Autocrine IFN-α/β is responsible for the increased IP-10 production in diffDCs stimulated by TLR agonists. (A) Kinetics of mRNA expression of IFN-α and IFN-β in imDCs and diffDCs stimulated with or without LPS. (B-C) IFN-α and IFN-β production by imDCs and diffDCs (1 × 10⁶ cells/mL) after stimulation with various concentrations of LPS for 24 hours. (D-E) IFN-α and IFN-β production by imDCs and diffDCs (1 × 10⁶ cells/mL) after stimulation with 500 ng/mL LPS for indicated time. (F-G) IFN-α and IFN-β production was measured by ELISA in culture supernatants of imDCs and diffDCs (1 × 10⁶ cells/mL) stimulated with different TLR agonists as in Figure 1D for 24 hours. Data are shown as means ± SD of 3 independent experiments. (H-I) imDCs and diffDCs were pretreated with 6.25 μg/mL and 12.5 μg/mL neutralizing antibody of mIFN-α or mIFN-β or isotype antibody, respectively, for 30 minutes and then stimulated with 500 ng/mL LPS or poly(I:C) for 24 hours. The level of IP-10 in supernatants was determined by ELISA. imDCs and diffDCs cultured in medium (untreated DCs) were used as controls. *P < .05.