Effect of IL-4 on Already Existing Natural or Inducible Treg Cells
(A) CD4+CD25high nTreg cells were FACS-sorted and activated with plate-bound anti-CD3/CD28 plus IL-2 during 3 d and in the presence or absence of IL-4 (100 ng/ml) and harvested for real-time PCR analysis. The results shown represent the mean +/- SD of three independent experiments. 
(B) iTreg cells were induced in vitro. FOXP3 espression was assessed by real-time PCR analysis in resting cells, in cells re-stimulated with plate-bound anti-CD3/CD28, with or without TGF-beta, plus IL-2 during 3 d and in the presence (black bar) or absence (white bar) of IL-4 (100 ng/ml). 
(C) Activation dramatically increases CD4+CD25+ Treg cells suppressive capacity of CD4+CD25+ nTreg cells. CD4+CD25+ nTreg cells were preactivated during 2 d in the presence or absence of an increasing IL-4 concentration. After vigorous washing, their suppressive capacity on responder CD4+CD25- was tested. IL-4 pretreatment did not affect the suppressive capacity of FACS-sorted CD4+CD25high cells. 1 x 104 CD4+CD25+ nTreg cells were added to 5 x 104 CD4+CD25- and 5 x 104 irradiated PBMCs. The results are representative of three independent experiments. 
(269 KB AI). 
