FIG. 5.

Demonstration that HlyA and ShlA produce pores in T cells that are either permeable (HlyA) or nonpermeable (ShlA) to propidium iodide. Cells were treated with 1 μg of HlyA/ml and 4 μg of ShlA/ml in HBSS buffered with 10 mM HEPES, pH 7.4. ShlA evoked an ATP depletion to 10% of the original ATP level after 60 min of incubation at 37°C. The medium was then replaced with HBSS supplemented with 10 μg of propidium iodide/ml. After 30 min at 37°C, samples were subjected to flow cytometric analysis. Experiments were carried out in duplicate, and similar results were obtained.