title: Interferon-gamma protects against the development of structural damage in experimental arthritis by regulating polymorphonuclear neutrophil influx into diseased joints.
abstract: OBJECTIVE
  Local interaction between soluble mediators within the inflamed synovium is a key factor that governs the pathologic outcome of inflammatory arthritides. Our aim was to investigate the interplay between the Th1 lymphokine interferon-gamma (IFNgamma) and pivotal cytokines that drive rheumatoid arthritis (RA) pathology (interleukin-1beta [IL-1beta] and tumor necrosis factor alpha [TNFalpha]) in modulating inflammation and arthritis in vitro and in vivo.
  
  
  METHODS
  Monarticular antigen-induced arthritis (AIA) was initiated in IFNgamma-deficient (IFNgamma(-/-)) mice and age-matched wild-type (IFNgamma(+/+)) mice. Joint swelling was measured and histologic analysis was performed in order to assess changes in both inflammatory and degenerative parameters in vivo. In vitro, the influence of IFNgamma in regulating IL-1beta- and TNFalpha-driven CXCL8 and CCL2 production was quantified by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  In murine AIA, both inflammatory and degenerative arthritis parameters were significantly exacerbated in the absence of IFNgamma. IFNgamma appeared to be a crucial factor in regulating CXCR2+ neutrophil influx in the joint. In in vitro studies using RA fibroblast-like synoviocytes, IFNgamma modulated both IL-1beta- and TNFalpha-driven chemokine synthesis, resulting in the down-regulation of CXCL8 production.
  
  
  CONCLUSIONS
  IFNgamma exerts antiinflammatory, chondroprotective, and antiosteoclastogenic effects in murine AIA through a mechanism that involves the regulation of chemokine synthesis and local neutrophil recruitment. These studies suggest a potential therapeutic role of modulating IFNgamma signaling in the treatment of inflammatory arthritides.
authors.affiliation: Wales College of Medicine, Cardiff University, Heath Park, Cardiff, UK. wmdasw@cardiff.ac.uk
authors.forename: Anwen S
authors.initials: AS
authors.lastname: Williams
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Richards
authors.forename: Eleri
authors.initials: E
authors.lastname: Thomas
authors.forename: Sara
authors.initials: S
authors.lastname: Carty
authors.forename: Mari A
authors.initials: MA
authors.lastname: Nowell
authors.forename: Rhian M
authors.initials: RM
authors.lastname: Goodfellow
authors.forename: Colin M
authors.initials: CM
authors.lastname: Dent
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Williams
authors.forename: Simon A
authors.initials: SA
authors.lastname: Jones
authors.forename: Nicholas
authors.initials: N
authors.lastname: Topley
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000473:pathology*; D018450:Disease Progression; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000172:deficiency* / Q000502:physiology*; D007596:Joints / Q000098:blood supply* / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009504:Neutrophils / Q000502:physiology*
chemical_list: D007371:Interferon-gamma