POST-TRANSCRIPTIONAL GENE REGULATION BY EBV SM PROTEIN

描述（由申请人提供）：我们的主要目标是了解EB病毒（EBV）与其宿主细胞的相互作用。EBV在B淋巴细胞中维持持续但间歇性的再活化感染，并促进淋巴和上皮恶性肿瘤的发展，影响全世界数百万人。EBV基因表达如何调节细胞基因表达。维持与宿主免疫反应的稳态平衡是我们建议的总体重点。 宿主细胞和EBV基因表达的关键调节因子是早期裂解性EBV蛋白SM。SM是EBV裂解性复制所必需的核蛋白，其增强mRNA稳定、输出和加工。EBV SM还通过以高度特异性的方式指导选择性剪接来调节细胞和EBV基因表达。 我们已经表明，SM的行为，以改变剪接的细胞STAT1 mRNA和改变模式的STAT1的表达。因此，我们的观察表明，SM可以调节宿主的先天性免疫反应过程中的再激活和裂解复制的EBV。了解病毒对选择性剪接的影响的关键参与者有可能为使用定向小分子或RNA抑制病毒复制开辟新的靶点。 我们最近发现SM诱导的某些干扰素刺激基因（ISGs）通过靶向特定的EBV基因来抑制EBV复制。这些细胞质ISG在EBV再活化期间被诱导，这表明了新的假设，即当它们产生离开细胞核的病毒核酸和蛋白质时，它们可以检测并作用于再活化潜伏病毒。本申请的一个主要假设是，细胞采用先天免疫分子以不同于用于外部病原体的方式来对抗内部潜伏病毒的再活化。这是先天免疫系统与潜伏感染相互作用的新范例，可能广泛适用于疱疹病毒和其他持久性病原体。因此，这一提议有可能揭示具有抗病毒活性的新型效应物的基本作用机制。了解免疫反应和EBV再激活之间的新交叉点对于设计新的治疗策略非常重要。 因此，我们建议研究以下两个具体目标：1。确定干扰素刺激基因（ISGs）抑制或增强EBV复制的机制。2.明确选择性剪接和细胞RNA结合蛋白在EB病毒裂解性复制和SM基因反式激活中的作用。

DESCRIPTION (provided by applicant): Our broad goals are to understand the interactions of Epstein-Barr virus (EBV) with its host cell. EBV maintains a persistent but intermittently reactivating infection in B lymphocytes and contributes to the development of lymphoid and epithelial malignancies affecting millions of humans worldwide. How EBV gene expression modulates cellular gene expression. to maintain a homeostatic balance with the host immune response is the overall focus of our proposal. A key regulator of host cell and EBV gene expression is the early lytic EBV protein SM. SM is a nuclear protein essential for EBV lytic replication that enhances mRNA stabilization, export and processing. EBV SM also regulates cell and EBV gene expression by directing alternative splicing in a highly specific manner. We have shown that SM acts to alter splicing of cellular STAT1 mRNA and change the pattern of STAT1 expression. Our observations therefore indicate that SM may modulate host innate immune responses during the reactivation and lytic replication of EBV. Understanding the key players in viral effects on alternative splicing has the potential to open up new targets for inhibiting virus replication using directed small molecules or RNAs. We have recently found that certain interferon-stimulated genes (ISGs) induced by SM inhibit EBV replication by targeting specific EBV genes. These cytoplasmic ISGs are induced during EBV reactivation, suggesting the novel hypothesis that they may detect and act on reactivating latent viruses when they produce viral nucleic acids and proteins that exit the nucleus. A major hypothesis of this application is that cells employ innate immunity molecules to combat reactivation of internal latent viruses in ways different from those used for external pathogens. This is a new paradigm for the interaction of the innate immune system with latent infections that may broadly apply to herpesviruses and other persistent pathogens. This proposal therefore has the potential to reveal basic mechanisms of action of novel effectors with antiviral activity. Understanding new points of intersection between the immune response and EBV reactivation is important for devising new treatment strategies. We therefore propose studies with the following two specific aims: 1. Determine the mechanisms by which interferon-stimulated genes (ISGs) inhibit or enhance EBV replication. 2. Define the role of alternative splicing and cellular RNA binding proteins in EBV lytic replication and gene transactivation by SM.