Paramyxovirus-like particles for therapeutic delivery of base editors
Research Poster Health & Life Sciences 2025 Graduate ExhibitionPresentation by Srijana Adhikari
Exhibition Number 113
Abstract
CRISPR-Cas base editors (BEs) are powerful tools for precise genome modification without inducing double-strand breaks. The two major types, adenine and cytosine base editors (ABEs/CBEs) can potentially correct ~60% of genetic disorders caused by single-nucleotide variations. However, efficient delivery remains a significant challenge. The commonly used delivery tools, such as AAV vector, are limited by cargo size restrictions, potential genomic integration into the host genome, and prolonged transgene expression, which increases the risk of off-target effects. Delivering BEs as proteins offers a safer, more controlled approach, minimizing genomic integration risks and enabling rapid editing activity. Here, we employed paramyxovirus-like particles (VLPs) as a delivery platform for ABEs as paramyxovirus VLPs have broad and malleable tropism and a flexible structure that accommodates large cargoes. To facilitate ABE packaging into paramyxovirus VLPs, we engineered the ABE by appending a 20-amino-acid sequence from the C-terminal end of the paramyxovirus nucleocapsid (NP) protein. This modification enabled efficient incorporation of ABE into budding VLPs during viral assembly. The resulting VLPs retained their ability to bind and fuse with target cell membranes, directly releasing the ABE cargo into the target cell cytoplasm. To evaluate the effectiveness of VLP-mediated ABE delivery, we developed a novel reporter cell system in which ABE-mediated genome editing at a specific site induces red fluorescent protein expression. Using this system, we demonstrated that ABE-loaded VLPs efficiently delivered ABE to target cells, enabling precise genomic edits. These findings highlight the potential of this approach for safe and effective therapeutic delivery of base editors.
Importance
Therapeutic proteins such as genome editors and transcription factors have enormous clinical potential but are currently limited in part due to the challenges of safely and efficiently delivering these proteins to the target cell interiors. Here, we have developed a strategy for protein delivery based on the manipulation of paramyxovirus genome packaging interactions.