Fig. 2

IL-33^−/− mice exhibit decreased neutrophil recruitment and leukocyte–endothelial interactions in brain microvessels after i.c.v. LPS administration. WT and IL-33^−/− mice received i.c.v. saline or LPS administration, and after 12 or 24 h, MPO staining was performed to quantitate the neutrophils infiltrating the cortex (a). IL-33^−/− mice exhibited significantly reduced MPO-positive neutrophils in the cortex (a, b). At 4 h after LPS injection, intravital microscopy was employed to visualize leukocyte–endothelial interactions. WT and IL-33^−/− mice were treated with saline (c, d) or LPS (e, f). Quantitative data of infiltrated neutrophils (b) and leukocyte rolling (g) and adhesion (h) are shown as the mean ± SEM. n = 4 mice per group. **P < 0.01 and ***P < 0.001