Benedicenti Ottavia, Wang Tiehui, Wangkahart Eakapol, Milne Douglas J, Holland Jason W, Collins Catherine, Secombes Christopher J
Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK; Marine Scotland Science Marine Laboratory, 375 Victoria Rd, Aberdeen AB11 9DB, UK.
Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
Fish Shellfish Immunol. 2017 Feb;61:138-151. doi: 10.1016/j.fsi.2016.12.024. Epub 2016 Dec 23.
In this study we show that four arginase isoforms (arg1a, arg1b, arg2a, arg2b) exist in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). We have characterised these molecules in terms of a) sequence analysis, b) constitutive expression in different tissues, and modulated expression following c) stimulation of head kidney macrophages in vitro, or d) vaccination/infection with Yersinia ruckeri and e) parasite infection (AGD caused by Paramoeba perurans and PKD caused by Tetracapsuloides bryosalmonae). Synteny analysis suggested that these arginase genes are paralogues likely from the Ss4R duplication event, and amino acid identity/similarity analyses showed that the proteins are relatively well conserved across species. In rainbow trout constitutive expression of one or both paralogues was seen in most tissues but different constitutive expression patterns were observed for the different isoforms. Stimulation of rainbow trout head kidney macrophages with PAMPs and cytokines also revealed isoform specific responses and kinetics, with arg1a being particularly highly modulated by the PAMPs and pro-inflammatory cytokines. In contrast the type II arginase paralogues were induced by rIl-4/13, albeit to a lesser degree. Vaccination and infection with Y. ruckeri also revealed isoform specific responses, with variation in tissue expression level and kinetics. Lastly, the impact of parasite infection was studied, where down regulation of arg1a and arg1b was seen in two different models (AGD in salmon and PKD in trout) and of arg2a in AGD. The differential responses seen are discussed in the context of markers of type II responses in fish and paralogue subfunctionalization.
在本研究中，我们发现虹鳟（Oncorhynchus mykiss）和大西洋鲑（Salmo salar）中存在四种精氨酸酶亚型（arg1a、arg1b、arg2a、arg2b）。我们从以下几个方面对这些分子进行了表征：a）序列分析；b）在不同组织中的组成性表达，以及在以下情况下的表达调控：c）体外刺激头肾巨噬细胞；d）用鲁氏耶尔森菌进行疫苗接种/感染；e）寄生虫感染（由秘鲁变形虫引起的AGD和由鲑居尾孢虫引起的PKD）。共线性分析表明，这些精氨酸酶基因可能是来自Ss4R复制事件的旁系同源物，氨基酸同一性/相似性分析表明，这些蛋白质在不同物种间相对保守。在虹鳟中，大多数组织中都观察到一种或两种旁系同源物的组成性表达，但不同亚型的组成性表达模式有所不同。用PAMP和细胞因子刺激虹鳟头肾巨噬细胞也揭示了亚型特异性反应和动力学，其中arg1a受到PAMP和促炎细胞因子的特别高度调节。相比之下，II型精氨酸酶旁系同源物虽也受到重组白细胞介素-4/13的诱导，但程度较低。用鲁氏耶尔森菌进行疫苗接种和感染也显示出亚型特异性反应，组织表达水平和动力学存在差异。最后，研究了寄生虫感染的影响，在两种不同模型中（鲑鱼的AGD和虹鳟的PKD）观察到arg1a和arg1b的下调，在AGD中观察到arg2a的下调。我们在鱼类II型反应标志物和旁系同源物亚功能化的背景下讨论了观察到的差异反应。
