FIG. 1.

(A) Dose-effect curve of VEGF secretion by human neutrophils (2.5 × 10⁶ neutrophils ml⁻¹) following stimulation with different doses of heat-killed S. pneumoniae R6 at 37°C for 4 h. (B) Kinetics of VEGF secretion by human neutrophils (2.5 × 10⁶ neutrophils ml⁻¹) following stimulation with heat-killed S. pneumoniae R6 at a concentration of 10⁹ CFU ml⁻¹ at 37°C for 0 to 4 h. Results are means ± SD of ≥2 independent experiments with blood from different donors and ELISA performed in duplicate. Symbols for stimuli: ■, R6; ◊, medium alone; ▵, cytochalasin B (10 μg ml⁻¹) plus fMLP (10 μM).