Mechanisms of Trained Immunity in HIV Immune Responses

项目摘要/摘要 急性艾滋病毒感染的特征是强大的先天免疫反应，这决定了最终的临床 病程。先天免疫激活和转录变化可以持续到急性感染之后 句号。先天免疫系统的细胞可以通过先前的暴露重新编程或“训练”，而这 持久的变化会影响未来的免疫反应。这种现象被称为训练免疫或先天免疫 免疫记忆，是表观遗传编码的，允许刺激依赖的转录因子不仅结合 到可用的细胞类型特异性增强子，也到以前无法接触到的 基因组。尽管早期先天反应在确定艾滋病毒病程方面很重要，但 关于艾滋病毒感染的训练有素的免疫力还没有得到探索。此外，物质使用对这些方面的影响 早期的先天免疫反应尚不清楚。该项目将利用艾滋病毒免疫学和 物质使用(富尔彻博士)、先天免疫记忆表观遗传机制(程博士)和艾滋病毒 免疫学与细胞毒性T淋巴细胞(杨博士)探讨训练性免疫在整形中的作用机制 艾滋病毒免疫反应以及艾滋病毒本身如何对先天免疫细胞进行重新编程。我们假设 在单核细胞分化过程中暴露于某些刺激会导致产生细胞因子的能力不同 并刺激HIV特异性CD8+T细胞反应。在艾滋病毒感染的背景下，我们假设艾滋病毒 暴露诱导单核细胞重编程导致二次反应增强，这可能有助于 慢性炎症和免疫衰竭。为了检验这些假设，我们将：(1)确定先天免疫 训练单核细胞以获得最佳HIV特异性免疫反应的刺激，包括检查 滥用药物对这些反应的影响以及(2)表征艾滋病毒产生的先天免疫记忆 并确定培训所需的病毒因子和宿主信号通路。我们会训练 原代人类单核细胞，从吸毒者或不吸毒者那里获得，在 分化为巨噬细胞，然后暴露于HIV，并使用功能免疫分析比较结果。 路径将使用RNAseq进行询问。我们接下来将用HIV培养单核细胞，然后检查表观遗传学 用RNAseq和ATACseq研究二次刺激(LPS)后转录的变化。结果来自 这些研究将促进对训练有素的免疫如何形成艾滋病毒免疫反应以及如何 艾滋病毒可能会影响后来的免疫反应。这一知识可以为治疗学带来新的免疫靶点 改进艾滋病毒防治工作。

PROJECT SUMMARY / ABSTRACT Acute HIV infection is characterized by a robust innate immune response that determines the ultimate clinical disease course. Innate immune activation and transcriptional changes can persist beyond the acute infection period. Cells of the innate immune system can be reprogrammed or “trained” by prior exposures, and this lasting changes influence future immune responses. This phenomenon, termed trained immunity or innate immune memory, is epigenetically encoded, allowing stimulus-dependent transcription factors to bind not only to available cell type-specific enhancers, but also to previously inaccessible regions of the chromatin in the genome. Despite the importance of early innate responses in determining HIV disease course, the role of trained immunity in HIV infection has not been explored. Moreover, the effects of substance use on these early innate immune responses are not known. This project will leverage expertise in HIV immunology and substance use (Dr. Fulcher), innate immune memory epigenetic mechanisms (Dr. Cheng), and HIV immunology and cytotoxic T lymphocytes (Dr. Yang) to investigate mechanisms of trained immunity in shaping HIV immune responses and how HIV itself may reprogram innate immune cells. We hypothesize that exposure to certain stimuli during monocyte differentiation will lead to differential ability to produce cytokines and stimulate HIV-specific CD8+ T cell responses. In the setting of HIV infection, we hypothesize that HIV exposure induces monocyte reprogramming resulting in heightened secondary responses that may contribute to chronic inflammation and immune exhaustion. To test these hypotheses we will: (1) identify innate immune stimuli that train monocytes for optimal HIV-specific immune responses, including examining the effects of drugs of abuse on these responses and (2) characterize the innate immune memory produced by HIV infection and determine the viral factors and host signaling pathways required for training. We will train primary human monocytes, obtained from persons who do or do not use drugs, with different ligands during differentiation to macrophages then expose to HIV and compare outcomes using functional immune assays. Pathways will be interrogated using RNAseq. We will next train monocytes with HIV then examine epigenetic and transcription changes following secondary stimulus (LPS) using RNAseq and ATACseq. Results from these studies will advance understanding of how trained immunity shapes HIV immune responses, and how HIV may affect later immune responses. This knowledge can lead to novel immune targets for therapeutics to improve HIV prevention and treatment.