Epstein-Barr virus LMP1 mediated oncogenicity

摘要 伽马疱疹病毒驱动的淋巴增生性疾病在HIV+中导致显著死亡 人口。尽管进行了高效的抗逆转录病毒治疗，但艾滋病毒携带者的风险仍然很高 爱泼斯坦-巴尔病毒(EBV)相关B细胞癌。EBV在&gt；40%的 免疫母细胞性弥漫性大B细胞淋巴瘤和几乎100%的霍奇金淋巴瘤和 HIV阳性个体中的原发性中枢神经系统淋巴瘤。EBV转化人类B细胞 转化成淋巴母细胞系(LCL)，EBV驱动的免疫母细胞淋巴瘤的主要模型 免疫抑制的宿主。然而，EBV诱导的宿主依赖的关键因素仍然是 已澄清。因此，我们使用系统的方法来洞察关键的EBV癌蛋白 目标。我们使用：1)全基因组CRISPR筛查来确定宿主依赖因素 EBV癌蛋白下游；2)建立蛋白质组图谱的多重质谱学 EBV介导的B细胞转化；3)芯片序列法鉴定EBV癌蛋白宿主 基因组靶标发现了第一个病毒超级增强子(SE)，由5个LMP1- 激活核因子-kB和4个EBV核抗原亚基。这些都汇聚在转录上 BATF、IRF4和IRF2因子是LMP1靶向的关键宿主依赖因子。我们的预赛 研究表明，BATF/IRF4和IRF2复合体在EBV中具有关键的依赖因子作用 癌蛋白驱动的MYC表达，是LCL生长和生存所必需的。我们建议 明确病毒癌蛋白超级增强子、BATF/IRF4和IRF2之间的相互作用 复合体促进淋巴母细胞样B细胞MYC的表达。我们的具体目标是(1) 确定EBV癌蛋白如何激活依赖因子BATF/IRF4复合体诱导 (2)确定BATF/IRF4在EB病毒癌蛋白诱导的MYC中的关键作用。 以及(3)确定病毒SE驱动的依赖因子IRF2是如何 支持淋巴母细胞MYC表达所必需的。这些研究专门针对 PA-16-426通过促进对肿瘤的发生、发展和治疗的了解 在潜在艾滋病毒感染者身上观察到的恶性肿瘤。建议进行的研究包括 有望有助于理解EBV癌蛋白和关键基因是如何定义的 下游宿主依赖因子重新编程淋巴母细胞MYC的表达。EB病毒 癌蛋白可能无法下药，但SE和IRF4正日益成为治疗的靶点。自.以来 病毒癌蛋白诱导的MYC表达对EBV转化的B细胞生长至关重要 这些研究的长期目标是支持抑制病毒癌基因的合理方法 对MYC的颠覆。

Abstract Gamma-herpesvirus-driven lymphoproliferative disorders cause significant mortality in HIV+ populations. Despite highly active antiretroviral therapy, HIV+ individuals remain at elevated risk for Epstein-Barr virus (EBV)-associated B-cell cancers. EBV is identified in >40% of immunoblastic diffuse large B-cell lymphomas and nearly 100% of Hodgkin lymphoma and primary central nervous system lymphomas in HIV+ individuals. EBV transforms human B-cells into lymphoblastoid cell lines (LCL), a major model of EBV-driven immunoblastic lymphomas of immunosuppressed hosts. Yet, key EBV-induced host dependency factors remain to be elucidated. We therefore used systematic approaches to gain insights into key EBV oncoprotein targets. We used: 1) Genome-wide CRISPR screens to identify host dependency factors downstream of EBV oncoproteins; 2) Multiplexed mass spectrometry to create a proteomic map of EBV-mediated B-cell transformation; and 3) ChIP-seq to identify EBV oncoprotein host genomic targets, which found the first viral super-enhancers (SE), comprised of 5 LMP1- activated NF-kB and 4 EBV nuclear antigen subunits. These converged on the transcription factors BATF, IRF4 and IRF2 as key LMP1-targeted host dependency factors. Our preliminary studies indicate that BATF/IRF4 and IRF2 complexes have key dependency factor roles in EBV oncoprotein-driven MYC expression, necessary for LCL growth and survival. We propose to define how the interplay between viral oncoprotein superenhancers, BATF/IRF4 and IRF2 complexes drive MYC expression in lymphoblastoid B-cells. Our Specific Aims are to (1) Identify how EBV oncoproteins activate dependency factor BATF/IRF4 complexes to induce MYC; (2) Identify key BATF/IRF4 roles in EBV oncoprotein-induced MYC induction in lymphoblastoid B-cells; and (3) Identify how the viral SE-driven dependency factor IRF2 is necessary to support lymphoblastoid cell MYC expression. These studies specifically address PA-16-426 by advancing understanding of development, progression and treatment of malignancies observed in individuals with underlying HIV infection. The proposed studies are expected to contribute to understanding of how EBV oncoproteins and key genetically-defined downstream host dependency factors reprogram lymphoblastoid cell MYC expression. EBV oncoproteins may not be druggable, but SE and IRF4 are increasingly therapeutic targets. Since viral oncoprotein-induced MYC expression is critical for EBV-transformed B-cell growth, the longterm goal of these studies is to support rational approaches to restrain viral oncogene subversion of MYC.