Objective To separate the CD1c+ MDC and CD304 PDC subsets and analyze their immunobiologic properties.Methods MDC or PDC were separated by immunomagnetic beads and then induced by TNF-α or CpG2006 OND.The phenotype of different DC subsets and allogeneic T-cell-stimulating capacity were detected,respectively.Results The purlty of separated DC was about ninety-five percent.MDC expressed HLA-DR,CD11c,CD4 and CD33,PDC expressed HLA-DR,CD4 and CD45RA,and the percentage of CD40,CD80 were up-regulation after induced to mature.The results of mixed lymphocyte reaction(MLR):MDC had strong potential to stimulate allogeneic T lymphocytes proliferation,while PDC had the weak stimslate potential.The supematant IFN-r in all groups was increased.which the groups of MDC and mMDC were more obviously.The supematant IL-10 was increased obviously in groups of PDC and mPDC.The expression of IFN-r in CD4+ cells were increased obviously after stimulated by MDC or mMDC.PDC and mPDC had the effect of inducing of CIM+ CD25high regulatory T lymphocyte in MLR.The expressing of Foxp3 mRNA had no evident difference in all groups.Conclusion Two different DC subsets in the donors peripheral blood which mobilized with G-CSF were in the state of immature and could be induced to mature in the suitable condition.although expressed high constitutive levels of HLA,DR.No matter how MDC was mature or not,they had strong potential to stimulate allogeneic T lymphocytes proliferation.MDC enhanced the production of IFN-r among T lymphocytes,and the increase of IFN-r was probably the result of TH1 polarization.Unlike MDC,PDC was less efficient present antigens and had poor T-cell-stimulating capacity,probably because of their lesser ability to phagocytose,process and present antigens to the MHC molecules.Although PDC could promote the production of IFN-r,it seemed that did not produced by TH 1.PDC could not promote TH2 cells to product IL-4,and the polarization of TH2 probably reflect the production of IL-10.PDC could induce the generation of CD4+ CD25high regulatory T cells.