Characterization of the SARS-CoV-2 Genome 3'-Untranslated Region Interactions with Host MicroRNAs

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• The SARS-CoV-2 pandemic highlights the need to understand viral mechanisms of disease severity and immune evasion.
• The 3'-untranslated region (UTR) of viral genomes contains conserved elements that can influence host-virus interactions.
• Host microRNAs (miRs) are known to regulate gene expression and play roles in immune responses.

Purpose of the Study:

• To investigate the binding of host cellular miRs to the SARS-CoV-2 genome 3'-UTR.
• To characterize the biophysical interactions between SARS-CoV-2 3'-UTR and specific miRs.
• To explore the potential of miR-binding inhibitors as antiviral strategies.

Main Methods:

• In vitro binding assays using native gel electrophoresis and fluorescence spectroscopy.
• Identification of potential miR binding sites within the SARS-CoV-2 3'-UTR.
• Investigation of 2'-fluoro-d-arabinonucleic acid (FANA) analogs as competitive inhibitors.

Main Results:

• Demonstrated direct binding of host miRs (miR-34a-5p, miR-34b-5p, miR-760-3p) to the SARS-CoV-2 3'-UTR.
• Biophysically characterized the sequence-specific interactions between miRs and the viral UTR.
• Identified FANA analogs capable of inhibiting these miR-binding interactions.

Conclusions:

• SARS-CoV-2 may hijack host miRs via its 3'-UTR to modulate host immune responses, specifically targeting genes like GRN, IL-6, and IL-6R involved in JAK/STAT3 signaling.
• This viral hijacking mechanism provides a novel avenue for understanding SARS-CoV-2 pathogenesis.
• Targeting the virus-host interface, specifically these miR interactions, holds promise for developing new antiviral therapeutics.