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间中存在病毒库和 不受抗逆转录病毒治疗(ART)影响的细胞类型。在中枢神经系统(CNS)，这些 储存库由髓系细胞组成，如血管周围巨噬细胞和小胶质细胞。关键的是，这些 储藏库通常在ART启动之前建立，而ART在CNS的存在并不 会影响长寿的髓系人群中已建立的蓄水池。因此，即使在个人对压抑艺术的研究中， 持续感染的中枢神经系统巨噬细胞和小胶质细胞可以推动持续的神经炎症，并提供 在药物治疗中断或失败期间，病毒复发的艾滋病毒来源。我们消灭这些水库的能力 严重受限于对髓系中HIV转录和表观遗传调控的了解 细胞。为了有效地针对和消除艾滋病毒携带者(PLWH)中的中枢神经系统宿主，关键是要确定 不同中枢神经系统髓系群体持续感染的转录机制。 艾滋病毒感染在中枢神经系统的影响在患有药物使用障碍的PLWH中更高，包括 服用和/或滥用苯二氮卓(BDZ)等治疗药物的人。苯二氮卓类药物由 3000多万美国人，有很高的滥用倾向，滥用这些药物占15%-20% 它们的用途。苯二氮卓类药物被开给越来越多的PLWH，并与增加的 这一人群中出现神经认知症状的风险。人们对BDZ撞击的机制知之甚少 艾滋病病毒的神经发病机制。我们已发表的和初步的数据表明，BDZ可以改变转录 对艾滋病毒感染的监管。为了更好地了解和治疗使用和/或使用和/或 滥用苯二氮卓类药物，确定是谁影响了髓系细胞的转录程序是至关重要的。 我们假设巨噬细胞和小胶质细胞都进入半静止的转录状态。 在ART暴露期间，苯二氮卓类药物破坏这种状态并增加转录活性 和病毒复制。我们的数据显示，BDZ Xanax以及一些潜伏期再激活剂， 受感染的ART处理细胞中p24产量的剂量依赖性增加。我们的初步研究表明 这些效应可能是BDZ与表观遗传调控因子RUNX1相互作用的结果。我们假设这些变化 在HIV中，髓系细胞的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患者发生更严重的神经病变的风险更大。它还表明，BDZ可能会提供 在髓系细胞中操作HIV转录的新疗法的基础。因此，我们将评估 转录和表观遗传机制维持艾滋病毒转录的半静止状态- 经处理的人巨噬细胞(目标1)，定义转录和表观遗传过程中的差异 使用人类同基因IPSC来源的巨噬细胞和小胶质细胞的不同类型的髓系细胞(AIM 2)，以及 检查苯二氮卓类药物对艾滋病毒感染的、经抗逆转录病毒治疗的髓系细胞转录的影响(目标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).