Covalent binding of C3b to monoclonal antibodies selectively up-regulates heavy chain epitope recognition by T cells.

Détails

ID Serval
serval:BIB_A178295983A8
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Covalent binding of C3b to monoclonal antibodies selectively up-regulates heavy chain epitope recognition by T cells.
Périodique
European Journal of Immunology
Auteur⸱e⸱s
Santoro L., Drouet C., Reboul A., Mach J.P., Colomb M.G.
ISSN
0014-2980 (Print)
ISSN-L
0014-2980
Statut éditorial
Publié
Date de publication
1994
Peer-reviewed
Oui
Volume
24
Numéro
7
Pages
1620-1626
Langue
anglais
Résumé
Protein C3 of the complement system is known for its role in the nonspecific immune response. Covalent binding of C3b to antigen upon complement activation also plays a significant role in specific T cell immune response. C3b-antigen complexes can bind to complement receptors on the antigen-presenting cell, and the C3b antigen link (most often an ester link) remains fairly stable inside the cells. In this study, IgG1,kappa and IgG2a,kappa murine monoclonal antibodies (mAb) were used as antigens; covalent complexes between mAb and C3b were produced and purified in vitro from purified proteins; human B cell lines and T cell clones were raised from tumor patients who received mAb injections for cancer therapy or diagnosis. Recognition of epitopes of these mAb by T cell clones when the mAb were processed alone or bound to C3b was compared. IgG or IgG-C3b complexes presented by B cell lines were able to stimulate proliferation of kappa light chain-specific T cell clones at similar concentrations. In contrast, IgG-C3b complex recognition by heavy chain-specific T cell clones required 100-fold less IgG-C3b than uncomplexed IgG. As C3b was shown to be covalently bound only to the IgG heavy chains in the complexes, C3b chaperoning is restricted to only the IgG heavy chain and selectively influences intracellular steps of IgG heavy chain processing. This differential modulation of C3b suggests an early dissociation of IgG heavy and light chains in antigen-presenting cells.
Mots-clé
Animals, Antibodies, Monoclonal/metabolism, Antigen-Antibody Complex/immunology, B-Lymphocytes/immunology, Cells, Cultured, Complement C3b/metabolism, Humans, Immunoblotting, Immunoglobulin G/immunology, Immunoglobulin G/metabolism, Immunoglobulin Heavy Chains/immunology, Immunoglobulin Heavy Chains/metabolism, Lymphocyte Activation, Mice, Radioligand Assay, T-Lymphocytes/immunology, Up-Regulation
Pubmed
Web of science
Création de la notice
18/11/2009 11:43
Dernière modification de la notice
20/08/2019 15:07
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