Cytotoxic effects of antibodies to proteinase 3 (C-ANCA) on human endothelial cells

Clin Exp Immunol. 1994 Sep;97(3):458-65. doi: 10.1111/j.1365-2249.1994.tb06110.x.


Autoantibodies directed against cytoplasmic antigens of neutrophils (ANCA), especially those with specificity for proteinase 3 (PR-3) and myeloperoxidase, are valuable markers for differential diagnosis and monitoring of disease activity in Wegener's granulomatosis (WG) and other vasculitides. Till now, several concepts concerning a direct role of antibodies against PR-3 in the pathogenesis of WG have been discussed. Recently we were able to show that these antibodies recognize PR-3 translocated into the membrane of human endothelial cells. The aim of this study was to investigate putative cytotoxic effects of antibodies to PR-3 on human endothelial cells. Antibodies were obtained by affinity purification of sera from patients with active WG. Purified antibodies to Ro (SS-A), La (SS-B) and RNP served as controls. Purified antibodies to PR-3 displayed a lytic activity against endothelial cells treated with tumour necrosis factor-alpha (TNF-alpha) with the help of cytokine-primed neutrophils as measured in a Cr-release assay. About 100% specific cytotoxicity occurred after 4 h and was independent of complement. Cytotoxic effects were inhibited by coincubation with unprimed neutrophils or preincubation of PR-3 antibodies with purified antigen. Antibodies to Ro (SS-A), La (SS-B) or RNP had no cytotoxic effect. In summary, PR-3 antibody-induced cytotoxicity required (i) expression of PR-3 on the surface of TNF-alpha-treated endothelial cells; and (ii) co-cultivation of cytokine-primed neutrophils. This is to the best of our knowledge the first report on direct cytotoxic effects of PR-3 antibodies on vascular endothelium. Our data give a hint at a PR-3 antibody-mediated mechanism of endothelial injury via antibody-dependent cellular cytotoxicity in WG and other ANCA-related vasculitides.

MeSH terms

  • Antibodies, Antineutrophil Cytoplasmic
  • Antibody-Dependent Cell Cytotoxicity / immunology*
  • Autoantibodies / immunology*
  • Autoantibodies / isolation & purification
  • Autoantigens / immunology*
  • Cells, Cultured
  • Chromatography, Affinity
  • Cytotoxicity, Immunologic / drug effects
  • Endothelium, Vascular / enzymology
  • Endothelium, Vascular / immunology*
  • Granulomatosis with Polyangiitis / enzymology
  • Granulomatosis with Polyangiitis / immunology*
  • Humans
  • Lupus Erythematosus, Systemic / immunology
  • Mixed Connective Tissue Disease / immunology
  • Myeloblastin
  • Serine Endopeptidases / immunology*
  • Sjogren's Syndrome / immunology


  • Antibodies, Antineutrophil Cytoplasmic
  • Autoantibodies
  • Autoantigens
  • Serine Endopeptidases
  • Myeloblastin