Germline IGHV3-53-encoded RBD-targeting neutralizing antibodies are commonly present in the antibody repertoires of COVID-19 patients

Q Yan, P He, X Huang, K Luo, Y Zhang… - Emerging microbes & …, 2021 - Taylor & Francis
Q Yan, P He, X Huang, K Luo, Y Zhang, H Yi, Q Wang, F Li, R Hou, X Fan, P Li, X Liu…
Emerging microbes & infections, 2021Taylor & Francis
Monoclonal antibodies (mAbs) encoded by IGHV3-53 (VH3-53) targeting the spike receptor-
binding domain (RBD) have been isolated from different COVID-19 patients. However, the
existence and prevalence of shared VH3-53-encoded antibodies in the antibody repertoires
is not clear. Using antibody repertoire sequencing, we found that the usage of VH3-53
increased after SARS-CoV-2 infection. A highly shared VH3-53-J6 clonotype was identified
in 9 out of 13 COVID-19 patients. This clonotype was derived from convergent gene …
Abstract
Monoclonal antibodies (mAbs) encoded by IGHV3-53 (VH3-53) targeting the spike receptor-binding domain (RBD) have been isolated from different COVID-19 patients. However, the existence and prevalence of shared VH3-53-encoded antibodies in the antibody repertoires is not clear. Using antibody repertoire sequencing, we found that the usage of VH3-53 increased after SARS-CoV-2 infection. A highly shared VH3-53-J6 clonotype was identified in 9 out of 13 COVID-19 patients. This clonotype was derived from convergent gene rearrangements with few somatic hypermutations and was evolutionary conserved. We synthesized 34 repertoire-deduced novel VH3-53-J6 heavy chains and paired with a common IGKV1-9 light chain to produce recombinant mAbs. Most of these recombinant mAbs (23/34) possess RBD binding and virus-neutralizing activities, and recognize ACE2 binding site via the same molecular interface. Our computational analysis, validated by laboratory experiments, revealed that VH3-53 antibodies targeting RBD are commonly present in COVID-19 patients’ antibody repertoires, indicating many people have germline-like precursor sequences to rapidly generate SARS-CoV-2 neutralizing antibodies. Moreover, antigen-specific mAbs can be digitally obtained through antibody repertoire sequencing and computational analysis.
Taylor & Francis Online