Role of HCMV UL7-8 genes in the regulation of host cell signaling during viral latency and reactivation

摘要--项目4 人巨细胞病毒是一种疱疹病毒，感染44%-100%的人，至今仍是一种 实体器官移植和异基因造血干细胞致病和死亡的重要原因 细胞移植(SCT)接受者。我们先前证明了人巨细胞病毒RL11基因UL7的靶向信号转导 参与细胞分化的途径对病毒的重新激活和造血很重要。我们 最近发现，另一个RL11基因UL8是病毒所必需的，它是从拼接的UL7转录本中表达的 重新激活。PUL8与pUL7共享相同的N-末端Ig样结构域，具有更长的茎结构域和 独特的细胞质尾巴。用接近感应器方法鉴定HEK293细胞中UL8相互作用组 细胞中，我们发现了RhoA、Wnt和EGFR途径中的蛋白质。此外，我们的初步数据显示， PUL7通过Rho A与UL8结合并增强UL8介导的非正则Wnt途径。 UL8信号对病毒的重新激活很重要，UL7和UL8之间的相互作用塑造了细胞内 有利于CD34+HPC分化和向宿主组织扩散的事件。因此，在SA1中我们 将在巨细胞病毒感染的竞争中对UL8相互作用体进行定义和功能鉴定。在SA2中，我们将 重点关注UL7和UL8形成的细胞信号，以及这对延迟和重新激活的影响。终于 基于我们最近发表的关于UL7、HCMV miR-UL112-3p和-US5-1对FOXO_3灭活的研究报告 对细胞凋亡的保护以及初步数据表明UL8和几种人巨细胞病毒参与其中 MiRNA在促进HCMV CD34+HPC感染细胞存活中的作用 UL7-8和HCMV miRNAs灭活FOXO的机制及其对细胞凋亡和凋亡的影响 建立潜伏期。

SUMMARY – PROJECT 4 Human cytomegalovirus (HCMV) is a -herpesvirus infecting 44-100% of the population and remains a significant cause of morbidity and mortality in solid organ transplant (SOT) and allogeneic hematopoietic stem cell transplant (SCT) recipients. We previously demonstrated that HCMV RL11 gene UL7 targets signaling pathways involved in cellular differentiation that are important for viral reactivation and hematopoiesis. We recently found that another RL11 gene, UL8, expressed from the spliced UL7 transcript, is required for viral reactivation. pUL8 shares the same N-terminal Ig-like domain with pUL7, with a longer stalk domain and a distinctive cytoplasmic tail. Using a proximity sensor approach to identify UL8 interactome in HEK293 transfected cells, we identified proteins in the RhoA, Wnt, and EGFR pathways. Moreover, our preliminary data shows that pUL7 binds to UL8 and enhances UL8-mediated non-canonical Wnt pathway via Rho A. We hypothesize that UL8 signaling is important for viral reactivation and the interaction between UL7 and UL8 shapes the intracellular events conducive to CD34+ HPCs differentiation and dissemination into the host tissues. Therefore, in SA1 we will define and functionally characterize the UL8 interactome in the contest of HCMV infection. In SA2 we will focus on the cellular signaling shaped by UL7 and UL8 and how this impact latency and reactivation. Finally based on our recently publication on FOXO3 inactivation by UL7, HCMV miR-UL112-3p and -US5-1 and protection from apoptosis as well as preliminary data suggesting an involvement of UL8 and several HCMV miRNA in promoting survival of HCMV CD34+ HPC infected cells, we propose in SA3 to investigate the mechanisms of FOXOs inactivation by UL7-8 and HCMV miRNAs and the impact on apoptosis and establishment of latency.