Fig. 3: EndoS drives deglycosylation of human IVIG.
From: Pathogen-driven degradation of endogenous and therapeutic antibodies during streptococcal infections
Representative elution profiles of IgG glycopeptides based on extracted ion chromatograms (XIC) of the N-acetylglucosamine (GlcNAc) oxonium ion m/z 204.09, and purified from (a), infected mouse plasma 36 h p.i., (b) pharmaceutical-grade IVIGs, (c) infected mouse plasma spiked with IVIG and incubated ex-vivo, (d) plasma from IVIG-treated mice, (e) IVIG-treated mice challenged with wildtype GAS, (f) IVIG-treated mice challenged with EndoS (KO) GAS. Red stars denote truncated mouse IgG; black stars denote truncated human IgG. g Quantification of human IgG1 and IgG2 Fc- glycopeptides in plasma at 24 h p.i. and derived from mice infected with wildtype vs EndoS (KO) GAS strains and treated with IVIG (n = 4 mice/condition). Statistical significance is denoted with starts and was assessed by two-sided Student’s t-test (p < 0.05). Upper whisker extends from the hinge to the largest value no further than 1.5 * IQR from the hinge (where IQR is the inter-quartile range). The lower whisker extends from the hinge to the smallest value, at most 1.5 * IQR of the hinge. Data beyond the end of the whiskers are called outliers and are plotted individually. h Human IgG levels circulating in mouse plasma.
