Classical Dendritic Cell Development Excludes Alternative Myeloid Cell Fates Characterized by Distinct Transcription Factors

Dendritic cells (DCs) play key roles in the interface between innate and adaptive immunity. They are capable of detecting a wide range of pathogens and other stimuli; they internalize, process, and present antigens; and they modulate the activity of other immune cells. Recent advances have demonstrated that distinct subsets of DCs play unique roles at steady state and under inflammatory conditions. We found that the transcription factors Bcl11a and Zeb2 are each essential for development of plasmacytoid DCs but dispensable for development of classical DCs in vivo. Zeb2-deficient bone marrow cells are also deficient in replenishment of monocytes, which along with their macrophage progeny represent a hematopoietic lineage closely related to that of DCs. Finally, we developed a lineage-tracing mouse strain using Cre recombinase under the control of the transcription factor-encoding locus Mafb; with that model, we determined that Langerhans cells in the skin are unique in displaying certain characteristics of both macrophages and DCs