两株H1N1亚型猪流感病毒NS1蛋白抑制Ⅰ型IFN功能比较

本研究分离得到两株猪源H1N1流感病毒,通过进化树分析发现分别是欧亚类禽H1N1猪流感病毒和类鸭源H1N1猪流感病毒,为了研究两株毒株的NS1蛋白对Ⅰ型IFN产生的抑制能力,分别构建了2个毒株的NS1基因的真核表达载体,将NS1真核表达质粒、Ⅰ型IFN报告质粒与干扰素刺激质粒RIG-I共转染293T细胞,利用双荧光素酶报告基因检测Ⅰ型IFN激活水平。结果显示:欧亚类禽H1N1猪流感病毒NS1蛋白对人源细胞干扰素的拮抗作用明显强于类鸭源H1N1猪流感病毒;2种NS1蛋白对RIG-I与TBK-1激活的IFN-I抑制能力存在显著的差别,但是对IRF-3激活的IFN-I抑制能力没有显著差别。本研究结果初步揭示了欧亚类禽与类鸭源H1N1猪流感病毒抑制IFN-I能力的差异,及H1N1禽流感适应猪群的潜在分子机制。

Interferon Antagonism Comparison of NS1 Proteins of Two H1N1 Swine Influenza Viruses

In this study,two strains of Swine influenza H1N1 viruses were isolated and identified by phylogenetic analysis,which showed that the two strains belong to Eurasian avian-like H1N1 Swine influenza viruses and duck-like H1N1 lineages.In order to study the inhibitory effect of the two NS1 proteins on the production of typeⅠIFN,two eukaryotic expression vectors of NS1 genes were constructed.The NS1 expression plasmid,typeⅠIFN reporter plasmid,and interferon stimulated RIG-I expression plasmid were co-transfected into 293T cells.The activation level of typeⅠIFN was detected by dual luciferase reporter gene.The antagonistic effect of Eurasian H1N1 NS1 was significantly stronger than that of duck-like H1N1 virus.The difference of IFN-I inhibition between the two NS1 proteins was further studied by using the molecules at different nodes of the IFN-I pathway.The results showed that there were significant differences between the two NS1 proteins in inhibition of RIG-I and TBK-1 activated IFN-I,but there was no significant difference in inhibition of IRF3 activated IFN-I.The results of this study preliminarily reveal the difference of IFN-I inhibition ability between Eurasian H1N1 and duck origin H1N1 NS1 proteins and the potential molecular mechanisms of Eurasian avian-like H1N1 influenza adaptation to pig herds.