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Changes in IgG sialylation and glycosylation in pulmonary arterial hypertension (1089.3)
Author(s) -
Morrow Rebekah,
Cioffi Eugene,
Murphy Frank,
Cioffi Donna
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1089.3
Subject(s) - sialic acid , glycosylation , glycan , sialidase , immunoglobulin g , chemistry , antibody , glycoprotein , biochemistry , microbiology and biotechnology , immunology , biology , neuraminidase , enzyme
Rationale: Anti‐endothelial cell antibodies are found in both idiopathic and connective tissue disease associated pulmonary arterial hypertension (PAH). IgG is the most abundant immunoglobulin and is heavily glycosylated. Sialic acid is a monosaccharide often found on the end of glycan chains, and sialylation of IgG can alter IgG binding to its receptors. Changes in IgG sialylation and N‐linked glycan composition occur in numerous diseases, but it is unknown whether changes occur in PAH. We sought to determine whether IgG sialylation and glycosylation are altered in PAH patients, and if these changes affect IgG binding to endothelial cells (EC). Methods: We purified IgG from healthy volunteers (HV), idiopathic PAH (IPAH), or connective tissue disease‐associated PAH (CTD) patients. Lectin blots were used to analyze IgG sialic acid linkages and glycosylation residues. IgG was treated with sialidases to remove sialic acids or glycosidases to remove N‐linked glycans. The cleaved glycans were analyzed by ESI mass spectrometry. Both untreated IgG and sialidase‐treated IgG were used in a cell based ELISA to examine the effect of sialylation on IgG binding to EC. Results: Lectin blots and mass spec show marked differences between HV and PAH IgG. PAH IgG treated with sialidase has decreased binding to EC, whilst untreated PAH IgG has increased binding to EC as compared to HV IgG. These data suggest that sialylation and glycosylation differences in IgG from PAH patients affect binding to EC. Grant Funding Source : Supported by R01HL107778