Prenatal exposure of staphylococcal enterotoxin B attenuates the development and function of blood regulatory T cells to repeated staphylococcal enterotoxin B exposure in adult offspring rats.

Introduction. Staphylococcal enterotoxin B (SEB) is an extensively studied super-antigen. A previous study by us suggested that SEB exposure during pregnancy could alter the percentage of CD4(+) and CD8(+) T cells in the peripheral blood of neonatal offspring rats. Aim. It is unknown whether SEB exposure during pregnancy can influence the development of regulatory T cells (Tregs) in the peripheral blood of neonatal offspring rats. Methodology. Pregnant rats at gestational day 16 were intravenously injected with 15 mu g SEB. Peripheral blood was acquired from neonatal offspring rats on days 1, 3 and 5 after delivery and from adult offspring rats for determination of Treg number by cytometry, cytokines by ELISA, and FoxP3 expression by real-time PCR and western blot. Results. SEB given to pregnant rats significantly increased the absolute number of Tregs and the expression levels of FoxP3, IL-10 and TGF-beta(P<0.05, P<0.01) in the peripheral blood of not only neonatal but also adult offspring rats. Furthermore, repeated SEB exposure in adult offspring rats significantly decreased the absolute number of Tregs (P<0.01). and the expression levels of FoxP3, IL-10 and TGF-beta (P<0.05. P<0.01) in their peripheral blood. Conclusion. Prenatal SEB exposure attenuates the development and function of Tregs to repeated SEB exposure in the peripheral blood of adult offspring rats.