Epstein Barr Virus Latency

描述(申请人提供)：爱泼斯坦-巴尔病毒是一种疱疹病毒，感染90%的人类人口。它有两个明显的特点。首先，它能够在健康的宿主中保持终身持续感染，其次，它与几种人类淋巴瘤和癌症有关。这项提案将解决与这两个物业有关的核心问题。 持久性：EBV在记忆B细胞中建立了一种持久的潜伏感染。关于它是如何做到这一点的，人们知道得很多，但对潜伏感染的细胞如何产生传染性病毒以传播给其他宿主的了解较少。我们的初步数据表明，病毒复制的信号是潜伏感染的细胞向浆细胞的末端分化。我们将使用标准的分子生物学工具来确定浆细胞特异性转录因子在激活EBV裂解周期中的作用。由于浆细胞只有在完全分化时才会复制病毒，所以当浆细胞迁移到骨髓时，它们很可能会释放传染性病毒。这将导致早期的B细胞前体细胞被感染。这些细胞还可以提供一个终生持续感染的场所。因此，这项研究的第二个目的将是测试骨髓作为病毒持续存在的第二个部位的作用。这将通过将骨髓分离成已知的B细胞亚群，并通过我们开发的定量DNA和RT PCR技术检测病毒的存在来实现。 肿瘤：与EB病毒相关的最常见的肿瘤之一是鼻咽癌。关于这种肿瘤的分子基础及其与EBV的关系仍知之甚少。我们将使用Affymetrix芯片技术提供鼻咽癌的分子遗传学定义，以区分II型和III型(低分化和未分化的NPC)以及EBV编码的癌基因LMP1阴性和阳性的肿瘤。我们的初步数据证明了这种方法的可行性。这项分析将确定不同类型鼻咽癌的候选标记基因，并测试它们在体外和体内模型中的作用。具体地说，这种方法将被用来识别LMP1激活的基因和信号通路。这将为解释LMP1在鼻咽癌中的作用提供分子基础。

DESCRIPTION (provided by applicant): Epstein-Barr virus is a herpesvirus that infects >90% of the human population. It has two distinguishing characteristics. First it is able to maintain a life long persistent infection in healthy hosts and second it is associated with several human lymphomas and carcinomas. This proposal will address central issues related to these two properties. Persistence: EBV establishes a persistent latent infection in memory B cells. Much is known about how it does this but less is known about how the latently infected cell produces infectious virus to spread to other hosts. Our preliminary data indicate that the signal for viral replication is the terminal differentiation of the latently infected cell into a plasma cell. We will use standard molecular biological tools to identify the role of plasma cell specific transcription factors in activating the EBV lytic cycle. Since plasma cells replicate the virus only when they are fully differentiated it is likely that they release infectious virus when they migrate to the bone marrow. This would result in early B cell progenitors becoming infected. These cells could also provide a site of life time persistent infection. Therefore, the second aim of this study will be to test the role of the bone marrow as a second site of viral persistence. This will be achieved by fractionating the bone marrow into the known subsets of B cells and testing for the presence of the virus by quantitative DNA and RT PCR techniques that we have developed. Neoplasia: One of the commonest tumors associated with EBV is nasopharyngeal carcinoma. There remains little known about the molecular basis of this tumor and its association with EBV. We will use Affymetrix chip technology to provide a molecular genetic definition of NPC that distinguishes Type II and Type III (poorly and undifferentiated NPC) and tumors negative and positive for the EBV encoded oncogene LMP1. Our preliminary data demonstrates the feasibility of this approach. This analysis will identify candidate marker genes for the different types of NPC and test their roles in in vitro and in vivo models. Specifically this approach will be used to identify genes and signaling pathways activated by LMP1. This will provide a molecular basis for explaining the role of LMP1 in NPC.