Yang Hui, Lan Qingjing, Liu Ranran, Cui Dan, Liu Haixia, Xiong Dongmei, Li Fenggang, Liu Xiaolin, Wang Lixin
College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling, Shaanxi, 712100, China.
Yellow River Fisheries Research Institute, Chinese Academy of Fishery Science, Xi'an, Shaanxi, 710086, China.
Dev Comp Immunol. 2017 May;70:59-68. doi: 10.1016/j.dci.2017.01.004. Epub 2017 Jan 5.
Galectins are considered as a multifunctional protein which play essential roles in cell adhesion and apoptosis, inflammation, tumor progression and immune response. In spite of extensive studies of galectin importance in immune system among different animals, few studies have been devoted to their functions in amphibian. In the present study, we characterized one proto type of galectin (named AdGal1) from Chinese giant salamander Andrias davidianus and studied its function in immune response. AdGal1 cDNA possesses an open reading frame of 598 bp, which encodes a putative galectin of 134 amino acids containing one carbohydrate recognition domains (CRDs). The constitutive expression of mRNA transcripts was detected in a wide range of tissues, with the highest expression in kidney. Immune challenges with Aeromonas hydrophila and Chinese giant salamander iridovirus (GSIV), the transcript level of AdGal1 in kidney was significantly upregulated. The mature protein of AdGal1 was successfully expressed and purified in Escherichia coli BL21 (DE3). The recombinant AdGal1 (rAdGal1) could show bind activity to different Gram negative and Gram positive bacteria. It could also strongly agglutinate different kinds of bacteria at different concentrations. Collectively, these data from the present study indicate that AdGal1 is a vital pattern recognition receptor to recognize different microbes in the innate immune system of Andrias davidianus.
半乳糖凝集素被认为是一种多功能蛋白质，在细胞黏附与凋亡、炎症、肿瘤进展及免疫反应中发挥着重要作用。尽管在不同动物中对半乳糖凝集素在免疫系统中的重要性进行了广泛研究，但针对其在两栖动物中的功能研究却很少。在本研究中，我们从中国大鲵（Andrias davidianus）中鉴定出一种半乳糖凝集素原型（命名为AdGal1），并研究了其在免疫反应中的功能。AdGal1 cDNA具有一个598 bp的开放阅读框，编码一个推定的含134个氨基酸的半乳糖凝集素，其中包含一个碳水化合物识别结构域（CRD）。在多种组织中检测到mRNA转录本的组成型表达，在肾脏中表达最高。用嗜水气单胞菌和中国大鲵虹彩病毒（GSIV）进行免疫刺激后，肾脏中AdGal1的转录水平显著上调。AdGal1的成熟蛋白在大肠杆菌BL21（DE3）中成功表达并纯化。重组AdGal1（rAdGal1）可显示出对不同革兰氏阴性菌和革兰氏阳性菌的结合活性。它还能在不同浓度下强烈凝集不同种类的细菌。总体而言，本研究的这些数据表明AdGal1是中国大鲵先天免疫系统中识别不同微生物的重要模式识别受体。
