Single Adult Human CD341/Lin2/CD382 Progenitors Give Rise to Natural Killer

Marrow stromal cultures support adult CD341/Lin2/HLA-DR2 or CD341/Lin2/CD382 cell differentiation into natural killer (NK) or myeloid cells, but unlike committed lymphoid progenitors (CD341/Lin2/CD45RA1/CD101), no B cells are generated. We tested whether different microenvironments could establish a developmental link between the NK and B-cell lineages. Progenitors were cultured in limiting dilu-tions with interleukin-7 (IL-7), flt3 ligand (FL), c-kit ligand (KL), IL-3, IL-2, and AFT024, a murine fetal liver line, which supports culture of transplantable murine stem cells. NK cells, CD101/CD191 B-lineage cells and dendritic cells (DC) developed from the same starting population and IL-7, FL, and KL were required in this process. Single cell deposition of 3,872 CD341/Lin2/CD382 cells onto AFT024 with IL-7, FL, KL, IL-2, and IL-3 showed that a one time addition of IL-3 a