Varenicline Prevents SARS-CoV-2 Infection In Vitro and in Rhesus Macaques

  1. Jeffrey Nau
  2. Priya Luthra
  3. Kathleen Lanzer
  4. Frank Szaba
  5. Tres Cookenham
  6. Eric Carlson

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Abstract

Background

SARS-CoV-2 infections have resulted in a global pandemic, but an antiviral therapy for this novel strain of coronavirus does not currently exist. The objective of our study was to investigate the antiviral potential of the nicotinic acetylcholine receptor (nACHR) agonist varenicline tartrate against SARS-CoV-2.

Methods

We assessed antiviral activity using in vitro human cell assays and we assessed in vivo efficacy in a rhesus macaque model.

Results

In vitro studies found that varenicline tartrate, over a range of concentrations, reduced the infectivity of SARS-CoV-2 wildtype, alpha, and beta variants in Calu-3 cells and Caco-2 cells, with maintenance of cell viability. In vivo studies found that varenicline tartrate, administered as a nasal spray to rhesus macaques, reduced SARS-CoV-2 wildtype viral load and inhibited viral replication in the nasal mucosa and upper airway.

Conclusion

Although the study reported here was exploratory, we have confirmed that the nAChR agonist varenicline has the potential to interact with and inhibit SARS-CoV-2 infection and replication.

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  1. ScreenIT

    SciScore for 10.1101/2021.06.29.450426: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsField Sample Permit: In vivo SARS-CoV-2 challenge study in Rhesus Macaques: Studies were conducted under the BIOQUAL Inc.
    IACUC: Institute Institutional Animal Care and Use Committee (IACUC)-approved protocol 20-069P, which is in compliance with the Animal Welfare Act and other federal statutes and regulations relating to animals and experiments involving animals.
    Euthanasia Agents: On Days 2 to 5, 4 doses of OC-01 were given, and on Day 6, 2 doses of OC-01 were given, and then animals were euthanized (with an intravenous overdose of sodium pentobarbital) for necropsy and tissue collection.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    In vitro antiviral activity in Calu-3 and Caco-2 cells: Reagents: Antiviral activity assays were conducted in Calu-3 and Caco-2 cells.
    Calu-3
    suggested: KCLB Cat# 30055, RRID:CVCL_0609)
    Calu-3 cells (ATCC ATB-55) are a line of epithelial cells derived from a lung adenocarcinoma and Caco-2 cells (ATCC HTB-37) are a line of epithelial cells from a colorectal adenocarcinoma: both are anticipated to express both ACE2 and nAChR receptors.
    Caco-2
    suggested: None
    All viruses were passaged in Vero E6 cells to create the virus working stock.
    Vero E6
    suggested: RRID:CVCL_XD71)
    For plaque titration, confluent Vero-E6 cells were inoculated with 5-fold serial dilutions of cell culture supernatant and incubated for 1 hour at 37°C and 5% CO2.
    Vero-E6
    suggested: None
    Recombinant DNA
    SentencesResources
    To generate a standard curve, the SARS-CoV-2E gene sgRNA was cloned into a pcDNA3.1 expression plasmid; this insert was transcribed using an AmpliCap-Max T7 High Yield MessageMaker Kit (Cellscript) to obtain RNA for standards.
    pcDNA3.1
    suggested: RRID:Addgene_79663)
    Software and Algorithms
    SentencesResources
    Varenicline tartrate was purchased from Tocris Biosciences (Minneapolis, MN)
    Tocris Biosciences
    suggested: (Tocris Bioscience, RRID:SCR_003689)
    Statistical analyses: All statistical analyses were performed using GraphPad Prism (version 9, GraphPad Software, Inc.).
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2021.06.29.450426v1 on bioRxiv