CBF-1 role in regulating HIV reservoir in microglial cells

CBF-1在调节小胶质细胞中HIV储存库中的作用

基本信息

批准号：
10403065
负责人：
Mudit Tyagi
金额：
$ 19.5万
依托单位：
THOMAS JEFFERSON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-01 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10403065
关键词：
Address Anti-HIV Therapy Area Autopsy Binding Binding Sites Biological Models Brain CD4 Positive T Lymphocytes Cells Chromatin Structure Complex Drops Economic Burden Enzymes Epigenetic Process Exploratory/Developmental Grant Failure Functional disorder Gene Expression Generations Genetic Transcription Goals Grant HIV HIV Long Terminal Repeat HIV-1 HIV-associated neurocognitive disorder Heterochromatin Highly Active Antiretroviral Therapy Human Individual Inflammation Investigation Knowledge Long Terminal Repeats Lymphocyte Lymphoid Cell Maintenance Mediating Microglia Modification Molecular Myelogenous Myeloid Cells Neuraxis Nuclear Paper Patients Phase Play Proviruses Public Health Publishing Research Rest Role Series Site Specimen Structure Targeted Research Testing Time Viral reservoir base brain cell cell type chromatin modification design epigenetic silencing experimental study gene repression genetic corepressor histone modification inhibitor innovation knock-down latent HIV reservoir macrophage memory CD4 T lymphocyte novel novel therapeutics promoter reactivation from latency recruit targeted treatment therapeutic target transcription factor treatment optimization

项目摘要

Project Summary: Although the resting memory CD4+ T cells are the best-recognized long-lived reservoirs of latent HIV provirus, it is now well accepted that the myeloid cells, especially of the central nervous system (CNS)- -including perivascular macrophages and microglial cells--can also contribute to viral reservoirs. The molecular mechanisms relevant to HIV latency are primarily defined by analyzing HIV latency in latently infected CD4+ lymphoid cells. However, very little is known about HIV latency/persistence in myeloid cells. Notably, the presence of HIV-harboring myeloid cells in the CNS are documented to be the key factor contributing to CNS inflammation and promoting HIV-associated neurocognitive disorder (HAND) in HIV patients. Microglial cells are the main HIV reservoir in the CNS, yet a gap in the knowledge regarding our understanding of the molecular mechanisms that maintains HIV reservoirs in those cells. Our long term goal is identifying and characterizing the underlying molecular mechanisms that regulate HIV latency in microglial cells. The important role of CBF-1-mediated transcriptional inhibition during HIV latency is well established in lymphoid cells. The objective of this grant is to characterize the role of CBF-1 during HIV latency in microglial cells. Based on our published and preliminary findings, we have hypothesized that, similar to lymphocytes, in microglial cells CBF- 1 promotes HIV latency/slowdown by inducing the generation of transcriptionally-repressive heterochromatin structures at HIV LTR. Our rationale is that since HIV latency is primarily regulated at the transcriptional level, defining the precise mechanism(s) that regulate HIV transcription in microglial cells will offer new therapeutic opportunities to target HIV reservoirs in the CNS. In Aim 1, we will examine the role of CBF-1-induced epigenetic changes in restricting HIV transcription and their eventual impact on the establishment and the maintenance phases of HIV latency. In Aim 2, we will characterize the corepressor complexes that CBF-1 recruits at HIV LTR and their functional significance in promoting HIV reservoir in microglial cells. Upon conclusion, we will be able to define the CBF-1-mediated mechanisms that facilitate the establishment and maintenance of HIV latency in microglial cells. These studies will also provide a well-defined therapeutic target in the form of CBF-1 and its corepressor complexes in order to relieve multiple repressive epigenetic modifications simultaneously. Proposed research is innovative because it uses human primary microglial cells, and a novel ex vivo model system for HIV latency in microglial cells that, for the first time, allows the studies of the molecular correlates for HIV entry and exit into latency in microglial cells, which is otherwise an impossible task due to insufficient availability of brain autopsy specimens. This contribution is significant since the identified mechanisms, which regulate HIV transcription and latency in microglial cells, will facilitate the designing of optimized therapies targeting CNS reservoirs of HIV, contributing to cure approaches.

项目摘要：尽管静息记忆 CD4+ T 细胞是最受认可的长寿命储存库潜伏的 HIV 原病毒，现在人们普遍认为骨髓细胞，尤其是中枢神经系统 (CNS) 的骨髓细胞 - 包括血管周围巨噬细胞和小胶质细胞 - 也可以形成病毒库。与HIV潜伏期相关的分子机制主要是通过分析HIV潜伏期来定义的。感染 CD4+ 淋巴细胞。然而，人们对艾滋病毒在骨髓细胞中的潜伏期/持续性知之甚少。值得注意的是，中枢神经系统中携带艾滋病毒的骨髓细胞的存在被证明是导致艾滋病毒感染的关键因素。影响中枢神经系统炎症并促进 HIV 患者的 HIV 相关神经认知障碍 (HAND)。小胶质细胞细胞是中枢神经系统中主要的艾滋病毒储存库，但我们对艾滋病毒的理解还存在差距。在这些细胞中维持艾滋病毒储存库的分子机制。我们的长期目标是识别和表征调节小胶质细胞中 HIV 潜伏期的潜在分子机制。重要的 HIV潜伏期CBF-1介导的转录抑制作用在淋巴细胞中已得到充分证实。这这笔资助的目的是描述 CBF-1 在 HIV 潜伏期间小胶质细胞中的作用。基于我们的已发表的初步研究结果表明，我们假设，与淋巴细胞类似，在小胶质细胞 CBF- 1 通过诱导转录抑制异染色质的生成促进 HIV 潜伏期/减慢 HIV LTR 的结构。我们的理由是，由于 HIV 潜伏期主要在转录水平上受到调节，确定小胶质细胞中调节 HIV 转录的精确机制将提供新的治疗方法有机会针对中枢神经系统中的艾滋病毒储存库。在目标 1 中，我们将研究 CBF-1 诱导的表观遗传的作用 HIV转录限制的变化及其对建立和维持的最终影响 HIV潜伏期的各个阶段。在目标 2 中，我们将描述 CBF-1 在 HIV LTR 处招募的辅阻遏物复合物的特征及其在促进小胶质细胞中 HIV 储存的功能意义。得出结论后，我们将能够定义CBF-1介导的机制，促进HIV潜伏期的建立和维持小胶质细胞。这些研究还将以 CBF-1 及其形式提供明确的治疗靶点辅阻遏物复合物，以同时解除多种抑制性表观遗传修饰。拟议的研究具有创新性，因为它使用人类原代小胶质细胞和新颖的离体模型小胶质细胞中 HIV 潜伏期系统，首次允许研究 HIV 潜伏期的分子相关性 HIV进入和退出小胶质细胞中处于潜伏期，否则由于缺乏足够的药物，这是一项不可能完成的任务脑部尸检标本的可用性。这一贡献意义重大，因为已确定的机制调节小胶质细胞中的 HIV 转录和潜伏期，将有助于优化疗法的设计针对艾滋病毒的中枢神经系统储存库，有助于治愈方法。