Efficient inhibition of SARS-CoV-2 strains by a novel ACE2-IgG4-Fc fusion protein with a stabilized hinge region

This article has been Reviewed by the following groups

Read the full article See related articles

Discuss this preprint

Start a discussion What are Sciety discussions?

Abstract

The novel severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) enters its host cells after binding to the angiotensin-converting enzyme 2 (ACE2) via its spike glycoprotein. This interaction is critical for virus entry and virus-host membrane fusion. Soluble ACE2 ectodomains bind and neutralize the virus but the short in vivo half-lives of soluble ACE2 limits its therapeutic use. Fusion of the fragment crystallizable (Fc) part of human immunoglobulin G (IgG) to the ACE2 ectodomain can prolong the in vivo half-life but bears the risk of unwanted Fc-receptor activation and antibody-dependent disease enhancement. Here, we describe optimized ACE2-Fc fusion constructs that avoid Fc-receptor binding by using IgG4-Fc as a fusion partner. The engineered ACE2-IgG4-Fc fusion proteins described herein exhibit promising pharmaceutical properties and a broad antiviral activity at single-digit nanomolar concentration. In addition, they allow to maintain the beneficial enzymatic activity of ACE2 and thus are very promising candidate antivirals broadly acting against coronaviruses.

Article activity feed

  1. SciScore for 10.1101/2020.12.06.413443: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    SARS-CoV-2-April was propagated by the infection of Caco-2 cells followed by passaging in Vero E6 cells.
    Caco-2
    suggested: None
    Briefly, HepG2 or Vero E6 cells were plated in a 12-well plate at 5 x 10E5 cells/well in DMEM medium (Gibco) supplemented with 5% FCS, 1% P/S, 200 mmol/L L-glutamine, 1% MEM-NEAA, 1% sodium-pyruvate (all from Gibco) and incubated overnight at 37°C and 5% CO2.
    HepG2
    suggested: None
    Vero E6
    suggested: None
    Experimental Models: Organisms/Strains
    SentencesResources
    Virus strains: SARS-CoV-2-GFP (kindly provided by Volker Thiel, University of Bern, Switzerland) is based on the original Wuhan SARS-CoV-2 isolate (GenBank accession MT108784) and was reconstituted from a synthetic construct derived from SARS-2 BetaCoV/Wuhan/IVDC-HB-01/2019 [39].
    SARS-CoV-2-GFP
    suggested: None
    Software and Algorithms
    SentencesResources
    Protein expression: Using the FreeStyle 293 Expression System (ThermoFisher), the different ACE2-Fc fusion proteins were transiently expressed in 3 x 240 mL culture media.
    ThermoFisher
    suggested: (ThermoFisher; SL 8; Centrifuge, RRID:SCR_020809)
    The main peak was pooled, the protein concentration was determined by slope spectrometry [67] and adjusted to 1 mg/mL.
    slope
    suggested: (SLOPE, RRID:SCR_001185)
    The chromatograms were evaluated with the Astra software.
    Astra
    suggested: (ASTRA, RRID:SCR_016255)

    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 did not find any issues relating to the usage of bar graphs.


    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.

    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. SciScore for 10.1101/2020.12.06.413443: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board Statementnot detected.Randomizationnot detected.Blindingnot detected.Power Analysisnot detected.Sex as a biological variablenot detected.Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Subsequently, Vero E6 cells were incubated with a 1:500 dilution of an antidsRNA J2 antibody (Jena Bioscience) in PBS supplemented with 1% FCS at 4°C overnight with shaking.
    antidsRNA J2
    suggested: None
    Next, the plates were incubated with a 1:2,000 dilution of a goat anti-mouse IgG2aHRP antibody (Southern Biotech) in PBS supplemented with 1% FCS and incubated with gently shaking at RT for one hour.
    anti-mouse IgG2aHRP
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    Briefly, HepG2 or Vero E6 cells were plated in a 12-well plate at 5 x 10E5 cells/well in DMEM medium (Gibco) supplemented with 5% FCS, 1% P/S, 200 mmol/L L-glutamine, 1% MEM-non-essential amino acids, 1% sodium-pyruvate (all from Gibco) and incubated overnight at 37°C and 5% CO2.
    HepG2
    suggested: None
    SARS-CoV-2 virus neutralization assay Viral neutralization assay followed by in-cell ELISA Vero E6 cells were plated in a 96-well plate at 1.6 x 10E04 cells/well in DMEM medium (Gibco) supplemented with 5% FCS, 1% penicillin-streptomycin, 200 mmol/L L-glumatine, 1% MEM-nonessential amino acids, 1% sodium-pyruvate (all from Gibco) and incubated overnight at 37°C and 5% CO2.
    Vero E6
    suggested: None
    Software and Algorithms
    SentencesResources
    Protein expression Using the FreeStyle 293 Expression System (ThermoFisher), the different ACE2-Fc fusion proteins were transiently expressed in 3 x 240 mL culture media.
    ThermoFisher
    suggested: None
    The main peak was pooled, the protein concentration determined by slope spectrometry [63] and adjusted to 1 mg/mL.
    slope
    suggested: (SLOPE, RRID:SCR_001185)
    The chromatograms were evaluated with the Astra software.
    Astra
    suggested: (ASTRA, RRID:SCR_016255)

    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 did not find any issues relating to the usage of bar graphs.


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


    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.