Figure 4: Effect of pretreatment with anti-IL-33 or a control antibody to β-galactosidase on the airway inflammatory response. (a) Relative accumulation of eosinophils, assessed by eosinophil peroxidase activity. (b) Number of neutrophils in lung tissue, assessed by immunostaining. (c) Concentration of IL-6 in BAL fluid. (d) Concentration of CXCL-1 in BAL fluid. Data are mean ± SEM ( samples per group). Significant differences relative to the naïve group are shown as , , and and those relative to the control antibody-treated group are shown as , , and .