The Contribution of IgG Fc Glycans on Antibody-mediated Immune Suppression (AMIS) to Murine Erythrocytes

The ability of anti-D to prevent hemolytic disease of the fetus and newborn (HDFN) is an example of antibody-mediated immune suppression (AMIS). A recombinant monoclonal antibody to replace anti-D is desired, however, none of the developed therapies have been as effective and some antibodies have unexpectedly led to enhanced immune responses. The requirement for IgG glycosylation for AMIS was analyzed for five antibodies reactive with erythrocytes in a murine model. The antibodies recognized the HOD (hen egg lysozyme [HEL] linked to ovalbumin and the human Duffy transmembrane protein) antigen. It was observed that glycosylation in the Fc region of polyclonal AMIS-inducing antibodies was not essential for complete suppression. In contrast, monoclonal AMIS-inducing antibodies were partially sensitive to removal of the glycan structure. These results may help explain the superiority of polyclonal antibodies to monoclonal therapeutics for AMIS induction and could influence the development of effective therapies to replace anti-D.M.Sc.2018-01-09 00:00:0