Ex vivo development, expansion and in vivo analysis of a novel lineage of dendritic cells from hematopoietic stem cells
1 Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, 32610 USA
2 Vectorite Biomedica Inc., Taipei, Taiwan
3 Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, Florida, 32610 USA
4 Department of Medicine, University of Florida, Gainesville, Florida, 32610 USA
Journal of Immune Based Therapies and Vaccines 2010, 8:8 doi:10.1186/1476-8518-8-8Published: 24 November 2010
Dendritic cells (DCs) play a key role in innate and adaptive immunity but the access to sufficient amount of DCs for basic and translational research has been limited.
We established a novel ex vivo system to develop and expand DCs from hematopoietic stem/progenitor cells (HPCs). Both human and mouse HPCs were expanded first in feeder culture supplemented with c-Kit ligand (KL, stem cell factor, steel factor or CD117 ligand), Flt3 ligand (fms-like tyrosine kinase 3, Flt3L, FL), thrombopoietin (TPO), IL-3, IL-6, and basic fibroblast growth factor (bFGF), and then in a second feeder culture ectopically expressing all above growth factors plus GM-CSF and IL-15.
In the dual culture system, CD34+ HPCs differentiated toward DC progenitors (DCPs), which expanded more than five orders of magnitude. The DCPs showed myeloid DC surface phenotype with up-regulation of transcription factors PU.1 and Id2, and DC-related factors homeostatic chemokine ligand 17 (CCL17) and beta-chemokine receptor 6 (CCR6). Multiplex ELISA array and cDNA microarray analyses revealed that the DCPs shared some features of IL-4 and IL-15 DCs but displayed a pronounced proinflammatory phenotype. DCP-derived DCs showed antigen-uptake and immune activation functions analogous to that of the peripheral blood-derived DCs. Furthermore, bone marrow HPC-derived DCP vaccines of tumor-bearing mice suppressed tumor growth in vivo.
This novel approach of generating DCP-DCs, which are different from known IL-4 and IL-15 DCs, overcomes both quantitative and qualitative limitations in obtaining functional autologous DCs from a small number of HPCs with great translational potential.