Characterization of a tandem-repeat galectin-9 from Nile tilapia (Oreochromis niloticus) involved in the immune response against bacterial infection
Characterization of a tandem-repeat galectin-9 from Nile tilapia (Oreochromis niloticus) involved in the immune response against bacterial infection
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尼罗罗非鱼（Oreochromis niloticus）串联重复半乳糖凝集素 9 的表征，该半乳糖凝集素 9 参与针对细菌感染的免疫反应
DOI：
10.1016/j.fsi.2019.05.061
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发表时间：
2019-09-01
影响因子：
4.7
通讯作者：
Jian, Jichang
中科院分区：
文献类型：
--
作者：
Niu, Jinzhong;Huang, Yu;Jian, Jichang
半乳糖凝集素-9（Galectin-9）是一种β< beta >-半乳糖苷结合凝集素，具有识别、聚集和清除病原菌等多种生物学功能。本研究从尼罗罗非鱼（Oreochromis niloticus）中鉴定了半乳糖凝集素-9（galectin-9）的同源物OnGal-9，并分析了其表达模式和对细菌感染的生物学效应。OrtGal-9序列开放阅读框为975，编码324个氨基酸。它与其他galectin-9蛋白有45%-92%的同源性。OnGal-9的成熟肽具有两个保守的糖识别结构域（CRD），CRD通过连接肽连接。表达分析表明OnGal-9在健康罗非鱼各组织中均有表达。无乳链球菌攻击后，OnGal-9在脾脏、头肾和小肠中的表达显著上调。同时，重组OnGal-9（rOnGal-9）蛋白对无乳链球菌和嗜水气单胞菌均表现出较强的结合和凝集活性。rOnGal-9还能促进巨噬细胞的吞噬功能。总之，这里的结果表明OnGal-9可能参与尼罗罗非鱼对细菌感染的免疫应答。
Galectin-9 is a < beta > -galactoside-binding lectin which could modulate a variety of biological functions including recognition, aggregation and clearance of pathogen. In this study, a galectin-9 homologue (OnGal-9) was identified from Nile tilapia (Oreochromis niloticus) and its expression model and biological effects on bacterial infection were analyzed. The open reading frame of OrtGal-9 sequence was 975 by encoding 324 amino acids. It shares 45%-92% identities with other galectin-9 proteins. The deduced mature peptide of OnGal-9 possesses two conserved carbohydrate recognition domain (CRD) that connected with a linker peptide. Expression analysis indicated that OnGal-9 was distributed in all the tested tissues of healthy tilapia. The OnGal-9 expression was significantly up-regulated in spleen, head kidney, and intestine after challenged by Streptococcus agalactiae. Meanwhile, the recombinant OnGal-9 (rOnGal-9) protein displayed strong binding and agglutination activity toward both Streptococcus agalactiae and Aeromonas hydrophda. Moreover, rOnGal-9 could promote phagocytosis of macrophages. Taken together, the results here indicate that OnGal-9 might be involved in the immune response of Nile tilapia against bacterial infection.