Cytomegalovirus Pathogenesis in Immunodeficiency

描述（由申请人提供）：人巨细胞病毒（CMV）仍然是感音神经性听力损失最重要的感染性原因，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。巨细胞病毒的发病机制依赖于白细胞相关病毒血症在宿主内传播病毒。所有巨细胞病毒都编码有效的趋化因子，小鼠巨细胞病毒趋化因子MCK-2利用宿主的炎症反应，动员骨髓白细胞祖细胞到感染的初始部位，成为通过血流增强传播到感染宿主特定部位的载体。人类巨细胞病毒vCXCL-1趋化因子在发病机制或潜伏期中的作用尚不清楚。该项目旨在定义人类和小鼠巨细胞病毒感染期间的初始事件，以了解病毒利用宿主炎症反应如何促进传播和潜伏期。小鼠CMV MCK-2的特性将在小鼠细胞和小鼠宿主中进行研究，以表征从骨髓募集骨髓祖细胞的机制以及病毒在宿主内传播的途径。人类巨细胞病毒vCXCL-1的特性将在具有功能的人类造血细胞重组的小鼠中进行研究，以确定由该趋化因子募集的髓细胞类型，并可能是传播的中介。First Aim将确定对MCK-2有反应的细胞的表型，确定MCK-2受体，研究通过外周血传播病毒的髓系类型，并确定促进MCK-2反应的宿主趋化因子和细胞因子成分。本研究还将比较研究vCXCL-1对培养和小鼠人类细胞的生物学影响，以确定可能与人类巨细胞病毒传播有关的应答髓细胞类型。第二个目标将追踪小鼠巨细胞病毒传播途径，以确定髓细胞是直接在组织中感染还是作为中间宿主细胞从血管内皮细胞获得病毒导致病毒血症。第三个目标将研究感染细胞和组织中的病毒和细胞基因表达谱，使用编码尿嘧啶磷酸核糖基转移酶的病毒，允许在未感染细胞群体中特异性富集受感染细胞的mRNA，例如在组织中。这些研究将为人类和小鼠巨细胞病毒的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.