In Vitro Production of Anti-Neutrophilocyte-Cytoplasm-Antibodies (Anca) by Epstein-Barr Virus-Transformed B-Cell Lines in Wegener's Granulomatosis

Abstract

The frequent detection of anti-neutrophilocyte-cytoplasm-antibodies (ANCA) in patients with Wegener's granulomatosis (WG) led to the supposition that this disease might be of autoimmune nature. For some authors assume that Epstein-Barr virus (EBV) infection of human B-lymphocytes besides polyclonal activation could reveal the cryptic immune status against different autoantigens in patients with autoimmune diseases we investigated EBV-transformed B-lymphocytes from patients with Sjögren's syndrome, mixed connective tissue disease, WG and healthy blood donors. Two stable B-cell lines (Ho3, We1) could be established. Inhibition experiments showed that antibodies produced by transformed B-lymphocytes and serum ANCA (C-ANCA type) of 10 WG patients recognized the identical antigen. Stimulation of one clone (Ho3) with interleukin 6 (IL-6) led to a switch from IgM to IgG production. Antibodies produced by this clone also stained glomeruli of human frozen kidney sections. Western blot analysis using immunoaffinity purified antigen prepared from human granulocytes revealed a reaction with a protein of approx. 29 kD MW. Our data underscore some new aspects concerning the direct pathogenicity of C-ANCA confirming the hypothesis that the autoimmune B-cell repertoire in WG not only reflects a polyclonal B-cell activation but is shaped by antigen driven responses.