College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou 510642, China.
Viruses. 2021 Oct 12;13(10):2048. doi: 10.3390/v13102048.
RIG-I functions as a virus sensor that induces a cellular antiviral response. Although it has been investigated in other species, there have been no further studies to date on canine RIG-I against canine influenza virus (CIV). In the present study, we cloned the RIG-I gene of beagle dogs and characterized its expression, subcellular localization, antiviral response, and interactions with CIV proteins. RIG-I was highly expressed and mainly localized in the cytoplasm, with low levels detected in the nucleus. The results revealed that overexpression of the CARD domain of RIG-I and knockdown of RIG-I showed its ability to activate the RLR pathway and induced the expression of downstream interferon-stimulated genes. Moreover, overexpression of canine RIG-I suppressed the replication of CIV. The association between RIG-I and CIV was evaluated with the luciferase assay and by indirect immunofluorescence and bimolecular fluorescence complementation analyses. The results showed that CIV nonstructural protein 1 (NS1) can strongly suppress the RIG-I-mediated innate immune response, and the novel interactions between CIV matrix proteins (M1 and M2) and canine RIG-I were disclosed. These findings provide a basis for investigating the antiviral mechanism of canine RIG-I against CIV, which can lead to effective strategies for preventing CIV infection in dogs.
RIG-I 作为一种病毒传感器，可诱导细胞抗病毒反应。尽管它已在其他物种中进行了研究，但迄今为止，针对犬流感病毒（CIV）的犬 RIG-I 尚无进一步的研究。在本研究中，我们克隆了比格犬的 RIG-I 基因，并对其表达、亚细胞定位、抗病毒反应以及与 CIV 蛋白的相互作用进行了表征。RIG-I 高度表达，主要定位于细胞质中，细胞核中检测到的水平较低。结果表明，RIG-I 的 CARD 结构域的过表达和 RIG-I 的敲低显示了其激活 RLR 途径和诱导下游干扰素刺激基因表达的能力。此外，过表达犬 RIG-I 抑制了 CIV 的复制。通过荧光素酶测定、间接免疫荧光和双分子荧光互补分析评估了 RIG-I 与 CIV 之间的关联。结果表明，CIV 非结构蛋白 1（NS1）可以强烈抑制 RIG-I 介导的先天免疫反应，并揭示了 CIV 基质蛋白（M1 和 M2）与犬 RIG-I 之间的新相互作用。这些发现为研究犬 RIG-I 针对 CIV 的抗病毒机制提供了基础，这可以为预防犬 CIV 感染提供有效的策略。
