Cytokine responsiveness of circulating human embryonic hematopoietic stem cells is unique compared to other stages of human ontogeny

We have previously identified a novel circulating embryonic blood stem cell that is distinct from both adult bone marrow (BM) and cord blood (CB) derived human repopulating cells, that may serve as an ideal target cell for in utero stem cell therapy. Towards this goal, we examined the ability to maintain these fetal blood (FB) stem cells in ex vivo culture conditions previously optimized for repopulating cells derived from later stages of human …