CRISPR-Cas13d effectively targets SARS-CoV-2 variants, including Delta and Omicron, and inhibits viral infection

Area of Science:

• Molecular Biology
• Virology
• Gene Editing Technologies

Background:

• The COVID-19 pandemic caused by SARS-CoV-2 variants of concern necessitates novel therapeutic strategies beyond vaccines and antivirals.
• Effective RNA degradation is crucial for controlling viral replication and spread.

Purpose of the Study:

• To develop and validate a CRISPR-Cas13-based system for targeting and degrading SARS-CoV-2 viral RNA.
• To assess the efficacy of this system against various SARS-CoV-2 strains, including emerging variants.

Main Methods:

• Cytological infection experiments and in vitro validation of CRISPR-associated RNAs (crRNAs).
• Screening of crRNAs targeting conserved viral regions, specifically NSP13, NSP14, and nucleocapsid transcripts.
• Bioinformatics and phylogenetic analysis of viral sequences to assess targeting breadth.

Main Results:

• CRISPR-Cas13d effectors achieved >99% silencing efficiency in human cells infected with SARS-CoV-2, including Alpha, Beta, and Delta variants.
• Bioinformatic analysis indicated that the crRNAs could target nearly 100% of SARS-CoV family members, including Omicron.
• The system demonstrated high specificity, efficiency, and rapid deployment capabilities.

Conclusions:

• The reprogrammed Cas13d system is a potent tool for degrading SARS-CoV-2 RNA, showing significant potential for antiviral drug development.
• This CRISPR-Cas13 strategy offers a flexible and effective approach to combat current and future SARS-CoV-2 variants, including those with multiple mutations.