title: Induction of HLA-DR antigen expression on human colonic epithelium by tumor necrosis factor-alpha and interferon-gamma.
abstract: BACKGROUND
  We investigated the effects of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on HLA-DR expression on human normal colonic epithelium, using an organ culture technique.
  
  
  METHODS
  Biopsy specimens from normal colonic mucosa were cultured for 24 h with various concentrations of TNF-alpha and/or IFN-gamma. Epithelial HLA-DR antigens were identified by an indirect immunoperoxidase staining method.
  
  
  RESULTS
  No expression of epithelial HLA-DR antigens was observed in specimens cultured with medium alone. Concentrations of 10(3) U/ml or higher of TNF-alpha and 10(2) U/ml or higher of IFN-gamma induced expression of HLA-DR antigens in a dose-dependent manner. Expression of HLA-DR was increased in specimens cultured with both TNF-alpha and IFN-gamma compared with those cultured with either cytokine alone.
  
  
  CONCLUSIONS
  Our findings suggest that both TNF-alpha and IFN-gamma play important roles in regulating the expression of HLA-DR on colonic epithelium in patients with inflammatory bowel disease.
authors.affiliation: First Dept. of Internal Medicine, Akita University School of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ishii
authors.forename: M
authors.initials: M
authors.lastname: Chiba
authors.forename: M
authors.initials: M
authors.lastname: Iizuka
authors.forename: Y
authors.initials: Y
authors.lastname: Horie
authors.forename: O
authors.initials: O
authors.lastname: Masamune
mesh_terms: D000368:Aged; D012809:Colon, Sigmoid / Q000187:drug effects / Q000378:metabolism*; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006684:HLA-DR Antigens / Q000096:biosynthesis* / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009924:Organ Culture Techniques; D012007:Rectum / Q000187:drug effects / Q000378:metabolism*; D013194:Staining and Labeling; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D006684:HLA-DR Antigens; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma