Cui Min, Chen Shuling, Zhang Shaqiu, Cheng Anchun, Pan Yuhong, Huang Juan, Hu Zhiqiang, Zhang Xingcui, Wang Mingshu, Zhu Dekang, Chen Shun, Liu Mafeng, Zhao Xinxin, Wu Yin, Yang Qiao, Liu Yunya, Zhang Ling, Yu Yanling, Yin Zhongqiong, Jing Bo, Rehman Mujeeb Ur, Tian Bin, Pan Leichang, Jia Renyong
Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Front Microbiol. 2020 Apr 21;11:596. doi: 10.3389/fmicb.2020.00596. eCollection 2020.
Duck Tembusu virus (DTMUV), a member of family, causes acute egg-drop syndrome in ducks. MicroRNAs (miRNAs) have been found to be involved in various biological processes, including tumor genesis, viral infection, and immune response. However, the functional effect of miRNAs on DTMUV replication remains largely unclear. This study aimed to elucidate the role of host microRNA-221-3p (miR-221-3p) in regulating DTMUV replication. Here, we indicated that the expression of miR-221-3p was significantly upregulated in duck embryo fibroblasts (DEFs) during DTMUV infection. Transfection of miR-221-3p mimic significantly reduced interferon (IFN) β production, whereas transfection of miR-221-3p inhibitor conversely significantly increased the expression of IFN-β in DTMUV-infected DEF. Moreover, we found that viral RNA copies, viral E protein expression level, and virus titer, which represent the replication and proliferation of virus, were all enhanced when transfecting the miR-221-3p mimic into DEF; reverse results were also observed by transfecting the miR-221-3p inhibitor. We also found that the expression of suppressor of cytokine signaling 5 (SOCS5) was downregulated in DEF infected with DTMUV. Besides, we further proved that SOCS5 is a target of miR-221-3p and that miR-221-3p could negatively modulate SOCS5 expression at both mRNA and protein levels. Finally, our results showed that overexpression of SOCS5 inhibited DTMUV replication and knockdown of SOCS5 enhanced DTMUV replication. Thus, our findings reveal a novel host evasion mechanism adopted by DTMUV miR-221-3p, which may hew out novel strategies for designing miRNA-based vaccines and therapies.
鸭坦布苏病毒（DTMUV）是黄病毒科的成员，可引起鸭的急性产蛋下降综合征。微小RNA（miRNA）已被发现参与多种生物学过程，包括肿瘤发生、病毒感染和免疫反应。然而，miRNA对DTMUV复制的功能作用仍不清楚。本研究旨在阐明宿主微小RNA-221-3p（miR-221-3p）在调节DTMUV复制中的作用。在此，我们表明在DTMUV感染期间，鸭胚成纤维细胞（DEFs）中miR-221-3p的表达显著上调。转染miR-221-3p模拟物显著降低了干扰素（IFN）β的产生，而转染miR-221-3p抑制剂则相反地显著增加了DTMUV感染的DEF中IFN-β的表达。此外，我们发现，当将miR-221-3p模拟物转染到DEF中时，代表病毒复制和增殖的病毒RNA拷贝数、病毒E蛋白表达水平和病毒滴度均增加；转染miR-221-3p抑制剂也观察到相反的结果。我们还发现，在感染DTMUV的DEF中，细胞因子信号转导抑制因子5（SOCS5）的表达下调。此外，我们进一步证明SOCS5是miR-221-3p的靶标，并且miR-221-3p可以在mRNA和蛋白质水平上负调节SOCS5的表达。最后，我们的结果表明，SOCS5的过表达抑制了DTMUV的复制，而SOCS5的敲低增强了DTMUV的复制。因此，我们的研究结果揭示了DTMUV利用miR-221-3p的一种新的宿主逃避机制，这可能为设计基于miRNA的疫苗和疗法开辟新的策略。
