Inhibition of monkeypox virus replication by RNA interference

Area of Science:

• Virology
• Molecular Biology
• RNA Interference Therapeutics

Background:

• Orthopoxviruses, including monkeypox virus (MPV), are significant human pathogens.
• Current MPV countermeasures rely solely on vaccination, with no approved antiviral therapies.
• RNA interference (RNAi) presents a potential therapeutic avenue for viral infections.

Purpose of the Study:

• To evaluate the efficacy of RNA interference (RNAi) as a therapeutic strategy against orthopoxvirus infections.
• To identify specific small interfering RNA (siRNA) constructs targeting essential MPV genes for replication inhibition.

Main Methods:

• Genome-wide expression studies and bioinformatic analysis identified 12 MPV target genes.
• Forty-eight siRNA constructs were designed and tested in vitro for antiviral activity.
• MPV replication inhibition and cytotoxicity were assessed using cell cultures and recombinant MPV.

Main Results:

• Seven siRNA constructs targeting two MPV genes (A6R and E8L) significantly inhibited viral replication (65-95%).
• No apparent cytotoxicity was observed with the effective siRNA constructs.
• The siRNA construct siA6-a demonstrated potent inhibition of MPV replication for up to 7 days at 10 nM.

Conclusions:

• The A6R gene plays a critical role in MPV replication.
• RNAi is a viable therapeutic approach for developing oligonucleotide-based treatments for MPV and other orthopoxviruses.
• This study highlights the potential of siRNA therapy for managing orthopoxvirus infections.