FIG 3.

Deletion of CD18 renders Jurkat cells resistant to LtxA-mediated cell death. (A) Jurkat E6.1 cells and both Jurkat CD18^−/− clones were treated with LtxA for 24 h. Staurosporine (STS; 1 μM) was used as a positive control for cell death. (B and C) Jurkat E6.1 cells and Jurkat CD18^−/− clones were treated with 0.1 μg/ml or 1.0 μg/ml LtxA for 24, 48, or 72 h, and cell death was assessed via flow cytometry. Cytotoxicity was determined by flow cytometry, and the percent cell death is defined as the sum of annexin V⁺/7-AAD⁻ and annexin V⁺/7-AAD⁺ cells. Data represent the average from three independent experiments. Error bars represent SEM. The significance of differences between results for Jurkat E6.1 cells and those for each Jurkat CD18^−/− clone was determined using Student's t test. ***, P ≤ 0.001; ns, not significant.