Stimulation of murine intestinal intraepithelial lymphocytes by the bacterial superantigen staphylococcal enterotoxin B

Publisher Website
Google Scholar
Abstract
To gain insight into the specificity and function of intestinal intraepithellal 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 αβ+ 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 αβ and γδ+ IEL bearing a unique form of the CD8 molecule, expressed as an αα homodimer. CD8α+β- IEL are thymus independent and appear to mature extrathymically in the gut epithellum. 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 CD8α+β− 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 CD8α+β- IEL from class II deficient mice also failed to respond to stimulation with SEB. Depletion of CD8β+ 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 CD8α+β− IEL extends to antigens other than SEB.

This publication has 0 references indexed in Scilit: