Computational analysis of antigenic epitopes of avian influenza A (H7N9) viruses  

作　　者：LIU Mi SONG TingRui HUA Sha WU AiPing JIANG TaiJiao 

机构地区：[1]Institute of Biophysics, Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Science China(Life Sciences)》2015年第7期687-693,共7页中国科学（生命科学英文版）

基　　金：supported by the National Basic Research Program of China(2015CB910501);the Major National Earmark Project for Infectious Diseases(2014ZX10004002-001);the Key Research Program of the Chinese Academy of Sciences(KJZD-EW-L09-1-2)to Jiang Tai Jiao;the National Natural Science Foundation of China(31470273)to Wu Ai Ping

摘　　要：Influenza virus can rapidly change its antigenicity, via mutation in the hemagglutinin(HA) protein, to evade host immunity. The emergence of the novel human-infecting avian H7N9 virus in China has caused widespread concern. However, evolution of the antigenicity of this virus is not well understood. Here, we inferred the antigenic epitopes of the HA protein from all H7 viruses, based on the five well-characterized HA epitopes of the human H3N2 virus. By comparing the two major H7 phylogenetic lineages, i.e., the Eurasian lineage and the North American lineage, we found that epitopes A and B are more frequently mutated in the Eurasian lineage, while epitopes B and C are more frequently mutated in the North American lineage. Furthermore, we found that the novel H7N9 virus(derived from the Eurasian lineage) isolated in China in the year 2013, contains six frequently mutated sites on epitopes that include site 135, which is located in the receptor binding domain. This indicates that the novel H7N9 virus that infects human may already have been subjected to gradual immune pressure and receptor-binding variation. Our results not only provide insights into the antigenic evolution of the H7 virus but may also help in the selection of suitable vaccine strains.Influenza virus can rapidly change its antigenicity, via mutation in the hemagglutinin （HA） protein, to evade host immunity. The emergence of the novel human-infecting avian H7N9 virus in China has caused widespread concern. However, evolution of the antigenicity of this virus is not well understood. Here, we inferred the antigenic epitopes of the HA protein from all H7 viruses, based on the five well-characterized HA epitopes of the human H3N2 virus. By comparing the two major H7 phylogenetic lineages, i.e., the Eurasian lineage and the North American lineage, we found that epitopes A and B are more frequently mutated in the Eurasian lineage, while epitopes B and C are more frequently mutated in the North American lineage. Furthermore, we found that the novel H7N9 virus （derived from the Eurasian lineage） isolated in China in the year 2013, contains six frequently mutated sites on epitopes that include site 135, which is located in the receptor binding domain. This indicates that the novel H7N9 virus that infects human may already have been subjected to gradual immune pressure and recep- tor-binding variation. Our results not only provide insights into the antigenic evolution of the H7 virus but may also help in the selection of suitable vaccine strains.

关 键 词：antigenic epitope antigenic evolution HEMAGGLUTININ influenza H7N9 virus 

分 类 号：R511.7[医药卫生—内科学]