Pulmonary Regnase-1 orchestrates the interplay of epithelium and adaptive immune systems to protect against pneumonia

Mucosal Immunol. 2018 Jul;11(4):1203-1218. doi: 10.1038/s41385-018-0024-5. Epub 2018 Apr 25.

Abstract

Inhaled pathogens including Pseudomonas aeruginosa initially encounter airway epithelial cells (AECs), which are poised to evoke cell-intrinsic innate defense, affecting second tier of hematopoietic cell-mediated immune reaction. However, it is largely unknown how pulmonary immune responses mediated by a variety of immune cells are coordinated. Here we show that Regnase-1, an endoribonuclease expressed in AECs and immune cells, plays an essential role in coordinating innate responses and adaptive immunity against P. aeruginosa infection. Intratracheal treatment of mice with heat-killed P. aeruginosa resulted in prolonged disappearance of Regnase-1 consistent with sustained expression of Regnase-1 target inflammatory genes, whereas the transcription factor NF-κB was only transiently activated. AEC-specific deletion of Regnase-1 not only augmented innate defenses against P. aeruginosa but also enhanced secretion of Pseudomonas-specific IgA and Th17 accumulation in the lung, culminating in conferring significant resistance against P. aeruginosa re-infection in vivo. Although Regnase-1 directly controls distinct sets of genes in each of AECs and T cells, degradation of Regnase-1 in both cell types is beneficial for maximizing acquired immune responses. Collectively, these results demonstrate that Regnase-1 orchestrates AEC-mediated and immune cell-mediated host defense against pulmonary bacterial infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity
  • Animals
  • Antibodies, Bacterial / metabolism
  • Immunity, Innate
  • Immunoglobulin A / metabolism
  • Lung / immunology*
  • Lung / microbiology
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NF-kappa B / metabolism
  • Pneumonia, Bacterial / immunology*
  • Pseudomonas Infections / immunology*
  • Pseudomonas aeruginosa / physiology*
  • Respiratory Mucosa / metabolism*
  • Ribonucleases / genetics
  • Ribonucleases / metabolism*
  • Signal Transduction
  • Th17 Cells / immunology*

Substances

  • Antibodies, Bacterial
  • Immunoglobulin A
  • NF-kappa B
  • Ribonucleases
  • Zc3h12a protein, mouse