scholarly journals SARS-CoV-2 RBD in vitro evolution parrots and predicts contagious mutation spread

2021 ◽  
Author(s):  
Gideon Schreiber ◽  
Jiri Zahradník ◽  
Shir Marciano ◽  
Maya Shemesh ◽  
Eyal Zoler ◽  
...  
Keyword(s):  
South African ◽  
Convergent Evolution ◽  
Vaccine Development ◽  
Spike Protein ◽  
Structural Basis ◽  
Receptor Binding Domain ◽  
In Vitro Evolution ◽  
High Affinity ◽  
Future Drug

Abstract SARS-CoV-2 is continually evolving, with more contagious mutations spreading rapidly. Using in vitro evolution to affinity maturate the receptor-binding domain (RBD) of the spike protein towards ACE2 resulted in the more contagious mutations, S477N, E484K, and N501Y, to be among the first selected, explaining the convergent evolution of the “European” (20E-EU1), “British” (501.V1),”South African” (501.V2), and Brazilian variants (501.V3). Plotting the binding affinity to ACE2 of all RBD mutations against their incidence in the population shows a strong correlation between the two. Further in vitro evolution enhancing binding by 600-fold provides guidelines towards potentially new evolving mutations with even higher infectivity. For example, Q498R epistatic to N501Y. Nevertheless, the high-affinity RBD is also an efficient drug, inhibiting SARS-CoV-2 infection. The 2.9Å Cryo-EM structure of the high-affinity complex, including all rapidly spreading mutations, provides a structural basis for future drug and vaccine development and for in silico evaluation of known antibodies.

scholarly journals SARS-CoV-2 RBD in vitro evolution follows contagious mutation spread, yet generates an able infection inhibitor

2021 ◽  
Author(s):  
Jiri Zahradnik ◽  
Shir Marciano ◽  
Maya Shemesh ◽  
Eyal Zoler ◽  
Jeanne Chiaravalli ◽  
...  
Keyword(s):  
South African ◽  
Receptor Binding ◽  
Vaccine Development ◽  
Spike Protein ◽  
Structural Basis ◽  
Receptor Binding Domain ◽  
In Vitro Evolution ◽  
High Affinity ◽  
Future Drug

SARS-CoV-2 is constantly evolving, with more contagious mutations spreading rapidly. Using in vitro evolution to affinity maturate the receptor-binding domain (RBD) of the spike protein towards ACE2, resulted in the more contagious mutations, S477N, E484K, and N501Y to be among the first selected. This includes the British and South African variants. Plotting the binding affinity to ACE2 of all RBD mutations against their incidence in the population shows a strong correlation between the two. Further in vitro evolution enhancing binding by 600-fold provides guidelines towards potentially new evolving mutations with even higher infectivity. For example, Q498R in combination with N501Y. This said, the high-affinity RBD is also an efficient drug, inhibiting SARS-CoV-2 infection. The 2.9A Cryo-EM structure of the high-affinity complex, including all rapidly spreading mutations provides structural basis for future drug and vaccine development and for in silico evaluation of known antibodies.

scholarly journals Antibodies that potently inhibit or enhance SARS-CoV-2 spike protein-ACE2 interaction isolated from synthetic single-chain antibody libraries

2020 ◽  
Author(s):  
Matthew D. Beasley ◽  
Sanja Aracic ◽  
Fiona M. Gracey ◽  
Ruban Kannan ◽  
Avisa Masarati ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Single Chain ◽  
Single Chain Antibody ◽  
High Affinity ◽  
Scfv Library ◽  
Antibody Libraries ◽  
Prophylactic Use

AbstractAntibodies with high affinity against the receptor binding domain (RBD) of the SARS-CoV-2 S1 ectodomain were identified from screens using the Retained Display™ (ReD) platform employing a 1 × 1011 clone single-chain antibody (scFv) library. Numerous unique scFv clones capable of inhibiting binding of the viral S1 ectodomain to the ACE2 receptor in vitro were characterized. To maximize avidity, selected clones were reformatted as bivalent diabodies and monoclonal antibodies (mAb). The highest affinity mAb completely neutralized live SARS-CoV-2 virus in cell culture for four days at a concentration of 6.7 nM, suggesting potential therapeutic and/or prophylactic use. Furthermore, scFvs were identified that greatly increased the interaction of the viral S1 trimer with the ACE2 receptor, with potential implications for vaccine development.

scholarly journals Stereotypic neutralizing VH antibodies against SARS-CoV-2 spike protein receptor binding domain in COVID-19 patients and healthy individuals

2021 ◽  
pp. eabd6990
Author(s):  
Sang Il Kim ◽  
Jinsung Noh ◽  
Sujeong Kim ◽  
Younggeun Choi ◽  
Duck Kyun Yoo ◽  
...  
Keyword(s):  
B Cells ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
De Novo ◽  
Binding Domain ◽  
Host Cells ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Healthy Individuals

Stereotypic antibody clonotypes exist in healthy individuals and may provide protective immunity against viral infections by neutralization. We observed that 13 out of 17 patients with COVID-19 had stereotypic variable heavy chain (VH) antibody clonotypes directed against the receptor-binding domain (RBD) of SARS-CoV-2 spike protein. These antibody clonotypes were comprised of immunoglobulin heavy variable (IGHV)3-53 or IGHV3-66 and immunoglobulin heavy joining (IGHJ)6 genes. These clonotypes included IgM, IgG3, IgG1, IgA1, IgG2, and IgA2 subtypes and had minimal somatic mutations, which suggested swift class switching after SARS-CoV-2 infection. The different immunoglobulin heavy variable chains were paired with diverse light chains resulting in binding to the RBD of SARS-CoV-2 spike protein. Human antibodies specific for the RBD can neutralize SARS-CoV-2 by inhibiting entry into host cells. We observed that one of these stereotypic neutralizing antibodies could inhibit viral replication in vitro using a clinical isolate of SARS-CoV-2. We also found that these VH clonotypes existed in six out of 10 healthy individuals, with IgM isotypes predominating. These findings suggest that stereotypic clonotypes can develop de novo from naïve B cells and not from memory B cells established from prior exposure to similar viruses. The expeditious and stereotypic expansion of these clonotypes may have occurred in patients infected with SARS-CoV-2 because they were already present.

In Vitro Evolution of Functional Nucleic Acids: High-Affinity RNA Ligands of the HIV-1 rev Protein

1994 ◽  
pp. 233-243 ◽  
Author(s):  
Craig Tuerk ◽  
Sheela MacDougal-Waugh ◽  
Gerald Z. Hertz ◽  
Larry Gold
Keyword(s):  
Nucleic Acids ◽  
In Vitro Evolution ◽  
High Affinity ◽  
Rna Ligands ◽  
Functional Nucleic Acids ◽  
Hiv 1 ◽  
Rev Protein

scholarly journals Spike Protein Targeting "Nano-Glue" that Captures and Promotes SARS-CoV-2 Elimination

2021 ◽  
Author(s):  
Guofang Zhang ◽  
Yalin Cong ◽  
Guoli Cao ◽  
Liang Li ◽  
Peng Yu ◽  
...  
Keyword(s):  
Protein Targeting ◽  
Binding Capacity ◽  
Spike Protein ◽  
Therapeutic Drug ◽  
Receptor Binding Domain ◽  
Airway Epithelial ◽  
Β Sheet ◽  
Toxicity In Vitro

The global emergency caused by the SARS-CoV-2 pandemics can only be solved with adequate preventive and therapeutic strategies, both currently missing. The electropositive Receptor Binding Domain (RBD) of SARS-CoV-2 spike protein with abundant β-sheet structure serves as target for COVID-19 therapeutic drug design. Here, we discovered that ultrathin 2D CuInP2S6 (CIPS) nanosheets as a new agent against SARS-CoV-2 infection, which also able to promote viral host elimination. CIPS exhibits extremely high and selective binding capacity with the RBD of SARS-CoV-2 spike protein, with consequent inhibition of virus entry and infection in ACE2-bearing cells and human airway epithelial organoids. CIPS displays nano-viscous properties in selectively binding with spike protein (KD < 1 pM) with negligible toxicity in vitro and in vivo. Further, the CIPS-bound SARS-CoV-2 was quickly phagocytosed and eliminated by macrophages, suggesting CIPS could be successfully used to capture and facilitate the virus host elimination with possibility of triggering anti-viral immunization. Thus, we propose CIPS as a promising nanodrug for future safe and effective anti-SARS-CoV-2 therapy, as well as for use as disinfection agent and surface coating material to constrain the SARS-CoV-2 spreading.

scholarly journals VLP-Based COVID-19 Vaccines: An Adaptable Technology against the Threat of New Variants

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1409
Author(s):  
Wasim A. Prates-Syed ◽  
Lorena C. S. Chaves ◽  
Karin P. Crema ◽  
Larissa Vuitika ◽  
Aline Lira ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immune Evasion ◽  
Convergent Evolution ◽  
Vaccine Development ◽  
Receptor Binding Domain ◽  
Vaccine Platform ◽  
Cellular Immune Responses ◽  
Alpha Beta ◽  
Cellular Immune ◽  
Financial Losses

Virus-like particles (VLPs) are a versatile, safe, and highly immunogenic vaccine platform. Recently, there are developmental vaccines targeting SARS-CoV-2, the causative agent of COVID-19. The COVID-19 pandemic affected humanity worldwide, bringing out incomputable human and financial losses. The race for better, more efficacious vaccines is happening almost simultaneously as the virus increasingly produces variants of concern (VOCs). The VOCs Alpha, Beta, Gamma, and Delta share common mutations mainly in the spike receptor-binding domain (RBD), demonstrating convergent evolution, associated with increased transmissibility and immune evasion. Thus, the identification and understanding of these mutations is crucial for the production of new, optimized vaccines. The use of a very flexible vaccine platform in COVID-19 vaccine development is an important feature that cannot be ignored. Incorporating the spike protein and its variations into VLP vaccines is a desirable strategy as the morphology and size of VLPs allows for better presentation of several different antigens. Furthermore, VLPs elicit robust humoral and cellular immune responses, which are safe, and have been studied not only against SARS-CoV-2 but against other coronaviruses as well. Here, we describe the recent advances and improvements in vaccine development using VLP technology.

scholarly journals Structural Basis for Specific, High-Affinity Tetracycline Binding by an In Vitro Evolved Aptamer and Artificial Riboswitch

2008 ◽  
Vol 15 (10) ◽  
pp. 1125-1137 ◽  
Author(s):  
Hong Xiao ◽  
Thomas E. Edwards ◽  
Adrian R. Ferré-D'Amaré
Keyword(s):  
Structural Basis ◽  
High Affinity

scholarly journals High affinity nanobodies block SARS-CoV-2 spike receptor binding domain interaction with human angiotensin converting enzyme

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Thomas J. Esparza ◽  
Negin P. Martin ◽  
George P. Anderson ◽  
Ellen R. Goldman ◽  
David L. Brody
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Receptor Binding ◽  
Binding Domain ◽  
Spike Protein ◽  
Hek293 Cells ◽  
Scale Production ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
High Affinity ◽  
Diagnostic Potential

AbstractThere are currently few approved effective treatments for SARS-CoV-2, the virus responsible for the COVID-19 pandemic. Nanobodies are 12–15 kDa single-domain antibody fragments that can be delivered by inhalation and are amenable to relatively inexpensive large scale production compared to other biologicals. We have isolated nanobodies that bind to the SARS-CoV-2 spike protein receptor binding domain and block spike protein interaction with the angiotensin converting enzyme 2 (ACE2) with 1–5 nM affinity. The lead nanobody candidate, NIH-CoVnb-112, blocks SARS-CoV-2 spike pseudotyped lentivirus infection of HEK293 cells expressing human ACE2 with an EC50 of 0.3 µg/mL. NIH-CoVnb-112 retains structural integrity and potency after nebulization. Furthermore, NIH-CoVnb-112 blocks interaction between ACE2 and several high affinity variant forms of the spike protein. These nanobodies and their derivatives have therapeutic, preventative, and diagnostic potential.

scholarly journals Identification of Common Deletions in the Spike Protein of Severe Acute Respiratory Syndrome Coronavirus 2

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Zhe Liu ◽  
Huanying Zheng ◽  
Huifang Lin ◽  
Mingyue Li ◽  
Runyu Yuan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Virus Replication ◽  
Receptor Binding ◽  
Cleavage Site ◽  
Spike Protein ◽  
Clinical Samples ◽  
Receptor Binding Domain ◽  
Flanking Sequence

ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus first identified in December 2019. Notable features that make SARS-CoV-2 distinct from most other previously identified betacoronaviruses include a receptor binding domain and a unique insertion of 12 nucleotides or 4 amino acids (PRRA) at the S1/S2 boundary. In this study, we identified two deletion variants of SARS-CoV-2 that either directly affect the polybasic cleavage site itself (NSPRRAR) or a flanking sequence (QTQTN). These deletions were verified by multiple sequencing methods. In vitro results showed that the deletion of NSPRRAR likely does not affect virus replication in Vero and Vero-E6 cells; however, the deletion of QTQTN may restrict late-phase viral replication. The deletion of QTQTN was detected in 3 of 68 clinical samples and 12 of 24 in vitro-isolated viruses, while the deletion of NSPRRAR was identified in 3 in vitro-isolated viruses. Our data indicate that (i) there may be distinct selection pressures on SARS-CoV-2 replication or infection in vitro and in vivo; (ii) an efficient mechanism for deleting this region from the viral genome may exist, given that the deletion variant is commonly detected after two rounds of cell passage; and (iii) the PRRA insertion, which is unique to SARS-CoV-2, is not fixed during virus replication in vitro. These findings provide information to aid further investigation of SARS-CoV-2 infection mechanisms and a better understanding of the NSPRRAR deletion variant observed here. IMPORTANCE The spike protein determines the infectivity and host range of coronaviruses. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has two unique features in its spike protein, the receptor binding domain and an insertion of 12 nucleotides at the S1/S2 boundary resulting in a furin-like cleavage site. Here, we identified two deletion variants of SARS-CoV-2 that either directly affect the furin-like cleavage site itself (NSPRRAR) or a flanking sequence (QTQTN), and we investigated these deletions in cell isolates and clinical samples. The absence of the polybasic cleavage site in SARS-CoV-2 did not affect virus replication in Vero or Vero-E6 cells. Our data indicate the PRRAR sequence and the flanking QTQTN sequence are not fixed in vitro; thus, there appears to be distinct selection pressures on SARS-CoV-2 sequences in vitro and in vivo. Further investigation of the mechanism of generating these deletion variants and their infectivity in different animal models would improve our understanding of the origin and evolution of this virus.

scholarly journals Nanobody Repertoires for Exposing Vulnerabilities of SARS-CoV-2

2021 ◽  
Author(s):  
Fred D Mast ◽  
Peter C Fridy ◽  
Natalia E Ketaren ◽  
Junjie Wang ◽  
Erica Y Jacobs ◽  
...  
Keyword(s):  
Airway Epithelial Cells ◽  
Spike Protein ◽  
Great Promise ◽  
Antigen Binding ◽  
Receptor Binding Domain ◽  
Airway Epithelial ◽  
Viral Neutralization ◽  
High Affinity ◽  
Naturally Occurring ◽  
Large Repertoire

Despite the great promise of vaccines, the COVID-19 pandemic is ongoing and future serious outbreaks are highly likely, so that multi-pronged containment strategies will be required for many years. Nanobodies are the smallest naturally occurring single domain antigen binding proteins identified to date, possessing numerous properties advantageous to their production and use. We present a large repertoire of high affinity nanobodies against SARS-CoV-2 Spike protein with excellent kinetic and viral neutralization properties, which can be strongly enhanced with oligomerization. This repertoire samples the epitope landscape of the Spike ectodomain inside and outside the receptor binding domain, recognizing a multitude of distinct epitopes and revealing multiple neutralization targets of pseudoviruses and authentic SARS-CoV-2, including in primary human airway epithelial cells. Combinatorial nanobody mixtures show highly synergistic activities, and are resistant to mutational escape and emerging viral variants of concern. These nanobodies establish an exceptional resource for superior COVID-19 prophylactics and therapeutics.

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