The avian influenza A(H7N9) virus has caused high mortality in humans, especially in the elderly; however, little is known about the mechanistic basis for this. In this study, we employed non-human primates to evaluate the effect of aging on the pathogenicity of A(H7N9) virus. We observed that A(H7N9) virus infection of aged animals (defined as 20-26 years) caused more severe symptoms than infection of young animals (defined as 2-3 years). In aged animals, lung inflammation was weak and virus infection was sustained. Although cytokine and chemokine expression in the lungs of most aged animals was lower than that in the lungs of young animals, one aged animal showed severe symptoms and dysregulated proinflammatory cytokine and chemokine production. These results suggest that attenuated or dysregulated immune responses in aged animals are responsible for the severe symptoms observed among elderly patients infected with A(H7N9) virus.
Keywords: Aging; dysregulated immunity; immune senescence; influenza; non-human primate.
© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: firstname.lastname@example.org.
A(H7N9) virus results in early induction of proinflammatory cytokine responses in both human lung epithelial and endothelial cells and shows increased human adaptation compared with avian H5N1 virus.J Virol. 2015 Apr;89(8):4655-67. doi: 10.1128/JVI.03095-14. Epub 2015 Feb 11. J Virol. 2015. PMID: 25673714 Free PMC article.
Differences in the pathogenicity and inflammatory responses induced by avian influenza A/H7N9 virus infection in BALB/c and C57BL/6 mouse models.PLoS One. 2014 Mar 27;9(3):e92987. doi: 10.1371/journal.pone.0092987. eCollection 2014. PLoS One. 2014. PMID: 24676272 Free PMC article.
Inhibition of reactive oxygen species production ameliorates inflammation induced by influenza A viruses via upregulation of SOCS1 and SOCS3.J Virol. 2015 Mar;89(5):2672-83. doi: 10.1128/JVI.03529-14. Epub 2014 Dec 17. J Virol. 2015. PMID: 25520513 Free PMC article.
A review on current trends in the treatment of human infection with H7N9-avian influenza A.J Infect Public Health. 2019 Mar-Apr;12(2):153-158. doi: 10.1016/j.jiph.2018.08.005. Epub 2018 Sep 10. J Infect Public Health. 2019. PMID: 30213468 Review.
Research progress in human infection with avian influenza H7N9 virus.Sci China Life Sci. 2017 Dec;60(12):1299-1306. doi: 10.1007/s11427-017-9221-4. Epub 2017 Dec 1. Sci China Life Sci. 2017. PMID: 29270791 Review.