A novel multitargeted self-assembling peptide-siRNA complex for simultaneous inhibition of SARS-CoV-2-host cell...

Area of Science:

• Biochemistry
• Virology
• Drug Delivery

Background:

• Severe COVID-19 necessitates advanced therapeutics beyond vaccines.
• Small interfering RNA (siRNA) offers a strategy to inhibit SARS-CoV-2 replication by targeting viral genes.
• Cell-penetrating peptides enhance siRNA stability and cellular uptake for targeted delivery.

Purpose of the Study:

• To develop and evaluate a peptide-based delivery system for siRNA targeting SARS-CoV-2.
• To investigate the mechanisms by which the peptide HE25 facilitates siRNA delivery and viral inhibition.
• To assess the efficacy of the siRNA/HE25 complex against SARS-CoV-2 variants in vitro and in vivo.

Main Methods:

• Development of HE25 peptide for binding SARS-CoV-2 entry receptors (ACE2, integrins, NRP1).
• Utilizing HE25 as a vehicle for delivering RNA-dependent RNA polymerase siRNA into cells.
• Investigating siRNA release via the histidine-proton sponge effect and HE25 cleavage by cathepsin B.
• Evaluating inhibition of SARS-CoV-2 (ancestral and Omicron BA.5) replication in vitro.
• Assessing biodistribution of HE25 after intravenous injection or inhalation in vivo.

Main Results:

• HE25 effectively delivered siRNA into cells, inhibiting SARS-CoV-2 replication in vitro.
• The siRNA/HE25 complex demonstrated efficacy against both ancestral SARS-CoV-2 and the Omicron BA.5 variant.
• In vivo administration showed HE25 accumulation in lung tissues, indicating potential for respiratory delivery.
• Gene silencing was observed in lung cells treated with the siRNA/HE25 complex in vitro.

Conclusions:

• The HE25 peptide serves as an effective delivery vehicle for siRNA targeting SARS-CoV-2.
• The developed siRNA/HE25 complex exhibits potent antiviral activity against SARS-CoV-2 in vitro and in vivo.
• This therapeutic strategy holds potential for managing COVID-19 and combating future viral outbreaks.