Human Cytomegalovirus dysregulation of host hematopoietic progenitor cell signaling pathways to modulate latency and reactivation

摘要--总体 人巨细胞病毒(HCMV)是造血干细胞发病和死亡的重要原因 经常表现出与病毒感染相关的骨髓抑制的移植(HSCT)患者。CD34+ 造血祖细胞是潜伏的巨细胞病毒的重要储存库，对细胞因子和生长有影响。 因子信号分化为单核细胞，再分化为巨噬细胞，激活产生 组织中的传染性病毒。CD34+造血干细胞中的表皮生长因子受体(EGFR)信号转导通路 不仅对确定HCMV潜伏期和重新激活至关重要，而且对调节祖细胞的稳态也是至关重要的 和造血术。在过去的3.5年里，我们已经确定了关键的EGFR信号通路，受 UL138、UL136、UL135、US28、UL7、UL8和多个对保持延迟或 诱导病毒重新激活。这些途径中的大多数与CD34+HPC的增殖密切相关 维持骨髓龛中的祖细胞以及骨髓的生成。我们已经证明了 多个人巨细胞病毒miRNAs协同或拮抗地与巨细胞病毒蛋白共同调节这些 潜伏期或病毒重新激活所需的信号通路。此外，我们观察到UL138是 与参与STAT1信号转导的蛋白质有关，并且HCMV miRNAs针对其中的一些因子。我们 假设UL138-WDR48-USP1和-USP12与US28和HCMV miRNAs相互作用 调节STAT1和AKT响应以抑制病毒复制的潜伏期。我们还表明，US28 趋化因子诱导的信号调节潜伏期或重新激活，并且是配体特异性的。此外，我们还有 观察到RhoA的US28激活受HCMV miRNAs和UL8信号的高度调控 非规范的Wnt途径。我们假设，MEK/ERK信号对维持潜伏期至关重要，而 RhoA通路的激活是重新激活所必需的。 虽然目前的HCMV PPG主要集中在鉴定UL138、UL136、UL135、US28、UL7和病毒 MiRNA EGFR信号靶点，拟议的更新将集中在不同的HCMV基因如何与 相互调节这些途径以及它们如何控制病毒的生命周期。信令的复杂性 全面解决病毒潜伏和造血问题的事件和方法只能是 通过PPG机制下的合作努力实现。因此，我们提出了五个高度整合的方案 研究项目(项目1：UL133/8对宿主细胞信号在病毒潜伏和重新激活中的调节；项目2： MiRNA在病毒潜伏和重新激活中对宿主细胞信号的调节；项目3：US28对宿主细胞的调节 病毒潜伏期和重新激活中的信号传递；项目4：病毒潜伏期和再激活中宿主细胞信号的UL7-8调节 重新激活；项目5：HCMV对病毒重新激活中单核/巨噬细胞宿主细胞信号的调节)，2 科学核心(人性化鼠标核心；生物统计学和生物信息学核心)，以服务于这些项目，以及 监督和协调整个计划的行政核心。

SUMMARY - OVERALL Human Cytomegalovirus (HCMV) is a significant cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) patients who often exhibit myelosuppression associated with virus infection. CD34+ Hematopoietic Progenitor Cells (HPCs) are a critical reservoir of latent HCMV that upon cytokine and growth factor signals differentiate into monocytes that further differentiate into macrophages activating production of infectious virus in tissues. Epidermal Growth Factor Receptor (EGFR) signaling pathways in CD34+ HPCs are critical not only for determining HCMV latency and reactivation but also for regulating progenitor cell homeostasis and hematopoiesis. Over the past 3.5 years we have identified critical EGFR signaling pathways regulated by UL138, UL136, UL135, US28, UL7, UL8, and multiple HCMV miRNAs that are important to maintain latency or induce viral reactivation. Most of these pathways are integrally linked with CD34+ HPC proliferation for maintenance of the progenitor cell in the bone marrow niche as well as myelopoiesis. We have shown that multiple HCMV miRNAs synergistically or antagonistically work together with HCMV proteins to regulate these signaling pathways necessary for latency or viral reactivation. In addition, we have observed that UL138 is associated with proteins involved in STAT1 signaling and that HCMV miRNAs target some of these factors. We hypothesize that UL138-WDR48-USP1 and -USP12 interactions along with US28 and the HCMV miRNAs regulate a STAT1 and AKT response to suppress virus replication for latency. We have also shown that US28 signaling induced by chemokines regulate latency or reactivation and is ligand specific. Additionally, we have observed that US28 activation of RhoA is highly regulated by HCMV miRNAs as well as UL8 signaling through the non-canonical Wnt pathway. We hypothesize that MEK/ERK signaling is essential to maintain latency while activation of the RhoA pathway is necessary for reactivation. While the current HCMV PPG has focused on identification of UL138, UL136, UL135, US28, UL7, and viral miRNA EGFR signaling targets, the proposed renewal will focus on how the different HCMV genes interact with one another to regulate these pathways and how they control the virus life cycle. The complexity of signaling events and approaches to comprehensively address questions on viral latency and hematopoiesis can only be achieved through a collaborative effort under a PPG mechanism. Therefore we propose five highly integrated research projects (Project 1: UL133/8 regulation of host cell signaling in viral latency and reactivation; Project 2: miRNA regulation of host cell signaling in viral latency and reactivation; Project 3: US28 regulation of host cell signaling in viral latency and reactivation; Project 4: UL7-8 regulation of host cell signaling in viral latency and reactivation; Project 5: HCMV regulation of monocyte/macrophage host cell signaling in viral reactivation), two scientific cores (Humanized Mouse Core; Biostatistics and Bioinformatics Core) to service these projects, and an Administrative Core to oversee and coordinate the entire program.