HIV-1 Preintegration Trafficking and Nuclear Localization

项目摘要 这项长期的NIH资助在其生命周期中对核内免疫的机制做出了开创性的发现。 HIV-1贩运和核定位。在之前的资助周期中，我们确定核孔复合体 蛋白质核孔蛋白153与病毒蛋白质衣壳相互作用以影响传入病毒的易位， 复制复合物进入细胞核和人类基因组中病毒DNA整合的位点。我们也 首次鉴定了细胞交替多聚腺苷酸化蛋白切割和多聚腺苷酸化特异性因子6 （CPSF 6）作为病毒衣壳的直接结合伴侣，并揭示了这种相互作用在以下方面的重要作用： 病毒逆转录物整合到活性染色质中。在最近的融资周期中，我们的工作 已经阐明capture-CPSF 6相互作用对于病毒复制复合物进入细胞核至关重要， 结构，在那里它们与被称为核斑点的核细胞器结构共定位。使用 新的生物信息学工具，我们的工作还揭示了HIV-1整合到 与核斑点相关的基因组区域。通过这种方式，我们最近的研究 已经阐明了最有利于和最吸引HIV-1的核结构的粒度， 整合的染色体位点。展望未来，我们将确定几个未知的方面， 基本的病毒-宿主相互作用，包括CPSF 6在HIV-1核内 靶向以及误靶向的功能后果，其中已知HIV-1 非典型地整合到异染色质层近端序列中，朝向细胞的外周， 核结构此外，我们还将研究其他宿主因子的参与情况， 被指定为在生物化学上与CPSF 6相似，因为它们在HIV-1的核心贩运中发挥作用， 首选的整合地点。我们还将研究这些病毒宿主的功能后果， 单核细胞类型中的相互作用，其中HIV-1复制复合物可以被细胞固有的 抵抗感染过程的机器。这种基础科研的转化相关性是 通过衣壳蛋白抑制剂的作用机制，如lenacapavir，这是在后期突出 临床试验阶段，并已知抑制HIV-1衣壳与Nup 153和CPSF 6的相互作用 蛋白质，并诱导细胞中的HIV-1整合重靶向。我们提出的工作将涉及 在HIV-1感染期间发生的病毒-宿主相互作用的基本方面，以保护病毒免受感测 在先天免疫细胞中，导航整合到优选的基因组DNA位点，以及 对病毒功能的误导性整合和潜伏期的重新激活。

PROJECT SUMMARY This longstanding NIH grant over its lifetime has made seminal discoveries on the mechanisms of intranuclear HIV-1 trafficking and nuclear localization. In prior funding cycles, we determined that the nuclear pore complex protein nucleoporin 153 interacted with the viral protein capsid to affect the translocation of incoming viral replication complexes into the cell nucleus and sites of viral DNA integration in the human genome. We also first identified the cellular alternate polyadenylation protein cleavage and polyadenylation specificity factor 6 (CPSF6) as a direct binding partner of the viral capsid and revealed an important role for this interaction in integration of the viral reverse transcript into active chromatin. Over the most recent funding cycle, our work has clarified that the capsid-CPSF6 interaction is critical for viral replication complexes to travel into the nuclear structure, where they colocalize with nuclear organelle structures that are known as nuclear speckles. Using novel bioinformatic tools, our work moreover revealed the significant preference for HIV-1 to integrate into regions of our genome that physically associate with nuclear speckles. In this way, our most recent research has clarified the granularity of nuclear architectural structure that most favors and most attracts HIV-1 to its chromosomal sites of integration. Moving forward, we will determine several unknown aspects of this fundamental virus-host interaction, including the mechanistic basis of CPSF6 action in HIV-1 intranuclear targeting as well as the functional consequences of mistargeting, wherein HIV-1 is known to uncharacteristically integrate into heterochromatic lamina-proximal sequences out towards the periphery of the nuclear structure. We furthermore will investigate the participations of other host factors that we have earmarked as behaving biochemically similar to CPSF6 for their roles in HIV-1 trafficking in the nucleus to preferred sites of integration. We will also investigate the functional consequences of these virus-host interactions in monocytic cell types, wherein HIV-1 replication complexes can be sensed by cellular innate machinery to counteract the infection process. The translational relevance of this basic scientific research is highlighted through the mechanism of action of capsid protein inhibitors such as lenacapavir, which are in late stage clinical trials and are known to inhibit the interaction of the HIV-1 capsid with Nup153 and CPSF6 proteins in vitro, and to induce HIV-1 integration retargeting in cells. Our proposed work in total will address fundamental aspects of virus-host interactions that occur during HIV-1 infection to shield the virus from sensing in innate immune cells, navigate integration to preferred genomic DNA sites, as well as the consequences of misguided integration on virus function and reactivation from latency.