EBV Entry and Spread in the Oral Cavity

描述（由申请人提供）：eb病毒（EBV）是一种口腔传播的人类疱疹病毒，在全世界几乎所有成年人中建立持续性感染。病毒库在记忆性B细胞群中处于潜伏状态，但目前的模型表明，它是通过在终末分化的质母细胞中偶发的再激活、上皮细胞的扩增和B细胞池的再感染来补充的。EBV的长期携带可能与淋巴和上皮恶性肿瘤有关，免疫抑制的个体，特别是感染了人类免疫缺陷病毒（HIV）的个体，患这些肿瘤的风险增加。这种风险增加的部分原因可能是病毒复制失控。EBV在肿瘤发生中的作用是复杂的，但血清流行病学研究表明，正常平衡的紊乱和病毒载量的增加先于恶性肿瘤的出现。这项研究的长期目标是了解感染的动力学，特别是病毒如何在B细胞和上皮细胞之间运输并在宿主内扩增。五种EBV包膜蛋白gp350、gH、gL、gp42和BMRF2与病毒进入B细胞和上皮细胞有不同的关联。该实验室的新研究表明，上皮细胞的肿瘤前变化可能使它们更容易受到感染，因为它们不同地表达与gHgL和gp350相互作用重要的细胞蛋白，并激活那些可以诱导病毒在邻近B细胞中复制的蛋白。此外，新发现的与BMRF2相互作用并可能依赖于BDLF2的包膜蛋白BDLF2可能与病毒传播有关。这个应用程序的直接目标是测试这些假设。第一个目标是使用可溶形式的温室气体和温室气体。基于细胞的融合实验和表面等离子体共振评估gHgL和γ - v - γ之间的相互作用。6在触发病毒细胞融合我们将探索其他整合素介导相同功能的可能性，研究gH与整合素结合对病毒胞内运动的下游影响，并确定整合素在体内正常和发育不良组织中的表达。目的二将探讨CR2在提高上皮细胞感染效率中的作用。将评估体内发育不良上皮细胞中CR2的表达，并通过比较全长和截断的CR2来确定gp350刺激的与formmins相互作用对感染的影响。目标3将通过制造无BDLF2病毒和无BMRF2病毒来研究BMRF2/BDLF2复合体的作用。我们还将制作一种缺乏BMRF2 RGD基序的病毒，以探索gH和BMRF2结合整合素的独特作用。EBV是与HIV口腔并发症相关的几种病毒之一，反映了其在口咽中的持续复制和脱落。公共卫生相关性：eb病毒（EBV）与几种不同的恶性肿瘤有关，感染人类免疫缺陷病毒的个体患这些恶性肿瘤的风险增加。这种风险增加的部分原因可能是免疫系统无法控制eb病毒在上皮细胞中的复制。该应用程序旨在了解病毒与细胞蛋白之间的相互作用，使病毒能够进入上皮细胞并启动复制，并在此过程中寻求识别风险因素和潜在的新治疗靶点。

DESCRIPTION (provided by applicant): Epstein-Barr virus (EBV) is an orally-transmitted human herpesvirus that establishes persistent infections in almost all adults worldwide. The reservoir of virus is in a latent state in the memory B cell population but current models suggest that it is replenished by sporadic reactivation in terminally differentiating plasmablasts, amplification in epithelial cells and reinfection of the B cell pool. Long term carriage of EBV can be associated with both lymphoid and epithelial malignancies and individuals who are immunosuppressed, particularly those infected with the human immunodeficiency virus (HIV), are at increased risk of developing them. Part of this increased risk may reflect a loss of control of replication of virus. The role that EBV plays in tumorigenesis is complex, but seroepidemiologic studies suggest that the disturbance of the normal equilibrium and an increase in virus load precedes the appearance of malignancy. The long term goal of this research is to understand the dynamics of infection, particularly how virus traffics between B cells and epithelial cells to amplify within the host. Five EBV envelope proteins have been differentially implicated in virus entry into B cells and epithelial cells, gp350, gH, gL, gp42 and BMRF2. New work from this laboratory suggests that preneoplastic changes in epithelial cells may make them more susceptible to infection as they differentially express cell proteins important for interaction with gHgL and gp350 and activate those that can induce virus replication in adjacent B cells. Further, that a newly identified envelope protein, BDLF2, which interacts with and may be dependent on BMRF2 may be relevant to virus spread. The immediate goals of this application are to test these hypotheses. Aim one will use soluble forms of gHgL and ?v?6, cell-based fusion assays and Surface Plasmon Resonance to evaluate interactions between gHgL and ?v?6 in triggering virus-cell fusion. The possibility that additional integrins can mediate the same function will be explored, the downstream effects of gH binding to integrins on intracellular movement of virus will be examined and the expression of integrins on normal and dysplastic tissues in vivo will be determined. Aim two will explore the role that CR2 plays in increasing efficiency of epithelial cell infection. Expression of CR2 on dysplastic epithelial cells in vivo will be evaluated and the effects on infection of a gp350-stimulated interaction with formins will be determined by comparison of full length and truncated CR2. Aim three will investigate the role of the BMRF2/BDLF2 complex by making a BDLF2-null virus and a BMRF2-null virus. A virus lacking the BMRF2 RGD motif will also be made to explore unique effects of gH and BMRF2 binding to integrins. EBV is one of a several viruses associated with oral complications of HIV disease reflecting its continued replication and shedding in the oropharynx. Unraveling mechanisms by which virus is targeted to cells newly prone to infection is important to understanding pathogenesis and developing evasive strategies PUBLIC HEALTH RELEVANCE: Epstein-Barr virus (EBV) is associated with several different malignancies and individuals with the human immunodeficiency virus are at increased risk of developing them. Part of this increased risk may represent a failure of the immune system to control EBV replication in epithelial cells. This application seeks to understand the interactions between virus and cell proteins that enable virus to enter epithelial cells and initiate replication and in doing so seeks to identify risk factors and potential novel therapeutic targets.