Skinner Camille M, Ivanov Nikita S, Barr Sarah A, Chen Yan, Skalsky Rebecca L
Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA.
Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
J Virol. 2017 Oct 13;91(21). doi: 10.1128/JVI.00530-17. Print 2017 Nov 1.
Epstein-Barr virus (EBV) encodes >44 viral microRNAs (miRNAs) that are differentially expressed throughout infection, can be detected in Epstein-Barr virus (EBV)-positive tumors, and manipulate several biological processes, including cell proliferation, apoptosis, and immune responses. Here, we show that EBV BHRF1-2 miRNAs block NF-κB activation following treatment with proinflammatory cytokines, specifically interleukin-1β (IL-1β). Analysis of EBV PAR-CLIP miRNA targetome data sets combined with pathway analysis revealed multiple BHRF1-2 miRNA targets involved in interleukin signaling pathways. By further analyzing changes in cellular gene expression patterns, we identified the IL-1 receptor 1 (IL1R1) as a direct target of miR-BHRF1-2-5p. Targeting the IL1R1 3' untranslated region (UTR) by EBV miR-BHRF1-2-5p was confirmed using 3'-UTR luciferase reporter assays and Western blot assays. Manipulation of EBV BHRF1-2 miRNA activity in latently infected B cells altered steady-state cytokine levels and disrupted IL-1β responsiveness. These studies demonstrate functionally relevant BHRF1-2 miRNA interactions during EBV infection, which is an important step in understanding their roles in pathogenesis. IL-1 signaling plays an important role in inflammation and early activation of host innate immune responses following virus infection. Here, we demonstrate that a viral miRNA downregulates the IL-1 receptor 1 during EBV infection, which consequently alters the responsiveness of cells to IL-1 stimuli and changes the cytokine expression levels within infected cell populations. We postulate that this viral miRNA activity not only disrupts IL-1 autocrine and paracrine signaling loops that can alert effector cells to sites of infection but also provides a survival advantage by dampening excessive inflammation that may be detrimental to the infected cell.
爱泼斯坦-巴尔病毒（EBV）编码超过44种病毒微小RNA（miRNA），这些miRNA在整个感染过程中差异表达，可在爱泼斯坦-巴尔病毒（EBV）阳性肿瘤中检测到，并可调控多种生物学过程，包括细胞增殖、凋亡和免疫反应。在此，我们表明EBV BHRF1-2 miRNA在用促炎细胞因子，特别是白细胞介素-1β（IL-1β）处理后可阻断核因子κB（NF-κB）的激活。对EBV PAR-CLIP miRNA靶标组数据集进行分析并结合通路分析，揭示了多个参与白细胞介素信号通路的BHRF1-2 miRNA靶标。通过进一步分析细胞基因表达模式的变化，我们确定白细胞介素-1受体1（IL1R1）是miR-BHRF1-2-5p的直接靶标。使用3'-UTR荧光素酶报告基因检测和蛋白质免疫印迹检测证实了EBV miR-BHRF1-2-5p对IL1R1 3'非翻译区（UTR）的靶向作用。在潜伏感染的B细胞中操纵EBV BHRF1-2 miRNA的活性会改变稳态细胞因子水平并破坏IL-1β反应性。这些研究证明了EBV感染期间功能相关的BHRF1-2 miRNA相互作用，这是理解它们在发病机制中作用的重要一步。IL-1信号在病毒感染后炎症和宿主先天免疫反应的早期激活中起重要作用。在此，我们证明在EBV感染期间一种病毒miRNA下调IL-1受体1，从而改变细胞对IL-1刺激的反应性并改变感染细胞群体内的细胞因子表达水平。我们推测这种病毒miRNA活性不仅破坏了可提醒效应细胞感染部位的IL-1自分泌和旁分泌信号回路，还通过减轻可能对感染细胞有害的过度炎症提供了生存优势。
