Complement C3b fragment covalently linked to tetanus toxin increases lysosomal sodium dodecyl sulfate-stable HLA-DR dimer production
| Autor: | Françoise M. Gabert, Patrice N. Marche, François Cretin, Elsa Pépin, Vincent A. Serra |
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| Rok vydání: | 1997 |
| Předmět: |
Detergents
Immunology chemical and pharmacologic phenomena Peptide Complement receptor Biology Transfection Major histocompatibility complex chemistry.chemical_compound Tetanus Toxin Antigen HLA-DR Humans Immunology and Allergy Sodium dodecyl sulfate Cell Line Transformed chemistry.chemical_classification Antigen Presentation B-Lymphocytes MHC class II HLA-DR1 Antigen Histocompatibility Antigens Class II Sodium Dodecyl Sulfate Biological Transport Molecular biology Antigens Differentiation B-Lymphocyte Antibody opsonization chemistry Biochemistry Complement C3b biology.protein Lysosomes Dimerization Protein Binding circulatory and respiratory physiology |
| Zdroj: | European Journal of Immunology. 27:2673-2679 |
| ISSN: | 1521-4141 0014-2980 |
| Popis: | Processing and presentation of covalently linked C3b-tetanus toxin (TT) complexes, as compared to unlinked C3b + TT, lead to increased T cell proliferation. The aim of this study was to analyze the effect of coupling C3b to TT on the efficiency of TT peptide loading on HLA-DR1 molecules. In the Epstein-Barr virus-transformed B cell line HOM 2, we detected a significant increase of sodium dodecyl sulfate (SDS)-stable major histocompatibility complex (MHC) class II molecules after exposure to C3b-TT as compared to unlinked C3b and TT. The ratio of compact form/unbound form (C/U ratio) obtained with C3b-TT as antigen (Ag) is about twice that obtained with uncomplexed TT + C3b as Ag. Similar results were obtained using HLA-DR1-transfected fibroblasts that do not express C3b complement receptors, indicating that the SDS-stable HLA-DR1 increase did not result simply from C3b opsonization but rather from a direct effect of C3b-TT linkage on peptide generation. Exposure of HOM 2 cells to C3b-TT resulted in an increase in concentration of SDS-stable HLA-DR molecules in lysosomes but not in endosomes. Thus, C3b attachment to Ag induces a redistribution of peptide/MHC complex which results in a higher efficiency of Ag presentation by MHC class II molecules. |
| Databáze: | OpenAIRE |
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