Enhancing DNA Vaccine Delivery Through Stearyl-Modified Cell-Penetrating Peptides: Improved Antigen Expression and Immune Response In Vitro and In Vivo.

BACKGROUND

Inefficient cellular uptake is a significant limitation to the efficacy of DNA vaccines. In this study, we introduce S-Cr9T, a stearyl-modified cell-penetrating peptide (CPP) designed to enhance DNA vaccine delivery by forming stable complexes with plasmid DNA, thereby protecting it from degradation and promoting efficient intracellular uptake.

METHODS AND RESULTS

In vitro studies showed that S-Cr9T significantly improved plasmid stability and transfection efficiency, with optimal performance at an N/P ratio of 0.25. High-content imaging revealed that the S-Cr9T-plasmid complex stably adhered to the cell membrane, leading to enhanced plasmid uptake and transfection. In vivo, S-Cr9T significantly increased antigen expression and triggered a robust immune response, including a threefold increase in IFN-γ secretion and several hundred-fold increases in antibody levels compared to control groups.

CONCLUSIONS

These findings underscore the potential of S-Cr9T to enhance DNA vaccine efficacy, offering a promising platform for advanced gene therapy and vaccination strategies.