Cell-Permeable Peptide Nucleic Acid Antisense Oligonucleotide Platform Targeting Human Betacoronaviruses

Numerous studies have been conducted around the world in an effort to find a treatment for coronavirus-related diseases. Antisense oligonucleotides (ASOs) with therapeutic potential have recently been reported to target the SARS-CoV-2 genome. Peptide nucleic acids (PNAs)-based ASOs have been regarded as promising drug candidates, but intracellular delivery has been a significant obstacle. Here, we present novel modified PNAs, termed OPNAs, with excellent cell permeability that disrupt various critical conserved regions of the SARS-CoV-2 and HCoV-OC43 genome.Treatment with OPNAs designed to target the conserved regions of the SARS-CoV-2 and HCoVOC43 genomes reduced viral titers and protein expression significantly.Several modifications (oligo size and position, etc.) were introduced to enhance the efficacy ofOPNAs. Improved OPNAs exhibited a dose-dependent reduction in viral replication and nucleoprotein (NP) protein. When a mixture of oligoes was applied to infected cells, viral titer and NP levels decreased by more than eightfold.In this study, we have developed a modified PNA ASO platform with exceptional chemical stability, high binding affinity, and cellular permeability. These findings indicate that OPNAs are a promising platform for the development of antivirals to combat future pandemic viral infections that do not require a carrier.