CD4⁺CD25⁺ cells did not inhibit APC function.

(A) Immature monocyte-derived dendritic cells (1 × 10⁶) were cocultured with either CD4⁺CD25⁻ or CD4⁺CD25⁺ (1 × 10⁶) cells or medium for 48 hours. The cells were stained with FITC-conjugated monoclonal antibodies. The mean florescence intensities were measured. Dendritic cells were gated according to the forward and side scatter characteristics. (B) Notch signaling was specifically increased in CD4⁺CD25⁺ cells upon stimulation. Transcription of Notch-4, Delta-1, Hes-1, and deltex in CD4⁺CD25⁺ and CD4⁺CD25⁻ cells, before and after activation with anti-CD3 and anti-CD28. Transcription of each gene is normalized to that of GAPDH.