人脐血造血干/祖细胞的磁力搅拌悬浮培养及移植实验

目的 探讨磁搅拌大规模培养体系对人脐血造血祖细胞的扩增效果以及扩增的人造血祖细胞植入动物体内后的造血重建情况.方法 从新鲜抗凝脐血中分离出单个核细胞(MNC),以添加干细胞因子、酪氨酸激酶受体3配基及血小板生成素的无血清培养体系进行培养.静态扩增组的细胞置于T25培养瓶中培养,磁搅拌悬浮扩增组(磁搅拌扩增组)的细胞采用Celstir装置进行培养,培养体系为50～100 ml.培养7 d后进行细胞计数、集落培养检测和细胞表面分子表达的测定.以不进行培养者为对照组.非肥胖糖尿病重症联合免疫缺陷(NOD/SCID)小鼠在接受2.5 Gy的亚致死剂量X射线照射后分别从尾静脉输入上述静态扩增组、磁搅拌扩增组和对照组的MNC(5×106个),另设不移植的空白对照组.观察小鼠的存活情况,6周后处死存活小鼠,检测骨髓细胞中CD34+细胞、CD3+细胞、CD19+细胞、CD33+细胞及CD45+细胞的含量以及人特异的Cart-Ⅰ和Alu基因的表达.结果 经过7天的培养,磁搅拌扩增组的造血祖细胞扩增倍数为(2.8±0.45)倍,明显高于静态扩增组的(2.1±0.48)倍(P<0.01).磁搅拌扩增组形成的红系集落、粒-巨噬细胞集落数均明显高于静态扩增组(P<0.05).静态扩增组扩增后的CD34+细胞、CD34+CD38-细胞和CD133+细胞含量均高于磁搅拌扩增组(P<0.05),而CD184+细胞和CD62L+细胞含量低于磁搅拌扩增组(P<0.01).移植后6周,对照组、静态扩增组和磁搅拌扩增组分别有3、4、5只小鼠存活,三组间两两比较,6周存活率的差异无统计学意义(P>0.05).存活6周的小鼠,其骨髓中能检人特异性CD34+细胞,以及CD3+细胞、CD19+细胞、CD33+细胞及CD45+细胞,也检测到人Alu基因和Cart-Ⅰ基因的表达.结论 磁搅拌培养能大规模扩增脐带血造血祖细胞,扩增的细胞能植入x射线照射的NOD/SCID小鼠,并重建其多系造血.

Hematopoietic stem/progenitor cells of cord blood expanded at large scale by magnet stirred culture and engrafted intoNOD/SCIDmice

Objective To expand hematopoietic stem/progenitor cells at large scale in magnet stirred culture system. Methods Mononuclear cells from human umbilical cord blood were cultured in serum-free medium supplemented with stem cell factor (SCF), fh-3 ligand (FL3) and thrombopoietin (TPO). The expansion fold of cells, colony-forming and expression of surface molecules were studied in magnet stirred culture by cell counting, colony-forming assay and flow cytometry. And the engraftment to non-obese diabetic (NOD)/severe-combined immunodeficient (SCID) mice and repopulation of expanded cells by magnet stirred culture were studied through transplantation. Results After culture for 7 days, the folds of total cell expansion in magnet stirred culture were higher than in static culture(P<0.01). The number of colony-forming unit-granulocyte/macrophage (CFU-GM) and erythroid colony forming unit (CFU-E) in magnet stirred culture was greater than that in static culture(both P<0.05). The primitive cells (CD34+, CD34+ CD38 or CD133+) of the expanded cells in magnet stirred culture were less than those in static culture, P<0.05. However, the CD184+ or CD62L+ expanded cells were more than those in static culture, P<0.05. There was no significant difference in survival rate between three cell transplantation groups, all P>0.05. The analysis of multilineage hematopoiesis showed that transplanted human hematopoietic cells were represented in murine bone marrow cells by detecting the percentage of human cells identified with human specific anti-CD3/19/33/34/45 MoAb by FACS and the human specific gene Alu and Cat-1 by PCR. Conclusion Magnet stirred culture favors large-scale expansion of hematopoietic progenitor cells with the hematopoietic repopulation potential in NOD/SCID mice.