Autoantibodies developing to myeloperoxidase and proteinase 3 in systemic vasculitis stimulate neutrophil cytotoxicity toward cultured endothelial cells

Am J Pathol. 1992 Aug;141(2):335-42.


The ability of vasculitis-associated anti-neutrophil cytoplasm antibodies (ANCA) to activate neutrophils and mediate release of radiolabel from 111Indium-labeled cultured human umbilical vein endothelial cells (HUVEC) was determined as a measure of the potential cytotoxicity of ANCA-activated neutrophils against vascular endothelium. Priming of neutrophils with low doses of phorbol 12-myristate 13-acetate (PMA) (1 ng/ml) and ionomycin (0.1 mumol/1) was required, together with pretreatment of endothelial cells with BCNU (1,3-bis-[2-chloroethyl]-1-nitrosourea; 0.26 mmol/l). Under these conditions and using a 4-hour serum-free assay system, mouse monoclonal antibodies (MAb) to the target autoantigens proteinase-3 (Pr-3) and myeloperoxidase (MPO) mediated enhanced release of 111Indium from HUVEC compared with control MAb. Human IgG Fab2 C-ANCA (recognizing Pr-3) and P-ANCA (recognizing MPO) did likewise. Preactivation of HUVEC with TNF (50 U/ml, 4 hr) enhanced the release of 111Indium from HUVEC generated by neutrophils activated with anti-Pr-3 and anti-MPO MAb. These data support the suggestion that activation of neutrophils by ANCA within the vascular lumen may contribute to endothelial cell injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Antineutrophil Cytoplasmic
  • Antibodies, Monoclonal / immunology
  • Antibody Formation
  • Autoantibodies / immunology*
  • Carmustine / pharmacology
  • Cytotoxicity, Immunologic
  • Endothelium, Vascular / cytology*
  • Endothelium, Vascular / drug effects
  • Humans
  • Immunoglobulin Fab Fragments / immunology
  • Ionomycin / pharmacology
  • Myeloblastin
  • Neutrophils / immunology*
  • Neutrophils / physiology
  • Peroxidase / immunology*
  • Serine Endopeptidases / immunology*
  • Tetradecanoylphorbol Acetate / pharmacology
  • Tumor Necrosis Factor-alpha / pharmacology
  • Vasculitis / blood
  • Vasculitis / immunology*


  • Antibodies, Antineutrophil Cytoplasmic
  • Antibodies, Monoclonal
  • Autoantibodies
  • Immunoglobulin Fab Fragments
  • Tumor Necrosis Factor-alpha
  • Ionomycin
  • Peroxidase
  • Serine Endopeptidases
  • Myeloblastin
  • Tetradecanoylphorbol Acetate
  • Carmustine