Figure 4. CCR6 regulates homeostatic γδT17 cell recruitment to dermis.

(a) Representative flow cytometry and quantitation of CD45⁺CD3^loTCR-γδ^lo (γδT^lo) cells from ear skin dermis of naïve wild type (WT) (n=13), Ccr6^−/− (n=11), Ccr2^−/− (n=10) and Ccr2^−/−Ccr6^−/− mice (n=5). (b) Representative flow cytometry of Vγ4 expression by dermal γδT^lo cells and quantitation of Vγ4⁺ and Vγ4⁻ γδT^lo cells in dermis of WT and Ccr6^−/− mice (n=7/group). (c) WT or Ccr6^−/− lymphocytes were transferred i.v. into naïve Ly5.1 mice (n=4/group). After 36 h, number of CD45.2⁺ γδT^lo/γδT17 cells recovered was expressed as % of number transferred. Representative flow cytometry of dermal CD45.2⁺ cells and quantitation of γδT17 cell recovery and Vγ4⁺:Vγ4⁻ ratio (normalized to input). (d) Ccl20 mRNA from whole tissues or sorted CD45⁻ epidermal keratinoctyes (Sca-1⁺Ep-CAM^lo interfollicular epidermis (IE), Sca-1^lo/+Ep-CAM⁺ infundibulum and isthmus (IF & IS), Sca-1^loEp-CAM^lo double negative (DN)) or CD45⁻ dermal populations (CD31⁻CD90⁺CD140α⁺ fibroblast, gp38⁺CD31⁺ lymphatic endothelial cells (LEC), gp38^loCD31⁺ blood endothelial cells (BEC), CD31⁻CD90⁻CD140α⁻ double negative (DN)) from naïve WT mice (pooled from 5 mice/experiment). ND, not detected. See also Supplementary Fig. 5. Mean±s.e.m. (a,d) Pooled from three experiments, (c) representative of two similar experiments. (a) One-way ANOVA with Bonferroni's multiple comparisons test, (b,c) unpaired two-tailed Student's t-test. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.