Figure 6. Stability of AH-induced FoxP3 expression.

(A) FoxP3 expression is initially unstable, but can be stabilized by DNA demethylation or continued presence of AH. CD4⁺ T cells from C57BL/6 FoxP3-GFP reporter mice were activated with anti-CD3/CD28 in the presence of AH for 72 h (1^st culture). GFP⁺ cells from 1^st culture were re-stimulated for another 72 h in the absence or presence of AH or Aza (2^nd culture). (B) FoxP3 expression stabilizes after three cycles of stimulation in AH. CD4⁺ T cells were stimulated as in panel A, with or without AH, for 3 cycles. After the 3^rd stimulation cells were re-stimulated for the 4^th time without AH. Expression of FoxP3 was determined by flow cytometry. Shown is a representative experiment of three.