淋病奈瑟菌全基因组中外膜蛋白的筛选及其表位分析

Screening and epitope analysis of membrane proteins in the whole genome of Neisseria gonorrhoeae

目的利用生物信息学软件从淋病奈瑟菌全基因组数据中筛选外膜蛋白候选抗原,并对候选抗原进行T细胞和B细胞表位分析,为淋病奈瑟菌疫苗和分子诊断制剂的研制奠定基础。方法对淋病奈瑟菌标准菌株FA1090基因组数据库中推定的2 002个编码蛋白,用SingnalP和PrediSi软件预测信号肽。在具有信号肽的蛋白序列中以TMHMM和Phobius软件为主预测跨膜螺旋结构并构建ORF-TMH外膜蛋白库;利用PSORTb和Cell-Ploc软件进行蛋白表达的亚细胞定位分析,得到ORF-SCL外膜蛋白库。综合"双库"的结果,筛选最有可能表达在淋病奈瑟菌外膜的候选外膜蛋白抗原库。利用BLASTp筛除同源性较低的外膜蛋白;运用ABCpred和BepiPred分析B细胞表位;运用NetCTLpan和SYFPEITHI分析CTL表位;运用SYFPEITHI和NetMHCIIpan分析Th表位。结果预测有信号肽的蛋白序列共350个,"双库"筛选出30个最有可能表达在淋病奈瑟菌外膜的蛋白。通过同源性分析、T细胞表位和B细胞表位分析,得到26个蛋白序列为最有潜力的候选疫苗抗原。结论从淋病奈瑟菌标准菌株FA1090全基因组数据中反向筛选出26个最有可能成为外膜蛋白的候选抗原,为淋病奈瑟菌疫苗的研究奠定了基础。

Objective To screen for candidate antigens from among outer membrane proteins(OMPs) in the whole genome of Neisseria gonorrhoeae using bioinformatic software and to analyze the T-cell and B-cell epitopes of the candidate antigens in order to lay the foundation for the development of N. gonorrhoeae vaccines and molecular diagnostic agents. Methods The 2,002 putative coding proteins of N. gonorrhoeae FA1090 were predicted using the software singnalp and predisi. In these protein sequences with signal peptides, the software TMHMM and Phobius was used to predict transmembrane helices and construct an ORF-TMH OMP library. The software PSORTb and cell PLOC were used to analyze the subcellular localization of protein expression and to obtain an ORF-SCL OMP library. Based on the results of the "dual libraries, " the OMP libraries were screened for candidate antigens that are most likely to be expressed in the outer membrane of N. gonorrhoeae. BLASTp was used to screen OMPs with a low level of similarity. B-cell epitopes were analyzed using ABCpred and BepiPred, CTL epitopes were analyzed using SYFPEITHI and NetCTLpan, and Th epitopes were analyzed using SYFPEITHI and NetMHCIIpan. Results A total of 350 protein sequences with signaling peptides were predicted, and 30 proteins that were most likely to be expressed in the outer membrane of N. gonorrhoeae were screened out using the "dual libraries." Homology analysis and T-cell epitope and B-cell epitope analysis yielded 26 protein sequences with the most potential to be candidate antigens for vaccines. Conclusion Screening of the whole genome of the FA1090 reference strain of N. gonorrhoeae yielded 26 candidate antigens that are most likely to be outer membrane proteins. This finding has laid the foundation for research on N. gonorrhoeae vaccines.