Interleukin-3Ralpha+ myeloid dendritic cells and mast cells develop simultaneously from different bone marrow precursors in cultures with interleukin-3.

The distinct developmental routes of dendritic cells and mast cells from murine bone marrow cultures with interleukin-3 are unclear. We found that short-term bone marrow cultures with interleukin-3 after 8-10 d consist of about 10%-30% dendritic cells and 70%-90% mast cell precursors, and only after 4-6 wk do homogeneous populations of mast cells emerge. Phenotypical and functional analysis of interleukin-3/dendritic cells revealed a high similarity with myeloid dendritic cells generated with granulocyte-macrophage colony stimulating factor in the expression of myeloid dendritic cell markers (CD11c+ B220- CD8alpha- CD11b+), major histocompatibility complex II and costimulatory molecules, endocytosis, maturation potential, interleukin-12 production, and T cell priming.