Suppressive functions of CD4⁺ T lymphocytes stimulated with GILZ-expressing DCs. (A-B) Inhibition of GILZ expression and induction of Tregs. DCs, nucleofected with siC or siGILZ and treated or not treated with DEX (10⁻⁷ M), were pulsed with PPD and used to stimulate CD4⁺ T lymphocytes, which were then added in various numbers to CFSE-labeled PBMCs stimulated with PPD. Proliferation of CD4⁺ responders was assessed by flow cytometry. Means ± SEM of 7 experiments are shown in (A), and a representative experiment with 5 × 10⁴ CD4⁺ T lymphocytes added to PBMCs is shown in (B). *P < .05. (C) Induction of Tregs by GILZ-transfected DCs. DCs were nucleofected with pCTRL or pGILZ, pulsed with PPD, and used to stimulate CD4⁺ T lymphocytes; the suppressive function of these lymphocytes was tested on the PPD-induced proliferation of CFSE-labeled CD4⁺ responders. Results shown are representative of 7 experiments. Percentages represent the fraction of CFSE^lo CD4⁺ T lymphocytes cells among CD3⁺CD4⁺ cells.