Superantigens: mechanism of T-cell stimulation and role in immune responses.
Superantigens combine with MHC class-II molecules to form the ligands that stimulate T cells via the V beta element of the T-cell receptor. Two groups of superantigens have been described so far: first, endogenous murine products that include the Mls determinants, and second, bacterial products such as the Staphylococcal enterotoxins. Here, we review studies that address the interactions between the foreign superantigens and MHC class-II molecules, the mechanism of T-cell stimulation, and the role that tolerance to self-superantigens plays in shaping the T-cell repertoire. We speculate on the possible evolutionary significance of superantigens.
Herman
A
A
Howard Hughes Medical Institute, Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
Kappler
J W
JW
Marrack
P
P
Pullen
A M
AM
D000818:Animals; D000941:Antigens; D001324:Autoantigens; D001419:Bacteria / Q000276:immunology; D000949:Histocompatibility Antigens Class II; D006801:Humans; D016747:Minor Lymphocyte Stimulatory Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D001324:Autoantigens; D000949:Histocompatibility Antigens Class II; D016747:Minor Lymphocyte Stimulatory Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta