Gene expression profiling of mouse splenic Dendritic cells subsets

We describe a novel subset of CD8+ DCs in lymphoid organs of naïve mice characterized by expression of the CX3CR1 chemokine receptor. CX3CR1+CD8+ DCs lack hallmarks of classical CD8+ DCs, including IL12 secretion, the capacity to cross-present antigen and their developmental independence of the transcriptional factor BatF3. Gene expression profiling showed that CX3CR1+CD8+ DCs resemble CD8- cDCs. The microarray analysis further revealed a unique plasmacytoid DC (PDC) gene signature of CX3CR1+ CD8+ DCs. A PDC relationship of the cells is further supported by the fact that they harbor characteristic D-J immunoglobulin gene rearrangements and that development of CX3CR1+CD8+ DCs requires E2-2, the critical transcriptional regulator of PDCs. Thus, CX3CR1+ CD8+ DCs represent a unique DC subset, related to but distinct from PDCs. After collagenase D digestion, spleens from Cx3cr1gfp/+ C57BL/6 mice were enriched for CD11c+ cells by magnetic separation according to the manufacturer’s protocol (MiltenyiBiotec GmbH). Splenic CD11chi cells were isolated using the FACS ARIA high-speed sorter (Becton-Dickinson). Total RNA was extracted and subjected to gene expression profiling using the Mouse Genome 430.2 Affymetrix GeneChip