FIG. 1.

Flow cytometric analysis of peripheral blood mononuclear cells (PBMCs). (A) PBMCs were stained with antigen-presenting cell (APC)-conjugated anti-CD4 (y-axis) and phycoerythrin (PE)-conjugated anti-CD25 (x-axis) and analyzed by flow cytometry. The CD4⁺CD25^high cells exhibiting a slightly reduced expression of CD4 were considered regulatory T cells (Tregs). (B, C) PMBCs were stained either with PE-conjugated antihuman FoxP3 or an isotype control as well as fluorescein isothiocyanate (FITC)-conjugated anti-CD4 and APC-conjugated anti-CD25 and analyzed by flow cytometry. (B) Histogram demonstrating FoxP3 expression in gated CD4⁺CD25^high cells (Tregs). (C) Histogram demonstrating absence of FoxP3 expression in gated CD4⁺CD25⁻ cells (T effector [Teff] cells). ---, FoxP3 stain; ---, isotype control.