The total CD4+CD127−/lowCD25+ Treg cell (total Treg cells) population (purity: mean, 91.9% (82.8-95.9%) of total sorted live CD4+ cells) was sorted into 3 phenotypically distinct subpopulations, based on expression of CD25 and the naive T cell marker CD45RA: CD127−/lowCD25intCD45RA− (CD25int memory Treg [mTreg]) and CD127−/lowCD25hiCD45RA− memory Treg (CD25hi mTreg); and CD127−/lowCD25intCD45RA+ naive Treg (naive Treg) (Figure 1A). Purity of sorted populations was mean 87.6% (81.0-95.3%) CD25int mTreg, mean 73.8% (63.9-84.7%) CD25hi mTreg and mean 75.6% (36.9-94.9%) naive Treg of total live CD4+ cells.