Cell Biology of Enterovirus Infection in Polarized Epithelial Cells

摘要：肠道病毒通过粪便-口腔途径传播，必须通过肠道粘膜传播。 引发感染。肠由极化的上皮细胞排列，具有明显的顶端和基底外侧。 表面；细胞间的紧密连接阻止病毒进入基侧膜上的受体。许多 肠道病毒，包括许多柯萨奇B组病毒(CBV)和埃科病毒(EV)似乎已经进化 能独立结合衰变加速因子(DAF)，一种表达在表面极化的分子 上皮组织。我们认为这些病毒使用DAF与肠腔内的上皮细胞相互作用 DAF不仅仅是为病毒附件提供了一个站点。我们最近发现，它始于 极化细胞中CBV进入和感染所需的至少两条细胞内信号通路：激活 ABL激酶导致肌动蛋白重排和病毒移动到紧密连接，在那里与 柯萨奇病毒和腺病毒受体(CAR)启动释放病毒RNA的脱壳过程； 激活Fyn激酶触发病毒在小窝内的内化，并将其传递到内质网 (Er)在随后复制之前完成去涂层的情况。这些结果表明，感染 极化细胞可能涉及独特的细胞生物学机制。我们提出了三套 检测极化上皮中感染的细胞生物学的实验。 1.我们将确定DAF结合的EV在进入极化上皮后进入极化上皮的途径 标记的病毒，并使用特定的抑制物(药物，siRNA)来剖析潜在的细胞过程。 2.我们将确定微绒毛结构中肌动蛋白重排和变化的功能 在病毒进入过程中，并确定启动肌动蛋白重组的机制，以响应病毒- DAF交互。 3.我们将筛选siRNA文库，以确定CBV进入极化所需的信号分子 并确定特定的信号分子在感染过程中的作用。 相关性：肠道病毒是病毒性脑膜炎的主要原因，也是第二个主要原因。 美国的心肌炎，与极化上皮的相互作用是感染的第一步。理解 它们感染极化细胞的特殊机制将揭示新的潜在药物靶点。

Summary: Enteroviruses are transmitted by the fecal-oral route, and must cross the intestinal mucosa to initiate infection. The intestines are lined by polarized epithelial cells, with distinct apical and basolateral surfaces; intercellular tight junctions prevent virus access to receptors on basolateral membranes. Many enteroviruses, including many coxsackie B viruses (CBV) and echoviruses (EV), appear to have evolved independently to bind to decay accelerating factor (DAF), a molecule expressed on the surface of polarized epithelium. We believe that these viruses use DAF to interact with epithelial cells in the intestinal lumen DAF does more than simply provide a site for virus attachment. We recently found that it initiates at least two intracellular signaling pathways required for CBV entry and infection in polarized cells: activation of Abl kinase leads to actin rearangements and virus movement to the tight junction, where interaction with the coxsackievirus and adenovirus receptor (CAR) initiates the uncoating process that releases viral RNA; activation of Fyn kinase triggers virus internalization in caveolae, and delivery to the endoplasmic reticulum (ER) where uncoating is completed before replication ensues. These results suggest that infection of polarized cells is likely to involve distinctive cell biological mechanisms. We propose three sets of experiments to examine the cell biology of infection in polarized epithelium. 1. We will define the pathway by which DAF-binding EV enter polarized epithelium, following the entry of labeled virus, and using specific inhibitors (drugs, siRNAs) to dissect the underlying cellular processes. 2. We will determine the function of actin rearrangements and changes in microvillus architecture during virus entry, and identify the mechanism by which actin reorganization is initiated in response to virus- DAF interaction. 3. We will screen an siRNA library to identify signaling molecules required for CBV entry into polarized epithelium, and define the role of specific signaling molecules in the process of infection. Relevance: Enteroviruses are the major cause of viral meningitis, and the second major cause of myocarditis in the US, and interaction with polarized epithelium is the first step in infection. Understanding the special mechanisms by which they infect polarized cells will reveal new potential drug targets.