scholarly journals A chicken IgY can efficiently inhibit the entry and replication of SARS-CoV-2 by targeting the ACE2 binding domain in vitro

2021 ◽  
Author(s):  
Wei Jingchen ◽  
Lu Yunfei ◽  
Rui Ying ◽  
Zhu Xuanyu ◽  
He Songqing ◽  
...  
Keyword(s):  
Immunofluorescence Microscopy ◽  
Egg Yolk ◽  
Antiviral Effect ◽  
Effective Concentration ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
The Third ◽  
Cell Experiment ◽  
The World

COVID-19 pneumonia has now spread widely in the world. Currently, no specific antiviral drugs are available. The vaccine is the most effective way to control the epidemic. Passive immune antibodies are also an effective method to prevent and cure COVID-19 pneumonia. We used the SARS-CoV-2 S receptor- binding domain (RBD) as an antigen to immunize layers in order to extract, separate, and purify SARS-CoV-2-IgY from egg yolk. SARS-CoV-2-IgY (S-IgY) can block the entry of SARS-CoV-2 into the Cells and reduce the viral load in cells. The Half effective concentration (EC50) of W3-IgY (S-IgY in the third week after immunization) is 1.35 plusm 0.15nM. The EC50 of W9-IgY (S-IgY in the ninth week after immunization) is 2.76 plusm 1.54 nM. When the dose of S-IgY is 55 nM, the fluorescence representing intracellular viral protein is obviously weakened in Immunofluorescence microscopy. Results of Sars-CoV-2 /Vero E6 cell experiment confirmed that S-IgY has a strong antiviral effect on SARS-CoV-2, and its (EC50) is 27.78 plusm1.54 nMvs 3,259 plusm 159.62 nM of Redesivir (differ ﹥106 times P＜0.001 ). S-IgY can inhibit the entry and replication of SARS-CoV-2, which is related to its targeting the ACE2 binding domain. S-IgY is safe, efficient, stable, and easy to obtain. This antibody can be an effective tool for preventing and treating COVID-19 pneumonia.

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.

scholarly journals Investigation of the effects of six medicinal plants with antiviral effects against COVID-19

2021 ◽  
Author(s):  
Harun ALP ◽  
Hasan ASİL ◽  
Demet Duman
Keyword(s):  
Medicinal Plants ◽  
Nigella Sativa ◽  
Water Extract ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Glycyrrhiza Glabra ◽  
Crocus Sativus ◽  
Medicinal And Aromatic Plants ◽  
The World

Abstract Today, the coronavirus epidemic, which caused the death of 79 million cases and 1743 thousand people in 218 countries around the world, continues to increase its impact all over the world. Researchers are still trying to develop an effective solution against covid-19, including vaccines and drugs. However, there are few studies that determine the effect of natural products obtained from plants on covid-19. Medicinal and aromatic plants have been used for therapeutic purposes since the existence of humanity. In this study, the effects of some important medicinal plants including Licorice (Glycyrrhiza glabra), Saffron (Crocus sativus L.), Nigella (Nigella sativa L.), Laurel (Lauris nobilis), Karabaş (Lavandula stoechas), and Zahter (Thymbra spicata L. var. Spicata) against Covid-19 were investigated in vitro conditions. The six plants were evaluated for cytotoxic effect on Vero cells and determining inhibition of viral replication in Vero-E6 cells at concentrations of broad-spectrum antiviral non-cytotoxic against Covid-19 in cell culture and an additional antiviral effect against Covid-19. According to the results, the five examined plants (Saffron, Nigella, Laurel, Karabaş, Zahter) were ineffective against Covid-19 in vitro conditions. Interisingly, the water extract obtained from the root of the licorice plant (Glycyrrhiza glabra) inhibited Covid-19 in vitro conditions in the 2nd dilution (1: 4) following the initial concentration in Vero-E6 cells.

scholarly journals The in vitro and in vivo potency of CT-P59 against Delta and its associated variants of SARS-CoV-2

2021 ◽  
Author(s):  
Dong-Kyun Ryu ◽  
Hye-Min Woo ◽  
Bobin Kang ◽  
Hanmi Noh ◽  
Jong-In Kim ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Respiratory Tract ◽  
Animal Studies ◽  
Antiviral Effect ◽  
The World ◽  
Symptom Remission ◽  
Challenge Experiment ◽  
Reduced Activity

The Delta variant originally from India is rapidly spreading across the world and causes to resurge infections of SARS-CoV-2. We previously reported that CT-P59 presented its in vivo potency against Beta and Gamma variants, despite its reduced activity in cell experiments. Yet, it remains uncertain to exert the antiviral effect of CT-P59 on the Delta and its associated variants (L452R). To tackle this question, we carried out cell tests and animal study. CT-P59 showed reduced antiviral activity but enabled neutralization against Delta, Epsilon, and Kappa variants in cells. In line with in vitro results, the mouse challenge experiment with the Delta variant substantiated in vivo potency of CT-P59 showing symptom remission and virus abrogation in the respiratory tract. Collectively, cell and animal studies showed that CT-P59 is effective against the Delta variant infection, hinting that CT-P59 has therapeutic potency for patients infected with Delta and its associated variants.

Discovery of potential inhibitors of the receptor-binding domain (RBD) of pandemic disease-causing SARS-CoV-2 Spike Glycoprotein from Triphala through molecular docking

2021 ◽  
Vol 01 ◽  
Author(s):  
Sharuk L. Khan ◽  
Falak A. Siddiqui ◽  
Mohd Sayeed Shaikh ◽  
Nitin V. Nema ◽  
Aijaz A. Shaikh
Keyword(s):  
Molecular Docking ◽  
Hydrogen Bonds ◽  
Receptor Binding ◽  
Chemical Constituents ◽  
Antioxidant Properties ◽  
Binding Domain ◽  
Quality Data ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein

Background: COVID-19 (SARS-CoV-2 infection) has affected almost every region of the world. Presently, there is no defined line of treatment available for it. Triphala is already proven to have a safe biological window and well known for its antioxidant and immunomodulatory properties. Objective: Present work has been carried out to study Triphala's effectiveness for the treatment of COVID-19. Methods: The Receptor-binding domain (RBD) of SARS-CoV-2 Spike Glycoprotein responsible for the invasion into the host cell, which leads to further infection. The molecular docking (MD) was performed to explore the binding affinities (kcal/mol) of Triphala's chemical constituents and compared them with the existing drugs under investigation for the treatment of COVID-19 epidemiology. Results: Chebulinic acid binding affinity -8.5 kcal/mol with the formation of 10 hydrogen bonds. Almost all the major chemical constituents have formed two or more hydrogen bonds with RBD of SARS-CoV-2 Spike Glycoprotein. Conclusion: The present study showed that Triphala might perform vital roles in the treatment of COVID-19 and expand its usefulness to physicians to treat this illness. There is a need to complete the in-vitro, in-vivo biological testing of Triphala on SARS-CoV-2 disease to create more quality data. The binding mode of Chebulinic acid in the allosteric cavity allows a better understanding of RBD of SARS-CoV-2 Spike Glycoprotein target and provides insight for the design of new inhibitors. Triphala is already proven to have a safe biological window, which indicates we can skip the pre-clinical trials. Apart from this, Triphala is well known for its antioxidant properties, which ultimately improves the immunity of the COVID-19 patient.

scholarly journals A synthetic bispecific antibody capable of neutralizing SARS-CoV-2 Delta and Omicron

2022 ◽  
Author(s):  
Tom Z Yuan ◽  
Carolina Lucas ◽  
Valter S Monteiro ◽  
Akiko Iwasaki ◽  
Marisa L Yang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Bispecific Antibody ◽  
Immune Escape ◽  
Binding Domain ◽  
Bispecific Antibodies ◽  
Receptor Binding Domain ◽  
Promising Strategy

Bispecific antibodies have emerged as a promising strategy for curtailing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune escape. This brief report highlights RBT-0813 (also known as TB493-04), a synthetic, humanized, receptor-binding domain (RBD)-targeted bispecific antibody that retains picomolar affinity to the Spike (S) trimers of all major variants of concern and neutralizes both SARS-CoV-2 Delta and Omicron in vitro.

scholarly journals Structural classification of neutralizing antibodies against the SARS-CoV-2 spike receptor-binding domain suggests vaccine and therapeutic strategies

2020 ◽  
Author(s):  
Christopher O. Barnes ◽  
Claudia A. Jette ◽  
Morgan E. Abernathy ◽  
Kim-Marie A. Dam ◽  
Shannon R. Esswein ◽  
...  
Keyword(s):  
Immune Responses ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Health Crisis ◽  
Naturally Occurring ◽  
Insight Into

AbstractThe COVID-19 pandemic presents an urgent health crisis. Human neutralizing antibodies (hNAbs) that target the host ACE2 receptor-binding domain (RBD) of the SARS-CoV-2 spike1–5 show therapeutic promise and are being evaluated clincally6–8. To determine structural correlates of SARS-CoV-2 neutralization, we solved 8 new structures of distinct COVID-19 hNAbs5 in complex with SARS-CoV-2 spike trimer or RBD. Structural comparisons allowed classification into categories: (1) VH3-53 hNAbs with short CDRH3s that block ACE2 and bind only to “up” RBDs, (2) ACE2-blocking hNAbs that bind both “up” and “down” RBDs and can contact adjacent RBDs, (3) hNAbs that bind outside the ACE2 site and recognize “up” and “down” RBDs, and (4) Previously-described antibodies that do not block ACE2 and bind only “up” RBDs9. Class 2 comprised four hNAbs whose epitopes bridged RBDs, including a VH3-53 hNAb that used a long CDRH3 with a hydrophobic tip to bridge between adjacent “down” RBDs, thereby locking spike into a closed conformation. Epitope/paratope mapping revealed few interactions with host-derived N-glycans and minor contributions of antibody somatic hypermutations to epitope contacts. Affinity measurements and mapping of naturally-occurring and in vitro-selected spike mutants in 3D provided insight into the potential for SARS-CoV-2 escape from antibodies elicited during infection or delivered therapeutically. These classifications and structural analyses provide rules for assigning current and future human RBD-targeting antibodies into classes, evaluating avidity effects, suggesting combinations for clinical use, and providing insight into immune responses against SARS-CoV-2.

scholarly journals Antibodies with potent and broad neutralizing activity against antigenically diverse and highly transmissible SARS-CoV-2 variants

2021 ◽  
Author(s):  
Lingshu Wang ◽  
Tongqing Zhou ◽  
Yi Zhang ◽  
Eun Sung Yang ◽  
Chaim A. Schramm ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Therapeutic Antibodies ◽  
Resistance Development ◽  
Neutralizing Activity ◽  
Escape Mutants

AbstractThe emergence of highly transmissible SARS-CoV-2 variants of concern (VOC) that are resistant to therapeutic antibodies highlights the need for continuing discovery of broadly reactive antibodies. We identify four receptor-binding domain targeting antibodies from three early-outbreak convalescent donors with potent neutralizing activity against 12 variants including the B.1.1.7 and B.1.351 VOCs. Two of them are ultrapotent, with sub-nanomolar neutralization titers (IC50 <0.0006 to 0.0102 μg/mL; IC80 < 0.0006 to 0.0251 μg/mL). We define the structural and functional determinants of binding for all four VOC-targeting antibodies, and show that combinations of two antibodies decrease the in vitro generation of escape mutants, suggesting potential means to mitigate resistance development. These results define the basis of therapeutic cocktails against VOCs and suggest that targeted boosting of existing immunity may increase vaccine breadth against VOCs.One Sentence SummaryUltrapotent antibodies from convalescent donors neutralize and mitigate resistance of SARS-CoV-2 variants of concern.

scholarly journals Bacterial expression and purification of functional recombinant SARS-CoV-2 spike receptor binding domain

2021 ◽  
Author(s):  
Janani Prahlad ◽  
Lucas R. Struble ◽  
William E. Lutz ◽  
Savanna A. Wallin ◽  
Surender Khurana ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Disulfide Bonds ◽  
Rapid Diagnosis ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Expression And Purification ◽  
Protein Receptor ◽  
The World ◽  
Active Antigen

AbstractThe COVID-19 pandemic caused by SARS-CoV-2 has applied significant pressure on overtaxed healthcare around the world, underscoring the urgent need for rapid diagnosis and treatment. We have developed a bacterial strategy for the expression and purification of the SARS-CoV-2 spike protein receptor binding domain using the CyDisCo system to create and maintain the correct disulfide bonds for protein integrity and functionality. We show that it is possible to quickly and inexpensively produce functional, active antigen in bacteria capable of recognizing and binding to the ACE2 (angiotensin-converting enzyme) receptor as well as antibodies in COVID-19 patient sera.

scholarly journals Ivermectin the Promising Drug to Stave off the COVID-19 Crisis: A Review

2021 ◽  
Vol 7 (2) ◽  
pp. 95-98
Author(s):  
Zakia Jahan ◽  
Masudul Hassan
Keyword(s):  
Infectious Diseases ◽  
Specific Treatment ◽  
In Vitro Study ◽  
Antiviral Effect ◽  
Viral Particles ◽  
The World ◽  
Infected Cells ◽  
Almost All ◽  
First Time

The Coronavirus disease 2019 (COVID-19) outbreak, forcing us to face unprecedented moments in the world. The huge devastating impact of the world due to the covid-19 attack causes the brink of no return. However, there is no proven and specific treatment for Covid -19. Very few medications have received Emergency Use of Authorization. A recent in vitro study was the first time to find out and to assess the antiviral effect of Ivermectin on COVID-19. The study showed that Ivermectin was active against COVID- 19-infected cells, was able to kill effectively almost all viral particles within 48 h. In these moments of crisis, FDA-approved ivermectin is a ray of hope. Bangladesh Journal of Infectious Diseases 2020;7(2):95-98

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