D ear swelling andeosinophilia observed in CCR22/2 IL-23-Epigenetics injected mouse skin. WT and CCR22/2 mice were injected intradermally in the ear every other day with IL-23, and on day 12, the injected ear skin was isolated and analyzed for mRNA expression of Th1 (IFN-c), Th2 (IL-4, IL-5, IL-13, TSLP) and Th17 (IL-17a, IL-17f) cytokines. In this model of cutaneous inflammation, we did not detect any difference in the expression of IFN-c in the ears of IL23-injected WT and CCR22/2 mice. Similarly, expression of IL17A and IL-17F were comparable in mice of both genotypesIL-23 Induces Th2 Inflammation in CCR22/2 MiceFigure 4. CCR2 ligands are expressed in IL-23-injected WT and CCR22/2 mouse ears. (A) On days 0, 3, 6, 9 and 12, CCL2, CCL7 and CCL12 mRNA were measured by real-time RT-PCR from ears of PBS-injected or IL-23-injected WT mice. Average of three mice. (B) On day 6 and 12, CCL2, CCL7 and CCL12 mRNA was measured by real-time RT-PCR from ears of WT and CCR22/2 IL-23-injected mice. Day 6 results are an average of 11 mice in 3 experiments. Day 12 results are an average of 8 mice in 2 experiments. *p,0.02. doi:10.1371/journal.pone.0058196.gFigure 5. IL-22 mRNA is expressed in IL-23-injected CCR22/2 mouse ears. On days 6 and 12, IL-22 mRNA was measured by real-time RT-PCR from ears of WT PBS-injected or WT and CCR22/2 IL-23-injected mice. Day 6 results are an average of 11 mice per genotype in 3 experiments. Day 12 results are an average of 14 mice per genotype in 4 experiments. doi:10.1371/journal.pone.0058196.g(Figure 6a). The IL-17 family member, IL-17E is known to induce Th2 cytokine responses [50,51], but we failed to detect its 
expression in either WT or CCR22/2 mice (Figure 6a). However, quantitative RT-PCR analysis demonstrated that ears of CCR22/ 2 mice expressed increased IL-4 mRNA compared to ears of WT mice (Figure 6a). Of note, although we detected increased IL-4 mRNA expression in IL-23-injected CCR22/2 ears, WT and CCR22/2 draining lymph nodes and ears contained comparable numbers of IL-4-secreting T cells (Figure 6b). However, we did measure increased mRNA expression of TSLP ?a cytokine known to Epigenetic Reader Domain promote and amplify Th2-type immune responses [52,53], in the ears of CCR22/2 mice (Figure 6a). Additionally, tissue lysate ELISA demonstrated increased TSLP protein expression in the ears of CCR22/2 mice compared to WT mice (Figure 6c), providing a possible mechanistic link to the increased Th2-type immune response observed in these mice. Immunofluorescence staining confirmed TSLP expression by epidermal cells within IL23-injected ears of both WT and CCR22/2 mice (Figure 6d). We did not detect any specific TSLP staining in the dermis. Given the epidermal hyperplasia observed in CCR22/2 mice, the increased TSLP detected in IL-23-injected CCR22/2 mouse skin is likely produced by keratinocytes, although other cell types may also contribute to its production.IL-23 Induces Th2 Inflammation in CCR22/2 MiceFigure 6. Increased TSLP and IL-4 in ears of IL-23-injected CCR22/2 compared to WT mice. On day 12, (A) mRNA of indicated cytokines was measured by real-time RT-PCR from ears of WT PBS-injected or WT and CCR22/2 IL-23-injected mice. Average of 11 mice per genotype in 3 experiments. *p,0.01. (B) Intracellular cytokine staining for IL-4 on gated CD3+ CD4+ T cells following stimulation with PMA and ionomycin was performed and day 12 and analyzed by flow cytometry. Number of IL-4+ CD3+ CD4+ T cells in draining lymph node (left panel) or IL-23-injec.D ear swelling andeosinophilia observed in CCR22/2 IL-23-injected mouse skin. WT and CCR22/2 mice were injected intradermally in the ear every other day with IL-23, and on day 12, the injected ear skin was isolated and analyzed for mRNA expression of Th1 (IFN-c), Th2 (IL-4, IL-5, IL-13, TSLP) and Th17 (IL-17a, IL-17f) cytokines. In this model of cutaneous inflammation, we did not detect any difference in the expression of IFN-c in the ears of IL23-injected WT and CCR22/2 mice. Similarly, expression of IL17A and IL-17F were comparable in mice of both genotypesIL-23 Induces Th2 Inflammation in CCR22/2 MiceFigure 4. CCR2 ligands are expressed in IL-23-injected WT and CCR22/2 mouse ears. (A) On days 0, 3, 6, 9 and 
12, CCL2, CCL7 and CCL12 mRNA were measured by real-time RT-PCR from ears of PBS-injected or IL-23-injected WT mice. Average of three mice. (B) On day 6 and 12, CCL2, CCL7 and CCL12 mRNA was measured by real-time RT-PCR from ears of WT and CCR22/2 IL-23-injected mice. Day 6 results are an average of 11 mice in 3 experiments. Day 12 results are an average of 8 mice in 2 experiments. *p,0.02. doi:10.1371/journal.pone.0058196.gFigure 5. IL-22 mRNA is expressed in IL-23-injected CCR22/2 mouse ears. On days 6 and 12, IL-22 mRNA was measured by real-time RT-PCR from ears of WT PBS-injected or WT and CCR22/2 IL-23-injected mice. Day 6 results are an average of 11 mice per genotype in 3 experiments. Day 12 results are an average of 14 mice per genotype in 4 experiments. doi:10.1371/journal.pone.0058196.g(Figure 6a). The IL-17 family member, IL-17E is known to induce Th2 cytokine responses [50,51], but we failed to detect its expression in either WT or CCR22/2 mice (Figure 6a). However, quantitative RT-PCR analysis demonstrated that ears of CCR22/ 2 mice expressed increased IL-4 mRNA compared to ears of WT mice (Figure 6a). Of note, although we detected increased IL-4 mRNA expression in IL-23-injected CCR22/2 ears, WT and CCR22/2 draining lymph nodes and ears contained comparable numbers of IL-4-secreting T cells (Figure 6b). However, we did measure increased mRNA expression of TSLP ?a cytokine known to promote and amplify Th2-type immune responses [52,53], in the ears of CCR22/2 mice (Figure 6a). Additionally, tissue lysate ELISA demonstrated increased TSLP protein expression in the ears of CCR22/2 mice compared to WT mice (Figure 6c), providing a possible mechanistic link to the increased Th2-type immune response observed in these mice. Immunofluorescence staining confirmed TSLP expression by epidermal cells within IL23-injected ears of both WT and CCR22/2 mice (Figure 6d). We did not detect any specific TSLP staining in the dermis. Given the epidermal hyperplasia observed in CCR22/2 mice, the increased TSLP detected in IL-23-injected CCR22/2 mouse skin is likely produced by keratinocytes, although other cell types may also contribute to its production.IL-23 Induces Th2 Inflammation in CCR22/2 MiceFigure 6. Increased TSLP and IL-4 in ears of IL-23-injected CCR22/2 compared to WT mice. On day 12, (A) mRNA of indicated cytokines was measured by real-time RT-PCR from ears of WT PBS-injected or WT and CCR22/2 IL-23-injected mice. Average of 11 mice per genotype in 3 experiments. *p,0.01. (B) Intracellular cytokine staining for IL-4 on gated CD3+ CD4+ T cells following stimulation with PMA and ionomycin was performed and day 12 and analyzed by flow cytometry. Number of IL-4+ CD3+ CD4+ T cells in draining lymph node (left panel) or IL-23-injec.
