Project description:Defense against attaching and effacing (A/E) bacteria requires the sequential generation of IL-23 and IL-22 to induce protective mucosal responses. While the critical source of IL-22 has been identified as CD4+ and Nkp46+ innate lymphoid cells (ILCs), the precise source of IL-23 is unclear. Here, we use genetic techniques to deplete specific classical dendritic cell (cDC) subsets and analyze immunity to the A/E pathogen Citrobacter rodentium. We find that Zbtb46+ cDCs, and specifically Notch2-dependent intestinal CD11b+ cDCs, but not Batf3-dependent CD103+ cDCs, are required for IL-23 production and immunity against C. rodentium. Notch2 controls cDC differentiation at a terminal step mediated by lymphotoxin signaling. Importantly, these results provide the first demonstration of a non-redundant function of CD11b+ cDCs in vivo. Analysis of Notch2-dependent genes in CD11b+ and DEC205+ splenic classical DC subsets. Splenocytes were harvested from littermate WT Notch2 f/f C57Bl/6 or Notch2 CD11c-cre C57Bl/6 mice and DC subsets sorted to >95% purity on the FACSAriaII.
Project description:Defense against attaching and effacing (A/E) bacteria requires the sequential generation of IL-23 and IL-22 to induce protective mucosal responses. While the critical source of IL-22 has been identified as CD4+ and Nkp46+ innate lymphoid cells (ILCs), the precise source of IL-23 is unclear. Here, we use genetic techniques to deplete specific classical dendritic cell (cDC) subsets and analyze immunity to the A/E pathogen Citrobacter rodentium. We find that Zbtb46+ cDCs, and specifically Notch2-dependent intestinal CD11b+ cDCs, but not Batf3-dependent CD103+ cDCs, are required for IL-23 production and immunity against C. rodentium. Notch2 controls cDC differentiation at a terminal step mediated by lymphotoxin signaling. Importantly, these results provide the first demonstration of a non-redundant function of CD11b+ cDCs in vivo. Analysis of differentially expressed genes in ESAM+ and ESAM- CD11b+ and DEC205+ splenic classical DC subsets. Splenocytes were harvested from WT C57Bl/6 or WT Cx3cr1-gfp mice and cDC subsets sorted to >95% purity on the FACSAriaII.
Project description:Analysis of L-Myc-dependent genes in pDCs and classical DC subsets with and without stimulation. Splenocytes were harvested from C57BL/6 wild-type (WT) or 10 generation C57BL/6 backcrossed Mycl1-gfp/gfp (LmycKO) mice and DC subsets sorted to >95% purity on the FACSAriaII.
Project description:Analysis of the differential transcriptome of DC derived from tissue vs. LN origin. The overall hypothesis is these data would reveal how migratory DC may be differently programmed from classical DC and might also suggest difference within migratory DC subsets relating to function. RNA obtained from migratory DC subsets and classical CD8a DC isolated by flow cytometry sorting from skin draining LNs of Flt3L treated mice or LPS treated mice
Project description:Dendritic cells (DCs) in tissues and lymphoid organs comprise distinct functional subsets that differentiate in situ from circulating progenitors. Tissue-specific signals that regulate DC subset differentiation are poorly understood. We report that DC-specific deletion of the Notch2 receptor caused a reduction of DC populations in the spleen. Within the splenic CD11b+ DCs, Notch signaling blockade ablated a distinct population marked by high expression of adhesion molecule Esam. The Notch-dependent Esamhi DC subset also required lymphotoxin beta receptor signaling, proliferated in situ and facilitated efficient CD4+ T cell priming. The Notch-independent Esamlo DCs expressed monocyte-related genes and showed superior cytokine responses. In addition, Notch2 deletion led to the loss of CD11b+ CD103+ DCs in the intestinal lamina propria and to the corresponding decrease of IL-17-producing CD4+ T cells in the intestine. Thus,Notch2 is a common differentiation signal for T cell-priming CD11b+ DC subsets in the spleen and intestine.
Project description:Dendritic cells (DCs) in tissues and lymphoid organs comprise distinct functional subsets that differentiate in situ from circulating progenitors. Tissue-specific signals that regulate DC subset differentiation are poorly understood. We report that DC-specific deletion of the Notch2 receptor caused a reduction of DC populations in the spleen. Within the splenic CD11b+ DCs, Notch signaling blockade ablated a distinct population marked by high expression of adhesion molecule Esam. The Notch-dependent Esamhi DC subset also required lymphotoxin beta receptor signaling, proliferated in situ and facilitated efficient CD4+ T cell priming. The Notch-independent Esamlo DCs expressed monocyte-related genes and showed superior cytokine responses. In addition, Notch2 deletion led to the loss of CD11b+ CD103+ DCs in the intestinal lamina propria and to the corresponding decrease of IL-17-producing CD4+ T cells in the intestine. Thus,Notch2 is a common differentiation signal for T cell-priming CD11b+ DC subsets in the spleen and intestine. We compared genome-wide expression profiles of wild-type Esam(hi) and Esam(lo) splenic CD11b+ DC populations, along with CD11b+ DCs from DC-RBPJΔ mice. Spleens from 2-3 Cx3cr1-GFP+ RBPJflox/flox CD11c-Cre+ mice or Cx3cr1-GFP+ RBPJflox/flox Cre-negative littermate controls were isolated, pooled and depleted of lymphoid and erythroid cells by negative selection on MACS columns. Live cells were stained for surface expression of CD11c, CD11b and Esam. CD11c(hi) CD11b+ DCs from control mice could be separated into Esam(lo) GFP(hi) versus Esam(hi) GFP(lo) subsets. CD11c(hi) CD11b+ DCs from RBPJ-targeted mice spleens were uniformly Esam(lo) GFP(hi). The two subsets from control mice and single Esam(lo) GFP(hi) subset from RBPJ-targeted mice were sorted using FACSAria II flow sorter and analyzed using GeneChip Mouse Gene 1.0 ST Array (Affymetrix).