Shanghai Key Laboratory of Veterinary Biotechnology, Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
Front Immunol. 2019 Sep 18;10:2224. doi: 10.3389/fimmu.2019.02224. eCollection 2019.
The stimulator of interferon genes (STING) protein has been shown to play a pivotal role in response to both cytosolic RNA and dsDNA to elicit interferon (IFN) production in mammals. However, the role of duck STING (DuSTING) in antiviral innate immunity, especially in anti-RNA virus infection, has yet to be elucidated. In this study, the function of DuSTING in IFN induction and its role in anti-RNA virus infections were studied. DuSTING was amplified via reverse transcription-polymerase chain reaction (RT-PCR) from Pekin duck, showing that its cDNA sequence contains an open reading frame (ORF) of 1,149 bp and encodes 382 amino acids (aa). Sequence alignment showed that DuSTING protein shares 71.1, 43.4, and 33.3% identity with chickens, humans, and zebra fish, respectively. Overexpression of DuSTING in duck embryo fibroblasts (DEFs) strongly activated IFN-β promotor activity. Deletion mutant analysis revealed that the first 42 aa containing the first transmembrane (TM) domains and the last 32 aa containing a part of the C-terminal tail (CTT) are essential for its IFN-β activation. experiments showed that the mRNA levels of DuSTING and IFNs were all upregulated when the DEFs were infected with H9N2 avian influenza virus (AIV) SH010, while overexpression of DuSTING inhibited the replication of this virus. studies showed that DuSTING mRNA was widely expressed in different tissues, and was up-regulated in the spleen and lung of ducks challenged with SH010. In conclusion, our results indicate that DuSTING is an essential IFN mediator and plays a role in anti-RNA virus innate immunity.
干扰素基因刺激蛋白（STING）已被证明在哺乳动物中对细胞质 RNA 和双链 DNA 的反应中发挥关键作用，以引发干扰素（IFN）的产生。然而，鸭 STING（DuSTING）在抗病毒先天免疫中的作用，特别是在抗 RNA 病毒感染中的作用，尚未阐明。在本研究中，研究了 DuSTING 在 IFN 诱导中的功能及其在抗 RNA 病毒感染中的作用。通过逆转录聚合酶链反应（RT-PCR）从北京鸭扩增 DuSTING，表明其 cDNA 序列包含 1149bp 的开放阅读框（ORF），并编码 382 个氨基酸（aa）。序列比对表明，DuSTING 蛋白与鸡、人和斑马鱼的分别具有 71.1%、43.4%和 33.3%的同源性。在鸭胚胎成纤维细胞（DEFs）中过表达 DuSTING 可强烈激活 IFN-β启动子活性。缺失突变分析表明，包含第一个跨膜（TM）结构域的前 42 aa 和包含 C 末端尾部（CTT）一部分的最后 32 aa 是其 IFN-β 激活所必需的。实验表明，当 DEF 感染 H9N2 禽流感病毒（AIV）SH010 时，DuSTING 和 IFNs 的 mRNA 水平均上调，而过表达 DuSTING 抑制了该病毒的复制。研究表明，DuSTING mRNA 在不同组织中广泛表达，在受到 SH010 挑战的鸭的脾脏和肺部中上调。总之，我们的结果表明 DuSTING 是一种必需的 IFN 介体，在抗 RNA 病毒先天免疫中发挥作用。
