State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, 430072, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, 430072, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province, 266237, China; School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province, 266109, China.
Dev Comp Immunol. 2021 Feb;115:103877. doi: 10.1016/j.dci.2020.103877. Epub 2020 Sep 29.
Interferon (IFN)-stimulated genes (ISGs) exert multiple functions in immune system, and IFN-induced protein 35 (IFP35), which is a member of ISG, has been suggested to be involved in numerous cellular activities including the regulation of antiviral immunity in mammals. However, the role of IFP35 in fish innate immunity remains largely unknown. In the present study, we characterized the IFP35 gene in mandarin fish Siniperca chuatsi, which contains two conserved Nmi/IFP35 homology domains (NIDs) at C-terminus, but no leucine zipper motif, with its genomic DNA sequence consisting of eight exons and seven introns. High and constitutive mRNA level of IFP35 was observed in all examined tissues, with the highest level being observed in gills. Moreover, the IFP35 gene was significantly induced in vivo for 120 h following the infection of infectious spleen and kidney necrosis virus (ISKNV), and its mRNA and protein level was also significantly induced in vitro following the treatment of poly I:C, IFNh, IFNc, as well as IFN-γ. The subcellular localization results indicated that exogenous IFP35 protein was mainly located in cytoplasm, while endogenous IFP35 protein was transferred into, or aggregated around, the nucleus with the induction of poly I:C or IFNs. The dual luciferase activity analysis indicated that the IFP35 promoter was activated by type I and type II IFNs through ISRE site. It is considered that IFP35 in fish is involved in antiviral, as well as in IFN-induced innate immunity.
干扰素（IFN）刺激基因（ISGs）在免疫系统中发挥多种功能，IFN 诱导蛋白 35（IFP35）是 ISG 的成员之一，被认为参与多种细胞活动，包括调节哺乳动物的抗病毒免疫。然而，IFP35 在鱼类先天免疫中的作用在很大程度上尚不清楚。在本研究中，我们对中华乌塘鳢（Siniperca chuatsi）的 IFP35 基因进行了表征，该基因在 C 端包含两个保守的 Nmi/IFP35 同源结构域（NIDs），但没有亮氨酸拉链基序，其基因组 DNA 序列由八个外显子和七个内含子组成。IFP35 在所有检测组织中均表现出高且组成型的 mRNA 水平，其中在鳃中表达水平最高。此外，IFP35 基因在感染传染性脾坏死病毒（ISKNV）后 120 小时体内显著诱导，其 mRNA 和蛋白水平在体外经多聚 I:C、IFNh、IFNc 以及 IFN-γ处理后也显著诱导。亚细胞定位结果表明，外源性 IFP35 蛋白主要位于细胞质中，而内源性 IFP35 蛋白在多聚 I:C 或 IFNs 诱导下被转移到或聚集在核周围。双荧光素酶活性分析表明，IFP35 启动子通过 ISRE 位点被 I 型和 II 型 IFN 激活。可以认为鱼类中的 IFP35 参与抗病毒以及 IFN 诱导的先天免疫。
