Sun T, Guo Y, Zhao L, Fan M, Huang N, Tian M, Liu. Evolution of the PB1 gene of human influenza A(H3N2) viruses circulating between 1968 and 2019. Transbound Emerg Dis. 2021 May 25
One avian H3N2 influenza virus, providing its PB1 and HA segments, reassorted with one human H2N2 virus and caused a pandemic outbreak in 1968, killing over one million people. After its introduction to humanity, the pandemic H3N2 virus continued adapting to humans and has resulted in epidemic outbreaks every influenza season. To understand the functional roles of the originally avian PB1 gene in the circulating strains of human H3N2 influenza viruses, we analyzed the evolution of the PB1 gene in all human H3N2 isolates from 1968 to 2019. We found several specific residues dramatically changed around 2002-2009 and remained stable through to 2019. Then, we verified the functions of these PB1 mutations in the genetic background of the early pandemic virus, A/Hong Kong/1/1968(HK/68), as well as a recent seasonal strain, A/Jiangsu/34/2016 (JS/16). The PB1 V709I or PB1 V113A/K586R/D619N/V709I induced higher polymerase activity of HK/68 in human cells. And the four mutations acted cooperatively that had an increased replication capacity in vitro and in vivo at an early stage of infection. In contrast, the backward mutant, A113V/R586K/N619D/I709V reduced polymerase activity in human cells. The PB1 I709V decreased viral replication in vitro, but this mutant only showed less effect on mice infection experiment suggested influenza A virus evolved in human host was not always consisted with highly replication efficiency and pathogenicity in other mammalian host. Overall, our results demonstrated that the identified PB1 mutations contributed to the viral evolution of human influenza A(H3N2) viruses.
See Also:
Latest articles in those days:
- The evolution, complexity, and diversity of swine influenza viruses in China: A hidden public health threat 1 days ago
- MHC class II proteins mediate sialic acid independent entry of human and avian H2N2 influenza A viruses 1 days ago
- Histopathologic Features and Viral Antigen Distribution of H5N1 Highly Pathogenic Avian Influenza Virus Clade 2.3.4.4b from the 2022–2023 Outbreak in Iowa Wild Birds 1 days ago
- Detection and characterization of H5N1 HPAIV in environmental samples from a dairy farm 1 days ago
- Genomic Characterization of Highly Pathogenic Avian Influenza A H5N1 Virus Newly Emerged in Dairy Cattle 1 days ago
[Go Top] [Close Window]