Figure 2.

Effect of PI-PLC treatment on VacA-induced vacuolation of HEp-2 cells. Neutral red uptake was measured either 1) in cells previously exposed to VacA pulse (both as VacA⁺ BCF and as purified VacA) and then treated or not with PI-PLC (VacA preloaded), or 2) in cells treated or not with PI-PLC and then exposed or not to VacA pulse (VacA afterloaded) (see Methods). Incubation for vacuole development: 3 h at 37°C in HBSS containing 5 mM NH₄Cl. Means ± SEM of three independent experiments.* = p < 0.05 versus paired monolayers not exposed to VacA.