Transcriptional regulatory mechanisms shaping HIV proviral fate

项目总结 在过去的二十年里，生物医学研究中最令人兴奋的突破之一就是这一发现 抗逆转录病毒疗法(ART)，它将活跃的艾滋病毒复制限制到几乎检测不到的水平。尽管如此 伟大的成就，抗逆转录病毒疗法未能治愈艾滋病毒感染，因为潜伏的蓄水池持续存在于含有 静息的CD4淋巴细胞和其他类型的细胞，表达低水平的病毒产物，可以重新激活 对免疫刺激的反应。因此，这些潜在的储集层是功能性治愈的关键障碍， 这使得对新方法的需求变得更加迫切。为了实现这一重大目标，我们必须首先确定 新的、关键的宿主因素，在我们可以利用这一知识进行治疗之前，可以进行靶向治疗 临床干预。为此，该提案将调查牵涉到的一个主宿主因子(KAP1 将各种生理性免疫信号输入到前病毒转录输出中以揭示 分子机制和治疗潜力的评估。我们的工作与以前的研究不同，因为 这将有助于解开影响前病毒转录和命运的三个主要特征的贡献 (复杂转录电路体系结构、集成环境和免疫细胞状态)来帮助设计 根除艾滋病毒的基本方法。我们假设整合环境和免疫细胞 国家通过关键大师的功能调节感染的结果(活跃的、潜伏的、重新激活的) 宿主因素，如KAP1。研究这一问题的新技术和实验方法提供了 检验这一假说和定义潜在分子机制的独特机会。具体来说，我们 将研究：1)KAP1如何与其他宿主辅助因子交流以组装正转录 促进反应免疫刺激的潜伏期-再激活开关的复合体，2)如何整合 景观和细胞状态影响KAP1介导的前病毒转录激活和克隆性扩张，3) KAP1如何识别前染色质作为连接转录启动和转录调控的“脚手架” 伸长，以及4)KAP1的酶功能如何帮助缓解新的转录给予的抑制 在潜伏期-重新激活开关期间，协同抑制物在前病毒组装。中产生的知识 该研究将为干扰各种“可用药口袋”的功能奠定基础(例如， 酶和染色质读取域)用于根除艾滋病毒的策略。高度意义的结合， 在生理相关系统中创新和使用不同的实验方法(初级 潜伏期模型和患者样本)使这一建议独一无二。总的来说，这些研究可能会有一个 对我们对艾滋病毒潜伏期生物学的理解产生了革命性的影响，并具有治疗意义。

PROJECT SUMMARY Over the past two decades, one of the most exciting breakthroughs in biomedical research was the discovery of anti-retroviral therapy (ART), which curbs active HIV replication to nearly undetectable levels. Despite this great achievement, ART fails to cure HIV infection because latent reservoirs persist in tissues containing resting CD4 lymphocytes and other cell types that express low levels of viral products and can be reactivated in response to immune stimulation. Thus, these latent reservoirs are a critical barrier for a functional cure, making the need for new approaches even more urgent. To achieve this major goal, we must first identify novel, critical host factors that can be targeted therapeutically before we can leverage this knowledge for clinical intervention. To this end, this proposal will investigate a master host factor (KAP1) implicated in transducing a variety of physiologic immune signal inputs into proviral transcriptional outputs to reveal the molecular mechanisms and evaluate therapeutic potential. Our work is different from previous studies because it will help uncouple the contribution of the three major features influencing proviral transcription and fate (complex transcriptional circuit architecture, integration landscape, and immune cell state) to help devise rationale approaches for HIV eradication. We hypothesize that both the integration landscape and immune cell state regulate the outcome of an infection (active, latent, reactivated) through the function of critical master host factors like KAP1. New technologies and experimental approaches for investigating this problem provide unique opportunities to test this hypothesis and define the underlying molecular mechanisms. Specifically, we will investigate: 1) how KAP1 communicates with other host co-factors to assemble a positive transcription complex to promote the latency-reactivation switch in response to immune stimulation, 2) how the integration landscape and cell state influence KAP1-mediated proviral transcription activation and clonal expansion, 3) how KAP1 recognizes proviral chromatin to function as a ‘scaffold’ to couple transcription initiation and elongation, and 4) how KAP1 enzymatic functions help relieve the repression imparted by novel transcriptional co-repressors assembled at the provirus during the latency-reactivation switch. The knowledge generated in this study will establish the groundwork for interfering with the function of various “druggable pockets” (e.g., enzymatic and chromatin reader domains) for HIV eradication strategies. The combination of high significance, innovation and use of a diverse set of experimental approaches in physiologically relevant systems (primary models of latency and patient samples) make this proposal unique. Collectively, these studies could have a revolutionary impact on our understanding of HIV latency biology and have therapeutic implications.