Metabolic Network Remodeling in Epstein-Barr Virus Lymphomagenesis

摘要 爱泼斯坦-巴尔病毒(EBV)是第一个被发现的人类肿瘤病毒，它将静止的B细胞转化为 快速生长的淋巴母细胞。EB病毒驱动的淋巴瘤会导致严重的疾病 原发或获得性免疫缺陷，包括移植后，合并艾滋病毒感染或 与年龄相关的免疫衰老。EBV通过一种程序转化人类B细胞 至少涉及三个早期阶段。首先，EBV导致主要的B细胞合成代谢重构，在此之前 细胞周期进入。其次，EB病毒随后会像B细胞一样驱动Burkitt淋巴瘤(BL)快速增长， 每隔8-12小时触发细胞分裂。最后，EB病毒LMP1和2A癌蛋白表达 导致向淋巴母细胞系(LCL)样生长的过渡，其中细胞每天分裂并 完成永生计划。为了实现这一非凡的转变，EBV颠覆了关键 托管代谢网络，以提供能量、生物合成构建块和保护 活性氧物种。然而，还没有使用全面的方法来确定关键 EB病毒介导的B细胞生长所依赖的线粒体代谢途径 转型。因此，我们使用多路复用质谱学来创建时间 EB病毒介导的原代人B细胞转化的蛋白质组学图谱及其在全基因组中的应用 CRISPR筛查以确定EBV诱导的B细胞依赖因素。这些方法 确认了EBV诱导的线粒体一碳(1C)代谢的核心作用，以及 能使细胞快速生长的胚胎程序，但在许多成年组织中被关闭。 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EBV诱导的 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代谢在初级B细胞重塑中的作用；(2)确定One-C的作用 支持Burkitt样快速生长的代谢；(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如何颠覆一种关键 胚胎线粒体途径，以实现有效的生长转化。1C新陈代谢有 在EBV发病机制中尚未被研究，但与宿主酶靶标被阻断密切相关 抗叶酸淋巴瘤疗法。因此，我们的研究可能会支持发展理性的策略 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.