EBV Antigen and Cell Cycle Regulation

描述（由申请人提供）：普遍存在的人EB病毒（EBV）已被证明与广泛的人类癌症有关，包括伯基特淋巴瘤、鼻咽癌、霍奇金淋巴瘤、成人T细胞淋巴瘤和免疫功能低下患者的淋巴增生性疾病。在体外，EBV可以有效地在体外转化人原代B细胞，导致感染的原代B细胞持续增殖成转化的淋巴母细胞系（LCL）。EB病毒转化的B淋巴细胞是严格潜伏的，因为表达了一组选择的基因，其中之一是EB病毒核抗原（EBNA）3C。通过病毒的遗传分析，EBNA 3C已经显示出对于体外B细胞转化是必需的。在过去的十年中，与EBNA 3C相关的功能已经将这种必需分子通过与转录阻遏物CSL、Nm 23-H1、肿瘤抑制分子Rb和其他细胞周期调节因子（包括细胞周期蛋白A和细胞周期蛋白D1）的相互作用而与病毒和细胞转录的调节相关联。本研究将探讨EBV核抗原3C与细胞因子E2 F和c-Myc的相互作用，这些因子参与细胞增殖、细胞周期、转录和维持细胞稳态的信号传导的调节。这些细胞靶点c-Myc和E2 F与3C相互作用的特定氨基酸将被探索，并在B细胞转化和永生化方面检查功能关系。c-Myc和E2 F的翻译后修饰对激活其调节功能至关重要，也将进行充分研究。同时，我们将产生位点特异性重组EBNA 3C分子，其因EBV基因组内的特异性相互作用而被敲除，以确定其在原代B细胞转化中的作用。公共卫生相关性：普遍存在的γ疱疹病毒爱泼斯坦巴尔病毒与一系列人类癌症有关。至少有6个潜伏基因已被证明是关键的细胞转化在体外。这些抗原中的一些与细胞周期调节蛋白直接相关，并且还与细胞事件的特异性调节相关，所述细胞事件包括转录调节、染色质重塑、细胞增殖和细胞周期调节。该建议将探索必需核抗原之一EBNA 3C在确定EBNA 3C通过翻译后修饰和细胞周期调节导致人B细胞转化的主要细胞癌蛋白E2 F和c-Myc的调节中的相关功能的更全面的模型中的作用。

DESCRIPTION (provided by applicant): The ubiquitous human Epstein-Barr virus (EBV) has been shown to be linked to a wide range of human cancers which include Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's lymphoma, adult T-cell lymphomas and lymphoproliferative diseases in immunocompromised patients. In vitro, EBV can efficiently transform human primary B-cells in vitro resulting in continual proliferation of the infected primary B-cells into transformed lymphoblastoid cell lines (LCLs). The nascently transformed B-lymphocytes by EBV are strictly latent in that a select set of genes are expressed, one of which is Epstein-Barr nuclear antigen (EBNA) 3C. EBNA3C has been shown to be essential for B cell transformation in vitro by genetic analysis of the virus. Over the last decade the functions associated with EBNA3C has linked this essential molecule to regulation of viral and cellular transcription through interaction with the transcription repressor CSL, Nm23-H1, the tumor suppressor molecule Rb and other cell cycle regulatory factors which include Cyclin A and Cyclin D1. This proposal will investigate the interactions of the essential EBV nuclear antigen 3C and the cellular factors E2F and c-Myc involved in regulation of cell proliferation, cell cycle, transcription, and signaling involved in maintenance of cellular homeostasis. The specific amino acids of these cellular targets c-Myc and E2F interacting with 3C will be explored and the functional relationships examined in terms of B cell transformation and immortalization. The post-translational modifications of c-Myc and E2F important for activation of their regulatory functions will also be fully investigated. Simultaneously, we will generate site specific recombinant EBNA3C molecules that are knocked out for the specific interactions within the EBV genome to determine their role in primary B cell transformation. PUBLIC HEALTH RELEVANCE: The ubiquitous gammaherpesvirus Epstein Barr virus is associated with a range of human cancers. At least 6 latent genes have been shown to be critical for cell transformation in vitro. Some of these antigens associate directly with cell cycle regulatory proteins and are also linked to the specific regulation of cellular events which include regulation of transcription, chromatin remodeling, cell proliferation and cell cycle regulation. This proposal will explore the role of one of the essential nuclear antigens EBNA3C in determining a more comprehensive model for the related functions of EBNA3C in regulation of the major cellular oncoproteins E2F and c-Myc through post-translation modification and cell cycle regulation leading to transformation of human B cells.