Figure 3.

Eos^−/− mice have normal numbers of Treg with normal suppressive capacities in vitro. Percentage (A) and number (B) of CD4⁺Foxp3⁺ Treg in the spleen, lymph node and thymus of WT and Eos^−/− mice. CD62L expression (C) and BrdU incorporation (D) by Treg in WT and Eos^−/− mice. For measurement of homeostatic proliferation, BrdU (1 mg/mouse) was injected i.p., and the cells were harvested and stained with anti-BrdU and anti-ki67 24 h later. (E) In vitro suppressive capacity of WT and Eos^−/− Treg. WT T effector cells (CD4⁺CD25⁻CD44^lowCD62L^high, 5×10⁴) were activated with soluble anti-CD3 and irradiated T-depleted splenocytes (5×10⁴) either in the absence or presence of Treg (CD4⁺CD25⁺) from WT or Eos^−/− mice for 3 d. Cultures were pulsed with [³H]-thymidine for the last 6 hours of the culture. (F) WT T effector cells (CD4⁺Foxp3-GFP⁻CD44^lowCD62L^high, 5×10⁴) were labeled with cell proliferation dye and placed in culture with irradiated T-depleted splenocytes (5×10⁴) and soluble anti-CD3 either in the absence or presence of Treg (CD4⁺Foxp3-GFP⁺) from WT or Eos^−/− mice. Dilution of cell proliferation dye was measured on day 3.