混合脐血移植的实验研究

Mixed near-term cord blood transplantation in experimental mice

为探讨混合脐血移植重建免疫造血系统的可行性 ,扩大脐血移植 (CBT)的应用范围 ,将孕 2 0日的C5 7BL / 6 (H- 2 b)小鼠和 6 15 (H - 2 k)小鼠经剖腹产取出胎盘和胎鼠 ,剪碎后分离出脐血单个核细胞 (MNC) ,将二者各 1× 10 6个 MNC混匀后经尾静脉注入 X线直线加速器致死量照射的 BAL B/ c(H- 2 d)小鼠。1个月后 ,用抗小鼠 H- 2 Db和 H- 2 Kk单克隆本检测受鼠中嵌合体的存在 ;用混合淋巴细胞培养检测特异性的免疫耐受。结果未行MNC移植的对照组小鼠 3周内全部死亡 ;移植组 70 %存活 ,且体内形成稳定的混合嵌合体。体外混合淋巴细胞培养发现 ,受鼠对两个供者均产生了特异的免疫耐受。证明 2份小鼠脐血可在同一个受鼠体内产生混合嵌合体 ,能重建同种异基因小鼠的免疫造血系统而不引起明显的移植物抗宿主反应 (GVHD) ,这一模型可用于研究临床混合脐血移植中遇到的许多问题。

To investigate the potential possibility to reconstitute the immunohematopietic system in adult mice recipients across major histocompatibility complex by mixed near-term cord blood transplantation.1×10 6 fetal blood cells from 20-day-old C57BL/6(H-2b)pups and 1×10 6 fetal blood cells from 20-day-old 615(H-2k) pups delivered by cesarean were injected into a lethally irradiated(8.5Gy)BAB/c(H-2d)adult mouse in the same time.After one month,anti-H-2Db and anti-H-2Kk antibody were used to investigate donor chimera in Recipients.In vitro mixed lymphocyte response(MLR) was used to investigate specific tolerance.Results showed that all of the control mice died within three weeks after radiation.70% recipients survived within the observation period of three months.Two donors′mixed chimera was demonstrated by using anti-H-2Db and anti-H-2Kk antibody in the same recipient.In vitro mixed lymphocyte response showed Immune tolerance.Te results confirmed that two kinds of fetal blood can form mixed chimera in the same adult mice recipients.Mixed fetal blood transplantation can reconstitute the immunohematopietic system in adult mice recipients without causing serous GVHD.This model may be suitable to address many questions raised in chinical mixed cord blood transplantation.