摘要
OBJECTIVE: To compare the morphological, phenotypical, and functional characteristics of dendritic cells (DCs) generated from two precursor cell sources (CD 14+ monocyte and CD34+ hematopoietic stem cell) of human umbilical cord blood (UCB) under identical ex vivo generation conditions and to determine the best cellular source for DCs-based anticancer immunotherapy. METHODS: CD14+ monocytes and CD34+ hematopoietic stem cells were isolated from human UCB and induced to differentiate into DCs under identical culture conditions using granulocyte macrophage colony stimulating factor (800 U/mL) and IL-4 (500 U/mL). Then maturation of DCs was induced with IFN-gamma (1000 U/mL) and LPS (1 microgram/mL). Morphology was compared with confocal microscopy and phenotypical analysis was done with FACS. The level of IL-12p70 production was determined with ELISA kit and T cell proliferation capacity was assessed with mixed lymphocyte reaction (MLR). RESULTS: Eight-day-old mature DCs from CD14+ monocytes or CD34+ hematopoietic stem cells had identical morphology. Flow cytometric analysis revealed that CD14+ monocyte-derived DCs (M-DCs) and CD34+ hematopoietic stem cell-derived DCs (CD34-DCs) showed similar enhanced expression of CD80, CD83, and CD86 (P>0.05). The level of IL-12p70 production was significantly higher in mature DCs (8-day-old) than immature DCs (6-day-old) of either source (P<0.05), but it was significantly highly elevated in CD34-DCs (P<0.05). DCs of both precursors showed potent stimulation capacity in MLR, with CD34-DCs having a maximum effect at 1:2 ratio and M-DCs at 1:20 ratio, although CD34-DCs had significantly greater proliferative effects at all ratios (P<0.05). CONCLUSION: These findings suggest that CD34-DCs may be a more attractive source for DC-based immunotherapy. But because of morphologic, phenotypical, and functional similarities between the two cellular sources, both are good sources for generating DCs and one is not superior to the other. Thus cellular availability could be an important factor in determining DC-generation protocol to be used if all other issues are equal. Further comparative testing for these two precursors is in need.