Role of gammaherpesvirus lytic replication-associated genes in the establishment

描述（由申请方提供）：人γ疱疹病毒感染与多种类型恶性肿瘤的发生相关。这些病毒对免疫功能低下的患者（如感染HIV的患者）构成特别重大的风险。γ-疱疹病毒在B细胞中建立稳定的终生潜伏感染，提供最终可促成恶性疾病发展的病毒的终生储库。我们的长期目标是确定γ疱疹病毒用于在B细胞中建立潜伏期的机制，从而阐明预防γ疱疹病毒相关恶性肿瘤的新靶点。我们的方法是解剖潜伏期建立的最早期的事件，使用突变病毒在鼠γ疱疹病毒（γ HV 68，MHV 68）系统，不能进行裂解复制。通过比较早期裂解基因与晚期裂解基因突变的病毒，我们发现了裂解复制相关基因产物在B细胞潜伏期建立中的惊人作用。我们假设这些关键的裂解基因产物对于诱导表观遗传修饰是至关重要的，而表观遗传修饰对于保留潜伏的病毒附加体是至关重要的。本提案的目标是定义在B细胞感染后最早几小时内发生的关键分子事件，这些事件最终导致病毒附加体在潜伏期期间稳定维持。具体而言，我们将定义在B细胞潜伏期建立阶段发生的病毒转录和基因组事件（目标1），我们将定义建立稳定潜伏期所需的特异性晚期裂解基因（目标2），我们将检验关键裂解基因诱导对B细胞中潜伏期建立至关重要的表观遗传修饰的假设。拟议的研究应提供重要的新的洞察力，发生在最早的时刻，γ疱疹病毒感染的B细胞的关键分子事件。

DESCRIPTION (provided by applicant): Human gammaherpesvirus infection is linked to the development of multiple types of malignancies. These viruses pose a particularly significant risk to immunocompromised patients such as those infected with HIV. Gammaherpesviruses establish stable life-long latent infection in B cells, providing a lifelong reservoir of virus that can eventually contribute to the development of malignant disease. Our long-term goal is to define the mechanisms that gammaherpesviruses use to establish latency in B cells, thereby elucidating new targets for the development of modalities to prevent gammaherpesvirus-associated malignancies. Our approach is to dissect the earliest events of latency establishment using mutant viruses in the murine gammaherpesvirus (gammaHV68, MHV68) system that are unable to undergo lytic replication. By comparing viruses that are mutated in early versus late lytic genes, we have uncovered a surprising role for lytic replication-associated gene products in the establishment of latency in B cells. We hypothesize that these key lytic gene products are critical for the induction of epigenetic modifications that are critical for retention of latent viral episomes. The goals of this proposal are to define the critical molecular events that occur in the earliest hours following B cell infection that ultimately result in stable maintenance of the viral episome during latency. Specifically, we will define the viral transcriptional and genomic events that occur during the establishment phase of B cell latency (Aim 1), we will define the specific late lytic gene that is required for the establishment of stable latency (Aim 2), and we will test the hypothesis that the crucial lytic gene induces epigenetic modifications that are critical for latency establishment in B cells. The proposed studies should provide significant new insight into the critical molecular events that occur during the earliest moments of gammaherpesvirus infection of B cells.