Amplification of the synovial inflammatory response through activation of mitogen-activated protein kinases and nuclear factor kappaB using ligation of CD40 on CD14+ synovial cells from patients with rheumatoid arthritis

Arthritis Rheum. 2004 Jul;50(7):2167-77. doi: 10.1002/art.20340.


Objective: To determine the signal transduction pathways in CD14+ synovial cells from patients with rheumatoid arthritis (RA) after CD40 ligation, and to examine their role in amplifying synovial inflammation in affected joints.

Methods: Expression of messenger RNA was analyzed using quantitative reverse transcription-polymerase chain reaction. Cytokines and chemokines were measured using enzyme-linked immunosorbent assay. Activation of kinases was detected using Western blotting. Nuclear translocation of NF-kappaB was examined using immunohistochemistry. CD14+ synovial cells were enriched using magnetic cell sorting. Fibroblast-like synoviocytes (FLS) were obtained by passaging primary synovial cell culture.

Results: Stimulation of CD14+ synovial cells from RA patients by recombinant soluble CD154 (rsCD154) significantly induced expression of tumor necrosis factor alpha (TNFalpha), interleukin-1alpha (IL-1alpha), and IL-1beta. CD14+ RA synovial cells stimulated with rsCD154 plus interferon-gamma (IFNgamma) induced significantly higher production of IL-6, IL-8, and monocyte chemoattractant protein 1 by FLS compared with unstimulated CD14+ synovial cells, through TNFalpha-, IL-1alpha-, and IL-1beta-mediated pathways. Stimulation with rsCD154 plus IFNgamma induced the activation of ERK-1/2, p38 MAPK, and NF-kappaB. Specific inhibitors of MAPK/ERK-1/2 kinases and p38 MAPK significantly reduced the production of TNFalpha and IL-1beta by rsCD154 plus IFNgamma-stimulated CD14+ synovial cells, and also inhibited production of these cytokines by freshly isolated synovial cells from RA patients.

Conclusion: These data indicate that the CD40-CD154 interaction activates the ERK, p38, and NF-kappaB pathways in CD14+ synovial cells from RA patients to produce TNFalpha, IL-1alpha, and IL-1beta, which in turn amplifies inflammatory responses by stimulating FLS. Inhibition of the CD40-CD154 interaction or its signal transduction pathways would be a strong and efficient strategy for the management of synovial inflammation in RA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arthritis, Rheumatoid / complications
  • Arthritis, Rheumatoid / metabolism*
  • Arthritis, Rheumatoid / pathology
  • Biological Transport / drug effects
  • CD40 Ligand / chemistry
  • CD40 Ligand / genetics
  • CD40 Ligand / metabolism*
  • CD40 Ligand / pharmacology
  • Cells, Cultured
  • Cytokines / metabolism
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Female
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Humans
  • Interferon-gamma / pharmacology
  • Lipopolysaccharide Receptors / metabolism*
  • Middle Aged
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism*
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / metabolism*
  • Osteoarthritis / metabolism
  • Phosphorylation / drug effects
  • RNA, Messenger / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / pharmacology
  • Signal Transduction
  • Solubility
  • Synovial Membrane / drug effects
  • Synovial Membrane / metabolism*
  • Synovial Membrane / pathology
  • Synovitis / etiology
  • Synovitis / metabolism*
  • Synovitis / pathology


  • Cytokines
  • Enzyme Inhibitors
  • Lipopolysaccharide Receptors
  • NF-kappa B
  • RNA, Messenger
  • Recombinant Proteins
  • CD40 Ligand
  • Interferon-gamma
  • Mitogen-Activated Protein Kinases