Cheng Yuqiang, Huang Qingqing, Ji Wenhui, Du Bin, Fu Qiang, An Huiting, Li Jing, Wang Hengan, Yan Yaxian, Ding Chan, Sun Jianhe
Key Laboratory for Veterinary Biotechnology of Shanghai, School of Agricuture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Shandong Vocational Animal Science and Veterinary College, Weifang 261061, Shandong, China.
Vet Immunol Immunopathol. 2015 Feb 15;163(3-4):183-93. doi: 10.1016/j.vetimm.2014.12.009. Epub 2014 Dec 23.
Retinoic acid inducible gene I (RIG-I) is a cytosolic pattern recognition receptor that senses pathogen-associated molecular patterns (PAMPs). Muscovy duck (Cairina moschata) is a large duck different from other species of ducks, and is more susceptible to some microbial pathogens. In this study, the Muscovy duck RIG-I gene (MdRIG-I) was identified. Quantitative RT-PCR showed that MdRIG-I mRNA was widely expressed in different tissues, especially in those with mucosa. RIG-I null DF-1 cells transfected with DNA constructs encoding MdRIG-I or CARDs domain can activate IRF-3 and NF-κB to up-regulated activity of IFN-β promoter. The components of the signaling pathway downstream of RIG-I in mammalian cells including IRF-3, NF-κB, IFN-β and the IFN-stimulated genes Mx-1, PKR and MDA5 were significantly up-regulated in CARDs-overexpressing-DF-1 cells. Implicating RIG-I in the antiviral response to an infection in vivo, we found that RIG-I expression in brain, spleen, lung and bursa were up-regulated in ducks challenged with H9N2 avian influenza virus (AIV), whose six internal genes were closely related to the H7N9 and H10N8 AIV. In vitro, DF-1 cells transfected with MdRIG-I plasmid can respond significantly to H9N2 AIV, evident through enhancement of IFN-β promoter activity and decreased virus titer. Altogether, these results indicated that MdRIG-I is a novel member of RLR gene family, engaging in the early stage of antiviral innate immunity.
视黄酸诱导基因I（RIG-I）是一种胞质模式识别受体，可感知病原体相关分子模式（PAMP）。番鸭（Cairina moschata）是一种与其他鸭种不同的大型鸭，对某些微生物病原体更易感。在本研究中，鉴定了番鸭RIG-I基因（MdRIG-I）。定量RT-PCR显示，MdRIG-I mRNA在不同组织中广泛表达，尤其是在有黏膜的组织中。用编码MdRIG-I或CARD结构域的DNA构建体转染的RIG-I基因敲除DF-1细胞可激活IRF-3和NF-κB，上调IFN-β启动子的活性。在过表达CARD结构域的DF-1细胞中，哺乳动物细胞中RIG-I下游信号通路的组分包括IRF-3、NF-κB、IFN-β以及IFN刺激基因Mx-1、PKR和MDA5均显著上调。为了探究RIG-I在体内对感染的抗病毒反应中的作用，我们发现，用H9N2禽流感病毒（AIV）攻击的鸭，其脑、脾、肺和法氏囊中RIG-I的表达上调，该病毒的六个内部基因与H7N9和H10N8 AIV密切相关。在体外，用MdRIG-I质粒转染的DF-1细胞对H9N2 AIV有显著反应，表现为IFN-β启动子活性增强和病毒滴度降低。总之，这些结果表明MdRIG-I是RLR基因家族的一个新成员，参与抗病毒先天免疫的早期阶段。
