CD4⁺CD25⁺ cells inhibit the production of Th1 cytokines by sorted CD4⁺CD69⁺ T cells.

(A) CD4⁺CD25⁺ and CD4⁺CD69⁺ cells were sorted from purified CD4⁺ T cells. (B) Production of IFN-γ and TNF-α by sorted CD4⁺CD69⁺ and CD4⁺CD25⁺ cells in the presence of purified CD14⁺ T cells following stimulation with P1–P6. (C–E) Sorted CD4⁺CD25⁺ and CD4⁺CD69⁺ cells were cultured at different ratios and cocultured with purified CD14⁺ cells in the presence or absence of P1–P6. The supernatants were collected, and cytokine production was assessed by ELISA. One representative result from three independent experiments with similar results is shown. Significant differences compared with incubation with P1–P6 in the absence of Tregs are indicated (*, not significant;**, P<0.05;***, P<0.001).