EBV Entry and Spread in the Oral Cavity

描述（由申请人提供）：EB 病毒 (EBV) 是一种经口传播的人类疱疹病毒，在全世界几乎所有成年人中造成持续感染。病毒库在记忆 B 细胞群中处于潜伏状态，但目前的模型表明，病毒库通过终末分化浆母细胞中的零星重新激活、上皮细胞中的扩增和 B 细胞库的重新感染来补充。 EB 病毒的长期携带可能与淋巴和上皮恶性肿瘤有关，而免疫抑制的个体，特别是感染人类免疫缺陷病毒 (HIV) 的个体，患上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病毒复制失去控制。 EBV 在肿瘤发生中发挥的作用很复杂，但血清流行病学研究表明，正常平衡的破坏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态，特别是病毒如何在 B 细胞和上皮细胞之间流动并在宿主体内扩增。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相关性。该实验室的新工作表明，上皮细胞的肿瘤前变化可能使它们更容易受到感染，因为它们差异表达对于与 gHgL 和 gp350 相互作用至关重要的细胞蛋白，并激活那些可以诱导相邻 B 细胞中病毒复制的蛋白。此外，新发现的包膜蛋白 BDLF2 与 BMRF2 相互作用并可能依赖于 BMRF2，这可能与病毒传播有关。该应用程序的直接目标是测试这些假设。目标之一将使用可溶形式的 gHgL 和 ?v?6、基于细胞的融合测定和表面等离子共振来评估 gHgL 和 ?v?6 在触发病毒-细胞融合中的相互作用。将探索额外的整合素可以介导相同功能的可能性，将检查gH与整合素结合对病毒细胞内运动的下游影响，并确定整合素在体内正常和发育异常组织中的表达。目标二将探讨 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上CR2的表达，并通过比较全长和截短的CR2来确定gp350刺激的与福尔明相互作用对感染的影响。目标三将通过制作 BDLF2 无效病毒和 BMRF2 无效病毒来研究 BMRF2/BDLF2 复合物的作用。还将制造一种缺乏 BMRF2 RGD 基序的病毒，以探索 gH 和 BMRF2 与整合素结合的独特作用。 EBV 是与 HIV 疾病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。阐明病毒针对新易感染细胞的机制对于了解发病机制和制定规避策略非常重要。 公共卫生相关性：EB 病毒 (EBV) 与多种不同的恶性肿瘤相关，携带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上皮细胞中的 EBV 复制。该应用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.