Host transcriptional corepressor TLE1 is commonly exploited by RNA viruses for replication

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Viral genomes encode transcriptional regulators that manipulate host gene expression for replication.
• The intricate regulatory networks governing these interactions are not fully understood.
• Influenza A virus (IAV) serves as a model to investigate these mechanisms.

Purpose of the Study:

• To elucidate the role of viral transcriptional regulators in host gene modulation.
• To identify host factors exploited by viruses for replication and immune evasion.
• To explore potential therapeutic strategies targeting viral-host interactions.

Main Methods:

• Utilized IAV as a model system.
• Investigated the interaction between viral nucleoprotein (NP) and host transcriptional corepressor TLE1.
• Employed peptide inhibition (AH49A) to block NP-TLE1 interaction.
• Analyzed conserved motifs (basic helix-loop-helix-like) across different RNA viruses, including SARS-CoV-2.
• Performed loss-of-function substitutions in motif regions.

Main Results:

• IAV NP harnesses host TLE1 to boost viral polymerase activity and suppress innate immune responses.
• A conserved basic helix-loop-helix (bHLH)-like motif in NP mediates TLE1 recognition, recruiting KLF4 to suppress antiviral signaling.
• Peptide AH49A targeting the NP-TLE1 interaction demonstrated antiviral protection in vitro and in vivo.
• The NP-TLE1-KLF4 axis and bHLH-like motifs are conserved across various RNA viruses, including SARS-CoV-2.
• Mutations in the bHLH-like motif attenuated replication of both IAV and SARS-CoV-2.

Conclusions:

• RNA viruses exploit host transcriptional machinery components for replication.
• The NP-TLE1-KLF4 interaction pathway is a conserved mechanism for viral immune evasion and replication enhancement.
• Targeting viral-host transcriptional interactions, specifically the bHLH-like motif, presents a promising antiviral strategy.