Persistent HIV-1 expression and microglia dysfunction

摘要/项目摘要 小胶质细胞是驻留在中枢神经系统(CNS)中的具有关键免疫功能的长寿先天免疫细胞 大脑的监视功能和稳态功能，包括清除病原体和维持 神经元突触的完整性。小胶质细胞是HIV的靶标，已被认为是HIV的储存库 持续感染，是艾滋病毒相关炎症和神经发病的媒介。重要的是 小胶质细胞功能障碍被认为与HIV相关的神经变性和炎症有关，甚至 在抗逆转录病毒治疗期间艾滋病毒复制被抑制。直接或间接的机制， 在HIV感染过程中，驱动小胶质细胞促进炎症尚未阐明。在这项研究中，我们将 利用从多能干细胞衍生的小胶质细胞-神经元共培养模型来检验这一假说 小胶质细胞中的艾滋病毒建立了持续感染的小胶质细胞，这些小胶质细胞表达异常的病毒RNA，包括 那些保留内含子序列的基因，这些内含子序列介导炎性小体激活以驱动小胶质细胞功能障碍， 中枢神经系统炎症和神经元损伤。支持我们假设的初步数据包括结果 表明原代巨噬细胞携带有缺陷的艾滋病毒前病毒，尽管存在缺失和 削弱病毒产生，产生HIV RNA的突变。此外，我们之前的工作建立了 HIV内含子RNA在激活巨噬细胞和小胶质细胞炎症活动中的潜在作用。 这项提案涉及的具体问题包括：1)艾滋病毒感染者的前病毒状态是什么 小胶质细胞；2)什么机制驱动艾滋病毒RNA在小胶质细胞中持续表达；以及3)什么是 HIV激活的巨噬细胞中引发炎性小体激活的机制？本项目竣工 将提供对HIV-1的持续和表达在以下背景下的影响的一般见解 小胶质细胞。重要的是，这些研究将提供对HIV-1致病机制的洞察 中枢神经系统并发症，即使在ART中也存在，并可能导致新的目标和战略 将改善艾滋病毒携带者生活的治疗。

ABSTRACT/PROJECT SUMMARY Microglia are long-lived central nervous system (CNS)-resident innate immune cells that have critical immune surveillance functions and homeostatic functions in the brain including clearance of pathogens and maintaining integrity of neuronal synapses. Microglia are targeted by HIV, have been proposed to be a reservoir for HIV persistent infection and are mediators of HIV-associated inflammation and neuropathogenesis. Importantly, microglia dysfunction is proposed to contribute to HIV associated neurodegeneration and inflammation even when HIV replication is suppressed during antiretroviral treatments. The mechanisms, direct or indirect, that drive microglia to promote inflammation during HIV infection have not been elucidated. In this study, we will utilize a primary microglia-neuron coculture model derived from pluripotent stem cells to test the hypothesis that HIV in microglia establishes persistently infected microglia that express aberrant viral RNAs, including those that retain intronic sequences, which mediate inflammasome activation to drive microglia dysfunction, CNS inflammation and neuronal injury. Our preliminary data supporting our hypothesis includes results demonstrating that primary macrophages harbor defective HIV proviruses and, despite harboring deletions and mutations that attenuate virus production, generate HIV RNAs. Furthermore, our previous work established the potential role of HIV intron containing RNA in activating inflammatory activities in macrophages and microglia. Specific questions addressed in this proposal include: 1) what is the status of proviruses in HIV infected microglia; 2) what mechanisms drive persistent expression of HIV RNA in microglia; and 3) what are the mechanisms that trigger inflammasome activation in HIV-activated macrophages? Completion of this project will provide general insights into the impact of HIV-1 persistence and expression in the context of microglia. Importantly, these studies will provide insights into mechanisms that contribute to HIV-1 CNS comorbidities which persist even with ART and could lead to new targets and strategies for treatments that will improve the lives of people living with HIV.