FIGURE 7.

CD28 activation upregulates the prdm1 promoter activity. (A) J558 cells were cultured ± control Ig or αCD28 mAb-coated beads for 24 h. Lysates were made, and BLIMP-1 expression was analyzed by Western analysis. Densitometry relative to actin is the mean ± SD of three independent experiments. *p < 0.05. (B) J558 cells were transfected with 10 μg each reporter and Renilla constructs. Two hours later, cells were left unstimulated (black bars) or stimulated with control (white) or αCD28 mAb-coated beads (gray) for 16 h, and then assayed for luciferase activity relative to the Renilla transfection control. Results representative of three independent experiments. *p < 0.05, **p < 0.01.