FIGURE 5.

Degranulation protects neutrophils from LLO-mediated perforation. (A) Neutrophils were incubated ± 5–500 nM LLO for 15 min at 37°C in HBSS ± Ca²⁺. Asterisks indicate a statistically significant difference between LDH release in the presence and absence of Ca²⁺. (B) Neutrophils were preincubated at 37°C for 10 min in HBSS⁺ with 0, 1.5, or 2 μg/ml TAT inhibitors (TI) consisting of equivalent concentrations of TAT–SNAP-23 and TAT–syntaxin-4 or control TAT-GST. Cells were then incubated with cell culture medium alone (Control) or 5 nM LLO in HBSS⁺ for 15 min at 37°C in the presence of the TAT constructs. (A and B) The release of LDH is expressed as the mean percentage of maximal LDH release ± SEM of at least three independent experiments, each performed in duplicate. *p < 0.05, **p < 0.01.