RESUMO
Objective To study the immunity suppressive effect of the staphylococcal enterotoxin as a super-antigen and investigate its mechanism.Methods BALB/c mice aged 8-12 weeks were randomly assigned to receive 0.2 ml injection of 50 ?g/ml staphylococcal enterotoxin B(SEB)(n=20) or 0.2 ml physiological saline(n=20).One day later,all mice were sacrifice to collect the splenocytes which were employed to detect the expression of TGF-?1 and to countthe cells expressing CD4 and CD25 by flow cytometry(FCM).Results FMC showed that a remarkable increase of cells that expressed CD4 and CD25 in the SEB-primed splenocytes as compared with the saline primed splenocytes.Conclusion SEB,which is used as a superantigen in vivo,can induce the regulatory cells bearing suppressive activity.This may be partial mechanism of SEB-induced hyporesponsiveness.