EGF domain peptide of Developmentally regulated endothelial locus1 facilitates gene expression of extracellularly...

The successful development of messenger RNA vaccines for SARS-CoV-2 opened up venues for clinical nucleotide-based vaccinations. For development of DNA vaccines, we tested whether the EGF domain peptide of Developmentally regulated endothelial locus1 (E3 peptide) enhances uptake of extracellularly applied plasmid DNA.

DNA plasmid encoding lacZ or GFP was applied with a conditioned culture medium containing E3 peptide to cell lines in vitro or mouse soleus muscles in vivo, respectively. After 48 h incubation, gene expression was examined by β-galactosidase (β-gal) assay and fluorescent microscope, respectively.

Application of E3 peptide-containing medium to cultured cell lines induced intense β-gal activity in a dose-dependent manner. Intra-gastrocnemius injection of E3 peptide-containing medium to mouse soleus muscle succeeded in the induction of GFP fluorescence in many cells around the injection site.

The administration of E3 peptide facilitates transmembrane uptake of extracellular DNA plasmid which induces sufficient extrinsic gene expression.