title: Vitamin D receptor agonists inhibit pro-inflammatory cytokine production from the respiratory epithelium in cystic fibrosis.
abstract: BACKGROUND
  1,25-Dihydroxycholecalciferol (1,25(OH)(2)D(3)) has been shown to mitigate epithelial inflammatory responses after antigen exposure. Patients with cystic fibrosis (CF) are at particular risk for vitamin D deficiency. This may contribute to the exaggerated inflammatory response to pulmonary infection in CF.
  
  
  METHODS
  CF respiratory epithelial cell lines were exposed to Pseudomonas aeruginosa lipopolysaccharide (LPS) and Pseudomonas conditioned medium (PCM) in the presence or absence of 1,25(OH)(2)D(3) or a range of vitamin D receptor (VDR) agonists. Levels of IL-6 and IL-8 were measured in cell supernatants, and cellular total and phosphorylated IκBα were determined. Levels of human cathelicidin antimicrobial peptide (hCAP18) mRNA and protein were measured in cells after treatment with 1,25(OH)(2)D(3).
  
  
  RESULTS
  Pretreatment with 1,25(OH)(2)D(3) was associated with significant reductions in IL-6 and IL-8 protein secretion after antigen exposure, a finding reproduced with a range of low calcaemic VDR agonists. 1,25(OH)(2)D(3) treatment led to a decrease in IκBα phosphorylation and increased total cellular IκBα. Treatment with 1,25(OH)(2)D(3) was associated with an increase in hCAP18/LL-37 mRNA and protein levels.
  
  
  CONCLUSIONS
  Both 1,25(OH)(2)D(3) and other VDR agonists significantly reduce the pro-inflammatory response to antigen challenge in CF airway epithelial cells. VDR agonists have significant therapeutic potential in CF.
authors.affiliation: Department of Paediatric Respiratory Medicine, Adelaide and Meath Hospital incorporating the National Children's Hospital, Dublin 24, Ireland. paul.mcnally@olchc.ie
authors.forename: P
authors.initials: P
authors.lastname: McNally
authors.forename: C
authors.initials: C
authors.lastname: Coughlan
authors.forename: G
authors.initials: G
authors.lastname: Bergsson
authors.forename: M
authors.initials: M
authors.lastname: Doyle
authors.forename: C
authors.initials: C
authors.lastname: Taggart
authors.forename: L
authors.initials: L
authors.lastname: Adorini
authors.forename: M R
authors.initials: MR
authors.lastname: Uskokovic
authors.forename: B
authors.initials: B
authors.lastname: El-Nazir
authors.forename: P
authors.initials: P
authors.lastname: Murphy
authors.forename: P
authors.initials: P
authors.lastname: Greally
authors.forename: C M
authors.initials: CM
authors.lastname: Greene
authors.forename: N G
authors.initials: NG
authors.lastname: McElvaney
mesh_terms: D002117:Calcitriol / Q000494:pharmacology*; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000276:immunology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D016209:Interleukin-8 / Q000096:biosynthesis*; D018167:Receptors, Calcitriol / Q000819:agonists*; D020545:Respiratory Mucosa / Q000166:cytology* / Q000276:immunology*; D014815:Vitamins / Q000494:pharmacology*
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8; D018167:Receptors, Calcitriol; D014815:Vitamins; D002117:Calcitriol