TGFβ-induced FOXP3⁺ T cells were neither anergic nor suppressive. (A) Suppression assay of allogeneic CD4⁺CD25⁻ responder cells cultured alone (CD4, □) or with non-TGFβ-treated CD45RA⁺ cells (CD45RA + d7, ♦), TGFβ-treated CD45RA⁺ cells (CD45RA + d7 + TGFβ, ■), activated CD25^hi nTregs (CD25hi d7, ▴), or fresh CD25^hi nTregs (CD25hi d0, ●). The top panel represents the percentage and MFI of the FOXP3⁺ cells. (B) Suppression assay of CFSE-labeled allogeneic CD4⁺CD25⁻ cells cultured alone (right column, clear histogram) or at 1:1 ratio (right column, shaded histogram) with fresh CD25^hi nTregs (CD25hi d0, right top panel), non–TGFβ-treated CD45RA⁺ cells (CD45RA + d7, right middle panel) or TGFβ-treated CD45RA⁺ cells (CD45RA + d7 + TGFβ, right bottom panel). Center column represents proliferation of CFSE-labeled fresh CD25^hi (top panel), non–TGFβ-treated CD45RA⁺ (center panel), or TGFβ-treated CD45RA⁺ cells (bottom panel). Left column represents the FOXP3 expression of each population. Data above are representative of 3 independent experiments. Numbers in each quadrant as in Figure 1.