Characteristics of a monoclonal antibody (WT-31) that recognizes a common epitope on the human T cell receptor for antigen.
We describe a monoclonal antibody, WT-31, that reacted with all human T lymphocytes. Electrophoretic analysis of the material reacting with WT-31 revealed that it precipitated predominantly an 80-kD disulfide-linked heterodimer from the cell surface-labeled T leukemic cell line HPB-ALL. This heterodimer was identical to the one precipitated with a recently described monoclonal reagent, T40/25, which recognizes a clonotypic structure on HPB-ALL. The target antigen of WT-31 comodulated with T3 after incubation of T cells with excess anti-T3 antibody, indicating that the WT-31 target antigen is associated with T3. We also found that anti-T3 reagents, but not the clonotypic reagent T40/25, blocked binding of FITC-labeled WT-31 to HPB-ALL cells. This indicates that the T cell receptor epitope recognized by WT-31 is located close to the epitopes recognized by the anti-T3 reagents anti-Leu-4 and SPV-T3b but distal from the clonotypic T40/25 epitope. Functional studies showed that WT-31 reacts similar to anti-T3 antibodies. It is mitogenic for resting T cells, blocks cytolysis mediated by alloantigen-specific CTL clones, and induces antigen-nonspecific cytolysis by CTL clones against Daudi target cells. WT-31 did not inhibit the formation of conjugates, but it blocked cytolysis just before or during the Ca2++-dependent programming for lysis. We conclude that WT-31 is an antibody that recognizes a common determinant on the T cell receptor for antigen. The present results support the notion that the two chains of the T cell receptor (alpha and beta) form a functional protein ensemble with the three invariable T3 polypeptide chains (T3-gamma-, delta-, epsilon).
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Borst
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Capel
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Terhorst
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de Vries
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D000911:Antibodies, Monoclonal / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D006801:Humans; D007945:Leukemia, Lymphoid / Q000276:immunology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D000939:Epitopes; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell