Fortuitous somatic mutations during antibody evolution endow broad neutralization against SARS-CoV-2 Omicron variants

Cell Rep. 2023 May 30;42(5):112503. doi: 10.1016/j.celrep.2023.112503. Epub 2023 May 3.

Abstract

Striking antibody evasion by emerging circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants drives the identification of broadly neutralizing antibodies (bNAbs). However, how a bNAb acquires increased neutralization breadth during antibody evolution is still elusive. Here, we identify a clonally related antibody family from a convalescent individual. One of the members, XG005, exhibits potent and broad neutralizing activities against SARS-CoV-2 variants, while the other members show significant reductions in neutralization breadth and potency, especially against the Omicron sublineages. Structural analysis visualizing the XG005-Omicron spike binding interface reveals how crucial somatic mutations endow XG005 with greater neutralization potency and breadth. A single administration of XG005 with extended half-life, reduced antibody-dependent enhancement (ADE) effect, and increased antibody product quality exhibits a high therapeutic efficacy in BA.2- and BA.5-challenged mice. Our results provide a natural example to show the importance of somatic hypermutation during antibody evolution for SARS-CoV-2 neutralization breadth and potency.

Keywords: CP: Immunology; CP: Microbiology; SARS-CoV-2; bNAb; broadly neutralizing antibody; clonally related antibody family; somatic hypermutation; variant of concern.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Broadly Neutralizing Antibodies
  • COVID-19*
  • Mice
  • Mutation / genetics
  • SARS-CoV-2*

Substances

  • Antibodies
  • Broadly Neutralizing Antibodies
  • Antibodies, Viral
  • Antibodies, Neutralizing

Supplementary concepts

  • SARS-CoV-2 variants