scholarly journals Monospecific and bispecific monoclonal SARS-CoV-2 neutralizing antibodies that maintain potency against B.1.617

2021 ◽  
Author(s):  
Lei Peng ◽  
Yingxia Hu ◽  
Madeleine Mankowski ◽  
Ping Ren ◽  
Rita Chen ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Bispecific Antibody ◽  
Receptor Binding Domain ◽  
Single Digit ◽  
Single Cell Sequencing ◽  
Functional Analyses ◽  
Therapeutic Settings ◽  
Original Virus

COVID-19 pathogen SARS-CoV-2 has infected hundreds of millions and caused over 5 million deaths to date. Although multiple vaccines are available, breakthrough infections occur especially by emerging variants. Effective therapeutic options such as monoclonal antibodies (mAbs) are still critical. Here, we report the development, cryo-EM structures, and functional analyses of mAbs that potently neutralize SARS-CoV-2 variants of concern. By high-throughput single cell sequencing of B cells from spike receptor binding domain (RBD) immunized animals, we identified two highly potent SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity, and generated a bispecific antibody. Lead antibodies showed strong inhibitory activity against historical SARS-CoV-2 and several emerging variants of concern. We solved several cryo-EM structures at ~3 Angstrom resolution of these neutralizing antibodies in complex with prefusion spike trimer ectodomain, and revealed distinct epitopes, binding patterns, and conformations. The lead clones also showed potent efficacy in vivo against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We also generated and characterized a humanized antibody to facilitate translation and drug development. The humanized clone also has strong potency against both the original virus and the B.1.617.2 Delta variant. These mAbs expand the repertoire of therapeutics against SARS-CoV-2 and emerging variants.

scholarly journals Murine monoclonal antibodies against RBD of SARS-CoV-2 neutralize authentic wild type SARS-CoV-2 as well as B.1.1.7 and B.1.351 viruses and protect in vivo in a mouse model in a neutralization dependent manner

2021 ◽  
Author(s):  
Fatima Amanat ◽  
Shirin Strohmeier ◽  
Wen-Hsin Lee ◽  
Sandhya Bangaru ◽  
Andrew B Ward ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Severe Acute Respiratory Syndrome ◽  
Mouse Model ◽  
Neutralizing Antibodies ◽  
Dependent Manner ◽  
Receptor Binding Domain ◽  
Wild Type ◽  
Murine Monoclonal Antibodies

After first emerging in December 2019 in China, severe acute respiratory syndrome 2 (SARS-CoV-2) has since caused a pandemic leading to millions of infections and deaths worldwide. Vaccines have been developed and authorized but supply of these vaccines is currently limited. With new variants of the virus now emerging and spreading globally, it is essential to develop therapeutics that are broadly protective and bind conserved epitopes in the receptor binding domain (RBD) or the whole spike of SARS-CoV-2. In this study, we have generated mouse monoclonal antibodies (mAbs) against different epitopes on the RBD and assessed binding and neutralization against authentic SARS-CoV-2. We have demonstrated that antibodies with neutralizing activity, but not non-neutralizing antibodies, lower viral titers in the lungs when administered in a prophylactic setting in vivo in a mouse challenge model. In addition, most of the mAbs cross-neutralize the B.1.351 as well as the B.1.1.7 variants in vitro.

scholarly journals The Impact on Infectivity and Neutralization Efficiency of SARS-CoV-2 Lineage B.1.351 Pseudovirus

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 633
Author(s):  
Yeong Jun Kim ◽  
Ui Soon Jang ◽  
Sandrine M. Soh ◽  
Joo-Youn Lee ◽  
Hye-Ra Lee
Keyword(s):  
South Africa ◽  
Monoclonal Antibodies ◽  
Cell Fusion ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Receptor Binding Domain ◽  
Viral Spread ◽  
New Variant ◽  
Global Concern ◽  
The Impact

A new variant of SARS-CoV-2 B.1.351 lineage (first found in South Africa) has been raising global concern due to its harboring of multiple mutations in the spike that potentially increase transmissibility and yield resistance to neutralizing antibodies. We here tested infectivity and neutralization efficiency of SARS-CoV-2 spike pseudoviruses bearing particular mutations of the receptor-binding domain (RBD) derived either from the Wuhan strains (referred to as D614G or with other sites) or the B.1.351 lineage (referred to as N501Y, K417N, and E484K). The three different pseudoviruses B.1.351 lineage related significantly increased infectivity compared with other mutants that indicated Wuhan strains. Interestingly, K417N and E484K mutations dramatically enhanced cell–cell fusion than N501Y even though their infectivity were similar, suggesting that K417N and E484K mutations harboring SARS-CoV-2 variant might be more transmissible than N501Y mutation containing SARS-CoV-2 variant. We also investigated the efficacy of two different monoclonal antibodies, Casirivimab and Imdevimab that neutralized SARS-CoV-2, against several kinds of pseudoviruses which indicated Wuhan or B.1.351 lineage. Remarkably, Imdevimab effectively neutralized B.1.351 lineage pseudoviruses containing N501Y, K417N, and E484K mutations, while Casirivimab partially affected them. Overall, our results underscore the importance of B.1.351 lineage SARS-CoV-2 in the viral spread and its implication for antibody efficacy.

Impact of the B.1.1.7 variant on neutralizing monoclonal antibodies recognizing diverse epitopes on SARS–CoV–2 Spike

2021 ◽  
Author(s):  
Carl Graham ◽  
Jeffrey Seow ◽  
Isabella Huettner ◽  
Hataf Khan ◽  
Neophytos Kouphou ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Infectious Virus ◽  
Antigenic Drift ◽  
Host Cells ◽  
Receptor Binding Domain ◽  
Neutralization Activity ◽  
Neutralizing Activity ◽  
Neutralizing Epitopes

The interaction of the SARS–CoV–2 Spike receptor binding domain (RBD) with the ACE2 receptor on host cells is essential for viral entry. RBD is the dominant target for neutralizing antibodies and several neutralizing epitopes on RBD have been molecularly characterized. Analysis of circulating SARS–CoV–2 variants has revealed mutations arising in the RBD, the N–terminal domain (NTD) and S2 subunits of Spike. To fully understand how these mutations affect the antigenicity of Spike, we have isolated and characterized neutralizing antibodies targeting epitopes beyond the already identified RBD epitopes. Using recombinant Spike as a sorting bait, we isolated >100 Spike–reactive monoclonal antibodies from SARS–CoV–2 infected individuals. ≈45% showed neutralizing activity of which ≈20% were NTD–specific. None of the S2–specific antibodies showed neutralizing activity. Competition ELISA revealed that NTD–specific mAbs formed two distinct groups: the first group was highly potent against infectious virus, whereas the second was less potent and displayed glycan–dependant neutralization activity. Importantly, mutations present in B.1.1.7 Spike frequently conferred resistance to neutralization by the NTD–specific neutralizing antibodies. This work demonstrates that neutralizing antibodies targeting subdominant epitopes need to be considered when investigating antigenic drift in emerging variants.

scholarly journals Neutralizing Monoclonal Antibodies That Target the Spike Receptor Binding Domain Confer Fc Receptor-Independent Protection against SARS-CoV-2 Infection in Syrian Hamsters

mBio ◽  
2021 ◽  
Author(s):  
Wen Su ◽  
Sin Fun Sia ◽  
Aaron J. Schmitz ◽  
Traci L. Bricker ◽  
Tyler N. Starr ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Fc Receptor ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Syrian Hamsters ◽  
Convalescent Phase ◽  
Main Target

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is the main target for neutralizing antibodies. These antibodies can be elicited through immunization or passively transferred as therapeutics in the form of convalescent-phase sera or monoclonal antibodies (MAbs).

scholarly journals Low-dose in vivo protection and neutralization across SARS-CoV-2 variants by monoclonal antibody combinations

2021 ◽  
Author(s):  
Vincent Dussupt ◽  
Rajeshwer S. Sankhala ◽  
Letzibeth Mendez-Rivera ◽  
Samantha M. Townsley ◽  
Fabian Schmidt ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Low Dose ◽  
Viral Escape ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Viral Inactivation ◽  
Angiotensin Converting Enzyme 2 ◽  
Therapeutic Monoclonal Antibodies ◽  
Potent Protection

AbstractPrevention of viral escape and increased coverage against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern require therapeutic monoclonal antibodies (mAbs) targeting multiple sites of vulnerability on the coronavirus spike glycoprotein. Here we identify several potent neutralizing antibodies directed against either the N-terminal domain (NTD) or the receptor-binding domain (RBD) of the spike protein. Administered in combinations, these mAbs provided low-dose protection against SARS-CoV-2 infection in the K18-human angiotensin-converting enzyme 2 mouse model, using both neutralization and Fc effector antibody functions. The RBD mAb WRAIR-2125, which targets residue F486 through a unique heavy-chain and light-chain pairing, demonstrated potent neutralizing activity against all major SARS-CoV-2 variants of concern. In combination with NTD and other RBD mAbs, WRAIR-2125 also prevented viral escape. These data demonstrate that NTD/RBD mAb combinations confer potent protection, likely leveraging complementary mechanisms of viral inactivation and clearance.

scholarly journals Structures of SARS-CoV-2 B.1.351 neutralizing antibodies provide insights into cocktail design against concerning variants

2021 ◽  
Author(s):  
Shuo Du ◽  
Pulan Liu ◽  
Zhiying Zhang ◽  
Tianhe Xiao ◽  
Ayijiang Yasimayi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibodies ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Antibody Responses ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Humoral Antibody ◽  
Cryo Electron Microscopy ◽  
Antibody Cocktail

The spread of the SARS-CoV-2 variants could seriously dampen the global effort to tackle the COVID-19 pandemic. Recently, we investigated the humoral antibody responses of SARS-CoV-2 convalescent patients and vaccinees towards circulating variants, and identified a panel of monoclonal antibodies (mAbs) that could efficiently neutralize the B.1.351 (Beta) variant. Here we investigate how these mAbs target the B.1.351 spike protein using cryo-electron microscopy. In particular, we show that two superpotent mAbs, BD-812 and BD-836, have non-overlapping epitopes on the receptor-binding domain (RBD) of spike. Both block the interaction between RBD and the ACE2 receptor; and importantly, both remain fully efficacious towards the B.1.617.1 (Kappa) and B.1.617.2 (Delta) variants. The BD-812/BD-836 pair could thus serve as an ideal antibody cocktail against the SARS-CoV-2 VOCs.

scholarly journals Potent Neutralizing Antibodies Directed to Multiple Epitopes on SARS-CoV-2 Spike

2020 ◽  
Author(s):  
Lihong Liu ◽  
Pengfei Wang ◽  
Manoj S. Nair ◽  
Jian Yu ◽  
Micah Rapp ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Global Economy ◽  
Epitope Mapping ◽  
Severe Disease ◽  
Clinical Development ◽  
Receptor Binding Domain ◽  
Cryo Electron Microscopy ◽  
Novel Coronavirus

AbstractThe SARS-CoV-2 pandemic rages on with devasting consequences on human lives and the global economy1,2. The discovery and development of virus-neutralizing monoclonal antibodies could be one approach to treat or prevent infection by this novel coronavirus. Here we report the isolation of 61 SARS-CoV-2-neutralizing monoclonal antibodies from 5 infected patients hospitalized with severe disease. Among these are 19 antibodies that potently neutralized the authentic SARS-CoV-2 in vitro, 9 of which exhibited exquisite potency, with 50% virus-inhibitory concentrations of 0.7 to 9 ng/mL. Epitope mapping showed this collection of 19 antibodies to be about equally divided between those directed to the receptor-binding domain (RBD) and those to the N-terminal domain (NTD), indicating that both of these regions at the top of the viral spike are immunogenic. In addition, two other powerful neutralizing antibodies recognized quaternary epitopes that are overlapping with the domains at the top of the spike. Cryo-electron microscopy reconstructions of one antibody targeting RBD, a second targeting NTD, and a third bridging two separate RBDs revealed recognition of the closed, “all RBD-down” conformation of the spike. Several of these monoclonal antibodies are promising candidates for clinical development as potential therapeutic and/or prophylactic agents against SARS-CoV-2.

scholarly journals Humanized Monoclonal Antibodies Derived from Chimpanzee Fabs Protect against Japanese Encephalitis Virus In Vitro and In Vivo

2008 ◽  
Vol 82 (14) ◽  
pp. 7009-7021 ◽  
Author(s):  
Ana P. Goncalvez ◽  
Cheng-Hsin Chien ◽  
Kamolchanok Tubthong ◽  
Inna Gorshkova ◽  
Carrie Roll ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Neutralizing Antibodies ◽  
Therapeutic Potential ◽  
Encephalitis Virus ◽  
Domain Iii ◽  
Humanized Monoclonal Antibodies

ABSTRACT Japanese encephalitis virus (JEV)-specific Fab antibodies were recovered by repertoire cloning from chimpanzees initially immunized with inactivated JE-VAX and then boosted with attenuated JEV SA14-14-2. From a panel of 11 Fabs recovered by different panning strategies, three highly potent neutralizing antibodies, termed Fabs A3, B2, and E3, which recognized spatially separated regions on the virion, were identified. These antibodies reacted with epitopes in different domains: the major determinant for Fab A3 was Lys179 (domain I), that for Fab B2 was Ile126 (domain II), and that for Fab E3 was Gly302 (domain III) in the envelope protein, suggesting that these antibodies neutralize the virus by different mechanisms. Potent neutralizing antibodies reacted with a low number of binding sites available on the virion. These three Fabs and derived humanized monoclonal antibodies (MAbs) exhibited high neutralizing activities against a broad spectrum of JEV genotype strains. Demonstration of antibody-mediated protection of JEV infection in vivo is provided using the mouse encephalitis model. MAb B2 was most potent, with a 50% protective dose (ED50) of 0.84 μg, followed by MAb A3 (ED50 of 5.8 μg) and then MAb E3 (ED50 of 24.7 μg) for a 4-week-old mouse. Administration of 200 μg/mouse of MAb B2 1 day after otherwise lethal JEV infection protected 50% of mice and significantly prolonged the average survival time compared to that of mice in the unprotected group, suggesting a therapeutic potential for use of MAb B2 in humans.

scholarly journals Identification of a neutralizing epitope within minor repeat region of Plasmodium falciparum CS protein

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
J. Mauricio Calvo-Calle ◽  
Robert Mitchell ◽  
Rita Altszuler ◽  
Caroline Othoro ◽  
Elizabeth Nardin
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
In Vivo Studies ◽  
Repeat Region ◽  
Fine Specificity ◽  
Humoral Immune ◽  
Major Surface ◽  
Murine Monoclonal Antibodies

AbstractMalaria remains a major cause of morbidity and mortality worldwide with 219 million infections and 435,000 deaths predominantly in Africa. The infective Plasmodium sporozoite is the target of a potent humoral immune response that can protect murine, simian and human hosts against challenge by malaria-infected mosquitoes. Early murine studies demonstrated that sporozoites or subunit vaccines based on the sporozoite major surface antigen, the circumsporozoite (CS) protein, elicit antibodies that primarily target the central repeat region of the CS protein. In the current murine studies, using monoclonal antibodies and polyclonal sera obtained following immunization with P. falciparum sporozoites or synthetic repeat peptides, we demonstrate differences in the ability of these antibodies to recognize the major and minor repeats contained in the central repeat region. The biological relevance of these differences in fine specificity was explored using a transgenic P. berghei rodent parasite expressing the P. falciparum CS repeat region. In these in vitro and in vivo studies, we demonstrate that the minor repeat region, comprised of three copies of alternating NANP and NVDP tetramer repeats, contains an epitope recognized by sporozoite-neutralizing antibodies. In contrast, murine monoclonal antibodies specific for the major CS repeats (NANP)n could be isolated from peptide-immunized mice that had limited or no sporozoite-neutralizing activity. These studies highlight the importance of assessing the fine specificity and functions of antirepeat antibodies elicited by P. falciparum CS-based vaccines and suggest that the design of immunogens to increase antibody responses to minor CS repeats may enhance vaccine efficacy.

scholarly journals An anti-SARS-CoV-2 non-neutralizing antibody with Fc-effector function defines a new NTD epitope and delays neuroinvasion and death in K18-hACE2 mice

2021 ◽  
Author(s):  
Guillaume Beaudoin-Bussières ◽  
Yaozong Chen ◽  
Irfan Ullah ◽  
Jérémie Prévost ◽  
William D. Tolbert ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Animal Models ◽  
Mouse Model ◽  
Transgenic Mouse ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Transgenic Mouse Model ◽  
Effector Function ◽  
Effector Functions

SummaryEmerging evidence in animal models indicate that both neutralizing activity and Fc- mediated effector functions of neutralizing antibodies contribute to protection against SARS-CoV-2. It is unclear if antibody effector functions alone could protect against SARS-CoV-2. Here we isolated CV3-13, a non-neutralizing antibody from a convalescent individual with potent Fc-mediated effector functions that targeted the N- terminal domain (NTD) of SARS-CoV-2 Spike. The cryo-EM structure of CV3-13 in complex with SAR-CoV-2 spike revealed that the antibody bound from a distinct angle of approach to a novel NTD epitope that partially overlapped with a frequently mutated NTD supersite in SARS-CoV-2 variants. While CV3-13 did not alter the replication dynamics of SARS-CoV-2 in a K18-hACE2 transgenic mouse model, an Fc-enhanced CV3-13 significantly delayed neuroinvasion and death in prophylactic settings. Thus, we demonstrate that efficient Fc-mediated effector functions can contribute to the in vivo efficacy of anti-SARS-CoV-2 monoclonal antibodies in the absence of neutralization.

Sign in / Sign up

Export Citation Format

Share Document