IFNAR signaling in DCs is required for B. fragilis–induced immune responses. WT and IFNAR1-deficient BMDCs were pulsed with B. fragilis for 18 h. (A, C, and D) Cells were harvested and analyzed by qRT-PCR for expression of (A) Ifng, (C) Il6, and (D) Tnfa relative to β-actin. (B and E–H) Supernatant from BMDC cultures were collected and protein secretion was measured for (B) IFNγ, (E) TNF-α, (F) RANTES, (G) CXCL1, and (H) IP-10 by ELISA. Data are representative of two experiments. Statistical significance was determined by two-way ANOVA. P < 0.01 (**), P < 0.001 (***), and P < 0.0001 (****).