Turning off HIV White Noise: Switching from Long-Lived to Short-Lived Reservoir

艾滋病毒在所有接受治疗的个体中持续存在，在大多数情况下，抗逆转录病毒治疗后病毒迅速反弹 治疗中断（ATI）。组织是cART期间HIV持续存在的主要部位，特别是， 胃肠道是通过SIV末端ImmunoPET/CT在活体SIV中可检测到反弹的第一个部位 感染的动物。然而，关于病毒在组织中持续存在的机制仍有很多未知之处。 这主要是因为深层组织取样的后勤障碍和艾滋病毒/SIV感染的局部性质。 我们的团队开发了一种基于ImmunoPET/CT信号的采样工作流程， 困难，并允许在活体动物的组织中对“回弹能力储库”区域进行采样。TGF-β是 一种重要的免疫抑制因子，协调组织免疫。TGF-β的水平仍然升高 在HIV感染者中，即使在多年的完全抑制性cART之后， 以及通过促纤维化机制导致非艾滋病相关的非传染性疾病的发展。 TGF-β抑制TCR驱动的T细胞增殖以及其他免疫细胞亚群的成熟和功能。 重要的是，TGF-β目前被用于在具有原代T细胞的体外模型中诱导HIV潜伏期。我们 初步数据表明，阻断体内TGF-β信号转导有利于逆转HIV潜伏期，特别是在 组织中此外，我们发现TGF-β阻断剂刺激SIV特异性免疫应答， BCL-2在体内和体外记忆T细胞中的表达。这些令人兴奋的新数据支持TGF-β的观点 作为维持免疫细胞进入主要抵抗凋亡的静止状态的关键因素。所以我们 假设阻断TGF-β不仅会增加潜伏期逆转事件的频率， 通过增加其对免疫和病毒介导的细胞的易感性来增强病毒储库的消除 死亡我们将通过关注三个具体目标来验证这一假设。目标1将是调查 体内TGF-β阻断的机制。我们将利用PET/CT引导的采样来获得组织区域 其中病毒在TGF-β阻断后逆转，并分析这些组织中的细胞的转录组， 在他们自己的微环境中。在目标2中，我们将剖析TGF-β阻断离体的机制， 了解TGF-β阻断对HIV潜伏期和存活率的影响的途径依赖性 中央记忆T细胞最后，在目标3中，我们将剖析TGF-β阻断和 PD-1对携带病毒库的细胞的分化程序和凋亡敏感性的阻断 in vivo.最后，我们设计了一个全面的战略，这将有助于我们了解 这个新的策略让我们离治愈艾滋病更近了一步。

HIV persists in all treated individuals and in most cases viral rebound occurs promptly upon antiretroviral treatment interruption (ATI). Tissues are major sites of HIV persistence during cART and, notably, the gastrointestinal tract is the first site were rebound is detectable via SIV-end ImmunoPET/CT in a live SIV infected animal upon ATI. However, a lot is still unknown about the mechanisms of viral persistence in tissues. This is mostly because of logistical barriers in sampling deep tissues and the focal nature of HIV/SIV infection. Our team has developed a sampling workflow based on ImmunoPET/CT signal that overcomes these difficulties and allows sampling of areas of “rebound-competent reservoir” in tissues in a live animal. TGF-β is an important immune suppressor factor, which orchestrates tissue immunity. Levels of TGF-β remain elevated in HIV infected individuals even after years of fully suppressive cART and contribute to immune suppression as well as to the development of non-AIDS-related, non-communicable disorders via pro-fibrotic mechanisms. TGF-β inhibits TCR-driven T cell proliferation and the maturation and function of other immune cell subsets. Importantly, TGF-β is currently being used to induce HIV latency in in vitro models with primary T cells. Our preliminary data demonstrate that blocking TGF-β signaling in vivo favors HIV latency reversal especially in tissues. Moreover, we found that TGF-β blockade stimulates SIV-specific immune responses and decreases BCL-2 expression in memory T cells both in vivo and in vitro. These exciting new data support a view of TGF-β as a critical factor in maintaining immune cells into a resting state mostly resistant to apoptosis. Hence, we hypothesize that blocking TGF-β will not only increase the frequency of latency reversal events, but also enhance the elimination of the viral reservoir by increasing its susceptibility to immune and viral-mediated cell death. We will test this hypothesis by focusing on 3 specific aims. Aim 1 will be an investigation of the mechanisms of TGF-β blockade in vivo. We will leverage PET/CT-guided sampling to obtain tissue areas where virus reverses following TGF-β blockade and analyze the cells in these tissues for their transcriptomic profiles in their own microenviroment. In Aim 2, we will dissect the mechanisms of TGF-β blockade ex vivo to understand the pathways dependence of the effect of TGF-β blockade on HIV latency and on the survival program of central memory T cells. Finally, in Aim 3, we will dissect the combination of TGF-β blockade and PD-1 blockade on the differentiation program and apoptosis sensitivity of the cells harboring the viral reservoir in vivo. In conclusion, we designed a comprehensive strategy that will help us understanding the potential of this novel strategy to bring us closer to an HIV cure.