HIV-1 Replication Without Integration

描述（由申请方提供）：HIV-1感染的持续性是许多因素的结果，包括病毒快速进化以逃避免疫、潜伏和隐蔽复制病毒的储存库的建立以及病毒复制直接或间接引起的免疫系统损伤。我们对这些因素的理解仍然不足以充分解释HIV-1的持久性和发病机制。这些研究将描述我们发现的一种以前未知的HIV-1复制途径，这种途径可能有助于HIV-1适应、病毒库的建立和发病机制。作为一种逆转录病毒，HIV-1 DNA整合到细胞染色体中是生产性感染所必需的。有趣的是，90-99%的HIV-1 DNA在体内和体外仍然是未整合的，本身无法产生足够的RNA和蛋白质来制造新的病毒体。然而，我们已发表的研究表明，在一个生产性感染的细胞中，uDNA是由整合的前病毒补充，并完成其复制周期。换句话说，uDNA有助于复制病毒群体并放大多重感染的数量。其结果是增加了有效的病毒群体大小，潜在的不同病毒之间的丰富的相互作用，并通过重组和突变增强病毒进化。这种HIV-1复制的新机制与整合前的潜伏期不同，并且不依赖于随后通过uDNA的整合。新的初步数据表明，HIV-1可以重复感染细胞并绕过整合，导致加速病毒复制，这是病毒适应性的一个重要参数。我们推测，uDNA对病毒的进化，持久性和发病机制有很大的影响。由于在非增殖细胞中的环状形式的UDNA的高稳定性，我们假设，UDNA构成了一个长寿的水库病毒的复制恢复生产性再感染的宿主细胞。通过实验和分析相结合的方法，以下具体目标将测试这些假设。目标1. uDNA对复制病毒种群的贡献是什么？目标二。检验uDNA可以作为T细胞和巨噬细胞中潜伏病毒的储存库的假设。目标3：检测uDNA对HIV-1复制动力学的影响。目标4。开发描述性和预测性的数学模型的uDNA的贡献HIV-1的复制和多样化，探索我们的主要假设。公共卫生相关性：如果我们要开发疫苗并改进目前可用的抗病毒药物治疗，了解HIV-1如何演变至关重要。到目前为止，人们一直认为体内99%的病毒无法到达宿主细胞的染色体，但我们发现，通过一种新的复制途径，这些病毒可以复制并帮助HIV-1进化。该项目将描述这种新的HIV-1复制形式及其对HIV-1进化和发病机制的影响。

DESCRIPTION (provided by applicant): The persistence of HIV-1 infection is the result of many factors, including rapid viral evolution to evade immunity, the establishment of reservoirs of both latent and cryptically replicating virus, and damage to the immune system caused directly or indirectly by virus replication. Our understanding of each of these factors remains inadequate to fully explain HIV-1 persistence and pathogenesis. The studies proposed will describe a previously unknown pathway of HIV-1 replication we have discovered that likely contributes to HIV-1 adaptation, to the establishment of viral reservoirs, and to pathogenesis. As a retrovirus, integration of HIV-1 DNA into the cellular chromosome is necessary for productive infection. Interestingly, 90-99% of HIV-1 DNA in vivo and in vitro remains unintegrated and by itself is unable to generate sufficient RNA and proteins to make new virions. However, our published studies reveal that in a productively infected cell, uDNA is complemented by the integrated provirus and completes its replication cycle. In other words, uDNA contributes to the replicating virus population and magnifies the amount of multiple infection. The result is an increased effective virus population size, abundant interactions among potentially divergent viruses, and enhanced virus evolution through recombination and mutation. This novel mechanism for HIV-1 replication is distinct from pre-integration latency and does not depend on subsequent integration by the uDNA. New preliminary data indicate the HIV-1 can superinfect cells and bypass integration, resulting in accelerated viral replication, an important parameter of viral fitness. We hypothesize that uDNA exerts a strong influence on viral evolution, persistence and pathogenesis. Owing to the high stability of circular forms of uDNA in non-proliferating cells, we hypothesize that uDNA constitutes a long-lived reservoir of virus whose replication is restored by productive reinfection of the host cell. Through a combination of experimental and analytical approaches, the following specific aims will test these hypotheses. Aim 1. What is the contribution of uDNA to the replicating virus population? Aim 2. Test the hypothesis that uDNA can function as a reservoir of latent viruses in T cells and macrophages. Aim 3. Examine the influence of uDNA on HIV-1 replication kinetics. Aim 4. Develop descriptive and predictive mathematical models of uDNA's contribution to HIV-1 replication and diversification to explore our main hypothesis. PUBLIC HEALTH RELEVANCE: Relevance Understanding how HIV-1 evolves is critically important if we are to develop vaccines and improve upon the currently available antiviral drug treatments. Up to now it has been thought that 99% of the viruses in the body which fail to reach the host cell's chromosomes are lost, but we have found that through a novel pathway of replication, these viruses can reproduce and help HIV-1 evolve. This project will describe this new form of HIV-1 replication an its impact on HIV-1 evolution and pathogenesis.