scholarly journals Identification of B- and T-Cell Epitopes of BB, a Carrier Protein Derived from the G Protein of Streptococcus Strain G148

2003 ◽  
Vol 10 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Liliane Goetsch ◽  
Jean Francois Haeuw ◽  
Thierry Champion ◽  
Christine Lacheny ◽  
Thien N’Guyen ◽  
...  

ABSTRACT Most conventional vaccines consist of killed organisms or purified antigenic proteins. Such molecules are generally poorly immunogenic and need to be coupled to carrier proteins. We have identified a new carrier molecule, BB, derived from the G protein of Streptococcus strain G148. We show that BB is able to induce strong antibody responses when conjugated to peptides or polysaccharides. In order to localize T and B cell epitopes in BB and match them with the albumin-binding region of the molecule, we immunized mice with BB, performed B and T pepscan analyses, and compared the results with pepscan done with sera and cells from humans. Our results indicate that BB has two distinct T helper epitopes, seven linear B-cell epitopes, and one conformational B-cell epitope in BALB/c mice. Four linear B-cell epitopes were identified from human sera, three of which overlapped mouse B-cell epitopes. Finally, three human T-cell epitopes were detected on the BB protein. One of these T-cell epitopes is common to BALB/c mice and humans and was localized in the region that contains the albumin-binding site. These data are of interest for the optimization of new carrier molecules derived from BB.

2004 ◽  
Vol 72 (12) ◽  
pp. 7360-7366 ◽  
Author(s):  
Jeffrey R. Abbott ◽  
Guy H. Palmer ◽  
Chris J. Howard ◽  
Jayne C. Hope ◽  
Wendy C. Brown

ABSTRACT Organisms in the genus Anaplasma express an immunodominant major surface protein 2 (MSP2), composed of a central hypervariable region (HVR) flanked by highly conserved regions. Throughout Anaplasma marginale infection, recombination results in the sequential appearance of novel MSP2 variants and subsequent control of rickettsemia by the immune response, leading to persistent infection. To determine whether immune evasion and selection for variant organisms is associated with a predominant response against HVR epitopes, T-cell and linear B-cell epitopes were localized by measuring peripheral blood gamma interferon-secreting cells, proliferation, and antibody binding to 27 overlapping peptides spanning MSP2 in 16 cattle. Similar numbers of MSP2-specific CD4+ T-cell epitopes eliciting responses of similar magnitude were found in conserved and hypervariable regions. T-cell epitope clusters recognized by the majority of animals were identified in the HVR (amino acids [aa] 171 to 229) and conserved regions (aa 101 to 170 and 272 to 361). In contrast, linear B-cell epitopes were concentrated in the HVR, residing within hydrophilic sequences. The pattern of recognition of epitope clusters by T cells and of HVR epitopes by B cells is consistent with the influence of protein structure on epitope recognition.


Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 432 ◽  
Author(s):  
Jessica M. van Loben Sels ◽  
Kim Y. Green

Human norovirus (HuNoV) is the leading cause of acute nonbacterial gastroenteritis. Vaccine design has been confounded by the antigenic diversity of these viruses and a limited understanding of protective immunity. We reviewed 77 articles published since 1988 describing the isolation, function, and mapping of 307 unique monoclonal antibodies directed against B cell epitopes of human and murine noroviruses representing diverse Genogroups (G). Of these antibodies, 91, 153, 21, and 42 were reported as GI-specific, GII-specific, MNV GV-specific, and G cross-reactive, respectively. Our goal was to reconstruct the antigenic topology of noroviruses in relationship to mapped epitopes with potential for therapeutic use or inclusion in universal vaccines. Furthermore, we reviewed seven published studies of norovirus T cell epitopes that identified 18 unique peptide sequences with CD4- or CD8-stimulating activity. Both the protruding (P) and shell (S) domains of the major capsid protein VP1 contained B and T cell epitopes, with the majority of neutralizing and HBGA-blocking B cell epitopes mapping in or proximal to the surface-exposed P2 region of the P domain. The majority of broadly reactive B and T cell epitopes mapped to the S and P1 arm of the P domain. Taken together, this atlas of mapped B and T cell epitopes offers insight into the promises and challenges of designing universal vaccines and immunotherapy for the noroviruses.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Julio Alonso-Padilla ◽  
Esther M. Lafuente ◽  
Pedro A. Reche

Epstein-Barr virus is a very common human virus that infects 90% of human adults. EBV replicates in epithelial and B cells and causes infectious mononucleosis. EBV infection is also linked to various cancers, including Burkitt’s lymphoma and nasopharyngeal carcinomas, and autoimmune diseases such as multiple sclerosis. Currently, there are no effective drugs or vaccines to treat or prevent EBV infection. Herein, we applied a computer-aided strategy to design a prophylactic epitope vaccine ensemble from experimentally defined T and B cell epitopes. Such strategy relies on identifying conserved epitopes in conjunction with predictions of HLA presentation for T cell epitope selection and calculations of accessibility and flexibility for B cell epitope selection. The T cell component includes 14 CD8 T cell epitopes from early antigens and 4 CD4 T cell epitopes, targeted during the course of a natural infection and providing a population protection coverage of over 95% and 81.8%, respectively. The B cell component consists of 3 experimentally defined B cell epitopes from gp350 plus 4 predicted B cell epitopes from other EBV envelope glycoproteins, all mapping in flexible and solvent accessible regions. We discuss the rationale for the formulation and possible deployment of this epitope vaccine ensemble.


2018 ◽  
Vol 49 (4) ◽  
pp. 1600-1614 ◽  
Author(s):  
Shudong He ◽  
Jinlong Zhao ◽  
Walid Elfalleh ◽  
Mohamed Jemaà ◽  
Hanju  Sun ◽  
...  

Background/Aims: The incidence of lectin allergic disease is increasing in recent decades, and definitive treatment is still lacking. Identification of B and T-cell epitopes of allergen will be useful in understanding the allergen antibody responses as well as aiding in the development of new diagnostics and therapy regimens for lectin poisoning. In the current study, we mainly addressed these questions. Methods: Three-dimensional structure of the lectin from black turtle bean (Phaseolus vulgaris L.) was modeled using the structural template of Phytohemagglutinin from P. vulgaris (PHA-E, PDB ID: 3wcs.1.A) with high identity. The B and T-cell epitopes were screened and identified by immunoinformatics and subsequently validated by ELISA, lymphocyte proliferation and cytokine profile analyses. Results: Seven potential B-cell epitopes (B1 to B7) were identified by sequence and structure based methods, while three T-cell epitopes (T1 to T3) were identified by the predictions of binding score and inhibitory concentration. The epitope peptides were synthesized. Significant IgE binding capability was found in B-cell epitopes (B2, B5, B6 and B7) and T2 (a cryptic B-cell epitope). T1 and T2 induced significant lymphoproliferation, and the release of IL-4 and IL-5 cytokine confirmed the validity of T-cell epitope prediction. Abundant hydrophobic amino acids were found in B-cell epitope and T-cell epitope regions by amino acid analysis. Positively charged amino acids, such as His residue, might be more favored for B-cell epitope. Conclusion: The present approach can be applied for the identification of epitopes in novel allergen proteins and thus for designing diagnostics and therapies in lectin allergy.


2004 ◽  
Vol 83 (12) ◽  
pp. 936-940 ◽  
Author(s):  
J.-I. Choi ◽  
S.-W. Chung ◽  
H.-S. Kang ◽  
B.Y. Rhim ◽  
Y.-M. Park ◽  
...  

To identify T- and/or cross-reactive B-cell epitopes of P. gingivalis and human heat-shock protein (HSP)60 in atherosclerosis patients, we synthesized 104 overlapping synthetic peptides spanning whole molecules of P. gingivalis HSP60 and human HSP60, respectively. T-cell epitopes of P. gingivalis HSP were identified with the use of previously established P. gingivalis HSP-reactive T-cell lines. B-cell epitopes of P. gingivalis HSP60 and human HSP60 were identified by the use of patients’ sera. Anti- P. gingivalis, anti- P. gingivalis HSP60, or anti-human HSP60 IgG antibody titers were higher in the atherosclerosis patients compared with the healthy subjects. Five immunodominant peptides of P. gingivalis HSP60, identified as T-cell epitopes, were also found to be B-cell epitopes. Moreover, 6 cross-reactive B-cell epitopes of human HSP60 were identified. It was concluded that P. gingivalis HSP60 might be involved in the immunoregulatory process of atherosclerosis, with common T- and/or B-cell epitope specificities and with cross-reactivity with human HSP60.


2020 ◽  
Author(s):  
Jian Zhou ◽  
Sun Jingjing ◽  
Gang Lu ◽  
Wanchun Wang ◽  
Lin Wang

Abstract Background: Coronavirus disease 2019 (COVID-19) poses a great threat to human health and life. We performed a bioinformatics analysis to compare the sequence, structure, and epitopes of SARS-CoV-2 spike (S) protein in 10 different countries. Methods: The amino acid sequences of SARS-CoV-2 S protein were obtained from the NCBI database. We used DNASTAR Lasergene software to analyze the protein’s secondary structures. SWISS-MODEL combined with VMD software was used to construct a 3D model of SARS-CoV-2 S protein. DNASTAR Protean and the IEDB database were used to analyze the B cell epitopes and T cell epitopes, respectively. Results: The results of B cell epitopes analysis indicated that the epitopes of SARS-CoV-2 S protein in Korea and American increased, which suggested that the antigenicity of SARS-CoV-2 in Czech, Korea and American might be enhanced. A small number of B cell epitopes disappeared in the SARS-CoV-2 S protein sequence from Greece, Australia, Sweden and India, which suggested that the antigenicity of SARS-CoV-2 in Greece, Australia, Sweden and India may be weakened. T cell epitope analysis indicated that the antigenicity of SARS-CoV-2 in Czech, Korea and American was enhanced, while antigenicity of SARS-CoV-2 in Greece, Australia, Inida, Sweden and Thailand may be weakened. The sequence of SARS-CoV-2 S protein has changed as the virus has spread, and the structures and epitopes have changed accordingly. Conclusion: The mutation leads to a decrease in the antigenicity of SARS-CoV-2, which may be a mechanism for the virus to evade surveillance by the immune system.


2020 ◽  
Author(s):  
Parvez Slathia ◽  
Preeti Sharma,

<p>The world is currently battling the Covid-19 pandemic for which there is no therapy available. Prophylactic measures like vaccines can effectively thwart the disease burden. The current methods of detection are PCR based and require skilled manpower to operate. The availability of cheap and ready to use diagnostics like serological methods can ease the detection of SARS-CoV-2 virus. In the current study, immunoinformatics tools have been used to predict T and B cell epitopes present in all the proteins of this virus. NetMHCPan, NetCTL and NetMHCII servers were used for T cell epitope prediction while BepiPred and ABCPred were used for B cell epitope prediction. Population coverage analysis for T cell epitopes revealed that these could provide protection to the people throughout world. The T cell epitopes can exclusively used for vaccine design whereas B cell epitopes can be used for both vaccine design and developing diagnostic kits. </p> <p> </p>


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9855
Author(s):  
Rajesh Anand ◽  
Subham Biswal ◽  
Renu Bhatt ◽  
Bhupendra N. Tiwary

Background The present pandemic COVID-19 is caused by SARS-CoV-2, a single-stranded positive-sense RNA virus from the Coronaviridae family. Due to a lack of antiviral drugs, vaccines against the virus are urgently required. Methods In this study, validated computational approaches were used to identify peptide-based epitopes from six structural proteins having antigenic properties. The Net-CTL 1.2 tool was used for the prediction of CD8+ T-cell epitopes, while the robust tools Bepi-Pred 2 and LBtope was employed for the identification of linear B-cell epitopes. Docking studies of the identified epitopes were performed using HADDOCK 2.4 and the structures were visualized by Discovery Studio and LigPlot+. Antigenicity, immunogenicity, conservancy, population coverage and allergenicity of the predicted epitopes were determined by the bioinformatics tools like VaxiJen v2.0 server, the Immune Epitope Database tools and AllerTOP v.2.0, AllergenFP 1.0 and ElliPro. Results The predicted T cell and linear B-cell epitopes were considered as prime vaccine targets in case they passed the requisite parameters like antigenicity, immunogenicity, conservancy, non-allergenicity and broad range of population coverage. Among the predicted CD8+ T cell epitopes, potential vaccine targets from surface glycoprotein were; YQPYRVVVL, PYRVVVLSF, GVYFASTEK, QLTPTWRVY, and those from ORF3a protein were LKKRWQLAL, HVTFFIYNK. Similarly, RFLYIIKLI, LTWICLLQF from membrane protein and three epitopes viz; SPRWYFYYL, TWLTYTGAI, KTFPPTEPK from nucleocapsid phosphoprotein were the superior vaccine targets observed in our study. The negative values of HADDOCK and Z scores obtained for the best cluster indicated the potential of the epitopes as suitable vaccine candidates. Analysis of the 3D and 2D interaction diagrams of best cluster produced by HADDOCK 2.4 displayed the binding interaction of leading T cell epitopes within the MHC-1 peptide binding clefts. On the other hand, among linear B cell epitopes the majority of potential vaccine targets were from nucleocapsid protein, viz; 59−HGKEDLKFPRGQGVPINTNSSPDDQIGYYRRATRRIRGGDGKMKDLS−105, 227−LNQLE SKMSGKGQQQQGQTVTKKSAAEASKKPRQKRTATK−266, 3−DNGPQNQRNAPRITFGGP−20, 29−GERSGARSKQRRPQGL−45. Two other prime vaccine targets, 370−NSASFSTFKCYGVSPTKLNDLCFTNV−395 and 260−AGAAAYYVGYLQPRT−274 were identified in the spike protein. The potential B-cell conformational epitopes were predicted on the basis of a higher protrusion index indicating greater solvent accessibility. These conformational epitopes were of various lengths and belonged to spike, ORF3a, membrane and nucleocapsid proteins. Conclusions Taken together, eleven T cell epitopes, seven B cell linear epitopes and ten B cell conformational epitopes were identified from five structural proteins of SARS-CoV-2 using advanced computational tools. These potential vaccine candidates may provide important timely directives for an effective vaccine against SARS-CoV-2.


2020 ◽  
Author(s):  
Parvez Slathia ◽  
Preeti Sharma,

<p>The world is currently battling the Covid-19 pandemic for which there is no therapy available. Prophylactic measures like vaccines can effectively thwart the disease burden. The current methods of detection are PCR based and require skilled manpower to operate. The availability of cheap and ready to use diagnostics like serological methods can ease the detection of SARS-CoV-2 virus. In the current study, immunoinformatics tools have been used to predict T and B cell epitopes present in all the proteins of this virus. NetMHCPan, NetCTL and NetMHCII servers were used for T cell epitope prediction while BepiPred and ABCPred were used for B cell epitope prediction. Population coverage analysis for T cell epitopes revealed that these could provide protection to the people throughout world. The T cell epitopes can exclusively used for vaccine design whereas B cell epitopes can be used for both vaccine design and developing diagnostic kits. </p> <p> </p>


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