Endogenous CD28 up-regulates transcription of an RE/AP reporter in myeloma cell lines.
The human myeloma cell line RPMI8226 and murine myeloma cell line S194/5.XXO were transfected with an RE/AP reporter. The following day, the 105 live cells were unstimulated or stimulated with PMA/ionomycin (25 ng/mL and 1 mM, respectively) and anti-CD28 (Caltag) for 6 hours as denoted in the figure. RPMI 8226 cells were stimulated with antihuman CD28 (Caltag) at 1 μg/mL. S194/5.XXO cells were stimulated with a 1:1000 dilution of antimurine CD28 ascites. Luciferase activity was standardized to the unstimulated control for each cell line (n = 1). The actual average counts for background RE/AP luciferase activity were 649 in RPMI 8226 and 402 in S194/5.XXO. The results shown are the average of 4 independent transfections. Error bars reflect the SD from the mean.
