Figure 4. Genetic ablation of IL-22 and αIL-17 Ab treatment led to amelioration of the psoriatic skin phenotype in R26STAT3C^stopfl/fl CD4Cre mice.

(A) Phenotype score of R26STAT3C^stopfl/fl CD4Cre mice, R26STAT3C^stopfl/fl CD4Cre IL-22^−/− mice, and R26STAT3C^stopfl/fl CD4Cre αIL-17 treated mice at 6, 7, and 8 weeks of age. Data represents 10 to 21 mice per group. The scale ranges from 0 (no phenotype) to 3 (greater than 50% fur loss and/or visibly dry/crusty skin). See methods for detailed description of the scoring system. (B) Representative H&E staining of skin sections from control and R26STAT3C^stopfl/fl CD4Cre mice. Mice are 8 weeks old. Scale bar = 100 μm. Top panel: skin from untreated mice. Middle panel: skin from mice on an IL-22 knockout background. Bottom panel: skin from αIL-17 treated mice. (C) Fold difference of CD3+CD4+ T cells from the skin of R26STAT3C^stopfl/fl CD4Cre and control mice, normalized to the untreated controls within each experiment. (D) Percentage of neutrophils from skin of R26STAT3C^stopfl/fl CD4Cre and control mice. Mice are untreated controls, IL-22^−/−, or αIL-17 treated. For C–D Data is representative of n ≥ 3 independent experiments with n ≥ 6 for each genotype, 6–10 weeks old. Statistical significance was assessed using the (C) Sign test and (C–D) the nonparametric two-tailed Mann-Whitney U test. Significance values are as follows: ns p > 0.05; ** p ≤ 0.01; *** p ≤ 0.001; **** p ≤ 0.0001.