scholarly journals The landscape of antibody binding in SARS-CoV-2 infection

2020 ◽  
Author(s):  
Anna S Heffron ◽  
Sean J McIlwain ◽  
Maya F Amjadi ◽  
David A Baker ◽  
Saniya Khullar ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Diagnostic Accuracy ◽  
B Cell ◽  
Immunosorbent Assay ◽  
Antibody Binding ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peptide Microarray ◽  
B Cell Epitopes ◽  
Homologous Peptide

The search for potential antibody-based diagnostics, vaccines, and therapeutics for pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has focused almost exclusively on the spike (S) and nucleocapsid (N) proteins. Coronavirus membrane (M), ORF3a, and ORF8 proteins are humoral immunogens in other coronaviruses (CoVs) but remain largely uninvestigated for SARS-CoV-2. Here we use ultradense peptide microarray mapping to show that SARS-CoV-2 infection induces robust antibody responses to epitopes throughout the SARS-CoV-2 proteome, particularly in M, in which one epitope achieved excellent diagnostic accuracy. We map 79 B cell epitopes throughout the SARS-CoV-2 proteome and demonstrate that antibodies that develop in response to SARS-CoV-2 infection bind homologous peptide sequences in the six other known human CoVs. We also confirm reactivity against four of our top-ranking epitopes by enzyme-linked immunosorbent assay (ELISA). Illness severity correlated with increased reactivity to nine SARS-CoV-2 epitopes in S, M, N, and ORF3a in our population. Our results demonstrate previously unknown, highly reactive B cell epitopes throughout the full proteome of SARS-CoV-2 and other CoV proteins.

scholarly journals The landscape of antibody binding in SARS-CoV-2 infection

PLoS Biology ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. e3001265
Author(s):  
Anna S. Heffron ◽  
Sean J. McIlwain ◽  
Maya F. Amjadi ◽  
David A. Baker ◽  
Saniya Khullar ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Diagnostic Accuracy ◽  
B Cell ◽  
Immunosorbent Assay ◽  
Antibody Binding ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peptide Microarray ◽  
B Cell Epitopes ◽  
Homologous Peptide

The search for potential antibody-based diagnostics, vaccines, and therapeutics for pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has focused almost exclusively on the spike (S) and nucleocapsid (N) proteins. Coronavirus membrane (M), ORF3a, and ORF8 proteins are humoral immunogens in other coronaviruses (CoVs) but remain largely uninvestigated for SARS-CoV-2. Here, we use ultradense peptide microarray mapping to show that SARS-CoV-2 infection induces robust antibody responses to epitopes throughout the SARS-CoV-2 proteome, particularly in M, in which 1 epitope achieved excellent diagnostic accuracy. We map 79 B cell epitopes throughout the SARS-CoV-2 proteome and demonstrate that antibodies that develop in response to SARS-CoV-2 infection bind homologous peptide sequences in the 6 other known human CoVs. We also confirm reactivity against 4 of our top-ranking epitopes by enzyme-linked immunosorbent assay (ELISA). Illness severity correlated with increased reactivity to 9 SARS-CoV-2 epitopes in S, M, N, and ORF3a in our population. Our results demonstrate previously unknown, highly reactive B cell epitopes throughout the full proteome of SARS-CoV-2 and other CoV proteins.

scholarly journals Natural immunogenic properties of bioinformatically predicted linear B-cell epitopes of dengue envelope and pre-membrane proteins

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Mahesha N. Nadugala ◽  
Chandima Jeewandara ◽  
Ramesh S. Jadi ◽  
Gathsaurie N. Malavige ◽  
Aravinda M. de Silva ◽  
...  
Keyword(s):  
Antibody Response ◽  
B Cell ◽  
Healthy Volunteers ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
B Cell Epitopes ◽  
Viral Neutralization ◽  
Denv Serotypes ◽  
Loop Region ◽  
Positive Antibody

Abstract Background The natural antibody responses to B-cell epitopes from dengue structural proteins were assessed using immune sera from people having well-defined past dengue infections with one of the four serotypes. Method Based on an immune-computational analysis previously conducted, nineteen epitopes from the envelope (E) and eight epitopes from pre-membrane (prM), which were more than 50% conserved across all the four DENV serotypes, were selected. Peptides to represent these B-cell epitopes were obtained from commercially available arrays, and were subjected to enzyme linked immunosorbent assay with sera obtained from dengue seropositive healthy volunteers (DENV1 n = 12: DENV2 n = 12: DENV3 n = 12 and DENV4 n = 12), and 10 dengue seronegative healthy volunteers from Sri Lanka. The cut-off value for the positive antibody response was set by taking the mean response of a peptide to the negative sera plus three standard deviations. The peptides (N = 7) showing the broad immune responses were used to generate antibodies in three mice (Balb/c) batches. The mice antisera were then subjected to microneutralization assays against all the four DENV serotypes. An EC50 viral neutralization ≥ 40 times the serum dilution was considered as neutralizing. Results Five of the E-peptide and two prM peptides were recognised by most individuls exposed to infections with each of the four serotypes, showing a serotype cross-reactive broad antibody response. The mice immune sera against the peptides representing the five E protein epitopes neutralized all the four DENV serotypes. Two of these five epitopes are from the Domain II, whereas one of them includes the whole bc-loop region. Conclusion The antibody responses of highly conserved epitopes across the serotypes, were broadly responsive with sera of all four DENV serotypes collected from individuals infected with only one DENV serotype. Weakly conserved epitopes showed rather specific antibody responses dominated by one or few serotypes.

scholarly journals Identification of Continuous B-Cell Epitopes on the Protein Moiety of the 58-Kilodalton Cell Wall Mannoprotein ofCandida albicans Belonging to a Family of Immunodominant Fungal Antigens

2001 ◽  
Vol 69 (5) ◽  
pp. 2909-2919 ◽  
Author(s):  
Angel Viudes ◽  
Sofia Perea ◽  
Jose L. Lopez-Ribot
Keyword(s):  
Amino Acid ◽  
B Cell ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Amino Acid Residues ◽  
B Cell Epitopes ◽  
C Terminus ◽  
Elisa Testing ◽  
Fungal Antigens ◽  
Protein Moiety

ABSTRACT The 58-kiloDalton mannoprotein (mp58) on the surface ofCandida albicans is highly immunogenic, is expressed by allC. albicans isolates tested, and elicits strong antibody responses during candidiasis. It belongs to a family of immunodominant fungal antigens with representatives also in different species ofAspergillus. The amino acid sequence of the protein portion of mp58 as deduced from the DNA sequence of its encoding gene (FBP1/PRA1) was used to synthesize a complete set of overlapping dodecapeptides (overlap, 7; offset, 5) covalently attached to the surface of derivatized polyethylene pins. The pin-coupled peptides were used in a modified enzyme-linked immunosorbent assay (ELISA) to identify continuous epitopes recognized by a number of antiserum preparations containing anti-mp58 antibodies. This comprehensive epitope-scanning study revealed the presence of multiple immunoreactive continuous B-cell epitopes within the protein sequence. Regions of increased reactivity included both the amino and carboxy termini of the mature protein (encompassing amino acid residues 16 to 50 and 286 to 299, respectively) and four internal regions spanning amino acids at positions 66 to 92, 121 to 142, 148 to 192, and 211 to 232. Further delineation of epitopic regions and identification of the boundaries of the antigenic sites was performed upon ELISA testing with a second Pepset consisting of completely overlapping 8-mer peptides spanning these reactive regions in the protein moiety of mp58. The highly reactive epitopic region at the C terminus of the protein was further evaluated using both window net and replacement net analyses. A synthetic peptide corresponding to the last 10 amino acid residues at the C terminus of the protein was immunogenic when injected into mice after being coupled to a carrier protein. Moreover, antibodies in the resulting sera specifically recognized the homologus mp58 in ELISAs and immunoblot assays. Delineation of the antibody responses to mp58 could provide the basis for the development of novel immunity-based prophylactic, therapeutic, and diagnostic techniques for the management of candidiasis.

scholarly journals Limited Diagnostic Capacities of Two Commercial Assays for the Detection of Leptospira Immunoglobulin M Antibodies in Laos

2006 ◽  
Vol 13 (10) ◽  
pp. 1166-1169 ◽  
Author(s):  
Stuart D. Blacksell ◽  
Lee Smythe ◽  
Rattanaphone Phetsouvanh ◽  
Michael Dohnt ◽  
Rudy Hartskeerl ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Immunosorbent Assay ◽  
Gold Standard ◽  
Agglutination Test ◽  
Immunoglobulin M ◽  
Microscopic Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Utility

ABSTRACT The diagnostic utility of immunochromatographic (Leptotek) and enzyme-linked immunosorbent assay (ELISA; Panbio) tests for the detection of Leptospira immunoglobulin M antibodies was assessed in febrile adults admitted in Vientiane, Laos. Both tests demonstrated poor diagnostic accuracy using admission serum (Leptotek sensitivity of 47.3% and specificity of 75.5%: ELISA sensitivity of 60.9% and specificity of 65.6%) compared to the Leptospira “gold standard” microscopic agglutination test.

Diagnostic accuracy of alpha-defensin enzyme-linked immunosorbent assay in the clinical evaluation of painful hip and knee arthroplasty with possible prosthetic joint infection

2019 ◽  
Vol 101-B (8) ◽  
pp. 970-977 ◽  
Author(s):  
S. Kleiss ◽  
N. M. Jandl ◽  
A. Novo de Oliveira ◽  
W. Rüther ◽  
A. Niemeier
Keyword(s):  
Synovial Fluid ◽  
Diagnostic Accuracy ◽  
Immunosorbent Assay ◽  
Knee Arthroplasty ◽  
Prosthetic Joint Infection ◽  
Joint Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Coagulase Negative Staphylococci ◽  
Predictive Values ◽  
Prosthetic Joint

Aims The aim of this study was to evaluate the diagnostic accuracy of the synovial alpha-defensin enzyme-linked immunosorbent assay (ELISA) for the diagnosis of prosthetic joint infection (PJI) in the work-up prior to revision of total hip (THA) and knee arthroplasty (TKA). Patients and Methods Inclusion criteria for this prospective cohort study were acute or chronic symptoms of the index joint without specific exclusion criteria. Synovial fluid aspirates of 202 patients were analyzed and semiquantitative laboratory alpha-defensin ELISA was performed. Final diagnosis of PJI was established by examination of samples obtained during revision surgery. Results Sensitivity and specificity of the alpha-defensin ELISA for PJI were 78.2% (95% confidence interval (CI) 66.7 to 88.5) and 96.6% (95% CI 93.0 to 99.3). Positive and negative predictive values were 89.6% (95% CI 80.6 to 97.8) and 92.2% (95% CI 87.5 to 96.1). The test remained false-negative in 22% of septic revisions, most of which were due to coagulase-negative staphylococci all occurring in either late-chronic or early-postoperative PJI. Conclusion The routine use of synovial fluid alpha-defensin laboratory ELISA in the preoperative evaluation of symptomatic THAs and TKAs is insufficient to accurately diagnose PJI. Particularly in cases involving low-virulence organisms, such as coagulase-negative staphylococci, there remains a need for tests with a higher sensitivity. Cite this article: Bone Joint J 2019;101-B:970–977.

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