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）感染的一个标志是肠道炎症和免疫功能受损。 肠上皮屏障功能。这些缺陷被认为是通过允许艾滋病病毒感染， 管腔微生物产物易位到循环中，这引发慢性全身免疫 激活和疾病进展。虽然抗逆转录病毒疗法（ART）有效地抑制了病毒感染， 它在血液中复制，即使经过多年的治疗，它也不能恢复肠道的稳态。这 导致炎性非传染性疾病（NCD）的发病率和死亡率增加 如艾滋病病毒感染者的心脏病和中风。尽管肠道屏障的核心作用 虽然在HIV疾病发病机制中起着重要作用，但对HIV导致HIV感染的具体机制知之甚少。 上皮损伤HIV肠上皮细胞（IEC）功能障碍的研究主要依靠 基于组织学或外周生物标志物的相关观察。我们的提案解决了以下方面的关键差距： 通过利用来自PWH和HIV未感染者的良好表征的队列的肠组织样本， 个体，沿着新的体内小鼠和离体人细胞模型和最先进的技术， 探讨艾滋病毒导致威尔斯亲王医院IEC死亡的具体机制。我们假设艾滋病毒- CD 8 + T细胞脂肪酸（FA）代谢的相关缺陷导致它们从附近的脂质中吸收脂质。 IEC，导致IEC死亡。这种IEC死亡然后导致肠屏障破坏。解决这些 假设，我们提出两个互补的目标。在目标1中，我们将表征体内和离体 使用内窥镜检查获得结肠组织样本研究HIV感染对PWH中IEC死亡的影响， 表征IEC死亡和CD 8 + T细胞表型。我们还将利用新的微肠类器官模型， 结合自体组织驻留免疫细胞和深入的单细胞测序分析 利用麻省理工学院的合作者开发的针对小样本量优化的平台。在目标2中，我们 确定肠道CD 8 + T细胞中HIV相关的FA代谢失调的机制， 细胞破坏结肠上皮屏障。在这个目标中，我们将利用离体人类器官和体内鼠类器官， 模型来测试受损的FA代谢在CD 8 + T细胞介导的IEC死亡中的机制作用， 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。执行这些 我们的目标是组建一支拥有艾滋病毒疾病、粘膜免疫学和胃肠道专业知识的团队 病理学，他们能够很好地揭示肠道上皮功能障碍的具体机制 艾滋病毒感染。该提案将解决IEC生物学的重要未知机制，这可能有助于 开发新的策略来逆转HIV感染中的肠道屏障缺陷。

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.