Functional maturation of iNKT cells. (A) CD8-depleted thymocytes (n = 5), CB cells (n = 6), or PBMCs (n = 6) were stimulated with agonistic anti-CD3 mAb-coated plates followed by staining of iNKT cells with 6B11 and detection of intracellular IL-4 and IFN-γ by flow cytometry. Diagrams show expression of IL-4 and IFN-γ after gating on 6B11-positive events. (B) Staining for intracellular cytokines is repeated in iNKT cells from thymus (top) and CB (middle, bottom) after in vitro expansion with 6B11 and IL-2. Expression of cytokines in expanded CB iNKT cells is plotted against CFSE fluorescence. Representative results from 5 independent experiments are shown.