State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, College of Life Sciences, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275, PR China.
J Fish Biol. 2013 Sep;83(3):642-58. doi: 10.1111/jfb.12202.
In this study, the cDNA sequence encoding interleukin-1 (Il-1) receptor-like protein of orange-spotted grouper Epinephelus coioides was obtained. The newly identified sequence was named soluble type I Il-1 receptor (sIl-1rI) owing to its structural composition, which had two Ig-like domains, lack of transmembrane region and the Toll/interleukin-1 receptor (TIR) domain, similar to the brown rat Rattus norvegicus soluble Il-1rI. In addition, sequence comparison and phylogenetic analysis indicated that E. coioides sequence had a closer relationship with Il-1rI than Il-1rII. Real-time PCR revealed that sil-1rI mRNA expression presented a process of decrease, restoration and increase in Cryptocaryon irritans-infected E. coioides. The negative correlation between Il-1β and sil-1rI mRNA in C. irritans-infected head-kidney implied the potential negative regulatory role of sil-1rI in E. coioides Il-1 system. The leucocytes incubated with lipopolysaccharide or polyriboinosinic polyribocytidylic acid exhibited different expression profiles of sil-1rI. Recombinant Il-1β (rIl-1β) protein was capable of inducing sil-1rI mRNA under the concentration of 100 ng ml(-1) , suggesting that high dosage or excess Il-1β would stimulate the expression of sil-1rI to maintain the homoeostasis of E. coioides Il-1 system. For the first time, the role of teleost Il-1rI in parasite infection has been identified, and soluble Il-1r was found in fish.
在这项研究中，我们获得了尖吻鲈 Epinephelus coioides 白细胞介素-1（Il-1）受体样蛋白的 cDNA 序列。由于其结构组成，新鉴定的序列被命名为可溶性 I 型 Il-1 受体（sIl-1rI），它具有两个 Ig 样结构域、缺乏跨膜区和 Toll/白细胞介素-1 受体（TIR）结构域，与棕色大鼠 Rattus norvegicus 可溶性 Il-1rI 相似。此外，序列比较和系统发育分析表明，E. coioides 序列与 Il-1rI 的关系比 Il-1rII 更密切。实时 PCR 显示，在 Cryptocaryon irritans 感染的尖吻鲈中，sIl-1rI mRNA 表达呈现下降、恢复和增加的过程。在 C. irritans 感染的头肾中，Il-1β 和 sIl-1rI mRNA 之间存在负相关关系，这表明 sIl-1rI 在尖吻鲈 Il-1 系统中可能发挥负调控作用。白细胞在脂多糖或聚肌苷酸聚胞苷酸孵育后表现出不同的 sIl-1rI 表达谱。重组 Il-1β（rIl-1β）蛋白在 100ng/ml 的浓度下能够诱导 sIl-1rI mRNA 的表达，这表明高剂量或过量的 Il-1β 会刺激 sIl-1rI 的表达，以维持尖吻鲈 Il-1 系统的内环境稳定。首次鉴定了硬骨鱼 Il-1rI 在寄生虫感染中的作用，并发现了鱼类中的可溶性 Il-1r。
