Antigen binding to secretory immunoglobulin A results in decreased sensitivity to intestinal proteases and increased binding to cellular Fc receptors.

Détails

ID Serval
serval:BIB_CA5206798A40
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Antigen binding to secretory immunoglobulin A results in decreased sensitivity to intestinal proteases and increased binding to cellular Fc receptors.
Périodique
Journal of Biological Chemistry
Auteur(s)
Duc M., Johansen F.E., Corthésy B.
ISSN
1083-351X[electronic], 0021-9258[linking]
Statut éditorial
Publié
Date de publication
2010
Volume
285
Numéro
2
Pages
953-960
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
In intestinal secretions, secretory IgA (SIgA) plays an important sentinel and protective role in the recognition and clearance of enteric pathogens. In addition to serving as a first line of defense, SIgA and SIgA x antigen immune complexes are selectively transported across Peyer's patches to underlying dendritic cells in the mucosa-associated lymphoid tissue, contributing to immune surveillance and immunomodulation. To explain the unexpected transport of immune complexes in face of the large excess of free SIgA in secretions, we postulated that SIgA experiences structural modifications upon antigen binding. To address this issue, we associated specific polymeric IgA and SIgA with antigens of various sizes and complexity (protein toxin, virus, bacterium). Compared with free antibody, we found modified sensitivity of the three antigens assayed after exposure to proteases from intestinal washes. Antigen binding further impacted on the immunoreactivity toward polyclonal antisera specific for the heavy and light chains of the antibody, as a function of the antigen size. These conformational changes promoted binding of the SIgA-based immune complex compared with the free antibody to cellular receptors (Fc alphaRI and polymeric immunoglobulin receptor) expressed on the surface of premyelocytic and epithelial cell lines. These data reveal that antigen recognition by SIgA triggers structural changes that confer to the antibody enhanced receptor binding properties. This identifies immune complexes as particular structural entities integrating the presence of bound antigens and adds to the known function of immune exclusion and mucus anchoring by SIgA.
Mots-clé
Animals, Antigen-Antibody Complex/immunology, Antigen-Antibody Complex/metabolism, Antigens/immunology, Antigens/metabolism, Antigens, CD/immunology, Antigens, CD/metabolism, Biological Transport/immunology, Immunoglobulin A/immunology, Immunoglobulin A/metabolism, Mice, Mice, Inbred BALB C, Peptide Hydrolases/immunology, Peptide Hydrolases/metabolism, Peyer's Patches/enzymology, Peyer's Patches/immunology, Receptors, Fc/immunology, Receptors, Fc/metabolism, Receptors, Polymeric Immunoglobulin/immunology, Receptors, Polymeric Immunoglobulin/metabolism
Pubmed
Web of science
Création de la notice
26/01/2010 16:10
Dernière modification de la notice
03/03/2018 21:24
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