Figure 1.

Binding and phagocytosis of wild type P. aeruginosa and its lasI-/rhlI- mutant. (A) Macrophages were infected with GFP (green) wild type bacteria or lasI-/rhlI- mutant, stained for P. aeruginosa (blue) and F-actin (red), and analyzed by LSCM. White squares show three ingested bacteria distinguished by sole GFP (green). White arrows point to bound bacteria recognized by combined GFP (green) and P. aeruginosa (blue). Bar 10 μm. (B) Quantification of phagocytosis presented as the percentage of phagocytic-positive (containing ingested bacteria) cells among total macrophages. (C) Quantification of binding presented as the percentage of cells containing bound and ingested bacteria (associated bacteria) among total macrophages. Shown are the mean ± SE of seven independent experiments performed at separate days from different donors (color coded). The means ± SE are based on 100–200 cells for each condition per experiment. Significant differences were considered at ^*P < 0.05 and ^**P < 0.01, as calculated by two-tailed paired Student's t-test.