Single-step antigen loading and maturation of dendritic cells through mRNA electroporation of a tumor-associated antigen and a TriMix of costimulatory molecules.

Dendritic cells (DC) are key players in several types of cancer vaccines. Large numbers of DC can easily be generated in closed systems from the monocyte fraction of the peripheral blood. They are the professional antigen-presenting cells, and electroporation of mRNA-encoding tumor antigens is a very efficient and a relatively simple way to load the DC with antigen. The co-electroporation of a tumor antigen of choice and the combination of 3 costimulatory molecules, including CD70, caTLR4, and CD40L (TriMix-DC), leads to fully potent antigen-presenting DC able to generate a broad immune response.Here we describe the in vitro transcription of the mRNA and the subsequent generation and electroporation of autologous DC used for the treatment of melanoma patients.