HCMV receptors, signaling and entry

项目总结/摘要 人巨细胞病毒（HCMV）是导致婴儿出生缺陷的主要感染原因。HCMV也可导致 免疫功能低下的个体中的多种严重疾病。越来越多的证据表明HCMV 感染导致某些癌症，最显著的是恶性胶质瘤。在过去一年中取得了重大进展， 在理解病毒进入和复制的分子机制方面有十年的时间。多种宿主受体和 信号分子已经显示出调节HCMV感染。最近，我们使用CRISPR/Cas9基因， 基于编辑的筛选策略，以寻找HCMV感染上皮细胞所需的细胞蛋白质， 细胞我们发现，沉默孤儿嗅觉受体OR 14 I1的表达， 感染这些细胞。进一步的研究表明，OR 14 I1与HCMV五聚体复合物（PC）相互作用。 结合其他证据，我们证实OR 14 I1是HCMV受体，可能在HCMV感染中起关键作用。 定义PC依赖性向性。尽管鉴定HCMV的几种宿主受体取得了进展， 是我们目前对病毒进入和随后的病毒感染的分子机制的认识中的几个关键空白。 生命周期具体来说，目前还不清楚HCMV如何利用多种宿主受体进入以及病毒如何破坏宿主 细胞信号传导途径促进病毒复制和传播。我们的长期目标是确定 HCMV利用正常的宿主细胞过程来促进病毒感染，以阐明与HCMV感染相关的进入机制。 病毒的嗜性，确定进入信号通路，并通过阐明HCMV的细胞核转运， OR 14 I1和其他受体的作用与其广泛的向性和发病机制有关。立足过去 根据我们小组和其他人的工作，我们建议就三个具体目标进行研究，以实现这些目标：（1） 为了阐明HCMV-OR 14 I1结合激活的信号通路及其在病毒感染中的作用， 揭示OR 14 I1在细胞间扩散和运输中的作用;（2）确定不同的 （3）确定HCMV PC-OR 14 I1的结构， 确定相关的分子相互作用。总的来说，我们提出的研究将广泛影响该领域， 表征宿主受体，特别是OR 14 I1，在促进病毒进入中发挥的重要作用， 复制和传播。这些研究将有可能揭示新的分子机制 潜在的HCMV感染和HCMV治疗的分子靶点。

PROJECT SUMMARY/ABSTRACT Human cytomegalovirus (HCMV) is the leading infectious cause of birth defects in infants. HCMV can also cause a variety of severe diseases in immunocompromised individuals. Mounting evidence have linked HCMV infections to some cancers, most notably malignant glioma. Major progress has been made during the last decade in understanding the molecular mechanism of viral entry and replication. A variety of host receptors and signaling molecules have been shown to regulate HCMV infection. Recently, we used a CRISPR/Cas9 gene editing based screening strategy to search for cellular proteins that are required for HCMV infection of epithelial cells. We found that silencing the expression of an orphan olfactory receptor, OR14I1, drastically reduced HCMV infection in these cells. Further work showed that OR14I1 interacts with the HCMV Pentamer complex (PC). Together with additional evidence, we confirmed that OR14I1 is an HCMV receptor and may play critical role in defining PC-dependent tropism. Despite the progress of identification of several host receptors for HCMV, there are several critical gaps in our current knowledge of the molecular mechanism of viral entry and subsequent viral life cycle. Specifically, it is unclear how HCMV uses multiple host receptors for entry and how virus subvert host cellular signaling pathways facilitate viral replication and spreading. Our long-term goals are to identify how HCMV uses normal host cellular processes to facilitate viral infection, to elucidate the entry mechanism related to viral tropism, define the entry signaling pathways, and trafficking of HCMV to the nucleus by clarifying the roles of OR14I1 and other receptors associated with its broad tropism and pathogenesis. Building on the past work of our group and others, we propose to conduct research on three Specific Aims to address these goal: (1) To elucidate the signaling pathways activated by HCMV-OR14I1 binding and their roles in virus infection and uncover the role OR14I1 plays in cell-cell spread and trafficking; (2) To determine the contribution of different HCMV PC receptors to infection and tropism; and (3) determine the structure of HCMV PC-OR14I1 and determine relevant molecular interactions. Collectively, our proposed research will broadly impact the field by characterizing the essential roles that host receptors, in particular, OR14I1, play in promoting viral entry, replication, and spreading. These studies will have the potential to uncover novel molecular mechanisms underlying HCMV infection, and molecular targets for HCMV therapy.