Figure 3. Generation of Foxp3⁺ Treg cells from conventional splenic cells induced by FTY720.

The percentage of Foxp3⁺ Treg cells was significantly increased upon FTY720 induction in vitro. CD4⁺CD25⁺ and CD4⁺CD25⁻ cells were purified as indicated and cultured in the presence of FTY720 to generate Foxp3⁺ Treg cells from CD4⁺CD25⁻ cells or increase the percentage of Foxp3⁺ cells in CD4⁺CD25⁺ cells. Foxp3 expression was measured using flow cytometry. (A) Representative results in flow cytometry. CD4⁺ cells were gated. A considerable proportion of Foxp3⁺ cells were found in FTY720-induced CD4⁺CD25⁻ cells from both NOD and WT mice. (B and C) Data summary of flow cytometry. The percentage of Foxp3⁺ subset of CD4⁺ cells was significantly increased in both FTY720-induced CD4⁺CD25⁺ cells and FTY720-induced CD4⁺CD25⁻ cells. The same trend was observed in both NOD and WT mice. (D and E) Absolute number of indicated cells with or without FTY720-induction in MACS-purified CD4⁺CD25⁺ cells (×10⁵). * P<0.01. Experiments were conducted independently for 4 times.