title: 1,25-dihydroxycholecalciferol enhances the expression of MHC class II antigens and intercellular adhesion molecule-1 by human renal tubular epithelial cells.
abstract: OBJECTIVE
  Beside its role in calcium and phosphorus metabolism, 1,25-dihydroxycholecalciferol (1,25-D3) exerts multiple effects on cytokine and major histocompatibility complex (MHC) class II expression in monocytes and lymphocytes. In different renal diseases tubular epithelial cells express MHC class II molecules and cell adhesion molecules,, such as intracellular adhesion molecule-1 (ICAM-1). Therefore, modulation of MHC class II and ICAM-1 expression in renal tubular epithelial cells by 1,25-D3 may be relevant to lymphocyte adhesion to tubular epithelial cells and immune mediated renal injury. However, the expression of MHC class II antigens and cellular adhesion molecules by renal tubular epithelial cells in response to 1,25-D3 has not been investigated.
  
  
  METHODS
  We generated human renal tubular epithelial cells and SV40 transfected tubular epithelial cells to investigate immune modulation of 1,25 on renal epithelial cells. Major histocompatibility complex class II molecules and ICAM-1 were detected by a specific enzyme linked immunoassay.
  
  
  RESULTS
  We found a dose-dependent increase of both constitutive and induced MHC class II and ICAM-1 expression in tubular epithelial cells stimulated with 1,25-D3. Dose-dependent stimulation of MHC class II and ICAM-1 expression was not restricted to primary human renal tubular epithelial cells but was also detected in SV40 transfected cells.
  
  
  CONCLUSIONS
  Expression of MHC class II and ICAM-1 is crucial for antigen presentation by and lymphocyte adhesion to renal tubular epithelial cells. Modulatory effects of 1,25-D3 on immune accessory function of renal tubular epithelial cells may be of clinical significance in renal diseases.
authors.affiliation: Department of Internal Medicine, Medical University of Lübeck, Lübeck, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Kreft
authors.forename: S
authors.initials: S
authors.lastname: Brzoska
authors.forename: C
authors.initials: C
authors.lastname: Doehn
authors.forename: M R
authors.initials: MR
authors.lastname: Daha
authors.forename: F J
authors.initials: FJ
authors.lastname: Van Der Woude
authors.forename: K
authors.initials: K
authors.lastname: Sack
mesh_terms: D002117:Calcitriol / Q000494:pharmacology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis*; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D013539:Simian virus 40; D014162:Transfection
chemical_list: D000949:Histocompatibility Antigens Class II; D018799:Intercellular Adhesion Molecule-1; D002117:Calcitriol