Paper Title
Evaluation of Staphylococcal Enterotoxin Beffect on the Endoplasmic Reticulum Mediated Apoptosis

Abstract
Staphylococcal enterotoxin B is known as a potent superantigen that is able to attach to MHC II molecules located on the surface of antigen presenting cells and induce a robust immune response via proliferation and activation of T cells. Numerous previous studies used this superantigen as an adjuvant and immune enhancer for cancer therapy. Their finding showed that SEB had an anti-tumor effects. Furthermore, a modeling analysis reported the influence of SEB on the FASmediated apoptosis. Here, we aimed to survey the apoptotic effects of SEB on the breast cancer cell line. To identify the cytotoxic and apoptotic impacts of SEB, MDA MB-231 cells were treated with 5, 25, 50 and 100 μg/ ml SEB and then, the expression ratio of GRP-78, IRE-1 and CHOP genes involved in apoptosis was assessed by Real time –PCR.GRP-78 level was significantly attenuated after 24 h (P <0.05) but the expression ratio of CHOPand IRE-1 had no difference compared with control group. SEB has apoptotic properties against tumor cells and effect on factors involved in endoplasmic reticulum mediated apoptosis. Keywords- Staphylococcal enterotoxin B, cell death, superantigen, breast cancer