Development of highly potent neutralising nanobodies against multiple SARS-CoV-2 variants including the variant of concern B.1.351

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Abstract

The pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. During the years of 2020-2021, millions of humans have died due to SARS-CoV-2 infection and severe economic damage to the global economy has occurred. Unprecedented rapid investments in vaccine development have been made to counter the spread of SARS-CoV-2 among humans. While vaccines are a key pillar of modern medicine, SARS-CoV-2 has mutated as it spread among humans. Vaccines previously developed and approved by regulators are becoming less effective against new variants. One variant of SARS-CoV-2 known as B.1.351 that was first reported to be present in South Africa significantly reduces the efficacy of vaccines developed to date. Therapeutic options that work against the B.1.351 variant are therefore urgently needed to counteract reduced vaccine efficacy. We present here the discovery of recombinant alpaca antibodies that neutralise live virus of B.1.351 and other SARS-CoV-2 variants potently. The antibodies described here may be a useful tool for clinicians who are treating patients infected with B.1.351 and other SARS-CoV-2 for which there is currently no known highly effective treatment.

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  1. SciScore for 10.1101/2021.04.11.439360: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIACUC: All animal work was approved by the Afrobodies Institutional ethics and animal care committee.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableAlpaca immunisation: One adult male alpaca was immunized subcutaneously over a 12-week period at the following time points; week 0, 2, 4, 8, 10 and 12.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Testing of recombinant alpaca antibody binding to antigen, isolation of sequences and production of recombinant alpaca antibodies was done as described previously34.
    antigen,
    suggested: None
    After paraformaldehyde fixation, cells were immunostained using a rabbit anti-spike monoclonal antibody (mAb BS-R2B12, GenScript A02058)
    anti-spike
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    Virus Neutralisation test against SARS-CoV-2-CVR-GLA-1 variant: Vero E6 F5 cells, which were subcloned from Vero E6 cells, were maintained in DMEM-Glutamax supplemented with 10% fetal bovine serum26 (Gibco Thermo Fisher Scientific).
    Vero E6
    suggested: None
    F5
    suggested: None
    Vero E6 F5 cells in 12 well plates were infected with the virus/serum mixture.
    Vero E6 F5
    suggested: None
    HEK293T cells were transfected with the appropriate SARS-CoV-2 S gene expression vector (wild type or mutant) in conjunction with p8.9138 and pCSFLW39 using polyethylenimine (PEI, Polysciences, Warrington, USA).
    HEK293T
    suggested: None
    Software and Algorithms
    SentencesResources
    Plates were scanned with a 2x objective on a Nikon Ti-E microscope, and foci were counted using a custom script in MATLAB (MathWorks).
    MATLAB
    suggested: (MATLAB, RRID:SCR_001622)
    50% neutralization titers were calculated in GraphPad Prism 9 by performing a sigmoidal four-parameter logistic curve fit with the bottom parameter constrained to zero, and the top parameter constrained to the average of the no-antibody controls for each respective virus; the “IC50” calculated by Prism was reported as the NT50 for each antibody.
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    Prism
    suggested: (PRISM, RRID:SCR_005375)

    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.