IgG subclass and vaccination stimulus determine changes in antigen specific antibody glycosylation in mice

Abstract

Immunoglobulin G (IgG) glycosylation can modulate antibody effector functions. Depending on the precise composition of the sugar moiety attached to individual IgG glycovariants either pro- or anti-inflammatory effector pathways can be initiated via differential binding to type I or type II Fc-receptors. However, an in depth understanding of how individual IgG subclasses are glycosylated during the steady state and how their glycosylation pattern changes during vaccination is missing. To monitor IgG subclass glycosylation during the steady state and upon vaccination of mice with different T-cell dependent and independent antigens, tryptic digests of serum, and antigen-specific IgG preparations were analyzed by reversed phase-liquid chromatography-mass spectrometry. We show that there is a remarkable difference with respect to how individual IgG subclasses are glycosylated during the steady state. More importantly, upon T-cell dependent and independent vaccinations, individual antigen-specific IgG subclasses reacted differently with respect to changes in individual glycoforms, suggesting that the IgG subclass itself is a major determinant of restricting or allowing alterations in specific IgG glycovariants.

Fc-Linked IgG N-Glycosylation in FcγR Knock-Out Mice

“…Finally, the cohort of mice used in this experiment was healthy and immunologically not stimulated. Since IgG glycosylation in mice is known to change following immune activation (Oefner et al, 2012;Hess et al, 2013;Kao et al, 2017), the results might have been different if the study had been performed on immune-stimulated and challenged mice. Studying an adaptive immune response in individual FcγR knock-out mice in vivo, however, creates a high complex scenario.…”

Selective induction of antibody effector functional responses using MF59-adjuvanted vaccination

“…MF59 induces a unique functional humoral response. Emerging data suggest that adjuvants may induce higher antibody titers and enhanced affinity maturation and may shape the Fc-profile of antibodies (31). To initially define whether adjuvants also shape influenza-specific humoral immune responses, we applied a systems serology (30) approach to broadly and comprehensively profile the functional and Fc-biophysical profiles of antibodies generated by vaccinees receiving pandemic influenza H5 immunization alone or adjuvanted with MF59 or alum.…”

Endoglycosidase S Enables a Highly Simplified Clinical Chemistry Procedure for Direct Assessment of Serum IgG Undergalactosylation in Chronic Inflammatory Disease

“…There seems to be no consensus on the choice of glycans for calculating the level of galactosylation. Often, the peak height or area of NGA2F (also known as G0F, sometimes just G0) is used, most often normalized to the total signal or to the monogalactosylated glycan peak NG1A2F (G1F, sometimes G1) (33,34). Another approach is to take the contribution of the galactosylation status of individual anten-nae on all glycans in the profile into account (35).…”