Characterization of murine dendritic cells derived from adherent blood mononuclear cells in vitro

The therapeutic potential of dendritic cells loaded with tumour antigens fo r the induction of effective immune responses against cancer is currently b eing tested in numerous clinical trials. In most cases, the dendritic cells are generated in vitro from peripheral blood monocytes. Many aspects of de ndritic cell-based vaccination have not yet been examined in detail, and ho mologous mouse model systems may prove very valuable for optimizing clinica l procedures. In the murine system, however, dendritic cells are usually is olated from either lymphoid tissues or bone marrow cultures. To date, murin e monocyte-derived dendritic cells have been described only sporadically. H ere, we describe a culture system for the generation of murine dendritic ce lls from adherent peripheral blood mononuclear cells by culturing in the pr esence of granulocyte-macrophage colony stimulating factor and interleukin- 4. After 7 days of culture the nonadherent cells were harvested from the cu ltures. Most of these cells exhibited well-accepted characteristics of matu re dendritic cells (e.g. veiled appearance, high expression of major histoc ompatibility complex class II and CD86) and stimulated vigorous proliferati on of allogeneic T cells in a primary mixed leucocyte reaction following st imulation with bacterial lipopolysaccharide. Interestingly, staining the ce lls for expression of the putative antigen-uptake receptor DEC-205 revealed a distinct bimodal distribution.