Figure 2.

Preferential role of the Bim/Bcl-2 axis in controlling iTreg survival. (a and b) Tconv were isolated from WT or Bim^−/− Foxp3^GFP mice and activated with anti-CD3/CD28-coated beads in the presence of TGF-β (5 ng/ml) and IL-2 (100 U/ml) for 3 days to induce iTreg differentiation. The iTregs (GFP⁺) and activated Tconv (GFP⁻) were then sorted by FACS and cultured for additional 3 days in the absence of IL-2. Percentage of live iTregs and Tconv was determined by flow cytometry with propidium iodide (PI) and anti-Annexin V. Data are the mean±S.E. of four independent experiments with statistical analysis performed using standard paired t-test (^*P<0.05). (c) iTregs (GFP⁺) and activated Tconv (GFP⁻) were cultured in the presence of various IL-2 concentrations for 3 days and percentage of live cells determined by PI and anti-Annexin V. Data is representative of two independent experiments