title: Vitamin D modulates the expression of HLA-DR and CD38 after in vitro activation of T-cells.
abstract: OBJECTIVE
  Vitamin D (VitD) is an anti-inflammatory hormone; however, some evidence shows that VitD may induce the expression of activation markers, such as CD38 and HLA-DR. We explored its effect on the expression of these markers on CD4+ and CD8+ T-cells in vitro, and their potential correlations in vivo.
  
  
  METHODS
  CD38 and HLA-DR expression was measured by flow cytometry in PHA/IL-2-activated mononuclear cells cultured under VitD precursors: three cholecalciferol (10-11M, 10-9M, 10-7M; n=11) and two calcidiol (40 ng/mL, 80 ng/mL; n=9) concentrations. The correlation between the expression of these markers in freshly isolated blood cells and serum levels of calcidiol was also explored (n=10).
  
  
  RESULTS
  Cholecalciferol at 10-7M increased the proportion of CD4+ CD38+ and CD8+ CD38+ cells, and decreased CD8+HLA-DR+ cells. As co-expression, it increased the CD38+HLA-DR- and decreased CD38-HLA-DR+ subpopulations in both CD4+ and CD8+ T-cells, and decreased CD4+CD38-HLA-DR- and CD8+ CD38+HLA-DR+; whereas both calcidiol concentrations decreased the proliferation of CD38-HLA-DR- and CD38-HLA-DR+ subpopulations. Both forms of VitD increased the number of CD38 molecules per cell. In contrast, there was a positive but non-significant correlation between serum calcidiol levels and the expression of CD38 and HLA-DR in CD4+ and CD8+ T-cells.
  
  
  CONCLUSIONS
  Although no significant correlations were observed in vivo in healthy subjects, VitD treatment in vitro modulated immune activation by increasing the expression of CD38 and decreasing the proliferation of HLA-DR+ and resting cells, which may correlate with improved effector and decreased proliferative capabilities. These results highlight the potential use of VitD as therapeutic strategy in immune disorders.
authors.forename: Simon
authors.initials: S
authors.lastname: Villegas-Ospina
authors.forename: Wbeimar
authors.initials: W
authors.lastname: Aguilar-Jimenez
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Gonzalez
authors.forename: María T
authors.initials: MT
authors.lastname: Rugeles
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects*; D006684:HLA-DR Antigens / Q000378:metabolism*; D006801:Humans; D016130:Immunophenotyping; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D014807:Vitamin D / Q000494:pharmacology*; D014815:Vitamins / Q000494:pharmacology
chemical_list: D006684:HLA-DR Antigens; D014815:Vitamins; D014807:Vitamin D; D051997:ADP-ribosyl Cyclase 1