Figure 3.

Induction of Foxp3 is dependent on TGF-β. (A) CD4⁺ T cells from DO11.10 SCID mice were cultured with 5 × 10⁴ CD103⁺ or CD103⁻ MLN DCs, 0.2 μg/ml OVA peptide, and 50 μg/ml anti–TGF-β or isotype control. At day 6 of culture, T cells were stained for CD4 and Foxp3 and analyzed by FACS. Representative plots from two independent experiments are gated on CD4⁺ cells, and numbers represent the percentage of CD4⁺ cells in each quadrant. (B) CD103⁺ and CD103⁻ DCs were sorted from the MLNs of BALB/c mice. Tgfb2, ltbp3, and plat gene expression was assayed by quantitative PCR and normalized relative to expression of HPRT. Data shown are representative of two independent experiments. (C) CD4⁺ T cells from DO11.10 SCID mice were cultured with 10⁵ CD103⁺ or CD103⁻ MLN DCs, 0.2 ug/ml OVA peptide, and the indicated concentrations of rhTGF-β. At day 6 of culture, T cells were stained for CD4 and Foxp3 and analyzed by FACS. Representative plots from three similar experiments are gated on CD4⁺ cells, and numbers represent the percentage of Foxp3⁺ cells among CD4⁺ T cells.