Role of B7 family members in the ability of systemic and MLN CD11c⁺ DCs to generate antigen-specific CD4⁺Foxp3⁺ iT_regs from CD4⁺Foxp3^– T cells. Generation of KJ1-26⁺Foxp3^EGFP+ T cells from Sp KJ1-26⁺Foxp3^EGFP− T cells by Sp or MLN CD11c⁺ DCs obtained from WT mice and the B7^−/− mice in neutral conditions in the presence or absence of TGF-β1 (A-B) or TGF-β1 plus RA (C-D) was analyzed by flow cytometry. Data are represented by a dot plot, and numbers represent the proportion of Foxp3^EGFP+ cells among gated CD4⁺ T cells in each quadrant (A,C) and are the percentage of positive cells (B,D). *P < .01 compared with WT mice. Data are the mean ± SD, and the results are representative of 4 independent experiments.