Mouse Antibodies with Activity Against the SARS-CoV-2 D614G and B.1.351 Variants

  1. Larisa Troitskaya
  2. Nelson Lap Shun Chan
  3. Brendon Frank
  4. Daniel J. Capon
  5. Brian A. Zabel
  6. Xiaomei Ge
  7. Dan Luo
  8. Rachel Martinelli
  9. Jing Jin
  10. Graham Simmons

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Abstract

With the rapid spread of SARS-CoV-2 variants, including those that are resistant to antibodies authorized for emergency use, it is apparent that new antibodies may be needed to effectively protect patients against more severe disease. Differences between the murine and human antibody repertoires may allow for the isolation of murine monoclonal antibodies that recognize a different or broader range of SARS-CoV-2 variants than the human antibodies that have been characterized so far. We describe mouse antibodies B13 and O24 that demonstrate neutralizing potency against SARS-CoV-2 Wuhan (D614G) and B.1.351 variants. Such murine antibodies may have advantages in protecting against severe symptoms when individuals are exposed to new SARS-CoV-2 variants.

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  1. ScreenIT

    SciScore for 10.1101/2021.07.05.451203: (What is this?)

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

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Lentiviruses pseudotyped by Wuhan D614G (Cat# RVP-702L) and B.1.351 (Cat# RVP-707L) spikes were purchased from Integral Molecular, Philadelphia, PA. Antibodies: LY-CoV555 (bamlanivimab), LY-CoV016 (etesevimab), AZD1061 (cilgavimab), AZD8895 (tixagevimab), VIR-7831 (sotrovimab), CT-P59 (regdanvimab), REGN10987 (imdevimab), and REGN10933 (casirivimab) were expressed in Chinese hamster ovary (CHO) cells and purified by Protein A affinity chromatography.
    B.1.351
    suggested: (LSBio (LifeSpan Cat# LS-B1351-50, RRID:AB_1015723)
    LY-CoV555
    suggested: None
    REGN10933
    suggested: None
    The B13 and O24 mouse variable (V) regions were expressed as human chimeric antibodies combining the human immunoglobulin G1 (IgG1) and kappa chain constant regions (Supplemental Figure S1).
    IgG1
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    Cells and viruses: Vero E6 cells (ATCC) were cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% (v/v) fetal bovine serum (FBS) and 2 mM penicillin-streptomycin (100 U/mL).
    Vero E6
    suggested: None
    293T-hsACE2 cells (Cat# C-HA102) were purchased from Integral Molecular and cultured according to manufacturer’s recommendations.
    293T-hsACE2
    suggested: None
    Lentiviruses pseudotyped by Wuhan D614G (Cat# RVP-702L) and B.1.351 (Cat# RVP-707L) spikes were purchased from Integral Molecular, Philadelphia, PA. Antibodies: LY-CoV555 (bamlanivimab), LY-CoV016 (etesevimab), AZD1061 (cilgavimab), AZD8895 (tixagevimab), VIR-7831 (sotrovimab), CT-P59 (regdanvimab), REGN10987 (imdevimab), and REGN10933 (casirivimab) were expressed in Chinese hamster ovary (CHO) cells and purified by Protein A affinity chromatography.
    Chinese hamster ovary (CHO)
    suggested: None
    Production of proteins was carried out by transient expression in CHO-K1 cells adapted to serum-free suspension culture (TunaCHO™, LakePharma Inc., Belmont, CA).
    CHO-K1
    suggested: CLS Cat# 603480/p693_CHO-K1, RRID:CVCL_0214)
    Suspension CHO cells were seeded in a shake flask and expanded using a serum-free and chemically defined medium.
    CHO
    suggested: CLS Cat# 603479/p746_CHO, RRID:CVCL_0213)
    Virus was pre-incubated for 1 hour at 37 °C with serial dilutions of antibody and then plated in replicates of 8 on Vero/TMPRSS2 cells.
    Vero/TMPRSS2
    suggested: JCRB Cat# JCRB1818, RRID:CVCL_YQ48)
    Software and Algorithms
    SentencesResources
    In brief, SARS-CoV-1 spike protein (UniProtKB Accession No. P59594) containing an engineered carboxyl-terminal T4 fibritin trimerization domain was expressed using the TunaCHO™ platform (LakePharma) and used to coat wells in a 384-well plate (1 μg/mL in PBS) overnight at 4°C.
    UniProtKB
    suggested: (UniProtKB, RRID:SCR_004426)
    These data were processed by Prism 9 (GraphPad) to fit a 4PL curve and calculate the log EC50.
    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 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.
    • No funding statement was detected.
    • No protocol registration statement was detected.

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

    About SciScore

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  2. Version published to 10.1101/2021.07.05.451203v1 on bioRxiv