Figure 2.

CD40 binding enhances apoptosis induction by scFv:CD40-TRAIL. (a) HT1080-CD40 and HeLa-CD40 transfectants and the corresponding parental cell lines were seeded in 96-well plates and were stimulated the next day in triplicates with the indicated concentration of scFv:G28-TRAIL. After an additional day, cellular viability was determined by crystal violet staining and normalized the help of untreated cells and a cell sample treated with mixture of toxic compounds. Cells were sensitized with CHX (2.5 μg/ml) to enhance apoptosis. (b) OVCAR3, BJAB, Mino, 786-O and CD40-negative Jurkat cells were analyzed for endogenous CD40 expression by FACS. (c) Triplicates of cells were treated in 96-well plates with the indicated concentrations of scFv:G28-TRAIL in the presence and absence of scFv:G28-Fc-GpL (2 μg/ml) as a competitor. Next day, cellular viability was determined by crystal violet staining or using the MTT assay