甲型H1N1病毒HA、NA氨基酸序列比较及抗原性表位预测

Comparison of HA,NA Amino Acid Sequences of Novel Influenza Virus A/H1N1 and Prediction of Antigenic Epitopes

目的:比较新型甲型H1N1流感病毒分离株HA、NA氨基酸序列之间的差异,分析HA、NA蛋白可能的抗原性细胞表位。方法:从GenBank中选取28株世界各地的新型甲型H1N1流感病毒分离株并下载各株HA、NA的氨基酸序列;使用ClustalX和MEGA2.0软件对氨基酸序列的进行进化树分析;用Protean软件预测HA、NA蛋白的B细胞表位;用NetMHCⅡ2.2预测T细胞抗原表位。结果:世界范围的毒株之间氨基酸序列相对保守,HA及NA均只有少数位点的变异,HA蛋白氨基酸序列之间较NA蛋白氨基酸序列之间变异较大;预测HA蛋白具有8个B细胞表位和10个T细胞表位;NA蛋白有12个B细胞表位和7个T细胞表位。结论:HA、NA蛋白的少数区域抗原性相对比较稳定,可以作为检测以及疫苗研究的靶区域。

Objective：To compare the amino acid sequences difference of HA,NA novel influenza virus A/H1N1 isolates,and decipher possible B cell epitopes and T cell epitopes of HA,NA protein.Method：The amino acid sequences of 28 novel influenza A/H1N1 virus isolates around the world were downloaded from Genbank. Phylogenetic trees were constructed based on the amino acid sequences of HA and NA by using software Clustal X and MEGA 2.0.B cell and T cell epitopes were respectively predicted with Protean software and NetMHC Ⅱ 2.2 online server.Result：HA protein sequences showed a relatively larger variation comparing to NA protein sequences,nevertheless both of them each had very less divergent amino acid residues. Software predictions revealed the presence of 8 B cell epitopes and 10 T cell epitopes randomly distributed throughout HA sequence and 12 B cell epitopes and 7 T cell epitopes throughout NA sequence. Conclusion：The antigenicity of HA,NA protein is relatively stable in certain regions which can be used as the target area in diagnosis and vaccine research.