Lysis of Fibrillar Collagen by Neutrophils in Synovial Fluid. A Role for Surface-Bound Immunoglobulins

Arthritis Rheum. 1990 Sep;33(9):1333-9. doi: 10.1002/art.1780330905.

Abstract

Synovial fluids (SF) contain inhibitors capable of neutralizing the activity of proteases secreted by inflammatory cells and fibroblasts. To further define a potential role for SF polymorphonuclear neutrophils (PMN) in mediating joint destruction, peripheral blood PMN were suspended in SF and incubated with reconstituted collagen fibrils. Incubation of PMN-SF mixtures with collagen fibrils precoated with monomeric IgG resulted in significant lysis of the underlying fibrils relative to that seen with uncoated fibrils. Augmented fibril lysis by PMN-SF mixtures in which the PMN were activated with fluid-phase ligands such as phorbol myristate acetate or heat-aggregated IgG was not seen. Lysis of IgG-coated fibrils by PMN-SF was inhibited in the presence of EDTA or sodium azide. PMN-mediated resorption of fibrillar collagen occurred despite the presence of protease inhibitors in the SF at a concentration capable of neutralizing human neutrophil collagenase. These results suggest that the focal release and activation of human neutrophil collagenase during PMN stimulation by tissue-bound immunoglobulins may mediate the resorption of joint tissue collagens in rheumatoid arthritis, even in the presence of protease inhibitors.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Azides / pharmacology
  • Collagen / metabolism*
  • Edetic Acid / pharmacology
  • Humans
  • Immunoglobulin G / pharmacology
  • Immunoglobulin G / physiology
  • Ligands
  • Microbial Collagenase / metabolism
  • Neutrophils / immunology*
  • Rats
  • Sodium Azide
  • Synovial Fluid / cytology*

Substances

  • Azides
  • Immunoglobulin G
  • Ligands
  • Collagen
  • Sodium Azide
  • Edetic Acid
  • Microbial Collagenase