Monitoring kinetic changes and restriction of influenza A virus RNA species during infection using a Flu-Stranded CRISPR platform.

Flu-Stranded CRISPR-Cas12a enables sensitive, strand-specific detection of influenza A virus RNA, revealing early genome decline during infection with a detection limit of 10² copies.

• Why it matters: Understanding the early dynamics of influenza virus genomes is crucial for insights into infection establishment and potential intervention points, yet current methods lack sensitivity and resolution at low RNA levels.
• What they did: The team developed a platform combining tagged reverse transcription, segment-specific PCR, and Cas12a collateral cleavage to quantify vRNA, cRNA, and mRNA across a broad range, validated in various biological samples.
• The result: They discovered a reproducible early decline in vRNA during post-entry, localized to cytoplasmic genomes, which is modulated by RIG-I and dependent on nuclear import, providing new insights into early influenza infection stages.