人胸腺和脐血造血干/祖细胞联合移植对裸鼠细胞免疫功能的影响

背景：T细胞在抗感染、抗肿瘤和免疫调节等中起重要作用,但T细胞分化发育机制尚未完全阐明。目的：观察人胸腺、人脐血联合移植后裸鼠体内T细胞分布及免疫功能的重建。方法：Balb/cnu/nu裸鼠30只,随机分为2组：实验组肾被膜下移植胸腺组织,2周后将新鲜分离的脐血CD34＋细胞悬液经小鼠静脉输入,对照组不经胸腺移植直接给予CD34＋细胞移植,两组小鼠饲养至60d时检测免疫功能。结果与结论：人胸腺在裸鼠肾被膜下存活并且表达CD3、HLA-DR分子,胸腺与CD34＋细胞联合移植组小鼠脾脏可见点块状分布的CD3＋细胞。实验组CD3＋细胞、CD4＋细胞、CD8＋细胞及CD4＋CD25＋细胞比例均显著高于对照组。实验组裸鼠对移植人胃癌BGC823细胞有排斥作用,而对照组没有。结果显示胸腺和CD34＋细胞联合移植能使裸鼠获得T细胞介导的细胞免疫功能,具有抗肿瘤能力。

Effects of combined human thymus and cord blood hematopoietic stem/progenitor cell transplantation on cellular immunity of nude mice

BACKGROUND：T cells are believed to play an important role in anti-infection,anti-tumor and immune function. However,the mechanism underlying the differentiation and development remains poorly understood. OBJECTIVE：To investigate the distribution of T cells in nude mice that are jointly transplanted human thymus and cord blood and the reconstruction of the immune function. METHODS：Thirty Balb/c nu/nu nude mice were randomly divided into two groups：an experimental group and a control group. In the experimental group,human thymus tissue was transplanted into the renal capsule of nude mice. Two weeks later,freshly isolated human cord blood CD34＋ cells suspension was back perfused into the nude mice via the vein. In the control group,CD34＋ cells transplantation was performed directly without thymus transplantation. After 60 days of breeding,the immune function of nude mice was detected in two groups. RESULTS AND CONCLUSION：Human thymus tissue in the renal capsule of nude mice survived and expressed CD3 and HLA-DR molecule. In the experimental group,CD3＋ cells which distributed in the form of dots were observed in the mouse spleen. The proportion of CD3＋,CD4＋,CD8＋,and CD4＋CD25＋ cells were significantly higher in the experimental group than in the control group. The nude mice from the experimental group rejected human gastric cancer BGC823 cells,while those from the control group did not. These findings demonstrated that combined human thymus and CD34＋ cell transplantation allow nude mice to acquire T cell-mediated cellular immune function and possess the ability of anti-tumor.