Group 3 innate lymphoid cells secret neutrophil chemoattractants and are insensitive to glucocorticoid via aberrant GR phosphorylation

Respir Res. 2023 Mar 23;24(1):90. doi: 10.1186/s12931-023-02395-5.

Abstract

Background: Patients with neutrophil-mediated asthma have poor response to glucocorticoids. The roles and mechanisms of group 3 innate lymphoid cells (ILC3s) in inducing neutrophilic airway inflammation and glucocorticoid resistance in asthma have not been fully clarified.

Methods: ILC3s in peripheral blood were measured by flow cytometry in patients with eosinophilic asthma (EA) and non-eosinophilic asthma (NEA). ILC3s were sorted and cultured in vitro for RNA sequencing. Cytokines production and signaling pathways in ILC3s after IL-1β stimulation and dexamethasone treatment were determined by real-time PCR, flow cytometry, ELISA and western blot.

Results: The percentage and numbers of ILC3s in peripheral blood was higher in patients with NEA compared with EA, and negatively correlated with blood eosinophils. IL-1β stimulation significantly enhanced CXCL8 and CXCL1 production in ILC3s via activation of p65 NF-κB and p38/JNK MAPK signaling pathways. The expression of neutrophil chemoattractants from ILC3s was insensitive to dexamethasone treatment. Dexamethasone significantly increased phosphorylation of glucocorticoid receptor (GR) at Ser226 but only with a weak induction at Ser211 residues in ILC3s. Compared to human bronchial epithelial cell line (16HBE cells), the ratio of p-GR S226 to p-GR S211 (p-GR S226/S211) was significantly higher in ILC3s at baseline and after dexamethasone treatment. In addition, IL-1β could induce Ser226 phosphorylation and had a crosstalk effect to dexamethasone via NF-κB pathway.

Conclusions: ILC3s were elevated in patients with NEA, and associated with neutrophil inflammation by release of neutrophil chemoattractants and were glucocorticoid (GC) resistant. This paper provides a novel cellular and molecular mechanisms of neutrophil inflammation and GC-resistance in asthma. Trial registration The study has been prospectively registered in the World Health Organization International Clinical Trials Registry Platform (ChiCTR1900027125).

Keywords: Asthma; Glucocorticoid resistant; Group 3 innate lymphoid cells; Neutrophil chemoattractant; Neutrophilic inflammation.

MeSH terms

  • Asthma* / drug therapy
  • Asthma* / metabolism
  • Bronchi / metabolism
  • Dexamethasone / pharmacology
  • Glucocorticoids* / pharmacology
  • Glucocorticoids* / therapeutic use
  • Humans
  • Immunity, Innate
  • Inflammation / drug therapy
  • Lymphocytes / metabolism
  • NF-kappa B / metabolism
  • Neutrophils / metabolism
  • Phosphorylation
  • Receptors, Glucocorticoid

Substances

  • Glucocorticoids
  • Receptors, Glucocorticoid
  • NF-kappa B
  • Dexamethasone

Supplementary concepts

  • Glucocorticoid Receptor Deficiency