异基因骨髓移植小鼠供体骨髓细胞在受体内的分布及淋巴细胞供受体来源比例分析

The distribution of donor hematopoietic stem cell and the ratio of lymphocytes from donor origin to recipient origin in recipient mice after allogeneic bone marrow transplantation

目的观察小鼠异基因骨髓移植(alloBMT)后供体骨髓细胞在受体内的分布以及嵌合体内T、B淋巴细胞增殖分化规律。方法以绿色荧光蛋白(GFP)转基因C57BL/6J(H2b)小鼠为供体,以137Cs5.5Gy×2照射的BALB/c(H2d)小鼠为受体,分别于移植后3天(+3天)、+7天、+21天、+35天和+70天取外周血、骨髓、胸腺、脾脏、肠集合淋巴结及肝脏,用流式细胞仪和荧光显微镜观察供体来源的骨髓细胞分布。用藻红蛋白标记的抗CD4、抗CD8、抗B220抗体检测+21天小鼠体内骨髓、外周血及其他免疫器官中T、B淋巴细胞的构成比例。结果①+3天、+7天供体骨髓细胞在受体脾脏中分布最多,分别为(1.06±0.02)%、(76.60±1.80)%;骨髓中分别为(0.37±0.06)%、(39.70±5.38)%。②+21天受体骨髓、脾脏、淋巴结、胸腺及外周血中供体细胞达60%～90%。③+3天受体肠集合淋巴结中供体骨髓细胞达(0.36±0.04)%,与受体骨髓中供体骨髓细胞的比例相当。结论①alloBMT后早期供体骨髓细胞可分布到受体的骨髓、脾脏、肠集合淋巴结中,脾脏中最多。②+21天受体内骨髓及其他免疫器官以供体细胞为主。③受体肠道集合淋巴结也是移植后供体骨髓细胞的早期寄居点和B淋巴细胞增殖后的迁移部位。

Objective To explore the hematopoietic stem cell distribution and lymphocyte proliferation and differentiation in recipient mice after allogeneic bone marrow transplantation (allo-BMT). Methods BALB/c(H-2 d) mice were total body irradiated 5.5 Gy×2 by 137Cs and then transplanted with bone marrow cells from GFP transgenic C57BL/6J(H-2b) mice. The femur, spleen, Peyer patches, thymus, liver and peripheral blood of the host were collected on days 3, 7,21,35 and 70 post transplantation, and their sections were observed by fluorescent microscopy. The green fluorescent cells were counted with FACS. The phycoerythrin (PE) labeled antibodies to CD4, CD8 and B220 were used for sorting T and B lymphocytes. Results ① On day 3 and day 7 after allo-BMT, there were (1.06±0.02)% and (76.60±1.80)% of donor’s green bone marrow cells in host’s spleen respectively, whereas only (0.37±0.06)% and (39.70± 5.38)% in the bone marrow, respectively. ② In bone marrow and other organs of 21 day-old chimerism mice, over 60% cells were of donor origin. ③ There were (0.36±0.04)% donor’s bone marrow cells lodging at host’s Peyer patches, similar to that in bone marrow. Conclusion ① The engrafted allogeneic hematopoietic stem cell can move into spleen, bone marrow, Peyer patches and thymus. The spleen is the main lodging place of the engrafted cells early after all-BMT. ② The majority of cells in chimerism mice immunologic organs were of donor origin. ③ Peyer patches is another lodging place early after allo-BMT.