scholarly journals Single-domain antibodies efficiently neutralize SARS-CoV-2 variants of concern

2021 ◽  
Author(s):  
Irina A Favorskaya ◽  
Dmitry V Shcheblyakov ◽  
Ilias B Esmagambetov ◽  
Inna V Dolzhikova ◽  
Irina A Alekseeva ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Neutralizing Antibodies ◽  
Treatment Options ◽  
Fold Increase ◽  
Single Domain ◽  
Drug Candidate ◽  
Receptor Binding Domain ◽  
Neutralizing Activity ◽  
Single Domain Antibodies ◽  
Alpha Beta

Virus-neutralizing antibodies are one of the few treatment options for COVID-19. The evolution of SARS-CoV-2 virus has led to the emergence of virus variants with reduced sensitivity to some antibody-based therapies. The development of potent antibodies with a broad spectrum of neutralizing activity is urgently needed. Here we isolated a panel of single-domain antibodies that specifically bind to the receptor-binding domain of SARS-CoV-2 S glycoprotein. Three of the selected antibodies exhibiting most robust neutralization potency were used to generate dimeric molecules. We observed that these modifications resulted in up to a 200-fold increase in neutralizing activity. The most potent heterodimeric molecule efficiently neutralized each of SARS-CoV-2 variant of concern, including Alpha, Beta, Gamma and Delta variants. This heterodimeric molecule could be a promising drug candidate for a treatment for COVID-19 caused by virus variants of concern.

scholarly journals Humanized single domain antibodies neutralize SARS-CoV-2 by targeting the spike receptor binding domain

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaojing Chi ◽  
Xiuying Liu ◽  
Conghui Wang ◽  
Xinhui Zhang ◽  
Xiang Li ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Binding Domain ◽  
Single Domain ◽  
Receptor Binding Domain ◽  
Antiviral Therapies ◽  
Single Domain Antibodies ◽  
Equilibrium Dissociation ◽  
Medical Burden

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads worldwide and leads to an unprecedented medical burden and lives lost. Neutralizing antibodies provide efficient blockade for viral infection and are a promising category of biological therapies. Here, using SARS-CoV-2 spike receptor-binding domain (RBD) as a bait, we generate a panel of humanized single domain antibodies (sdAbs) from a synthetic library. These sdAbs reveal binding kinetics with the equilibrium dissociation constant (KD) of 0.99–35.5 nM. The monomeric sdAbs show half maximal neutralization concentration (EC50) of 0.0009–0.07 µg/mL and 0.13–0.51 µg/mL against SARS-CoV-2 pseudotypes, and authentic SARS-CoV-2, respectively. Competitive ligand-binding experiments suggest that the sdAbs either completely block or significantly inhibit the association between SARS-CoV-2 RBD and viral entry receptor ACE2. Fusion of the human IgG1 Fc to sdAbs improve their neutralization activity by up to ten times. These results support neutralizing sdAbs as a potential alternative for antiviral therapies.

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 The self-assembled nanoparticle-based trimeric RBD mRNA vaccine elicits robust and durable protective immunity against SARS-CoV-2 in mice

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wenqiang Sun ◽  
Lihong He ◽  
He Zhang ◽  
Xiaodong Tian ◽  
Zhihua Bai ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Humoral Immunity ◽  
Broad Spectrum ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Cellular Response ◽  
Low Dose ◽  
The Self ◽  
Receptor Binding Domain ◽  
Self Assembled

AbstractAs COVID-19 continues to spread rapidly worldwide and variants continue to emerge, the development and deployment of safe and effective vaccines are urgently needed. Here, we developed an mRNA vaccine based on the trimeric receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein fused to ferritin-formed nanoparticles (TF-RBD). Compared to the trimeric form of the RBD mRNA vaccine (T-RBD), TF-RBD delivered intramuscularly elicited robust and durable humoral immunity as well as a Th1-biased cellular response. After further challenge with live SARS-CoV-2, immunization with a two-shot low-dose regimen of TF-RBD provided adequate protection in hACE2-transduced mice. In addition, the mRNA template of TF-RBD was easily and quickly engineered into a variant vaccine to address SARS-CoV-2 mutations. The TF-RBD multivalent vaccine produced broad-spectrum neutralizing antibodies against Alpha (B.1.1.7) and Beta (B.1.351) variants. This mRNA vaccine based on the encoded self-assembled nanoparticle-based trimer RBD provides a reference for the design of mRNA vaccines targeting SARS-CoV-2.

scholarly journals Fungal Glucosylceramide-Specific Camelid Single Domain Antibodies Are Characterized by Broad Spectrum Antifungal Activity

2017 ◽  
Vol 8 ◽  
Author(s):  
Barbara De Coninck ◽  
Peter Verheesen ◽  
Christine M. Vos ◽  
Inge Van Daele ◽  
Miguel F. De Bolle ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Broad Spectrum ◽  
Single Domain ◽  
Single Domain Antibodies

scholarly journals Fast Restoration of a Broad-Spectrum SARS-Cov Therapeutic Antibody for SARS-Cov-2

2020 ◽  
Author(s):  
Sara Zhang ◽  
Mike Young ◽  
Jason Pan
Keyword(s):  
Broad Spectrum ◽  
Neutralizing Antibodies ◽  
Global Economy ◽  
Therapeutic Antibody ◽  
Receptor Binding Domain ◽  
Promising Candidate ◽  
Rapid Spread ◽  
Antibody Design ◽  
Potential Therapeutics ◽  
Conserved Epitope

<p>The rapid spread of SARS-Cov-2 remains a major threat for public health and global economy, both preventative and therapeutic solutions are therefore urgently needed. Through the use of epitope-guided antibody design, we successfully restored a broad-spectrum SARS-Cov therapeutic antibody for SARS-Cov-2. Compared to the precursor antibody CR3022, the newly designed antibody NOVOAB-20 binds to SARS-Cov-2 receptor binding domain (RBD) with a more than 10-fold higher affinity. Because this antibody targets a highly conserved epitope and the mutations on SARS-Cov-2 known so far are all not in this region, it also has the potential to block future SARS-Cov-2 mutants. As a fully humanized antibody, NOVOAB-20 is a promising candidate to be developed as potential therapeutics for SARS-Cov-2, either as monotherapy or in combination with other neutralizing antibodies targeting different epitopes (e.g. the ACE2 binding site).</p>

Transglutaminase-catalyzed covalent multimerization of camelidae anti-human TNF single domain antibodies improves neutralizing activity

2009 ◽  
Vol 142 (2) ◽  
pp. 170-178 ◽  
Author(s):  
Ingo Plagmann ◽  
Athena Chalaris ◽  
Andrei A. Kruglov ◽  
Sergei Nedospasov ◽  
Philip Rosenstiel ◽  
...  
Keyword(s):  
Single Domain ◽  
Neutralizing Activity ◽  
Single Domain Antibodies

scholarly journals Elicitation of broadly protective sarbecovirus immunity by receptor-binding domain nanoparticle vaccines

2021 ◽  
Author(s):  
Alexandra C Walls ◽  
Marcos C Miranda ◽  
Minh N Pham ◽  
Alexandra Schaefer ◽  
Allison Greaney ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Polyclonal Antibodies ◽  
Clinical Stage ◽  
Binding Domain ◽  
Single Shot ◽  
Receptor Binding Domain ◽  
Negative Consequences ◽  
Neutralizing Activity

Understanding the ability of SARS-CoV-2 vaccine-elicited antibodies to neutralize and protect against emerging variants of concern and other sarbecoviruses is key for guiding vaccine development decisions and public health policies. We show that a clinical stage multivalent SARS-CoV-2 receptor-binding domain nanoparticle vaccine (SARS-CoV-2 RBD-NP) protects mice from SARS-CoV-2-induced disease after a single shot, indicating that the vaccine could allow dose-sparing. SARS-CoV-2 RBD-NP elicits high antibody titers in two non-human primate (NHP) models against multiple distinct RBD antigenic sites known to be recognized by neutralizing antibodies. We benchmarked NHP serum neutralizing activity elicited by RBD-NP against a lead prefusion-stabilized SARS-CoV-2 spike immunogen using a panel of single-residue spike mutants detected in clinical isolates as well as the B.1.1.7 and B.1.351 variants of concern. Polyclonal antibodies elicited by both vaccines are resilient to most RBD mutations tested, but the E484K substitution has similar negative consequences for neutralization, and exhibit modest but comparable neutralization breadth against distantly related sarbecoviruses. We demonstrate that mosaic and cocktail sarbecovirus RBD-NPs elicit broad sarbecovirus neutralizing activity, including against the SARS-CoV-2 B.1.351 variant, and protect mice against severe SARS-CoV challenge even in the absence of the SARS-CoV RBD in the vaccine. This study provides proof of principle that sarbecovirus RBD-NPs induce heterotypic protection and enables advancement of broadly protective sarbecovirus vaccines to the clinic.

scholarly journals A Recombinant Protein SARS-CoV-2 Candidate Vaccine Elicits High-titer Neutralizing Antibodies in Macaques.

2021 ◽  
Author(s):  
Gary Baisa ◽  
David Rancour ◽  
Keith Mansfield ◽  
Monika Burns ◽  
Lori Martin ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Binding Domain ◽  
Pseudotyped Virus ◽  
Receptor Binding Domain ◽  
Binding Assays ◽  
Neutralizing Activity ◽  
Terminal Domain

Abstract BackgroundVaccines that generate robust and long-lived protective immunity against SARS-CoV-2 infection are urgently required. MethodsWe assessed the potential of vaccine candidates based on the SARS-CoV-2 spike in cynomolgus macaques (M. fascicularis) by examining their ability to generate spike binding antibodies with neutralizing activity. Antigens were derived from two distinct regions of the spike S1 subunit, either the N-terminal domain or an extended C-terminal domain containing the receptor-binding domain and were fused to the human IgG1 Fc domain. Three groups of 2 animals each were immunized with either antigen, alone or in combination. The development of antibody responses was evaluated through 20 weeks post-immunization. ResultsA robust IgG response to the spike protein was detected as early as 2 weeks after immunization with either protein and maintained for over 20 weeks. Sera from animals immunized with antigens derived from the RBD were able to prevent binding of soluble spike proteins to the ACE2 receptor, shown by in vitro binding assays, while sera from animals immunized with the N-terminal domain alone lacked this activity. Crucially, sera from animals immunized with the extended receptor binding domain but not the N-terminal domain had potent neutralizing activity against SARS-CoV-2 pseudotyped virus, with titers in excess of 10,000, greatly exceeding that typically found in convalescent humans. Neutralizing activity persisted for more than 20 weeks. ConclusionsThese data support the utility of spike subunit-based antigens as a vaccine for use in humans.

scholarly journals Potent single-domain antibodies that arrest respiratory syncytial virus fusion protein in its prefusion state

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Iebe Rossey ◽  
Morgan S. A. Gilman ◽  
Stephanie C. Kabeche ◽  
Koen Sedeyn ◽  
Daniel Wrapp ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Fusion Protein ◽  
Respiratory Tract Infections ◽  
Antiviral Agents ◽  
Single Domain ◽  
Neutralizing Activity ◽  
Inflammatory Monocytes ◽  
Single Domain Antibodies ◽  
Syncytial Virus ◽  
Tract Infections

Abstract Human respiratory syncytial virus (RSV) is the main cause of lower respiratory tract infections in young children. The RSV fusion protein (F) is highly conserved and is the only viral membrane protein that is essential for infection. The prefusion conformation of RSV F is considered the most relevant target for antiviral strategies because it is the fusion-competent form of the protein and the primary target of neutralizing activity present in human serum. Here, we describe two llama-derived single-domain antibodies (VHHs) that have potent RSV-neutralizing activity and bind selectively to prefusion RSV F with picomolar affinity. Crystal structures of these VHHs in complex with prefusion F show that they recognize a conserved cavity formed by two F protomers. In addition, the VHHs prevent RSV replication and lung infiltration of inflammatory monocytes and T cells in RSV-challenged mice. These prefusion F-specific VHHs represent promising antiviral agents against RSV.

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