CD34+和CD34-细胞在NOD/SCID小鼠体内的造血重建

Hematopoietic Repopulating Ability of Human CD34+ Cells and CD34- Cells in NOD/SCID Mice

摘要:

利用非肥胖糖尿病型重症联合免疫缺陷型(NOD/SCID)小鼠模型, 比较了新鲜及培养后的CD34+和CD34-细胞在体内植入及重建造血能力。从新鲜脐血及培养后的单个核细胞(MNC)中分离出CD34+和CD34-细胞, 经尾静脉输注入经亚致死剂量照射的NOD/SCID小鼠体内, 6周后处死存活的小鼠, 取其骨髓、脾脏和外周血细胞, 分别进行细胞表型分析、造血集落形成单位和人特异性基因的检测。经检测, 输注CD34+细胞和混合细胞的小鼠, 其体内CD45+细胞及人源各系血细胞的含量相近, 两者均远远高于输注CD34-细胞的小鼠。输注培养后CD34-细胞的小鼠饲养6周后全部死亡,输注培养后CD34+细胞的小鼠存活率约为66.7%, 而输注培养后混合细胞的小鼠全部存活, 且在两组存活的小鼠体内均能检测到CD45+细胞及人源各系血细胞。结果表明: 无论是新鲜还是培养后的CD34+细胞均具有在NOD/SCID小鼠体内植入和重建造血能力, 而CD34-细胞不具有该能力, 但CD34-细胞与CD34+细胞同时输注有助于提高小鼠的存活率, 说明其对CD34+细胞在小鼠体内发挥植入和造血重建能力有一定的辅助作用。

Abstract:

The hematopoietic repopulating ability of fresh and cultured CD34+ cells and CD34- cells derived from cord blood were compared by nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mouse model. Fresh CD34+ cells and CD34- cells were isolated from fresh cord blood. Cultured CD34+ cells and CD34- cells were separated from cultured mononuclear cells (MNC). We transplanted these cells into sublethally irradiated NOD/SCID mice via the tail vein and sacrificed surviving mice after 6 weeks. The peripheral blood, spleen and bone marrow from each mouse were harvested for flow cytometry, colony-forming cells and human Alu sequences analyses. The proportions of CD45+ cells and human multilineage hematopoietic cells in NOD/SCID mice received CD34+ cells were close to that in the mice received both CD34+ cells and CD34- cells, while it was significantly higher than that in the mice received CD34- cells. Six weeks after transplantation, all the mice injected with cultured CD34- cells dead. The survival rate of mice injected with cultured CD34+ cells was 66.7%. All of the mice injected with both cultured CD34- and CD34+ cells survived. Moreover, CD45+ cells could be detected in all surviving mice, and human CD34, CD3, CD19, CD33 and CD71 antigen also could be detected on these CD45+ cells. The results showed that both fresh and cultured CD34+ cells had the capability of engraftment and hematopoiesis reconstitution, but CD34- cells hadn’t the ability. However, CD34- cells had assistant effect on the hematopoietic repopulating ability of CD34+ cells.