Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, 100094, China.
Chinese Academy of Sciences Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing, 100101, China.
Vet Microbiol. 2021 Apr;255:109039. doi: 10.1016/j.vetmic.2021.109039. Epub 2021 Mar 12.
The H1N1 influenza virus of swine-origin was responsible for the H1N1 pandemic in 2009 (pdm/09 H1N1), where the virus was transmitted to humans and then spread between people, and its continued circulation has resulted in it becoming a seasonal human flu virus. Since 2016, the matrix (M) gene of pdm/09 H1N1 has been involved in the reassortment of swine influenza viruses (SIVs) in China and has gradually become a dominant genotype in pigs. However, whether M gene substitution will influence the fitness of emerging SIVs remains unclear. Here, we analyzed the biological characteristics of SIVs with the M gene from Eurasian avian-like (EA) SIV or pdm/09 H1N1 in mammals and found that SIVs containing the pdm/09-M gene exhibit stronger virulence in mice, more efficient respiratory droplet transmission between ferrets, and increased transcription of viral genes in A549 cells compared with those containing EA-M. We also determined the functional significance of the pdm/09-M gene in conferring an elevated release of progeny viruses comprised of largely filamentous virions rather than spherical virions. Our study suggests that pdm/09-M plays a crucial role in the genesis of emerging SIVs in terms of the potential prevalence in the population.
猪源 H1N1 流感病毒引发了 2009 年的 H1N1 大流行（pdm/09 H1N1），该病毒在人类中传播并在人与人之间传播，其持续循环导致其成为季节性人类流感病毒。自 2016 年以来，pdm/09 H1N1 的基质（M）基因参与了中国猪流感病毒（SIV）的重配，并逐渐成为猪中的主要基因型。然而，M 基因替换是否会影响新出现的 SIV 的适应性尚不清楚。在这里，我们分析了具有欧亚类禽样（EA）SIV 或哺乳动物中 pdm/09 H1N1 的 M 基因的 SIV 的生物学特性，发现含有 pdm/09-M 基因的 SIV 在小鼠中表现出更强的毒力，在雪貂之间更有效地通过呼吸道飞沫传播，并且在 A549 细胞中转录的病毒基因增加与含有 EA-M 的 SIV 相比。我们还确定了 pdm/09-M 基因在赋予主要由丝状病毒粒子而不是球形病毒粒子组成的大量子代病毒释放方面的功能意义。我们的研究表明，pdm/09-M 在新兴 SIV 的产生中发挥了关键作用，这可能会在人群中流行。
