title: 25-Hydroxy vitamin D3 modulates dendritic cell phenotype and function in Crohn's disease.
abstract: BACKGROUND
  In Crohn's disease (CrD), vitamin D may help to balance an exaggerated immune response and thereby improve the disease course. The immunomodulating effects depend on the activation of 25-hydroxy vitamin D3 (25-D3), into 1,25-dihydroxy vitamin D3 (1,25-D3). This activation has previously been shown to take place in dendritic cells (DC) from healthy individuals. We hypothesised that DC from CrD patients are able to regulate and control inflammatory responses through 25-D3 activation.
  
  
  METHODS
  During differentiation, monocyte-derived DC from 20 CrD patients were cultured with either 25-D3 or 1,25-D3 and matured with lipopolysaccharide (LPS). We examined DC surface marker expression, cytokine production, and the ability to induce cell proliferation in an allogeneic mixed leukocyte reaction.
  
  
  RESULTS
  Following stimulation with LPS, DC exposed to either 25-D3 or 1,25-D3 exhibited lower expression levels of CD80, CD83, CD86, and HLA-DR and diminished TNF-α production compared with DC cultured with LPS alone. In contrast, CD14 expression and IL-6 production were higher following 25-D3 or 1,25-D3 treatment. Compared with LPS alone, both forms of vitamin D3 reduced the ability of DC to activate lymphocytes.
  
  
  CONCLUSIONS
  Following stimulation with 25-D3, DC from CrD patients displayed a reduced response to LPS with a diminished capability to activate T cells compared with DC stimulated with LPS alone. These data indicate that intrinsic activation of 25-D3 occurs in DC from CrD patients and show that 25-D3 can modulate DC function in CrD. Our data suggest that vitamin D deficiency may contribute to the uncontrolled inflammatory process seen in CrD.
authors: Department of Medicine V (Hepatology and Gastroenterology), Gastro-Immuno Research Laboratory (GIRL), Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus, Denmark. larsbart@rm.dk
authors: Lars E
authors: LE
authors: Bartels
authors: Søren P
authors: SP
authors: Jørgensen
authors: Mia
authors: M
authors: Bendix
authors: Christian L
authors: CL
authors: Hvas
authors: Jørgen
authors: J
authors: Agnholt
authors: Ralf
authors: R
authors: Agger
authors: Jens F
authors: JF
authors: Dahlerup
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000276:immunology; D002762:Cholecalciferol / Q000276:immunology* / Q000494:pharmacology; D003424:Crohn Disease / Q000097:blood / Q000276:immunology*; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D005260:Female; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D056747:Immunomodulation / Q000276:immunology*; D015850:Interleukin-6 / Q000276:immunology; D007962:Leukocytes / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D010641:Phenotype; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D055815:Young Adult
chemical_list: D015703:Antigens, CD; D006684:HLA-DR Antigens; D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D002762:Cholecalciferol