Broad-spectrum CRISPR-Cas13d-mediated strategy for combating human coronaviruses

Area of Science:

• Molecular Biology
• Virology
• Biotechnology

Background:

• RNA viruses, including coronaviruses (CoVs), exhibit rapid evolution, leading to immune evasion and challenges in developing effective antiviral therapies and diagnostics.
• There is a critical need for innovative strategies that offer broad-spectrum viral suppression and detection capabilities.

Purpose of the Study:

• To design and evaluate CRISPR-Cas13d-based RNA-guided enzymes for simultaneous antiviral activity and sensitive detection of human coronaviruses.
• To assess the conserved nature of the target sequence across animal coronaviruses for pandemic preparedness.

Main Methods:

• Development of four Cas13d CRISPR guide RNAs (crRNAs) targeting a conserved sequence in the nsp12 gene of coronaviruses.
• In vitro evaluation of antiviral efficacy against all seven human CoVs.
• Adaptation of crRNAs for a Cas13d-based SHERLOCK (specific high-sensitivity enzymatic reporter unlocking) assay for viral detection.
• Bioinformatic analysis to determine the conservation of target sequences across animal coronaviruses.

Main Results:

• The designed crRNAs demonstrated potent in vitro antiviral activity against all tested human CoVs.
• The Cas13d-based SHERLOCK assay exhibited high sensitivity, detecting as few as one copy of SARS-CoV-2 RNA.
• The assay showed specificity, with no detectable signal for other respiratory viruses like influenza.
• Bioinformatic analysis confirmed high conservation of the target sequence in animal coronaviruses.

Conclusions:

• CRISPR-Cas13d technology presents a versatile dual-function platform for both suppressing and detecting a wide range of coronaviruses.
• The conserved nature of the targeted sequence offers a promising strategy for rapid development of diagnostics and therapeutics against emerging coronaviruses, enhancing pandemic preparedness.