Inhibition of SARS-CoV-2 in Vero cell cultures by peptide-conjugated morpholino oligomers.

Abstract

BACKGROUND:

As the causative agent of COVID-19, SARS-CoV-2 is a pathogen of immense importance to global public health. Development of innovative direct-acting antiviral agents is sorely needed to address this virus. Peptide-conjugated morpholino oligomers (PPMO) are antisense compounds composed of a phosphorodiamidate morpholino oligomer covalently conjugated to a cell-penetrating peptide. PPMO require no delivery assistance to enter cells and are able to reduce expression of targeted RNA through sequence-specific steric blocking.

METHODS:

Five PPMO designed against sequences of genomic RNA in the SARS-CoV-2 5'-untranslated region and a negative control PPMO of random sequence were synthesized. Each PPMO was evaluated for its effect on the viability of uninfected cells and its inhibitory effect on the replication of SARS-CoV-2 in Vero-E6 cell cultures. Cell viability was evaluated with an ATP-based method using a 48 h PPMO treatment time. Viral growth was measured with quantitative RT-PCR and TCID50 infectivity assays from experiments where cells received a 5 h PPMO treatment time.

RESULTS:

PPMO designed to base-pair with sequence in the 5' terminal region or the leader transcription regulatory sequence region of SARS-CoV-2 genomic RNA were highly efficacious, reducing viral titres by up to 4-6 log10 in cell cultures at 48-72 h post-infection, in a non-toxic and dose-responsive manner.

CONCLUSIONS:

The data indicate that PPMO have the ability to potently and specifically suppress SARS-CoV-2 growth and are promising candidates for further preclinical development.

• Authors: Kyle Rosenke, Shanna Leventhal, Hong M Moulton, Susan Hatlevig, David Hawman, Heinz Feldmann, David A Stein
• Journal: The Journal of antimicrobial chemotherapy (J Antimicrob Chemother) Vol. 76 Issue 2 Pg. 413-417 (01 19 2021) ISSN: 1460-2091 [Electronic] England
• PMID: 33164048 (Publication Type: Journal Article, Research Support, N.I.H., Intramural)
• Copyright: © The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: [email protected].

Chemical References

• Antiviral Agents
• Cell-Penetrating Peptides
• Morpholinos

Topics

• Animals
• Antiviral Agents (chemistry, pharmacology)
• COVID-19 (virology)
• Cell Survival (drug effects)
• Cell-Penetrating Peptides (chemistry, pharmacology)
• Chlorocebus aethiops
• Cytopathogenic Effect, Viral (drug effects)
• Morpholinos (chemistry, pharmacology)
• SARS-CoV-2 (drug effects, genetics)
• Vero Cells
• Virus Replication (drug effects)