HUMAN B CELL TRANSFORMATION BY EPSTEIN BARR VIRUS

EB病毒（EBV）是一种人类病原体， 良性和恶性B细胞淋巴增生， 鼻咽癌 免疫力低下的人，如艾滋病 患者和移植受者患EBV的风险很高， 相关的B细胞淋巴瘤。 病毒引起的生长变化 受感染的B细胞的特性可能是EBV的作用的基础 淋巴组织增生性疾病 原发性人B- 细胞体外EBV导致静息B细胞活化， 从静止状态转变为增殖状态。 这些被感染的细胞进入 细胞周期，能够无限增殖，因此， 不朽 EB病毒是独一无二的，它能够使原发性静息 体外B细胞。 EBV感染的B细胞进入细胞周期， 细胞增殖状态的维持完全依赖于 病毒基因的表达。 本建议的总体目标是 分析EBV的一种特定基因产物（LMP-1）对 永生 LMP-1的研究对人类的免疫学研究具有重要意义。 原因如下：1）LMP-1是4种潜在基因产物之一， 膜蛋白，显示为EBV永生化所必需; ii） LMP-1对培养物中细胞的生长具有深远的影响（即，LMP-1 在啮齿动物细胞中作为致癌基因起作用）; iii）LMP-1位于 质膜，通过其细胞质氨基， 末端，与细胞骨架。 LMP-1必须与细胞信号相互作用 调节正常B细胞增殖的转导途径， 这是识别参与的信号通路的理想起点， EB病毒永生化。 这项工作的具体目标是使用 LMP-1的生物化学和遗传分析，以：i）确定 ii）研究LMP-1的四级结构; LMP-1及其与功能的相关性;以及iii）确定 LMP-1的氨基和羧基末端的结构与功能之间， 细胞骨架结合、周转和修补。 这些实验 预计将提供有助于识别 LMP-1的生化活性导致细胞表型改变 并应允许生成LMP-1如何 在EVB介导的永生化中发挥作用。 了解信号 EBV导致B细胞永生化的转导机制将 提供了对控制正常细胞的细胞机制的见解， 人类B细胞的恶性增殖状态，并可能提供基础 用于临床相关研究，旨在开发治疗 预防和治疗EBV依赖性淋巴瘤以及其他 病毒和非病毒引起的恶性肿瘤。

Epstein-Barr Virus (EBV) is a human pathogen that is causally associated with both benign and malignant B-cell lymphoproliferations and nasopharyngeal carcinoma. Immunocompromised individuals such as AIDS patients and transplant recipients are at high risk for developing EBV- associated B-cell lymphomas. Virally-induced alterations of the growth properties of infected B-cells are likely to underlie EBV's contribution to these lymphoproliferative disorders. Infection of primary human B- cells in vitro EBV results in activation of the resting B-cell from a quiescent state to one of proliferation. These infected cells enter the cell cycle and are able to proliferate indefinitely and thus are immortalized. EBV is unique in its ability to immortalize primary resting B-cells in vitro. Entry of EBV-infected B-cells into the cell cycle and maintenance of the proliferative state of the cell is absolutely dependent upon viral gene expression. The overall aim of this proposal is to analyze the contribution of one particular gene product (LMP-1) of EBV to immortalization. The study of LMP-1 is of particular significance for the following reasons: 1) LMP-1 is one of 4 latent gene products, and the only membrane protein, shown to be essential for immortalization by EBV; ii) LMP-1 has profound effects on the growth of cells in culture (i.e., LMP-1 functions as an oncogene in rodent cells); iii) LMP-1 is located in the plasma membrane where it is associated, via its cytoplasmic amino- terminus, with the cytoskeleton. LMP-1 must interact with cell signal transduction pathways regulating normal B-cell proliferation and thus is the ideal starting point for identifying signaling pathways involved in immortalization by EBV. The specific objectives of this work are to use biochemical and genetic analyses of LMP-1 to: i) determine the transmembrane topology of LMP-1; ii) study the quaternary structure of LMP-1 and its relevance to function; and iii) determine the relationship between the structure of LMP-1's amino- and carboxy-termini and function, cytoskeletal association, turnover and patching. These experiments are expected to provide information that will aid in the identification of LMP-1's biochemical activity that results in altered cellular phenotypes and should allow the generation of rational models of how LMP-1 may function in EVB-mediated immortalization. Understanding the signal transduction mechanisms resulting B-cell immortalization by EBV will provide insights into the cellular mechanisms controlling the normal and malignant proliferative status of human B-cells, and may provide the basis for clinically relevant research aimed at the development of therapies for the prevention and treatment of EBV-dependent lymphomas as well as other virally and nonvirally induced malignancies.