Potent SARS-CoV-2 neutralizing antibodies with protective efficacy against newly emerged mutational variants

AbstractAccumulating mutations in the SARS-CoV-2 Spike (S) protein can increase the possibility of immune escape, challenging the present COVID-19 prophylaxis and clinical interventions. Here, 3 receptor binding domain (RBD) specific monoclonal antibodies (mAbs), 58G6, 510A5 and 13G9, with high neutralizing potency blocking authentic SARS-CoV-2 virus display remarkable efficacy against authentic B.1.351 virus. Surprisingly, structural analysis has revealed that 58G6 and 13G9 both recognize the steric region S470–495 on the RBD, overlapping the E484K mutation presented in B.1.351. Also, 58G6 directly binds to another region S450–458 in the RBD. Significantly, 58G6 and 510A5 both demonstrate prophylactic efficacy against authentic SARS-CoV-2 and B.1.351 viruses in the transgenic mice expressing human ACE2 (hACE2), protecting weight loss and reducing virus loads. Together, we have evidenced 2 potent neutralizing Abs with unique mechanism targeting authentic SARS-CoV-2 mutants, which can be promising candidates to fulfill the urgent needs for the prolonged COVID-19 pandemic.

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Ultrapotent SARS-CoV-2 neutralizing antibodies with protective efficacy against newly emerged mutational variants

10.1101/2021.04.19.440481 ◽

2021 ◽

Author(s):

Tingting Li ◽

Xiaojian Han ◽

Chenjian Gu ◽

Hangtian Guo ◽

Huajun Zhang ◽

...

Keyword(s):

Weight Loss ◽

Monoclonal Antibodies ◽

Structural Analysis ◽

Synergistic Effect ◽

Neutralizing Antibodies ◽

Immune Escape ◽

Protective Efficacy ◽

Receptor Binding Domain ◽

Prophylactic Efficacy ◽

Germline Genes

AbstractAccumulating mutations in the SARS-CoV-2 Spike (S) protein can increase the possibility of immune escape, challenging the present COVID-19 prophylaxis and clinical interventions. Here, 3 receptor binding domain (RBD) specific monoclonal antibodies (mAbs), 58G6, 510A5 and 13G9, with high neutralizing potency blocking authentic SARS-CoV-2 virus displayed remarkable efficacy against authentic B.1.351 virus. Each of these 3 mAbs in combination with one neutralizing Ab recognizing non-competing epitope exhibited synergistic effect against authentic SARS-CoV-2 virus. Surprisingly, structural analysis revealed that 58G6 and 13G9, encoded by the IGHV1-58 and the IGKV3-20 germline genes, both recognized the steric region S470-495 on the RBD, overlapping the E484K mutation presented in B.1.351. Also, 58G6 directly bound to another region S450-458 in the RBD. Significantly, 58G6 and 510A5 both demonstrated prophylactic efficacy against authentic SARS-CoV-2 and B.1.351 viruses in the transgenic mice expressing human ACE2 (hACE2), protecting weight loss and reducing virus loads. These 2 ultrapotent neutralizing Abs can be promising candidates to fulfill the urgent needs for the prolonged COVID-19 pandemic.

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Effect of RBD (Y453F) mutation in spike glycoprotein of SARS-CoV-2 on neutralizing IgG affinity

10.1101/2021.01.28.21250577 ◽

2021 ◽

Author(s):

Takuma Hayashi ◽

Nobuo Yaegashi ◽

Ikuo Konishi

Keyword(s):

Monoclonal Antibodies ◽

Structural Analysis ◽

Severe Acute Respiratory Syndrome ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Virus Disease ◽

Three Dimensional ◽

Binding Domain ◽

Receptor Binding Domain ◽

Spike Glycoprotein

AbstractBackgroundInfection with receptor binding domain (RBD) mutant (Y453F) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from farmed minks is known to widely spread among humans.MethodsWe investigated the characteristics of SARS-CoV-2 RBD Y453F mutant using three- dimensional structural analysis. We investigated the effect of the RBD Y453F mutant of SARS-CoV- 2 on neutralizing antibodies in serum derived from Corona virus Disease 2019 (COVID-19) positive patients.ResultsOur studies suggest that virus variants with RBD Y453F mutation partially escaped detection by four neutralizing monoclonal antibodies and neutralizing antibodies in serum.ConclusionsConsequently, raising a concern that infection of SARS-CoV-2 mutants that cause serious symptoms in humans may spread globally.

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Effect of RBD mutations in spike glycoprotein of SARS-CoV-2 on neutralizing IgG affinity

10.21203/rs.3.rs-363352/v1 ◽

2021 ◽

Author(s):

Takuma Hayashi ◽

Nobuo Yaegashi ◽

Ikuo Konishi

Keyword(s):

Monoclonal Antibodies ◽

Structural Analysis ◽

Receptor Binding ◽

Neutralizing Antibodies ◽

Three Dimensional ◽

Binding Domain ◽

Receptor Binding Domain ◽

Spike Glycoprotein ◽

Mutant Strains

Abstract Background: Certain mutant strains of SARS-CoV-2 are known to spread widely among humans, including the receptor binding domain (RBD) mutant, Y453F, from farmed minks, and the RBD mutant, N501Y, a mutation common to three major SARS-CoV-2 subspecies (B.1.1.7, B.1.351, and B.1.1.248). Methods: We investigated the characteristics of the RBD mutants, Y453F and N501Y, using three-dimensional structural analysis. We also investigated the effect of Y453F and N501Y on neutralizing antibodies in serum derived from COVID-19-positive patients. Results: Our results suggest that SARS-CoV-2 subspecies with the RBD mutations Y453F or N501Y partially escaped detection by 4 neutralizing monoclonal antibodies and 21 neutralizing antibodies in serums derived from COVID-19-positive patients.Conclusions: Infection with SARS-CoV-2 subspecies that cause serious symptoms in humans may spread globally.

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

Viruses ◽

10.3390/v13040633 ◽

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.

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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

10.1101/2021.04.05.438547 ◽

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.

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ANALYSIS OF IMMUNE ESCAPE VARIANTS FROM ANTIBODY-BASED THERAPEUTICS AGAINST COVID-19.

10.1101/2021.11.11.21266207 ◽

2021 ◽

Author(s):

Daniele Focosi ◽

Fabrizio Maggi ◽

Massimo Franchini ◽

Scott McConnell ◽

Arturo Casadevall

Keyword(s):

Public Health ◽

Monoclonal Antibodies ◽

Immune Evasion ◽

Immune Escape ◽

Selective Pressure ◽

Neutralizing Antibody ◽

Spike Protein ◽

Single Amino Acid ◽

Receptor Binding Domain ◽

Amino Acid Mutations

Accelerated SARS-CoV-2 evolution under selective pressure by massive deployment of neutralizing antibody-based therapeutics is a concern with potentially severe implications for public health. We review here reports of documented immune escape after treatment with monoclonal antibodies and COVID19 convalescent plasma (CCP). While the former is mainly associated with specific single amino acid mutations at residues within the receptor-binding domain (e.g., E484K/Q, Q493R, and S494P), the few cases of immune evasion after CCP were associated with recurrent deletions within the N-terminal domain of Spike protein (e.g, delHV69-70, delLGVY141-144 and delAL243-244). Continuous genomic monitoring of non-responders is needed to better understand immune escape frequencies and fitness of emerging variants.

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Nucleocapsid vaccine elicits spike-independent SARS-CoV-2 protective immunity

10.1101/2021.04.26.441518 ◽

2021 ◽

Author(s):

William E. Matchett ◽

Vineet Joag ◽

J. Michael Stolley ◽

Frances K. Shepherd ◽

Clare F. Quarnstrom ◽

...

Keyword(s):

Weight Loss ◽

Viral Load ◽

Neutralizing Antibodies ◽

Protective Immunity ◽

Protein A ◽

Receptor Binding Domain ◽

Immune Effector ◽

N Protein ◽

Viral Antigens ◽

Successful Vaccine

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. Neutralizing antibodies target the receptor binding domain of the spike (S) protein, a focus of successful vaccine efforts. Concerns have arisen that S-specific vaccine immunity may fail to neutralize emerging variants. We show that vaccination with HAd5 expressing the nucleocapsid (N) protein can establish protective immunity, defined by reduced weight loss and viral load, in both Syrian hamsters and k18-hACE2 mice. Challenge of vaccinated mice was associated with rapid N-specific T cell recall responses in the respiratory mucosa. This study supports the rationale for including additional viral antigens, even if they are not a target of neutralizing antibodies, to broaden epitope coverage and immune effector mechanisms.

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

10.1101/2021.02.03.429355 ◽

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.

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Immunogenetic and structural analysis of a class of HCV broadly neutralizing antibodies and their precursors

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1802378115 ◽

2018 ◽

Vol 115 (29) ◽

pp. 7569-7574 ◽

Cited By ~ 6

Author(s):

Fernando Aleman ◽

Netanel Tzarum ◽

Leopold Kong ◽

Kenna Nagy ◽

Jiang Zhu ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Structural Analysis ◽

Neutralizing Antibodies ◽

Antigenic Site ◽

The Other ◽

Maturation Process ◽

Broadly Neutralizing Antibodies ◽

Vaccine Candidates ◽

Rational Vaccine Design ◽

Hairpin Conformation

Elicitation of broadly neutralizing antibodies (bnAbs) is a leading strategy in rational vaccine design against antigenically diverse pathogens. Here, we studied a panel of monoclonal antibodies (mAbs) from mice immunized with the hepatitis C virus (HCV) envelope glycoproteins E1E2. Six of the mAbs recognize the conserved E2 antigenic site 412–423 (AS412) and cross-neutralize diverse HCV genotypes. Immunogenetic and structural analysis revealed that the antibodies originated from two different germline (GL) precursors and bind AS412 in a β-hairpin conformation. Intriguingly, the anti-HCV activity of one antibody lineage is associated with maturation of the light chain (LC), whereas the other lineage is dependent on heavy-chain (HC) maturation. Crystal structures of GL precursors of the LC-dependent lineage in complex with AS412 offer critical insights into the maturation process of bnAbs to HCV, providing a scientific foundation for utilizing the mouse model to study AS412-targeting vaccine candidates.

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Neutralizing antibody-independent immunity to SARS-CoV-2 in hamsters and hACE-2 transgenic mice immunized with a RBD/Nucleocapsid fusion protein

10.1101/2021.09.16.460663 ◽

2021 ◽

Author(s):

Julia Castro ◽

Marcilio Fumagalli ◽

Natalia Hojo-Souza ◽

Patrick Azevedo ◽

Natalia Salazar ◽

...

Keyword(s):

T Cell ◽

Transgenic Mice ◽

Lung Inflammation ◽

Neutralizing Antibodies ◽

Chimeric Protein ◽

Neutralizing Antibody ◽

Receptor Binding Domain ◽

Wild Type ◽

N Protein ◽

Cell Responses

The nucleocapsid (N) and the receptor binding domain (RBD) of the Spike (S) proteins elicit robust antibody and T cell responses either in vaccinated or COVID-19 convalescent individuals. We generated a chimeric protein that comprises the sequences of RBD from S and N antigens (SpiN). SpiN was highly immunogenic and elicited a strong IFNγ response from T cells and high levels of antibodies to the inactivated virus, but no neutralizing antibodies. Importantly, hamsters and the human Angiotensin Convertase Enzyme-2-transgenic mice immunized with SpiN were highly resistant to challenge with the wild type SARS-CoV-2, as indicated by viral load, clinical outcome, lung inflammation and lethality. Thus, the N protein should be considered to induce T-cell-based immunity to improve SARS-CoV-2 vaccines, and eventually to circumvent the immune scape by variants.

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