多西环素诱导表达下IL-3基因转染小鼠骨髓基质细胞促进造血

本研究探讨用多西环素调控IL-3基因表达的小鼠骨髓基质细胞系对小鼠造血干细胞增殖分化的促进作用。构建含小鼠IL-3基因逆转录病毒载体系统，转染小鼠骨髓基质细胞系，获得QXMSClTet-on-IL-3；体外加入多西环素诱导IL-3基因表达并检测IL-3表达活性；观察细胞培养条件上清液对造血祖细胞集落形成单位的作用及QXMSClTet-on-IL-3与骨髓细胞共培养对造血干细胞增殖分化的影响。结果表明：多西环素提高了QXMSClTet-on-IL-3细胞系IL-3的表达，促进骨髓造血祖细胞克隆形成数；与骨髓细胞共培养可促进造血干细胞的增殖分化。结论：应用多西环素诱导外源基因转染的骨髓基质细胞IL-3的表达，可促进造血。

The Enhancing Effects of IL-3 Gene Transfected Murine Bone Marrow Stromal Cells on Hematopoiesis under Control of Doxycycline

To study enhancing effect of IL 3 gene transfected bone marrow stromal cell which can be induced by doxycycline (Dox) to express IL 3 cytokine on the proliferation and differentiation of hematopoietic stem cell, retrovirus vector system contained mIL 3 cDNA was established and bone marrow stromal cell line was transfected, and obtained QXMSC1Tet on IL 3, in which expression level of IL 3 can be modulated by Dox. The activities of IL 3 were measured under different Dox concentrations. The numbers of hematopoietic progenitors (CFU GM, CFU E, CFU GEMM and LTC IC) were measured and the capacity of QXMSC1Tet on IL 3 sustaining hematopoietic progenitor cell growth was evaluated. The results showed that IL 3 gene transfected stromal cell line QXMSC1 Tet on+IL 3 expressed high concentration of IL 3 in vitro under control of Dox. The supernatant of QXMSC1 Tet on+IL 3 was able to increase the number of CFU GM, CFU E and CFU GEMM. The total numbers of nucleated cells and long term cultured colonies increased in LTC IC assay. It is concluded that in the culture of QXMSC1 Tet on+IL 3 cells, Dox actually enhanced IL 3 expression, and thus augmented the proliferation and differentiation of hematopoietic stem/progenitor cells in vitro.