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1.
Science ; 378(6620): 619-627, 2022 11 11.
Article in English | MEDLINE | ID: covidwho-2078696

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant-neutralizing antibody that is a strong candidate for clinical development.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , COVID-19 , Immune Evasion , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Humans , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Neutralization Tests , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Immunologic Memory , Memory B Cells/immunology
2.
Science ; 377(6604): 420-424, 2022 07 22.
Article in English | MEDLINE | ID: covidwho-1909562

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved variants with substitutions in the spike receptor-binding domain (RBD) that affect its affinity for angiotensin-converting enzyme 2 (ACE2) receptor and recognition by antibodies. These substitutions could also shape future evolution by modulating the effects of mutations at other sites-a phenomenon called epistasis. To investigate this possibility, we performed deep mutational scans to measure the effects on ACE2 binding of all single-amino acid mutations in the Wuhan-Hu-1, Alpha, Beta, Delta, and Eta variant RBDs. Some substitutions, most prominently Asn501→Tyr (N501Y), cause epistatic shifts in the effects of mutations at other sites. These epistatic shifts shape subsequent evolutionary change-for example, enabling many of the antibody-escape substitutions in the Omicron RBD. These epistatic shifts occur despite high conservation of the overall RBD structure. Our data shed light on RBD sequence-function relationships and facilitate interpretation of ongoing SARS-CoV-2 evolution.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Epistasis, Genetic , Evolution, Molecular , Receptors, Virus , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/virology , Humans , Mutation , Protein Binding , Receptors, Virus/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
3.
Science ; 375(6583): 864-868, 2022 02 25.
Article in English | MEDLINE | ID: covidwho-1650843

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant of concern evades antibody-mediated immunity that comes from vaccination or infection with earlier variants due to accumulation of numerous spike mutations. To understand the Omicron antigenic shift, we determined cryo-electron microscopy and x-ray crystal structures of the spike protein and the receptor-binding domain bound to the broadly neutralizing sarbecovirus monoclonal antibody (mAb) S309 (the parent mAb of sotrovimab) and to the human ACE2 receptor. We provide a blueprint for understanding the marked reduction of binding of other therapeutic mAbs that leads to dampened neutralizing activity. Remodeling of interactions between the Omicron receptor-binding domain and human ACE2 likely explains the enhanced affinity for the host receptor relative to the ancestral virus.


Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Antibodies, Viral/chemistry , Immune Evasion , Receptors, Coronavirus/chemistry , SARS-CoV-2/chemistry , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/chemistry , Amino Acid Substitution , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/metabolism , Antibodies, Viral/immunology , Antibodies, Viral/metabolism , Antigenic Drift and Shift , Broadly Neutralizing Antibodies/chemistry , Broadly Neutralizing Antibodies/immunology , Broadly Neutralizing Antibodies/metabolism , Cryoelectron Microscopy , Crystallography, X-Ray , Humans , Models, Molecular , Mutation , Protein Binding , Protein Conformation , Protein Domains/genetics , Protein Interaction Domains and Motifs/genetics , Receptors, Coronavirus/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism
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