scholarly journals MG1141A as a Highly Potent Monoclonal Neutralizing Antibody Against SARS-CoV-2 Variants

2021 ◽  
Vol 12 ◽  
Author(s):  
Sua Lee ◽  
Shina Jang ◽  
Jihoon Kang ◽  
Soo Bin Park ◽  
Young Woo Han ◽  
...  
Keyword(s):  
South Africa ◽  
Monoclonal Antibody ◽  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibody ◽  
Disease Outbreak ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Antibody Therapeutics ◽  
Humanized Monoclonal Antibody ◽  
Mouse Immunization

Since the coronavirus disease outbreak in 2019, several antibody therapeutics have been developed to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Antibody therapeutics are effective in neutralizing the virus and reducing hospitalization in patients with mild and moderate infections. These therapeutics target the spike protein of SARS-CoV-2; however, emerging mutations in this protein reduce their efficiency. In this study, we developed a universal SARS-CoV-2 neutralizing antibody. We generated a humanized monoclonal antibody, MG1141A, against the receptor-binding domain of the spike protein through traditional mouse immunization. We confirmed that MG1141A could effectively neutralize live viruses, with an EC50 of 92 pM, and that it exhibited effective Fc-mediated functions. Additionally, it retained its neutralizing activity against the alpha (UK), beta (South Africa), and gamma (Brazil) variants of SARS-CoV-2. Taken together, our study contributes to the development of a novel antibody therapeutic approach, which can effectively combat emerging SARS-CoV-2 mutations.

Escape of SARS-CoV-2 501Y.V2 variants from neutralization by convalescent plasma

2021 ◽  
Author(s):  
Sandile Cele ◽  
Inbal Gazy ◽  
Laurelle Jackson ◽  
Shi-Hsia Hwa ◽  
Houriiyah Tegally ◽  
...  
Keyword(s):  
South Africa ◽  
Antibody Response ◽  
Genome Sequencing ◽  
Receptor Binding ◽  
Natural Infection ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Whole Genome ◽  
Receptor Binding Domain ◽  
Neutralization Activity

AbstractNew SARS-CoV-2 variants with mutations in the spike glycoprotein have arisen independently at multiple locations and may have functional significance. The combination of mutations in the 501Y.V2 variant first detected in South Africa include the N501Y, K417N, and E484K mutations in the receptor binding domain (RBD) as well as mutations in the N-terminal domain (NTD). Here we address whether the 501Y.V2 variant could escape the neutralizing antibody response elicited by natural infection with earlier variants. We were the first to outgrow two variants of 501Y.V2 from South Africa, designated 501Y.V2.HV001 and 501Y.V2.HVdF002. We examined the neutralizing effect of convalescent plasma collected from six adults hospitalized with COVID-19 using a microneutralization assay with live (authentic) virus. Whole genome sequencing of the infecting virus of the plasma donors confirmed the absence of the spike mutations which characterize 501Y.V2. We infected with 501Y.V2.HV001 and 501Y.V2.HVdF002 and compared plasma neutralization to first wave virus which contained the D614G mutation but no RBD or NTD mutations. We observed that neutralization of the 501Y.V2 variants was strongly attenuated, with IC50 6 to 200-fold higher relative to first wave virus. The degree of attenuation varied between participants and included a knockout of neutralization activity. This observation indicates that 501Y.V2 may escape the neutralizing antibody response elicited by prior natural infection. It raises a concern of potential reduced protection against re-infection and by vaccines designed to target the spike protein of earlier SARS-CoV-2 variants.

scholarly journals Comparative Structural Analyses of Selected Spike Protein-RBD Mutations in SARS-CoV-2 Lineages

2021 ◽  
Author(s):  
Urmi Roy
Keyword(s):  
South Africa ◽  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Point Mutations ◽  
Spike Protein ◽  
Multiple Point ◽  
Receptor Binding Domain ◽  
Virulent Mutant ◽  
The World ◽  
Mutant Strains

The severity of the covid 19 has been observed throughout the world as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had spread globally claiming more than 2 million lives and left a devastating impact on peoples life. Recently several virulent mutant strains of this virus, such as the B.1.1.7, B.1.351, and P1 lineages have emerged. These strains are predominantly observed in UK, South Africa and Brazil. Another extremely pathogenic B.1.617 lineage and its sub-lineages, first detected in India, are now affecting some countries at notably stronger spread-rates. This paper computationally examines the time-based structures of B.1.1.7, B.1.351, P1 lineages with selected spike protein mutations. Additionally, the mutations in the more recently found B.1.617 lineage and some of its sub-lineages are explored, and the implications for multiple point mutations of the spike proteins receptor-binding domain (RBD) are described.

scholarly journals Cross neutralization of emerging SARS-CoV-2 variants of concern by antibodies targeting distinct epitopes on spike

2021 ◽  
Author(s):  
Patrick Wilson ◽  
Siriruk Changrob ◽  
Yanbin Fu ◽  
Jenna Guthmiller ◽  
Peter Halfmann ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Specific Antibody ◽  
Neutralizing Antibodies ◽  
Natural Infection ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Cross Neutralization

Abstract Several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have arisen that exhibit increased viral transmissibility and partial evasion of immunity induced by natural infection and vaccination. To address the specific antibody targets that were affected by recent viral variants, we generated 43 monoclonal antibodies (mAbs) from 10 convalescent donors that bound three distinct domains of the SARS-CoV-2 spike. Viral variants harboring mutations at K417, E484 and N501 could escape most of the highly potent antibodies against the receptor binding domain (RBD). Despite this, we identified 12 neutralizing mAbs against three distinct regions of the spike protein that neutralize SARS-CoV-2 and the variants of concern, including B.1.1.7 (alpha), P.1 (gamma) and B.1.617.2 (delta). Notably, antibodies targeting distinct epitopes could neutralize discrete variants, suggesting different variants may have evolved to disrupt the binding of particular neutralizing antibody classes. These results underscore that humans exposed to wildtype (WT) SARS-CoV-2 do possess neutralizing antibodies against current variants and that it is critical to induce antibodies targeting multiple distinct epitopes of the spike that can neutralize emerging variants of concern.

scholarly journals Structural Basis of a Human Neutralizing Antibody Specific to the SARS-CoV-2 Spike Protein Receptor-Binding Domain

2021 ◽  
Author(s):  
Mei Yang ◽  
Jiaqi Li ◽  
Zhaoxia Huang ◽  
Heng Li ◽  
Yueming Wang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Global Health ◽  
Respiratory Disease ◽  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Spike Protein ◽  
Structural Basis ◽  
Receptor Binding Domain ◽  
Protein Receptor

COVID-19 is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The COVID-19 pandemic has posed a serious threat to global health and the economy, so it is necessary to find safe and effective antibody drugs and treatments.

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

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.

scholarly journals Long-term persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific and neutralizing antibodies in recovered COVID-19 patients

2021 ◽  
Author(s):  
Jira Chansaenroj ◽  
Ritthideach Yorsaeng ◽  
Nasamon Wanlapakorn ◽  
Chintana Chirathaworn ◽  
Natthinee Sudhinaraset ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Symptom Onset ◽  
Neutralizing Antibodies ◽  
Serum Antibody ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Spike Protein ◽  
Immunological Study ◽  
Igg Antibody ◽  
Vaccine Schedule

Abstract Understanding antibody responses after natural severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can guide the coronavirus disease 2019 (COVID-19) vaccine schedule. This study aimed to assess the dynamics of SARS-CoV-2 antibodies, including anti-spike protein 1 (S1) immunoglobulin (Ig)G, anti-receptor-binding domain (RBD) total Ig, anti-S1 IgA, and neutralizing antibody against wild-type SARS-CoV-2 in a cohort of patients who were previously infected with SARS-CoV-2. Between March and May 2020, 531 individuals with virologically confirmed cases of SARS-CoV-2 infection were enrolled in our immunological study. The neutralizing titers against SARS-CoV-2 were detected in 95.2%, 86.7%, 85.0%, and 85.4% of recovered COVID-19 patients at 3, 6, 9, and 12 months after symptom onset, respectively. The seropositivity rate of anti-S1 IgG, anti-RBD total Ig, anti-S1 IgA, and neutralizing titers remained at 68.6%, 89.6%, 77.1%, and 85.4%, respectively, at 12 months after symptom onset. The half-life of neutralizing titers was estimated at 100.7 days (95% confidence interval = 44.5 – 327.4 days, R2 = 0.106). These results support that the decline in serum antibody levels over time depends on the symptom severity, and the individuals with high IgG antibody titers experienced a significantly longer persistence of SARS-CoV-2-specific antibody responses than those with lower titers.

scholarly journals Structure of Severe Acute Respiratory Syndrome Coronavirus Receptor-binding Domain Complexed with Neutralizing Antibody

2006 ◽  
Vol 281 (23) ◽  
pp. 15829-15836 ◽  
Author(s):  
Ponraj Prabakaran ◽  
Jianhua Gan ◽  
Yang Feng ◽  
Zhongyu Zhu ◽  
Vidita Choudhry ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Receptor Binding Domain

scholarly journals Combining a Fusion Inhibitory Peptide Targeting the MERS-CoV S2 Protein HR1 Domain and a Neutralizing Antibody Specific for the S1 Protein Receptor-Binding Domain (RBD) Showed Potent Synergism against Pseudotyped MERS-CoV with or without Mutations in RBD

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 31 ◽  
Author(s):  
Cong Wang ◽  
Chen Hua ◽  
Shuai Xia ◽  
Weihua Li ◽  
Lu Lu ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Inhibitory Peptide ◽  
Protein Receptor ◽  
Neutralizing Monoclonal Antibody ◽  
Peptide Targeting ◽  
Combinatorial Strategy

Middle East respiratory syndrome coronavirus (MERS-CoV) has continuously posed a threat to public health worldwide, yet no therapeutics or vaccines are currently available to prevent or treat MERS-CoV infection. We previously identified a fusion inhibitory peptide (HR2P-M2) targeting the MERS-CoV S2 protein HR1 domain and a highly potent neutralizing monoclonal antibody (m336) specific to the S1 spike protein receptor-binding domain (RBD). However, m336 was found to have reduced efficacy against MERS-CoV strains with mutations in RBD, and HR2P-M2 showed low potency, thus limiting the clinical application of each when administered separately. However, we herein report that the combination of m336 and HR2P-M2 exhibited potent synergism in inhibiting MERS-CoV S protein-mediated cell–cell fusion and infection by MERS-CoV pseudoviruses with or without mutations in the RBD, resulting in the enhancement of antiviral activity in contrast to either one administered alone. Thus, this combinatorial strategy could be used in clinics for the urgent treatment of MERS-CoV-infected patients.

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