title: Stimulation of murine intestinal intraepithelial lymphocytes by the bacterial superantigen staphylococcal enterotoxin B.
abstract: To gain insight into the specificity and function of intestinal intraepithelial lymphocytes (IEL), we have examined their response to staphylococcal enterotoxin B (SEB), a significant cause of food poisoning and a potent T cell mitogen. IEL include two populations of TCR alpha beta+ T cells. One of these resembles the T cells found in the Peyer's patch and is thymus dependent. The other subset is characterized by both TCR alpha beta and gamma delta+ IEL bearing a unique form of the CD8 molecule, expressed as an alpha alpha homodimer. CD8 alpha+ beta- IEL are thymus independent and appear to mature extrathymically in the gut epithelium. Two-color flow cytometric analysis showed that in vitro stimulation of IEL with SEB resulted in the expansion of the thymus dependent but not the thymus independent IEL; the CD8 alpha+ beta- IEL were functionally non-responsive to stimulation with SEB. 'Forbidden' self-superantigen reactive T cells present among IEL were also non-responsive to stimulation with SEB. The presence or absence of class II MHC molecules does not appear to play a role in the non-responsiveness to SEB, since CD8 alpha+ beta- IEL from class II deficient mice also failed to respond to stimulation with SEB. Depletion of CD8 beta+ and CD4+ T cells from total IEL decreased IL-2 production by IEL in response to cross-linking with anti-CD3, suggesting that the non-responsiveness of CD8 alpha+ beta- IEL extends to antigens other than SEB.
authors.affiliation: Mucosal Immunology Laboratory, Massachusetts General Hospital East Charlestown 02129.
authors.forename: M S
authors.initials: MS
authors.lastname: Siebrecht
authors.forename: E
authors.initials: E
authors.lastname: Hsia
authors.forename: C
authors.initials: C
authors.lastname: Spychalski
authors.forename: C
authors.initials: C
authors.lastname: Nagler-Anderson
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D004768:Enterotoxins / Q000276:immunology*; D004848:Epithelium / Q000276:immunology; D007422:Intestines / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D015704:CD4 Antigens; D016827:CD8 Antigens; D004768:Enterotoxins; D016693:Receptors, Antigen, T-Cell, alpha-beta; C031818:enterotoxin B, staphylococcal