转染hjagged1基因的基质细胞对脐血干细胞体外增殖的作用

In ex vivo culture, how to harness the differentiation and increase the number of hematopoietic stem cells, it is a point which the researchers have focused on. Recently studies suggested, Norch receptor families such as Notch1 and Norch2 expressed by hematopoietic stem /progenitor cells is one of the important factors which affects the asymmetric splitting of the stem cell. Jagged1, the ligand of Norch, is expressed by bone marrow stroma cells. We have delved into the effect of the express of Jagged1 and Notch1 gene on the process of differentiation of HL60 and CD34+ cells in umbilical cord blood as well as its effect on the expansion process of CD34+ cells in umbilical cord blood. We have constructed a retroviral vector MSCV-Jagged1/neoR containing human full length sequence of Jagged1cDNA, and established a bone marrow stroma cell line expressing extrogene Jagged1 stably. The results suggested that the expression of Jagged1 gene could inhibit the differentiation of HL60 and CD34+ cells in umbilical cord blood, and augment the efficiency of expansion of CD34+, the CFU-G and CFU-Mix were nearly two times and nearly three times than controls, respectively. We have acquired a transgeneic clone by introducing the retroviral vector MSCV-ICN/GFP containing human Notch1 gene sequence and control vector MSCV-GFP into L60 cells. The experiment confirmed that the continuous expression of Notch1 could inhibit the differentiation of HL60 cells and CD34+ umbilical cord blood in ex vivo culture significantly. During the experiments, we also established a method to select CD34+ cells in umbilical cord blood with high efficiency. Our research make an investigation to comprehend the biology characteristics of hematopoietic stem cells and explore how to expand the CD34+ cells in umbilical cord blood efficiently.

应用基因转移技术将Notch蛋白的配体Hjagged1基因转染至骨基髓质细胞内，建立稳定表达玫鞍椎幕蛳赴担暄狢D34阳性细胞与基质细胞共培养后，测定脐血干细胞体外扩增男屎投許CID小鼠造血重建的影响，探讨Notch信号系统对脐血干细胞增殖的作用和高效体外扩增脐血干细胞的新途径，为临床脐血干细胞移植的广泛应用打下基础。