胎盘血移植特性的研究——Ⅰ.人胎盘血粒单系祖细胞体外长期培养观察

STUDY ON CHARACTERISTICS OF TRANSPLANTATION OF UMBILICAL CORD BLOOD I. OBSERVATION OF UMBILICAL CORD BLOOD CFU-GM BY LONG-TERM CULTURE IN VITRO

本文采用体外甲基纤维素长期培养观察脐血(又称胎盘血)粒单系集落形成单位(CFU—GM)生长情况。结果:脐血(n=20)7、14、21、28天CFU—GM产率分别为28.78±37.82、143.30±168.64、286.40±497.00、107.93±131.98/2×10~5,35天(n=13)为93.27±111.20,42天(n=6)为68.67±103.30/2×10~5;14、21、28天脐血与7天骨髓的产率(180.91±134.07)无明显差异(P>0.05)。正常骨髓CFU-GM产率:14天(n=11)、21天(n=9)、28天(n=6)分别为115.14±87.85、59.81±68.05、25.00±20.45/2×10~5,14天集落产率开始下降,21天后明显减少;14天后集落脐血明显大于骨髓,细胞>1000个细胞,有些特大集落,>5000个细胞;脐血集落细胞于35天开始部分溶解(骨髓为14天,21天时多已完全溶解)。可见脐血造血细胞体外培养维持时间明显长于骨髓造血细胞(4～6^+周/3周~±),表明脐血造血细胞的生物学特性不同于骨髓造血细胞——富含扩增潜能更强、可维持长期造血重建的早期造血干细胞群。

Growth condition of umbilical cord blood (UB) CFU-GM was observed by long-term culture in methylcellulose. As a result, the plating efficiencies of UB CFU-GM were 28.78 ± 37.80, 143.30 ±168.64, 286.40±497.00 and 107.93±131.98/2 ×105 on day 7, 14,21 and 28, respectively (n = 20) and 68.67±103.34/2×105 on day 42 (n = 6). The plating efficiencies showed no difference between day 7 bone marrow (BM) CFU-GM (180.91±134.07) and day 14, 21, 28 UB CFU-GM (P>0.05). The plating efficiencies of BM CFU-GM were 115.14± 87.85 (n=11), 59.81 ±68.05 (n = 9) and 25.00 ± 20.45 / 2 ×105(n = 6) on day 14, 21 and 28, respectively. The colony number decreased slightly on day 14 and decreased significantly on day 21. After 14 days of culture, the colony size of UB CFU-GM became much larger than that of BM CFU-GM and mostly consisted of more than 1000 cells, even more than 5000 cells. The UB colonies began to degenerate on day 35, but those of BM, on day 14. That showed UB hematopoietic cells could be cultured for a longer period than those of BM (4- 6 weeks versus 3 weeks). The result indicated different biological specificity in hematopsietic cells of UB. UB hematopoietic cells had stronger amplification potential. They were a group of hematopoietic stem cells in early stage for persistent reconstitution of hematopoietic system.