A Potent SARS-CoV-2 Neutralizing Human Monoclonal Antibody That Reduces Viral Burden and Disease Severity in Syrian Hamsters

  1. Anna C. Fagre
  2. John Manhard
  3. Rachel Adams
  4. Miles Eckley
  5. Shijun Zhan
  6. Juliette Lewis
  7. Savannah M. Rocha
  8. Catherine Woods
  9. Karina Kuo
  10. Wuxiang Liao
  11. Lin Li
  12. Adam Corper
  13. Dilip Challa
  14. Emily Mount
  15. Christine Tumanut
  16. Ronald B. Tjalkens
  17. Tawfik Aboellail
  18. Xiaomin Fan
  19. Tony Schountz

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Abstract

The emergence of COVID-19 has led to a pandemic that has caused millions of cases of disease, variable morbidity and hundreds of thousands of deaths. Currently, only remdesivir and dexamethasone have demonstrated limited efficacy, only slightly reducing disease burden, thus novel approaches for clinical management of COVID-19 are needed. We identified a panel of human monoclonal antibody clones from a yeast display library with specificity to the SARS-CoV-2 spike protein receptor binding domain that neutralized the virus in vitro . Administration of the lead antibody clone to Syrian hamsters challenged with SARS-CoV-2 significantly reduced viral load and histopathology score in the lungs. Moreover, the antibody interrupted monocyte infiltration into the lungs, which may have contributed to the reduction of disease severity by limiting immunopathological exacerbation. The use of this antibody could provide an important therapy for treatment of COVID-19 patients.

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  1. Version published to 10.3389/fimmu.2020.614256
  2. ScreenIT

    SciScore for 10.1101/2020.09.25.313601: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIACUC: Study design for animal infections: Approval of the study protocol was obtained from the Colorado State University Institutional Animal Care and Use Committee (protocol 993).
    Randomizationnot detected.
    BlindingImmunoreactions were visualized and blindly scored by a single pathologist.
    Power Analysisnot detected.
    Sex as a biological variableMale Syrian hamsters (n=20, 10 weeks of age, obtained from Charles River Laboratory).
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Assessing antibody binding to native spike protein: A vector encoding a full-length spike protein sequence encompassing residues 13-1273 of UniProtKB accession number P0DTC2, that was fused to green fluorescent protein (GFP) as a reporter (Sino Biologicals, Cat# VG40590-ACG) was used to transiently transfect 293F cells using the FreeStyle™ 293F Expression System (ThermoFisher Scientific, cat# K90001).
    GFP
    suggested: None
    After 2 days, when a robust GFP signal was observed, aliquots of the transfected cells and untransfected 293F cells were washed in ice cold phosphate-buffered saline containing EDTA and 0.5% BSA, pH 7.4 (PBSM) then incubated in the presence of AvGn-B, isotype control antibody or ACE2-Fc for 45 mins with rotation at 4° C, washed 3 times in ice-cold PBSM and then bound antibody detected with goat anti-human kappa-A647 (SouthernBiotech, cat# 2060-31) After washing, cell-bound Alexa-657 was analyzed using an IntelliCyt® iQue Screener PLUS and ForeCyt Software (Sartorius).
    AvGn-B,
    suggested: None
    anti-human kappa-A647
    suggested: None
    Antibodies to SARS-CoV-2 nucleocapsid protein (mouse, 1:500), pancytokeratin, factor-VIII and ionized calcium binding adaptor molecule (IBA-1) (Leica Biosystems) or negative control slides primary antibody was replaced by a rabbit non-specific IgG isotype negative control antibody for 20 minutes.
    SARS-CoV-2 nucleocapsid protein (mouse, 1:500), pancytokeratin, factor-VIII and ionized calcium binding adaptor molecule (IBA-1
    suggested: None
    non-specific IgG
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    After 2 days, when a robust GFP signal was observed, aliquots of the transfected cells and untransfected 293F cells were washed in ice cold phosphate-buffered saline containing EDTA and 0.5% BSA, pH 7.4 (PBSM) then incubated in the presence of AvGn-B, isotype control antibody or ACE2-Fc for 45 mins with rotation at 4° C, washed 3 times in ice-cold PBSM and then bound antibody detected with goat anti-human kappa-A647 (SouthernBiotech, cat# 2060-31) After washing, cell-bound Alexa-657 was analyzed using an IntelliCyt® iQue Screener PLUS and ForeCyt Software (Sartorius).
    293F
    suggested: None
    Determining the viral neutralization activity of antibody clones in vitro: Vero E6 cells were plated overnight in 96-well plates at 20,000 cells per well.
    Vero E6
    suggested: None
    Software and Algorithms
    SentencesResources
    The OD readings were plotted against concentration using Prism software (Graphpad CA) for curve fitting and determination of the apparent KD value.
    Graphpad
    suggested: (GraphPad, RRID:SCR_000306)
    After 1 h, bound RBD was detected using HRP-labeled streptavidin and the OD readings plotted against antibody concentration using Prism software.
    Prism
    suggested: (PRISM, RRID:SCR_005375)
    Assessing antibody binding to native spike protein: A vector encoding a full-length spike protein sequence encompassing residues 13-1273 of UniProtKB accession number P0DTC2, that was fused to green fluorescent protein (GFP) as a reporter (Sino Biologicals, Cat# VG40590-ACG) was used to transiently transfect 293F cells using the FreeStyle™ 293F Expression System (ThermoFisher Scientific, cat# K90001).
    UniProtKB
    suggested: (UniProtKB, RRID:SCR_004426)
    Male Syrian hamsters (n=20, 10 weeks of age, obtained from Charles River Laboratory).
    Charles River Laboratory
    suggested: None
    Co-localization and intensity measurements were obtained using the Count and Measure feature of cellSens.
    cellSens
    suggested: None

    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: Please consider improving the rainbow (“jet”) colormap(s) used on page 27. At least one figure is not accessible to readers with colorblindness and/or is not true to the data, i.e. not perceptually uniform.

    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.

  3. Version published to 10.1101/2020.09.25.313601v2 on bioRxiv
  4. Version published to 10.1101/2020.09.25.313601v1 on bioRxiv