Viruses (Feb 2024)

Fast-Track Discovery of SARS-CoV-2-Neutralizing Antibodies from Human B Cells by Direct Functional Screening

  • Matthias Hillenbrand,
  • Christoph Esslinger,
  • Jemima Seidenberg,
  • Marcel Weber,
  • Andreas Zingg,
  • Catherine Townsend,
  • Barbara Eicher,
  • Justina Rutkauskaite,
  • Peggy Riese,
  • Carlos A. Guzman,
  • Karsten Fischer,
  • Simone Schmitt

DOI
https://doi.org/10.3390/v16030339
Journal volume & issue
Vol. 16, no. 3
p. 339

Abstract

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As the COVID-19 pandemic revealed, rapid development of vaccines and therapeutic antibodies are crucial to guarantee a quick return to the status quo of society. In early 2020, we deployed our droplet microfluidic single-cell-based platform DROPZYLLA® for the generation of cognate antibody repertoires of convalescent COVID-19 donors. Discovery of SARS-CoV-2-specific antibodies was performed upon display of antibodies on the surface of HEK293T cells by antigen-specific sorting using binding to the SARS-CoV-2 spike and absence of binding to huACE2 as the sort criteria. This efficiently yielded antibodies within 3–6 weeks, of which up to 100% were neutralizing. One of these, MTX-COVAB, displaying low picomolar neutralization IC50 of SARS-CoV-2 and with a neutralization potency on par with the Regeneron antibodies, was selected for GMP manufacturing and clinical development in June 2020. MTX-COVAB showed strong efficacy in vivo and neutralized all identified clinically relevant variants of SARS-CoV-2 at the time of its selection. MTX-COVAB completed GMP manufacturing by the end of 2020, but clinical development was stopped when the Omicron variant emerged, a variant that proved to be detrimental to all monoclonal antibodies already approved. The present study describes the capabilities of the DROPZYLLA® platform to identify antibodies of high virus-neutralizing capacity rapidly and directly.

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