Effect of prior depletion of CD4⁺CD25⁺ T cells by anti-CD25 antibody on tolerance induction. (A) Diagram of anti-CD25 dosing schedule. (B-C) Anti-CD25 treatment depleted CD4⁺CD25⁺ T cells but not CD4⁺CD25⁻FoxP3⁺ T cells in peripheral blood at day 8 after plasmid injection. (B) Representative dot plots of staining. (C) Summary of the data. (D) FVIII activities in hemophilia A mice treated with anti-CD25⁺FVIII plasmid + anti-CD3 (n = 4/group) or with IgG1 + FVIII plasmid + anti-CD3 control (n = 4/group). One of 2 independent experiments is shown.