title: Sequences in both class II major histocompatibility complex alpha and beta chains contribute to the binding of the superantigen toxic shock syndrome toxin 1.
abstract: Class II major histocompatibility complex (MHC) molecules present peptides derived from processed antigen to antigen-specific CD4-positive T cells. In addition, class II molecules bind with high affinity another class of antigens, termed superantigens. T cell stimulation by superantigens depends almost exclusively on the V beta segment expressed by the T cell receptor (TCR). Mapping of the superantigen binding site on class II molecules should provide valuable information on how MHC and TCR molecules interact. Recombinant mouse I-A class II molecules expressed on transfected L cells were analyzed for their ability to bind the toxic shock syndrome toxin 1. Polymorphic residues in the alpha helices of both the alpha and beta chains of I-A contributed to quantitative toxin binding, suggesting that the toxin binds to either a combinatorial or a conformational site on class II MHC molecules.
authors.affiliation: Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
authors.forename: N S
authors.initials: NS
authors.lastname: Braunstein
authors.forename: D A
authors.initials: DA
authors.lastname: Weber
authors.forename: X C
authors.initials: XC
authors.lastname: Wang
authors.forename: E O
authors.initials: EO
authors.lastname: Long
authors.forename: D
authors.initials: D
authors.lastname: Karp
mesh_terms: D000818:Animals; D001427:Bacterial Toxins; D002460:Cell Line; D004768:Enterotoxins / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism*; D007739:L Cells; D051379:Mice; D011994:Recombinant Proteins / Q000276:immunology; D018089:Superantigens; D014162:Transfection
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D011994:Recombinant Proteins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal