Choose your models wisely: How differentmurine bonemarrow-derived dendritic cell protocols influence the success of nanoparticulate vaccines in vitro

摘要

Dendritic cell (DC)-based cancer vaccination has shown great potential in cancer immunotherapy. As a result, novel nanoparticles aiming to load DCs with tumor antigens are being developed and evaluated in vitro. For this,murine bonemarrow-derived DCs (BM-DCs) aremost commonly used asmodel DCs. However, many different protocols exist to generate these cells. Therefore, we investigated to what extent different BM-DC culture protocols impact on the immunobiology of the cells, as well as their response to particulate antigens.We evaluated 4 different BM-DC protocols with 2 main variables: bovine serum and cytokine combinations. Our results show distinct differences in yield, phenotypical maturation status and the production of immune stimulatory and immune suppressive cytokines by the different BM-DCs. Importantly, we demonstrate that the antigenloading of these different BM-DCs via transfection with mRNA lipoplexes results in large differences in transfection efficiency aswell as in the capacity ofmRNA-transfected BM-DCs to stimulate antigen-specific T cells. Thus, it is clear that theBM-DCmodel can have significant confounding effects on the evaluation of novel nanoparticulate vaccines. To take this into accountwhen testing novel particulate antigen-delivery systems in BM-DCmodels,we propose to (1) perform a thorough immunological characterization of the BM-DCs and to (2) not only judge a particle's potential for cancer vaccination based on transfection efficiency, but also to include an evaluation of functional end-points such as T cell activation.