Programming human dendritic cells with mRNA.

Transfecting with in vitro transcribed, protein-encoding mRNA is a simple yet effective method to express high levels of the desired RNA-encoded proteins in primary cells. Cells can be transfected with antigen-encoding mRNA, which is translated into protein and is processed by the cellular antigen-processing pathway to generate antigen-presenting cells. Another elegant and increasingly popular application is to transfect cells with mRNA that encodes immune modulating molecules (cytokines, chemokines, toll-like receptors (TLRs), immune receptor ligands, immune receptor targeting antibodies) which, when translated into protein, can program cell behavior and/or function. In this chapter we describe an efficient method to deliver mRNA into human dendritic cells (DCs) by electroporation. This is currently the method of choice to deliver mRNA into antigen-presenting cells for generating vaccines for cancer immunotherapy.