In vitro T cell differentiation.
CD4+ CD45RA+ magnetically-sorted (CD45RO depletion, MACS, according to the protocol of the manufacturer) cells were stimulated with immobilized plate-bound anti-CD3 (1 mug/ml, Okt3, IgG1) and anti-CD28 (2 mug/ml) in Th1 conditions: 25 ng/ml IL-12, 5 mug/ml anti-IL-4 (R&D systems); in Th2 conditions: 25 ng/ml IL-4, 5 mug/ml anti-IFN-gamma, 5 mug/ml anti-IL-12 (R&D systems); or in Treg conditions: 10 ng/ml TGF-beta, 5 mug/ml anti-IFN-gamma, 5 mug/ml anti-IL-12, 5 mug/ml anti-IL-4. Proliferating cells were expanded in medium containing IL-2 (30 ng/ml). 
