Phenotype and Function of Antigen-Presenting Dendritic Cells Generated from Peripheral Blood Monocytes

Background: Dendritic cells (DC) are specialized for the primary activation of helper and cytotoxic T cells and have therefore been denominated ‘professional’ antigen-presenting cells. Their potent antigen-presenting capacity qualifies these cells as a promising tool in vaccination protocols, in particular in the induction of tumor-specific immunity. Functionally active DC can be generated from peripheral blood monocytes in vitro. Consequently, these cells gained interest in the field of transfusion medicine. Material and Methods: Here we describe a simplified protocol for the generation of large numbers of DC from peripheral blood monocytes and their phenotype and function. DC were generated from CD14+ monocytes by culture in the presence of granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). Results: On day 7 of culture the expression of the surface markers CD1a, CD80 and HLA-DR was upregulated, whereas CD14 and CD64 were almost completely downregulated, compared to day 0. Moreover, the in vitro generated DC were shown to induce antigen-specific proliferation of autologous T cells after pulsing with tetanus toxoid. Conclusion: The presented protocol allows to generate large numbers of DC for immunotherapy and vaccination.