Human autoimmune anti‐proteinase 3 scFv from a phage display library

• Published in: Clinical and experimental immunology Vol. 107; no. 2; pp. 269 - 281
• Main Authors: FINNERN, R., PEDROLLO, E., FISCH, I., WIESLANDER, J., MARKS, J. D., LOCKWOOD, C. M., OUWEHAND, W. H.
• Format: Journal Article
• Language: English
• Published: Oxford BSL Blackwell Science Ltd 01.02.1997; Blackwell; Blackwell Science Inc
• Subjects: Amino Acid Sequence; Autoantigens - immunology; Autoimmunity - genetics; autoimmunity proteinase 3; Bacteriophages - genetics; Base Sequence; Biological and medical sciences; Gene Library; General aspects; Genes, Immunoglobulin; Granulomatosis with Polyangiitis - immunology; human V gene phage display libraries; Humans; Immunoglobulin Fragments - analysis; Immunoglobulin Heavy Chains - genetics; Immunoglobulin Variable Region - genetics; Immunopathology; Male; Medical sciences; Middle Aged; Molecular Sequence Data; Myeloblastin; Original; scFv antibody fragment; Serine Endopeptidases - immunology; Human; Immunopathology; Serine endopeptidases; Enzyme; Antibody; Variable region; Autoantibody; Autoimmune disease; Fv-Fragment; Virus; Peptidases; Gene; Immunologic repertory; Hydrolases; Myeloblastin; Phage
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.1997.254-ce1127.x

This is the first study describing recombinant human antibody fragments directed to the autoantigen proteinase 3 (PR3) from an immune B cell source. Detection of these autoantibodies has proven valid for the diagnosis and monitoring of Wegener's granulomatosis. The described antibody fragment (scFv) was isolated from a phage display library prepared from the IgG‐positive splenic lymphocytes of a patient with systemic autoimmunity. The cloning strategy was designed to maintain the diversity of the antibody variable gene repertoire, and sequencing of several variable genes demonstrated that all major heavy and light chain families were represented. We found an over‐representation of particular heavy chain variable domains in splenic lymphocytes which differ from the ones frequently found in peripheral blood lymphocytes. It was possible to obtain specific scFv to PR3 after a single round of selection and the binding could be inhibited by the patients' sera. Although the antibody fragments in the splenic repertoire were found to be highly mutated, it was interesting to find that the selected scFv showed only limited somatic mutation. Furthermore, we could demonstrate that the removal of the mutations had no effect on binding specificity.