Efficient ex vivo generation of human dendritic cells from mobilized CD34(+) peripheral blood progenitors

We tried to efficiently generate human dendritic cells (DCs) from CD34(+) p eripheral blood hematopoietic progenitor cells mobilized by high-dose chemo therapy and subsequent administration of granulocyte colony-stimulating fac tor, using a liquid suspension culture system. Among various combinations, the combination of c-kit ligand, flt-3 ligand, c-mpl ligand (TPO), and inte rleukin (IL)-4 most potently generated the number of CD1a(+)CD14(-) DCs in cultures containing granulocyte-macrophage colony-stimulating factor (GM-CS F) and tumor necrosis factor alpha (TNF-alpha). The delayed addition of IL- 4 on day 6 of culture gave rise to an additional increase in the yield of C D1a(+)CD14(-) DCs that were characterized by the expression of HLA-ABC, HLA -DR, CD80, CD86, and CD83. The majority of the sorted CD1a(-)CD14(+) cells derived from 6-day culture of CD34(+) cells gave rise to CD1a(+)CD14(-) DCs and CD1a(-)CD14(+) macrophages on day 12 of culture in the presence and ab sence of IL-4, respectively. These findings suggest that IL-4 promotes the differentiation of CD1a(-)CD14(+) cells derived from mobilized CD34(+) peri pheral blood hematopoietic progenitors to CD1a(+)CD14(-) DCs. The majority of these DCs expressed CD68 but not the Langerhans-associated granule antig en, a finding that suggests they emerge through the monocyte differentiatio n pathway. The addition of TPO and IL-4 to cultures did not affect the pote ntial of DCs to stimulate the primary allogeneic T-cell response. These fin dings demonstrated that the combination of c-kit ligand plus flt-3 ligand p lus TPO with GM-CSF plus TNF-alpha, followed by IL-4, is useful for ex vivo generation of human DCs from mobilized CD34(+) peripheral blood progenitor s. (C) 2001 The Japanese Society of Hematology.