Human neutrophils are unresponsive to IL-17A and IL-17F. (A-D) Neutrophils were cultured with IL-17A or IL-17F for up to 21 hours, in the presence or absence of IFN-γ, LPS, or GM-CSF as indicated. (A) Neutrophils were harvested after 3 hours for gene expression analysis by real-time RT-PCR. Results are expressed as MNE units ± SE. (B-D) Neutrophils were incubated for 3 and 21 hours before measuring: (B) CXCL8, VEGF, and lactoferrin supernatant levels (n = 3); (C) their degree of apoptosis (as assessed by annexin V/propidium iodide staining; n = 4); (D) CD16 and CD11b surface expression. (E) Neutrophils were incubated with IL-17A, IL-17F, or GM-CSF and then evaluated for phospho-ERK1/2 (P-ERK1/2) analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. (F) Neutrophils were incubated with fMLF in the presence of IL-17A or LPS, and superoxide anion (O2−) generation was measured for up to 2 hours. (A,D-F) One representative of at least 3 independent experiments with similar results. *P < .05.
