Nfkb1–/– C-Rel–/– pDCs do not undergo morphologic or phenotypic activation in response to CpG-ODN stimulation. Purified splenic pDCs isolated from wt, Nfkb1–/–, C-Rel–/–, and Nfkb1–/–C-Rel–/– mice were incubated for 16 hours in culture in the absence or presence of CpG1668-ODN. (A) The morphology of CpG-stimulated CD11cintCD45RAhi pDCs. These data are representative of 5 independent experiments. (B) Impaired induction of the activation markers CD8 and MHCII in Nfkb1–/–C-Rel–/– pDCs. The expression of CD8 and MHCII are shown on viable unstimulated (heavy dark line) or CpG-stimulated (gray shaded) pDCs from mice of different genotypes. Unstained controls are represented by dotted histograms. This data are representative of results obtained from 5 independent experiments. (C) The Nfkb1–/–C-Rel–/– pDC activation defect is common to TLR-7 and different TLR-9 ligands. MHCII expression was monitored on wt (heavy line) and Nfkb1–/–C-Rel–/– (gray shaded) pDC stimulated with the TLR-7 ligand R848 (splenic pDCs), influenza virus (splenic pDCs), or CpG (thymic pDCs). Unstained controls are represented by dotted histograms. These data are representative of 5 and 2 experiments done with the splenic and thymic pDC populations, respectively.
