title: Apoptosis of monocytes and the influence on yield of monocyte-derived dendritic cells.
abstract: Monocyte-derived dendritic cells (DC) are currently under extensive evaluation as cell vaccines for cancer treatment. The requirement for large-scale cell products demands optimized and standardized protocols. However, the yield of DCs from inoculated monocytes is reported to be always lower than 50%. In this present study we investigated whether this cell loss was caused by the properties of the starting population of inoculated monocytes. CD14 cells were enriched by immunomagnetic-bead selection and analyzed for apoptosis by an annexin V/propidium iodide assay. We found that 37.8+/-11.1% (n=8) of freshly isolated monocytes from buffy coats of healthy donors underwent programmed cell death. Further analysis of the fate of apoptotic cells during differentiation suggested phagocytosis. Monocytes were differentiated with GM-CSF and interleukin-4 into a viable, non-apoptotic population of immature dendritic cells. Addition of tumor necrosis factor-alpha and prostaglandin E2 resulted in fully matured dendritic cells, which were evaluated by phenotypic analysis and by allogeneic and MHC class-I-restricted T-cell responses. About 90.2+/-16.7% of the non-apoptotic monocyte population differentiated to viable matured dendritic cells. These results indicate that the yield of dendritic cells is mainly influenced by the percentage of apoptotic cells in the inoculum, and this has implications for DC generation in clinical applications.
authors.affiliation: Institute of Biotechnology 2, Research Center Jülich GmbH, Leo-Brandt-Strasse 1, 52428 Jülich, Germany. hermann.bohenkamp@cancer.org.uk
authors.forename: Hermann R
authors.initials: HR
authors.lastname: Bohnenkamp
authors.forename: Joy M
authors.initials: JM
authors.lastname: Burchell
authors.forename: Joyce
authors.initials: J
authors.lastname: Taylor-Papadimitriou
authors.forename: Thomas
authors.initials: T
authors.lastname: Noll
mesh_terms: D017304:Annexin A5 / Q000032:analysis; D017209:Apoptosis; D019496:Cancer Vaccines / Q000276:immunology / Q000627:therapeutic use; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology*; D002469:Cell Separation; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000637:transplantation; D015232:Dinoprostone / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D016219:Immunotherapy, Adoptive; D018950:Lipopolysaccharide Receptors / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D009000:Monocytes / Q000166:cytology / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology / Q000628:therapy; D010120:Oxytocics / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology; D010641:Phenotype; D011419:Propidium / Q000737:chemistry; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D017304:Annexin A5; D019496:Cancer Vaccines; D016207:Cytokines; D015395:Histocompatibility Antigens Class I; D018950:Lipopolysaccharide Receptors; D010120:Oxytocics; D011419:Propidium; D015232:Dinoprostone