The nude mice model of human cryopreserved umbilical cord blood transplantation

Abstract

目的 探讨长期深低温冻存脐血的移植活性及干细胞在裸鼠体内的迁移规律。方法 选取30 只BALB/ C nu + 裸鼠,随机分为3 组。经致死量放射线照射后分别给予裸鼠人冻存后脐血单个核细胞、新鲜脐血以及生理盐水外周静脉输入,观察并比较小鼠存活情况和移植存活证据,采用PCR 法及流式细胞术检测干细胞在小鼠体内的迁移、定居情况。结果 冻存脐血组小鼠存活率及存活时间均显著高于生理盐水组,而与新鲜脐血组无显著性差异( P > 0. 05) ;PCR 法及流式细胞术检测小鼠体内人特异性基因及细胞均证实人冻存脐血已在小鼠骨髓内定居并植入存活,持续至少130 d ;但冻存脐血组干细胞的迁移情况与新鲜脐血组有所差异,裸鼠的肝和肾不易出现人特异性基因。结论 冻存可长期保存干细胞活性,但可能影响干细胞表面定居相关粘附分子,从而影响其迁移行为

Objective To evaluate the hematopoietic potential of long-term cryopreserved human umbilical cord blood as well as the migration of the stem cells in nude mice. Methods Thirty lethally irradiated BALB/ C nu + mice were randomized into 3 groups. One group was injected cryopreserved human umbilical cord blood cells intravenously and one group was injected fresh cord blood and the other one was injected normal saline as control. The survival rates of mice and the successful transplantation evidence were observed and compared among three groups. The migration of the stem cells was analyzed by PCR and fluid cytometry. Results The survival rate of the cryopreserved group was much higher than that of the saline group , but there was no significant difference between the fresh group and the cryopreserved group. The evidence of human hematopoiesis was observed by PCR and fluid cytometry and lasted for at least 130 days. In addition , the migration of the cryopreserved stem cells was not the same as that of fresh cord blood , where human gene was hardly detected in liver and kidneys. Conclusion Cryopreservation can keep the hematopoietic potential of cord blood for a long time , but may influence the adhesion molecular of the stem cells , hence influence the homing behavior of the stem cells.