Defining the causes and consequences of viral rebound

用抗逆转录病毒疗法(ART)治疗HIV感染者通常可以抑制血浆病毒载量 检测不到的水平。然而，艾滋病毒在治疗过程中持续存在，如果ART停止，病毒载量会迅速增加 反弹，使疾病继续发展。虽然很明显，潜伏感染的CD4+T细胞 细胞和其他可能被感染的罕见细胞可以作为复制能力强的病毒重新激活的来源 在感染方面，许多问题仍然存在，即如果ART停止使用，如何以及为什么会发生反弹。特定区域 需要更多研究的地方包括确定什么可以启动反弹过程，如何选择时机和 反弹的大小与潜在储集层的大小和特征有关，并定义 允许反弹发生的后果是什么。 本PO1应用程序总体目标是对HIV反弹有更全面的了解 通过使用骨髓-肝脏-胸腺(BLT)小鼠，一个高度相关的人源化小鼠模型进行研究 体内的HIV病毒。该模型支持小鼠体内许多组织中的多血统人类免疫重建 代表了最先进的小动物模型之一，可用于研究艾滋病毒持久性和 发病机制。我们和其他人已经证明，BLT小鼠模型可以有效地感染艾滋病毒和 在静息的CD4+T细胞中形成真实的整合后潜伏期。临床应用可抑制病毒载量 相关的抗逆转录病毒药物，如果抗逆转录病毒治疗被停止，病毒载量就会迅速反弹。我们已经进一步推进了这一点 通过利用表型中性、遗传多样性的条形码艾滋病毒群体进行感染来建立模型。 这使得各种带有基因标签的病毒可以形成一个潜在的储存库。然后反弹就可以 通过监测病毒载量来测试病毒重新出现的时间和大小 血浆或组织，并对反弹病毒进行深度测序，以量化单个条形码的数量 变种对反弹起到了作用。这一结合的方法将提供对艾滋病毒的前所未有的看法 水库的形成和病毒的反弹。在项目1中，我们将使用此模型来确定Pre ART感染至病毒自发反弹的时间(目标1)，测试是否有常见的生理/药理 刺激改变反弹的频率(目标2)，并量化结构化治疗中断(STI)的影响 关于艾滋病毒潜伏宿主的规模和多样性(目标3)。总之，这些研究将在临床上检验关键 相关参数，以确定它们如何影响停止抗逆转录病毒疗法后艾滋病毒的反弹，并将评估 允许反弹发生的后果。这将提供对以下机制的新见解 艾滋病病毒反弹。

Treatment of HIV-infected individuals with antiretroviral therapy (ART) can often suppress plasma viral loads to undetectable levels. However HIV persists during therapy and if ART is stopped then viral loads rapidly rebound allowing disease progression to continue. While it is clear that reservoirs of latently-infected CD4+ T cells and potentially other rare infected cells can serve as a source of replication-competent virus to rekindle infection, many questions remain about how and why rebound occurs if ART is discontinued. Particular areas where more study is needed include determining what can initiate the rebound process, how the timing and magnitude of rebound relates to the size and characteristics of the underlying latent reservoir, and defining what the consequences of allowing rebound to occur are. The overall goal of this PO1 application is to develop a more complete understanding of HIV rebound by using the bone marrow-liver-thymus (BLT) mouse, a highly relevant humanized mouse model for studying HIV in vivo. This model supports multi-lineage human immune reconstitution in many tissues within the mouse and represents one of the most advanced small animal models available for investigating HIV persistence and pathogenesis. We and others have shown that the BLT mouse model can be efficiently infected with HIV and forms authentic post-integration latency in resting CD4+ T cells. Viral loads can be suppressed using clinically relevant ART drugs, and if ART is stopped then viral loads quickly rebound. We have further advanced this model by utilizing a phenotypically neutral, genetically diverse barcoded HIV swarm to perform the infections. This allows a latent reservoir to be formed with diverse genetically tagged viruses. Rebound can then be tracked both through monitoring of viral loads to test the timing and magnitude of virus re-emergence in the plasma or tissues, and deep-sequencing of the rebounding virus to quantify the number of individual barcoded variants contributing to the rebound. This combined approach will provide an unprecedented view of HIV reservoir formation and viral rebound. In project 1 we will use this model to determine the contribution of Pre- ART infection time to spontaneous viral rebound (Aim 1), test whether common physiologic/pharmacologic stimuli alter the frequency of rebound (Aim 2), and quantify the effects of structured treatment interruption (STI) on the size and diversity of the latent HIV reservoir (Aim 3). Together, these studies will test key, clinically relevant parameters to determine how they affect rebound of HIV upon stopping ART, and will assess the consequences of allowing rebound to occur. This will provide new insights into the mechanisms contributing to HIV rebound.