Receptor binding domain (RBD) antibodies contribute more to SARS-CoV-2 neutralization when target cells express high levels of ACE2

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2022, Номер unknown

Опубликована: Авг. 30, 2022

Neutralization assays are experimental surrogates for the effectiveness of infection- or vaccine-elicited polyclonal antibodies and therapeutic monoclonal targeting SARS-CoV-2. However, measured neutralization can depend on details assay. Here we systematically assess how ACE2 expression in target cells affects by to different spike epitopes lentivirus pseudovirus assays. For high ACE2-expressing cells, receptor binding domain (RBD) account nearly all neutralizing activity human sera. But lower regions outside RBD make a larger (although still modest) contribution serum neutralization. These serum-level results mirrored antibodies: N-terminal (NTD) that do not compete incompletely neutralize but completely with expression. Our show level is an important variable, emphasizes role subset RBD-directed antibodies.

Язык: Английский

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Primary SARS-CoV-2 variant of concern infections elicit broad antibody Fc-mediated effector functions and memory B cell responses

PLoS Pathogens, Год журнала: 2024, Номер 20(8), С. e1012453 - e1012453

Опубликована: Авг. 15, 2024

Neutralization of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by human sera is a strong correlate protection against symptomatic and severe Disease 2019 (COVID-19). The emergence antigenically distinct SARS-CoV-2 variants concern (VOCs) the relatively rapid waning serum antibody titers, however, raises questions about sustainability protection. In addition to neutralization, other functionalities memory B cell (MBC) response are suggested help maintaining this study, we investigate breadth spike (S) protein-specific antibodies that mediate effector functions interacting with Fc-gamma receptor IIa (FcγRIIa) FcγRIIIa, binding domain (RBD)-specific MBCs, following primary infection D614G, Alpha, Beta, Gamma, Delta, Omicron BA.1 or BA.2 variant. Irrespectively variant causing infection, S interact FcγRIIa FcγRIIIa RBD-specific MBC responses exceeded although Alpha-induced seemed more strain-specific. Between VOC groups, both quantitative qualitative differences in immune were observed, suggesting immunogenicity. Overall, study contributes understanding protective humoral light emerging VOCs, highlights need system beyond neutralization gain better variants.

Язык: Английский

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The accomplices: Heparan sulfates and N-glycans foster SARS-CoV-2 spike:ACE2 receptor binding and virus priming

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(43)

Опубликована: Окт. 14, 2024

Although it is well established that the SARS-CoV-2 spike glycoprotein binds to host cell ACE2 receptor initiate infection, far less known about tissue tropism and susceptibility virus. Differential expression across different types of heparan sulfate (HS) proteoglycans, with variably sulfated glycosaminoglycans (GAGs), their synergistic interactions viral N-glycans may contribute susceptibility. Nevertheless, contribution remains unclear since HS evade experimental characterization. We, therefore, carried out microsecond-long all-atom molecular dynamics simulations, followed by random acceleration fully glycosylated spike:ACE2 complex without highly GAG chains bound. By considering model GAGs as surrogates for expressed in lung cells, we identified key entry mechanisms SARS-CoV-2. We find promotes structural energetic stabilization active conformation receptor-binding domain (RBD) reorientation toward N-terminal same subunit RBD. Spike exert effects, promoting better packing, strengthening protein:protein interaction, prolonging residence time complex. binding trigger rearrangement S2’ functional protease cleavage site through allosteric interdomain communication. These results thus show has a multifaceted role facilitating they provide mechanistic basis development derivatives anti-SARS-CoV-2 potential.

Язык: Английский

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Performance of SARS COV-2 IgG Anti-N as an Independent Marker of Exposure to SARS COV-2 in an Unvaccinated West African Population

American Journal of Tropical Medicine and Hygiene, Год журнала: 2023, Номер 109(4), С. 890 - 894

Опубликована: Авг. 14, 2023

Determination of previous SARS-COV-2 infection is hampered by the absence a standardized test. The marker used to assess exposure IgG antibody nucleocapsid (IgG anti-N), although it known wane quickly from peripheral blood. accuracies seven tests (virus neutralization test, anti-N, anti-spike [anti-S], anti-receptor binding domain [anti-RBD], anti-N + anti-RBD, anti-S, and anti-S anti-RBD), either singly or in combination, were evaluated on 502 cryopreserved serum samples collected before COVID-19 vaccination rollout Kumasi, Ghana. accuracy each index test was measured using composite reference standard based combination tests. According reference, 262 participants previously exposed; most sensitive virus with 95.4% sensitivity (95% CI: 93.6-97.3), followed 79.0% for 76.3-83.3). specific both 100% specificity. Viral overall accurate tests, specificity/sensitivity 100/95.2% 79.0/92.1%, respectively. Our findings indicate that alone an inadequate prior SARS COV-2 this population. Virus assay appears be discerning infection. A also suited assessment low-resource settings.

Язык: Английский

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SARS-CoV-2 Spike Protein Mutation at Cysteine-488 Impairs Its Golgi Localization and Intracellular S1/S2 Processing

International Journal of Molecular Sciences, Год журнала: 2022, Номер 23(24), С. 15834 - 15834

Опубликована: Дек. 13, 2022

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to the cellular receptor—angiotensin-converting enzyme-2 (ACE2) as first step in viral cell entry. SARS-CoV-2 expression ACE2-expressing surface induces cell–cell membrane fusion, thus forming syncytia. To exert its fusogenic activity, is typically processed at a specific site (the S1/S2 site) by proteases such furin. C488 residue, located spike–ACE2 interacting surface, critical for and infectious roles of protein. We have demonstrated that residue involved subcellular targeting processing. mutant localization Golgi apparatus were impaired. Consequently, processing protein, probed anti-Ser-686-cleaved antibody, markedly decreased proteins. Moreover, brefeldin-A-mediated endoplasmic-reticulum-to-Golgi traffic suppression also suppressed As brefeldin A treatment mutation inhibited syncytia formation, required functional

Язык: Английский

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