Ni Xiao-dan, Wang Na, Liu Yong-jie, Lu Cheng-ping
Nanjing Agricultural University, China.
FEMS Immunol Med Microbiol. 2010 Apr;58(3):363-73. doi: 10.1111/j.1574-695X.2009.00646.x.
Aeromonas hydrophila is a gram-negative bacterium that can infect a variety of aquatic and terrestrial animals. It is essential to develop a vaccine to reduce the economic losses caused by this bacterium in aquaculture worldwide. Here, an immunoproteomic assay was used to identify the immunogenic extracellular proteins of the Chinese vaccine strain J-1. Ten unique immunogenic proteins were identified from the two-dimensional electrophoresis immunoblot profiles by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) or MALDI-TOF-TOF-MS. One protein of interest, Omp38, was detected by antisera on two-dimensional immunoblots, suggesting that it might be located both extracellularly and in the membrane. In exploring the potential of Omp38 as a vaccine candidate in fish, we found the omp38 gene to be prevalent by PCR among different (36/48) A. hydrophila isolates. The recombinant Omp38 induced a strong antibody response in rabbits, and the polyclonal antibody could recognize a band of approximately 38 kDa in the immunoblots of outer membrane protein extracts from most (24/40) of the A. hydrophila strains, including different predominant serotypes in China. These results indicated that the outer membrane antigen identified in this study could be developed as a vaccine candidate to induce protective immunity against A. hydrophila infection.
嗜水气单胞菌是一种革兰氏阴性菌，可感染多种水生和陆生动物。研发一种疫苗以减少这种细菌在全球水产养殖中造成的经济损失至关重要。在此，采用免疫蛋白质组学分析来鉴定中国疫苗株J-1的免疫原性细胞外蛋白。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）或MALDI-TOF-TOF-MS从二维电泳免疫印迹图谱中鉴定出十种独特的免疫原性蛋白。在二维免疫印迹上，一种感兴趣的蛋白Omp38被抗血清检测到，这表明它可能既存在于细胞外，也存在于细胞膜中。在探索Omp38作为鱼类疫苗候选物的潜力时，我们发现omp38基因在不同的（36/48）嗜水气单胞菌分离株中通过PCR检测普遍存在。重组Omp38在兔体内诱导了强烈的抗体反应，并且多克隆抗体能够在大多数（24/40）嗜水气单胞菌菌株的外膜蛋白提取物的免疫印迹中识别出一条约38 kDa的条带，包括中国不同的优势血清型。这些结果表明，本研究中鉴定出的外膜抗原可开发为疫苗候选物，以诱导针对嗜水气单胞菌感染的保护性免疫。
