FOXO3a regulates rhinovirus-induced innate immune responses in airway epithelial cells

Sci Rep. 2019 Dec 3;9(1):18180. doi: 10.1038/s41598-019-54567-3.

Abstract

Forkhead transcription factor class O (FOXO)3a, which plays a critical role in a wide variety of cellular processes, was also found to regulate cell-type-specific antiviral responses. Airway epithelial cells express FOXO3a and play an important role in clearing rhinovirus (RV) by mounting antiviral type I and type III interferon (IFN) responses. To elucidate the role of FOXO3a in regulating antiviral responses, we generated airway epithelial cell-specific Foxo3a knockout (Scga1b1-Foxo3a-/-) mice and a stable FOXO3a knockout human airway epithelial cell line. Compared to wild-type, Scga1b1-Foxo3a-/- mice show reduced IFN-α, IFN-β, IFN-λ2/3 in response to challenge with RV or double-stranded (ds)RNA mimic, Poly Inosinic-polycytidylic acid (Poly I:C) indicating defective dsRNA receptor signaling. RV-infected Scga1b1-Foxo3a-/- mice also show viral persistence, enhanced lung inflammation and elevated pro-inflammatory cytokine levels. FOXO3a K/O airway epithelial cells show attenuated IFN responses to RV infection and this was associated with conformational change in mitochondrial antiviral signaling protein (MAVS) but not with a reduction in the expression of dsRNA receptors under unstimulated conditions. Pretreatment with MitoTEMPO, a mitochondrial-specific antioxidant corrects MAVS conformation and restores antiviral IFN responses to subsequent RV infection in FOXO3a K/O cells. Inhibition of oxidative stress also reduces pro-inflammatory cytokine responses to RV in FOXO3a K/O cells. Together, our results indicate that FOXO3a plays a critical role in regulating antiviral responses as well as limiting pro-inflammatory cytokine expression. Based on these results, we conclude that FOXO3a contributes to optimal viral clearance and prevents excessive lung inflammation following RV infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cells, Cultured
  • Cytokines / immunology
  • Epithelial Cells / immunology*
  • Epithelial Cells / virology
  • Female
  • Forkhead Box Protein O3 / immunology*
  • Gene Expression Regulation / immunology
  • Immunity, Innate / immunology*
  • Interferons / immunology
  • Male
  • Mice
  • Mice, Knockout
  • Picornaviridae Infections / immunology*
  • Picornaviridae Infections / virology
  • Poly I-C / immunology
  • Respiratory Mucosa / immunology*
  • Respiratory Mucosa / virology
  • Rhinovirus / immunology*

Substances

  • Cytokines
  • Forkhead Box Protein O3
  • FoxO3 protein, mouse
  • Interferons
  • Poly I-C