State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
Department of Preventive Veterinary Medicine, College of Animal Medicine, Huazhong Agricultural University, Wuhan 430070, China.
Genes (Basel). 2020 Mar 13;11(3):308. doi: 10.3390/genes11030308.
RIG-I and MDA5 are two key pattern recognition receptors that sense RNA virus invasion, but RIG-I is absent in chickens. Although chickens have intact MDA5, the genes downstream of chicken MDA5 (chMDA5) that may mediate antiviral response are not well studied. We compared the transcriptional profile of chicken embryonic fibroblasts (DF1) transfected with chMDA5, and poly(I:C), using RNA-seq. Transfected chMDA5 and poly(I:C) in DF1 cells were associated with the marked induction of many antiviral innate immune genes compared with control. Interestingly, nine interferon-stimulated genes (ISGs) were listed in the top 15 upregulated genes by chMDA5 and poly(I:C) transfection. We used real-time PCR to confirm the upregulation of the nine ISGs, namely, MX1, IFI6, IFIT5, RSAD2, OASL, CMPK2, HELZ2, EPSTI1, and OLFML1, by chMDA5 and poly(I:C) transfection in DF1 cells. However, avian influenza virus H5N6 infection only increased MX1, IFI6, IFIT5, RSAD2, and OASL expression levels. Further study showed that the overexpression of these five genes could significantly inhibit H5N6 virus replication. These results provide some insights into the gene expression pattern induced by chMDA5, which would be beneficial for understanding and identifying innate immune genes of chicken that may lead to new antiviral therapies.
RIG-I 和 MDA5 是两种识别 RNA 病毒入侵的关键模式识别受体，但鸡中不存在 RIG-I。尽管鸡具有完整的 MDA5，但鸡 MDA5（chMDA5）下游可能介导抗病毒反应的基因尚未得到充分研究。我们使用 RNA-seq 比较了转染 chMDA5 和 poly(I:C)的鸡胚成纤维细胞（DF1）的转录谱。与对照相比，转染的 chMDA5 和 poly(I:C)在 DF1 细胞中与许多抗病毒先天免疫基因的显著诱导有关。有趣的是，有 9 个干扰素刺激基因（ISGs）被列为 chMDA5 和 poly(I:C)转染上调的前 15 个基因之一。我们使用实时 PCR 确认了 9 个 ISGs（MX1、IFI6、IFIT5、RSAD2、OASL、CMPK2、HELZ2、EPSTI1 和 OLFML1）在 DF1 细胞中转染 chMDA5 和 poly(I:C)后的上调。然而，禽流感病毒 H5N6 感染仅增加了 MX1、IFI6、IFIT5、RSAD2 和 OASL 的表达水平。进一步的研究表明，这五个基因的过表达可显著抑制 H5N6 病毒复制。这些结果提供了对 chMDA5 诱导的基因表达模式的一些见解，这将有助于理解和鉴定可能导致新的抗病毒疗法的鸡先天免疫基因。
