[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.