Host pathways regulating Epstein-Barr virus-mediated B cell growth transformation

摘要 我们的最终目标是确定EBV介导的B细胞代谢控制的分子基础， 肿瘤发生在这个建议中，我们将重点关注EBV如何促进氧化应激的平衡上调。 磷酸化（OXPHOS）和糖酵解支持B细胞永生化和肿瘤发生。这是我们的中心 病毒潜伏转录因子EBNA-LP作为OXPHOS转录因子的模拟物发挥作用的假说 辅激活剂PGC-1介导的糖酵解和氧化还原平衡通过乳酸的病毒上调来维持， 转运蛋白MCT 1和4。我们已经根据初步数据制定了我们的中心假设，包括 定义EBNA-LP和OXPHOS转录因子之间相互作用的正交方法，定义了一个 EBNA-LP上的新的翻译后修饰，并表征抑制EBNA-LP的代谢后果。 病毒介导的乳酸输出。我们发现，病毒EBNA-LP蛋白与NRF-1、ERR β和YY-1相关。 1模拟细胞共激活因子PGC-1 β。我们描述了EBNA-LP的一种新的翻译后修饰， 羟基丙酸，我们提出是关键的更高层次的复合物的形成，使转录 activation.与EBNA-LP促进的OXPHOS增加平衡，糖酵解酶的上调 EBNA 2和c-MYC的作用导致细胞中乳酸的积累，这些乳酸必须被输出以维持B细胞 增殖我们发现，细胞单羧酸转运蛋白，MCT 1和MCT 4， EBV通过维持NAD+/NADH比率和谷胱甘肽水平来维持B细胞增殖， 活性氧的积累。因此，这项拟议研究的基本原理是， 了解EBV在B细胞永生化过程中如何调节细胞代谢， 靶向EBV感染的B细胞淋巴瘤的治疗方式。我们计划测试我们的中心假设， 通过以下两个具体目标完成本提案中的目标：i）确定 EBNA-LP协调EBV调节的氧化磷酸化使幼稚B永生化的机制 细胞和ii）为了确定单羧酸转运蛋白的时间调节的病毒介导的机制， MCT 1和4，通过B细胞生长及其拮抗作用的后果。

ABSTRACT It is our ultimate goal to define the molecular basis for EBV-mediated metabolic control critical for B-cell tumorigenesis. In this proposal, we will focus on how EBV promotes the balanced upregulation of oxidative phosphorylation (OXPHOS) and glycolysis supporting B-cell immortalization and tumorigenesis. It is our central hypothesis that the viral latent transcription factor, EBNA-LP, functions as a mimic of the OXPHOS transcriptional co-activator PGC-1 while glycolysis and redox balance are maintained through viral upregulation of the lactate transporters MCT1 and 4. We have formulated our central hypothesis based on preliminary data including orthogonal approaches that define interactions between EBNA-LP and OXPHOS transcription factors, define a new post-translational modification on EBNA-LP, and characterize the metabolic consequences of suppressing viral-mediated lactate export. We found that the viral EBNA-LP protein associates with NRF-1, ERR, and YY- 1 mimicking the cellular co-activator PGC-1. We describe a novel post-translational modification of EBNA-LP, hydroxyprolination, that we propose is critical for higher order complex formation enabling transcriptional activation. Balanced with an increase in OXPHOS promoted by EBNA-LP, the upregulation of glycolytic enzymes by EBNA2 and c-MYC leads to an accumulation of lactate in cells that must be exported to sustain B-cell proliferation. We found that cellular monocarboxylate transporters, MCT1 and MCT4, are temporally regulated by EBV to sustain B-cell proliferation through maintaining NAD+/NADH ratios and glutathione levels to counter the accumulation of reactive oxygen species. Therefore, the rationale for this proposed research is that understanding how EBV regulates cellular metabolism during B-cell immortalization could reveal novel therapeutic modalities to target EBV-infected B-cell lymphomas. We plan to test our central hypothesis and complete the objectives in this proposal through the following two specific aims: i) to determine the molecular mechanism by which EBNA-LP coordinates EBV-regulated oxidative phosphorylation to immortalize naïve B cells and ii) to define the viral-mediated mechanism for temporal regulation of the monocarboxylate transporters, MCT1 and 4, through B-cell outgrowth and the consequences of their antagonism.