EBV BMRF-2 Protein in Infection of Oral Epithelial Cells

描述：eb病毒（EBV）最初通过口咽粘膜感染，但EBV进入上皮细胞的机制尚不清楚。利用极化口咽上皮细胞，我们发现EBV通过两种不依赖cd21的途径进入这些细胞：感染EBV的淋巴细胞与顶端上皮细胞膜直接细胞间接触，以及无细胞的EBV病毒粒子通过基底外膜进入这些细胞。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粒子进入中起关键作用。我们发现后代版本从感染细胞到未感染细胞的细胞间传播发生在外侧膜上。BMRF-2的氨基酸序列揭示了几个潜在的基底外侧分选信号，我们已经证明它被运输到基底外侧膜。我们假设BMRF-2可能参与了细胞内子代病毒粒子对基底外膜的靶向，并可能促进病毒粒子通过外侧细胞间连接的易位。本研究的目的是表征BMRF-2/beta1整合素相互作用的分子机制及其在EBV在单层极化和多层分层口咽上皮细胞感染和传播中的功能意义。本研究的具体目的是：1)研究EBV BMRF- 2在病毒粒子附着和进入口咽上皮细胞中的作用；2)鉴定BMRF-2转运至极化口咽上皮细胞基底外膜的分选信号；3)研究BMRF-2蛋白在EBV在口咽上皮细胞间传播中的作用。这些数据将极大地促进对EBV感染口咽上皮细胞机制的认识，并可能对设计预防初始EBV感染的新方法有价值。

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.