A. CD8+ T cells from C57BL/6 spleens were treated in medium in the absence or presence of staurosporine with Sp1, mSp1 (100 µg/ml, respectively), or without antigen for 12 h. Magnetically separated CD8+CD28− and CD8+CD28+ cells were stained with FITC-conjugated Annexin V and 5 µl propidium iodide (PI), and prepared for flow cytometry. One representative result out of three stainings with cells from 3 mice, respectively, is displayed. The numbers in the quadrants of the dot plots represent the percentage ±SD (n = 3) of cells stained positive for the respective markers. B. Sp1 inhibits staurosporine-induced caspase 3 activity in CD8+CD28− T cells. CD8+, CD8+CD28−, and CD8+CD28+ T cells were treated for 4 h with mSp1, mSp1 (100 µg/ml, respectively), or in medium alone. SDS-PAGE of the whole cell extract was performed. One representative out of four western blots performed with a caspase 3- and a β-actin-specific antibody as a control is shown.