Computational analysis of antigenic epitopes of avian influenza A (H7N9) viruses
Computational analysis of antigenic epitopes of avian influenza A (H7N9) viruses
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甲型禽流感 (H7N9) 病毒抗原表位的计算分析。
DOI：
10.1007/s11427-015-4886-4
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发表时间：
2015-07-01
影响因子：
9.1
通讯作者：
Jiang TaiJiao
中科院分区：
文献类型：
--
作者：
Liu Mi;Song TingRui;Jiang TaiJiao
流感病毒可以通过血凝素(HA)蛋白的突变迅速改变其抗原性，以逃避宿主免疫。新型人感染禽流感病毒H7N9在中国的出现引起了广泛关注。然而，这种病毒抗原性的进化还不是很清楚。在这里，我们根据人类H3N2病毒的五个已被很好描述的HA表位，推断出所有H7病毒的HA蛋白的抗原表位。通过比较两个主要的H7系统发生谱系，即欧亚谱系和北美谱系，我们发现表位A和B在欧亚谱系中突变更频繁，而B和C表位在北美谱系中突变更频繁。此外，我们还发现，2013年在中国分离到的新型H7N9病毒(源于欧亚血统)在抗原表位上含有6个频繁突变的位点，其中第135位位于受体结合区。这表明，感染人类的新型H7N9病毒可能已经受到逐渐的免疫压力和受体结合变异。我们的结果不仅为H7病毒的抗原进化提供了洞察力，而且可能有助于选择合适的疫苗株。
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.