Targeted interventions to reduce or eliminate the SIV reservoir in a novel model of elite control

项目摘要 HIV-1感染通常通过联合抗逆转录病毒疗法(ART)得到很好的控制。然而，病毒 抗逆转录病毒疗法停用后，病毒蓄积者残留在淋巴组织中，导致病毒血症迅速反弹。这个 病毒持续存在的机制包括潜伏、增殖或克隆生长 完整的病毒基因组，以及不足以访问或杀死受感染细胞的免疫反应。几乎过了一个小时 经过十年的密集研究来治愈艾滋病毒感染，在消除甚至减少艾滋病毒感染方面收效甚微 艾滋病毒-1蓄水池，这表明实现这一目标的障碍是巨大的。很明显，Basic 病毒持久性如何维持的问题和机制需要在相关动物身上解决 可以揭示这些水库中的脆弱性并为假说驱动的干预措施提供信息的模型 它们的大小和耐用性。霍克西实验室描述了一种独特的非人类灵长类动物模型，在该模型中，2-氨基 SIVmac239被膜胞质尾部的酸缺失，扰乱高度保守的细胞转运 信号，产生一种名为∆GY的病毒，该病毒在急性感染期间高度适合复制，但很快得到控制 在没有中和抗体的情况下，通过细胞免疫反应无法检测到血浆中的水平。病毒式传播 正如抗CD8细胞耗竭研究所证明的那样，感染数年后明显存在储存库，以及 已经通过最先进的检测方法在PBMC和淋巴组织中进行了检测和定量。这项提议将 使用精英细胞控制的∆GY模型来检验这样一个假设，即有效且长期的干预- 持久中和抗体，具有或不具有CD8细胞耗竭的潜伏期逆转样活性，因此 对病毒库施加细胞和体液免疫攻击，将加速病毒的腐烂和/或 消除复制能力强的病毒。提出了四个具体目标：1)定义和量化病毒 在∆GY的精英免疫控制期间的储存库，特征相关的细胞类型，转录活性， 整合位点和持久存在的机制；2)决定eCD4-Ig、a)的长期表达 具有强大中和和非中和功能的新型工程抗体样分子 SIVmac239和∆GY在有或没有CD8细胞耗尽的情况下都能激活病毒的产生，可以与宿主协同作用 减少宿主的细胞免疫反应；3)将研究结果从AIMS 1和2扩展到SIVmac239感染 其中，在eCD4-Ig和CD8细胞耗尽之前通过ART而不是细胞实施病毒控制 免疫控制；以及4)创造包含类似于∆GY的突变的新的SIV和HIV1分离株 突变用于未来研究，以探索干预措施，以此建议的结果为基础，减少或 消除持续存在的HIV-1病毒宿主。如果∆GY模型中的病毒库能够减少或消除，这 研究将提供这一目标是可行的概念证明，并为免疫干预提供信息 抑制艺术的动物模型和人类。

Project Summary HIV-1 infection is typically well controlled with combination antiretroviral therapy (ART). However, viral reservoirs persist in lymphoid tissues leading to rapid rebound viremia following ART discontinuation. The mechanisms that underlie viral persistence include latency, proliferation or clonal outgrowth of cells harboring intact viral genomes, and immune responses that are inadequate to access or kill infected cells. After almost a decade of intensive research to cure HIV infection, there has been little success in eliminating or even reducing HIV-1 reservoirs, indicating that barriers to achieving this goal are formidable. It has become clear that basic questions and mechanisms of how viral persistence is maintained need to be addressed in relevant animal models that can reveal vulnerabilities in these reservoirs and inform hypothesis-driven interventions to impact their size and durability. The Hoxie lab has described a unique nonhuman primate model in which a 2 amino acid deletion in the SIVmac239 envelope cytoplasmic tail, disrupting a highly conserved cellular trafficking signal, produces a virus termed ∆GY that is highly replication fit during acute infection but is rapidly controlled to undetectable levels in plasma by cellular immune responses in the absence of neutralizing antibodies. Viral reservoirs are clearly present years after infection, as demonstrated by anti-CD8 cell depletion studies, and have been detected and quantified by state of the art assays in PBMCs and lymphoid tissue. This proposal will use the ∆GY model of elite cellular control to test the hypothesis that an intervention with a potent and long- lasting neutralizing antibody, with or without the latency reversing-like activity of CD8 cell depletion, thus exerting both cellular and humoral immune attack on the viral reservoir, will accelerate the decay of and/or eliminate replication competent viruses. Four Specific Aims are proposed: 1) to define and quantify viral reservoirs during elite immunologic control of ∆GY, characterizing relevant cell types, transcriptional activity, integration sites, and mechanisms that underlie persistence; 2) determine if long term expression of eCD4-Ig, a novel engineered antibody-like molecule with potent neutralizing and non-neutralizing functions against SIVmac239 and ∆GY, with or without CD8 cell depletion to activate virus production, can synergize with host cellular immune responses to reduce reservoirs; 3) extend findings from Aims 1 and 2 to SIVmac239 infection in which viral control prior to eCD4-Ig and CD8 cell depletion is exerted through ART rather than cellular immune control; and 4) create novel SHIV and HIV-1 isolates that contain mutations analogous to the ∆GY mutation for future studies to explore interventions that can build on the findings of this proposal to reduce or eliminate persisting HIV-1 reservoirs. If viral reservoirs in the ∆GY model can be reduced or eliminated, this study will provide a proof of concept that this goal is feasible, and inform immunological interventions during ART-suppression animal models and in humans.