A B220+ CD117+ CD19± hematopoietic progenitor with potent lymphoid and myeloid developmental potential

In this report, we identify in the bone marrow (BM) of normal mice a subpopulation of B220+ CD117+ CD19– NK1.1– cells with potent lymphoid and myeloid developmental potential. These cells represent 0.1–0.2% of nucleated BM cells. By limiting dilution analysis in the presence of the appropriate combination of stromal cells and cytokines, 1 in 5–10 sorted cells formed B cells, 1 in 10–15 formed T cells and 1 in 5–10 generated macrophages. When cultured on a mixture of OP9 stroma and OP9 stromal cells expressing the Notch ligand Delta-like-1, single cells generated both T and B cells. Following intravenous infusion, freshly sorted cells transiently reconstituted both the T and B cell progenitor compartments, generating cohorts of mature T and B lymphocytes. The relationship between B220+ CD117+ CD19– NK1.1– cells of wild-type mice and other multi-lineage BM progenitors is discussed. See accompanying commentary: http://dx.doi.org/10.1002/eji.200535106