Expression of functional IL-2 receptors on mature splenic dendritic cells

We report here the expression of functional IL-2 receptor (IL-2R) on mature splenic dendritic cells (DC) and synergistic effect of IL-2 on IFN-gamma p roduction by DC. IL-2 augmented IL-12-dependent IFN-gamma production by DC purified from both splenocytes of wild-type and anti-asialoGM1 Ab-treated R ag-2(-/-) splenocytes devoid of T, B, NK and NKT cells. A neutralizing mAb against IL-2R alpha blocked such enhancing effect of IL-2 on IFN-gamma prod uction, indicating the presence of functional IL-2R on DC. Synergistic effe cts of IL-2 were also observed on IFN-gamma production by DC stimulated thr ough CD40 or MHC class II, suggesting that T cell-derived IL-2 can act on D C during antigen presentation. Furthermore, we provide evidence that DC pro duce IFN-gamma during interaction with allogeneic CD4(+) T cells from IFN-g amma(-/-) mice. These results suggest that IL-2 produced by naive T cells u pon antigen stimulation is an important factor during Th0 to Th1 differenti ation by inducing IFN-gamma from DC.