pol-miR-194a of Japanese flounder (Paralichthys olivaceus) suppresses type I interferon response and facilitates Edwardsiella tarda infection
pol-miR-194a of Japanese flounder (Paralichthys olivaceus) suppresses type I interferon response and facilitates Edwardsiella tarda infection
复制标题
日本牙鲆 (Paralichthys olivaceus) 的 pol-miR-194a 抑制 I 型干扰素反应并促进迟缓爱德华氏菌感染
DOI：
10.1016/j.fsi.2019.01.017
复制
发表时间：
2019-04-01
影响因子：
4.7
通讯作者：
Sun, Li
中科院分区：
文献类型：
--
作者：
Guan, Xiao-lu;Zhang, Bao-cun;Sun, Li
MicroRNAs （miRNAs）是一类小的非编码rna，参与多种细胞过程，包括微生物入侵和免疫防御。在之前的研究中，我们发现了大量对巨细胞病毒感染有反应的日本比目鱼（parichthys olivaceus） mirna。在本研究中，我们研究了其中一种mirna pol-miR-194a的功能，它与迟发爱德华菌的感染性有关，迟发爱德华菌是一种细胞内细菌病原体，可感染包括比目鱼在内的许多鱼类。我们发现，pol-miR-194a在被迟芽胞杆菌感染的牙鲆的脾脏、肝脏和鳃中被显著诱导表达。用pol-miR-194a mimic转染牙鲆细胞后，可显著增强迟缓棘球蚴的细胞内复制。pol-miR-194a能够特异性与IRF7的3'UTR负向相互作用，从而抑制IRF7的表达。与此一致，pol-miR-194a显著阻断I型干扰素启动子活性。综上所示，这些结果表明，pol-miR-194a在调节牙鲆免疫应答和微生物感染中发挥了重要作用，pol-miR-194a可能是迟缓芽孢杆菌操纵和逃避宿主免疫防御的靶标。
MicroRNAs (miRNAs) are a type of small non-coding RNAs that participate in diverse cellular processes including microbial invasion and immune defense. In a previous study, we identified a large amount of Japanese flounder (Paralichthys olivaceus) miRNAs responsive to megalocytivirus infection. In the present study, we examined the function of one of these miRNAs, pol-miR-194a, in association with the infectivity of Edwardsiella tarda, an intracellular bacterial pathogen to many fish species including flounder. We found that pol-miR-194a was induced in expression to a significant extent in the spleen, liver, and gill of Japanese flounder infected by E. tarda. Transfection of flounder cells with pol-miR-194a mimic significantly enhanced the intracellular replication of E. tarda. pol-miR-194a was able to interact specifically with the 3'UTR of IRF7 in a negative manner, resulting in inhibition of IRF7 expression. Consistently, pol-miR-194a significantly blocked the promoter activity of type I interferon. Taken together, these results indicate that pol-miR-194a plays an important role in the regulation of flounder immune response as well as microbial infection, and that pol-miR-194a probably serves as a target for E. tarda to manipulate and escape host immune defense.