Effects of anti–Gr-1 (Ly6G/C) and anti-Ly6G mAbs on depletion of neutrophils before and after the onset of CIA. (A) Myeloid and CD8 T-cell counts in peripheral blood (cells × 106/mL blood; mean ± SEM) from mice with high G-CSF levels (day 22 after CII/CFA immunization). WT DBA/1 mice were primed with CII/CFA, then injected intraperitoneally on days 15, 17, and 20 with 0.5 mg mAb (anti–Gr-1, anti-Ly6G, or 1:1 mix of rat IgG2a and rat IgG2b) and analyzed on day 22 (n = 4 mice per treatment). *P < .05. (B) Myeloid cell counts in WT DBA/1 mice treated with either isotype control mAb or anti-Ly6G mAb 14 days after the onset of CIA. *P < .001. Representative flow cytometric profiles are shown in panels A and B. Numbers indicate the percentage of total cells within the gate.