scholarly journals Delta variant of COVID-19: A simple explanation

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Mohamed A. Hendaus ◽  
Fatima A. Jomha
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Spike Protein ◽  
Simple Explanation ◽  
Initial Identification

Severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease (COVID-19), has undergone numerous mutations since its initial identification, leading to challenges in controlling the pandemic. Till date, several variants of concern have been identified. However, currently, the Delta variant (B.1.617.2) is the most dreaded one owing to its enhanced transmissibility and increased virulence. In addition, this variant can potentially facilitate fusion of the spike protein to cells or inhibit antibodies from binding to it. In this commentary, we have simplified the complexity of the nomenclature of variants related to COVID-19, concentrating on the Delta variant including its transmissibility, response to vaccines, and prevention.

scholarly journals Immunological imprinting of the antibody response in COVID-19 patients

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Teresa Aydillo ◽  
Alexander Rombauts ◽  
Daniel Stadlbauer ◽  
Sadaf Aslam ◽  
Gabriela Abelenda-Alonso ◽  
...  
Keyword(s):  
Immune Response ◽  
Severe Acute Respiratory Syndrome ◽  
Antibody Response ◽  
Humoral Immune Response ◽  
Nucleocapsid Protein ◽  
Spike Protein ◽  
Ongoing Research ◽  
Variable Regions ◽  
Humoral Immune ◽  
Human Coronaviruses

AbstractIn addition to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), humans are also susceptible to six other coronaviruses, for which consecutive exposures to antigenically related and divergent seasonal coronaviruses are frequent. Despite the prevalence of COVID-19 pandemic and ongoing research, the nature of the antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here we longitudinally profile the early humoral immune response against SARS-CoV-2 in hospitalized coronavirus disease 2019 (COVID-19) patients and quantify levels of pre-existing immunity to OC43, HKU1 and 229E seasonal coronaviruses, and find a strong back-boosting effect to conserved but not variable regions of OC43 and HKU1 betacoronaviruses spike protein. However, such antibody memory boost to human coronaviruses negatively correlates with the induction of IgG and IgM against SARS-CoV-2 spike and nucleocapsid protein. Our findings thus provide evidence of immunological imprinting by previous seasonal coronavirus infections that can potentially modulate the antibody profile to SARS-CoV-2 infection.

scholarly journals Replication, pathogenicity, and transmission of SARS-CoV-2 in minks

2020 ◽  
Author(s):  
Lei Shuai ◽  
Gongxun Zhong ◽  
Quan Yuan ◽  
Zhiyuan Wen ◽  
Chong Wang ◽  
...  
Keyword(s):  
Animal Model ◽  
Severe Acute Respiratory Syndrome ◽  
Subunit Vaccine ◽  
Lung Damage ◽  
Spike Protein ◽  
Pulmonary Lesions ◽  
Potential Strategy ◽  
Respiratory Droplets

Abstract Minks are raised in many countries and have transmitted severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) to humans. However, the biologic properties of SARS-CoV-2 in minks are largely unknown. Here, we investigated and found that SARS-CoV-2 replicates efficiently in both the upper and lower respiratory tracts, and transmits efficiently in minks via respiratory droplets; pulmonary lesions caused by SARS-CoV-2 in minks are similar to those seen in humans with COVID-19. We further found that a spike protein-based subunit vaccine largely prevented SARS-CoV-2 replication and lung damage caused by SARS-CoV-2 infection in minks. Our study indicates that minks are a useful animal model for evaluating the efficacy of drugs or vaccines against COVID-19 and that vaccination is a potential strategy to prevent minks from transmitting SARS-CoV-2.

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 SPIKE PROTEIN AND ITS PROTEASES ROLE IN SARS-COV-2 PATHOGENICITY AND TREATMENT; A REVIEW

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Fateme Tavakoli Far ◽  
◽  
Ehsan Amiri-Ardekani ◽  
Keyword(s):  
Blood Pressure ◽  
Severe Acute Respiratory Syndrome ◽  
Small Molecules ◽  
Cathepsin B ◽  
Host Cells ◽  
Spike Protein ◽  
Pressure Regulation ◽  
Common Receptor ◽  
The World

Since December 2019, a novel beta coronavirus has spread around the world. This virus can cause severe acute respiratory syndrome (SARS). In this study, we reviewed proteases of SARS-CoV-2 based on related articles published in journals indexed by Scopus, PubMed, and Google Scholar from December 2019 to April 2020. Based on this study, we can claim that this coronavirus has about 76% genotype similarity to SARS coronavirus (SARS-CoV). Also, similarities between these two viruses have been found in the mechanism of entry into host cells and pathogenicity. ACE 2, the angiotensin convertase enzyme 2, plays a role in the Renin-Angiotensin-Aldosterone system (RAAS) and blood pressure regulation. Some mechanisms have been reported for the role of ACE 2 in the pathogenicity of SARS-CoV-2. For example, the interaction between the ACE 2 receptor and spike protein mediated by TMPRSS2, Cathepsin B/L, and other enzymes is responsible for the entry of the virus into human cells and pathogenicity. Some host cell endosomal enzymes are necessary to cleavage coronavirus spike protein and cause binding to their common receptor. So, we conclude that molecules like antibodies or small molecules like ACE 2 antagonists and soluble ACE 2 can be used as a good therapeutic candidate to prevent SARS-CoV-2.

scholarly journals Development of a Colloidal Gold-Based Immunochromatographic Strip for Rapid Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein

2021 ◽  
Vol 12 ◽  
Author(s):  
Ge Li ◽  
Aiping Wang ◽  
Yumei Chen ◽  
Yaning Sun ◽  
Yongkun Du ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Colloidal Gold ◽  
Global Economy ◽  
Chinese Hamster ◽  
Influenza Viruses ◽  
Spike Protein ◽  
Disease Spread ◽  
Ovary Cell ◽  
Immunochromatographic Strip ◽  
Specific Reactions

The outbreak and worldwide pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have a significant impact on global economy and human health. In order to reduce the disease spread, 16 monoclonal antibodies (McAbs) again SARS-CoV-2 were generated by immunized mice with the spike protein receptor binding domain (RBD), which was expressed in Chinese hamster ovary cell (CHO). A colloidal gold-based immunochromatographic strip was developed with two McAbs to detect SARS-CoV-2 spike protein, which can play a potential role in monitoring vaccine quality. The strip is highly specific, detecting only SARS-CoV-2 spike protein, and does not show any non-specific reactions with syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and other coronavirus and influenza viruses. The strip detected subunit vaccine in our laboratory with a detection limit of spike protein of 62.5 ng/mL. This strip provides an effective method in monitoring vaccine quality by detecting the antigen content of spike protein.

scholarly journals Engineered ACE2 receptor traps potently neutralize SARS-CoV-2

2020 ◽  
Vol 117 (45) ◽  
pp. 28046-28055 ◽  
Author(s):  
Anum Glasgow ◽  
Jeff Glasgow ◽  
Daniel Limonta ◽  
Paige Solomon ◽  
Irene Lui ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Surface Display ◽  
Random Mutagenesis ◽  
Yeast Surface Display ◽  
Host Cells ◽  
Spike Protein ◽  
Receptor Protein ◽  
Yeast Surface

An essential mechanism for severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection begins with the viral spike protein binding to the human receptor protein angiotensin-converting enzyme II (ACE2). Here, we describe a stepwise engineering approach to generate a set of affinity optimized, enzymatically inactivated ACE2 variants that potently block SARS-CoV-2 infection of cells. These optimized receptor traps tightly bind the receptor binding domain (RBD) of the viral spike protein and prevent entry into host cells. We first computationally designed the ACE2–RBD interface using a two-stage flexible protein backbone design process that improved affinity for the RBD by up to 12-fold. These designed receptor variants were affinity matured an additional 14-fold by random mutagenesis and selection using yeast surface display. The highest-affinity variant contained seven amino acid changes and bound to the RBD 170-fold more tightly than wild-type ACE2. With the addition of the natural ACE2 collectrin domain and fusion to a human immunoglobulin crystallizable fragment (Fc) domain for increased stabilization and avidity, the most optimal ACE2 receptor traps neutralized SARS-CoV-2–pseudotyped lentivirus and authentic SARS-CoV-2 virus with half-maximal inhibitory concentrations (IC50s) in the 10- to 100-ng/mL range. Engineered ACE2 receptor traps offer a promising route to fighting infections by SARS-CoV-2 and other ACE2-using coronaviruses, with the key advantage that viral resistance would also likely impair viral entry. Moreover, such traps can be predesigned for viruses with known entry receptors for faster therapeutic response without the need for neutralizing antibodies isolated from convalescent patients.

scholarly journals Preventing SARS-CoV-2 infection by blocking a tissue serine protease

2020 ◽  
Vol 7 ◽  
pp. 204993612093307
Author(s):  
Katherine C. Jankousky ◽  
Jonathan Schultz ◽  
Samuel Windham ◽  
Andrés F. Henao-Martínez ◽  
Carlos Franco-Paredes ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Severe Acute Respiratory Syndrome ◽  
Serine Protease ◽  
Viral Entry ◽  
Clinical Impact ◽  
Spike Protein ◽  
Viral Pathogens ◽  
Pharmacological Targets ◽  
Alternative Approach ◽  
Viral Surface

Currently, there are no proven pharmacologic interventions to reduce the clinical impact and prevent complications of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, the cause of the ongoing Coronavirus Disease of 2019 (COVID-19) pandemic. Selecting specific pharmacological targets for the treatment of viral pathogens has traditionally relied in blockage of specific steps in their replicative lifecycle in human cells. However, an alternative approach is reducing the molecular cleavage of the viral surface spike protein of SARS-CoV-2 to prevent viral entry into epithelial cells.

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