Human bone marrow stromal cells in combination with exogenous cytokines to support in vitro expansion of cord blood CD_(34)~+ cells / 中国输血杂志

ABSTRACT

Objective To elucidate the role of human bone marrow stromal cells (hBMSC) in combination with exogenous cytokines such as stem cell factor(SCF) and FLT 3 ligand (FL) in supporting the in vitro expansion of CD 34 + cells purified from cord blood.Methods CD 34 + cells were isolated from umbilical cord blood by using a high gradient magnetic cell sorting system(MACS),expanded in combination with SCF,IL3 (interleukin 3),IL 6 (interleukin 6),FL,EPO (erythropoietin),and were planted onto the pre established irradiated (20Gy) stroma layer(hBMSC plus combinations of cytokines) respectively.On day 10,total cells were counted, and hematopoietic progenitor cells were assessed by semisolid culture assay,CD 34 + cells were quantitated by FACS.Results After separation by MACS,the frequency of CD 34 + cells was 92%?0.04%.On day 2,almost all the inoculated cells adhered to the stroma layer,with only a small number in the supernatant.Then,cells in the supernatant increased gradually, but the percentage of CD 34 + cells decreased.Compared with control, expansion fold of CD 34 + cells, CFU GM, BFU E were significantly higher in hBMSC group (P 0.5).Conclusion ① CD 34 + cells from cord blood formed foci adherent to the monolayer and colony forming cells remained in the culture of 10days,indicating that hBMSC can support hematopoiesis in vitro;②using human bone marrow stromal cells in cooperation with exogenous cytokines may be a feasible way to expand hematopoietic stem/progenitor cells.