Characterization of distinct conventional and plasmacytoid dendritic cell-committed precursors in murine bone marrow

The developmental pathways and differentiation relationship of dendritic cell (DC) subsets remain unclear. We report that murine CD11c⁺MHC II^- bone marrow cells, which are immediate DC precursors of CD8α⁺, CD8α^-, and B220⁺ DC in vivo, can be separated into B220⁺ and B220^- DC precursor subpopulations. Purified B220^- DC precursors expand, and generate exclusively mature CD11c⁺CD11b⁺B220^- DC in vitro and after adoptive transfer. B220⁺ DC precursors, which resemble plasmacytoid pre-DC, have a lower proliferate potential than B220 ^- DC precursors and generate both CD11b^- B220⁺ and CD11b⁺B22^- DC populations. Both DC precursor populations can give rise to CD8α⁺ and CD8α^- DC subtypes. Our findings indicate that CD11c⁺MHC II ^-B220⁺ and CD11c⁺MHC II^-B22 ^- bone marrow cells are distinct DC lineage-restricted precursors.