Baculovirus-induced recombinant protein expression in human mesenchymal stromal stem cells: A promoter study

Human mesenchymal stem cells (hMSCs) are the current workhorses of regenerative medicine and gene therapy. The corresponding vectors are usually based on lentiviruses, adenoviruses, retroviruses or adeno-associated viruses, but recently they have been joined by baculoviruses, which are more widely known for their role in the development of pesticides and vaccines. Here we show that gene transfer to an immortalized human mesenchymal stroma cell line can be achieved by baculovirus transduction. We also compared the performance of five different constitutive promoters controlling GFP expression. The human elongation factor 1a promoter (EF1a) achieved the strongest GFP expression, whereas the mouse phosphoglycerate kinase 1 promoter (PGK) was the weakest. The human EF1a promoter is therefore recommended for the regulation of genes introduced into hMSC-TERTs by baculovirus vectors.