scholarly journals SARS-CoV-2 neutralizing human recombinant antibodies selected from pre-pandemic healthy donors binding at RBD-ACE2 interface

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Federico Bertoglio ◽  
Doris Meier ◽  
Nora Langreder ◽  
Stephan Steinke ◽  
Ulfert Rand ◽  
...  
Keyword(s):  
Recombinant Antibodies ◽  
Cell Entry ◽  
Receptor Binding Domain ◽  
Acute Respiratory Disease ◽  
Healthy Human ◽  
Human Antibodies ◽  
Healthy Donors ◽  
Gene Libraries ◽  
Antibody Gene ◽  
Subsequent Identification

AbstractCOVID-19 is a severe acute respiratory disease caused by SARS-CoV-2, a new recently emerged sarbecovirus. This virus uses the human ACE2 enzyme as receptor for cell entry, recognizing it with the receptor binding domain (RBD) of the S1 subunit of the viral spike protein. We present the use of phage display to select anti-SARS-CoV-2 spike antibodies from the human naïve antibody gene libraries HAL9/10 and subsequent identification of 309 unique fully human antibodies against S1. 17 antibodies are binding to the RBD, showing inhibition of spike binding to cells expressing ACE2 as scFv-Fc and neutralize active SARS-CoV-2 virus infection of VeroE6 cells. The antibody STE73-2E9 is showing neutralization of active SARS-CoV-2 as IgG and is binding to the ACE2-RBD interface. Thus, universal libraries from healthy human donors offer the advantage that antibodies can be generated quickly and independent from the availability of material from recovering patients in a pandemic situation.

scholarly journals SARS-CoV-2 neutralizing human recombinant antibodies selected from pre-pandemic healthy donors binding at RBD-ACE2 interface

2020 ◽  
Author(s):  
Federico Bertoglio ◽  
Doris Meier ◽  
Nora Langreder ◽  
Stephan Steinke ◽  
Ulfert Rand ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Cell Entry ◽  
Molar Ratio ◽  
Viral Fusion ◽  
Host Cell Membrane ◽  
Healthy Human ◽  
Healthy Donors ◽  
Similar Strategy ◽  
Gene Libraries ◽  
Antibody Gene

AbstractCOVID-19 is a severe acute respiratory disease caused by SARS-CoV-2, a novel betacoronavirus discovered in December 2019 and closely related to the SARS coronavirus (CoV). Both viruses use the human ACE2 receptor for cell entry, recognizing it with the Receptor Binding Domain (RBD) of the S1 subunit of the viral spike (S) protein. The S2 domain mediates viral fusion with the host cell membrane. Experience with SARS and MERS coronaviruses has shown that potent monoclonal neutralizing antibodies against the RBD can inhibit the interaction with the virus cellular receptor (ACE2 for SARS) and block the virus cell entry. Assuming that a similar strategy would be successful against SARS-CoV-2, we used phage display to select from the human naïve universal antibody gene libraries HAL9/10 anti-SARS-CoV-2 spike antibodies capable of inhibiting interaction with ACE2. 309 unique fully human antibodies against S1 were identified. 17 showed more than 75% inhibition of spike binding to cells expressing ACE2 in the scFv-Fc format, assessed by flow cytometry and several antibodies showed even an 50% inhibition at a molar ratio of the antibody to spike protein or RBD of 1:1. All 17 scFv-Fc were able to bind the isolated RBD, four of them with sub-nanomolar EC50. Furthermore, these scFv-Fc neutralized active SARS-CoV-2 virus infection of VeroE6 cells. In a final step, the antibodies neutralizing best as scFv-Fc were converted into the IgG format. The antibody STE73-2E9 showed neutralization of active SARS-CoV-2 with an IC50 0.43 nM and is binding to the ACE2-RBD interface. Universal libraries from healthy human donors offer the advantage that antibodies can be generated quickly and independent from the availability of material from recovered patients in a pandemic situation.

scholarly journals Stereotypic Neutralizing VH Clonotypes Against SARS-CoV-2 RBD in COVID-19 Patients and the Healthy Population

2020 ◽  
Author(s):  
Sang Il Kim ◽  
Jinsung Noh ◽  
Sujeong Kim ◽  
Younggeun Choi ◽  
Duck Kyun Yoo ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Host Cell ◽  
Receptor Binding ◽  
Cell Entry ◽  
Light Chains ◽  
Healthy Population ◽  
Receptor Binding Domain ◽  
Healthy Individuals ◽  
Human Antibodies ◽  
Host Cell Entry

AbstractIn six of seven severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients, VH clonotypes, encoded by either immunoglobin heavy variable (IGHV)3-53 or IGHV3-66 and immunoglobin heavy joining (IGHJ)6, were identified in IgG1, IgA1, and IgA2 subtypes, with minimal mutations, and could be paired with diverse light chains, resulting in binding to the SARS-CoV-2 receptor-binding domain (RBD). Because most human antibodies against the RBD neutralized the virus by inhibiting host cell entry, we selected one of these clonotypes and demonstrated that it could potently inhibit viral replication. Interestingly, these VH clonotypes pre-existed in six of 10 healthy individuals, predominantly as IgM isotypes, which could explain the expeditious and stereotypic development of these clonotypes among SARS-CoV-2 patients.

Selection of Recombinant Antibodies from Antibody Gene Libraries

2013 ◽  
pp. 305-320 ◽  
Author(s):  
Michael Hust ◽  
André Frenzel ◽  
Thomas Schirrmann ◽  
Stefan Dübel
Keyword(s):  
Recombinant Antibodies ◽  
Gene Libraries ◽  
Antibody Gene ◽  
Selection Of

Cross-neutralization antibodies against SARS-CoV-2 and RBD mutations from convalescent patient antibody libraries

2020 ◽  
Author(s):  
Yan Lou ◽  
Wenxiang Zhao ◽  
Haitao Wei ◽  
Min Chu ◽  
Ruihua Chao ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Viral Infections ◽  
Therapeutic Agents ◽  
Therapeutic Interventions ◽  
Receptor Binding Domain ◽  
Angiotensin Converting Enzyme 2 ◽  
Human Antibodies ◽  
Global Pandemic ◽  
Antibody Libraries ◽  
Cross Neutralization

AbstractThe emergence of coronavirus disease 2019 (COVID-19) pandemic led to an urgent need to develop therapeutic interventions. Among them, neutralizing antibodies play crucial roles for preventing viral infections and contribute to resolution of infection. Here, we describe the generation of antibody libraries from 17 different COVID-19 recovered patients and screening of neutralizing antibodies to SARS-CoV-2. After 3 rounds of panning, 456 positive phage clones were obtained with high affinity to RBD (receptor binding domain). Then the positive clones were sequenced and reconstituted into whole human IgG for epitope binning assays. After that, all 19 IgG were classified into 6 different epitope groups or Bins. Although all these antibodies were shown to have ability to bind RBD, the antibodies in Bin2 have more superiority to inhibit the interaction between spike protein and angiotensin converting enzyme 2 receptor (ACE2). Most importantly, the antibodies from Bin2 can also strongly bind with mutant RBDs (W463R, R408I, N354D, V367F and N354D/D364Y) derived from SARS-CoV-2 strain with increased infectivity, suggesting the great potential of these antibodies in preventing infection of SARS-CoV-2 and its mutations. Furthermore, these neutralizing antibodies strongly restrict the binding of RBD to hACE2 overexpressed 293T cells. Consistently, these antibodies effectively neutralized pseudovirus entry into hACE2 overexpressed 293T cells. In Vero-E6 cells, these antibodies can even block the entry of live SARS-CoV-2 into cells at only 12.5 nM. These results suggest that these neutralizing human antibodies from the patient-derived antibody libraries have the potential to become therapeutic agents against SARS-CoV-2 and its mutants in this global pandemic.

scholarly journals The ancient fusogen EnvP(b)1 is expressed in human tissues and its structure informs the evolution of gammaretrovirus envelope proteins

2020 ◽  
Author(s):  
Kevin R. McCarthy ◽  
Joseph L. Timpona ◽  
Simon Jenni ◽  
Vesna Brusic ◽  
Welkin E. Johnson ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Transcriptional Control ◽  
Purifying Selection ◽  
Binding Domain ◽  
Endogenous Retroviruses ◽  
Envelope Gene ◽  
Human Tissues ◽  
Receptor Binding Domain ◽  
Functional Protein ◽  
Healthy Human

ABSTRACTHost genomes have acquired diversity from viruses through the capture of viral elements, often from endogenous retroviruses (ERVs). These viral elements contribute new transcriptional control elements and new protein encoding genes, and their refinement through evolution can generate novel physiological functions for the host. EnvP(b)1 is an endogenous retroviral envelope gene found in human and other primate genomes. We show that EnvP(b)1 arose very early in the evolution of primates, i.e. at least 40-47 million years ago, but has nevertheless retained its ability to fuse primate cells. We have detected similar sequences in the genome of a lemur species, suggesting that a progenitor virus may have circulated 55+ million years ago. We demonstrate that EnvP(b)1 protein is expressed in multiple human tissues and is fully processed, rendering it competent to fuse cells. This activated fusogen is expressed in multiple healthy human tissues and is under purifying selection, suggesting that its expression is selectively advantageous. We determined a structure of the inferred receptor binding domain of human EnvP(b)1, revealing close structural similarities between this Env protein and those of currently circulating leukemia viruses, despite poor sequence conservation. This observation highlights a common scaffold from which novel receptor binding specificities have evolved. The evolutionary plasticity of this domain may underlie the diversity of related Envs in circulating viruses and coopted elements alike. The function of EnvP(b)1 in primates remains unknown.SIGNIFICANCE STATEMENTOrganisms can access genetic and functional novelty by capturing viral elements within their genomes, where they can evolve to drive new cellular or organismal processes. We demonstrate that a retrovirus envelope gene, EnvP(b)1, has been maintained as a functional protein for 40 to ≥55 million years and is expressed as a protein in multiple healthy human tissues. We believe it has an unknown function in primates. We determined the structure of its inferred receptor binding domain and compared it with the same domain in modern viruses. We find a common conserved architecture that underlies the varied receptor binding activity of divergent Env genes. The modularity and versatility of this domain may underpin the evolutionary success of this clade of fusogens.

scholarly journals ACE2-like carboxypeptidase B38-CAP protects from SARS-CoV-2-induced lung injury

2020 ◽  
Author(s):  
Takafumi Minato ◽  
Midori Hoshizaki ◽  
Tomokazu Yamaguchi ◽  
Jianbo An ◽  
Mayumi Niiyama ◽  
...  
Keyword(s):  
Lung Injury ◽  
Enzymatic Activity ◽  
Therapeutic Strategy ◽  
Cell Entry ◽  
Mrna Levels ◽  
Receptor Binding Domain ◽  
Ang Ii ◽  
Cytokine Mrna ◽  
Angiotensin Converting Enzyme 2

Abstract Angiotensin-converting enzyme 2 (ACE2) is a receptor for cell entry of SARS-CoV-2, and recombinant soluble ACE2 protein inhibits SARS-CoV-2 infection as a decoy. ACE2 is the carboxypeptidase to degrade angiotensin II (Ang II) to angiotensin 1-7 and improves the pathologies of cardiovascular disease and acute lung injury. To address whether the carboxypeptidase enzymatic activity of ACE2 is protective against COVID-19, we investigated the effects of B38-CAP, an ACE2-like enzyme, on SARS-CoV-2-induced lung injury. Expression of ACE2 protein was significantly downregulated in the lungs of SARS-CoV-2-infected hamsters. Recombinant S1 domain or receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein also directly downregulated ACE2 expression and elevated Ang II levels and considerably worsened acid-induced lung injury in hamsters. Treatment with B38-CAP downregulated Spike RBD-induced high Ang II levels, severe inflammation and pulmonary edema through its ACE2-like enzymatic activity. Consistently, elevated cytokine mRNA levels and impaired lung functions were improved by B38-CAP treatment. Moreover, in SARS-CoV-2-infected humanized ACE2 transgenic mice, B38-CAP significantly improved the pathologies of lung injury, alleviated the cytokine storms and downregulated viral RNA levels. These results provide the first experimental in vivo evidence that increasing ACE2-like enzymatic activity is a potential and powerful therapeutic strategy for lung pathologies in COVID-19.

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