title: Direct binding of secreted T-cell receptor beta chain to superantigen associated with class II major histocompatibility complex protein.
abstract: The interaction of the T-cell receptor (TCR) with peptide antigen plus major histocompatibility complex (MHC) protein requires both alpha and beta chains of the TCR. The "superantigens" are a group of molecules that are recognized in association with MHC class II but that do not appear to conform to this pattern. Superantigens are defined as such because they cause the activation or thymic deletion of many or all T cells bearing specific TCR beta-chain variable region (V beta) elements. The strong association of particular V beta S with T-cell responses to superantigens suggests that their interaction with the TCR is fundamentally different from that of most antigens. We have directly investigated the involvement of the beta chain in recognition of a superantigen by using a secreted, truncated TCR beta chain and the bacterial superantigen staphylococcal enterotoxin A complexed to cell-surface MHC class II. We demonstrate that this interaction is specific for the enterotoxin and is dependent on MHC class II expression by the cell. The reaction can be inhibited by antibodies against the three components of the reaction: V beta, enterotoxin, and class II. This shows that the TCR beta chain is sufficient to mediate the interaction with a superantigen-class II complex. The TCR alpha chain and co-receptors such as CD4 are not required.
authors.affiliation: Department of Immunology, Research Institute of Scripps Clinic, La Jolla 92037.
authors.forename: N R
authors.initials: NR
authors.lastname: Gascoigne
authors.forename: K T
authors.initials: KT
authors.lastname: Ames
mesh_terms: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D002051:Burkitt Lymphoma; D002460:Cell Line; D004768:Enterotoxins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000276:immunology; D046911:Macromolecular Substances; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D007135:Immunoglobulin Variable Region; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell; C026066:enterotoxin A, Staphylococcal