Differential percentage of donor-type CD103⁺FoxP3⁺ Treg cells in chimeric recipients with or without chronic GVHD. (A,B) Sublethally irradiated BALB/c recipients were transplanted with 6.25 or 100 × 10⁶ DBA/2 donor spleen cells. The recipients were monitored for proteinuria and survival weekly. There were 12 mice in each group combined from 3 replicate experiments. (C,D) Spleen cells from additional recipients with or without clinical chronic GVHD 20 days after transplantation and control DBA/2 donor mice were stained with anti-CD5.1 (donor T cell marker), CD4, CD103, and FoxP3. A representative staining pattern of 4 recipients and the percentage (mean ± SE) of CD103⁺FoxP3⁺ and CD103⁻FoxP3⁺ cells among total CD5.1⁺CD4⁺ cells are shown.