Effect of IL-17 neutralization on systemic neutrophilia in THP−/− mice. (A) Bar graphs are means±SEM of the IL-17 level in sera from THP+/+ and THP−/− mice (n=5 per group) measured with ELISA. (B) Neutrophil counts in THP−/− mice injected with IL-17 neutralizing antibody or IgG isotype at various time points during treatment (n=5 each group). (C) Serum G-CSF on day 7 after IL-17 neutralization or treatment with IgG isotype. (D and E) Flow cytometry of the kidneys from both groups of mice probing specifically for neutrophils. Representative scatter plots from each group are presented in D, whereas E shows the quantitation of neutrophils shown as bar graphs±SEM. The wild-type bar in E is derived from the data presented in Figure 2, and is shown for comparison. IL-17 neutralization in THP−/− significantly reduced serum G-CSF levels, neutrophilia in the periphery and within the kidney. Asterisk denotes statistical significance compared to IgG controls, whereas the symbol # denotes significance compared to Day 0 (P<0.05). Neut, neutrophil.