0.2x105 magnetic-activated cell sorting (MACS)-purified (Pan TC Isolation Kit, Miltenyi, Germany) carboxyfluorescein succinimidyl ester (CFSE)-stained (BioLegend) T cells from naive C57BL/6 mice treated with DMF or control were plated in 96-well plates and stimulated with 0, 0.125 or 0.25 microg/mL LEAF purified anti-mouse CD3 (BioLegend) and 0.5 microg/mL LEAF purified anti-mouse CD28 antibodies (BioLegend) for 72 h