Study On The Effects Of Ex Vivo Expansion On The Homing-related Molecules Expression Of UCB CD133～+ Cells

ObjectiveHuman umbilical cord blood (UCB) is an alternative important source of hematopoietic stem/progenitor cells (HSPC),which have the characteristic of self-renewal, proliferation and differentiation to their daughter cells. However, there is a limitation of the widespread use of UCB in clinical setting because of the decreased number of HSPC in single UCB sample. Ex-vivo expansion of HSPC is expected to solve this limitation. Although the expansion of stem cells derived from cord blood has been demonstrated to increase the numbers of CD34~+ /CD38-cells and long-term culture initiating cells(LTC-IC) and could engraft the NOD/SCID mouse, some researches indicated that the ex-vivo expanded population shows a delayed or diminished engraftment, which effect proliferation and differentiation of HSPC, accordingly, effect the restitution of hematogenesis and immunity.In this study, We used CD133~+ stem cells which replace CD34~+ /CD38-stem cells as a target cells to investigate the feasibility of ex-vivo expansion of CD133~+ cells from human UCB during short-term culture containing the combination of HGF and serum and the effects of ex vivo expansion on the homing-related molecules expression of UCB CD133~+ cells。MethodsCD133~+ stem cells isolated from fresh cord blood samples were cultured in a IMDM medium containing serum and combination of four cytokines. The...