A new rapid cell-penetrating peptide based strategy to produce bacterial ghosts for plasmid delivery.

The production of bacterial ghosts involves the lysis gene E plasmid in order to lyse and empty the bacteria of their cytoplasmic contents. After lysis the ghosts can either be loaded with new desired DNA and used for delivery to mammalian cells or used in vaccination. Cell-penetrating peptides have been used as delivery vehicles of drugs and oligonucleotides. Although many of them show low toxicity they have been compared to antimicrobial peptides involved in innate immunity. Recently we showed that cell-penetrating peptides also could be antimicrobial. In this study we take advantage of the antimicrobial effect of one cell-penetrating peptide, namely MAP, which is a model amphipathic peptide and treat bacteria with the peptide to produce bacterial ghosts. This new peptide based strategy is not dependent on the lysis gene E plasmid thus; several tiresome steps are removed in the production of ghosts. In addition the ghosts can be preloaded with a desired plasmid or DNA further removing time consuming reprocessing steps. To our knowledge this is the first study that uses a cell-penetrating peptide based strategy to produce bacterial ghosts to be used in plasmid delivery.