T cells constitutively expressing CD25 were responsible for production of IL-10, whereas IFN-γ was produced from CD25⁻ T cells.

The CD25⁺ population was 83% pure. (A) Addition of 1 × 10⁴ H-ferritin– (1 μg/mL) pretreated DCs to 1 × 10⁵ anti-CD3–stimulated CD25⁺ and CD25⁻ subpopulations increased IL-10 production (24 hours) only in the CD25⁺ T-cell population. (B) H-ferritin induces IFN-γ production in CD25⁻ T cells, and this is amplified through the depletion of CD25⁺ T cells.