HCMV UL133/8 regulation of host cell signaling in viral latency and hematopoiesis

项目总结 我们计划的目标是阐明HCMV调节宿主信号的分子机制。 CD34+造血祖细胞用于建立和维持病毒潜伏期和 重新激活，并确定病毒信号调节失调如何导致HCMV骨髓抑制。 人巨细胞病毒仍然是导致发病率和死亡率的重要原因，其原因是实体器官和 尽管在诊断和治疗方面取得了进展，但还是进行了造血干细胞移植。巨细胞病毒潜伏期为 建立和维持HCMV潜伏期的复杂和信号机制，以及 人们对病毒的重新激活知之甚少。我们的程序已经确定了一些病毒蛋白和miRNAs 通过靶向表皮生长因子受体(EGFR)和 EGFR下游的信号通路。发信号通知事件的复杂性和方法 全面解决病毒潜伏期和造血问题只能通过 合作努力。利用最先进的体外模型在原代、人CD34+HPC和在体模型中 用骨髓、肝脏和胸腺人源化的小鼠，我们的计划将针对个体和组合 病毒因子在调节宿主信号中的作用。我们的项目(项目1)将解决蛋白质的作用 在调制主机信令时在UL133/8“延迟轨迹”内编码。我们已经为这四个人定义了角色 UL133/8基因座编码的基因对病毒维持的正向或负向调节作用 延迟。有趣的是，这些基因相反地调控着EGFR的运输和激活。我们已经展示了 EGFR和下游PI3K信号对维持EGFR的潜伏期和抑制物很重要 或PI3K刺激重新激活和复制。我们假设EGFR是一个关键的信号轴，它被 UL133/8蛋白调节病毒潜伏、再激活和造血。在目标1中，我们将使用一个系统 在CD34+细胞感染中确定UL133/8蛋白调控的全球通路的方法 HPC。然后我们将定义UL133/8-宿主信号的调制对病毒潜伏期和 AIM 2中的重新激活和AIM 3中的造血。在整个研究过程中，我们将把我们的数据集与 确定UL133/8如何与其他病毒蛋白相互作用的其他项目(项目3中的US28； 项目4中的UL7)和病毒miRNAs(项目2)，并有助于更广泛地调节宿主信号 调节潜伏期、复活和造血。项目5，重点是定义造血信号 HCMV靶向的途径，将有助于我们理解UL133/8蛋白靶向的途径 调节造血。总体而言，我们的项目将提供第一批全面和机械性的见解 对宿主信号的多方面调节，以控制HCMV潜伏期和骨髓抑制。这个 我们已经确定的病毒因子网络使我们能够确定抗病毒的新宿主和病毒靶点 控制巨细胞病毒潜伏期、再激活和骨髓抑制的策略。

PROJECT SUMMARY The goal of our Program is to elucidate the molecular mechanisms by which HCMV regulates host signaling in CD34+ hematopoietic progenitor cells (HPCs) for the establishment and maintenance of viral latency and reactivation, and to determine how viral dysregulation of signaling contributes to HCMV myelosuppression. HCMV remains a significant cause of morbidity and mortality via myelosuppression after solid organ and hematopoietic stem cell transplantation despite advances in diagnostics and therapeutics. HCMV latency is complex and the signaling mechanisms for establishment and maintenance of HCMV latency, as well as for reactivation of virus are poorly understood. Our program has identified a number of viral proteins and miRNAs that regulate both latency and hematopoiesis by targeting epidermal growth factor receptor (EGFR) and signaling pathways downstream of EGFR. The complexity of signaling events and approaches to comprehensively address questions on viral latency and hematopoiesis can only be achieved through a collaborative effort. Using state-of-the art in vitro models in primary, human CD34+ HPCs and in vivo models in mice humanized with bone marrow, liver and thymus, our Program will address the individual and combined roles of viral factors modulating host signaling. Our Project (Project 1) will address the roles of proteins encoded within the UL133/8 “latency locus” in modulating host signaling. We have defined roles for the four genes encoded by the UL133/8 locus in either positively or negatively regulating the maintenance of viral latency. Intriguingly, these genes opposingly regulate the trafficking and activation of EGFR. We have shown that EGFR and downstream PI3K signaling is important for the maintenance of latency and inhibitors of EGFR or PI3K stimulate reactivation and replication. We hypothesize that EGFR is a critical signaling axis targeted by UL133/8 proteins to modulate viral latency, reactivation and hematopoiesis. In Aim 1, we will use a systems approach to define the global pathways regulated by UL133/8 proteins in the context of infection in CD34+ HPCs. We will then define the significance of UL133/8-modulation of host signaling to viral latency and reactivation in Aim 2 and to hematopoiesis in Aim 3. Throughout our studies we will integrate our data sets with those of the other Projects to determine how UL133/8 interfaces with other viral proteins (US28 in Project 3; UL7 in Project 4) and viral miRNAs (Project 2) and contributes to the broader regulation of host signaling in regulating latency, reactivation and hematopoiesis. Project 5, focused on defining the hematopoieitic signaling pathways targeted by HCMV, will inform our understanding of pathways targeted by UL133/8 proteins to regulate hematopoiesis. Collectively, our projects will provide the first comprehensive and mechanistic insights into the multi-faceted regulation of host signaling for the control of HCMV latency and myelosuppression. The network of viral factors we have identified uniquely position us to define novel host and viral targets for antiviral strategies to control HCMV latency, reactivation and myelosuppression.