Objective: To elucidate the effect of the combination of cytokines on ex vivo expansion and self-renewal potential of human umbilical cord blood hematopoietic stem/progenitor cells.
Methods: CD34+ cells from cord blood were expanded for 14 days in the culture containing FL + Tpo + SCF + IL-6 + IL-3 + G-CSF and the expanded cells were transplanted into sublethally irradiated SCID mice.
Results: The expanded cells were engrafted smoothly in the SCID recipients and reconstituted their hematopoiesis. Furthermore, human hematopoietic cells could be detected in the marrow of the recipients 6 weeks after transplantation.
Conclusion: It is possible to expand hematopoietic cells ex vivo efficiently and maintain concomitantly their self-renewal and hematopoietic reconstitution capacities by the combination of FL + Tpo + SCF + IL-6 + IL-3 + G-CSF.