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 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 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 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 Identification of Foot-and-Mouth Disease Virus-Specific Linear B-Cell Epitopes To Differentiate between Infected and Vaccinated Cattle

2003 ◽  
Vol 77 (16) ◽  
pp. 8633-8639 ◽  
Author(s):  
Bettina-Judith Höhlich ◽  
Karl-Heinz Wiesmüller ◽  
Tobias Schlapp ◽  
Bernd Haas ◽  
Eberhard Pfaff ◽  
...  
Keyword(s):  
B Cell ◽  
Foot And Mouth Disease ◽  
The United States ◽  
Mouth Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infected Cattle ◽  
B Cell Epitopes ◽  
Foot And Mouth ◽  
Fmdv Strain ◽  
Linear B

ABSTRACT Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. For several years, vaccination of animals, which had proven to be successful for the eradication of the disease, has been forbidden in the United States and the European Community because of the difficulty of differentiating between vaccinated and infected animals. In this study, detailed investigations of the bovine humoral immune response against FMD virus (FMDV) were performed with the aim of identifying viral epitopes recognized specifically by sera derived from FMDV-infected animals. The use of overlapping 15-mer synthetic peptides, covering the whole open reading frame of FMDV strain O1K in a peptide enzyme-linked immunosorbent assay, allowed the identification of 12 FMDV strain O1K-specific linear B-cell epitopes. Six of these linear B-cell epitopes, located in the nonstructural proteins, were used in further assays to compare the reactivities of sera from vaccinated and infected cattle. Antibodies recognizing these peptides could be detected only in sera derived from infected cattle. In further experiments, the reactivity of the six peptides with sera from animals infected with different strains of FMDV was tested, and strain-independent infection-specific epitopes were identified. Thus, these results clearly demonstrate the ability of a simple peptide-based assay to discriminate between infected and conventionally FMD-vaccinated animals.

scholarly journals T- and B-Cell Immune Responses of Patients Who Had Undergone Colectomies to Oral Administration of Salmonella enterica Serovar Typhi Ty21a Vaccine

2003 ◽  
Vol 10 (3) ◽  
pp. 426-430 ◽  
Author(s):  
Jan Kilhamn ◽  
Samuel B. Lundin ◽  
Hans Brevinge ◽  
Ann-Mari Svennerholm ◽  
Marianne Jertborn
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
B Cell ◽  
Healthy Volunteers ◽  
Vaccine Strain ◽  
Salmonella Enterica ◽  
Antibody Responses ◽  
Igg Antibody ◽  
Iga Antibody ◽  
Ifn Γ

ABSTRACT The capacity of an oral live attenuated Salmonella enterica serovar Typhi Ty21a vaccine to induce immune responses in patients who had undergone colectomies because of ulcerative colitis was evaluated, and these responses were compared with those of healthy volunteers. Purified CD4+ and CD8+ T cells from peripheral blood were stimulated in vitro by using the heat-killed Ty21a vaccine strain, and the proliferation and gamma interferon (IFN-γ) production were measured before and 7 or 8 days after vaccination. Salmonella-specific immunoglobulin A (IgA) and IgG antibody responses in serum along with IgA antibody responses in ileostomy fluids from the patients who had undergone colectomies were also evaluated. Three doses of vaccine given 2 days apart failed to induce proliferative T-cell responses in all the six patients who had undergone colectomies, and increases in IFN-γ production were found only among the CD8+ cells from three of the patients. In contrast, both proliferative responses and increased IFN-γ production were observed among CD4+ and CD8+ T cells from 3 and 6 of 10 healthy volunteers, respectively. Salmonella-specific IgA and/or IgG antibody responses in serum were observed for five (56%) of nine patients who had undergone colectomies and in 15 (88%) of 17 healthy volunteers. In ileostomy fluids, significant anti-Salmonella IgA antibody titer increases were detected in six (67%) of nine patients who had undergone colectomies. The impaired T- and B-cell immune responses found after vaccination in the circulation of patients who have undergone colectomies may be explained by a diminished colonization of the Ty21a vaccine strain due to the lack of a terminal ileum and colon.

scholarly journals A Multi-Epitope Fusion Protein-Based p-ELISA Method for Diagnosing Bovine and Goat Brucellosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Dehui Yin ◽  
Qiongqiong Bai ◽  
Xiling Wu ◽  
Han Li ◽  
Jihong Shao ◽  
...  
Keyword(s):  
Fusion Protein ◽  
B Cell ◽  
Sensitivity And Specificity ◽  
Outer Membrane Proteins ◽  
Economic Losses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Method ◽  
Roc Curve Analysis ◽  
Predictive Values ◽  
B Cell Epitopes

In recent years, the incidence of brucellosis has increased annually, causing tremendous economic losses to animal husbandry in a lot of countries. Therefore, developing rapid, sensitive, and specific diagnostic techniques is critical to control the spread of brucellosis. In this study, bioinformatics technology was used to predict the B cell epitopes of the main outer membrane proteins of Brucella, and the diagnostic efficacy of each epitope was verified by an indirect enzyme-linked immunosorbent assay (iELISA). Then, a fusion protein containing 22 verified epitopes was prokaryotically expressed and used as an antigen in paper-based ELISA (p-ELISA) for serodiagnosis of brucellosis. The multi-epitope-based p-ELISA was evaluated using a collection of brucellosis-positive and -negative sera collected from bovine and goat, respectively. Receiver operating characteristic (ROC) curve analysis showed that the sensitivity and specificity of detection-ELISA in diagnosing goat brucellosis were 98.85 and 98.51%. The positive and the negative predictive values were 99.29 and 98.15%, respectively. In diagnosing bovine brucellosis, the sensitivity and specificity of this method were 97.85 and 96.61%, with the positive and negative predictive values being identified as 98.28 and 97.33%, respectively. This study demonstrated that the B cell epitopes contained in major antigenic proteins of Brucella can be a very useful antigen source in developing a highly sensitive and specific method for serodiagnosis of brucellosis.

scholarly journals Heterogeneous Antibody Responses in Tuberculosis

1998 ◽  
Vol 66 (8) ◽  
pp. 3936-3940 ◽  
Author(s):  
Konstantin Lyashchenko ◽  
Roberto Colangeli ◽  
Michel Houde ◽  
Hamdan Al Jahdali ◽  
Dick Menzies ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antibody Response ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Antigen Recognition ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protein Antigens ◽  
Tuberculosis Patients ◽  
Specific Antibodies

ABSTRACT Antibody responses during tuberculosis were analyzed by an enzyme-linked immunosorbent assay with a panel of 10 protein antigens of Mycobacterium tuberculosis. It was shown that serum immunoglobulin G antibodies were produced against a variety of M. tuberculosis antigens and that the vast majority of sera from tuberculosis patients contained antibodies against one or more M. tuberculosis antigens. The number and the species of serologically reactive antigens varied greatly from individual to individual. In a given serum, the level of specific antibodies also varied with the antigen irrespective of the total number of antigens recognized by that particular serum. These findings indicate that person-to-person heterogeneity of antigen recognition, rather than recognition of particular antigens, is a key attribute of the antibody response in tuberculosis.

scholarly journals Decreased Serum Antibody Responses to RecombinantPneumocystisAntigens in HIV-Infected and Uninfected Current Smokers

2010 ◽  
Vol 18 (3) ◽  
pp. 380-386 ◽  
Author(s):  
Kristina Crothers ◽  
Kieran R. Daly ◽  
David Rimland ◽  
Matthew Bidwell Goetz ◽  
Cynthia L. Gibert ◽  
...  
Keyword(s):  
Antibody Response ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Surface Glycoprotein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chronic Obstructive ◽  
Tobit Regression ◽  
Serum Samples ◽  
Cross Sectional ◽  
Prospective Longitudinal

ABSTRACTSerologic studies can provide important insights into the epidemiology and transmission ofPneumocystis jirovecii. Exposure toP. jiroveciican be assessed by serum antibody responses to recombinant antigens from the major surface glycoprotein (MsgC), although factors that influence the magnitude of the antibody response are incompletely understood. We determined the magnitudes of antibody responses toP. jiroveciiin comparison to adenovirus and respiratory syncytial virus (RSV) in HIV-infected and uninfected patients and identified predictors associated with the magnitude of the response. We performed a cross-sectional analysis using serum samples and data from 153 HIV-positive and 92 HIV-negative subjects enrolled in a feasibility study of the Veterans Aging Cohort 5 Site Study (VACS 5). Antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). Independent predictors of antibody responses were determined using multivariate Tobit regression models. The results showed that serum antibody responses toP. jiroveciiMsgC fragments were significantly and independently decreased in current smokers. Antibodies toP. jiroveciialso tended to be lower with chronic obstructive pulmonary disease (COPD), hazardous alcohol use, injection drug use, and HIV infection, although these results were not statistically significant. These results were specific toP. jiroveciiand did not correlate with adenovirus. Antibody responses to RSV were in the inverse direction. Thus, current smoking was independently associated with decreasedP. jiroveciiantibody responses. Whether smoking exerts an immunosuppressive effect that affects theP. jiroveciiantibody response, colonization, or subsequent risk for disease is unclear; prospective, longitudinal studies are needed to evaluate these findings further.

scholarly journals Type I IFN enhances follicular B cell contribution to the T cell–independent antibody response

2010 ◽  
Vol 207 (7) ◽  
pp. 1485-1500 ◽  
Author(s):  
Cristina L. Swanson ◽  
Timothy J. Wilson ◽  
Pamela Strauch ◽  
Marco Colonna ◽  
Roberta Pelanda ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
Antibody Response ◽  
B Cell ◽  
Antibody Responses ◽  
Type I ◽  
Igg Isotypes ◽  
Encapsulated Bacteria ◽  
Follicular B Cells

Humoral immunity to viruses and encapsulated bacteria is comprised of T cell–independent type 2 (TI-2) antibody responses that are characterized by rapid antibody production by marginal zone and B1 B cells. We demonstrate that toll-like receptor (TLR) ligands influence the TI-2 antibody response not only by enhancing the overall magnitude but also by skewing this response to one that is dominated by IgG isotypes. Importantly, TLR ligands facilitate this response by inducing type I interferon (IFN), which in turn elicits rapid and significant amounts of antigen-specific IgG2c predominantly from FO (follicular) B cells. Furthermore, we show that although the IgG2c antibody response requires B cell–autonomous IFN-α receptor signaling, it is independent of B cell–intrinsic TLR signaling. Thus, innate signals have the capacity to enhance TI-2 antibody responses by promoting participation of FO B cells, which then elaborate effective IgG anti-pathogen antibodies.

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