Treg cells preferentially inhibit the accumulation of E CD8⁺ T cells. Total CD8⁺ T cells were stimulated for 5 days with anti-CD3 mAb in the presence of CD4⁺CD25⁻ T cells (open symbols) or Treg cells (filled symbols). (A) Percentages of CFSE^low M and E CD8 T-cell subsets (n = 9). (B) Pooled data from 9 donors: mean percentages of inhibition of the proliferation of CD8⁺ T-cell M and E subsets. (C) Sorted M and E CD8⁺ T cells were stimulated in the presence of Treg cells or CD4⁺CD25⁻ cells. Pooled data from 5 donors: mean percentages of inhibition of the proliferation are shown. The mean values are depicted with horizontal lines. P values were calculated using a paired Student t test.