IL-8 and LTB4 did not increase actin polymerization and protein tyrosine phosphorylation from septic neutrophils. The contents of F-actin (A, C) and phosphotyrosine (B, D) were analyzed by cytofluorescence in neutrophils from volunteers (i-iii; □) or patients with sepsis (iv-vi; ▦), treated with medium alone (i, iv), IL-8 (10–9 M; ii-iii), or LTB4 (10–8 M; iv-v). Actin filaments were stained with TRITC-phalloidin (A), and tyrosine-phosphorylated proteins were immunolabeled with FITC-conjugated antiphosphotyrosine Ab (B). Panels show images representative of at least 5 independent experiments. In addition, cells were imaged (×1000) as described, and the fluorescence intensity of F-actin (C) or phosphotyrosine (D) was quantified. Data are means ± SD from 5 independent experiments. *P < .05 compared with cells incubated with medium alone (ANOVA followed by Bonferroni); #P < .05 compared with control neutrophils (unpaired t test).
