Low and high affinity cellular receptors for interleukin 2. Implications for the level of Tac antigen
Autor: | Richard J. Robb, Warner C. Greene, Cynthia M. Rusk |
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Rok vydání: | 1984 |
Předmět: |
Cytotoxic
T-Lymphocytes Lymphocyte Activation Medical and Health Sciences Mice Competitive Immunologic Receptors Monoclonal Immunology and Allergy 2.1 Biological and endogenous factors Receptors Immunologic Aetiology Receptor biology Tumor Necrosis Factor Receptor Superfamily Antibodies Monoclonal Articles Surface medicine.anatomical_structure Antigen Antigens Surface Antibody medicine.drug Interleukin 2 T cell Immunology Receptors Antigen T-Cell Binding Competitive Antibodies Cell Line Member 7 Cell surface receptor medicine Animals Humans Binding site Antigens Binding Sites Ligand binding assay Receptors Interleukin-2 Binding T-Cell Molecular biology Tumor Necrosis Factor Receptor Superfamily Member 7 Kinetics biology.protein Interleukin-2 Binding Sites Antibody T-Lymphocytes Cytotoxic |
Zdroj: | The Journal of experimental medicine, vol 160, iss 4 The Journal of Experimental Medicine |
Popis: | Interleukin 2 promotes proliferation of T cells by virtue of its interaction with a high-affinity cell surface receptor. This receptor is a 55,000 mol wt glycoprotein that is also recognized by the murine monoclonal antibody, anti-Tac. Quantitative binding studies with radiolabeled IL-2 and anti-Tac, however, initially indicated far more antibody binding sites per cell than IL-2 binding sites. Extension of the IL-2 binding analysis to concentrations several thousand-fold higher than that necessary for the T cell proliferative response demonstrated the existence of a class (or classes) of low-affinity IL-2 binding sites. Inclusion of the low-affinity IL-2 binding greatly reduced the quantitative discrepancy in the ligand binding assays. That the low-affinity binding, as well as the high-affinity interaction, was associated with the Tac molecule was indicated by the finding that the antibody could substantially or totally block the entire spectrum of IL-2 binding and by the finding that IL-2 could in turn block all radiolabeled anti-Tac binding. The low-affinity sites were found on activated T cells, several human and murine T cell lines and two examples of Tac-positive B cells. The physiological role of the low-affinity IL-2 binding sites and the molecular changes in the Tac protein that give rise to the affinity differences remain open to investigation. |
Databáze: | OpenAIRE |
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