[Studies on the properties of dendritic cells from cord blood CD34+ cells and peripheral blood monocytes].

OBJECTIVE: Ex vivo expansion and purification of dendritic cells(DC) with typical phenotype, morphology and function are critical to the further studies on DC and their clinical application. METHODS: CD34+ cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system (MACS), and peripheral blood mononuclear cells (PBMC) were depleted of T and B cells by mixing them with T/CD2 and B/CD19 magnetic beads. DC were induced and expanded with different combinations of cytokines. They were identified for their properties by FACS, electronic microscopy, microscopy, and mixed lymphocyte reaction (MLR). RESULTS: Cultures of cord blood CD34+ cells with the combination of GM-CSF + TNF-alpha + SCF + FL yielded (27.18 +/- 1.56)% CD1a+ cells, much higher than that (0.65 +/- 0.38)% with GM-CSF alone. The combination of GM-CSF and high dose IL-4(1,000 U/ml) was the most potential for expanding CD1a+ cells [(21.8 +/- 0.32)%] for PBMC. Both of the DC from different sources were similar in phenotype and morphology, and had the capacity to stimulate proliferation of allogeneic T lymphocytes. CONCLUSION: Both of cord blood and peripheral blood are the source for generation of a large number of typical DC, and can be adopted for the application according to different purposes. These results lay foundation for the immunotherapy with DC.