Potent and specific human monoclonal antibodies against SARS-CoV-2 Omicron variant by rapid mRNA immunization of humanized mice

  1. Ping Ren
  2. Lei Peng
  3. Zhenhao Fang
  4. Kazushi Suzuki
  5. Paul Renauer
  6. Qianqian Lin
  7. Meizhu Bai
  8. Luojia Yang
  9. Tongqing Li
  10. Paul Clark
  11. Daryl Klein
  12. Sidi Chen

Reviewed by

Read the full article

Listed in

Log in to save this article

Abstract

The Omicron variant (B.1.1.529) of SARS-CoV-2 rapidly becomes dominant globally. Its extensive mutations confer severe efficacy reduction to most of existing antibodies or vaccines. Here, we developed RAMIHM , a highly efficient strategy to generate fully human monoclonal antibodies (mAbs), directly applied it with Omicron-mRNA immunization, and isolated three potent and specific clones against Omicron. Rapid mRNA immunization elicited strong anti-Omicron antibody response in humanized mice, along with broader anti-coronavirus activity. Customized single cell BCR sequencing mapped the clonal repertoires. Top-ranked clones collectively from peripheral blood, plasma B and memory B cell populations showed high rate of Omicron-specificity (93.3%) from RAMIHM-scBCRseq. Clone-screening identified three highly potent neutralizing antibodies that have low nanomolar affinity for Omicron RBD, and low ng/mL level IC50 in neutralization, more potent than majority of currently approved or authorized clinical RBD-targeting mAbs. These lead mAbs are fully human and ready for downstream IND-enabling and/or translational studies.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2022.03.17.484817: (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.
    RandomizationReplication, randomization, blinding and reagent validations: Sample size: Sample size determination was performed according to similar work in the field.
    BlindingReplication, randomization, blinding and reagent validations: Sample size: Sample size determination was performed according to similar work in the field.
    Power Analysisnot detected.
    Cell Line AuthenticationContamination: All cell lines tested negative for mycoplasma.

    Table 2: Resources

    Antibodies
    SentencesResources
    Thereafter, memory B cells were labeled with memory B cell biotin-antibody cocktail combined with anti-biotin microbeads and isolated using a magnetic rack.
    anti-biotin
    suggested: None
    After incubation, the complex was washed and respectively incubated with anti-his-APC antibody and anti-APC microbeads.
    anti-his-APC
    suggested: None
    anti-APC
    suggested: None
    Antibody binding kinetics, epitope mapping by bio-layer interferometry (BLI): Antibody binding kinetics for anti-Omicron RBD mAbs were evaluated by BLI on an Octet RED96e instrument (FortéBio) at RT.
    anti-Omicron RBD
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    Briefly, full length Omicron spike gene was constructed into GFP encoding (pCCNanoLuc2AEGFP) human immunodeficiency vector backbone, then Omicron spike protein expression vectors were combined with HIV-1 structural corresponding plasmids and co-transfected into HEK-293T cells with PEI (1mg/ml, PEI MAX, Polyscience)
    HEK-293T
    suggested: None
    Thereafter, the virus-antibody mixture was added triplicate onto HEK-293T-hACE2 cells and incubated at 37°C for additional 24 hours.
    HEK-293T-hACE2
    suggested: RRID:CVCL_A7UK)
    Recombinant DNA
    SentencesResources
    Briefly, full length Omicron spike gene was constructed into GFP encoding (pCCNanoLuc2AEGFP) human immunodeficiency vector backbone, then Omicron spike protein expression vectors were combined with HIV-1 structural corresponding plasmids and co-transfected into HEK-293T cells with PEI (1mg/ml, PEI MAX, Polyscience)
    pCCNanoLuc2AEGFP
    suggested: None
    Software and Algorithms
    SentencesResources
    Half-maximal inhibitory concentration (IC50) for mAbs was calculated with a four-parameter logistic regression using GraphPad Prism (GraphPad Software Inc.)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)
    Half-maximal inhibitory concentration (IC50) for mAbs was calculated with a four-parameter logistic regression using GraphPad Prism (GraphPad Software Inc.).
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    Schematic illustrations: Schematic illustrations were created with Affinity Designer or BioRender.
    BioRender
    suggested: (Biorender, RRID:SCR_018361)
    Replication: Biological or technical replicate samples were randomized where appropriate.
    Replication: Biological
    suggested: None

    Results from OddPub: Thank you for sharing your data.

    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.

    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 10.1101/2022.03.17.484817v1 on bioRxiv