FIG 3 .

ExoS, specifically the ADPRT domain, inhibits neutrophil phagocytic uptake in vitro. (A) Murine bone marrow neutrophils were infected for 30 min with strain PA99S, PA99null, PA99null+S(R146A), or PA99null+S(E379A/E381A). Following infection, bacteria were removed, and cells were incubated with fluorescently labeled latex beads for 30 min. Phagocytosis of beads was assessed by flow cytometry. Data represent the average percentage of neutrophils containing intracellular beads (three mice for each strain). Error bars represent standard errors of the means. (B) Following 30 min of infection, LDH release was assessed as a measure of neutrophil lysis. Cell lysis was normalized using a Triton X-100-lysed control. Background lysis was measured in uninfected neutrophils incubated without bacteria and subtracted from all experimental values. Data represent the average percentage of neutrophil lysis (three mice for each strain). Error bars represent standard errors of the means.