Since the COVID-19 pandemic onset, the antibody response to SARS-CoV-2 has been extensively characterized. Antibodies to the receptor binding domain (RBD) on the spike protein are frequently encoded by IGHV3-53/3-66 with a short complementarity-determining region (CDR) H3. Germline-encoded sequence motifs in heavy chain CDRs H1 and H2 have a major function, but whether any common motifs are present in CDR H3, which is often critical for binding specificity, is not clear. Here, we identify two public clonotypes of IGHV3-53/3-66 RBD antibodies with a 9-residue CDR H3 that pair with different light chains. Distinct sequence motifs on CDR H3 are present in the two public clonotypes that seem to be related to differential light chain pairing. Additionally, we show that Y58F is a common somatic hypermutation that results in increased binding affinity of IGHV3-53/3-66 RBD antibodies with a short CDR H3. These results advance understanding of the antibody response to SARS-CoV-2. Public antibody clonotypes that recognize SARS-CoV-2 spike protein are important for protection against COVID-19. Here, the authors characterize sequence motifs in the heavy chain complementarity-determining region (CDR) H3s of two public clonotypes and their association with light chain identity.
【저자키워드】 antibodies, SARS-CoV-2, X-ray crystallography, 【초록키워드】 COVID-19, antibody, COVID-19 pandemic, Antibody Response, binding affinity, Spike protein, Receptor binding domain, specificity, RBD, SARS-CoV-2 spike protein, Critical, CDR, binding, association, heavy chain, light chain, identity, motif, Sequence motifs, Public, CDR H3, complementarity-determining region, identify, characterized, recognize, the spike protein, the antibody response, sequence motif, 【제목키워드】 antibody, SARS-CoV-2 receptor, binding domain,