An Experiment Study Of Expansion And Culture Of Fetal Blood Hematopoietic Stem/progenitor Cells In Vitro

Objective: To study the capacity for expansion and forming colonies in vitro of hematopoietic stem /progenitor cells of human fetal blood. Material and Methods: Granulocyte/macrophage progenitor assays (colony forming unit -granulocyte/macrophage, CFU-GM )were established with mononuclear cells (MNC) from 14 fresh cord blood samples and 26 fresh fetal blood samples by using the methylcellulose semisolid culture method . MNC from 9 cord blood samples and 10 fetal blood samples were cultured for 18-24 days in serum-free media containing rhIL-3, rhIL-6, rhSCF, rhFL.And clonogenic assays for CFU-GM were performed at day 0,6th, 12th, 18th, 24th with fresh cells or expanded cells of those samples by using the same techniques as describded above .Results: 1,There were more CFU-GM in fetal blood (276±104/1×105MNC) than that in cord blood (243±92/1×105 MNC), but there were no significantly statistical difference between them (P＞0.05). 2,After being cultured for 18-24 days, the expansion of CFU-GM of fetal blood and cord blood reached their peaks by 50.69±38.71-fold at day 24th and by 1.88±1.44-fold at day 12th respectively; the expansion of MNC of fetal blood and cord blood reached their peaks by 101.85±108.13-fold at day 21st and by 5.61±3.12-fold at day 15th respectively. The expansion of MNC and CFU-GM of fetal blood were better than that of cord blood(P<0.01). The expansion of those cells accompanied with their differentiation. Conclusion: Significant numbers of hematopoietic stem/progenitor cells with capaity for expansion circulate in fetal blood, their capacity for expansion and forming colonies is greater than the cord blood's.