scholarly journals Potent neutralization of 2019 novel coronavirus by recombinant ACE2-Ig

2020 ◽  
Author(s):  
Changhai Lei ◽  
Wenyan Fu ◽  
Kewen Qian ◽  
Tian Li ◽  
Sheng Zhang ◽  
...  
Keyword(s):  
Fusion Proteins ◽  
Antiviral Treatment ◽  
Cross Reactivity ◽  
Cell Entry ◽  
Receptor Binding Domain ◽  
Potential Applications ◽  
Novel Coronavirus ◽  
Entry Receptor ◽  
Potent Neutralization

Abstract2019-nCoV, which is a novel coronavirus emerged in Wuhan, China, at the end of 2019, has caused at least infected 11,844 as of Feb 1, 2020. However, there is no specific antiviral treatment or vaccine currently. Very recently report had suggested that novel CoV would use the same cell entry receptor, ACE2, as the SARS-CoV. In this report, we generated a novel recombinant protein by connecting the extracellular domain of human ACE2 to the Fc region of the human immunoglobulin IgG1. An ACE2 mutant with low catalytic activity was also used in the study. The fusion proteins were then characterized. Both fusion proteins has high affinity binding to the receptor-binding domain (RBD) of SARS-CoV and 2019-nCoV and exerted desired pharmacological properties. Moreover, fusion proteins potently neutralized SARS-CoV and 2019-nCoV in vitro. As these fusion proteins exhibit cross-reactivity against coronaviruses, they could have potential applications for diagnosis, prophylaxis, and treatment of 2019-nCoV.

Synthetic and semi-synthetic drugs as promising therapeutic option for the treatment of COVID-19

2020 ◽  
Vol 20 ◽  
Author(s):  
Ekta Shirbhate ◽  
Preeti Patel ◽  
Vijay K Patel ◽  
Ravichandran Veerasamy ◽  
Prabodh C Sharma ◽  
...  
Keyword(s):  
Therapeutic Option ◽  
Antiviral Treatment ◽  
The Novel ◽  
Clinical Experiences ◽  
Synthetic Compounds ◽  
Synthetic Drugs ◽  
Global Pandemic ◽  
The World ◽  
Novel Coronavirus

: The novel coronavirus disease-19 (COVID-19), a global pandemic that emerged from Wuhan, China has today travelled all around the world, so far 216 countries or territories with 21,732,472 people infected and 770,866 deaths globally (as per WHO COVID-19 update dated August 18, 2020). Continuous efforts are being made to repurpose the existing drugs and develop vaccines for combating this infection. Despite, to date, no certified antiviral treatment or vaccine prevails. Although, few candidates have displayed their efficacy in in vitro studies and are being repurposed for COVID-19 treatment. This article summarizes synthetic and semi-synthetic compounds displaying potent activity in their clinical experiences or studies against COVID-19 and also focuses on mode of action of drugs being repositioned against COVID-19.

scholarly journals Potent Neutralizing Antibodies Directed to Multiple Epitopes on SARS-CoV-2 Spike

2020 ◽  
Author(s):  
Lihong Liu ◽  
Pengfei Wang ◽  
Manoj S. Nair ◽  
Jian Yu ◽  
Micah Rapp ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neutralizing Antibodies ◽  
Global Economy ◽  
Epitope Mapping ◽  
Severe Disease ◽  
Clinical Development ◽  
Receptor Binding Domain ◽  
Cryo Electron Microscopy ◽  
Novel Coronavirus

AbstractThe SARS-CoV-2 pandemic rages on with devasting consequences on human lives and the global economy1,2. The discovery and development of virus-neutralizing monoclonal antibodies could be one approach to treat or prevent infection by this novel coronavirus. Here we report the isolation of 61 SARS-CoV-2-neutralizing monoclonal antibodies from 5 infected patients hospitalized with severe disease. Among these are 19 antibodies that potently neutralized the authentic SARS-CoV-2 in vitro, 9 of which exhibited exquisite potency, with 50% virus-inhibitory concentrations of 0.7 to 9 ng/mL. Epitope mapping showed this collection of 19 antibodies to be about equally divided between those directed to the receptor-binding domain (RBD) and those to the N-terminal domain (NTD), indicating that both of these regions at the top of the viral spike are immunogenic. In addition, two other powerful neutralizing antibodies recognized quaternary epitopes that are overlapping with the domains at the top of the spike. Cryo-electron microscopy reconstructions of one antibody targeting RBD, a second targeting NTD, and a third bridging two separate RBDs revealed recognition of the closed, “all RBD-down” conformation of the spike. Several of these monoclonal antibodies are promising candidates for clinical development as potential therapeutic and/or prophylactic agents against SARS-CoV-2.

scholarly journals Pharmacophore-based peptide biologics neutralize SARS-CoV-2 S1 and deter S1-ACE2 interaction in vitro

2020 ◽  
Author(s):  
Masaud Shah ◽  
Sung Ung Moon ◽  
Hyun Goo Woo
Keyword(s):  
Cell Attachment ◽  
Immune Surveillance ◽  
Cell Entry ◽  
Viral Fusion ◽  
Receptor Binding Domain ◽  
Spontaneous Movement ◽  
Viral Receptor ◽  
Dose Dependent ◽  
Host Immune Surveillance

AbstractEffective therapeutics and stable vaccine are the urgent need of the day to combat COVID-19 pandemic. SARS-CoV-2 spike protein has a pivotal role in cell-entry and host immune response, thus regarded as potential drug- and vaccine-target. As the virus utilizes the S1 domain of spike to initiate cell-attachment and S2 domain for membrane fusion, several attempts have been made to design viral-receptor and viral-fusion blockers. Here, by deploying interactive structure-based design and pharmacophore-based approaches, we designed short and stable peptide-biologics i.e. CoV-spike-neutralizing peptides (CSNPs) including CSNP1, CSNP2, CSNP3, CSNP4. We could demonstrate in cell culture experiments that CSNP2 binds to S1 at submicromolar concentration and abrogates the S1-hACE2 interaction. CSNP3, a modified and downsized form of CSNP2, could neither interfere with the S1-hACE2 interaction nor bind to S1. CSNP4 exhibited dose-dependent binding to both S1 and hACE2 and abolished the S1-hACE2 interaction in vitro. CSNP4 possibly enhance the mAb-based S1 neutralization by limiting the spontaneous movement of spike receptor-binding domain (RBD), whereas CSNP2 allowed RBD-mAb binding without any steric hindrance. Taken together, we suggest that CSNP2 and CSNP4 are potent and stable candidate peptides that can neutralize the SARS-CoV-2 spike and possibly pose the virus to host immune surveillance.

scholarly journals Cross-reactive neutralization of SARS-CoV-2 by serum antibodies from recovered SARS patients and immunized animals

2020 ◽  
Author(s):  
Yuanmei Zhu ◽  
Danwei Yu ◽  
Yang Han ◽  
Hongxia Yan ◽  
Huihui Chong ◽  
...  
Keyword(s):  
Public Health ◽  
Receptor Binding ◽  
Cross Reactivity ◽  
Social Stability ◽  
Receptor Binding Domain ◽  
Serum Antibodies ◽  
Serum Samples ◽  
S Protein ◽  
Palm Civet ◽  
Novel Coronavirus

AbstractThe current COVID-19 pandemic, caused by a novel coronavirus SARS-CoV-2, poses serious threats to public health and social stability, calling for urgent need for vaccines and therapeutics. SARS-CoV-2 is genetically close to SARS-CoV, thus it is important to define the between antigenic cross-reactivity and neutralization. In this study, we firstly analyzed 20 convalescent serum samples collected from SARS-CoV infected individuals during the 2003 SARS outbreak. All patient sera reacted strongly with the S1 subunit and receptor-binding domain (RBD) of SARS-CoV, cross-reacted with the S ectodomain, S1, RBD, and S2 proteins of SARS-CoV-2, and neutralized both SARS-CoV and SARS-CoV-2 S protein-driven infections. Multiple panels of antisera from mice and rabbits immunized with a full-length S and RBD immunogens of SARS-CoV were also characterized, verifying the cross-reactive neutralization against SARS-CoV-2. Interestingly, we found that a palm civet SARS-CoV-derived RBD elicited more potent cross-neutralizing responses in immunized animals than the RBD from a human SARS-CoV strain, informing a strategy to develop a universe vaccine against emerging CoVs.SummarySerum antibodies from SARS-CoV infected patients and immunized animals cross-neutralize SARS-CoV-2 suggests strategies for universe vaccines against emerging CoVs.

scholarly journals Rapid isolation and profiling of a diverse panel of human monoclonal antibodies targeting the SARS-CoV-2 spike protein

2020 ◽  
Author(s):  
Seth J. Zost ◽  
Pavlo Gilchuk ◽  
Rita E. Chen ◽  
James Brett Case ◽  
Joseph X. Reidy ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Cross Reactivity ◽  
The Novel ◽  
Receptor Binding Domain ◽  
Human Monoclonal Antibodies ◽  
S Protein ◽  
Global Pandemic ◽  
Antibody Discovery ◽  
Novel Coronavirus ◽  
Rapid Antibody

Antibodies are a principal determinant of immunity for most RNA viruses and have promise to reduce infection or disease during major epidemics. The novel coronavirus SARS-CoV-2 has caused a global pandemic with millions of infections and hundreds of thousands of deaths to date1,2. In response, we used a rapid antibody discovery platform to isolate hundreds of human monoclonal antibodies (mAbs) against the SARS-CoV-2 spike (S) protein. We stratify these mAbs into five major classes based on their reactivity to subdomains of S protein as well as their cross-reactivity to SARS-CoV. Many of these mAbs inhibit infection of authentic SARS-CoV-2 virus, with most neutralizing mAbs recognizing the receptor-binding domain (RBD) of S. This work defines sites of vulnerability on SARS-CoV-2 S and demonstrates the speed and robustness of new antibody discovery methodologies.

scholarly journals Potent binding of 2019 novel coronavirus spike protein by a SARS coronavirus-specific human monoclonal antibody

2020 ◽  
Author(s):  
Xiaolong Tian ◽  
Cheng Li ◽  
Ailing Huang ◽  
Shuai Xia ◽  
Sicong Lu ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Binding Site ◽  
Neutralizing Antibodies ◽  
Rapid Development ◽  
Antiviral Treatment ◽  
Human Monoclonal Antibody ◽  
Cross Reactivity ◽  
Spike Protein ◽  
The Cross ◽  
Novel Coronavirus

ABSTRACTThe newly identified 2019 novel coronavirus (2019-nCoV) has caused more than 800 laboratory-confirmed human infections, including 25 deaths, posing a serious threat to human health. Currently, however, there is no specific antiviral treatment or vaccine. Considering the relatively high identity of receptor binding domain (RBD) in 2019-nCoV and SARS-CoV, it is urgent to assess the cross-reactivity of anti-SARS-CoV antibodies with 2019-nCoV spike protein, which could have important implications for rapid development of vaccines and therapeutic antibodies against 2019-nCoV. Here, we report for the first time that a SARS-CoV-specific human monoclonal antibody, CR3022, could bind potently with 2019-nCoV RBD (KD of 6.3 nM). The epitope of CR3022 does not overlap with the ACE2 binding site within 2019-nCoV RBD. Therefore, CR3022 has the potential to be developed as candidate therapeutics, alone or in combination with other neutralizing antibodies, for the prevention and treatment of 2019-nCoV infections. Interestingly, some of the most potent SARS-CoV-specific neutralizing antibodies (e.g., m396, CR3014) that target the ACE2 binding site of SARS-CoV failed to bind 2019-nCoV spike protein, indicating that the difference in the RBD of SARS-CoV and 2019-nCoV has a critical impact for the cross-reactivity of neutralizing antibodies, and that it is still necessary to develop novel monoclonal antibodies that could bind specifically to 2019-nCoV RBD.

scholarly journals Enhanced uptake of polyethylene glycol coated gold nanoparticles for improved therapeutics

2021 ◽  
Author(s):  
Charmainne Cruje
Keyword(s):  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Intracellular Localization ◽  
Cell Entry ◽  
Cell Uptake ◽  
Enhanced Permeability And Retention ◽  
Peg Chain Length ◽  
Surface Modified ◽  
Entry Receptor

Polyethylene glycol (PEG) has promoted the prospective cancer treatment applications of gold nanoparticles (GNPs). PEG is widely used in providing GNPs with stealth properties, hence prolonging blood circulation times. GNPs coated with PEG (PEG-GNPs) take advantage of the enhanced permeability and retention effect in tumor environments, making them suitable for targeted treatment. The cellular uptake of PEG-GNPs is significantly lower than uncoated GNPs in vitro. PEG minimizes PEG-GNP interaction with ligands that mediate cancer cell uptake, causing reduced GNP uptake in comparison to uncoated GNP. As intracellular localization of GNPs maximizes its therapeutic enhancement, there is a need to improve the uptake of PEG-GNPs. To improve cell entry, receptor mediated endocytosis peptides were conjugated with PEG-GNPs of varying core sizes. Spherical GNPs of diameters 14, 50 and 70 nm with a PEG chain length of 2 kDa were used to determine a preferred core size for uptake in vitro in HeLa and MDA-MB-231 cells. A preliminary study using surface-modified GNPs as a radiosensitizer to a megavoltage clinical photon beam was done to assess its therapeutic application.

scholarly journals The monoclonal antibody 26 raised against tetanus toxoid also recognizes tetanus toxin and β2-glycoprotein I - its binding properties in vitro and potential applications

2009 ◽  
Vol 74 (3) ◽  
pp. 245-257 ◽  
Author(s):  
Aleksandra Inic-Kanada ◽  
Marijana Stojanovic ◽  
Irena Zivkovic ◽  
Vladimir Petrusic ◽  
Ljiljana Dimitrijevic
Keyword(s):  
Tetanus Toxoid ◽  
Tetanus Toxin ◽  
Molecular Mimicry ◽  
Cross Reactivity ◽  
Affinity Constant ◽  
Glycoprotein I ◽  
Relative Affinity ◽  
Potential Applications ◽  
Scatchard Plots

A murine monoclonal IgG1 antibody, marked as MAb26, specific for tetanus toxoid has been immunochemically characterized. By performing enzyme-linked immunosorbent assays (ELISAs) and western blot analyses, it was demonstrated that MAb26 reacted with tetanus toxoid, tetanus toxin and ?2-glycoprotein I (?2GPI). According to the results, MAb26 recognized the sequential epitope on the tetanus heavy chain. The affinity constant, calculated from Scatchard plots of MAb26 binding to tetanus toxoid, was 1.145?108 M-1 and the measurement of the relative affinity of MAb26 by ELISA using thiocyanate elution showed a significantly higher affinity of MAb26 to the toxoid (p = 0.0012) in comparison to the toxin. Additionally, the reactivity of MAb26 toward the toxoid forms increased when the tetanus toxin was detoxified using 8 mM and higher formaldehyde concentrations. The similarity of the tetanus toxoid to several sera proteins, either at the level of its conformation (IL-1?) or at the level of peptide sequences (?2GPI, laminin) favors its role in autoimmunity by the mechanism of molecular mimicry. As the induction of an autoimmune disease is dependent on the breakdown of tolerance, which could be the result of an overt hyperstimulation, the control of the presence and concentration of self-reactive epitopes in vaccine preparations is a prerequisite. In this study, it was shown that MAb26 can: 1) discriminate between the tetanus toxin and different toxoid forms, which makes it a good candidate for antibody control during vaccine preparation; 2) due to its cross-reactivity with ?2GPI, it could provide information on the presence of a potentially dangerous sequential epitope expressed at the protein surface.

scholarly journals Revisiting the phosphotyrosine binding pocket of Fyn SH2 domain led to the Identification of novel SH2 superbinders

2020 ◽  
Author(s):  
Shuhao Li ◽  
Yang Zou ◽  
Dongping Zhao ◽  
Yuqing Yin ◽  
Jingyi Song ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Binding Pocket ◽  
Cross Reactivity ◽  
Dissociation Rate ◽  
Sh2 Domain ◽  
Binding Affinities ◽  
Wild Type ◽  
Triple Mutant ◽  
Potential Applications

AbstractProtein engineering through directed evolution is an effective way to obtain proteins with novel functions with the potential applications as tools for diagnosis or therapeutics. Many natural proteins, largely antibodies as well as some non-antibody proteins, have undergone directed evolution in vitro in the test tubes in the laboratories around the world, resulted in the numerous protein variants with novel or enhanced functions. In this study, we constructed a Fyn SH2 variant library by randomizing the 8 variable residues in its phosphotyrosine (pTyr) binding pocket. Selection of this library by a pTyr peptide from MidT antigen led to the identification of SH2 variants with enhanced affinities to the peptide, compared to the wild type SH2, by EC50 assay. Fluorescent polarization (FP) was then applied to quantify the binding affinity of the newly identified SH2 variants. As a result, three SH2 variants, named V3, V13 and V24, have comparable binding affinities with the previously identified SH2 triple-mutant superbinder (refer to Trm). Biolayer Interferometry (BLI) assay was employed to disclose the kinetics of the binding of these SH2 superbinders, in addition to the wild type SH2, to the phosphotyrosine peptide. The results indicated that all the SH2 superbinders have two-orders increase of the dissociation rate when binding the pTyr peptide while there was no significant change in their associate rates. The previously identified SH2 superbinder Trm as well as the V13 and V24 discovered in this study have cross-reactivity with the sulfotyrosine (sTyr) containing peptide while the wild type SH2 does not. Intriguingly, though binding the pTyr peptide with comparable affinity with other SH2 superbinders, the V3 does not bind to the sTyr peptide, implying it binds to the pTyr peptide with a different pattern from the other superbinders. The newly identified superbinders could be utilized as tools for the identification of pTyr-containing proteins from tissues under different physiological or pathophysiological conditions and may have the potential in the therapeutics.

scholarly journals Broad ultra-potent neutralization of SARS-CoV-2 variants by monoclonal antibodies specific to the tip of RBD

2021 ◽  
Author(s):  
Hang Ma ◽  
Yingying Guo ◽  
Haoneng Tang ◽  
Chien-Te Tseng ◽  
Lei Wang ◽  
...  
Keyword(s):  
Hydrophobic Effect ◽  
Receptor Binding Domain ◽  
Contact Interface ◽  
Block Interaction ◽  
Cryo Electron Microscopy ◽  
Binding Epitope ◽  
Clinical Illness ◽  
Animal Safety ◽  
Potent Neutralization

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) continue to wreak havoc across the globe. Higher transmissibility and immunologic resistance of VOCs bring unprecedented challenges to epidemic extinguishment. Here we describe a monoclonal antibody, 2G1, that neutralizes all current VOCs and has surprising tolerance to mutations adjacent to or within its interaction epitope. Cryo-electron microscopy structure showed that 2G1 bound to the tip of receptor binding domain (RBD) of spike protein with small contact interface but strong hydrophobic effect, which resulted in nanomolar to sub-nanomolar affinities to spike proteins. The epitope of 2G1 on RBD partially overlaps with ACE2 interface, which gives 2G1 ability to block interaction between RBD and ACE2. The narrow binding epitope but high affinity bestow outstanding therapeutic efficacy upon 2G1 that neutralized VOCs with sub-nanomolar IC50 in vitro. In SARS-CoV-2 and Beta- and Delta- variant-challenged transgenic mice and rhesus macaque models, 2G1 protected animals from clinical illness and eliminated viral burden, without serious impact to animal safety. Mutagenesis experiments suggest that 2G1 could be potentially capable of dealing with emerging SARS-CoV-2 variants in future. This report characterized the therapeutic antibodies specific to the tip of spike against SARS-CoV-2 variants and highlights the potential clinical applications as well as for developing vaccine and cocktail therapy.

Sign in / Sign up

Export Citation Format

Share Document