Experimental Study on Skeletal Tissue Allotransplant

虽然在同种异体器官移植中已经注意到细胞从移植物进入受者和从受者进入移植物，但在全肢体同种异体移植后，人们对此知之甚少。由于带血管的肢体移植在骨髓中有大量未分化的干细胞，与其他器官移植相比，供体细胞迁移到受者体内的频率可能更高。本研究通过聚合酶链式反应确定供受者之间的细胞迁移。67例带血管的同种异体大鼠后肢移植跨越主要和次要组织相容障碍。受体动物接受FK506免疫抑制治疗，并在移植后48周内进行评估。供受者细胞比例用Y染色体特异性引物进行半定量聚合酶链式反应，移植肢体在最终评估前均无排斥反应发生。男性受体细胞不是在移植后1周出现在女性移植物中，而是在移植后48周出现。受体细胞在股骨、胫骨中占10%以上，在腓肠肌、腿部皮肤和足底皮肤中占1~10%以上。48周时，在女性受者的肱骨和胫骨中检测到男性供体细胞，供体细胞比例为1%~10%。受者的腓肠肌和腿部皮肤中未检测到供体细胞。我们的结果表明，随着时间的推移，受者来源的细胞逐渐迁移到移植的骨、肌肉和皮肤细胞中。供体来源的细胞迁移到健康的骨骼(双向细胞交通)，但不迁移到健康的肌肉和皮肤(单向细胞交通)。由于移植肢体发生了活跃的再生，以补偿继发于缺血和手术干预的移植物损伤，受体来源的干细胞可能介导肌肉和真皮的更新。

Although cell traffic from the graft into the recipient and from the recipient into the graft had been noticed in allogeneic organ transplantation, little is known following whole-limb allografting. Because vascularized limb grafts have numerous undifferentiated stem cells in the bone marrow, donor cell migration into the recipient may be more frequent as compared to other organ transplants. This study was conducted to define cell migration between donor and recipient by use of polymerase chain reaction.Sixty-seven vascularized hind limb allotransplantations were performed in rat sex-mismatched pairs across minor and major histocompatibility barriers. The recipient animals were treated with FK506 immunosuppression and assessed for a period of 48 weeks post-transplantation. The ratio of donor and recipient cells was evaluated by semi-quantitative PCR using the specific primers of the Y-chromosome.Allografted limbs had no rejection episode until the final assessment. The male recipient cells were detected in female grafts not at 1 week but at 48 weeks after transplantation. The ratio of recipient cells was more than 10% in the femur, tibia and 1 to more than 10% in the gastrocnemius muscle, leg skin and plantar skin. The male donor cells were detected in the humerus and tibia in the female recipient and the ratio of donor cells was 1% to 10% at 48 weeks. No donor cells were detected in the gastrocnemius muscle and leg skin in recipient.Our results demonstrated that recipient derived cells gradually migrated into the grafted bone, muscle and skin cells with the duration of time. Donor derived cells migrated into the healthy bones (two-way cell traffic) but not into the healthy muscle and skin (one-way cell traffic). Because active regeneration occurs in the grafted limb to compensate graft damage secondary to ischemia and operative intervention, recipient-derived stem cells may mediate a muscular and dermo-epidermal renewal.