Modulation of BRD4 to epigenetically suppress HIV

调节 BRD4 以表观遗传抑制 HIV

基本信息

批准号：
10624845
负责人：
Haitao Hu
金额：
$ 30.14万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-17 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10624845
关键词：
Aftercare Binding Binding Sites Biotinylation Bromodomain Bromodomains and extra-terminal domain inhibitor CD4 Positive T Lymphocytes Cell model Cells Chemicals Chromatin Chromatin Structure Complex Docking Epigenetic Process Future Genetic Transcription Genome Goals HIV Histones Human In Vitro Infection Investigation Knock-out Laboratories Lead Lysine Mediating Microglia Molecular Molecular Probes Mus Myeloid Cells Pathway interactions Peripheral Blood Mononuclear Cell Protein Family Protein Isoforms Proteins Reader Regulation Repression Research Residual state Role Site Structure T-Lymphocyte Tertiary Protein Structure Testing Toxic effect Transactivation Transcription Elongation Withholding Treatment analog design epigenetic regulation humanized mouse in vivo innovation latent infection mouse model multidisciplinary novel novel strategies overexpression analysis pandemic disease prevent protein protein interaction recruit scaffold small molecule transcriptome sequencing transcriptomics viral DNA

Aftercare Binding Binding Sites Biotinylation Bromodomain Bromodomains and extra-terminal domain inhibitor CD4 Positive T Lymphocytes Cell model Cells Chemicals Chromatin Chromatin Structure Complex Docking Epigenetic Process Future Genetic Transcription Genome Goals HIV Histones Human In Vitro Infection Investigation Knock-out Laboratories Lead Lysine Mediating Microglia Molecular Molecular Probes Mus Myeloid Cells Pathway interactions Peripheral Blood Mononuclear Cell Protein Family Protein Isoforms Proteins Reader Regulation Repression Research Residual state Role Site Structure T-Lymphocyte Tertiary Protein Structure Testing Toxic effect Transactivation Transcription Elongation Withholding Treatment analog design epigenetic regulation humanized mouse in vivo innovation latent infection mouse model multidisciplinary novel novel strategies overexpression analysis pandemic disease prevent protein protein interaction recruit scaffold small molecule transcriptome sequencing transcriptomics viral DNA

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项目摘要

ABSTRACT Integration of HIV viral DNA into host cell genomes and establishment of stable latent infection have posed a major obstacle for finding an HIV cure. HIV proviral expression in cell reservoirs is regulated by host epigenetic and transcriptional mechanisms. Identification of effective approaches targeting host machineries to disrupt or enforce HIV latency is a significant goal. BRD4 is an epigenetic reader that belongs to the bromodomain (BD) and extra-terminal domain (ET) protein family (BET). Via the BDs, BRD4 binds to acetyl-lysine (KAc) residues in chromatin histones and serves as a scaffolding platform for recruiting partner proteins through protein-protein interactions (PPI) to regulate gene transcription, including HIV. Modulation of BET/BRD4 by a pan-BET inhibitor (JQ1), which targets the classic KAc binding site in BDs, has been shown to activate HIV transcription. Recent studies by my group and others indicate that BRD4 is functionally versatile, and its activity on gene transcription is tailored by specific partner proteins it engages. Using structure-aided design, our studies (1, 2) have identified a lead small molecule (ZL0580) and several analogs that are distinct from JQ1 but induce HIV transcriptional suppression through BRD4. We demonstrate that ZL0580 induces suppression of both transcriptionally active and latent HIV in multiple cell models, including J-Lat, CD4 T cells and myeloid cells/microglia. Docking analyses of binding modes and mechanistic investigations indicate that unlike JQ1, ZL0580 targets a distinct new region of BRD4 BD1 for binding [non-acetyl-lysine (KAc) site] and induces HIV transcriptional suppression by inhibiting Tat transactivation and by inducing a repressive chromatin structure at the HIV LTR. Based on these novel findings, our central hypothesis is that host BRD4 and its associated epigenetic machinery can be modulated to repress HIV, leading to enforced HIV latency. Other than ZL0580, our ongoing research has identified another analog (YL0255) that is structurally close to ZL0580 and induces stronger HIV suppression. In this application, we will use ZL0580 and YL0255 as two novel molecular probes to systemically investigate modulation of BRD4 in HIV epigenetic suppression. In Aim 1, we will determine if BRD4 is a selective protein target for ZL0580/YL0255 and the underlying structural basis. In Aim 2, we will elucidate the molecular mechanisms by which modulation of BRD4 by ZL0580/YL0255 induces HIV epigenetic suppression. In Aim 3, as a proof of concept, we will examine if modulation of BRD4 by ZL0580/YL0255 induces repression of latent HIV in vivo. Collectively, these studies are critical for better understanding HIV epigenetic regulation and latency and will lay critical groundwork for developing novel strategies for inducing HIV suppression and/or silencing in future.

抽象的将HIV病毒DNA整合到宿主细胞基因组中并建立稳定的潜在感染已提出寻找艾滋病毒治疗的主要障碍。细胞库中的HIV病毒表达受宿主表观遗传学调节和转录机制。识别针对主机机械的有效方法，以破坏或执行艾滋病毒潜伏期是一个重要目标。 BRD4是属于溴结构域（BD）的表观遗传学读者和末端结构域（ET）蛋白家族（BET）。通过BDS，BRD4与乙酰赖氨酸（KAC）残基结合在染色质组蛋白中，是通过蛋白质蛋白招募伴侣蛋白的脚手架平台相互作用（PPI）调节基因转录，包括HIV。通过泛膏抑制剂对BET/BRD4的调节（JQ1）针对BDS中经典的KAC结合位点的（JQ1）已显示可激活HIV转录。最近的我小组和其他人的研究表明，BRD4在功能上是通用的，其在基因转录上的活性由特定的合作伙伴蛋白量身定制。使用结构辅助设计，我们的研究（1，2）已确定铅小分子（ZL0580）和几种与JQ1不同但诱导HIV转录的类似物通过BRD4抑制。我们证明ZL0580诱导了两种转录活性的抑制在多个细胞模型中，包括J-LAT，CD4 T细胞和髓样细胞/小胶质细胞中的潜在HIV。对接分析结合模式和机械研究表明，与JQ1不同，ZL0580针对一个独特的新区域 BRD4 BD1的结合[非乙酰基赖氨酸（KAC）位点]，并通过抑制HIV转录抑制 TAT反式激活并通过在HIV LTR处诱导抑制性染色质结构。基于这些小说调查结果是，我们的中心假设是可以调节宿主BRD4及其相关的表观遗传机制压抑艾滋病毒，导致艾滋病毒潜伏期。除了ZL0580，我们正在进行的研究已经确定了另一项在结构上接近ZL0580并引起更强的HIV抑制，类似于类似物（YL0255）。在此应用程序中我们将使用ZL0580和YL0255作为两个新的分子探针，以系统地研究BRD4的调节在艾滋病毒表观遗传抑制中。在AIM 1中，我们将确定BRD4是否是选择性蛋白质靶标 ZL0580/YL0255和基础结构基础。在AIM 2中，我们将通过 ZL0580/YL0255对BRD4的调节会诱导HIV表观遗传抑制。在AIM 3中，作为证明概念，我们将检查ZL0580/YL0255对BRD4的调节是否会诱导体内潜在艾滋病毒的抑制。总的来说，这些研究对于更好地理解HIV表观遗传调节和潜伏期至关重要制定新的策略来诱导HIV抑制和/或沉默的重要基础。