Chicken DDX1 Acts as an RNA Sensor to Mediate IFN-β Signaling Pathway Activation in Antiviral Innate Immunity.
Chicken DDX1 Acts as an RNA Sensor to Mediate IFN-β Signaling Pathway Activation in Antiviral Innate Immunity.
复制标题
鸡 DDX1 作为 RNA 传感器介导抗病毒先天免疫中 IFN-β 信号通路激活
DOI：
10.3389/fimmu.2021.742074
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发表时间：
2021
影响因子：
7.3
通讯作者：
Cheng Y
中科院分区：
文献类型：
--
作者：
Lin Z;Wang J;Zhu W;Yu X;Wang Z;Ma J;Wang H;Yan Y;Sun J;Cheng Y
鸡是纽卡斯尔病毒（NDV）和禽流感病毒（AIV）的天然宿主。RIG-I基因是哺乳动物中主要的RNA病毒模式识别受体（PRR），但在鸡中天然缺失，这一发现引起了人们对鸡RNA PRR及其在抗病毒免疫应答中功能的研究。本研究将Asp-Glu-Ala-Asp（DEAD）-box helicase 1（DDX 1）鉴定为鸡体内一种重要的RNA病毒PRR，并对其在抗RNA病毒感染中的作用进行了研究。克隆了chDDX 1基因，跨物种序列比对和系统发育树分析表明，DDX 1基因在脊椎动物中高度保守。定量RT-PCR结果表明，chDDX 1 mRNA在健康鸡的不同组织中广泛表达。此外，chDDX 1显着上调后感染AIV，NDV，或GFP表达水泡性口炎病毒（VSV-GFP）。在DF-1细胞中过表达chDDX 1可诱导IFN-β、IFN刺激基因（ISG）和促炎细胞因子的表达;它还可抑制NDV和VSV的复制。敲低chDDX 1基因可提高NDV和VSV的病毒产量，降低IFN-β的产生，而IFN-β的产生是由RNA类似物poly[I：C]、AIV和NDV诱导的。我们在一系列实验中使用鸡IRF 7（chIRF 7）敲除DF-1细胞系来证明chDDX 1通过chIRF 7途径激活IFN信号传导。最后，体外pulldown试验显示poly（I：C）和chDDX 1蛋白之间存在强烈而直接的相互作用，表明chDDX 1可能在IFN活化过程中充当RNA PRR。简而言之，我们的研究结果表明，chDDX 1是IFN-β的重要介质，并参与RNA和RNA病毒介导的chDDX 1-IRF 7-IFN-β信号通路。
Chickens are the natural host of Newcastle disease virus (NDV) and avian influenza virus (AIV). The discovery that the RIG-I gene, the primary RNA virus pattern recognition receptor (PRR) in mammals, is naturally absent in chickens has directed attention to studies of chicken RNA PRRs and their functions in antiviral immune responses. Here, we identified Asp-Glu-Ala-Asp (DEAD)-box helicase 1 (DDX1) as an essential RNA virus PRR in chickens and investigated its functions in anti-RNA viral infections. The chDDX1 gene was cloned, and cross-species sequence alignment and phylogenetic tree analyses revealed high conservation of DDX1 among vertebrates. A quantitative RT-PCR showed that chDDX1 mRNA are widely expressed in different tissues in healthy chickens. In addition, chDDX1 was significantly upregulated after infection with AIV, NDV, or GFP-expressing vesicular stomatitis virus (VSV-GFP). Overexpression of chDDX1 in DF-1 cells induced the expression of IFN-β, IFN-stimulated genes (ISGs), and proinflammatory cytokines; it also inhibited NDV and VSV replications. The knockdown of chDDX1 increased the viral yield of NDV and VSV and decreased the production of IFN-β, which was induced by RNA analog polyinosinic-polycytidylic acid (poly[I:C]), by AIV, and by NDV. We used a chicken IRF7 (chIRF7) knockout DF-1 cell line in a series of experiments to demonstrate that chDDX1 activates IFN signaling via the chIRF7 pathway. Finally, an in-vitro pulldown assay showed a strong and direct interaction between poly(I:C) and the chDDX1 protein, indicating that chDDX1 may act as an RNA PRR during IFN activation. In brief, our results suggest that chDDX1 is an important mediator of IFN-β and is involved in RNA- and RNA virus-mediated chDDX1-IRF7-IFN-β signaling pathways.