scholarly journals Changes in SARS-CoV-2 Spike versus Nucleoprotein Antibody Responses Impact the Estimates of Infections in Population-Based Seroprevalence Studies

2020 ◽  
Author(s):  
Craig Fenwick ◽  
Antony Croxatto ◽  
Alix T. Coste ◽  
Florence Pojer ◽  
Cyril André ◽  
...  
Keyword(s):  
General Population ◽  
Antibody Response ◽  
Specific Antibody ◽  
Post Infection ◽  
Acute Infection ◽  
Population Based ◽  
Antibody Responses ◽  
S Protein ◽  
N Protein ◽  
Protein Assays

SARS-CoV-2-specific antibody responses to the Spike (S) protein monomer, S protein native trimeric form or the nucleocapsid (N) proteins were evaluated in cohorts of individuals with acute infection (n=93) and in individuals enrolled in a post-infection seroprevalence population study (n=578) in Switzerland. Commercial assays specific for the S1 monomer, for the N protein and a newly developed Luminex assay using the S protein trimer were found to be equally sensitive in antibody detection in the acute infection phase samples. Interestingly, as compared to anti-S antibody responses, those against the N protein appear to wane in the post-infection cohort. Seroprevalence in a ‘positive patient contacts’ group (n=177) was underestimated by N protein assays by 10.9 to 32.2% and the ‘random selected’ general population group (n=311) was reduced up to 45% reduction relative to S protein assays. The overall reduction in seroprevalence targeting only anti-N antibodies for the total cohort ranged from 9.4 to 31%. Of note, the use of the S protein in its native trimer form was significantly more sensitive as compared to monomeric S proteins. These results indicate that the assessment of anti-S IgG antibody responses against the native trimeric S protein should be implemented to estimate SARS-CoV-2 infections in population-based seroprevalence studies. IMPORTANCE In the present study, we have determined SARS-CoV-2-specific antibody responses in sera of acute and post-infection phase subjects. Our results indicate that antibody responses against viral S and N proteins were equally sensitive in the acute phase of infection but that responses against N appear to wane in the post-infection phase while those against S protein persist over time. The most sensitive serological assay in both acute and post-infection phases used the native S protein trimer as binding antigen that has significantly greater conformational epitopes for antibody binding compared to the S1 monomer protein used in other assays. We believe that these results are extremely important in order to generate correct estimates of SARS-CoV-2 infections in the general population. Furthermore, the assessment of antibody responses against the trimeric S protein will be critical to evaluate the durability of the antibody response and for the characterization of a vaccine-induced antibody response.

scholarly journals Changes in SARS-CoV-2 Antibody Responses Impact the Estimates of Infections in Population-Based Seroprevalence Studies

2020 ◽  
Author(s):  
Craig Fenwick ◽  
Antony Croxatto ◽  
Alix T. Coste ◽  
Florence Pojer ◽  
Cyril Andre ◽  
...  
Keyword(s):  
General Population ◽  
Acute Infection ◽  
Population Based ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Igg Antibody ◽  
S Protein ◽  
N Protein ◽  
Total Cohort

We have determined SARS-CoV-2-specific antibody responses in a cohort of 96 individuals with acute infection and in 578 individuals enrolled in a seroprevalence population study in Switzerland including three groups, i.e. subjects with previous RT-PCR confirmed SARS-CoV-2 infections (n=90), positive patient contacts (n=177) and random selected subjects (n=311). SARS-CoV-2 antibody responses specific to the Spike (S), in the monomeric and native trimeric forms, and/or the nucleocapsid (N) proteins were equally sensitive in the acute infection phase. Interestingly, as compared to anti-S antibody responses, those against the N protein appear to wane in the post-infection and substantially underestimated the proportion of SARS-CoV-2 infections in the groups of patient positive contacts, i.e. 10.9 to 32.2% reduction and in the random selected general population, i.e. up to 45% reduction. The overall reduction in seroprevalence targeting only anti-N IgG antibodies for the total cohort ranged from 9.4 to 31%. Of note, the use of the S protein in its native trimer form was more sensitive as compared to monomeric S proteins. These results indicate that the assessment of anti-S IgG antibody responses against the native trimeric S protein should be implemented to estimate SARS-CoV-2 infections in population-based seroprevalence studies.

scholarly journals From Multiplex Serology to Serolomics—A Novel Approach to the Antibody Response against the SARS-CoV-2 Proteome

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 749
Author(s):  
Julia Butt ◽  
Rajagopal Murugan ◽  
Theresa Hippchen ◽  
Sylvia Olberg ◽  
Monique van Straaten ◽  
...  
Keyword(s):  
Antibody Response ◽  
High Throughput ◽  
Large Population ◽  
High Sensitivity ◽  
Population Based ◽  
Antibody Responses ◽  
Hek293 Cells ◽  
Novel Approach ◽  
Assay Performance ◽  
Multiplex Serology

The emerging SARS-CoV-2 pandemic entails an urgent need for specific and sensitive high-throughput serological assays to assess SARS-CoV-2 epidemiology. We, therefore, aimed at developing a fluorescent-bead based SARS-CoV-2 multiplex serology assay for detection of antibody responses to the SARS-CoV-2 proteome. Proteins of the SARS-CoV-2 proteome and protein N of SARS-CoV-1 and common cold Coronaviruses (ccCoVs) were recombinantly expressed in E. coli or HEK293 cells. Assay performance was assessed in a COVID-19 case cohort (n = 48 hospitalized patients from Heidelberg) as well as n = 85 age- and sex-matched pre-pandemic controls from the ESTHER study. Assay validation included comparison with home-made immunofluorescence and commercial enzyme-linked immunosorbent (ELISA) assays. A sensitivity of 100% (95% CI: 86–100%) was achieved in COVID-19 patients 14 days post symptom onset with dual sero-positivity to SARS-CoV-2 N and the receptor-binding domain of the spike protein. The specificity obtained with this algorithm was 100% (95% CI: 96–100%). Antibody responses to ccCoVs N were abundantly high and did not correlate with those to SARS-CoV-2 N. Inclusion of additional SARS-CoV-2 proteins as well as separate assessment of immunoglobulin (Ig) classes M, A, and G allowed for explorative analyses regarding disease progression and course of antibody response. This newly developed SARS-CoV-2 multiplex serology assay achieved high sensitivity and specificity to determine SARS-CoV-2 sero-positivity. Its high throughput ability allows epidemiologic SARS-CoV-2 research in large population-based studies. Inclusion of additional pathogens into the panel as well as separate assessment of Ig isotypes will furthermore allow addressing research questions beyond SARS-CoV-2 sero-prevalence.

Interferon activation status underlies higher antibody response to viral antigens in patients with systemic lupus erythematosus receiving no or light treatment

Rheumatology ◽  
2020 ◽  
Author(s):  
Albin Björk ◽  
Rui Da Silva Rodrigues ◽  
Elina Richardsdotter Andersson ◽  
Jorge I Ramírez Sepúlveda ◽  
Johannes Mofors ◽  
...  
Keyword(s):  
Antibody Response ◽  
Specific Antibody ◽  
Lupus Erythematosus ◽  
Serum Proteins ◽  
Light Treatment ◽  
Antibody Responses ◽  
Type I ◽  
Specific Antibody Response ◽  
Viral Antigens

Abstract Objectives Infections have been proposed as an environmental risk factor for autoimmune disease. Responses to microbial antigens may be studied in vivo during vaccination. We therefore followed patients with SLE and controls during split-virion influenza vaccination to quantify antibody responses against viral antigens and associated cellular and proteome parameters. Methods Blood samples and clinical data were collected from female patients with SLE with no or HCQ and/or low-dose prednisolone treatment (n = 29) and age- and sex-matched healthy controls (n = 17). Vaccine-specific antibody titres were measured by ELISA and IFN-induced gene expression in monocytes by quantitative PCR. Serum proteins were measured by proximity extension assay and disease-associated symptoms were followed by questionnaires. Results The vaccine-specific antibody response was significantly higher in patients compared with controls and titres of IgG targeting the viral proteins were higher in patients than controls at both 1 and 3 months after immunization. Clinical disease symptoms and autoantibody titres remained unchanged throughout the study. Notably, a positive pre-vaccination mRNA-based IFN score was associated with a significantly higher vaccine-specific antibody response and with a broader profile of autoantibody specificities. Screening of serum protein biomarkers revealed higher levels of IFN-regulated proteins in patients compared with controls and that levels of such proteins correlated with the vaccine-specific IgG response, with C-C motif chemokine ligand 3 exhibiting the strongest association. Conclusion Augmented antibody responses to viral antigens develop in patients with SLE on no or light treatment and associate with markers of type I IFN system activation at the RNA and protein levels.

scholarly journals A Comprehensive View on the Human Antibody Repertoire Against Staphylococcus aureus Antigens in the General Population

2021 ◽  
Vol 12 ◽  
Author(s):  
Tanja C. Meyer ◽  
Stephan Michalik ◽  
Silva Holtfreter ◽  
Stefan Weiss ◽  
Nele Friedrich ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
General Population ◽  
Antibody Response ◽  
Dynamic Range ◽  
Population Based ◽  
Antibody Detection ◽  
Individual Response ◽  
Human Antibody ◽  
Comprehensive Overview ◽  
Suspension Array

Our goal was to provide a comprehensive overview of the antibody response to Staphylococcus aureus antigens in the general population as a basis for defining disease-specific profiles and diagnostic signatures. We tested the specific IgG and IgA responses to 79 staphylococcal antigens in 996 individuals from the population-based Study of Health in Pomerania. Using a dilution-based multiplex suspension array, we extended the dynamic range of specific antibody detection to seven orders of magnitude, allowing the precise quantification of high and low abundant antibody specificities in the same sample. The observed IgG and IgA antibody responses were highly heterogeneous with differences between individuals as well as between bacterial antigens that spanned several orders of magnitude. Some antigens elicited significantly more IgG than IgA and vice versa. We confirmed a strong influence of colonization on the antibody response and quantified the influence of sex, smoking, age, body mass index, and serum glucose on anti-staphylococcal IgG and IgA. However, all host parameters tested explain only a small part of the extensive variability in individual response to the different antigens of S. aureus.

scholarly journals Design and proof-of-concept for targeted phage-based COVID-19 vaccination strategies with a streamlined cold-free supply chain

2021 ◽  
Author(s):  
Daniela I. Staquicini ◽  
Fenny H. F. Tang ◽  
Christopher Markosian ◽  
Virginia J. Yao ◽  
Fernanda I. Staquicini ◽  
...  
Keyword(s):  
Antibody Response ◽  
Specific Antibody ◽  
Human Population ◽  
Large Scale ◽  
Protein Gene ◽  
Scale Production ◽  
Proof Of Concept ◽  
Specific Antibody Response ◽  
S Protein ◽  
Large Scale Production

AbstractDevelopment of effective vaccines against Coronavirus Disease 2019 (COVID-19) is a global imperative. Rapid immunization of the world human population against a widespread, continually evolving, and highly pathogenic virus is an unprecedented challenge, and many different vaccine approaches are being pursued to meet this task. Engineered filamentous bacteriophage (phage) have unique potential in vaccine development due to their inherent immunogenicity, genetic plasticity, stability, cost-effectiveness for large-scale production, and proven safety profile in humans. Herein we report the design, development, and initial evaluation of targeted phage-based vaccination approaches against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) by using dual ligand peptide-targeted phage and adeno-associated virus/phage (AAVP) particles. Towards a unique phage- and AAVP-based dual-display candidate approach, we first performed structure-guided antigen design to select six solvent-exposed epitopes of the SARS-CoV-2 spike (S) protein for display on the recombinant major capsid coat protein pVIII. Targeted phage particles carrying one of these epitopes induced a strong and specific humoral response. In an initial experimental approach, when these targeted phage particles were further genetically engineered to simultaneously display a ligand peptide (CAKSMGDIVC) on the minor capsid protein pIII, which enables receptor-mediated transport of phage particles from the lung epithelium into the systemic circulation (termed “dual-display”), they enhanced a systemic and specific spike (S) protein-specific antibody response upon aerosolization into the lungs of mice. In a second line of investigation, we engineered targeted AAVP particles to deliver the entire S protein gene under the control of a constitutive cytomegalovirus (CMV) promoter, which induced tissue-specific transgene expression stimulating a systemic S protein-specific antibody response. As proof-of-concept preclinical experiments, we show that targeted phage- and AAVP-based particles serve as robust yet versatile enabling platforms for ligand-directed immunization and promptly yield COVID-19 vaccine prototypes for further translational development.SignificanceThe ongoing COVID-19 global pandemic has accounted for over 2.5 million deaths and an unprecedented impact on the health of mankind worldwide. Over the past several months, while a few COVID-19 vaccines have received Emergency Use Authorization and are currently being administered to the entire human population, the demand for prompt global immunization has created enormous logistical challenges--including but not limited to supply, access, and distribution--that justify and reinforce the research for additional strategic alternatives. Phage are viruses that only infect bacteria and have been safely administered to humans as antibiotics for decades. As experimental proof-of-concept, we demonstrated that aerosol pulmonary vaccination with lung-targeted phage particles that display short epitopes of the S protein on the capsid as well as preclinical vaccination with targeted AAVP particles carrying the S protein gene elicit a systemic and specific immune response against SARS-CoV-2 in immunocompetent mice. Given that targeted phage- and AAVP-based viral particles are sturdy yet simple to genetically engineer, cost-effective for rapid large-scale production in clinical grade, and relatively stable at room temperature, such unique attributes might perhaps become additional tools towards COVID-19 vaccine design and development for immediate and future unmet needs.

scholarly journals Antibody Responses against Enterovirus Proteases are Potential Markers for an Acute Infection

Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Niila V. V. Saarinen ◽  
Virginia M. Stone ◽  
Minna M. Hankaniemi ◽  
Magdalena A. Mazur ◽  
Tytti Vuorinen ◽  
...  
Keyword(s):  
Antibody Response ◽  
Respiratory Infections ◽  
Acute Infection ◽  
Diagnostic Odds Ratio ◽  
Antibody Responses ◽  
Structural Proteins ◽  
Igg Antibody ◽  
Potential Marker ◽  
Igm Elisa ◽  
Immunological Assays

Background: Enteroviruses are a group of common non-enveloped RNA viruses that cause symptoms ranging from mild respiratory infections to paralysis. Due to the abundance of enterovirus infections it is hard to distinguish between on-going and previous infections using immunological assays unless the IgM fraction is studied. Methods: In this study we show using Indirect ELISA and capture IgM ELISA that an IgG antibody response against the nonstructural enteroviral proteins 2A and 3C can be used to distinguish between IgM positive (n = 22) and IgM negative (n = 20) human patients with 83% accuracy and a diagnostic odds ratio of 30. Using a mouse model, we establish that the antibody response to the proteases is short-lived compared to the antibody response to the structural proteins in. As such, the protease antibody response serves as a potential marker for an acute infection. Conclusions: Antibody responses against enterovirus proteases are shorter-lived than against structural proteins and can differentiate between IgM positive and negative patients, and therefore they are a potential marker for acute infections.

scholarly journals The study of antibody responses to influenza neuraminidase using a lentiviral pseudotype based ELLA

2017 ◽  
Author(s):  
Fabrizio Biuso ◽  
George Carnell ◽  
Emanuele Montomoli ◽  
Nigel Temperton
Keyword(s):  
Antibody Response ◽  
Specific Antibody ◽  
Virus Entry ◽  
Antibody Responses ◽  
Surface Glycoprotein ◽  
Wild Type Virus ◽  
Target Cells ◽  
Type Virus ◽  
Wild Type ◽  
Reassortant Viruses

AbstractInfluenza pseudotypes represent an alternative to wild type virus for serological assays. To date, pseudotypes (PV) have predominantly been used as surrogates for wild type viruses in microneutralisation assays, where the surface glycoprotein of interest and a reporter gene (such as Luciferase) are used to assess if virus entry into target cells could be inhibited by serum antibodies. The influenza neuraminidase (NA) has the ability to bud and release new virions with or without the contribution of Haemagglutinin (HA). Influenza pseudotypes expressing NA alone, or with HA, were produced to evaluate the antibody response against NA using the enzyme-linked lectin assay (ELLA). The expression of an avian HA with human NAs has enabled the detection of specific antibody reponses against the human circulating subtypes of NA. Within this study a PV-based ELLA assay has been investigated with a pilot panel of sera prepared for an international CONSISE study. Preliminary results have confirmed that the assay is sensitive and could potentially represent a valid alternative to the classical ELLA assay, which requires the employment of reassortant viruses.

scholarly journals Anti-Leptospira immunoglobulin profiling in mice reveals strain specific IgG and persistent IgM responses associated with virulence and renal colonization

2020 ◽  
Author(s):  
Frédérique Vernel-Pauillac ◽  
Gerald Murray ◽  
Ben Adler ◽  
Ivo G. Boneca ◽  
Catherine Werts
Keyword(s):  
Immune Response ◽  
Antibody Response ◽  
Post Infection ◽  
Severe Disease ◽  
Humoral Response ◽  
Antibody Responses ◽  
High Dose ◽  
Leptospira Interrogans ◽  
Homologous Challenge

AbstractLeptospira interrogans is a pathogenic spirochete responsible for leptospirosis, a neglected, zoonotic reemerging disease. Humans are sensitive hosts and may develop severe disease. Some animal species, such as rats and mice can become asymptomatic renal carriers. More than 350 leptospiral serovars have been identified, classified on the basis of the antibody response directed against the lipopolysaccharide (LPS). Similarly to whole inactivated bacteria used as human vaccines, this response is believed to confer only short-term, serogroup-specific protection. The immune response of hosts against leptospires has not been thoroughly studied and correlates of protection would be required to test vaccine candidates. In this work, we studied the immunoglobulin (Ig) profiles in mice infected with L. interrogans over time to determine whether this humoral response confers long-term protection after homologous challenge six months post-infection.Groups of mice were injected intraperitoneally with 2×107 leptospires of one of three pathogenic serovars (Manilae, Copenhageni or Icterohaemorrhagiae), attenuated mutants or heat-killed bacteria. Leptospira-specific immunoglobulin (IgA, IgM, IgG and 4 subclasses) produced in the first weeks up to 6 months post-infection were measured by ELISA. Strikingly, we found sustained high levels of IgM in mice infected with the pathogenic Manilae and Copenhageni strains, both colonizing the kidney. In contrast, the Icterohaemorrhagiae strain did not lead to kidney colonization, even at high dose, and triggered a classical IgM response that peaked at day 8 post-infection and disappeared. The virulent Manilae and Copenhageni serovars elicited high levels and similar profiles of IgG subclasses in contrast to Icterohaemorrhagiae strains that stimulated weaker antibody responses. Inactivated heat-killed Manilae strains elicited very low responses. However, all mice pre-injected with leptospires challenged with high doses of homologous bacteria did not develop acute leptospirosis, and all antibody responses were boosted after challenge. Furthermore, we showed that 2 months post challenge, mice pre-infected with the M895 Manilae LPS mutant or heat-killed bacterin were completely protected against renal colonization. In conclusion, we observed a sustained IgM response potentially associated with chronic leptospiral renal infection. We also demonstrated in mice different profiles of protective antibody response after L. interrogans infection, depending on the serovar and virulence of strains.Author summaryLeptospira interrogans is a pathogenic spirochete responsible for leptospirosis, a neglected zoonotic reemerging disease. The immune response of hosts against these bacteria has not been thoroughly studied. Here, we studied over 6 months the immunoglobulin (Ig) profiles in mice infected with L. interrogans and determined whether this humoral response confers long-term protection after homologous challenge six months after primary infection. Groups of mice were infected intraperitoneally with 2×107 bacteria of one of three different pathogenic serovars (Manilae, Copenhageni and Icterohaemorrhagiae) and some corresponding attenuated avirulent mutants. We measured by ELISA each type of Leptospira-specific Ig (IgA, IgM, IgG and 4 subclasses) produced in the first weeks up to 6 months post-infection. We showed different profiles of antibody response after L. interrogans challenge in mice, depending on the serovar and virulence of strains. However, all infected mice, including the ones harboring low antibody levels, like mice vaccinated with an inactivated, heat-killed strain, were protected against leptospirosis after challenge. Notably, we also showed an unusual sustained IgM response associated with chronic leptospiral colonization. Altogether, this long-term immune protection is different from what is known in humans and warrants further investigation.

scholarly journals Comparative analysis of antigen-specific anti-SARS-CoV-2 antibody isotypes in COVID-19 patients

2020 ◽  
Author(s):  
Hidetsugu Fujigaki ◽  
Masato Inaba ◽  
Michiko Osawa ◽  
Saya Moriyama ◽  
Yoshimasa Takahashi ◽  
...  
Keyword(s):  
Specific Antibody ◽  
Serological Test ◽  
Polymerase Chain Reaction Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
S Protein ◽  
Neutralizing Activity ◽  
N Protein ◽  
Specificity And Sensitivity ◽  
Antibody Isotypes

AbstractSerological tests for detection of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in blood are expected to identify individuals who have acquired immunity against SARS-CoV-2 and indication of seroprevalence of SARS-CoV-2 infection. Many serological tests have been developed to detect antibodies against SARS-CoV-2. However, these tests have considerable variations in their specificity and sensitivity, and whether they can predict levels of neutralizing activity is yet to be determined. This study aimed to investigate the kinetics and neutralizing activity of various antigen-specific antibody isotypes against SARS-CoV-2 in serum of coronavirus disease 2019 (COVID-19) patients confirmed via polymerase chain reaction test. We developed IgG, IgM and IgA measurement assays for each antigen, including receptor-binding domain (RBD) of spike (S) protein, S1 domain, full length S protein, S trimer and nucleocapsid (N) domain, based on enzyme-linked immunosorbent assay. The assays of the S protein for all isotypes showed high specificity, while the assays for all isotypes against N protein showed lower specificity. The sensitivity of all antigen-specific antibody isotypes depended on the timing of the serum collection and all of them, except for IgM against N protein, reached more than 90% at 15-21 days post-symptom onset. The best correlation with virus neutralizing activity was found for IgG against RBD (RBD-IgG), and levels of RBD-IgG in sera from four severe COVID-19 patients increased concordantly with neutralizing activity. Our results provide valuable information regarding the selection of serological test for seroprevalence and vaccine evaluation studies.

scholarly journals Impaired Cellular Immunity to SARS-CoV-2 in Severe COVID-19 Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Ling Ni ◽  
Meng-Li Cheng ◽  
Yu Feng ◽  
Hui Zhao ◽  
Jingyuan Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cellular Immunity ◽  
Specific Antibody ◽  
Peripheral Blood ◽  
Neutralizing Antibodies ◽  
Acute Infection ◽  
Peripheral Blood Lymphocytes ◽  
Antibody Responses ◽  
Humoral Immune

The high infection rate and rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) make it a world-wide pandemic. Individuals infected by the virus exhibited different degrees of symptoms, and most convalescent individuals have been shown to develop both cellular and humoral immune responses. However, virus-specific adaptive immune responses in severe patients during acute phase have not been thoroughly studied. Here, we found that in a group of COVID-19 patients with acute respiratory distress syndrome (ARDS) during hospitalization, most of them mounted SARS-CoV-2-specific antibody responses, including neutralizing antibodies. However, compared to healthy controls, the percentages and absolute numbers of both NK cells and CD8+ T cells were significantly reduced, with decreased IFNγ expression in CD4+ T cells in peripheral blood from severe patients. Most notably, their peripheral blood lymphocytes failed in producing IFNγ against viral proteins. Thus, severe COVID-19 patients at acute infection stage developed SARS-CoV-2-specific antibody responses but were impaired in cellular immunity, which emphasizes on the role of cellular immunity in COVID-19.

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