title: Autoantibodies developing to myeloperoxidase and proteinase 3 in systemic vasculitis stimulate neutrophil cytotoxicity toward cultured endothelial cells.
abstract: 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.
authors.affiliation: Section of Vascular Biology, Royal Postgraduate Medical School, London, United Kingdom.
authors.forename: C O
authors.initials: CO
authors.lastname: Savage
authors.forename: B E
authors.initials: BE
authors.lastname: Pottinger
authors.forename: G
authors.initials: G
authors.lastname: Gaskin
authors.forename: C D
authors.initials: CD
authors.lastname: Pusey
authors.forename: J D
authors.initials: JD
authors.lastname: Pearson
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic; D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation; D001323:Autoantibodies / Q000276:immunology*; D002330:Carmustine / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D015759:Ionomycin / Q000494:pharmacology; D053146:Myeloblastin; D009504:Neutrophils / Q000276:immunology* / Q000502:physiology; D009195:Peroxidase / Q000276:immunology*; D012697:Serine Endopeptidases / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014657:Vasculitis / Q000097:blood / Q000276:immunology*
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D007140:Immunoglobulin Fab Fragments; D014409:Tumor Necrosis Factor-alpha; D015759:Ionomycin; D009195:Peroxidase; D012697:Serine Endopeptidases; D053146:Myeloblastin; D013755:Tetradecanoylphorbol Acetate; D002330:Carmustine