The CD4 molecule is not always required for the T cell response to bacterial enterotoxins.
T cells respond in a V beta-restricted fashion to bacterial enterotoxins bound to major histocompatibility complex (MHC) class II molecules. The requirement for CD4 in MHC class II-restricted T cell responses is very well established. We have assessed the role of CD4 in the T cell response to the bacterial enterotoxins Staphylococcal enterotoxin A (SEA), SEB, and toxic shock syndrome toxin 1. Three CD4- murine T cell hybridomas were transfected with the human CD4 molecule and assayed for interleukin 2 production in the presence of accessory cells bearing human MHC class II molecules and of the appropriate enterotoxin. The results clearly indicate that CD4- cells responded even to suboptimal concentrations of enterotoxin(s) equally well as CD4+ cells. Furthermore, expression of CD4 did not result in the acquisition of previously undetectable reactivity to enterotoxins. These results suggest that unlike the case with antigen-specific responses, formation of a T cell receptor-CD3/CD4 supramolecular complex is not always essential for T cell activation by bacterial enterotoxins.
Sékaly
R P
RP
Institut de Recherches Cliniques de Montréal, Canada.
Croteau
G
G
Bowman
M
M
Scholl
P
P
Burakoff
S
S
Geha
R S
RS
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001427:Bacterial Toxins / Q000276:immunology*; D015704:CD4 Antigens / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D004768:Enterotoxins / Q000276:immunology*; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D013210:Staphylococcus; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
D001427:Bacterial Toxins; D015704:CD4 Antigens; D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2