Wörmann Xenia, Lesch Markus, Welke Robert-William, Okonechnikov Konstantin, Abdurishid Mirshat, Sieben Christian, Geissner Andreas, Brinkmann Volker, Kastner Markus, Karner Andreas, Zhu Rong, Hinterdorfer Peter, Anish Chakkumkal, Seeberger Peter H, Herrmann Andreas, Meyer Thomas F, Karlas Alexander
Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany.
Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany; Steinbeis Innovation gGmbH, Center for Systems Biomedicine, Falkensee, Germany.
Virology. 2016 May;492:118-29. doi: 10.1016/j.virol.2016.02.002. Epub 2016 Feb 23.
The 2009 influenza pandemic originated from a swine-origin H1N1 virus, which, although less pathogenic than anticipated, may acquire additional virulence-associated mutations in the future. To estimate the potential risk, we sequentially passaged the isolate A/Hamburg/04/2009 in A549 human lung epithelial cells. After passage 6, we observed a 100-fold increased replication rate. High-throughput sequencing of viral gene segments identified five dominant mutations, whose contribution to the enhanced growth was analyzed by reverse genetics. The increased replication rate was pinpointed to two mutations within the hemagglutinin (HA) gene segment (HA1 D130E, HA2 I91L), near the receptor binding site and the stem domain. The adapted virus also replicated more efficiently in mice in vivo. Enhanced replication rate correlated with increased fusion pH of the HA protein and a decrease in receptor affinity. Our data might be relevant for surveillance of pre-pandemic strains and development of high titer cell culture strains for vaccine production.
2009年流感大流行起源于一种猪源H1N1病毒，尽管其致病性低于预期，但未来可能会获得其他与毒力相关的突变。为了评估潜在风险，我们在A549人肺上皮细胞中对分离株A/Hamburg/04/2009进行了连续传代。传代6次后，我们观察到复制率提高了100倍。对病毒基因片段进行高通量测序鉴定出五个主要突变，通过反向遗传学分析了它们对生长增强的作用。复制率的提高被确定为血凝素（HA）基因片段内的两个突变（HA1 D130E、HA2 I91L），靠近受体结合位点和茎域。适应性病毒在小鼠体内也能更有效地复制。复制率的提高与HA蛋白融合pH值的增加和受体亲和力的降低相关。我们的数据可能与大流行前毒株的监测以及用于疫苗生产的高滴度细胞培养毒株的开发有关。
