Signaling through Erk and p38 is required for neutrophil degranulation events. (A) WT neutrophils pretreated with dimethyl sulfoxide vehicle, 20μM PD98059, 3μM SB203580, or both compounds were stimulated for 60 minutes with S aureus (MOI = 5) or E coli (MOI = 10), then analyzed by flow cytometry for CD11b and CD62L. Quantitation of (B) CD11b MFI ± SD, and (C) percentage of CD62L⁻ mean ± SD. Data are ± SD and are representative of 3 or more independent experiments. (D) WT neutrophils pretreated as in panel A were plated in microtiter wells containing S aureus (MOI = 5) or E coli (MOI = 10), in cytochrome c media, and assessed for superoxide (SOx) production as in Figure 3. Data are representative of at least 3 independent experiments. Error bars represent ± SD. **P < .01, ^#P < .001, by 2-way ANOVA with Bonferroni posttests.