A Foxp3 Staining Buffer Set (eBioscience) was used for Foxp3 or T-bet staining or when cells were analyzed for Foxp3 and cytokine expression simultaneously; otherwise, BD Cytofix/Cytoperm and Perm/Wash buffers (BD Biosciences) were used in intracellular cytokine staining assays. Cell sorting was performed with a FACSDiva or FACSAria and cell analysis with a FACSCalibur or LSRII (BD Biosciences).