Wang Xiaoyu, Yuan Gaoliang, Zhu Lei, Li Lei, Pei Chao, Hou Libo, Li Chen, Jiang Xinyu, Kong Xianghui
Engineering Lab of Henan Province for Aquatic Animal Disease Control, College of Fisheries, Henan Normal University, Xinxiang, Henan, 453007, China.
Engineering Lab of Henan Province for Aquatic Animal Disease Control, College of Fisheries, Henan Normal University, Xinxiang, Henan, 453007, China.
Dev Comp Immunol. 2023 Feb;139:104566. doi: 10.1016/j.dci.2022.104566. Epub 2022 Oct 12.
Fish interleukin (IL)-17A/F is homologous with mammalian IL-17A and IL-17F, which plays a key role in regulating inflammatory responses and autoimmune diseases. In fish, IL-17A/F1, 2, and 3 have been identified and described. However, IL-17A/F3 has received little attention in fish. In this study, a homolog of IL-17A/F3 was identified in common carp (Cyprinus carpio L.), which was termed as Cc_IL-17A/F3. The deduced amino acid sequence of Cc_IL-17A/F3 has four conserved cysteine residues, which could form two intrachain disulfide bonds. Homology comparison showed that the Cc_IL-17A/F3 was in the range of 31.7-71.9% of sequence similarity with these of other fishes. The Cc_IL-17A/F3 gene was constitutively expressed in various tissues, with higher expression levels in the skin and gills. After common carp were infected by Aeromonas. hydrophila, the mRNA expression levels of Cc_IL-17A/F3 were significantly up-regulated in the spleen, head kidney, gills, and intestine. Based on the indirect immunofluorescence assay, Cc_IL-17A/F3 proteins were found to be obviously increased in the intestine and spleen upon A. hydrophila infection at 24 h post-infection. The recombinant protein rCc_IL-17A/F3 could enhance the gene expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IFN-γ, and TNF-α) as well as chemokines (CXCL8 and CXCL20) in primary head kidney leukocytes. In vivo and in vitro experiments have similar stimulatory effects. When Cc_IL-17A/F3 was overexpressed in common carp, the expressions of pro-inflammatory cytokines and chemokines were significantly up-regulated in head kidney and spleen. In summary, the results derived from the present study suggested that the Cc_IL-17A/F3 plays an important role in defending against bacterial infections, and probably participates in mucosal immunity of the host.
鱼类白细胞介素（IL）-17A/F与哺乳动物的IL-17A和IL-17F同源，在调节炎症反应和自身免疫性疾病中起关键作用。在鱼类中，已鉴定并描述了IL-17A/F1、2和3。然而，IL-17A/F3在鱼类中很少受到关注。在本研究中，在鲤鱼（Cyprinus carpio L.）中鉴定出IL-17A/F3的一个同源物，命名为Cc_IL-17A/F3。Cc_IL-17A/F3推导的氨基酸序列有四个保守的半胱氨酸残基，可形成两个链内二硫键。同源性比较表明，Cc_IL-17A/F3与其他鱼类的序列相似性在31.7%-71.9%之间。Cc_IL-17A/F3基因在各种组织中组成性表达，在皮肤和鳃中表达水平较高。鲤鱼感染嗜水气单胞菌后，Cc_IL-17A/F3在脾脏、头肾、鳃和肠道中的mRNA表达水平显著上调。基于间接免疫荧光分析，发现在感染嗜水气单胞菌24小时后，肠道和脾脏中的Cc_IL-17A/F3蛋白明显增加。重组蛋白rCc_IL-17A/F3可增强原代头肾白细胞中促炎细胞因子（IL-1β、IL-6、IFN-γ和TNF-α）以及趋化因子（CXCL8和CXCL20）的基因表达水平。体内和体外实验具有相似的刺激作用。当Cc_IL-17A/F3在鲤鱼中过表达时，头肾和脾脏中促炎细胞因子和趋化因子的表达显著上调。总之，本研究结果表明，Cc_IL-17A/F3在抵御细菌感染中起重要作用，可能参与宿主的黏膜免疫。
