季节性流感病毒H1N1BALB/c鼠肺适应株的建立及其分子机制

Establishment of a mouse-adapted seasonal H1N1 virus strain via BALB/c mice and its molecular mechanism

目的建立季节性流感病毒H1N1的鼠肺适应株,并对适应的分子机理进行研究。方法以病毒滴鼻感染小鼠,通过在BALB/c小鼠肺组织中连续传代,观察小鼠存活情况及肺病理改变,来获得季节性流感病毒H1N1的鼠肺适应株。结果季节性流感H1N1 A/Brisbane/59/2007病毒野生型毒株,经过在小鼠体内进行8次传代后,毒力逐渐增强,从无致病力到致死率达到100%,对鼠肺适应株与野生型毒株进行基因比对,发现适应株HA基因发生了3个有义突变。结论野生季节性低致病力H1N1流感病毒可经在小鼠中经过多次传代而获得高致病力H1N1鼠肺适应株,HA蛋白89位Thr至Ile的突变对毒力的增强起决定性作用。

Objective To establish adapted strain of seasonal H1N1 influenza virus in mice and infection model. Methods The mice model was induced by nose dropping method with influenza virus, by continuous passage in the lung tissue of BALB/c, to get the adapted strain of seasonal H1N1 in mice and seasonal influenza virus infection model, and the lung index and death rate was observed. Results After 8 times consecutive passages in the lung tissue of BALB/c, virulence of wild type seasonal H1N1 virus was increased to a high level. Genome sequencing and alignment indicated that the HA gene was mutated. Conclusion The virulent mouse-adapted variant A/Brisbane/59/2007-MA can be acquired from the avirulent A/Brisbane/59/2007 strain by continuous passage in the lung tissues of mice. Mutation of Thr to Ile at residue 89 of HA protein is the key virulence determinant.