Functional studies with IgM and IgA immunoglobulins : binding to pIgR, FcαμR, FcμR, and CDC activities

© 2024 Scandinavian Societies for Pathology, Medical Microbiology and Immunology..

IgMs are the first antibodies produced by the immune system upon encounter of a possible pathogen and are one of five antibody subclasses in humans. For IgG, the most intensively studied antibody class, the N-linked glycosylation site located in the Fc-domain is directly involved in high affinity binding to the respective receptors and initiation of corresponding immune response. IgM molecules have five N-glycosylation sites and one N-glycosylation site in the J-chain, which can be incorporated in IgM or IgA molecules. There is only limited knowledge available concerning the function of these N-glycosylations in IgMs. To address this question, we produced IgM molecules lacking a particular N-glycosylation site and tested these variants as well as IgA molecules for binding to the known receptors: the polymeric immunoglobulin receptor (pIgR), the dual receptor for IgA and IgM, FcαμR, and the specific receptor for IgM, FcμR. The single glycosylation sites did not show an impact on expression and multimerization, except for variant N402Q, which could not be expressed. In SPR measurements, no major impact on the binding to the receptors by particular glycosylation sites could be detected. In cellular assays, deglycosylated variants showed some alterations in induction of CDC activity. Most strikingly, we observed also binding of IgA to the FcμR in the same affinity range as IgM, suggesting that this might have a physiological role. To further substantiate the binding of IgA to FcμR we used IgA from different origins and were able to confirm binding of IgA preparations to the FcμR.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:132

Enthalten in:

APMIS : acta pathologica, microbiologica, et immunologica Scandinavica - 132(2024), 4 vom: 12. März, Seite 277-288

Sprache:

Englisch

Beteiligte Personen:

Beyer, Hanna [VerfasserIn]
Sommerfeld, Mark [VerfasserIn]
Grandien, Kaj [VerfasserIn]
Faust, Christine [VerfasserIn]
Tillmann, Bodo [VerfasserIn]
Leuschner, Wulf Dirk [VerfasserIn]
Régnier-Vigouroux, Anne [VerfasserIn]
Weil, Sandra [VerfasserIn]
Rao, Ercole [VerfasserIn]
Langer, Thomas [VerfasserIn]

Links:

Volltext

Themen:

CDC
Deglycosylation
FcμR
IgA
IgM
Immunoglobulin A
Immunoglobulin M
Journal Article
Protein engineering
Receptor binding
Receptors, Fc
Receptors, Polymeric Immunoglobulin

Anmerkungen:

Date Completed 14.03.2024

Date Revised 14.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/apm.13377

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367226103