The Structural Role of N-Glycosylation in interactions between Antibodies and Receptors

Immunoglobulin G1 (IgG1) is the most abundant circulating human antibody and also the most common scaffold for therapeutic monoclonal antibodies (mAbs). The destruction of IgG-coated targets by cell-mediated pathways begins with an interaction between the IgG Fc region and multiple varieties of membrane-bound Fc g receptors (FcgRs) on the surface of leucocytes. This interaction requires the presence of an asparagine-linked (N-)glycan on the Fc. Furthermore, changes to the N-glycan composition are known to affect FcgR binding affinity. Our laboratory studies the role of N-glycosylation on the structure and function of IgG1 Fc and the FcgRs. This seminar will describe our efforts to characterize how the IgG N-glycan impacts affinity for the FcgRs and recent results describing the structural consequence and functional role of FcgR N-glycan composition.