新鲜及冻存的人脐血移植于裸鼠的实验研究

目的　探讨人新鲜脐血及冻存脐血移植于裸鼠的规律及差别。方法　采用Balb/Cnu +裸鼠致死量放射线照射后输入人新鲜或冻存脐血单个核细胞 ,观察小鼠存活率、存活时间 ,检测移植成活证据及干细胞在小鼠体内的迁移 ,定居情况。结果　新鲜脐血组及冻存脐血组小鼠存活率及存活时间均显著高于对照组 ,前两组则无显著差异 ;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了人冻存脐血已在小鼠骨髓内定居并植入成活 ,持续至少 130d ;但冻存脐血干细胞的迁移情况与新鲜脐血有所差异。结论　脐血中富含造血干细胞 ,能使免疫缺陷小鼠获得造血和免疫重建 ;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。

Exprimentol Study on Nude Mice as a Model of Human Fresh and Cryopreserved Umbilical Cord Blood Transplantation

Objective To evaluate the differences between fresh and cryopreserved human umbilical cord blood as well as the stem cell homing.Methods Fresh or cryopreserved human umbilical cord blood cells were injected into lethally irradiated BALB/C nu+ mice.The mice survival rates,the successful transplantation evidence and the migration phenomenon were observed.Results The survival rates of the fresh group and the cryopreserved group were much higher than the control group,but there was no difference between the former two groups.Evidence of human hematopoiesis were observed by means of PCR or FACS.However,the pattern of migration was different berween fresh and cryopreserved cord blood stem cells. Conclusion Human cord blood contains high hematopoietic potential stem cells to cross xenogenetic barriers and successfully engraft in mice.Cryopreservation can keep the hematopoietic potential of cord blood,but may influence the adhesion molecular of the stem cells and thus influence their homing behavior.