Superantigen-induced peripheral tolerance inhibits T cell responses to immunogenic peptides in TCR (beta-chain)...

TCR (beta-chain) transgenic mice were tolerized with the superantigen staphylococcal enterotoxin B (SEB). Three to 28 days after tolerization with SEB, flow cytometry of peripheral T cells showed the persistence of SEB-unresponsive T cells that did not express reduced levels of the TCR (beta-chain) transgene. Stimulation of the tolerized T cells with a panel of superantigens (SEC1), mitogens (Con A, PHA, and pertussis toxin) and mAb (anti-CD3 epsilon) did not induce T cell proliferation. In contrast to other models, exogenous rIL-2 did not reverse unresponsiveness and induce proliferation. In addition, lymphokines rIL-4 and rIL-6 also did not induce proliferation. However, the unresponsive T cells did respond to the combination of PMA plus ionomycin, but not to PMA or ionomycin alone. Thus, the block in signal transduction in the anergic state occurs between the stimulation of cell surface receptors and the activation of protein kinase C and the increase in intracellular calcium. In addition, these results show that mature T cells tolerized with the superantigen SEB are unresponsive to a wide array of T cell stimuli, indicating a block in a common signal transduction pathway.