title: Skewed Fc glycosylation profiles of anti-proteinase 3 immunoglobulin G1 autoantibodies from granulomatosis with polyangiitis patients show low levels of bisection, galactosylation, and sialylation.
abstract: Granulomatosis with polyangiitis (GPA) is associated with circulating immunoglobulin (Ig) G anti-proteinase 3 specific (anti-PR3) anti-neutrophil cytoplasm antibodies (ANCA), which activate cytokine primed neutrophils via Fcgamma receptors. ANCA are class switched IgG antibodies implying T cell help in their production. Glycosylation of IgG Fc, under the control of T cell cytokines, determines the interaction between IgG and its receptors. Previous studies have reported aberrant glycosylation of Ig Fc in GPA patients. We investigated whether aberrant Fc glycosylation was present on anti-PR3 ANCA as well as whole IgG subclass preparations compared to healthy controls and whether this correlated with Birmingham vasculitis activity scores (BVAS), serum cytokines, and time to remission. Here, IgG Fc glycosylation of GPA patients and controls and anti-PR3 ANCA Fc glycosylation were determined by mass spectrometry of glycopeptides. IgG1 and IgG2 subclasses from GPA patients showed reduced galactosylation, sialylation, and bisection compared to healthy controls. Anti-PR3 IgG1 ANCA Fc galactosylation, sialylation, and bisection were reduced compared to total IgG1 in GPA. Galactosylation of anti-PR3 ANCA Fc correlated with inflammatory cytokines and time to remission but not BVAS. Bisection of anti-PR3 ANCA Fc correlated with BVAS. Total IgG1 and anti-PR3 IgG1 Fc galactosylation were weakly correlated, while bisection of IgG1 and anti-PR3 showed no correlation. Our data indicate that aberrant ANCA galactosylation may be driven in an antigen-specific manner.
authors.affiliation: †Center for Proteomics and Metabolomics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.|‡Division of BioAnalytical Chemistry, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands.|§Department of Molecular Cell Biology and Immunology, VU University Medical Center, 1081 BT Amsterdam, The Netherlands.
authors.forename: Manfred
authors.initials: M
authors.lastname: Wuhrer
authors.affiliation: †Center for Proteomics and Metabolomics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.|‡Division of BioAnalytical Chemistry, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Stavenhagen
authors.affiliation: †Center for Proteomics and Metabolomics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
authors.forename: Carolien A M
authors.initials: CA
authors.lastname: Koeleman
authors.affiliation: †Center for Proteomics and Metabolomics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
authors.forename: Maurice H J
authors.initials: MH
authors.lastname: Selman
authors.affiliation: ⊥School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, U.K.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Harper
authors.affiliation: ¶Department of Immunology and Department of Neurology, Erasmus MC, University Medical Center Rotterdam, 3015 CE Rotterdam, The Netherlands.
authors.forename: Bart C
authors.initials: BC
authors.lastname: Jacobs
authors.affiliation: ⊥School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, U.K.
authors.forename: Caroline O S
authors.initials: CO
authors.lastname: Savage
authors.affiliation: ⊥School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, U.K.
authors.forename: Roy
authors.initials: R
authors.lastname: Jefferis
authors.affiliation: †Center for Proteomics and Metabolomics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
authors.forename: André M
authors.initials: AM
authors.lastname: Deelder
authors.affiliation: ⊥School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, U.K.
authors.forename: Matthew
authors.initials: M
authors.lastname: Morgan
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology / Q000378:metabolism*; D016207:Cytokines / Q000097:blood; D006031:Glycosylation; D014890:Granulomatosis with Polyangiitis / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism*; D013058:Mass Spectrometry; D008875:Middle Aged; D053146:Myeloblastin / Q000276:immunology*; D014657:Vasculitis / Q000473:pathology
chemical_list: D001323:Autoantibodies; D016207:Cytokines; D007074:Immunoglobulin G; D053146:Myeloblastin
keywords: autoantibody; glycopeptide; glycosylation; immunoglobulin; mass spectrometry