Cotransfer of CD4⁺CD25⁺ T cells into Rag2^-/- recipient mice with CD25-depleted Tgf-β1^-/- cells. (A) Expression of CD25 on CD4⁺CD3⁺ T cells isolated from Rag2^-/- recipients of CD25-depleted Tgf-β1^-/- cells (n = 4) with cotransfer of either Tgf-β1^-/- CD4⁺CD25⁺ T cells (ii) or Tgf-β1^+/+ CD4⁺CD25⁺ T cells (iii) (n = 3), or without cotransfer (i). (B) CFSE labeling of CD4⁺CD25⁺ T cells in the recipient mice described in panel A. Dot plots are shown for CD4⁺CD3⁺-gated populations, and are representative of the groups described above. Percentages over the inner box gate indicate total CD4⁺CD25⁺ T cells. Arrows indicate CD4⁺ T cells with high expression of CD25⁺. Percentages in panel B indicate percentage of CD4⁺CD25⁺ T cells positive for CFSE.