G-CSF decreases CD62L and increases CD11b expression by neutrophils in vitro. (A) CD62L expression on purified neutrophils treated in vitro with G-CSF (1 pg/mL-10 μg/mL) or saline. P < .05; at 15 and 30 minutes, saline versus 1 to 100 pg/mL or 10 μg/mL G-CSF. (B) LFA-1 (CD11a/CD18) expression on purified neutrophils treated in vitro with G-CSF (1 pg/mL-10 μg/mL) or saline. P < .05; saline versus 100 pg/mL G-CSF at 15 minutes, saline versus 1 to 100 pg/mL or 10 μg/mL G-CSF at 30 minutes. (C) CD11b expression on purified neutrophils treated with or without G-CSF, in the presence or absence of P-selectin fusion protein (P-sel; 10 μg/mL). P < .05 at 15 and 30 minutes; saline versus 1 to 100 pg/mL or 10 μg/mL G-CSF, each dose of G-CSF alone versus the equivalent dose of G-CSF + P-selectin. Data in panels A to C show mean MFI (mean fluorescence intensity) plus or minus SD for duplicate samples, representative of at least 2 independent experiments, each using neutrophils pooled from 4 WT C57BL/6 mice. Representative confocal images showing CD11b in green and DAPI-stained nuclei in blue of neutrophils treated for 30 minutes with (D) saline, (E) 10 μg/mL G-CSF, or (F) 10 μg/mL G-CSF and 10 μg/mL P-selectin fusion protein (P-sel).