Predictions of T-cell receptor- and major histocompatibility complex-binding sites on staphylococcal enterotoxin C1. Infect Immun 1994 Aug;62(8):3396-407
Date
08/01/1994Pubmed ID
8039910Pubmed Central ID
PMC302971DOI
10.1128/iai.62.8.3396-3407.1994Scopus ID
2-s2.0-0027931694 (requires institutional sign-in at Scopus site) 65 CitationsAbstract
We have focused on regions of staphylococcal enterotoxin C1 (SEC1) causing immunomodulation. N-terminal deletion mutants lacking residues 6 through 13 induced T-cell proliferation similar to that induced by native toxin. However, mutants with residues deleted between positions 19 and 33, although nonmitogenic themselves, were able to inhibit both SEC1-induced T-cell proliferation and binding of the native toxin to major histocompatibility complex (MHC) class II. Presumably, these deletions define a part of SEC1 that interacts with the T-cell receptor. Three synthetic peptides containing residues located in a region analogous to the alpha 5 groove of SEC3 had residual mitogenic activity or blocked T-cell proliferation induced by SEC1 and appear to recognize the same site as SEC1 on a receptor for the toxin, presumably MHC class II. We conclude that isolated portions of the SEC1 molecule can retain residual mitogenic activity but that the entire protein is needed to achieve maximal superantigenic stimulation. Our results, together with the results of other investigators, support a model in which SEC1 binds to an alpha helix of MHC class II through a central groove in the toxin and thereby promotes or stabilizes the interaction between antigen-presenting cells and T cells.
Author List
Hoffmann ML, Jablonski LM, Crum KK, Hackett SP, Chi YI, Stauffacher CV, Stevens DL, Bohach GAAuthor
Young-In Chi PhD Assistant Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Amino Acid SequenceBase Sequence
Binding Sites
Cytokines
Enterotoxins
Histocompatibility Antigens Class II
Humans
Lymphocyte Activation
Molecular Sequence Data
Mutation
Peptide Fragments
Receptors, Antigen, T-Cell
Staphylococcus aureus