FIG 2.

Protein synthesis in Calu-3 cells following treatments with ricin and/or TRAIL. Calu-3 cells were plated at a density of 5 × 10⁴ cells/well in a 96-well clear-bottom black plate. After confluence was achieved, cells were treated with ricin (0.25 µg/ml) or TRAIL (0.1 μg/ml) or a mixture of ricin and TRAIL with or without anti-ricin MAb PB10 (15 µg/ml) for 24 h. As a control, cells were treated with cycloheximide (250 µg/ml). Cells were then incubated for 2 h in culture medium alone, culture medium containing OPP, or culture media containing OPP and the treatments as described above. The cells were then processed for detection of protein synthesis, as described in Materials and Methods. The results (means ± standard deviations [SD]) represent a single experiment done in triplicate and repeated twice. ***, P  < 0.001; ****, P  < 0.0001 (versus only OPP-treated cells).