Chen Xiaowu, Shen Yawei, Wu Minglin, Zhao Jinliang
National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China.
Fisheries Research Institute, Anhui Academy of Agricultural Sciences, NO.40 South Nongke Road, Luyang District, Hefei, 230000, Anhui, China.
Fish Physiol Biochem. 2019 Feb;45(1):133-144. doi: 10.1007/s10695-018-0543-8. Epub 2018 Jul 28.
Interferon regulatory factors (IRFs) are transcription factors of the interferon (IFN)-inducible signaling pathway essential for host immunity against antimicrobial infection by virus and bacteria. Interferon regulatory factor 3 (IRF3) regulates the expression of IFNs and IFN-stimulated genes by binding to the IFN stimulatory response element (ISRE). In this study, we analyze the thymus transcriptome of the mandarin fish Siniperca chuatsi and report the functional analysis of Irf3 from the thymus as an emerging model of antiviral approaches. The predicted S. chuatsi IRF3 (Sc-Irf3) protein has 465 amino acid residues and evolutionarily conserved domains and is clustered in the IRF3 subfamily on a phylogenetic tree. Sc-Irf3 upon transgenic expression was mainly found in the cytoplasm through Western blot analysis and microscopy, but it translocated to the nucleus after polyinosinic:polycytidylic acid (ploly I:C) treatment. Endogenous Sc-irf3 RNA expression was detected in all eight adult organs examined. Importantly, Sc-irf3 RNA expression was significantly upregulated by ploly(I:C) treatment in the adult organs. Concurrently, reporter assays revealed that Sc-Irf3 increased the transcriptional activity of the ifnβ promoter, a minimal ISRE-containing promoter, and ifn promoter of mandarin fish. Therefore, Sc-Irf3 plays a major role in the IFN immune defense system against virus infection.
干扰素调节因子（IRFs）是干扰素（IFN）诱导信号通路的转录因子，对于宿主抵抗病毒和细菌的抗菌感染的免疫至关重要。干扰素调节因子3（IRF3）通过与IFN刺激反应元件（ISRE）结合来调节IFN和IFN刺激基因的表达。在本研究中，我们分析了鳜鱼（Siniperca chuatsi）的胸腺转录组，并报告了来自胸腺的Irf3作为抗病毒方法新模型的功能分析。预测的鳜鱼IRF3（Sc-Irf3）蛋白有465个氨基酸残基且具有进化保守结构域，在系统发育树上聚类于IRF3亚家族。通过蛋白质免疫印迹分析和显微镜观察发现，转基因表达后的Sc-Irf3主要存在于细胞质中，但在聚肌苷酸:聚胞苷酸（poly I:C）处理后会转移至细胞核。在所检测的所有八个成体器官中均检测到内源性Sc-irf3 RNA表达。重要的是，在成体器官中，poly（I:C）处理显著上调了Sc-irf3 RNA表达。同时，报告基因检测显示，Sc-Irf3增强了鳜鱼ifnβ启动子（一个含最小ISRE的启动子）和ifn启动子的转录活性。因此，Sc-Irf3在IFN免疫防御系统抵抗病毒感染中起主要作用。
