scholarly journals Comprehensive characterization of the antibody responses to SARS-CoV-2 Spike protein after infection and/or vaccination

2021 ◽  
Author(s):  
Meghan E. Garrett ◽  
Jared G. Galloway ◽  
Caitlin Wolf ◽  
Jennifer K. Logue ◽  
Nicholas Franko ◽  
...  
Keyword(s):  
Immune Escape ◽  
Severe Disease ◽  
Vaccine Dose ◽  
Principal Component ◽  
Fusion Peptide ◽  
Antibody Binding ◽  
Spike Protein ◽  
Heptad Repeat ◽  
Medical Institute ◽  
Vaccine Type

ABSTRACTBackgroundControl of the COVID-19 pandemic will rely on SARS-CoV-2 vaccine-elicited antibodies to protect against emerging and future variants; an understanding of the unique features of the humoral responses to infection and vaccination, including different vaccine platforms, is needed to achieve this goal.MethodsThe epitopes and pathways of escape for Spike-specific antibodies in individuals with diverse infection and vaccination history were profiled using Phage-DMS. Principal component analysis was performed to identify regions of antibody binding along the Spike protein that differentiate the samples from one another. Within these epitope regions we determined potential escape mutations by comparing antibody binding of peptides containing wildtype residues versus peptides containing a mutant residue.ResultsIndividuals with mild infection had antibodies that bound to epitopes in the S2 subunit within the fusion peptide and heptad-repeat regions, whereas vaccinated individuals had antibodies that additionally bound to epitopes in the N- and C-terminal domains of the S1 subunit, a pattern that was also observed in individuals with severe disease due to infection. Epitope binding appeared to change over time after vaccination, but other covariates such as mRNA vaccine dose, mRNA vaccine type, and age did not affect antibody binding to these epitopes. Vaccination induced a relatively uniform escape profile across individuals for some epitopes, whereas there was much more variation in escape pathways in in mildly infected individuals. In the case of antibodies targeting the fusion peptide region, which was a common response to both infection and vaccination, the escape profile after infection was not altered by subsequent vaccination.ConclusionsThe finding that SARS-CoV-2 mRNA vaccination resulted in binding to additional epitopes beyond what was seen after infection suggests protection could vary depending on the route of exposure to Spike antigen. The relatively conserved escape pathways to vaccine-induced antibodies relative to infection-induced antibodies suggests that if escape variants emerge, they may be readily selected for across vaccinated individuals. Given that the majority of people will be first exposed to Spike via vaccination and not infection, this work has implications for predicting the selection of immune escape variants at a population level.FundingThis work was supported by NIH grants AI138709 (PI Overbaugh) and AI146028 (PI Matsen). Julie Overbaugh received support as the Endowed Chair for Graduate Education (FHCRC). The research of Frederick Matsen was supported in part by a Faculty Scholar grant from the Howard Hughes Medical Institute and the Simons Foundation. Scientific Computing Infrastructure at Fred Hutch was funded by ORIP grant S10OD028685.

scholarly journals Importation, circulation, and emergence of variants of SARS-CoV-2 in the South Indian State of Karnataka

2021 ◽  
Author(s):  
Chitra Pattabiraman ◽  
Pramada Prasad ◽  
Anson K George ◽  
Darshan Sreenivas ◽  
Risha Rasheed ◽  
...  
Keyword(s):  
Amino Acid ◽  
Immune Escape ◽  
Severe Disease ◽  
Warning System ◽  
Amino Acid Replacement ◽  
International Travel ◽  
Spike Protein ◽  
Local Circulation ◽  
South Indian ◽  
The Uk

As the pandemic of COVID-19 caused by the coronavirus SARS-CoV-2 continues, the selection of genomic variants which can influence how the pandemic progresses is of growing concern. Of particular concern, are those variants that carry mutations/amino acid changes conferring higher transmission, more severe disease, re-infection, and immune escape. These can broadly be classified as Variants of Concern (VOCs). VOCs have been reported from several parts of the world- UK (lineage B.1.1.7), South Africa (lineage B.1.351) and, Brazil (lineage P.1/B.1.1.28). The conditions that contribute to the emergence of VOCs are not well understood. International travel remains an important means of spread. To track importation, spread, and the emergence of variants locally; we sequenced whole genomes of SARS-CoV-2 from international travellers (n=75) entering Karnataka, a state in South India, between Dec 22, 2020- Jan 31, 2021, and from positive cases in the city of Bengaluru (n=108), between Nov 22, 2020- Jan 22, 2021. The resulting 176 SARS-CoV-2 genomes could be classified into 34 lineages, that were either imported (73/176) or circulating (103/176) in this time period. The lineage B.1.1.7 (a.k.a the UK variant) was the major lineage imported into the state (24/73, 32.9%), followed by B.1.36 (20/73, 27.4%) and B.1 (14/73, 19.2%). We identified B.1.36 (45/103; 43.7%), B.1 (26/103; 25.2%), B.1.1.74 (5/103; 4.9%) and B.1.468 (4/103; 3.9%) as the major variants circulating in Bengaluru city. A distinct clade within the B.1.36 lineage was associated with a local outbreak. Analysis of the complete genomes predicted multiple amino acid replacements in the Spike protein. In total, we identified nine amino acid changes (singly or in pairs) in the Receptor Binding Domain of the Spike protein. Of these, the amino acid replacement N440K was found in 37/65 (56.92%) sequences in the B.1.36 lineage. The E484K amino acid change which is present in both VOCs, B.1.351 and P.1/B.1.1.28, was found in a single circulating virus in the B.1.36 lineage. This study highlights the introduction of VOCs by travel and the local circulation of viruses with amino acid replacements in the Spike protein. These were spread across lineages, suggesting that multiple paths can lead to the emergence of VOCs, this, in turn, highlights the need to sequence and limit outbreaks of SARS-CoV-2 locally. Our data support the use of concentrated and continued genomic surveillance of SARS-CoV-2 to direct public health measures, suggest revisions to vaccines, and serve as an early warning system to prepare for a surge in COVID-19 cases.

scholarly journals Impact of the Double Mutants on Spike Protein of SARS-CoV-2 B.1.617 Lineage to the Human ACE2 Receptor Binding: A Structural Insight

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2295
Author(s):  
Mohd Imran Khan ◽  
Mohammad Hassan Baig ◽  
Tanmoy Mondal ◽  
Mohammed Alorabi ◽  
Tanuj Sharma ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Receptor Binding ◽  
Immune Escape ◽  
Principal Component ◽  
Spike Protein ◽  
Human Host ◽  
Recent Emergence ◽  
Novel Variants ◽  
Structural Insight ◽  
The Impact

The recent emergence of novel SARS-CoV-2 variants has threatened the efforts to contain the COVID-19 pandemic. The emergence of these “variants of concern” has increased viral transmissibility or immune escape and has supplanted the ancestral strains. The novel variants harbored by the B.1.617 lineage (Kappa and Delta) carry mutations within the receptor-binding domain of spike (S) protein (L452R + E484Q and L452R + T478K), the region binding to the host receptor. The double mutations carried by these novel variants are primarily responsible for an upsurge number of COVID-19 cases in India. In this study, we thoroughly investigated the impact of these double mutations on the binding capability to the human host receptor. We performed several structural analyses and found that the studied double mutations increase the binding affinity of the spike protein to the human host receptor (ACE2). Furthermore, our study showed that these double mutants might be a dominant contributor enhancing the receptor-binding affinity of SARS-CoV-2 and consequently making it more stable. We also investigated the impact of these mutations on the binding affinity of two monoclonal antibodies (Abs) (2-15 and LY-CoV555) and found that the presence of the double mutations also hinders its binding with the studied Abs. The principal component analysis, free energy landscape, intermolecular interaction, and other investigations provided a deeper structural insight to better understand the molecular mechanism responsible for increased viral transmissibility of these variants.

scholarly journals The Coronavirus Spike Protein Is a Class I Virus Fusion Protein: Structural and Functional Characterization of the Fusion Core Complex

2003 ◽  
Vol 77 (16) ◽  
pp. 8801-8811 ◽  
Author(s):  
Berend Jan Bosch ◽  
Ruurd van der Zee ◽  
Cornelis A. M. de Haan ◽  
Peter J. M. Rottier
Keyword(s):  
Fusion Protein ◽  
Membrane Fusion ◽  
Fusion Proteins ◽  
Limited Proteolysis ◽  
Fusion Peptide ◽  
Spike Protein ◽  
Class I ◽  
Heptad Repeat ◽  
Viral Fusion ◽  
Viral Fusion Protein

ABSTRACT Coronavirus entry is mediated by the viral spike (S) glycoprotein. The 180-kDa oligomeric S protein of the murine coronavirus mouse hepatitis virus strain A59 is posttranslationally cleaved into an S1 receptor binding unit and an S2 membrane fusion unit. The latter is thought to contain an internal fusion peptide and has two 4,3 hydrophobic (heptad) repeat regions designated HR1 and HR2. HR2 is located close to the membrane anchor, and HR1 is some 170 amino acids (aa) upstream of it. Heptad repeat (HR) regions are found in fusion proteins of many different viruses and form an important characteristic of class I viral fusion proteins. We investigated the role of these regions in coronavirus membrane fusion. Peptides HR1 (96 aa) and HR2 (39 aa), corresponding to the HR1 and HR2 regions, were produced in Escherichia coli. When mixed together, the two peptides were found to assemble into an extremely stable oligomeric complex. Both on their own and within the complex, the peptides were highly alpha helical. Electron microscopic analysis of the complex revealed a rod-like structure ∼14.5 nm in length. Limited proteolysis in combination with mass spectrometry indicated that HR1 and HR2 occur in the complex in an antiparallel fashion. In the native protein, such a conformation would bring the proposed fusion peptide, located in the N-terminal domain of HR1, and the transmembrane anchor into close proximity. Using biological assays, the HR2 peptide was shown to be a potent inhibitor of virus entry into the cell, as well as of cell-cell fusion. Both biochemical and functional data show that the coronavirus spike protein is a class I viral fusion protein.

scholarly journals Waning of SARS-CoV-2 antibodies targeting the Spike protein in individuals post second dose of ChAdOx1 and BNT162b2 COVID-19 vaccines and risk of breakthrough infections: analysis of the Virus Watch community cohort.

2021 ◽  
Author(s):  
Robert William Aldridge ◽  
Alexei Yavlinsky ◽  
Vincent Grigori Nguyen ◽  
Max T Eyre ◽  
Madhumita Shrotri ◽  
...  
Keyword(s):  
Severe Disease ◽  
Vaccine Dose ◽  
Antibody Test ◽  
The Elderly ◽  
Spike Protein ◽  
Control Analysis ◽  
Correlate Of Protection ◽  
Increased Risk ◽  
Log Linear ◽  
Case Control Analysis

Background: SARS-CoV-2 vaccines stimulate production of antibodies targeting the spike protein (anti-S). The level of antibodies following vaccination and trajectories of waning may differ between vaccines influencing the level of protection, how soon protection is reduced and, consequently the optimum timing of booster doses. Methods: We measured SARS-CoV-2 anti-S titre in the context of seronegativity for SARS-CoV-2 anti-Nucleocapsid (anti-N), in samples collected between 1st July and 24th October 2021 in a subset of adults in the Virus Watch community cohort. We compared anti-S levels after BNT162b2 (BioNTech/Pfizer) or ChAdOx1 (AstraZeneca/Oxford) vaccination using time since second dose of vaccination, age, sex and clinical vulnerability to investigate antibody waning. To investigate the use of anti-S levels as a correlate of protection against SARS-CoV-2 infection, we undertook a survival analysis (Kaplan-Meier and Cox) with individuals entering 21 days after their second dose of vaccine, or first antibody test after 1st July (whichever was latest) and exiting with the outcome of SARS-Cov-2 infection or at the end of follow up 24th October 2021. We also undertook a negative test design case-control analysis of infections occurring after the second vaccine dose (breakthrough infections) to determine whether the type of vaccine affected the risk of becoming infected. Results: 24049 samples from 8858 individuals (5549 who received a second dose of ChAdOx1 and 3205 BNT162b2) who remained anti-N negative were included in the analysis of anti-S waning over time. Three weeks after the second dose of vaccine BNT162b2 mean anti-S levels were 9039 (95%CI: 7946-10905) U/ml and ChadOx1 were 1025 (95%CI: 917-1146) U/ml. For both vaccines, waning anti-S levels followed a log linear decline from three weeks after the second dose of vaccination. At 20 weeks after the second dose of vaccine, the mean anti-S levels were 1521 (95%CI: 1432-1616) U/ml for BNT162b2 and 342 (95%CI: 322-365) U/ml for ChadOx1. We identified 197 breakthrough infections and found a reduced risk of infection post second dose of vaccine for individuals with anti-S levels greater than or equal to 500 U/ml compared to those with levels under 500 U/ml (HR 0.62; 95%CIs:0.44-0.87; p=0.007). Time to reach an anti-S threshold of 500 U/ml was estimated at 96 days for ChAdOx1 and 257 days for BNT162b2. We found an increased risk of a breakthrough infection for those who received the ChAdOx1 compared to those who received BNT162b2 (OR: 1.43, 95% CIs:1.18-1.73, p<0.001). Discussion: Anti-S levels are substantially higher following the second dose of BNT162b2 compared to ChAdOx1. There is a log linear waning in levels for both vaccines following the second dose. Anti-S levels are an important correlate of protection as demonstrated by those with anti-S levels < 500U/ml following vaccination being at significantly greater risk of subsequent infection. Since anti-S levels are substantially lower in ChAdOx1 than in BNT162b2 and both decline at similar rates we would expect waning immunity to occur earlier in ChAdOx1 compared to BNT162b2. Our results showing an increased risk of breakthrough infections for those who were vaccinated with ChAdOx1 compared to BNT162b2 are in line with this hypothesis. Consistent with our data, national analyses of vaccine effectiveness also suggest that waning of immunity for infection and, to a lesser extent for severe disease, is seen earlier in ChAdOx1 than in BNT162b2. Our data demonstrate the importance of booster doses to maintain protection in the elderly and clinically vulnerable and suggest that these should be prioritised to those who received ChAdOx1 as their primary course.

scholarly journals Reduced neutralization of SARS-CoV-2 variants by convalescent plasma and hyperimmune intravenous immunoglobulins for treatment of COVID-19

2021 ◽  
Author(s):  
Juanjie Tang ◽  
Your Lee ◽  
Supriya Ravichandran ◽  
Gabrielle Grubbs ◽  
Chang Huang ◽  
...  
Keyword(s):  
Intravenous Immunoglobulins ◽  
Neutralization Assay ◽  
Phage Display Library ◽  
Fusion Peptide ◽  
Significant Loss ◽  
Antibody Binding ◽  
Heptad Repeat ◽  
Minimal Loss ◽  
Neutralizing Capacity ◽  
In The Wild

Hyperimmune immunoglobulin (hCoV-2IG) preparations generated from SARS-CoV-2 convalescent plasma (CP) are under evaluation in several clinical trials of hospitalized COVID-19 patients. Here we explored the antibody epitope repertoire, antibody binding and virus neutralizing capacity of six hCoV-2IG batches as well as nine convalescent plasma (CP) lots against SARS-CoV-2 and emerging variants of concern (VOC). The Gene-Fragment Phage display library spanning the SARS-CoV-2 spike demonstrated broad recognition of multiple antigenic sites spanning the entire spike including NTD, RBD, S1/S2 cleavage site, S2-fusion peptide and S2-heptad repeat regions. Antibody binding to the immunodominant epitopes was higher for hCoV-2IG than CP, with predominant binding to the fusion peptide. In the pseudovirus neutralization assay (PsVNA) and in the wild-type SARS-CoV-2 PRNT assay, hCoV-2IG lots showed higher titers against the WA-1 strain compared with CP. Neutralization of SARS-CoV-2 VOCs from around the globe were reduced to different levels by hCoV-2IG lots. The most significant loss of neutralizing activity was seen against the B.1.351 (9-fold) followed by P.1 (3.5-fold), with minimal loss of activity against the B.1.17 and B.1.429 (<2-fold). Again, the CP showed more pronounced loss of cross-neutralization against the VOCs compared with hCoV-2IG. Significant reduction of hCoV-2IG binding was observed to the RBD-E484K followed by RBD-N501Y and minimal loss of binding to RBD-K417N compared with unmutated RBD. This study suggests that post-exposure treatment with hCoV-2IG is preferable to CP. In countries with co-circulating SARS-CoV-2 variants, identifying the infecting virus strain could inform optimal treatments, but would likely require administration of higher volumes or repeated infusions of hCOV-2IG or CP, in patients infected with the emerging SARS-CoV-2 variants.

scholarly journals Distribution and Severity of Placental Lesions Caused by the Chlamydia abortus 1B Vaccine Strain in Vaccinated Ewes

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 543
Author(s):  
Sergio Gastón Caspe ◽  
Javier Palarea-Albaladejo ◽  
Clare Underwood ◽  
Morag Livingstone ◽  
Sean Ranjan Wattegedera ◽  
...  
Keyword(s):  
Disease Outbreaks ◽  
Principal Component ◽  
Placental Pathology ◽  
Wild Type ◽  
Cell Infiltrate ◽  
Chlamydia Abortus ◽  
Vaccine Type ◽  
The Difference ◽  
Enzootic Abortion Of Ewes

Chlamydia abortus infects livestock species worldwide and is the cause of enzootic abortion of ewes (EAE). In Europe, control of the disease is achieved using a live vaccine based on C. abortus 1B strain. Although the vaccine has been useful for controlling disease outbreaks, abortion events due to the vaccine have been reported. Recently, placental pathology resulting from a vaccine type strain (vt) infection has been reported and shown to be similar to that resulting from a natural wild-type (wt) infection. The aim of this study was to extend these observations by comparing the distribution and severity of the lesions, the composition of the predominating cell infiltrate, the amount of bacteria present and the role of the blood supply in infection. A novel system for grading the histological and pathological features present was developed and the resulting multi-parameter data were statistically transformed for exploration and visualisation through a tailored principal component analysis (PCA) to evaluate the difference between them. The analysis provided no evidence of meaningful differences between vt and wt strains in terms of the measured pathological parameters. The study also contributes a novel methodology for analysing the progression of infection in the placenta for other abortifacient pathogens.

scholarly journals ANALYSIS OF IMMUNE ESCAPE VARIANTS FROM ANTIBODY-BASED THERAPEUTICS AGAINST COVID-19.

2021 ◽  
Author(s):  
Daniele Focosi ◽  
Fabrizio Maggi ◽  
Massimo Franchini ◽  
Scott McConnell ◽  
Arturo Casadevall
Keyword(s):  
Public Health ◽  
Monoclonal Antibodies ◽  
Immune Evasion ◽  
Immune Escape ◽  
Selective Pressure ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Single Amino Acid ◽  
Receptor Binding Domain ◽  
Amino Acid Mutations

Accelerated SARS-CoV-2 evolution under selective pressure by massive deployment of neutralizing antibody-based therapeutics is a concern with potentially severe implications for public health. We review here reports of documented immune escape after treatment with monoclonal antibodies and COVID19 convalescent plasma (CCP). While the former is mainly associated with specific single amino acid mutations at residues within the receptor-binding domain (e.g., E484K/Q, Q493R, and S494P), the few cases of immune evasion after CCP were associated with recurrent deletions within the N-terminal domain of Spike protein (e.g, delHV69-70, delLGVY141-144 and delAL243-244). Continuous genomic monitoring of non-responders is needed to better understand immune escape frequencies and fitness of emerging variants.

scholarly journals The Potential for SARS-CoV-2 to Evade Both Natural and Vaccine-induced Immunity

2020 ◽  
Author(s):  
Emily Shang ◽  
Paul Axelsen
Keyword(s):  
Human Infection ◽  
Antibody Binding ◽  
Spike Protein ◽  
Wild Type ◽  
Binding Interface ◽  
Naturally Occurring ◽  
Binding Interfaces ◽  
Induced Immunity ◽  
Wild Type Form

SARS-CoV-2 attaches to the surface of susceptible cells through extensive interactions between the receptor binding domain (RBD) of its spike protein and angiotensin converting enzyme type 2 (ACE2) anchored in cell membranes. To investigate whether naturally occurring mutations in the spike protein are able to prevent antibody binding, yet while maintaining the ability to bind ACE2 and viral infectivity, mutations in the spike protein identified in cases of human infection were mapped to the crystallographically-determined interfaces between the spike protein and ACE2 (PDB entry 6M0J), antibody CC12.1 (PDB entry 6XC2), and antibody P2B-2F6 (PDB entry 7BWJ). Both antibody binding interfaces partially overlap with the ACE2 binding interface. Among 16 mutations that map to the RBD:CC12.1 interface, 11 are likely to disrupt CC12.1 binding but not ACE2 binding. Among 12 mutations that map to the RBD:P2B-2F6 interface, 8 are likely to disrupt P2B-2F6 binding but not ACE2 binding. As expected, none of the mutations observed to date appear likely to disrupt the RBD:ACE2 interface. We conclude that SARS-CoV-2 with mutated forms of the spike protein may retain the ability to bind ACE2 while evading recognition by antibodies that arise in response to the original wild-type form of the spike protein. It seems likely that immune evasion will be possible regardless of whether the spike protein was encountered in the form of infectious virus, or as the immunogen in a vaccine. Therefore, it also seems likely that reinfection with a variant strain of SARS-CoV-2 may occur among people who recover from Covid-19, and that vaccines with the ability to generate antibodies against multiple variant forms of the spike protein will be necessary to protect against variant forms of SARS-CoV-2 that are already circulating in the human population.

scholarly journals Crucial Mutations of Spike Protein on SARS-CoV-2 Evolved to Variant Strains Escaping Neutralization of Convalescent Plasmas and RBD-Specific Monoclonal Antibodies

2021 ◽  
Vol 12 ◽  
Author(s):  
Chengchao Ding ◽  
Jun He ◽  
Xiangyu Zhang ◽  
Chengcheng Jiang ◽  
Yong Sun ◽  
...  
Keyword(s):  
Immune Response ◽  
Monoclonal Antibodies ◽  
Humoral Immune Response ◽  
Immune Escape ◽  
Spike Protein ◽  
Single Amino Acid ◽  
Humoral Immune ◽  
Cross Neutralization ◽  
Altered Sensitivity ◽  
Single Amino Acid Mutation

Small number of SARS-CoV-2 epidemic lineages did not efficiently exhibit a neutralization profile, while single amino acid mutation in the spike protein has not been confirmed in altering viral antigenicity resulting in immune escape. To identify crucial mutations in spike protein that escape humoral immune response, we evaluated the cross-neutralization of convalescent plasmas and RBD-specific monoclonal antibodies (mAbs) against various spike protein-based pseudoviruses. Three of 24 SARS-CoV-2 pseudoviruses containing different mutations in spike protein, including D614G, A475V, and E484Q, consistently showed an altered sensitivity to neutralization by convalescent plasmas. A475V and E484Q mutants are highly resistant to neutralization by mAb B38 and 2-4, suggesting that some crucial mutations in spike protein might evolve SARS-CoV-2 variants capable of escaping humoral immune response.

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