scholarly journals Tiger team: a panel of human neutralizing mAbs targeting SARS-CoV-2 spike at multiple epitopes

2020 ◽  
Author(s):  
Tal Noy-Porat ◽  
Efi Makdasi ◽  
Ron Alcalay ◽  
Adva Mechaly ◽  
Yinon Levy ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Phage Display Library ◽  
Therapeutic Drug ◽  
The Novel ◽  
Receptor Binding Domain ◽  
Human Coronavirus ◽  
Isolation And Characterization ◽  
Emerging Virus

AbstractThe novel highly transmissible human coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Thus far, there is no approved therapeutic drug, specifically targeting this emerging virus. Here we report the isolation and characterization of a panel of human neutralizing monoclonal antibodies targeting the SARS-CoV-2 receptor binding domain (RBD). These antibodies were selected from a phage display library constructed using peripheral circulatory lymphocytes collected from patients at the acute phase of the disease. These neutralizing antibodies are shown to recognize distinct epitopes on the viral spike RBD, therefore they represent a promising basis for the design of efficient combined post-exposure therapy for SARS-CoV-2 infection.

scholarly journals Therapeutic antibodies, targeting the SARS-CoV-2 spike N-terminal domain, protect lethally infected K18-hACE2 mice

2021 ◽  
Author(s):  
Tal Noy-Porat ◽  
Adva Mechaly ◽  
Yinon Levy ◽  
Efi Makdasi ◽  
Ron Alcalay ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Phage Display Library ◽  
Host Cells ◽  
Terminal Domain ◽  
Isolation And Characterization ◽  
Recent Emergence ◽  
Therapeutic Monoclonal Antibodies

AbstractSince the onset of the current COVID-19 pandemic, high priority is given to the development of neutralizing antibodies, as a key approach for the design of therapeutic strategies to countermeasure and eradicate the disease. Previously, we reported the development of human therapeutic monoclonal antibodies (mAbs) exhibiting very high protective ability. These mAbs recognize epitopes on the spike receptor binding domain (RBD) of SARS-CoV-2 that is considered to represent the main rout of receptor engagement by the SARS-CoV-2 virus. The recent emergence of viral variants emphasizes the notion that efficient antibody treatments need to rely on mAbs against several distinct key epitopes in order to circumvent the occurrence of therapy escape-mutants. Here we report the isolation and characterization of 12 neutralizing mAbs, identified by screening a phage-display library constructed from lymphatic cells collected from severe COVID-19 patients. The antibodies target three distinct epitopes on the spike N-terminal domain (NTD) of SARS-CoV-2, one of them defining a major site of vulnerability of the virus. Extensive characterization of these mAbs suggests a neutralization mechanism which relies both on amino-acid and N-glycan recognition on the virus, and involvement of receptors other than the hACE2 on the target cell. Two of the selected mAbs, which demonstrated superior neutralization potency in vitro, were further evaluated in vivo, demonstrating their ability to fully protect K18-hACE2 transgenic mice even when administered at low doses and late after infection. The study demonstrates the high potential of the mAbs for therapy of SARS-CoV-2 infection and underlines the possible role of the NTD in mediating infection of host cells via alternative cellular portals other than the canonical ACE2 receptor.

scholarly journals Selection, biophysical and structural analysis of synthetic nanobodies that effectively neutralize SARS-CoV-2

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tânia F. Custódio ◽  
Hrishikesh Das ◽  
Daniel J. Sheward ◽  
Leo Hanke ◽  
Samuel Pazicky ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Combined Approach ◽  
Emerging Viruses ◽  
Medium Term ◽  
Neutralization Activity ◽  
High Affinity ◽  
Isolation And Characterization

Abstract The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Therapeutic neutralizing antibodies constitute a key short-to-medium term approach to tackle COVID-19. However, traditional antibody production is hampered by long development times and costly production. Here, we report the rapid isolation and characterization of nanobodies from a synthetic library, known as sybodies (Sb), that target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Several binders with low nanomolar affinities and efficient neutralization activity were identified of which Sb23 displayed high affinity and neutralized pseudovirus with an IC50 of 0.6 µg/ml. A cryo-EM structure of the spike bound to Sb23 showed that Sb23 binds competitively in the ACE2 binding site. Furthermore, the cryo-EM reconstruction revealed an unusual conformation of the spike where two RBDs are in the ‘up’ ACE2-binding conformation. The combined approach represents an alternative, fast workflow to select binders with neutralizing activity against newly emerging viruses.

scholarly journals Isolation and Characterization of Cross-Neutralizing Coronavirus Antibodies from COVID-19+ Subjects

2021 ◽  
Author(s):  
Madeleine F. Jennewein ◽  
Anna J. MacCamy ◽  
Nicholas R. Akins ◽  
Junli Feng ◽  
Leah J. Homad ◽  
...  
Keyword(s):  
Mouse Model ◽  
Transgenic Mouse ◽  
Neutralizing Antibodies ◽  
Transgenic Mouse Model ◽  
Human Coronavirus ◽  
Epitope Specificity ◽  
The Past ◽  
Isolation And Characterization

SUMMARYSARS-CoV-2 is one of three coronaviruses that have crossed the animal-to-human barrier in the past two decades. The development of a universal human coronavirus vaccine could prevent future pandemics. We characterized 198 antibodies isolated from four COVID19+ subjects and identified 14 SARS-CoV-2 neutralizing antibodies. One targeted the NTD, one recognized an epitope in S2 and twelve bound the RBD. Three anti-RBD neutralizing antibodies cross-neutralized SARS-CoV-1 by effectively blocking binding of both the SARS-CoV-1 and SARS-CoV-2 RBDs to the ACE2 receptor. Using the K18-hACE transgenic mouse model, we demonstrate that the neutralization potency rather than the antibody epitope specificity regulates the in vivo protective potential of anti-SARS-CoV-2 antibodies. The anti-S2 antibody also neutralized SARS-CoV-1 and all four cross-neutralizing antibodies neutralized the B.1.351 mutant strain. Thus, our study reveals that epitopes in S2 can serve as blueprints for the design of immunogens capable of eliciting cross-neutralizing coronavirus antibodies.

scholarly journals Selection, biophysical and structural analysis of synthetic nanobodies that effectively neutralize SARS-CoV-2

2020 ◽  
Author(s):  
Tânia F. Custódio ◽  
Hrishikesh Das ◽  
Daniel J Sheward ◽  
Leo Hanke ◽  
Samuel Pazicky ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Combined Approach ◽  
Emerging Viruses ◽  
Medium Term ◽  
Neutralization Activity ◽  
High Affinity ◽  
Isolation And Characterization

AbstractThe coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Therapeutic neutralizing antibodies constitute a key short-to-medium term approach to tackle COVID-19. However, traditional antibody production is hampered by long development times and costly production. Here, we report the rapid isolation and characterization of nanobodies from a synthetic library, known as sybodies (Sb), that target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Several binders with low nanomolar affinities and efficient neutralization activity were identified of which Sb23 displayed high affinity and neutralized pseudovirus with an IC50 of 0.6 µg/ml. A cryo-EM structure of the spike bound to Sb23 showed that Sb23 binds competitively in the ACE2 binding site. Furthermore, the cryo-EM reconstruction revealed a novel conformation of the spike where two RBDs are in the ‘up’ ACE2-binding conformation. The combined approach represents an alternative, fast workflow to select binders with neutralizing activity against newly emerging viruses.

scholarly journals Isolation and Characterization of Broadly Neutralizing Human Monoclonal Antibodies to the E1 Glycoprotein of Hepatitis C Virus

2007 ◽  
Vol 82 (2) ◽  
pp. 966-973 ◽  
Author(s):  
Jean-Christophe Meunier ◽  
Rodney S. Russell ◽  
Vera Goossens ◽  
Sofie Priem ◽  
Hugo Walter ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Hcv Infection ◽  
Envelope Glycoproteins ◽  
Human Monoclonal Antibodies ◽  
Humoral And Cellular Immunity ◽  
Isolation And Characterization

ABSTRACT The relative importance of humoral and cellular immunity in the prevention or clearance of hepatitis C virus (HCV) infection is poorly understood. However, there is considerable evidence that neutralizing antibodies are involved in disease control. Here we describe the detailed analysis of human monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly neutralize HCVpp bearing the envelope glycoproteins of genotype 2a. Genotype 3a was not neutralized. The epitopes for both MAbs were mapped to the region encompassing amino acids 313 to 327. In addition, robust neutralization was also observed against cell culture-adapted viruses of genotypes 1a and 2a. Results from this study suggest that these MAbs may have the potential to prevent HCV infection.

scholarly journals Isolation and Characterization of Salmonella Jumbo-Phage pSal-SNUABM-04

Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Jun Kwon ◽  
Sang Guen Kim ◽  
Hyoun Joong Kim ◽  
Sib Sankar Giri ◽  
Sang Wha Kim ◽  
...  
Keyword(s):  
Morphological Traits ◽  
Open Reading Frames ◽  
Genome Comparison ◽  
The Novel ◽  
Promising Alternative ◽  
Isolation And Characterization ◽  
Global Issue ◽  
Reading Frames ◽  
Predicted Function

The increasing emergence of antimicrobial resistance has become a global issue. Therefore, many researchers have attempted to develop alternative antibiotics. One promising alternative is bacteriophage. In this study, we focused on a jumbo-phage infecting Salmonella isolated from exotic pet markets. Using a Salmonella strain isolated from reptiles as a host, we isolated and characterized the novel jumbo-bacteriophage pSal-SNUABM-04. This phage was investigated in terms of its morphology, host infectivity, growth and lysis kinetics, and genome. The phage was classified as Myoviridae based on its morphological traits and showed a comparatively wide host range. The lysis efficacy test showed that the phage can inhibit bacterial growth in the planktonic state. Genetic analysis revealed that the phage possesses a 239,626-base pair genome with 280 putative open reading frames, 76 of which have a predicted function and 195 of which have none. By genome comparison with other jumbo phages, the phage was designated as a novel member of Machinavirus composed of Erwnina phages.

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.

scholarly journals Development of Neutralizing Monoclonal Antibodies for Oncogenic Human Papillomavirus Types 31, 33, 45, 52, and 58

2014 ◽  
Vol 21 (4) ◽  
pp. 587-593 ◽  
Author(s):  
Martha J. Brown ◽  
Hanna Seitz ◽  
Victoria Towne ◽  
Martin Müller ◽  
Adam C. Finnefrock
Keyword(s):  
Monoclonal Antibodies ◽  
Human Papillomavirus ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Cervical Cancers ◽  
Hpv Types ◽  
Oncogenic Hpv ◽  
Neutralizing Epitopes ◽  
Selection Of

ABSTRACTHuman papillomavirus (HPV) is the etiological agent for all cervical cancers, a significant number of other anogenital cancers, and a growing number of head and neck cancers. Two licensed vaccines offer protection against the most prevalent oncogenic types, 16 and 18, responsible for approximately 70% of cervical cancer cases worldwide and one of these also offers protection against types 6 and 11, responsible for 90% of genital warts. The vaccines are comprised of recombinantly expressed major capsid proteins that self-assemble into virus-like particles (VLPs) and prevent infection by eliciting neutralizing antibodies. Adding the other frequently identified oncogenic types 31, 33, 45, 52, and 58 to a vaccine would increase the coverage against HPV-induced cancers to approximately 90%. We describe the generation and characterization of panels of monoclonal antibodies to these five additional oncogenic HPV types, and the selection of antibody pairs that were high affinity and type specific and recognized conformation-dependent neutralizing epitopes. Such characteristics make these antibodies useful tools for monitoring the production and potency of a prototype vaccine as well as monitoring vaccine-induced immune responses in the clinic.

Near-germline human monoclonal antibodies neutralize and protect against multiple arthritogenic alphaviruses

2021 ◽  
Vol 118 (37) ◽  
pp. e2100104118
Author(s):  
Ryan J. Malonis ◽  
James T. Earnest ◽  
Arthur S. Kim ◽  
Matthew Angeliadis ◽  
Frederick W. Holtsberg ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Natural Infection ◽  
Human Mabs ◽  
Isolation And Characterization ◽  
Neutralizing Capacity ◽  
Rheumatological Disease ◽  
Mayaro Virus ◽  
Alphavirus Infection ◽  
Globally Distributed

Arthritogenic alphaviruses are globally distributed, mosquito-transmitted viruses that cause rheumatological disease in humans and include Chikungunya virus (CHIKV), Mayaro virus (MAYV), and others. Although serological evidence suggests that some antibody-mediated heterologous immunity may be afforded by alphavirus infection, the extent to which broadly neutralizing antibodies that protect against multiple arthritogenic alphaviruses are elicited during natural infection remains unknown. Here, we describe the isolation and characterization of MAYV-reactive alphavirus monoclonal antibodies (mAbs) from a CHIKV-convalescent donor. We characterized 33 human mAbs that cross-reacted with CHIKV and MAYV and engaged multiple epitopes on the E1 and E2 glycoproteins. We identified five mAbs that target distinct regions of the B domain of E2 and potently neutralize multiple alphaviruses with differential breadth of inhibition. These broadly neutralizing mAbs (bNAbs) contain few somatic mutations and inferred germline–revertants retained neutralizing capacity. Two bNAbs, DC2.M16 and DC2.M357, protected against both CHIKV- and MAYV-induced musculoskeletal disease in mice. These findings enhance our understanding of the cross-reactive and cross-protective antibody response to human alphavirus infections.

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