Role of IL-10 and TGF-β in suppression mediated by T_(imm) cells. (A) After 3 rounds of activation with immature DCs, T_(imm) cells were tested for their ability to suppress the proliferation of CD4⁺ T cells in response to mature DCs, in the absence or presence of anti–IL-10R (30 μg/mL) and anti–TGF-β (50 μg/mL) mAbs. (B) Similar experiments were performed to assess the suppression of IFN-γ production by CD4⁺ T cells in response to mature DCs. (C) In parallel, proliferation and suppression in response to allogeneic monocytes was tested. [³H]-Thymidine was added at the indicated time for an additional 16 hours. Results are representative of 3 independent experiments.