Cells from small and large intestinal lamina propria were prepared as previously described (Sun et al., 2007 (link)). Skin and lung tissues were diced and subsequently digested with 0.25 mg/ml Liberase TL (Roche) at 37°C for 45 min (lung) or Liberase TL and 1 mg/ml DNase I at 37°C for 1 h and 15 min (skin). Isolated lung cells were further purified using a 37.5% Percoll gradient followed by lysis of red blood cells with ACK buffer. Single-cell suspensions were stained with anti-CD16/32 (eBioscience) and with fluorochrome-conjugated antibodies against any combination of the following surface antigens: CD4, CD8α, CD11b, CD11c, DX5, CD49b, TCRβ, TCRγδ, CD19, Ter119, NK1.1, Gr-1, and Thy1.2. Before fixation, Live/Dead Fixable Blue Cell Stain kit (Invitrogen) was used to exclude dead cells. For examination of transcription factors and cellular proliferation, cells were subsequently treated with the Foxp3 fixation/permeabilization kit (eBioscience) in accordance with the manufacturer’s instructions and stained for 20 min at room temperature with fluorochrome-conjugated antibodies against RORγt, GATA3, and T-bet.