Cytomegalovirus Pathogenesis in Immunodeficiency

描述（由申请方提供）：人巨细胞病毒（CMV）仍然是感音神经性听力损失的最重要感染原因，也是实体器官和造血细胞移植受者急性和慢性疾病的重要原因。CMV的发病机制依赖于白细胞相关的病毒血症在宿主体内传播病毒。所有CMV编码有效的趋化因子，并且鼠CMV趋化因子MCK-2利用宿主炎症反应，将骨髓白细胞祖细胞动员到感染的初始位点，所述感染的初始位点成为通过血流增强传播到感染宿主中的特定位点的媒介物。关于人CMV vCXCL-1趋化因子在发病机制或潜伏期中的作用知之甚少。该项目旨在定义人类和小鼠CMV感染期间的初始事件，以了解病毒如何利用宿主炎症反应促进传播和潜伏。将在小鼠细胞和小鼠宿主中研究鼠CMV MCK-2的特性，以表征从骨髓募集髓系祖细胞的机制以及病毒在宿主内传播的途径。将在用功能性人造血细胞重建的小鼠中研究人CMV vCXCL-1的特性，以鉴定由该趋化因子募集的髓样细胞类型，其可能是传播的中介。第一个目标将鉴定对MCK-2应答的细胞表型，鉴定MCK-2受体，研究通过外周血传播病毒的髓样类型，并鉴定有助于MCK-2应答的宿主趋化因子和细胞因子组分。该目的还将比较研究vCXCL-1对培养物中的人细胞和小鼠中的人细胞的生物学影响，以鉴定可能与人CMV传播有关的响应骨髓细胞类型。第二个目标将跟踪小鼠CMV传播途径，以确定髓系细胞是否直接在组织中感染或从血管内皮细胞获得病毒作为中间宿主细胞导致病毒血症。第三个目标将研究病毒和细胞基因表达谱在感染的细胞和组织，采用病毒编码尿嘧啶磷酸核糖转移酶，允许特定的富集mRNA从感染的细胞内未感染的细胞群体，如组织中发生。这些研究将为人类和小鼠CMV发病机制和潜伏期提供重要的新的比较见解。

DESCRIPTION (provided by applicant): Human cytomegalovirus (CMV) remains the most important infectious cause of sensorineural hearing loss as well as a significant cause of acute and chronic disease in solid organ and hematopoietic cell transplant recipients. CMV pathogenesis relies on leukocyte-associated viremia to disseminate virus within the host. All CMVs encode potent chemokines and murine CMV chemokine MCK-2 exploits the host inflammatory response, mobilizing bone marrow leukocyte progenitors to initial sites of infection that become vehicles to enhanced dissemination via the bloodstream to specific sites in the infected host. Less is known about the role of human CMV vCXCL-1 chemokine in pathogenesis or latency. This project seeks to define the initial events during human and murine CMV infection to understand how viral exploitation of the host inflammatory response contributes to dissemination and latency. Properties of murine CMV MCK-2 will be studied in mouse cells and the mouse host in order to characterize the mechanism of recruitment of myeloid progenitors from bone marrow and the pathway that the virus follows to disseminate within the host. Properties of human CMV vCXCL-1 will be studied in mice reconstituted with functioning human hematopoietic cells to identify the myeloid cell type that is recruited by this chemokine and that may be intermediaries in dissemination. The First Aim will identify the phenotype of cells that respond to MCK-2, identify the MCK-2 receptor, investigate the myeloid type that disseminates virus via the peripheral blood and identify host chemokine and cytokine components that contribute to the MCK-2 response. This aim will also investigate comparatively the biological impact of vCXCL-1 on human cells in culture and in mice to identify responding myeloid cell types that may be implicated in human CMV dissemination. The Second Aim will track the murine CMV dissemination pathway to determine whether myeloid cells become infected directly in tissues or acquire virus from vascular endothelial cells as intermediate host cells leading to viremia. The Third Aim will investigate viral and cellular gene expression profiles in infected cells and tissues, employing viruses that encode a uracil phosphoribosyl transferase enzyme to allow specific enrichment of mRNA from infected cells within populations of uninfected cells, such as occurs in tissues. These studies will provide important new comparative insights on human and murine CMV pathogenesis and latency.