Benzodiazepine mediated mechanisms of transcriptional semi-quiescence in discrete myeloid populations

治愈艾滋病毒的主要障碍之一是在不同的隔室中存在病毒储存库， 不受抗逆转录病毒疗法（ART）影响的细胞类型。在中枢神经系统（CNS）中， 储库由骨髓细胞如血管周围巨噬细胞和小胶质细胞组成。关键是，这些 储库通常在ART开始之前建立，并且CNS中ART的存在不 影响长寿髓系人群中已建立的储库。因此，即使在接受抑制性ART的个体中， 持续感染的CNS巨噬细胞和小胶质细胞可以驱动持续的神经炎症， 在药物中断或失败期间，病毒复发的HIV来源。我们消除这些水库的能力 由于缺乏对骨髓中HIV的转录和表观遗传调控的了解， 细胞为了有效地靶向和消除HIV感染者（PLWH）的CNS储库， 在不同的中枢神经系统骨髓细胞群中介导持续感染的转录机制。 艾滋病毒感染对中枢神经系统的影响在患有物质使用障碍的艾滋病毒携带者中更为严重，包括 服用和/或滥用治疗药物，如苯二氮卓类（BDZ）的人。苯二氮卓类药物被 超过3000万美国人，有很高的滥用倾向和滥用这些药物占15 - 20%， 他们的使用。苯二氮卓类药物被用于越来越多的PLWH患者， 神经认知症状的风险。关于BDZ影响的机制知之甚少 HIV神经发病机制我们发表的和初步的数据表明，BDZ可以改变转录水平， 艾滋病毒感染的控制。为了更好地了解和治疗使用和/或使用艾滋病毒的PLWH中神经HIV的发展， 为了防止滥用BDZ，确定苯二氮卓类药物影响骨髓细胞中的转录程序至关重要。 我们假设巨噬细胞和小胶质细胞都进入半静止转录状态 在ART暴露期间，苯二氮卓类药物破坏了这种状态并增加了转录活性， 和病毒复制。我们的数据显示，BDZ Xanax以及一些延迟再激活剂介导了 在感染的ART处理的细胞中p24产生的剂量依赖性增加。我们的初步研究表明 这些作用可能是BDZ与表观遗传调节因子RUNX 1相互作用的结果。我们认为这些变化 在骨髓细胞中的HIV复制反映了前病毒的表观遗传状态。因此，不断增长的人口 使用BDZ的PLWH发生更严重神经发病的风险更大。这也表明BDZ可能提供 新疗法的基础，以操纵艾滋病毒在骨髓细胞转录。因此，我们将评估 转录和表观遗传机制维持ART中HIV转录的半静止状态， 处理的人巨噬细胞（目的1），定义转录和表观遗传过程中的差异， 使用人同源iPSC衍生的巨噬细胞和小胶质细胞的不同类型的骨髓细胞（Aim 2），和 检测苯二氮卓类药物对HIV感染的ART处理的骨髓细胞转录的影响（目的3）。

One of the principal obstacles to curing HIV is the existence of viral reservoirs in distinct compartments and cell types that are unaffected by antiretroviral therapy (ART). In the central nervous system (CNS), these reservoirs are comprised of myeloid cells, such as perivascular macrophages and microglia. Critically, these reservoirs are generally established prior to the initiation of ART and the presence of ART in the CNS does not affect the established reservoir in long-lived myeloid populations. Thus, even in individuals on suppressive ART, persistently infected CNS macrophages and microglia can drive ongoing neuroinflammation and provide a source of HIV for viral recrudescence during medication hiatus or failure. Our ability to eliminate these reservoirs is severely limited by the lack of understanding of the transcriptional and epigenetic regulation of HIV in myeloid cells. To effectively target and eliminate CNS reservoirs in people living with HIV (PLWH), it is critical to define the transcriptional mechanisms mediating persistent infection in distinct CNS myeloid populations. The impact of HIV infection in the CNS is heightened in PLWH who have substance use disorders, including those who take and/or misuse therapeutic drugs such as benzodiazepines (BDZ). Benzodiazepines are used by more than 30 million Americans, have high abuse liability and misuse of these drugs accounts for 15 – 20% of their use. Benzodiazepines are prescribed to a growing number of PLWH and are associated with an increased risk of neurocognitive symptoms in this population. Little is known about the mechanisms by which BDZ impact HIV neuropathogenesis. Our published and preliminary data indicate that BDZ can alter the transcriptional regulation of HIV infection. To better understand and treat the development of neuroHIV in PLWH who use and/or misuse BDZ, it is vital to determine who benzodiazepines affect the transcriptional programs in myeloid cells. We hypothesize that both macrophages and microglia enter a semi-quiescent transcriptional state during ART exposure and that benzodiazepines disrupt this state and increase transcriptional activity and viral replication. Our data show that the BDZ Xanax, as well as some latency reactivation agents, mediate a dose-dependent increase in p24 production in infected, ART-treated cells. Our preliminary studies suggest these effects may result from BDZ interactions with the epigenetic regulator RUNX1. We posit that these changes in HIV replication in myeloid cells reflect the epigenetic state of the provirus. Thus, the growing population of PLWH who use BDZ is at greater risk of more severe neuropathogenesis. It also suggests that BDZ may provide the basis for novel therapeutics to manipulate HIV transcription in myeloid cells. Therefore, we will evaluate the transcriptional and epigenetic mechanisms sustaining the semi-quiescent state of HIV transcription in ART- treated human macrophages (Aim 1), define the differences in transcriptional and epigenetic processes in different types of myeloid cells using human syngeneic iPSC-derived macrophages and microglia (Aim 2), and examine the effect of benzodiazepines on transcription HIV-infected, ART-treated myeloid cells (Aim 3).