Fig. 4.

FOXP3 expression in IPEX. (A and B) Normal (1745), IPEX-like (A), and IPEX (B) PBMC were stained for cell-surface markers and FOXP3 with mAb 3G3. Gated CD4⁺ cells are shown. Histograms show FOXP3 expression (A) and side scatter (B) on CD4⁺ cells expressing varying degrees of CD25 as delineated in the adjacent 2D plots. Because the staining procedure results in a decrease in forward scatter, side scatter is a better indicator of cell size. Staining was performed before the development of protocols by using digoxigenin-conjugated rabbit antibody, but additional PBMC from these patients were not available for further study. PBMC shown in A and B were stained in separate experiments. (C) Freshly isolated or simulated (100 ng/ml anti-CD3; 3 days) normal (2020) or IPEX-2-P2 PBMC were stained for FOXP3 with mAb 259D (14).