Circulating cholesterol fuels SARS-CoV-2 replication via ORF3a.

High circulating LDL cholesterol enhances SARS-CoV-2 replication through ORF3a-mediated cholesterol uptake, especially in the Beta variant, potentially worsening COVID-19 severity.

• Why it matters: Understanding how cholesterol influences viral replication addresses the gap in knowledge about why high LDL levels correlate with more severe COVID-19 outcomes, which could inform targeted treatments.
• What they did: The study used cell culture and hamster models to demonstrate that LDL boosts SARS-CoV-2 RNA replication, with ORF3a increasing cholesterol entry by stabilizing LDL receptors and differing in function between variants.
• The result: Findings reveal that SARS-CoV-2 exploits host cholesterol pathways via ORF3a, suggesting new antiviral strategies that could benefit individuals with high cholesterol by disrupting this viral-host interaction.