Figure 6.

Neutralization of host acidic compartments induced by PFO and PLY toxins. Acridine orange‐stained HeLa cells were treated with wild‐type or pore‐deficient LLO, PFO, or PLY toxins for 10 or 30 min. (a) Wild‐type toxins were used at various hemolytic titres (a titre of 10 A.U. corresponds to the hemolytic activity of 3 nM LLO). (b) Wild‐type toxins were used at a hemolytic titre of 10 A.U. Mutant toxins were used at similar protein concentration than the corresponding wild‐type. Geometric means of acridine orange fluorescence, as measured by flow cytometry analysis are represented, normalized to that of untreated cells (mean ± SD from three independent experiments)