Figure 4.

Decreased frequency of cytokine-secreting splenic DCs in the absence of RBP-J. (A) The frequency of IL-12–secreting DCs after TLR ligand challenge in vivo. Control (RBP-J^fl/fl) and CKO (RBP-J^fl/fl CD11c-Cre⁺) mice were injected with saline, LPS, or imiquimod, and IL-12 production in DCs was detected by intracellular staining. Shown are the representative staining profiles of MHC class II⁺ splenocytes and the frequency of IL-12⁺ DCs among total splenocytes (mean ± SD of four to five mice; P < 0.05 for both stimuli). (B and C) The frequency of cytokine-secreting DCs after TLR ligand challenge in vitro. Lymphoid lineage-depleted splenocytes were cultured in the presence of the indicated TLR ligands, and cytokine production in DCs was detected by intracellular staining for IL-12 and TNF-α. Shown are the representative staining profiles of CD11c^high MHC class II⁺ DCs (B) and the frequency of cytokine-secreting total and CD8⁻ and CD8⁺ DCs among the splenocytes (C). The data represent the mean ± SD of three to four mice per genotype; the differences between control and CKO CD8⁻ DCs are statistically significant (P = 0.0002 and P < 0.03 for CpG and imiquimod, respectively).