The steady-state development of splenic dendritic cells.

Dendritic cells (DCs) are a heterogenous population of cells that can be grouped into the conventional DCs (cDCs) and plasmacytoid DCs (pDCs), or interferon-producing cells. pDCs are thought to develop in the bone marrow and migrate to the periphery as mature cells. In contrast, cDC precursors are thought to migrate to the periphery, where they further differentiate into cDCs. In the case of migratory cDCs, these precursors are thought to be monocytes, whereas resident cDCs derive from a different precursor. Recent activity on this subject has shed some light on the precursors that differentiate into resident cDCs and pDCs, but often with conflicting findings. Here, we review some of these findings and discuss some of the outstanding issues in the field.