The Genomic Contributions of Avian H1N1 Influenza A Viruses to the Evolution of Mammalian Strains
The Genomic Contributions of Avian H1N1 Influenza A Viruses to the Evolution of Mammalian Strains
复制标题
禽 H1N1 流感病毒对哺乳动物品系进化的基因组贡献
作者：
Zeynep A Koçer;R. Carter;Gang Wu;Jinghui Zhang;R. Webster
在野生水禽中的甲型流感病毒（IAV）中，只有H1、H2和H3亚型在人类中引起流行。禽源性H1N1病毒也引起了5次大流行中的3次。为了了解H1N1在大流行出现的背景下重新出现，我们调查了禽H1N1 IAV是否有助于人类，猪和2009年大流行H1N1 IAV的进化。在系统发育分析的基础上，我们得出结论，在北美禽流感H1N1 IAV中循环的聚合酶基因片段（特别是PB 2和PA）已被多次重新引入猪，导致不同的谱系，导致2009年大流行H1N1 IAV的出现。此外，血凝素和核蛋白和神经氨酸酶和基质基因片段的相似拓扑结构表明，每个表面糖蛋白与H1N1亚型内的内部基因片段共同进化。2009年分离出的来自形目的H1N1禽流感病毒的基因型与来自雁形目的H1N1禽流感病毒的基因型不同。当考虑所有31种北美禽类H1N1 IAV的血凝素中的抗原位点时，抗原位点处60%-80%的氨基酸与1918年和/或2009年大流行性H1N1病毒中的氨基酸相同。因此，尽管由于数据集较小，无法从遗传学推断禽H1N1 IAV的致病性，但H1N1 IAV亚型内的进化过程表明，H1N1 IAV在野鸟中的传播对未来人类流感大流行构成持续威胁。
Among the influenza A viruses (IAVs) in wild aquatic birds, only H1, H2, and H3 subtypes have caused epidemics in humans. H1N1 viruses of avian origin have also caused 3 of 5 pandemics. To understand the reappearance of H1N1 in the context of pandemic emergence, we investigated whether avian H1N1 IAVs have contributed to the evolution of human, swine, and 2009 pandemic H1N1 IAVs. On the basis of phylogenetic analysis, we concluded that the polymerase gene segments (especially PB2 and PA) circulating in North American avian H1N1 IAVs have been reintroduced to swine multiple times, resulting in different lineages that led to the emergence of the 2009 pandemic H1N1 IAVs. Moreover, the similar topologies of hemagglutinin and nucleoprotein and neuraminidase and matrix gene segments suggest that each surface glycoprotein coevolved with an internal gene segment within the H1N1 subtype. The genotype of avian H1N1 IAVs of Charadriiformes origin isolated in 2009 differs from that of avian H1N1 IAVs of Anseriformes origin. When the antigenic sites in the hemagglutinin of all 31 North American avian H1N1 IAVs were considered, 60%-80% of the amino acids at the antigenic sites were identical to those in 1918 and/or 2009 pandemic H1N1 viruses. Thus, although the pathogenicity of avian H1N1 IAVs could not be inferred from the phylogeny due to the small dataset, the evolutionary process within the H1N1 IAV subtype suggests that the circulation of H1N1 IAVs in wild birds poses a continuous threat for future influenza pandemics in humans.