RNA Electroporation as a New Gene Transfer Method in Hematopoietic Progenitor Cells, Mesenchymal Cells and Activated T-Cells.

Electroporation of messenger RNA has become an established method for gene transfer into dendritic cells for immunotherapeutic purposes. When electroporating dendritic cells, this method combines high transient gene expression with low cell mortality without the risk for insertional mutagenesis. Here, we have investigated the potential of mRNA electroporation to induce short-term transgene expression in other cell types such as bone marrow CD34+ progenitor cells, in vitro cultured bone marrow mesenchymal cells and phytohemagglutinin A (PHA)-stimulated peripheral blood T-cells. Transgene expression after electroporation with mRNA encoding the enhanced green fluorescent protein (EGFP) was evaluated by flow cytometry. Flow cytometric analysis 24h after EGFP mRNA electroporation revealed that 35% of fresh uncultured bone marrow-derived CD34+ hematopoietic progenitor cells was efficiently transfected. In the population of in vitro cultured mesenchymal cells, 90% of the viable CD45-CD13+ cells showed detectable EGFP expression. The level of transient EGFP expression in the PHA-stimulated T-cell population was 47% at 24h after electroporation. Importantly, no significant difference of cell mortality between electroporated and non-electroporated cells was observed, due to the mild electroporation procedure ensuring high cell viability. When looking at the kinetics of EGFP expression, we saw that EGFP was still expressed at day 7 after electroporation with highest expression at day 4. Short-term gene introduction by mRNA electroporation in hematopoietic progenitor cells, mesenchymal cells and T-cells could be used to direct the differentiation and/or to modulate the function of these cells. We conclude that mRNA electroporation is an efficient method for short-term gene transfer in CD34+ cells, mesenchymal cells and activated T-cells with potential applications in gene therapy procedures.