Abstract Nonsense mutations, resulting from a premature termination codon (PTC), make up ∼11% of all genetic lesions causing disease, affecting millions of people worldwide. Nonsense suppressor anticodon-edited transfer RNAs (ACE-tRNAs) have emerged as a therapeutic modality for the rescue of PTCs. Delivery of ACE-tRNAs in vivo has been achieved by adeno-associated viral vector and RNA-lipid nanoparticle; however, due to drawbacks associated with these approaches, DNA delivery remains an attractive approach. DNA-based approaches afford ease of manufacturing at a relatively low cost and exhibit improved therapeutic durability and safety as compared to viral vector- or RNA-based approaches. Due to the small size of human tRNA genes employed as ACE-tRNAs, in principle, DNA vectors 200 base pairs (bp) in size (minivectors) could be utilized for delivery of actively transcribed ACE-tRNAs. Here, we demonstrate that linear DNA ACE-tRNA vectors as small as 200 bp effectively suppress several nonsense mutations in CFTR and REP1, and that ACE-tRNA minivectors, when tested in cell or ex vivo models, display significantly improved bioavailability, reduced innate immune burden, and superior biostability as compared to conventional plasmid DNA vectors.
Porter et al. (Fri,) studied this question.