Persistent HIV-1 expression and microglia dysfunction

摘要/项目总结 小胶质细胞是长寿命的中枢神经系统（CNS）固有免疫细胞，其具有关键的免疫调节作用。 脑中的监视功能和稳态功能，包括病原体的清除和维持 神经元突触的完整性小胶质细胞是HIV的靶细胞，被认为是HIV的储存库 持续感染，是HIV相关炎症和神经发病机制的介质。重要的是， 小胶质细胞功能障碍被认为有助于HIV相关的神经变性和炎症， 在抗逆转录病毒治疗期间，艾滋病毒复制受到抑制。直接或间接的机制， 驱动小胶质细胞促进HIV感染期间的炎症尚未阐明。在这项研究中，我们将 利用来源于多能干细胞的原代小胶质细胞-神经元共培养模型来检验假设 小胶质细胞中的HIV建立了表达异常病毒RNA的持续感染的小胶质细胞，包括 保留内含子序列的那些，其介导炎性体活化以驱动小胶质细胞功能障碍， CNS炎症和神经元损伤。我们的初步数据支持我们的假设包括结果 表明原代巨噬细胞携带有缺陷的HIV前病毒，尽管携带有缺失， 减弱病毒产生的突变，产生HIV RNA。此外，我们以前的工作建立了 含有HIV内含子的RNA在激活巨噬细胞和小胶质细胞炎症活动中的潜在作用。 本提案中涉及的具体问题包括：1）在HIV感染者中， 2）是什么机制驱动HIV RNA在小胶质细胞中持续表达; 3） HIV激活的巨噬细胞中触发炎性小体激活的机制？完成本项目 将提供对HIV-1持续存在和表达的影响的一般见解， 小胶质细胞重要的是，这些研究将提供有助于HIV-1的机制的见解 CNS合并症即使在ART治疗下也持续存在，可能导致新的靶点和策略， 这些治疗将改善艾滋病毒感染者的生活。

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.