scholarly journals Neutralizing and protective human monoclonal antibodies recognizing the N-terminal domain of the SARS-CoV-2 spike protein

2021 ◽  
Author(s):  
Naveenchandra Suryadevara ◽  
Swathi Shrihari ◽  
Pavlo Gilchuk ◽  
Laura A. VanBlargan ◽  
Elad Binshtein ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Natural Infection ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Alanine Scanning Mutagenesis ◽  
S Protein ◽  
Angiotensin Converting Enzyme 2 ◽  
Terminal Domain ◽  
Protein Receptor ◽  
Virus Interactions

SummaryMost human monoclonal antibodies (mAbs) neutralizing SARS-CoV-2 recognize the spike (S) protein receptor-binding domain and block virus interactions with the cellular receptor angiotensin-converting enzyme 2. We describe a panel of human mAbs binding to diverse epitopes on the N-terminal domain (NTD) of S protein from SARS-CoV-2 convalescent donors and found a minority of these possessed neutralizing activity. Two mAbs (COV2-2676 and COV2-2489) inhibited infection of authentic SARS-CoV-2 and recombinant VSV/SARS-CoV-2 viruses. We mapped their binding epitopes by alanine-scanning mutagenesis and selection of functional SARS-CoV-2 S neutralization escape variants. Mechanistic studies showed that these antibodies neutralize in part by inhibiting a post-attachment step in the infection cycle. COV2-2676 and COV2-2489 offered protection either as prophylaxis or therapy, and Fc effector functions were required for optimal protection. Thus, natural infection induces a subset of potent NTD-specific mAbs that leverage neutralizing and Fc-mediated activities to protect against SARS-CoV-2 infection using multiple functional attributes.

scholarly journals Human monoclonal antibodies block the binding of SARS-CoV-2 spike protein to angiotensin converting enzyme 2 receptor

2020 ◽  
Author(s):  
Xiangyu Chen ◽  
Ren Li ◽  
Zhiwei Pan ◽  
Chunfang Qian ◽  
Yang Yang ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Angiotensin Converting Enzyme ◽  
Virus Disease ◽  
Pseudotyped Virus ◽  
Converting Enzyme ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
S Protein ◽  
Angiotensin Converting Enzyme 2 ◽  
Global Pandemic

AbstractThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of novel corona virus disease (COVID-19). To date, no prophylactic vaccines or approved therapeutic agents are available for preventing and treating this highly transmittable disease. Here we report two monoclonal antibodies (mAbs) cloned from memory B cells of patients recently recovered from COVID-19, and both mAbs specifically bind to the spike (S) protein of SARS-CoV-2, block the binding of receptor binding domain (RBD) of SARS-CoV-2 to human angiotensin converting enzyme 2 (hACE2), and effectively neutralize S protein-pseudotyped virus infection. These human mAbs hold the promise for the prevention and treatment of the ongoing pandemic of COVID-19.

scholarly journals Cryo-EM structures elucidate neutralizing mechanisms of anti-chikungunya human monoclonal antibodies with therapeutic activity

2015 ◽  
Vol 112 (45) ◽  
pp. 13898-13903 ◽  
Author(s):  
Feng Long ◽  
Rachel H. Fong ◽  
Stephen K. Austin ◽  
Zhenguo Chen ◽  
Thomas Klose ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Chikungunya Virus ◽  
Structural Basis ◽  
Binding Studies ◽  
Viral Glycoprotein ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Alanine Scanning Mutagenesis ◽  
Viral Surface ◽  
Fusion Loop

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes severe acute and chronic disease in humans. Although highly inhibitory murine and human monoclonal antibodies (mAbs) have been generated, the structural basis of their neutralizing activity remains poorly characterized. Here, we determined the cryo-EM structures of chikungunya virus-like particles complexed with antibody fragments (Fab) of two highly protective human mAbs, 4J21 and 5M16, that block virus fusion with host membranes. Both mAbs bind primarily to sites within the A and B domains, as well as to the B domain’s β-ribbon connector of the viral glycoprotein E2. The footprints of these antibodies on the viral surface were consistent with results from loss-of-binding studies using an alanine scanning mutagenesis-based epitope mapping approach. The Fab fragments stabilized the position of the B domain relative to the virus, particularly for the complex with 5M16. This finding is consistent with a mechanism of neutralization in which anti-CHIKV mAbs that bridge the A and B domains impede movement of the B domain away from the underlying fusion loop on the E1 glycoprotein and therefore block the requisite pH-dependent fusion of viral and host membranes.

scholarly journals Neutralizing and protective human monoclonal antibodies recognizing the N-terminal domain of the SARS-CoV-2 spike protein

Cell ◽  
2021 ◽  
Author(s):  
Naveenchandra Suryadevara ◽  
Swathi Shrihari ◽  
Pavlo Gilchuk ◽  
Laura A. VanBlargan ◽  
Elad Binshtein ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Spike Protein ◽  
Human Monoclonal Antibodies ◽  
Terminal Domain

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.

scholarly journals Mutations from bat ACE2 orthologs markedly enhance ACE2-Fc neutralization of SARS-CoV-2

2020 ◽  
Author(s):  
Huihui Mou ◽  
Brian D. Quinlan ◽  
Haiyong Peng ◽  
Yan Guo ◽  
Shoujiao Peng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Converting Enzyme ◽  
Viral Receptor ◽  
S Protein ◽  
Angiotensin Converting Enzyme 2 ◽  
Binding Domains ◽  
Protein Receptor ◽  
Horseshoe Bat ◽  
Horseshoe Bats

SUMMARYThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein mediates infection of cells expressing angiotensin-converting enzyme 2 (ACE2). ACE2 is also the viral receptor of SARS-CoV (SARS-CoV-1), a related coronavirus that emerged in 2002-2003. Horseshoe bats (genus Rhinolophus) are presumed to be the original reservoir of both viruses, and a SARS-like coronavirus, RaTG13, closely related SARS-CoV-2, has been isolated from one horseshoe-bat species. Here we characterize the ability of S-protein receptor-binding domains (RBDs) of SARS-CoV-1, SARS-CoV-2, and RaTG13 to bind a range of ACE2 orthologs. We observed that the SARS-CoV-2 RBD bound human, pangolin, and horseshoe bat (R. macrotis) ACE2 more efficiently than the SARS-CoV-1 or RaTG13 RBD. Only the RaTG13 RBD bound rodent ACE2 orthologs efficiently. Five mutations drawn from ACE2 orthologs of nine Rhinolophus species enhanced human ACE2 binding to the SARS-CoV-2 RBD and neutralization of SARS-CoV-2 by an immunoadhesin form of human ACE2 (ACE2-Fc). Two of these mutations impaired neutralization of SARS-CoV-1. An ACE2-Fc variant bearing all five mutations neutralized SARS-CoV-2 five-fold more efficiently than human ACE2-Fc. These data narrow the potential SARS-CoV-2 reservoir, suggest that SARS-CoV-1 and -2 originate from distinct bat species, and identify a more potently neutralizing form of ACE2-Fc.

scholarly journals Functional cooperativity mediated by rationally selected combinations of human monoclonal antibodies targeting the henipavirus receptor binding protein

2021 ◽  
Author(s):  
Michael P. Doyle ◽  
Nurgun Kose ◽  
Viktoriya Borisevich ◽  
Elad Binshtein ◽  
Moushimi Amaya ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Receptor Binding ◽  
Binding Protein ◽  
Severe Disease ◽  
Hendra Virus ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Viral Attachment ◽  
Antigenic Sites ◽  
Receptor Binding Protein

AbstractHendra virus (HeV) and Nipah virus (NiV), the prototypic members of the Henipavirus (HNV) genus, are emerging, zoonotic paramyxoviruses known to cause severe disease across six mammalian orders, including humans (Eaton et al., 2006). While several research groups have made strides in developing candidate vaccines and therapeutics against henipaviruses, such countermeasures have not been licensed for human use, and significant gaps in knowledge about the human immune response to these viruses exist. To address these gaps, we isolated a large panel of human monoclonal antibodies (mAbs) from the B cells of an individual with prior occupation-related exposure to the equine HeV vaccine (Equivac® HeV). Competition-binding and hydrogen-deuterium exchange mass spectrometry (HDX-MS) studies identified at least six distinct antigenic sites on the HeV/NiV receptor binding protein (RBP) that are recognized by human mAbs. Antibodies recognizing multiple antigenic sites potently neutralized NiV and/or HeV isolates in vitro. The most potent class of cross-reactive antibodies achieved neutralization by blocking viral attachment to the host cell receptors ephrin-B2 and ephrin-B3. Antibodies from this class mimic receptor binding by inducing a receptor-bound conformation to the HeV-RBP protein tetramer, exposing an epitope that appears to lie hidden in the interface between protomers within the HeV-RBP tetramer. Antibodies that recognize this cryptic epitope potently neutralized HeV and NiV. Flow cytometric studies using cell-surface-displayed HeV-RBP protein showed that cross-reactive, neutralizing mAbs from each of these classes cooperate for binding. In a highly stringent hamster model of NiVB infection, antibodies from both classes reduced morbidity and mortality and achieved synergistic protection in combination and provided therapeutic benefit when combined into two bispecific platforms. These studies identified multiple candidate mAbs that might be suitable for use in a cocktail therapeutic approach to achieve synergistic antiviral potency and reduce the risk of virus escape during treatment.

scholarly journals Broadly reactive human monoclonal antibodies targeting the pneumococcal histidine triad protein protect against fatal pneumococcal infection

2021 ◽  
Author(s):  
Jiachen Huang ◽  
Aaron D. Gingerich ◽  
Fredejah Royer ◽  
Amy V. Paschall ◽  
Alma Pena-Briseno ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Disease Prevention ◽  
Disease Incidence ◽  
Protein A ◽  
Pneumococcal Infection ◽  
Surface Protein ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Prevention And Treatment ◽  
Pneumococcal Serotype

AbstractStreptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most vaccine-included serotypes, a rise in infection due to non-vaccine serotypes, and moderate efficacy against some vaccine included serotypes have contributed to high disease incidence. Additionally, numerous isolates of S. pneumoniae are antibiotic or multi-drug resistant. Several conserved pneumococcal proteins prevalent in the majority of serotypes have been examined as vaccines in preclinical and clinical trials. An additional, yet unexplored tool for disease prevention and treatment is the use of human monoclonal antibodies (mAbs) targeting conserved pneumococcal proteins. Here, we isolate the first human mAbs (PhtD3, PhtD6, PhtD7, PhtD8, PspA16) against the pneumococcal histidine triad protein (PhtD), and the pneumococcal surface protein A (PspA), two conserved and protective antigens. mAbs to PhtD target diverse epitopes on PhtD, and mAb PspA16 targets the N-terminal segment of PspA. The PhtD-specific mAbs bind to multiple serotypes, while mAb PspA16 serotype breadth is limited. mAbs PhtD3 and PhtD8 prolong the survival of mice infected with pneumococcal serotype 3. Furthermore, mAb PhtD3 prolongs the survival of mice in intranasal and intravenous infection models with pneumococcal serotype 4, and in mice infected with pneumococcal serotype 3 when administered 24 hours after pneumococcal infection. All PhtD and PspA mAbs demonstrate opsonophagocytic activity, suggesting a potential mechanism of protection. Our results provide new human mAbs for pneumococcal disease prevention and treatment, and identify epitopes on PhtD and PspA recognized by human B cells.

scholarly journals Comparison of Two Strategies to Generate Antigen-Specific Human Monoclonal Antibodies: Which Method to Choose for Which Purpose?

2021 ◽  
Vol 12 ◽  
Author(s):  
Anna M. Ehlers ◽  
Constance F. den Hartog Jager ◽  
Tineke Kardol-Hoefnagel ◽  
Miriam M.D. Katsburg ◽  
André C. Knulst ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Heterologous Expression ◽  
Single Cell ◽  
Antigen Binding ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Single Cell Sequencing ◽  
2S Albumins ◽  
Functional Features ◽  
Set Up

Human monoclonal antibodies (mAbs) are valuable tools to link genetic information with functional features and to provide a platform for conformational epitope mapping. Additionally, combined data on genetic and functional features provide a valuable mosaic for systems immunology approaches. Strategies to generate human mAbs from peripheral blood have been described and used in several studies including single cell sequencing of antigen-binding B cells and the establishment of antigen-specific monoclonal Epstein-Barr Virus (EBV) immortalized lymphoblastoid cell lines (LCLs). However, direct comparisons of these two strategies are scarce. Hence, we sought to set up these two strategies in our laboratory using peanut 2S albumins (allergens) and the autoantigen anti-Rho guanosine diphosphate dissociation inhibitor 2 (RhoGDI2, alternatively ‘ARHGDIB’) as antigen targets to directly compare these strategies regarding costs, time expenditure, recovery, throughput and complexity. Regarding single cell sequencing, up to 50% of corresponding V(D)J gene transcripts were successfully amplified of which 54% were successfully cloned into expression vectors used for heterologous expression. Seventy-five percent of heterologously expressed mAbs showed specific binding to peanut 2S albumins resulting in an overall recovery of 20.3%, which may be increased to around 29% by ordering gene sequences commercially for antibody cloning. In comparison, the establishment of monoclonal EBV-LCLs showed a lower overall recovery of around 17.6%. Heterologous expression of a mAb carrying the same variable region as its native counterpart showed comparable concentration-dependent binding abilities. By directly comparing those two strategies, single cell sequencing allows a broad examination of antigen-binding mAbs in a moderate-throughput manner, while the establishment of monoclonal EBV-LCLs is a powerful tool to select a small number of highly reactive mAbs restricted to certain B cell subpopulations. Overall, both strategies, initially set-up for peanut 2S albumins, are suitable to obtain human mAbs and they are easily transferrable to other target antigens as shown for ARHGDIB.

scholarly journals Broadly Reactive Human Monoclonal Antibodies Targeting the Pneumococcal Histidine Triad Protein Protect against Fatal Pneumococcal Infection

2021 ◽  
Vol 89 (5) ◽  
Author(s):  
Jiachen Huang ◽  
Aaron D. Gingerich ◽  
Fredejah Royer ◽  
Amy V. Paschall ◽  
Alma Pena-Briseno ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Disease Prevention ◽  
Disease Incidence ◽  
Protein A ◽  
Pneumococcal Infection ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Content Type ◽  
Prevention And Treatment ◽  
Pneumococcal Serotype

ABSTRACT Streptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most serotypes included in vaccines, a rise in infection due to nonvaccine serotypes and moderate efficacy against some vaccine serotypes have contributed to high disease incidence. Additionally, numerous isolates of S. pneumoniae are antibiotic or multidrug resistant. Several conserved pneumococcal proteins prevalent in the majority of serotypes have been examined for their potential as vaccines in preclinical and clinical trials. An additional, yet-unexplored tool for disease prevention and treatment is the use of human monoclonal antibodies (MAbs) targeting conserved pneumococcal proteins. Here, we isolated the first human MAbs (PhtD3, PhtD6, PhtD7, PhtD8, and PspA16) against the pneumococcal histidine triad protein (PhtD) and the pneumococcal surface protein A (PspA), two conserved and protective antigens. MAbs to PhtD target diverse epitopes on PhtD, and MAb PspA16 targets the N-terminal segment of PspA. The PhtD-specific MAbs bind to multiple serotypes, while MAb PspA16 serotype breadth is limited. MAbs PhtD3 and PhtD8 prolong the survival of mice infected with pneumococcal serotype 3. Furthermore, MAb PhtD3 prolongs the survival of mice in intranasal and intravenous infection models with pneumococcal serotype 4 and in mice infected with pneumococcal serotype 3 when administered 24 h after pneumococcal infection. All PhtD and PspA MAbs demonstrate opsonophagocytic activity, suggesting a potential mechanism of protection. Our results identify new human MAbs for pneumococcal disease prevention and treatment and identify epitopes on PhtD and PspA recognized by human B cells.

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