采用MLL-AF9转基因小鼠造血细胞移植的方法建立白血病小鼠模型

Establishment of AML Mouse Model by Transplantation of Hematopoietic Cells from MLL-AF9 Transgenic Mice

目的:采用混合谱系白血病(MLL)-AF9转基因小鼠造血细胞移植的方法建立白血病小鼠模型,为急性髓系白血病的机制研究和治疗药物筛选提供基础。方法:繁育和鉴定MLL-AF9转基因小鼠,当小鼠自然发病后,经外周血白细胞计数检测、流式细胞术和形态学方法鉴定。待外周血白细胞数>100×10^(9)/L后,收集骨髓细胞和脾细胞冻存。将细胞复苏后经尾静脉注射入4.5 Gy照射的野生C57BL/6J小鼠体内,观察小鼠的成模情况,最后采用阳性药物在该模型上进行疗效评价。结果:本实验繁育的MLL-AF9转基因小鼠的自然发病时间为22-28周,发病后的转基因小鼠脾脏增大,骨髓呈髓系白血病细胞的幼稚形态,骨髓和脾细胞均高表达CD11b和Gr-1髓系标志。最低0.5×10^(6)骨髓细胞和2.5×10^(6)脾细胞移植就能使受体小鼠全部造模成功,小鼠的中位生存时间分别为20和36 d。在脾细胞移植的小鼠发病模型上进行实验治疗,发现传统化疗药物阿糖胞苷能延缓发病,并延长模型小鼠的生存时间。结论:成功建立基于MLL-AF9转基因小鼠造血细胞移植的小鼠白血病发病模型,有望用于MLL相关白血病的发病机制研究和疗效评价。

Objective:To establish a leukemia mouse model induced by transplantation of hematopoietic cells from mixed lineage leukemia(MLL)-AF9 transgenic mice so as to provide the basis for the mechanism research and drug screening of acute myeloid leukemia(AML).Methods:MLL-AF9 knock-in mice were bred and identified.When the mice developed leukemia,white blood cell(WBC)count in peripheral blood,flow cytometry and morphology method were analyzed to identify the disease.When the WBC count in peripheral blood was more than 100×109/L,bone marrow cells and spleen cells were collected and cryopresevated.After resuscitation,the cells were injected into 4.5 Gy irradiated wild C57 BL/6 J mice through the tail vein to develop MLL-AF9 leukemia mouse model.Finally,the therapeutic effect was evaluated by positive drug on the model.Results:The natural onset times of leukemia on MLL-AF9 knock-in mice were 22-28 weeks.The spleens of the transgenic mice enlarged and the bone marrow showed the immature forms of myeloid leukemia cells.Both the bone marrow and spleen cells highly expressed myeloid markers,CD11 b and Gr-1.At least 0.5×106 bone marrow cells and 2.5×106 spleen cells could induce leukemia in all recipient mice,and the median survival times of mice were 20 days and 36 days,respectively.Experimental treatment was carried out on the leukemia mouse model transplanted with MLL-AF9 spleen cells,and it was found that the traditional chemotherapy drug cytarabine could delay the onset of leukemia and prolong the survival time of the mouse model.Conclusion:The leukemia model of hematopoietic cell transplantation based on MLL-AF9 transgenic mice is successfully established,which can be used for the study of the pathogenesis and evaluation of therapeutic effect of AML.