基于基因序列聚类的甲型流行性感冒病毒H3抗原变异规律研究

目的 利用聚类分析方法探讨全球甲型流行性感冒病毒(流感)H3亚型抗原的变异规律。方法下载NCBI GenBank和流感病毒数据库中全部的甲型流感病毒RNA4节段H3亚型基因序列,在Clustalx中进行序列对齐后,使用两阶段聚类法进行分析,并随后探讨各类的三间分布。结果 所有序列可被分为10类,其中7类主要为人流感病毒,人流感病毒和鸟类、其他哺乳动物的流感病毒被明确的分为不同类别,但和猪流感病毒则共存于数个类中。各类呈现出明显的时间分布和宿主分布规律,但并未发现地域分布规律。结论 由于受到人类免疫系统的选择压力,H3抗原呈现出5-7年出现一次较大变异的流行特征,且这一趋势随着近十年来流感疫苗的普遍使用而呈现加速趋势。同时,猪流感病毒和人流感病毒出现在同一类别中,两者的遗传距离较近,这为猪作为病毒重配的载体提供了新的佐证。

Application of gene sequence cluster in research for H3 antigenic evolution of influenza A virus

Objective Gene sequence data were clustered to explore evolution lineages of H3 antigen of influenza A virus. Methods All data of H3 RNA sequence in NCBI Genbank and Influenza sequence database were downloaded and aligned in ClustalX while two step cluster method were applied to explore the data. Results All sequences were aggregated into ten clusters, while seven of them mainly were human virus. Human virus and avam/other mammal virus were separated into different clusters distinctively, but coexisted into same clusters with swine virus. Time and host distribution were very distinctive in these clusters, but no geographic distribution features were found. Conclusion With the interaction of human immuruty system, H3 antigen mutated sigmficantly every 5-7 years, and the speed of mutation had accelerated with the application of influenza vaccines in recent years. Meanwhile, human and swine influenza virus were not separated distinctly between clusters mdicting that they had short mheritance distance Result showed again that swine served as the mixer for antigenic recombination of different influenza virus.