空肠弯曲菌主要外膜蛋白OMP18的B细胞抗原表位分析及功能鉴定

目的 从生物信息学角度了解空肠弯曲菌主要外膜蛋白OMP18的跨膜结构、B细胞抗原表位及其抗原性、基因序列保守性等特征,并鉴定空肠弯曲菌主要外膜蛋白优势B细胞抗原表位,为后续抗体检测和疫苗研究提供实验依据。方法 使用NCBI/Blast,TMHMM Server V2.0,DNA Star等生物信息学分析软件对空肠弯曲菌主要外膜蛋白OMP18进行蛋白跨膜结构预测、线性B细胞抗原表位及其抗原性分析、并对不同空肠弯曲菌OMP18蛋白的氨基酸序列同源性进行比较。采用空肠弯曲菌全菌抗体IgG为一抗,基于ELISA技术对优势线性B细胞抗原表位进行筛选鉴定。结果 生物信息学预测结果表明外膜蛋白OMP18定位于空肠弯曲菌外膜且不存在跨膜结构。蛋白序列保守存在于各空肠弯曲菌株中,序列同源性达95%以上。同时,我们发现该外膜蛋白中存在3个明显的B细胞线性表位,且具有很强的抗原性。ELISA检测鉴定结果表明3个B细胞抗原表位都能有效识别空肠弯曲菌全菌抗体。结论 空肠弯曲菌主要外膜蛋白OMP18保守存在于细菌表面,存在3个重要的B细胞线性抗原表位,可用于后续的抗体检测和疫苗开发研究。

Analysis and identification of B cell epitopes of the OMP18 from Campylobacter jejuni

In this study, we aimed to understand the sequence characteristics, transmembrane structures, line B cell epitopes present in the OMP18 from Campylobacter jejuni, and provide candidate antigens for the antibody detection and vaccine development. NCBI/Blast, TMHMM Server V2 and DNA Star softwares were used for the OMP18 sequence analysis. Based on the ELISA, the whole bacterial antibody IgG of Campylobacter jejuni was used for the identification of the predicted line B cell epitopes. The OMP18 gene was found conserved in different Campylobacter jejuni strains. The OMP18 was predicted to be located on the outer surface of the bacteria. And three line B cell epitopes were determined to be present in the OMP18 protein. As a conclusion, the OMP18 protein was confirmed to be an important outer membrane protein; three line B cell epitopes were identified in the OMP18, which could be further used for Campylobacter jejuni antibody detection and vaccine development.