Reclassifying plasmacytoid dendritic cells as innate lymphocytes

With respect to their ontogeny, emerging data support a lymphoid origin of plasmacytoid dendritic cells (pDCs), which seem to share a developmental trajectory with B cells. By contrast, conventional dendritic cells (DCs) have a myeloid origin in the common dendritic cell progenitor. Furthermore, pDCs do not seem in most cases to share the classical functional properties of conventional DCs, such as presentation of native antigen and migration via the lymphatics. Therefore, we propose here that pDCs should not be classified as dendritic cells and suggest instead that they should be assigned to a subcategory of innate lymphocytes. We emphasize their potent interferon-producing capacity as a defining feature of these cells.