ROLE OF CMV ENVELOPE GLYCOPROTEINS IN POLARIZED CELLS

描述(摘自申请者摘要)：人巨细胞病毒(CMV) 极化细胞的感染是侵袭入口处和 病毒在宿主体内传播。这位申请人的假设是关键的CMV 囊膜糖蛋白Gb和Gh复合体含有分选信号 被内吞途径中的同源伙伴识别，这些伙伴被增选为 病毒粒子直接被包裹并从胞质隔间中排出。CMV GB， 病毒粒子被膜的主要成分被输送到顶膜 病毒粒子在极化的人上皮细胞中外泄的区域。在转基因中 细胞，GH靶向基底膜。这两种糖蛋白都在 内吞途径。我们意想不到的新发现，GB和GH复合体 与病毒基质蛋白汇聚在核周的胞内隔间， 证实包膜发生在上皮细胞的胞液小泡中 这表明病毒粒子的外泄可能受到体内糖蛋白的调节 常见的内小体和/或顶端循环室。一个中心问题是 Gb和Gh复合体中的分选信号层次如何调制病毒粒子 在两种极化信元类型的上下文中的包络和出口路由： 上皮细胞和内皮细胞。具体目标是：(1)完成 CMV Gb和Gh复合体中功能分选信号的鉴定 贩卖极化细胞。我们的假设是，胞浆结构域 这些糖蛋白含有多部分信号，调节它们的 内吞途径的贩运。(二)继续认定同源词绑定 在CMV gB和Gh复合体中，伴侣被胞质分选信号所吸引。这个 目标是确定哪些细胞蛋白调节它们在体内的运输 内吞/循环途径。(3)阐明CMV病毒粒子的包膜和出口 极化上皮细胞感染的途径和信号 调节这一途径的等级制度。(4)CMV糖蛋白分选研究 以及内皮细胞中的病毒粒子包膜和出口途径，另一种 在CMV感染中起关键作用的极化细胞类型。这些 实验将促进对运输模体和细胞分子的了解 在极化上皮细胞中调节病毒粒子包膜和出口途径的基因 细胞，并提高对病毒从内皮细胞释放的理解 活体血管床传播模型。可以想象，这些发现 将引起细胞生物学家的兴趣，并可能与医学相关 血管生物学和器官移植。可能，美国政府使用的策略 可以加入选择性靶向内吞亚室的CMV 探索将抗病毒化合物引入胞浆的新方法 极化细胞中的小泡，以阻止病毒粒子的包裹和外流。

DESCRIPTION (Adapted from applicant's abstract): Human cytomegalovirus (CMV) infection of polarized cells is central to invasion at the portal of entry and virus dissemination in the host. This applicant's hypothesis is that key CMV envelope glycoproteins, gB and the gH complex, contain sorting signals recognized by cognate partners in the endocytic pathway that are co-opted to direct virion envelopment and egress from a cytosolic compartment. CMV gB, the major component of the virion envelope, is transported to the apical membrane domain where virions egress in polarized human epithelial cells. In transfected cells, gH targets to basolateral membranes. Both glycoproteins traffic in the endocytic pathway. Our unexpected new finding, that gB and the gH complex converge in a perinuclear endocytic compartment with virion matrix proteins, establishes that envelopment occurs in cytosolic vesicles of epithelial cells and suggests that virion egress could be regulated by glycoproteins sorted in common endosomes and/or the apical recycling compartment. A central question is how the sorting signal hierarchy in gB and gH complex modulates virion envelopment and egress routes in the context of two polarized cell types: epithelial and endothelial cells. The specific aims are to: (1) Finish identifying functional sorting signals in CMV gB and gH complex used for trafficking in polarized cells. The hypothesis is that the cytosolic domains of these glycoproteins contain multipartite signals that regulate their trafficking in endocytic pathways. (2) Continue to identify cognate binding partners co-opted by cytosolic sorting signals in CMV gB and gH complex. The goal is to determine which cellular proteins regulate their transport in the endocytic/recycling pathway. (3) Elucidate CMV virion envelopment and egress routes in the context of infected polarized epithelial cells and the signal hierarchy that modulates this pathway. (4) Investigate CMV glycoprotein sorting and virion envelopment and egress pathways in endothelial cells, another polarized cell type that plays a critical role in CMV infection. These experiments will advance knowledge of transport motifs and cellular molecules that modulate virion envelopment and egress routes in polarized epithelial cells and improve understanding of virus release from endothelial cells as a model for transmission from vascular beds in vivo. Conceivably, these findings will be of interest to cell biologists and could have medical relevance to vascular biology and organ transplantation. Possibly, the strategies used by CMV for selective targeting to endocytic subcompartments could be incorporated into novel approaches for introducing antiviral compounds into cytosolic vesicles in polarized cells in order to preclude virion envelopment and egress.