An Epstein-Barr Virus MicroRNA Blocks Interleukin-1 (IL-1) Signaling by Targeting IL-1 Receptor 1

作者：Skinner Camille M; Ivanov Nikita S; Barr Sarah A; Chen Yan; Skalsky Rebecca L

来源：Journal of Virology, 2017, 91(21): UNSP e00530-17.

DOI：10.1128/JVI.00530-17

<jats:title>ABSTRACT</jats:title>
<jats:p>Epstein-Barr virus (EBV) encodes &gt;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.</jats:p>
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<jats:bold>IMPORTANCE</jats:bold>
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.
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• 出版日期2017-11