Multiorgan engraftment and multilineage differentiation by human fetal bone marrow Flk1+/CD31-/CD34- Progenitors.

We previously reported that Flk1(+)/CD31(-)/CD34(-) cells isolated from human fetal bone marrow can differentiate at the single cell level into endothelial and hematopoietic cells in vitro. Here we report that within this cell population reside cells that can differentiate into the epithelium of liver, lung, gut, as well as the cells of both hematopoietic and endothelial system after primary or secondary transplantation into irradiated nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Hence, Flk1(+)/CD31(-)/CD34(-) cells possess remarkable differentiation potential and may thereby provide an alternative to hematopoietic stem cells for transplantation. In addition, our results show this stem cell population effectively accelerated wound healing in NOD/SCID mice and thus holds therapeutic promise for treatment of genetic disorders, organ dysfunction, and tissue repair in humans.