体外扩增脐血CD_(34)^+细胞

Ex vivo expansion of CD+34 stem cells and progenitor cells from cord blood

目的探讨某些造血细胞因子对脐血造血干细胞的扩增效应。方法脐血ＣＤ＋３４细胞经免疫磁珠法分选后，在含有重组人Ｆｌｔ３配基（ｒｈＦｌｔ３Ｌ）、干细胞因子（ｒｈＳＣＦ）、白细胞介素１β（ｒｈＩＬ１β）、ｒｈＩＬ３和ｒｈＩＬ６的液体培养体系中培养７至１４天。采用流式细胞仪、造血细胞集落和长期培养起始细胞（ＬＴＣＩＣ）方法检测扩增后的细胞。结果在上述细胞因子作用下，脐血ＣＤ＋３４细胞明显扩增。细胞总数、ＣＤ＋３４细胞和造血细胞集落总数在第７天分别扩增３１±１９、４±５、１０±６７倍、第９天分别扩增２３６±１０６、２０±２０、５７±６２，第１４天分别扩增７７０±５０５、３０±３０、１８９±１３３。扩增的细胞以髓系祖细胞为主，极少红系祖细胞，无淋巴系细胞，并含有ＬＴＣＩＣ。结论理想的造血细胞因子的组合可以加速体外扩增脐血ＣＤ＋３４细胞。

Objective To expand umbilical cord blood (UCB) in the presence of cytokine combinations.Methods CD+34 cells were enriched using immunomagnetic beads and cultured in cytokine combinations. The expanded cells were characterized by flow cytometry, colony forming units (CFU) and long term culture initiating cells (LTCIC) assays.Results UCB CD+34 cells could be significantly expanded in the presence of flt3ligand (Flt3L), stem cell factor (SCF), interleukin 3 (IL3), IL6, and IL1β. The total haematopoietic cells, CD+34 cells and CFU were increased by 31±19, 4±5, and 10±67 folds on day 7 of culture; 236±106, 20±20, 57±62 folds on day 9 of culture, and 770±505, 30±30, 189±133 folds on day 14 of culture. These cells were mostly of the myeloid lineage (CD+34, CD+33, CD+45, CD+14, CD+38), with very few erythropoietin progenitors, and no lymphocyte (CD-3, CD-19, CD-16, CD-56). Expanded cells also contained LTCIC, which may contribute to long term engraftment if transplanted. Conclusion The results indicate that it is possible to expand UCB CD+34 cells ex vivo with the appropriate combination of cytokines. This approach may provide stem and progenitor cells for adult transplantation.