胎肝造血干细胞在扩散盒培养条件下移植特性的变化

经体内扩散盒培养6d 后的 LACA 小鼠胎肝细胞移植给照射的同系成年小鼠,造血干细胞在受体脾脏和骨髓中的有效植入率比正常胎肝细胞明显提高。但这种效果在同种异基因受体小鼠中则完全消失。实验结果表明,个体发育屏障和移植免疫屏障是决定同种胎肝移植能否成功的两个重要因素。胎肝细胞经体内或体外培养后可以模拟造血干细胞在体内的发育成熟,从而增强对成年造血微环境的适应性。用短期体内培养的方法,可以改变胎肝造血干细胞的某些生理特性,从而减弱个体发育屏障,但不能克服胎肝同种移植中的免疫性抗力。为了保证同种胎肝移植的成功,必须进一步同时克服两种屏障。

CHANGES OF TRANSPLANTATION PECURIALITIES OF FETAL LIVER HEMOPOIETIC STEM CELLS AFTER SHORT-TERM CULTURE IN DIFFUSION CHAMBER IN VIVO

Fetal liver cells from LACA inbred mice after 6 days of in vivo culture weretransplanted into a group of syngeneic irradiated adult mice,the seeding efficiencyof hemopoietic stem cells both in recipient spleen and bone marrow,in comparingwith the normal fetal liver cells,was obviously increased.This effect was comple-tely abolished in allogeneic transplantation of fetal liver cells from LACA mice intolethally irradiated C_(57) adult mice.Experimental results showed that ontogeneticand histoincompatibal barriers are the major factors determining the success ofallogeneic fetal liver transplantation.In vitro or in vivo culture of fetal liver cellsmay create favourable conditions to accelerate the development of hemopoieticstem cells from the fetal immature stage to adult mature state,and therefore makesthem adaptable to lodge in adult bone marrow microenvironment.The short-term in vivo culture as reported in this paper showed an effect of transformation ofsome genetic characters across the ontogenetic barrier but could not overcome thebarrier of allogenetic resistance.Hence it is likely that the histoincompatablebarrier plays more important role than ontogenetic barrier to ensure the success-ful engraftment in allogenetic fetal liver transplantation and the final achievementto this end requires further removal of this obstacle.