EBV BMRF-2 Protein in Infection of Oral Epithelial Cells

产品说明：最初的EB病毒（EBV）感染通过口咽粘膜发生，但EBV进入上皮细胞的机制知之甚少。使用极化的口咽上皮细胞，我们发现，EBV进入这些细胞通过两个CD 21非依赖性途径：直接细胞与细胞接触的顶端上皮细胞膜与EBV感染的淋巴细胞，和无细胞EBV病毒粒子通过基底外侧膜进入。我们的数据表明，EBV BMRF-2糖蛋白和β 1整合素之间的相互作用在无细胞病毒体进入中起关键作用。我们发现，从感染到未感染细胞的后代版本的细胞间传播发生在侧膜上。BMRF-2的氨基酸序列揭示了几个潜在的基底外侧分选信号，我们已经表明，它被转运到基底外侧膜。我们认为BMRF-2可能参与靶向细胞内子代病毒体的基底外侧膜，并可能促进病毒体跨横向细胞间连接的易位。本研究的目的是表征BMRF-2/β 1整合素相互作用的分子机制及其在EBV感染和单层极化和多层分层口咽上皮细胞中传播的功能意义。本研究的具体目的是：1）研究EBV BMRF- 2在病毒体附着和进入口咽上皮细胞中的作用; 2）鉴定BMRF-2的分选信号，所述分选信号控制其转运至极化口咽上皮细胞的基底外侧膜;和3）研究BMRF-2蛋白在口咽上皮中EBV细胞间扩散中的功能。这些数据将大大推进知识的机制，EBV感染的口咽上皮细胞，并可能有价值的设计新的方法来预防初始EBV感染。

DESCRIPTION: Initial Epstein-Barr virus (EBV) infection occurs via the oropharyngeal mucosa, but mechanisms of EBV entry into epithelial cells are poorly understood. Using polarized oropharyngeal epithelial cells, we showed that EBV enters these cells through two CD21-independent pathways: direct cell-to-cell contact of apical epithelial cell membranes with EBV-infected lymphocytes, and entry of cell-free EBV virions through basolateral membranes. Our data show that interaction between the EBV BMRF-2 glycoprotein and beta1 integrin play a key role in cell-free virion entry. We showed that cell-to-cell spread of progeny versions from infected into uninfected cells occurs across lateral membranes. The amino acid sequence of BMRF-2 reveals several potential basolateral-sorting signals, and we have shown that it is transported to basolateral membranes. We posit that BMRF-2 may be involved in targeting of intracellular progeny virions to the basolateral membrane and may facilitate translocation of virions across lateral intercellular junctions. The goal of this study is to characterize molecular mechanisms of BMRF-2/beta1 integrin interactions and their functional significance in EBV infection and dissemination in single-layer polarized and multi-layer stratified oropharyngeal epithelial cells. The Specific Aims of the study are: 1) To investigate the role of EBV BMRF- 2 in virion attachment and entry in oropharyngeal epithelial cells; 2) To identify the sorting signals of BMRF-2 that govern its transport to the basolateral membranes of polarized oropharyngeal epithelial cells; and 3) To study the functions of the BMRF-2 protein in EBV cell-to-cell spread in oropharyngeal epithelium. These data will greatly advance knowledge of the mechanisms of EBV infection of oropharyngeal epithelial cells and may be of value to design new approaches to prevention of initial EBV infection.