F4 80 percp cy 5

Each mouse lymph nodes and spleen were minced separately and passed through a 70 μm cell strainer to obtain single-cell suspensions. Single cells from the draining lymph nodes were used for the detection of innate immune cells and were stained with the following monoclonal antibodies: F4/80-PerCP-Cy 5.5, CD11c-PE, CD11b-APC, and Ly6G-FITC (BD Biosciences, USA). The γδT and Th17 cells from the spleen samples were detected with the following fluorescent antibodies: CD45-PerCP-Cy 5.5, γδT-PE, CD4-APC, and IL-17A-PE (BD Biosciences, USA). For the surface antigen staining, cells were incubated with the antibodies for 30 min at room temperature (RT) after washing the cells with PBS. To stain the intracellular cytokines, the cells were stimulated with a cell stimulation cocktail (eBiosicence) for 4 h. After that, the cells were stained for surface antigens and then fixed with BD Cytofix buffer, permeabilized by using Perm/Wash reagent (BD Biosciences) and then stained with anti-IL-17A antibodies. The cells were acquired using an LSR II Flow Cytometer (BD Biosciences), and the data were analyzed using the Flow Jo software version 7.0 (Tree Star, California, USA).

Skin samples were separated into dermis and epidermis layers after digestion with dispase II (10 mg/ml, Solarbio, Beijing, China) for 2 h at 37°C. To obtain single cells, shredded dermal tissue was treated with collagenase II (3 mg/ml, Solarbio) and DNase I (5 mg/ml, Solarbio) at 37°C for 120 min. Single cells were also prepared from inguinal lymph nodes and spleen from mice by maceration. Surface staining was performed with fluorescent-labeled antibodies F4/80-PerCP-Cy 5.5, CD11c-PE, CD11b-APC, Ly6C/6G-FITC, CD45-PerCP-Cy 5.5, γδ T-PE (BD Biosciences, New Jersey) for 30 min at room temperature. FACS was performed using LSR II (BD Biosciences) and data were analyzed using Flow Jo version 7.0 (Tree Star, California). Gating strategy for different cell populations was given in Supplementary Figure S3.