Engineered virus-like particles for efficient in vivo delivery of therapeutic proteins
Banskota S. et al. (2022) Engineered virus-like particles for efficient in vivo delivery of therapeutic proteins. Cell. 185, 250–265. DOI: 10.1016/j.cell.2021.12.021
This study presents a transformative advancement in therapeutic delivery using engineered virus-like particles (eVLPs) to deliver gene editing proteins without the need for DNA. Traditional delivery systems using viral vectors or plasmid DNA pose risks such as prolonged expression, off-target editing, and genomic integration. The authors overcome these challenges by designing DNA-free eVLPs capable of encapsulating and delivering base editor and Cas9 ribonucleoproteins (RNPs) directly to target cells.
Through iterative design optimizations addressing packaging, cargo release, and cellular localization, fourth-generation (v4) eVLPs were developed. These particles demonstrated significantly improved base editing efficiency—up to 95% in vitro—and reduced off-target activity compared to DNA-based delivery systems. The v4 eVLPs achieved therapeutically relevant editing levels in vivo, including 63% editing of the Pcsk9 gene in mouse liver and partial restoration of vision in a mouse model of genetic blindness (Leber congenital amaurosis, LCA). Additionally, eVLPs enabled efficient editing in primary human fibroblasts and T cells, further validating their clinical potential.
Notably, these eVLPs achieved transient, targeted delivery, minimizing the risk of DNA integration and RNA off-target effects. The modular architecture of eVLPs also allows for tropism modification by substituting viral envelope glycoproteins, enabling tissue-specific delivery.
Keywords: virus-like particles, base editing, gene therapy, ribonucleoprotein delivery, Cas9, Pcsk9, Leber congenital amaurosis, LCA, adenine base editors, eVLP, off-target minimization, nonviral delivery, 2025 Breakthrough Prize, D.R. Liu
