Laboratory for Marine Biology and Biotechnology of Qingdao National Laboratory for Marine Science and Technology, College of Life Sciences, Zhejiang University, Hangzhou, China.
Front Immunol. 2018 Dec 18;9:2999. doi: 10.3389/fimmu.2018.02999. eCollection 2018.
MicroRNAs (miRNAs) function as crucial suppressors of gene expression via translational repression or direct mRNA degradation. However, the mechanism of multi-gene regulation by a host miRNA in antiviral immunity has not been extensively explored. In this study, the regulation of two white spot syndrome virus (WSSV) genes by its host ( shrimp) miRNA (shrimp miR-1000) was characterized. The miRNA target gene prediction showed that only two virus genes ( and ) might be the targets of miR-1000. The results of insect cell transfection assays revealed that shrimp miR-1000 could target multiple virus genes ( and ). The mRNA degradation analysis and RNA FISH (fluorescence hybridization) analysis indicated that miR-1000 triggered the mRNA degradation of target genes through 5'-3' exonucleolytic digestion and thereby inhibited the virus infection in shrimp. The miRNA-mediated 5'-3' exonucleolytic digestion of target mRNAs stopped near the 3'UTR (3'untranslated region) sequence complementary to the seed sequence of miR-1000. Therefore, our study provided novel insights into how a host miRNA targeted multiple viral genes and prevented host from virus infection.
微小 RNA（miRNA）通过翻译抑制或直接 mRNA 降解，作为基因表达的关键抑制剂发挥作用。然而，宿主 miRNA 在抗病毒免疫中对多个基因的调控机制尚未得到广泛探索。在本研究中，我们对白斑综合征病毒（WSSV）宿主（虾）miRNA（虾 miR-1000）对两种 WSSV 基因的调控进行了研究。miRNA 靶基因预测表明，只有两种病毒基因（和）可能是 miR-1000 的靶标。昆虫细胞转染实验的结果表明，虾 miR-1000 可以靶向多个病毒基因（和）。mRNA 降解分析和 RNA FISH（荧光杂交）分析表明，miR-1000 通过 5'-3'外切核酸酶消化触发靶基因的 mRNA 降解，从而抑制虾中的病毒感染。miRNA 介导的靶 mRNA 的 5'-3'外切核酸酶消化在与 miR-1000 的种子序列互补的 3'UTR（3'非翻译区）序列附近停止。因此，我们的研究为宿主 miRNA 如何靶向多个病毒基因并防止宿主病毒感染提供了新的见解。
