连接粘附分子(JAM),免疫球蛋白超家族(IgSF)的一个亚家族,具有几个免疫球蛋白结构域,可以作为调节脊椎动物的稳态和炎症。在本研究中,从牡蛎中筛选出JAM-A(命名为CgJAM-A-L)的结构同源物,Crassostreagigas,通过搜索JAM-AD1域(JAM-A中的N端Ig域)。CgJAM-A-L的cDNA为1188bp,编码395个氨基酸的预测多肽。CgJAM-A-L的免疫反应区主要分布在血细胞的质膜上。脾振动或肿瘤坏死因子(CgTNF-1)刺激后,血细胞中CgJAM-A-L的mRNA转录比对照组明显增加4.46倍和9.00倍(p<0.01),分别。重组CgJAM-A-L蛋白(rCgJAM-A-L)可结合多种PAMPs,包括脂多糖(LPS),肽聚糖(PGN),脂磷壁酸(LTA),甘露糖(MAN),β-葡聚糖(GLU)和聚(I:C),和各种微生物,包括藤黄微球菌,金黄色葡萄球菌,大肠杆菌,anguillarum振动,五、脾,帕斯托里斯·帕斯托里斯和亚罗瓦·利多利。rCgJAM-A-L孵育后,牡蛎血细胞对革兰氏阴性菌的吞噬率显着提高。甚至在rCgJAM-A-L与微生物预孵育后增加更显著(p<0.01)。结果共同表明,CgJAM-A-L在针对牡蛎入侵病原体的免疫防御中充当重要的模式识别受体(PRR)和调理素。此外,作为与JAMs同源的最原始的物种,牡蛎中CgJAM-A-L的信息将为JAM和免疫球蛋白的进化研究提供有用的线索。
Junctional adhesion molecule (JAM), a subfamily of immunoglobulin superfamily (IgSF) with a couple of immunoglobulin domains, can act as regulator in homeostasis and inflammation of vertebrates. In the present study, a structural homolog of JAM-A (designated CgJAM-A-L) was screened out from oyster, Crassostrea gigas, through a search of JAM-A D1 domain (N-terminal Ig domain in JAM-A). The cDNA of CgJAM-A-L was of 1188 bp encoding a predicted polypeptide of 395 amino acids. The immunoreactive area of CgJAM-A-L mainly distributed over the plasma membrane of hemocytes. After Vibro splendidus or tumor necrosis factor (CgTNF-1) stimulation, the mRNA transcripts of CgJAM-A-L in hemocytes increased significantly by 4.46-fold and 9.00-fold (p < 0.01) of those in control group, respectively. The recombinant CgJAM-A-L protein (rCgJAM-A-L) could bind multiple PAMPs including lipopolysaccharides (LPS), peptidoglycan (PGN), lipoteichoic acid (LTA), mannose (MAN), β-glucan (GLU) and poly(I:C), and various microorganisms including Micrococcus luteus, Staphylococcus aureus, Escherichia coli, Vibro anguillarum, V. splendidus, Pastoris pastoris and Yarrowia lipolytica. The phagocytic rates of oyster hemocytes towards Gram-negative bacteria V. anguillarum and yeast P. pastoris were significantly enhanced after the incubation of rCgJAM-A-L, and even increased more significantly after the pre-incubation of rCgJAM-A-L with microbes (p < 0.01). The results collectively indicated that CgJAM-A-L functioned as an important pattern recognition receptor (PRR) and
opsonin in the immune defense against invading pathogen in oyster. Moreover, as the most primitive specie with homolog of JAMs, the information of CgJAM-A-L in oyster would provide useful clues for the evolutionary study of JAMs and immunoglobulins.