Metabolic Network Remodeling in Epstein-Barr Virus Lymphomagenesis

摘要 EB病毒（EBV）是第一种被鉴定的人类肿瘤病毒，它将静息B细胞转化为 快速生长的淋巴母细胞EB病毒驱动的淋巴瘤在以下患者中引起显著疾病： 原发性或获得性免疫缺陷，包括移植后，合并HIV感染，或 与年龄相关的免疫衰老。EBV通过一个程序转化人类B细胞， 至少有三个早期阶段。首先，EBV导致主要的B细胞合成代谢重塑， 细胞周期进入其次，EBV驱动快速伯基特淋巴瘤（BL）样B细胞生长， 每8-12小时触发细胞分裂最后，EBV LMP 1和2A癌蛋白表达 导致向淋巴母细胞样细胞系（LCL）样生长的转变，其中细胞每天分裂， 完成永生计划为了实现这一显着的转变，EBV颠覆了关键 宿主代谢网络提供能量，生物合成构建模块和保护， 活性氧然而，还没有采用全面的办法来确定关键的 EB病毒介导的B细胞生长的基础--EB病毒靶向线粒体代谢途径 转型因此，我们使用多路复用质谱法来创建一个时间 EBV介导的原代人B细胞转化的蛋白质组图谱，并在全基因组范围内使用 CRISPR筛选以鉴定EBV诱导的B细胞依赖性因子。这些方法 确定了EBV诱导的线粒体一碳（1C）代谢的核心作用， 一种胚胎程序，能使细胞快速生长，但在许多成人组织中被关闭。 我们的初步数据表明，EBV癌蛋白诱导1C代谢，包括在 淋巴增生性疾病的小鼠模型。我们的中心假设是， 线粒体一碳代谢在EBV的每个阶段都具有关键但不同的作用， 介导的B细胞生长转化。因此，我们的具体目标是：1）确定角色 EBV诱导的1C代谢在原发性B细胞重塑中的作用;（2）确定一碳 （3）确定线粒体1C在LCL样生长中的作用; 细胞氧化还原防御总的来说，这些研究有望确定EBV如何颠覆一个关键的 胚胎线粒体途径，使有力的增长转化。1C代谢具有 尚未在EBV发病机制中进行研究，但与宿主酶靶点密切相关， 抗叶酸淋巴瘤疗法。因此，我们的研究可能支持制定合理的战略， 阻止EBV相关恶性肿瘤的治疗方案。

Abstract Epstein-Barr virus (EBV), the first identified human tumor virus, transforms resting B-cells into rapidly growing lymphoblasts. EBV-driven lymphomas cause significant disease in patients with primary or acquired immunodeficiency, including post-transplantation, with HIV co-infection or with age-related immune-senescence. EBV transforms human B-cells through a program that involves at least three early stages. First, EBV causes major B-cell anabolic remodeling, prior to cell cycle entry. Second, EBV then drives rapid Burkitt-lymphoma (BL) like B-cell growth, triggering cell division every 8-12 hours. Finally, EBV LMP1 and 2A oncoprotein expression cause a transition to lymphoblastoid cell line (LCL)-like growth, where cells divide daily and complete the immortalization program. To achieve this remarkable transition, EBV subverts key host metabolic networks to provide energy, biosynthetic building blocks and protection from reactive oxygen species. Yet, comprehensive approaches have not been used to identify key EBV-targeted mitochondrial metabolic pathways that underlie EBV-mediated B-cell growth transformation. We therefore used multiplexed mass spectrometry to create a temporal proteomic map of EBV-mediated primary human B-cell transformation, and used genome-wide CRISPR screens to identify EBV-induced B-cell dependency factors. These approaches identified a central role for EBV-induced mitochondrial one-carbon (1C) metabolism, an embryonic program that enables rapid cell growth but which is shut off in many adult tissues. Our preliminary data indicates that EBV oncoproteins induce 1C metabolism, including in a mouse model of lymphoproliferative disease. Our central hypothesis is that EBV-induced mitochondrial one-carbon metabolism has critical but distinct roles in each stage of EBV- mediated B-cell growth transformation. Our Specific Aims are therefore to: 1) Identify the role of EBV-induced 1C metabolism in primary B-cell remodeling; (2) Identify the role of one-carbon metabolism in support of rapid Burkitt-like growth; (3) Identify mitochondrial 1C roles in LCL-like cell redox defense. Collectively, these studies are expected to identify how EBV subverts a key embryonic mitochondrial pathway to enable potent growth transformation. 1C metabolism has not been studied in EBV pathogenesis, but is closely related to host enzyme targets blocked by antifolate lymphoma therapies. Our studies may therefore support strategies to develop rational therapeutic regimens to halt EBV-associated malignancies.