Aims. Exposure of T cells with staphylococcal enterotoxns invitro condition is known to activate T cells in a subset restricted manner based on β-chain variable region (Vβ) gene expression. In particular, staphylococcal enterotoxin B (SEB) activates T cells bearing V β8. Methods. We examined the ability of SEB to activate T cells in vitro. Exposure of lymphocyte cells origin of lymph node Balb/c mice (auxiliary , Inguinal and Mesenteric node) with doses of SEB ranging from 1, 10, 100, 1000 and 10000 ng/µl resulted in a dose dependent activation of T cells as reflected by increased proliferation that was detected by MTT assay. Results. Our results showed that in order increase of proliferation T cells, 1000 ng/µl of SEB was the best concentration. In additional, we studied the ability of SEB in create of apoptosis with Hoechst staining. Our result demonstrate that in a statistically there are not significant difference between above SEB concentrations and negative control. Therefore 1000 ng/µl of SEB don’t create apoptosis but it is just inducible lymphocyte cell. Conclusion. Staphylococcal Enterotoxins is the best super antigen, and induce T-Cell suppressor, that it increase tumor cell death. Therefore, SEB is a very excellent candidate for tumor therapy. | 
