人脐血造血干/祖细胞的生物反应器大规模扩增及移植实验

目的 利用生物反应器大规模扩增人脐血造血干/祖细胞,并通过动物移植实验检验该方法的有效性.方法 采集抗凝脐血10份,分离出单个核细胞(MNC),分别进行生物反应器扩增培养和静态扩增培养.检测扩增前后细胞表面CD34、CD38、CD133、CD184和CD62L分子的表达,并进行造血干/祖细胞集落的培养.取非肥胖糖尿病重症联合免疫缺陷小鼠,以X射线照射后,分为4组,其中MNC组小鼠注射未经扩增培养的MNC;静态扩增组小鼠注射经过静态扩增培养的细胞;反应器扩增组小鼠注射经过生物反应器扩增培养的细胞;空白对照组小鼠注射生理盐水.移植后6周处死存活小鼠,收集骨髓细胞,检测其中CD45+、CD3+、CD19+和CD33+细胞的含量以及人特异的Cart-Ⅰ和Alu基因的表达.结果 生物反应器扩增前MNC为(1.2～2.8)×108个,扩增后为(3.7～12.6)×108个,扩增后的细胞数明显高于静态扩增培养者(P<0.01).经生物反应器扩增后所形成的红系集落形成单位、粒-巨噬细胞集落形成单位数明显高于经静态扩增者(P<0.05).移植6周后,空白对照组小鼠均死亡,MNC组存活率为35%,静态扩增组存活率为30%,反应器扩增组存活率为62.9%,后者明显高于前二者(P<0.05).各组存活小鼠骨髓细胞中均检测到Alu基因和Cart-Ⅰ基因的表达以及人源CD33+、CD45+、CD3+及CD19+细胞.结论 利用生物反应器可大规模扩增人脐血造血干/祖细胞,所得细胞能植入小鼠体内,并能获得造血功能重建.

Expansion of hematopoietic stem/progenitor cells of cord blood by bioreactor and the transplantation into NOD/SCID mice

Objective To expand hematopoietic stem/progenitor cells of cord blood in large scale by bioreactor. Methods Mononuclear cells from human umbilical cord blood were cultured in serum-free medium with stem cell factor (SCF), flt-3 ligand (FL3) and thrombopoietin (TPO). The expansion fold of cells, colony-forming and expression of surface molecules were analyzed by cell counting, colony-forming assay and flow cytometry, respectively. And the engraftment of these expanded cells was studied through cell transplantation into irradiated non-obese diabetic/severe-combined immunodeficient (NOD/SCID) mice. Results After culture for 7 days,the folds of total cell expansion in bioreactor were higher than those in static culture, P<0.01. The number of colony-forming unit-granulocyte/macrophage (CFU-GM) and erythroid colony forming unit (CFU-E) in bioreactor were increased as compared with those in static culture, P<0.05. The positive rate of surface marks of CD34+, CD34+ CD38- and CD133+ on expanded cells bioreactor didn't show decrease compared to unexpanded cells but was lower than that in static culture, P<0.05. However, the expression levels of CD184 or CD62L on cells expanded in bioreactor were higher than those in static culture, P<0.05, while without significant difference from unexpanded cells (P>0.05). The cells expanded in bioreactor were successfully engrafted into irradiated NOD/SCID mice and reconstructed the multi-lineage hematopoiesis. Conclusion The bioreactor favors large-scale expansion of hematopoietic progenitor cells and keeps the hematopoietic repopulation potential.