The biological characteristics of cord blood CD123~+ myeloid dendritic cell

To investigate the biological properties of CD123+DC derived from cord blood monocytes in myeloid culture system,the monocytes isolated from cord blood were cultured with GM-CSF and IL-4 for 7 days to induce DC,and the related phenotype of DC was analyzed by flow cytometery.CD123+DC were purified with magnetic cell sorting separation technique.The morphological characteristics of CD123+DC was observed under confocal laser-scanning microscope and scan electron microscope.Immune function was evaluated by allogeneic mixed T lymphocyte reaction by 3H-TdR assay,in which the ratio of DC and T cells were 1∶10.FACS analysis showed the high expression of HLA-DR,CD86,CD11c and CD123,low levels of CD83 on DC after induction by GM-CSF and IL-4 for 7 days,while the expression of CD14 was rather low.Well-distributed CD123 and CD11c were detected on DC.Purified CD123+DC showed typical morphology of immature DC with similar short cytoplasmic projections as CD123-DC.CD123+DC stimulated the proliferation of allogeneic T cells,but the stimulated effect of CD1+DC was lower than that of CD123―DC(P0.05).It is apparent that the CD123+DC induced with GM-CSF and IL-4 might be the immature myeloid DC of earlier phase along with the DC differentiation and with special biological properties.