DC-10 induce Tr1 cells. Naive CD4⁺ T cells were stimulated with allogeneic iDCs [T(iDC)], DC-10 [T(DC-10)], or mDCs [T(mDC)] for 14 days. After stimulation, T cells were activated with immobilized anti-CD3 mAb and phorbol myristate acetate (TPA), and cytokine production was determined by intracytoplasmic staining and cytofluorometric analysis. (A) One representative experiment of 9 performed is presented. (B) Percentages of IFN-γ–, IL-2–, IL-4–, and IL-10–producing cells in T(iDC), T(DC-10), and T(mDC) cells generated from each of the 9 donors tested are presented. ***P ≤ .001, IL-10 production by T(DC-10) cells vs T(iDC) cells. °°P ≤ .01, °°°P ≤ .001, IL-10, IL-2, and IFN-γ production by T(DC-10) cells vs T(mDC) cells.