EPSTEIN BARR VIRUS LATENCY

EB病毒（EBV）是一种B淋巴细胞嗜疱疹病毒，通常在感染宿主的一生中良性持续存在，但可能诱发某些淋巴瘤和癌的发展。 健康携带者外周血中的持续感染是静止的，仅限于潜伏感染的静止记忆B细胞，其中最多表达一个或两个潜伏基因。 相比之下，粘膜淋巴组织中的持续感染似乎更为复杂。 存在感染的初始和记忆B细胞、病毒复制以产生感染性病毒和至少一个具有非常高频率的潜伏感染B细胞的完全新的亚群。 病毒并不是随机分布在所有的B细胞亚群中。 我们的假设是，病毒感染细胞的分布可以通过与次级淋巴组织中正常B细胞活化和分化的类比来解释。为了验证这个想法，我们将集中在三个主要问题：1。 我们在扁桃体中发现的高度富集潜伏感染细胞（约1/500被感染）的新型B细胞亚群（CD 38 + CD 10-IgD-）的性质是什么？它与经典定义的记忆B细胞（CD 38-CD 10-IgD-）的关系是什么？ EB病毒是粘膜特异性病毒，即病毒持续活跃地维持在整个淋巴组织中，还是除粘膜淋巴组织外的任何地方都静止？ 病毒是在所有淋巴组织中复制还是仅在粘膜淋巴组织中复制？3. 淋巴组织中被病毒感染的细胞是否能够通过生发中心反应进入记忆区。

Epstein-Barr virus (EBV) is a B lymphotropic herpesvirus that usually persists benignly for the life time of the infected host, but can be predisposing for the development of certain lymphomas and carcinomas. Persistent infection in the peripheral blood of healthy carriers is quiescent, being restricted to latently infected, resting, memory B cells in which, at most, one or two latent genes are expressed. By comparison persistent infection in the mucosal lymphoid tissue appears to be more complex. There are infected naive and memory B cells, viral replication to produce infectious virus and at least one completely novel subset with a very high frequency of latently infected B cells. The virus is not randomly distributed through all of the B cells subsets. It is our hypothesis that the distribution of virus infected cells can be explained through analogy to normal B cell activation and differentiation within secondary lymphoid tissue. To test this idea we will focus on three main issues: 1. What is the nature of the novel B cell subset (CD38+CD10-IgD-) that we have found in the tonsils to be highly enriched for latently infected cells (approximately 1 in 500 are infected) and what is its relationship to classically defined memory B cells (CD38- CD10-IgD-) 2. Is EBV a mucosal specific virus i.e. is viral persistence actively maintained throughout the lymphoid tissue or quiescent everywhere except mucosal lymphoid tissue? Does the virus replicate in all lymphoid tissue or only mucosal lymphoid tissue? 3. Are virus infected cells in the lymphoid tissue able to undergo a germinal center reaction to enter the memory compartment.