scholarly journals The receptor binding domain of the viral spike protein is an immunodominant and highly specific target of antibodies in SARS-CoV-2 patients

2020 ◽  
Vol 5 (48) ◽  
pp. eabc8413 ◽  
Author(s):  
Lakshmanane Premkumar ◽  
Bruno Segovia-Chumbez ◽  
Ramesh Jadi ◽  
David R. Martinez ◽  
Rajendra Raut ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Clinical Symptoms ◽  
Severe Disease ◽  
Population Level ◽  
Respiratory Illness ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Specific Antibodies

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that first emerged in late 2019 is responsible for a pandemic of severe respiratory illness. People infected with this highly contagious virus can present with clinically inapparent, mild, or severe disease. Currently, the virus infection in individuals and at the population level is being monitored by PCR testing of symptomatic patients for the presence of viral RNA. There is an urgent need for SARS-CoV-2 serologic tests to identify all infected individuals, irrespective of clinical symptoms, to conduct surveillance and implement strategies to contain spread. As the receptor binding domain (RBD) of the spike protein is poorly conserved between SARS-CoVs and other pathogenic human coronaviruses, the RBD represents a promising antigen for detecting CoV-specific antibodies in people. Here we use a large panel of human sera (63 SARS-CoV-2 patients and 71 control subjects) and hyperimmune sera from animals exposed to zoonotic CoVs to evaluate RBD's performance as an antigen for reliable detection of SARS-CoV-2-specific antibodies. By day 9 after the onset of symptoms, the recombinant SARS-CoV-2 RBD antigen was highly sensitive (98%) and specific (100%) for antibodies induced by SARS-CoVs. We observed a strong correlation between levels of RBD binding antibodies and SARS-CoV-2 neutralizing antibodies in patients. Our results, which reveal the early kinetics of SARS-CoV-2 antibody responses, support using the RBD antigen in serological diagnostic assays and RBD-specific antibody levels as a correlate of SARS-CoV-2 neutralizing antibodies in people.

scholarly journals The RBD Of The Spike Protein Of SARS-Group Coronaviruses Is A Highly Specific Target Of SARS-CoV-2 Antibodies But Not Other Pathogenic Human and Animal Coronavirus Antibodies

2020 ◽  
Author(s):  
Lakshmanane Premkumar ◽  
Bruno Segovia-Chumbez ◽  
Ramesh Jadi ◽  
David R. Martinez ◽  
Rajendra Raut ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Clinical Symptoms ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Population Level ◽  
Respiratory Illness ◽  
Specific Antibodies ◽  
Antibody Assays ◽  
Human Sera ◽  
Human Coronaviruses

AbstractA new Severe Acute Respiratory Syndrome Coronavirus variant (SARS-CoV-2) that first emerged in late 2019 is responsible for a pandemic of severe respiratory illness. People infected with this highly contagious virus present with clinically inapparent, mild or severe disease. Currently, the presence of the virus in individual patients and at the population level is being monitored by testing symptomatic cases by PCR for the presence of viral RNA. There is an urgent need for SARS-CoV-2 serologic tests to identify all infected individuals, irrespective of clinical symptoms, to conduct surveillance and implement strategies to contain spread. As the receptor binding domain (RBD) of the viral spike (S) protein is poorly conserved between SARS-CoVs and other pathogenic human coronaviruses, the RBD represents a promising antigen for detecting CoV specific antibodies in people. Here we use a large panel of human sera (70 SARS-CoV-2 patients and 71 control subjects) and hyperimmune sera from animals exposed to zoonotic CoVs to evaluate the performance of the RBD as an antigen for accurate detection of SARS-CoV-2-specific antibodies. By day 9 after the onset of symptoms, the recombinant SARS-CoV-2 RBD antigen was highly sensitive (98%) and specific (100%) to antibodies induced by SARS-CoVs. We observed a robust correlation between levels of RBD binding antibodies and SARS-CoV-2 neutralizing antibodies in patients. Our results, which reveal the early kinetics of SARS-CoV-2 antibody responses, strongly support the use of RBD-based antibody assays for population-level surveillance and as a correlate of neutralizing antibody levels in people who have recovered from SARS-CoV-2 infections.

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.

Construction and immunogenic studies of a mFc fusion receptor binding domain (RBD) of spike protein as a subunit vaccine against SARS-CoV-2 infection

2020 ◽  
Vol 56 (61) ◽  
pp. 8683-8686 ◽  
Author(s):  
Xiaoxiao Qi ◽  
Bixia Ke ◽  
Qian Feng ◽  
Deying Yang ◽  
Qinghai Lian ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fusion Protein ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Humoral And Cellular Immunity ◽  
A Subunit

Herein, we report that a recombinant fusion protein, containing a 457 amino acid SARS-CoV-2 receptor binding domain and a mouse IgG1 Fc domain, could induce highly potent neutralizing antibodies and stimulate humoral and cellular immunity in mice.

scholarly journals The spike protein of SARS-CoV-2 induces endothelial inflammation through integrin α5β1 and NF-κB

2021 ◽  
Author(s):  
Juan Pablo Robles ◽  
Magdalena Zamora ◽  
Gonzalo Martinez de la Escalera ◽  
Carmen Clapp
Keyword(s):  
Receptor Binding ◽  
Nuclear Translocation ◽  
Umbilical Vein ◽  
Vascular Inflammation ◽  
Severe Disease ◽  
Binding Domain ◽  
Spike Protein ◽  
Whole Body ◽  
Receptor Binding Domain ◽  
Integrin Α5β1

Vascular endothelial cells (EC) form a critical interface between blood and tissues that maintains whole-body homeostasis. In COVID-19, disruption of the EC barrier results in edema, vascular inflammation, and coagulation, the hallmarks of the severe disease. However, the mechanisms by which EC are dysregulated in COVID-19 are unclear. Here, we show that the spike protein of SARS-CoV-2 alone activates the EC inflammatory phenotype in a manner dependent on integrin α5β1 signaling. Incubation of human umbilical vein EC with whole spike, its receptor-binding domain, or the integrin-binding tripeptide RGD induced the nuclear translocation of NF-κB and enhanced the expression of leukocyte adhesion molecules VCAM1 and ICAM1, the adhesion of peripheral blood leukocytes, and the permeability of the monolayer. Inhibitors of integrin α5β1 activation prevented these effects. We suggest that the spike protein, through its RGD motif in the receptor-binding domain, binds to integrin α5β1 in EC to activate Rho GTPases, eNOS pathways, and the NF-κB gene expression program responsible for vascular leakage and leukocyte infiltration, respectively. These findings uncover a new direct action of SARS-CoV-2 on EC dysfunction and introduce integrin α5β1 as a promising target for treating vascular inflammation in COVID-19.

scholarly journals Development of spike receptor-binding domain nanoparticle as a vaccine candidate against SARS-CoV-2 infection in ferrets

2021 ◽  
Author(s):  
Young-Il Kim ◽  
Dokyun Kim ◽  
Kwang-Min Yu ◽  
Hogyu David Seo ◽  
Shin-Ae Lee ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Mammalian Cells ◽  
Neutralizing Antibodies ◽  
Vaccine Candidate ◽  
Clinical Symptoms ◽  
Binding Domain ◽  
Host Cells ◽  
Antigen Delivery ◽  
Receptor Binding Domain ◽  
Protein Vaccine

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a causative agent of COVID-19 pandemic, enters host cells via the interaction of its Receptor-Binding Domain (RBD) of Spike protein with host Angiotensin-Converting Enzyme 2 (ACE2). Therefore, RBD is a promising vaccine target to induce protective immunity against SARS-CoV-2 infection. In this study, we report the development of RBD protein-based vaccine candidate against SARS-CoV-2 using self-assembling H. pylori-bullfrog ferritin nanoparticles as an antigen delivery. RBD-ferritin protein purified from mammalian cells efficiently assembled into 24-mer nanoparticles. 16-20 months-old ferrets were vaccinated with RBD-ferritin nanoparticles (RBD-nanoparticles) by intramuscular or intranasal inoculation. All vaccinated ferrets with RBD-nanoparticles produced potent neutralizing antibodies against SARS-CoV-2. Strikingly, vaccinated ferrets demonstrated efficient protection from SARS-CoV-2 challenge, showing no fever, body weight loss and clinical symptoms. Furthermore, vaccinated ferrets showed rapid clearance of infectious viruses in nasal washes and lungs as well as viral RNA in respiratory organs. This study demonstrates the Spike RBD-nanoparticle as an effective protein vaccine candidate against SARS-CoV-2.

scholarly journals Protein Footprinting, Conformational Dynamics and Interface-Adjacent Neutralization ‘Hotspots’ in the SARS-CoV-2 Spike Protein Receptor Binding Domain / Human ACE2 Interaction

2020 ◽  
Author(s):  
Dominic Narang ◽  
Matthew Balmer ◽  
D. Andrew James ◽  
Derek Wilson
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Conformational Dynamics ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Angiotensin Converting Enzyme 2 ◽  
Additional Information ◽  
Protein Receptor ◽  
Hdx Ms

This study provides an HDX-MS based analysis of the interaction between the SARS-CoV-2 spike protein and the human Angiotensin Converting Enzyme 2. <div><br></div><div>- The data agree exactly with the X-ray co-crystal structure of this complex, but provide additional information based on shifts in dynamics that are observed just outside the interface. </div><div><br></div><div>- These dynamic changes occur specifically in regions that are the primary targets of neutralizing antibodies that target spike protein, suggesting that the neutralization mechanism may result from suppression of dynamic shifts in the spike Receptor Binding Domain (RBD) that are necessary for favorable binding thermodynamics in the spike / ACE2 interaction.</div>

scholarly journals SARS-CoV-2 Infection Is Asymptomatic in Nearly Half of Adults with Robust Anti-Spike Protein Receptor-Binding Domain Antibody Response

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 207
Author(s):  
Ourania E. Tsitsilonis ◽  
Dimitrios Paraskevis ◽  
Evi Lianidou ◽  
Evangelos Terpos ◽  
Athanasios Akalestos ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Clinical Symptoms ◽  
Binding Domain ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Humoral Immune ◽  
Protein Receptor ◽  
Previous Infection ◽  
And Gender ◽  
Asymptomatic Individuals

Between June and November 2020, we assessed plasma antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein in 4996 participants (aged 18–82 years, 34.5% men) from the National and Kapodistrian University of Athens. The weighted overall prevalence was 1.6% and monthly prevalence correlated with viral RNA-confirmed SARS-CoV-2 infections in Greece, in the same period. Notably, 49% of seropositive cases reported no history of SARS-CoV-2 infection-related clinical symptoms and 33% were unsuspected of their previous infection. Additionally, levels of anti-SARS-CoV-2 antibodies against the spike-protein receptor-binding domain were similar between symptomatic and asymptomatic individuals, irrespective of age and gender. Using Food and Drug Administration Emergency Use Authorization-approved assays, these results support the need for such studies on pandemic evaluation and highlight the development of robust humoral immune responses even among asymptomatic individuals. The high percentage of unsuspected/asymptomatic active cases, which may contribute to community transmission for more days than that of cases who are aware and self-isolate, underscores the necessity of measures across the population for the efficient control of the pandemic.

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