cDCs-derived macrophages suppress T-cell proliferation. (A) Serial 2-fold diluted DC-d-Ms or cDCs were added into the wells containing 1 × 105 OT-I T cells and 1 × 104 OVA-peptide–pulsed cDCs. The cells were incubated for 60 hours. Tritiated thymidine was added to the wells for last 12 hours. Results are expressed as mean cpm × 103 ± SD. Data are representative of > 3 independent experiments. (B) Expression of indicated antigens on DC-d-Ms. (C-E) Production of IL-10, nitric oxide, and arginase by DCs and DC-d-Ms stimulated with or without LPS for 16 hours. Data are representative of 3 independent experiments with similar results. (F) Proliferation of OT-I T cells cultured for 60 hours as in panel A in the presence or absence of anti–IL-10R mAb (10 μg/mL), anti–PD-L1 mAb (10 μg/mL), Nor-NOHA (500μM), or L-NIL (200μM). Data are representative of > 3 independent experiments. NS indicates not significant (P > .05); *P < .05, **P < .005, ***P < .001.