物产物进入血液循环，从而触发慢性系统免疫 激活和疾病进展。尽管抗逆转录病毒疗法(ART)能有效抑制病毒 在血液中复制，即使在多年的治疗后，它也不能恢复肠道的动态平衡。这 导致炎症性非传染性疾病(NCDs)发病率和死亡率增加 例如艾滋病(PWH)患者的心脏病和中风。尽管肠道屏障起着核心作用 在HIV疾病发病机制中的作用，对HIV导致 上皮损伤。对HIV患者肠道上皮细胞(IEC)功能障碍的研究主要依赖于 基于组织学或外周生物标记物的相关观察。我们的建议解决了以下方面的严重差距 利用具有良好特征的PWH和HIV未感染队列的肠道组织样本获得的知识 个体，以及新的体内小鼠和体外人类细胞模型和最先进的技术 探讨HIV导致威斯康星医院IEC死亡的具体机制。我们假设HIV病毒- CD8 T细胞脂肪酸(FA)代谢的相关缺陷导致他们从附近清除脂质 IEC，导致IEC死亡。这种IEC的死亡会导致肠道屏障的破坏。要解决这些问题 假设，我们提出了两个互补的目标。在目标1中，我们将描述体内和体外的 应用内窥镜获取的结肠组织标本研究HIV感染对重症肝炎患者IEC死亡的影响 鉴定IEC死亡和CD8 T细胞表型。我们还将利用新的迷你肠道器官模型 结合自体组织常驻免疫细胞和深入的单细胞测序分析 利用麻省理工学院合作者开发的针对小样本而优化的平台。在目标2中，我们将 确定HIV相关肠道CD8 T细胞FA代谢异常的机制 细胞破坏结肠上皮屏障。在这个目标中，我们将利用体外的人类有机化合物和体内的小鼠 检测FA代谢受损在CD8 T细胞介导的IEC死亡和死亡机制中作用的模型 肠屏障功能障碍。这种方法将确定特定的细胞和分子机制 HIV感染对肠道屏障功能和全身免疫激活的影响。为了实现这些目标 目标我们已经组建了一支在艾滋病毒疾病、粘膜免疫学和胃肠道疾病方面拥有综合专业知识的团队 病理学，他们能够很好地揭示肠道上皮功能障碍背后的特定机制 在艾滋病毒感染方面。该提案将解决IEC生物学中重要的未知机制，这些机制可能有助于 开发逆转艾滋病毒感染中肠道屏障缺陷的新策略。

A hallmark of human immunodeficiency virus (HIV) infection is intestinal inflammation and impairment of gut epithelial barrier function. These defects are thought to drive HIV disease progression by allowing translocation of luminal microbial products into the circulation, which triggers chronic systemic immune activation and disease progression. Although antiretroviral therapy (ART) effectively suppresses viral replication in the blood, it does not restore homeostasis in the intestine, even after years of treatment. This contributes to increased morbidity and mortality due to inflammatory non-communicable diseases (NCDs) such as heart disease and stroke in people with HIV (PWH). Despite the central role of intestinal barrier function in HIV disease pathogenesis, little is known about the specific mechanisms by which HIV results in epithelial damage. Studies of intestinal epithelial cell (IEC) dysfunction in HIV have relied primarily on correlative observations based on histology or peripheral biomarkers. Our proposal addresses critical gaps in knowledge by utilizing intestinal tissue samples from well-characterize cohorts of PWH and HIV-uninfected individuals, along with novel in vivo mouse and ex vivo human cell models and state-of-the-art technologies to explore specific mechanisms by which HIV contributes to IEC death in PWH. We hypothesize that HIV- associated defects in CD8+ T cell fatty acid (FA) metabolism cause them to scavenge lipids from nearby IEC, which leads to IEC death. This IEC death then results in intestinal barrier disruption. To address these hypotheses, we are proposing two complementary aims. In Aim 1 we will characterize the in vivo and ex vivo impact of HIV infection on IEC death in PWH using colon tissue samples obtained by endoscopy to characterize IEC death and CD8+ T cell phenotypes. We will also utilize novel mini-gut organoid models that incorporate autologous tissue resident immune cells and in-depth single cell sequencing analysis leveraging a platform optimized for small sample sizes developed by collaborators at MIT. In Aim 2, we will determine the mechanisms by which HIV-associated dysregulation of FA metabolism in intestinal CD8+ T cells disrupts the colonic epithelial barrier. In this aim we will utilize ex vivo human organoid and in vivo murine models to test the mechanistic role of impaired FA metabolism in CD8+ T cell mediated IEC death and intestinal barrier dysfunction. This approach will identify specific cellular and molecular mechanisms underlying the impact of HIV infection on intestinal barrier function and systemic immune activation. To carry out these Aims we have assembled a team with combined expertise in HIV disease, mucosal immunology, and GI pathology, who are well positioned to uncover specific mechanisms that underlie intestinal epithelial dysfunction in HIV infection. This proposal will address important unknown mechanisms of IEC biology that may help in the development of new strategies to reverse gut barrier defects in HIV infection.