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Sample records for b-cell epitope prediction

  1. In silico quantitative prediction of B-cell epitope

    Directory of Open Access Journals (Sweden)

    Raúl Isea

    2015-11-01

    Full Text Available This paper shows a computational approach for quantitative prediction of B cell epitopes. The function was defined, which reflects the average value of B epitopes, according to eight predictors of different B epitopes, as well as structural and energetic considerations of the origin protein. The proposed methodology could be useful to develop both dengue and chikungunya vaccines

  2. In silico quantitative prediction of B-cell epitope

    OpenAIRE

    Raúl Isea

    2015-01-01

    This paper shows a computational approach for quantitative prediction of B cell epitopes. The function was defined, which reflects the average value of B epitopes, according to eight predictors of different B epitopes, as well as structural and energetic considerations of the origin protein. The proposed methodology could be useful to develop both dengue and chikungunya vaccines

  3. Reliable B cell epitope predictions: impacts of method development and improved benchmarking

    DEFF Research Database (Denmark)

    Kringelum, Jens Vindahl; Lundegaard, Claus; Lund, Ole;

    2012-01-01

    evaluation data set improved from 0.712 to 0.727. Our results thus demonstrate that given proper benchmark definitions, B-cell epitope prediction methods achieve highly significant predictive performances suggesting these tools to be a powerful asset in rational epitope discovery. The updated version......The interaction between antibodies and antigens is one of the most important immune system mechanisms for clearing infectious organisms from the host. Antibodies bind to antigens at sites referred to as B-cell epitopes. Identification of the exact location of B-cell epitopes is essential in several...... of B-cell epitopes has been moderate. Several issues regarding the evaluation data sets may however have led to the performance values being underestimated: Rarely, all potential epitopes have been mapped on an antigen, and antibodies are generally raised against the antigen in a given biological...

  4. Towards a consensus on datasets and evaluation metrics for developing B-cell epitope prediction tools

    DEFF Research Database (Denmark)

    Greenbaum, Jason A.; Andersen, Pernille; Blythe, Martin;

    2007-01-01

    and immunology communities. Improving the accuracy of B-cell epitope prediction methods depends on a community consensus on the data and metrics utilized to develop and evaluate such tools. A workshop, sponsored by the National Institute of Allergy and Infectious Disease (NIAID), was recently held in Washington......, DC to discuss the current state of the B-cell epitope prediction field. Many of the currently available tools were surveyed and a set of recommendations was devised to facilitate improvements in the currently existing tools and to expedite future tool development. An underlying theme...... of the recommendations put forth by the panel is increased collaboration among research groups. By developing common datasets, standardized data formats, and the means with which to consolidate information, we hope to greatly enhance the development of B-cell epitope prediction tools. (c) 2007 John Wiley & Sons, Ltd....

  5. B-Pred, a structure based B-cell epitopes prediction server

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    Giacò L

    2012-07-01

    Full Text Available Luciano Giacò,1 Massimo Amicosante,2 Maurizio Fraziano,1 Pier Federico Gherardini,1 Gabriele Ausiello,1 Manuela Helmer-Citterich,1 Vittorio Colizzi,1 Andrea Cabibbo11Department of Biology, 2Department of Internal Medicine, University of Rome "Tor Vergata", Rome, ItalyAbstract: The ability to predict immunogenic regions in selected proteins by in-silico methods has broad implications, such as allowing a quick selection of potential reagents to be used as diagnostics, vaccines, immunotherapeutics, or research tools in several branches of biological and biotechnological research. However, the prediction of antibody target sites in proteins using computational methodologies has proven to be a highly challenging task, which is likely due to the somewhat elusive nature of B-cell epitopes. This paper proposes a web-based platform for scoring potential immunological reagents based on the structures or 3D models of the proteins of interest. The method scores a protein's peptides set, which is derived from a sliding window, based on the average solvent exposure, with a filter on the average local model quality for each peptide. The platform was validated on a custom-assembled database of 1336 experimentally determined epitopes from 106 proteins for which a reliable 3D model could be obtained through standard modeling techniques. Despite showing poor sensitivity, this method can achieve a specificity of 0.70 and a positive predictive value of 0.29 by combining these two simple parameters. These values are slightly higher than those obtained with other established sequence-based or structure-based methods that have been evaluated using the same epitopes dataset. This method is implemented in a web server called B-Pred, which is accessible at http://immuno.bio.uniroma2.it/bpred. The server contains a number of original features that allow users to perform personalized reagent searches by manipulating the sliding window's width and sliding step, changing the

  6. Conformational B-Cell Epitopes Prediction from Sequences Using Cost-Sensitive Ensemble Classifiers and Spatial Clustering

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    Jian Zhang

    2014-01-01

    Full Text Available B-cell epitopes are regions of the antigen surface which can be recognized by certain antibodies and elicit the immune response. Identification of epitopes for a given antigen chain finds vital applications in vaccine and drug research. Experimental prediction of B-cell epitopes is time-consuming and resource intensive, which may benefit from the computational approaches to identify B-cell epitopes. In this paper, a novel cost-sensitive ensemble algorithm is proposed for predicting the antigenic determinant residues and then a spatial clustering algorithm is adopted to identify the potential epitopes. Firstly, we explore various discriminative features from primary sequences. Secondly, cost-sensitive ensemble scheme is introduced to deal with imbalanced learning problem. Thirdly, we adopt spatial algorithm to tell which residues may potentially form the epitopes. Based on the strategies mentioned above, a new predictor, called CBEP (conformational B-cell epitopes prediction, is proposed in this study. CBEP achieves good prediction performance with the mean AUC scores (AUCs of 0.721 and 0.703 on two benchmark datasets (bound and unbound using the leave-one-out cross-validation (LOOCV. When compared with previous prediction tools, CBEP produces higher sensitivity and comparable specificity values. A web server named CBEP which implements the proposed method is available for academic use.

  7. Conformational B-cell epitopes prediction from sequences using cost-sensitive ensemble classifiers and spatial clustering.

    Science.gov (United States)

    Zhang, Jian; Zhao, Xiaowei; Sun, Pingping; Gao, Bo; Ma, Zhiqiang

    2014-01-01

    B-cell epitopes are regions of the antigen surface which can be recognized by certain antibodies and elicit the immune response. Identification of epitopes for a given antigen chain finds vital applications in vaccine and drug research. Experimental prediction of B-cell epitopes is time-consuming and resource intensive, which may benefit from the computational approaches to identify B-cell epitopes. In this paper, a novel cost-sensitive ensemble algorithm is proposed for predicting the antigenic determinant residues and then a spatial clustering algorithm is adopted to identify the potential epitopes. Firstly, we explore various discriminative features from primary sequences. Secondly, cost-sensitive ensemble scheme is introduced to deal with imbalanced learning problem. Thirdly, we adopt spatial algorithm to tell which residues may potentially form the epitopes. Based on the strategies mentioned above, a new predictor, called CBEP (conformational B-cell epitopes prediction), is proposed in this study. CBEP achieves good prediction performance with the mean AUC scores (AUCs) of 0.721 and 0.703 on two benchmark datasets (bound and unbound) using the leave-one-out cross-validation (LOOCV). When compared with previous prediction tools, CBEP produces higher sensitivity and comparable specificity values. A web server named CBEP which implements the proposed method is available for academic use. PMID:25045691

  8. B-Pred, a structure based B-cell epitopes prediction server.

    Science.gov (United States)

    Giacò, Luciano; Amicosante, Massimo; Fraziano, Maurizio; Gherardini, Pier Federico; Ausiello, Gabriele; Helmer-Citterich, Manuela; Colizzi, Vittorio; Cabibbo, Andrea

    2012-01-01

    The ability to predict immunogenic regions in selected proteins by in-silico methods has broad implications, such as allowing a quick selection of potential reagents to be used as diagnostics, vaccines, immunotherapeutics, or research tools in several branches of biological and biotechnological research. However, the prediction of antibody target sites in proteins using computational methodologies has proven to be a highly challenging task, which is likely due to the somewhat elusive nature of B-cell epitopes. This paper proposes a web-based platform for scoring potential immunological reagents based on the structures or 3D models of the proteins of interest. The method scores a protein's peptides set, which is derived from a sliding window, based on the average solvent exposure, with a filter on the average local model quality for each peptide. The platform was validated on a custom-assembled database of 1336 experimentally determined epitopes from 106 proteins for which a reliable 3D model could be obtained through standard modeling techniques. Despite showing poor sensitivity, this method can achieve a specificity of 0.70 and a positive predictive value of 0.29 by combining these two simple parameters. These values are slightly higher than those obtained with other established sequence-based or structure-based methods that have been evaluated using the same epitopes dataset. This method is implemented in a web server called B-Pred, which is accessible at http://immuno.bio.uniroma2.it/bpred. The server contains a number of original features that allow users to perform personalized reagent searches by manipulating the sliding window's width and sliding step, changing the exposure and model quality thresholds, and running sequential queries with different parameters. The B-Pred server should assist experimentalists in the rational selection of epitope antigens for a wide range of applications. PMID:22888263

  9. Computational approach for predicting the conserved B-cell epitopes of hemagglutinin H7 subtype influenza virus

    Science.gov (United States)

    Wang, Xiangyu; Sun, Qi; Ye, Zhonghua; Hua, Ying; Shao, Na; Du, Yanli; Zhang, Qiwei; Wan, Chengsong

    2016-01-01

    An avian-origin influenza H7N9 virus epidemic occurred in China in 2013–2014, in which >422 infected people suffered from pneumonia, respiratory distress syndrome and septic shock. H7N9 viruses belong to the H7 subtype of avian-origin influenza viruses (AIV-H7). Hemagglutinin (HA) is a vital membrane protein of AIV that has an important role in host recognition and infection. The epitopes of HA are significant determinants of the regularity of epidemic and viral mutation and recombination mechanisms. The present study aimed to predict the conserved B-cell epitopes of AIV-H7 HA using a bioinformatics approach, including the three most effective epitope prediction softwares available online: Artificial Neural Network based B-cell Epitope Prediction (ABCpred), B-cell Epitope Prediction (BepiPred) and Linear B-cell Epitope Prediction (LBtope). A total of 24 strains of Euro-Asiatic AIV-H7 that had been associated with a serious poultry pandemic or had infected humans in the past 30 years were selected to identify the conserved regions of HA. Sequences were obtained from the National Center for Biotechnology Information and Global Initiative on Sharing Avian Influenza Data databases. Using a combination of software prediction and sequence comparisons, the conserved epitopes of AIV-H7 were predicted and clarified. A total of five conserved epitopes [amino acids (aa) 37–52, 131–142, 215–234, 465–484 and 487–505] with a suitable length, high antigenicity and minimal variation were predicted and confirmed. Each obtained a score of >0.80 in ABCpred, 60% in LBtope and a level of 0.35 in Bepipred. In addition, a representative amino acid change (glutamine235-to-leucine235) in the HA protein of the 2013 AIV-H7N9 was discovered. The strategy adopted in the present study may have profound implications on the rapid diagnosis and control of infectious disease caused by H7N9 viruses, as well as by other virulent viruses, such as the Ebola virus.

  10. On the Meaning of Affinity Limits in B-Cell Epitope Prediction for Antipeptide Antibody-Mediated Immunity

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    Salvador Eugenio C. Caoili

    2012-01-01

    Full Text Available B-cell epitope prediction aims to aid the design of peptide-based immunogens (e.g., vaccines for eliciting antipeptide antibodies that protect against disease, but such antibodies fail to confer protection and even promote disease if they bind with low affinity. Hence, the Immune Epitope Database (IEDB was searched to obtain published thermodynamic and kinetic data on binding interactions of antipeptide antibodies. The data suggest that the affinity of the antibodies for their immunizing peptides appears to be limited in a manner consistent with previously proposed kinetic constraints on affinity maturation in vivo and that cross-reaction of the antibodies with proteins tends to occur with lower affinity than the corresponding reaction of the antibodies with their immunizing peptides. These observations better inform B-cell epitope prediction to avoid overestimating the affinity for both active and passive immunization; whereas active immunization is subject to limitations of affinity maturation in vivo and of the capacity to accumulate endogenous antibodies, passive immunization may transcend such limitations, possibly with the aid of artificial affinity-selection processes and of protein engineering. Additionally, protein disorder warrants further investigation as a possible supplementary criterion for B-cell epitope prediction, where such disorder obviates thermodynamically unfavorable protein structural adjustments in cross-reactions between antipeptide antibodies and proteins.

  11. The Relationship between B-cell Epitope and Mimotope Sequences.

    Science.gov (United States)

    Zhang, Chunhua; Li, Yunyun; Tang, Weina; Zhou, Zhiguo; Sun, Pingping; Ma, Zhiqiang

    2016-01-01

    B-cell epitope is a group of residues which is on the surface of an antigen. It invokes humoral responses. Locating B-cell epitope is important for effective vaccine design, and the development of diagnostic reagents. Mimotope-based B-cell epitope prediction method is a kind of conformational B-cell epitope prediction, and the core idea of the method is mapping the mimotope sequences which are obtained from a random phage display library. However, current mimotope-based B-cell epitope prediction methods cannot maintain a high degree of satisfaction in the circumstances of employing only mimotope sequences. In this study, we did a multi-perspective analysis on parameters for conformational B-cell epitopes and characteristics between epitope and mimotope on a benchmark datasets which contains 67 mimotope sets, corresponding to 40 unique complex structures. In these 67 cases, there are 25 antigen-antibody complexes and 42 protein-protein interactions. We analyzed the two parts separately. The results showed the mimotope sequences do have some epitope features, but there are also some epitope properties that mimotope sequences do not contain. In addition, the numbers of epitope segments with different lengths were obviously different between the antigen-antibody complexes and the protein-protein interactions. This study reflects how similar do mimotope sequence and genuine epitopes have; and evaluates existing mimotope-based B-cell epitope prediction methods from a novel viewpoint. PMID:26715528

  12. Pep-3D-Search: a method for B-cell epitope prediction based on mimotope analysis

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    Wang Yan

    2008-12-01

    Full Text Available Abstract Background The prediction of conformational B-cell epitopes is one of the most important goals in immunoinformatics. The solution to this problem, even if approximate, would help in designing experiments to precisely map the residues of interaction between an antigen and an antibody. Consequently, this area of research has received considerable attention from immunologists, structural biologists and computational biologists. Phage-displayed random peptide libraries are powerful tools used to obtain mimotopes that are selected by binding to a given monoclonal antibody (mAb in a similar way to the native epitope. These mimotopes can be considered as functional epitope mimics. Mimotope analysis based methods can predict not only linear but also conformational epitopes and this has been the focus of much research in recent years. Though some algorithms based on mimotope analysis have been proposed, the precise localization of the interaction site mimicked by the mimotopes is still a challenging task. Results In this study, we propose a method for B-cell epitope prediction based on mimotope analysis called Pep-3D-Search. Given the 3D structure of an antigen and a set of mimotopes (or a motif sequence derived from the set of mimotopes, Pep-3D-Search can be used in two modes: mimotope or motif. To evaluate the performance of Pep-3D-Search to predict epitopes from a set of mimotopes, 10 epitopes defined by crystallography were compared with the predicted results from a Pep-3D-Search: the average Matthews correlation oefficient (MCC, sensitivity and precision were 0.1758, 0.3642 and 0.6948. Compared with other available prediction algorithms, Pep-3D-Search showed comparable MCC, specificity and precision, and could provide novel, rational results. To verify the capability of Pep-3D-Search to align a motif sequence to a 3D structure for predicting epitopes, 6 test cases were used. The predictive performance of Pep-3D-Search was demonstrated to be

  13. Identification of strain-specific B-cell epitopes in Trypanosoma cruzi using genome-scale epitope prediction and high-throughput immunoscreening with peptide arrays.

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    Tiago Antônio de Oliveira Mendes

    Full Text Available BACKGROUND: The factors influencing variation in the clinical forms of Chagas disease have not been elucidated; however, it is likely that the genetics of both the host and the parasite are involved. Several studies have attempted to correlate the T. cruzi strains involved in infection with the clinical forms of the disease by using hemoculture and/or PCR-based genotyping of parasites from infected human tissues. However, both techniques have limitations that hamper the analysis of large numbers of samples. The goal of this work was to identify conserved and polymorphic linear B-cell epitopes of T. cruzi that could be used for serodiagnosis and serotyping of Chagas disease using ELISA. METHODOLOGY: By performing B-cell epitope prediction on proteins derived from pair of alleles of the hybrid CL Brener genome, we have identified conserved and polymorphic epitopes in the two CL Brener haplotypes. The rationale underlying this strategy is that, because CL Brener is a recent hybrid between the TcII and TcIII DTUs (discrete typing units, it is likely that polymorphic epitopes in pairs of alleles could also be polymorphic in the parental genotypes. We excluded sequences that are also present in the Leishmania major, L. infantum, L. braziliensis and T. brucei genomes to minimize the chance of cross-reactivity. A peptide array containing 150 peptides was covalently linked to a cellulose membrane, and the reactivity of the peptides was tested using sera from C57BL/6 mice chronically infected with the Colombiana (TcI and CL Brener (TcVI clones and Y (TcII strain. FINDINGS AND CONCLUSIONS: A total of 36 peptides were considered reactive, and the cross-reactivity among the strains is in agreement with the evolutionary origin of the different T. cruzi DTUs. Four peptides were tested against a panel of chagasic patients using ELISA. A conserved peptide showed 95.8% sensitivity, 88.5% specificity, and 92.7% accuracy for the identification of T. cruzi in

  14. Prediction of B Cell Epitope of DMRT Protein in Oreochromis niloticus%尼罗罗非鱼DMRT蛋白 B细胞表位的预测

    Institute of Scientific and Technical Information of China (English)

    杨东; 刘红艳; 张繁荣; 余来宁

    2008-01-01

    [Objective] The research aimed to predict the B cell epitope of DMRT protein in Oreochromis niloticus. [Method] The secondary structure of amino acid sequence of DMRT protein was revealed by Garnier-Robson, Chou-Fasman and Karplus-Schulz methods. The hydrophilicity plot, surface probability and antigenic index were obtained by Kyte-Doolittle, Emini and Jameson-Wolf methods, respectively. Based on the above results, the B cell epitopes for DMRT were predicted. [Result] Both the prediction results from Garnier-Robson, Chou-Fasman methods indicated that the α-helix centers of DMRT protein in O. niloticus were in the N terminal No. 31-56, 68-75, 110-116, 209-211 and 239-243; the β-sheet centers of DMRT protein in O. niloticus were in the N terminal No. 95-99, 177-183, 225-234 and 251-254. With the assistant of Kyte-Doolittle, Emini and Jameson-Wolf methods, the B cell epitopes for DMRT were located in or nearby the N terminal No. 13-16, 35-38, 47-54,84-93, 101-109, 127-156, 166-177 and 198-201. [Conclusion] These results are helpful for preparing the antibody of DMRT protein and revealing the sex determination mechanism of O. niloticus.

  15. Identifying Novel B Cell Epitopes within Toxoplasma gondii GRA6.

    Science.gov (United States)

    Wang, Yanhua; Wang, Guangxiang; Cai, Jian Ping

    2016-08-01

    The study of antigenic epitopes from Toxoplasma gondii has not only enhanced our understanding of the structure and function of antigens, the reactions between antigens and antibodies, and many other aspects of immunology, but it also plays a significant role in the development of new diagnostic reagents and vaccines. In the present study, T. gondii GRA6 epitopes were identified using bioinformatics tools and a synthetic peptide technique. The potential B cell epitopes of GRA6 predicted by bioinformatics tools concentrated upon 3 regions of GRA6, 1-20 aa, 44-103 aa, and 172-221 aa. Ten shorter peptides from the 3 regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the 10 peptides (amino acids 44-63, 172-191, and 192-211) tested were recognized by all sera and determined to be immunodominant B-cell epitopes of GRA6. The results indicated that we precisely and accurately located the T. gondii GRA6 epitopes using pig sera collected at different time points after infection. The identified epitopes may be very useful for further studies of epitope-based vaccines and diagnostic reagents. PMID:27658594

  16. Synthetic B-Cell Epitopes Eliciting Cross-Neutralizing Antibodies: Strategies for Future Dengue Vaccine.

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    Babu Ramanathan

    Full Text Available Dengue virus (DENV is a major public health threat worldwide. A key element in protection from dengue fever is the neutralising antibody response. Anti-dengue IgG purified from DENV-2 infected human sera showed reactivity against several peptides when evaluated by ELISA and epitope extraction techniques. A multi-step computational approach predicted six antigenic regions within the E protein of DENV-2 that concur with the 6 epitopes identified by the combined ELISA and epitope extraction approach. The selected peptides representing B-cell epitopes were attached to a known dengue T-helper epitope and evaluated for their vaccine potency. Immunization of mice revealed two novel synthetic vaccine constructs that elicited good humoral immune responses and produced cross-reactive neutralising antibodies against DENV-1, 2 and 3. The findings indicate new directions for epitope mapping and contribute towards the future development of multi-epitope based synthetic peptide vaccine.

  17. Synthetic B-Cell Epitopes Eliciting Cross-Neutralizing Antibodies: Strategies for Future Dengue Vaccine.

    Science.gov (United States)

    Ramanathan, Babu; Poh, Chit Laa; Kirk, Kristin; McBride, William John Hannan; Aaskov, John; Grollo, Lara

    2016-01-01

    Dengue virus (DENV) is a major public health threat worldwide. A key element in protection from dengue fever is the neutralising antibody response. Anti-dengue IgG purified from DENV-2 infected human sera showed reactivity against several peptides when evaluated by ELISA and epitope extraction techniques. A multi-step computational approach predicted six antigenic regions within the E protein of DENV-2 that concur with the 6 epitopes identified by the combined ELISA and epitope extraction approach. The selected peptides representing B-cell epitopes were attached to a known dengue T-helper epitope and evaluated for their vaccine potency. Immunization of mice revealed two novel synthetic vaccine constructs that elicited good humoral immune responses and produced cross-reactive neutralising antibodies against DENV-1, 2 and 3. The findings indicate new directions for epitope mapping and contribute towards the future development of multi-epitope based synthetic peptide vaccine. PMID:27223692

  18. Prediction of Secondary Structure and B Cell Epitope of GH Protein from Acipenser sinensis%中华鲟GH蛋白二级结构和B细胞抗原表位的预测

    Institute of Scientific and Technical Information of China (English)

    刘红艳; 杨东; 张繁荣; 余来宁

    2009-01-01

    [Objective] The aim was to predict the secondary structure and B cell epitope of growth hormone (GH) protein from Acipenser sinensis. [Method] With the amino acid sequence of GH protein from A.sinensis as the base, the secondary structure of GH protein from A.sinensis was predicted by the method of Garnier-Robson, Chou-Fasman and Karplus-Schulz, and its cell epitope was predicted by the method of Kyte-Doolittle, Emini and Jameson-Wolf. [Result] The sections of 18-23, 55-56, 67-73, 83-86, 112-114, 151-157 and 209-211 in the N terminal of GH protein molecule had softer structure and these sections could sway or fold to produce more complex tertiary structure. The sections of 19-23, 51-71, 84-95, 128-139, 164-176 and 189-196 in the N terminal of GH protein could be the epitope of B cell and there were flexible regions in these sections or near these sections of GH protein molecule. So the dominant regions could be in these sections or near these sections. [Conclusion] The research provided the basis for the preparation of monoclonal antibody of GH protein from A.sinensis and provided the reference for the discussion for the molecular regulation mechanism of A.sinensis.

  19. Epitope-driven DNA vaccine design employing immunoinformatics against B-cell lymphoma: a biotech's challenge.

    Science.gov (United States)

    Iurescia, Sandra; Fioretti, Daniela; Fazio, Vito Michele; Rinaldi, Monica

    2012-01-01

    DNA vaccination has been widely explored to develop new, alternative and efficient vaccines for cancer immunotherapy. DNA vaccines offer several benefits such as specific targeting, use of multiple genes to enhance immunity and reduced risk compared to conventional vaccines. Rapid developments in molecular biology and immunoinformatics enable rational design approaches. These technologies allow construction of DNA vaccines encoding selected tumor antigens together with molecules to direct and amplify the desired effector pathways, as well as highly targeted vaccines aimed at specific epitopes. Reliable predictions of immunogenic T cell epitope peptides are crucial for rational vaccine design and represent a key problem in immunoinformatics. Computational approaches have been developed to facilitate the process of epitope detection and show potential applications to the immunotherapeutic treatment of cancer. In this review a number of different epitope prediction methods are briefly illustrated and effective use of these resources to support experimental studies is described. Epitope-driven vaccine design employs these bioinformatics algorithms to identify potential targets of vaccines against cancer. In this paper the selection of T cell epitopes to develop epitope-based vaccines, the need for CD4(+) T cell help for improved vaccines and the assessment of vaccine performance against tumor are reviewed. We focused on two applications, namely prediction of novel T cell epitopes and epitope enhancement by sequence modification, and combined rationale design with bioinformatics for creation of new synthetic mini-genes. This review describes the development of epitope-based DNA vaccines and their antitumor effects in preclinical research against B-cell lymphoma, corroborating the usefulness of this platform as a potential tool for cancer therapy. Achievements in the field of DNA vaccines allow to overcome hurdles to clinical translation. In a scenario where the vaccine

  20. Advances of Bioinformatics Tools Applied in Virus Epitopes Prediction

    Institute of Scientific and Technical Information of China (English)

    Ping Chen; Simon Rayner; Kang-hong Hu

    2011-01-01

    In recent years, the in silico epitopes prediction tools have facilitated the progress of vaccines development significantly and many have been applied to predict epitopes in viruses successfully. Herein, a general overview of different tools currently available, including T cell and B cell epitopes prediction tools, is presented. And the principles of different prediction algorithms are reviewed briefly. Finally, several examples are present to illustrate the application of the prediction tools.

  1. Epitope prediction methods

    DEFF Research Database (Denmark)

    Karosiene, Edita

    leucocyte antigen (HLA) molecules, are encoded by extremely polymorphic genes on chromosome 6. Due to this polymorphism, thousands of different MHC molecules exist, making the experimental identification of peptide-MHC interactions a very costly procedure. This has primed the need for in silico peptide......-MHC prediction methods, and over the last decade several such methods have been successfully developed and used for epitope discovery purposes. My PhD project has been dedicated to improve methods for predicting peptide-MHC interactions by developing new strategies for training prediction algorithms based...... on machine learning techniques. Several MHC class I binding prediction algorithms have been developed and due to their high accuracy they are used by many immunologists to facilitate the conventional experimental process of epitope discovery. However, the accuracy of these methods depends on data defining...

  2. Analysis of Conformational B-Cell Epitopes in the Antibody-Antigen Complex Using the Depth Function and the Convex Hull.

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    Full Text Available The prediction of conformational b-cell epitopes plays an important role in immunoinformatics. Several computational methods are proposed on the basis of discrimination determined by the solvent-accessible surface between epitopes and non-epitopes, but the performance of existing methods is far from satisfying. In this paper, depth functions and the k-th surface convex hull are used to analyze epitopes and exposed non-epitopes. On each layer of the protein, we compute relative solvent accessibility and four different types of depth functions, i.e., Chakravarty depth, DPX, half-sphere exposure and half space depth, to analyze the location of epitopes on different layers of the proteins. We found that conformational b-cell epitopes are rich in charged residues Asp, Glu, Lys, Arg, His; aliphatic residues Gly, Pro; non-charged residues Asn, Gln; and aromatic residue Tyr. Conformational b-cell epitopes are rich in coils. Conservation of epitopes is not significantly lower than that of exposed non-epitopes. The average depths (obtained by four methods for epitopes are significantly lower than that of non-epitopes on the surface using the Wilcoxon rank sum test. Epitopes are more likely to be located in the outer layer of the convex hull of a protein. On the benchmark dataset, the cumulate 10th convex hull covers 84.6% of exposed residues on the protein surface area, and nearly 95% of epitope sites. These findings may be helpful in building a predictor for epitopes.

  3. 猪丹毒杆菌SpaA基因的克隆与生物信息学分析%Cloning, sequecing, secondary structure and B-cell epitopes prediction of swine Erysipelothrix rhusiopathiae SpaA

    Institute of Scientific and Technical Information of China (English)

    林琳; 江斌; 吴胜会; 张世忠

    2013-01-01

    The aims of this study was to clone and sequence the SpaA gene of Erysipelothrix rhusiopathiae and predict its secondary structure and B-cell epitopes,which provides a theoretical basis for the study of immune mechanism and subunit vaccine.The SpaA gene was amplified,cloned,sequenced and phylogenetic analyzed.By using bioinformatics methods,the secondary structure and B-cell preponderant epitope of SpaA were predicted.The results showed that the spaA gene is 1 881 bp,encoding 626 amino acids.The phylogenetic analysis of the SpaA gene indicated the distance between 2 separated strain of Erysipelothrix rhusiopathiae and those of GenBank was far,and 2 separated strain became a new branch.Using the SOPMA method,prediction of the secondary structure of the SpaA showed thatα-helix,random coils and extended strand were the main structural type of the flexible region in secondary structure,and contain a small amount of β-turn.It was supposed the SpaA protein contain 14 potential antigen epitopes and 8 potential Nmyristoylation sites.These results provided a theoretical basis for the further study of immune mechanisms and epitope vaccine design for the pathogen.%旨在克隆猪丹毒杆菌表面保护性抗原A(surface protein A,SpaA)的编码基因,并预测该蛋白的二级结构和B细胞抗原表位,从而探讨猪丹毒杆菌SpaA蛋白在免疫保护中所起的作用.首先对猪丹毒杆菌SpaA基因进行PCR扩增、克隆和测序,并进行同源性比较.应用生物信息学方法,对猪丹毒杆菌SpaA蛋白的二级结构和B细胞抗原表位进行预测.结果显示,猪丹毒杆菌SpaA基因全长1 881 bp,编码626个氨基酸,发育进化树结果表明分离的2株猪丹毒杆菌菌株与GenBank中其他菌株在进化树中关系较远,自成一个分支.二级结构的预测结果显示该蛋白主要以无规则卷曲、α螺旋和延伸链为主,只有少数的β转角;推测该蛋白有14个B细胞优势抗原表位区域、8个N-肉豆蔻酰化

  4. B-Cell Receptor Epitope Recognition Correlates With the Clinical Course of Chronic Lymphocytic Leukemia

    NARCIS (Netherlands)

    Binder, Mascha; Mueller, Fabian; Jackst, Antje; Lechenne, Barbara; Pantic, Milena; Bacher, Ulrike; Eulenburg, Christine Zu; Veelken, Hendrik; Mertelsmann, Roland; Pasqualini, Renata; Arap, Wadih; Trepel, Martin

    2011-01-01

    BACKGROUND: B-cell receptors (BCRs) and their recognition of specific epitopes may play a pivotal role in the development and progression of chronic lymphocytic leukemia (CLL). In this study, the authors set up a model system to explore epitope reactivity and its clinical relevance in CLL. METHODS:

  5. Determination of B-Cell Epitopes in Patients with Celiac Disease: Peptide Microarrays.

    Directory of Open Access Journals (Sweden)

    Rok Seon Choung

    Full Text Available Most antibodies recognize conformational or discontinuous epitopes that have a specific 3-dimensional shape; however, determination of discontinuous B-cell epitopes is a major challenge in bioscience. Moreover, the current methods for identifying peptide epitopes often involve laborious, high-cost peptide screening programs. Here, we present a novel microarray method for identifying discontinuous B-cell epitopes in celiac disease (CD by using a silicon-based peptide array and computational methods.Using a novel silicon-based microarray platform with a multi-pillar chip, overlapping 12-mer peptide sequences of all native and deamidated gliadins, which are known to trigger CD, were synthesized in situ and used to identify peptide epitopes.Using a computational algorithm that considered disease specificity of peptide sequences, 2 distinct epitope sets were identified. Further, by combining the most discriminative 3-mer gliadin sequences with randomly interpolated3- or 6-mer peptide sequences, novel discontinuous epitopes were identified and further optimized to maximize disease discrimination. The final discontinuous epitope sets were tested in a confirmatory cohort of CD patients and controls, yielding 99% sensitivity and 100% specificity.These novel sets of epitopes derived from gliadin have a high degree of accuracy in differentiating CD from controls, compared with standard serologic tests. The method of ultra-high-density peptide microarray described here would be broadly useful to develop high-fidelity diagnostic tests and explore pathogenesis.

  6. Prediction and identification of Taenia solium oncosphere TSO45-4B antigen FnⅢ structure domain linear B cell epitopes%猪带绦虫六钩蚴TSO45-4B抗原FnⅢ结构域线性B细胞表位预测及鉴定

    Institute of Scientific and Technical Information of China (English)

    王媛媛; 王小莉; 常雪莲; 陶志勇; 夏惠; 方强

    2012-01-01

    Objective To predict and identify Taenia solium oncosphere TSO45-4B antigen FnⅢ structure domain linear B cell epitopes. Methods The B cell epitopes of TSO45-4B FnⅢ structure domain were predicted through the sequence analysis by using bioinformatics online tools and the protein space conformation was predicted by SWISS-MODEL. The peptides were synthesized according to the predicted linear epitopes. The immunoreactivity of sera of cysticercosis patients to the peptides synthesized was tested by using ELISA. Results Two linear B cell epitopes of TSO45-4B FnⅢ structure domain were predicted, and one of the predicted epitope peptides synthesized could be recognized by the sera of cysticercosis patients. Conclusion Two linear B cell epitopes of TSO45-4B Fn Ⅲ structure domain are predicted and one of them has been confirmed successfully.%目的 预测并鉴定猪带绦虫六钩蚴TSO45-4B抗原FnⅢ结构域线性B细胞表位.方法 利用生物信息学在线工具分析TSO45-4B抗原FnⅢ结构域序列并预测其线性B细胞表位;采用SWISS-MODEL软件预测TSO45-4B的蛋白空间结构,并合成两条预测表位肽.采用酶联免疫吸附试验(ELISA)检测猪囊尾蚴病人血清与两条预测表位肽的免疫反应性.结果 获得2个TSO45-4B抗原FnⅢ结构域线性B细胞预测表位,其中1条预测表位合成肽可为猪囊尾蚴病患者血清识别.结论 成功预测并鉴定了猪带绦虫六钩蚴TSO45-4B抗原FnⅢ结构域线性B细胞表位.

  7. Prediction of the Spatial Structure and B-cell Epitopes of Mycoplasma suis ORF4 Protein%猪附红细胞体ORF4蛋白的空间结构与B细胞抗原表位预测

    Institute of Scientific and Technical Information of China (English)

    单思; 巴彩凤

    2012-01-01

    To predict the spatial structure and B-cell epitopes of Mycoplasma suis ORF4 protein. The secondary structure, tertiary structure, hydrophilicity, flexible region, antigenic index and surface probability were predicted through the nucleotide sequence of AJ504999-ORF4 were analyzed by bioinformatics software and internet routine. The results showed that the potential B cell antigenic epitopes of Mycoplasma suis ORF4 protein were located at 28-34, 54-61aa, whose the secondary structure were without α-helix but rich in β-pleated sheet. Prediction of the spatial structure and B-cell epitopes of Mycoplasma suis ORF4 protein might laid the basis for studies of the design of epitopes vaccine.%为了预测猪附红细胞体(Mycoplasma suis)ORF4蛋白的空间结构和B细胞抗原表位.选择Genebank序列号AJ504999中ORF4基因,应用生物信息软件和互联网在线程序分析ORF4的氨基酸序列预测二、三级结构、亲水性、柔韧性、抗原指数及表面可及性.结果表明:ORF4蛋白二级结构没有α-螺旋,其中柔性结构以β-转角为主,潜在的优势B细胞抗原表位区段主要分布在28~34、54~61氨基酸区段.本研究预测了ORF4蛋白空间结构和B细胞抗原表位,为猪附红细胞体表位疫苗的设计研发提供了指导意义.

  8. B-cell epitope mapping for the design of vaccines and effective diagnostics

    Directory of Open Access Journals (Sweden)

    Tarek A. Ahmad

    2016-01-01

    Full Text Available The increasing resistance of many microbial strains to antibiotics, delayed laboratory results, and side effects of many chemotherapeutics has raised the need to search for sensitive diagnostics and new prophylactic strategies especially prevention by vaccination. Understanding the epitope/antibody interaction is the key to constructing potent vaccines and effective diagnostics. B-cell epitope mapping is a promising approach to identifying the main antigenic determinants of microorganisms, in special concern the discontinuous conformational ones. Epitope-based vaccines have remarkable privilege over the conventional ones since they are specific, able to avoid undesirable immune responses, generate long lasting immunity, and are reasonably cheaper. This up-to-date review discusses and compares the different physical, computational, and molecular methods that have been used in epitope mapping. The role of each method in the identification of potent epitopes in viruses, bacteria, fungi, parasites, as well as human diseases are tagged and documented. Simultaneously, frequent combinatorial methods are highlighted. The article aims to assist researchers to design the most suitable protocol for mapping their B-cell epitopes.

  9. Characterization of a Partially Protective B-cell Epitope within the 62 kDa Antigen of Schistosoma japonicun

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Xue YANG; Yanfen YANG; Jiaqing ZHAO; Jianghua YANG; Feng LIU; Zhaosong ZHANG; Guanling WU; Chuan SU

    2007-01-01

    Approximately 200 million people worldwide currently suffer from schistosomiasis, one of the most important human parasitic diseases. Although an established infection can be treated with anthelminthics and praziquantel, vaccination would be the ideal method for integral control of schistosomiasis. Schistosoma mansoni IrⅤ-5, recommended as a vaccine candidate by the World Health Organization/Special Programme for Research and Training in Tropical Diseases, produced high protection in animal models. We therefore focused on its homolog, the Schistosoma japonicum 62 kDa antigen, and analyzed it using B cell/antibodyrelated databases and analysis tools for the prediction of B-cell epitopes. Epitope B3 was selected for further investigation. Experiments using a murine model indicated that mice immunized with B3 resulted in lymphocytes proliferation and produced high levels of specific immunoglobulin G and G1, but did not produce impressive cytokines. The vaccination showed partial protective immunity, measured by worm burden and anti-fecundity immunity against S. japonicum. These results indicated that the epitope B3 from S. japonicum 62-kDa antigen might act as a candidate immunogen for future epitope vaccine investigation.

  10. Prediction of Antibody Epitopes

    DEFF Research Database (Denmark)

    Nielsen, Morten; Marcatili, Paolo

    2015-01-01

    self-proteins. Given the sequence or the structure of a protein of interest, several methods exploit such features to predict the residues that are more likely to be recognized by an immunoglobulin.Here, we present two methods (BepiPred and DiscoTope) to predict linear and discontinuous antibody...

  11. Docking of B-cell epitope antigen to specific hepatitis B antibody

    Indian Academy of Sciences (India)

    R Rajkannan; E J Padma Malar

    2007-09-01

    The interaction of pres1 region of hepatitis B virus B-cell epitope antigen with specific hepatitis B neutralizing monoclonal antibody was examined by docking study. We modelled the 3D complex structure of B-cell epitope antigen residues CTTPAQGNSMFPSCCCTKPTDGNCY by homology modelling and docked it with the crystal structure of monoclonal antibody specific for the pres1 region of the hepatitis B virus. At the optimized docked conformation, the interactions between the amino acids of antigen and antibody were examined. It is found that the docked complex is stabilized by 59.3 kcal/mol. The stability of the docked antigen-antibody complex is due to hydrogen bonding and van der Waals interactions. The amino acids of the antigen and antibody responsible for the interaction were identified.

  12. Analysis of Genome Sequence of App ApxIIA and Its Prediction of Related B Cell Epitopes%猪胸膜肺炎放线杆菌ApxIIA基因的序列分析及其B细胞表位预测

    Institute of Scientific and Technical Information of China (English)

    李任峰; 田香勤; 何启盖; 王自良; 赵坤; 李学斌; 王三虎

    2009-01-01

    The research was to analyze the identity matrix of ApxIIA genes of App isolates and to predict the B cell epitopes of this ApxIIA protein. The ApxIIA genes of the six different App were selected from GenBank to analyze their identity matrix of nucleotide and amino acid by the bioinformatics analysis software. The B cell epitopes of the AY232288.1 ApxIIA protein were predicted based on the analysis parameters of B cell epitopes and the characteristicof the secondary structure. The results showed the ApxIIA genes of six strains share 65.56 % and 88.42% homology at nucleotide and amino acid level respectively. The B cell epitope of ApxIIA protein of AY232288.1 was probably locate or adjacent to its N-terminal region 745~751和801~807. These results provided references for further research of ApxIIA protein function and design of multiepitope-based vaccine of APP.%为了进一步研究猪胸膜肺炎放线杆菌(Actionobacillus pleuropneumoniae,App)ApxIIA基因的结构和功能,选取GenBank中6株不同App分离株,采用生物信息学方法对其ApxIIA基因及其编码氨基酸序列进行同源性比对,并选择其中AY232288.1菌株(湖北分离株)ApxIIA基因为研究对象,分析该基因所编码蛋白质的理化性质,并对其可能形成的二级结构及B细胞表位进行预测和分析.结果表明,6株不同App分离株ApxIIA基因核苷酸及氨基酸序列同源性分别为65.56﹪和88.42﹪,在AY232288.1菌株ApxIIA蛋白的肽链中,745~751和801~807区段可能是其B细胞表位优势区.本研究首次利用生物信息学方法对ApxIIA基因及其蛋白质结构进行了分析和预测,为ApxIIA基因功能的深入研究及APP多表位疫苗的设计奠定了基础.

  13. Full protection of swine against foot-and-mouth disease by a bivalent B-cell epitope dendrimer peptide

    NARCIS (Netherlands)

    Blanco, Esther; Guerra, Beatriz; Torre, de la Beatriz; Defaus, Sira; Dekker, A.; Andreu, D.; Sobrino, Francisco

    2016-01-01

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have reported (Cubillos et al., 2008) that a synthetic dendrimeric peptide consisting of four copies of a B-cell epitope [VP1(136–154)] linked through thioether bonds to a T-cell epitope [3A(21–35)] o

  14. Identification of a Coccidioides immitis antigen 2 domain that expresses B-cell-reactive epitopes.

    OpenAIRE

    Zhu, Y; Tryon, V; Magee, D M; Cox, R. A.

    1997-01-01

    Antigen 2 (Ag2), a major immunoreactive component of Coccidioides immitis mycelium- and spherule-phase cell walls, was recently cloned in our laboratory and was shown to elicit T-cell responses in Coccidioides-immune mice. In this investigation, we evaluated recombinant Ag2 (rAg2) and PCR-generated Ag2 truncations for expression of B-cell-reactive epitopes in enzyme-linked immunosorbent and immunoblot assays with sera from patients with active coccidioidomycosis, a hyperimmune goat anti-Ag2 s...

  15. Rabbit hemorrhagic disease virus capsid, a versatile platform for foreign B-cell epitope display inducing protective humoral immune responses.

    Science.gov (United States)

    Moreno, Noelia; Mena, Ignacio; Angulo, Iván; Gómez, Yolanda; Crisci, Elisa; Montoya, María; Castón, José R; Blanco, Esther; Bárcena, Juan

    2016-01-01

    Virus-like particles (VLPs), comprised of viral structural proteins devoid of genetic material, are tunable nanoparticles that can be chemically or genetically engineered, to be used as platforms for multimeric display of foreign antigens. Here, we report the engineering of chimeric VLPs, derived from rabbit hemorrhagic disease virus (RHDV) for presentation of foreign B-cell antigens to the immune system. The RHDV capsid comprises 180 copies of a single capsid subunit (VP60). To evaluate the ability of chimeric RHDV VLPs to elicit protective humoral responses against foreign antigens, we tested two B-cell epitopes: a novel neutralizing B-cell epitope, derived from feline calicivirus capsid protein, and a well characterized B-cell epitope from the extracellular domain of influenza A virus M2 protein (M2e). We generated sets of chimeric RHDV VLPs by insertion of the foreign B-cell epitopes at three different locations within VP60 protein (which involved different levels of surface accessibility) and in different copy numbers per site. The immunogenic potential of the chimeric VLPs was analyzed in the mouse model. The results presented here indicated that chimeric RHDV VLPs elicit potent protective humoral responses against displayed foreign B-cell epitopes, demonstrated by both, in vitro neutralization and in vivo protection against a lethal challenge. PMID:27549017

  16. Fine mapping and conservation analysis of linear B-cell epitopes of peste des petits ruminants virus nucleoprotein.

    Science.gov (United States)

    Yu, Ruisong; Fan, Xiaoming; Xu, Wanxiang; Li, Wentao; Dong, Shijuan; Zhu, Yumin; He, Yaping; Tang, Haiping; Du, Rong; Li, Zhen

    2015-01-30

    Nucleoprotein (NP) is the most abundant and highly immunogenic protein of morbillivirus, and is presently the basis of most diagnostic assays for peste des petits ruminants virus (PPRV). In this study, fine epitope mapping and conservation analysis of linear B-cell epitopes on the PPRV NP has been undertaken using biosynthetic peptides. Nineteen linear B-cell epitopes were identified and their corresponding minimal motifs were located on the NP of PPRV China/Tibet/Geg/07-30. Conservation analysis indicated that ten of the 19 minimal motifs were conserved among 46 PPRV strains. Peptides containing the minimal motifs were recognized using anti-PPRV serum from a goat immunized with PPRV vaccine strain Nigeria 75/1. Identified epitopes and their motifs improve our understanding of the antigenic characteristics of PPRV NP and provide a basis for the development of epitope-based diagnostic assays. PMID:25465659

  17. Cloning,Sequencing,Secondary Structure and B-cell Epitopes Prediction of Bordetella avium Outer Membrane Protein OmpA%禽波氏杆菌外膜蛋白A的克隆测序与生物信息分析

    Institute of Scientific and Technical Information of China (English)

    谭燕玲; 朱瑞良; 王慧; 王新建; 魏凯; 孙振红; 盛鹏程

    2011-01-01

    The aims of this study was to clone and sequence the ompA gene of Bordetella avium,and predict its secondary structure and B-cell epitopes, which provides a theoretical basis for the study of immune mechanism and B. avium subunit vaccine. The B. avium ompA gene was amplified, cloned, and sequenced. By using bioinformatics softwares and methods, the secondary structure and B-cell preponderant epitope of B. avium OmpA were predicted. The results indicated that B. avium ompA gene is 597 bp, encoding 199 amino acids. Using three methods, prediction of the secondary structure of B. avium OmpA indicated that random coils were the main structural type of the flexible region in secondary structure, and contain a small amount of α-helix, β-sheet and a rare β-turn. The OmpA protein was supposed contain 5 potential antigen epitopes and 2 potential glycosylated sites. These results provide a theoretical basis for the further study of immune mechanisms, monoclonal antibodies preparation and epitope vaccine design.%本文旨在克隆禽波氏杆菌外膜蛋白OmpA的编码基因,并预测OmpA蛋白二级结构和B细胞抗原表位,从而探讨禽波氏杆菌外膜蛋白OmpA在免疫保护中所起的作用.作者对禽波氏杆菌的外膜蛋白ompA基因进行PCR扩增、克隆及序列测定.应用生物信息学相关软件和方法,对禽波氏杆菌OmpA蛋白的二级结构和B细胞抗原表位进行预测.禽波氏杆菌ompA基因全长597 bp,编码199个氨基酸.二级结构以无规卷曲为主,有少量的α-螺旋和β-片层,少见β-转角;推测OmpA蛋白有5个B细胞优势抗原表位区域、2个糖基化位点.本研究为进一步分析禽波氏杆菌免疫机理、制备单克隆抗体和设计表位疫苗等奠定理论基础.

  18. In silico Identification and Validation of a Linear and Naturally Immunogenic B-Cell Epitope of the Plasmodium vivax Malaria Vaccine Candidate Merozoite Surface Protein-9

    Science.gov (United States)

    Rodrigues-da-Silva, Rodrigo Nunes; Martins da Silva, João Hermínio; Singh, Balwan; Jiang, Jianlin; Meyer, Esmeralda V. S.; Santos, Fátima; Banic, Dalma Maria; Moreno, Alberto; Galinski, Mary R.; Oliveira-Ferreira, Joseli; Lima-Junior, Josué da Costa

    2016-01-01

    Synthetic peptide vaccines provide the advantages of safety, stability and low cost. The success of this approach is highly dependent on efficient epitope identification and synthetic strategies for efficacious delivery. In malaria, the Merozoite Surface Protein-9 of Plasmodium vivax (PvMSP9) has been considered a vaccine candidate based on the evidence that specific antibodies were able to inhibit merozoite invasion and recombinant proteins were highly immunogenic in mice and humans. However the identities of linear B-cell epitopes within PvMSP9 as targets of functional antibodies remain undefined. We used several publicly-available algorithms for in silico analyses and prediction of relevant B cell epitopes within PMSP9. We show that the tandem repeat sequence EAAPENAEPVHENA (PvMSP9E795-A808) present at the C-terminal region is a promising target for antibodies, given its high combined score to be a linear epitope and located in a putative intrinsically unstructured region of the native protein. To confirm the predictive value of the computational approach, plasma samples from 545 naturally exposed individuals were screened for IgG reactivity against the recombinant PvMSP9-RIRII729-972 and a synthetic peptide representing the predicted B cell epitope PvMSP9E795-A808. 316 individuals (58%) were responders to the full repetitive region PvMSP9-RIRII, of which 177 (56%) also presented total IgG reactivity against the synthetic peptide, confirming it validity as a B cell epitope. The reactivity indexes of anti-PvMSP9-RIRII and anti-PvMSP9E795-A808 antibodies were correlated. Interestingly, a potential role in the acquisition of protective immunity was associated with the linear epitope, since the IgG1 subclass against PvMSP9E795-A808 was the prevalent subclass and this directly correlated with time elapsed since the last malaria episode; however this was not observed in the antibody responses against the full PvMSP9-RIRII. In conclusion, our findings identified and

  19. Babesia bigemina: identification of B cell epitopes associated with parasitized erythrocytes.

    Science.gov (United States)

    Vidotto, O; McElwain, T F; Machado, R Z; Perryman, L E; Suarez, C E; Palmer, G H

    1995-12-01

    Rhoptries are involved in host cell invasion and rhoptry polypeptides, including the Babesia bigemina rhoptry-associated protein-1 (RAP-1), are targets for protective immune responses. Polyclonal antisera produced against isolated rhoptries is directed predominantly against RAP-1 and reacts with both the merozoite and the membrane of parasitized erythrocytes. To determine whether these B cell epitopes associated with the parasitized erythrocyte are derived from RAP-1 or, alternatively, from previously undetected merozoite polypeptides, monoclonal antibodies (mAbs) were generated from mice immunized with rhoptries isolated from the JG-29 clone of the Mexico strain. The anti-RAP-1 mAbs bound only merozoites in a punctate immunofluorescence pattern. A second group of four mAbs, none of which were reactive with RAP-1, bound the parasitized erythrocyte. Two of these latter mAbs, 64/44.17.3 and 64/05.7.2, reacted only with parasitized erythrocytes that had been permeabilized. MAb 64/44.17.3 bound a 54-kDa merozoite polypeptide while 64/05.7.2 bound a > or = 225-kDa merozoite polypeptide. MAbs 64/32.8.5 and 64/38.5.3 recognized epitopes on 17.5- and 76-kDa polypeptides exposed on the external surface of intact parasitized erythrocytes. The results indicate that the identified RAP-1 epitopes are not associated with the erythrocyte cytoskeleton or membrane and that anti-RAP-1 immunity is most likely generated against the free merozoite. All new mAbs reacted with every B. bigemina strain tested (Mexico, Puerto Rico, St. Croix, Texcoco, Jaboticabal). The conservation of RAP-1 epitopes among these strains supports the continued testing of RAP-1 as a vaccine component. In addition, the identification of epitopes expressed on the surface of erythrocytes infected with all five strains provides new candidate immunogens.

  20. Identification of a highly antigenic linear B cell epitope within Plasmodium vivax apical membrane antigen 1 (AMA-1.

    Directory of Open Access Journals (Sweden)

    Lilian Lacerda Bueno

    Full Text Available Apical membrane antigen 1 (AMA-1 is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1 have shown a higher prevalence of specific antibodies to domain II (DII of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/disordered regions (IURs. The B cell epitope comprising the amino acid sequence 290-307 of PvAMA-1 (SASDQPTQYEEEMTDYQK, with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both, respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies.

  1. The Analysis of B-Cell Epitopes of Influenza Virus Hemagglutinin.

    Science.gov (United States)

    Shcherbinin, D N; Alekseeva, S V; Shmarov, M M; Smirnov, Yu A; Naroditskiy, B S; Gintsburg, A L

    2016-01-01

    Vaccination has been successfully used to prevent influenza for a long time. Influenza virus hemagglutinin (HA), which induces a humoral immune response in humans and protection against the flu, is the main antigenic component of modern influenza vaccines. However, new seasonal and pandemic influenza virus variants with altered structures of HA occasionally occur. This allows the pathogen to avoid neutralization with antibodies produced in response to previous vaccination. Development of a vaccine with the new variants of HA acting as antigens takes a long time. Therefore, during an epidemic, it is important to have passive immunization agents to prevent and treat influenza, which can be monoclonal or single-domain antibodies with universal specificity (broad-spectrum agents). We considered antibodies to conserved epitopes of influenza virus antigens as universal ones. In this paper, we tried to characterize the main B-cell epitopes of hemagglutinin and analyze our own and literature data on broadly neutralizing antibodies. We conducted a computer analysis of the best known conformational epitopes of influenza virus HAs using materials of different databases. The analysis showed that the core of the HA molecule, whose antibodies demonstrate pronounced heterosubtypic activity, can be used as a target for the search for and development of broad-spectrum antibodies to the influenza virus. PMID:27099781

  2. Conserved B-cell epitopes among human bocavirus species indicate potential diagnostic targets.

    Directory of Open Access Journals (Sweden)

    Zhuo Zhou

    Full Text Available BACKGROUND: Human bocavirus species 1-4 (HBoV1-4 have been associated with respiratory and enteric infections in children. However, the immunological mechanisms in response to HBoV infections are not fully understood. Though previous studies have shown cross-reactivities between HBoV species, the epitopes responsible for this phenomenon remain unknown. In this study, we used genomic and immunologic approaches to identify the reactive epitopes conserved across multiple HBoV species and explored their potential as the basis of a novel diagnostic test for HBoVs. METHODOLOGY/PRINCIPAL FINDINGS: We generated HBoV1-3 VP2 gene fragment phage display libraries (GFPDLs and used these libraries to analyze mouse antisera against VP2 protein of HBoV1, 2, and 3, and human sera positive for HBoVs. Using this approach, we mapped four epitope clusters of HBoVs and identified two immunodominant peptides--P1 (¹MSDTDIQDQQPDTVDAPQNT²⁰, and P2 (¹⁶²EHAYPNASHPWDEDVMPDL¹⁸⁰--that are conserved among HBoV1-4. To confirm epitope immunogenicity, we immunized mice with the immunodominant P1 and P2 peptides identified in our screen and found that they elicited high titer antibodies in mice. These two antibodies could only recognize the VP2 of HBoV 1-4 in Western blot assays, rather than those of the two other parvoviruses human parvovirus B19 and human parvovirus 4 (PARV4. Based on our findings, we evaluated epitope-based peptide-IgM ELISAs as potential diagnostic tools for HBoVs IgM antibodies. We found that the P1+P2-IgM ELISA showed a higher sensitivity and specificity in HBoVs IgM detection than the assays using a single peptide. CONCLUSIONS/SIGNIFICANCE: The identification of the conserved B-cell epitopes among human bocavirus species contributes to our understanding of immunological cross-reactivities of HBoVs, and provides important insights for the development of HBoV diagnostic tools.

  3. Construction and characterization of an HCV-derived multi-epitope peptide antigen containing B-cell HVR1 mimotopes and T-cell conserved epitopes

    Institute of Scientific and Technical Information of China (English)

    GAO; Jun; GONG; Yuping; ZHAO; Ping; ZHU; Qing; YANG; Xiaoping; QI; Zhongtian

    2006-01-01

    Hepatitis C (HCV) genome is highly variable, particularly in the hypervariable region 1(HVR1) of its E2 envelope gene. The variability of HCV genome has been a major obstacle for developing HCV vaccines. Due to B-cell HVR1 mimotopes mimicking the antigenicity of natural HVR1 epitopes and some T-cell epitopes from the consensus sequence of HCV genes conserving among the different HCV genotypes, we synthesized an minigene of HCV-derived multi-epitope peptide antigen (CMEP), which contains 9 B-cell HVR1 mimotopes in E2, 2 conserved CTL epitopes in C, 1conserved CTL epitope in NS3 and 1 conserved Th epitope in NS3. This minigene was cloned into a GST expression vector to generate a fusion protein GST-CMER The immunogenic properties of CEMP were characterized by HCV infected patients' sera, and found that the reactivity frequency reached 75%. The cross reactivity of anti-CEMP antibody with different natural HVR1 variants was up to 90%. Meanwhile, we constructed an HCV DNA vaccine candidate, plasmid pVAX1.0-st-CMEP carrying the recombinant gene (st) of a secretion signal peptide and PADRE universal Th cell epitope sequence in front of the CMEP minigene. Immunization of rabbits with pVAX1.0-st-CMEP resulted in the production of antibody, which was of the same cross reactivity as the fusion protein GST-CMEP.Our findings indicate that the HCV-derived multi-epitope peptide antigen in some degree possessed the characteristics of neutralizing HCV epitopes, and would be of the value as a candidate for the development of HCV vaccines.

  4. Multiple linear B-cell epitopes of classical swine fever virus glycoprotein E2 expressed in E.coli as multiple epitope vaccine induces a protective immune response

    Directory of Open Access Journals (Sweden)

    Wei Jian-Chao

    2011-07-01

    Full Text Available Abstract Classical swine fever is a highly contagious disease of swine caused by classical swine fever virus, an OIE list A pathogen. Epitope-based vaccines is one of the current focuses in the development of new vaccines against classical swine fever virus (CSFV. Two B-cell linear epitopes rE2-ba from the E2 glycoprotein of CSFV, rE2-a (CFRREKPFPHRMDCVTTTVENED, aa844-865 and rE2-b (CKEDYRYAISSTNEIGLLGAGGLT, aa693-716, were constructed and heterologously expressed in Escherichia coli as multiple epitope vaccine. Fifteen 6-week-old specified-pathogen-free (SPF piglets were intramuscularly immunized with epitopes twice at 2-week intervals. All epitope-vaccinated pigs could mount an anamnestic response after booster vaccination with neutralizing antibody titers ranging from 1:16 to 1:256. At this time, the pigs were subjected to challenge infection with a dose of 1 × 106 TCID50 virulent CSFV strain. After challenge infection, all of the rE2-ba-immunized pigs were alive and without symptoms or signs of CSF. In contrast, the control pigs continuously exhibited signs of CSF and had to be euthanized because of severe clinical symptoms at 5 days post challenge infection. The data from in vivo experiments shown that the multiple epitope rE2-ba shown a greater protection (similar to that of HCLV vaccine than that of mono-epitope peptide(rE2-a or rE2-b. Therefore, The results demonstrated that this multiple epitope peptide expressed in a prokaryotic system can be used as a potential DIVA (differentiating infected from vaccinated animals vaccine. The E.coli-expressed E2 multiple B-cell linear epitopes retains correct immunogenicity and is able to induce a protective immune response against CSFV infection.

  5. Mechanisms, safety and efficacy of a B cell epitope-based vaccine for immunotherapy of grass pollen allergy

    Directory of Open Access Journals (Sweden)

    Petra Zieglmayer

    2016-09-01

    Conclusion: The B cell epitope-based recombinant grass pollen allergy vaccine BM32 is well tolerated and few doses are sufficient to suppress immediate allergic reactions as well as allergen-specific T cell responses via a selective induction of allergen-specific IgG antibodies. (ClinicalTrials.gov number, NCT01445002.

  6. Identification of critical residues of linear B cell epitope on Goodpasture autoantigen.

    Directory of Open Access Journals (Sweden)

    Xiao-yu Jia

    Full Text Available The autoantigen of anti-glomerular basement membrane (GBM disease has been identified as the non-collagenous domain 1 of α3 chain of type IV collagen, α3(IVNC1. Our previous study revealed a peptide on α3(IVNC1 as a major linear epitope for B cells and potentially nephrogenic, designated as P14 (α3129-150. This peptide has also been proven to be the epitope of auto-reactive T cells in anti-GBM patients. This study was aimed to further characterize the critical motif of P14.16 patients with anti-GBM disease and positive anti-P14 antibodies were enrolled. A set of truncated and alanine substituted peptides derived from P14 were synthesized. Circulating antibodies against the peptides were detected by enzyme linked immunosorbent assay (ELISA.We found that all sera with anti-P14 antibodies reacted with the 13-mer sequence in the C-terminus of P14 (P14c exclusively. The level of antibodies against P14 was highly correlated with the level of antibodies against P14c (r=0.970, P<0.001. P14c was the core immunogenic region and the amino acid sequence (ISLWKGFSFIMFT was highly hydrophobic. Each amino acid residue in P14c was sequentially replaced by alanine. Three residues of glycine142, phenylalanine143, and phenylalanine145 were identified crucial for antibody binding based on the remarkable decline (P<0.001 of antibody reaction after each residue replacement.We defined GFxF (α3142, 143,145 as the critical motif of P14. It may provide some clues for understanding the etiology of anti-GBM disease.

  7. ElliPro: a new structure-based tool for the prediction of antibody epitopes

    Directory of Open Access Journals (Sweden)

    Fusseder Nicholas

    2008-12-01

    Full Text Available Abstract Background Reliable prediction of antibody, or B-cell, epitopes remains challenging yet highly desirable for the design of vaccines and immunodiagnostics. A correlation between antigenicity, solvent accessibility, and flexibility in proteins was demonstrated. Subsequently, Thornton and colleagues proposed a method for identifying continuous epitopes in the protein regions protruding from the protein's globular surface. The aim of this work was to implement that method as a web-tool and evaluate its performance on discontinuous epitopes known from the structures of antibody-protein complexes. Results Here we present ElliPro, a web-tool that implements Thornton's method and, together with a residue clustering algorithm, the MODELLER program and the Jmol viewer, allows the prediction and visualization of antibody epitopes in a given protein sequence or structure. ElliPro has been tested on a benchmark dataset of discontinuous epitopes inferred from 3D structures of antibody-protein complexes. In comparison with six other structure-based methods that can be used for epitope prediction, ElliPro performed the best and gave an AUC value of 0.732, when the most significant prediction was considered for each protein. Since the rank of the best prediction was at most in the top three for more than 70% of proteins and never exceeded five, ElliPro is considered a useful research tool for identifying antibody epitopes in protein antigens. ElliPro is available at http://tools.immuneepitope.org/tools/ElliPro. Conclusion The results from ElliPro suggest that further research on antibody epitopes considering more features that discriminate epitopes from non-epitopes may further improve predictions. As ElliPro is based on the geometrical properties of protein structure and does not require training, it might be more generally applied for predicting different types of protein-protein interactions.

  8. CD20 mutations involving the rituximab epitope are rare in diffuse large B-cell lymphomas and are not a significant cause of R-CHOP failure

    OpenAIRE

    Johnson, Nathalie A.; Leach, Stephen; Woolcock, Bruce; deLeeuw, Ronald J; Bashashati, Ali; Sehn, Laurie H.; Connors, Joseph M; Chhanabhai, Mukesh; Brooks-Wilson, Angela; Gascoyne, Randy D.

    2009-01-01

    The findings of this study indicate that CD20 mutations nvolving the rituximab epitope are rare in both de novo and relapsed diffuse large B-cell lymphoma, and do not represent a significant cause of R-CHOP resistance.

  9. Full protection of swine against foot-and-mouth disease by a bivalent B-cell epitope dendrimer peptide.

    Science.gov (United States)

    Blanco, Esther; Guerra, Beatriz; de la Torre, Beatriz G; Defaus, Sira; Dekker, Aldo; Andreu, David; Sobrino, Francisco

    2016-05-01

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have reported (Cubillos et al., 2008) that a synthetic dendrimeric peptide consisting of four copies of a B-cell epitope [VP1(136-154)] linked through thioether bonds to a T-cell epitope [3A(21-35)] of FMDV [B4T(thi)] elicits potent B- and T-cell specific responses and confers solid protection in pigs to type C FMDV challenge. Herein we show that downsized versions of this peptide bearing two copies of a B-cell epitope from a type O isolate and using thioether [B2T(thi)] or maleimide [B2T(mal)] conjugation chemistries for their synthesis elicited in swine similar or higher B and T-cell specific responses than tetravalent B4T(thi). Moreover, while partial protection was observed in animals immunized with B4T(thi) (60%) and B2T(thi) (80%), B2T(mal) conferred full (100%) protection against FMDV challenge, associated to high levels of circulating IgG2 and mucosal IgGA, and entirely prevented virus shedding. Interestingly, B2T(mal) is also the most advantageous option in terms of synthetic practicality. Taken together, the results reported here point out to B2T(mal) as a highly valuable, cost-effective FMDV candidate vaccine. PMID:26956030

  10. Identification of Immunodominant B-cell Epitope Regions of Reticulocyte Binding Proteins in Plasmodium vivax by Protein Microarray Based Immunoscreening.

    Science.gov (United States)

    Han, Jin-Hee; Li, Jian; Wang, Bo; Lee, Seong-Kyun; Nyunt, Myat Htut; Na, Sunghun; Park, Jeong-Hyun; Han, Eun-Taek

    2015-08-01

    Plasmodium falciparum can invade all stages of red blood cells, while Plasmodium vivax can invade only reticulocytes. Although many P. vivax proteins have been discovered, their functions are largely unknown. Among them, P. vivax reticulocyte binding proteins (PvRBP1 and PvRBP2) recognize and bind to reticulocytes. Both proteins possess a C-terminal hydrophobic transmembrane domain, which drives adhesion to reticulocytes. PvRBP1 and PvRBP2 are large (> 326 kDa), which hinders identification of the functional domains. In this study, the complete genome information of the P. vivax RBP family was thoroughly analyzed using a prediction server with bioinformatics data to predict B-cell epitope domains. Eleven pvrbp family genes that included 2 pseudogenes and 9 full or partial length genes were selected and used to express recombinant proteins in a wheat germ cell-free system. The expressed proteins were used to evaluate the humoral immune response with vivax malaria patients and healthy individual serum samples by protein microarray. The recombinant fragments of 9 PvRBP proteins were successfully expressed; the soluble proteins ranged in molecular weight from 16 to 34 kDa. Evaluation of the humoral immune response to each recombinant PvRBP protein indicated a high antigenicity, with 38-88% sensitivity and 100% specificity. Of them, N-terminal parts of PvRBP2c (PVX_090325-1) and PvRBP2 like partial A (PVX_090330-1) elicited high antigenicity. In addition, the PvRBP2-like homologue B (PVX_116930) fragment was newly identified as high antigenicity and may be exploited as a potential antigenic candidate among the PvRBP family. The functional activity of the PvRBP family on merozoite invasion remains unknown.

  11. 应用生物信息学分析大米过敏原RAG1的B细胞表位(英文)%Bioinformatics Analysis on B cell Epitopes of Rice Allergen RAG1

    Institute of Scientific and Technical Information of China (English)

    李燕芳; 何颖; 邹泽红

    2012-01-01

    [Objective] To predict the secondary structure and B cell epitopes of the rice major allergen RAG1. [Method] The amino acid sequence of rice allergen RAG1 was acquired from Expasy protein database. The secondary structure of RAG1 was predicted by DNAStar Protean software with Gamier-Robson program, Chou-Fasman program and Karplus-Schulz program; the B cell epitopes of RAG1 was predicted with the Kyte Doolittle hydrophilic program, Emini surface accessibility program and Jameson-Wolf antigenic index program. [Result] The predictions on secondary structure and B cell epitopes showed that the regions of 33-44, 119-129, 155-163 were the dominant B cell epitopes. [Conclusion] This study predicted the potential dominant B cell epitopes in rice allergen RAG1 by comprehensive use of multi-methods and multi-parameters, and provided a theoretical basis for further researches on identification, antigen modification and epitope vaccine design of RAG1 B cell epitopes.%[目的]预测大米主要过敏原RAG1的二级结构及B细胞表位。[方法]从Expasy蛋白质数据库中获得编码大米过敏原RAG1的氨基酸序列并以此氨基酸序列为基础,通过DNAStarProtean软件,采用Gamier-Robson方案、Chou-Fasman方案和Karplus-Schulz方案预测RAG1的二级结构,用Kyte-Doolittle亲水性方案、Emini表面可及性方案、Jameson-Wolf抗原性指数方案综合预测RAG1的B细胞表位。[结果]对大米过敏原RAG1的二级结构和B细胞表位预测的结果表明,第33~44、119~129、155~163区段可能是B细胞的优势表位。[结论]本研究综合应用多方法多参数预测大米过敏原RAG1潜在的B细胞优势表位,为RAG1B细胞表位的进一步鉴定及其抗原性改造、表位疫苗设计等研究提供了理论依据。

  12. Multiple B-cell epitope vaccine induces a Staphylococcus enterotoxin B-specific IgG1 protective response against MRSA infection.

    Science.gov (United States)

    Zhao, Zhuo; Sun, He-Qiang; Wei, Shan-Shan; Li, Bin; Feng, Qiang; Zhu, Jiang; Zeng, Hao; Zou, Quan-Ming; Wu, Chao

    2015-01-01

    No vaccine against methicillin-resistant Staphylococcus aureus (MRSA) has been currently approved for use in humans. Staphylococcus enterotoxin B (SEB) is one of the most potent MRSA exotoxins. In the present study, we evaluated the efficacy and immunologic mechanisms of an SEB multiple B-cell epitope vaccine against MRSA infection. Synthetic overlapping peptide ELISA identified three novel B-cell immunodominant SEB epitopes (in addition to those previously known): SEB31-48, SEB133-150, and SEB193-210. Six B-cell immunodominant epitopes (amino acid residues 31-48, 97-114, 133-150, 193-210, 205-222, and 247-261) were sufficient to induce robust IgG1/IgG2b-specific protective responses against MRSA infection. Therefore, we constructed a recombinant MRSA SEB-specific multiple B-cell epitope vaccine Polypeptides by combining the six SEB immunodominant epitopes and demonstrated its ability to induce a robust SEB-specific IgG1 response to MRSA, as well as a Th2-directing isotype response. Moreover, Polypeptides-induced antisera stimulated synergetic opsonophagocytosis killing of MRSA. Most importantly, Polypeptides was more effective at clearing the bacteria in MRSA-infected mice than the whole SEB antigen, and was able to successfully protect mice from infection by various clinical MRSA isolates. Altogether, these results support further evaluation of the SEB multiple B-cell epitope-vaccine to address MRSA infection in humans.

  13. Identification and fine mapping of a linear B cell epitope of human vimentin

    DEFF Research Database (Denmark)

    Dam, Catharina Essendrup; Houen, Gunnar; Hansen, Paul R.;

    2014-01-01

    Knowledge about antibody-antigen interactions is important for the understanding of the immune system mechanisms and for supporting development of drugs and biomarkers. A tool for identification of these antigenic epitopes of specific antibodies is epitope mapping. In this study, a modified enzym...... that charged amino acids are essential for antibody reactivity and that the vimentin antibody is dependent on side-chain interactions in combination with backbone interactions....

  14. Immune Epitope Database and Analysis Resource (IEDB)

    Data.gov (United States)

    U.S. Department of Health & Human Services — This repository contains antibody/B cell and T cell epitope information and epitope prediction and analysis tools for use by the research community worldwide....

  15. Bioinformatics Analysis on B Cell Epitopes of Rice Allergen RAG1%应用生物信息学分析大米过敏原RAG1的B细胞表位

    Institute of Scientific and Technical Information of China (English)

    李燕芳; 何颖; 邹泽红

    2012-01-01

    [目的]预测大米主要过敏原RAG1的二级结构及B细胞表位.[方法]从Expasy蛋白质数据库中获得编码大米过敏原RAG1的氨基酸序列并以此氨基酸序列为基础,通过DNAStar Protean软件,采用Gamier-Robson方案、Chou-Fasman方案和Karplus-Schulz方案预测RAG1的二级结构,用Kyte-Doolittle亲水性方案、Emini表面可及性方案、Jameson-Wolf抗原性指数方案综合预测RAG1的B细胞表位.[结果]对大米过敏原RAG1的二级结构和B细胞表住预测的结果表明,第33 ~44、119 ~129、155~163区段可能是B细胞的优势表位.[结论]该研究综合应用多方法多参数预测大米过敏原RAG1潜在的B细胞优势表位,为RAG1 B细胞表位的进一步鉴定及其抗原性改造、表位疫苗设计等研究提供了理论依据.%[Objective] To predict secondary structure and B cell epilopes of the rice major allergen RAG1. [ Method ] The amino acid sequence of rice allergen RAG1 was acquired from Expasy protein database. The secondary structure of RAG1 was predicted by DNAStar Protean software with Gamier-Robson program, Chou-Fasman program and Karplus-Schulz program; the B cell epitopes of RAG1 was predicted with the Kyte-Doolittle hydrophilic program, Emini surface accessibility program and Jameson-Wolf antigenic index program. [ Result] The predictions on secondary structure and B cell epitopes showed that the regions of 33 -44, 119 - 129, 155 - 163 were the dominant B cell epitopes. [Conclusion] This study predicted the potential dominant B cell epitopes in rice allergen RAG1 by comprehensive use of multi-methods and multi-parameters, and provided a theoretical basis for further researches on identification, antigen modification and epitope vaccine design of RAG1 B cell epitopes.

  16. A Nanoparticle Based Sp17 Peptide Vaccine Exposes New Immuno-Dominant and Species Cross-reactive B Cell Epitopes

    Directory of Open Access Journals (Sweden)

    Sue D. Xiang

    2015-10-01

    Full Text Available Sperm protein antigen 17 (Sp17, expressed in primary as well as in metastatic lesions in >83% of patients with ovarian cancer, is a promising ovarian cancer vaccine candidate. Herein we describe the formulation of nanoparticle based vaccines based on human Sp17 (hSp17 sequence derived peptides, and map the immuno-dominant T cell and antibody epitopes induced using such formulations. The primary T and B cell immuno-dominant region within Sp17 was found to be the same when using biocompatible nanoparticle carriers or the conventional “mix-in” pro-inflammatory adjuvant CpG, both mapping to amino acids (aa 111–142. However, delivery of hSp17111–142 as a nanoparticle conjugate promoted a number of new properties, changing the dominant antibody isotype induced from IgG2a to IgG1 and the fine specificity of the B cell epitopes within hSp17111–142, from an immuno-dominant region 134–142 aa for CpG, to region 121–138 aa for nanoparticles. Associated with this change in specificity was a substantial increase in antibody cross-reactivity between mouse and human Sp17. These results indicate conjugation of antigen to nanoparticles can have major effects on fine antigen specificity, which surprisingly could be beneficially used to increase the cross-reactivity of antibody responses.

  17. A Nanoparticle Based Sp17 Peptide Vaccine Exposes New Immuno-Dominant and Species Cross-reactive B Cell Epitopes.

    Science.gov (United States)

    Xiang, Sue D; Gao, Qian; Wilson, Kirsty L; Heyerick, Arne; Plebanski, Magdalena

    2015-01-01

    Sperm protein antigen 17 (Sp17), expressed in primary as well as in metastatic lesions in >83% of patients with ovarian cancer, is a promising ovarian cancer vaccine candidate. Herein we describe the formulation of nanoparticle based vaccines based on human Sp17 (hSp17) sequence derived peptides, and map the immuno-dominant T cell and antibody epitopes induced using such formulations. The primary T and B cell immuno-dominant region within Sp17 was found to be the same when using biocompatible nanoparticle carriers or the conventional "mix-in" pro-inflammatory adjuvant CpG, both mapping to amino acids (aa) 111-142. However, delivery of hSp17111-142 as a nanoparticle conjugate promoted a number of new properties, changing the dominant antibody isotype induced from IgG2a to IgG1 and the fine specificity of the B cell epitopes within hSp17111-142, from an immuno-dominant region 134-142 aa for CpG, to region 121-138 aa for nanoparticles. Associated with this change in specificity was a substantial increase in antibody cross-reactivity between mouse and human Sp17. These results indicate conjugation of antigen to nanoparticles can have major effects on fine antigen specificity, which surprisingly could be beneficially used to increase the cross-reactivity of antibody responses. PMID:26529027

  18. Identification of protective B-cell epitopes of Atroxlysin-I: A metalloproteinase from Bothrops atrox snake venom.

    Science.gov (United States)

    Schneider, F S; de Almeida Lima, S; Reis de Ávila, G; Castro, K L; Guerra-Duarte, C; Sanchez, E F; Nguyen, C; Granier, C; Molina, F; Chávez-Olortegui, C

    2016-03-29

    Atroxlysin-I (Atr-I) is a hemorrhagic snake venom metalloproteinase (SVMP) from Bothrops atrox venom, the snake responsible for the majority of bites in the north region of South America. SVMPs like Atr-I produce toxic effects in victims including hemorrhage, inflammation, necrosis and blood coagulation deficiency. Mapping of B-cell epitopes in SVMPs might result in the identification of non-toxic molecules capable of inducing neutralizing antibodies and improving the anti-venom therapy. Here, using the SPOT-synthesis technique we identified two epitopes located in the N-ter region of Atr-I (AtrEp1-(22)YNGNSDKIRRRIHQM(36); and AtrEp2-(55)GVEIWSNKDLINVQ(68)). Based on the sequence of AtrEp1 and AtrEp2 a third peptide named Atr-I biepitope (AtrBiEp) was designed and synthesized ((23)NGNSDKIRRRIH(34)GG(55)GVEIWSNKDLINVQ(68)). AtrBiEp was used to immunize BALB/c mice. Anti-AtrBiEp serum cross-reacted against Atr-I in western blot and was able to fully neutralize the hemorrhagic activity of Atr-I. Our results provide a rational basis for the identification of neutralizing epitopes on Atr-I snake venom toxin and show that the use of synthetic peptides could improve the generation of immuno-therapeutics. PMID:26917009

  19. Identification of continuous human B-cell epitopes in the VP35, VP40, nucleoprotein and glycoprotein of Ebola virus.

    Directory of Open Access Journals (Sweden)

    Pierre Becquart

    Full Text Available Ebola virus (EBOV is a highly virulent human pathogen. Recovery of infected patients is associated with efficient EBOV-specific immunoglobulin G (IgG responses, whereas fatal outcome is associated with defective humoral immunity. As B-cell epitopes on EBOV are poorly defined, we sought to identify specific epitopes in four EBOV proteins (Glycoprotein (GP, Nucleoprotein (NP, and matrix Viral Protein (VP40 and VP35. For the first time, we tested EBOV IgG+ sera from asymptomatic individuals and symptomatic Gabonese survivors, collected during the early humoral response (seven days after the end of symptoms and the late memory phase (7-12 years post-infection. We also tested sera from EBOV-seropositive patients who had never had clinical signs of hemorrhagic fever or who lived in non-epidemic areas (asymptomatic subjects. We found that serum from asymptomatic individuals was more strongly reactive to VP40 peptides than to GP, NP or VP35. Interestingly, anti-EBOV IgG from asymptomatic patients targeted three immunodominant regions of VP40 reported to play a crucial role in virus assembly and budding. In contrast, serum from most survivors of the three outbreaks, collected a few days after the end of symptoms, reacted mainly with GP peptides. However, in asymptomatic subjects the longest immunodominant domains were identified in GP, and analysis of the GP crystal structure revealed that these domains covered a larger surface area of the chalice bowl formed by three GP1 subunits. The B-cell epitopes we identified in the EBOV VP35, VP40, NP and GP proteins may represent important tools for understanding the humoral response to this virus and for developing new antibody-based therapeutics or detection methods.

  20. Characterisation of a protective linear B cell epitope against feline parvoviruses

    NARCIS (Netherlands)

    Langeveld, J.P.; Martinez Torrecuadrada, J.; Boshuizen, R.S.; Meloen, R.H.; Ignacio Casal, J.

    2001-01-01

    Monoclonal antibody 3C9 was the starting material in the definition of the epitope that led to the synthesis of the first efficient peptide vaccine against a viral disease (canine parvovirus) in the natural host (dog). In this report, we have analysed the specificity of the antibody at the single am

  1. Prediction on Antigenic Epitope Characteristics of Bt Cry2Ab Protein in Transgenic Crops

    Institute of Scientific and Technical Information of China (English)

    Jierong GAO; Ying HE; Zehong ZOU; Ailin TAO; Yuncan AI

    2012-01-01

    Abstract [Objective] This study aimed to predict the structural characteristics of Bt Cry2Ab protein in transgenic crops with bioinformatic analysis to provide the theoreti- cal clues for design of antibody Cry2Ab. [Method] The amino acid sequence of Cry2Ab protein was searched from NCBI database. The B cell epitopes were pre- dicted with DNAStar. The binding affinity between Cry2Ab protein and MHC-II molecules was analyzed with NetMHCII 2.2 Server to predict the T cell epitopes. [Result] Prediction result suggested the potential B cell epitope of Cry2Ab locating in the region of 208-215. Analysis of the binding affinity between Cry2Ab and MHC-II molecules suggested the regions of 177-185, 299-307 and 255-263 were the po- tential T cell epitopes. Human with HLA-DRB10101 alleles and HLA-DRB10701 al- leles were more sensitive to Cry2Ab protein. [Conclusion] This study facilitates to un- derstand the structural characteristics of Cry2Ab protein and provides a new clue to improve the assessment method for potential allergenicity of genetically modified food.

  2. In silico cloning and B/T cell epitope prediction of triosephosphate isomerase from Echinococcus granulosus.

    Science.gov (United States)

    Wang, Fen; Ye, Bin

    2016-10-01

    Cystic echinococcosis is a worldwide zoonosis caused by Echinococcus granulosus. Because the methods of diagnosis and treatment for cystic echinococcosis were limited, it is still necessary to screen target proteins for the development of new anti-hydatidosis vaccine. In this study, the triosephosphate isomerase gene of E. granulosus was in silico cloned. The B cell and T cell epitopes were predicted by bioinformatics methods. The cDNA sequence of EgTIM was composition of 1094 base pairs, with an open reading frame of 753 base pairs. The deduced amino acid sequences were composed of 250 amino acids. Five cross-reactive epitopes, locating on 21aa-35aa, 43aa-57aa, 94aa-107aa, 115-129aa, and 164aa-183aa, could be expected to serve as candidate epitopes in the development of vaccine against E. granulosus. These results could provide bases for gene cloning, recombinant expression, and the designation of anti-hydatidosis vaccine.

  3. Identification of a human immunodominant B-cell epitope within the immunoglobulin A1 protease of Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Felici Franco

    2007-12-01

    Full Text Available Abstract Background The IgA1 protease of Streptococcus pneumoniae is a proteolytic enzyme that specifically cleaves the hinge regions of human IgA1, which dominates most mucosal surfaces and is the major IgA isotype in serum. This protease is expressed in all of the known pneumococcal strains and plays a major role in pathogen's resistance to the host immune response. The present work was focused at identifying the immunodominant regions of pneumococcal IgA1 protease recognized by the human antibody response. Results An antigenic sequence corresponding to amino acids 420–457 (epiA of the iga gene product was identified by screening a pneumococcal phage display library with patients' sera. The epiA peptide is conserved in all pneumococci and in two out of three S. mitis strains, while it is not present in other oral streptococci so far sequenced. This epitope was specifically recognized by antibodies present in sera from 90% of healthy adults, thus representing an important target of the humoral response to S. pneumoniae and S. mitis infection. Moreover, sera from 68% of children less than 4 years old reacted with the epiA peptide, indicating that the human immune response against streptococcal antigens occurs during childhood. Conclusion The broad and specific recognition of the epiA polypeptide by human sera demonstrate that the pneumococcal IgA1 protease contains an immunodominant B-cell epitope. The use of phage display libraries to identify microbe or disease-specific antigens recognized by human sera is a valuable approach to epitope discovery.

  4. Prediction of promiscuous epitopes in the e6 protein of three high risk human papilloma viruses: a computational approach.

    Science.gov (United States)

    Subramanian, Nirmala; Chinnappan, Sudandiradoss

    2013-01-01

    A najor current challenge and constraint in cervical cancer research is the development of vaccines against human papilloma virus (HPV) epitopes. Although many studies are done on epitope identification on HPVs, no computational work has been carried out for high risk forms which are considered to cause cervical cancer. Of all the high risk HPVs, HPV 16, HPV 18 and HPV 45 are responsible for 94% of cervical cancers in women worldwide. In this work, we computationally predicted the promiscuous epitopes among the E6 proteins of high risk HPVs. We identified the conserved residues, HLA class I, HLA class II and B-cell epitopes along with their corresponding secondary structure conformations. We used extremely precise bioinformatics tools like ClustalW2, MAPPP, NetMHC, EpiJen, EpiTop 1.0, ABCpred, BCpred and PSIPred for achieving this task. Our study identified specific regions 'FAFR(K)DL' followed by 'KLPD(Q)LCTEL' fragments which proved to be promiscuous epitopes present in both human leukocyte antigen (HLA) class I, class II molecules and B cells as well. These fragments also follow every suitable character to be considered as promiscuous epitopes with supporting evidences of previously reported experimental results. Thus, we conclude that these regions should be considered as the important for design of specific therapeutic vaccines for cervical cancer.

  5. Identification of two linear B-cell epitopes from West Nile virus NS1 by screening a phage-displayed random peptide library

    Directory of Open Access Journals (Sweden)

    Qin Yong-Li

    2011-07-01

    Full Text Available Abstract Background The West Nile virus (WNV nonstructural protein 1 (NS1 is an important antigenic protein that elicits protective antibody responses in animals and can be used for the serological diagnosis of WNV infection. Although previous work has demonstrated the vital role of WNV NS1-specific antibody responses, the specific epitopes in the NS1 have not been identified. Results The present study describes the identification of two linear B-cell epitopes in WNV NS1 through screening a phage-displayed random 12-mer peptide library with two monoclonal antibodies (mAbs 3C7 and 4D1 that directed against the NS1. The mAbs 3C7 and 4D1 recognized phages displaying peptides with the consensus motifs LTATTEK and VVDGPETKEC, respectively. Exact sequences of both motifs were found in the NS1 (895LTATTEK901 and 925VVDGPETKEC934. Further identification of the displayed B cell epitopes were conducted using a set of truncated peptides expressed as MBP fusion proteins. The data indicated that 896TATTEK901 and925VVDGPETKEC934 are minimal determinants of the linear B cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. Antibodies present in the serum of WNV-positive horses recognized the minimal linear epitopes in Western blot analysis, indicating that the two peptides are antigenic in horses during infection. Furthermore, we found that the epitope recognized by 3C7 is conserved only among WNV strains, whereas the epitope recognized by 4D1 is a common motif shared among WNV and other members of Japanese encephalitis virus (JEV serocomplex. Conclusions We identified TATTEK and VVDGPETKEC as NS1-specific linear B-cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against WNV and other viruses of JEV serocomplex.

  6. Large-scale analysis of B-cell epitopes on influenza virus hemagglutinin - implications for cross-reactivity of neutralizing antibodies

    Directory of Open Access Journals (Sweden)

    Jing eSun

    2014-02-01

    Full Text Available Influenza viruses continue to cause substantial morbidity and mortality worldwide. Fast gene mutation on surface proteins of influenza virus result in increasing resistance to current vaccines and available antiviral drugs. Broadly neutralizing antibodies represent targets for prophylactic and therapeutic treatments of influenza. We performed a systematic bioinformatics study of cross-reactivity of neutralizing antibodies against influenza virus surface glycoprotein hemagglutinin (HA. This study utilized the available crystal structures of HA complexed with the antibodies for the analysis of tens of thousands of HA sequences. The detailed description of B-cell epitopes, measurement of epitope area similarity among different strains, and estimation of antibody neutralizing coverage provide insights into cross-reactivity status of existing neutralizing antibodies against influenza virus. We have developed a method to assess the likely cross-reactivity potential of broadly neutralizing antibodies for influenza strains, either newly emerged or existing. Our method catalogs influenza strains by a new concept named discontinuous peptide, and then provide assessment of cross-reactivity. Potentially cross-reactive strains are those that share 100% identity with experimentally verified neutralized strains. By cataloging influenza strains and their B-cell epitopes for known broadly neutralizing antibodies, our method provides guidance for selection of representative strains for further experimental design. The knowledge of sequences, their B-cell epitopes, and differences between historical influenza strains, we enhance our preparedness and the ability to respond to the emerging pandemic threats.

  7. Amyloid-β-Anti-Amyloid-β Complex Structure Reveals an Extended Conformation in the Immunodominant B-Cell Epitope

    Energy Technology Data Exchange (ETDEWEB)

    Miles, Luke A; Wun, Kwok S; Crespi, Gabriela A.N.; Fodero-Tavoletti, Michelle T; Galatis, Denise; Bagley, Christopher J; Beyreuther, Konrad; Masters, Colin L; Cappai, Roberto; McKinstry, William J; Barnham, Kevin J; Parker, Michael W [SVIMR-A; (Hanson); (Heidelberg); (Melbourne)

    2012-04-17

    Alzheimer's disease (AD) is the most common form of dementia. Amyloid-β (Aβ) peptide, generated by proteolytic cleavage of the amyloid precursor protein, is central to AD pathogenesis. Most pharmaceutical activity in AD research has focused on Aβ, its generation and clearance from the brain. In particular, there is much interest in immunotherapy approaches with a number of anti-Aβ antibodies in clinical trials. We have developed a monoclonal antibody, called WO2, which recognises the Aβ peptide. To this end, we have determined the three-dimensional structure, to near atomic resolution, of both the antibody and the complex with its antigen, the Aβ peptide. The structures reveal the molecular basis for WO2 recognition and binding of Aβ. The Aβ peptide adopts an extended, coil-like conformation across its major immunodominant B-cell epitope between residues 2 and 8. We have also studied the antibody-bound Aβ peptide in the presence of metals known to affect its aggregation state and show that WO2 inhibits these interactions. Thus, antibodies that target the N-terminal region of Aβ, such as WO2, hold promise for therapeutic development.

  8. Large-scale analysis of B-cell epitopes on influenza virus hemagglutinin - implications for cross-reactivity of neutralizing antibodies

    DEFF Research Database (Denmark)

    Sun, Jing; Kudahl, Ulrich J.; Simon, Christian;

    2014-01-01

    Influenza viruses continue to cause substantial morbidity and mortality worldwide. Fast gene mutation on surface proteins of influenza virus result in increasing resistance to current vaccines and available antiviral drugs. Broadly neutralizing antibodies (bnAbs) represent targets for prophylactic...... and therapeutic treatments of influenza. We performed a systematic bioinformatics study of cross-reactivity of neutralizing antibodies (nAbs) against influenza virus surface glycoprotein hemagglutinin (HA). This study utilized the available crystal structures of HA complexed with the antibodies for the analysis...... that share 100% identity with experimentally verified neutralized strains. By cataloging influenza strains and their B-cell epitopes for known bnAbs, our method provides guidance for selection of representative strains for further experimental design. The knowledge of sequences, their B-cell epitopes...

  9. Molecular evolution of a central region containing B cell epitopes in the gene encoding the p67 sporozoite antigen within a field population of Theileria parva

    OpenAIRE

    Obara, Isaiah; Ulrike, Seitzer; Musoke, Tony; Paul R Spooner; Jabbar, Ahmed; Odongo, David; Kemp, Stephen; Silva, Joana C.; Bishop, Richard P.

    2015-01-01

    Protective immunity induced by the infective sporozoite stage of Theileria parva indicates a potential role for antibodies directed against conserved serologically reactive regions of the major sporozoite surface antigen p67 in vaccination to control the parasite. We have examined the allelic variation and determined the extent of B cell epitope polymorphism of the gene encoding p67 among field isolates originating from cattle exposed to infected ticks in the Marula area of the rift valley in...

  10. Design and Antigenic Epitopes Prediction of a New Trial Recombinant Multiepitopic Rotaviral Vaccine: In Silico Analyses.

    Science.gov (United States)

    Jafarpour, Sima; Ayat, Hoda; Ahadi, Ali Mohammad

    2015-01-01

    Rotavirus is the major etiologic factor of severe diarrheal disease. Natural infection provides protection against subsequent rotavirus infection and diarrhea. This research presents a new vaccine designed based on computational models. In this study, three types of epitopes are considered-linear, conformational, and combinational-in a proposed model protein. Several studies on rotavirus vaccines have shown that VP6 and VP4 proteins are good candidates for vaccine production. In the present study, a fusion protein was designed as a new generation of rotavirus vaccines by bioinformatics analyses. This model-based study using ABCpred, BCPREDS, Bcepred, and Ellipro web servers showed that the peptide presented in this article has the necessary properties to act as a vaccine. Prediction of linear B-cell epitopes of peptides is helpful to investigate whether these peptides are able to activate humoral immunity.

  11. Design and Antigenic Epitopes Prediction of a New Trial Recombinant Multiepitopic Rotaviral Vaccine: In Silico Analyses.

    Science.gov (United States)

    Jafarpour, Sima; Ayat, Hoda; Ahadi, Ali Mohammad

    2015-01-01

    Rotavirus is the major etiologic factor of severe diarrheal disease. Natural infection provides protection against subsequent rotavirus infection and diarrhea. This research presents a new vaccine designed based on computational models. In this study, three types of epitopes are considered-linear, conformational, and combinational-in a proposed model protein. Several studies on rotavirus vaccines have shown that VP6 and VP4 proteins are good candidates for vaccine production. In the present study, a fusion protein was designed as a new generation of rotavirus vaccines by bioinformatics analyses. This model-based study using ABCpred, BCPREDS, Bcepred, and Ellipro web servers showed that the peptide presented in this article has the necessary properties to act as a vaccine. Prediction of linear B-cell epitopes of peptides is helpful to investigate whether these peptides are able to activate humoral immunity. PMID:25965449

  12. Prediction of Epitope-Based Peptides for the Utility of Vaccine Development from Fusion and Glycoprotein of Nipah Virus Using In Silico Approach

    Directory of Open Access Journals (Sweden)

    M. Sadman Sakib

    2014-01-01

    Full Text Available This study aims to design epitope-based peptides for the utility of vaccine development by targeting glycoprotein G and envelope protein F of Nipah virus (NiV that, respectively, facilitate attachment and fusion of NiV with host cells. Using various databases and tools, immune parameters of conserved sequence(s from G and F proteins of different isolates of NiV were tested to predict probable epitope(s. Binding analyses of the peptides with MHC class-I and class-II molecules, epitope conservancy, population coverage, and linear B cell epitope prediction were analyzed. Predicted peptides interacted with seven or more MHC alleles and illustrated population coverage of more than 99% and 95%, for G and F proteins, respectively. The predicted class-I nonamers, SLIDTSSTI and EWISIVPNF, superimposed on the putative decameric B cell epitopes, were also identified as core sequences of the most probable class-II 15-mer peptides GPKVSLIDTSSTITI and EWISIVPNFILVRNT. These peptides were further validated for their binding to specific HLA alleles using in silico docking technique. Our in silico analysis suggested that the predicted epitopes, either GPKVSLIDTSSTITI or EWISIVPNFILVRNT, could be a better choice as universal vaccine component against NiV irrespective of different isolates which may elicit both humoral and cell-mediated immunity.

  13. HCV 抗原表位预测%Prediction of HCV antigenic epitopes

    Institute of Scientific and Technical Information of China (English)

    贾帅争; 孙红琰; 王全立

    2001-01-01

    应用网络生物信息资源查找丙型肝炎病毒基因组全序列,用软件Lasergene中的EditSeq将来自中国河北株mRNA序列翻译为氨基酸序列,尔后用程序Protean进行氨基酸序列分析,对HCV各区段的B细胞抗原指数进行预测。同时又在两个网站对中国汉族人中频率较高的HLA基因型进行CD8和CD4 T细胞表位预测。B细胞和T细胞抗原表位预测结果对于HCV诊断试剂和疫苗研制有重要的指导意义。%The complete genome of Hepatitis C China virus was gotten from world wide web site NCBI (National Center for Biotechnology Information). HCV mRNA was translated into amino acids(AA) sequence by program EditSeq of a computer software Lasergene and this amino acids sequence was analysed by program Protean. B cell epitopes index of these HCV AA fragments was caculated by this computational program and those epitopes with high index can be used as candidate epitopes for HCV antibody diagnositic reagent. CD8 T cell and CD4 T cell epitopes were predicted at Internet sites (SYFPEITHI and BIMAS). Because those HLA which appear with higher frequence in Chinese Nationalities were chosen to predict T cell epitopes, these predicted sequences can be used to design anti HCV vaccine suitable for Chinese.

  14. Immune epitope database analysis resource

    DEFF Research Database (Denmark)

    Kim, Yohan; Ponomarenko, Julia; Zhu, Zhanyang;

    2012-01-01

    The immune epitope database analysis resource (IEDB-AR: http://tools.iedb.org) is a collection of tools for prediction and analysis of molecular targets of T- and B-cell immune responses (i.e. epitopes). Since its last publication in the NAR webserver issue in 2008, a new generation of peptide:MH...

  15. Linear B-cell epitope mapping of MAPK3 and MAPK4 from Leishmania braziliensis: implications for the serodiagnosis of human and canine leishmaniasis.

    Science.gov (United States)

    Menezes-Souza, Daniel; de Oliveira Mendes, Tiago Antônio; de Araújo Leão, Ana Carolina; de Souza Gomes, Matheus; Fujiwara, Ricardo Toshio; Bartholomeu, Daniella Castanheira

    2015-02-01

    The correct and early identification of humans and dogs infected with Leishmania are key steps in the control of leishmaniasis. Additionally, a method with high sensitivity and specificity at low cost that allows the screening of a large number of samples would be extremely valuable. In this study, we analyzed the potential of mitogen-activated protein kinase 3 (MAPK3) and mitogen-activated protein kinase 4 (MAPK4) proteins from Leishmania braziliensis to serve as antigen candidates for the serodiagnosis of human visceral and tegumentary leishmaniasis, as well as canine visceral disease. Moreover, we mapped linear B-cell epitopes in these proteins and selected those epitopes with sequences that were divergent in the corresponding orthologs in Homo sapiens, in Canis familiaris, and in Trypanosoma cruzi. We compared the performance of these peptides with the recombinant protein using ELISA. Both MAPK3 and MAPK4 recombinant proteins showed better specificity in the immunodiagnosis of human and canine leishmaniasis than soluble parasite antigens and the EIE-leishmaniose-visceral-canina-bio-manguinhos (EIE-LVC) kit. Furthermore, the performance of this serodiagnosis assay was improved using synthetic peptides corresponding to B-cell epitopes derived from both proteins.

  16. Evaluation and use of in-silico structure-based epitope prediction with foot-and-mouth disease virus.

    Directory of Open Access Journals (Sweden)

    Daryl W Borley

    Full Text Available Understanding virus antigenicity is of fundamental importance for the development of better, more cross-reactive vaccines. However, as far as we are aware, no systematic work has yet been conducted using the 3D structure of a virus to identify novel epitopes. Therefore we have extended several existing structural prediction algorithms to build a method for identifying epitopes on the appropriate outer surface of intact virus capsids (which are structurally different from globular proteins in both shape and arrangement of multiple repeated elements and applied it here as a proof of principle concept to the capsid of foot-and-mouth disease virus (FMDV. We have analysed how reliably several freely available structure-based B cell epitope prediction programs can identify already known viral epitopes of FMDV in the context of the viral capsid. To do this we constructed a simple objective metric to measure the sensitivity and discrimination of such algorithms. After optimising the parameters for five methods using an independent training set we used this measure to evaluate the methods. Individually any one algorithm performed rather poorly (three performing better than the other two suggesting that there may be value in developing virus-specific software. Taking a very conservative approach requiring a consensus between all three top methods predicts a number of previously described antigenic residues as potential epitopes on more than one serotype of FMDV, consistent with experimental results. The consensus results identified novel residues as potential epitopes on more than one serotype. These include residues 190-192 of VP2 (not previously determined to be antigenic, residues 69-71 and 193-197 of VP3 spanning the pentamer-pentamer interface, and another region incorporating residues 83, 84 and 169-174 of VP1 (all only previously experimentally defined on serotype A. The computer programs needed to create a semi-automated procedure for carrying out

  17. Antibodies to both terminal and internal B-cell epitopes of Francisella tularensis O-polysaccharide produced by patients with tularemia.

    Science.gov (United States)

    Lu, Zhaohua; Perkins, Hillary M; Sharon, Jacqueline

    2014-02-01

    Francisella tularensis, the Gram-negative bacterium that causes tularemia, is considered a potential bioterrorism threat due to its low infectivity dose and the high morbidity and mortality from respiratory disease. We previously characterized two mouse monoclonal antibodies (MAbs) specific for the O-polysaccharide (O antigen [OAg]) of F. tularensis lipopolysaccharide (LPS): Ab63, which targets a terminal epitope at the nonreducing end of OAg, and Ab52, which targets a repeating internal OAg epitope. These two MAbs were protective in a mouse model of respiratory tularemia. To determine whether these epitope types are also targeted by humans, we tested the ability of each of 18 blood serum samples from 11 tularemia patients to inhibit the binding of Ab63 or Ab52 to F. tularensis LPS in a competition enzyme-linked immunosorbent assay (ELISA). Although all serum samples had Ab63- and Ab52-inhibitory activities, the ratios of Ab63 to Ab52 inhibitory potencies varied 75-fold. However, the variation was only 2.3-fold for sequential serum samples from the same patient, indicating different distributions of terminal- versus internal-binding antibodies in different individuals. Western blot analysis using class-specific anti-human Ig secondary antibodies showed that both terminal- and internal-binding OAg antibodies were of the IgG, IgM, and IgA isotypes. These results support the use of a mouse model to discover protective B-cell epitopes for tularemia vaccines or prophylactic/therapeutic antibodies, and they present a general strategy for interrogating the antibody responses of patients and vaccinees to microbial carbohydrate epitopes that have been characterized in experimental animals.

  18. Identification of a novel canine distemper virus B-cell epitope using a monoclonal antibody against nucleocapsid protein.

    Science.gov (United States)

    Yi, Li; Cheng, Yuening; Zhang, Miao; Cao, Zhigang; Tong, Mingwei; Wang, Jianke; Zhao, Hang; Lin, Peng; Cheng, Shipeng

    2016-02-01

    Canine distemper virus (CDV) is a member of the genus Morbillivirus within the family Paramyxoviridae and has caused severe economic losses in China. Nucleocapsid protein (N) is the major structural viral protein and can be used to diagnose CDV and other morbilliviruses. In this study, a specific monoclonal antibody, 1N8, was produced against the CDV N protein (amino acids 277-471). A linear N protein epitope was identified by subjecting a series of partially overlapping synthesized peptides to enzyme-linked immunosorbent assay (ELISA) analysis. The results indicated that (350)LNFGRSYFDPA(360) was the minimal linear epitope that could be recognized by mAb 1N8. ELISA assays revealed that mouse anti-CDV sera could also recognize the minimal linear epitope. Alignment analysis of the amino acid sequences indicated that the epitope was highly conserved among CDV strains. Furthermore, the epitope was conserved among other morbilliviruses, which was confirmed with PRRV using western blotting. Taken together, the results of this study may have potential applications in the development of suitable diagnostic techniques for CDV or other morbilliviruses. PMID:26514066

  19. MHC Class II epitope predictive algorithms

    DEFF Research Database (Denmark)

    Nielsen, Morten; Lund, Ole; Buus, S;

    2010-01-01

    Major histocompatibility complex class II (MHC-II) molecules sample peptides from the extracellular space, allowing the immune system to detect the presence of foreign microbes from this compartment. To be able to predict the immune response to given pathogens, a number of methods have been...

  20. Mapping B-cell epitopes for the peroxidoxin of Leishmania (Viannia braziliensis and its potential for the clinical diagnosis of tegumentary and visceral leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Daniel Menezes-Souza

    Full Text Available The search toward the establishment of novel serological tests for the diagnosis of leishmaniasis and proper differential diagnosis may represent one alternative to the invasive parasitological methods currently used to identify infected individuals. In the present work, we investigated the potential use of recombinant peroxidoxin (rPeroxidoxin of Leishmania (Viannia braziliensis as a potential antigen for the immunodiagnosis of human tegumentary (TL and visceral leishmaniasis (VL and canine visceral leishmaniasis (CVL. Linear B-cell epitope mapping was performed to identify polymorphic epitopes when comparing orthologous sequences present in Trypanosoma cruzi, the agent for Chagas disease (CD, and the Homo sapiens and Canis familiaris hosts. The serological assay (ELISA demonstrated that TL, VL and CVL individuals showed high levels of antibodies against rPeroxidoxin, allowing identification of infected ones with considerable sensitivity and great ability to discriminate (specificity between non-infected and CD individuals (98.46% and 100%; 98.18% and 95.71%; 95.79% and 100%, respectively. An rPeroxidoxin ELISA also showed a greater ability to discriminate between vaccinated and infected animals, which is an important requirement for the public campaign control of CVL. A depletion ELISA assay using soluble peptides of this B-cell epitope confirmed the recognition of these sites only by Leishmania-infected individuals. Moreover, this work identifies two antigenic polymorphic linear B-cell epitopes of L. braziliensis. Specific recognition of TL and VL patients was confirmed by significantly decreased IgG reactivity against rPeroxidoxin after depletion of peptide-1- and peptide-2-specific antibodies (peptide 1: reduced by 32%, 42% and 5% for CL, ML and VL, respectively; peptide-2: reduced by 24%, 22% and 13% for CL, ML and VL, respectively and only peptide-2 for CVL (reduced 9%. Overall, rPeroxidoxin may be a potential antigen for the

  1. T cell-independent type I antibody response against B cell epitopes expressed repetitively on recombinant virus particles

    OpenAIRE

    Fehr, Thomas; Skrastina, Dace; Pumpens, Paul; Zinkernagel, Rolf M.

    1998-01-01

    Recombinant viral or virus-like particles offer new tools for vaccine development. This study investigated hepatitis B core antigen (HBcAg) capsids and RNA phage Qβ coats as carriers of a foreign epitope to induce antibody responses in mice. HBcAg capsids were shown to induce T cell-independent (TI) antibodies. We found that these particles behave as antigen-specific TI type 1 (TI-1) Ag comparable to other rigidly structured viruses. When a 5-aa long epitope of the pre-S1 domain of hepatitis ...

  2. Antigen presentation by non-immune B-cell hybridoma clones: presentation of synthetic antigenic sites reveals clones that exhibit no specificity and clones that present only one epitope

    Science.gov (United States)

    Cohly, H. H.; Morrison, D. R.; Atassi, M. Z.

    1989-01-01

    Recently, we reported the preparation and antigen-presenting properties of hybridoma B-cell clones obtained after fusing non-secreting, non-antigen presenting Balb/c 653-myeloma cells with non-immune SJL spleen cells. It was found that antigen presentation at the clonal level can be specific or non-specific, depending on the particular B-cell clone. In the present work, one specific and one general presenter B-cell clones were tested for their epitope presentation ability to SJL T-cells that were specific to lysozyme or myoglobin. B-cell clone A1G12, a general presenter which presented both lysozyme and myoglobin to their respective T-cell lines, was found to present all five myoglobin epitopes while clone A1L16, a lysozyme specific presenter presented only one of the three epitopes of lysozyme. The latter reveals a hitherto unknown submolecular specificity (to a given epitope within a protein) for antigen presenting cells at the clonal level. Therefore, the specificity of T-cell recognition does not only derive from the T-cell but may also be dependent on the epitope specificity of the antigen-presenting B-cell.

  3. Computational prediction and analysis of envelop glycoprotein epitopes of DENV-2 and DENV-3 Pakistani isolates: a first step towards Dengue vaccine development.

    Directory of Open Access Journals (Sweden)

    Hafsa Amat-ur-Rasool

    Full Text Available Dengue fever of tropics is a mosquito transmitted devastating disease caused by dengue virus (DENV. There is no effective vaccine available, so far, against any of its four serotypes (DENV-1, DENV-2, DENV-3, and DENV-4. There is a need for the development of preventive and therapeutic vaccines against DENV to decrease the prevalence of dengue fever, especially in Pakistan. In this research, linear and conformational B-cell epitopes of envelope glycoprotein of DENV-2 and DENV-3 (the most prevalent serotypes in Pakistan were predicted. We used Kolaskar and Tongaonkar method for linear epitope prediction, Emini's method for surface accessibility prediction and Karplus and Schulz's algorithm for flexibility determination. To propose three dimensional epitopes, the E proteins for both serotypes were homology modeled by using Phyre2 V 2.0 server, and ElliPro was used for the prediction of surface epitopes on their globular structure. Total 21 and 19 linear epitopes were predicted for DENV-2 and DENV-3 Pakistani isolates respectively. Whereas, 5 and 4 discontinuous epitopes were proposed for DENV-2 and DENV-3 Pakistani isolates respectively. Moreover, the values of surface accessibility, flexibility and solvent-accessibility can be helpful in analyzing vaccines against DENV-2 and DENV-3. In conclusion, the proposed continuous and discontinuous antigenic peptides can be valuable candidates for diagnostic and therapeutics of DENV.

  4. 猪带绦虫六钩蚴TSO45-4B抗原FnⅢ结构域相应的线性B细胞表位肽免疫原性研究%Research on immunity response about Taenia solium oncosphere TSO45-4B antigens FnⅢ structure domain linear B cells epitope peptides

    Institute of Scientific and Technical Information of China (English)

    王媛媛; 陶志勇; 杨小迪; 王小莉; 常雪莲; 陈勇; 孙新; 夏惠; 方强

    2013-01-01

    Objective: To observe the humoral immune response induced by Taenia solium oncosphere TSO45-4B antigens Fn Ⅲ structure domain linear B cells epitope peptides in mice. Methods: The two predicted B cell epitope peptides of TSO45-4B Fn Ⅲ structure domain conjugated with carrier protein of keyhole limpet hemocyanin were synthesized and used to immunize mice. The mice specific serum antibody titer to the epitope peptides synthesized was tested by ELISA. Results: The specific antibody to one of the predicted epitope peptides synthesized was found in mice serum,and the titer was 1: 1 280. Conclusions: One of the two predicted linear B cell epitope peptides of TSO45-4B FnⅢ structure domain can induce the humoral immune response in mice.%目的:观察载体蛋白偶联的TSO45-4B抗原FnⅢ结构域相应的线性B细胞表位肽诱导的体液免疫反应.方法:人工合成TSO45-4B抗原FnⅢ结构域2条预测表位肽,偶联钥孔血蓝蛋白免疫小鼠,采用ELISA法检测小鼠血清中预测表位肽特异性抗体滴度.结果:免疫小鼠血清中检测到1条预测表位肽特异性抗体,其效价达到1:1 280.结论:设计的1条TSO45-4B抗原FnⅢ结构域线性B细胞表位肽可诱导小鼠产生体液免疫反应.

  5. Induction of neutralizing antibodies by a tobacco chloroplast-derived vaccine based on a B cell epitope from canine parvovirus

    International Nuclear Information System (INIS)

    The 2L21 epitope of the VP2 protein from the canine parvovirus (CPV), fused to the cholera toxin B subunit (CTB-2L21), was expressed in transgenic tobacco chloroplasts. Mice and rabbits that received protein-enriched leaf extracts by parenteral route produced high titers of anti-2L21 antibodies able to recognize the VP2 protein. Rabbit sera were able to neutralize CPV in an in vitro infection assay with an efficacy similar to the anti-2L21 neutralizing monoclonal antibody 3C9. Anti-2L21 IgG and seric IgA antibodies were elicited when mice were gavaged with a suspension of pulverized tissues from CTB-2L21 transformed plants. Combined immunization (a single parenteral injection followed by oral boosters) shows that oral boosters help to maintain the anti-2L21 IgG response induced after a single injection, whereas parenteral administration of the antigen primes the subsequent oral boosters by promoting the induction of anti-2L21 seric IgA antibodies. Despite the induced humoral response, antibodies elicited by oral delivery did not show neutralizing capacity in the in vitro assay. The high yield of the fusion protein permits the preparation of a high number of vaccine doses from a single plant and makes feasible the oral vaccination using a small amount of crude plant material. However, a big effort has still to be done to enhance the protective efficacy of subunit vaccines by the oral route

  6. Bioinformatics prediction on glutathione S-transferase antigen epitopes of Echinoccocus granulosus%细粒棘球蚴 GST 抗原表位的生物信息学预测∗

    Institute of Scientific and Technical Information of China (English)

    李宗吉; 楚元奎; 于欣; 丁淑琴; 刘学英; 赵巍

    2015-01-01

    Objective To analyse the secondary structure of glutathions S-transferase of Echinoccocus granulosus(EgGST)and predict the B cell and T cell epitopes with informatics tools,in order to provide basic data and references for the following design of epitope vaccine.Methods The B cell and T cell epitopes of EgGST were predicted by DNAstar,Biosun software and Propred MHC class-Ⅱ Binding Peptide Prediction Server software.Results Many distinct antigenic epitopes of EgGST were identified by comput-er,there existed 8 B cell epitopes and 7 T cell epitopes.Conclusion Analysis of predicted epitopes of EgGST antigenic might be sig-nificant for future research of epitope vaccine.%目的:应用生物信息软件分析细粒棘球蚴谷胱甘肽 S-转移酶(EgGST)的蛋白二级结构并预测 B 淋巴细胞表位和 T淋巴细胞表位,为后续表位疫苗的设计研究提供基本的数据和资料。方法采用 DNAstar 软件、ProPred MHC Class-Ⅱ Binding Peptide Prediction Server 和 Biosun 软件对 EgGST 的 B 淋巴细胞表位和 T 淋巴细胞表位进行预测。结果预测 EgGST 存在8个 B 淋巴细胞表位区域和7个 T 淋巴细胞表位。结论分析预测的 EgGST 抗原表位将对后续的表位疫苗研究具有重要意义。

  7. Serum Concentrations of Antibodies against Outer Membrane Protein P6, Protein D, and T- and B-Cell Combined Antigenic Epitopes of Nontypeable Haemophilus influenzae in Children and Adults of Different Ages.

    Science.gov (United States)

    Hua, Chun-Zhen; Hu, Wei-Lin; Shang, Shi-Qiang; Li, Jian-Ping; Hong, Li-Quan; Yan, Jie

    2016-02-01

    Nontypeable Haemophilus influenzae (NTHi) is one of the most common etiologies of acute otitis media, rhinosinusitis, and pneumonia. Outer membrane proteins (OMPs) are the main focus in new vaccine development against NTHi, as the H. influenzae type b (Hib) vaccine does not cover noncapsulated NTHi. The OMPs P6 and protein D are the most promising candidate antigens for an NTHi vaccine, and low antibody levels against them in serum may be correlated with infection caused by NTHi. In the current study, we measured the antibody titers against P6, protein D, and their T- and B-cell combined peptide epitopes in healthy individuals of different ages. We found that children B-cell combined antigenic epitopes. Antibody titers increased at ages 1 to 6 months, peaked at 7 months to 3 years, and remained high at 4 to 6 years. The antibody titers started to decrease after 6 years and were the lowest in the 21- to 30-year group. The geometric mean titers (GMTs) of T- and B-cell combined antigenic epitopes in P6 and protein D were positively correlated with those of the protein antigens. Among 12 peptides tested, P6-61, P6-123, and protein D-167 epitopes were better recognized than others in human serum. These findings might contribute to the development of an effective serotype-independent vaccine for H. influenzae. PMID:26677200

  8. Construction and immunogenicity prediction of Plasmodium falciparum CTL epitope minigene vaccine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The minigenes encoding Plasmodium falciparum CTL epitopesrestricted to human MHC class I molecular HLA-A2 and HLA-B51, which were both at high frequency among Chinese population, were constructed as mono-epitope CTL vaccines named pcDNA3.1/tr and pcDNA3.1/ sh. The minigenes of the two epitopes were then tandem linked to form a dimeric CTL epitope minigene recombinant vaccine. After DNA transfection, the epitope minigenes were expressed respectively in two human cell lines, each bearing one MHC class I molecule named CIR/HLA-A2.1 and K562/HLA-B51. The intracellular expression of the CTL epitope minigenes not only enhanced the stability of HLA-A2.1 and HLA-B51 molecules but also increased the assemblage of MHC class I molecules on cell surfaces, which testified the specific process and presentation of those endogenous expressed epitopes. For the cells transfected with the dimeric minigene encoding two tandem linked epitopes, the expression and presentation of each epitope were also detected on cell membranes that bore different MHC class I molecules. It meant that the adjacency of the two CTL epitopes did not interfere with the specific process and presentation of each epitope. Compared with the ordinary CTL studies that inoculated synthesized epitope peptides with peripheral blood cells, this work aimed to process the epitopes directly inside HLA class I allele specific human cells, and thus theoretically imitated the same procedure in vivo. It was also an economical way to predict the immunogenicity of CTL epitopes at an early stage especially in laboratories with limited financial resource.

  9. NetCTLpan: pan-specific MHC class I pathway epitope predictions

    DEFF Research Database (Denmark)

    Stranzl, Thomas; Larsen, Mette Voldby; Lundegaard, Claus;

    2010-01-01

    Reliable predictions of immunogenic peptides are essential in rational vaccine design and can minimize the experimental effort needed to identify epitopes. In this work, we describe a pan-specific major histocompatibility complex (MHC) class I epitope predictor, NetCTLpan. The method integrates...

  10. Computational prediction of neutralization epitopes targeted by human anti-V3 HIV monoclonal antibodies.

    Directory of Open Access Journals (Sweden)

    Evgeny Shmelkov

    Full Text Available The extreme diversity of HIV-1 strains presents a formidable challenge for HIV-1 vaccine design. Although antibodies (Abs can neutralize HIV-1 and potentially protect against infection, antibodies that target the immunogenic viral surface protein gp120 have widely variable and poorly predictable cross-strain reactivity. Here, we developed a novel computational approach, the Method of Dynamic Epitopes, for identification of neutralization epitopes targeted by anti-HIV-1 monoclonal antibodies (mAbs. Our data demonstrate that this approach, based purely on calculated energetics and 3D structural information, accurately predicts the presence of neutralization epitopes targeted by V3-specific mAbs 2219 and 447-52D in any HIV-1 strain. The method was used to calculate the range of conservation of these specific epitopes across all circulating HIV-1 viruses. Accurately identifying an Ab-targeted neutralization epitope in a virus by computational means enables easy prediction of the breadth of reactivity of specific mAbs across the diversity of thousands of different circulating HIV-1 variants and facilitates rational design and selection of immunogens mimicking specific mAb-targeted epitopes in a multivalent HIV-1 vaccine. The defined epitopes can also be used for the purpose of epitope-specific analyses of breakthrough sequences recorded in vaccine clinical trials. Thus, our study is a prototype for a valuable tool for rational HIV-1 vaccine design.

  11. Influenza A HA's conserved epitopes and broadly neutralizing antibodies: a prediction method.

    Science.gov (United States)

    Ren, Jing; Ellis, John; Li, Jinyan

    2014-10-01

    A conserved epitope is an epitope retained by multiple strains of influenza as the key target of a broadly neutralizing antibody. Identification of conserved epitopes is of strong interest to help design broad-spectrum vaccines against influenza. Conservation score measures the evolutionary conservation of an amino acid position in a protein based on the phylogenetic relationships observed amongst homologous sequences. Here, Average Amino Acid Conservation Score (AAACS) is proposed as a method to identify HA's conserved epitopes. Our analysis shows that there is a clear distinction between conserved epitopes and nonconserved epitopes in terms of AAACS. This method also provides an excellent classification performance on an independent dataset. In contrast, alignment-based comparison methods do not work well for this problem, because conserved epitopes to the same broadly neutralizing antibody are usually not identical or similar. Location-based methods are not successful either, because conserved epitopes are located at both the less-conserved globular head (HA1) and the more-conserved stem (HA2). As a case study, two conserved epitopes on HA are predicted for the influenza A virus H7N9: One should match the broadly neutralizing antibodies CR9114 or FI6v3, while the other is new and requires validation by wet-lab experiments.

  12. Large-scale validation of methods for cytotoxic T-lymphocyte epitope prediction

    DEFF Research Database (Denmark)

    Larsen, Mette Voldby; Lundegaard, Claus; Lamberth, K.;

    2007-01-01

    BACKGROUND: Reliable predictions of Cytotoxic T lymphocyte (CTL) epitopes are essential for rational vaccine design. Most importantly, they can minimize the experimental effort needed to identify epitopes. NetCTL is a web-based tool designed for predicting human CTL epitopes in any given protein....... of the other methods achieved a sensitivity of 0.64. The NetCTL-1.2 method is available at http://www.cbs.dtu.dk/services/NetCTL.All used datasets are available at http://www.cbs.dtu.dk/suppl/immunology/CTL-1.2.php....

  13. In Vivo Validation of Predicted and Conserved T Cell Epitopes in a Swine Influenza Model

    Science.gov (United States)

    Gutiérrez, Andres H.; Loving, Crystal; Moise, Leonard; Terry, Frances E.; Brockmeier, Susan L.; Hughes, Holly R.; Martin, William D.; De Groot, Anne S.

    2016-01-01

    Swine influenza is a highly contagious respiratory viral infection in pigs that is responsible for significant financial losses to pig farmers annually. Current measures to protect herds from infection include: inactivated whole-virus vaccines, subunit vaccines, and alpha replicon-based vaccines. As is true for influenza vaccines for humans, these strategies do not provide broad protection against the diverse strains of influenza A virus (IAV) currently circulating in U.S. swine. Improved approaches to developing swine influenza vaccines are needed. Here, we used immunoinformatics tools to identify class I and II T cell epitopes highly conserved in seven representative strains of IAV in U.S. swine and predicted to bind to Swine Leukocyte Antigen (SLA) alleles prevalent in commercial swine. Epitope-specific interferon-gamma (IFNγ) recall responses to pooled peptides and whole virus were detected in pigs immunized with multi-epitope plasmid DNA vaccines encoding strings of class I and II putative epitopes. In a retrospective analysis of the IFNγ responses to individual peptides compared to predictions specific to the SLA alleles of cohort pigs, we evaluated the predictive performance of PigMatrix and demonstrated its ability to distinguish non-immunogenic from immunogenic peptides and to identify promiscuous class II epitopes. Overall, this study confirms the capacity of PigMatrix to predict immunogenic T cell epitopes and demonstrate its potential for use in the design of epitope-driven vaccines for swine. Additional studies that match the SLA haplotype of animals with the study epitopes will be required to evaluate the degree of immune protection conferred by epitope-driven DNA vaccines in pigs. PMID:27411061

  14. Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections

    Directory of Open Access Journals (Sweden)

    Liu Wen-Xin

    2010-09-01

    Full Text Available Abstract Background Differential diagnose of Japanese encephalitis virus (JEV infection from other flavivirus especially West Nile virus (WNV and Dengue virus (DV infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV. Results To map the epitopes on the PrM/M protein, we designed a set of 20 partially overlapping fragments spanning the whole PrM, fused them with GST, and expressed them in an expression vector. Linear epitope M14 (105VNKKEAWLDSTKATRY120 was detected by enzyme-linked immunosorbent assay (ELISA. By removing amino acid residues individually from the carboxy and amino terminal of peptide M14, we confirmed that the minimal unit of the linear epitope of PrM/M was M14-13 (108KEAWLDSTKAT118. This epitope was highly conserved across different JEV strains. Moreover, this epitope did not cross-react with WNV-positive and DENV-positive sera. Conclusion Epitope M14-13 was a JEV specific lineal B-cell epitpe. The results may provide a useful basis for the development of epitope-based virus specific diagnostic clinical techniques.

  15. Conjugation of alginate to a synthetic peptide containing T- and B-cell epitopes as an induction for protective immunity against Pseudomonas aeruginosa.

    Science.gov (United States)

    Farjaha, Ali; Owlia, Parviz; Siadat, Seyed Davar; Mousavi, Seyed Fazlollah; Shafieeardestani, Mehdi

    2014-12-20

    Pseudomonas aeruginosa is a major cause of respiratory tract infections worldwide, particularly in hospitalized patients with immunosuppressed conditions and cystic fibrosis (CF). Excessive use of antibiotics means that there is currently resistance among bacterial infections to many drugs. Vaccination is a strategy that can reduce mortality and morbidity rates in infections such as those caused by P. aeruginosa. Alginate has a critical role in such infections and affects pathogenicity of the bacterium. In this work, the bioinformatics approach was used to design and synthesis a carrier peptide (ERRANAVRDVLVNEY), derived from OMP F P. aeruginosa. This peptide contained both B- and T-cell epitopes based on prediction models. Conjugation of alginate to carrier peptide was performed and then analyzed by Fourier transform infrared spectroscopy (FTIR). Results of this study on mice showed that the conjugate elicited anti-alginate-IgG that were not detected after immunization with naive alginate. The effect of the antibodies to alginate conjugate was evaluated as highly opsonic and showed moderate to high-level killing activity against two mucoid strains. IgG1 was also dominant among IgG subclasses. Mice vaccinated with the conjugate vaccine survived lethal challenges (2 ×LD 50). Furthermore, using an acute pneumonia model of infection in mice, determined that levels of P. aeruginosa in mice were significantly reduced in the vaccinated group. Thus, tests confirmed ability of this conjugate to elicit protective and opsonophagocytic antibodies that candidate our vaccine for further studies. PMID:25449544

  16. Assessment of CD37 B-cell antigen and cell-of-origin significantly improves risk prediction in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Xu-Monette, Zijun Y; Li, Ling; Byrd, John C;

    2016-01-01

    CD37 (tetraspanin TSPAN26) is a B-cell surface antigen widely expressed on mature B-cells. CD37 is involved in immune regulation and tumor suppression but its function has not been fully elucidated. In this study, we assessed CD37 expression in de novo diffuse large B-cell lymphoma (DLBCL), and i...

  17. Design and prediction of multi-epitope gene of influenza A virus%流感病毒多表位基因盒的设计与预测

    Institute of Scientific and Technical Information of China (English)

    邵京京; 丰锋; 张强; 李虹; 李明远; 王保宁; 李婉宜

    2012-01-01

    目的 预测流感病毒抗原表位并设计合成多表位基因盒.方法 收集不同类型流感病毒基因序列,联合运用Syf-peithi、ProPred、Muhipred2、Bcepred、Clastal X1.83、SWISS - MODEL等多种生物信息学软件进行分析,预测流感病毒Matrix1(M1)、Matrix2( M2)、Nucleoprotein (NP)和HA蛋白上的抗原表位,设计并合成流感病毒多表位基因盒.结果 在不同亚型流感病毒的HA蛋白抗原上成功筛选出2个B细胞表位,在M1、M2及NP蛋白上分别筛选出3个T细胞表位,以一定的间隔序列串联各表位,设计并合成流感多表位基因盒.预测结果显示该多表位基因盒具有良好的同源性及抗原性.结论 成功设计出包含T细胞表位及B细胞表位的流感病毒多表位基因盒Eg,为流感多表位基因疫苗的研发奠定了基础.%OBJECTIVE To design and predict multi - epitope gene of influenza A virus. METHODS Different gene sequences of current popular influenza A virus were searched. The epitopes on Matrixlprotein ( Ml ) , Matrix2 protein ( M2) , Nucleoprotein ( NP) and Hemagglutinin (HA) were analyzed and screened using bioinformatics programs such as Syfpeithi, ProPred, Multipred2, Bcepred, Clastal XI. 83 and SWISS - MODEL. The multi - epitope gene of influenza A virus was designed and synthesized by series connection. RESULTS Two B cell epitopes on HA and three T cell epitopes on Ml ,M2 or NP were screened and multi - epitope gene of influenza A virus was designed successfully. Prediction of epitope showed that the multi - epitope gene had better homology and antigenicity, and could keep better biologicalactivity after incised by protease. CONCLUSION The Multi - epitope gene combined with T cell epitopes and B cell epitopes, has been successfully prepared and lays the foundation for further study on the multi -epitope gene vaccine against influenza A virus.

  18. Predicting population coverage of T-cell epitope-based diagnostics and vaccines

    Directory of Open Access Journals (Sweden)

    Newman Mark J

    2006-03-01

    Full Text Available Abstract Background T cells recognize a complex between a specific major histocompatibility complex (MHC molecule and a particular pathogen-derived epitope. A given epitope will elicit a response only in individuals that express an MHC molecule capable of binding that particular epitope. MHC molecules are extremely polymorphic and over a thousand different human MHC (HLA alleles are known. A disproportionate amount of MHC polymorphism occurs in positions constituting the peptide-binding region, and as a result, MHC molecules exhibit a widely varying binding specificity. In the design of peptide-based vaccines and diagnostics, the issue of population coverage in relation to MHC polymorphism is further complicated by the fact that different HLA types are expressed at dramatically different frequencies in different ethnicities. Thus, without careful consideration, a vaccine or diagnostic with ethnically biased population coverage could result. Results To address this issue, an algorithm was developed to calculate, on the basis of HLA genotypic frequencies, the fraction of individuals expected to respond to a given epitope set, diagnostic or vaccine. The population coverage estimates are based on MHC binding and/or T cell restriction data, although the tool can be utilized in a more general fashion. The algorithm was implemented as a web-application available at http://epitope.liai.org:8080/tools/population. Conclusion We have developed a web-based tool to predict population coverage of T-cell epitope-based diagnostics and vaccines based on MHC binding and/or T cell restriction data. Accordingly, epitope-based vaccines or diagnostics can be designed to maximize population coverage, while minimizing complexity (that is, the number of different epitopes included in the diagnostic or vaccine, and also minimizing the variability of coverage obtained or projected in different ethnic groups.

  19. Homology Modeling and Conformational Epitope Prediction of Envelope Protein of Alkhumra Haemorrhagic Fever Virus

    Directory of Open Access Journals (Sweden)

    Naghmeh Poorinmohammad

    2015-10-01

    Full Text Available Background: The aim of this study was to generate in silico 3D-structure of the envelope protein of AHFV using homology modeling method to further predict its conformational epitopes and help other studies to investigate itsstructural features using the model.Methods: A 3D-structure prediction was developed for the envelope protein of Alkhumra haemorrhagic fever virus (AHFV, an emerging tick-borne flavivirus, based on a homology modeling method using M4T and Modwebservers, as the 3D-structure of the protein is not available yet. Modeled proteins were validated using Modfold 4 server and their accuracies were calculated based on their RSMDs. Having the 3D predicted model with high quality, conformational epitopes were predicted using DiscoTope 2.0.Results: Model generated by M4T was more acceptable than the Modweb-generated model. The global score and Pvalue calculated by Modfold 4 ensured that a certifiable model was generated by M4T, since its global score was almost near 1 which is the score for a high resolution X-ray crystallography structure. Furthermore, itsthe P-value was much lower than 0.001 which means that the model is completely acceptable. Having 0.46 Å rmsd, this model was shown to be highly accurate. Results from DiscoTope 2.0 showed 26 residues as epitopes, forming conformational epitopes of the modeled protein.Conclusion: The predicted model and epitopes for envelope protein of AHFV can be used in several therapeutic and diagnostic approaches including peptide vaccine development, structure based drug design or diagnostic kit development in order to facilitate the time consuming experimental epitope mapping process.

  20. State of the art and challenges in sequence based T-cell epitope prediction

    DEFF Research Database (Denmark)

    Lundegaard, Claus; Hoof, Ilka; Lund, Ole;

    2010-01-01

    field has evolved significantly. Methods have now been developed that produce highly accurate binding predictions for many alleles and integrate both proteasomal cleavage and transport events. Moreover have so-called pan-specific methods been developed, which allow for prediction of peptide binding to......Sequence based T-cell epitope predictions have improved immensely in the last decade. From predictions of peptide binding to major histocompatibility complex molecules with moderate accuracy, limited allele coverage, and no good estimates of the other events in the antigen-processing pathway, the...... MHC alleles characterized by limited or no peptide binding data. Most of the developed methods are publicly available, and have proven to be very useful as a shortcut in epitope discovery. Here, we will go through some of the history of sequence-based predictions of helper as well as cytotoxic T cell...

  1. Towards universal structure-based prediction of class II MHC epitopes for diverse allotypes.

    Directory of Open Access Journals (Sweden)

    Andrew J Bordner

    Full Text Available The binding of peptide fragments of antigens to class II MHC proteins is a crucial step in initiating a helper T cell immune response. The discovery of these peptide epitopes is important for understanding the normal immune response and its misregulation in autoimmunity and allergies and also for vaccine design. In spite of their biomedical importance, the high diversity of class II MHC proteins combined with the large number of possible peptide sequences make comprehensive experimental determination of epitopes for all MHC allotypes infeasible. Computational methods can address this need by predicting epitopes for a particular MHC allotype. We present a structure-based method for predicting class II epitopes that combines molecular mechanics docking of a fully flexible peptide into the MHC binding cleft followed by binding affinity prediction using a machine learning classifier trained on interaction energy components calculated from the docking solution. Although the primary advantage of structure-based prediction methods over the commonly employed sequence-based methods is their applicability to essentially any MHC allotype, this has not yet been convincingly demonstrated. In order to test the transferability of the prediction method to different MHC proteins, we trained the scoring method on binding data for DRB1*0101 and used it to make predictions for multiple MHC allotypes with distinct peptide binding specificities including representatives from the other human class II MHC loci, HLA-DP and HLA-DQ, as well as for two murine allotypes. The results showed that the prediction method was able to achieve significant discrimination between epitope and non-epitope peptides for all MHC allotypes examined, based on AUC values in the range 0.632-0.821. We also discuss how accounting for peptide binding in multiple registers to class II MHC largely explains the systematically worse performance of prediction methods for class II MHC compared with

  2. Towards universal structure-based prediction of class II MHC epitopes for diverse allotypes.

    Science.gov (United States)

    Bordner, Andrew J

    2010-01-01

    The binding of peptide fragments of antigens to class II MHC proteins is a crucial step in initiating a helper T cell immune response. The discovery of these peptide epitopes is important for understanding the normal immune response and its misregulation in autoimmunity and allergies and also for vaccine design. In spite of their biomedical importance, the high diversity of class II MHC proteins combined with the large number of possible peptide sequences make comprehensive experimental determination of epitopes for all MHC allotypes infeasible. Computational methods can address this need by predicting epitopes for a particular MHC allotype. We present a structure-based method for predicting class II epitopes that combines molecular mechanics docking of a fully flexible peptide into the MHC binding cleft followed by binding affinity prediction using a machine learning classifier trained on interaction energy components calculated from the docking solution. Although the primary advantage of structure-based prediction methods over the commonly employed sequence-based methods is their applicability to essentially any MHC allotype, this has not yet been convincingly demonstrated. In order to test the transferability of the prediction method to different MHC proteins, we trained the scoring method on binding data for DRB1*0101 and used it to make predictions for multiple MHC allotypes with distinct peptide binding specificities including representatives from the other human class II MHC loci, HLA-DP and HLA-DQ, as well as for two murine allotypes. The results showed that the prediction method was able to achieve significant discrimination between epitope and non-epitope peptides for all MHC allotypes examined, based on AUC values in the range 0.632-0.821. We also discuss how accounting for peptide binding in multiple registers to class II MHC largely explains the systematically worse performance of prediction methods for class II MHC compared with those for class I MHC

  3. Identification of immunodominant regions and linear B cell epitopes of the gE envelope protein of varicella-zoster virus.

    Science.gov (United States)

    Fowler, W J; Garcia-Valcarcel, M; Hill-Perkins, M S; Murphy, G; Harper, D R; Jeffries, D J; Burns, N R; Adams, S E; Kingsman, A J; Layton, G T

    1995-12-20

    The envelope proteins of varicella-zoster virus (VZV) are highly immunogenic and one of the most abundant is glycoprotein E (gE). However, its immunodominant regions and epitopes have not been identified. In this study, using human sera from individuals with recent varicella or zoster infections, we have localized antigenic sequences of gE using recombinant hybrid Ty-virus-like particles (VLPs) carrying overlapping fragments of the gE protein. gE(1-134)-VLPs (particles carrying amino acids 1-134 of gE) and, to a lesser extent, gE(101-161)-VLPs were found to be the most antigenic when tested by Western blotting and ELISA. Other fragments of gE (spanning residues 161-623) showed weak or no antigenicity. Pepscan analysis of human sera on overlapping synthetic peptides representing residues 1-135 of gE revealed that the most antigenic region was between residues 50 and 135. Three immunodominant sequences (residues 86-105, 116-135, and, to a lesser extent, 56-75) were detected using sera from both varicella and zoster patients. All sera from varicella, but not zoster, patients reacted strongly with an epitope in peptide 66-85. Other epitopes were recognized weakly by some varicella or zoster sera. More sera need to be tested to assess the potential disease specificity of these epitopes. The neutralizing monoclonal antibody (MAb) IF-B9 reacted with residues 71-90; however, another neutralizing MAb, SG1A, which bound to both gE(1-134)-VLPs and gE(101-161)-VLPs did not bind to any peptide. The identification of immunodominant sequences of gE will help toward the development of a subunit VZV vaccine. PMID:8553555

  4. Prediction and identification of mouse cytotoxic T lymphocyte epitopes in Ebola virus glycoproteins

    Directory of Open Access Journals (Sweden)

    Wu Shipo

    2012-06-01

    Full Text Available Abstract Background Ebola viruses (EBOVs cause severe hemorrhagic fever with a high mortality rate. At present, there are no licensed vaccines or efficient therapies to combat EBOV infection. Previous studies have shown that both humoral and cellular immune responses are crucial for controlling Ebola infection. CD8+ T cells play an important role in mediating vaccine-induced protective immunity. The objective of this study was to identify H-2d-specific T cell epitopes in EBOV glycoproteins (GPs. Results Computer-assisted algorithms were used to predict H-2d-specific T cell epitopes in two species of EBOV (Sudan and Zaire GP. The predicted peptides were synthesized and identified in BALB/c mice immunized with replication-deficient adenovirus vectors expressing the EBOV GP. Enzyme-linked immunospot assays and intracellular cytokine staining showed that the peptides RPHTPQFLF (Sudan EBOV, GPCAGDFAF and LYDRLASTV (Zaire EBOV could stimulate splenoctyes in immunized mice to produce large amounts of interferon-gamma. Conclusion Three peptides within the GPs of two EBOV strains were identified as T cell epitopes. The identification of these epitopes should facilitate the evaluation of vaccines based on the Ebola virus glycoprotein in a BALB/c mouse model.

  5. Prediction of T-cell Epitopes for Therapeutic and Prophylactic Vaccines

    DEFF Research Database (Denmark)

    Larsen, Mette Voldby

    2007-01-01

    The spread of existing infectious diseases and the emergence of new ones call for efficient methods for vaccine development. Some of the important players in conferring immunity against pathogens are the Cytotoxic T Lymphocytes (CTL), which eliminate infected cells. Due to their deleterious effects...... vaccine design as well as for diagnostic purposes and is the centre of focus of this thesis: Part I of the thesis is an introduction to the field. In part II, I describe how we generated a method, NetCTL, for predicting CTL epitopes by integrating existing methods for predicting proteasomal cleavage, TAP......: The bacteria Mycobacterium tuberculosis, Influenza A virus, HIV, Yellow fever virus, and West Nile virus. For each of the above-mentioned viruses, a number of predicted CTL epitopes was subsequently selected in such a way that they together constitute a broad coverage of the available viral strains. Part IV...

  6. Prediction of epitopes using neural network based methods

    DEFF Research Database (Denmark)

    Lundegaard, Claus; Lund, Ole; Nielsen, Morten

    2011-01-01

    In this paper, we describe the methodologies behind three different aspects of the NetMHC family for prediction of MHC class I binding, mainly to HLAs. We have updated the prediction servers, NetMHC-3.2, NetMHCpan-2.2, and a new consensus method, NetMHCcons, which, in their previous versions, hav...

  7. Generation of a predictive melphalan resistance index by drug screen of B-cell cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Martin Boegsted

    Full Text Available BACKGROUND: Recent reports indicate that in vitro drug screens combined with gene expression profiles (GEP of cancer cell lines may generate informative signatures predicting the clinical outcome of chemotherapy. In multiple myeloma (MM a range of new drugs have been introduced and now challenge conventional therapy including high dose melphalan. Consequently, the generation of predictive signatures for response to melphalan may have a clinical impact. The hypothesis is that melphalan screens and GEPs of B-cell cancer cell lines combined with multivariate statistics may provide predictive clinical information. MATERIALS AND METHODS: Microarray based GEPs and a melphalan growth inhibition screen of 59 cancer cell lines were downloaded from the National Cancer Institute database. Equivalent data were generated for 18 B-cell cancer cell lines. Linear discriminant analyses (LDA, sparse partial least squares (SPLS and pairwise comparisons of cell line data were used to build resistance signatures from both cell line panels. A melphalan resistance index was defined and estimated for each MM patient in a publicly available clinical data set and evaluated retrospectively by Cox proportional hazards and Kaplan-Meier survival analysis. PRINCIPAL FINDINGS: Both cell line panels performed well with respect to internal validation of the SPLS approach but only the B-cell panel was able to predict a significantly higher risk of relapse and death with increasing resistance index in the clinical data sets. The most sensitive and resistant cell lines, MOLP-2 and RPMI-8226 LR5, respectively, had high leverage, which suggests their differentially expressed genes to possess important predictive value. CONCLUSION: The present study presents a melphalan resistance index generated by analysis of a B-cell panel of cancer cell lines. However, the resistance index needs to be functionally validated and correlated to known MM biomarkers in independent data sets in order to

  8. An integrative approach to CTL epitope prediction: A combined algorithm integrating MHC class I binding, TAP transport efficiency, and proteasomal cleavage predictions

    DEFF Research Database (Denmark)

    Larsen, Mette Voldby; Lundegaard, Claus; Lamberth, K;

    2005-01-01

    Reverse immunogenetic approaches attempt to optimize the selection of candidate epitopes, and thus minimize the experimental effort needed to identify new epitopes. When predicting cytotoxic T cell epitopes, the main focus has been on the highly specific MHC class I binding event. Methods have al.......The method is available at http://www.cbs.dtu.dk/services/NetCTL. Supplementary material is available at http://www.cbs.dtu.dk/suppl/immunology/CTL.php....

  9. Computational Analysis of Cysteine Proteases(Clan CA, Family C1)of Leishmania major to Find Potential Epitopic Regions

    Institute of Scientific and Technical Information of China (English)

    Babak Saffari; Hassan Mohabatkar

    2009-01-01

    Leishmania is associated with a broad spectrum of diseases, ranging from simple cutaneous to invasive visceral leishmaniasis. Here, the sequences of ten cysteine proteases of types A, B and C of Leishmania major were obtained from GeneDB database. Prediction of MHC class I epitopes of these cysteine proteases was per-formed by NetCTL program version 1.2. In addition, by using BcePred server, different structural properties of the proteins were predicted to find out their po-tential B cell epitopes. According to this computational analysis, nine regions were predicted as B cell epitopes. The results provide useful information for designing peptide-based vaccines.

  10. 空肠弯曲菌主要外膜蛋白 OMP18的B 细胞抗原表位分析及功能鉴定%Analysis and identification of B cell epitopes of the OMP18 from Campy lobacter jejuni

    Institute of Scientific and Technical Information of China (English)

    楼宏强; 胡野; 王岚; 单小云; 盛秀胜; 高素华

    2014-01-01

    目的:从生物信息学角度了解空肠弯曲菌主要外膜蛋白OM P18的跨膜结构、B细胞抗原表位及其抗原性、基因序列保守性等特征,并鉴定空肠弯曲菌主要外膜蛋白优势B细胞抗原表位,为后续抗体检测和疫苗研究提供实验依据。方法使用NCBI/Blast ,TMHMM Server V2.0,DNA Star等生物信息学分析软件对空肠弯曲菌主要外膜蛋白OMP18进行蛋白跨膜结构预测、线性B细胞抗原表位及其抗原性分析、并对不同空肠弯曲菌OM P18蛋白的氨基酸序列同源性进行比较。采用空肠弯曲菌全菌抗体IgG为一抗,基于ELISA技术对优势线性B细胞抗原表位进行筛选鉴定。结果生物信息学预测结果表明外膜蛋白OM P18定位于空肠弯曲菌外膜且不存在跨膜结构。蛋白序列保守存在于各空肠弯曲菌株中,序列同源性达95%以上。同时,我们发现该外膜蛋白中存在3个明显的B细胞线性表位,且具有很强的抗原性。ELISA检测鉴定结果表明3个B细胞抗原表位都能有效识别空肠弯曲菌全菌抗体。结论空肠弯曲菌主要外膜蛋白O M P18保守存在于细菌表面,存在3个重要的B细胞线性抗原表位,可用于后续的抗体检测和疫苗开发研究。%In this study ,we aimed to understand the sequence characteristics ,transmembrane structures ,line B cell epitopes present in the OMP18 from Campylobacter jejuni ,and provide candidate antigens for the antibody detection and vac-cine development .NCBI/Blast ,TMHMM Server V2 and DNA Star softwares were used for the OMP18 sequence analysis . Based on the ELISA ,the whole bacterial antibody IgG of Campylobacter jejuni was used for the identification of the predicted line B cell epitopes .The OMP18 gene was found conserved in different Campylobacter jejuni strains .The OMP18 was predic-ted to be located on the outer surface of the bacteria .And three line B cell epitopes were determined to be present in

  11. Two highly similar LAEDDTNAQKT and LTDKIGTEI epitopes in G glycoprotein may be useful for effective epitope based vaccine design against pathogenic Henipavirus.

    Science.gov (United States)

    Parvege, Md Masud; Rahman, Monzilur; Nibir, Yead Morshed; Hossain, Mohammad Shahnoor

    2016-04-01

    Nipah virus and Hendra virus, two members of the genus Henipavirus, are newly emerging zoonotic pathogens which cause acute respiratory illness and severe encephalitis in human. Lack of the effective antiviral therapy endorses the urgency for the development of vaccine against these deadly viruses. In this study, we employed various computational approaches to identify epitopes which has the potential for vaccine development. By analyzing the immune parameters of the conserved sequences of G glycoprotein using various databases and bioinformatics tools, we identified two potential epitopes which may be used as peptide vaccines. Using different B cell epitope prediction servers, four highly similar B cell epitopes were identified. Immunoinformatics analyses revealed that LAEDDTNAQKT is a highly flexible and accessible B-cell epitope to antibody. Highly similar putative CTL epitopes were analyzed for their binding with the HLA-C 12*03 molecule. Docking simulation assay revealed that LTDKIGTEI has significantly lower binding energy, which bolstered its potential as epitope-based vaccine design. Finally, cytotoxicity analysis has also justified their potential as promising epitope-based vaccine candidate. In sum, our computational analysis indicates that either LAEDDTNAQKT or LTDKIGTEI epitope holds a promise for the development of universal vaccine against all kinds of pathogenic Henipavirus. Further in vivo and in vitro studies are necessary to validate the obtained findings.

  12. Generation and characterization of a recombinant chimeric protein (rCpLi) consisting of B-cell epitopes of a dermonecrotic protein from Loxosceles intermedia spider venom.

    Science.gov (United States)

    Mendes, T M; Oliveira, D; Figueiredo, L F M; Machado-de-Avila, R A; Duarte, C G; Dias-Lopes, C; Guimarães, G; Felicori, L; Minozzo, J C; Chávez-Olortegui, C

    2013-06-01

    A chimeric protein was constructed expressing three epitopes of LiD1, a dermonecrotic toxin from the venom of Loxosceles intermedia spider. This species is responsible for a large number of accidents involving spiders in Brazil. We demonstrated that the chimeric protein (rCpLi) generated is atoxic and that antibodies previously developed in rabbits against synthetic epitopes reactive with rCpLi in ELISA and immunoblot assays. The antibody response in rabbits against the rCpLi was evaluated by ELISA and we have detected an antibody response in all immunized animals. Overlapping peptides covering the amino acid sequence of the rCpLi were synthesized on a cellulose membrane, and their recognition by rabbit anti-rCpLi serum assessed. Three different antigenic regions were identified. The percentage of inhibition of the dermonecrotic, hemorrhagic and edematogenic activities caused by the recombinant protein LiD1r in naïve rabbits was assessed by pre-incubation with anti-rCpLi antibodies. Anti-rCpLi induced good dermonecrotic and hemorrhagic protection. The levels of protection were similar to the antiboides anti-LiD1r. In summary, we have developed a polyepitope recombinant chimeric protein capable of inducing multiple responses of neutralizing antibodies in a rabbit model. This engineered protein may be a promising candidate for therapeutic serum development or vaccination.

  13. Inherited polymorphisms in hyaluronan synthase 1 predict risk of systemic B-cell malignancies but not of breast cancer.

    Directory of Open Access Journals (Sweden)

    Hemalatha Kuppusamy

    Full Text Available Genetic variations in the hyaluronan synthase 1 gene (HAS1 influence HAS1 aberrant splicing. HAS1 is aberrantly spliced in malignant cells from multiple myeloma (MM and Waldenstrom macroglobulinemia (WM, but not in their counterparts from healthy donors. The presence of aberrant HAS1 splice variants predicts for poor survival in multiple myeloma (MM. We evaluated the influence of inherited HAS1 single nucleotide polymorphisms (SNP on the risk of having a systemic B cell malignancy in 1414 individuals compromising 832 patients and 582 healthy controls, including familial analysis of an Icelandic kindred. We sequenced HAS1 gene segments from 181 patients with MM, 98 with monoclonal gammopathy of undetermined significance (MGUS, 72 with Waldenstrom macroglobulinemia (WM, 169 with chronic lymphocytic leukemia (CLL, as well as 34 members of a monoclonal gammopathy-prone Icelandic family, 212 age-matched healthy donors and a case-control cohort of 295 breast cancer patients with 353 healthy controls. Three linked single nucleotide polymorphisms (SNP in HAS1 intron3 are significantly associated with B-cell malignancies (range p = 0.007 to p = 10(-5, but not MGUS or breast cancer, and predict risk in a 34 member Icelandic family (p = 0.005, Odds Ratio = 5.8 (OR, a relatively homogeneous cohort. In contrast, exon3 SNPs were not significantly different among the study groups. Pooled analyses showed a strong association between the linked HAS1 intron3 SNPs and B-cell malignancies (OR = 1.78, but not for sporadic MGUS or for breast cancer (OR<1.0. The minor allele genotypes of HAS1 SNPs are significantly more frequent in MM, WM, CLL and in affected members of a monoclonal gammopathy-prone family than they are in breast cancer, sporadic MGUS or healthy donors. These inherited changes may increase the risk for systemic B-cell malignancies but not for solid tumors.

  14. Factors predicting long-term survival in low-risk diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Møller, Michael B; Pedersen, Niels T; Christensen, Bjarne E

    2003-01-01

    The International Prognostic Index (IPI) is widely used for risk stratification of patients with diffuse large B-cell lymphoma (DLBCL). However, even among patients with low-risk disease, according to the IPI a substantial proportion of patients ultimately succumb to their disease. Using mature...... at 5 years and 10 years was 85% and 75%, respectively. Stage II was associated with poor response to treatment (P=0.044). In a multivariate analysis, Stage II (P=0.001) and age >50 years (P=0.043) were independently associated with poor outcome. Patients without these adverse factors had an excellent...

  15. Improved prediction of MHC class I and class II epitopes using a novel Gibbs sampling approach

    DEFF Research Database (Denmark)

    Nielsen, Morten; Lundegaard, Claus; Worning, Peder;

    2004-01-01

    binding peptides and to guiding the process of rational vaccine design. Results: We apply the motif sampler method to the complex problem of MHC class II binding. The input to the method is amino acid peptide sequences extracted from the public databases of SYFPEITHI and MHCPEP and known to bind......Prediction of which peptides will bind a specific major histocompatibility complex (MHC) constitutes an important step in identifying potential T-cell epitopes suitable as vaccine candidates. MHC class II binding peptides have a broad length distribution complicating such predictions. Thus...

  16. B-cell epitopes in NTS-DBL1α of PfEMP1 recognized by human antibodies in Rosetting Plasmodium falciparum.

    Science.gov (United States)

    Albrecht, Letusa; Angeletti, Davide; Moll, Kirsten; Blomqvist, Karin; Valentini, Davide; D'Alexandri, Fabio Luiz; Maurer, Markus; Wahlgren, Mats

    2014-01-01

    Plasmodium falciparum is the most lethal of the human malaria parasites. The virulence is associated with the capacity of the infected red blood cell (iRBC) to sequester inside the deep microvasculature where it may cause obstruction of the blood-flow when binding is excessive. Rosetting, the adherence of the iRBC to uninfected erythrocytes, has been found associated with severe malaria and found to be mediated by the NTS-DBL1α-domain of Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1). Here we show that the reactivity of plasma of Cameroonian children with the surface of the FCR3S1.2-iRBC correlated with the capacity to disrupt rosettes and with the antibody reactivity with a recombinant PfEMP1 (NTS-DBL1α of IT4var60) expressed by parasite FCR3S1.2. The plasma-reactivity in a microarray, consisting of 96 overlapping 15-mer long peptides covering the NTS-DBL1α domain from IT4var60 sequence, was compared with their capacity to disrupt rosettes and we identified five peptides where the reactivity were correlated. Three of the peptides were localized in subdomain-1 and 2. The other two peptide-sequences were localized in the NTS-domain and in subdomain-3. Further, principal component analysis and orthogonal partial least square analysis generated a model that supported these findings. In conclusion, human antibody reactivity with short linear-peptides of NTS-DBL1α of PfEMP1 suggests subdomains 1 and 2 to hold anti-rosetting epitopes recognized by anti-rosetting antibodies. The data suggest rosetting to be mediated by the variable areas of PfEMP1 but also to involve structurally relatively conserved areas of the molecule that may induce biologically active antibodies.

  17. Prediction of CD8+ Epitopes in Leishmania braziliensis Proteins Using EPIBOT: In Silico Search and In Vivo Validation.

    Directory of Open Access Journals (Sweden)

    Angelo Duarte

    Full Text Available Leishmaniasis is caused by intracellular Leishmania parasites that induce a T-cell mediated response associated with recognition of CD4+ and CD8+ T cell Line 1Lineepitopes. Identification of CD8+ antigenic determinants is crucial for vaccine and therapy development. Herein, we developed an open-source software dedicated to search and compile data obtained from currently available on line prediction algorithms.We developed a two-phase algorithm and implemented in an open source software called EPIBOT, that consolidates the results obtained with single prediction algorithms, generating a final output in which epitopes are ranked. EPIBOT was initially trained using a set of 831 known epitopes from 397 proteins from IEDB. We then screened 63 Leishmania braziliensis vaccine candidates with the EPIBOT trained tool to search for CD8+ T cell epitopes. A proof-of-concept experiment was conducted with the top eight CD8+ epitopes, elected by EPIBOT. To do this, the elected peptides were synthesized and validated for their in vivo cytotoxicity. Among the tested epitopes, three were able to induce lysis of pulsed-target cells.Our results show that EPIBOT can successfully search across existing prediction tools, generating a compiled list of candidate CD8+ epitopes. This software is fast and a simple search engine that can be customized to search over different MHC alleles or HLA haplotypes.

  18. Optimization screening for the B cell epitope of the extracellular domain of the follicle stimulating hormone receptor%卵泡刺激素受体(FSHR)胞外区B细胞表位的优化筛选

    Institute of Scientific and Technical Information of China (English)

    杨利华; 李鸥; 王树峰; 梁志清; 吴玉章; 何畏

    2012-01-01

    目的:采用生物信息学技术,对前期研究获得的卵泡刺激素受体(FSHR)的B细胞表位肽段进一步筛选、优化,以获得理想的FSHR靶标抗原.方法:①利用InsightⅡ分子模拟软件寻找FSHR与FSH相互作用的区域.②应用DNA STAR 软件中的Protein模块对优化后抗原进行综合分析.③肽结合实验对优化后抗原进行免疫原性检测.结果:≥5个氨基酸片段的柔性区域位于FSHR第30 - 44、52 - 65、112 - 121、174 - 182、190 - 210、223 - 245区段.当FSHR胞外区第37位缬氨酸被赖氨酸或谷氨酸替代时,具有较好的亲水性及抗原性.而肽结合实验证实肽32 - 44具有更好的免疫原性.结论:FSHR胞外区肽段32-44有可能成为避孕疫苗的理想抗原.%Objective; To obtain the desired antigen targeting - FSHR, we screened and optimized the B cell epitope for the extracellular domain of the follicle stimulating hormone receptor (FSHR) . Methods; ①Insight II molecular simulation software was used to i-dentity amino acid sites of interaction interface between FSH and FSHR. ②The secondary structure and surface properties of the extracellular domain of FSHR, such as physical and chemical properties, hydrophilicity, antigenicity and plasticity, were analyzed by a variety of methods. ③The peptide of the epitopes was synthesized and used for coating streptavidin plate. The immunogenicity of the peptides was determined. Results; Many distinct antigenic epitopes in the extracellular domain of FSHR were identified by computation, the possible location of which was in the regions of 30 ~ 44, 52 ~ 65 , 112 ~ 121, 174 ~ 182, 190 ~ 210 and 223 ~ 245. When the FSHR ectodomain 37th valine was replaced by lysine and glutamic acid, the antigen had better hydrophilicity and antigenic. However, the peptide 32-44 was confirmed the best immunogenicity in ELISA assay. Conclusion; FSHR ectodomain peptide 32 ~44 can be the ideal contraceptive vaccine antigens.

  19. miR expression profiling at diagnosis predicts relapse in pediatric precursor B-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Avigad, Smadar; Verly, Iedan R N; Lebel, Asaf; Kordi, Oshrit; Shichrur, Keren; Ohali, Anat; Hameiri-Grossman, Michal; Kaspers, Gertjan J L; Cloos, Jacqueline; Fronkova, Eva; Trka, Jan; Luria, Drorit; Kodman, Yona; Mirsky, Hadar; Gaash, Dafna; Jeison, Marta; Avrahami, Galia; Elitzur, Sarah; Gilad, Gil; Stark, Batia; Yaniv, Isaac

    2016-04-01

    Our aim was to identify miRNAs that can predict risk of relapse in pediatric patients with acute lymphoblastic leukemia (ALL). Following high-throughput miRNA expression analysis (48 samples), five miRs were selected for further confirmation performed by real time quantitative PCR on a cohort of precursor B-cell ALL patients (n = 138). The results were correlated with clinical parameters and outcome. Low expression of miR-151-5p, and miR-451, and high expression of miR-1290 or a combination of all three predicted inferior relapse free survival (P = 0.007, 0.042, 0.025, and <0.0001, respectively). Cox regression analysis identified aberrant expression of the three miRs as an independent prognostic marker with a 10.5-fold increased risk of relapse (P = 0.041) in PCR-MRD non-high risk patients. Furthermore, following exclusion of patients harboring IKZF1 deletion, the aberrant expression of all three miRs could identify patients with a 24.5-fold increased risk to relapse (P < 0.0001). The prognostic relevance of the three miRNAs was evaluated in a non-BFM treated precursor B-cell ALL cohort (n = 33). A significant correlation between an aberrant expression of at least one of the three miRs and poor outcome was maintained (P < 0.0001). Our results identify an expression profile of miR-151-5p, miR-451, and miR-1290 as a novel biomarker for outcome in pediatric precursor B-cell ALL patients, regardless of treatment protocol. The use of these markers may lead to improved risk stratification at diagnosis and allow early therapeutic interventions in an attempt to improve survival of high risk patients. PMID:26684414

  20. Comparative analysis of evolutionarily conserved motifs of epidermal growth factor receptor 2 (HER2) predicts novel potential therapeutic epitopes

    DEFF Research Database (Denmark)

    Deng, Xiaohong; Zheng, Xuxu; Yang, Huanming;

    2014-01-01

    druggable epitopes/targets. We employed the PROSITE Scan to detect structurally conserved motifs and PRINTS to search for linearly conserved motifs of ECD HER2. We found that the epitopes recognized by trastuzumab and pertuzumab are located in the predicted conserved motifs of ECD HER2, supporting our...... relevant anti-HER2 antibodies. In the present study, we present a novel computational approach as an auxiliary tool for identification of novel HER2 epitopes. We hypothesized that the structurally and linearly evolutionarily conserved motifs of the extracellular domain of HER2 (ECD HER2) contain potential...... initial hypothesis. Considering that structurally and linearly conserved motifs can provide functional specific configurations, we propose that by comparing the two types of conserved motifs, additional druggable epitopes/targets in the ECD HER2 protein can be identified, which can be further modified...

  1. Prediction of HLA-A2-restricted CTL epitope specific to HCC by SYFPEITHI combined with polynomial method

    Institute of Scientific and Technical Information of China (English)

    Hai-Long Dong; Yan-Fang Sui

    2005-01-01

    AIM: To predict the HLA-A2-restricted CTL epitopes of tumor antigens associated with hepatocellular carcinoma (HCC).METHODS: MAGE-1, MAGE-3, MAGE-8, P53 and AFP were selected as objective antigens in this study for the close association with HCC. The HLA-A*0201 restricted CTL epitopes of objective tumor antigens were predicted by SYFPEITHI prediction method combined with the polynomial quantitative motifs method. The threshold of polynomial scores was set to -24.RESULTS: The SYFPEITHI prediction values of all possible nonamers of a given protein sequence were added together and the ten high-scoring peptides of each protein were chosen for further analysis in primary prediction. Thirtyfive candidates of CTL epitopes (nonamers) derived from the primary prediction results were selected by analyzing with the polynomial method and compared with reported CTL epitopes.CONCLUSION: The combination of SYFPEITHI prediction method and polynomial method can improve the prediction efficiency and accuracy. These nonamers may be useful in the design of therapeutic peptide vaccine for HCC and as immunotherapeutic strategies against HCC after identified by immunology experiment.

  2. Comparative analysis of evolutionarily conserved motifs of epidermal growth factor receptor 2 (HER2 predicts novel potential therapeutic epitopes.

    Directory of Open Access Journals (Sweden)

    Xiaohong Deng

    Full Text Available Overexpression of human epidermal growth factor receptor 2 (HER2 is associated with tumor aggressiveness and poor prognosis in breast cancer. With the availability of therapeutic antibodies against HER2, great strides have been made in the clinical management of HER2 overexpressing breast cancer. However, de novo and acquired resistance to these antibodies presents a serious limitation to successful HER2 targeting treatment. The identification of novel epitopes of HER2 that can be used for functional/region-specific blockade could represent a central step in the development of new clinically relevant anti-HER2 antibodies. In the present study, we present a novel computational approach as an auxiliary tool for identification of novel HER2 epitopes. We hypothesized that the structurally and linearly evolutionarily conserved motifs of the extracellular domain of HER2 (ECD HER2 contain potential druggable epitopes/targets. We employed the PROSITE Scan to detect structurally conserved motifs and PRINTS to search for linearly conserved motifs of ECD HER2. We found that the epitopes recognized by trastuzumab and pertuzumab are located in the predicted conserved motifs of ECD HER2, supporting our initial hypothesis. Considering that structurally and linearly conserved motifs can provide functional specific configurations, we propose that by comparing the two types of conserved motifs, additional druggable epitopes/targets in the ECD HER2 protein can be identified, which can be further modified for potential therapeutic application. Thus, this novel computational process for predicting or searching for potential epitopes or key target sites may contribute to epitope-based vaccine and function-selected drug design, especially when x-ray crystal structure protein data is not available.

  3. Prediction of MHC binding peptides and epitopes from alfalfa mosaic virus.

    Science.gov (United States)

    Gomase, Virendra S; Kale, Karbhari V; Chikhale, Nandkishor J; Changbhale, Smruti S

    2007-08-01

    Peptide fragments from alfalfa mosaic virus involved multiple antigenic components directing and empowering the immune system to protect the host from infection. MHC molecules are cell surface proteins, which take active part in host immune reactions and involvement of MHC class-I & II in response to almost all antigens. Coat protein of alfalfa mosaic virus contains 221 aa residues. Analysis found five MHC ligands in coat protein as 64-LSSFNGLGV-72; 86- RILEEDLIY-94; 96-MVFSITPSY-104; 100- ITPSYAGTF-108; 110- LTDDVTTED-118; having rescaled binding affinity and c-terminal cleavage affinity more than 0.5. The predicted binding affinity is normalized by the 1% fractil. The MHC peptide binding is predicted using neural networks trained on c-terminals of known epitopes. In analysis predicted MHC/peptide binding is a log transformed value related to the IC50 values in nM units. Total numbers of peptides found are 213. Predicted MHC binding regions act like red flags for antigen specific and generate immune response against the parent antigen. So a small fragment of antigen can induce immune response against whole antigen. This theme is implemented in designing subunit and synthetic peptide vaccines. The sequence analysis method allows potential drug targets to identify active sites against plant diseases. The method integrates prediction of peptide MHC class I binding; proteosomal c-terminal cleavage and TAP transport efficiency. PMID:17691913

  4. Promiscuous prediction and conservancy analysis of CTL binding epitopes of HCV 3a viral proteome from Punjab Pakistan: an In Silico Approach

    Directory of Open Access Journals (Sweden)

    Idrees Muhammad

    2011-02-01

    Full Text Available Abstract Background HCV is a positive sense RNA virus affecting approximately 180 million people world wide and about 10 million Pakistani populations. HCV genotype 3a is the major cause of infection in Pakistani population. One of the major problems of HCV infection especially in the developing countries that limits the limits the antiviral therapy is the long term treatment, high dosage and side effects. Studies of antigenic epitopes of viral sequences of a specific origin can provide an effective way to overcome the mutation rate and to determine the promiscuous binders to be used for epitope based subunit vaccine design. An in silico approach was applied for the analysis of entire HCV proteome of Pakistani origin, aimed to identify the viral epitopes and their conservancy in HCV genotypes 1, 2 and 3 of diverse origin. Results Immunoinformatic tools were applied for the predictive analysis of HCV 3a antigenic epitopes of Pakistani origin. All the predicted epitopes were then subjected for their conservancy analysis in HCV genotypes 1, 2 and 3 of diverse origin (worldwide. Using freely available web servers, 150 MHC II epitopes were predicted as promiscuous binders against 51 subjected alleles. E2 protein represented the 20% of all the predicted MHC II epitopes. 75.33% of the predicted MHC II epitopes were (77-100% conserve in genotype 3; 47.33% and 40.66% in genotype 1 and 2 respectively. 69 MHC I epitopes were predicted as promiscuous binders against 47 subjected alleles. NS4b represented 26% of all the MHC I predicted epitopes. Significantly higher epitope conservancy was represented by genotype 3 i.e. 78.26% and 21.05% for genotype 1 and 2. Conclusions The study revealed comprehensive catalogue of potential HCV derived CTL epitopes from viral proteome of Pakistan origin. A considerable number of predicted epitopes were found to be conserved in different HCV genotype. However, the number of conserved epitopes in HCV genotype 3 was

  5. A hybrid approach for predicting promiscuous MHC class I restricted T cell epitopes

    Indian Academy of Sciences (India)

    Manoj Bhasin; G P S Raghava

    2007-01-01

    In the present study, a systematic attempt has been made to develop an accurate method for predicting MHC class I restricted T cell epitopes for a large number of MHC class I alleles. Initially, a quantitative matrix (QM)-based method was developed for 47 MHC class I alleles having at least 15 binders. A secondary artificial neural network (ANN)-based method was developed for 30 out of 47 MHC alleles having a minimum of 40 binders. Combination of these ANN- and QM-based prediction methods for 30 alleles improved the accuracy of prediction by 6% compared to each individual method. Average accuracy of hybrid method for 30 MHC alleles is 92.8%. This method also allows prediction of binders for 20 additional alleles using QM that has been reported in the literature, thus allowing prediction for 67 MHC class I alleles. The performance of the method was evaluated using jack-knife validation test. The performance of the methods was also evaluated on blind or independent data. Comparison of our method with existing MHC binder prediction methods for alleles studied by both methods shows that our method is superior to other existing methods. This method also identifies proteasomal cleavage sites in antigen sequences by implementing the matrices described earlier. Thus, the method that we discover allows the identification of MHC class I binders (peptides binding with many MHC alleles) having proteasomal cleavage site at C-terminus. The user-friendly result display format (HTML-II) can assist in locating the promiscuous MHC binding regions from antigen sequence. The method is available on the web at www.imtech.res.in/raghava/nhlapred and its mirror site is available at http://bioinformatics.uams.edu/mirror/nhlapred/.

  6. MHC class I epitope binding prediction trained on small data sets

    DEFF Research Database (Denmark)

    Lundegaard, Claus; Nielsen, Morten; Lamberth, K.;

    2004-01-01

    The identification of potential T-cell epitopes is important for development of new human or vetenary vaccines, both considering single protein/subunit vaccines, and for epitope/peptide vaccines as such. The highly diverse MHC class I alleles bind very different peptides, and accurate binding pre...... in situations where only very limited data are available for training....

  7. Cloning,expression and purification of B cell epitope antigen peptide of EGFR dimerization%EGFR二聚化B细胞表位抗原肤基因克隆、表达与纯化

    Institute of Scientific and Technical Information of China (English)

    朱磊; 吴梅芝; 赵林; 黄绮玲; 梁梅; 李黄金

    2011-01-01

    目的 利用基因工程手段建立表皮生长因子受体(EGFR)二聚化B细胞表位抗原肽MVF-ER的高效制备方法.方法 采用重叠延伸PCR扩增MVF-ER后克隆于表达载体pET32a,于大肠杆菌BL21(DE3)进行表达,产物采用肠激酶酶切和镍离子鳌合亲和层析法纯化.结果 通过10对引物5步重叠延伸得到273bp的扩增产物,目的基因与硫氧环蛋白(Trx)融合后可高效表达,经酶切和层析后得到纯度为95%的抗原肤.结论 成功建立抗原肽"MVF-ER"的高效制备方法,为进一步研究EGFR过表达恶性肿瘤的治疗性疫苗打下了坚实基础.%We aim to establish a high performance preparation system for B cell epitope antigen peptide of EGFR dimerization for further research on therapeutic vaccine of EGFR over-expression tumors. The MVF-ER gene of 273 bp was amplified by splicing overlap extension PCR (SOE-PCR), then cloned into the vector of pET32a, and expressed in E.coli BL21 (DE3) in the form of fusion with Trx. The expression product was purified by Ni+ affinity chromatography. The antigen peptide was recovered from the fusion protein by enterokinase and purified to a purity of 95% confirmed by SDS-PAGE. The results above showed that the preparation method of MVF-ER antigen peptide was successfully established, which will facilitate further study of the therapeutic cancer vaccine.

  8. LMO2 expression reflects the different stages of blast maturation and genetic features in B-cell acute lymphoblastic leukemia and predicts clinical outcome

    Science.gov (United States)

    Malumbres, Raquel; Fresquet, Vicente; Roman-Gomez, Jose; Bobadilla, Miriam; Robles, Eloy F.; Altobelli, Giovanna G.; Calasanz, M.ª José; Smeland, Erlend B.; Aznar, Maria Angela; Agirre, Xabier; Martin-Palanco, Vanesa; Prosper, Felipe; Lossos, Izidore S.; Martinez-Climent, Jose A.

    2011-01-01

    Background LMO2 is highly expressed at the most immature stages of lymphopoiesis. In T-lymphocytes, aberrant LMO2 expression beyond those stages leads to T-cell acute lymphoblastic leukemia, while in B cells LMO2 is also expressed in germinal center lymphocytes and diffuse large B-cell lymphomas, where it predicts better clinical outcome. The implication of LMO2 in B-cell acute lymphoblastic leukemia must still be explored. Design and Methods We measured LMO2 expression by real time RT-PCR in 247 acute lymphoblastic leukemia patient samples with cytogenetic data (144 of them also with survival and immunophenotypical data) and in normal hematopoietic and lymphoid cells. Results B-cell acute lymphoblastic leukemia cases expressed variable levels of LMO2 depending on immunophenotypical and cytogenetic features. Thus, the most immature subtype, pro-B cells, displayed three-fold higher LMO2 expression than pre-B cells, common-CD10+ or mature subtypes. Additionally, cases with TEL-AML1 or MLL rearrangements exhibited two-fold higher LMO2 expression compared to cases with BCR-ABL rearrangements or hyperdyploid karyotype. Clinically, high LMO2 expression correlated with better overall survival in adult patients (5-year survival rate 64.8% (42.5%–87.1%) vs. 25.8% (10.9%–40.7%), P= 0.001) and constituted a favorable independent prognostic factor in B-ALL with normal karyotype: 5-year survival rate 80.3% (66.4%–94.2%) vs. 63.0% (46.1%–79.9%) (P= 0.043). Conclusions Our data indicate that LMO2 expression depends on the molecular features and the differentiation stage of B-cell acute lymphoblastic leukemia cells. Furthermore, assessment of LMO2 expression in adult patients with a normal karyotype, a group which lacks molecular prognostic factors, could be of clinical relevance. PMID:21459790

  9. An overview of bioinformatics tools for epitope prediction: implications on vaccine development.

    Science.gov (United States)

    Soria-Guerra, Ruth E; Nieto-Gomez, Ricardo; Govea-Alonso, Dania O; Rosales-Mendoza, Sergio

    2015-02-01

    Exploitation of recombinant DNA and sequencing technologies has led to a new concept in vaccination in which isolated epitopes, capable of stimulating a specific immune response, have been identified and used to achieve advanced vaccine formulations; replacing those constituted by whole pathogen-formulations. In this context, bioinformatics approaches play a critical role on analyzing multiple genomes to select the protective epitopes in silico. It is conceived that cocktails of defined epitopes or chimeric protein arrangements, including the target epitopes, may provide a rationale design capable to elicit convenient humoral or cellular immune responses. This review presents a comprehensive compilation of the most advantageous online immunological software and searchable, in order to facilitate the design and development of vaccines. An outlook on how these tools are supporting vaccine development is presented. HIV and influenza have been taken as examples of promising developments on vaccination against hypervariable viruses. Perspectives in this field are also envisioned.

  10. The Cancer Exome Generated by Alternative mRNA Splicing Dilutes Predicted HLA Class I Epitope Density

    DEFF Research Database (Denmark)

    Stranzl, Thomas; Larsen, Mette Voldby; Lund, Ole;

    2012-01-01

    is frequently observed in various types of cancer. Down-regulation of genes related to HLA class I antigen processing has been observed in several cancer types, leading to fewer HLA class I antigens on the cell surface. Here, we use a peptidome wide analysis of predicted alternative splice forms, based......Several studies have shown that cancers actively regulate alternative splicing. Altered splicing mechanisms in cancer lead to cancer-specific transcripts different from the pool of transcripts occurring only in healthy tissue. At the same time, altered presentation of HLA class I epitopes...... on a publicly available database, to show that peptides over-represented in cancer splice variants comprise significantly fewer predicted HLA class I epitopes compared to peptides from normal transcripts. Peptides over-represented in cancer transcripts are in the case of the three most common HLA class I...

  11. Structural profiles of TP53 gene mutations predict clinical outcome in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Young, Ken H; Leroy, Karen; Møller, Michael Boe;

    2008-01-01

    The purpose of this study is to correlate the presence of TP53 gene mutations with the clinical outcome of a cohort of patients with diffuse large B-cell lymphoma (DLBCL) assembled from 12 medical centers. TP53 mutations were identified in 102 of 477 patients and the overall survival (OS) of pati...

  12. Hypermethylation of DAPK1 is an independent prognostic factor predicting survival in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Kristensen, Lasse Sommer; Asmar, Fazila; Dimopoulos, Konstantinos;

    2014-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Improvements in overall survival have been observed with the introduction of rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), however, prognostic markers are ...

  13. Identification of a variant antigenic neutralizing epitope in hypervariable region 1 of avian leukosis virus subgroup J.

    Science.gov (United States)

    Hou, Minbo; Zhou, Defang; Li, Gen; Guo, Huijun; Liu, Jianzhu; Wang, Guihua; Zheng, Qiankun; Cheng, Ziqiang

    2016-03-01

    Avian leukosis virus subgroup J (ALV-J) is a hypervariable oncogenic retrovirus that causes great economic loss in poultry. Antigenic variations in the variable regions make the development of an effective vaccine a challenging task. In the present study, we identified a variant antigenic neutralizing epitope using reverse vaccinology methods. First, we predicted the B-cell epitopes in gp85 gene of ALV-J strains by DNAman and bioinformatics. Fourteen candidate epitopes were selected and linked in tandem with glycines or serines as a multi-epitope gene. The expressed protein of multi-epitope gene can induce high-titer antibody that can recognize nature ALV-J and neutralize the infectivity of ALV-J strains. Next, we identified a high effective epitope using eight overlapping fragments of gp85 gene reacting with mAb 2D5 and anti-multi-epitope sera. The identified epitope contained one of the predicted epitopes and localized in hyervariable region 1 (hr1), indicating a variant epitope. To better understand if the variants of the epitope have a good antigenicity, we synthesized four variants to react with mAb 2D5 and anti-ALV-J sera. The result showed that all variants could react with the two kinds of antibodies though they showed different antigenicity, while could not react with ALV-J negative sera. Thus, the variant antigenic neutralizing epitope was determined as 137-LRDFIA/E/TKWKS/GDDL/HLIRPYVNQS-158. The result shows a potential use of this variant epitopes as a novel multi-epitope vaccine against ALV-J in poultry.

  14. Using epitope predictions to evaluate efficacy and population coverage of the Mtb72f vaccine for tuberculosis

    Directory of Open Access Journals (Sweden)

    He Yongqun

    2010-03-01

    Full Text Available Abstract Background The Mtb72f subunit vaccine for tuberculosis, currently in clinical trials, is hoped to provide improved protection compared to the current BCG vaccine. It is not clear, however, whether Mtb72f would be equally protective in the different human populations suffering from a high burden of tuberculosis. Previous work by Hebert and colleagues demonstrated that the PPE18 protein of Mtb72f had significant variability in a sample of clinical M. tuberculosis isolates. However, whether this variation might impact the efficacy of Mtb72f in the context of the microbial and host immune system interactions remained to be determined. The present study assesses Mtb72f's predicted efficacy in people with different DRB1 genotypes to predict whether the vaccine will protect against diverse clinical strains of M. tuberculosis in a diverse host population. Results We evaluated the binding of epitopes in the vaccine to different alleles of the human DRB1 Class II MHC protein using freely available epitope prediction programs and compared protein sequences from clinical isolates to the sequences included in the Mtb72f vaccine. This analysis predicted that the Mtb72f vaccine would be less effective for several DRB1 genotypes, due either to limited vaccine epitope binding to the DRB1 proteins or to binding primarily by unconserved PPE18 epitopes. Furthermore, we found that these less-protective DRB1 alleles are found at a very high frequency in several populations with a high burden of tuberculosis. Conclusion Although the Mtb72f vaccine candidate has shown promise in animal and clinical trials thus far, it may not be optimally effective in some genotypic backgrounds. Due to variation in both M. tuberculosis protein sequences and epitope-binding capabilities of different HLA alleles, certain human populations with a high burden of tuberculosis may not be optimally protected by the Mtb72f vaccine. The efficacy of the Mtb72f vaccine should be further

  15. Dominant epitopes and allergic cross-reactivity

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ipsen, H;

    2000-01-01

    as defined by the Bet v 1 Ab interaction surface. Molecular interactions predicted to occur in the interface are likewise in agreement with earlier observations on Ag-Ab complexes. The epitope is formed by amino acids that are conserved among major allergens from related species within the Fagales order......The symptoms characteristic of allergic hypersensitivity are caused by the release of mediators, i.e., histamine, from effector cells such as basophils and mast cells. Allergens with more than one B cell epitope cross-link IgE Abs bound to high affinity FcepsilonRI receptors on mast cell surfaces...... leading to aggregation and subsequent mediator release. Thus, allergen-Ab complexes play a crucial role in the cascade leading to the allergic response. We here report the structure of a 1:1 complex between the major birch pollen allergen Bet v 1 and the Fab fragment from a murine monoclonal IgG1 Ab, BV16...

  16. Prediction and identification of T cell epitopes in the H5N1 influenza virus nucleoprotein in chicken.

    Directory of Open Access Journals (Sweden)

    Yanxia Hou

    Full Text Available T cell epitopes can be used for the accurate monitoring of avian influenza virus (AIV immune responses and the rational design of vaccines. No T cell epitopes have been previously identified in the H5N1 AIV virus nucleoprotein (NP in chickens. For the first time, this study used homology modelling techniques to construct three-dimensional structures of the peptide-binding domains of chicken MHC class Ι molecules for four commonly encountered unique haplotypes, i.e., B4, B12, B15, and B19. H5N1 AIV NP was computationally parsed into octapeptides or nonapeptides according to the peptide-binding motifs of MHC class I molecules of the B4, B12, B15 and B19 haplotypes. Seventy-five peptide sequences were modelled and their MHC class I molecule-binding abilities were analysed by molecular docking. Twenty-five peptides (Ten for B4, six for B12, two for B15, and seven for B19 were predicted to be potential T cell epitopes in chicken. Nine of these peptides and one unrelated peptide were manually synthesized and their T cell responses were tested in vitro. Spleen lymphocytes were collected from SPF chickens that had been immunised with a NP-expression plasmid, pCAGGS-NP, and they were stimulated using the synthesized peptides. The secretion of chicken IFN-γ and the proliferation of CD8(+ T cells were tested using an ELISA kit and flow cytometry, respectively. The significant secretion of chicken IFN-γ and proliferation of CD8(+ T lymphocytes increased by 13.7% and 11.9% were monitored in cells stimulated with peptides NP(89-97 and NP(198-206, respectively. The results indicate that peptides NP(89-97 (PKKTGGPIY and NP(198-206 (KRGINDRNF are NP T cell epitopes in chicken of certain haplotypes. The method used in this investigation is applicable to predicting T cell epitopes for other antigens in chicken, while this study also extends our understanding of the mechanisms of the immune response to AIV in chicken.

  17. HLArestrictor-a tool for patient-specific predictions of HLA restriction elements and optimal epitopes within peptides

    DEFF Research Database (Denmark)

    Larsen, Malene Erup; Kloverpris, H.; Stryhn, A.;

    2011-01-01

    , protein, or even proteome. However, no current tools address the complexity caused by the highly polymorphic nature of the restricting HLA molecules, which effectively individualizes T cell responses. To fill this gap, we here present an easy-to-use prediction tool named HLArestrictor ( http......://www.cbs.dtu.dk/services/HLArestrictor ), which is based on the highly versatile and accurate NetMHCpan predictor, which here has been optimized for the identification of both the MHC restriction element and the corresponding minimal epitope of a T cell response in a given individual. As input, it requires high-resolution (i.e., 4-digit) HLA...

  18. Linear B-cell epitopes in BthTX-1, BthTX-II and BthA-1, phospholipase A₂'s from Bothrops jararacussu snake venom, recognized by therapeutically neutralizing commercial horse antivenom.

    Science.gov (United States)

    De-Simone, Salvatore G; Napoleão-Pego, Paloma; Teixeira-Pinto, Luiz A L; Santos, Jonathas D L; De-Simone, Thatiane S; Melgarejo, Anibal R; Aguiar, Aniesse S; Marchi-Salvador, Daniela P

    2013-09-01

    The benefits from treatment with antivenom sera are indubitable. However, the mechanism for toxin neutralization has not been completely elucidated. A mixture of anti-bothropic and anti-crotalic horse antivenom has been reported to be more effective in neutralizing the effects of Bothrops jararacussu snake venom than anti-bothropic antivenom alone. This study determined which regions in the three PLA₂s from B. jararacussu snake venom are bound by antibodies in tetravalent anti-bothropic and monovalent anti-crotalic commercial horse antivenom. Mapping experiments of BthTX-I, BthTX-II and BthA-I using two small libraries of 69 peptides each revealed six major IgG-binding epitopes that were recognized by both anti-bothropic and anti-crotalic horse antivenom. Two epitopes in BthTX-I were only recognized by the anti-bothropic horse antivenom, while anti-crotalic horse antivenom recognized four unique epitopes across the three PLA₂s. Our studies suggest that the harmful activities of the PLA₂s present in the venom of B. jararacussu are neutralized by the combinatorial treatment with both antivenom sera through their complementary binding sites, which provides a wide coverage on the PLA₂s. This is the first peptide microarray of PLA₂s from B. jararacussu snake venom to survey the performance of commercial horse antiophidic antivenom. Regions recognized by the protective antivenom sera are prime candidates for improved venom cocktails or a chimeric protein encoding the multiple epitopes to immunize animals as well as for designing future synthetic vaccines. PMID:23792452

  19. From Viral genome to specific peptide epitopes - Methods for identifying porcine T cell epitopes based on in silico predictions, in vitro identification and ex vivo verification

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Rasmussen, Michael; Harndahl, Mikkel;

    between high affinity and high stability peptides bound by the highly expressed SLA molecules, SLA-1*0401, SLA-2*0401, and SLA-3*0401, using a luminescence oxygen channeling (LOCI) and a scintillation proximity assay, respectively. With this procedure, high affinity and highly stable SLA peptide epitopes...... can be identified within a given viral genome, along with the elimination of hundreds, or even thousands, of peptide sequences, which are not likely to be bound. Applying these methods can save enormous amounts of time and costs of epitope discovery studies and MHC binding analysis not only in swine...

  20. Flanking p10 contribution and sequence bias in matrix based epitope prediction: revisiting the assumption of independent binding pockets

    Directory of Open Access Journals (Sweden)

    Parry Christian S

    2008-10-01

    Full Text Available Abstract Background Eluted natural peptides from major histocompatibility molecules show patterns of conserved residues. Crystallographic structures show that the bound peptide in class II major histocompatibility complex adopts a near uniform polyproline II-like conformation. This way allele-specific favoured residues are able to anchor into pockets in the binding groove leaving other peptide side chains exposed for recognition by T cells. The anchor residues form a motif. This sequence pattern can be used to screen large sequences for potential epitopes. Quantitative matrices extend the motif idea to include the contribution of non-anchor peptide residues. This report examines two new matrices that extend the binding register to incorporate the polymorphic p10 pocket of human leukocyte antigen DR1. Their performance is quantified against experimental binding measurements and against the canonical nine-residue register matrix. Results One new matrix shows significant improvement over the base matrix; the other does not. The new matrices differ in the sequence of the peptide library. Conclusion One of the extended quantitative matrices showed significant improvement in prediction over the original nine residue matrix and over the other extended matrix. Proline in the sequence of the peptide library of the better performing matrix presumably stabilizes the peptide conformation through neighbour interactions. Such interactions may influence epitope prediction in this test of quantitative matrices. This calls into question the assumption of the independent contribution of individual binding pockets.

  1. High levels of nuclear MYC protein predict the presence of MYC rearrangement in diffuse large B-cell lymphoma

    DEFF Research Database (Denmark)

    Green, Tina Marie; Nielsen, Ole; de Stricker, Karin;

    2012-01-01

    Determining the presence of MYC gene rearrangements is becoming an increasingly important part of the diagnostic workup in aggressive lymphoma. Cytogenetic MYC alterations aid in differentiating diffuse large B-cell lymphoma (DLBCL) from Burkitt lymphoma. In addition, MYC aberrations are associated...... with poor prognosis in DLBCL. Fluorescence in situ hybridization and karyotyping are standard tests for detecting MYC aberrations, but these techniques are laborious and expensive. Here, we studied MYC status of 219 DLBCLs and Burkitt lymphomas using fluorescence in situ hybridization, immunohistochemistry......, and quantitative real-time polymerase chain reaction (QRT-PCR). Overall, 15% of the cases had an MYC break. QRT-PCR analysis of MYC expression showed that 72% of DLBCLs with an MYC break had aberrantly high or low levels of MYC transcript. Excluding the cases with aberrantly low MYC expression, we found...

  2. The expression of CD30 based on immunohistochemistry predicts inferior outcome in patients with diffuse large B-cell lymphoma.

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Hao

    Full Text Available The prognostic value of CD30 expression in diffuse large B-cell lymphoma (DLBCLremains controversial. Herein, we performed this retrospective study to investigate the clinical and prognostic significance of CD30 expression in patients with DLBCL.Among all the 146 patients, the expression of CD30 was observed in 23 cases (15.7%.The DLBCL patients with CD30 expression showed more likely to present B symptoms, bone marrow involvement, non-germinal centre B-cell-like (Non-GCB DLBCL, BCL-2 and Ki-67 overexpression (p<0.05. Patients with CD30 expression showed significantly poor overall and event-free survival compared with CD30 negative patients(p = 0.031 and 0.041, respectively, especially those with the high intermediate/high-risk international prognostic index (IPI(p = 0.001 and 0.007, respectively. The prognostic value of CD30 expression retained in DLBCL patients treated with either CHOP (cyclophosphamide, doxorubicin, vincristine,prednisone or R-CHOP(rituximab+CHOP. The multivariate analysis revealed that the expression of CD30 remained an unfavorable factor for both overall and event-free survival (p = 0.001 and 0.002, respectively. In conclusion, these data suggest that CD30 is expressed predominantly in Non-GCBDLBCL. The expression of CD30 implied poor outcome in DLBCL patients treated with either CHOP or R-CHOP, especially those with the high intermediate/high-risk IPI, possibly indicating that anti-CD30 monoclonal antibody could be of clinical interest.

  3. From viral genome to specific peptide epitopes: methods for identifying porcine T cell epitopes based on in silico predictions, in vitro identification and ex vivo verification

    DEFF Research Database (Denmark)

    Pedersen, Lasse Eggers; Rasmussen, Michael; Harndah, Mikkel;

    2013-01-01

    was determined using luminescence oxygen channeling (LOCI) and scintillation proximity assay (SPA) for peptides bound by the commonly occurring SLA molecules, SLA-1*0401, SLA-2*0401, and SLA-3*0401. Using these tools, peptides bound by SLA with high affinity and stability were identified from a library of 10.......000 peptides. T cell epitopes were identified using peptide-SLA complexes assembled into fluorescent tetramers to stain swine influenza specific CTLs derived from immunized animals and MHC-defined pigs vaccinated against foot-and-mouth disease virus. These results demonstrate the broad applicability of methods...... originally developed for analysis of human leukocyte antigen (HLA) presentation of peptides. The methods presented provide a timely and cost-effective approach to CTL epitope discovery that can be applied to diseases of swine and of other mammalian species of interest....

  4. Bioinformatics prediction of swine MHC class I epitopes from Porcine Reproductive and Respiratory Syndrome Virus

    DEFF Research Database (Denmark)

    Welner, Simon; Nielsen, Morten; Lund, Ole;

    of the host cell antiviral machinery, to the deceptive induction of a non-neutralizing antibody response through decoy antigen presentation. This, combined with a very high mutation rate, has hampered the development of safe and effective vaccines. With the overall aim to design a vaccine that induces...... strains of high quality. For each strain, a library of all possible 9- and 10-mer peptides was generated considering the known ribosomal frame shift sites and sites for post translational cleavage. All peptides were in silico analyzed for binding affinity to either of five common SLA class I alleles...... by the PopCover algorithm, providing a final list of 54 epitopes prioritized according to maximum coverage of PRRSV strains and SLA alleles. This bioinformatics approach provides a rational strategy for selecting peptides for a CTL-activating vaccine with broad coverage of both virus and swine diversity...

  5. Prediction of T cell epitopes of Brucella abortus and evaluation of their protective role in mice.

    Science.gov (United States)

    Afley, Prachiti; Dohre, Sudhir K; Prasad, G B K S; Kumar, Subodh

    2015-09-01

    Brucellae are Gram-negative intracellular bacteria that cause an important zoonotic disease called brucellosis. The animal vaccines are available but have disadvantage of causing abortions in a proportion of pregnant animals. The animal vaccines are also pathogenic to humans. Recent trend in vaccine design has shifted to epitope-based vaccines that are safe and specific. In this study, efforts were made to identify MHC-I- and MHC-II-restricted T cell epitopes of Brucella abortus and evaluate their vaccine potential in mice. The peptides were designed using online available immunoinformatics tools, and five MHC-I- and one MHC-II-restricted T cell peptides were selected on the basis of their ability to produce interferon gamma (IFN-γ) in in vivo studies. The selected peptides were co-administered with poly DL-lactide-co-glycolide (PLG) microparticles and evaluated for immunogenicity and protection in BALB/c mice. Mice immunized with peptides either entrapped in PLG microparticles (EPLG-Pep) or adsorbed on PLG particles (APLG-Pep) showed significantly higher splenocyte proliferation and IFN-γ generation to all selected peptides than the mice immunized with corresponding irrelevant peptides formulated PLG microparticles or phosphate-buffered saline (PBS). A significant protection compared to PBS control was also observed in EPLG-Pep and APLG-Pep groups. A plasmid DNA vaccine construct (pVaxPep) for peptides encoding DNA sequences was generated and injected to mice by in vivo electroporation. Significant protection was observed (1.66 protection units) when compared with PBS and empty vector control group animals. Overall, the MHC-I and MHC-II peptides identified in this study are immunogenic and protective in mouse model and support the feasibility of peptide-based vaccine for brucellosis. PMID:26150246

  6. Lymphoid-Like Structures with Distinct B Cell Areas in Kidney Allografts are not Predictive for Graft Rejection. A Non-human Primate Study

    NARCIS (Netherlands)

    Jonker, Margreet; Wubben, Jacqueline A. M.; 't Hart, Bert A.; Haanstra, Krista G.

    2015-01-01

    Kidney allograft biopsies were analyzed for the presence of B cell clusters/aggregates using CD20 staining. Few B cells were found in the diffuse interstitial infiltrates, but clusters of B cells were found in nodular infiltrates. These nodular infiltrates were smaller shortly after transplantation,

  7. Cell of origin predicts outcome to treatment with etoposide-containing chemotherapy in young patients with high-risk diffuse large B-cell lymphoma.

    Science.gov (United States)

    Gang, Anne O; Pedersen, Mette Ø; Knudsen, Helle; Lauritzen, Anne F; Pedersen, Michael; Nielsen, Signe L; Brown, Peter; Høgdall, Estrid; Klausen, Tobias W; Nørgaard, Peter

    2015-07-01

    Addition of etoposide to the R-CHOP chemotherapy regimen with cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab (R-CHOEP) has resulted in improved survival in young patients with high-risk diffuse large B-cell lymphoma (DLBCL). It is not known whether biological factors can predict this effect. In this study, 245 patients representing all young patients with high-risk DLBCL treated with R-CHOP or R-CHOEP in 2004-2012 in Denmark were extracted from the Danish lymphoma database. Patients were stratified according to cell of origin (COO) into germinal-center B-cell-like (GCB) or non-GCB by Hans' algorithm. Only in patients with the GCB phenotype was treatment with R-CHOEP associated with improved progression-free survival (PFS) and overall survival (OS) compared with R-CHOP. Patients with GCB phenotype treated with R-CHOEP also had superior OS compared with patients with non-GCB phenotype treated with R-CHOEP. This was not seen in R-CHOP treated patients. This could suggest that R-CHOEP should be restricted to patients with GCB phenotype.

  8. Body mass index and other anthropometric parameters in patients with diffuse large B-cell lymphoma: physiopathological significance and predictive value in the immunochemotherapy era.

    Science.gov (United States)

    Sarkozy, Clémentine; Camus, Vincent; Tilly, Hervé; Salles, Gilles; Jardin, Fabrice

    2015-07-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common form of aggressive non-Hodgkin lymphoma, accounting for 30-40% of newly diagnosed cases. Obesity is a well-defined risk factor for DLBCL. However, the impact of body mass index (BMI) on DLBCL prognosis is controversial. Recent studies suggest that skeletal muscle wasting (sarcopenia) or loss of fat mass can be detected by computed tomography (CT) images and is useful for predicting the clinical outcome in several types of cancer including DLBCL. Several hypotheses have been proposed to explain the differences in DLBCL outcome according to BMI or weight that include tolerance to treatment, inflammatory background and chemotherapy or rituximab metabolism. In this review, we summarize the available literature, addressing the impact and physiopathological relevance of simple anthropometric tools including BMI and tissue distribution measurements. We also discuss their relationship with other nutritional parameters and their potential role in the management of patients with DLBCL. PMID:25363401

  9. Construction and immunogenicity prediction of Plasmodium falciparum CTL epitope minigene vaccine

    Institute of Scientific and Technical Information of China (English)

    TANG; Yuyang

    2001-01-01

    [1]Hill, A. V., Elvin, J., Willis, A. C. et al., Molecular analysis of the association of HLA-B53 and resistance to severe malaria, Nature, 1992, 360: 434.[2]Perlmann, P., Miller, L., Fogarty/WHO international conference on cellular mechanisms in malaria immunity, Immun. Letter, 1990, 25: 1.[3]Perkus, M. E., Tartaglia, J., Paoletti, E. et al., Poxvirus-based vaccine candidates for cancer, AIDS and other infectious diseases, J. Leukocyte Biol., 1995, 58(1): 1.[4]Shen, H., Slifka, M. K., Matloubian, M. et al., Recombinant Listeria monocytogenes as a live vaccine vehicle for the induction of protective anti-viral cell-mediated immunity, Proc. Natl. Acad. Sci. USA, 1995, 92: 3987.[5]Waine, G. J., McManus, D. P., Nucleic acids: vaccines of the future, Parasitol Today, 1995, 11: 113.[6]Whitton, J. L., Sheng, N., Oldstone, M. B. A. et al., A "string-of beads" vaccine, comprising linked minigenes, confers protection from lethal-dose virus challenge, J. Virol., 1993, 67: 348.[7]Lalvani, A., Aidoo, M., Allsopp, C. E. et al., An-HLA-based approach to design of a CTL-inducing vaccine against Plasmodium falciparum, Res. Immunol., 1994, 145: 461.[8]Sidney, J., Grey, H. M., Kubo, R. T. et al., Practical, biochemical and evolutionary implications of the discovery of HLA class I supermotifs, Immunology Today, 1996, 17: 261.[9]Thomson, S. A., Elliott, S. L., Sherritt, M. A. et al., Recombinant polyepitope vaccines for the delivery of multiple CD8 cytotoxic T cell epitopes, J. Immun., 1996, 157: 822.[10] Hanke, T., Schneider, J., Gilbert, S. C. et al., DNA multi-CTL epitope vaccines for HIV and Plasmodium falciparum: immunogenicity in mice, Vaccine, 1998, 16: 426.[11] Townsend, A. R. M., Rothbard, J., Gotch, F. M. et al., The epitopes of influenza nucleoprotein recognized by cytotoxic T lymphocytes can be defined with short synthetic peptides, Cell, 1986, 44: 959.[12] Ojcius, D. M., Abastado, J. P., Casrouge, A. et al., Dissociation of

  10. Analysis of structures and epitopes of a novel secreted protein MYR1 in Toxoplasma gondii.

    Science.gov (United States)

    Zhou, Jian; Lu, Gang; He, Shenyi

    2016-01-01

    Toxoplasma gondii (Nicolle et Manceaux, 1908) is an obligate intracellular apicomplexan parasite and can infect warmblooded animals and humans all over the world. Development of effective vaccines is considered the only ideal way to control infection with T. gondii. However, only one live vaccine is commercially available for use in sheep and goats. Thus more effective antigenic proteins are searched for. In the present study we report a novel protein by secreted T. gondii termed Myc regulation 1 (MYR1). The physical and chemical characteristics, epitopes, hydrophilicity and functional sites of MYR1 were analysed by multiple bioinformatic approaches. The 3D models of MYR1 proteins were constructed and analysed. Furthermore, liner B-cell epitopes and T-cell epitopes of MYR1 protein and SAG1 were predicted. Compared to SAG1, MYR1 with good B-cell epitopes and T-cell epitopes had a potentiality to become a more successful vaccine against T. gondii. The bioinformatics analysis of MYR1 proteins could laid the foundation for further studies of its biological function experimentally and provide valuable information necessary for a better prevention and treatment of toxoplasmosis. PMID:27580381

  11. Design of targeted B cell killing agents.

    Directory of Open Access Journals (Sweden)

    Alexey V Stepanov

    Full Text Available B cells play an important role in the pathogenesis of both systemic and organ-specific autoimmune diseases. Autoreactive B cells not only produce autoantibodies, but also are capable to efficiently present specific autoantigens to T cells. Furthermore, B cells can secrete proinflammatory cytokines and amplify the vicious process of self-destruction. B cell-directed therapy is a potentially important approach for treatment of various autoimmune diseases. The depletion of B cells by anti-CD20/19 monoclonal antibody Retuximab® used in autoimmune diseases therapy leads to systemic side effects and should be significantly improved. In this study we designed a repertoire of genetically engineered B cell killers that specifically affected one kind of cells carrying a respective B cell receptor. We constructed immunotoxins (ITs, fused with c-myc epitope as a model targeting sequence, based on barnase, Pseudomonas toxin, Shiga-like toxin E.coli and Fc domain of human antibody IgGγ1. C-MYC hybridoma cell line producing anti-c-myc IgG was chosen as a model for targeted cell depletion. C-myc sequence fused with toxins provided addressed delivery of the toxic agent to the target cells. We demonstrated functional activity of designed ITs in vitro and showed recognition of the fusion molecules by antibodies produced by targeted hybridoma. To study specificity of the proposed B cells killing molecules, we tested a set of created ITs ex vivo, using C-MYC and irrelevant hybridoma cell lines. Pseudomonas-containing IT showed one of the highest cytotoxic effects on the model cells, however, possessed promiscuous specificity. Shiga-like toxin construct demonstrated mild both cytotoxicity and specificity. Barnase and Fc-containing ITs revealed excellent balance between their legibility and toxic properties. Moreover, barnase and Fc molecules fused with c-myc epitope were able to selectively deplete c-myc-specific B cells and decrease production of anti

  12. The Chikungunya Virus Capsid Protein Contains Linear B Cell Epitopes in the N- and C-Terminal Regions that are Dependent on an Intact C-Terminus for Antibody Recognition

    Directory of Open Access Journals (Sweden)

    Lucas Y. H. Goh

    2015-06-01

    Full Text Available Chikungunya virus (CHIKV is an arthropod-borne agent that causes severe arthritic disease in humans and is considered a serious health threat in areas where competent mosquito vectors are prevalent. CHIKV has recently been responsible for several millions of cases of disease, involving over 40 countries. The recent re-emergence of CHIKV and its potential threat to human health has stimulated interest in better understanding of the biology and pathogenesis of the virus, and requirement for improved treatment, prevention and control measures. In this study, we mapped the binding sites of a panel of eleven monoclonal antibodies (mAbs previously generated towards the capsid protein (CP of CHIKV. Using N- and C-terminally truncated recombinant forms of the CHIKV CP, two putative binding regions, between residues 1–35 and 140–210, were identified. Competitive binding also revealed that five of the CP-specific mAbs recognized a series of overlapping epitopes in the latter domain. We also identified a smaller, N-terminally truncated product of native CP that may represent an alternative translation product of the CHIKV 26S RNA and have potential functional significance during CHIKV replication. Our data also provides evidence that the C-terminus of CP is required for authentic antigenic structure of CP. This study shows that these anti-CP mAbs will be valuable research tools for further investigating the structure and function of the CHIKV CP.

  13. The Chikungunya Virus Capsid Protein Contains Linear B Cell Epitopes in the N- and C-Terminal Regions that are Dependent on an Intact C-Terminus for Antibody Recognition.

    Science.gov (United States)

    Goh, Lucas Y H; Hobson-Peters, Jody; Prow, Natalie A; Baker, Kelly; Piyasena, Thisun B H; Taylor, Carmel T; Rana, Ashok; Hastie, Marcus L; Gorman, Jeff J; Hall, Roy A

    2015-06-08

    Chikungunya virus (CHIKV) is an arthropod-borne agent that causes severe arthritic disease in humans and is considered a serious health threat in areas where competent mosquito vectors are prevalent. CHIKV has recently been responsible for several millions of cases of disease, involving over 40 countries. The recent re-emergence of CHIKV and its potential threat to human health has stimulated interest in better understanding of the biology and pathogenesis of the virus, and requirement for improved treatment, prevention and control measures. In this study, we mapped the binding sites of a panel of eleven monoclonal antibodies (mAbs) previously generated towards the capsid protein (CP) of CHIKV. Using N- and C-terminally truncated recombinant forms of the CHIKV CP, two putative binding regions, between residues 1-35 and 140-210, were identified. Competitive binding also revealed that five of the CP-specific mAbs recognized a series of overlapping epitopes in the latter domain. We also identified a smaller, N-terminally truncated product of native CP that may represent an alternative translation product of the CHIKV 26S RNA and have potential functional significance during CHIKV replication. Our data also provides evidence that the C-terminus of CP is required for authentic antigenic structure of CP. This study shows that these anti-CP mAbs will be valuable research tools for further investigating the structure and function of the CHIKV CP.

  14. Predictions versus high-throughput experiments in T-cell epitope discovery: competition or synergy?

    DEFF Research Database (Denmark)

    Lundegaard, Claus; Lund, Ole; Nielsen, Morten

    2012-01-01

    and limitations regarding the number of proteins and MHC alleles that are feasibly handled by such experimental methods have made in silico prediction models of high interest. MHC binding prediction methods are today of a very high quality and can predict MHC binding peptides with high accuracy. This is possible...

  15. Expression of T and B cells combined epitopes protein of Leptospira interrogans and the immunity analysis%问号钩端螺旋体T和B细胞表位联合基因的原核表达及其产物免疫性分析

    Institute of Scientific and Technical Information of China (English)

    丁士标; 李召东; 严杰; 林旭瑷

    2011-01-01

    目的 构建问号钩端螺旋体(简称钩体)LipL32、OmpL1和LipL21蛋白的优势T-和B-细胞联合表位融合基因及其原核表达系统,并对表达产物的免疫原性进行鉴定.方法 人工合成多表位联合基因并构建其原核表达系统.采用SDS-PAGE检测重组蛋白;采用MAT检测重组蛋白兔抗血清与我国钩体标准参考株的凝集效价;Western blot和ELISA检测重组蛋白的免疫原性.结果 获得了多表位融合基因并构建了原核表达系统.表达产物的相对分子质量约为23×103,且主要以可溶性形式存在;重组蛋白兔抗血清免疫双扩散效价为1∶8,该抗血清能与我国15群的钩体标准参考株发生凝集反应,ELISA证明该重组蛋白能检测不同群型钩体感染患者血清中的抗钩体抗体.结论 成功构建了包含钩体LipL32、OmpL1和LipL21蛋白的优势T和B细胞联合表位基因及其原核表达系统,表达产物具有良好的抗原性和交叉免疫反应性,可作为研制通用型问号钩体基因工程疫苗及血清学检测的抗原.%Objective To construct the T-cells and B-cells combined epitope peptide gene based on the LipL32,OmpL1 and LipL21 protein from Leptospira interrogans and E.coli expression system,and better understanding of the immunological activity of the recombinant protein. Methods The immunodomaint T- and B-cells combined epitopes of LipL32,OmpL1 and LipL21 were identified and used to synthetic a new gene and then construct its prokaryotic expression system.The expression of recombinant protein was determined by SDS-PAGE; MAT was used to determine the titer of the antiserum to L. interrogans standard strains of China ; Western blot and ELISA were used to identify the immunity activity of the recombinant protein.Results The synthetic gene was effectively expressed in E.coli BL21 ( DE3 ) strain and mainly presented in dissoluble protein.Western blot result showed that the expression protein react well with the

  16. Immunoinformatics Approach in Designing Epitope-based Vaccine Against Meningitis-inducing Bacteria (Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae Type b)

    Science.gov (United States)

    Zahroh, Hilyatuz; Ma’rup, Ahmad; Tambunan, Usman Sumo Friend; Parikesit, Arli Aditya

    2016-01-01

    Meningitis infection is one of the major threats during Hajj season in Mecca. Meningitis vaccines are available, but their uses are limited in some countries due to religious reasons. Furthermore, they only give protection to certain serogroups, not to all types of meningitis-inducing bacteria. Recently, research on epitope-based vaccines has been developed intensively. Such vaccines have potential advantages over conventional vaccines in that they are safer to use and well responded to the antibody. In this study, we developed epitope-based vaccine candidates against various meningitis-inducing bacteria, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b. The epitopes were selected from their protein of polysaccharide capsule. B-cell epitopes were predicted by using BCPred, while T-cell epitope for major histocompatibility complex (MHC) class I was predicted using PAProC, TAPPred, and Immune Epitope Database. Immune Epitope Database was also used to predict T-cell epitope for MHC class II. Population coverage and molecular docking simulation were predicted against previously generated epitope vaccine candidates. The best candidates for MHC class I- and class II-restricted T-cell epitopes were MQYGDKTTF, MKEQNTLEI, ECTEGEPDY, DLSIVVPIY, YPMAMMWRNASNRAI, TLQMTLLGIVPNLNK, ETSLHHIPGISNYFI, and SLLYILEKNAEMEFD, which showed 80% population coverage. The complexes of class I T-cell epitopes–HLA-C*03:03 and class II T-cell epitopes–HLA-DRB1*11:01 showed better affinity than standards as evaluated from their ΔGbinding value and the binding interaction between epitopes and HLA molecules. These peptide constructs may further be undergone in vitro and in vivo testings for the development of targeted vaccine against meningitis infection. PMID:27812281

  17. MYC expression in concert with BCL2 and BCL6 expression predicts outcome in Chinese patients with diffuse large B-cell lymphoma, not otherwise specified.

    Directory of Open Access Journals (Sweden)

    Li-Xu Yan

    Full Text Available Recent studies provide convincing evidence that a combined immunohistochemical or fluorescence in situ hybridization (FISH score of MYC, BCL2, BCL6 proteins and MYC translocations predicted outcome in diffuse large B-cell lymphoma (DLBCL patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP. However, by far, all these researches are based on Western populations. Therefore, we investigate the prognostic relevance of MYC-, BCL2- and BCL6-rearrangements and protein expression by immunohistochemistry and FISH from 336 de novo DLBCL, NOS treated with CHOP or R-CHOP. Breaks in MYC and BCL6, and fusion in IGH/BCL2 were detected in 9.7%, 20.0%, and 11.1% of the cases, respectively, and were not significantly associated with clinical outcomes. Protein overexpression of MYC (≥40%, BCL2 (≥70% and BCL6 (≥50% was encountered in 51%, 51% and 36% of the tumors, respectively. On the basis of MYC, BCL2 and BCL6 expression, double-hit scores (DHSs and triple-hit score (THS were assigned to all patients with DLBCL. Patients with high MYC/BCL2 DHS, high MYC/BCL6 DHS and high THS had multiple adverse prognostic factors including high LDH level, poor performance status, advanced clinical stage, high International Prognostic Index (IPI score, and non-germinal center B-cell. In univariate analysis, high MYC/BCL2 DHS, high MYC/BCL6 DHS and high THS were associated with inferior OS and PFS in both CHOP and R-CHOP cohorts (P0.05. These data together suggest that the immunohistochemical DHSs and THS defined a large subset of DLBCLs with double-hit biology and was strongly associated with poor outcome in patients treated with R-CHOP or CHOP.

  18. Predicting promiscuous antigenic T cell epitopes of Mycobacterium tuberculosis mymA operon proteins binding to MHC Class I and Class II molecules.

    Science.gov (United States)

    Saraav, Iti; Pandey, Kirti; Sharma, Monika; Singh, Swati; Dutta, Prasun; Bhardwaj, Anshu; Sharma, Sadhna

    2016-10-01

    Limited efficacy of Bacillus Calmette-Guérin vaccine has raised the need to explore other immunogenic candidates to develop an effective vaccine against Mycobacterium tuberculosis (Mtb). Both CD4+ and CD8+ T cells play a critical role in host immunity to Mtb. Infection of macrophages with Mtb results in upregulation of mymA operon genes thereby suggesting their importance as immune targets. In the present study, after exclusion of self-peptides mymA operon proteins of Mtb were analyzed in silico for the presence of Human Leukocyte Antigen (HLA) Class I and Class II binding peptides using Bioinformatics and molecular analysis section, NetMHC 3.4, ProPred and Immune epitope database software. Out of 56 promiscuous epitopes obtained, 41 epitopes were predicted to be antigenic for MHC Class I. In MHC Class II, out of 336 promiscuous epitopes obtained, 142 epitopes were predicted to be antigenic. The comparative bioinformatics analysis of mymA operon proteins found Rv3083 to be the best vaccine candidate. Molecular docking was performed with the most antigenic peptides of Rv3083 (LASGAASVV with alleles HLA-B51:01, HAATSGTLI with HLA-A02, IVTATGLNI and EKIHYGLKVNTA with HLA-DRB1_01:01) to study the structural basis for recognition of peptides by various HLA molecules. The software binding prediction was validated by the obtained molecular docking score of peptide-HLA complex. These peptides can be further investigated for their immunological relevance in patients of tuberculosis using major histocompatibility complex tetramer approach. PMID:27389362

  19. Major histocompatibility complex class I binding predictions as a tool in epitope discovery

    DEFF Research Database (Denmark)

    Lundegaard, Claus; Lund, Ole; Buus, Søren;

    2010-01-01

    Over the last decade, in silico models of the major histocompatibility complex (MHC) class I pathway have developed significantly. Before, peptide binding could only be reliably modelled for a few major human or mouse histocompatibility molecules; now, high-accuracy predictions are available...... for any human leucocyte antigen (HLA) -A or -B molecule with known protein sequence. Furthermore, peptide binding to MHC molecules from several non-human primates, mouse strains and other mammals can now be predicted. In this review, a number of different prediction methods are briefly explained...

  20. Antibody-protein interactions: benchmark datasets and prediction tools evaluation

    Directory of Open Access Journals (Sweden)

    Ponomarenko Julia V

    2007-10-01

    Full Text Available Abstract Background The ability to predict antibody binding sites (aka antigenic determinants or B-cell epitopes for a given protein is a precursor to new vaccine design and diagnostics. Among the various methods of B-cell epitope identification X-ray crystallography is one of the most reliable methods. Using these experimental data computational methods exist for B-cell epitope prediction. As the number of structures of antibody-protein complexes grows, further interest in prediction methods using 3D structure is anticipated. This work aims to establish a benchmark for 3D structure-based epitope prediction methods. Results Two B-cell epitope benchmark datasets inferred from the 3D structures of antibody-protein complexes were defined. The first is a dataset of 62 representative 3D structures of protein antigens with inferred structural epitopes. The second is a dataset of 82 structures of antibody-protein complexes containing different structural epitopes. Using these datasets, eight web-servers developed for antibody and protein binding sites prediction have been evaluated. In no method did performance exceed a 40% precision and 46% recall. The values of the area under the receiver operating characteristic curve for the evaluated methods were about 0.6 for ConSurf, DiscoTope, and PPI-PRED methods and above 0.65 but not exceeding 0.70 for protein-protein docking methods when the best of the top ten models for the bound docking were considered; the remaining methods performed close to random. The benchmark datasets are included as a supplement to this paper. Conclusion It may be possible to improve epitope prediction methods through training on datasets which include only immune epitopes and through utilizing more features characterizing epitopes, for example, the evolutionary conservation score. Notwithstanding, overall poor performance may reflect the generality of antigenicity and hence the inability to decipher B-cell epitopes as an

  1. Residue analysis of a CTL epitope of SARS-CoV spike protein by IFN-gamma production and bioinformatics prediction

    Directory of Open Access Journals (Sweden)

    Huang Jun

    2012-09-01

    Full Text Available Abstract Background Severe acute respiratory syndrome (SARS is an emerging infectious disease caused by the novel coronavirus SARS-CoV. The T cell epitopes of the SARS CoV spike protein are well known, but no systematic evaluation of the functional and structural roles of each residue has been reported for these antigenic epitopes. Analysis of the functional importance of side-chains by mutational study may exaggerate the effect by imposing a structural disturbance or an unusual steric, electrostatic or hydrophobic interaction. Results We demonstrated that N50 could induce significant IFN-gamma response from SARS-CoV S DNA immunized mice splenocytes by the means of ELISA, ELISPOT and FACS. Moreover, S366-374 was predicted to be an optimal epitope by bioinformatics tools: ANN, SMM, ARB and BIMAS, and confirmed by IFN-gamma response induced by a series of S358-374-derived peptides. Furthermore, each of S366-374 was replaced by alanine (A, lysine (K or aspartic acid (D, respectively. ANN was used to estimate the binding affinity of single S366-374 mutants to H-2 Kd. Y367 and L374 were predicated to possess the most important role in peptide binding. Additionally, these one residue mutated peptides were synthesized, and IFN-gamma production induced by G368, V369, A371, T372 and K373 mutated S366-374 were decreased obviously. Conclusions We demonstrated that S366-374 is an optimal H-2 Kd CTL epitope in the SARS CoV S protein. Moreover, Y367, S370, and L374 are anchors in the epitope, while C366, G368, V369, A371, T372, and K373 may directly interact with TCR on the surface of CD8-T cells.

  2. 麻疹病毒血凝素蛋白抗原表位的预测与分析%Prediction and analysis of epitopes of hemagglutinin of measles virus

    Institute of Scientific and Technical Information of China (English)

    冯燕; 钟淑玲; 徐昌平; 卢亦愚

    2015-01-01

    Objective To discuss the antigenic change caused by the mutation of amino acid on the epitopes of the hemagglutinin of measles virus.Methods The B cell linear epitopes in the hemagglutinin were predicted with bioinformatics software.Peptide pairs,which located on the same region but originated from measles vaccine and wild-type virus respectively,were designed and synthesized.After detecting the immunogenicity of peptides with indirect ELISA assay,sera against each peptide was prepared.Antigenic specificity between the two peptides within each peptide pair were tested by using cross ELISA assay,and then antigen ratios were calculated.Results All the synthesized peptides could bind with immune sera against measles virus,of which the peptide pair CW23/CW22 designed on the epitope region (273-282 aa) possessed the highest binding ability,while the peptide pair CW150/CW151 designed on the non-epitope region (418-427 aa) showed the lowest binding ability.The difference in antigenic specificity between the two peptides from different sources was significant.The antigenic ratio was up to 16 between CW23 (vaccine-originated) and CW22 (wild-type originated),and 2.877 ± 0.583 between CW123 (vaccine-originated) and CW124 (wild-type originated) (236-246 aa).On the non-epitope regions,the antigenic ratios was only 1.631 ± 0.481 between peptide pair CW125 and CW126(356-364 aa),but reached to 10.367± 1.617 between CW150 and CW151.Conclusion Although there were several conservative epitopes,specific amino acid mutation on the predicted epitope or non-epitope regions might cause the antigenic change of wild-type measles virus.%目的 探讨麻疹病毒(MeV)流行株血凝素蛋白(H)抗原表位上氨基酸(aa)变异对病毒抗原性的可能影响.方法 利用生物信息学软件预测MeV H蛋白上B细胞线性表位,设计并合成来源于疫苗株和流行株表位以及同一区域非表位上的多肽对.间接ELISA法检测合成多肽的免疫原性,并制备多肽

  3. The nature and combination of subunits used in epitope-based Schistosoma japonicum vaccine formulations affect their efficacy

    Directory of Open Access Journals (Sweden)

    Liu Feng

    2010-11-01

    Full Text Available Abstract Background Schistosomiasis remains a major public health problem in endemic countries and is caused by infections with any one of three primary schistosome species. Although there are no vaccines available to date, this strategy appears feasible since natural immunity develops in individuals suffering from repeated infection during a lifetime. Since vaccinations resulting in both Th1- and Th2-type responses have been shown to contribute to protective immunity, a vaccine formulation with the capacity for stimulating multiple arms of the immune response will likely be the most effective. Previously we developed partially protective, single Th- and B cell-epitope-based peptide-DNA dual vaccines (PDDV (T3-PDDV and B3-PDDV, respectively capable of eliciting immune responses against the Schistosoma japonicum 22.6 kDa tegument antigen (Sj22.6 and a 62 kDa fragment of myosin (Sj62, respectively. Results In this study, we developed PDDV cocktails containing multiple epitopes of S. japonicum from Sj22.6, Sj62 and Sj97 antigens by predicting cytotoxic, helper, and B-cell epitopes, and evaluated vaccine potential in vivo. Results showed that mice immunized with a single-epitope PDDV elicited either Tc, Th, or B cell responses, respectively, and mice immunized with either the T3- or B3- single-epitope PDDV formulation were partially protected against infection. However, mice immunized with a multicomponent (3 PDDV components formulation elicited variable immune responses that were less immunoprotective than single-epitope PDDV formulations. Conclusions Our data show that combining these different antigens did not result in a more effective vaccine formulation when compared to each component administered individually, and further suggest that immune interference resulting from immunizations with antigenically distinct vaccine targets may be an important consideration in the development of multicomponent vaccine preparations.

  4. CD8 and CD4 epitope predictions in RV144: no strong evidence of a T-cell driven sieve effect in HIV-1 breakthrough sequences from trial participants.

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    Kalpana Dommaraju

    Full Text Available The modest protection afforded by the RV144 vaccine offers an opportunity to evaluate its mechanisms of protection. Differences between HIV-1 breakthrough viruses from vaccine and placebo recipients can be attributed to the RV144 vaccine as this was a randomized and double-blinded trial. CD8 and CD4 T cell epitope repertoires were predicted in HIV-1 proteomes from 110 RV144 participants. Predicted Gag epitope repertoires were smaller in vaccine than in placebo recipients (p = 0.019. After comparing participant-derived epitopes to corresponding epitopes in the RV144 vaccine, the proportion of epitopes that could be matched differed depending on the protein conservation (only 36% of epitopes in Env vs 84-91% in Gag/Pol/Nef for CD8 predicted epitopes or on vaccine insert subtype (55% against CRF01_AE vs 7% against subtype B. To compare predicted epitopes to the vaccine, we analyzed predicted binding affinity and evolutionary distance measurements. Comparisons between the vaccine and placebo arm did not reveal robust evidence for a T cell driven sieve effect, although some differences were noted in Env-V2 (0.022≤p-value≤0.231. The paucity of CD8 T cell responses identified following RV144 vaccination, with no evidence for V2 specificity, considered together both with the association of decreased infection risk in RV 144 participants with V-specific antibody responses and a V2 sieve effect, lead us to hypothesize that this sieve effect was not T cell specific. Overall, our results did not reveal a strong differential impact of vaccine-induced T cell responses among breakthrough infections in RV144 participants.

  5. Predicted Indirectly Recognizable HLA Epitopes Presented by HLA-DRB1 Are Related to HLA Antibody Formation During Pregnancy

    NARCIS (Netherlands)

    Geneugelijk, K; Hönger, G; van Deutekom, H W M; Thus, K A; Kesmir, C.; Hösli, I; Schaub, S; Spierings, E

    2015-01-01

    Pregnancy can prime maternal immune responses against inherited paternal HLA of the fetus, leading to the production of child-specific HLA antibodies. We previously demonstrated that donor-specific HLA antibody formation after kidney transplantation is associated with donor-derived HLA epitopes pres

  6. Predicted indirectly recognizable HLA epitopes presented by HLA-DRB1 are related to HLA antibody formation during pregnancy

    NARCIS (Netherlands)

    Geneugelijk, K.; Hönger, G.; Van Deutekom, H. W M; Thus, K. A.; Keşmir, C.; Hösli, I.; Schaub, S.; Spierings, E.

    2015-01-01

    Pregnancy can prime maternal immune responses against inherited paternal HLA of the fetus, leading to the production of child-specific HLA antibodies. We previously demonstrated that donor-specific HLA antibody formation after kidney transplantation is associated with donor-derived HLA epitopes pres

  7. Epitope prediction methods

    OpenAIRE

    Karosiene, Edita; Nielsen, Morten; Lund, Ole

    2013-01-01

    Major histocompatibility complex (MHC molekyler spiller en afgørende rolle i adaptiv immunitet, ved at udvælge peptider fra egne og ikke-egne proteiner til genkendelse af immunsystemet. MHC molekyler præsenterer peptider på celleoverfladen, som så genkendes af CD8+ og CD4+ T lymfocytter, som er i stand til at initiere et immunrespons. Det er derfor yderst vigtigt at kunne identificere peptider, som binder til MHC molekyler, for derved at kunne forstå arten af immunresponset, samt at opdage T ...

  8. Reciprocal expression of the endocytic protein HIP1R and its repressor FOXP1 predicts outcome in R-CHOP-treated diffuse large B-cell lymphoma patients

    DEFF Research Database (Denmark)

    Wong, K K; Gascoyne, D M; Brown, P J;

    2014-01-01

    We previously identified autoantibodies to the endocytic-associated protein Huntingtin-interacting protein 1-related (HIP1R) in diffuse large B-cell lymphoma (DLBCL) patients. HIP1R regulates internalization of cell surface receptors via endocytosis, a process relevant to many therapeutic strateg...

  9. Lymphoid-Like Structures with Distinct B Cell Areas in Kidney Allografts are not Predictive for Graft Rejection. A Non-human Primate Study.

    Science.gov (United States)

    Jonker, Margreet; Wubben, Jacqueline A M; 't Hart, Bert A; Haanstra, Krista G

    2015-12-01

    Kidney allograft biopsies were analyzed for the presence of B cell clusters/aggregates using CD20 staining. Few B cells were found in the diffuse interstitial infiltrates, but clusters of B cells were found in nodular infiltrates. These nodular infiltrates were smaller shortly after transplantation, and their size increased over time. At the time of clinical rejection, the nodules often presented as tertiary lymphoid structures (TLS) with lymphoid-like follicles. The presence of small B cell clusters during the first 2 months after transplantation was not associated with early rejection. Even in animals that did not reject their allograft, TLS-like structures were present and could disappear over time. Although TLS were more often found in samples with interstitial fibrosis and tubular atrophy (IFTA), TLS were also present in samples without IFTA. The presence and density of clusters resembling tertiary lymphoid structures most likely reflect an ongoing immune response inside the graft and do not necessarily signify a poor graft outcome or IFTA.

  10. Qualitative visual trichotomous assessment improves the value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in predicting the prognosis of diffuse large B-cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    Xu Zhang; Wei Fan; Ying-Ying Hu; Zhi-Ming Li; Zhong-Jun Xia; Xiao-Ping Lin; Ya-Rui Zhang; Pei-Yan Liang; Yuan-Hua Li

    2015-01-01

    Introduction:Fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) is a powerful tool for monitoring the response of diffuse large B-cell lymphoma (DLBCL) to therapy, but the criteria to interpret PET/CT results remain under debate. We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment (QVTA) criteria compared with the Deauvil e criteria. Methods:In this retrospective study, final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria. Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test. Results:A total of 253 patients were enrol ed. The interpretation according to the Deauvil e criteria revealed that 181 patients had negative PET/CT scan results and 72 had positive results. The 3 year overal survival (OS) rate was significantly higher in patients with negative scan results than in those with positive results (91.6%vs. 57.5%, P<0.001). The 72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results, and 43 had positive results. The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results (91.2%vs. 33.5%, P<0.001) but was similar between patients with negative and indeterminate scan results (91.6%vs. 91.2%, P=0.921). Conclusions:Compared with the Deauvil e criteria, using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results. The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy.

  11. B Epitope Multiplicity and B/T Epitope Orientation Influence Immunogenicity of Foot-and-Mouth Disease Peptide Vaccines

    Directory of Open Access Journals (Sweden)

    Esther Blanco

    2013-01-01

    Full Text Available Synthetic peptides incorporating protective B- and T-cell epitopes are candidates for new safer foot-and-mouth disease (FMD vaccines. We have reported that dendrimeric peptides including four copies of a B-cell epitope (VP1 136 to 154 linked to a T-cell epitope (3A 21 to 35 of FMD virus (FMDV elicit potent B- and T-cell specific responses and confer protection to viral challenge, while juxtaposition of these epitopes in a linear peptide induces less efficient responses. To assess the relevance of B-cell epitope multivalency, dendrimers bearing two (B2T or four (B4T copies of the B-cell epitope from type O FMDV (a widespread circulating serotype were tested in CD1 mice and showed that multivalency is advantageous over simple B-T-epitope juxtaposition, resulting in efficient induction of neutralizing antibodies and optimal release of IFNγ. Interestingly, the bivalent B2T construction elicited similar or even better B- and T-cell specific responses than tetravalent B4T. In addition, the presence of the T-cell epitope and its orientation were shown to be critical for the immunogenicity of the linear juxtaposed monovalent peptides analyzed in parallel. Taken together, our results provide useful insights for a more accurate design of FMD subunit vaccines.

  12. 4种血清型登革病毒NS1蛋白序列及B细胞抗原表位特异性分析%Analysis on genome and amino acids sequence and B cell epitopes for 4 serotypes of dengue virus NS1 protein

    Institute of Scientific and Technical Information of China (English)

    陈艳佳; 熊建英; 朱利; 曹虹; 赵卫

    2013-01-01

    目的 比较4种血清型登革病毒NS1蛋白型特异性抗原表位基因序列及氨基酸序列之间的差异,为利用基因差异进行血清学分型及疫苗研究提供新的线索.方法 利用DNAstar数据包中的Editseq程序,从20株登革病毒分离株的全基因组序列中将NS1基因型特异性抗原表位序列截取出来,再用Clustal X软件进行多序列比对,进行同源性分析,找出型内最为保守的抗原表位序列.并将比对结果在120株登革病毒序列中进一步验证.结果 NS1蛋白36~45和71~85位氨基酸为型特异性抗原表位,高度保守,型内完全相同,型间不同.结论 NS1蛋白36~45位氨基酸可以作为登革病毒血清分型和研制亚单位疫苗的靶标.%OBJECTIVE To compare genome and amino acids sequences and possible B cell epitopes of 4 serotypes of dengue virus NS1 protein, to explore a new method of gene typing and provide new clues to vaccine research. METHODS Cut off the corresponding gene sequences of NS1 protein from the complete genome of 20 dengue virus isolates, then multisequencing was carried out to find the gene which was conservative within the same serotype and variant in the other serotypes. RESULTS Specific antigens of NS1 protein (36-45 and 71-85 amino acids) were conservative within the same serotype and variant in other serotypes. CONCLUSION Specific antigens of NS1 protein (36-45 amino acids) are the bases of dengue virus typing and targets of subunit vaccine development.

  13. IDEPI: rapid prediction of HIV-1 antibody epitopes and other phenotypic features from sequence data using a flexible machine learning platform.

    Science.gov (United States)

    Hepler, N Lance; Scheffler, Konrad; Weaver, Steven; Murrell, Ben; Richman, Douglas D; Burton, Dennis R; Poignard, Pascal; Smith, Davey M; Kosakovsky Pond, Sergei L

    2014-09-01

    Since its identification in 1983, HIV-1 has been the focus of a research effort unprecedented in scope and difficulty, whose ultimate goals--a cure and a vaccine--remain elusive. One of the fundamental challenges in accomplishing these goals is the tremendous genetic variability of the virus, with some genes differing at as many as 40% of nucleotide positions among circulating strains. Because of this, the genetic bases of many viral phenotypes, most notably the susceptibility to neutralization by a particular antibody, are difficult to identify computationally. Drawing upon open-source general-purpose machine learning algorithms and libraries, we have developed a software package IDEPI (IDentify EPItopes) for learning genotype-to-phenotype predictive models from sequences with known phenotypes. IDEPI can apply learned models to classify sequences of unknown phenotypes, and also identify specific sequence features which contribute to a particular phenotype. We demonstrate that IDEPI achieves performance similar to or better than that of previously published approaches on four well-studied problems: finding the epitopes of broadly neutralizing antibodies (bNab), determining coreceptor tropism of the virus, identifying compartment-specific genetic signatures of the virus, and deducing drug-resistance associated mutations. The cross-platform Python source code (released under the GPL 3.0 license), documentation, issue tracking, and a pre-configured virtual machine for IDEPI can be found at https://github.com/veg/idepi. PMID:25254639

  14. Theoretical analysis of the neuraminidase epitope of the Mexican A H1N1 influenza strain, and experimental studies on its interaction with rabbit and human hosts.

    Science.gov (United States)

    Loyola, Paola Kinara Reyes; Campos-Rodríguez, R; Bello, Martiniano; Rojas-Hernández, S; Zimic, Mirko; Quiliano, Miguel; Briz, Verónica; Muñoz-Fernández, M Angeles; Tolentino-López, Luis; Correa-Basurto, Jose

    2013-05-01

    The neuraminidase (NA) epitope from the Mexican AH1N1 influenza virus was identified by using sequences registered at the GenBank during the peak of a pandemic (from April 2009 to October 2010). First, NA protein sequences were submitted for multiple alignment analysis, and their three-dimensional models (3-D) were then built by using homology modeling. The most common sequence (denominated wild-type) and its mutants were submitted to linear and nonlinear epitope predictors, which included the major histocompatibility complex type II (MHC II) and B-cell peptides. The epitope prediction was in accordance with evolutionary behavior and some protein structural properties. The latter included a low NA mutation rate, NA 3-D surface exposure, and the presence of high hindrance side chain residues. After selecting the epitope, docking studies and molecular dynamics (MD) simulations were used to explore interactions between the epitope and MHC II. Afterward, several experimental assays were performed to validate the theoretical study by using antibodies from humans (infected by pandemic H1N1) and rabbits (epitope vaccination). The results show 119 complete sequences that were grouped into 28 protein sequences according to their identity (one wild-type and 27 representative mutants (1-5 mutations)). The predictors yielded several epitopes, with the best fit being the one located in the C-terminal region. Theoretical methods demonstrated that the selected epitope reached the P4, P6, P7, and P9 pockets of MHC II, whereas the experimental evidence indicates that the epitope is recognized by human antibodies and also by rabbit antibodies immunized with the peptide.

  15. A transplant "immunome" screening platform defines a targetable epitope fingerprint of multiple myeloma.

    Science.gov (United States)

    Schieferdecker, Aneta; Oberle, Anna; Thiele, Benjamin; Hofmann, Fabian; Göthel, Markus; Miethe, Sebastian; Hust, Michael; Braig, Friederike; Voigt, Mareike; von Pein, Ute-Marie; Koch-Nolte, Friedrich; Haag, Friedrich; Alawi, Malik; Indenbirken, Daniela; Grundhoff, Adam; Bokemeyer, Carsten; Bacher, Ulrike; Kröger, Nicolaus; Binder, Mascha

    2016-06-23

    Multiple myeloma (MM) is a hematological cancer for which immune-based treatments are currently in development. Many of these rely on the identification of highly disease-specific, strongly and stably expressed antigens. Here, we profiled the myeloma B-cell immunome both to explore its predictive role in the context of autologous and allogeneic hematopoietic stem cell transplantation (HSCT) and to identify novel immunotherapeutic targets. We used random peptide phage display, reverse immunization, and next-generation sequencing-assisted antibody phage display to establish a highly myeloma-specific epitope fingerprint targeted by B-cell responses of 18 patients in clinical remission. We found that allogeneic HSCT more efficiently allowed production of myeloma-specific antibodies compared with autologous HSCT and that a highly reactive epitope recognition signature correlated with superior response to treatment. Next, we performed myeloma cell surface screenings of phage-displayed patient transplant immunomes. Although some of the screenings yielded clear-cut surface binders, the majority of screenings did not, suggesting that many of the targeted antigens may in fact not be accessible to the B-cell immune system in untreated myeloma cells. This fit well with the identification of heat-shock proteins as a class of antigens that showed overall the broadest reactivity with myeloma patient sera after allogeneic HSCT and that may be significantly translocated to the cell surface upon treatment as a result of immunogenic cell death. Our data reveal a disease-specific epitope signature of MM that is predictive for response to treatment. Mining of transplant immunomes for strong myeloma surface binders may open up avenues for myeloma immunotherapy. PMID:27034429

  16. Automatic Generation of Validated Specific Epitope Sets

    Directory of Open Access Journals (Sweden)

    Sebastian Carrasco Pro

    2015-01-01

    Full Text Available Accurate measurement of B and T cell responses is a valuable tool to study autoimmunity, allergies, immunity to pathogens, and host-pathogen interactions and assist in the design and evaluation of T cell vaccines and immunotherapies. In this context, it is desirable to elucidate a method to select validated reference sets of epitopes to allow detection of T and B cells. However, the ever-growing information contained in the Immune Epitope Database (IEDB and the differences in quality and subjects studied between epitope assays make this task complicated. In this study, we develop a novel method to automatically select reference epitope sets according to a categorization system employed by the IEDB. From the sets generated, three epitope sets (EBV, mycobacteria and dengue were experimentally validated by detection of T cell reactivity ex vivo from human donors. Furthermore, a web application that will potentially be implemented in the IEDB was created to allow users the capacity to generate customized epitope sets.

  17. Expression and immunoreactivity of an epitope of HCV in a foreign epitope presenting system

    Institute of Scientific and Technical Information of China (English)

    Mei Peng; Chang-Bai Dai; Yuan-Ding Chen

    2005-01-01

    AIM: To construct and highly express an epitope of hepatitis C virus (HCV) in a foreign epitope presenting vectorbased on an insect virus, and to study the antigenicity of the epitope.METHODS: The HCV epitope sequence (amino acidresidues 315 to 328: EGHRMAWDMMMNWS) of the E1 region was constructed at different positions of a foreign epitope presenting vector based on an insect virus, flock house virus (FHV) capsid protein encoding gene as a vector, and expressed in E. coli cells. Western blottingand ELISA were used to detect the immunoreactivity of these recombinant proteins.RESULTS: The gene encoding of the concerned B-cell epitope of HCV E1 envelope protein was expressed on FHV capsid carrier protein at positions I1 (aa 106), I2 (aa153) and I3 (aa 305), respectively, on the surface of FHV capsid protein. The recombinant proteins in this system could be highly expressed in more than 40% of total cell protein of E. coli BL21. All the expressed recombinant proteins were in inclusion body form, and showed obvious immunoreactivity by Western blotting. Further purified recombinant proteins were detected by indirect ELISA as coating antigen respectively. All recombinant proteins could still show immunoreactivity.CONCLUSION: The epitope of HCV E1 envelope protein can be highly expressed in FHV carrier system as a chimeric protein with high immunoreactivity. This system has multiple entry sites conferring many possible conformations closer to the native one for a given sequence.

  18. Prediction of a common neutralizing epitope of H5N1 avian influenza virus by in silico molecular docking

    Institute of Scientific and Technical Information of China (English)

    YAN YuanQing; XIA NingShao; LI ShaoWei; YANG ChunYan; LUO WenXin; WANG MingQiao; CHEN YiXin; LUO HaiFeng; WU Ting; ZHANG Jun

    2008-01-01

    The H5N1 avian influenza virus (AIV) has widely spread in Asia, Europe and Africa, making a large amount of economic loss. Recently, our research group has screened a common neutralizing mono-clonal antibody named 8H5, which can neutralize almost all H5 subtype AIV ever isolated so far. Obvi-ously, this monoclonal antibody would benefit for research and development of the universal AIV vac-cine and design of the drug against H5N1 AIV in high mutation rate. In this study, the homology mod-eling was applied to generate the 3D structure of 8H5 Fab fragment, and "canonical structure" method was used to define the specified loop conformation of CDR regions. The model was subjected to en-ergy minimization in cvff force field with Discovery module in Insight Ⅱ program. The resulting model has correct stereochemistry as gauged from the Ramachandran plot calculation and good 3D-structure compatibility as assessed by interaction energy analysis, solvent accessible surface (SAS) analysis, and Profiles-3D approach. Furthermore, the 8H5 Fab model was subjected to docking with three H5 subtype hemagglutinin (HA) structures deposited in PDB (ID No: 1jsm, 2ibx and 2fk0) respectively. The result indicates that the three docked complexes share a common binding interface, but differ in bind-ing angle related with HA structure similarity between viral subtypes. In the light of the three HA inter-faces with structural homology analysis, the common neutralizing epitope on HA recognized by 8H5 consists of 9 incontinuous amino acid residues: Asp68, Asn72, Glu112, Lys113, Ile114, Pro118, Ser120, Tyr137, Tyr252 (numbered as for 1jsm sequence), The primary purpose of the present work is to provide some insight into structure and binding details of a common neutralizing epitope of H5N1 AIV, thereby aiding in the structure-based design of universal AIV vaccines and anti-virus therapeutic drugs.

  19. Ibrutinib for B cell malignancies

    OpenAIRE

    Novero, Aileen; Ravella, Pavan M; Chen, Yamei; Dous, George; Liu, Delong

    2014-01-01

    Research over the role of Bruton’s agammaglobulinemia tyrosine kinase (BTK) in B-lymphocyte development, differentiation, signaling and survival has led to better understanding of the pathogenesis of B-cell malignancies. Down-regulation of BTK activity is an attractive novel strategy for treating patients with B-cell malignancies. Ibrutinib (PCI-32765), a potent inhibitor of BTK induces impressive responses in B-cell malignancies through irreversible bond with cysteine-481 in the active site ...

  20. Plasmodium vivax Promiscuous T-Helper Epitopes Defined and Evaluated as Linear Peptide Chimera Immunogens

    Science.gov (United States)

    Caro-Aguilar, Ivette; Rodríguez, Alexandra; Calvo-Calle, J. Mauricio; Guzmán, Fanny; De la Vega, Patricia; Elkin Patarroyo, Manuel; Galinski, Mary R.; Moreno, Alberto

    2002-01-01

    Clinical trials of malaria vaccines have confirmed that parasite-derived T-cell epitopes are required to elicit consistent and long-lasting immune responses. We report here the identification and functional characterization of six T-cell epitopes that are present in the merozoite surface protein-1 of Plasmodium vivax (PvMSP-1) and bind promiscuously to four different HLA-DRB1∗ alleles. Each of these peptides induced lymphoproliferative responses in cells from individuals with previous P. vivax infections. Furthermore, linear-peptide chimeras containing the promiscuous PvMSP-1 T-cell epitopes, synthesized in tandem with the Plasmodium falciparum immunodominant circumsporozoite protein (CSP) B-cell epitope, induced high specific antibody titers, cytokine production, long-lasting immune responses, and immunoglobulin G isotype class switching in BALB/c mice. A linear-peptide chimera containing an allele-restricted P. falciparum T-cell epitope with the CSP B-cell epitope was not effective. Two out of the six promiscuous T-cell epitopes exhibiting the highest anti-peptide response also contain B-cell epitopes. Antisera generated against these B-cell epitopes recognize P. vivax merozoites in immunofluorescence assays. Importantly, the anti-peptide antibodies generated to the CSP B-cell epitope inhibited the invasion of P. falciparum sporozoites into human hepatocytes. These data and the simplicity of design of the chimeric constructs highlight the potential of multimeric, multistage, and multispecies linear-peptide chimeras containing parasite promiscuous T-cell epitopes for malaria vaccine development. PMID:12065487

  1. Molecular modeling and conformational IgG epitope mapping on bovine β-casein

    NARCIS (Netherlands)

    Liu, Fahui; Gao, Jinyan; Li, Xin; Chen, Hongbing

    2016-01-01

    Characterizing conformational B-cell epitopes is a key step for understanding the immunological basis of allergy contributed by β-casein. There is no resolved conformational structure of β-casein in protein data bank, and most of the previous research on epitope identification of β-casein focused

  2. Virus-Like Particles of Chimeric Recombinant Porcine Circovirus Type 2 as Antigen Vehicle Carrying Foreign Epitopes

    OpenAIRE

    2014-01-01

    Virus-like particles (VLPs) of chimeric porcine circovirus type 2 (PCV2) were generated by replacing the nuclear localization signal (NLS; at 1–39 aa) of PCV2 capsid protein (Cap) with classical swine fever virus (CSFV) T-cell epitope (1446–1460 aa), CSFV B-cell epitope (693–716 aa) and CSFV T-cell epitope conjugated with B-cell epitope. The recombinant proteins were expressed using the baculovirus expression system and detected by immunoblotting and indirect immunofluorescence assay. The ab...

  3. Rhipicephalus microplus lipocalins (LRMs): genomic identification and analysis of the bovine immune response using in silico predicted B and T cell epitopes.

    Science.gov (United States)

    Rodriguez-Valle, Manuel; Moolhuijzen, Paula; Piper, Emily K; Weiss, Olivia; Vance, Megan; Bellgard, Matthew; Lew-Tabor, Ala

    2013-08-01

    The attachment to host skin by Rhipicephalus microplus larvae induces a series of physiological events at the attachment site. The host-parasite interaction might induce a rejection of the larvae, as is frequently observed in Bos taurus indicus cattle, and under certain conditions in Bos taurus taurus cattle. Ticks deactivate the host rejection response by secreting specific proteins and lipids that play an essential role in manipulation of the host immune response. The available genomic information on the R. microplus tick was mined using bioinformatics approaches to identify R. microplus lipocalins (LRMs). This in silico examination revealed a total of 12 different putative R. microplus LRMs (LRM1-LRM12). The identity of the LRM family showed high sequence variability: from 6% between LRM7 and LRM8 to 55.9% between LRM2 and LRM6. However, the three-dimensional structure of the lipocalin family was conserved in the LRMs. The B and T cell epitopes in these lipocalins were then predicted, and six of the LRMs (5, 6, 9, 10, 11 and 12) were used to examine the host immune interactions with sera and peripheral blood mononuclear cells (PBMCs) collected from tick-susceptible and tick-resistant cattle challenged with R. microplus. On days 28-60 after tick infestation, the anti-LRM titres were higher in the resistant group compared with the susceptible cattle. After 60 day, the anti-LRM titres (except LRM9 and LRM11) decreased to zero in the sera of both the tick-resistant and tick-susceptible cattle. Using cell proliferation assays, the PBMCs challenged with some of the predicted T cell epitopes (LRM1_T1, T2; LRM_T1, T2 and LRM12_T) exhibited a significantly higher number of IFN-γ-secreting cells (Th1) in tick-susceptible Holstein-Friesians compared with tick-resistant Brahman cattle. In contrast, expression of the Th2 cytokine (IL-4) was lower in Holstein-Friesians cattle compared with Brahman cattle. Moreover, this study found that LRM6, LRM9 and LRM11 play important

  4. De Novo Transcriptome Analysis of Allium cepa L. (Onion Bulb to Identify Allergens and Epitopes.

    Directory of Open Access Journals (Sweden)

    Hemalatha Rajkumar

    Full Text Available Allium cepa (onion is a diploid plant with one of the largest nuclear genomes among all diploids. Onion is an example of an under-researched crop which has a complex heterozygous genome. There are no allergenic proteins and genomic data available for onions. This study was conducted to establish a transcriptome catalogue of onion bulb that will enable us to study onion related genes involved in medicinal use and allergies. Transcriptome dataset generated from onion bulb using the Illumina HiSeq 2000 technology showed a total of 99,074,309 high quality raw reads (~20 Gb. Based on sequence homology onion genes were categorized into 49 different functional groups. Most of the genes however, were classified under 'unknown' in all three gene ontology categories. Of the categorized genes, 61.2% showed metabolic functions followed by cellular components such as binding, cellular processes; catalytic activity and cell part. With BLASTx top hit analysis, a total of 2,511 homologous allergenic sequences were found, which had 37-100% similarity with 46 different types of allergens existing in the database. From the 46 contigs or allergens, 521 B-cell linear epitopes were identified using BepiPred linear epitope prediction tool. This is the first comprehensive insight into the transcriptome of onion bulb tissue using the NGS technology, which can be used to map IgE epitopes and prediction of structures and functions of various proteins.

  5. Positron Emission Tomography/Computed Tomography Findings During Therapy Predict Outcome in Patients With Diffuse Large B-Cell Lymphoma Treated With Chemotherapy Alone but Not in Those Who Receive Consolidation Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dabaja, Bouthaina S., E-mail: bdabaja@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hess, Kenneth [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Shihadeh, Ferial [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Podoloff, Donald A. [Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Medeiros, L. Jeffrey [Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mawlawi, Osama [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Arzu, Isidora [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Oki, Yasuhiro; Hagemeister, Fredrick B.; Fayad, Luis E. [Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Reed, Valerie K.; Kedir, Aziza; Wogan, Christine F. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rodriguez, Alma [Office of the Executive Vice President and Physician-in-Chief, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-06-01

    Purpose: To assess the value of mid-therapy positron emission tomography (PET) findings for predicting survival and disease progression in patients with diffuse large B-cell lymphoma, considering type of therapy (chemotherapy with or without radiation therapy). Methods and Materials: We retrospectively evaluated 294 patients with histologically confirmed diffuse large B-cell lymphoma with respect to age, sex, disease stage, International Prognostic Index score, mid-therapy PET findings (positive or negative), and disease status after therapy and at last follow-up. Overall survival (OS) and progression-free survival (PFS) were compared according to mid-therapy PET findings. Results: Of the 294 patients, 163 (55%) were male, 144 (49%) were age >61 years, 110 (37%) had stage I or II disease, 219 (74%) had International Prognostic Index score ≤2, 216 (73%) received ≥6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, and 88 (30%) received consolidation radiation therapy. Five-year PFS and OS rates were associated with mid-therapy PET status: PFS was 78% for those with PET-negative (PET−) disease versus 63% for PET-positive (PET+) disease (P=.024), and OS was 82% for PET− versus 62% for PET+ (P<.002). These associations held true for patients who received chemotherapy only (PFS 71% for PET− vs 52% PET+ [P=.012], OS 78% for PET− and 51% for PET+ [P=.0055]) but not for those who received consolidation radiation therapy (PFS 84% PET− vs 81% PET+ [P=.88]; OS 90% PET− vs 81% PET+ [P=.39]). Conclusion: Mid-therapy PET can predict patient outcome, but the use of consolidation radiation therapy may negate the significance of mid-therapy findings.

  6. The Use of the Immune Epitope Database to Study Autoimmune Epitope Data Related to Alopecia Areata.

    Science.gov (United States)

    Sette, Alessandro; Paul, Sinu; Vaughan, Kerrie; Peters, Bjoern

    2015-11-01

    The Immune Epitope Database (IEDB) is a repository of published epitope data for infectious diseases, allergy, transplantation and autoimmunity. Herein we provide an introduction to the IEDB search interface, focusing on data related to autoimmune diseases, including alopecia areata (AA). We demonstrate how common questions related can be answered, such as how to search for specific autoantigens, epitope sequences, response types (B- and/or T-cell assays), or host, as well as how to search for epitopes of known major histocompatibility complex restriction and for data related to a specific disease. Our survey of the data found that while as a whole Autoimmunity-specific records represent a significant portion (∼30%); epitopes reported for AA are remarkably few, just 23 epitopes from six antigens. This reveals a significant knowledge gap for AA, and suggests that additional mapping of epitopes and identification of novel AA-associated autoantigens is warranted. Citing recently published examples, we show how bioinformatic, proteomic, and technological advances make it now increasingly feasible to identify epitopes and novel antigens in human disease. The goal herein was to increase awareness of the IEDB as a free resource for the scientific community and to demonstrate its use in finding (existing) and analyzing (prediction) epitope data. PMID:26551944

  7. Epitope discovery with phylogenetic hidden Markov models.

    LENUS (Irish Health Repository)

    Lacerda, Miguel

    2010-05-01

    Existing methods for the prediction of immunologically active T-cell epitopes are based on the amino acid sequence or structure of pathogen proteins. Additional information regarding the locations of epitopes may be acquired by considering the evolution of viruses in hosts with different immune backgrounds. In particular, immune-dependent evolutionary patterns at sites within or near T-cell epitopes can be used to enhance epitope identification. We have developed a mutation-selection model of T-cell epitope evolution that allows the human leukocyte antigen (HLA) genotype of the host to influence the evolutionary process. This is one of the first examples of the incorporation of environmental parameters into a phylogenetic model and has many other potential applications where the selection pressures exerted on an organism can be related directly to environmental factors. We combine this novel evolutionary model with a hidden Markov model to identify contiguous amino acid positions that appear to evolve under immune pressure in the presence of specific host immune alleles and that therefore represent potential epitopes. This phylogenetic hidden Markov model provides a rigorous probabilistic framework that can be combined with sequence or structural information to improve epitope prediction. As a demonstration, we apply the model to a data set of HIV-1 protein-coding sequences and host HLA genotypes.

  8. Epitope-specific antibody levels in tuberculosis: biomarkers of protection, disease and response to treatment.

    Directory of Open Access Journals (Sweden)

    Graham H Bothamley

    2014-06-01

    Full Text Available Monoclonal antibodies restricted to Mycobacterium tuberculosis can measure epitope-specific antibody levels in a competition assay. Immunodominant epitopes were defined from clinical samples and related to the clinical spectrum of disease. Antibody to the immunodominant epitopes was associated with HLA-DR15. Occupational exposure showed a different response and was consistent with recognition of dormancy related proteins and protection despite exposure to tuberculosis. Studies in leprosy revealed the importance of immune deviation and the relationships between T and B cell epitopes. During treatment, antibody levels increased, epitope spreading occurred, but the affinity constants remained the same after further antigen exposure, suggesting constraints on the process of epitope selection. Epitope-specific antibody levels have a potential role as biomarkers for new vaccines which might prevent the progression of latent to active tuberculosis and as tools to measure treatment effects on subpopulations of tubercle bacilli.

  9. Treatment Success in Trypanosoma cruzi Infection Is Predicted by Early Changes in Serially Monitored Parasite-Specific T and B Cell Responses.

    Directory of Open Access Journals (Sweden)

    María G Alvarez

    2016-04-01

    Full Text Available Chagas disease is the highest impact parasitic disease in Latin America. We have proposed that changes in Trypanosoma cruzi-specific immune responses might serve as surrogate indicators of treatment success. Herein, we addressed in a long-term follow-up study whether cure achieved after treatment can be predicted by changes in non-conventional indexes of anti-parasite serological and T cell activities.T. cruzi-specific T cell responses, as measured by interferon-γ ELISPOT and T. cruzi-specific antibodies assessed by ELISA, hemagglutination and immunofluorescence tests as well as by a multiplex assay incorporating 14 recombinant T. cruzi proteins were measured in 33 patients at 48-150 months post-benznidazole treatment. Cure - as assessed by conventional serological tests - was associated with an early decline in T. cruzi-specific IFN-γ-producing T cells and in antibody titers measured by the multiplex serological assay. Changes in the functional status and potential of T. cruzi-specific T cells, indicative of reduced antigen stimulation, provided further evidence of parasitological cure following benznidazole treatment. Patients showing a significant reduction in T. cruzi-specific antibodies had higher pre-therapy levels of T. cruzi-specific IFN-γ- producing T cells compared to those with unaltered humoral responses post-treatment.Monitoring of appropriate immunological responses can provide earlier and robust measures of treatment success in T. cruzi infection.

  10. Treatment Success in Trypanosoma cruzi Infection Is Predicted by Early Changes in Serially Monitored Parasite-Specific T and B Cell Responses

    Science.gov (United States)

    Cooley, Gretchen; Albareda, María C.; Viotti, Rodolfo; Perez-Mazliah, Damián E.; Lococo, Bruno; Castro Eiro, Melisa; Laucella, Susana A.; Tarleton, Rick L.

    2016-01-01

    Background Chagas disease is the highest impact parasitic disease in Latin America. We have proposed that changes in Trypanosoma cruzi-specific immune responses might serve as surrogate indicators of treatment success. Herein, we addressed in a long-term follow-up study whether cure achieved after treatment can be predicted by changes in non-conventional indexes of anti-parasite serological and T cell activities. Methodology/Principal Findings T. cruzi-specific T cell responses, as measured by interferon-γ ELISPOT and T. cruzi-specific antibodies assessed by ELISA, hemagglutination and immunofluorescence tests as well as by a multiplex assay incorporating 14 recombinant T. cruzi proteins were measured in 33 patients at 48–150 months post-benznidazole treatment. Cure — as assessed by conventional serological tests — was associated with an early decline in T. cruzi-specific IFN-γ-producing T cells and in antibody titers measured by the multiplex serological assay. Changes in the functional status and potential of T. cruzi-specific T cells, indicative of reduced antigen stimulation, provided further evidence of parasitological cure following benznidazole treatment. Patients showing a significant reduction in T. cruzi-specific antibodies had higher pre-therapy levels of T. cruzi-specific IFN-γ- producing T cells compared to those with unaltered humoral responses post-treatment. Conclusions/Significance Monitoring of appropriate immunological responses can provide earlier and robust measures of treatment success in T. cruzi infection. PMID:27128444

  11. Some epitopes conservation in non structural 3 protein dengue virus serotype 4

    Directory of Open Access Journals (Sweden)

    Tegar A. P. Siregar

    2016-03-01

    Full Text Available AbstrakLatar belakang: Protein Non Struktural 3 (NS3 virus dengue menginduksi respon antibodi netralisasidan respon sel T CD4+ dan CD8+, serta berperan dalam replikasi virus. Protein NS3 memiliki epitopepitopsel T dan B yang terdapat perbedaan kelestarian pada berbagai strain virus dengue serotipe 4(DENV-4. Penelitian ini bertujuan untuk mengetahui kelestarian epitop sel T dan B pada protein NS3DENV-4 strain-strain dunia dan keempat serotipe virus dengue strain Indonesia.Metode: Penelitian ini dilakukan di Departemen Mikrobiologi Fakultas Kedokteran UI sejak Juni 2013 - April2014. Sekuens asam amino NS3 DENV-4 strain 081 didapatkan setelah produk PCR gen NS3 DENV-4 081disekuensing. Epitop-epitop sel T dan sel B protein NS3 DENV-4 081 dianalisis dan dibandingkan dengansekuens asam amino protein NS3 dari 124 strain DENV-4 di dunia dan keempat serotipe DENV strain Indonesia.Strain-strain dunia merupakan strain yang ada di benua Amerika (Venezuela, Colombia, dll dan Asia (Cina,Singapura, dll. Referensi posisi epitop sel T dan B protein NS3 diperoleh dari laporan penelitian terdahulu.Hasil: Delapan epitop sel T dan 2 epitop sel B dari protein NS3 DENV-4 081 ternyata identik dan lestaripada protein NS3 dari 124 strain DENV-4 dunia. Epitop sel B di posisi asam amino 537-544 pada proteinNS3 DENV-4 081 ternyata identik dan lestari dengan epitop sel B protein NS3 dari keempat serotipeDENV strain Indonesia.Kesimpulan: Kelestarian yang luas dari epitop sel T dan B pada hampir seluruh strain DENV-4 dunia danserotipe-serotipe DENV strain Indonesia. (Health Science Journal of Indonesia 2015;6:126-31Kata kunci: virus dengue, protein NS3, epitop sel T, epitop sel B AbstractBackground: Non Structural 3 (NS3 protein of dengue virus (DENV is known to induce antibody, CD4+and CD8+ T cell responses, and playing role in viral replication. NS3 protein has T and B cell epitopes,which has conservation difference between DENV-4 strains. This study aimed to identify

  12. In silico design of discontinuous peptides representative of B and T-cell epitopes from HER2-ECD as potential novel cancer peptide vaccines.

    Science.gov (United States)

    Manijeh, Mahdavi; Mehrnaz, Keyhanfar; Violaine, Moreau; Hassan, Mohabatkar; Abbas, Jafarian; Mohammad, Rabbani

    2013-01-01

    At present, the most common cause of cancer-related death in women is breast cancer. In a large proportion of breast cancers, there is the overexpression of human epidermal growth factor receptor 2 (HER2). This receptor is a 185 KDa growth factor glycoprotein, also known as the first tumor-associated antigen for different types of breast cancers. Moreover, HER2 is an appropriate cell-surface specific antigen for passive immunotherapy, which relies on the repeated application of monoclonal antibodies that are transferred to the patient. However, vaccination is preferable because it would stimulate a patient's own immune system to actively respond to a disease. In the current study, several bioinformatics tools were used for designing synthetic peptide vaccines. PEPOP was used to predict peptides from HER2 ECD subdomain III in the form of discontinuous-continuous B-cell epitopes. Then, T-cell epitope prediction web servers MHCPred, SYFPEITHI, HLA peptide motif search, Propred, and SVMHC were used to identify class-I and II MHC peptides. In this way, PEPOP selected 12 discontinuous peptides from the 3D structure of the HER2 ECD subdomain III. Furthermore, T-cell epitope prediction analyses identified four peptides containing the segments 77 (384-391) and 99 (495-503) for both B and T-cell epitopes. This work is the only study to our knowledge focusing on design of in silico potential novel cancer peptide vaccines of the HER2 ECD subdomain III that contain epitopes for both B and T-cells. These findings based on bioinformatics analyses may be used in vaccine design and cancer therapy; saving time and minimizing the number of tests needed to select the best possible epitopes.

  13. Immunogenicity of multiple antigen peptides containing Plasmodium vivax CS epitopes in BALB/c mice

    Directory of Open Access Journals (Sweden)

    Myriam A. Herrera

    1994-01-01

    Full Text Available Multiple antigen peptide systems (MAPs allow the incorporation of various epitopes in to a single synthetic peptide immunogen. We have characterized the immune response of BALB/c mice to a series of MAPs assembled with different B and T cell epitopes derived from the Plasmodium vivax circumsporozoite (CS protein. A B-cell epitope from the central repeat domain and two T-cell epitopes from the amino and carboxyl flanking regions were used to assembled eight different MAPs. An additional universal T cell epitope (ptt-30 from tetanus toxin protein was included. Immunogenicity in terms of antibody responses and in vitro T lymphocyte proliferation was evaluated. MAPs containing B and T cell epitopes induced high titers of anti-peptides antibodies, which recognized the native protein on sporozoites as determined by IFAT. The antibody specificity was also determined by a competitive inhibition assay with different MAPs. A MAP containing the B cell epitope (p11 and the universal epitope ptt-30 together with another composed of p11 and the promiscuous T cell epitope (p25 proved to be the most immunogenic. The strong antibody response and specificity for the cognate protein indicates that further studies designed to assess the potential of these proteins as human malaria vaccine candidates are warranted.

  14. Prevention and control of reciprocal T-B cell diversification: implications for lupus-like autoimmunity.

    Science.gov (United States)

    Singh, Ram Raj

    2004-02-01

    Autoimmunity is fundamentally a continuously evolving process. The autoimmune responses shift, drift and diversify with time not only to other epitopes in the original antigen but also to other related and sometimes to unrelated antigens. We have described a form of immune diversification--reciprocal T-B epitope spreading--where the activation of first T cells by epitopes from an autoantibody molecule could lead to help provided to a variety of B cells displaying a cross-reactive version of the original epitope. The response spreads in this way until large cohorts of T and B cells have expanded in lupus-prone mice. Such reciprocal T-B cell response can also be induced in normal animals, its extent is limited by the emergence of inhibitory T cells. The induction of such inhibitory T cells is generally impaired in lupus mice. The delivery of T cell epitopes via plasmid DNA vectors, however, can overcome this impairment in lupus mice. The inhibitory T cells thus induced can suppress autoantibody production and lupus disease by ablating or inhibiting autoreactive B cells. Thus, T-B diversification that develops spontaneously in lupus mice could be curtailed in normal animals by inhibitory T cells that emerge whenever there is an impending 'danger' of pathologic autoimmunity. We have successfully exploited this regulatory potential of the normal immune response to inhibit clinical autoimmunity. Understanding the mechanisms of autoimmune diversification in lupus mice and of its down-regulation in normal animals may pave the way for developing novel treatments for autoantibody-mediated diseases such as lupus.

  15. 人白细胞介素-38的特性分析及B细胞表位的预测%Characteristic Analysis of Human Interleukin-38 and Prediction of Its B-Cell Epitope

    Institute of Scientific and Technical Information of China (English)

    袁仙丽; 李明才; 李燕; 高雪明; 高巧艳

    2014-01-01

    目的:为进一步了解人白细胞介素(IL)-38蛋白质的特性和B细胞表位,从GenBank中查得其序列,用生物信息学等方法预测人IL-38蛋白质的二级结构等特性,并对其B细胞表位进行预测.方法:应用ProtParam tool、ProtScale、Emini和Kolas-kar等程序或方法,对IL-38的组成、理化特性、亲水性、柔韧性和可及性等进行分析,以进一步预测其二级结构和抗原表位.结果:IL-38的二级结构主要由无规则卷曲(44.08%)和β-折叠(39.47%)组成.其B细胞表位可能位于第26-36、45-55、78-98和124-143等氨基酸区段.结论:首次利用生物信息学方法对IL-38基因及其蛋白质结构进行了分析和预测,预测结果将有助于确定IL-38的B细胞表位,为IL-38基因功能的深入研究及研制IL-38单克隆抗体提供了理论依据.

  16. Conserved regions ofPlasmodium vivax potential vaccine candidate antigens in Sri Lanka:Consciousin silico analysis of prospective conformational epitope regions

    Institute of Scientific and Technical Information of China (English)

    Shanika Amarasinghe; Hashendra Kathriarachchi; Preethi Udagama

    2014-01-01

    Objective:To do mapping and modeling of conformationalB cell epitope regions of highly conserved and protective regions of three merozoitecandidate vaccine proteins ofPlasmodium vivax(P. vivax) ,ie. merozoite purface protein-1(PvMSP-1), apical membrane antigen -1 domainⅡ(PvAMA1-DⅡ) and regionⅡ of theDuffy binding protein(PvDBPⅡ), and to analyze the immunogenic properties of these predicted epitopes.Methods:3-D structures of amino acid haplotypes fromSriLanka(available inGeneBank) ofPvMSP-119(n=27),PvAMA1-DⅡ(n=21) andPvDBPⅡ(n=33) were modeled.SEPPA, selected as the best online server was used for conformational epitope predictions, while prediction and modeling of protein structure and properties related to immunogenicity was carried out withGeno3D server,SCRATCHProtein Server,NetSurfPServer and standalonesoftware,Genious5.4.4.Results:SEPPA revealed that regions of predicted conformational epitopes formed4 clusters inPvMSP-I19, and3 clusters each inPvAMA1-DⅡ andPvDBPⅡ, all of which displayed a high degree of hydrophilicity, contained solvent exposed residues, displayed high probability of antigenicity and showed positive antigenic propensity values, that indicated high degree of immunogenicity.Conclusions:Findings of this study revealed and confirmed that different parts of the sequences of each of the conserved regions of the three selected potential vaccine candidate antigens ofP. vivax are important with regard to conformational epitope prediction that warrants further laboratory experimental investigations in in vivo animal models.

  17. Design and evaluation of a multi-epitope assembly Peptide (MEAP against herpes simplex virus type 2 infection in BALB/c mice

    Directory of Open Access Journals (Sweden)

    Pan Mingjie

    2011-05-01

    Full Text Available Abstract Background Human herpes simplex virus (HSV 1 and 2 causes oral, ocular, or genital infections, which remains a significant health problem worldwide. HSV-1 and -2 infections in humans range from localized skin infections of the oral, ocular, and genital regions to severe and often disseminated infections in immunocompromised hosts. Epitope based vaccination is a promising mean to achieve protective immunity and to avoid infections with Human herpes simplex virus type 2 (HSV-2. Methods The twelve selected epitopes, six B cell epitopes from different glycoprotein of HSV-2 (amino acid residues 466-473 (EQDRKPRN from envelope glycoprotein B, 216-223 (GRTDRPSA from C, 6-18 (DPSLKMADPNRFR from D, 483-491 (DPPERPDSP from E, 572-579 (EPPDDDDS from G and 286-295 (CRRRYRRPRG from I glycoprotein of HSV-2, four CD4+ T cell epitopes (amino acid residues 21-28 (NLPVLDQL from D, 162-177 (KDVTVSQVWFGHRYSQ from B, 205-224 (KAYQQGVTVDSIGMLPRFIP from D and 245-259 (KPPYTSTLLPPELSD from D and two CD8+ T cell epitopes (amino acid residues 10-20 (KMADPNRFRGK from D and 268-276 (ALLEDPAGT from D, are responsible for the elicitation of the neutralizing antibodies and cytotoxic T lymphocytes (CTLs that impart protective immunity to the host. In this study, all above epitopes were inserted into the extracellular fragment (amino acid residues 1-290 of HSV-2 glycoprotein D to construct multi-epitope assembly peptides (MEAPs by replacing some non-epitope amino acid sequences. The epitope independency of the MEAPs was predicted by three-dimensional software algorithms. The gene of the selected MEAP was expressed in E.coli BL21(DE3, and its protective efficacy against HSV-2 infection was assessed in BALB/c mice. Results The MEAP, with each inserted epitopes independently displayed on the molecule surface, was selected as candidate proteins. The results showed that the MEAP was highly immunogenic and could elicit high titer neutralizing antibodies and cell

  18. Antigen epitope of Helicobacter pylorivacuolating cytotoxin A

    Institute of Scientific and Technical Information of China (English)

    Xiu-Li Liu; Shu-Qin Li; Chun-Jie Liu; Hao-Xia Tao; Zhao-Shan Zhang

    2004-01-01

    AIM: To construct and select antigen epitopes of vacuolating cytotoxin A (VacA) for nontoxic VacA vaccine against Helicobacter pylori (H pylori) infection.METHODS: Eleven VacA epitopes were predicted according to VacA antigenic bioinformatics. Three candidates of VacA epitope were constructed through different combined epitopes. The candidate was linked with E. coli heat-labile enterotoxin B (LTB) by a linker of 7 amino acids, and cloned into plasmid pQE-60 in which fusion LTB-VacA epitope was efficiently expressed. To test the antigencity of the candidate, 6 BALB/c mice were treated with the fusion LTB-VacA epitope through intraperitoneal injection. To explore the ability of inhibiting the toxicity of VacA, cantiserum against the candidate was used to counteract VacA that induced HeLa cells to produce cell vacuoles in vitro.RESULTS: Serum IgG against the candidate was induced in the BALB/c mice. In vitro, the three antisera against the candidate efficiently counteracted the toxicity of VacA, and decreased the number of cell vacuoles by 14.17%, 20.20%and 30.41% respectively.CONCLUSION: Two of the three candidates, LZ-VacA1and LZ-VacA2, can be used to further study the mechanism of vacuolating toxicity of VacA, and to construct nontoxic VacA vaccine against H pylori infection.

  19. Thyrotropin Receptor Epitope and Human Leukocyte Antigen in Graves' Disease.

    Science.gov (United States)

    Inaba, Hidefumi; De Groot, Leslie J; Akamizu, Takashi

    2016-01-01

    Graves' disease (GD) is an organ-specific autoimmune disease, and thyrotropin (TSH) receptor (TSHR) is a major autoantigen in this condition. Since the extracellular domain of human TSHR (TSHR-ECD) is shed into the circulation, TSHR-ECD is a preferentially immunogenic portion of TSHR. Both genetic factors and environmental factors contribute to development of GD. Inheritance of human leukocyte antigen (HLA) genes, especially HLA-DR3, is associated with GD. TSHR-ECD protein is endocytosed into antigen-presenting cells (APCs), and processed to TSHR-ECD peptides. These peptide epitopes bind to HLA-class II molecules, and subsequently the complex of HLA-class II and TSHR-ECD epitope is presented to CD4+ T cells. The activated CD4+ T cells secrete cytokines/chemokines that stimulate B-cells to produce TSAb, and in turn hyperthyroidism occurs. Numerous studies have been done to identify T- and B-cell epitopes in TSHR-ECD, including (1) in silico, (2) in vitro, (3) in vivo, and (4) clinical experiments. Murine models of GD and HLA-transgenic mice have played a pivotal role in elucidating the immunological mechanisms. To date, linear or conformational epitopes of TSHR-ECD, as well as the molecular structure of the epitope-binding groove in HLA-DR, were reported to be related to the pathogenesis in GD. Dysfunction of central tolerance in the thymus, or in peripheral tolerance, such as regulatory T cells, could allow development of GD. Novel treatments using TSHR antagonists or mutated TSHR peptides have been reported to be effective. We review and update the role of immunogenic TSHR epitopes and HLA in GD, and offer perspectives on TSHR epitope specific treatments. PMID:27602020

  20. Immune epitope database analysis resource (IEDB-AR)

    DEFF Research Database (Denmark)

    Zhang, Qing; Wang, Peng; Kim, Yohan;

    2008-01-01

    We present a new release of the immune epitope database analysis resource (IEDB-AR, http://tools.immuneepitope.org), a repository of web-based tools for the prediction and analysis of immune epitopes. New functionalities have been added to most of the previously implemented tools, and a total...

  1. Repeated epitope in the recombinant epitope-peptide could enhance ELDKWA-epitope-specific antibody response

    Institute of Scientific and Technical Information of China (English)

    LIU Zuqiang; WANG Zuguang; CHEN Yinghua

    2005-01-01

    Based on the hypothesis suggested by us that epitope-vaccine may be a new strategy against HIV mutation, we have studied several neutralizing epitopes on HIV envelope proteins. However we do not know whether a repeated epitope in a recombinant epitope-peptide can enhance epitope-specific antibody response or not. ELDKWA-epitope (aa669-674) on the C-domain of HIV-1 gp41 is a neutralizing epitope defined by the monoclonal antibody (mAb) 2F5 with broad neutralizing activity. In this study, we designed and prepared a series of the recombinant epitope-peptides bearing 1, 4 and 8 copies of ELDKWA-epitope respectively. In the comparison of the antisera induced by the three recombinant antigens, an obviously increased titre of ELDKWA-epitope-specific antibody was observed in the case of four and eight repeated epitopes. In flow cytometry analysis, the epitope-specific antibodies in both antisera showed stronger activity to bind the transfected CHO-WT cells that stably express HIV-1 envelope glycoprotein on the cell surfaces. These experimental results indicated that repeated epitope in the recombinant epitope-peptide could enhance ELDKWA-epitope-specific antibody response, which could contribute to designing an effective recombinant epitope-vaccine.

  2. Lassa Fever Virus Peptides Predicted by Computational Analysis Induce Epitope-Specific Cytotoxic-T-Lymphocyte Responses in HLA-A2.1 Transgenic Mice

    OpenAIRE

    Boesen, Agnieszka; Sundar, Krishnan; Coico, Richard

    2005-01-01

    Lassa fever is a hemorrhagic disease caused by Lassa fever virus (LV). Although the precise host defense mechanism(s) that affords protection against LV is not completely understood, cellular immunity mediated by cytotoxic T lymphocytes (CTLs) plays a pivotal role in controlling viral replication and LV infection. To date, there have been no reports mapping major histocompatibility complex (MHC) class I-binding CTL epitopes for LV. Using computer-assisted algorithms, we identified five HLA-A2...

  3. Human Antibodies that Recognize Novel Immunodominant Quaternary Epitopes on the HIV-1 Env Protein.

    Directory of Open Access Journals (Sweden)

    Mark D Hicar

    Full Text Available Numerous broadly neutralizing antibodies (Abs target epitopes that are formed or enhanced during mature HIV envelope formation (i.e. quaternary epitopes. Generally, it is thought that Env epitopes that induce broadly neutralizing Abs are difficult to access and poorly immunogenic because of the characteristic oligomerization, conformational flexibility, sequence diversity and extensive glycosylation of Env protein. To enhance for isolation of quaternary epitope-targeting Abs (QtAbs, we previously used HIV virus-like particles (VLPs to bind B cells from long-term non-progressor subjects to identify a panel of monoclonal Abs. When expressed as recombinant full-length Abs, a subset of these novel Abs exhibited the binding profiles of QtAbs, as they either failed to bind to monomeric Env protein or showed much higher affinity for Env trimers and VLPs. These QtAbs represented a significant proportion of the B-cell response identified with VLPs. The Ab genes of these clones were highly mutated, but they did not neutralize common HIV strains. We sought to further define the epitopes targeted by these QtAbs. Competition-binding and mapping studies revealed these Abs targeted four separate epitopes; they also failed to compete for binding by Abs to known major neutralizing epitopes. Detailed epitope mapping studies revealed that two of the four epitopes were located in the gp41 subunit of Env. These QtAbs bound pre-fusion forms of antigen and showed differential binding kinetics depending on whether oligomers were produced as recombinant gp140 trimers or as full-length Env incorporated into VLPs. Antigenic regions within gp41 present unexpectedly diverse structural epitopes, including these QtAb epitopes, which may be targeted by the naturally occurring Ab response to HIV infection.

  4. Human Antibodies that Recognize Novel Immunodominant Quaternary Epitopes on the HIV-1 Env Protein.

    Science.gov (United States)

    Hicar, Mark D; Chen, Xuemin; Sulli, Chidananda; Barnes, Trevor; Goodman, Jason; Sojar, Hakimuddin; Briney, Bryan; Willis, Jordan; Chukwuma, Valentine U; Kalams, Spyros A; Doranz, Benjamin J; Spearman, Paul; Crowe, James E

    2016-01-01

    Numerous broadly neutralizing antibodies (Abs) target epitopes that are formed or enhanced during mature HIV envelope formation (i.e. quaternary epitopes). Generally, it is thought that Env epitopes that induce broadly neutralizing Abs are difficult to access and poorly immunogenic because of the characteristic oligomerization, conformational flexibility, sequence diversity and extensive glycosylation of Env protein. To enhance for isolation of quaternary epitope-targeting Abs (QtAbs), we previously used HIV virus-like particles (VLPs) to bind B cells from long-term non-progressor subjects to identify a panel of monoclonal Abs. When expressed as recombinant full-length Abs, a subset of these novel Abs exhibited the binding profiles of QtAbs, as they either failed to bind to monomeric Env protein or showed much higher affinity for Env trimers and VLPs. These QtAbs represented a significant proportion of the B-cell response identified with VLPs. The Ab genes of these clones were highly mutated, but they did not neutralize common HIV strains. We sought to further define the epitopes targeted by these QtAbs. Competition-binding and mapping studies revealed these Abs targeted four separate epitopes; they also failed to compete for binding by Abs to known major neutralizing epitopes. Detailed epitope mapping studies revealed that two of the four epitopes were located in the gp41 subunit of Env. These QtAbs bound pre-fusion forms of antigen and showed differential binding kinetics depending on whether oligomers were produced as recombinant gp140 trimers or as full-length Env incorporated into VLPs. Antigenic regions within gp41 present unexpectedly diverse structural epitopes, including these QtAb epitopes, which may be targeted by the naturally occurring Ab response to HIV infection. PMID:27411063

  5. Multiple Curricula for B Cell Developmental Programming.

    Science.gov (United States)

    Rothenberg, Ellen V

    2016-09-20

    B-1 B cells differ from conventional B-2 B cells functionally, but how these differences relate to the ontogeny of these lineages has been unclear. Two recent Immunity articles, Kristiansen et al. (2016) and Montecino-Rodriguez et al. (2016), now provide insight into the origins of B-1 and B-2 B cells, revealing a multi-layered developmental program and successive waves of B cell precursors.

  6. New helping friends for B cells.

    OpenAIRE

    Cerutti, Andrea; Puga, Irene; Cols, Montserrat

    2012-01-01

    Over the past decade, a growing recognition of the importance of neutralizing antibodies in host defense combined with the success of B-cell depletion therapies in treating autoimmune disorders has led to an increased focus on better understanding the pathways underpinning B-cell antibody production. In general, B cells require cognate interaction with T helper cells in the germinal center of lymphoid follicles to generate protective antibodies. However, recent evidence shows that B cells rec...

  7. Multiple Curricula for B Cell Developmental Programming.

    Science.gov (United States)

    Rothenberg, Ellen V

    2016-09-20

    B-1 B cells differ from conventional B-2 B cells functionally, but how these differences relate to the ontogeny of these lineages has been unclear. Two recent Immunity articles, Kristiansen et al. (2016) and Montecino-Rodriguez et al. (2016), now provide insight into the origins of B-1 and B-2 B cells, revealing a multi-layered developmental program and successive waves of B cell precursors. PMID:27653594

  8. Experimental validation of multi-epitope peptides including promising MHC class I- and class II-restricted epitopes of four known Leishmania infantum proteins

    Directory of Open Access Journals (Sweden)

    Maria eAgallou

    2014-06-01

    Full Text Available Leishmaniasis is a significant worldwide health problem for which no vaccine exists. Activation of CD4+ and CD8+ T cells is crucial for the generation of protective immunity against parasite. Recent trend in vaccine design has been shifted to epitope-based vaccines that are more specific, safe, and easy to produce. In the present study, four known antigenic Leishmania (L. infantum proteins, CPA, histone H1, KMP-11 and LeIF were analysed for the prediction of binding epitopes to H2d MHC class I and class II molecules, using online available algorithms. Based on in silico analysis, eight peptides including highly scored MHC class I- and class II-restricted epitopes were synthesized. Peptide immunogenicity was validated in MHC compatible BALB/c mice immunized with each synthetic peptide emulsified in CFA/IFA. CPA_p2, CPA_p3, H1_p1 and LeIF_p6 induced strong spleen cell proliferation upon in vitro peptide re-stimulation. In addition, the majority of the peptides, except of LeIF_p1 and KMP-11_p1, induced IFN-γ secretion, while KMP-11_p1 indicated a suppressive effect on IL-10 production. CPA_p2, CPA_p3, LeIF_p3 and LeIF_p6 induced IFN-γ-producing CD4+ T cells indicating a TH1 type response. In addition, CPA_p2, CPA_p3 and H1_p1 induced also the induction of CD8+ T cells. The induction of peptide-specific IgG in immunized mice designated also the existence of B cell epitopes in peptide sequences. Combining immunoinformatic tools and experimental validation, we demonstrated that CPA_p2, CPA_p3, H1_p1, H1_p3, CPA_p2, LeIF_p3 and LeIF_p6 are likely to include potential epitopes for the induction of protective cytotoxic and/or TH1-type immune responses supporting the feasibility of peptide-based vaccine development for leishmaniasis.

  9. B Cell Autonomous TLR Signaling and Autoimmunity

    Science.gov (United States)

    Meyer-Bahlburg, Almut; Rawlings, David J

    2009-01-01

    B cells play a central role in the pathogenesis of multiple autoimmune diseases and the recognition of importance of B cells in these disorders has grown dramatically in association with the remarkable success of B-cell depletion as a treatment for autoimmunity. The precise mechanisms that promote alterations in B cell tolerance remain incompletely defined. There is increasing evidence, however, that TLRs play a major role in these events. Stimulation of B cells via the TLR pathway not only leads to an increase in antibody production but also promotes additional changes including cytokine production and upregulation of activation markers increasing the effectiveness of B cells as APCs. Understanding the role of TLRs in systemic autoimmunity will not only provide insight into the disease pathogenesis but may also lead to the development of novel therapies. This article gives an overview of TLR signaling in B cells and the possible involvement of such signals in autoimmune diseases. PMID:18295736

  10. HCV Infection and B-Cell Lymphomagenesis

    Directory of Open Access Journals (Sweden)

    Masahiko Ito

    2011-01-01

    Full Text Available Hepatitis C virus (HCV has been recognized as a major cause of chronic liver diseases worldwide. It has been suggested that HCV infects not only hepatocytes but also mononuclear lymphocytes including B cells that express the CD81 molecule, a putative HCV receptor. HCV infection of B cells is the likely cause of B-cell dysregulation disorders such as mixed cryoglobulinemia, rheumatoid factor production, and B-cell lymphoproliferative disorders that may evolve into non-Hodgkin's lymphoma (NHL. Epidemiological data indicate an association between HCV chronic infection and the occurrence of B-cell NHL, suggesting that chronic HCV infection is associated at least in part with B-cell lymphomagenesis. In this paper, we aim to provide an overview of recent literature, including our own, to elucidate a possible role of HCV chronic infection in B-cell lymphomagenesis.

  11. Applying generalized hydrophobicity scale of amino acids to quantitative prediction of human leukocyte antigen-A*0201-restricted cytotoxic T lymphocyte epitope

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peng; TIAN Feifei; ZHANG Mengjun; LI Zhiliang

    2006-01-01

    Derived from 149 hydrophobic factors of 20 natural amino acids, a novel amino acid descriptor termed as generalized hydrophobicity scale (GH-scale) was proposed by principal component analysis (PCA). Via genetic algorithm-partial least square (GPLS) method, quantitative structure-activity relationship (QSAR) model was constructed by GH-scale for 152 human leukocyte antigen (HLA)-A*0201-restricted cytotoxic T lymphocyte (CTL) epitopes with the model estimated and cross-validated correlative coefficients of R2 = 0.813 and Q2 = 0.725, respectively. It was indicated that hydrophobic interaction played an important role in HLA-A*0201-CTL interaction, prominently at anchor residues.

  12. P. falciparum and P. vivax Epitope-Focused VLPs Elicit Sterile Immunity to Blood Stage Infections.

    Directory of Open Access Journals (Sweden)

    David C Whitacre

    Full Text Available In order to design P. falciparum preerythrocytic vaccine candidates, a library of circumsporozoite (CS T and B cell epitopes displayed on the woodchuck hepatitis virus core antigen (WHcAg VLP platform was produced. To test the protective efficacy of the WHcAg-CS VLPs, hybrid CS P. berghei/P. falciparum (Pb/Pf sporozoites were used to challenge immunized mice. VLPs carrying 1 or 2 different CS repeat B cell epitopes and 3 VLPs carrying different CS non-repeat B cell epitopes elicited high levels of anti-insert antibodies (Abs. Whereas, VLPs carrying CS repeat B cell epitopes conferred 98% protection of the liver against a 10,000 Pb/Pf sporozoite challenge, VLPs carrying the CS non-repeat B cell eptiopes were minimally-to-non-protective. One-to-three CS-specific CD4/CD8 T cell sites were also fused to VLPs, which primed CS-specific as well as WHcAg-specific T cells. However, a VLP carrying only the 3 T cell domains failed to protect against a sporozoite challenge, indicating a requirement for anti-CS repeat Abs. A VLP carrying 2 CS repeat B cell epitopes and 3 CS T cell sites in alum adjuvant elicited high titer anti-CS Abs (endpoint dilution titer >1x10(6 and provided 80-100% protection against blood stage malaria. Using a similar strategy, VLPs were constructed carrying P. vivax CS repeat B cell epitopes (WHc-Pv-78, which elicited high levels of anti-CS Abs and conferred 99% protection of the liver against a 10,000 Pb/Pv sporozoite challenge and elicited sterile immunity to blood stage infection. These results indicate that immunization with epitope-focused VLPs carrying selected B and T cell epitopes from the P. falciparum and P. vivax CS proteins can elicit sterile immunity against blood stage malaria. Hybrid WHcAg-CS VLPs could provide the basis for a bivalent P. falciparum/P. vivax malaria vaccine.

  13. Virus-Like Display of a Neo-Self Antigen Reverses B Cell Anergy in a B Cell Receptor Transgenic Mouse Model1

    Science.gov (United States)

    Chackerian, Bryce; Durfee, Marisa R.; Schiller, John T.

    2012-01-01

    The ability to distinguish between self and foreign Ags is a central feature of immune recognition. For B cells, however, immune tolerance is not absolute, and factors that include Ag valency, the availability of T help, and polyclonal B cell stimuli can influence the induction of autoantibody responses. Here, we evaluated whether multivalent virus-like particle (VLP)-based immunogens could induce autoantibody responses in well-characterized transgenic (Tg) mice that express a soluble form of hen egg lysozyme (HEL) and in which B cell tolerance to HEL is maintained by anergy. Immunization with multivalent VLP-arrayed HEL, but not a trivalent form of HEL, induced high-titer Ab responses against HEL in both soluble HEL Tg mice and double Tg mice that also express a monoclonal HEL-specific BCR. Induction of autoantibodies against HEL was not dependent on coadministration of strong adjuvants, such as CFA. In contrast to previous data showing the T-independent induction of Abs to foreign epitopes on VLPs, the ability of HEL-conjugated VLPs to induce anti-HEL Abs in tolerant mice was dependent on the presence of CD4+ Th cells, and could be enhanced by the presence of pre-existing cognate T cells. In in vitro studies, VLP-conjugated HEL was more potent than trivalent HEL in up-regulating surface activation markers on purified anergic B cells. Moreover, immunization with VLP-HEL reversed B cell anergy in vivo in an adoptive transfer model. Thus, Ag multivalency and T help cooperate to reverse B cell anergy, a major mechanism of B cell tolerance. PMID:18424700

  14. High epitope expression levels increase competition between T cells.

    Directory of Open Access Journals (Sweden)

    Almut Scherer

    2006-08-01

    Full Text Available Both theoretical predictions and experimental findings suggest that T cell populations can compete with each other. There is some debate on whether T cells compete for aspecific stimuli, such as access to the surface on antigen-presenting cells (APCs or for specific stimuli, such as their cognate epitope ligand. We have developed an individual-based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell competition is mainly for specific or aspecific stimuli. Under low epitope expression, competition is mainly for the specific epitope stimuli, and, hence, different epitope-specific T cell populations coexist readily. However, if epitope expression levels are high, aspecific competition becomes more important. Such between-specificity competition can lead to competitive exclusion between different epitope-specific T cell populations. Our model allows us to delineate the circumstances that facilitate coexistence of T cells of different epitope specificity. Understanding mechanisms of T cell coexistence has important practical implications for immune therapies that require a broad immune response.

  15. Generation of cytotoxic T lymphocytes specific for B-cell acute lymphoblastic leukemia family-shared peptides derived from immunoglobulin heavy chain framework region

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; ZHU Ping; HU Ya-mei

    2007-01-01

    Background Immunoglobulin heavy chain variable region (IgHV) is a well-characterized tumor antigen for B-cell malignancies. It can function as a target for T cell-mediated immune response. Clinical trials of IgHV protein vaccines against lymphoma have demonstrated induction of tumor-specific cytotoxic T lymphocyte (CTL) responses. However,complementary determining regions-based individual vaccines have disadvantages for wide clinical application. Although a recent study demonstrated that immunogenic peptides are derived from framework regions (FR) shared among patients with B-cell lymphoma, how to choose the appropriate peptides for each patient is still unsolved. The aim of this study was to investigate whether immunoglobulin heavy chain FR-derived peptides shared in each IgHV family are potential CTL epitopes presented by B-cell acute lymphoblastic leukemia (B-ALL). Such CTL epitopes might be beneficial to shifting vaccination strategies against B-ALL from individual specificity to family specificity.Methods Seven IgHV gene families were amplified respectively by PCR and sequenced directly from 71 childhood B-ALL cases. Bioinformatics was applied in analyzing characteristics of sequences available and predicting HLA-A*0201-restricted CTL epitopes for each IgHV family. An antigen-specific T cell expansion system was used to generate peptide-specific CTLs. The cytotoxicity of CTLs against B-ALL cells was assessed in the lactate dehydrogenase release assay.Results Complete IgHV rearrangements were identified in all of the 71 B-ALL cases. All of 40 sequences available showed ≥98% homology with the nearest germline IgHV genes, indicating IgHV genes in B-ALL of germline nature.Twelve nonapeptides of high HLA-A*0201-binding scores were obtained from 26 productive IgHV protein sequences. Ten (83%) of the peptides were located in FR1 and FR3 shared among the corresponding IgHV family. CTLs specific for the peptide QLVQSGAEV located in FR1 (3-11) shared among the IgHV1

  16. Innate B cells: oxymoron or validated concept?

    OpenAIRE

    Ware, Carl F.; Chris Benedict

    2012-01-01

    B lymphocytes promote the initial innate interferon response to viral pathogens without the need for antigen receptor activation. B cell dependent IFN production requires the cytokine, lymphotoxin-β. The LTβ pathway is well known to regulate lymphoid organogenesis and homeostasis by differentiating stromal cells and macrophages. However, in response to viral pathogens these same B cell-regulated populations rapidly produce type 1 interferons. Thus, B cells act as innate effector cells via LTβ...

  17. Tumour targeting and radiation dose of radioimmunotherapy with {sup 90}Y-rituximab in CD20+ B-cell lymphoma as predicted by {sup 89}Zr-rituximab immuno-PET: impact of preloading with unlabelled rituximab

    Energy Technology Data Exchange (ETDEWEB)

    Muylle, Kristoff [Vrije Universiteit Brussel, MIMA Research Group, Brussels (Belgium); Universite Libre de Bruxelles, Department of Nuclear Medicine, Jules Bordet Institute, Brussels (Belgium); Flamen, Patrick; Guiot, Thomas; Ghanem, Ghanem; Meuleman, Nathalie; Bourgeois, Pierre; Vanderlinden, Bruno; Vaes, Melanie; Bron, Dominique [Universite Libre de Bruxelles, Jules Bordet Institute, Brussels (Belgium); Vugts, Danielle J.; Dongen, Guus A.M.S. van [VU University Medical Centre, Amsterdam (Netherlands); Everaert, Hendrik [Vrije Universiteit Brussel, UZ Brussel, Brussels (Belgium); Vrije Universiteit Brussel, MIMA Research Group, Brussels (Belgium)

    2015-07-15

    To compare using immuno-PET/CT the distribution of {sup 89}Zr-labelled rituximab without and with a preload of unlabelled rituximab to assess the impact of preloading with unlabelled rituximab on tumour targeting and radiation dose of subsequent radioimmunotherapy with {sup 90}Y-labelled rituximab in CD20+ B-cell lymphoma. Five patients with CD20+ B-cell lymphoma and progressive disease were prospectively enrolled. All patients underwent three study phases: initial dosimetric phase with baseline {sup 89}Zr-rituximab PET/CT imaging without a cold preload, followed 3 weeks later by a second dosimetric phase with administration of a standard preload (250 mg/m{sup 2}) of unlabelled rituximab followed by injection of {sup 89}Zr-rituximab, and a therapeutic phase 1 week later with administration of unlabelled rituximab followed by {sup 90}Y-rituximab. PET/CT imaging and tracer uptake by organs and lesions were assessed. With a cold rituximab preload, the calculated whole-body dose of {sup 90}Y-rituximab was similar (mean 0.87 mSv/MBq, range 0.82-0.99 mSv/MBq) in all patients. Without a preload, an increase in whole-body dose of 59 % and 87 % was noted in two patients with preserved circulating CD20+ B cells. This increase in radiation dose was primarily due to a 12.4-fold to 15-fold higher dose to the spleen without a preload. No significant change in whole-body dose was noted in the three other patients with B-cell depletion. Without a preload, consistently higher tumour uptake was noticed in patients with B-cell depletion. Administration of the standard preload of unlabelled rituximab impairs radioconjugate tumour targeting in the majority of patients eligible for radioimmunotherapy, that is patients previously treated with rituximab-containing therapeutic regimens. This common practice may need to be reconsidered and further evaluated as the rationale for this high preload has its origin in the ''prerituximab era''. (orig.)

  18. Lassa fever virus peptides predicted by computational analysis induce epitope-specific cytotoxic-T-lymphocyte responses in HLA-A2.1 transgenic mice.

    Science.gov (United States)

    Boesen, Agnieszka; Sundar, Krishnan; Coico, Richard

    2005-10-01

    Lassa fever is a hemorrhagic disease caused by Lassa fever virus (LV). Although the precise host defense mechanism(s) that affords protection against LV is not completely understood, cellular immunity mediated by cytotoxic T lymphocytes (CTLs) plays a pivotal role in controlling viral replication and LV infection. To date, there have been no reports mapping major histocompatibility complex (MHC) class I-binding CTL epitopes for LV. Using computer-assisted algorithms, we identified five HLA-A2.1-binding peptides of LV glycoprotein (GP) and two peptides from LV nucleoprotein (NP). Synthesized peptides were examined for their ability to bind to MHC class I molecules using a flow cytometric assay that measures peptide stabilization of class I. Three of the LV-GP peptides tested (LLGTFTWTL, SLYKGVYEL, and YLISIFLHL) stabilized HLA-A2. The LV-NP peptides tested failed to stabilize this HLA-A2. We then investigated the ability of the HLA-A2-binding LV-GP peptides to generate peptide-specific CTLs in HLA-A2.1 transgenic mice. Functional assays used to confirm CTL activation included gamma interferon enzyme-linked immunospot (ELISPOT) assays and intracellular cytokine staining of CD8+ T cells from peptide-primed mice. CTL assays were also performed to verify the cytolytic activity of peptide-pulsed target cells. Each of the LV-GP peptides induced CTL responses in HLA-A2-transgenic mice. MHC class I tetramers prepared using one LV-GP peptide that showed the highest cytolytic index (LLGTFTWTL) confirmed that peptide-binding CD8+ T cells were present in pooled lymphocytes harvested from peptide-primed mice. These findings provide direct evidence for the existence of LV-derived GP epitopes that may be useful in the development of protective immunogens for this hemorrhagic virus. PMID:16210487

  19. Lassa Fever Virus Peptides Predicted by Computational Analysis Induce Epitope-Specific Cytotoxic-T-Lymphocyte Responses in HLA-A2.1 Transgenic Mice

    Science.gov (United States)

    Boesen, Agnieszka; Sundar, Krishnan; Coico, Richard

    2005-01-01

    Lassa fever is a hemorrhagic disease caused by Lassa fever virus (LV). Although the precise host defense mechanism(s) that affords protection against LV is not completely understood, cellular immunity mediated by cytotoxic T lymphocytes (CTLs) plays a pivotal role in controlling viral replication and LV infection. To date, there have been no reports mapping major histocompatibility complex (MHC) class I-binding CTL epitopes for LV. Using computer-assisted algorithms, we identified five HLA-A2.1-binding peptides of LV glycoprotein (GP) and two peptides from LV nucleoprotein (NP). Synthesized peptides were examined for their ability to bind to MHC class I molecules using a flow cytometric assay that measures peptide stabilization of class I. Three of the LV-GP peptides tested (LLGTFTWTL, SLYKGVYEL, and YLISIFLHL) stabilized HLA-A2. The LV-NP peptides tested failed to stabilize this HLA-A2. We then investigated the ability of the HLA-A2-binding LV-GP peptides to generate peptide-specific CTLs in HLA-A2.1 transgenic mice. Functional assays used to confirm CTL activation included gamma interferon enzyme-linked immunospot (ELISPOT) assays and intracellular cytokine staining of CD8+ T cells from peptide-primed mice. CTL assays were also performed to verify the cytolytic activity of peptide-pulsed target cells. Each of the LV-GP peptides induced CTL responses in HLA-A2-transgenic mice. MHC class I tetramers prepared using one LV-GP peptide that showed the highest cytolytic index (LLGTFTWTL) confirmed that peptide-binding CD8+ T cells were present in pooled lymphocytes harvested from peptide-primed mice. These findings provide direct evidence for the existence of LV-derived GP epitopes that may be useful in the development of protective immunogens for this hemorrhagic virus. PMID:16210487

  20. B-Cell Hematologic Malignancy Vaccination Registry

    Science.gov (United States)

    2015-09-15

    Monoclonal Gammopathy of Undetermined Significance; Multiple Myeloma; Waldenstrom Macroglobulinemia; Lymphocytosis; Lymphoma, Non-Hodgkin; B-Cell Chronic Lymphocytic Leukemia; Hematological Malignancies

  1. Tolerogenicity of resting and activated B cells

    OpenAIRE

    1994-01-01

    Antigen presentation by resting splenic B cells has been shown previously to induce T helper 1 cell (Th1) anergy. In contrast to expectations, it was found here that B cells treated with F(ab')2 goat anti-mouse immunoglobulin (IgM) for 24 or 48 h also presented antigen (Ag) to Th1 cells in a manner that induced dramatic Ag-specific proliferative inactivation. The tolerogenicity of the anti-Ig-treated B cells was consistent with the observation that these B cells were only slightly more effici...

  2. Comprehensive Mapping Antigenic Epitopes of NS1 Protein of Japanese Encephalitis Virus with Monoclonal Antibodies.

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    Rong-Hong Hua

    Full Text Available Japanese encephalitis virus (JEV non-structural protein 1 (NS1 contributes to virus replication and elicits protective immune responses during infection. JEV NS1-specific antibody responses could be a target in the differential diagnosis of different flavivirus infections. However, the epitopes on JEV NS1 are poorly characterized. The present study describes the full mapping of linear B-cell epitopes in JEV NS1. We generated eleven NS1-specific monoclonal antibodies from mice immunized with recombinant NS1. For epitope mapping of monoclonal antibodies, a set of 51 partially-overlapping peptides covering the entire NS1 protein were expressed with a GST-tag and then screened using monoclonal antibodies. Through enzyme-linked immunosorbent assay (ELISA, five linear epitope-containing peptides were identified. By sequentially removing amino acid residues from the carboxy and amino terminal of peptides, the minimal units of the five linear epitopes were identified and confirmed using monoclonal antibodies. Five linear epitopes are located in amino acids residues (5AIDITRK(11, (72RDELNVL(78, (251KSKHNRREGY(260, (269DENGIVLD(276, and (341DETTLVRS(348. Furthermore, it was found that the epitopes are highly conserved among JEV strains through sequence alignment. Notably, none of the homologous regions on NS1 proteins from other flaviviruses reacted with the MAbs when they were tested for cross-reactivity, and all five epitope peptides were not recognized by sera against West Nile virus or Dengue virus. These novel virus-specific linear B-cell epitopes of JEV NS1 would benefit the development of new vaccines and diagnostic assays.

  3. In silico-accelerated identification of conserved and immunogenic variola/vaccinia T-cell epitopes

    DEFF Research Database (Denmark)

    Moise, Leonard; McMurry, Julie A; Buus, Søren;

    2009-01-01

    Epitopes shared by the vaccinia and variola viruses underlie the protective effect of vaccinia immunization against variola infection. We set out to identify a subset of cross-reactive epitopes using bioinformatics and immunological methods. Putative T-cell epitopes were computationally predicted....... This experimental validation of computational predictions illustrates the potential for immunoinformatics methods to identify candidate immunogens for a new, safer smallpox vaccine....

  4. Identification of new HLA-A*0201-restricted cytotoxic T lymphocyte epitopes from neuritin

    OpenAIRE

    Yang , Zhao; Zhao, Tianzhi; Liu, Yong; Gong, Zili; Cheng, Saiyu; Yang, Qingwu

    2013-01-01

    Identification of cytotoxic T lymphocyte (CTL) epitopes from additional tumor antigens is essential for the development of specific immunotherapy of malignant tumors. Neuritin, a recently discovered antigen overexpressed in astrocytoma, is considered to be a promising target for biological therapy. In the present study, we predicted and identified HLA-A2-restricted CTL epitopes from neuritin by using the following four-step procedure: (1) computer-based epitope prediction from the amino acid ...

  5. Signaling Proteins and Transcription Factors in Normal and Malignant Early B Cell Development

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    Patricia Pérez-Vera

    2011-01-01

    Full Text Available B cell development starts in bone marrow with the commitment of hematopoietic progenitors to the B cell lineage. In murine models, the IL-7 and preBCR receptors, and the signaling pathways and transcription factors that they regulate, control commitment and maintenance along the B cell pathway. E2A, EBF1, PAX5, and Ikaros are among the most important transcription factors controlling early development and thereby conditioning mice homeostatic B cell lymphopoiesis. Importantly, their gain or loss of function often results in malignant development in humans, supporting conserved roles for these transcription factors. B cell acute lymphoblastic leukemia is the most common cause of pediatric cancer, and it is characterized by unpaired early B cell development resulting from genetic lesions in these critical signaling pathways and transcription factors. Fine mapping of these genetic abnormalities is allowing more specific treatments, more accurately predicting risk profiles for this disease, and improving survival rates.

  6. Identification of cytotoxic T lymphocyte epitopes on swine viruses: multi-epitope design for universal T cell vaccine.

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    Yu-Chieh Liao

    Full Text Available Classical swine fever (CSF, foot-and-mouth disease (FMD and porcine reproductive and respiratory syndrome (PRRS are the primary diseases affecting the pig industry globally. Vaccine induced CD8(+ T cell-mediated immune response might be long-lived and cross-serotype and thus deserve further attention. Although large panels of synthetic overlapping peptides spanning the entire length of the polyproteins of a virus facilitate the detection of cytotoxic T lymphocyte (CTL epitopes, it is an exceedingly costly and cumbersome approach. Alternatively, computational predictions have been proven to be of satisfactory accuracy and are easily performed. Such a method enables the systematic identification of genome-wide CTL epitopes by incorporating epitope prediction tools in analyzing large numbers of viral sequences. In this study, we have implemented an integrated bioinformatics pipeline for the identification of CTL epitopes of swine viruses including the CSF virus (CSFV, FMD virus (FMDV and PRRS virus (PRRSV and assembled these epitopes on a web resource to facilitate vaccine design. Identification of epitopes for cross protections to different subtypes of virus are also reported in this study and may be useful for the development of a universal vaccine against such viral infections among the swine population. The CTL epitopes identified in this study have been evaluated in silico and possibly provide more and wider protection in compared to traditional single-reference vaccine design. The web resource is free and open to all users through http://sb.nhri.org.tw/ICES.

  7. High-throughput epitope identification for snakebite antivenom

    DEFF Research Database (Denmark)

    Engmark, Mikael; De Masi, Federico; Laustsen, Andreas Hougaard;

    Insight into the epitopic recognition pattern for polyclonal antivenoms is a strong tool for accurate prediction of antivenom cross-reactivity and provides a basis for design of novel antivenoms. In this work, a high-throughput approach was applied to characterize linear epitopes in 966 individua...... toxins from pit vipers (Crotalidae) using the ICP Crotalidae antivenom. Due to an abundance of snake venom metalloproteinases and phospholipase A2s in the venoms used for production of the investigated antivenom, this study focuses on these toxin families.......Insight into the epitopic recognition pattern for polyclonal antivenoms is a strong tool for accurate prediction of antivenom cross-reactivity and provides a basis for design of novel antivenoms. In this work, a high-throughput approach was applied to characterize linear epitopes in 966 individual...

  8. Human Peripheral Blood B-Cell Compartments : A Crossroad in B-Cell Traffic

    NARCIS (Netherlands)

    Perez-Andres, M.; Paiva, B.; Nieto, W. G.; Caraux, A.; Schmitz, A.; Almeida, J.; Vogt, R. F.; Marti, G. E.; Rawstron, A. C.; Van Zelm, M. C.; Van Dongen, J. J. M.; Johnsen, H. E.; Klein, B.; Orfao, A.

    2010-01-01

    A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues.

  9. Identification of critical amino acids in an immunodominant IgE epitope of Pen c 13, a major allergen from Penicillium citrinum.

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    Jui-Chieh Chen

    Full Text Available BACKGROUND: Pen c 13, identified as a 33-kDa alkaline serine protease, is a major allergen secreted by Penicillium citrinum. Detailed knowledge about the epitopes responsible for IgE binding would help inform the diagnosis/prognosis of fungal allergy and facilitate the rational design of hypoallergenic candidate vaccines. The goal of the present study was to characterize the IgE epitopes of Pen c 13. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples were collected from 10 patients with mold allergy and positive Pen c 13 skin test results. IgE-binding epitopes on rPen c 13 were mapped using an enzymatic digestion and chemical cleavage method, followed by dot-blotting and mass spectrometry. A B-cell epitope-predicting server and molecular modeling were used to predict the residues most likely involved in IgE binding. Theoretically predicted IgE-binding regions were further confirmed by site-directed mutagenesis assays. At least twelve different IgE-binding epitopes located throughout Pen c 13 were identified. Of these, peptides S16 (A(148-E(166 and S22 (A(243-K(274 were recognized by sera from 90% and 100% of the patients tested, and were further confirmed by inhibition assays. Peptide S22 was selected for further analysis of IgE-binding ability. The results of serum screening showed that the majority of IgE-binding ability resided in the C-terminus. One Pen c 13 mutant, G270A (T(261-K(274, exhibited clearly enhanced IgE reactivity, whereas another, K274A, exhibited dramatically reduced IgE reactivity. CONCLUSIONS/SIGNIFICANCE: Experimental analyses confirmed in silico-predicted residues involved in an important antigenic region of Pen c 13. The G270A mutant of Pen c 13 has the potential to serve as an additional tool for the diagnosis/prognosis of mold allergy, and the K274A mutant, as a hypoallergenic form of the epitope, may provide a framework for the design and development of a safe and efficient therapeutic strategy for treating human allergic

  10. B Cells and Autoantibodies in Multiple Sclerosis

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    Anne-Katrin Pröbstel

    2015-07-01

    Full Text Available While over the past decades T cells have been considered key players in the pathogenesis of multiple sclerosis (MS, it has only recently become evident that B cells have a major contributing role. Our understanding of the role of B cells has evolved substantially following the clinical success of B cell-targeting therapies and increasing experimental evidence for significant B cell involvement. Rather than mere antibody-producing cells, it is becoming clear that they are team players with the capacity to prime and regulate T cells, and function both as pro- and anti-inflammatory mediators. However, despite tremendous efforts, the target antigen(s of B cells in MS have yet to be identified. The first part of this review summarizes the clinical evidence and results from animal studies pointing to the relevance of B cells in the pathogenesis of MS. The second part gives an overview of the currently known potential autoantigen targets. The third part recapitulates and critically appraises the currently available B cell-directed therapies.

  11. Differential radiosensitivity among B cell subpopulations

    Energy Technology Data Exchange (ETDEWEB)

    Riggs, J.E.; Lussier, A.M.; Lee, S.K.; Appel, M.C.; Woodland, R.T.

    1988-09-15

    We have previously shown that low doses of ionizing radiation selectively impair a functionally defined B cell subpopulation. Normal mice, after exposure to 200 rad of ionizing radiation, have normal or near normal splenic plaque-forming cell responses to thymus-independent type 1 Ag, but reduced responses to thymus-independent type 2 Ag. Here, we confirm and extend the original findings by using hapten-specific serum RIA to demonstrate this differential radiosensitivity is systemic. We also examined splenocytes stained with a panel of lymphocyte surface Ag by FACS analysis to determine if these functional changes are accompanied by a physical alteration of the B cell pool of irradiated mice. Single-parameter FACS analyses demonstrate a diminution in both B cell number and the heterogeneity of membrane Ag expression within the surviving B cell pool after irradiation. In contrast, T cells are relatively radioresistant as the relative percentage of T cells in the irradiated splenocyte pool increases, whereas the heterogeneity of membrane Ag expression remains constant. Multiparameter FACS analyses indicate that B cells with the sIgM much greater than sIgD phenotype are more radiosensitive than B cells of the sIgM much less than sIgD phenotype. In addition, immunohistochemical analysis of splenic sections stained with anti-IgM or anti-IgD reveal the enhanced radiosensitivity of marginal zone B cells.

  12. B Cell Tolerance in Health and Disease

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    Murali Gururajan

    2014-02-01

    Full Text Available B lymphocyte receptors are generated randomly during the bone marrow developmental phase of B cells. Hence, the B cell repertoire consists of both self and foreign antigen specificities necessitating specific tolerance mechanisms to eliminate self-reactive B cells. This review summarizes the major mechanisms of B cell tolerance, which include clonal deletion, anergy and receptor editing. In the bone marrow presentation of antigen in membrane bound form is more effective than soluble form and the role of dendritic cells in this process is discussed. Toll like receptor derived signals affect activation of B cells by certain ligands such as nucleic acids and have been shown to play crucial roles in the development of autoimmunity in several animal models. In the periphery availability of BAFF, a B cell survival factor plays a critical role in the survival of self-reactive B cells. Antibodies against BAFF have been found to be effective therapeutic agents in lupus like autoimmune diseases. Recent developments are targeting anergy to control the growth of chronic lymphocytic leukemia cells.

  13. Effects of type II collagen epitope carbamylation and citrullination in human leucocyte antigen (HLA)-DR4(+) monozygotic twins discordant for rheumatoid arthritis.

    Science.gov (United States)

    De Santis, M; Ceribelli, A; Cavaciocchi, F; Generali, E; Massarotti, M; Isailovic, N; Crotti, C; Scherer, H U; Montecucco, C; Selmi, C

    2016-09-01

    The aim of this study is to investigate the effect of the native, citrullinated or carbamylated type II human collagen T cell- and B cell-epitopes on the adaptive immune response in rheumatoid arthritis (RA). Peripheral blood T and B cells obtained from a human leucocyte D4-related (antigen DR4(-) HLA-DR4)(+) woman with early RA, her healthy monozygotic twin and an unrelated HLA-DR3(+) woman with early RA were analysed for activation (CD154/CD69), apoptosis (annexin/7-aminoactinomycin), cytokine production [interferon (IFN)γ/interleukin (IL)-17/IL-4/IL-10/IL-6] and functional phenotype (CD45Ra/CCR7) after stimulation with the collagen native T cell epitope (T261-273), the K264 carbamylated T cell epitope (carT261-273), the native B cell epitope (B359-369) or the R360 citrullinated B cell epitope (citB359-369), and the combinations of these. The T cell memory compartment was activated by T cell epitopes in both discordant DR4(+) twins, but not in the DR3(+) RA. The collagen-specific activation of CD4(+) T cells was induced with both the native and carbamylated T cell epitopes only in the RA twin. Both T cell epitopes also induced IL-17 production in the RA twin, but a greater IL-4 and IL-10 response in the healthy twin. The citrullinated B cell epitope, particularly when combined with the carbamylated T cell epitope, induced B cell activation and an increased IL-6/IL-10 ratio in the RA twin compared to a greater IL-10 production in the healthy twin. Our data suggest that circulating collagen-specific T and B cells are found in HLA-DR4(+) subjects, but only RA activated cells express co-stimulatory molecules and produce proinflammatory cytokines. Carbamylation and citrullination further modulate the activation and cytokine polarization of T and B cells. PMID:27314557

  14. Gluten-specific antibodies of celiac disease gut plasma cells recognize long proteolytic fragments that typically harbor T-cell epitopes

    Science.gov (United States)

    Dørum, Siri; Steinsbø, Øyvind; Bergseng, Elin; Arntzen, Magnus Ø.; de Souza, Gustavo A.; Sollid, Ludvig M.

    2016-01-01

    This study aimed to identify proteolytic fragments of gluten proteins recognized by recombinant IgG1 monoclonal antibodies generated from single IgA plasma cells of celiac disease lesions. Peptides bound by monoclonal antibodies in complex gut-enzyme digests of gluten treated with the deamidating enzyme transglutaminase 2, were identified by mass spectrometry after antibody pull-down with protein G beads. The antibody bound peptides were long deamidated peptide fragments that contained the substrate recognition sequence of transglutaminase 2. Characteristically, the fragments contained epitopes with the sequence QPEQPFP and variants thereof in multiple copies, and they typically also harbored many different gluten T-cell epitopes. In the pull-down setting where antibodies were immobilized on a solid phase, peptide fragments with multivalent display of epitopes were targeted. This scenario resembles the situation of the B-cell receptor on the surface of B cells. Conceivably, B cells of celiac disease patients select gluten epitopes that are repeated multiple times in long peptide fragments generated by gut digestive enzymes. As the fragments also contain many different T-cell epitopes, this will lead to generation of strong antibody responses by effective presentation of several distinct T-cell epitopes and establishment of T-cell help to B cells. PMID:27146306

  15. T and B cell cooperation: a dance of life and death.

    Science.gov (United States)

    Bernard, Alain; Coitot, Sylvie; Brémont, Aurore; Bernard, Ghislaine

    2005-02-15

    In order for the body to develop a good antibody response, B cells need to react intimately with antigen specific T cells. Experimental evidence using hapten-carriers revealed that T and B cells do not recognize the same epitope and this led to the view that the physical contact is mediated by the antigen. Although the modern concept of antigen presentation has changed our perception on how the antigen can bridge both cells, the basic virtues of earlier bridging models remain. Over the past few years, a number of surface ligand-receptor pathways have been described, most of them belonging either to the CD28/B7 Ig or to the TNF/TNFR-like families. These act in concert, whether they are agonist or antagonist, in a timely and spatially organized manner. They form cascades of successive induction and recruitment to ensure that T-B cooperation is closely controlled at all stages of antibody induction. PMID:15699753

  16. The Analysis of B-Cell Epitopes of Influenza Virus Hemagglutinin

    OpenAIRE

    Shcherbinin, D.N.; S. V Alekseeva; Shmarov, M.M.; Smirnov, Yu.A.; Naroditskiy, B.S.; Gintsburg, A.L.

    2016-01-01

    Vaccination has been successfully used to prevent influenza for a long time. Influenza virus hemagglutinin (HA), which induces a humoral immune response in humans and protection against the flu, is the main antigenic component of modern influenza vaccines. However, new seasonal and pandemic influenza virus variants with altered structures of HA occasionally occur. This allows the pathogen to avoid neutralization with antibodies produced in response to previous vaccination. Development of a va...

  17. THE ANALYSIS OF B-CELL EPITOPES OF INFLUENZA VIRUS HEMAGGLUTININ

    OpenAIRE

    Shcherbinin, D.N.; S. V Alekseeva; Shmarov, M.M.; SMIRNOV YU.A.; Naroditskiy, B.S.; Gintsburg, A.L.

    2016-01-01

    Vaccination has been successfully used to prevent influenza for a long time. Influenza virus hemagglutinin (HA), which induces a humoral immune response in humans and protection against the flu, is the main antigenic component of modern influenza vaccines. However, new seasonal and pandemic influenza virus variants with altered structures of HA occasionally occur. This allows the pathogen to avoid neutralization with antibodies produced in response to previous vaccination. Development of a va...

  18. Proinflammatory GM-CSF-producing B cells in multiple sclerosis and B cell depletion therapy.

    Science.gov (United States)

    Li, Rui; Rezk, Ayman; Miyazaki, Yusei; Hilgenberg, Ellen; Touil, Hanane; Shen, Ping; Moore, Craig S; Michel, Laure; Althekair, Faisal; Rajasekharan, Sathy; Gommerman, Jennifer L; Prat, Alexandre; Fillatreau, Simon; Bar-Or, Amit

    2015-10-21

    B cells are not limited to producing protective antibodies; they also perform additional functions relevant to both health and disease. However, the relative contribution of functionally distinct B cell subsets in human disease, the signals that regulate the balance between such subsets, and which of these subsets underlie the benefits of B cell depletion therapy (BCDT) are only partially elucidated. We describe a proinflammatory, granulocyte macrophage-colony stimulating factor (GM-CSF)-expressing human memory B cell subset that is increased in frequency and more readily induced in multiple sclerosis (MS) patients compared to healthy controls. In vitro, GM-CSF-expressing B cells efficiently activated myeloid cells in a GM-CSF-dependent manner, and in vivo, BCDT resulted in a GM-CSF-dependent decrease in proinflammatory myeloid responses of MS patients. A signal transducer and activator of transcription 5 (STAT5)- and STAT6-dependent mechanism was required for B cell GM-CSF production and reciprocally regulated the generation of regulatory IL-10-expressing B cells. STAT5/6 signaling was enhanced in B cells of untreated MS patients compared with healthy controls, and B cells reemerging in patients after BCDT normalized their STAT5/6 signaling as well as their GM-CSF/IL-10 cytokine secretion ratios. The diminished proinflammatory myeloid cell responses observed after BCDT persisted even as new B cells reconstituted. These data implicate a proinflammatory B cell/myeloid cell axis in disease and underscore the rationale for selective targeting of distinct B cell populations in MS and other human autoimmune diseases. PMID:26491076

  19. Predicting Hemagglutinin MHC-II Ligand Analogues in Anti-TNFα Biologics: Implications for Immunogenicity of Pharmaceutical Proteins.

    Directory of Open Access Journals (Sweden)

    Benjamin J Andrick

    Full Text Available The purpose of this study was to evaluate the extent of overlapping immunogenic peptides between three pharmaceutical biologics and influenza viruses. Clinical studies have shown that subsets of patients with rheumatoid arthritis (RA develop anti-drug antibodies towards anti-TNFα biologics. We postulate that common infectious pathogens, including influenza viruses, may sensitize RA patients toward recombinant proteins. We hypothesize that embedded within infliximab (IFX, adalimumab (ADA, and etanercept (ETN are ligands of class II major histocompatibility complex (MHC-II that mimic T cell epitopes derived from influenza hemagglutinin (HA. The rationale is that repeated administration of the biologics would reactivate HA-primed CD4 T cells, stimulating B cells to produce cross-reactive antibodies. Custom scripts were constructed using MATLAB to compare MHC-II ligands of HA and the biologics; all ligands were predicted using tools in Immune Epitope Database and Resources (IEDB. We analyzed three HLA-DR1 alleles (0101, 0401 and 1001 that are prominent in RA patients, and two alleles (0103 and 1502 that are not associated with RA. The results indicate that 0401 would present more analogues of HA ligands in the three anti-TNFα biologics compared to the other alleles. The approach led to identification of potential ligands in IFX and ADA that shares sequence homology with a known HA-specific CD4 T cell epitope. We also discovered a peptide in the complementarity-determining region 3 (CDR-3 of ADA that encompasses both a potential CD4 T cell epitope and a known B cell epitope in HA. The results may help generate new hypotheses for interrogating patient variability of immunogenicity of the anti-TNFα drugs. The approach would aid development of new recombinant biologics by identifying analogues of CD4 T cell epitopes of common pathogens at the preclinical stage.

  20. Characterising B cell numbers and memory B cells in HIV infected and uninfected Malawian adults

    Directory of Open Access Journals (Sweden)

    Gordon Stephen

    2010-09-01

    Full Text Available Abstract Background Untreated human immunodeficiency virus (HIV disease disrupts B cell populations causing reduced memory and reduced naïve resting B cells leading to increases in specific co-infections and impaired responses to vaccines. To what extent antiretroviral treatment reverses these changes in an African population is uncertain. Methods A cross-sectional study was performed. We recruited HIV-uninfected and HIV-infected Malawian adults both on and off antiretroviral therapy attending the Queen Elizabeth Central hospital in Malawi. Using flow cytometry, we enumerated B cells and characterized memory B cells and compared these measurements by the different recruitment groups. Results Overall 64 participants were recruited - 20 HIV uninfected (HIV-, 30 HIV infected ART naïve (HIV+N and 14 HIV-infected ART treated (HIV+T. ART treatment had been taken for a median of 33 months (Range 12-60 months. Compared to HIV- the HIV+N adults had low absolute number of naïve resting B cells (111 vs. 180 cells/μl p = 0.008; reduced memory B cells (27 vs. 51 cells/μl p = 0.0008. The HIV+T adults had B-cell numbers similar to HIV- except for memory B cells that remained significantly lower (30 vs. 51 cells/μl p = 0.02. In the HIV+N group we did not find an association between CD4 count and B cell numbers. Conclusions HIV infected Malawian adults have abnormal B-cell numbers. Individuals treated with ART show a return to normal in B-cell numbers but a persistent deficit in the memory subset is noted. This has important implications for long term susceptibility to co-infections and should be evaluated further in a larger cohort study.

  1. Persistent Polyclonal B Cell Lymphocytosis B Cells Can Be Activated through CD40-CD154 Interaction

    Directory of Open Access Journals (Sweden)

    Emmanuelle Dugas-Bourdages

    2014-01-01

    Full Text Available Persistent polyclonal B cell lymphocytosis (PPBL is a rare disorder, diagnosed primarily in adult female smokers and characterized by an expansion of CD19+CD27+IgM+ memory B cells, by the presence of binucleated lymphocytes, and by a moderate elevation of serum IgM. The clinical course is usually benign, but it is not known whether or not PPBL might be part of a process leading to the emergence of a malignant proliferative disorder. In this study we sought to investigate the functional response of B cells from patients with PPBL by use of an optimal memory B cell culture model based on the CD40-CD154 interaction. We found that the proliferation of PPBL B cells was almost as important as that of B cells from normal controls, resulting in high immunoglobulin secretion with in vitro isotypic switching. We conclude that the CD40-CD154 activation pathway is functional in the memory B cell population of PPBL patients, suggesting that the disorder may be due to either a dysfunction of other cells in the microenvironment or a possible defect in another B cell activation pathway.

  2. Virus-like particles of chimeric recombinant porcine circovirus type 2 as antigen vehicle carrying foreign epitopes.

    Science.gov (United States)

    Zhang, Huawei; Qian, Ping; Liu, Lifeng; Qian, Suhong; Chen, Huanchun; Li, Xiangmin

    2014-12-01

    Virus-like particles (VLPs) of chimeric porcine circovirus type 2 (PCV2) were generated by replacing the nuclear localization signal (NLS; at 1-39 aa) of PCV2 capsid protein (Cap) with classical swine fever virus (CSFV) T-cell epitope (1446-1460 aa), CSFV B-cell epitope (693-716 aa) and CSFV T-cell epitope conjugated with B-cell epitope. The recombinant proteins were expressed using the baculovirus expression system and detected by immunoblotting and indirect immunofluorescence assay. The abilities to form PCV2 VLPs were confirmed by transmission electron microscopy. Immunogenicities of the three recombinant proteins were evaluated in mice. Our Results indicated that Cap protein NLS deletion or substitution with CSFV epitopes did not affect the VLPs assembly. Three chimeric Cap proteins could form VLPs and induce efficient humoral and cellular immunity against PCV2 and CSFV in mice. Results show that PCV2 VLPs can be used as an efficient antigen carrier for delivery of foreign epitopes, and a potential novel vaccine. PMID:25490764

  3. Virus-Like Particles of Chimeric Recombinant Porcine Circovirus Type 2 as Antigen Vehicle Carrying Foreign Epitopes

    Directory of Open Access Journals (Sweden)

    Huawei Zhang

    2014-12-01

    Full Text Available Virus-like particles (VLPs of chimeric porcine circovirus type 2 (PCV2 were generated by replacing the nuclear localization signal (NLS; at 1–39 aa of PCV2 capsid protein (Cap with classical swine fever virus (CSFV T-cell epitope (1446–1460 aa, CSFV B-cell epitope (693–716 aa and CSFV T-cell epitope conjugated with B-cell epitope. The recombinant proteins were expressed using the baculovirus expression system and detected by immunoblotting and indirect immunofluorescence assay. The abilities to form PCV2 VLPs were confirmed by transmission electron microscopy. Immunogenicities of the three recombinant proteins were evaluated in mice. Our Results indicated that Cap protein NLS deletion or substitution with CSFV epitopes did not affect the VLPs assembly. Three chimeric Cap proteins could form VLPs and induce efficient humoral and cellular immunity against PCV2 and CSFV in mice. Results show that PCV2 VLPs can be used as an efficient antigen carrier for delivery of foreign epitopes, and a potential novel vaccine.

  4. YY1 plays an essential role at all stages of B-cell differentiation.

    Science.gov (United States)

    Kleiman, Eden; Jia, Haiqun; Loguercio, Salvatore; Su, Andrew I; Feeney, Ann J

    2016-07-01

    Ying Yang 1 (YY1) is a ubiquitously expressed transcription factor shown to be essential for pro-B-cell development. However, the role of YY1 in other B-cell populations has never been investigated. Recent bioinformatics analysis data have implicated YY1 in the germinal center (GC) B-cell transcriptional program. In accord with this prediction, we demonstrated that deletion of YY1 by Cγ1-Cre completely prevented differentiation of GC B cells and plasma cells. To determine if YY1 was also required for the differentiation of other B-cell populations, we deleted YY1 with CD19-Cre and found that all peripheral B-cell subsets, including B1 B cells, require YY1 for their differentiation. Transitional 1 (T1) B cells were the most dependent upon YY1, being sensitive to even a half-dosage of YY1 and also to short-term YY1 deletion by tamoxifen-induced Cre. We show that YY1 exerts its effects, in part, by promoting B-cell survival and proliferation. ChIP-sequencing shows that YY1 predominantly binds to promoters, and pathway analysis of the genes that bind YY1 show enrichment in ribosomal functions, mitochondrial functions such as bioenergetics, and functions related to transcription such as mRNA splicing. By RNA-sequencing analysis of differentially expressed genes, we demonstrated that YY1 normally activates genes involved in mitochondrial bioenergetics, whereas it normally down-regulates genes involved in transcription, mRNA splicing, NF-κB signaling pathways, the AP-1 transcription factor network, chromatin remodeling, cytokine signaling pathways, cell adhesion, and cell proliferation. Our results show the crucial role that YY1 plays in regulating broad general processes throughout all stages of B-cell differentiation. PMID:27335461

  5. Early T Cell Recognition of B Cells following Epstein-Barr Virus Infection: Identifying Potential Targets for Prophylactic Vaccination.

    Directory of Open Access Journals (Sweden)

    Jill M Brooks

    2016-04-01

    Full Text Available Epstein-Barr virus, a B-lymphotropic herpesvirus, is the cause of infectious mononucleosis, has strong aetiologic links with several malignancies and has been implicated in certain autoimmune diseases. Efforts to develop a prophylactic vaccine to prevent or reduce EBV-associated disease have, to date, focused on the induction of neutralising antibody responses. However, such vaccines might be further improved by inducing T cell responses capable of recognising and killing recently-infected B cells. In that context, EBNA2, EBNA-LP and BHRF1 are the first viral antigens expressed during the initial stage of B cell growth transformation, yet have been poorly characterised as CD8+ T cell targets. Here we describe CD8+ T cell responses against each of these three "first wave" proteins, identifying target epitopes and HLA restricting alleles. While EBNA-LP and BHRF1 each contained one strong CD8 epitope, epitopes within EBNA2 induced immunodominant responses through several less common HLA class I alleles (e.g. B*3801 and B*5501, as well as subdominant responses through common class I alleles (e.g. B7 and C*0304. Importantly, such EBNA2-specific CD8+ T cells recognised B cells within the first day post-infection, prior to CD8+ T cells against well-characterised latent target antigens such as EBNA3B or LMP2, and effectively inhibited outgrowth of EBV-transformed B cell lines. We infer that "first wave" antigens of the growth-transforming infection, especially EBNA2, constitute potential CD8+ T cell immunogens for inclusion in prophylactic EBV vaccine design.

  6. Novel CD8(+) cytotoxic T cell epitopes in bovine leukemia virus with cattle.

    Science.gov (United States)

    Bai, Lanlan; Takeshima, Shin-Nosuke; Isogai, Emiko; Kohara, Junko; Aida, Yoko

    2015-12-16

    Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis and is closely related to human T cell leukemia virus (HTLV). The cytotoxic T lymphocyte (CTL) plays a key role in suppressing the progression of disease caused by BLV. T and B cell epitopes in BLV have been studied, but CD8(+) CTL epitopes remain poorly understood. We used a library of 115 synthetic peptides covering the entirety of the Env proteins (gp51 and gp30), the Gag proteins (p15, p24, and p12), and the Tax protein of BLV to identify 11 novel CD8(+) T cell epitopes (gp51N5, gp51N11, gp51N12, gp30N5, gp30N6, gp30N8, gp30N16, tax16, tax18, tax19, and tax20) in four calves experimentally infected with BLV. The number of CD8(+) T cell epitopes that could be identified in each calf correlated with the BLV proviral load. Interestingly, among the 11 epitopes identified, only gp51N11 was capable of inducing CD8(+) T cell-mediated cytotoxicity in all four calves, but it is not a suitable vaccine target because it shows a high degree of polymorphism according to the Wu-Kabat variability index. By contrast, no CTL epitopes were identified from the Gag structural protein. In addition, several epitopes were obtained from gp30 and Tax, indicating that cellular immunity against BLV is strongly targeted to these proteins. CD8(+) CTL epitopes from gp30 and Tax were less polymorphic than epitopes from. Indeed, peptides tax16, tax18, tax19, and tax20 include a leucine-rich activation domain that encompasses a transcriptional activation domain, and the gp30N16 peptide contains a proline-rich region that interacts with a protein tyrosine phosphatase SHP1 to regulate B cell activation. Moreover, at least one CD8(+) CTL epitope derived from gp30 was identified in each of the four calves. These results indicate that BLV gp30 may be the best candidate for the development of a BLV vaccine. PMID:26552001

  7. Novel CD8(+) cytotoxic T cell epitopes in bovine leukemia virus with cattle.

    Science.gov (United States)

    Bai, Lanlan; Takeshima, Shin-Nosuke; Isogai, Emiko; Kohara, Junko; Aida, Yoko

    2015-12-16

    Bovine leukemia virus (BLV) is associated with enzootic bovine leukosis and is closely related to human T cell leukemia virus (HTLV). The cytotoxic T lymphocyte (CTL) plays a key role in suppressing the progression of disease caused by BLV. T and B cell epitopes in BLV have been studied, but CD8(+) CTL epitopes remain poorly understood. We used a library of 115 synthetic peptides covering the entirety of the Env proteins (gp51 and gp30), the Gag proteins (p15, p24, and p12), and the Tax protein of BLV to identify 11 novel CD8(+) T cell epitopes (gp51N5, gp51N11, gp51N12, gp30N5, gp30N6, gp30N8, gp30N16, tax16, tax18, tax19, and tax20) in four calves experimentally infected with BLV. The number of CD8(+) T cell epitopes that could be identified in each calf correlated with the BLV proviral load. Interestingly, among the 11 epitopes identified, only gp51N11 was capable of inducing CD8(+) T cell-mediated cytotoxicity in all four calves, but it is not a suitable vaccine target because it shows a high degree of polymorphism according to the Wu-Kabat variability index. By contrast, no CTL epitopes were identified from the Gag structural protein. In addition, several epitopes were obtained from gp30 and Tax, indicating that cellular immunity against BLV is strongly targeted to these proteins. CD8(+) CTL epitopes from gp30 and Tax were less polymorphic than epitopes from. Indeed, peptides tax16, tax18, tax19, and tax20 include a leucine-rich activation domain that encompasses a transcriptional activation domain, and the gp30N16 peptide contains a proline-rich region that interacts with a protein tyrosine phosphatase SHP1 to regulate B cell activation. Moreover, at least one CD8(+) CTL epitope derived from gp30 was identified in each of the four calves. These results indicate that BLV gp30 may be the best candidate for the development of a BLV vaccine.

  8. The Pre-B Cell Receptor and Its Function during B Cell Development

    Institute of Scientific and Technical Information of China (English)

    Min Zhang; Gopesh Srivastava1; Liwei Lu

    2004-01-01

    The process of B cell development in the bone marrow occurs by the stepwise rearrangements of the V, D, and Jsegments of the Ig H and L chain gene loci. During early B cell genesis, productive IgH chain generearrangement leads to assembly of the pre-B cell receptor (pre-BCR), which acts as an important checkpointat the pro-B/preB transitional stage. The pre-BCR, transiently expressed by developing precursor B cells,comprises the Ig μH chain, surrogate light (SL) chains VpreB and λ5, as well as the signal-transducing heterodimer Igα/Igβ. Signaling through the pre-BCR regulates allelic exclusion at the Ig H locus, stimulates cell proliferation, and induces differentiation to small post-mitotic pre-B cells that further undergo the rearrangement of the IgL chain genes. Recent advances in elucidating the key roles of pre-BCR in B cell development have provided a better understanding of normal B lymphopoiesis and its dysregulated state leading to B cell neoplasia.

  9. The Pre-B Cell Receptor and Its Function during B Cell Development

    Institute of Scientific and Technical Information of China (English)

    MinZhang; GopeshSrivastava; LiweiLu

    2004-01-01

    The process of B cell development in the bone marrow occurs by the stepwise rearrangements of the V, D, and J segments of the Ig H and L chain gene loci. During early B cell genesis, productive IgH chain gene rearrangement leads to assembly of the pre-B cell receptor (pre-BCR), which acts as an important checkpoint at the pro-B/preB transitional stage. The pre-BCR, transiently expressed by developing precursor B cells, comprises the Ig μH chain, surrogate light (SL) chains VpreB and λ5, as well as the signal-transducing hetero-dimer Igα/Igβ. Signaling through the pre-BCR regulates allelic exclusion at the Ig H locus, stimulates cell proliferation, and induces differentiation to small post-mitotic pre-B cells that further undergo the rearrangement of the IgL chain genes. Recent advances in elucidating the key roles of pre-BCR in B cell development have provided a better understanding of normal B lymphopoiesis and its dysregulated state leading to B cell neoplasia. Cellular & Molecular Immunology. 2004;1(2):89-94.

  10. From In silico Protein Epitope Density Prediction to Testing Escherichia coli O157:H7 Vaccine Candidates in a Murine Model of Colonization.

    Science.gov (United States)

    Tapia, Daniel; Ross, Brittany N; Kalita, Anjana; Kalita, Mridul; Hatcher, Christopher L; Muruato, Laura A; Torres, Alfredo G

    2016-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a leading cause of foodborne illnesses worldwide and is a common serotype linked to hemorrhagic colitis and an important cause of hemolytic uremic syndrome (HUS). Treatment of EHEC O157:H7 infections is complicated, as antibiotics can exacerbate Shiga toxin (Stx) production and lead to more severe symptoms including HUS. To date, no vaccines have been approved for human use, exposing a void in both treatment and prevention of EHEC O157:H7 infections. Previously, our lab has shown success in identifying novel vaccine candidates via bio- and immunoinformatics approaches, which are capable of reducing bacterial colonization in an in vivo model of intestinal colonization. In this study, we further characterized 17 of the identified vaccine candidates at the bioinformatics level and evaluated the protective capacity of the top three candidates when administered as DNA vaccines in our murine model of EHEC O157:H7 colonization. Based on further immunoinformatic predictions, these vaccine candidates were expected to induce neutralizing antibodies in a Th2-skewed immunological response. Immunization of BALB/c mice with two of these candidates resulted in reduced bacterial colonization following EHEC O157:H7 challenge. Additionally, immune sera was shown to prevent bacterial adhesion in vitro to Caco-2 cells. Together, this study provides further validation of our immunoinformatic analyses and identifies promising vaccine candidates against EHEC O157:H7. PMID:27625996

  11. T cell epitope-based allergy vaccines.

    Science.gov (United States)

    Larché, Mark

    2011-01-01

    Specific immunotherapy (SIT) with extracts containing intact allergen molecules is clinically efficacious, but associated with frequent adverse events related to the allergic sensitization of the patient. As a result, treatment is initiated in an incremental dose fashion which ultimately achieves a plateau (maintenance dose) that may be continued for several years. Reduction of allergic adverse events may allow safer and more rapid treatment Thus, many groups have developed and evaluated strategies to reduce allergenicity whilst maintaining immunogenicity, the latter being required to achieve specific modulation of the immune response. Peptide immunotherapy can be used to target T and/or B cells in an antigen-specific manner. To date, only approaches that target T cells have been clinically evaluated. Short, synthetic peptides representing immunodominant T cell epitopes of major allergens are able to modulate allergen-specific T cell responses in the absence of IgE cross linking and activation of effector cells. Here we review clinical and mechanistic studies associated with peptide immunotherapy targeting allergy to cats or to bee venom. 

  12. Impaired regulatory B cells in myasthenia gravis.

    Science.gov (United States)

    Sheng, Jian Rong; Rezania, Kourosh; Soliven, Betty

    2016-08-15

    Regulatory B cells (Bregs) attenuate the severity of experimental autoimmune myasthenia gravis (EAMG) in an interleukin-10 (IL-10)-dependent manner. The goal of this study was to investigate the role of human Bregs in MG focusing on CD19(+)CD1d(hi) CD5(+) and CD19(+)CD24(hi)CD38(hi) subsets. We found that MG patients exhibited a decrease in the frequency of both Breg subsets and IL-10 producing B cells within each subset, which correlated with disease severity. In addition, there was impaired suppression of Th1 polarization in MG. These findings, taken together with EAMG data, indicate that Bregs play an important role in regulating the severity of MG. PMID:27397074

  13. Primary Hepatosplenic Large B-Cell Lymphoma

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    M.R. Morales-Polanco

    2008-03-01

    Full Text Available Diffuse large B-cell lymphoma is the most common form of lymphoma. It usually begins in the lymph nodes; up to 40% may have an extranodal presentation. According to a definition of primary extranodal lymphoma with presentation only in extranodal sites, there are reports of large B-cell lymphomas limited to liver or spleen as separate entities, and to date there have been only three documented cases of primary hepatosplenic presentation. This paper reports a fourth case. Due to a review of the literature and the clinical course of the case reported, we conclude that primary hepatosplenic large B-cell lymphoma has been found predominantly in females older than 60 years. The patients reported had <2 months of evolution prior to diagnosis, prominent B symptoms, splenomegaly in three and hepatomegaly in two, none with lymph node involvement. All had thrombocytopenia and abnormal liver function tests; three had anemia and elevated serum lactic dehydrogenase levels, two with hemophagocytosis in bone marrow. Because of the previously mentioned data, it can be stated that primary hepatosplenic lymphoma is an uncommon and aggressive form of disease that requires immediate recognition and treatment.

  14. Confirmation of a new conserved linear epitope of Lyssavirus nucleoprotein.

    Science.gov (United States)

    Xinjun, Lv; Xuejun, Ma; Lihua, Wang; Hao, Li; Xinxin, Shen; Pengcheng, Yu; Qing, Tang; Guodong, Liang

    2012-05-01

    Bioinformatics analysis was used to predict potential epitopes of Lyssavirus nucleoprotein and highlighted some distinct differences in the quantity and localization of the epitopes disclosed by epitope analysis of monoclonal antibodies against Lyssavirus nucleoprotein. Bioinformatics analysis showed that the domain containing residues 152-164 of Lyssavirus nucleoprotein was a conserved linear epitope that had not been reported previously. Immunization of two rabbits with the corresponding synthetic peptide conjugated to the Keyhole Limpe hemocyanin (KLH) macromolecule resulted in a titer of anti-peptide antibody above 1:200,000 in rabbit sera as detected by indirect enzyme-linked immunosorbent assay (ELISA). Western blot analysis demonstrated that the anti-peptide antibody recognized denatured Lyssavirus nucleoprotein in sodium dodecylsulfonate-polyacrylate gel electrophoresis (SDS-PAGE). Affinity chromatography purification and FITC-labeling of the anti-peptide antibody in rabbit sera was performed. FITC-labeled anti-peptide antibody could recognize Lyssavirus nucleoprotein in BSR cells and canine brain tissues even at a 1:200 dilution. Residues 152-164 of Lyssavirus nucleoprotein were verified as a conserved linear epitope in Lyssavirus. PMID:22405880

  15. High Throughput T Epitope Mapping and Vaccine Development

    Directory of Open Access Journals (Sweden)

    Giuseppina Li Pira

    2010-01-01

    Full Text Available Mapping of antigenic peptide sequences from proteins of relevant pathogens recognized by T helper (Th and by cytolytic T lymphocytes (CTL is crucial for vaccine development. In fact, mapping of T-cell epitopes provides useful information for the design of peptide-based vaccines and of peptide libraries to monitor specific cellular immunity in protected individuals, patients and vaccinees. Nevertheless, epitope mapping is a challenging task. In fact, large panels of overlapping peptides need to be tested with lymphocytes to identify the sequences that induce a T-cell response. Since numerous peptide panels from antigenic proteins are to be screened, lymphocytes available from human subjects are a limiting factor. To overcome this limitation, high throughput (HTP approaches based on miniaturization and automation of T-cell assays are needed. Here we consider the most recent applications of the HTP approach to T epitope mapping. The alternative or complementary use of in silico prediction and experimental epitope definition is discussed in the context of the recent literature. The currently used methods are described with special reference to the possibility of applying the HTP concept to make epitope mapping an easier procedure in terms of time, workload, reagents, cells and overall cost.

  16. Designing an efficient multi-epitope peptide vaccine against Vibrio cholerae via combined immunoinformatics and protein interaction based approaches.

    Science.gov (United States)

    Nezafat, Navid; Karimi, Zeinab; Eslami, Mahboobeh; Mohkam, Milad; Zandian, Sanam; Ghasemi, Younes

    2016-06-01

    Cholera continues to be a major global health concern. Among different Vibrio cholerae strains, only O1 and O139 cause acute diarrheal diseases that are related to epidemic and pandemic outbreaks. The currently available cholera vaccines are mainly lived and attenuated vaccines consisting of V. cholerae virulence factors such as toxin-coregulated pili (TCP), outer membrane proteins (Omps), and nontoxic cholera toxin B subunit (CTB). Nowadays, there is a great interest in designing an efficient epitope vaccine against cholera. Epitope vaccines consisting of immunodominant epitopes and adjuvant molecules enhance the possibility of inciting potent protective immunity. In this study, V. cholerae protective antigens (OmpW, OmpU, TcpA and TcpF) and the CTB, which is broadly used as an immunostimulatory adjuvant, were analyzed using different bioinformatics and immunoinformatics tools. The common regions between promiscuous epitopes, binding to various HLA-II supertype alleles, and B-cell epitopes were defined based upon the aforementioned protective antigens. The ultimately selected epitopes and CTB adjuvant were fused together using proper GPGPG linkers to enhance vaccine immunogenicity. A three-dimensional model of the thus constructed vaccine was generated using I-TASSER. The model was structurally validated using the ProSA-web error-detection software and the Ramachandran plot. The validation results indicated that the initial 3D model needed refinement. Subsequently, a high-quality model obtained after various refinement cycles was used for defining conformational B-cell epitopes. Several linear and conformational B-cell epitopes were determined within the epitope vaccine, suggesting likely antibody triggering features of our designed vaccine. Next, molecular docking was performed between the 3D vaccine model and the tertiary structure of the toll like receptor 2 (TLR2). To gain further insight into the interaction between vaccine and TLR2, molecular dynamics

  17. A novel antibody discovery platform identifies anti-influenza A broadly neutralizing antibodies from human memory B cells.

    Science.gov (United States)

    Xiao, Xiaodong; Chen, Yan; Varkey, Reena; Kallewaard, Nicole; Koksal, Adem C; Zhu, Qing; Wu, Herren; Chowdhury, Partha S; Dall'Acqua, William F

    2016-07-01

    Monoclonal antibody isolation directly from circulating human B cells is a powerful tool to delineate humoral responses to pathological conditions and discover antibody therapeutics. We have developed a platform aimed at improving the efficiencies of B cell selection and V gene recovery. Here, memory B cells are activated and amplified using Epstein-Barr virus infection, co-cultured with CHO-muCD40L cells, and then assessed by functional screenings. An in vitro transcription and translation (IVTT) approach was used to analyze variable (V) genes recovered from each B cell sample and identify the relevant heavy/light chain pair(s). We achieved efficient amplification and activation of memory B cells, and eliminated the need to: 1) seed B cells at clonal level (≤1 cell/well) or perform limited dilution cloning; 2) immortalize B cells; or 3) assemble V genes into an IgG expression vector to confirm the relevant heavy/light chain pairing. Cross-reactive antibodies targeting a conserved epitope on influenza A hemagglutinin were successfully isolated from a healthy donor. In-depth analysis of the isolated antibodies suggested their potential uses as anti-influenza A antibody therapeutics and uncovered a distinct affinity maturation pathway. Importantly, our results showed that cognate heavy/light chain pairings contributed to both the expression level and binding abilities of our newly isolated VH1-69 family, influenza A neutralizing antibodies, contrasting with previous observations that light chains do not significantly contribute to the function of this group of antibodies. Our results further suggest the potential use of the IVTT as a powerful antibody developability assessment tool. PMID:27049174

  18. Immune recognition of citrullinated epitopes.

    Science.gov (United States)

    Nguyen, Hai; James, Eddie A

    2016-10-01

    Conversion of arginine into citrulline is a post-translational modification that is observed in normal physiological processes. However, abnormal citrullination can provoke autoimmunity by generating altered self-epitopes that are specifically targeted by autoantibodies and T cells. In this review we discuss the recognition of citrullinated antigens in human autoimmune diseases and the role that this modification plays in increasing antigenic diversity and circumventing tolerance mechanisms. Early published work demonstrated that citrullinated proteins are specifically targeted by autoantibodies in rheumatoid arthritis and that citrullinated peptides are more readily presented to T cells by arthritis-susceptible HLA class II 'shared epitope' proteins. Emerging data support the relevance of citrullinated epitopes in other autoimmune diseases, including type 1 diabetes and multiple sclerosis, whose susceptible HLA haplotypes also preferentially present citrullinated peptides. In these settings, autoimmune patients have been shown to have elevated responses to citrullinated epitopes derived from tissue-specific antigens. Contrasting evidence implicates autophagy or perforin and complement-mediated membrane attack as inducers of ectopic citrullination. In either case, the peptidyl deiminases responsible for citrullination are activated in response to inflammation or insult, providing a mechanistic link between this post-translational modification and interactions with the environment and infection. As such, it is likely that immune recognition of citrullinated epitopes also plays a role in pathogen clearance. Indeed, our recent data suggest that responses to citrullinated peptides facilitate recognition of novel influenza strains. Therefore, increased understanding of responses to citrullinated epitopes may provide important insights about the initiation of autoimmunity and recognition of heterologous viruses. PMID:27531825

  19. A B-Cell Superantigen Induces the Apoptosis of Murine and Human Malignant B Cells

    Science.gov (United States)

    Lorenzo, Daniela; Duarte, Alejandra; Mundiñano, Juliana; Berguer, Paula; Nepomnaschy, Irene; Piazzon, Isabel

    2016-01-01

    B-cell superantigens (Sags) bind to conserved sites of the VH or VL regions of immunoglobulin molecules outside their complementarity-determining regions causing the apoptosis of normal cognate B cells. No attempts to investigate whether B-cell Sags are able to induce the apoptosis of cognate malignant B cells were reported. In the present study we show that protein L (PpL), secreted by Finegoldia magna, a B-cell Sag which interacts with κ+ bearing cells, induces the apoptosis of murine and human κ+ lymphoma B cells both in vitro and in vivo. Apoptosis was not altered by caspase-8 inhibitor. No alterations in the levels of Bid, Fas and Fas-L were found suggesting that PpL does not activate the extrinsic pathway of apoptosis. The involvement of the intrinsic pathway was clearly indicated by: i) alterations in mitochondrial membrane potential (ΔΨm) both in murine and human lymphoma cells exposed to PpL; ii) decreased levels of apoptosis in the presence of caspase-9 inhibitor; iii) significant increases of Bim and Bax protein levels and downregulation of Bcl-2; iv) the translocation from the cytoplasm to the mitochondria of Bax and Bim pro-apoptotic proteins and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor and v) the translocation of Bcl-2 protein from the mitochondria to the cytosol and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor. The possibility of a therapeutic use of Sags in lymphoma/leukemia B cell malignancies is discussed. PMID:27603942

  20. A B-Cell Superantigen Induces the Apoptosis of Murine and Human Malignant B Cells.

    Science.gov (United States)

    Lorenzo, Daniela; Duarte, Alejandra; Mundiñano, Juliana; Berguer, Paula; Nepomnaschy, Irene; Piazzon, Isabel

    2016-01-01

    B-cell superantigens (Sags) bind to conserved sites of the VH or VL regions of immunoglobulin molecules outside their complementarity-determining regions causing the apoptosis of normal cognate B cells. No attempts to investigate whether B-cell Sags are able to induce the apoptosis of cognate malignant B cells were reported. In the present study we show that protein L (PpL), secreted by Finegoldia magna, a B-cell Sag which interacts with κ+ bearing cells, induces the apoptosis of murine and human κ+ lymphoma B cells both in vitro and in vivo. Apoptosis was not altered by caspase-8 inhibitor. No alterations in the levels of Bid, Fas and Fas-L were found suggesting that PpL does not activate the extrinsic pathway of apoptosis. The involvement of the intrinsic pathway was clearly indicated by: i) alterations in mitochondrial membrane potential (ΔΨm) both in murine and human lymphoma cells exposed to PpL; ii) decreased levels of apoptosis in the presence of caspase-9 inhibitor; iii) significant increases of Bim and Bax protein levels and downregulation of Bcl-2; iv) the translocation from the cytoplasm to the mitochondria of Bax and Bim pro-apoptotic proteins and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor and v) the translocation of Bcl-2 protein from the mitochondria to the cytosol and its inhibition by caspase-9 inhibitor but not by caspase-8 inhibitor. The possibility of a therapeutic use of Sags in lymphoma/leukemia B cell malignancies is discussed. PMID:27603942

  1. Higher proportions of peripheral CD19+CD5+ B cells predict the effect of corticosteroid in patients with late-onset hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation

    Institute of Scientific and Technical Information of China (English)

    FU Hai-xia; WANG Jing-zhi; ZHAO Ting; ZHANG Yuan-yuan; CHEN Yao; HUANG Xiao-jun; XU Lan-ping; LIU Dai-hong; LIU Kai-yan; CHEN Huan; HAN Wei; ZHANG Xiao-hui; WANG Yu; WANG Feng-rong

    2011-01-01

    Background The cause of late-onset hemorrhagic cystitis (LOHC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains obscure. In clinical practice, some LOHC patients respond to immunosuppression.The aim of this study was to determine the immune pathogenesis of LOHC post allo-HSCT.Methods With the diagnosis of LOHC, patients were given initial treatment consisting of fluid hydration, alkalization and forced diuresis, and empirical anti-viral therapy for 10-14 days or until a week after the virus became negative. The nonresponders were applied corticosteroid. Seven to ten days later, patients' response was evaluated. Along with treatment, CD19+ B lymphocyte subsets were measured at various study points.Results From October 2009 to March 2010, we found 28 cases of LOHC occurred in 25 patients who underwent allo-HSCT in our hospital. Except that three cases were not treated according to the protocol, the other 25 cases were divided into three groups: anti-virus responders (Group A, n=6), corticosteroid responders (Group B1, n=16),corticosteroid and anti-virus nonresponders (Group C, n=3) according to their clinical response. Percentages of CD19+CD5+ B lymphocytes were not significantly different among three groups at onset of LOCH. However, in Group B1after the first anti-virus phase, percentages of CD19+CD5+ lymphocytes significantly increased comparing with those at onset (P=0.022), and then significantly decreased at PR (P=0.003) and CR (P=0.002) with corticosteroid treatment. But significant change was not observed in Groups A and C.Conclusion The immune etiology seems to be involved in the development of LOHC and the proportion of CD19+CD5+lymphocytes may serve as a cellular biomarker to predict the response to corticosteroid in LOHC.

  2. Multi-epitope Models Explain How Pre-existing Antibodies Affect the Generation of Broadly Protective Responses to Influenza

    Science.gov (United States)

    Zarnitsyna, Veronika I.; Lavine, Jennie; Ellebedy, Ali; Ahmed, Rafi; Antia, Rustom

    2016-01-01

    The development of next-generation influenza vaccines that elicit strain-transcendent immunity against both seasonal and pandemic viruses is a key public health goal. Targeting the evolutionarily conserved epitopes on the stem of influenza’s major surface molecule, hemagglutinin, is an appealing prospect, and novel vaccine formulations show promising results in animal model systems. However, studies in humans indicate that natural infection and vaccination result in limited boosting of antibodies to the stem of HA, and the level of stem-specific antibody elicited is insufficient to provide broad strain-transcendent immunity. Here, we use mathematical models of the humoral immune response to explore how pre-existing immunity affects the ability of vaccines to boost antibodies to the head and stem of HA in humans, and, in particular, how it leads to the apparent lack of boosting of broadly cross-reactive antibodies to the stem epitopes. We consider hypotheses where binding of antibody to an epitope: (i) results in more rapid clearance of the antigen; (ii) leads to the formation of antigen-antibody complexes which inhibit B cell activation through Fcγ receptor-mediated mechanism; and (iii) masks the epitope and prevents the stimulation and proliferation of specific B cells. We find that only epitope masking but not the former two mechanisms to be key in recapitulating patterns in data. We discuss the ramifications of our findings for the development of vaccines against both seasonal and pandemic influenza. PMID:27336297

  3. Gastrointestinal B-cell lymphomas: From understanding B-cell physiology to classification and molecular pathology.

    Science.gov (United States)

    Sagaert, Xavier; Tousseyn, Thomas; Yantiss, Rhonda K

    2012-12-15

    The gut is the most common extranodal site where lymphomas arise. Although all histological lymphoma types may develop in the gut, small and large B-cell lymphomas predominate. The sometimes unexpected finding of a lymphoid lesion in an endoscopic biopsy of the gut may challenge both the clinician (who is not always familiar with lymphoma pathogenesis) and the pathologist (who will often be hampered in his/her diagnostic skill by the limited amount of available tissue). Moreover, the past 2 decades have spawned an avalanche of new data that encompasses both the function of the reactive B-cell as well as the pathogenic pathways that lead to its neoplastic counterpart, the B-cell lymphoma. Therefore, this review aims to offer clinicians an overview of B-cell lymphomas in the gut, and their pertinent molecular features that have led to new insights regarding lymphomagenesis. It addresses the question as how to incorporate all presently available information on normal and neoplastic B-cell differentiation, and how this knowledge can be applied in daily clinical practice (e.g., diagnostic tools, prognostic biomarkers or therapeutic targets) to optimalise the managment of this heterogeneous group of neoplasms. PMID:23443141

  4. Regulation of B cell linker protein transcription by PU.1 and Spi-B in murine B cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Xu, Li S; Sokalski, Kristen M; Hotke, Kathryn; Christie, Darah A; Zarnett, Oren; Piskorz, Jan; Thillainadesan, Gobi; Torchia, Joseph; DeKoter, Rodney P

    2012-10-01

    B cell acute lymphoblastic leukemia (B-ALL) is frequently associated with mutations or chromosomal translocations of genes encoding transcription factors. Conditional deletion of genes encoding the E26-transformation-specific transcription factors, PU.1 and Spi-B, in B cells (ΔPB mice) leads to B-ALL in mice at 100% incidence rate and with a median survival of 21 wk. We hypothesized that PU.1 and Spi-B may redundantly activate transcription of genes encoding tumor suppressors in the B cell lineage. Characterization of aging ΔPB mice showed that leukemia cells expressing IL-7R were found in enlarged thymuses. IL-7R-expressing B-ALL cells grew in culture in response to IL-7 and could be maintained as cell lines. Cultured ΔPB cells expressed reduced levels of B cell linker protein (BLNK), a known tumor suppressor gene, compared with controls. The Blnk promoter contained a predicted PU.1 and/or Spi-B binding site that was required for promoter activity and occupied by PU.1 and/or Spi-B as determined by chromatin immunoprecipitation. Restoration of BLNK expression in cultured ΔPB cells opposed IL-7-dependent proliferation and induced early apoptosis. We conclude that the tumor suppressor BLNK is a target of transcriptional activation by PU.1 and Spi-B in the B cell lineage.

  5. Analysis of memory B cell responses and isolation of novel monoclonal antibodies with neutralizing breadth from HIV-1-infected individuals.

    Directory of Open Access Journals (Sweden)

    Davide Corti

    Full Text Available BACKGROUND: The isolation of human monoclonal antibodies (mAbs that neutralize a broad spectrum of primary HIV-1 isolates and the characterization of the human neutralizing antibody B cell response to HIV-1 infection are important goals that are central to the design of an effective antibody-based vaccine. METHODS AND FINDINGS: We immortalized IgG(+ memory B cells from individuals infected with diverse clades of HIV-1 and selected on the basis of plasma neutralization profiles that were cross-clade and relatively potent. Culture supernatants were screened using various recombinant forms of the envelope glycoproteins (Env in multiple parallel assays. We isolated 58 mAbs that were mapped to different Env surfaces, most of which showed neutralizing activity. One mAb in particular (HJ16 specific for a novel epitope proximal to the CD4 binding site on gp120 selectively neutralized a multi-clade panel of Tier-2 HIV-1 pseudoviruses, and demonstrated reactivity that was comparable in breadth, but distinct in neutralization specificity, to that of the other CD4 binding site-specific neutralizing mAb b12. A second mAb (HGN194 bound a conserved epitope in the V3 crown and neutralized all Tier-1 and a proportion of Tier-2 pseudoviruses tested, irrespective of clade. A third mAb (HK20 with broad neutralizing activity, particularly as a Fab fragment, recognized a highly conserved epitope in the HR-1 region of gp41, but showed striking assay-dependent selectivity in its activity. CONCLUSIONS: This study reveals that by using appropriate screening methods, a large proportion of memory B cells can be isolated that produce mAbs with HIV-1 neutralizing activity. Three of these mAbs show unusual breadth of neutralization and therefore add to the current panel of HIV-1 neutralizing antibodies with potential for passive protection and template-based vaccine design.

  6. B-Cell Response during Protozoan Parasite Infections

    OpenAIRE

    Amezcua Vesely, María C; Bermejo, Daniela A.; Montes, Carolina L.; Acosta-Rodríguez, Eva V.; Adriana Gruppi

    2012-01-01

    In this review, we discuss how protozoan parasites alter immature and mature B cell compartment. B1 and marginal zone (MZ) B cells, considered innate like B cells, are activated during protozoan parasite infections, and they generate short lived plasma cells providing a prompt antibody source. In addition, protozoan infections induce massive B cell response with polyclonal activation that leads to hypergammaglobulnemia with serum antibodies specific for the parasites and self and/or non relat...

  7. MicroRNA expression profiling identifies activated B cell status in chronic lymphocytic leukemia cells.

    Directory of Open Access Journals (Sweden)

    Shuqiang Li

    Full Text Available Chronic lymphocytic leukemia (CLL is thought to be a disease of resting lymphocytes. However, recent data suggest that CLL cells may more closely resemble activated B cells. Using microRNA (miRNA expression profiling of highly-enriched CLL cells from 38 patients and 9 untransformed B cells from normal donors before acute CpG activation and 5 matched B cells after acute CpG activation, we demonstrate an activated B cell status for CLL. Gene set enrichment analysis (GSEA identified statistically-significant similarities in miRNA expression between activated B cells and CLL cells including upregulation of miR-34a, miR-155, and miR-342-3p and downregulation of miR-103, miR-181a and miR-181b. Additionally, decreased levels of two CLL signature miRNAs miR-29c and miR-223 are associated with ZAP70(+ and IgV(H unmutated status and with shorter time to first therapy. These data indicate an activated B cell status for CLL cells and suggest that the direction of change of individual miRNAs may predict clinical course in CLL.

  8. Activation-Induced Cytidine Deaminase Expression in Human B Cell Precursors Is Essential for Central B Cell Tolerance.

    Science.gov (United States)

    Cantaert, Tineke; Schickel, Jean-Nicolas; Bannock, Jason M; Ng, Yen-Shing; Massad, Christopher; Oe, Tyler; Wu, Renee; Lavoie, Aubert; Walter, Jolan E; Notarangelo, Luigi D; Al-Herz, Waleed; Kilic, Sara Sebnem; Ochs, Hans D; Nonoyama, Shigeaki; Durandy, Anne; Meffre, Eric

    2015-11-17

    Activation-induced cytidine deaminase (AID), the enzyme-mediating class-switch recombination (CSR) and somatic hypermutation (SHM) of immunoglobulin genes, is essential for the removal of developing autoreactive B cells. How AID mediates central B cell tolerance remains unknown. We report that AID enzymes were produced in a discrete population of immature B cells that expressed recombination-activating gene 2 (RAG2), suggesting that they undergo secondary recombination to edit autoreactive antibodies. However, most AID+ immature B cells lacked anti-apoptotic MCL-1 and were deleted by apoptosis. AID inhibition using lentiviral-encoded short hairpin (sh)RNA in B cells developing in humanized mice resulted in a failure to remove autoreactive clones. Hence, B cell intrinsic AID expression mediates central B cell tolerance potentially through its RAG-coupled genotoxic activity in self-reactive immature B cells.

  9. Generation of stable monoclonal antibody-producing B cell receptor-positive human memory B cells by genetic programming

    NARCIS (Netherlands)

    Kwakkenbos, Mark J.; Diehl, Sean A.; Yasuda, Etsuko; Bakker, Arjen Q.; van Geelen, Caroline M. M.; Lukens, Michaël; van Bleek, Grada M.; Widjojoatmodjo, Myra N.; Bogers, Willy M. J. M.; Mei, Henrik; Radbruch, Andreas; Scheeren, Ferenc A.; Spits, Hergen; Beaumont, Tim

    2010-01-01

    The B cell lymphoma-6 (Bcl-6) and Bcl-xL proteins are expressed in germinal center B cells and enable them to endure the proliferative and mutagenic environment of the germinal center. By introducing these genes into peripheral blood memory B cells and culturing these cells with two factors produced

  10. PepMapper: a collaborative web tool for mapping epitopes from affinity-selected peptides.

    Directory of Open Access Journals (Sweden)

    Wenhan Chen

    Full Text Available Epitope mapping from affinity-selected peptides has become popular in epitope prediction, and correspondingly many Web-based tools have been developed in recent years. However, the performance of these tools varies in different circumstances. To address this problem, we employed an ensemble approach to incorporate two popular Web tools, MimoPro and Pep-3D-Search, together for taking advantages offered by both methods so as to give users more options for their specific purposes of epitope-peptide mapping. The combined operation of Union finds as many associated peptides as possible from both methods, which increases sensitivity in finding potential epitopic regions on a given antigen surface. The combined operation of Intersection achieves to some extent the mutual verification by the two methods and hence increases the likelihood of locating the genuine epitopic region on a given antigen in relation to the interacting peptides. The Consistency between Intersection and Union is an indirect sufficient condition to assess the likelihood of successful peptide-epitope mapping. On average from 27 tests, the combined operations of PepMapper outperformed either MimoPro or Pep-3D-Search alone. Therefore, PepMapper is another multipurpose mapping tool for epitope prediction from affinity-selected peptides. The Web server can be freely accessed at: http://informatics.nenu.edu.cn/PepMapper/

  11. A tick B-cell inhibitory protein from salivary glands of the hard tick, Hyalomma asiaticum asiaticum

    International Nuclear Information System (INIS)

    Some studies done to date suggest that B-cell inhibitory factor occurred in tick saliva. In this study, a novel protein having B-cell inhibitory activity was purified and characterized from the salivary glands of the hard tick, Hyalomma asiaticum asiaticum. This protein was named B-cell inhibitory factor (BIF). The cDNA encoding BIF was cloned by cDNA library screening. The predicted protein from the cDNA sequence is composed of 138 amino acids including the mature BIF. No similarity was found by Blast search. The lipopolysaccharide-induced B-cell proliferation was inhibited by BIF. This is First report of the identification and characterization of B-cell inhibitory protein from tick. The current study facilitates the study of identifying the interaction among tick, Borrelia burgdorferi, the causative agent of Lyme disease, and host

  12. Dengue Virus Directly Stimulates Polyclonal B Cell Activation

    Science.gov (United States)

    Papa, Michelle Premazzi; de Morais, Ana Theresa Silveira; Peçanha, Ligia Maria Torres; de Arruda, Luciana Barros

    2015-01-01

    Dengue infection is associated to vigorous inflammatory response, to a high frequency of activated B cells, and to increased levels of circulating cross-reactive antibodies. We investigated whether direct infection of B cells would promote activation by culturing primary human B lymphocytes from healthy donors with DENV in vitro. B cells were susceptible, but poorly permissive to infection. Even though, primary B cells cultured with DENV induced substantial IgM secretion, which is a hallmark of polyclonal B cell activation. Notably, DENV induced the activation of B cells obtained from either DENV immune or DENV naïve donors, suggesting that it was not dependent on DENV-specific secondary/memory response. B cell stimulation was dependent on activation of MAPK and CD81. B cells cultured with DENV also secreted IL-6 and presented increased expression of CD86 and HLA-DR, which might contribute to B lymphocyte co-stimulatory function. Indeed, PBMCs, but not isolated B cells, secreted high amounts of IgG upon DENV culture, suggesting that interaction with other cell types in vivo might promote Ig isotype switching and IgG secretion from different B cell clones. These findings suggest that activation signaling pathways triggered by DENV interaction with non-specific receptors on B cells might contribute to the exacerbated response observed in dengue patients. PMID:26656738

  13. A new EV71 VP3 epitope in norovirus P particle vector displays neutralizing activity and protection in vivo in mice.

    Science.gov (United States)

    Jiang, Liping; Fan, Rongjun; Sun, Shiyang; Fan, Peihu; Su, Weiheng; Zhou, Yan; Gao, Feng; Xu, Fei; Kong, Wei; Jiang, Chunlai

    2015-11-27

    Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16), as the main agents causing hand, foot and mouth disease (HFMD), have become a serious public health concern in the Asia-Pacific region. Recently, various neutralizing B cell epitopes of EV71 were identified as targets for promising vaccine candidates. Structural studies of Picornaviridae indicated that potent immunodominant epitopes typically lie in the hypervariable loop of capsid surfaces. However, cross-neutralizing antibodies and cross-protection between EV71 and CVA16 have not been observed. Therefore, we speculated that divergent sequences of the two viruses are key epitopes for inducing protective neutralizing responses. In this study, we selected 10 divergent epitope candidates based on alignment of the EV71 and CVA16 P1 amino acid sequences using the Multalin interface page, and these epitopes are conserved among all subgenotypes of EV71. Simultaneously, by utilizing the norovirus P particle as a novel vaccine delivery carrier, we identified the 71-6 epitope (amino acid 176-190 of VP3) as a conformational neutralizing epitope against EV71 in an in vitro micro-neutralization assay as well as an in vivo protection assay in mice. Altogether, these results indicated that the incorporation of the 71-6 epitope into the norovirus P domain can provide a promising candidate for an effective synthetic peptide-based vaccine against EV71.

  14. A new EV71 VP3 epitope in norovirus P particle vector displays neutralizing activity and protection in vivo in mice.

    Science.gov (United States)

    Jiang, Liping; Fan, Rongjun; Sun, Shiyang; Fan, Peihu; Su, Weiheng; Zhou, Yan; Gao, Feng; Xu, Fei; Kong, Wei; Jiang, Chunlai

    2015-11-27

    Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16), as the main agents causing hand, foot and mouth disease (HFMD), have become a serious public health concern in the Asia-Pacific region. Recently, various neutralizing B cell epitopes of EV71 were identified as targets for promising vaccine candidates. Structural studies of Picornaviridae indicated that potent immunodominant epitopes typically lie in the hypervariable loop of capsid surfaces. However, cross-neutralizing antibodies and cross-protection between EV71 and CVA16 have not been observed. Therefore, we speculated that divergent sequences of the two viruses are key epitopes for inducing protective neutralizing responses. In this study, we selected 10 divergent epitope candidates based on alignment of the EV71 and CVA16 P1 amino acid sequences using the Multalin interface page, and these epitopes are conserved among all subgenotypes of EV71. Simultaneously, by utilizing the norovirus P particle as a novel vaccine delivery carrier, we identified the 71-6 epitope (amino acid 176-190 of VP3) as a conformational neutralizing epitope against EV71 in an in vitro micro-neutralization assay as well as an in vivo protection assay in mice. Altogether, these results indicated that the incorporation of the 71-6 epitope into the norovirus P domain can provide a promising candidate for an effective synthetic peptide-based vaccine against EV71. PMID:26529072

  15. Designing and structure evaluation of multi-epitope vaccine against ETEC and EHEC, an in silico approach.

    Science.gov (United States)

    Jeshvaghani, Fatemeh S; Rahjerdi, Ahmad K; Amani, Jafar; Rad, Iman; Jafari, Mahyat; Salmanian, Ali H

    2016-01-01

    Diarrheal diseases represent a major health problem in developing countries. Several viruses and bacterial agents, such as Enterotoxigenic Escherichia coli (ETEC) and Enterohemorrhagic Escherichia coli (EHEC) are responsible for human enteric infections. In humans, EHEC infections result in bloody or non-bloody diarrhea, which may be complicated by haemorrhagic colitis and haemolytic uraemic syndrome (HUS). Infection by ETEC is accompanied by a non inflammatory watery diarrhea. E. coli follows a common strategy of infection: colonization on a mucosal site, evasion of host defenses, multiplication, and host damage. Intimin, Stx, Lt and Cfa proteins are the virulence factors expressed by these strains. Antibiotic treatment is generally not recommended for most cases of diarrhea, since antibiotic usage may lead to antibiotic resistance in ETEC and may also change the intestinal flora. We hypothesized that the chimeric forms of these effectors as vaccine candidates would reduce the colonization of bacteria. This study is based on an in silico analysis of chimeric protein structure and its stability and solubility. The secondary and tertiary structures of selected domains were also predicted. Moreover, T and B cell epitopes were mapped. Protein structure Prediction showed that each domain of antigen was separated completely also stable for recombinant expression. We believe that this chimeric vaccine candidate is effective for prevention of bacteria caused diarrheal diseases. PMID:26497319

  16. Regulation of normal B-cell differentiation and malignant B-cell survival by OCT2.

    Science.gov (United States)

    Hodson, Daniel J; Shaffer, Arthur L; Xiao, Wenming; Wright, George W; Schmitz, Roland; Phelan, James D; Yang, Yandan; Webster, Daniel E; Rui, Lixin; Kohlhammer, Holger; Nakagawa, Masao; Waldmann, Thomas A; Staudt, Louis M

    2016-04-01

    The requirement for the B-cell transcription factor OCT2 (octamer-binding protein 2, encoded by Pou2f2) in germinal center B cells has proved controversial. Here, we report that germinal center B cells are formed normally after depletion of OCT2 in a conditional knockout mouse, but their proliferation is reduced and in vivo differentiation to antibody-secreting plasma cells is blocked. This finding led us to examine the role of OCT2 in germinal center-derived lymphomas. shRNA knockdown showed that almost all diffuse large B-cell lymphoma (DLBCL) cell lines are addicted to the expression of OCT2 and its coactivator OCA-B. Genome-wide chromatin immunoprecipitation (ChIP) analysis and gene-expression profiling revealed the broad transcriptional program regulated by OCT2 that includes the expression of STAT3, IL-10, ELL2, XBP1, MYC, TERT, and ADA. Importantly, genetic alteration of OCT2 is not a requirement for cellular addiction in DLBCL. However, we detected amplifications of the POU2F2 locus in DLBCL tumor biopsies and a recurrent mutation of threonine 223 in the DNA-binding domain of OCT2. This neomorphic mutation subtly alters the DNA-binding preference of OCT2, leading to the transactivation of noncanonical target genes including HIF1a and FCRL3 Finally, by introducing mutations designed to disrupt the OCT2-OCA-B interface, we reveal a requirement for this protein-protein interface that ultimately might be exploited therapeutically. Our findings, combined with the predominantly B-cell-restricted expression of OCT2 and the absence of a systemic phenotype in our knockout mice, suggest that an OCT2-targeted therapeutic strategy would be efficacious in both major subtypes of DLBCL while avoiding systemic toxicity. PMID:26993806

  17. Immune history profoundly affects broadly protective B cell responses to influenza

    Science.gov (United States)

    Andrews, Sarah F.; Huang, Yunping; Kaur, Kaval; Popova, Lyubov I.; Ho, Irvin Y.; Pauli, Noel T.; Dunand, Carole J. Henry; Taylor, William M; Lim, Samuel; Huang, Min; Qu, Xinyan; Lee, Jane-Hwei; Salgado-Ferrer, Marlene; Krammer, Florian; Palese, Peter; Wrammert, Jens; Ahmed, Rafi; Wilson, Patrick C.

    2016-01-01

    Generating a broadly protective influenza vaccine is critical to global health. Understanding how immune memory influences influenza immunity is central to this goal. We undertook an in-depth study of the B cell response to the pandemic 2009 H1N1 vaccine over consecutive years. Analysis of monoclonal Abs generated from vaccine-induced plasmablasts demonstrated that individuals with low preexisting serological titers to the vaccinating strain generated a broadly reactive, HA stalk-biased, response. Higher preexisting serum antibody levels correlated with a strain-specific HA head-dominated response. We demonstrate that this HA head immunodominance encompasses poor accessibility of the HA stalk epitopes. Further, we show polyreactivity of HA stalk-reactive antibodies that could cause counterselection of these cells. Thus, preexisting memory against HA head epitopes predominate, inhibiting a broadly protective response against the HA stalk upon revaccination with similar strains. Consideration of influenza exposure history is critical for new vaccine strategies designed to elicit broadly neutralizing antibodies. PMID:26631631

  18. The human intestinal B-cell response.

    Science.gov (United States)

    Spencer, J; Sollid, L M

    2016-09-01

    The intestinal immune system is chronically challenged by a huge plethora of antigens derived from the lumen. B-cell responses in organized gut-associated lymphoid tissues and regional lymph nodes that are driven chronically by gut antigens generate the largest population of antibody-producing cells in the body: the gut lamina propria plasma cells. Although animal studies have provided insights into mechanisms that underpin this dynamic process, some very fundamental differences in this system appear to exist between species. Importantly, this prevents extrapolation from mice to humans to inform translational research questions. Therefore, in this review we will describe the structures and mechanisms involved in the propagation, dissemination, and regulation of this immense plasma cell population in man. Uniquely, we will seek our evidence exclusively from studies of human cells and tissues. PMID:27461177

  19. Rheumatoid factors, B cells and immunoglobulin genes.

    Science.gov (United States)

    Jefferis, R

    1995-04-01

    The paradigm of self, non-self discrimination in the immune system is under review as autoreactive B or T cells are increasingly delineated within normal individuals. The products of autoreactive B cells are, mostly, polyspecific IgM antibodies of low affinity. These 'natural' antibodies include rheumatoid factors (RF) encoded by unmutated germline immunoglobulin genes. In rheumatoid arthritis (RA) the RF may be of the IgM, IgG or IgA isotype, show evidence of somatic mutation and have increased affinity; consistent with maturation of an antigen driven immune response. This response could be initiated or driven by an auto-immunogenic form of IgG or an exogenous cross-reactive antigen. Changes in galactosylation of IgG have been reported to be a valuable diagnostic and prognostic indicator in RA. Speculation that these changes may precipitate some of the disease processes is critically reviewed.

  20. The Transcription Factor Bach2 Is Phosphorylated at Multiple Sites in Murine B Cells but a Single Site Prevents Its Nuclear Localization.

    Science.gov (United States)

    Ando, Ryo; Shima, Hiroki; Tamahara, Toru; Sato, Yoshihiro; Watanabe-Matsui, Miki; Kato, Hiroki; Sax, Nicolas; Motohashi, Hozumi; Taguchi, Keiko; Yamamoto, Masayuki; Nio, Masaki; Maeda, Tatsuya; Ochiai, Kyoko; Muto, Akihiko; Igarashi, Kazuhiko

    2016-01-22

    The transcription factor Bach2 regulates the immune system at multiple points, including class switch recombination (CSR) in activated B cells and the function of T cells in part by restricting their terminal differentiation. However, the regulation of Bach2 expression and its activity in the immune cells are still unclear. Here, we demonstrated that Bach2 mRNA expression decreased in Pten-deficient primary B cells. Bach2 was phosphorylated in primary B cells, which was increased upon the activation of the B cell receptor by an anti-immunoglobulin M (IgM) antibody or CD40 ligand. Using specific inhibitors of kinases, the phosphorylation of Bach2 in activated B cells was shown to depend on the phosphatidylinositol 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway. The complex of mTOR and Raptor phosphorylated Bach2 in vitro. We identified multiple new phosphorylation sites of Bach2 by mass spectrometry analysis of epitope-tagged Bach2 expressed in the mature B cell line BAL17. Among the sites identified, serine 535 (Ser-535) was critical for the regulation of Bach2 because a single mutation of Ser-535 abolished cytoplasmic accumulation of Bach2, promoting its nuclear accumulation in pre-B cells, whereas Ser-509 played an auxiliary role. Bach2 repressor activity was enhanced by the Ser-535 mutation in B cells. These results suggest that the PI3K-Akt-mTOR pathway inhibits Bach2 by both repressing its expression and inducing its phosphorylation in B cells. PMID:26620562

  1. Interleukin 2 receptors on human B cells. Implications for the role of interleukin 2 in human B cell function

    OpenAIRE

    1985-01-01

    In the present study, we examined the expression of interleukin 2 (IL- 2) receptors on normal human B cells as well as established B cell lines. Anti-Tac monoclonal antibody did not bind to freshly separated normal human B cells. Unexpectedly, with the appropriate activation of the normal B cells by anti-mu antibody, phorbol myristate acetate, or Staphylococcus aureus Cowan I (SAC), Tac antigen was induced on the activated B cells. Anti-Tac antibody showed consistent reactivity with two B cel...

  2. The epitopes in wheat proteins for defining toxic units relevant to human health.

    Science.gov (United States)

    Juhász, Angéla; Gell, Gyöngyvér; Békés, Frank; Balázs, Ervin

    2012-11-01

    Wheat-related disorders are well-studied health problems. Knowledge of the composition and amounts of epitopes present in a single wheat sample represents a significant gap, and the detailed wheat proteome datasets now available can provide the necessary information to carry out an estimation of allergen prediction for a single cultivar. The combined use of genome sequence and allergen databases, prediction methodology, and cereal chemistry results in better understanding of the level of toxicity present in the end-products produced from wheat flour. The workflow presented in this review provides information about the number and distribution of epitopes at single protein, or protein fraction, levels. In addition, epitopes present in the highest frequency and harmful proteins expressed in the highest amount can be identified. The "epitope toxicity" value obtained in this way is a significant research output from the analysis of large datasets that can be applied to the food industry.

  3. Mapping of T cell epitopes using recombinant antigens and synthetic peptides.

    OpenAIRE

    Lamb, J R; Ivanyi, J.; Rees, A D; Rothbard, J B; Howland, K; Young, R. A.; Young, D B

    1987-01-01

    Two complementary approaches were used to determine the epitope specificity of clonal and polyclonal human T lymphocytes reactive with the 65-kd antigen of Mycobacterium leprae. A recombinant DNA sublibrary constructed from portions of the 65-kd gene was used to map T cell determinants within amino acid sequences 101-146 and 409-526. Independently, potential T cell epitopes within the protein were predicted based on an empirical analysis of specific patterns in the amino acid sequence. Of six...

  4. Initiation of immune tolerance–controlled HIV gp41 neutralizing B cell lineages

    Science.gov (United States)

    Zhang, Ruijun; Verkoczy, Laurent; Wiehe, Kevin; Alam, S. Munir; Nicely, Nathan I.; Santra, Sampa; Bradley, Todd; Pemble, Charles W.; Zhang, Jinsong; Gao, Feng; Montefiori, David C.; Bouton-Verville, Hilary; Kelsoe, Garnett; Larimore, Kevin; Greenberg, Phillip D.; Parks, Robert; Foulger, Andrew; Peel, Jessica N.; Luo, Kan; Lu, Xiaozhi; Trama, Ashley M.; Vandergrift, Nathan; Tomaras, Georgia D.; Kepler, Thomas B.; Moody, M. Anthony; Liao, Hua-Xin; Haynes, Barton F.

    2016-01-01

    Development of an HIV vaccine is a global priority. A major roadblock to a vaccine is an inability to induce protective broadly neutralizing antibodies (bnAbs). HIV gp41 bnAbs have characteristics that predispose them to be controlled by tolerance. We used gp41 2F5 bnAb germline knock-in mice and macaques vaccinated with immunogens reactive with germline precursors to activate neutralizing antibodies. In germline knock-in mice, bnAb precursors were deleted, with remaining anergic B cells capable of being activated by germline-binding immunogens to make gp41-reactive immunoglobulin M (IgM). Immunized macaques made B cell clonal lineages targeted to the 2F5 bnAb epitope, but 2F5-like antibodies were either deleted or did not attain sufficient affinity for gp41-lipid complexes to achieve the neutralization potency of 2F5. Structural analysis of members of a vaccine-induced antibody lineage revealed that heavy chain complementarity-determining region 3 (HCDR3) hydrophobicity was important for neutralization. Thus, gp41 bnAbs are controlled by immune tolerance, requiring vaccination strategies to transiently circumvent tolerance controls. PMID:27122615

  5. Comparison of in vitro immunogenicity, tolerogenicity and mitogenicity of dinitrophenyl-levan conjugates with varying epitope density.

    Science.gov (United States)

    Desaymard, C; Ivanyi, L

    1976-01-01

    The mitogenicity, immunogenicity and tolerogenicity of various DNP-levan (DNP-LE) conjugates were compared using in vitro methods. Anti-DNP antibody synthesis induced by DNP-LE conjugates was related to the epitope density of DNP, BUT WAS NOT AFFECTED BY Macrophage dependent and was not influenced by the degree of hapten conjugation. These results imply that mitogenicity of an antigen is not necessarily related to the specific triggering of B cells. PMID:58831

  6. Regulation of VH replacement by B cell receptor-mediated signaling in human immature B cells.

    Science.gov (United States)

    Liu, Jing; Lange, Miles D; Hong, Sang Yong; Xie, Wanqin; Xu, Kerui; Huang, Lin; Yu, Yangsheng; Ehrhardt, Götz R A; Zemlin, Michael; Burrows, Peter D; Su, Kaihong; Carter, Robert H; Zhang, Zhixin

    2013-06-01

    VH replacement provides a unique RAG-mediated recombination mechanism to edit nonfunctional IgH genes or IgH genes encoding self-reactive BCRs and contributes to the diversification of Ab repertoire in the mouse and human. Currently, it is not clear how VH replacement is regulated during early B lineage cell development. In this article, we show that cross-linking BCRs induces VH replacement in human EU12 μHC(+) cells and in the newly emigrated immature B cells purified from peripheral blood of healthy donors or tonsillar samples. BCR signaling-induced VH replacement is dependent on the activation of Syk and Src kinases but is inhibited by CD19 costimulation, presumably through activation of the PI3K pathway. These results show that VH replacement is regulated by BCR-mediated signaling in human immature B cells, which can be modulated by physiological and pharmacological treatments.

  7. Primary cardiac diffuse large B-cell lymphoma with activated B-cell-like phenotype

    Directory of Open Access Journals (Sweden)

    Vijaya Gadage

    2011-01-01

    Full Text Available Primary cardiac lymphoma (PCL is a rare and fatal disorder. It may often mimic other common cardiac tumors like cardiac myxoma because of similarities in the clinical presentation. We report a case of PCL of diffuse large B-cell type, in a 38-year-old, immunocompetent male who presented with superior vena cava syndrome that was excised as a myxoma. Histology revealed a large cell population diffusely and strongly expressing CD45, CD20, MUM1/IRF4 and FOXP1 hinting at an activated B-cell (ABC-like phenotype. After four cycles of Rituximab with CHOP (cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone the tumor regressed completely but the patient had a relapse and subsequently succumbed to the disease confirming the aggressive nature. The aggressive behavior of PCL may be possibly linked to its ABC-like origin.

  8. Epitope specific T-cell responses against influenza A in a healthy population.

    Science.gov (United States)

    Savic, Miloje; Dembinski, Jennifer L; Kim, Yohan; Tunheim, Gro; Cox, Rebecca J; Oftung, Fredrik; Peters, Bjoern; Mjaaland, Siri

    2016-02-01

    Pre-existing human CD4(+) and CD8(+) T-cell-mediated immunity may be a useful correlate of protection against severe influenza disease. Identification and evaluation of common epitopes recognized by T cells with broad cross-reactivity is therefore important to guide universal influenza vaccine development, and to monitor immunological preparedness against pandemics. We have retrieved an optimal combination of MHC class I and class II restricted epitopes from the Immune Epitope Database (www.iedb.org), by defining a fitness score function depending on prevalence, sequence conservancy and HLA super-type coverage. Optimized libraries of CD4(+) and CD8(+) T-cell epitopes were selected from influenza antigens commonly present in seasonal and pandemic influenza strains from 1934 to 2009. These epitope pools were used to characterize human T-cell responses in healthy donors using interferon-γ ELISPOT assays. Upon stimulation, significant CD4(+) and CD8(+) T-cell responses were induced, primarily recognizing epitopes from the conserved viral core proteins. Furthermore, the CD4(+) and CD8(+) T cells were phenotypically characterized regarding functionality, cytotoxic potential and memory phenotype using flow cytometry. Optimized sets of T-cell peptide epitopes may be a useful tool to monitor the efficacy of clinical trials, the immune status of a population to predict immunological preparedness against pandemics, as well as being candidates for universal influenza vaccines. PMID:26489873

  9. Gastrointestinal B-cell lymphomas: From understanding B-cell physiology to classification and molecular pathology

    OpenAIRE

    2012-01-01

    The gut is the most common extranodal site where lymphomas arise. Although all histological lymphoma types may develop in the gut, small and large B-cell lymphomas predominate. The sometimes unexpected finding of a lymphoid lesion in an endoscopic biopsy of the gut may challenge both the clinician (who is not always familiar with lymphoma pathogenesis) and the pathologist (who will often be hampered in his/her diagnostic skill by the limited amount of available tissue). Moreover, the past 2 d...

  10. Differential programming of B cells in AID deficient mice.

    Directory of Open Access Journals (Sweden)

    Marc A Hogenbirk

    Full Text Available The Aicda locus encodes the activation induced cytidine deaminase (AID and is highly expressed in germinal center (GC B cells to initiate somatic hypermutation (SHM and class switch recombination (CSR of immunoglobulin (Ig genes. Besides these Ig specific activities in B cells, AID has been implicated in active DNA demethylation in non-B cell systems. We here determined a potential role of AID as an epigenetic eraser and transcriptional regulator in B cells. RNA-Seq on different B cell subsets revealed that Aicda(-/- B cells are developmentally affected. However as shown by RNA-Seq, MethylCap-Seq, and SNP analysis these transcriptome alterations may not relate to AID, but alternatively to a CBA mouse strain derived region around the targeted Aicda locus. These unexpected confounding parameters provide alternative, AID-independent interpretations on genotype-phenotype correlations previously reported in numerous studies on AID using the Aicda(-/- mouse strain.

  11. Brucella abortus-infected B cells induce osteoclastogenesis.

    Science.gov (United States)

    Pesce Viglietti, Ayelén Ivana; Arriola Benitez, Paula Constanza; Giambartolomei, Guillermo Hernán; Delpino, María Victoria

    2016-09-01

    Brucella abortus is an intracellular bacterium that establishes lifelong infections in livestock and humans although the mechanisms of its chronicity are poorly understood. Activated B cells have long lifespan and B. abortus infection activates B cells. Our results indicate that the direct infection of B cells with B. abortus induced matrix metalloproteinase-9 (MMP-9), receptor activator for NF κB ligand (RANKL), tumor necrosis factor (TNF)-α and interleukin (IL)-6 secretion. In addition, supernatants from B. abortus-infected B cells induced bone marrow-derived monocytes to undergo osteoclastogenesis. Using osteoprotegerin, RANKL's decoy receptor, we determined that RANKL is involved in osteoclastogenesis induced by supernatants from B. abortus-infected B cells. The results presented here shed light on how the interactions of B. abortus with B cells may have a role in the pathogenesis of brucellar osteoarticular disease.

  12. The contribution of HGAL/GCET2 in immunohistological algorithms: a comparative study in 424 cases of nodal diffuse large B-cell lymphoma.

    Science.gov (United States)

    Gualco, Gabriela; Bacchi, Lívia M; Domeny-Duarte, Pollyanna; Natkunam, Yasodha; Bacchi, Carlos E

    2012-11-01

    Diffuse large B-cell lymphoma can be subclassified into at least two molecular subgroups by gene expression profiling: germinal center B-cell like and activated B-cell like diffuse large B-cell lymphoma. Several immunohistological algorithms have been proposed as surrogates to gene expression profiling at the level of protein expression, but their reliability has been an issue of controversy. Furthermore, the proportion of misclassified cases of germinal center B-cell subgroup by immunohistochemistry, in all reported algorithms, is higher compared with germinal center B-cell cases defined by gene expression profiling. We analyzed 424 cases of nodal diffuse large B-cell lymphoma with the panel of markers included in the three previously described algorithms: Hans, Choi, and Tally. To test whether the sensitivity of detecting germinal center B-cell cases could be improved, the germinal center B-cell marker HGAL/GCET2 was also added to all three algorithms. Our results show that the inclusion of HGAL/GCET2 significantly increased the detection of germinal center B-cell cases in all three algorithms (P<0.001). The proportions of germinal center B-cell cases in the original algorithms were 27%, 34%, and 19% for Hans, Choi, and Tally, respectively. In the modified algorithms, with the inclusion of HGAL/GCET2, the frequencies of germinal center B-cell cases were increased to 38%, 48%, and 35%, respectively. Therefore, HGAL/GCET2 protein expression may function as a marker for germinal center B-cell type diffuse large B-cell lymphoma. Consideration should be given to the inclusion of HGAL/GCET2 analysis in algorithms to better predict the cell of origin. These findings bear further validation, from comparison to gene expression profiles and from clinical/therapeutic data.

  13. Entry of Francisella tularensis into Murine B Cells: The Role of B Cell Receptors and Complement Receptors.

    Directory of Open Access Journals (Sweden)

    Lenka Plzakova

    Full Text Available Francisella tularensis, the etiological agent of tularemia, is an intracellular pathogen that dominantly infects and proliferates inside phagocytic cells but can be seen also in non-phagocytic cells, including B cells. Although protective immunity is known to be almost exclusively associated with the type 1 pathway of cellular immunity, a significant role of B cells in immune responses already has been demonstrated. Whether their role is associated with antibody-dependent or antibody-independent B cell functions is not yet fully understood. The character of early events during B cell-pathogen interaction may determine the type of B cell response regulating the induction of adaptive immunity. We used fluorescence microscopy and flow cytometry to identify the basic requirements for the entry of F. tularensis into B cells within in vivo and in vitro infection models. Here, we present data showing that Francisella tularensis subsp. holarctica strain LVS significantly infects individual subsets of murine peritoneal B cells early after infection. Depending on a given B cell subset, uptake of Francisella into B cells is mediated by B cell receptors (BCRs with or without complement receptor CR1/2. However, F. tularensis strain FSC200 ΔiglC and ΔftdsbA deletion mutants are defective in the ability to enter B cells. Once internalized into B cells, F. tularensis LVS intracellular trafficking occurs along the endosomal pathway, albeit without significant multiplication. The results strongly suggest that BCRs alone within the B-1a subset can ensure the internalization process while the BCRs on B-1b and B-2 cells need co-signaling from the co receptor containing CR1/2 to initiate F. tularensis engulfment. In this case, fluidity of the surface cell membrane is a prerequisite for the bacteria's internalization. The results substantially underline the functional heterogeneity of B cell subsets in relation to F. tularensis.

  14. Vaccination of mice with plasmids expressing processed capsid protein of foot-and-mouth disease virus - Importance of dominant and subdominant epitopes for antigenicity and protection

    DEFF Research Database (Denmark)

    Frimann, Tine; Barfoed, Annette Malene; Aasted, Bent;

    2007-01-01

    The capsid of foot-and-mouth disease virus (FMDV) displays several independent B cell epitopes, which stimulate the production of neutralising antibodies. Some of these epitopes are highly variable between virus strains, but dominate the immune response. The site A on VP1 is the most prominent...... example of a dominant and variable site. This variability is a problem when designing vaccines against this disease, because it necessitates a close match between vaccine strain and virus in an outbreak. We have introduced a series of mutations into viral capsid proteins with the aim of selectively...... silencing two dominant and highly variable epitopes and thereby divert immune responses toward less dominant but more conserved, protective epitopes. When mice were immunized with modified antigens, the resulting immune responses showed a higher degree of cross-reactivity towards heterologous virus...

  15. Regulatory T cells and B cells: implication on autoimmune diseases

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

    The regulatory T (Treg) cells play an important role in the maintenance of homeostasis and the prevention of autoimmune diseases. Although most studies are focusing on the role of Treg cells in T cells and T cells-mediated diseases, these cells also directly affect B cells and other non-T cells. This manuscript updates the role of Treg cells on the B cells and B cell-mediated diseases. In addition, the mechanisms whereby Treg cells suppress B cell responses have been discussed.

  16. Invited article: inhibition of B cell functions: implications for neurology.

    Science.gov (United States)

    Dalakas, Marinos C

    2008-06-01

    B cells are involved in the pathophysiology of many neurologic diseases, either in a causative or contributory role, via production of autoantibodies, cytokine secretion, or by acting as antigen-presenting cells leading to T cell activation. B cells are clonally expanded in various CNS disorders, such as multiple sclerosis (MS), paraneoplastic CNS disorders, or stiff-person syndrome, and are activated to produce pathogenic autoantibodies in demyelinating neuropathies and myasthenia. B cell activating factor (BAFF) and a proliferating inducing ligand (APRIL), key cytokines for B cell survival, are strongly unregulated in MS brain and in muscles of inflammatory myopathies. Modulation of B cell functions using a series of monoclonal antibodies against CD20+ B cells or the molecules that increase B cell survival, such as BAFF/APRIL and their receptors BAFF-R, TACI, and BCMA, provide a rational approach to the treatment of the aforementioned neurologic disorders. In controlled studies, rituximab, a B cell-depleting monoclonal antibody, has been encouraging in MS and paraproteinemic anti-MAG demyelinating neuropathy, exerting long-lasting remissions. In uncontrolled series, benefit has been reported in several disorders. B cell depletion is a well-tolerated therapeutic option currently explored in the treatment of several autoimmune neurologic disorders.

  17. B cells as a target of immune modulation

    Directory of Open Access Journals (Sweden)

    Hawker Kathleen

    2009-01-01

    Full Text Available B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts. MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell-targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target.

  18. B-Cell Response during Protozoan Parasite Infections

    Directory of Open Access Journals (Sweden)

    María C. Amezcua Vesely

    2012-01-01

    Full Text Available In this review, we discuss how protozoan parasites alter immature and mature B cell compartment. B1 and marginal zone (MZ B cells, considered innate like B cells, are activated during protozoan parasite infections, and they generate short lived plasma cells providing a prompt antibody source. In addition, protozoan infections induce massive B cell response with polyclonal activation that leads to hypergammaglobulnemia with serum antibodies specific for the parasites and self and/or non related antigens. To protect themselves, the parasites have evolved unique ways to evade B cell immune responses inducing apoptosis of MZ and conventional mature B cells. As a consequence of the parasite induced-apoptosis, the early IgM response and an already establish humoral immunity are affected during the protozoan parasite infection. Moreover, some trypanosomatides trigger bone marrow immature B cell apoptosis, influencing the generation of new mature B cells. Simultaneously with their ability to release antibodies, B cells produce cytokines/quemokines that influence the characteristic of cellular immune response and consequently the progression of parasite infections.

  19. The B-cell receptor orchestrates environment-mediated lymphoma survival and drug resistance in B-cell malignancies

    OpenAIRE

    Shain, KH; Tao, J.

    2013-01-01

    Specific niches within the lymphoma tumor microenvironment (TME) provide sanctuary for subpopulations of tumor cells through stromal cell–tumor cell interactions. These interactions notably dictate growth, response to therapy and resistance of residual malignant B cells to therapeutic agents. This minimal residual disease (MRD) remains a major challenge in the treatment of B-cell malignancies and contributes to subsequent disease relapse. B-cell receptor (BCR) signaling has emerged as essenti...

  20. B-cell-mediated strategies to fight chronic allograft rejection

    Directory of Open Access Journals (Sweden)

    Ali H Dalloul

    2013-12-01

    Full Text Available Solid organs have been transplanted for decades. Since the improvement in graft selection and in medical and surgical procedures, the likelihood of graft function after one year is now close to 90%. Nonetheless even well-matched recipients continue to need medications for the rest of their lives hence adverse side effects and enhanced morbidity. Understanding Immune rejection mechanisms, is of increasing importance since the greater use of living-unrelated donors and genetically unmatched individuals. Chronic rejection is devoted to T-cells, however the role of B-cells in rejection has been appreciated recently by the observation that B-cell depletion improve graft survival. By contrast however, B-cells can be beneficial to the grafted tissue. This protective effect is secondary to either the secretion of protective antibodies or the induction of B-cells that restrain excessive inflammatory responses, chiefly by local provision of IL-10, or inhibit effector T-cells by direct cellular interactions. As a proof of concept B-cell-mediated infectious transplantation tolerance could be achieved in animal models, and evidence emerged that the presence of such B-cells in transplanted patients correlate with a favorable outcome. Among these populations, regulatory B-cells constitute a recently described population. These cells may develop as a feedback mechanism to prevent uncontrolled reactivity to antigens and inflammatory stimuli. The difficult task for the clinician, is to quantify the respective ratios and functions of tolerant vs effector B-cells within a transplanted organ, at a given time point in order to modulate B-cell-directed therapy. Several receptors at the B-cell membrane as well as signaling molecules, can now be targeted for this purpose. Understanding the temporal expansion of regulatory B-cells in grafted patients and the stimuli that activate them will help in the future to implement specific strategies aimed at fighting chronic

  1. Conservation of HIV-1 T cell epitopes across time and clades

    DEFF Research Database (Denmark)

    Levitz, Lauren; Koita, Ousmane A; Sangare, Kotou;

    2012-01-01

    HIV genomic sequence variability has complicated efforts to generate an effective globally relevant vaccine. Regions of the viral genome conserved in sequence and across time may represent the "Achilles' heel" of HIV. In this study, highly conserved T-cell epitopes were selected using...... immunoinformatics tools combining HLA-A2 supertype binding predictions with relative global conservation. Analysis performed in 2002 on 10,803 HIV-1 sequences, and again in 2009, on 43,822 sequences, yielded 38 HLA-A2 epitopes. These epitopes were experimentally validated for HLA binding and immunogenicity with...... time, clades, and geography supports the hypothesis that such epitopes could provide effective coverage of virus diversity and would be appropriate for inclusion in a globally relevant HIV vaccine....

  2. BAFF enhances chemotaxis of primary human B cells: a particular synergy between BAFF and CXCL13 on memory B cells.

    Science.gov (United States)

    Badr, Gamal; Borhis, Gwenoline; Lefevre, Eric A; Chaoul, Nada; Deshayes, Frederique; Dessirier, Valérie; Lapree, Genevieve; Tsapis, Andreas; Richard, Yolande

    2008-03-01

    B-cell-activating factor of the TNF family, (BAFF), and a proliferation-inducing ligand (APRIL) regulate B-lymphocyte survival and activation. We report that BAFF, but not APRIL, increased the chemotactic response of primary human B cells to CCL21, CXCL12, and CXCL13. The BAFF-induced increase in B-cell chemotaxis was totally abolished by blockade of BAFF-R and was strongly dependent on the activation of PI3K/AKT, NF-kappaB, and p38MAPK pathways. BAFF had similar effects on the chemotaxis of naive and memory B cells in response to CCL21 but increased more strongly that of memory B cells to CXCL13 than that of naive B cells. Our findings indicate a previously unreported role for the BAFF/BAFF-R pair in mature B-cell chemotaxis. The synergy between CXCL13 and BAFF produced by stromal cells and follicular dendritic cells may have important implications for B-cell homeostasis, the development of normal B-cell areas, and for the formation of germinal center-like follicles that may be observed in various autoimmune diseases.

  3. Tissue-specific B-cell dysfunction and generalized memory B-cell loss during acute SIV infection.

    Directory of Open Access Journals (Sweden)

    Sandrine Peruchon

    Full Text Available BACKGROUND: Primary HIV-infected patients display severe and irreversible damage to different blood B-cell subsets which is not restored by highly efficient anti-retroviral therapy (HAART. Because longitudinal investigations of primary HIV-infection is limited by the availability of lymphoid organs, we studied the tissue-specific B-cell dysfunctions in acutely simian immunodeficiency virus (SIV mac251-infected Cynomolgus macaques. METHODS AND FINDINGS: Experiments were performed on three groups of macaques infected for 14, 21 or 28 days and on three groups of animals treated with HAART for two-weeks either initiated at 4 h, 7 or 14 days post-infection (p.i.. We have simultaneously compared changes in B-cell phenotypes and functions and tissue organization of B-cell areas in various lymphoid organs. We showed that SIV induced a steady decline in SIgG-expressing memory (SIgD(-CD27(+ B-cells in spleen and lymph nodes during the first 4 weeks of infection, concomitant to selective homing/sequestration of B-cells to the small intestine and spleen. SIV non-specific Ig production was transiently increased before D14p.i., whereas SIV-specific Ig production was only detectable after D14p.i., coinciding with the presence of CD8(+ T-cells and IgG-expressing plasma cells within germinal centres. Transient B-cell apoptosis on D14p.i. and commitment to terminal differentiation contributed to memory B-cell loss. HAART abrogated B-cell apoptosis, homing to the small intestine and SIV-specific Ig production but had minimal effect on early Ig production, increased B-cell proportions in spleen and loss of memory B-cells. Therefore, virus-B-cell interactions and SIV-induced inflammatory cytokines may differently contribute to early B-cell dysfunction and impaired SIV/HIV-specific antibody response. CONCLUSIONS: These data establish tissue-specific impairments in B-cell trafficking and functions and a generalized and steady memory B-cell loss in secondary lymphoid

  4. Therapeutic polypeptides based on HBV core 18-27 epitope can induce CD8+ CTL-mediated cytotoxicity in HLA-A2+ human PBMCs

    Institute of Scientific and Technical Information of China (English)

    Tong-Dong Shi; Yu-Zhang Wu; Zheng-Cai Jia; Li-Yun Zou; Wei Zhou

    2004-01-01

    AIM: To explore how to improve the immunogenicity of HBcAg CTL epitope based polypeptides and to trigger an HBV-specific HLA I-restricted CD8+ T cell response in vitro.METHODS: A new panel of mimetic therapeutic peptides based on the immunodominant B cell epitope of HBV PreS218-24 region, the CTL epitope of HBcAg18-27 and the universal T helper epitope of tetanus toxoid (TT) 830-843was designed using computerized molecular design method and synthesized by Merrifield's solid-phase peptide synthesis.Their immunological properties of stimulating activation and proliferation of lymphocytes, of inducing TH1 polarization,CD8+ T cell magnification and HBV-specific CD8+ CTL mediated cytotoxicity were investigatedin vitro using HLAA2+ human peripheral blood mononuclear cells (PBMCs) from healthy donors and chronic hepatitis B patients.RESULTS: Results demonstrated that the therapeutic polypeptides based on immunodominant HBcAg18-27 CTL,PreS2 B- and universal TH epitopes could stimulate the activation and proliferation of lymphocytes, induce specifically and effectively CD8+ T cell expansion and vigorous HBVspecific CTL-mediated cytotoxicity in human PBMCs.CONCLUSION: It indicated that the introduction of immunodominant T helper plus B-epitopes with short and flexible linkers could dramatically improve the immunogenicity of short CTL epitopes in vitro.

  5. Characterization of Immunodominant BK Polyomavirus 9mer Epitope T Cell Responses

    Science.gov (United States)

    Cioni, M.; Leboeuf, C.; Comoli, P.; Ginevri, F.

    2016-01-01

    Uncontrolled BK polyomavirus (BKPyV) replication in kidney transplant recipients (KTRs) causes polyomavirus‐associated nephropathy and allograft loss. Reducing immunosuppression is associated with clearing viremia and nephropathy and increasing BKPyV‐specific T cell responses in most patients; however, current immunoassays have limited sensitivity, target mostly CD4+ T cells, and largely fail to predict onset and clearance of BKPyV replication. To characterize BKPyV‐specific CD8+ T cells, bioinformatics were used to predict 9mer epitopes in the early viral gene region (EVGR) presented by 14 common HLAs in Europe and North America. Thirty‐nine EVGR epitopes were experimentally confirmed by interferon‐γ enzyme‐linked immunospot assays in at least 30% of BKPyV IgG–seropositive healthy participants. Most 9mers clustered in domains, and some were presented by more than one HLA class I, as typically seen for immunodominant epitopes. Specific T cell binding using MHC class I streptamers was demonstrated for 21 of 39 (54%) epitopes. In a prospective cohort of 118 pediatric KTRs, 19 patients protected or recovering from BKPyV viremia were experimentally tested, and 13 epitopes were validated. Single HLA mismatches were not associated with viremia, suggesting that failing immune control likely involves multiple factors including maintenance immunosuppression. Combining BKPyV load and T cell assays using immunodominant epitopes may help in evaluating risk and reducing immunosuppression and may lead to safe adoptive T cell transfer. PMID:26663765

  6. Induction of multi-epitope specific antibodies against HIV-1 by multi-epitope vaccines

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Some neutralizing antibodies against HIV-1 envelope proteins were highly effective to inhibit the infection of different strains in vitro, and existed in the infected individuals with very low levels. We suggested multi-epitope-vaccine as a new strategy to increase levels of neutralizing antibodies and the abilities against HIV mutation in vivo. Two candidate multi-epitope-vaccines induced antibodies with predefined multi-epitope-specificity in rhesus macaque. These antibodies recognized corresponding neutralizing epitopes on epitope-peptides, gp41 peptides, V3 loop peptide, rsgp41 and rgp120. Besides, three candidate epitope-vaccines in combination (another kind of multi-epitopevaccines) showed similar potency to induce predefined multiple immune responses in rabbits. These results suggest that multi-epitope-vaccines may be a new strategy to induce multi-antiviral activities against HIV-1 infection and mutafions.

  7. A Novel Algorithm for Macromolecular Epitope Matching

    Directory of Open Access Journals (Sweden)

    Stanislav Jakuschev

    2009-03-01

    Full Text Available Many macromolecules, namely proteins, show functional substructures or epitopes defined by characteristic spatial arrangements of groups of specific atoms or residues. The identification of such substructures in a set of macromolecular 3D-structures solves an important problem in molecular biology as it allows the assignment of functions to molecular moieties and thus opens the possibility of a mechanistic understanding of molecular function. We have devised an algorithm that models a functional epitope formed by a group of atoms or residues as set of points in cartesian space with associated functional properties. The algorithm searches for similar epitopes in a database of structures by an efficient multistage comparison of distance sets in the epitope and in the structures from the database. The search results in a list of optimal matches and corresponding optimal superpositions of query epitope and matching epitopes from the database. The algorithm is discussed against the background of related approaches, and it is successfully tested in three application scenarios: global match of two homologous proteins, search for an epitope on a homologous protein, and finding matching epitopes in a protein database.

  8. B cells as therapeutic targets in autoimmune neurological disorders.

    Science.gov (United States)

    Dalakas, Marinos C

    2008-10-01

    B cells have a fundamental role in the pathogenesis of various autoimmune neurological disorders, not only as precursors of antibody-producing cells, but also as important regulators of the T-cell activation process through their participation in antigen presentation, cytokine production, and formation of ectopic germinal centers in the intermeningeal spaces. Two B-cell trophic factors-BAFF (B-cell-activating factor) and APRIL (a proliferation-inducing ligand)-and their receptors are strongly upregulated in many immunological disorders of the CNS and PNS, and these molecules contribute to clonal expansion of B cells in situ. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules and trophic factors provides a rational approach to the treatment of autoimmune neurological diseases. This article reviews the role of B cells in autoimmune neurological disorders and summarizes the experience to date with rituximab, a B-cell-depleting monoclonal antibody against CD20, for the treatment of relapsing-remitting multiple sclerosis, autoimmune neuropathies, neuromyelitis optica, paraneoplastic neurological disorders, myasthenia gravis, and inflammatory myopathies. It is expected that ongoing controlled trials will establish the efficacy and long-term safety profile of anti-B-cell agents in several autoimmune neurological disorders, as well as exploring the possibility of a safe and synergistic effect with other immunosuppressants or immunomodulators.

  9. Therapeutic strategies targeting B-cells in multiple sclerosis.

    Science.gov (United States)

    Milo, Ron

    2016-07-01

    Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system (CNS) that traditionally has been considered to be mediated primarily by T-cells. Increasing evidence, however, suggests the fundamental role of B-cells in the pathogenesis of the disease. Recent strategies targeting B-cells in MS have demonstrated impressive and sometimes surprising results: B-cell depletion by monoclonal antibodies targeting the B-cell surface antigen CD20 (e.g. rituximab, ocrelizumab, ofatumumab) was shown to exert profound anti-inflammatory effect in MS with favorable risk-benefit ratio, with ocrelizumab demonstrating efficacy in both relapsing-remitting (RR) and primary-progressive (PP) MS in phase III clinical trials. Depletion of CD52 expressing T- and B-cells and monocytes by alemtuzumab resulted in impressive and durable suppression of disease activity in RRMS patients. On the other hand, strategies targeting B-cell cytokines such as atacicept resulted in increased disease activity. As our understanding of the biology of B-cells in MS is increasing, new compounds that target B-cells continue to be developed which promise to further expand the armamentarium of MS therapies and allow for more individualized therapy for patients with this complex disease.

  10. DNA breaks early in replication in B cell cancers

    Science.gov (United States)

    Research by scientists at the NCI has identified a new class of DNA sites in cells that break early in the replication process. They found that these break sites correlate with damage often seen in B cell cancers, such as diffuse large B cell lymphoma.

  11. Shaping T Cell – B Cell Collaboration in the Response to Human Immunodeficiency Virus Type 1 Envelope Glycoprotein gp120 by Peptide Priming

    Science.gov (United States)

    Steede, N. Kalaya; Rust, Blake J.; Hossain, Mohammad M.; Freytag, Lucy C.; Robinson, James E.; Landry, Samuel J.

    2013-01-01

    Prime-boost vaccination regimes have shown promise for obtaining protective immunity to HIV. Poorly understood mechanisms of cellular immunity could be responsible for improved humoral responses. Although CD4+ T-cell help promotes B-cell development, the relationship of CD4+ T-cell specificity to antibody specificity has not been systematically investigated. Here, protein and peptide-specific immune responses to HIV-1 gp120 were characterized in groups of ten mucosally immunized BALB/c mice. Protein and peptide reactivity of serum antibody was tested for correlation with cytokine secretion by splenocytes restimulated with individual gp120 peptides. Antibody titer for gp120 correlated poorly with the peptide-stimulated T-cell response. In contrast, titers for conformational epitopes, measured as crossreactivity or CD4-blocking, correlated with average interleukin-2 and interleukin-5 production in response to gp120 peptides. Antibodies specific for conformational epitopes and individual gp120 peptides typically correlated with T-cell responses to several peptides. In order to modify the specificity of immune responses, animals were primed with a gp120 peptide prior to immunization with protein. Priming induced distinct peptide-specific correlations of antibodies and T-cells. The majority of correlated antibodies were specific for the primed peptides or other peptides nearby in the gp120 sequence. These studies suggest that the dominant B-cell subsets recruit the dominant T-cell subsets and that T-B collaborations can be shaped by epitope-specific priming. PMID:23776539

  12. Shaping T cell - B cell collaboration in the response to human immunodeficiency virus type 1 envelope glycoprotein gp120 by peptide priming.

    Directory of Open Access Journals (Sweden)

    N Kalaya Steede

    Full Text Available Prime-boost vaccination regimes have shown promise for obtaining protective immunity to HIV. Poorly understood mechanisms of cellular immunity could be responsible for improved humoral responses. Although CD4+ T-cell help promotes B-cell development, the relationship of CD4+ T-cell specificity to antibody specificity has not been systematically investigated. Here, protein and peptide-specific immune responses to HIV-1 gp120 were characterized in groups of ten mucosally immunized BALB/c mice. Protein and peptide reactivity of serum antibody was tested for correlation with cytokine secretion by splenocytes restimulated with individual gp120 peptides. Antibody titer for gp120 correlated poorly with the peptide-stimulated T-cell response. In contrast, titers for conformational epitopes, measured as crossreactivity or CD4-blocking, correlated with average interleukin-2 and interleukin-5 production in response to gp120 peptides. Antibodies specific for conformational epitopes and individual gp120 peptides typically correlated with T-cell responses to several peptides. In order to modify the specificity of immune responses, animals were primed with a gp120 peptide prior to immunization with protein. Priming induced distinct peptide-specific correlations of antibodies and T-cells. The majority of correlated antibodies were specific for the primed peptides or other peptides nearby in the gp120 sequence. These studies suggest that the dominant B-cell subsets recruit the dominant T-cell subsets and that T-B collaborations can be shaped by epitope-specific priming.

  13. B-Cell Pathology in Juvenile Idiopathic Arthritis

    Directory of Open Access Journals (Sweden)

    V. Wiegering

    2010-01-01

    Full Text Available Juvenile Idiopathic Arthritis (JIA is the most common cause of chronic arthritis in childhood and adolescents and encompasses a heterogeneous group of different diseases. Due to the promising results of B-cell depleting therapies in rheumatoid arthritis the role of B-cells in autoimmune diseases has to be discussed in a new context. Additionally, experiments in mouse models have shed new light on the antibody-independent role of B-cells in the development of autoimmune diseases. In this review we will discuss the importance of B-cells in the pathogenesis of JIA appraising the question for an immunological basis of B-cell targeted therapy in JIA.

  14. Anti-B cell antibody therapies for inflammatory rheumatic diseases

    DEFF Research Database (Denmark)

    Faurschou, Mikkel; Jayne, David R W

    2014-01-01

    Several monoclonal antibodies targeting B cells have been tested as therapeutics for inflammatory rheumatic diseases. We review important observations from randomized clinical trials regarding the efficacy and safety of anti-B cell antibody-based therapies for rheumatoid arthritis, systemic lupus...... erythematosus, antineutrophil cytoplasmic antibody-associated vasculitis, polymyositis/dermatomyositis, and primary Sjögren's syndrome. For some anti-B cell agents, clinical benefits have been convincingly demonstrated, while other B cell-targeted therapies failed to improve outcomes when added to standard...... and functions in rheumatic disorders. Future studies should also evaluate how to maintain disease control by means of conventional and/or biologic immunosuppressants after remission-induction with anti-B cell antibodies....

  15. Prediction of the B Cell Antigenic Epitopes and Homology Modeling Study of Lentil Allergen Len c 3%扁豆过敏原Len c 3蛋白B细胞抗原表位预测及同源建模

    Institute of Scientific and Technical Information of China (English)

    郭予和; 何颖; 邹泽红; 刘雪婷; 许晨霞; 陶爱林

    2014-01-01

    目的:通过应用生物信息学软件模拟、分析预测扁豆过敏原Lenc3蛋白的结构、性质及B细胞抗原表位,为探索基于扁豆过敏原Len c 3抗原表位的改造提供依据.方法:从Uniprot蛋白质数据库中得到扁豆过敏原Len c 3的氨基酸序列,通过生物信息学软件Swiss-Model及Swiss-PdbViewer 4.0模拟和分析扁豆过敏原Lenc3蛋白的结构,使用DNAStar软件对其B细胞抗原表位进行模拟、分析预测.结果:扁豆过敏原Len c 3蛋白为疏水性蛋白,在氨基酸残基第7-26位有一跨膜区,Ramachandran图评估扁豆过敏原Len c 3蛋白的三维结构显示其空间构象稳定,Len c 3蛋白潜在的B细胞抗原表位为35-36,48-50,66-71,87-90.结论:本研究通过对扁豆过敏原Len c 3蛋白进行生物信息学分析获得了该过敏原的结构、性质及潜在的B细胞抗原表位,为进一步了解和掌握扁豆过敏原Len c 3蛋白的结构功能以及抗原性改造、单克隆抗体制备、表位疫苗设计等提供重要的线索.

  16. 奥利亚罗非鱼DMO和DMT蛋白二级结构和B细胞抗原表位的预测%Prediction of the Secondary Structure and B Cell Epitopes of DMO and DMT Protein in Oreochromis aureus

    Institute of Scientific and Technical Information of China (English)

    曹谨玲; 陈剑杰; 俞菊华; 吴婷婷

    2006-01-01

    以DMO和DMT氨基酸序列为基础,采用Garnier-Robson法、Chou-Fasman法和KarplusSchulz法预测蛋白质的二级结构;按Kyte-Doolittle法、Emini法和Jameson-Wolf法预测DMO和DMT蛋白的B细胞抗原表位.预测结果表明:在DMO蛋白N-端第80~112,144~147,193~194,251~255,260~269区段和279~283区段,DMT蛋白N-端61~86,98~105,140~146,239~241区段和第269~273区段,可能是α-螺旋中心;DMO蛋白N-端第59~61,69~70,148~150区段和383~390区段,DMT蛋白的N-端第125~129,207~213,255~264区段和第281~284区段,可能是β-折叠中心;在DMO蛋白分子N-端40~41,44~45,50~51,128~129,189~192,204~207,216~222,226~233,244~246,298~299区段和第323~326区段和DMT蛋白分子N-端第12~13,26~27,43~44,58~60,93~95,115~120,136~139区段和第149~151区段具有较柔软的结构,这些区段有可能进行一定幅度的摆动或折叠而形成较复杂的三级结构.DMO蛋白N-端第1~5,41~51,65~67,86~89,98~110,154~170,183~203,205~248,258~264,284~291,293~298,270~375,389~392,402~410区域和DMT蛋白N-端第1~9,17~28,77~84,114~123,131~139,157~184,196~207区域可能是B细胞表位优势区域.以蛋白质的二级结构预测作为辅助手段,用抗原指数,亲水性参数和可及性参数预测DMO和DMT蛋白的B细胞表位,为DMO和DMT蛋白单克隆抗体的制备提供了线索,为系统研究奥利亚罗非鱼DMO和DMT基因的性别调控机理提供参考.

  17. Prediction and verification of the B cell epitopes of the major virulent factors of piglet edema diseaseinducing Escherichia coli%猪水肿病大肠杆菌主要毒力因子的B细胞表位预测与验证

    Institute of Scientific and Technical Information of China (English)

    任文凯; 张美玲; 刘建飞; 陈林; 彭远义

    2010-01-01

    @@ 猪水肿病是由产类志贺毒素大肠杆菌引起的仔猪的一种急性、致死性传染病,其发病率为10%~35%,致死率在90%以上.研究表明,致猪水肿病大肠杆菌主要产生F18ab菌毛和类志贺毒素II型变异体(SLT-IIe)两类毒力因子,F18菌毛中的FedF是发生粘附作用所必需的结构单位,同时高度保守;SLT-IIe的B亚基具有免疫原性,是水肿病毒素保护性抗原所在处,且其核苷酸序列的同源性达到了100%[1-3].本研究旨在对致猪水肿病的两种主要毒力因子FedF和SLT-IIeB进行生物信息学分析,预测其可能的B细胞表位,人工合成短肽,分别与抗F18ab菌毛蛋白和抗大肠杆菌水肿毒素的猪血清进行反应,鉴定短肽的反应原性:与载体蛋白(BSA)偶联后免疫小鼠,测定反应原性,以期获得既有反应原性又有免疫原性的多肽,为猪水肿病表位疫苗及多表位疫苗的研制奠定基础.

  18. Epitope mapping and identification of amino acids critical for mouse IgG-binding to linear epitopes on Gly m Bd 28K.

    Science.gov (United States)

    Xi, Jun; Yan, Huili

    2016-10-01

    Gly m Bd 28K is one of the major allergens in soybeans, but there is limited information on its IgG-binding epitopes. Thirty-four overlapping peptides that covered the entire sequence of Gly m Bd 28K were synthesized, and 3 monoclonal antibodies against Gly m Bd 28K were utilized to identify the IgG-binding regions of Gly m Bd 28K. Three dominant peptides corresponding to (28)GDKKSPKSLFLMSNS(42)(G28-S42), (56)LKSHGGRIFYRHMHI(70)(L56-I70), and (154)ETFQSFYIGGGANSH(168)(E154-H168) were recognized. L56-I70 is the most important epitope, and a competitive ELISA indicated that it could inhibit the binding of monoclonal antibody to Gly m Bd 28K protein. Alanine scanning of L56-I70 documented that F64, Y65, and R66 were the critical amino acids of this epitope. Two bioinformatics tools, ABCpred and BepiPred, were used to predict the epitopes of Gly m Bd 28K, and the predictions were compared with the epitopes that we had located by monoclonal antibodies. PMID:27033966

  19. Memory B cell antibodies to HIV-1 gp140 cloned from individuals infected with clade A and B viruses.

    Directory of Open Access Journals (Sweden)

    Hugo Mouquet

    Full Text Available Understanding the antibody response to HIV-1 in humans that show broad neutralizing serologic activity is a crucial step in trying to reproduce such responses by vaccination. Investigating antibodies with cross clade reactivity is particularly important as these antibodies may target conserved epitopes on the HIV envelope gp160 protein. To this end we have used a clade B YU-2 gp140 trimeric antigen and single-cell antibody cloning methods to obtain 189 new anti-gp140 antibodies representing 51 independent B cell clones from the IgG memory B cells of 3 patients infected with HIV-1 clade A or B viruses and exhibiting broad neutralizing serologic activity. Our results support previous findings showing a diverse antibody response to HIV gp140 envelope protein, characterized by differentially expanded B-cell clones producing highly hypermutated antibodies with heterogenous gp140-specificity and neutralizing activity. In addition to their high-affinity binding to the HIV spike, the vast majority of the new anti-gp140 antibodies are also polyreactive. Although none of the new antibodies are as broad or potent as VRC01 or PG9, two clonally-related antibodies isolated from a clade A HIV-1 infected donor, directed against the gp120 variable loop 3, rank in the top 5% of the neutralizers identified in our large collection of 185 unique gp140-specific antibodies in terms of breadth and potency.

  20. CD83 Modulates B Cell Activation and Germinal Center Responses.

    Science.gov (United States)

    Krzyzak, Lena; Seitz, Christine; Urbat, Anne; Hutzler, Stefan; Ostalecki, Christian; Gläsner, Joachim; Hiergeist, Andreas; Gessner, André; Winkler, Thomas H; Steinkasserer, Alexander; Nitschke, Lars

    2016-05-01

    CD83 is a maturation marker for dendritic cells. In the B cell lineage, CD83 is expressed especially on activated B cells and on light zone B cells during the germinal center (GC) reaction. The function of CD83 during GC responses is unclear. CD83(-/-) mice have a strong reduction of CD4(+) T cells, which makes it difficult to analyze a functional role of CD83 on B cells during GC responses. Therefore, in the present study we generated a B cell-specific CD83 conditional knockout (CD83 B-cKO) model. CD83 B-cKO B cells show defective upregulation of MHC class II and CD86 expression and impaired proliferation after different stimuli. Analyses of GC responses after immunization with various Ags revealed a characteristic shift in dark zone and light zone B cell numbers, with an increase of B cells in the dark zone of CD83 B-cKO mice. This effect was not accompanied by alterations in the level of IgG immune responses or by major differences in affinity maturation. However, an enhanced IgE response was observed in CD83 B-cKO mice. Additionally, we observed a strong competitive disadvantage of CD83-cKO B cells in GC responses in mixed bone marrow chimeras. Furthermore, infection of mice with Borrelia burgdorferi revealed a defect in bacterial clearance of CD83 B-cKO mice with a shift toward a Th2 response, indicated by a strong increase in IgE titers. Taken together, our results show that CD83 is important for B cell activation and modulates GC composition and IgE Ab responses in vivo. PMID:26983787

  1. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking

    Directory of Open Access Journals (Sweden)

    Rocio Flores-Fernández

    2016-01-01

    Full Text Available Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE. In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease.

  2. Myeloma clonotypic B cells are hampered in their ability to undergo B-cell differentiation in vitro

    NARCIS (Netherlands)

    Guikema, JEJ; Vellenga, E; Bakkus, MHC; Bos, NA

    2002-01-01

    In the peripheral blood (PB) of multiple myeloma (MM) patients, clonotypic B cells are present that express the identical V( D) J rearrangements as the malignant plasma cells in the bone marrow. In the present study, the proliferative capacity of clonotypic B cells from MM patients (n = 10) and the

  3. Prolactin Rescues Immature B-Cells from Apoptosis Induced by B-Cell Receptor Cross-Linking

    Science.gov (United States)

    Flores-Fernández, Rocio; Blanco-Favela, Francisco; Fuentes-Pananá, Ezequiel M.; Chávez-Sánchez, Luis; Gorocica-Rosete, Patricia; Pizaña-Venegas, Alberto; Chávez-Rueda, Adriana Karina

    2016-01-01

    Prolactin has an immunomodulatory effect and has been associated with B-cell-triggered autoimmune diseases, such as systemic lupus erythematosus (SLE). In mice that develop SLE, the PRL receptor is expressed in early bone marrow B-cells, and increased levels of PRL hasten disease manifestations, which are correlated with a reduction in the absolute number of immature B-cells. The aim of this work was to determine the effect of PRL in an in vitro system of B-cell tolerance using WEHI-231 cells and immature B-cells from lupus prone MRL/lpr mice. WEHI-231 cells express the long isoform of the PRL receptor, and PRL rescued the cells from cell death by decreasing the apoptosis induced by the cross-linking of the B-cell antigen receptor (BCR) as measured by Annexin V and active caspase-3. This decrease in apoptosis may have been due to the PRL and receptor interaction, which increased the relative expression of antiapoptotic Bcl-xL and decreased the relative expression of proapoptotic Bad. In immature B-cells from MRL/lpr mice, PRL increased the viability and decreased the apoptosis induced by the cross-linking of BCR, which may favor the maturation of self-reactive B-cells and contribute to the onset of disease. PMID:27314053

  4. B-cell receptor signaling inhibitors for treatment of autoimmune inflammatory diseases and B-cell malignancies.

    Science.gov (United States)

    Puri, Kamal D; Di Paolo, Julie A; Gold, Michael R

    2013-08-01

    B-cell receptor (BCR) signaling is essential for normal B-cell development, selection, survival, proliferation, and differentiation into antibody-secreting cells. Similarly, this pathway plays a key role in the pathogenesis of multiple B-cell malignancies. Genetic and pharmacological approaches have established an important role for the Spleen tyrosine kinase (Syk), Bruton's tyrosine kinase (Btk), and phosphatidylinositol 3-kinase isoform p110delta (PI3Kδ) in coupling the BCR and other BCRs to B-cell survival, migration, and activation. In the past few years, several small-molecule inhibitory drugs that target PI3Kδ, Btk, and Syk have been developed and shown to have efficacy in clinical trials for the treatment of several types of B-cell malignancies. Emerging preclinical data have also shown a critical role of BCR signaling in the activation and function of self-reactive B cells that contribute to autoimmune diseases. Because BCR signaling plays a major role in both B-cell-mediated autoimmune inflammation and B-cell malignancies, inhibition of this pathway may represent a promising new strategy for treating these diseases. This review summarizes recent achievements in the mechanism of action, pharmacological properties, and clinical activity and toxicity of these BCR signaling inhibitors, with a focus on their emerging role in treating lymphoid malignancies and autoimmune disorders.

  5. Increased B Cell ADAM10 in Allergic Patients and Th2 Prone Mice.

    Directory of Open Access Journals (Sweden)

    Lauren Folgosa Cooley

    Full Text Available ADAM10, as the sheddase of the low affinity IgE receptor (CD23, promotes IgE production and thus is a unique target for attenuating allergic disease. Herein, we describe that B cell levels of ADAM10, specifically, are increased in allergic patients and Th2 prone WT mouse strains (Balb/c and A/J. While T cell help augments ADAM10 expression, Balb WT B cells exhibit increased ADAM10 in the naïve state and even more dramatically increased ADAM10 after anti-CD40/IL4 stimulation compared C57 (Th1 prone WT B cells. Furthermore, ADAM17 and TNF are reduced in allergic patients and Th2 prone mouse strains (Balb/c and A/J compared to Th1 prone controls. To further understand this regulation, ADAM17 and TNF were studied in C57Bl/6 and Balb/c mice deficient in ADAM10. C57-ADAM10B-/- were more adept at increasing ADAM17 levels and thus TNF cleavage resulting in excess follicular TNF levels and abnormal secondary lymphoid tissue architecture not noted in Balb-ADAM10B-/-. Moreover, the level of B cell ADAM10 as well as Th context is critical for determining IgE production potential. Using a murine house dust mite airway hypersensitivity model, we describe that high B cell ADAM10 level in a Th2 context (Balb/c WT is optimal for disease induction including bronchoconstriction, goblet cell metaplasia, mucus, inflammatory cellular infiltration, and IgE production. Balb/c mice deficient in B cell ADAM10 have attenuated lung and airway symptoms compared to Balb WT and are actually most similar to C57 WT (Th1 prone. C57-ADAM10B-/- have even further reduced symptomology. Taken together, it is critical to consider both innate B cell levels of ADAM10 and ADAM17 as well as Th context when determining host susceptibility to allergic disease. High B cell ADAM10 and low ADAM17 levels would help diagnostically in predicting Th2 disease susceptibility; and, we provide support for the use ADAM10 inhibitors in treating Th2 disease.

  6. Mature Epitope Density - A strategy for target selection based on immunoinformatics and exported prokaryotic proteins

    DEFF Research Database (Denmark)

    Santos, Anderson R; Pereira, Vanessa Bastos; Barbosa, Eudes;

    2013-01-01

    Mature Epitope Density (MED). Our method, though simple, is capable of identifying promising vaccine targets. Our online software implementation provides a computationally light and reliable analysis of bacterial exoproteins and their potential for vaccines or diagnosis projects against pathogenic......BACKGROUND: Current immunological bioinformatic approaches focus on the prediction of allele-specific epitopes capable of triggering immunogenic activity. The prediction of major histocompatibility complex (MHC) class I epitopes is well studied, and various software solutions exist for this purpose...... organisms. We evaluated our computational approach by using the Mycobacterium tuberculosis (Mtb) H37Rv exoproteome as a gold standard model. A literature search was carried out on 60 out of 553 Mtb's predicted exoproteins, looking for previous experimental evidence concerning their possible antigenicity...

  7. Phenotypic characterization of autoreactive B cells--checkpoints of B cell tolerance in patients with systemic lupus erythematosus.

    Directory of Open Access Journals (Sweden)

    Annett M Jacobi

    Full Text Available DNA-reactive B cells play a central role in systemic lupus erythematosus (SLE; DNA antibodies precede clinical disease and in established disease correlate with renal inflammation and contribute to dendritic cell activation and high levels of type 1 interferon. A number of central and peripheral B cell tolerance mechanisms designed to control the survival, differentiation and activation of autoreactive B cells are thought to be disturbed in patients with SLE. The characterization of DNA-reactive B cells has, however, been limited by their low frequency in peripheral blood. Using a tetrameric configuration of a peptide mimetope of DNA bound by pathogenic anti-DNA antibodies, we can identify B cells producing potentially pathogenic DNA-reactive antibodies. We, therefore, characterized the maturation and differentiation states of peptide, (ds double stranded DNA cross-reactive B cells in the peripheral blood of lupus patients and correlated these with clinical disease activity. Flow cytometric analysis demonstrated a significantly higher frequency of tetramer-binding B cells in SLE patients compared to healthy controls. We demonstrated the existence of a novel tolerance checkpoint at the transition of antigen-naïve to antigen-experienced. We further demonstrate that patients with moderately active disease have more autoreactive B cells in both the antigen-naïve and antigen-experienced compartments consistent with greater impairment in B cell tolerance in both early and late checkpoints in these patients than in patients with quiescent disease. This methodology enables us to gain insight into the development and fate of DNA-reactive B cells in individual patients with SLE and paves the way ultimately to permit better and more customized therapies.

  8. Automated Detection of Conformational Epitopes Using Phage Display Peptide Sequences

    Directory of Open Access Journals (Sweden)

    Surendra S Negi

    2009-01-01

    Full Text Available Background: Precise determination of conformational epitopes of neutralizing antibodies represents a key step in the rational design of novel vaccines. A powerful experimental method to gain insights on the physical chemical nature of conformational epitopes is the selection of linear peptides that bind with high affinities to a monoclonal antibody of interest by phage display technology. However, the structural characterization of conformational epitopes from these mimotopes is not straightforward, and in the past the interpretation of peptide sequences from phage display experiments focused on linear sequence analysis to find a consensus sequence or common sequence motifs.Results: We present a fully automated search method, EpiSearch that predicts the possible location of conformational epitopes on the surface of an antigen. The algorithm uses peptide sequences from phage display experiments as input, and ranks all surface exposed patches according to the frequency distribution of similar residues in the peptides and in the patch. We have tested the performance of the EpiSearch algorithm for six experimental data sets of phage display experiments, the human epidermal growth factor receptor-2 (HER-2/neu, the antibody mAb Bo2C11 targeting the C2 domain of FVIII, antibodies mAb 17b and mAb b12 of the HIV envelope protein gp120, mAb 13b5 targeting HIV-1 capsid protein and 80R of the SARS coronavirus spike protein. In all these examples the conformational epitopes as determined by the X-ray crystal structures of the antibody-antigen complexes, were found within the highest scoring patches of EpiSearch, covering in most cases more than 50% residues of experimental observed conformational epitopes. Input options of the program include mapping of a single peptide or a set of peptides on the antigen structure, and the results of the calculation can be visualized on our interactive web server.Availability: Users can access the EpiSearch from our web

  9. Exploiting human memory B cell heterogeneity for improved vaccine efficacy

    Directory of Open Access Journals (Sweden)

    Noel Thomas Pauli

    2011-12-01

    Full Text Available The major goal in vaccination is establishment of long-term, prophylactic humoral memory to a pathogen. Two major components to long-lived humoral memory are plasma cells for the production of specific immunoglobulin and memory B cells that survey for their specific antigen in the periphery for later affinity maturation, proliferation, and differentiation. The study of human B cell memory has been aided by the discovery of a general marker for B cell memory, expression of CD27; however, new data suggests the existence of CD27- memory B cells as well. These recently described non-canonical memory populations have increasingly pointed to the heterogeneity of the memory compartment. The novel B memory subsets in humans appear to have unique origins, localization, and functions compared to what was considered to be a classical memory B cell. In this article, we review the known B cell memory subsets, the establishment of B cell memory in vaccination and infection, and how understanding these newly described subsets can inform vaccine design and disease treatment.

  10. Salmonella induces PD-L1 expression in B cells.

    Science.gov (United States)

    Lopez-Medina, Marcela; Perez-Lopez, Araceli; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2015-10-01

    Salmonella persists for a long time in B cells; however, the mechanism(s) through which infected B cells avoid effector CD8 T cell responses has not been characterized. In this study, we show that Salmonella infects and survives within all B1 and B2 cell subpopulations. B cells are infected with a Salmonella typhimurium strain expressing an ovalbumin (OVA) peptide (SIINFEKL) to evaluate whether B cells process and present Salmonella antigens in the context of MHC-I molecules. Our data showed that OVA peptides are presented by MHC class I K(b)-restricted molecules and the presented antigen is generated through proteasomal degradation and vacuolar processing. In addition, Salmonella-infected B cells express co-stimulatory molecules such as CD40, CD80, and CD86 as well as inhibitory molecules such as PD-L1. Thus, the cross-presentation of Salmonella antigens and the expression of activation molecules suggest that infected B cells are able to prime and activate specific CD8(+) T cells. However, the Salmonella infection-stimulated expression of PD-L1 suggests that the PD-1/PD-L1 pathway may be involved in turning off the cytotoxic effector response during Salmonella persistent infection, thereby allowing B cells to become a reservoir for the bacteria.

  11. BTK Signaling in B Cell Differentiation and Autoimmunity.

    Science.gov (United States)

    Corneth, Odilia B J; Klein Wolterink, Roel G J; Hendriks, Rudi W

    2016-01-01

    Since the original identification of Bruton's tyrosine kinase (BTK) as the gene defective in the primary immunodeficiency X-linked agammaglobulinemia (XLA) in 1993, our knowledge on the physiological function of BTK has expanded impressively. In this review, we focus on the role of BTK during B cell differentiation in vivo, both in the regulation of expansion and in the developmental progression of pre-B cells in the bone marrow and as a crucial signal transducer of signals downstream of the IgM or IgG B cell antigen receptor (BCR) in mature B cells governing proliferation, survival, and differentiation. In particular, we highlight BTK function in B cells in the context of host defense and autoimmunity. Small-molecule inhibitors of BTK have very recently shown impressive anti-tumor activity in clinical studies in patients with various B cell malignancies. Since promising effects of BTK inhibition were also seen in experimental animal models for lupus and rheumatoid arthritis, BTK may be a good target for controlling autoreactive B cells in patients with systemic autoimmune disease.

  12. Design of a heterosubtypic epitope-based peptide vaccine fused with hemokinin-1 against influenza viruses

    Institute of Scientific and Technical Information of China (English)

    Shahla; Shahsavandi; Mohammad; Majid; Ebrahimi; Kaveh; Sadeghi; Homayoon; Mahravani

    2015-01-01

    Influenza viruses continue to emerge and re-emerge, posing new threats for public health. Control and treatment of influenza depends mainly on vaccination and chemoprophylaxis with approved antiviral drugs. Identification of specific epitopes derived from influenza viruses has significantly advanced the development of epitope-based vaccines. Here, we explore the idea of using HLA binding data to design an epitope-based vaccine that can elicit heterosubtypic T-cell responses against circulating H7N9, H5N1, and H9N2 subtypes. The hemokinin-1(HK-1) peptide sequence was used to induce immune responses against the influenza viruses. Five conserved high score cytotoxic T lymphocyte(CTL) epitopes restricted to HLA-A*0201-binding peptides within the hemagglutinin(HA) protein of the viruses were chosen, and two HA CTL/HK-1 chimera protein models designed. Using in silico analysis, which involves interferon epitope scanning, protein structure prediction, antigenic epitope determination, and model quality evaluation, chimeric proteins were designed. The applicability of one of these proteins as a heterosubtypic epitopebased vaccine candidate was analyzed.

  13. Human Memory B Cells in Healthy Gingiva, Gingivitis, and Periodontitis.

    Science.gov (United States)

    Mahanonda, Rangsini; Champaiboon, Chantrakorn; Subbalekha, Keskanya; Sa-Ard-Iam, Noppadol; Rattanathammatada, Warattaya; Thawanaphong, Saranya; Rerkyen, Pimprapa; Yoshimura, Fuminobu; Nagano, Keiji; Lang, Niklaus P; Pichyangkul, Sathit

    2016-08-01

    The presence of inflammatory infiltrates with B cells, specifically plasma cells, is the hallmark of periodontitis lesions. The composition of these infiltrates in various stages of homeostasis and disease development is not well documented. Human tissue biopsies from sites with gingival health (n = 29), gingivitis (n = 8), and periodontitis (n = 21) as well as gingival tissue after treated periodontitis (n = 6) were obtained and analyzed for their composition of B cell subsets. Ag specificity, Ig secretion, and expression of receptor activator of NF-κB ligand and granzyme B were performed. Although most of the B cell subsets in healthy gingiva and gingivitis tissues were CD19(+)CD27(+)CD38(-) memory B cells, the major B cell component in periodontitis was CD19(+)CD27(+)CD38(+)CD138(+)HLA-DR(low) plasma cells, not plasmablasts. Plasma cell aggregates were observed at the base of the periodontal pocket and scattered throughout the gingiva, especially apically toward the advancing front of the lesion. High expression of CXCL12, a proliferation-inducing ligand, B cell-activating factor, IL-10, IL-6, and IL-21 molecules involved in local B cell responses was detected in both gingivitis and periodontitis tissues. Periodontitis tissue plasma cells mainly secreted IgG specific to periodontal pathogens and also expressed receptor activator of NF-κB ligand, a bone resorption cytokine. Memory B cells resided in the connective tissue subjacent to the junctional epithelium in healthy gingiva. This suggested a role of memory B cells in maintaining periodontal homeostasis. PMID:27335500

  14. Hepatitis B synthetic immunogen comprised of nucleocapsid T-cell sites and an envelope B-cell epitope.

    OpenAIRE

    Milich, D R; Hughes, J L; A. McLachlan; Thornton, G B; Moriarty, A.

    1988-01-01

    Previous studies located T-cell recognition of the nucleocapsid of the hepatitis B virus (HBcAg) to residues 120-140 in mice bearing the H-2s or H-2b haplotypes. Herein, we demonstrate that B10.S (H-2s) and B10 (H-2b) H-2 congenic strains recognize distinct T-cell sites within the p120-140 (a synthetic peptide corresponding to residues 120-140 of HBcAg) sequence defined by p120-131 and p129-140, respectively. Peptide p120-131 stimulates B10.S HBcAg-primed T cells, and reciprocally p120-131-pr...

  15. Human pregnancy-associated malaria-specific B cells target polymorphic, conformational epitopes in VAR2CSA

    DEFF Research Database (Denmark)

    Barfod, L.; Bernasconi, N. L.; Dahlback, M.;

    2007-01-01

    Pregnancy-associated malaria (PAM) is caused by Plasmodium falciparum-infected erythrocytes (IEs) that bind to chondroitin sulphate A (CSA) in the placenta by PAM-associated clonally variant surface antigens (VSA). Pregnancy-specific VSA (VSA(PAM)), which include the PfEMP1 variant VAR2CSA, are t...

  16. Dominant B-cell epitopes from cancer/stem cell antigen SOX2 recognized by serum samples from cancer patients

    OpenAIRE

    Shih, Julia; Rahman, Munira; Luong, Quang T; Lomeli, Shirley H.; Riss, Joseph; Prins, Robert M.; Gure, Ali O.; Zeng, Gang

    2014-01-01

    Human sex determining region Y-box 2 (SOX2) is an important transcriptional factor involved in the pluripotency and stemness of human embryonic stem cells. SOX2 plays important roles in maintaining cancer stem cell activities of melanoma and cancers of the brain, prostate, breast, and lung. SOX2 is also a lineage survival oncogene for squamous cell carcinoma of the lung and esophagus. Spontaneous cellular and humoral immune responses against SOX2 present in cancer patients classify it as a tu...

  17. Epitope Mapping of Metuximab on CD147 Using Phage Display and Molecular Docking

    Directory of Open Access Journals (Sweden)

    Bifang He

    2013-01-01

    Full Text Available Metuximab is the generic name of Licartin, a new drug for radioimmunotherapy of hepatocellular carcinoma. Although it is known to be a mouse monoclonal antibody against CD147, the complete epitope mediating the binding of metuximab to CD147 remains unknown. We panned the Ph.D.-12 phage display peptide library against metuximab and got six mimotopes. The following bioinformatics analysis based on mimotopes suggested that metuximab recognizes a conformational epitope composed of more than 20 residues. The residues of its epitope may include T28, V30, K36, L38, K57, F74, D77, S78, D79, D80, Q81, G83, S86, N98, Q100, L101, H102, G103, P104, V131, P132, and K191. The homology modeling of metuximab and the docking of CD147 to metuximab were also performed. Based on the top one docking model, the epitope was predicted to contain 28 residues: AGTVFTTV (23–30, I37, D45, E84, V88, EPMGTANIQLH (92–102, VPP (131–133, Q164, and K191. Almost half of the residues predicted on the basis of mimotope analysis also appear in the docking result, indicating that both results are reliable. As the predicted epitopes of metuximab largely overlap with interfaces of CD147-CD147 interactions, a structural mechanism of metuximab is proposed as blocking the formation of CD147 dimer.

  18. The Immune Epitope Database 2.0

    DEFF Research Database (Denmark)

    Hoof, Ilka; Vita, R; Zarebski, L;

    2010-01-01

    of 4 years, the data from 180,978 experiments were curated manually from the literature, which covers approximately 99% of all publicly available information on peptide epitopes mapped in infectious agents (excluding HIV) and 93% of those mapped in allergens. In addition, data that would otherwise...... be unavailable to the public from 129,186 experiments were submitted directly by investigators. The curation of epitopes related to autoimmunity is expected to be completed by the end of 2010. The database can be queried by epitope structure, source organism, MHC restriction, assay type or host organism, among...

  19. B cell development in the bone marrow is regulated by homeostatic feedback exerted by mature B cells

    Directory of Open Access Journals (Sweden)

    Gitit eShahaf

    2016-03-01

    Full Text Available Cellular homeostasis in the B cell compartment is strictly imposed to balance cell production and cell loss. However, it is not clear whether B cell development in the bone marrow (BM is an autonomous process or subjected to regulation by the peripheral B cell compartment. To specifically address this question, we used mice transgenic for human CD20, where effective depletion of B lineage cells is obtained upon administration of mouse-anti-human CD20 antibodies, in the absence of any effect on other cell lineages and/or tissues. We followed the kinetics of B cell return to equilibrium by BrdU labeling and flow cytometry and analyzed the resulting data by mathematical modeling. Labeling was much faster in depleted mice. Compared to control mice, B cell-depleted mice exhibited a higher proliferation rate in the pro-/pre-B compartment, and higher cell death and lower differentiation in the immature B cell compartment. We validated the first result by analysis of the expression of Ki67, the nuclear protein expressed in proliferating cells, and the second using Annexin-V staining. Collectively, our results suggest that B lymphopoiesis is subjected to homeostatic feedback mechanisms imposed by mature B cells in the peripheral compartment.

  20. HIV-dependent depletion of influenza-specific memory B cells impacts B cell responsiveness to seasonal influenza immunisation

    Science.gov (United States)

    Wheatley, Adam K.; Kristensen, Anne B.; Lay, William N.; Kent, Stephen J.

    2016-01-01

    Infection with HIV drives significant alterations in B cell phenotype and function that can markedly influence antibody responses to immunisation. Anti-retroviral therapy (ART) can partially reverse many aspects of B cell dysregulation, however complete normalisation of vaccine responsiveness is not always observed. Here we examine the effects of underlying HIV infection upon humoral immunity to seasonal influenza vaccines. Serological and memory B cell responses were assessed in 26 HIV+ subjects receiving ART and 30 healthy controls immunised with the 2015 Southern Hemisphere trivalent inactivated influenza vaccine (IIV3). Frequencies and phenotypes of influenza hemagglutinin (HA)-specific B cells were assessed by flow cytometry using recombinant HA probes. Serum antibody was measured using hemagglutination inhibition assays. Serological responses to IIV3 were comparable between HIV+ and HIV− subjects. Likewise, the activation and expansion of memory B cell populations specific for vaccine-component influenza strains was observed in both cohorts, however peak frequencies were diminished in HIV+ subjects compared to uninfected controls. Lower circulating frequencies of memory B cells recognising vaccine-component and historical influenza strains were observed in HIV+ subjects at baseline, that were generally restored to levels comparable with HIV− controls post-vaccination. HIV infection is therefore associated with depletion of selected HA-specific memory B cell pools. PMID:27220898

  1. Transgelin-2 in B-Cells Controls T-Cell Activation by Stabilizing T Cell - B Cell Conjugates

    Science.gov (United States)

    Chae, Myoung-Won; Kim, Hye-Ran; Kim, Chang-Hyun; Jun, Chang-Duk; Park, Zee-Yong

    2016-01-01

    The immunological synapse (IS), a dynamic and organized junction between T-cells and antigen presenting cells (APCs), is critical for initiating adaptive immunity. The actin cytoskeleton plays a major role in T-cell reorganization during IS formation, and we previously reported that transgelin-2, an actin-binding protein expressed in T-cells, stabilizes cortical F-actin, promoting T-cell activation in response to antigen stimulation. Transgelin-2 is also highly expressed in B-cells, although no specific function has been reported. In this study, we found that deficiency in transgelin-2 (TAGLN2-/-) in B-cells had little effect on B-cell development and activation, as measured by the expression of CD69, MHC class II molecules, and CD80/86. Nevertheless, in B-cells, transgelin-2 accumulated in the IS during the interaction with T-cells. These results led us to hypothesize that transgelin-2 may also be involved in IS stability in B-cells, thereby influencing T-cell function. Notably, we found that transgelin-2 deficiency in B-cells reduced T-cell activation, as determined by the release of IL-2 and interferon-γ and the expression of CD69. Furthermore, the reduced T-cell activation was correlated with reduced B-cell–T-cell conjugate formation. Collectively, these results suggest that actin stability in B-cells during IS formation is critical for the initiation of adaptive T-cell immunity. PMID:27232882

  2. Gene expression-based risk score in diffuse large B-cell lymphoma.

    OpenAIRE

    Bret, Caroline; Klein, Bernard; Moreaux, Jérôme

    2012-01-01

    International audience Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma and displays heterogeneous clinical and molecular characteristics. In this study, high throughput gene expression profiling of DLBCL tumor samples was used to design a 12-gene expression-based risk score (GERS) predictive for patient's overall survival. GERS allowed identifying a high-risk group comprising 46,4% of the DLBCL patients in two independent cohorts (n=414 and n=69). GERS...

  3. 猪型布鲁氏菌Omp31基因的抗原表位预测与分析%Antigen Epitope Prediction and Analysis of Swine Brucella Omp31 Gene

    Institute of Scientific and Technical Information of China (English)

    杜志强; 刘丽娜; 王建英

    2012-01-01

    布鲁氏菌的外膜蛋白在维持细胞结构方面发挥着重要作用,其中,有些外膜蛋白与细菌本身的毒性相关,成为了重要的抗原决定簇相关分子.Omp31分子就是猪型布鲁氏菌的一个重要的抗原表位分子,在研制亚单位疫苗方面有重要作用.本论文以猪型布鲁氏菌Omp31基因作为研究对象,利用DNAStar生物学软件对Omp31分子的立体结构、分子的表面可能性、亲水性、蛋白骨架区的柔韧性、分子的抗原指数进行了详细分析.结果显示:猪型布鲁氏菌Omp31分子一级结构的氨基酸序列中存在4段可能的抗原表位区段,其中,51~80氨基酸残基组成的区段和193~228氨基酸残基组成的区段的抗原指数较高,成为抗原决定簇的可能性很大.%Brucella outer membrane proteins play an important part in maintaining cell structure. Some outer membrane proteins associated with bacterial toxicity. And they become important antigenic determinants related molecules. Swine Brucella 0mp31 is an important antigen epitope molecule, and plays an important part in researching and making subunit vaccine. In this study, swine Brucella 0mp31 was research object. And the molecular structure, hydrophilic, protein skeleton zone flexibility, molecular antigen index were analyzed, using DNAStar biology software. Results showed that the amino acids sequence of swine Brucella 0mp31 molecular included four possible epitopes section. And the antigen index of 51 -80 amino acids segment and 193 -228 amino acids segment was larger. The possibility of becoming antigenic determinants was much greater.

  4. Diversity of Francisella tularensis Schu4 antigens recognized by T lymphocytes after natural infections in humans: identification of candidate epitopes for inclusion in a rationally designed tularemia vaccine

    DEFF Research Database (Denmark)

    McMurry, Julie A; Gregory, Stephen H; Moise, Leonard;

    2007-01-01

    The T lymphocyte antigens, which may have a role in protection against tularemia, were predicted by immunoinformatics analysis of Francisella tularensis Schu4. Twenty-seven class II putative promiscuous epitopes and 125 putative class I supertype epitopes were chosen for synthesis; peptides were ...

  5. B-cell survival factors in autoimmune rheumatic disorders

    Science.gov (United States)

    Morais, Sandra A.; Vilas-Boas, Andreia

    2015-01-01

    Autoimmune rheumatic disorders have complex etiopathogenetic mechanisms in which B cells play a central role. The importance of factors stimulating B cells, notably the B-cell activating factor (BAFF) and A proliferation inducing ligand (APRIL) axis is now recognized. BAFF and APRIL are cytokines essential for B-cell proliferation and survival from the immature stages to the development of plasma cells. Their levels are increased in some subsets of patients with autoimmune disorders. Several recent biologic drugs have been developed to block this axis, namely belimumab [already licensed for systemic lupus erythematosus (SLE) treatment], tabalumab, atacicept and blisibimod. Many clinical trials to evaluate the safety and efficacy of these drugs in several autoimmune disorders are ongoing, or have been completed recently. This review updates the information on the use of biologic agents blocking BAFF/APRIL for patients with SLE, rheumatoid arthritis, Sjögren’s syndrome and myositis. PMID:26288664

  6. B-Cell waste classification sampling and analysis plan

    Energy Technology Data Exchange (ETDEWEB)

    HOBART, R.L.

    1999-09-22

    This report documents the methods used to collect and analyze samples to obtain data necessary to verify and/or determine the radionuclide content of the 324 Facility B-Cell decontamination and decommissioning waste stream.

  7. GPS-MBA: computational analysis of MHC class II epitopes in type 1 diabetes.

    Science.gov (United States)

    Cai, Ruikun; Liu, Zexian; Ren, Jian; Ma, Chuang; Gao, Tianshun; Zhou, Yanhong; Yang, Qing; Xue, Yu

    2012-01-01

    As a severe chronic metabolic disease and autoimmune disorder, type 1 diabetes (T1D) affects millions of people world-wide. Recent advances in antigen-based immunotherapy have provided a great opportunity for further treating T1D with a high degree of selectivity. It is reported that MHC class II I-A(g7) in the non-obese diabetic (NOD) mouse and human HLA-DQ8 are strongly linked to susceptibility to T1D. Thus, the identification of new I-A(g7) and HLA-DQ8 epitopes would be of great help to further experimental and biomedical manipulation efforts. In this study, a novel GPS-MBA (MHC Binding Analyzer) software package was developed for the prediction of I-A(g7) and HLA-DQ8 epitopes. Using experimentally identified epitopes as the training data sets, a previously developed GPS (Group-based Prediction System) algorithm was adopted and improved. By extensive evaluation and comparison, the GPS-MBA performance was found to be much better than other tools of this type. With this powerful tool, we predicted a number of potentially new I-A(g7) and HLA-DQ8 epitopes. Furthermore, we designed a T1D epitope database (TEDB) for all of the experimentally identified and predicted T1D-associated epitopes. Taken together, this computational prediction result and analysis provides a starting point for further experimental considerations, and GPS-MBA is demonstrated to be a useful tool for generating starting information for experimentalists. The GPS-MBA is freely accessible for academic researchers at: http://mba.biocuckoo.org.

  8. Specifically modified Env immunogens activate B-cell precursors of broadly neutralizing HIV-1 antibodies in transgenic mice.

    Science.gov (United States)

    McGuire, Andrew T; Gray, Matthew D; Dosenovic, Pia; Gitlin, Alexander D; Freund, Natalia T; Petersen, John; Correnti, Colin; Johnsen, William; Kegel, Robert; Stuart, Andrew B; Glenn, Jolene; Seaman, Michael S; Schief, William R; Strong, Roland K; Nussenzweig, Michel C; Stamatatos, Leonidas

    2016-01-01

    VRC01-class broadly neutralizing HIV-1 antibodies protect animals from experimental infection and could contribute to an effective vaccine response. Their predicted germline forms (gl) bind Env inefficiently, which may explain why they are not elicited by HIV-1 Env-immunization. Here we show that an optimized Env immunogen can engage multiple glVRC01-class antibodies. Furthermore, this immunogen activates naive B cells expressing the human germline heavy chain of 3BNC60, paired with endogenous mouse light chains in vivo. To address whether it activates B cells expressing the fully humanized gl3BNC60 B-cell receptor (BCR), we immunized mice carrying both the heavy and light chains of gl3BNC60. B cells expressing this BCR display an autoreactive phenotype and fail to respond efficiently to soluble forms of the optimized immunogen, unless it is highly multimerized. Thus, specifically designed Env immunogens can activate naive B cells expressing human BCRs corresponding to precursors of broadly neutralizing HIV-1 antibodies even when the B cells display an autoreactive phenotype. PMID:26907590

  9. Interleukin 2-induced proliferation of leukemic human B cells

    OpenAIRE

    1985-01-01

    The proliferative responses of purified leukemic human B cells from nine B cell chronic lymphocytic leukemias to recombinant interleukin 2 (IL-2), spontaneously, and after preactivation by Staphylococcus aureus Cowan I (SAC) or anti-mu antibodies were studied. Three patterns of response were observed: (a) no response (three cases); (b) a moderate spontaneous response enhanced by anti-mu (one case); (c) a high proliferative response after preactivation by anti-mu and/or SAC (five cases). IL-2 ...

  10. Origin of B-Cell Neoplasms in Autoimmune Disease.

    Directory of Open Access Journals (Sweden)

    Kari Hemminki

    Full Text Available Autoimmune diseases (ADs are associated with a number of B-cell neoplasms but the associations are selective in regard to the type of neoplasm and the conferred risks are variable. So far no mechanistic bases for these differential associations have been demonstrated. We speculate that developmental origin of B-cells might propose a mechanistic rationale for their carcinogenic response to autoimmune stimuli and tested the hypothesis on our previous studies on the risks of B-cell neoplasms after any of 33 ADs. We found that predominantly germinal center (GC-derived B-cells showed multiple associations with ADs: diffuse large B cell lymphoma associated with 15 ADs, follicular lymphoma with 7 ADs and Hodgkin lymphoma with 11 ADs. Notably, these neoplasms shared significant associations with 5 ADs (immune thrombocytopenic purpura, polymyositis/dermatomyositis, rheumatoid arthritis, Sjogren syndrome and systemic lupus erythematosis. By contrast, primarily non-GC neoplasms, acute lymphocytic leukemia, chronic lymphocytic leukemia and myeloma associated with 2 ADs only and mantle cell lymphoma with 1 AD. None of the neoplasms shared associated ADs. These data may suggest that autoimmune stimulation critically interferes with the rapid cell division, somatic hypermutation, class switch recombination and immunological selection of maturing B-cell in the GC and delivers damage contributing to transformation.

  11. B cells mediate chronic allograft rejection independently of antibody production.

    Science.gov (United States)

    Zeng, Qiang; Ng, Yue-Harn; Singh, Tripti; Jiang, Ke; Sheriff, Khaleefathullah A; Ippolito, Renee; Zahalka, Salwa; Li, Qi; Randhawa, Parmjeet; Hoffman, Rosemary A; Ramaswami, Balathiripurasundari; Lund, Frances E; Chalasani, Geetha

    2014-03-01

    Chronic rejection is the primary cause of long-term failure of transplanted organs and is often viewed as an antibody-dependent process. Chronic rejection, however, is also observed in mice and humans with no detectable circulating alloantibodies, suggesting that antibody-independent pathways may also contribute to pathogenesis of transplant rejection. Here, we have provided direct evidence that chronic rejection of vascularized heart allografts occurs in the complete absence of antibodies, but requires the presence of B cells. Mice that were deficient for antibodies but not B cells experienced the same chronic allograft vasculopathy (CAV), which is a pathognomonic feature of chronic rejection, as WT mice; however, mice that were deficient for both B cells and antibodies were protected from CAV. B cells contributed to CAV by supporting splenic lymphoid architecture, T cell cytokine production, and infiltration of T cells into graft vessels. In chimeric mice, in which B cells were present but could not present antigen, both T cell responses and CAV were markedly reduced. These findings establish that chronic rejection can occur in the complete absence of antibodies and that B cells contribute to this process by supporting T cell responses through antigen presentation and maintenance of lymphoid architecture.

  12. Altered B cell receptor signaling in human systemic lupus erythematosus

    Science.gov (United States)

    Jenks, Scott A.; Sanz, Iñaki

    2009-01-01

    Regulation of B cell receptor signaling is essential for the development of specific immunity while retaining tolerance to self. Systemic lupus erythematosus (SLE) is characterized by a loss of B cell tolerance and the production of anti-self antibodies. Accompanying this break down in tolerance are alterations in B cell receptor signal transduction including elevated induced calcium responses and increased protein phosphorylation. Specific pathways that negatively regulate B cell signaling have been shown to be impaired in some SLE patients. These patients have reduced levels of the kinase Lyn in lipid raft microdomains and this reduction is inversely correlated with increased CD45 in lipid rafts. Function and expression of the inhibitory immunoglobulin receptor FcγRIIB is also reduced in Lupus IgM- CD27+ memory cells. Because the relative contribution of different memory and transitional B cell subsets can be abnormal in SLE patients, we believe studies targeted to well defined B cell subsets will be necessary to further our understanding of signaling abnormalities in SLE. Intracellular flow cytometric analysis of signaling is a useful approach to accomplish this goal. PMID:18723129

  13. B cells mediate chronic allograft rejection independently of antibody production.

    Science.gov (United States)

    Zeng, Qiang; Ng, Yue-Harn; Singh, Tripti; Jiang, Ke; Sheriff, Khaleefathullah A; Ippolito, Renee; Zahalka, Salwa; Li, Qi; Randhawa, Parmjeet; Hoffman, Rosemary A; Ramaswami, Balathiripurasundari; Lund, Frances E; Chalasani, Geetha

    2014-03-01

    Chronic rejection is the primary cause of long-term failure of transplanted organs and is often viewed as an antibody-dependent process. Chronic rejection, however, is also observed in mice and humans with no detectable circulating alloantibodies, suggesting that antibody-independent pathways may also contribute to pathogenesis of transplant rejection. Here, we have provided direct evidence that chronic rejection of vascularized heart allografts occurs in the complete absence of antibodies, but requires the presence of B cells. Mice that were deficient for antibodies but not B cells experienced the same chronic allograft vasculopathy (CAV), which is a pathognomonic feature of chronic rejection, as WT mice; however, mice that were deficient for both B cells and antibodies were protected from CAV. B cells contributed to CAV by supporting splenic lymphoid architecture, T cell cytokine production, and infiltration of T cells into graft vessels. In chimeric mice, in which B cells were present but could not present antigen, both T cell responses and CAV were markedly reduced. These findings establish that chronic rejection can occur in the complete absence of antibodies and that B cells contribute to this process by supporting T cell responses through antigen presentation and maintenance of lymphoid architecture. PMID:24509079

  14. CTL epitopes for influenza A including the H5N1 bird flu; genome-, pathogen-, and HLA-wide screening

    DEFF Research Database (Denmark)

    Wang, M.J.; Lamberth, K.; Harndahl, M.;

    2007-01-01

    The purpose of the present study is to perform a global screening for new immunogenic HLA class I (HLA-I) restricted cytotoxic T cell (CTL) epitopes of potential utility as candidates of influenza A-virus diagnostics and vaccines. We used predictions of antigen processing and presentation......, the latter encompassing 12 different HLA class I supertypes with > 99% population coverage, and searched for conserved epitopes from available influenza A viral protein sequences. Peptides corresponding to 167 predicted peptide-HLA-1 interactions were synthesized, tested for peptide-HLA-1 interactions...... in a biochemical assay and for influenza-specific, HLA-1-restricted CTL responses in an IFN-gamma ELISPOT assay. Eighty-nine peptides could be confirmed as HLA-1 binders, and 13 could be confirmed as CTL targets. The 13 epitopes, are highly conserved among human influenza A pathogens, and all of these epitopes...

  15. Different sensitivity of germinal center B cell-like diffuse large B cell lymphoma cells towards ibrutinib treatment

    OpenAIRE

    Zheng, Xiaohui; Ding, Ning; Song, Yuqin; Feng, Lixia; Zhu, Jun

    2014-01-01

    Background Although rituximab in the combination of CHOP chemotherapy has been widely used as the standard treatment for several kinds of B-cell non-Hodgkin lymphoma (B-NHL), a great number of B-NHL patients treated with this immunotherapy still develop primary and secondary resistance. Recently Bruton’s tyrosine kinase (Btk) inhibitor ibrutinib showed promising therapeutic effect in relapsed/refractory CLL and B-cell NHL, which provided essential alternatives for these patients. Methods The ...

  16. Scope for using plant viruses to present epitopes from animal pathogens.

    Science.gov (United States)

    Porta; Lomonossoff

    1998-01-01

    Epitope presentation to the immune system for vaccination purposes can be achieved either via an inactivated or attenuated form of a pathogen or via its isolated antigenic sequences. When free, these peptides can adopt a variety of conformations, most of which will not exist in their native environment. Conjugation to carrier proteins restricts mobility of the peptides and increases their immunogenicity. A high local concentration of epitopes boosts the immune response further and can be generated by the use of self-aggregating carriers, such as the capsid proteins of viruses. In this regard plant viruses have in recent years started to make an impact as safer alternatives to the use of bacterial and attenuated animal viruses: the latter both require propagation in costly cell-culture systems where they can undergo reversion towards a virulent form and/or become contaminated by other pathogens. Plant virus-based vectors can be multiplied cheaply and to high yields (exceeding 1 mg/g plant tissue) in host plants. Both helical (tobacco mosaic virus, potato virus X, alfalfa mosaic virus) and icosahedral (cowpea mosaic virus, tomato bushy stunt virus) particles have been used to express a number of animal B-cell epitopes, whose immunogenic properties have been explored to varying degrees. Copyright 1998 John Wiley & Sons, Ltd. PMID:10398492

  17. Epitope peptides of influenza H3N2 virus neuraminidase gene designed by immunoinformatics

    Institute of Scientific and Technical Information of China (English)

    Lijun Liang; Ping Huang; Miaoheng Wen; Hanzhong Ni; Songnuan Tan; Yonghui Zhang; Qiuxia Chen

    2012-01-01

    The virus surface protein neuraminidase (NA) is a main subtype-specific antigen in influenza type A viruses.Neuraminidase functions as an enzyme to break the bonds between hemagglutinin (HA) and sialic acid to release newly formed viruses from infected cells.In this study,NA genes from the H3N2 subtype virus were sequenced and NA proteins were screened for B-cell epitopes and assessed based on immunoinformatics.Based on this information,three peptides ES8,RR9,and WK7 (covering amino acid residues 221-228,292-300,and 383-389,respectively) of the NA protein were selected and synthesized artificially.These peptides were used to immunize New Zealand rabbits subcutaneously to raise antisera.Results showed that these three peptides were capable of eliciting antibodies against H3N2 viruses in a specific and sensitive manner,detected in vitro by enzyme-linked immunosorbent assay. Furthermore,hemadsorption anti-releasing effects occurred in three antisera mixtures at a dilution of 1∶40.Alignment using database software showed that amino acid residues in these three epitope peptides were substituted at specific sites in all the NAs sequenced in this study.We suggest that these NA epitope peptides might be used in conjunction with HA proteins as vaccine antigens.

  18. The B-cell receptor orchestrates environment-mediated lymphoma survival and drug resistance in B-cell malignancies.

    Science.gov (United States)

    Shain, K H; Tao, J

    2014-08-01

    Specific niches within the lymphoma tumor microenvironment (TME) provide sanctuary for subpopulations of tumor cells through stromal cell-tumor cell interactions. These interactions notably dictate growth, response to therapy and resistance of residual malignant B cells to therapeutic agents. This minimal residual disease (MRD) remains a major challenge in the treatment of B-cell malignancies and contributes to subsequent disease relapse. B-cell receptor (BCR) signaling has emerged as essential mediator of B-cell homing, survival and environment-mediated drug resistance (EMDR). Central to EMDR are chemokine- and integrin-mediated interactions between lymphoma and the TME. Further, stromal cell-B cell adhesion confers a sustained BCR signaling leading to chemokine and integrin activation. Recently, the inhibitors of BCR signaling have garnered a substantial clinical interest because of their effectiveness in B-cell disorders. The efficacy of these agents is, at least in part, attributed to attenuation of BCR-dependent lymphoma-TME interactions. In this review, we discuss the pivotal role of BCR signaling in the integration of intrinsic and extrinsic determinants of TME-mediated lymphoma survival and drug resistance. PMID:24037527

  19. Analysis of cytotoxic T cell epitopes in relation to cancer

    DEFF Research Database (Denmark)

    Stranzl, Thomas

    CTL methods, the experimental effort to identify 90% of new epitopes can be reduced by 15% and 40%, respectively. Part III reports the results of an analysis investigating how the alternatively spliced cancer exome differs from the exome of normal tissue in terms of containing predicted MHC class I binding....... Part IV of the thesis deals with the analysis of 93 patient-donor pairs that underwent hematopoietic stem cell transplantation (HCT). HCT is a standard treatment for a variety of hematological diseases. Graft-versus-host disease is a possible complication after an HCT, where the recipient´s cells...

  20. Safety and Tolerability Study of PCI-32765 in B Cell Lymphoma and Chronic Lymphocytic Leukemia

    Science.gov (United States)

    2016-04-26

    B-cell Chronic Lymphocytic Leukemia; Small Lymphocytic Lymphoma; Diffuse Well-differentiated Lymphocytic Lymphoma; B Cell Lymphoma; Follicular Lymphoma,; Mantle Cell Lymphoma; Non-Hodgkin's Lymphoma; Waldenstrom Macroglobulinemia; Burkitt Lymphoma; B-Cell Diffuse Lymphoma

  1. Stereotyped patterns of B-cell receptor in splenic marginal zone lymphoma

    KAUST Repository

    Zibellini, S.

    2010-05-29

    Antigen stimulation may be important for splenic marginal zone lymphoma pathogenesis. To address this hypothesis, the occurrence of stereotyped B-cell receptors was investigated in 133 SMZL (26 HCV+) compared with 4,414 HCDR3 sequences from public databases. Sixteen SMZL (12%) showed stereotyped BCR; 7 of 86 (8%) SMZL sequences retrieved from public databases also belonged to stereotyped HCDR3 subsets. Three categories of subsets were identified: i) SMZL-specific subsets (n=5), composed only of 12 SMZL (9 HCV- from our series); ii) Non-Hodgkin\\'s lymphoma-like subsets (n=5), comprising 5 SMZL (4 from our series) clustering with other indolent lymphomas; iii) "CLL-like subsets" (n=6), comprising 6 SMZL (3 from our series) that belonged to known CLL subsets (n=4) or clustered with public CLL sequences. Immunoglobulin 3D modeling of 3 subsets revealed similarities in antigen binding regions not limited to HCDR3. Overall, data suggest that the pathogenesis of splenic marginal zone lymphoma may involve also HCV unrelated epitopes or an antigenic trigger common to other indolent lymphomas. ©2010 Ferrata Storti Foundation.

  2. Antigen presenting B cells facilitate CD4 T cell cooperation resulting in enhanced generation of effector and memory CD4 T cells.

    Directory of Open Access Journals (Sweden)

    David R Kroeger

    Full Text Available We show that the in vivo generation of cytokine-producing CD4 T cells specific for a given major histocompatibility class-II (MHCII-binding peptide of hen egg lysozyme (HEL is facilitated when mice are immunized with splenic antigen presenting cells (APC pulsed with this HEL peptide and another peptide that binds a different MHCII molecule. This enhanced generation of peptide-specific effector CD4 T cells requires that the same splenic APC be pulsed with both peptides. Pulsed B cells, but not pulsed dendritic cells (DCs, can mediate CD4 T cell cooperation, which can be blocked by disrupting OX40-OX40L (CD134-CD252 interactions. In addition, the generation of HEL peptide-specific CD4 T cell memory is greater when mice are primed with B cells pulsed with the two peptides than with B cells pulsed with the HEL- peptide alone. Based on our findings, we suggest CD4 T cell cooperation is important for vaccine design, underlies the phenomenon of "epitope-spreading" seen in autoimmunity, and that the efficacy of B cell-depletion in the treatment of human cell-mediated autoimmune disease is due to the abrogation of the interactions between autoimmune CD4 T cells that facilitates their activation.

  3. MicroRNA expression in nodal and extranodal Diffuse Large B-cell Lymphoma

    DEFF Research Database (Denmark)

    Mandrup, Charlotte; Petersen, Anders; Højfeldt, Anne Dirks;

    MicroRNA expression in nodal and extranodal Diffuse Large B-cell Lymphoma   C. Mandrup1, A. Petersen1, A. D. Hoejfeldt1, H. F. Thomsen1, J. Madsen1, J. Dahlgaard1, P. Johansen2, A. Bukh1, K. Dybkaer1 and H. E Johnsen1. 1Department of Hematology, 2Pathological Institute, Aalborg Hospital, Aarhus...... University Hospital, Aalborg, Denmark Introduction: The aim of this project was to analyse microRNA (miRNA) expression in nodal and extranodal diffuse large B-cell lymphoma (DLBCL). Manifestation at diagnosis may be nodal and/or extranodal. At present, there are no known determinants for none...... of the manifestations, and no way to predict the potential progression from nodal to extranodal disease. miRNA are small regulatory RNA molecules with core function to repress/cleave sequence complementary mRNA targets. Abnormalities in miRNA genetics and expression are known to affect initiation and development...

  4. T-cell epitope vaccine design by immunoinformatics.

    Science.gov (United States)

    Patronov, Atanas; Doytchinova, Irini

    2013-01-08

    Vaccination is generally considered to be the most effective method of preventing infectious diseases. All vaccinations work by presenting a foreign antigen to the immune system in order to evoke an immune response. The active agent of a vaccine may be intact but inactivated ('attenuated') forms of the causative pathogens (bacteria or viruses), or purified components of the pathogen that have been found to be highly immunogenic. The increased understanding of antigen recognition at molecular level has resulted in the development of rationally designed peptide vaccines. The concept of peptide vaccines is based on identification and chemical synthesis of B-cell and T-cell epitopes which are immunodominant and can induce specific immune responses. The accelerating growth of bioinformatics techniques and applications along with the substantial amount of experimental data has given rise to a new field, called immunoinformatics. Immunoinformatics is a branch of bioinformatics dealing with in silico analysis and modelling of immunological data and problems. Different sequence- and structure-based immunoinformatics methods are reviewed in the paper.

  5. Comprehensive mapping of common immunodominant epitopes in the West Nile virus nonstructural protein 1 recognized by avian antibody responses.

    Directory of Open Access Journals (Sweden)

    Encheng Sun

    Full Text Available West Nile virus (WNV is a mosquito-borne flavivirus that primarily infects birds but occasionally infects humans and horses. Certain species of birds, including crows, house sparrows, geese, blue jays and ravens, are considered highly susceptible hosts to WNV. The nonstructural protein 1 (NS1 of WNV can elicit protective immune responses, including NS1-reactive antibodies, during infection of animals. The antigenicity of NS1 suggests that NS1-reactive antibodies could provide a basis for serological diagnostic reagents. To further define serological reagents for diagnostic use, the antigenic sites in NS1 that are targeted by host immune responses need to be identified and the potential diagnostic value of individual antigenic sites also needs to be defined. The present study describes comprehensive mapping of common immunodominant linear B-cell epitopes in the WNV NS1 using avian WNV NS1 antisera. We screened antisera from chickens, ducks and geese immunized with purified NS1 for reactivity against 35 partially overlapping peptides covering the entire WNV NS1. This study identified twelve, nine and six peptide epitopes recognized by chicken, duck and goose antibody responses, respectively. Three epitopes (NS1-3, 14 and 24 were recognized by antibodies elicited by immunization in all three avian species tested. We also found that NS1-3 and 24 were WNV-specific epitopes, whereas the NS1-14 epitope was conserved among the Japanese encephalitis virus (JEV serocomplex viruses based on the reactivity of avian WNV NS1 antisera against polypeptides derived from the NS1 sequences of viruses of the JEV serocomplex. Further analysis showed that the three common polypeptide epitopes were not recognized by antibodies in Avian Influenza Virus (AIV, Newcastle Disease Virus (NDV, Duck Plague Virus (DPV and Goose Parvovirus (GPV antisera. The knowledge and reagents generated in this study have potential applications in differential diagnostic approaches and

  6. PD-L1 expression in B-cell lymphomas and virus-associated malignancies--letter

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2013-01-01

    actually trigger their own inhibition by secreting cytokines that drive tumor PD-L1 expression (3). However, the immune system itself seems also to have established a respective counteractive mechanism, that is, PD-L1–specific, CD8+, cytotoxic T cells. Thus, PD-L1–reactive T cells can readily be isolated...... processed and thus derived PD-L1 epitopes. PD-L1 antibodies target surface protein, whereas PD-L1–specific T cells recognize and kill cells, which are expressing PD-L1 epitopes on the surface derived from intracellular PD-L1. It is important to note that PD-L1 additionally is expressed on normal immune......In a very important recent study, Chen and colleagues describe that PD-L1 (B7-H1, CD274) is expressed on both malignant cells and infiltrating macrophages in a subset of aggressive B-cell lymphomas (1). The article highlights the possibilities of targeting the PD-1/PD-L1 pathway in these...

  7. Th1 and Th2 help for B cells

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1995-01-01

    Sustained interaction with Th1 cells has been shown to induce IL-2 responsiveness by murine B cells. This is equivalently dependent on CD40, CD54/ICAM-1 and MHC II ligation, and co-cross-linking of CD54 and MHC II in the presence of IL-5 up-regulates a functional IL-2R on B cells. We now show...... that IL-5 (125 U/ml) synergizes with Th1 cells to induce B cell responses to IL-2, that are maintained following T-cell removal, e.g. autonomous. Th1 help in the absence of IL-5 resulted in weak or undetectable responses following T cell removal. The mechanism of IL-5 synergy involved persistence of IL-2R...... beta expression following T cell removal, as opposed to enhancement of IL-2R induction or function. The level of contact-induced IL-2R expression on B cells was not itself modified by IL-5. The effects of IL-5 did not overcome the requirement for T contact signals and treatment of B cells with soluble...

  8. Chimeric peptide containing both B and T cells epitope of tumor-associated antigen L6 enhances anti-tumor effects in HLA-A2 transgenic mice.

    Science.gov (United States)

    Lin, Su-I; Huang, Ming-Hsi; Chang, Yu-Wen; Chen, I-Hua; Roffler, Steve; Chen, Bing-Mae; Sher, Yuh-Pyng; Liu, Shih-Jen

    2016-07-28

    Synthetic peptides are attractive for cancer immunotherapy because of their safety and flexibility. In this report, we identified a new B cell epitope of tumor-associated antigen L6 (TAL6) that could induce antibody-dependent cellular cytotoxicity (ADCC) in vivo. We incorporated the B cell epitope with a cytotoxic T lymphocyte (CTL) and a helper T (Th) epitope to form a chimeric long peptide. We formulated the chimeric peptide with different adjuvants to immunize HLA-A2 transgenic mice and evaluate their immunogenicity. The chimeric peptide formulated with an emulsion type nanoparticle (PELC) adjuvant and a toll-like receptor 9 agonist (CpG ODN) (PELC/CpG) induced the greatest ADCC and CTL responses. The induced anti-tumor immunity inhibited the growth of TAL6-positive cancer cells. Moreover, we observed that immunization with the chimeric peptide inhibited cancer cell migration in vitro and metastasis in vivo. These data suggest that a chimeric peptide containing both B and T cell epitopes of TAL6 formulated with PELC/CpG adjuvant is feasible for cancer immunotherapy. PMID:27130449

  9. CD4 T cell epitope specificity determines follicular versus non-follicular helper differentiation in the polyclonal response to influenza infection or vaccination

    Science.gov (United States)

    Knowlden, Zackery A. G.; Sant, Andrea J.

    2016-01-01

    Follicular helper T cells (Tfh) are essential for B cell production of high-affinity, class-switched antibodies. Much interest in Tfh development focuses on the priming environment of CD4 T cells. Here we explored the role that peptide specificity plays in the partitioning of the polyclonal CD4 T cell repertoire between Tfh and NonTfh lineages during the response to influenza. Surprisingly, we found that CD4 T cells specific for different epitopes exhibited distinct tendencies to segregate into Tfh or NonTfh. To alter the microenvironment and abundance, viral antigens were introduced as purified recombinant proteins in adjuvant as native proteins. Also, the most prototypical epitopes were expressed in a completely foreign protein. In many cases, the epitope-specific response patterns of Tfh vs. NonTfh persisted. The functional TcR avidity of only a subset of epitope-specific cells correlated with the tendency to drive a Tfh response. Thus, we conclude that in a polyclonal CD4 T cell repertoire, features of TcR-peptide:MHC class II complex have a strong deterministic influence on the ability of CD4 T cells to become a Tfh or a NonTfh. Our data is most consistent with at least 2 checkpoints of Tfh selection that include both TcR affinity and B cell presentation. PMID:27329272

  10. CD4 T cell epitope specificity determines follicular versus non-follicular helper differentiation in the polyclonal response to influenza infection or vaccination.

    Science.gov (United States)

    Knowlden, Zackery A G; Sant, Andrea J

    2016-01-01

    Follicular helper T cells (Tfh) are essential for B cell production of high-affinity, class-switched antibodies. Much interest in Tfh development focuses on the priming environment of CD4 T cells. Here we explored the role that peptide specificity plays in the partitioning of the polyclonal CD4 T cell repertoire between Tfh and NonTfh lineages during the response to influenza. Surprisingly, we found that CD4 T cells specific for different epitopes exhibited distinct tendencies to segregate into Tfh or NonTfh. To alter the microenvironment and abundance, viral antigens were introduced as purified recombinant proteins in adjuvant as native proteins. Also, the most prototypical epitopes were expressed in a completely foreign protein. In many cases, the epitope-specific response patterns of Tfh vs. NonTfh persisted. The functional TcR avidity of only a subset of epitope-specific cells correlated with the tendency to drive a Tfh response. Thus, we conclude that in a polyclonal CD4 T cell repertoire, features of TcR-peptide:MHC class II complex have a strong deterministic influence on the ability of CD4 T cells to become a Tfh or a NonTfh. Our data is most consistent with at least 2 checkpoints of Tfh selection that include both TcR affinity and B cell presentation. PMID:27329272

  11. Identification of new HLA-A*0201-restricted cytotoxic T lymphocyte epitopes from neuritin.

    Science.gov (United States)

    Yang, Zhao; Zhao, Tianzhi; Liu, Yong; Gong, Zili; Cheng, Saiyu; Yang, Qingwu

    2013-08-01

    Identification of cytotoxic T lymphocyte (CTL) epitopes from additional tumor antigens is essential for the development of specific immunotherapy of malignant tumors. Neuritin, a recently discovered antigen overexpressed in astrocytoma, is considered to be a promising target for biological therapy. In the present study, we predicted and identified HLA-A2-restricted CTL epitopes from neuritin by using the following four-step procedure: (1) computer-based epitope prediction from the amino acid sequence of neuritin; (2) peptide-binding assay to determine the affinity of the predicted peptide with HLA-A2.1 molecule; (3) stimulation of primary T cell response against the predicted peptides in vitro; and (4) testing of the induced CTLs toward target cells expressing neuritin and HLA-A2.1. The results demonstrated that effectors induced by peptides of neuritin containing residues 13-21, 121-129 and 4-12 could specifically-secrete interferon-γ and lyse target cells. Our results indicate that these peptides are new HLA-A2.1-restricted CTL epitopes, and may serve as valuable tools for astrocytoma immunotherapy. PMID:23754640

  12. Conservation analysis of dengue virust-cell epitope-based vaccine candidates using peptide block entropy

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Zhang, Guang Lan; Keskin, Derin B.;

    2011-01-01

    Broad coverage of the pathogen population is particularly important when designing CD8+ T-cell epitope vaccines against viral pathogens. Traditional approaches are based on combinations of highly conserved T-cell epitopes. Peptide block entropy analysis is a novel approach for assembling sets....... In contrast, the benchmark study by Khan et al. (2008) resulted in 165 conserved 9-mer peptides. Many of the conserved blocks are located consecutively in the proteins. Connecting these blocks resulted in 78 conserved regions. Of the 1551 blocks of 9-mer peptides 110 comprised predicted HLA binder sets...

  13. Microenvironment-Centred Dynamics in Aggressive B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Matilde Cacciatore

    2012-01-01

    Full Text Available Aggressive B-cell lymphomas share high proliferative and invasive attitudes and dismal prognosis despite heterogeneous biological features. In the interchained sequence of events leading to cancer progression, neoplastic clone-intrinsic molecular events play a major role. Nevertheless, microenvironment-related cues have progressively come into focus as true determinants for this process. The cancer-associated microenvironment is a complex network of nonneoplastic immune and stromal cells embedded in extracellular components, giving rise to a multifarious crosstalk with neoplastic cells towards the induction of a supportive milieu. The immunological and stromal microenvironments have been classically regarded as essential partners of indolent lymphomas, while considered mainly negligible in the setting of aggressive B-cell lymphomas that, by their nature, are less reliant on external stimuli. By this paper we try to delineate the cardinal microenvironment-centred dynamics exerting an influence over lymphoid clone progression in aggressive B-cell lymphomas.

  14. The role of B cells and autoantibodies in neuropsychiatric lupus.

    Science.gov (United States)

    Wen, Jing; Stock, Ariel D; Chalmers, Samantha A; Putterman, Chaim

    2016-09-01

    The central nervous system manifestations of SLE (neuropsychiatric lupus, NPSLE) occur frequently, though are often difficult to diagnose and treat. Symptoms of NPSLE can be quite diverse, including chronic cognitive and emotional manifestations, as well as acute presentations, such as stroke and seizures. Although the pathogenesis of NPSLE has yet to be well characterized, B-cell mediated damage is believed to be an important contributor. B-cells and autoantibodies may traverse the blood brain barrier promoting an inflammatory environment consisting of glia activation, neurodegeneration, and consequent averse behavioral outcomes. This review will evaluate the various suggested roles of B-cells and autoantibodies in NPSLE, as well as therapeutic modalities targeting these pathogenic mediators.

  15. Novel Therapies for Aggressive B-Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Kenneth A. Foon

    2012-01-01

    Full Text Available Aggressive B-cell lymphoma (BCL comprises a heterogeneous group of malignancies, including diffuse large B-cell lymphoma (DLBCL, Burkitt lymphoma, and mantle cell lymphoma (MCL. DLBCL, with its 3 subtypes, is the most common type of lymphoma. Advances in chemoimmunotherapy have substantially improved disease control. However, depending on the subtype, patients with DLBCL still exhibit substantially different survival rates. In MCL, a mature B-cell lymphoma, the addition of rituximab to conventional chemotherapy regimens has increased response rates, but not survival. Burkitt lymphoma, the most aggressive BCL, is characterized by a high proliferative index and requires more intensive chemotherapy regimens than DLBCL. Hence, there is a need for more effective therapies for all three diseases. Increased understanding of the molecular features of aggressive BCL has led to the development of a range of novel therapies, many of which target the tumor in a tailored manner and are summarized in this paper.

  16. Dataset of transcriptional landscape of B cell early activation

    Directory of Open Access Journals (Sweden)

    Alexander S. Garruss

    2015-09-01

    Full Text Available Signaling via B cell receptors (BCR and Toll-like receptors (TLRs result in activation of B cells with distinct physiological outcomes, but transcriptional regulatory mechanisms that drive activation and distinguish these pathways remain unknown. At early time points after BCR and TLR ligand exposure, 0.5 and 2 h, RNA-seq was performed allowing observations on rapid transcriptional changes. At 2 h, ChIP-seq was performed to allow observations on important regulatory mechanisms potentially driving transcriptional change. The dataset includes RNA-seq, ChIP-seq of control (Input, RNA Pol II, H3K4me3, H3K27me3, and a separate RNA-seq for miRNA expression, which can be found at Gene Expression Omnibus Dataset GSE61608. Here, we provide details on the experimental and analysis methods used to obtain and analyze this dataset and to examine the transcriptional landscape of B cell early activation.

  17. Identification of three new type-specific antigen epitopes in the capsid protein of porcine circovirus type 1.

    Science.gov (United States)

    Huang, Liping; Lu, Yuehua; Wei, Yanwu; Guo, Longjun; Liu, Changming

    2012-07-01

    Porcine circovirus type 1 (PCV1) has been identified as a contaminant of porcine kidney cell line (PK-15). Serological evidence and genetic studies have suggested that PCV1 is widespread in domestic pigs. In this study, monoclonal antibodies (mAbs) and polyclonal antibodies (pAbs) were generated against a recombinant PCV1 Cap protein (PCV1-Cap), which was expressed using the baculovirus system. PEPSCAN analysis was used to identify epitopes on the PCV1-Cap with mAbs and pAbs. Three linear B-cell epitopes, including residues (85)GGTNPLP(91), (162)FTPKPELDKTIDWFHPNNK(180) and (219)YVQFREFILKDPLNK(233), specific for PCV1-Cap, were finely defined. These results will facilitate future investigations into antigenic differences and differential diagnosis between PCV1 and PCV2. PMID:22437253

  18. Anti-beta-2 glycoprotein I epitope specificity: from experimental models to diagnostic tools.

    Science.gov (United States)

    Meroni, P L

    2016-07-01

    Beta-2 glycoprotein I (β2GPI) is the main antigenic target for anti-phospholipid antibodies (aPL), the serological markers of anti-phospholipid syndrome (APS). Conformational changes of the molecule seem to be essential for exposing the cryptic epitope for aPL binding and to trigger pathogenic pathways. There is increasing evidence that a conformational epitope located in the Domain I (DI) of the molecule is the main epitope targeted by human autoantibodies. The pathogenic role of the DI epitope has been recently supported by in vivo models and by immuno-histopathological findings in APS patients. Antibodies targeting β2GPI-DI are more frequently detected in patients with full-blown APS compared to asymptomatic aPL carriers or patients with infectious diseases who have antibodies directed against the whole molecule. Anti-DI antibodies are positively correlated with medium to high titres of aPL, with the presence of lupus anticoagulant and thrombotic and pregnancy manifestations, enabling identification of patients at higher risk of clinical events. However, some APS patients develop antibodies reacting against β2GPI epitopes other than DI, suggesting that other anti-β2GPI antibody subsets may be clinically relevant. Although preliminary results suggest that anti-DI antibodies can be detected by different assays in a comparable manner, further prospective studies are needed to support their use in the clinical setting and their predictive value. PMID:27252268

  19. T-24.B-cell differentiation factor induces immunoglobulin secretion in human B cells without prior cell replication.

    Science.gov (United States)

    Gallagher, G; Christie, J F; Stimson, W H; Guy, K; Dewar, A E

    1987-04-01

    Stimulation of B lymphocytes from B-cell chronic lymphocytic leukaemia (B-CLL) with 12-0-tetradecanoylphorbol-13-acetate (TPA) has shown that these cells are capable of differentiation (Totterman, Nilsson & Sundstrom, 1980). Increases in the expression of different class II MHC antigens (Guy et al., 1983, 1986) and responsiveness to growth factors (Kabelitz et al., 1985; Suzuki, Butler & Cooper, 1985) have been studied. Supernatant from the human bladder carcinoma line T-24 contains a B-cell differentiation factor (BCDF) able to induce immunoglobulin secretion from CESS cells. We investigated the induction of proliferation and immunoglobulin secretion in human B cells by studying the effects of this factor on B-CLL cells, in both the presence and absence of TPA. We report here that this material (termed T-24.BCDF) causes immunoglobulin secretion to be initiated in these cells, and that this is not accompanied by detectable DNA synthesis. These observations were extended to normal human B cells and demonstrate that human B cells can secrete immunoglobulin in the absence of clonal expansion. PMID:3495482

  20. Further progress on defining highly conserved immunogenic epitopes for a global HIV vaccine

    DEFF Research Database (Denmark)

    De Groot, Anne S; Levitz, Lauren; Ardito, Matthew T;

    2012-01-01

    Two major obstacles confronting HIV vaccine design have been the extensive viral diversity of HIV-1 globally and viral evolution driven by escape from CD8(+) cytotoxic T-cell lymphocyte (CTL)-mediated immune pressure. Regions of the viral genome that are not able to escape immune response...... and that are conserved in sequence and across time may represent the "Achilles' heel" of HIV and would be excellent candidates for vaccine development. In this study, T-cell epitopes were selected using immunoinformatics tools, combining HLA-A3 binding predictions with relative sequence conservation in the context...... of global HIV evolution. Twenty-seven HLA-A3 epitopes were chosen from an analysis performed in 2003 on 10,803 HIV-1 sequences, and additional sequences were selected in 2009 based on an expanded set of 43,822 sequences. These epitopes were tested in vitro for HLA binding and for immunogenicity with PBMCs...

  1. Regulation of AID, the B-cell genome mutator.

    Science.gov (United States)

    Keim, Celia; Kazadi, David; Rothschild, Gerson; Basu, Uttiya

    2013-01-01

    The mechanisms by which B cells somatically engineer their genomes to generate the vast diversity of antibodies required to challenge the nearly infinite number of antigens that immune systems encounter are of tremendous clinical and academic interest. The DNA cytidine deaminase activation-induced deaminase (AID) catalyzes two of these mechanisms: class switch recombination (CSR) and somatic hypermutation (SHM). Recent discoveries indicate a significant promiscuous targeting of this B-cell mutator enzyme genome-wide. Here we discuss the various regulatory elements that control AID activity and prevent AID from inducing genomic instability and thereby initiating oncogenesis.

  2. Surrogate light chain is required for central and peripheral B-cell tolerance and inhibits anti-DNA antibody production by marginal zone B cells.

    Science.gov (United States)

    Ren, Weicheng; Grimsholm, Ola; Bernardi, Angelina I; Höök, Nina; Stern, Anna; Cavallini, Nicola; Mårtensson, Inga-Lill

    2015-04-01

    Selection of the primary antibody repertoire takes place in pro-/pre-B cells, and subsequently in immature and transitional B cells. At the first checkpoint, μ heavy (μH) chains assemble with surrogate light (SL) chain into a precursor B-cell receptor. In mice lacking SL chain, μH chain selection is impaired, and serum autoantibody levels are elevated. However, whether the development of autoantibody-producing cells is due to an inability of the resultant B-cell receptors to induce central and/or peripheral B-cell tolerance or other factors is unknown. Here, we show that receptor editing is defective, and that a higher proportion of BM immature B cells are prone to undergoing apoptosis. Furthermore, transitional B cells are also more prone to undergoing apoptosis, with a stronger selection pressure to enter the follicular B-cell pool. Those that enter the marginal zone (MZ) B-cell pool escape selection and survive, possibly due to the B-lymphopenia and elevated levels of B-cell activating factor. Moreover, the MZ B cells are responsible for the elevated IgM anti-dsDNA antibody levels detected in these mice. Thus, the SL chain is required for central and peripheral B-cell tolerance and inhibits anti-DNA antibody production by MZ B cells.

  3. Primary B-cell deficiencies reveal a link between human IL-17-producing CD4 T-cell homeostasis and B-cell differentiation.

    Directory of Open Access Journals (Sweden)

    Rita R Barbosa

    Full Text Available IL-17 is a pro-inflammatory cytokine implicated in autoimmune and inflammatory conditions. The development/survival of IL-17-producing CD4 T cells (Th17 share critical cues with B-cell differentiation and the circulating follicular T helper subset was recently shown to be enriched in Th17 cells able to help B-cell differentiation. We investigated a putative link between Th17-cell homeostasis and B cells by studying the Th17-cell compartment in primary B-cell immunodeficiencies. Common Variable Immunodeficiency Disorders (CVID, defined by defects in B-cell differentiation into plasma and memory B cells, are frequently associated with autoimmune and inflammatory manifestations but we found no relationship between these and Th17-cell frequency. In fact, CVID patients showed a decrease in Th17-cell frequency in parallel with the expansion of activated non-differentiated B cells (CD21(lowCD38(low. Moreover, Congenital Agammaglobulinemia patients, lacking B cells due to impaired early B-cell development, had a severe reduction of circulating Th17 cells. Finally, we found a direct correlation in healthy individuals between circulating Th17-cell frequency and both switched-memory B cells and serum BAFF levels, a crucial cytokine for B-cell survival. Overall, our data support a relationship between Th17-cell homeostasis and B-cell maturation, with implications for the understanding of the pathogenesis of inflammatory/autoimmune diseases and the physiology of B-cell depleting therapies.

  4. In silico and in vivo analysis of Toxoplasma gondii epitopes by correlating survival data with peptide–MHC-I binding affinities

    Directory of Open Access Journals (Sweden)

    Si-Yang Huang

    2016-07-01

    Conclusions: In silico analysis clearly helped the search for protective vaccine antigens. The ELISPOT analysis confirmed that the predicted T-cell epitopes were immunogenic by their ability to release interferon gamma in spleen cells.

  5. Identification of conserved subdominant HIV Type 1 CD8(+) T Cell epitopes restricted within common HLA Supertypes for therapeutic HIV Type 1 vaccines

    DEFF Research Database (Denmark)

    Karlsson, Ingrid; Kløverpris, Henrik; Jensen, Kristoffer Jarlov;

    2012-01-01

    of a universal epitope peptide-based T cell vaccine with relevance for any geographic locations. The two major obstacles when designing such a vaccine are the high diversities of the HIV-1 genome and of the human major histocompatibility complex (MHC) class I. We selected 15 CD8-restricted epitopes predicted...... from conserved regions of HIV-1 that were subdominant (i.e., infrequently targeted) within natural infections. Moreover, the epitopes were predicted to be restricted to at least one of the five common HLA supertypes (HLA-A01, A02, A03, B07, and B44). Here, we validated the resulting peptide...

  6. Human CD4+ T cell epitopes from vaccinia virus induced by vaccination or infection.

    Directory of Open Access Journals (Sweden)

    J Mauricio Calvo-Calle

    2007-10-01

    Full Text Available Despite the importance of vaccinia virus in basic and applied immunology, our knowledge of the human immune response directed against this virus is very limited. CD4(+ T cell responses are an important component of immunity induced by current vaccinia-based vaccines, and likely will be required for new subunit vaccine approaches, but to date vaccinia-specific CD4(+ T cell responses have been poorly characterized, and CD4(+ T cell epitopes have been reported only recently. Classical approaches used to identify T cell epitopes are not practical for large genomes like vaccinia. We developed and validated a highly efficient computational approach that combines prediction of class II MHC-peptide binding activity with prediction of antigen processing and presentation. Using this approach and screening only 36 peptides, we identified 25 epitopes recognized by T cells from vaccinia-immune individuals. Although the predictions were made for HLA-DR1, eight of the peptides were recognized by donors of multiple haplotypes. T cell responses were observed in samples of peripheral blood obtained many years after primary vaccination, and were amplified after booster immunization. Peptides recognized by multiple donors are highly conserved across the poxvirus family, including variola, the causative agent of smallpox, and may be useful in development of a new generation of smallpox vaccines and in the analysis of the immune response elicited to vaccinia virus. Moreover, the epitope identification approach developed here should find application to other large-genome pathogens.

  7. Immunomodulatory effect of Mesenchymal Stem Cells on B cells

    Directory of Open Access Journals (Sweden)

    Marcella eFranquesa

    2012-07-01

    Full Text Available The research on T cell immunosuppression therapies has attracted most of the attention in clinical transplantation. However, B cells and humoral immune responses are increasingly acknowledged as crucial mediators of chronic allograft rejection. Indeed, humoral immune responses can lead to renal allograft rejection even in patients whose cell-mediated immune responses are well controlled. On the other hand, newly studied B cell subsets with regulatory effects have been linked to tolerance achievement in transplantation. Better understanding of the regulatory and effector B cell responses may therefore lead to new therapeutic approaches.Mesenchymal Stem Cells (MSC are arising as a potent therapeutic tool in transplantation due to their regenerative and immunomodulatory properties. The research on MSCs has mainly focused on their effects on T cells and although data regarding the modulatory effects of MSCs on alloantigen-specific humoral response in humans is scarce, it has been demonstrated that MSCs significantly affect B cell functioning. In the present review we will analyze and discuss the results in this field.

  8. Isolation of human monoclonal antibodies from peripheral blood B cells.

    Science.gov (United States)

    Huang, Jinghe; Doria-Rose, Nicole A; Longo, Nancy S; Laub, Leo; Lin, Chien-Li; Turk, Ellen; Kang, Byong H; Migueles, Stephen A; Bailer, Robert T; Mascola, John R; Connors, Mark

    2013-10-01

    Isolation of monoclonal antibodies is an important technique for understanding the specificities and characteristics of antibodies that underlie the humoral immune response to a given antigen. Here we describe a technique for isolating monoclonal antibodies from human peripheral blood mononuclear cells. The protocol includes strategies for the isolation of switch-memory B cells from peripheral blood, the culture of B cells, the removal of the supernatant for screening and the lysis of B cells in preparation for immunoglobulin heavy-chain and light-chain amplification and cloning. We have observed that the addition of cytokines IL-2, IL-21 and irradiated 3T3-msCD40L feeder cells can successfully stimulate switch-memory B cells to produce high concentrations of IgG in the supernatant. The supernatant may then be screened by appropriate assays for binding or for other functions. This protocol can be completed in 2 weeks. It is adaptable to use in other species and enables the efficient isolation of antibodies with a desired functional characteristic without prior knowledge of specificity. PMID:24030440

  9. Impact of Gastrointestinal Bacillus anthracis Infection on Hepatic B Cells

    Directory of Open Access Journals (Sweden)

    Natacha Colliou

    2015-09-01

    Full Text Available Ingestion of Bacillus anthracis results in rapid gastrointestinal (GI infection, known as GI anthrax. We previously showed that during GI anthrax, there is swift deterioration of intestinal barrier function leading to translocation of gut-associated bacteria into systemic circulation. Additionally, we described dysfunction in colonic B cells. In concordance with our previous studies, here, we report early migration of the Sterne strain of B. anthracis along with other gut-resident bacteria into the infected murine liver. Additionally, despite a global decrease in the B cell population, we observed an increase in both B-1a and marginal zone (MZ-like B cells. Both of these cell types are capable of producing immunoglobulins against common pathogens and commensals, which act as a general antibody barrier before an antigen-specific antibody response. Accumulation of these cells in the liver was associated with an increase in chemokine expression. These data suggest that the presence of Sterne and other commensals in the liver trigger migration of MZ-like B cells from the spleen to the liver to neutralize systemic spread. Further research is required to evaluate the possible cause of their failure to clear the infection within the liver, including the potential role of dysfunctional mitogen-activated protein kinase (MAPK signaling.

  10. Characterization of B cell responses in relation to organ transplantation

    NARCIS (Netherlands)

    Heidt, Sebastiaan

    2010-01-01

    Antibody-mediated rejection is increasingly recognised within the transplantation community as a cause or contributing factor in the rejection of transplanted organs. The humoral immune response towards allografts involves B cells that, after T cell dependent activation, can differentiate into antib

  11. Innate B Cells Tell ILC How It's Done.

    Science.gov (United States)

    Nguyen, Trang T T; Baumgarth, Nicole

    2016-07-19

    Innate lymphoid cells (ILCs) are known as first responders to infections and as instructors of subsequent CD4(+) T cell cytokine profiles. In this issue of Immunity, Fan and colleagues now demonstrate that even earlier responding innate-like B cells (NKB) induce these protective ILC responses. PMID:27438761

  12. Role of FDG-PET scan in the management of pediatric mature B cell non-Hodgkin’s lymphoma. CCHE experience

    OpenAIRE

    Hany Abdel Rahman; Mohamed Sedky; Asmaa Hamoda; Tarek Raafat; Ayda Youssef; Walid Omar; Omneya Hassanein; Emad Moussa

    2016-01-01

    Aim of work: To evaluate the sensitivity (Se), specificity (Sp), and predictive values (PV) of PET scan during management of pediatric mature B cell non-Hodgkin’s lymphoma (NHL) in comparison with conventional computed tomography (CT) scan. Patients and methods: A retrospective study enrolled on pediatric NHL patients at Children Cancer Hospital Egypt (CCHE) during the period from July 2007 to the end of June 2013. Results: For 115 pediatric patients diagnosed with mature B cell NHL, 15...

  13. DCs Pulsed with Novel HLA-A2-Restricted CTL Epitopes against Hepatitis C Virus Induced a Broadly Reactive Anti-HCV-Specific T Lymphocyte Response

    OpenAIRE

    Zhongsheng Guo; Henghui Zhang; Huiying Rao; Dong Jiang; Xu Cong; Bo Feng(Zhejiang Institute of Modern Physics, Zhejiang University, 38 Zheda Road Hangzhou, 310027 P.R. China); Jianghua Wang; Lai Wei; Hongsong Chen

    2012-01-01

    OBJECTIVE: To determine the capacity of dendritic cells (DCs) loaded with single or multiple-peptide mixtures of novel hepatitis C virus (HCV) epitopes to stimulate HCV-specific cytotoxic T lymphocyte (CTL) effector functions. METHODS: A bioinformatics approach was used to predict HLA-A2-restricted HCV-specific CTL epitopes, and the predicted peptides identified from this screen were synthesized. Subsequent IFN-γ ELISPOT analysis detected the stimulating function of these peptides in peripher...

  14. Characterization of T cell epitopes in bovine α-lactalbumin

    NARCIS (Netherlands)

    Meulenbroek, Laura A P M; den Hartog Jager, Constance F; Lebens, Ans F M; Knulst, André C; Bruijnzeel-Koomen, Carla A F M; Garssen, Johan; Knippels, Léon M J; van Hoffen, Els

    2014-01-01

    BACKGROUND: Recent studies have indicated that peptides containing T cell epitopes may be used for immunotherapy. While for several cow's milk allergens the T cell epitopes have been described, the T cell epitopes in the major allergen α-lactalbumin (α-LAC) are unknown. Therefore, the aim of this st

  15. Three novel NY-ESO-1 epitopes bound to DRB1*0803, DQB1*0401 and DRB1*0901 recognized by CD4 T cells from CHP-NY-ESO-1-vaccinated patients.

    Science.gov (United States)

    Mizote, Yu; Taniguchi, Taku; Tanaka, Kei; Isobe, Midori; Wada, Hisashi; Saika, Takashi; Kita, Shoichi; Koide, Yukari; Uenaka, Akiko; Nakayama, Eiichi

    2010-07-19

    Three novel NY-ESO-1 CD4 T cell epitopes were identified using PBMC obtained from patients who were vaccinated with a complex of cholesterol-bearing hydrophobized pullulan (CHP) and NY-ESO-1 protein (CHP-NY-ESO-1). The restriction molecules were determined by antibody blocking and using various EBV-B cells with different HLA alleles as APC to present peptides to CD4 T cells. The minimal epitope peptides were determined using various N- and C-termini truncated peptides deduced from 18-mer overlapping peptides originally identified for recognition. Those epitopes were DRB1*0901-restricted NY-ESO-1 87-100, DQB1*0401-restricted NY-ESO-1 95-107 and DRB1*0803-restricted NY-ESO-1 124-134. CD4 T cells used to determine those epitope peptides recognized EBV-B cells or DC that were treated with recombinant NY-ESO-1 protein or NY-ESO-1-expressing tumor cell lysate, suggesting that the epitope peptides are naturally processed. These CD4 T cells showed a cytokine profile with Th1 characteristics. Furthermore, NY-ESO-1 87-100 peptide/HLA-DRB1*0901 tetramer staining was observed. Multiple Th1-type CD4 T cell responses are beneficial for inducing effective anti-tumor responses after NY-ESO-1 protein vaccination.

  16. B cell autophagy mediates TLR7-dependent autoimmunity and inflammation.

    Science.gov (United States)

    Weindel, Chi G; Richey, Lauren J; Bolland, Silvia; Mehta, Abhiruchi J; Kearney, John F; Huber, Brigitte T

    2015-01-01

    Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease, defined by loss of B cell self-tolerance that results in production of antinuclear antibodies (ANA) and chronic inflammation. While the initiating events in lupus development are not well defined, overexpression of the RNA-recognizing toll-like receptor (TLR)7 has been linked to SLE in humans and mice. We postulated that autophagy plays an essential role in TLR7 activation of B cells for the induction of SLE by delivering RNA ligands to the endosomes, where this innate immune receptor resides. To test this hypothesis, we compared SLE development in Tlr7 transgenic (Tg) mice with or without B cell-specific ablation of autophagy (Cd19-Cre Atg5(f/f)). We observed that in the absence of B cell autophagy the 2 hallmarks of SLE, ANA and inflammation, were eliminated, thus curing these mice of lupus. This was also evident in the significantly extended survival of the autophagy-deficient mice compared to Tlr7.1 Tg mice. Furthermore, glomerulonephritis was ameliorated, and the serum levels of inflammatory cytokines in the knockout (KO) mice were indistinguishable from those of control mice. These data provide direct evidence that B cells require TLR7-dependent priming through an autophagy-dependent mechanism before autoimmunity is induced, thereafter involving many cell types. Surprisingly, hyper-IgM production persisted in Tlr7.1 Tg mice in the absence of autophagy, likely involving a different activation pathway than the production of autoantibodies. Furthermore, these mice still presented with anemia, but responded with a striking increase in extramedullary hematopoiesis (EMH), possibly due to the absence of pro-inflammatory cytokines.

  17. Genetic alterations in B-cell non-Hodgkin's lymphoma

    Directory of Open Access Journals (Sweden)

    Magić Zvonko

    2005-01-01

    Full Text Available Background. Although the patients with diagnosed B-NHL are classified into the same disease stage on the basis of clinical, histopathological, and immunological parameters, they respond significantly different to the applied treatment. This points out the possibility that within the same group of lymphoma there are different diseases at molecular level. For that reason many studies deal with the detection of gene alterations in lymphomas to provide a better framework for diagnosis and treatment of these hematological malignancies. Aim. To define genetic alterations in the B-NHL with highest possibilities for diagnostic purposes and molecular detection of MRD. Methods. Formalin fixed and paraffin embedded lymph node tissues from 45 patients were examined by different PCR techniques for the presence of IgH and TCR γ gene rearrangement; K-ras and H-ras mutations; c-myc amplification and bcl-2 translocation. There were 34 cases of B-cell non-Hodgkin’s lymphoma (B-NHL, 5 cases of T-cell non-Hodgkin’s lymphoma (T-NHL and 6 cases of chronic lymphadenitis (CL. The mononuclear cell fraction of the peripheral blood of 12 patients with B-NHL was analyzed for the presence of monoclonality at the time of diagnosis and in 3 to 6 months time intervals after an autologous bone marrow transplantation (BMT. Results. The monoclonality of B-lymphocytes, as evidenced by DNA fragment length homogeneity, was detected in 88 % (30/34 of B-NHL, but never in CL, T-NHL, or in normal PBL. Bcl-2 translocation was detected in 7/31 (22.6% B-NHL specimens, c-myc amplification 9/31 (29%, all were more than doubled, K-ras mutations in 1/31 (3.23% and H-ras mutations in 2/31 (6.45% of the examined B-NHL samples. In the case of LC and normal PBL, however, these gene alterations were not detected. All the patients (12 with B-NHL had dominant clone of B-lymphocyte in the peripheral blood at the time of diagnosis while only in 2 of 12 patients MRD was detected 3 or 6 months after

  18. Germinal center B cells recognize antigen through a specialized immune synapse architecture.

    Science.gov (United States)

    Nowosad, Carla R; Spillane, Katelyn M; Tolar, Pavel

    2016-07-01

    B cell activation is regulated by B cell antigen receptor (BCR) signaling and antigen internalization in immune synapses. Using large-scale imaging across B cell subsets, we found that, in contrast with naive and memory B cells, which gathered antigen toward the synapse center before internalization, germinal center (GC) B cells extracted antigen by a distinct pathway using small peripheral clusters. Both naive and GC B cell synapses required proximal BCR signaling, but GC cells signaled less through the protein kinase C-β-NF-κB pathway and produced stronger tugging forces on the BCR, thereby more stringently regulating antigen binding. Consequently, GC B cells extracted antigen with better affinity discrimination than naive B cells, suggesting that specialized biomechanical patterns in B cell synapses regulate T cell-dependent selection of high-affinity B cells in GCs. PMID:27183103

  19. Human B-cell cancer cell lines as a preclinical model for studies of drug effect in diffuse large B-cell lymphoma and multiple myeloma.

    Science.gov (United States)

    Laursen, Maria Bach; Falgreen, Steffen; Bødker, Julie Støve; Schmitz, Alexander; Kjeldsen, Malene Krag; Sørensen, Suzette; Madsen, Jakob; El-Galaly, Tarec Christoffer; Bøgsted, Martin; Dybkær, Karen; Johnsen, Hans Erik

    2014-11-01

    Drug resistance in cancer refers to recurrent or primary refractory disease following drug therapy. At the cellular level, it is a consequence of molecular functions that ultimately enable the cell to resist cell death-one of the classical hallmarks of cancer. Thus, drug resistance is a fundamental aspect of the cancer cell phenotype, in parallel with sustained proliferation, immortality, angiogenesis, invasion, and metastasis. Here we present a preclinical model of human B-cell cancer cell lines used to identify genes involved in specific drug resistance. This process includes a standardized technical setup for specific drug screening, analysis of global gene expression, and the statistical considerations required to develop resistance gene signatures. The state of the art is illustrated by the first-step classical drug screen (including the CD20 antibody rituximab, the DNA intercalating topoisomerase II inhibitor doxorubicin, the mitotic inhibitor vincristine, and the alkylating agents cyclophosphamide and melphalan) along with the generation of gene lists predicting the chemotherapeutic outcome as validated retrospectively in clinical trial datasets. This B-cell lineage-specific preclinical model will allow us to initiate a range of laboratory studies, with focus on specific gene functions involved in molecular resistance mechanisms. PMID:25072621

  20. Development of an epitope conservancy analysis tool to facilitate the design of epitope-based diagnostics and vaccines

    Directory of Open Access Journals (Sweden)

    Fusseder Nicolas

    2007-09-01

    Full Text Available Abstract Background In an epitope-based vaccine setting, the use of conserved epitopes would be expected to provide broader protection across multiple strains, or even species, than epitopes derived from highly variable genome regions. Conversely, in a diagnostic and disease monitoring setting, epitopes that are specific to a given pathogen strain, for example, can be used to monitor responses to that particular infectious strain. In both cases, concrete information pertaining to the degree of conservancy of the epitope(s considered is crucial. Results To assist in the selection of epitopes with the desired degree of conservation, we have developed a new tool to determine the variability of epitopes within a given set of protein sequences. The tool was implemented as a component of the Immune Epitope Database and Analysis Resources (IEDB, and is directly accessible at http://tools.immuneepitope.org/tools/conservancy. Conclusion An epitope conservancy analysis tool was developed to analyze the variability or conservation of epitopes. The tool is user friendly, and is expected to aid in the design of epitope-based vaccines and diagnostics.

  1. Interdisciplinary Analysis of HIV-Specific CD8(+) T Cell Responses against Variant Epitopes Reveals Restricted TCR Promiscuity

    DEFF Research Database (Denmark)

    Hoof, Ilka; Perez, C.L.; Buggert, M.;

    2010-01-01

    investigated in a genetically diverse cohort of HIV-1 infected patients. Using a novel bioinformatic binding prediction method, we aimed to explain the pattern of epitope-specific CTL responses based on the patients' HLA genotype and autologous virus sequence quantitatively. Sequences covering predicted and...

  2. Ibrutinib Before and After Stem Cell Transplant in Treating Patients With Relapsed or Refractory Diffuse Large B-cell Lymphoma

    Science.gov (United States)

    2016-10-20

    Activated B-Cell-Like Diffuse Large B-Cell Lymphoma; B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma

  3. Viral O-GalNAc peptide epitopes

    DEFF Research Database (Denmark)

    Olofsson, Sigvard; Blixt, Klas Ola; Bergström, Tomas;

    2016-01-01

    Viral envelope glycoproteins are major targets for antibodies that bind to and inactivate viral particles. The capacity of a viral vaccine to induce virus-neutralizing antibodies is often used as a marker for vaccine efficacy. Yet the number of known neutralization target epitopes is restricted o...

  4. IgE-binding epitopes: a reappraisal

    NARCIS (Netherlands)

    R.C. Aalberse; R. Crameri

    2011-01-01

    Here, we discuss various questions related to IgE epitopes: What are the technical possibilities and pitfalls, what is currently known, how can we put this information into hypothetical frameworks and the unavoidable question: how useful is this information for patient care or allergenicity predicti

  5. The B cell antigen receptor and overexpression of MYC can cooperate in the genesis of B cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yosef Refaeli

    2008-06-01

    Full Text Available A variety of circumstantial evidence from humans has implicated the B cell antigen receptor (BCR in the genesis of B cell lymphomas. We generated mouse models designed to test this possibility directly, and we found that both the constitutive and antigen-stimulated state of a clonal BCR affected the rate and outcome of lymphomagenesis initiated by the proto-oncogene MYC. The tumors that arose in the presence of constitutive BCR differed from those initiated by MYC alone and resembled chronic B cell lymphocytic leukemia/lymphoma (B-CLL, whereas those that arose in response to antigen stimulation resembled large B-cell lymphomas, particularly Burkitt lymphoma (BL. We linked the genesis of the BL-like tumors to antigen stimulus in three ways. First, in reconstruction experiments, stimulation of B cells by an autoantigen in the presence of overexpressed MYC gave rise to BL-like tumors that were, in turn, dependent on both MYC and the antigen for survival and proliferation. Second, genetic disruption of the pathway that mediates signaling from the BCR promptly killed cells of the BL-like tumors as well as the tumors resembling B-CLL. And third, growth of the murine BL could be inhibited by any of three distinctive immunosuppressants, in accord with the dependence of the tumors on antigen-induced signaling. Together, our results provide direct evidence that antigenic stimulation can participate in lymphomagenesis, point to a potential role for the constitutive BCR as well, and sustain the view that the constitutive BCR gives rise to signals different from those elicited by antigen. The mouse models described here should be useful in exploring further the pathogenesis of lymphomas, and in preclinical testing of new therapeutics.

  6. Identification of novel HLA-A(*)0201-restricted CTL epitopes from Pokemon.

    Science.gov (United States)

    Yuan, Bangqing; Zhao, Lin; Xian, Ronghua; Zhao, Gang

    2012-01-01

    Pokemon is a member of the POK family of transcriptional repressors and aberrant overexpressed in various human cancers. Therefore, the related peptide epitopes derived from Pokemon is essential for the development of specific immunotherapy of malignant tumors. In this study, we predicted and identified HLA-A(*)0201-restricted cytotoxic T lymphocyte (CTL) epitopes derived from Pokemon with computer-based epitope prediction, peptide-binding assay and testing of the induced CTLs toward different kinds of carcinoma cells. The results demonstrated that effectors induced by peptides of Pokemon containing residues 32-40, 61-69, 87-95, and 319-327 could specifically secrete IFN-γ and lyse tumor cell lines of Pokemon-positive and HLA-A2-matched. The results suggest that Pokemon32, Pokemon61, Pokemon87, and Pokemon319 peptides are novel HLA-A(*)0201-restricted restricted CTL epitopes, and could be utilized in the cancer immunotherapy against a broad spectrum of tumors. PMID:22405859

  7. Expression and immunoreactivity of HCV/HBV epitopes

    Institute of Scientific and Technical Information of China (English)

    Xin-Yu Xiong; Xiao Liu; Yuan-Ding Chen

    2005-01-01

    AIM: To develop the epitope-based vaccines to prevent Hepatitis C virus (HCV)/Hepatitis B virus (HBV) infections.METHODS: The HCV core epitopes C1 STNPKPQRKTKRNTNRRPQD (residuals aa2-21) and C2 VKFPGGGQIVGGVYLLPRR (residuals aa22-40), envelope epitope E GHRMAWDMMMNWSP (residuals aa315-328) and HBsAg epitope S CTTPAQGNSMFPSCCCTKPTDGNC (residuals aa124-147) were displayed in five different sites of the flock house virus capsid protein as a vector, and expressed in E. coli cells (pET-3 system).Immunoreactivity of the epitopes with anti-HCV and anti-HBV antibodies in the serum from hepatitis C and hepatitis B patients were determined.RESULTS: The expressed chimeric protein carrying the HCV epitopes C1, C2, E (two times), L3C1-I2E-L1C2-L2E could react with anti-HCV antibodies. The expressed chimeric protein carrying the HBV epitopes S, I3S could react with anti-HBs antibodies. The expressed chimeric proteins carrying the HCV epitopes C1, C2, E plus HBV epitope S, L3C1-I2E-L1C2-L2E-I3S could react with antiHCV and anti-HBs antibodies.CONCLUSION: These epitopes have highly specific and sensitive immunoreaction and are useful in the development of epitope-based vaccines.

  8. Measles Virus Hemagglutinin Protein Epitopes: The Basis of Antigenic Stability

    Science.gov (United States)

    Tahara, Maino; Bürckert, Jean-Philippe; Kanou, Kazuhiko; Maenaka, Katsumi; Muller, Claude P.; Takeda, Makoto

    2016-01-01

    Globally eliminating measles using available vaccines is biologically feasible because the measles virus (MV) hemagglutinin (H) protein is antigenically stable. The H protein is responsible for receptor binding, and is the main target of neutralizing antibodies. The immunodominant epitope, known as the hemagglutinating and noose epitope, is located near the receptor-binding site (RBS). The RBS also contains an immunodominant epitope. Loss of receptor binding correlates with an escape from the neutralization by antibodies that target the epitope at RBS. Another neutralizing epitope is located near RBS and is shielded by an N-linked sugar in certain genotype strains. However, human sera from vaccinees and measles patients neutralized all MV strains with similar efficiencies, regardless of the N-linked sugar modification or mutations at these epitopes. Two other major epitopes exist at a distance from RBS. One has an unstructured flexible domain with a linear neutralizing epitope. When MV-H forms a tetramer (dimer of dimers), these epitopes may form the dimer-dimer interface, and one of the two epitopes may also interact with the F protein. The neutralization mechanisms of antibodies that recognize these epitopes may involve inhibiting the H-F interaction or blocking the fusion cascade after MV-H binds to its receptors. PMID:27490564

  9. Deletion of genes encoding PU.1 and Spi-B in B cells impairs differentiation and induces pre-B cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Sokalski, Kristen M; Li, Stephen K H; Welch, Ian; Cadieux-Pitre, Heather-Anne T; Gruca, Marek R; DeKoter, Rodney P

    2011-09-01

    The E26 transformation-specific (Ets) transcription factor PU.1 is required to generate lymphoid progenitor cells from hematopoietic stem cells, but it is not required to generate B cells from committed B-cell lineage progenitors. We hypothesized that PU.1 function in B-cell differentiation is complemented by the related Ets transcription factor Spi-B. To test this hypothesis, mice were generated lacking both PU.1 and Spi-B in the B-cell lineage. Unlike mice lacking PU.1 or Spi-B, mice deficient in both PU.1 and Spi-B in the B-cell lineage had reduced frequencies of B cells as well as impaired B-cell differentiation. Strikingly, all PU.1 and Spi-B-deficient mice developed pre-B cell acute lymphoblastic leukemia before 30 weeks of age. Pre-B cells accumulated in the thymus resulting in massive thymic enlargement and dyspnea. These findings demonstrate that PU.1 and Spi-B are essential transcriptional regulators of B-cell differentiation as well as novel tumor suppressors in the B-cell lineage.

  10. Low GILT expression is associated with poor patient survival in diffuse large B-cell lymphoma

    Directory of Open Access Journals (Sweden)

    Hannah ePhipps-Yonas

    2013-12-01

    Full Text Available The MHC class II-restricted antigen processing pathway presents antigenic peptides acquired in the endocytic route for the activation of CD4+ T cells. Multiple cancers express MHC class II, which may influence the anti-tumor immune response and patient outcome. Low MHC class II expression is associated with poor survival in diffuse large B-cell lymphoma (DLBCL, the most common form of aggressive non-Hodgkin lymphoma. Therefore, we investigated whether gamma-interferon-inducible lysosomal thiol reductase (GILT, an upstream component of the MHC class II-restricted antigen processing pathway that is not regulated by the transcription factor class II transactivator, may be important in DLBCL biology. GILT reduces protein disulfide bonds in the endocytic compartment, exposing additional epitopes for MHC class II binding and facilitating antigen presentation. In each of four independent gene expression profiling cohorts with a total of 585 DLBCL patients, low GILT expression was significantly associated with poor overall survival. In contrast, low expression of a classical MHC class II gene, HLA-DRA, was associated with poor survival in one of four cohorts. The association of low GILT expression with poor survival was independent of established clinical and molecular prognostic factors, the International Prognostic Index and the cell of origin classification, respectively. Immunohistochemical analysis of GILT expression in 96 DLBCL cases demonstrated variation in GILT protein expression within tumor cells which correlated strongly with GILT mRNA expression. These studies identify a novel association between GILT expression and clinical outcome in lymphoma. Our findings underscore the role of antigen processing in DLBCL and suggest that molecules targeting this pathway warrant investigation as potential therapeutics.

  11. Cutaneous B cell lymphomas: Report of two interesting cases

    Directory of Open Access Journals (Sweden)

    Ravichandran Gurumurthy

    2015-01-01

    Full Text Available Cutaneous B cell lymphomas can arise primarily from the skin or may occur due to secondary spread from nodal lymphomas. Primary lymphomas are confined to the skin without systemic spread and they differ from secondary lymphomas in their clinical behavior, treatment and prognosis. Cutaneous lymphomas being relatively rare, lack of precise definition and understanding of their clinical behavior diseases leads to pitfalls in the diagnosis. We report two cases of cutaneous B cell lymphomas who presented with fever of unknown origin initially and later found to have skin lesions. Hence, skin can be a potential diagnostic clue in the evaluation of patients with fever of unknown origin. The distinctions between the primary and the secondary lymphomas become important in choosing the treatment and assessing the prognosis.

  12. 324 Facility B-cell quality process plan

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.L.

    1998-07-29

    B-Cell is currently being cleaned out (i.e., removal of equipment, fixtures and residual radioactive materials) and deactivated. TPA Milestone M-89-02 dictates that all mixed waste and equipment be removed from B-Cell by 5/31/99. The following sections describe the major activities that remain for completion of the TPA milestone. These include: Size Reduce Tank 119 and Miscellaneous Equipment; Load and Ship Low-Level Waste; Remove and Size Reduce the 1B Rack; Collect Dispersible Material from Cell Floor; Remove and Size Reduce the 2A Rack; Size Reduce the 1A Rack; Load and Ship Mixed Waste to PUREX Tunnels; and Move Spent Fuel to A-Cell;

  13. ANTI-B CELL THERAPY OF AUTOIMMUNE DISEASES

    Directory of Open Access Journals (Sweden)

    A. L. Masliansky

    2007-01-01

    Full Text Available Abstract. Our understanding of the multiple physiological and pathological functions of B-cells continues to expand at a fascinating rate. As pathogenic elements in the development of autoimmune diseases, B-cells have become the focus of new therapeutics. Based on the published data, rituximab, a chimeric monoclonal antibody to CD20, when used in combination with other agents (i.e., cyclophosphamide or methotrexate, appears to be a reasonable treatment option for refractory RA. There are now numerous case reports and small openlabel series using rituximab in many autoimmune diseases, others then RA. While these data must be interpreted with caution, they suggest that rituximab may be a promising addition to the therapeutic armamentarium in these diseases. However, additional controlled trials need to be conducted to confirm clinical efficacy, further define optimal dosage, response rates, comparative long-term efficacy, and treatment algorithm for rituximab in these patients.

  14. Diffuse Large B Cell Lymphoma of the Breast

    OpenAIRE

    Feryal Karaca; Vehbi Ercolak; Cigdem Usul Afsar; Meral Gunaldi

    2015-01-01

    Primary breast lymphoma is rarely encountered in Non-Hodgkin Lymphomas. However, if early diagnosis is made, and treatment is started immediately in patients with low grade and stage, patient survival is increased. 39-year old female patient applied us due to a palpable mass. She was diagnosed with the Non-Hodgkin Lymphoma Diffuse Large B Cell Lymphoma after the investigations. Curative external radiotherapy was applied after 6 courses of CHOP-R chemotherapy to the patient with Stage-IIE favo...

  15. Sources of DNA for detecting B cell monoclonality using PCR.

    OpenAIRE

    Diss, T. C.; Pan, L.; Peng, H; Wotherspoon, A C; Isaacson, P G

    1994-01-01

    AIMS--To evaluate the polymerase chain reaction (PCR) demonstration of clonal immunoglobulin heavy chain gene rearrangements using routinely prepared, unstained, and stained formalin fixed, paraffin wax embedded tissue samples. METHODS--Extracts from (a) fresh frozen tissue samples, (b) unstained, and (c) haematoxylin and eosin stained formalin fixed, paraffin wax embedded 5 microns tissue sections from 42 cases of low grade B cell lymphoma, all shown to be monoclonal by Southern blot analysi...

  16. [Significance of regulatory B cells in nosogenesis of immune thrombocytopenia].

    Science.gov (United States)

    Li, Xin; Wang, Fang; Ding, Kai Yang; Dai, Lan

    2014-04-01

    This study was aimed to investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia (ITP) and its clinical significance. A total of 35 ITP patients and 20 normal controls were enrolled in this study. The expression of CD19(+)CD24(hi)CD38(hi) B cells was detected by flow cytometry and the expression of IL-10 mRNA and TGF-β1 mRNA was assayed by RT-PCR. The results indicated that the expression level of CD19(+)CD24(hi)CD38(hi) B cells in peripheral blood of newly diagnosed ITP patients was obviously lower than that in normal controls (P < 0.05); the expression level of CD19(+)CD24(hi)CD38(hi) B cells in ITP patients with increased platelet count after treatment was higher than that before treatment (P < 0.05); the expression level of IL-10 mRNA in newly diagnosed ITP patients was significantly lower than that the in normal controls (P < 0.05), the expression level of TGF-β1 mRNA in newly diagnosed ITP patients increases as compared with normal controls (P < 0.05), after treatment with DXM the expression of IL-10 mRNA was enhanced, the expression of TGF-β1 mRNA was reduced as compared with expression level before treatment (P < 0.05). It is concluded that the Breg cells may play an important role in the pathogenesis of ITP via humoral immunity and its regulation of T lymphocytes.

  17. Characterization of Memory B-Cells from Thymus and its Impact for DLBCL Classification

    DEFF Research Database (Denmark)

    Bergkvist, Kim Steve; Nørgaard, Martin Agge; Bøgsted, Martin;

    2016-01-01

    The rare memory B-cells in thymus are considered the cell of origin for primary mediastinal large B-cell lymphoma (PMBL). The goals for the present study were to characterize the normal memory B-cell compartment in thymus and support its association to primary mediastinal B-cell lymphoma. Seven...... paired human tissue samples from thymus and sternum bone marrow were harvested during cardiac surgery. B-cell subsets were phenotyped by Euroflow standard and FACS-sorted for microarray analysis on the Human Exon 1.0 ST Arrays platform. Differentially expressed genes between thymus and bone marrow memory...... B-cells were identified and correlated to the molecular subclasses of diffuse large B-cell lymphoma. Within thymus, 4% (median, range 2-14%) of the CD45(+) haematopoietic cells were CD19(+) B-cells with a major fraction being CD27(+)/CD38(-) memory B-cells (median 80%, range 76-93%). The bone marrow...

  18. Targeting B cell responses in universal influenza vaccine design

    Science.gov (United States)

    Kaur, Kaval; Sullivan, Meghan; Wilson, Patrick C

    2011-01-01

    Since its first administration in the 1940s, the influenza vaccine has provided tremendous relief against influenza infections. However, time has revealed the vaccine’s ultimate limit and the call for its reinvention has now come, just as we are beginning to appreciate the antibody immune responses vital in preventing infections. New strategies to design the influenza vaccine rely on selectively inducing broadly neutralizing antibodies that are specific for highly conserved viral epitopes. Such approaches take us away from the limited range of protection provided by current seasonal influenza vaccines and towards a future with a pan-influenza vaccine capable of providing universal strain coverage. PMID:21940217

  19. Antigen Processing by Autoreactive B Cells Promotes Determinant Spreading

    Institute of Scientific and Technical Information of China (English)

    Yang D.Dai; George Carayanniotis; Eli Sercarz

    2005-01-01

    Acute primary immune responses tend to focus on few immunodominant determinants using a very limited number of T cell clones for expansion, whereas chronic inflammatory responses generally recruit a large number of different T cell clones to attack a broader range of determinants of the invading pathogens or the inflamed tissues.In T cell-mediated organ-specific autoimmune disease, a transition from the acute to the chronic phase contributes to pathogenesis, and the broadening process is called determinant spreading. The cellular components catalyzing the spreading reaction are not identified. It has been suggested that autoreactive B cells may play a central role in diversifying autoreactive T cell responses, possibly through affecting antigen processing and presentation. The clonal identity and diversity of the B cells and antibodies seem critical in regulating T cell activity and subsequent tissue damage or repair. Here, we use two autoimmune animal models, experimental autoimmune thyroiditis (EAT)and type 1 diabetes (T1D), to discuss how autoreactive B cells or antibodies alter the processing and presentation of autoantigens to regulate specific T cell response.

  20. The acquisition of cytokine responsiveness by murine B cells

    DEFF Research Database (Denmark)

    Poudrier, J; Owens, T

    1994-01-01

    The mechanism whereby small resting (high buoyant density) murine B cells are induced to express interleukin-2 receptors (IL-2R) and to respond to IL-2 was addressed by staining with anti-IL-2R alpha and -IL-2R beta monoclonal antibodies (mAb), and using receptor-specific cDNA probes. Resting B...... staining and mRNA were induced by the combination of LPS plus IL-5. LPS+IL-5-treated B cells responded to IL-2 by Ig secretion. This indicates that B cells regulate their responsiveness to IL-2 similarly to T cells, via the combined level of expression of IL-2R beta and IL-2R alpha. The synergy between IL...... cells expressed undetectable levels of both IL-2R alpha and beta chains on their surface and did not respond to IL-2, even at supra-physiological concentrations. Sepharose-coupled, but not streptavidin-cross-linked, plastic-adsorbed or soluble, anti-mu up-regulated the expression of IL-2R alpha and beta...

  1. Lenalidomide in Diffuse Large B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Annalisa Chiappella

    2012-01-01

    Full Text Available Diffuse Large B-cell Lymphomas (DLBCL are the most frequent Non-Hodgkin Lymphomas (NHL. The addition of Rituximab to the standard chemotherapy CHOP improved the outcome in this patients, but so far 40% of patients experienced relapse or progressive disease. Lenalidomide, an immunomodulatory agent, had direct tumoricidal and antiangiogenetic actions on tumor cells and was able to modulate tumor-cell microenvironment, with the restoration of impaired T-cell activity and the formation of immuno-synapsis. Based on these actions, lenalidomide represented an active drug on aggressive relapsed NHL. In this review, the most relevant clinical trials for the use of lenalidomide in DLBCL were reported. Monotherapy with lenalidomide showed an activity in term of overall response rate, with acceptable hematological and extrahematological toxicities in relapsed/refractory aggressive NHL. The role of lenalidomide as salvage therapy in both cell of origin patterns in DLBCL (germinal center B-cell/activated B-cell was reported in preliminary data. Preliminary data regarding the role of lenalidomide in addition to chemoimmunotherapy (R-CHOP in first line clinical trials were discussed; data of safety, feasibility and efficacy were promising.

  2. Small B cell lymphocytic lymphoma presenting as obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Chang Weng-Cheng

    2004-07-01

    Full Text Available Abstract Background Most lymphomas that involve the tonsil are large B cell lymphomas. Large B-cell lymphoma is a high grade malignancy which progresses rapidly. Tonsillar lymphoma usually presents as either a unilaterally enlarged palatine tonsil or as an ulcerative and fungating lesion over the tonsillar area. Small lymphocytic lymphomas (SLL of the Waldeyer's ring are uncommon. Case presentation We report a 41-year-old male who presented with a ten-year history of snoring. Physical examination revealed smooth bilateral symmetrically enlarged tonsils without abnormal surface change or cervical lymphadenopathy. Palatal redundancy and a narrowed oropharyngeal airway were also noted. The respiratory disturbance index (RDI was 66 per hour, and severe obstruction sleep apnea (OSA was suspected. No B symptoms, sore throat, odynophagia or dysphagia was found. We performed uvulopalatopharyngoplasty (UPPP and pathological examination revealed incidental small B-cell lymphocytic lymphoma (SLL. Conclusion It is uncommon for lymphoma to initially present as OSA. SLL is an indolent malignancy and is not easy to detect in the early stage. We conclude that SLL may be a contributing factor of OSA in the present case.

  3. B cell differentiation in EBV-positive Burkitt Lymphoma is impaired at post-transcriptional level by miRNA altered expression

    DEFF Research Database (Denmark)

    Leucci, E; Onnis, A; Cocco, M;

    2009-01-01

    suggested that EBV-positive and EBV-negative BL have different cells of origin. In particular, according to immunoglobulin gene mutation analysis, EBV-negative BLs may originate from early centroblasts, whereas EBV-positive BLs appear to arise from postgerminal center B cells or memory B cells...... investigated the expression of specific miRNAs predicted to be involved in B cell differentiation and we found that hsa-miR-127 is differentially expressed between EBV-positive and EBV-negative BLs. In particular, it was strongly up-regulated only in EBV-positive BL samples, whereas EBV-negative cases showed...... levels of expression similar to normal controls, including microdissected GC cells.In addition, we found evidence that hsa-miR-127 is involved in B cell differentiation process through post transcriptional regulation of BLIMP1 and XBP1. The over-expression of this miRNA may thus represent a key event...

  4. HLA-B7–Restricted Islet Epitopes Are Differentially Recognized in Type 1 Diabetic Children and Adults and Form Weak Peptide-HLA Complexes

    OpenAIRE

    Scotto, Matthieu; Afonso, Georgia; Østerbye, Thomas; Larger, Etienne; Luce, Sandrine; Raverdy, Cécile; Novelli, Giulia; Bruno, Graziella; Gonfroy-Leymarie, Céline; Launay, Odile; Lemonnier, François A.; Buus, Søren; Carel, Jean-Claude; Boitard, Christian; Mallone, Roberto

    2012-01-01

    The cartography of β-cell epitopes targeted by CD8+ T cells in type 1 diabetic (T1D) patients remains largely confined to the common HLA-A2 restriction. We aimed to identify β-cell epitopes restricted by the HLA-B7 (B*07:02) molecule, which is associated with mild T1D protection. Using DNA immunization on HLA-B7–transgenic mice and prediction algorithms, we identified GAD and preproinsulin candidate epitopes. Interferon-γ (IFN-γ) enzyme-linked immunospot assays on peripheral blood mononuclear...

  5. Role of Immunohistochemistry in Staging Diffuse Large B-cell Lymphoma (DLBCL)

    Science.gov (United States)

    Talaulikar, Dipti; Dahlstrom, Jane Esther; Shadbolt, Bruce; Broomfield, Amy; McDonald, Anne

    2008-01-01

    The use of immunohistochemistry (IHC) in staging bone marrow in non-Hodgkin's lymphoma (NHL) is largely limited to ambiguous cases, particularly those with lymphoid aggregates. Its role in routine clinical practice remains unestablished. This study aimed to determine whether the routine use of IHC in diffuse large B-cell lymphoma (DLBCL) would improve the detection of lymphomatous involvement in the bone marrow. It also sought to determine the impact of IHC on predicting survival compared with routine histological diagnosis using hematoxylin and eosin (H&E), Giemsa, and reticulin staining. The bone marrow trephines of 156 histologically proven DLBCL cases were assessed on routine histology, and IHC using two T-cell markers (CD45RO and CD3), two B-cell markers (CD20 and CD79a), and κ and λ light chains. IHC detected lymphomatous involvement on an additional 11% cases compared with histology alone. Although both routine histology and IHC were good predictors of survival, IHC was better at predicting survival on stepwise multivariate Cox regression analysis. IHC performed routinely on bone marrow trephines has the ability to improve detection of occult lymphoma in experienced hands. Furthermore, it is a better predictor of survival compared with routine histological examination alone. (J Histochem Cytochem 56:893–900, 2008) PMID:18574254

  6. Manipulation of immunodominant dengue virus E protein epitopes reduces potential antibody-dependent enhancement

    Directory of Open Access Journals (Sweden)

    Hughes Holly R

    2012-06-01

    Full Text Available Abstract Background Dengue viruses (DENV are the most important arboviruses of humans and cause significant disease. Infection with DENV elicits antibody responses to the envelope glycoprotein, predominantly against immunodominant, cross-reactive, weakly-neutralizing epitopes. These weakly-neutralizing antibodies are implicated in enhancing infection via Fcγ receptor bearing cells and can lead to increased viral loads that are associated with severe disease. Here we describe results from the development and testing of cross-reactivity reduced DENV-2 DNA vaccine candidates that contain substitutions in immunodominant B cell epitopes of the fusion peptide and domain III of the envelope protein. Results Cross-reactivity reduced and wild-type vaccine candidates were similarly immunogenic in outbred mice and elicited high levels of neutralizing antibody, however mice immunized with cross-reactivity reduced vaccines produced significantly reduced levels of immunodominant cross-reactive antibodies. Sera from mice immunized with wild-type, fusion peptide-, or domain III- substitution containing vaccines enhanced heterologous DENV infection in vitro, unlike sera from mice immunized with a vaccine containing a combination of both fusion peptide and domain III substitutions. Passive transfer of immune sera from mice immunized with fusion peptide and domain III substitutions also reduced the development of severe DENV disease in AG129 mice when compared to mice receiving wild type immune sera. Conclusions Reducing cross-reactivity in the envelope glycoprotein of DENV may be an approach to improve the quality of the anti-DENV immune response.

  7. Extensive Citrullination Promotes Immunogenicity of HSP90 through Protein Unfolding and Exposure of Cryptic Epitopes.

    Science.gov (United States)

    Travers, Timothy S; Harlow, Lisa; Rosas, Ivan O; Gochuico, Bernadette R; Mikuls, Ted R; Bhattacharya, Sanjoy K; Camacho, Carlos J; Ascherman, Dana P

    2016-09-01

    Post-translational protein modifications such as citrullination have been linked to the breach of immune tolerance and clinical autoimmunity. Previous studies from our laboratory support this concept, demonstrating that autoantibodies targeting citrullinated isoforms of heat shock protein 90 (HSP90) are associated with rheumatoid arthritis complicated by interstitial lung disease. To further explore the relationship between citrullination and structural determinants of HSP90 immunogenicity, we employed a combination of ELISA-based epitope profiling, computational modeling, and mass-spectrometric sequencing of peptidylarginine deiminase (PAD)-modified protein. Remarkably, ELISAs involving selected citrullinated HSP90β/α peptides identified a key epitope corresponding to an internal Arg residue (R502 [HSP90β]/R510 [HSP90α]) that is normally buried within the crystal structure of native/unmodified HSP90. In vitro time/dose-response experiments reveal an ordered pattern of PAD-mediated deimination events culminating in citrullination of R502/R510. Conventional as well as scaled molecular dynamics simulations further demonstrate that citrullination of selected Arg residues leads to progressive disruption of HSP90 tertiary structure, promoting exposure of R502/R510 to PAD modification and subsequent autoantibody binding. Consistent with this process, ELISAs incorporating variably deiminated HSP90 as substrate Ag indicate a direct relationship between the degree of citrullination and the level of ex vivo Ab recognition. Overall, these data support a novel structural paradigm whereby citrullination-induced shifts in protein structure generate cryptic epitopes capable of bypassing B cell tolerance in the appropriate genetic context.

  8. In Vitro Evolution of Allergy Vaccine Candidates, with Maintained Structure, but Reduced B Cell and T Cell Activation Capacity

    Science.gov (United States)

    Nilsson, Ola B.; Adedoyin, Justus; Rhyner, Claudio; Neimert-Andersson, Theresa; Grundström, Jeanette; Berndt, Kurt D.; Crameri, Reto; Grönlund, Hans

    2011-01-01

    Allergy and asthma to cat (Felis domesticus) affects about 10% of the population in affluent countries. Immediate allergic symptoms are primarily mediated via IgE antibodies binding to B cell epitopes, whereas late phase inflammatory reactions are mediated via activated T cell recognition of allergen-specific T cell epitopes. Allergen-specific immunotherapy relieves symptoms and is the only treatment inducing a long-lasting protection by induction of protective immune responses. The aim of this study was to produce an allergy vaccine designed with the combined features of attenuated T cell activation, reduced anaphylactic properties, retained molecular integrity and induction of efficient IgE blocking IgG antibodies for safer and efficacious treatment of patients with allergy and asthma to cat. The template gene coding for rFel d 1 was used to introduce random mutations, which was subsequently expressed in large phage libraries. Despite accumulated mutations by up to 7 rounds of iterative error-prone PCR and biopanning, surface topology and structure was essentially maintained using IgE-antibodies from cat allergic patients for phage enrichment. Four candidates were isolated, displaying similar or lower IgE binding, reduced anaphylactic activity as measured by their capacity to induce basophil degranulation and, importantly, a significantly lower T cell reactivity in lymphoproliferative assays compared to the original rFel d 1. In addition, all mutants showed ability to induce blocking antibodies in immunized mice.The approach presented here provides a straightforward procedure to generate a novel type of allergy vaccines for safer and efficacious treatment of allergic patients. PMID:21931754

  9. In vitro evolution of allergy vaccine candidates, with maintained structure, but reduced B cell and T cell activation capacity.

    Science.gov (United States)

    Nilsson, Ola B; Adedoyin, Justus; Rhyner, Claudio; Neimert-Andersson, Theresa; Grundström, Jeanette; Berndt, Kurt D; Crameri, Reto; Grönlund, Hans

    2011-01-01

    Allergy and asthma to cat (Felis domesticus) affects about 10% of the population in affluent countries. Immediate allergic symptoms are primarily mediated via IgE antibodies binding to B cell epitopes, whereas late phase inflammatory reactions are mediated via activated T cell recognition of allergen-specific T cell epitopes. Allergen-specific immunotherapy relieves symptoms and is the only treatment inducing a long-lasting protection by induction of protective immune responses. The aim of this study was to produce an allergy vaccine designed with the combined features of attenuated T cell activation, reduced anaphylactic properties, retained molecular integrity and induction of efficient IgE blocking IgG antibodies for safer and efficacious treatment of patients with allergy and asthma to cat. The template gene coding for rFel d 1 was used to introduce random mutations, which was subsequently expressed in large phage libraries. Despite accumulated mutations by up to 7 rounds of iterative error-prone PCR and biopanning, surface topology and structure was essentially maintained using IgE-antibodies from cat allergic patients for phage enrichment. Four candidates were isolated, displaying similar or lower IgE binding, reduced anaphylactic activity as measured by their capacity to induce basophil degranulation and, importantly, a significantly lower T cell reactivity in lymphoproliferative assays compared to the original rFel d 1. In addition, all mutants showed ability to induce blocking antibodies in immunized mice.The approach presented here provides a straightforward procedure to generate a novel type of allergy vaccines for safer and efficacious treatment of allergic patients.

  10. In vitro evolution of allergy vaccine candidates, with maintained structure, but reduced B cell and T cell activation capacity.

    Directory of Open Access Journals (Sweden)

    Ola B Nilsson

    Full Text Available Allergy and asthma to cat (Felis domesticus affects about 10% of the population in affluent countries. Immediate allergic symptoms are primarily mediated via IgE antibodies binding to B cell epitopes, whereas late phase inflammatory reactions are mediated via activated T cell recognition of allergen-specific T cell epitopes. Allergen-specific immunotherapy relieves symptoms and is the only treatment inducing a long-lasting protection by induction of protective immune responses. The aim of this study was to produce an allergy vaccine designed with the combined features of attenuated T cell activation, reduced anaphylactic properties, retained molecular integrity and induction of efficient IgE blocking IgG antibodies for safer and efficacious treatment of patients with allergy and asthma to cat. The template gene coding for rFel d 1 was used to introduce random mutations, which was subsequently expressed in large phage libraries. Despite accumulated mutations by up to 7 rounds of iterative error-prone PCR and biopanning, surface topology and structure was essentially maintained using IgE-antibodies from cat allergic patients for phage enrichment. Four candidates were isolated, displaying similar or lower IgE binding, reduced anaphylactic activity as measured by their capacity to induce basophil degranulation and, importantly, a significantly lower T cell reactivity in lymphoproliferative assays compared to the original rFel d 1. In addition, all mutants showed ability to induce blocking antibodies in immunized mice.The approach presented here provides a straightforward procedure to generate a novel type of allergy vaccines for safer and efficacious treatment of allergic patients.

  11. Identification and characterisation of T-cell epitopes for incorporation into dendritic cell-delivered Listeria vaccines.

    Science.gov (United States)

    Calderon-Gonzalez, Ricardo; Tobes, Raquel; Pareja, Eduardo; Frande-Cabanes, Elisabet; Petrovsky, Nikolai; Alvarez-Dominguez, Carmen

    2015-09-01

    Dendritic cells loaded with antigenic peptides, because of their safety and robust immune stimulation, would be ideal for induction of immunity to protect against listeriosis. However, there is no currently accepted method to predict which peptides derived from the Listeria proteome might confer protection. While elution of peptides from MHC molecules after Listeria infection yields high-affinity immune-dominant epitopes, these individual epitopes did not reliably confer Listeria protection. Instead we applied bioinformatic predictions of MHC class I and II epitopes to generate antigenic peptides that were then formulated with Advax™, a novel polysaccharide particulate adjuvant able to enhance cross-presentation prior to being screened for their ability to induce protective T-cell responses. A combination of at least four intermediate strength MHC-I binding epitopes and one weak MHC-II binding epitope when expressed in a single peptide sequence and formulated with Advax adjuvant induced a potent T-cell response and high TNF-α and IL-12 production by dendritic cells resulting in robust listeriosis protection in susceptible mice. This T-cell vaccine approach might be useful for the design of vaccines to protect against listeriosis or other intracellular infections.

  12. Combination of In Silico Methods in the Search for Potential CD4(+) and CD8(+) T Cell Epitopes in the Proteome of Leishmania braziliensis.

    Science.gov (United States)

    E Silva, Rafael de Freitas; Ferreira, Luiz Felipe Gomes Rebello; Hernandes, Marcelo Zaldini; de Brito, Maria Edileuza Felinto; de Oliveira, Beatriz Coutinho; da Silva, Ailton Alvaro; de-Melo-Neto, Osvaldo Pompílio; Rezende, Antônio Mauro; Pereira, Valéria Rêgo Alves

    2016-01-01

    The leishmaniases are neglected tropical diseases widespread throughout the globe, which are caused by protozoans from the genus Leishmania and are transmitted by infected phlebotomine flies. The development of a safe and effective vaccine against these diseases has been seen as the best alternative to control and reduce the number of cases. To support vaccine development, this work has applied an in silico approach to search for high potential peptide epitopes able to bind to different major histocompatibility complex Class I and Class II (MHC I and MHC II) molecules from different human populations. First, the predicted proteome of Leishmania braziliensis was compared and analyzed by modern linear programs to find epitopes with the capacity to trigger an immune response. This approach resulted in thousands of epitopes derived from 8,000 proteins conserved among different Leishmania species. Epitopes from proteins similar to those found in host species were excluded, and epitopes from proteins conserved between different Leishmania species and belonging to surface proteins were preferentially selected. The resulting epitopes were then clustered, to avoid redundancies, resulting in a total of 230 individual epitopes for MHC I and 2,319 for MHC II. These were used for molecular modeling and docking with MHC structures retrieved from the Protein Data Bank. Molecular docking then ranked epitopes based on their predicted binding affinity to both MHC I and II. Peptides corresponding to the top 10 ranked epitopes were synthesized and evaluated in vitro for their capacity to stimulate peripheral blood mononuclear cells (PBMC) from post-treated cutaneous leishmaniasis patients, with PBMC from healthy donors used as control. From the 10 peptides tested, 50% showed to be immunogenic and capable to stimulate the proliferation of lymphocytes from recovered individuals.

  13. Combination of In Silico Methods in the Search for Potential CD4(+) and CD8(+) T Cell Epitopes in the Proteome of Leishmania braziliensis.

    Science.gov (United States)

    E Silva, Rafael de Freitas; Ferreira, Luiz Felipe Gomes Rebello; Hernandes, Marcelo Zaldini; de Brito, Maria Edileuza Felinto; de Oliveira, Beatriz Coutinho; da Silva, Ailton Alvaro; de-Melo-Neto, Osvaldo Pompílio; Rezende, Antônio Mauro; Pereira, Valéria Rêgo Alves

    2016-01-01

    The leishmaniases are neglected tropical diseases widespread throughout the globe, which are caused by protozoans from the genus Leishmania and are transmitted by infected phlebotomine flies. The development of a safe and effective vaccine against these diseases has been seen as the best alternative to control and reduce the number of cases. To support vaccine development, this work has applied an in silico approach to search for high potential peptide epitopes able to bind to different major histocompatibility complex Class I and Class II (MHC I and MHC II) molecules from different human populations. First, the predicted proteome of Leishmania braziliensis was compared and analyzed by modern linear programs to find epitopes with the capacity to trigger an immune response. This approach resulted in thousands of epitopes derived from 8,000 proteins conserved among different Leishmania species. Epitopes from proteins similar to those found in host species were excluded, and epitopes from proteins conserved between different Leishmania species and belonging to surface proteins were preferentially selected. The resulting epitopes were then clustered, to avoid redundancies, resulting in a total of 230 individual epitopes for MHC I and 2,319 for MHC II. These were used for molecular modeling and docking with MHC structures retrieved from the Protein Data Bank. Molecular docking then ranked epitopes based on their predicted binding affinity to both MHC I and II. Peptides corresponding to the top 10 ranked epitopes were synthesized and evaluated in vitro for their capacity to stimulate peripheral blood mononuclear cells (PBMC) from post-treated cutaneous leishmaniasis patients, with PBMC from healthy donors used as control. From the 10 peptides tested, 50% showed to be immunogenic and capable to stimulate the proliferation of lymphocytes from recovered individuals. PMID:27621732

  14. Combination of In Silico Methods in the Search for Potential CD4+ and CD8+ T Cell Epitopes in the Proteome of Leishmania braziliensis

    Science.gov (United States)

    e Silva, Rafael de Freitas; Ferreira, Luiz Felipe Gomes Rebello; Hernandes, Marcelo Zaldini; de Brito, Maria Edileuza Felinto; de Oliveira, Beatriz Coutinho; da Silva, Ailton Alvaro; de-Melo-Neto, Osvaldo Pompílio; Rezende, Antônio Mauro; Pereira, Valéria Rêgo Alves

    2016-01-01

    The leishmaniases are neglected tropical diseases widespread throughout the globe, which are caused by protozoans from the genus Leishmania and are transmitted by infected phlebotomine flies. The development of a safe and effective vaccine against these diseases has been seen as the best alternative to control and reduce the number of cases. To support vaccine development, this work has applied an in silico approach to search for high potential peptide epitopes able to bind to different major histocompatibility complex Class I and Class II (MHC I and MHC II) molecules from different human populations. First, the predicted proteome of Leishmania braziliensis was compared and analyzed by modern linear programs to find epitopes with the capacity to trigger an immune response. This approach resulted in thousands of epitopes derived from 8,000 proteins conserved among different Leishmania species. Epitopes from proteins similar to those found in host species were excluded, and epitopes from proteins conserved between different Leishmania species and belonging to surface proteins were preferentially selected. The resulting epitopes were then clustered, to avoid redundancies, resulting in a total of 230 individual epitopes for MHC I and 2,319 for MHC II. These were used for molecular modeling and docking with MHC structures retrieved from the Protein Data Bank. Molecular docking then ranked epitopes based on their predicted binding affinity to both MHC I and II. Peptides corresponding to the top 10 ranked epitopes were synthesized and evaluated in vitro for their capacity to stimulate peripheral blood mononuclear cells (PBMC) from post-treated cutaneous leishmaniasis patients, with PBMC from healthy donors used as control. From the 10 peptides tested, 50% showed to be immunogenic and capable to stimulate the proliferation of lymphocytes from recovered individuals.

  15. Deletion modification enhances anthrax specific immunity and protective efficacy of a hepatitis B core particle-based anthrax epitope vaccine.

    Science.gov (United States)

    Yin, Ying; Zhang, Sheng; Cai, Chenguang; Zhang, Jun; Dong, Dayong; Guo, Qiang; Fu, Ling; Xu, Junjie; Chen, Wei

    2014-02-01

    Protective antigen (PA) is one of the major virulence factors of anthrax and is also the major constituent of the current anthrax vaccine. Previously, we found that the 2β2-2β3 loop of PA contains a dominant neutralizing epitope, the SFFD. We successfully inserted the 2β2-2β3 loop of PA into the major immunodominant region (MIR) of hepatitis B virus core (HBc) protein. The resulting fusion protein, termed HBc-N144-PA-loop2 (HBcL2), can effectively produce anthrax specific protective antibodies in an animal model. However, the protective immunity caused by HBcL2 could still be improved. In this research, we removed amino acids 79-81 from the HBc MIR of the HBcL2. This region was previously reported to be the major B cell epitope of HBc, and in keeping with this finding, we observed that the short deletion in the MIR not only diminished the intrinsic immunogenicity of HBc but also stimulated a higher titer of anthrax specific immunity. Most importantly, this deletion led to the full protection of the immunized mice against a lethal dose anthrax toxin challenge. We supposed that the conformational changes which occurred after the short deletion and foreign insertion in the MIR of HBc were the most likely reasons for the improvement in the immunogenicity of the HBc-based anthrax epitope vaccine.

  16. Deletion modification enhances anthrax specific immunity and protective efficacy of a hepatitis B core particle-based anthrax epitope vaccine.

    Science.gov (United States)

    Yin, Ying; Zhang, Sheng; Cai, Chenguang; Zhang, Jun; Dong, Dayong; Guo, Qiang; Fu, Ling; Xu, Junjie; Chen, Wei

    2014-02-01

    Protective antigen (PA) is one of the major virulence factors of anthrax and is also the major constituent of the current anthrax vaccine. Previously, we found that the 2β2-2β3 loop of PA contains a dominant neutralizing epitope, the SFFD. We successfully inserted the 2β2-2β3 loop of PA into the major immunodominant region (MIR) of hepatitis B virus core (HBc) protein. The resulting fusion protein, termed HBc-N144-PA-loop2 (HBcL2), can effectively produce anthrax specific protective antibodies in an animal model. However, the protective immunity caused by HBcL2 could still be improved. In this research, we removed amino acids 79-81 from the HBc MIR of the HBcL2. This region was previously reported to be the major B cell epitope of HBc, and in keeping with this finding, we observed that the short deletion in the MIR not only diminished the intrinsic immunogenicity of HBc but also stimulated a higher titer of anthrax specific immunity. Most importantly, this deletion led to the full protection of the immunized mice against a lethal dose anthrax toxin challenge. We supposed that the conformational changes which occurred after the short deletion and foreign insertion in the MIR of HBc were the most likely reasons for the improvement in the immunogenicity of the HBc-based anthrax epitope vaccine. PMID:24054942

  17. Characterization of xenoantiserum produced against B cell acute lymphoblastic leukemia cell line

    Directory of Open Access Journals (Sweden)

    Akagi,Tadaatsu

    1982-10-01

    Full Text Available Antiserum was produced in white rabbit by intravenously injecting living cells of a B cell acute lymphoblastic leukemia (ALL line (BALL-1. The reactivity of the antiserum against various lymphoid cell lines was examined by membrane immunofluorescence after appropriate absorption. Serum absorbed with non-T, non-B (NALL-1 and T-ALL (TALL-1 cells recognized B cell antigens distinct from Ia-like antigens on both normal and neoplastic B cells. After further absorption with tonsillar cells or normal B cell line (KO-HL-3, it reacted only with BALL-1 cells and did not react with other leukemia/lymphoma and normal B cell lines. The serum absorbed with tonsillar cells reacted only with BALL-1 and some B cell lines. Thus we were able to obtain antisera with specificity to B cell antigen, B-ALL antigen, and B cell line antigen.

  18. B cells exposed to enterobacterial components suppress development of experimental colitis

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Larsen, Hjalte List; Kristensen, Nanna Ny;

    2012-01-01

    BACKGROUND: B cells positively contribute to immunity by antigen presentation to CD4(+) T cells, cytokine production, and differentiation into antibody secreting plasma cells. Accumulating evidence implies that B cells also possess immunoregulatory functions closely linked to their capability of ...

  19. Cyclin Dl expression in B-cell non Hodgkin lymphoma.

    Science.gov (United States)

    Aref, Salah; Mossad, Y; El-Khodary, T; Awad, M; El-Shahat, E

    2006-10-01

    Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over-expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the effect of its expression on clinical behavior and outcome in B-cell Non-Hodgkin lymphoma (NHL). In this study, we investigated the expression of cyclin Dl in group of patients with NHL and correlated the results with the clinical and laboratory data. The degree of expression of cyclin Dl protein was evaluated by flow cytometry in a group of NHL patients (n = 46) and in normal control group (n = 10). Cyclin Dl over expression was detected in 10 out of 46 (21.7%) patients; they were 5/5-mantle cell lymphoma (MCL) (100%) and 5/28 large B-cell lymphoma (17.8%). All other NHL subtypes showed normal cyclin D1 expression. The clinical signs (hepatomegaly, splenomegaly and B-symptoms, clinical staging) and laboratory data (hemoglobin, white cell count (WBCs), platelet count, and bone marrow infiltration) were not significantly different between NHL subgroup with cyclin Dl over expression and that with normal cyclin Dl expression. Serum lactic dehydrogenase (LDH) levels and lymphadenopathy were significantly higher in NHL group with cyclin D1 over expression as compared to those without. Also, cyclin D1 over expression is associated with poor outcome of NHL patients. Cyclin Dl over expression was evident among all cases of MCL and few cases of large B-cell lymphoma. Cyclin Dl over expression might be used as adjuvant tool for diagnosis of MCL; has role in NHL biology and is bad prognostic index in NHL. PMID:17607588

  20. B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma: Report of a case in the oral cavity

    Directory of Open Access Journals (Sweden)

    Jumana M Jaradat

    2013-01-01

    Full Text Available B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (DLBCL/BL is a new category of B-cell lymphoma according to the 4 th edition of the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues (2008. The following report presents a case of this rare, newly described entity on the palate of a 59 year-old male.

  1. Proof of principle for epitope-focused vaccine design

    Science.gov (United States)

    Correia, Bruno E.; Bates, John T.; Loomis, Rebecca J.; Baneyx, Gretchen; Carrico, Chris; Jardine, Joseph G.; Rupert, Peter; Correnti, Colin; Kalyuzhniy, Oleksandr; Vittal, Vinayak; Connell, Mary J.; Stevens, Eric; Schroeter, Alexandria; Chen, Man; MacPherson, Skye; Serra, Andreia M.; Adachi, Yumiko; Holmes, Margaret A.; Li, Yuxing; Klevit, Rachel E.; Graham, Barney S.; Wyatt, Richard T.; Baker, David; Strong, Roland K.; Crowe, James E.; Johnson, Philip R.; Schief, William R.

    2014-03-01

    Vaccines prevent infectious disease largely by inducing protective neutralizing antibodies against vulnerable epitopes. Several major pathogens have resisted traditional vaccine development, although vulnerable epitopes targeted by neutralizing antibodies have been identified for several such cases. Hence, new vaccine design methods to induce epitope-specific neutralizing antibodies are needed. Here we show, with a neutralization epitope from respiratory syncytial virus, that computational protein design can generate small, thermally and conformationally stable protein scaffolds that accurately mimic the viral epitope structure and induce potent neutralizing antibodies. These scaffolds represent promising leads for the research and development of a human respiratory syncytial virus vaccine needed to protect infants, young children and the elderly. More generally, the results provide proof of principle for epitope-focused and scaffold-based vaccine design, and encourage the evaluation and further development of these strategies for a variety of other vaccine targets, including antigenically highly variable pathogens such as human immunodeficiency virus and influenza.

  2. Hepatitis C virus - associated B cell non-Hodgkin's lymphoma

    Science.gov (United States)

    Mihăilă, Romeo-Gabriel

    2016-01-01

    The hepatitis C virus (HCV) infected patients are prone to develop bone marrow or various tissue infiltrates with monoclonal B cells, monoclonal B lymphocytosis or different types of B cell non-Hodgkin’s lymphoma (BCNHL), of which the most common are splenic marginal zone BCNHL, diffuse large BCNHL and follicular lymphoma. The association between chronic HCV infection and non Hodgkin’s lymphoma has been observed especially in areas with high prevalence of this viral infection. Outside the limitations of some studies that have been conducted, there are also geographic, environmental, and genetic factors that contribute to the epidemiological differences. Various microenvironmental signals, such as cytokines, viral antigenic external stimulation of lymphocyte receptors by HCV antigens, and intercellular interactions contribute to B cell proliferation. HCV lymphotropism and chronic antigenic stimulation are involved in B-lymphocyte expansion, as mixted cryoglobulinemia or monoclonal gammopathy of undetermined significance, which can progress to BCNHL. HCV replication in B lymphocytes has oncogenic effect mediated by intracellular HCV proteins. It is also involved in an important induction of reactive oxygen species that can lead to permanent B lymphocyte damage, as DNA mutations, after binding to surface B-cell receptors. Post-transplant lymphoproliferative disorder could appear and it has a multiclonal potentiality that may develop into different types of lymphomas. The hematopoietic stem cell transplant made for lymphoma in HCV-infected patients can increase the risk of earlier progression to liver fibrosis and cirrhosis. HCV infected patients with indolent BCNHL who receive antiviral therapy can be potentially cured. Viral clearance was related to lymphoma response, fact that highlights the probable involvement of HCV in lymphomagenesis. Direct acting antiviral drugs could be a solution for the patients who did not tolerate or respond to interferon, as they

  3. Differential Effects of Tacrolimus versus Sirolimus on the Proliferation, Activation and Differentiation of Human B Cells

    OpenAIRE

    Traitanon, Opas; Mathew, James M.; La Monica, Giovanna; Xu, Luting; Mas, Valeria; Gallon, Lorenzo

    2015-01-01

    The direct effect of immunosuppressive drugs calcineurin inhibitor (Tacrolimus, TAC) and mTOR inhibitor (Sirolimus, SRL) on B cell activation, differentiation and proliferation is not well documented. Purified human B cells from healthy volunteers were stimulated through the B Cell Receptor with Anti-IgM + anti-CD40 + IL21 in the absence / presence of TAC or SRL. A variety of parameters of B cell activity including activation, differentiation, cytokine productions and proliferation were monit...

  4. Identification of Functional Human Splenic Memory B Cells by Expression of CD148 and CD27

    OpenAIRE

    Tangye, Stuart G.; Liu, Yong-Jun; Aversa, Gregorio; Phillips, Joseph H.; Vries, Jan E. de

    1998-01-01

    Memory B cells isolated from human tonsils are characterized by an activated cell surface phenotype, localization to mucosal epithelium, expression of somatically mutated immunoglobulin (Ig) variable (V) region genes, and a preferential differentiation into plasma cells in vitro. In spleens of both humans and rodents, a subset of memory B cells is believed to reside in the marginal zone of the white pulp. Similar to tonsil-derived memory B cells, splenic marginal zone B cells can be distingui...

  5. Targeting Bruton's tyrosine kinase signaling as an emerging therapeutic agent of B-cell malignancies

    OpenAIRE

    Xia, Bing; QU, FULIAN; Yuan, Tian; Zhang, Yizhuo

    2015-01-01

    It is becoming increasingly evident that B-cell receptor (BCR) signaling is central to the development and function of B cells. BCR signaling has emerged as a pivotal pathway and a key driver of numerous B-cell lymphomas. Disruption of BCR signaling can be lethal to malignant B cells. Recently, kinase inhibitors that target BCR signaling have induced notable clinical responses. These inhibitors include spleen tyrosine kinase, mammalian target of rapamycin, phosphoinositide 3′-kinase and Bruto...

  6. Aggressive B-cell lymphomas: how many categories do we need?

    OpenAIRE

    Said, Jonathan W.

    2012-01-01

    Aggressive B-cell lymphomas are diverse group of neoplasms that arise at different stages of B-cell development and by various mechanisms of neoplastic transformation. The aggressive B-cell lymphomas include many types, subtypes and variants of diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), mantle cell lymphoma and its blastoid variant, and B lymphoblastic lymphoma. Differences in histology, cytogenetic and molecular abnormalities, as well as the relationship with the tumor mic...

  7. Complement receptor 2, natural antibodies and innate immunity: Inter-relationships in B cell selection and activation.

    Science.gov (United States)

    Holers, V Michael; Kulik, Liudmila

    2007-01-01

    Complement receptor type 2 (CR2) is a receptor that serves as an important interface between the complement system and adaptive immunity. Recent studies have shown that CR2 is also centrally involved in innate immunity, and one key area is the development of potentially pathogenic natural antibodies that target neo-epitopes revealed in ischemic tissue undergoing reperfusion. Mice lacking either total immunoglobulins or CR2 alone are protected from the development of ischemia-reperfusion injury, and this effect can be reversed by introducing CR2-sufficient B-1 cells or by transferring polyclonal natural IgM antibody from wild type mice as well as monoclonal antibodies that recognize phospholipids, DNA or non-muscle myosin. We will report at the XXI ICW an additional membrane-associated protein to which pathogenic IgM antibodies are directed. Whether B cells producing these natural antibodies are differentially selected in CR2-deficient mice is as yet not well understood, and the complement-related mechanism(s) whereby this differential repertoire selection process could occur have yet to be explored in any detail. In addition to this important role in innate immunity, CR2 can also act as a receptor for other components or activators of innate immunity. One such component is interferon-alpha, an anti-viral cytokine that binds CR2 and induces a component of its mRNA signature in B cells through this receptor. Other potential CR2 ligands are DNA and DNA-containing complexes such as chromatin. The biologic role of these CR2 interactions with interferon-alpha and DNA-containing complexes is not well understood, but may be important in the development of the autoimmune disease systemic lupus erythematosus that is characterized by enhanced interferon-alpha levels and loss of self tolerance to DNA-containing self antigens. PMID:16876864

  8. Clinicopathological prognostic factors of 24 patients with B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma.

    Science.gov (United States)

    Miyamoto, Ken-Ichi; Kobayashi, Yukio; Maeshima, Akiko Miyagi; Taniguchi, Hirokazu; Nomoto, Junko; Kitahara, Hideaki; Fukuhara, Suguru; Munakata, Wataru; Maruyama, Dai; Tobinai, Kensei

    2016-06-01

    B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (iBL/DLBCL), is a rare, but an aggressive subtype. In iBL/DLBCL, clinicopathological prognostic factors, including MYC and BCL2 translocations (double hit translocation, DHT) and the expression of both MYC and BCL2 (double hit score 2, DHS2), have not been studied thoroughly. We retrospectively analyzed the prognostic impact of clinicopathological factors, including MYC split, IGH/BCL2 fusion, MYC and BCL2 expressions, in 24 iBL/DLBCL patients (median age: 47 years). Fifteen patients (62 %) underwent intensive chemotherapy, and nine patients (38 %) underwent rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). The 5-year progression-free (PFS) and overall survival (OS) rates of intensive chemotherapy and R-CHOP were 57 and 72 %, respectively. PFS was significantly shorter in patients with high IPI score (P < .0001), stage IV (P = .001), aged ≥60 years (P = .042), IGH/BCL2 fusion (P = .029), DHS2 (P = .015), and DHT (P = .03). OS was significantly shorter in patients with high IPI score (P < .0001) and aged ≥60 years (P = .008). In iBL/DLBCL, IGH/BCL2 fusion, DHS2, and DHT were pathological prognostic factors for poor PFS, while IPI remained as more predictive for PFS and OS. PMID:27095041

  9. B cell stimulatory factor 1 (BSF-1) prepares resting B cells to enter S phase in response to anti-IgM and lipopolysaccharide

    OpenAIRE

    1986-01-01

    BSF-1 prepares resting BALB/c, DBA/2, and BDF1 B cells to enter S phase more promptly in response to subsequent culture with anti-IgM-based stimulants. It prepares DBA/2 and BDF1 B cells to respond to LPS, but its preparative effect for LPS responses of BALB/c B cells is both inconstant and meager. Preparation mediated by BSF-1 requires extended contact of B cells with the stimulant for full effect. Half-maximal preparation requires approximately 12 h of contact, as judged by delayed addition...

  10. PAX5 promotes pre-B cell proliferation by regulating the expression of pre-B cell receptor and its downstream signaling.

    Science.gov (United States)

    Xue, Kai; Song, Jiazhe; Yang, Yan; Li, Zhi; Wu, Chunhua; Jin, Jinhua; Li, Wenzhe

    2016-05-01

    PAX5 is indispensable for the commitment of early lymphoid progenitors to the B cell lineage as well as for the development of B cells. Although previous studies have indicated that the Pax5-conditional-knockout mouse exhibited dedifferentiation of mature B cell and the development of aggressive lymphomas, the changes of Pax5 gene expressions in pre-B cells have not been analyzed. To understand the functional importance of Pax5 gene in the proliferation and survival of pre-B cells, we established a Pax5-knockdown model using 70Z/3 pre-B cell line. Pax5 knockdown 70Z/3 cells (70Z/3-KD cells) showed down-regulations of pre-BCR compounds such as CD19, BLNK, Id2 and λ5. The signaling via pre-BCRs was significantly diminished in the 70Z/3-KD cells, and this alteration was normalized by restored Pax5 gene expression. Loss of PAX5 reduced the growth rates in the 70Z/3-KD cells, compared to the mock cells. Meanwhile, the proliferation of pre-B cells was reduced by the knockdown of Pax5 gene. Moreover, further examinations showed that PAX5 was also activated in B cell acute lymphoblastic leukemia (B-ALL) as a cell proliferation enhancer. These findings suggested that pax5 is critically important for the proliferation and survival of pre-B cells. PMID:27016671

  11. Multiple HLA Epitopes Contribute to Type 1 Diabetes Susceptibility

    OpenAIRE

    Roark, Christina L.; Anderson, Kirsten M.; Simon, Lucas J.; Schuyler, Ronald P.; Aubrey, Michael T; Freed, Brian M.

    2013-01-01

    Disease susceptibility for type 1 diabetes is strongly associated with the inheritance of specific HLA alleles. However, conventional allele frequency analysis can miss HLA associations because many alleles are rare. In addition, disparate alleles that have similar peptide-binding sites, or shared epitopes, can be missed. To identify the HLA shared epitopes associated with diabetes, we analyzed high-resolution genotyping for class I and class II loci. The HLA epitopes most strongly associated...

  12. Therapeutic enzyme deimmunization by combinatorial T-cell epitope removal using neutral drift

    OpenAIRE

    Cantor, Jason R.; Yoo, Tae Hyeon; Dixit, Aakanksha; Iverson, Brent L.; Forsthuber, Thomas G.; Georgiou, George

    2011-01-01

    A number of heterologous enzymes have been investigated for cancer treatment and other therapeutic applications; however, immunogenicity issues have limited their clinical utility. Here, a new approach has been created for heterologous enzyme deimmunization whereby combinatorial saturation mutagenesis is coupled with a screening strategy that capitalizes on the evolutionary biology concept of neutral drift, and combined with iterative computational prediction of T-cell epitopes to achieve ext...

  13. R-ICE and Lenalidomide in Treating Patients With First-Relapse/Primary Refractory Diffuse Large B-Cell Lymphoma

    Science.gov (United States)

    2015-12-30

    Diffuse Large B-Cell Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Transformed Recurrent Non-Hodgkin Lymphoma

  14. File list: ALL.Bld.10.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.10.AllAg.Pro-B_cells mm9 All antigens Blood Pro-B cells SRX1553109,SRX15531...9,SRX1143902 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Bld.10.AllAg.Pro-B_cells.bed ...

  15. Cigarette smoke-induced emphysema : A role for the B cell?

    NARCIS (Netherlands)

    van der Strate, BWA; Postma, DS; Brandsma, CA; Melgert, BN; Luinge, MA; Geerlings, M; Hylkema, MN; van den Berg, Anke; Timens, W; Kerstjens, HAM

    2006-01-01

    Rationale: Little is known about what drives the inflammatory reaction in the development of chronic obstructive lung disease. B cells have been found. Objective: To study the involvement of B cells in the development of emphysema. Methods: The presence of B-cell follicles and their interaction with

  16. File list: His.Bld.50.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Bld.50.AllAg.Pro-B_cells mm9 Histone Blood Pro-B cells SRX668836,SRX1184113,SRX...09,SRX759800,SRX1143916,SRX1143902 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Bld.50.AllAg.Pro-B_cells.bed ...

  17. File list: ALL.Bld.20.AllAg.Pro-B_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.20.AllAg.Pro-B_cells mm9 All antigens Blood Pro-B cells SRX1553109,SRX15531...3,SRX1143907 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Bld.20.AllAg.Pro-B_cells.bed ...

  18. In vitro effects of rituximab on the proliferation, activation and differentiation of human B cells.

    NARCIS (Netherlands)

    Kamburova, E.G.; Koenen, H.J.P.M.; Boon, L.; Hilbrands, L.B.; Joosten, I.

    2012-01-01

    Rituximab is a chimeric anti-CD20 monoclonal antibody (mAb) used in B-cell malignancies, various autoimmune disorders and organ transplantation. Although administration of a single dose of rituximab results in full B-cell depletion in peripheral blood, there remains a residual B-cell population in s

  19. Characterization of Regulatory B Cells in Graves' Disease and Hashimoto's Thyroiditis

    DEFF Research Database (Denmark)

    Kristensen, Birte; Hegedüs, Laszlo; Lundy, Steven K;

    2015-01-01

    cells from patients with HT. In GD, B cells primed with TG induced IL-10-producing CD4+ T cells. To assess the maximal frequency of inducible IL-10+ B cells in the three donor groups PBMCs were stimulated with PMA/ionomycin. The resulting IL-10+ B-cell frequency was similar in the three groups and...

  20. Modulation of B-cell receptor and microenvironment signaling by a guanine exchange factor in B-cell malignancies

    Institute of Scientific and Technical Information of China (English)

    Wei Liao; Sanjai Sharma

    2016-01-01

    Objective: Chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) cells over-express a guanine exchange factor (GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods: N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor (BCR) and chemokine signaling pathways were compared in the Rasgrf-1 over-expressing and a control transfected cell line. Results: Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions: This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.

  1. MicroRNA signatures in B-cell lymphomas

    International Nuclear Information System (INIS)

    Accurate lymphoma diagnosis, prognosis and therapy still require additional markers. We explore the potential relevance of microRNA (miRNA) expression in a large series that included all major B-cell non-Hodgkin lymphoma (NHL) types. The data generated were also used to identify miRNAs differentially expressed in Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) samples. A series of 147 NHL samples and 15 controls were hybridized on a human miRNA one-color platform containing probes for 470 human miRNAs. Each lymphoma type was compared against the entire set of NHLs. BL was also directly compared with DLBCL, and 43 preselected miRNAs were analyzed in a new series of routinely processed samples of 28 BLs and 43 DLBCLs using quantitative reverse transcription-polymerase chain reaction. A signature of 128 miRNAs enabled the characterization of lymphoma neoplasms, reflecting the lymphoma type, cell of origin and/or discrete oncogene alterations. Comparative analysis of BL and DLBCL yielded 19 differentially expressed miRNAs, which were confirmed in a second confirmation series of 71 paraffin-embedded samples. The set of differentially expressed miRNAs found here expands the range of potential diagnostic markers for lymphoma diagnosis, especially when differential diagnosis of BL and DLBCL is required

  2. Dominant neurologic symptomatology in intravascular large B-cell lymphoma.

    Science.gov (United States)

    Kubisova, K; Martanovic, P; Sisovsky, V; Tomleinova, Z; Steno, A; Janega, P; Rychly, B; Babal, P

    2016-01-01

    Intravascular large B-cell lymphoma (IVLBCL) is a rare variant of extranodal large B-cell lymphoma and it is characterized by selective intravascular proliferation of malignant cells. Typical features of the disease include aggressive behavior, rapid and frequently fatal course. Clinical picture is non-specific and heterogeneous, depending on the affected organ. It is not uncommon that this unique type of lymphoma is diagnosed post mortem. Herein, we report two cases of IVLBCL with neurologic symptomatology. In our clinical study patient 1 was an 80-year-old male with mixed paraparesis of lower extremities and difficulties with sphincter control. Patient 2 (56-year-old male) had vision malfunction, mental status changes and defect in phatic and motor functions. In both cases definite diagnosis was established by histological examination of necroptic material. We propose to include IVLBCL in differential diagnostic considerations in patients presenting with gradually impairing neurological status and spinal cord damage of unknown etiology (Fig. 2, Ref. 9). PMID:27546361

  3. Diffuse Large B Cell Lymphoma with Extensive Cutaneous Relapse

    Science.gov (United States)

    Malkan, Umit Yavuz; Gunes, Gursel; Yayar, Okan; Demiroglu, Haluk

    2015-01-01

    Herein, we aimed to report a diffuse large B cell lymphoma (DLBCL) case that had extensive cutaneous relapse with no skin involvement previously. A 59-year-old man presented to hospital in April 2014 with fatigue, anorexia, fever, and anemia. Cervical lymph node biopsy revealed CD20+, BCL2+, MUM1+, BCL6+ high grade B lymphoproliferative neoplasm. After FISH investigation, he was diagnosed as DLBCL. He was given 7 cycles of R-CHOP and achieved remission. However, in November 2014, he had emerging skin lesions that cover nearly all of his body. A control PET-CT revealed diffuse cutaneous involvement. CD20+, BCL2+, MUM1+, BCL6+ high grade B cell lymphoma infiltration was detected with skin biopsy. He was diagnosed as relapse lymphoma, so 2 cycles of R-DHAP were given. There was no treatment response; therefore, R-ICE regimen was started. The patient had achieved second complete remission and his skin lesions were completely regressed. The involvement of skin with CD20+ cells after 7 cycles of rituximab therapy favors that there is a rituximab resistant disease which tends to involve the skin. To conclude, DLBCL may relapse extensively with cutaneous involvement and the best treatment option in these patients is salvage chemotherapy followed by autologous peripheral blood stem cell transplantation. PMID:26457084

  4. [Chronic B-cell lymphoproliferative disorders with hairy cells].

    Science.gov (United States)

    Troussard, Xavier; Cornet, Édouard

    2015-01-01

    The standardized blood smear examination is the first step in the diagnosis of a B-cell chronic lymphoproliferative disorder and can guide further investigations. In the laboratory, the identification of hairy cells on blood smear is a matter of daily practice. Hairy cell proliferations represent heterogeneous entities and their respective diagnoses can be difficult. If hairy cell leukemia (HCL) and splenic marginal zone lymphoma (SMZL) represent separate entities, the variant form of HCL (HCLv) and splenic diffuse red pulp small B-cell lymphoma (SDRPL) remain provisional entities in the 2008 WHO classification. We discuss the main clinical and biological characteristics of these four entities and appropriate means to characterize, identify and distinguish from each other; standardized blood smear examination, multiparameter flow cytometry analysis, analysis of the repertoire of immunoglobulins heavy chains genes and their mutational status (mutated or unmutated profile), molecular analyses: BRAF gene V600E mutation in HCL and MAP2K1 gene mutations in HCLv. We also discuss the main therapeutic aspects with emphasis on the new targeted drugs that enter into force in the therapeutic arsenal. PMID:25858127

  5. Anticancer Effect of Curcumin on B Cell non- Hodgkin's Lymphoma

    Institute of Scientific and Technical Information of China (English)

    SUN Chunyan; LIU Xinyue; CHEN Yan; LIU Fang

    2005-01-01

    To explore the anticancer effect of curcumin on human B cell non-Hodgkin's lymphoma and compare its effects on human B cell non-Hodgkin's lymphoma cells and normal peripheral blood mononuclear cells (NPBMNCs). MTT assay was used to study the effect of curcumin on the growth of Raji cells and NPBMNCs. The effect of curcumin on the apoptosis of Raji cells and NPBMNC were studied by flow cytometry and TDT-mediated dUTP nick and labeling (TUNEL). The effect of curcumin on the cell cycle of Raji cells were examined by propidium iodide staining flow cytometry. The results showed that curcumin strongly inhibited ±1.82 μmol/L and curcumin induced Raji cell apoptosis in a time- and dose-dependent manner. Raji cells treated with curcumin showed curcumin did not demonstrate apparent proliferation inhibition and apoptosis induction in NPBMNCs. It was concluded that curcumin is able to inhibit the proliferation of Raji cells by regulating the cell cycle and inducing the cell apoptosis. Morever, curcumin has low toxicity on NPBMNCs but can selectively induce apoptosis in Raji cells.

  6. DCs pulsed with novel HLA-A2-restricted CTL epitopes against hepatitis C virus induced a broadly reactive anti-HCV-specific T lymphocyte response.

    Directory of Open Access Journals (Sweden)

    Zhongsheng Guo

    Full Text Available OBJECTIVE: To determine the capacity of dendritic cells (DCs loaded with single or multiple-peptide mixtures of novel hepatitis C virus (HCV epitopes to stimulate HCV-specific cytotoxic T lymphocyte (CTL effector functions. METHODS: A bioinformatics approach was used to predict HLA-A2-restricted HCV-specific CTL epitopes, and the predicted peptides identified from this screen were synthesized. Subsequent IFN-γ ELISPOT analysis detected the stimulating function of these peptides in peripheral blood mononuclear cells (PBMCs from both chronic and self-limited HCV infected subjects (subjects exhibiting spontaneous HCV clearance. Mature DCs, derived in vitro from CD14(+ monocytes harvested from the study subjects by incubation with appropriate cytokine cocktails, were loaded with novel peptide or epitope peptide mixtures and co-cultured with autologous T lymphocytes. Granzyme B (GrB and IFN-γ ELISPOT analysis was used to test for epitope-specific CTL responses. T-cell-derived cytokines contained in the co-cultured supernatant were detected by flow cytometry. RESULTS: We identified 7 novel HLA-A2-restricted HCV-specific CTL epitopes that increased the frequency of IFN-γ-producing T cells compared to other epitopes, as assayed by measuring spot forming cells (SFCs. Two epitopes had the strongest stimulating capability in the self-limited subjects, one found in the E2 and one in the NS2 region of HCV; five epitopes had a strong stimulating capacity in both chronic and self-limited HCV infection, but were stronger in the self-limited subjects. They were distributed in E2, NS2, NS3, NS4, and NS5 regions of HCV, respectively. We also found that mDCs loaded with novel peptide mixtures could significantly increase GrB and IFN-γ SFCs as compared to single peptides, especially in chronic HCV infection subjects. Additionally, we found that DCs pulsed with multiple epitope peptide mixtures induced a Th1-biased immune response. CONCLUSIONS: Seven novel and

  7. Polyclonal B-cell lymphocytosis with binucleated lymphocytes (PPBL

    Directory of Open Access Journals (Sweden)

    Xavier Troussard

    2008-10-01

    Full Text Available Xavier Troussard1, Edouard Cornet1, Jean-François Lesesve2, Carine Kourel3, Hossein Mossafa31Laboratoire d’Hématologie Côte de Nacre, Université Caen Basse Normandie Caen, Registre Régional des Hémopathies Malignes de Basse Normandie, France; 2Laboratoire d’Hématologie, Vandoeuvre-Les-Nancy Cedex, France; 3Département de Génétique Humaine, Laboratoire pasteur-Cerba, Cergy-Pontoise, FranceFor the Groupe Français d’Hématologie cellulaire (GFHCAbstract: Persistent polyclonal B-cell lymphocytosis (PPBL is a rare and recently described entity. The review of the literature show PPBL is diagnosed predominantly but not exclusively in women, usually smokers. PPBL is recognized by a moderate, chronic and absolute lymphocytosis (>4 × 109/l in the peripheral blood. In 10% of cases without lymphocytosis, the PPBL diagnosis has to be suggested by peripheral blood examination showing in all cases atypical binucleated lymphocytes. A polyclonal serum IgM is also associated and HLA-DR7 expression is present in most cases. Contrary to B-cell chronic lymphoproliferative disorders (B-CLPD, peripheral B cells are polyclonal with kappa and lambda light-chain expression and no clonal rearrangement of immunoglobulin heavy chain genes is usually demonstrated. The detection of an extra isochromosome for the long arm of chromosome 3 +i(3(q10 has to be considered as a specific marker of PPBL. We performed conventional cytogenetic analysis (CCA in 111 patients with typical PPBL we followed-up more than 4 years. +i(3q was detected in 34% (33/98, PCC in 8% (8/98 and both abnormalities in 31% (30/98. CCA showed neither +i(3q nor PCC in 28% (27/98. Fluorescence in situ hybridization (FISH was also performed in 84 cases and +i(3q was detected in 71% (60/84. When combining both procedures in 84 patients, +i(3q was detected in 17 patients with negative CCA and was confirmed in 43 patients with positive CCA. CCA and FISH were both negative in 24 cases. Whether

  8. A human antibody recognizing a conserved epitope of H5 hemagglutinin broadly neutralizes highly pathogenic avian influenza H5N1 viruses.

    Science.gov (United States)

    Hu, Hongxing; Voss, Jarrod; Zhang, Guoliang; Buchy, Philippi; Zuo, Teng; Wang, Lulan; Wang, Feng; Zhou, Fan; Wang, Guiqing; Tsai, Cheguo; Calder, Lesley; Gamblin, Steve J; Zhang, Linqi; Deubel, Vincent; Zhou, Boping; Skehel, John J; Zhou, Paul

    2012-03-01

    Influenza A virus infection is a persistent threat to public health worldwide due to its ability to evade immune surveillance through rapid genetic drift and shift. Current vaccines against influenza A virus provide immunity to viral isolates that are similar to vaccine strains. High-affinity neutralizing antibodies against conserved epitopes could provide immunity to diverse influenza virus strains and protection against future pandemic viruses. In this study, by using a highly sensitive H5N1 pseudotype-based neutralization assay to screen human monoclonal antibodies produced by memory B cells from an H5N1-infected individual and molecular cloning techniques, we developed three fully human monoclonal antibodies. Among them, antibody 65C6 exhibited potent neutralization activity against all H5 clades and subclades except for subclade 7.2 and prophylactic and therapeutic efficacy against highly pathogenic avian influenza H5N1 viruses in mice. Studies on hemagglutinin (HA)-antibody complexes by electron microscopy and epitope mapping indicate that antibody 65C6 binds to a conformational epitope comprising amino acid residues at positions 118, 121, 161, 164, and 167 (according to mature H5 numbering) on the tip of the membrane-distal globular domain of HA. Thus, we conclude that antibody 65C6 recognizes a neutralization epitope in the globular head of HA that is conserved among almost all divergent H5N1 influenza stains. PMID:22238297

  9. Separation of plasmacytoid dendritic cells from B-cell-biased lymphoid progenitor (BLP and Pre-pro B cells using PDCA-1.

    Directory of Open Access Journals (Sweden)

    Kay L Medina

    Full Text Available B-cell-biased lymphoid progenitors (BLPs and Pre-pro B cells lie at a critical juncture between B cell specification and commitment. However, both of these populations are heterogenous, which hampers investigation into the molecular changes that occur as lymphoid progenitors commit to the B cell lineage. Here, we demonstrate that there are PDCA-1(+Siglec H(+ plasmacytoid dendritic cells (pDCs that co-purify with BLPs and Pre-pro B cells, which express little or no CD11c or Ly6C. Removal of PDCA-1(+ pDCs separates B cell progenitors that express high levels of a Rag1-GFP reporter from Rag1-GFP(low/neg pDCs within the BLP and Pre-pro B populations. Analysis of Flt3-ligand knockout and IL-7Rα knockout mice revealed that there is a block in B cell development at the all-lymphoid progenitor (ALP stage, as the majority of cells within the BLP or Pre-pro B gates were PDCA-1(+ pDCs. Thus, removal of PDCA-1(+ pDCs is critical for analysis of BLP and Pre-pro B cell populations. Analysis of B cell potential within the B220(+CD19(- fraction demonstrated that AA4.1(+Ly6D(+PDCA-1(- Pre-pro B cells gave rise to CD19(+ B cells at high frequency, while PDCA-1(+ pDCs in this fraction did not. Interestingly, the presence of PDCA-1(+ pDCs within CLPs may help to explain the conflicting results regarding the origin of these cells.

  10. CD83 modulates B cell function in vitro: increased IL-10 and reduced Ig secretion by CD83Tg B cells.

    Directory of Open Access Journals (Sweden)

    Birte Kretschmer

    Full Text Available The murine transmembrane glycoprotein CD83 is an important regulator for both thymic T cell maturation and peripheral T cell responses. Recently, we reported that CD83 also has a function on B cells: Ubiquitous transgenic (Tg expression of CD83 interfered with the immunoglobulin (Ig response to infectious agents and to T cell dependent as well as T cell independent model antigen immunization. Here we compare the function of CD83Tg B cells that overexpress CD83 and CD83 mutant (CD83mu B cells that display a drastically reduced CD83 expression. Correlating with CD83 expression, the basic as well as the lipopolysaccharide (LPS induced expression of the activation markers CD86 and MHC-II are significantly increased in CD83Tg B cells and reciprocally decreased in CD83mu B cells. Wild-type B cells rapidly upregulate CD83 within three hours post BCR or TLR engagement by de novo protein synthesis. The forced premature overexpression of CD83 on the CD83Tg B cells results in reduced calcium signaling, reduced Ig secretion and a reciprocally increased IL-10 production upon in vitro activation. This altered phenotype is mediated by CD83 expressed on the B cells themselves, since it is observed in the absence of accessory cells. In line with this finding, purified CD83mu B cells displayed a reduced IL-10 production and slightly increased Ig secretion upon LPS stimulation in vitro. Taken together, our data strongly suggest that CD83 is expressed by B cells upon activation and contributes to the regulation of B cell function.

  11. Phage display and immunological identification of efficient T- and B-combined antigenic epitopes in Helicobacter pylori adhesin A%幽门螺杆菌黏附素A有效T和B联合抗原表位噬菌体展示和抗原性测定

    Institute of Scientific and Technical Information of China (English)

    罗冬娇; 严瑾; 冯雪鸣; 丁威; 俞利平; 陈小囡; 严杰

    2010-01-01

    目的 分析并确定幽门螺杆菌黏附素A(HpaA)分子中有效T细胞和B细胞联合(T/B)抗原表位.方法 重组表达HpaA(rHpaA)并免疫家兔制备抗血清.采用生物信息学技术预测和分析HpaA分子中T细胞和B细胞表位,PCB扩增T/B联合表位肽片段并构建其噬菌体展示系统.采用PEG/NaCl沉淀法提纯展示了T/B联合表位的重组噬菌体PⅢ蛋白(rPⅢ).分别以商品化幽门螺杆菌全菌IgG抗体和rHpaA抗血清为一抗,采用Western blot和ELISA对rPⅢ蛋白中展示的T/B联合表位进行筛选和鉴定.采用MTT检测rHpaA免疫小鼠脾细胞在不同重组噬菌体蛋白刺激下的增殖情况.结果 HpaA分子中共有5个T/B联合表位:HpaA10、HpaA37、HpaA79、HpaA116和HpaA143.所有T/B联合表位均成功地展示于M13噬菌体PⅢ蛋白表面.Western blot、ELISA和淋巴细胞增殖试验结果 均显示,HpaA116是优势抗原表位,HpaA37和HpaA79为有效抗原表位,HpaA10和HpaA143为无效抗原表位.结论 本研究成功地构建了幽门螺杆菌HpaA的T/B联合表位肽噬菌体展示系统.HpaA37和HpaA79,尤其是HpaA116是HpaA有效T/B联合抗原表位.%Objective To analyze and determine the efficient T- and B-combined (T/B) antigenic epitopes in Helicobacter pylori adhesin A. Methods Recombinant HpaA (rHpaA) was expressed for immunizing rabbit to generate antiserum. T- and B-cell epitopes in HpaA molecule were predicted by using bioinformatic technique. The segments to encode T/B combined epitope peptides were amplified by PCR and the phage display systems of T/B combined epitopes were subsequently constructed. PEG/NaCl precipitation method was applied to extract the recombinant phage PⅢ (rPⅢ) that displayed T/B combined epitopes. By using either commercial IgG against whole-cell of Helicobacter pylori or rHpaA antiserum as the primary antibody, the T/B combined epitopes displayed in rP Ⅲ s were screened and identified by Western blot and ELISA. MTT was applied to

  12. EpViX: A cloud-based tool for epitope reactivity analysis and epitope virtual crossmatching to identify low immunologic risk donors for sensitized recipients.

    Science.gov (United States)

    Anunciação, Fernando Antonio Costa; Sousa, Luiz Claudio Demes da Mata; da Silva, Adalberto Socorro; Marroquim, Mário Sérgio Coelho; Coelho, Antônio Gilberto Borges; Willcox, Glauco Henrique; de Andrade, João Marcelo Medeiros; Corrêa, Bruno de Melo; Guimarães, Elisabeth Lima; do Monte, Semiramis Jamil Hadad

    2015-11-01

    One of the challenges facing solid organ transplantation programs globally is the identification of low immunological risk donors for sensitized recipients by HLA allele genotype. Because recognition of donor HLA alleles by host antibodies is at the core of organ rejection, the objective of this work was to develop a new version of the EpHLA software, named EpViX, which uses an HLAMatchmaker algorithm and performs automated epitope virtual crossmatching at the initiation of the organ donation process. EpViX is a free, web-based application developed for use over the internet on a tablet, smartphone or computer. This program was developed using the Ruby programming language and the Ruby-on-Rails framework. To improve the user experience, the EpViX software interface was developed based on the best human–computer interface practices. To simplify epitope analysis and virtual crossmatching, the program was integrated with important available web-based resources, such as OPTN, IMGT/HLA and the International HLA Epitope Registry. We successfully developed a program that allows people to work collaboratively and effectively during the donation process by accurately predicting negative crossmatches, saving time and other resources.

  13. EpViX: A cloud-based tool for epitope reactivity analysis and epitope virtual crossmatching to identify low immunologic risk donors for sensitized recipients.

    Science.gov (United States)

    Anunciação, Fernando Antonio Costa; Sousa, Luiz Claudio Demes da Mata; da Silva, Adalberto Socorro; Marroquim, Mário Sérgio Coelho; Coelho, Antônio Gilberto Borges; Willcox, Glauco Henrique; de Andrade, João Marcelo Medeiros; Corrêa, Bruno de Melo; Guimarães, Elisabeth Lima; do Monte, Semiramis Jamil Hadad

    2015-11-01

    One of the challenges facing solid organ transplantation programs globally is the identification of low immunological risk donors for sensitized recipients by HLA allele genotype. Because recognition of donor HLA alleles by host antibodies is at the core of organ rejection, the objective of this work was to develop a new version of the EpHLA software, named EpViX, which uses an HLAMatchmaker algorithm and performs automated epitope virtual crossmatching at the initiation of the organ donation process. EpViX is a free, web-based application developed for use over the internet on a tablet, smartphone or computer. This program was developed using the Ruby programming language and the Ruby-on-Rails framework. To improve the user experience, the EpViX software interface was developed based on the best human–computer interface practices. To simplify epitope analysis and virtual crossmatching, the program was integrated with important available web-based resources, such as OPTN, IMGT/HLA and the International HLA Epitope Registry. We successfully developed a program that allows people to work collaboratively and effectively during the donation process by accurately predicting negative crossmatches, saving time and other resources. PMID:26531328

  14. Epitope DNA vaccines against tuberculosis: spacers and ubiquitin modulates cellular immune responses elicited by epitope DNA vaccine

    Institute of Scientific and Technical Information of China (English)

    Wang QM; Sun SH; Hu ZL; Zhou FJ; Yin M; Xiao CJ; Zhang JC

    2005-01-01

    Cell-mediated immune responses are crucial in the protection against tuberculosis. In this study, we constructed epitope DNA vaccines (p3-M-38) encoding cytotoxic T lymphocyte (CTL) epitopes of MPT64 and 38 kDa proteins of Mycobacterium tuberculosis. In order to observe the influence of spacer sequence (Ala-Ala-Tyr) or ubiquitin (UbGR) on the efficacy of the two CTL epitopes, we also constructed DNA vaccines, p3-M-S(spacer)-38, p3-Ub (UbGR)-M-S-38 and p3-Ub-M-38. The immune responses elicited by the four DNA vaccines were tested in C57BL/6 (H-2b) mice. The cytotoxicity of T cells was detected by LDH-release method and by enzyme-linked immunospot assay for epitope-specific cells secreting interferon-gamma. The results showed that DNA immunization with p3-M-38 vaccine could induce epitope-specific CD8+ CTL response and that the spacer sequence (AAY) only enhanced M epitope presentation. The protein-targeting sequence (UbGR) enhanced the immunogenicity of the two epitopes. The finding that defined spacer sequences at C-terminus and protein-targeting degradation modulated the immune response of epitope string DNA vaccines will be of importance for the further development of multi-epitope DNA vaccines against tuberculosis.

  15. Structure modeling and spatial epitope analysis for HA protein of the novel H1N1 influenza virus

    Institute of Scientific and Technical Information of China (English)

    WU Di; XU TianLei; SUN Jing; DAI JianXin; DING GuoHui; HE YunGang; ZHOU ZhengFeng; XIONG Hui; DONG Hui; JIN WeiRong; BIAN Chao; JIN Li; WANG HongYan; WANG XiaoNing; YANG Zhong; ZHONG Yang; WANG Hao; CHE XiaoYan; HUANG Zhong; LAN Ke; SUN Bing; WU Fan; YUAN ZhenAn; ZHANG Xi; ZHOU XiaoNong; ZHOU JiaHai; MA ZhiYong; TONG GuangZhi; GUO YaJun; ZHAO GuoPing; LI YiXue; CAO ZhiWei

    2009-01-01

    In recent months,a novel influenza virus H1N1 broke out around the world.With bioinformatics technology,the 3D structure of HA protein was obtained,and the epitope residues were predicted with the method developed in our group for this novel flu virus.58 amino acids were identified as potential epitope residues,the majority of which clustered at the surface of the globular head of HA protein.Although it is located at the similar position,the epitope of HA protein for the novel H1N1 flu virus has obvious differences in the electrostatic potential compared to that of HA proteins from previous flu viruses.

  16. Feasibility of Telomerase-Specific Adoptive T-cell Therapy for B-cell Chronic Lymphocytic Leukemia and Solid Malignancies.

    Science.gov (United States)

    Sandri, Sara; Bobisse, Sara; Moxley, Kelly; Lamolinara, Alessia; De Sanctis, Francesco; Boschi, Federico; Sbarbati, Andrea; Fracasso, Giulio; Ferrarini, Giovanna; Hendriks, Rudi W; Cavallini, Chiara; Scupoli, Maria Teresa; Sartoris, Silvia; Iezzi, Manuela; Nishimura, Michael I; Bronte, Vincenzo; Ugel, Stefano

    2016-05-01

    Telomerase (TERT) is overexpressed in 80% to 90% of primary tumors and contributes to sustaining the transformed phenotype. The identification of several TERT epitopes in tumor cells has elevated the status of TERT as a potential universal target for selective and broad adoptive immunotherapy. TERT-specific cytotoxic T lymphocytes (CTL) have been detected in the peripheral blood of B-cell chronic lymphocytic leukemia (B-CLL) patients, but display low functional avidity, which limits their clinical utility in adoptive cell transfer approaches. To overcome this key obstacle hindering effective immunotherapy, we isolated an HLA-A2-restricted T-cell receptor (TCR) with high avidity for human TERT from vaccinated HLA-A*0201 transgenic mice. Using several relevant humanized mouse models, we demonstrate that TCR-transduced T cells were able to control human B-CLL progression in vivo and limited tumor growth in several human, solid transplantable cancers. TERT-based adoptive immunotherapy selectively eliminated tumor cells, failed to trigger a self-MHC-restricted fratricide of T cells, and was associated with toxicity against mature granulocytes, but not toward human hematopoietic progenitors in humanized immune reconstituted mice. These data support the feasibility of TERT-based adoptive immunotherapy in clinical oncology, highlighting, for the first time, the possibility of utilizing a high-avidity TCR specific for human TERT. Cancer Res; 76(9); 2540-51. ©2016 AACR.

  17. B-cell exposure to self-antigen induces IL-10 producing B cells as well as IL-6- and TNF-α-producing B-cell subsets in healthy humans

    DEFF Research Database (Denmark)

    Langkjær, Anina; Kristensen, Birte; Hansen, Bjarke E;

    2012-01-01

    Human B cells are able to secrete IL-10 after stimulation with mitogens, but their ability to produce IL-10 and regulate T-cell responses after stimulation with self-antigens is unclear. We co-cultured thyroglobulin-pulsed B cells from healthy donors with autologous T cells and observed production...... of IL-10 and TGF-β, in addition to TNF-α and IL-6. Pulsing with foreign antigen, tetanus toxoid (TT), induced a Th1-response with minimal IL-10 production. After thyroglobulin-pulsing, 1.10±0.50% of B cells and 1.00±0.20% of CD4(+) T cells produced IL-10, compared to 0.29±0.19% of B cells (P=0.......01) and 0.13±0.15% of CD4(+) T cells (P=0.006) following TT-pulsing. Thyroglobulin-stimulated, IL-10-secreting B cells were enriched within CD5(+) and CD24(high) cells. While thyroglobulin-pulsed B cells induced only modest proliferation of CD4(+) T cells, B cells pulsed with TT induced vigorous...

  18. Intravascular Large B-Cell Lymphoma: A Difficult Diagnostic Challenge.

    Science.gov (United States)

    Khan, Maria S; McCubbin, Mark; Nand, Sucha

    2014-01-01

    Case Presentation. A 69-year-old Hispanic male, with a past history of diabetes and coronary disease, was admitted for fever, diarrhea, and confusion of 4 weeks duration. Physical examination showed a disoriented patient with multiple ecchymoses, possible ascites, and bilateral scrotal swelling. Hemoglobin was 6.7, prothrombin time (PT) 21.4 seconds with international normalized ratio 2.1, partial thromboplastin time (PTT) 55.6 seconds, fibrin split 10 µg/L, and lactate dehydrogenase (LDH) 1231 IU/L. Except for a positive DNA test for Epstein-Barr virus (EBV) infection, extensive diagnostic workup for infections, malignancy, or a neurological cause was negative. Mixing studies revealed a nonspecific inhibitor of PT and PTT but Factor VIII levels were normal. The patient was empirically treated with antibiotics but developed hypotension and died on day 27 of admission. At autopsy, patient was found to have intravascular diffuse large B-cell lymphoma involving skin, testes, lung, and muscles. The malignant cells were positive for CD20, CD791, Mum-1, and Pax-5 and negative for CD3, CD5, CD10, CD30, and Bcl-6. The malignant cells were 100% positive for Ki-67. Discussion. Intravascular large cell B-cell lymphoma (IVLBCL) is rare form of diffuse large B-cell lymphoma and tends to proliferate within small blood vessels, particularly capillaries and postcapillary venules. The cause of its affinity for vascular bed remains unknown. In many reports, IVLBCL was associated with HIV, HHV8, and EBV infections. The fact that our case showed evidence of EBV infection lends support to the association of this diagnosis to viral illness. The available literature on this subject is scant, and in many cases, the diagnosis was made only at autopsy. The typical presentation of this disorder is with B symptoms, progressive neurologic deficits, and skin findings. Bone marrow, spleen, and liver are involved in a minority of patients. Nearly all patients have elevated LDH, and about 65% are

  19. CEACAM1 induces B-cell survival and is essential for protective antiviral antibody production.

    Science.gov (United States)

    Khairnar, Vishal; Duhan, Vikas; Maney, Sathish Kumar; Honke, Nadine; Shaabani, Namir; Pandyra, Aleksandra A; Seifert, Marc; Pozdeev, Vitaly; Xu, Haifeng C; Sharma, Piyush; Baldin, Fabian; Marquardsen, Florian; Merches, Katja; Lang, Elisabeth; Kirschning, Carsten; Westendorf, Astrid M; Häussinger, Dieter; Lang, Florian; Dittmer, Ulf; Küppers, Ralf; Recher, Mike; Hardt, Cornelia; Scheffrahn, Inka; Beauchemin, Nicole; Göthert, Joachim R; Singer, Bernhard B; Lang, Philipp A; Lang, Karl S

    2015-01-01

    B cells are essential for antiviral immune defence because they produce neutralizing antibodies, present antigen and maintain the lymphoid architecture. Here we show that intrinsic signalling of CEACAM1 is essential for generating efficient B-cell responses. Although CEACAM1 exerts limited influence on the proliferation of B cells, expression of CEACAM1 induces survival of proliferating B cells via the BTK/Syk/NF-κB-axis. The absence of this signalling cascade in naive Ceacam1(-/-) mice limits the survival of B cells. During systemic infection with cytopathic vesicular stomatitis virus, Ceacam1(-/-) mice can barely induce neutralizing antibody responses and die early after infection. We find, therefore, that CEACAM1 is a crucial regulator of B-cell survival, influencing B-cell numbers and protective antiviral antibody responses. PMID:25692415

  20. Anti-B-Cell Therapies in Autoimmune Neurological Diseases: Rationale and Efficacy Trials.

    Science.gov (United States)

    Alexopoulos, Harry; Biba, Angie; Dalakas, Marinos C

    2016-01-01

    B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antibody-producing cells and, most importantly, as sensors, coordinators, and regulators of the immune response. B cells, among other functions, regulate the T-cell activation process through their participation in antigen presentation and production of cytokines. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules or B-cell trophic factors bestows a rational approach for treating autoimmune neurological disorders, even when T cells are the main effector cells. This review summarizes basic aspects of B-cell biology, discusses the role(s) of B cells in neurological autoimmunity, and presents anti-B-cell drugs that are either currently on the market or are expected to be available in the near future for treating neurological autoimmune disorders.

  1. Cutting Edge: Redox Signaling Hypersensitivity Distinguishes Human Germinal Center B Cells.

    Science.gov (United States)

    Polikowsky, Hannah G; Wogsland, Cara E; Diggins, Kirsten E; Huse, Kanutte; Irish, Jonathan M

    2015-08-15

    Differences in the quality of BCR signaling control key steps of B cell maturation and differentiation. Endogenously produced H2O2 is thought to fine tune the level of BCR signaling by reversibly inhibiting phosphatases. However, relatively little is known about how B cells at different stages sense and respond to such redox cues. In this study, we used phospho-specific flow cytometry and high-dimensional mass cytometry (CyTOF) to compare BCR signaling responses in mature human tonsillar B cells undergoing germinal center (GC) reactions. GC B cells, in contrast to mature naive B cells, memory B cells, and plasmablasts, were hypersensitive to a range of H2O2 concentrations and responded by phosphorylating SYK and other membrane-proximal BCR effectors in the absence of BCR engagement. These findings reveal that stage-specific redox responses distinguish human GC B cells. PMID:26157177

  2. In-silico analysis of putative HCV epitopes against Pakistani human leukocyte antigen background: An approach towards development of future vaccines for Pakistani population.

    Science.gov (United States)

    Ashraf, Naeem Mahmood; Bilal, Muhammad; Mahmood, Malik Siddique; Hussain, Aadil; Mehboob, Muhammad Zubair

    2016-09-01

    Mounting burden of HCV-infected individuals and soaring cost of treatment is a serious source of unease for developing countries. Numbers of various approaches have been anticipated to develop a vaccine against HCV but the majority of them proved ineffective. Development of vaccine by considering geographical distribution of HCV genotypes and host genetics shows potential. In this research article, we have tried to predict most putative HCV epitopes which are efficiently restricted by most common HLA alleles in Pakistani population through different computational algorithms. Thirteen selected, experimentally identified epitopes sequences were used to derived consensus sequences in all genotypes of HCV. Obtained consensus sequences were used to predict their binding affinities with most prevalent HLA alleles in Pakistani population. Two Class-I epitopes from NS4B region, one from Class-I epitope from NS5A and one Class-II epitope from NS3 region showed effective binding and proved to be highly putative to boost immune response. A cocktail of these four have been checked for population coverage and they gave 75.53% for Pakistani Asian and 70.77% for Pakistani Mixed populations with no allergenic response. Computational algorithms are robust way to shortlist potential candidate epitopes for vaccine development but further, in vivo and in-vitro studies are required to confirm their immunogenic properties. PMID:27166094

  3. Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

    International Nuclear Information System (INIS)

    Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

  4. Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Weibin [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Chen, Aizhong [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Miao, Yi [Shanghai Xuhui Central Hospital, Shanghai 200031 (China); Xia, Shengli [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Ling, Zhiyang; Xu, Ke; Wang, Tongyan [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Shu, Yuelong [Chinese Center for Disease Control and Prevention, Beijing 102206 (China); Ma, Xiaowei [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Xu, Bianli; Zhang, Jin [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Lin, Xiaojun, E-mail: linxiaojun@hualan.com [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Bian, Chao, E-mail: cbian@sibs.ac.cn [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Sun, Bing, E-mail: bsun@sibs.ac.cn [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)

    2013-01-20

    Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in rec