Elucidating the mechanism of UL138 mediated suppression of lytic phase genes during human cytomegalovirus latency.

项目摘要 人巨细胞病毒（HCMV）是一种主要的人类病原体，感染60-90%的人口。的能力 建立潜伏期并持续宿主的生命有助于其作为病原体的广泛成功。而 健康成人感染相对无症状HCMV可导致免疫功能低下的严重疾病 患者，如移植和HIV/AIDS患者以及免疫系统未发育的患者。重要的 疾病可能是由病毒在潜伏数十年后重新激活引起的， 暴露了病毒蛋白UL 138是建立和维持潜伏期所必需的，并且在所有细胞中保留。 临床分离株，但在成纤维细胞中连续传代时丢失（25、26、28）。UL 138在延迟期间的关键作用 使其成为对抗潜伏感染的理想目标。当从潜伏缺陷型HCMV株表达时， AD 169、UL 138阻止组蛋白去乙酰化酶（HDAC）抑制剂丙戊酸（VPA）诱导的组蛋白去乙酰化酶（HDAC）的表达。 来自主要立即早期启动子（MIEP）的病毒蛋白IE 1;阻断裂解性感染的第一步（27）。 这个关键的检查点决定了HCMV是否会经历裂解或潜伏感染。初步研究表明， 发现UL 138阻止赖氨酸脱甲基酶（KDM）去除抑制性组蛋白修饰， MIEP（27）.有趣的是，UL 138定位于高尔基体，而在细胞核中没有发现， 它对MIEP的影响发生了。 本研究的主要目的是确定UL 138如何防止脱甲基酶被招募， MIEP允许建立延迟。更清楚地了解UL 138如何帮助HCMV 建立和维持潜伏期是开发治疗方法以对抗潜伏的HCMV和清除潜伏的HCMV所必需的。 水库通过我们的研究，将发现可能的细胞靶点来调节HCMV潜伏期。这 一项研究是由这样的假设驱动的，即UL 138改变了一种未知蛋白质的细胞运输。 阻止他们招募KDM加入MIEP UL 138含有四个高尔基体， 分类基序，并改变了几种蛋白质的亚细胞定位（33，34，35，37）。的要求 将对UL 138介导的MIEP抑制的这些分选基序和细胞分选机制进行测试 并且将鉴定UL 138必须与之相互作用以沉默MIEP的蛋白质。

Project summary Human cytomegalovirus (HCMV) is a major human pathogen infecting 60-90% of the population. Its ability to establish latency and persist for the life of the host contributes to its widespread success as a pathogen. While infection in healthy adults is relatively asymptomatic HCMV can cause severe disease in immunocompromised patients such as transplant and HIV/AIDS patients and those with undeveloped immune systems. Importantly disease can be caused by virus reactivating after decades of latency when immune defenses are compromised. The viral protein UL138 is required to establish and maintain latency and is retained in all clinical isolates but lost upon serial passage in fibroblasts (25, 26, 28). UL138’s critical role during latency makes it an ideal target to combat latent infection. When expressed from a latency defective HCMV strain AD169, UL138 prevents histone deacetylase (HDAC) inhibitor valproic acid (VPA) induced expression of the viral protein IE1 from the major immediate early promoter (MIEP); blocking the first step of a lytic infection (27). This critical checkpoint determines whether HCMV will undergo a lytic or latent infection. Initial studies have found UL138 prevents lysine demethylases (KDMs) from removing repressive histone modifications on the MIEP (27). Intriguingly, UL138 localizes to the Golgi apparatus and has not been found in the nucleus where its effect on the MIEP takes place. The primary goal of this study is to identify how UL138 prevents demethylases from being recruited to the MIEP allowing for the establishment of latency. A clearer understanding of how UL138 helps HCMV establish and maintain latency is needed to develop treatments to combat latent HCMV and to clear the latent reservoir. Through our studies possible cellular targets to modulate HCMV latency will be discovered. This research is driven by the hypothesis that UL138 alters cellular trafficking of an unidentified protein(s) preventing them from recruiting KDMs to the MIEP. Supporting this hypothesis UL138 contains four Golgi sorting motifs and alters the subcellular localization of several proteins (33, 34, 35, 37). The requirement for these sorting motifs and cellular sorting machinery for UL138 mediated suppression of the MIEP will be tested and the proteins UL138 must interact with to silence the MIEP will be identified.