Glycans influence IgE and IgG recognition by rodent IgG-Fc receptors.

Authors

Shirui Xu, Shuo Du, Meijie Deng, Guanbo Wang, Junyu Xiao

Published in

Proceedings of the National Academy of Sciences of the United States of America. Volume 123. Issue 38. Pages e2609841123. Sep 22, 2026. Epub Sep 16, 2026.

Abstract

Immunoglobulin E (IgE) drives allergic responses. The IgE-Fc (Fcε) receptor FcεRI plays a critical role in transducing IgE signaling; nevertheless, certain IgG-Fc (Fcγ) receptor (FcγR) can also bind IgE in murine models. Here, we characterize FcγR interactions with IgE and IgG in mice and rats, and report cryoelectron microscopy structures of rat FcγRIV-Fcε, mouse FcγRIV-Fcγ2b, and rat FcγRIIB-Fcε complexes. Together with biochemical analyses, we reveal N-linked glycans as critical determinants of affinity and isotype specificity. Specifically, rat FcγRIV exhibits preferential binding to IgE over IgG, while mouse FcγRIV shows the opposite preference. A unique glycan-glycan interaction involving Asn179 in rat FcγRIV underlies its high-affinity IgE binding, whereas the absence of this glycosylation site in rat FcγRIIB results in attenuated IgE recognition. In contrast, only hypoglycosylated mouse FcγRIV at the equivalent position engages strongly with fucosylated IgG2b. Together, these results provide insights into species-specific IgE- and IgG-mediated immune responses.

PMID:
42748145
Bibliographic data and abstract were imported from PubMed on 17 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.