Efficient delivery of gene editors using intein-engineered virus-like particles
Virus-like particles (VLPs) represent a promising next-generation drug delivery platform. However, conventional VLPs rely on multiple viral components for effective cargo encapsulation and delivery, raising safety concerns. Here, we present a novel strategy to engineer immature VLPs using a self-cleaving intein system. We employed viral Gag proteins as sorting domains, linking cargo proteins to Gag through inteins, thereby eliminating the need for the conventional protease cleavage typically mediated by the gag-pol protein. During VLP biogenesis, intein-mediated cleavage released cargo proteins into the lumen, enabling efficient intracellular delivery when VLP surfaces are pseudotyped with VSV-G. Optimal candidates for delivering Cre recombinase and gene editing tools (Cas9, Cas12a and base editors) were identified by screening various Gag proteins. Notably, these VLPs achieved robust gene editing in primary cells, including naive and activated T cells, as well as hematopoietic stem and progenitor cells (HSPCs). A single local intracerebroventricular (ICV) infusion of optimized particles induced up to 60% tdTomato expression in the brain regions of reporter mice, while intravenous injection resulted in significant recombination (up to 70%) of a variety of cell types across organs. Collectively, we developed a simplified, efficient VLP platform for intracellular cargo delivery with broad therapeutic potential for gene editing and treatment of human diseases.