Cell isolation
Inguinal lymph nodes were collected (draining lymph nodes [LNs]) and used for the experiments. CD4+ cells from draining LNs were isolated by positive selection using the magnetic activated cell sorting (MACS) system with anti-CD4 mAb (Miltenyi Biotec, Bergisch Gladbach, Germany). CD4+GFP+Treg (Foxp3+Treg) or CD4+GFP-T cells were isolated with MoFlo cell sorter (DakoCytomation, Glostrup, Denmark) from MACS-isolated CD4+ T cells of C57BL/6-Foxp3GFP mice. The isolated cells were then used forcell culture and flow cytometry.