Modeling HIV Microglia-Associated Infection and Inflammation in a Chimeric Mouse Brain

艾滋病毒相关的神经认知障碍在联合抗逆转录病毒治疗时代仍然存在 虽然HIV潜伏期和HIV转录物在人CNS中的细胞特异性表达仍然存在， 不完全理解。艾滋病毒相关神经系统疾病的患病率很高， 在cART稳定抑制的人群中识别CNS病毒逃逸，通常进一步复杂化， 艾滋病毒/艾滋病感染者中共同登记的药物使用障碍流行病， SUD对CNS功能也有深远的影响。我们实验室正在进行的工作首先提供了 评估细胞类型特异性HIV“分子特征”，包括基因组整合模式， 在奖赏和成瘾回路的转录组和表观基因组水平上的改变 人类死后大脑正如初步数据部分所详细描述的那样，我们发现， 在来自死后标本的小胶质细胞亚群中高水平的HIV表达，具有HIV转录物 水平在小胶质细胞中排名前5位的最高表达的RNA中，或所有表达的99.9%百分位数中， 小胶质细胞转录物。相应地，成瘾回路中的HIV基因组整合位点占主导地位， 小胶质细胞特异性基因，具有强烈的偏好活性染色质隔间。然而，在这方面， 在cART期间持续存在的潜伏感染的持续影响尚未得到很好的表征-部分 由于在确定小胶质细胞在多大程度上促进神经胶质细胞增殖方面存在根本性的挑战， 潜在油气藏我们的初步研究还提供了一个模型系统， 持续感染的细胞，可以应用于小胶质细胞区室，并将使我们能够定义 cART期间持续存在的基因组扰动。通过研究人类小胶质细胞中的艾滋病毒基因组学 并将其与跟踪持续感染的小胶质细胞的技术联系起来，我们将 能够建模，第一次，实验性疗法和干预措施，以补充我们的 人类死后大脑的描述性工作。具体来说，我们的基于Cre-reporter的HIV诱导谱系 追踪（HILT）标记系统将使我们能够量化和分离罕见的潜伏感染的小胶质细胞， 在cART期间持续存在，并分别绘制感染者的转录组和表观基因组改变， 未感染的小胶质细胞，两者都收集自同一小鼠大脑。重点介绍加法电路，我们将 研究用标准cART方案治疗的小鼠的神经炎症、认知和奖励行为 以及一种涉及大麻素受体2激动剂药物的实验性疗法，根据我们的研究， 初步数据显示，这与限制组织中HIV感染程度的抗炎活性有关。

HIV-associated neurocognitive disorders persist in the era of combination antiretroviral therapy (cART) while HIV latency, and cell-specific expression of HIV transcript in human CNS remains incompletely understood. There is high prevalence of HIV-associated neurologic disease and increasing recognition of CNS viral escape in people stably suppressed with cART, often further complicated by the co-registered epidemic of substance use disorders (SUD) in people living with HIV/AIDS (PLWHA), as SUD also have profound impact on CNS function. Ongoing work in our laboratory is providing first assessments of cell-type specific HIV 'molecular signatures', including genome integration patterns and alterations on the level of the transcriptome and epigenome in reward- and addiction circuitry of the human postmortem brain. As described in detail in the Preliminary Data section, we found dramatically high levels of HIV expression in a subset of microglia from postmortem specimens, with HIV transcript levels ranking among the top 5 highest expressed RNAs in microglia, or the 99.9% percentile of all microglial transcript. Correspondingly, HIV genome integration sites in addiction circuitry are dominated by microglia-specific genes, with strong preference for active chromatin compartments. However, lingering effects of latent infection that persist during cART have not been well characterized—in part because of fundamental challenges in identifying the extent to which microglial cells contribute to the latent reservoir. Our preliminary studies also provide a model system whereby we can track and isolate persistently infected cells which can be applied to the microglial compartment and will allow us to define the genomic perturbations that persist during cART. By studying HIV genomics in human microglia residing in the mouse brain and linking this with technology to track persistently infected microglia, we will be able to model, for the first time, experimental therapies and interventions to complement our descriptive work in human postmortem brain. Specifically, our Cre-reporter based HIV-induced lineage tracing (HILT) marking system will allow us to quantify and isolate the rare latently infected microglia that persist during cART, and map transcriptomic and epigenomic alterations separately both for infected, and non-infected microglia, both collected from the same mouse brain. With focus on addition circuitry, we will study neuroinflammation, cognition and reward behavior in mice treated with standard cART regimens and an experimental therapy involving Cannabinoid receptor 2 agonist drugs that, according to our preliminary data, are linked to anti-inflammatory activity limiting the extent of HIV infection in tissues.