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会迅速反弹 治疗中断(ATI)。组织是艾滋病毒在CART期间持续存在的主要部位，值得注意的是， 胃肠道是第一个被反弹的部位，是通过SIV-End免疫PET/CT检测到的一种活体SIV ATI上被感染的动物。然而，关于病毒在组织中持续存在的机制仍有许多未知之处。 这主要是因为对深层组织进行取样时的后勤障碍，以及艾滋病毒/SIV感染的局部性质。 我们的团队已经开发出一种基于免疫PET/CT信号的采样工作流程，可以克服这些问题 在活体动物的组织中采样“反弹能力储存库”的区域是困难的，并且允许采样。转化生长因子-β是 一种重要的免疫抑制因子，协调组织免疫。转化生长因子-β水平居高不下 在HIV感染者中，即使经过多年的全面抑制，也有助于免疫抑制，如 以及通过促纤维化机制发展与艾滋病无关的非传染性疾病。 转化生长因子-β抑制T细胞增殖和其他免疫细胞亚群的成熟和功能。 重要的是，转化生长因子-β目前正被用于在具有原代T细胞的体外模型中诱导艾滋病毒潜伏期。我们的 初步数据显示，体内阻断转化生长因子-β信号有利于艾滋病毒潜伏期的逆转，尤其是在 纸巾。此外，我们还发现，阻断转化生长因子-β可刺激SIV特异性免疫反应并降低 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了关于转化生长因子-β的观点 作为维持免疫细胞处于静息状态的关键因素，主要抵抗细胞凋亡。因此，我们 假设阻断转化生长因子-β不仅会增加潜伏期反转事件的频率，而且 通过增加其对免疫和病毒介导性细胞的敏感性来增强对病毒库的清除 死亡。我们将通过关注三个具体目标来检验这一假设。目标1将是对 转化生长因子β体内阻断机制的研究。我们将利用PET/CT引导的采样来获得组织区域 在阻断转化生长因子-β后病毒逆转的地方，并分析这些组织中的细胞转录 在他们自己的微环境中的个人资料。在目标2中，我们将剖析转化生长因子-β体外阻断的机制。 了解阻断转化生长因子-β对艾滋病毒潜伏期和存活率影响的途径依赖 中央记忆T细胞的编程。最后，在目标3中，我们将剖析转化生长因子-β阻断和 PD-1对携带病毒库的细胞分化程序和凋亡敏感性的阻断作用 在活体内。总而言之，我们设计了一个全面的战略，这将帮助我们了解 这一新战略使我们更接近治愈艾滋病毒的方法。

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.