CD11c⁺ DCs activated by TSLP together with CD40L prime naive CD4⁺ T cells to produce Th1 and Th2 cytokines. (A) DCs activated with TSLP, CD40L, or both stimuli were used to prime naive CD4⁺ T cells. After 6 days of coculture, T cells were restimulated for 24 hours with anti-CD3 and anti-CD28, and T cell-derived cytokines were measured in the culture supernatant using ELISA. (B) DCs activated by TSLP or IL-4 with or without CD40L were used to prime naive CD4⁺ T cells. After 6 days of coculture, T cells were restimulated for 5 hours with PMA and ionomycin, and T cell-derived cytokine production was determined by intracellular cytokine staining. Numbers indicate the percent of cells in each quadrant. Data shown are from 1 of 3 representative independent experiments.