Developing a novel gene-delivery vector system using the recombinant fusion protein of pseudomonas exotoxin a and hyperthermophilic archaeal histone HPhA

Abstract

Non-viral gene delivery system with many advantages has a great potential for the future of gene therapy. One inherent obstacle of such approach is the uptake by endocytosis into vesicular compartments. Receptor-mediated gene delivery method holds promise to overcome this obstacle. In this study, we developed a receptor-mediated gene delivery system based on a combination of the Pseudomonas exotoxin A (PE), which has a receptor binding and membrane translocation domain, and the hyperthermophilic archaeal histone (HPhA), which has the DNA binding ability. First, we constructed and expressed the RPE-HPhA fusion protein. We then examined the cytotoxicity and the DNA binding ability of RPE-HPhA. We further assessed the efficiency of transfection of the pEGF-C1 plasmid DNA to CHO cells by the RPE-HPhA system, in comparison to the cationic liposome method. The results showed that the transfection efficiency of RPE-HPhA was higher than that of cationic liposomes. In addition, the RPE-HPhA gene delivery system is non-specific to DNA sequence, topology or targeted cell type. Thus, the RPE-HPhA system can be used for delivering genes of interest into mammalian cells and has great potential to be applied for gene therapy.