Unraveling the Mechanisms of HIV Persistence and Rebound

项目总结/摘要（总体） 尽管cART长期抑制了病毒血症，但HIV感染的持续存在构成了主要障碍 艾滋病的治愈不幸的是，即使是在急性感染期间开始接受cART的患者也是如此。因此，长期 持续的HIV宿主在感染后迅速播种，这在非人灵长类动物中得到证实 (NHP)艾滋病模型。此外，来自几个小组和我们的数据强烈表明， 尽管cART完全抑制了病毒血症，但在组织中仍持续存在。我们正在进行的研究调查 cART中断后NHP模型中病毒反弹的"蚀相"。这个"月食阶段"是关键， 了解反弹过程，因为病毒在病毒血症之前在组织中传播，并且受到以下因素的影响： 适应性和先天反应以及宿主微环境。在我们的研究中，早期（4天后）， 感染）cART启动，我们创新的SIV-env免疫PET-CT引导分析和采样导致了几个 重要的，有时是意想不到的发现：1）我们检测到SIV在整个宿主中扩增> 1周 cART启动后，此后信号降低; 2）即使在cART 6 - 8个月后， 尽管血液中存在不可检测的病毒血症，但仍足够灵敏以检测组织中残留的病毒（蛋白质）信号; 3)在ART中断后，病毒信号早在cART中断后4天（ATI）反弹，但也在2 在血浆中检测到病毒前10周; 4）通过我们的PET-CT分析反弹时收集的组织 引导的尸检工作流程令人惊讶地显示，大多数感染的细胞是骨髓细胞。后 广泛的分析表明，这些细胞是肥大细胞（MC），一种主要存在于组织中的粒细胞， 我们证明表达CD4和CCR5。通过与当地的MC专家合作，我们能够证明 原代组织MC在体外易受HIV感染，它们易感性和支持病毒的能力 复制受环境刺激的影响很大。在这个PPG中，我们将利用几个重要的见解 在我们目前的PPG期间开发的创新技术，以研究MC有助于 cART期间组织中的HIV持续存在和/或导致cART中断后病毒反弹。而且我们 将通过使用组织对组织中的病毒种群进行解剖学分析来阐明病毒-宿主动力学， 通过我们创新的PET-CT引导采样工作流程分离细胞。这些组织也将被识别 通过对"回弹组织"的附加特征的分析， 问题研究该项目规划小组由3个独立但高度相互关联的项目组成，1个科学NHP核心项目， 1行政核心。这三个项目将以不同的方式使用NHP研究中的组织， 每个项目都有独特的资源，并将解决不同但互补的问题， 目的是剖析艾滋病毒持续存在和反弹的机制。

PROJECT SUMMARY/ABSTRACT (Overall) The persistence of HIV infection despite long term suppression of viremia by cART constitutes the major obstacle to HIV cure. This is unfortunately true even for patients initiated on cART during acute infection. Thus, long-term persistent HIV reservoirs are seeded rapidly post infection, and this was confirmed in the nonhuman primate (NHP) model of HIV. In addition, data from several groups and ours strongly suggest that residual viral replication is ongoing despite in tissues despite full suppression of viremia by cART. Our on-going studies investigate the “eclipse phase” of viral rebound in the NHP model after cART interruption. This “eclipse phase” is key to understand the rebound process since the virus is spreading in tissues before viremia and it is influenced by adaptive and innate responses as well as the host microenvironment. In our studies of early (4 days post- infection) cART initiation, our innovative SIV-env ImmunoPET-CT guided analysis and sampling led to several important, sometimes unexpected findings: 1) we detected SIV expansion throughout the entire host for >1 week post cART initiation, with signal decreasing thereafter; 2) Even after 6-8 months of cART, immunoPET/CT was sensitive enough to detect residual viral (protein) signal in tissues in spite of undetectable viremia in the blood; 3) upon ART interruption, viral signals rebounded as early as 4 days post cART interruption (ATI) but also 2 weeks before detection of virus in plasma; 4) analysis of the tissues collected at rebound through our PET-CT guided necropsy workflow surprisingly showed that the majority of infected cells were of myeloid cells. After extensive analysis, these cells revealed to be mast cells (MC), a predominantly tissue resident granulocytes that we demonstrate expresses CD4 and CCR5. By teaming up with a local MC expert, we were able to demonstrate that primary tissue MC are susceptible to HIV infection in vitro and their susceptibility and ability to support viral replication is heavily influenced by environmental stimuli. In this PPG, we will leverage several important insights and innovative techniques developed during our current PPG to investigate the hypothesis that MC contribute to HIV persistence in tissues during cART and/or contribute to viral rebound upon cART interruption. Moreover, we will clarify virus-host dynamics through phyloanatomical analysis of viral populations in tissues using tissues and cells isolated through our innovative PET-CT guided sampling workflow. These tissues will be identified also through the analysis of additional features of “rebound tissues” that we have recognized through our current studies. This PPG comprises of 3 independent, although highly interconnected projects, 1 scientific NHP core and 1 administrative core. The 3 projects will all use in different ways tissues from the NHP studies as well as resources unique to each project and will address different although complementary questions with the ultimate goal to dissect the mechanisms of HIV persistence and rebound.