Chen Liang, Liu Ji, Yan Jun, Pan Jiaji, Wu Hui, Xiao Jun, Feng Hao
State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China.
State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, China.
Dev Comp Immunol. 2023 Mar;140:104614. doi: 10.1016/j.dci.2022.104614. Epub 2022 Dec 9.
From mammals to fish, interferons (IFNs) play vital roles in the immune response. In this study, a newly identified type IV interferon (bcIFN-υ) from black carp (Mylopharyngodon piceus) has been cloned and characterized. The CDS of bcIFN-υ consists of 489 nucleotides, encoding 163 amino acids, with the first 20 amino acids predicted to be the signal peptide region. The immunoblot and immunofluorescence assays verified that bcIFN-υ was a secreted cytokine. qPCR analysis and reporter assay demonstrated that bcIFN-υ participated in innate immune defense and activated the transcription of fish ISRE promoter under spring viremia of carp virus (SVCV) stimulation. Additionally, compared with control group, EPC cells transfected with bcIFN-υ or incubated with the bcIFN-υ-containing conditioned media before SVCV infection showed greatly enhanced antiviral activity, and the transcription levels of MX1, PKR, ISG15 and Viperin genes were significantly increased. The subsequential co-immunoprecipitation assay identified the interaction between bcIFN-υ proteins. Collectively, our data conclude that bcIFN-υ is a kind of secretory protein with self-interaction and triggering the expression of downstream ISGs to enhance the antiviral activity of host cells.
从哺乳动物到鱼类，干扰素（IFNs）在免疫反应中发挥着至关重要的作用。在本研究中，已克隆并鉴定了一种新发现的来自草鱼（Mylopharyngodon piceus）的IV型干扰素（bcIFN-υ）。bcIFN-υ的CDS由489个核苷酸组成，编码163个氨基酸，预测前20个氨基酸为信号肽区域。免疫印迹和免疫荧光分析证实bcIFN-υ是一种分泌型细胞因子。qPCR分析和报告基因检测表明，bcIFN-υ参与先天性免疫防御，并在鲤春病毒血症病毒（SVCV）刺激下激活鱼类ISRE启动子的转录。此外，与对照组相比，在SVCV感染前用bcIFN-υ转染或用含bcIFN-υ的条件培养基孵育的EPC细胞显示出显著增强的抗病毒活性，并且MX1、PKR、ISG15和Viperin基因的转录水平显著增加。随后的免疫共沉淀分析确定了bcIFN-υ蛋白之间的相互作用。总的来说，我们的数据表明bcIFN-υ是一种具有自我相互作用并能触发下游ISGs表达以增强宿主细胞抗病毒活性的分泌蛋白。
