title: In vivo effects of calcitriol on phenotypic and functional properties of dendritic cells.
abstract: BACKGROUND
  Dendritic cells (DCs) play a central role in the initiation and expansion of T cell mediated immune responses with potential immunotherapy application. The compounds which have the ability to induce immunomodulatory effects on DCs may be employed for the treatment of immunopathologic conditions such as autoimmune diseases.
  
  
  OBJECTIVE
  The aim of this study was to investigate the in vivo effects of calcitriol (active form of vitamin D3) on DCs.
  
  
  METHODS
  0.1 microgram calcitriol was injected intra-peritoneally into C57BL/6 mice every other day within 3 weeks, and spleen DCs were extracted by magnetic beads. The phenotypic and functional properties of DCs were studied by flow cytometry and mixed lymphocyte reaction (MLR), respectively.
  
  
  RESULTS
  The expression of CD86 and MHC II, as maturation markers and costimulatory molecules were significantly decreased (p=0.028 and p=0.047, respectively) while CD11b expression, as a marker of mice myeloid DCs which mostly induces Th2 cytokine profile, was significantly increased (p=0.011). Allogeneic T cell stimulation in MLR was also significantly inhibited in comparison with the control groups (p<0.05).
  
  
  CONCLUSIONS
  Our data indicate that in vivo calcitriol administration inhibits maturation and activation of DCs in the same manner as in vitro conditions.
authors.affiliation: Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Mohammad Mahdi
authors.initials: MM
authors.lastname: Eftekharian
authors.forename: Amir Hassan
authors.initials: AH
authors.lastname: Zarnani
authors.forename: Seyed-Mohammad
authors.initials: SM
authors.lastname: Moazzeni
mesh_terms: D000818:Animals; D051940:B7-2 Antigen / Q000235:genetics / Q000378:metabolism; D039481:CD11b Antigen / Q000235:genetics / Q000378:metabolism; D002117:Calcitriol / Q000008:administration & dosage*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D051940:B7-2 Antigen; D039481:CD11b Antigen; D000949:Histocompatibility Antigens Class II; D002117:Calcitriol