A recombinant C-terminal fragment of staphylococcal enterotoxin A binds to human MHC class II products but does not activate T cells.
Binding of staphylococcal enterotoxin A (SEA) to MHC class II encoded proteins is a prerequisite for its subsequent activation of a large fraction of T lymphocytes through interaction with variable segments of the TCR-beta chain. We cloned SEA in Escherichia coli and produced four recombinant fragments covering both the N- and C-terminal regions. These fragments were used to analyze the interaction between SEA and the human MHC class II products. A C-terminal fragment of SEA, representing amino acids 107-233 bound to HLA-DR and HLA-DP but did not activate T cells. The three other fragments (amino acids 1-125, 1-179 and 126-233) neither bound to MHC class II Ag nor activated T cells. SEA apparently bind to HLA-DR and HLA-DP through its C-terminal part, whereas T cell activation is dependent on additional parts of the protein.
Hedlund
G
G
Kabi Pharmacia Therapeutics AB, Lund, Sweden.
Dohlsten
M
M
Herrmann
T
T
Buell
G
G
Lando
P A
PA
Segrén
S
S
Schrimsher
J
J
MacDonald
H R
HR
Sjögren
H O
HO
Kalland
T
T
D001483:Base Sequence; D002478:Cells, Cultured; D004768:Enterotoxins / Q000378:metabolism* / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; D011994:Recombinant Proteins; C026066:enterotoxin A, Staphylococcal