Cloning and expression analysis of a Toll-like receptor 22 (tlr22) gene from turbot, Scophthalmus maximus
Cloning and expression analysis of a Toll-like receptor 22 (tlr22) gene from turbot, Scophthalmus maximus
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DOI：
10.1016/j.fsi.2015.03.001
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发表时间：
2015-06-01
影响因子：
4.7
通讯作者：
Zhang, Shi-Cui
中科院分区：
文献类型：
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作者：
Hu, Guo-Bin;Zhang, Shou-Feng;Zhang, Shi-Cui
Toll样受体22（TLR 22）仅存在于水生动物中并识别双链RNA（dsRNA）。本研究从大菱鲆（Scophthalmus maximus）中克隆了tlr 22基因及其5 '侧翼序列，并对其在体内的免疫应答表达进行了研究。大菱鲆tlr 22基因全长5.6kb，由4个外显子-3内含子组成，编码962个氨基酸。该蛋白与日本比目鱼Tlr 22具有最高的序列同源性（76.7%），具有信号肽序列、由27个LRR基序组成的LRR结构域、跨膜区和Toll/白细胞介素1受体（TIR）结构域。系统发育分析将其与其他硬骨鱼类Tlr 22归类。在smtlr 22基因的5 '侧翼序列中预测了干扰素刺激的反应元件（ISRE）和信号转导和转录激活因子（STAT）结合位点，这些结合位点对TLR 3的基础转录活性具有重要作用。定量实时PCR（qPCR）分析表明，smtlr 22 mRNA的组成型表达在所有检查的组织中的头肾，肾脏和脾脏中的水平较高。此外，smtlr 22的表达显着上调后的挑战与聚肌胞苷酸（聚I：C），脂多糖（LPS）或大菱鲆红体病虹彩病毒（TRBIV）在鳃，头肾，脾脏和肌肉，最大增加范围从2.56至6.24倍，不同的免疫刺激剂和器官。这些发现表明Smtlr 22在对包括DNA和RNA病毒以及革兰氏阴性细菌在内的广泛病原体感染的免疫应答中可能起作用。(c)2015爱思唯尔有限公司版权所有。
Toll-like receptor 22 (TLR22) exists exclusively in aquatic animals and recognizes double stranded RNA (dsRNA). In the present study, a tlr22 gene and its 5'-flanking sequence were cloned from turbot, Scophthalmus maximus, its immune responsive expression was subsequently studied in vivo. The turbot (sm)tlr22 gene spans over 5.6 kb with a structure of 4 exon-3 intron and encodes 962 amino acids. The deduced protein shows the highest sequence identity (76.7%) to Japanese flounder Tlr22 and possesses a signal peptide sequence, a leucine-rich repeat (LRR) domain composed of 27 LRR motifs, a transmembrane region and a Toll/interleukin-1 receptor (TIR) domain. Phylogenetic analysis grouped it with other teleost Tlr22s. The interferon-stimulated response element (ISRE) and signal transducer and activator of transcription (STAT) binding site important for the basal transcriptional activity of TLR3 were predicted in the 5'-flanking sequence of smtlr22 gene. Quantitative real-time PCR (qPCR) analysis demonstrated the constitutive expression of smtlr22 mRNA in all examined tissues with higher levels in the head kidney, kidney and spleen. Further, smtlr22 expression was significantly up-regulated following challenge with polyinosinic: polycytidylic acid (poly I:C), lipopolysaccharide (LPS) or turbot reddish body iridovirus (TRBIV) in the gills, head kidney, spleen and muscle, with maximum increases ranging from 2.56 to 6.24 fold upon different immunostimulants and organs. These findings suggest a possible role of Smtlr22 in the immune responses to the infections of a broad range of pathogens that include DNA and RNA viruses and Gram-negative bacteria. (c) 2015 Elsevier Ltd. All rights reserved.