FIG. 6.
IL-18 enhances susceptibility of NK92 cells to Fas/FasL-mediated apoptosis. (A) NK92 cells were cultured with the medium (lane A) or with the medium supplemented with 10 ng of rhIL-18/ml (lane B) for 12 h, washed, and incubated for another 12 h with 1 μg of anti-Fas agonistic antibody/ml. The dead cells were counted by using a trypan blue exclusion assay. The results are representative of two independent experiments. (B) Cell lysates from NK92 cells cultured in medium alone (lane 1) or in medium supplemented with 10 ng of rhIL-18/ml (lane 2) for 24 h were analyzed by Western blotting with anti-Bcl-2 monoclonal antibody and Bcl-XL. A decrease in the expression of the latter protein in the IL-18-treated cell lysates is quite noticeable. The results are representative of three independent experiments.