EBV Entry and Spread in the Oral Cavity

描述(申请人提供)：EBV是一种人类伽马疱疹病毒，与淋巴系统和上皮性恶性肿瘤有关。该病毒在几乎所有成年人中都会持续感染，它在肿瘤发生中所起的作用是复杂的。免疫抑制的人，特别是那些感染了人类免疫缺陷病毒(HIV)的人，患EBV相关恶性肿瘤的风险更高。这种增加的风险可能部分反映了对病毒复制的控制和病毒载量的增加。这项研究的长期目标是了解病毒如何在宿主之间和宿主内部传播和放大，并确定单个病毒蛋白在这一过程中所扮演的角色。EBV囊膜上的5种糖蛋白gp350/220、Gh、g1、GP42和BMRF2在B细胞和上皮细胞的进入中起着不同的作用。这项应用的直接目标是评估糖蛋白与细胞受体和辅助受体的相互作用，并确定它们对病毒感染的意义。目的研究两组分gHgL复合体和三组分gHgL_GP42复合体在B细胞和上皮细胞间的细胞趋化和病毒转运中的作用。将对Gh序列进行突变分析，以区分对上皮细胞感染重要的区域，但不是B细胞感染的区域和进入两者的重要区域。Gh复合体的化学计量学将用于确定病毒在口咽部脱落的来源，将寻找上皮细胞上gHgL受体的身份，并将评估其在将病毒从B细胞转移到密切接触的上皮细胞中的潜在作用。目的2评价补体受体2(CR2)在附着后事件中的作用以及在癌前或恶性上皮细胞易感性中的作用。删除CR2的细胞质尾巴对病毒向细胞核传递的影响将被检测，并将确定CR2在从轻度不典型增生到浸润性癌的上皮病变中的表达。目的三确定BMRF2蛋白的RGD基序在极化上皮细胞感染中的作用。缺乏BMRF2或表达其中RGD序列已突变的BMRF2蛋白的重组病毒将在EBV Bac的背景下制造，并将检查其表型。了解EBV是如何针对变得恶性的细胞的，对于开发防止这一过程的方法很重要。

DESCRIPTION (provided by applicant): EBV is a human gammaherpesvirus that is associated with both lymphoid and epithelial malignancies. The virus establishes persistent infections in almost all adults and the role that it plays in tumorigenesis is complex. Individuals who are immunosuppressed, particularly those infected with the human immunodeficiency virus (HIV), are at increased risk of developing EBV-associated malignancies. Part of this increased risk probably reflects a loss of control of replication of virus and an increase in virus load. The long term goal of this research is to understand how virus spreads and amplifies between and within hosts and to determine the roles that individual virus proteins play in the process. Five glycoproteins in the EBV envelope, gp350/220, gH, gL, gp42 and BMRF2, have been implicated as playing different roles in entry of B cells and epithelial cells. The immediate goals of this application are to evaluate the interactions of the glycoproteins with cell receptors and coreceptors and to determine their significance to virus infection. Aim one will examine the role that two part gHgL complexes and three part gHgl_gp42 complexes play in cell tropism and trafficking of virus between B cells and epithelial cells. Mutational analysis will be made of gH sequences to discriminate regions that are important to infection of epithelial cells but not B cells from regions that are important for entry into both. The stoichiometry of the gH complexes will be used to identify the origin of virus shed in the oropharynx, the identity of the gHgL receptor on epithelial cells will be sought and its potential role in transfer of virus from B cells to epithelial cells in close contact will be evaluated. Aim two will evaluate a role for the complement receptor type 2 (CR2) in post attachment events and in susceptibility of premalignant or malignant epithelial cells. Effects of deleting the cytoplasmic tail of CR2 on delivery of virus to the nucleus of the cell will be examined and the expression of CR2 on epithelial lesions ranging from mild dysplasia to invasive carcinoma will be determined. Aim three will determine the role that the RGD motif of the BMRF2 protein plays in infection of polarized epithelial cells. Recombinant viruses that lack BMRF2 or expresses a BMRF2 protein in which RGD sequences have been mutated will be made in the context of an EBV Bac and their phenotypes will be examined. Understanding how EBV targets cells that become malignant is important for development of ways to prevent the process.