title: Ligation of CD40 induced tumor necrosis factor-alpha in rheumatoid arthritis: a novel mechanism of activation of synoviocytes.
abstract: OBJECTIVE
  To determine the immunopathological significance of CD40/CD40 ligand (CD40L) interaction in rheumatoid arthritis (RA).
  
  
  METHODS
  The expression of CD40 ligand (CD40L) in synovial tissues (ST) from patients with RA was examined by immunohistochemistry. Tumor necrosis factor-alpha (TNF-alpha) was measured by ELISA. Expression of CD40 on ST cells was quantified by anti-CD40 monoclonal antibodies and 125I labelled anti-mouse IgG.
  
  
  RESULTS
  Immunohistochemistry showed CD40L+ T cells in RA ST. Ligation of CD40 on RA ST cells significantly increased the production of TNF-alpha in a dose dependent fashion. Adherent, but not non-adherent, fraction of ST cells responded to ligation of CD40 to produce TNF-alpha. Interferon-gamma (IFN-gamma), interleukin 4 (IL-4), or IL-13 acted synergistically with CD40 ligation to enhance TNF-alpha production by ST cells. IL-10 exerted inhibitory effects on both CD40 ligation induced and CD40 ligation plus IFN-gamma induced TNF-alpha production by ST cells.
  
  
  CONCLUSIONS
  These data indicate activated T cells participate in synovial inflammation of RA via CD40L to stimulate the production of TNF-alpha by ST cells. The effect of CD40 ligation is modulated by the presence of several cytokines, e.g., IFN-gamma, IL-4, IL-10, and IL-13.
authors.affiliation: Institute of Rheumatology, Tokyo Women's Medical University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Harigai
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: S
authors.initials: S
authors.lastname: Nakazawa
authors.forename: C
authors.initials: C
authors.lastname: Fukasawa
authors.forename: S
authors.initials: S
authors.lastname: Ohta
authors.forename: T
authors.initials: T
authors.lastname: Sugiura
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: S
authors.initials: S
authors.lastname: Kashiwazaki
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D019013:CD40 Antigens / Q000378:metabolism; D023201:CD40 Ligand; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000378:metabolism*; D013583:Synovial Membrane / Q000378:metabolism / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D019013:CD40 Antigens; D016207:Cytokines; D008562:Membrane Glycoproteins; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D023201:CD40 Ligand