异体骨髓基质细胞的免疫性研究

目的研究异体骨髓基质细胞（BMSCs）的免疫原性，同时探讨异体骨髓基质细胞作为组织工程种子细胞的可行性。方法抽取大耳白兔胫骨结节及股骨转子处骨髓，经密度梯度离心，贴壁筛选，获取BMSCs并培养、扩增。24只成年新西兰兔随机分成两组，每组12只，造成双侧12mm桡骨缺损，A组缺损区移植吸附异体BMSCs的明胶海绵，B组缺损区移植吸附自体BMSCs的明胶海绵。分别于术后2、4、8周抽取外周静脉血，样本用流式细胞术检测T淋巴细胞亚群CD^＋4、CD^＋8的阳性率及CD^＋4／CD^＋8比值；于术后第2、4、8、10周拍摄X线片动态观察新生骨痂生长及骨组织愈合情况，于术后第2、4、8、10周取材进行组织学染色，观察骨缺损修复过程中的组织形态学变化。结果术后第2、4、8周A组、B组外周血T淋巴细胞亚群CD^＋4、CD^＋8的阳性率和CD^＋4／CD^＋8比值三者差异均无显著性（P〉0．05）；组织形态学显示A组无明显淋巴细胞浸润，A组与B组新骨形成方式及骨愈合时间两者无明显差异（P〉0．05）。结论异体骨髓基质细胞移植免疫性低，可作为组织工程理想的种子细胞。

The Study on Immunity of Allogeneic Bone Marrow Stromal Cells

Objective To investigate immunological rejection reaction of allogeneic bone marrow stromal cells. Methods Bone marrow stromal cells were obtained from tibial tuberosity and femur greater trochanter of New Zealand rabbits, the adherent cells from marrow were grown in culture. 12mm long segmental defects were created in the diaphyses of both radii in the rabbits. The defect was bridged with a silicon tube, allogeneic bone marrow stromal ceils at the density 2 × 10^6 were instilled into the tubes as group A, autologous bone marrow stromal cells were instilled into the tubes as group B, T lyphocyte subsets CD ^＋ 4,CD ^＋ 8 and CD ^＋ 4/CD ^＋ 8 were tested at 2,4,8 weeks. X - ray, histological examination and HE staining were applied to studies on the repair of the models of guided bone regeneration in the two groups in different times. Result T lyphocyte subsets CD ^＋ 4, CD ^＋ 8 and CD ^＋ 4/CD ^＋ 8 at 2,4,8 weeks in the group A had no significant difference compared to group B. The transplantation of the allogenic bone marrow stromal cells caused no obvious immunological rejection. The new bone formation of group A compared to that of group B had no significant difference （P 〉 0.05）. Conclusion No obvious immunological rejection reaction can be seen during the repair of bone. Allogeneic bone marrow stromal cells can provide ideal source of seed cells for bone tissue engineering.