During infections and inflammation, plasmacytoid dendritic cells (pDCs) are the most potent type I interferon (IFN-I) producing cells. However, the developmental origin of pDCs and the signals dictating pDC generation remain incompletely understood. Here, we report a synergistic role for IFN-I and Flt3 ligand (FL) in pDC development from common lymphoid progenitors (CLPs). Both conventional DCs and pDCs were generated from CLPs in response to FL, while pDC generation required higher concentrations of FL and concurrent IFN-I signaling. An absence of IFN-I receptor, impairment of IFN-I signaling, or neutralization of IFN-I significantly impeded pDC development from CLPs. Furthermore, FL induced IFN-I in CLPs, resulting in Flt3 upregulation that promotes survival and proliferation of CLPs, as well as their differentiation into pDCs. Collectively, these results define a critical role for the FL/IFN-I/Flt3 axis in pDC differentiation from CLPs and identify a potential target for therapeutic intervention in inflammatory and autoimmune diseases associated with pDCs.
- Copyright © 2013 by The American Association of Immunologists, Inc.