Role of RhCMV in shaping the SIV proviral landscape

项目摘要/摘要 治愈HIV-1感染的主要障碍是由静止的记忆CD4T细胞组成的蓄水池，其基因组 含有可诱导和复制能力强的HIV-1前病毒。水库的腐烂是缓慢的，需要终生 抗逆转录病毒疗法(ART)。越来越清楚的是，维持HIV-1持续的主要机制 在ART期间是潜伏感染的记忆性CD4T细胞的生理性增殖。感染的CD4T细胞可以增殖 不产生病毒，其结果将导致子细胞含有扩展的HIV-1前病毒克隆，这些克隆共享 相同的序列和宿主整合位点。然而，在此设置中，不同的前病毒克隆之间的扩展速度为 不平等。在一些个体中，超过30%的前病毒样本可能属于高度无性系的种群 扩大，这是一种与通过抗原相遇而克隆增殖一致的机制。在特定对象之间建立链接 然而，抗原以及它们在多大程度上独立地对艾滋病毒的持久性做出贡献，是一个悬而未决的问题。 巨细胞病毒(CMV)是一种潜伏的β疱疹病毒，虽然在免疫活性宿主中无症状，但持续存在 刺激记忆T细胞池。艾滋病毒携带者几乎普遍同时感染巨细胞病毒。在这个项目中，我们 已经组建了一个多学科的调查团队，直接评估慢性抗原刺激的程度 通过CMV(I)促进记忆CD4T细胞池的增殖(II)有助于克隆的多样性和HIV- ART期间的1个宿主和(Iii)影响ART中断时病毒复发的时间。具体来说，我们将 利用ART治疗感染SIV的恒河猴的成熟模型，对这些问题进行双重检验 接近。第一个将利用无病原体恒河猴巨细胞病毒(RhCMV)-幼稚恒河猴(RMS)的可用性来 比较有无CMV的SIV储集层动力学。第二项将评估SIV持久性的衡量标准 当CMV复制被抗病毒药物西多福韦阻断时。对我们的目标至关重要的是，我们将 在多个纵向时间点，在多个组织中，用几种分析方法询问SIV前病毒DNA 从定量和定性两个方面对SIV储集层进行研究。我们相信，全面、高度协同和 我们提出的严格控制的研究将(I)确定一个促进记忆更新的免疫优势靶点 在抗逆转录病毒治疗期间的CD4T细胞，并由此延伸，HIV-1储存库的持久性和(Ii)提供了使用最近的 耐受性良好的FDA批准的CMV抗病毒药物作为加速HIV-1清除的一种手段。

Project Summary/Abstract The main obstacle to curing HIV-1 infection is a reservoir that consists of resting memory CD4 T cells whose genomes contain inducible and replication-competent HIV-1 proviruses. Decay of the reservoir is slow and requires lifelong antiretroviral therapy (ART). It has become increasingly clear that the predominant mechanism sustaining HIV-1 persistence during ART is the physiologic proliferation of latent-infected memory CD4 T cells. Infected CD4 T cells can proliferate without producing virus, the result of which will lead to daughter cells harboring expanded HIV-1 proviral clones that share identical sequence and host integration sites. The rate of expansion among distinct proviral clones in this setting however is not equal. In some individuals, upwards of 30% of proviruses sampled can belong to populations that are highly clonally expanded, a mechanism consistent with clonal proliferation by antigen encounter. Establishing a link between particular antigens and the degree to which they independently contribute to HIV persistence, however, is an unresolved question. Cytomegalovirus (CMV) is a latent betaherpesvirus that while asymptomatic in immunocompetent hosts, persistently stimulates the memory T cell pool. Persons living with HIV are near universally coinfected with CMV. In this project, we have assembled a multidisciplinary team of investigators to directly assess the degree to which chronic antigenic stimulation by CMV (i) promotes proliferation of the memory CD4 T cell pool (ii) contributes to clonal diversity and size of the HIV- 1 reservoir during ART and (iii) impacts the time to viral recrudescence when ART is interrupted. Specifically, we will utilize the well-established model of ART-treated SIV-infected rhesus macaques to examine these questions by a dual approach. The first will exploit availability of pathogen-free, rhesus CMV (RhCMV)-naïve rhesus macaques (RMs) to compare SIV reservoir dynamics in the presence or absence of CMV. The second will assess measures of SIV persistence when CMV replication is blocked pharmacologically with antiviral Cidofovir. Critical to our aims are that we will interrogate SIV proviral DNA at multiple longitudinal timepoints, in multiple tissues, and with several assays that inform both quantitative and qualitative aspects of the SIV reservoir. We believe that the comprehensive, highly synergistic, and rigorously controlled studies we propose will (i) identify an immunodominant target that promotes turnover of memory CD4 T cells during ART and by extension, persistence of the HIV-1 reservoir and (ii) provide a rationale to employ recent well-tolerated FDA-approved CMV antivirals as a means to accelerate HIV-1 clearance.