Página 1 dos resultados de 11306 itens digitais encontrados em 0.025 segundos

A majority of Brazilian patients with rheumatoid arthritis HLA-DRB1 alleles carry both the HLA-DRB1 shared epitope and anti-citrunillated peptide antibodies

LOUZADA-JÚNIOR, P.; FREITAS, M.V.C.; OLIVEIRA, R.D.R.; DEGHAIDE, N.H.S.; CONDE, R.A.; BERTOLO, M.B.; DONADI, E.A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.47%
The objective of the present study was to evaluate the contribution of the shared epitope (SE), the rheumatoid arthritis (RA) protection model, and the occurrence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA patients from a genetically diverse population. One hundred and forty Brazilian RA patients and 161 matched controls were typed for HLA-DRB1 alleles using amplified DNA hybridized with sequence-specific oligonucleotide probes or primers. Patients were stratified according to the presence or absence of SE (DRB1*0401, *0404, *0405, *0101, *1001, and *1402), of the DERAA alleles (DRB1*0103, *0402, *1102, *1103, *1301, *1302, and *1304), and X (all other alleles). Anti-CCP antibodies were measured by ELISA. The combined frequency of SE-positive alleles was significantly greater (76.4 vs 23.6%, P < 0.0001) than the controls. The SE/SE and SE/X genotypes were over-represented (P < 0.0001, OR = 6.02) and DERAA/X was under-represented in RA patients (P < 0.001, OR = 0.49), whereas the frequencies of the SE/DERAA, X/X and X/DERAA genotypes were not significantly different from controls. The frequency of anti-CCP antibodies was higher in SE-positive patients than in SE-negative patients (64.6 vs 44.7%, P = 0.03; OR = 2.25). Although the Brazilian population is highly miscegenated...

Laminin-binding epitope on gp43 from Paracoccidioides brasiliensis is recognized by a monoclonal antibody raised against Staphylococcus aureus laminin receptor

Vicentini, A. P.; Moraes, J. Z.; Gesztesi, J. L.; Franco, M. F.; De Souza, W.; Lopes, J. D.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 37-43
Português
Relevância na Pesquisa
36.47%
Adhesion is regarded as an important step in the pathogenesis of several microorganisms. Thus, the ability to recognize extracellular matrix proteins, such as laminin or fibronectin, has been correlated with invasiveness. Studying the already characterized laminin-binding protein of Paracoccidioides brasiliensis, the 43 kDa glycoprotein (gp43), we evaluated whether MAb 1.H12, raised against the laminin-binding protein from Staphylococcus aureus, cross-reacts with that fungal protein. By immunoblot analysis we show that MAb 1.H12 recognizes gp43. This interaction is able to inhibit the laminin-mediated adhesion to epithelial cells as well as the P. brasiliensis infection in vivo. Moreover, through immunoenzymatic assays, we show that MAb 1.H12 recognizes gp43 in solid phase and that this interaction is partially inhibited by the addition of anti-gp43 MAbs. These results show that MAb 1.H12 recognizes the gp43, suggesting the presence of an epitope similar to those found in the other laminin-binding proteins from phylogenetically very distant cells. These findings reinforce the possibility of evolutionary conservation of such epitopes.

A majority of Brazilian patients with rheumatoid arthritis HLA-DRB1 alleles carry both the HLA-DRB1 shared epitope and anti-citrunillated peptide antibodies

LOUZADA-JÚNIOR, P.; FREITAS, M.V.C.; OLIVEIRA, R.D.R.; DEGHAIDE, N.H.S.; CONDE, R.A.; BERTOLO, M.B.; DONADI, E.A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.47%
The objective of the present study was to evaluate the contribution of the shared epitope (SE), the rheumatoid arthritis (RA) protection model, and the occurrence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA patients from a genetically diverse population. One hundred and forty Brazilian RA patients and 161 matched controls were typed for HLA-DRB1 alleles using amplified DNA hybridized with sequence-specific oligonucleotide probes or primers. Patients were stratified according to the presence or absence of SE (DRB1*0401, *0404, *0405, *0101, *1001, and *1402), of the DERAA alleles (DRB1*0103, *0402, *1102, *1103, *1301, *1302, and *1304), and X (all other alleles). Anti-CCP antibodies were measured by ELISA. The combined frequency of SE-positive alleles was significantly greater (76.4 vs 23.6%, P < 0.0001) than the controls. The SE/SE and SE/X genotypes were over-represented (P < 0.0001, OR = 6.02) and DERAA/X was under-represented in RA patients (P < 0.001, OR = 0.49), whereas the frequencies of the SE/DERAA, X/X and X/DERAA genotypes were not significantly different from controls. The frequency of anti-CCP antibodies was higher in SE-positive patients than in SE-negative patients (64.6 vs 44.7%, P = 0.03; OR = 2.25). Although the Brazilian population is highly miscegenated...

A majority of Brazilian patients with rheumatoid arthritis HLA-DRB1 alleles carry both the HLA-DRB1 shared epitope and anti-citrunillated peptide antibodies

Louzada-Júnior,P.; Freitas,M.V.C.; Oliveira,R.D.R.; Deghaide,N.H.S.; Conde,R.A.; Bertolo,M.B.; Donadi,E.A.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 Português
Relevância na Pesquisa
36.47%
The objective of the present study was to evaluate the contribution of the shared epitope (SE), the rheumatoid arthritis (RA) protection model, and the occurrence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA patients from a genetically diverse population. One hundred and forty Brazilian RA patients and 161 matched controls were typed for HLA-DRB1 alleles using amplified DNA hybridized with sequence-specific oligonucleotide probes or primers. Patients were stratified according to the presence or absence of SE (DRB1*0401, *0404, *0405, *0101, *1001, and *1402), of the DERAA alleles (DRB1*0103, *0402, *1102, *1103, *1301, *1302, and *1304), and X (all other alleles). Anti-CCP antibodies were measured by ELISA. The combined frequency of SE-positive alleles was significantly greater (76.4 vs 23.6%, P < 0.0001) than the controls. The SE/SE and SE/X genotypes were over-represented (P < 0.0001, OR = 6.02) and DERAA/X was under-represented in RA patients (P < 0.001, OR = 0.49), whereas the frequencies of the SE/DERAA, X/X and X/DERAA genotypes were not significantly different from controls. The frequency of anti-CCP antibodies was higher in SE-positive patients than in SE-negative patients (64.6 vs 44.7%, P = 0.03; OR = 2.25). Although the Brazilian population is highly miscegenated...

Immunologic cross-reactivity between Muscovy duck parvovirus and goose parvovirus on the basis of epitope prediction

Li,Ming; Yu,Tian-fei
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
Relevância na Pesquisa
36.47%
Through bioinformatic prediction, between Muscovy duck parvovirus (MDPV) and goose parvovirus (GPV), there were one epitope AA503-509 (RANEPKE) on non-structural protein and three epitopes AA426-430 (SQDLD), 540-544 (DPYRS), 685-691 (KENSKRW) on structural protein might cross-react with each other. Furthermore, the four epitops were expressed in Escherichia coli. All the four recombinant proteins could react with GPV-antisera and MDPV-antisera in Western blot.

Quantitation of CD8+ T-Lymphocyte Responses to Multiple Epitopes from Simian Virus 40 (SV40) Large T Antigen in C57BL/6 Mice Immunized with SV40, SV40 T-Antigen-Transformed Cells, or Vaccinia Virus Recombinants Expressing Full-Length T Antigen or Epitope Minigenes

Mylin, Lawrence M.; Schell, Todd D.; Roberts, Debra; Epler, Melanie; Boesteanu, Alina; Collins, Edward J.; Frelinger, Jeffrey A.; Joyce, Sebastian; Tevethia, Satvir S.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2000 Português
Relevância na Pesquisa
26.87%
The cytotoxic T-lymphocyte response to wild-type simian virus 40 large tumor antigen (Tag) in C57BL/6 (H2b) mice is directed against three H2-Db-restricted epitopes, I, II/III, and V, and one H2-Kb-restricted epitope, IV. Epitopes I, II/III, and IV are immunodominant, while epitope V is immunorecessive. We investigated whether this hierarchical response was established in vivo or was due to differential expansion in vitro by using direct enumeration of CD8+ T lymphocytes with Tag epitope/major histocompatibility complex class I tetramers and intracellular gamma interferon staining. The results demonstrate that epitope IV-specific CD8+ T cells dominated the Tag-specific response in vivo following immunization with full-length Tag while CD8+ T cells specific for epitopes I and II/III were detected at less than one-third of this level. The immunorecessive nature of epitope V was apparent in vivo, since epitope V-specific CD8+ T cells were undetectable following immunization with full-length Tag. In contrast, high levels of epitope V-specific CD8+ T lymphocytes were recruited in vivo following immunization and boosting with a Tag variant in which epitopes I, II/III, and IV had been inactivated. In addition, analysis of the T-cell receptor β (TCRβ) repertoire of Tag epitope-specific CD8+ cells revealed that multiple TCRβ variable regions were utilized for each epitope except Tag epitope II/III...

A Glycine-Rich Bovine Herpesvirus 5 (BHV-5) gE-Specific Epitope within the Ectodomain Is Important for BHV-5 Neurovirulence†

Al-Mubarak, A.; Zhou, Y.; Chowdhury, S. I.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2004 Português
Relevância na Pesquisa
26.92%
The bovine herpesvirus 5 (BHV-5) gE ectodomain contains a glycine-rich epitope coding region (gE5 epitope), residues 204 to 218, that is significantly different from the corresponding gE region of BHV-1. Deletion of the gE epitope significantly reduced the neurovirulence of BHV-5 in rabbits. Pulse-chase analyses revealed that the epitope-deleted and wild-type gE were synthesized as N-glycosylated endoglycosidase H-sensitive precursors with approximate molecular masses of 85 kDa and 86 kDa, respectively. Like the wild-type gE, epitope-deleted gE complexed with gI and was readily transported from the endoplasmic reticulum. Concomitantly, the epitope-deleted and wild-type gE acquired posttranslational modifications in the Golgi leading to an increased apparent molecular mass of 93-kDa (epitope-deleted gE) and 94-kDa (wild-type gE). The kinetics of mutant and wild-type gE processing were similar, and both mature proteins were resistant to endoglycosidase H but sensitive to glycopeptidase F. The gE epitope-deleted BHV-5 formed wild-type-sized plaques in MDBK cells, and the epitope-deleted gE was expressed on the cell surface. However, rabbits infected intranasally with gE epitope-deleted BHV-5 did not develop seizures, and only 20% of the infected rabbits showed mild neurological signs. The epitope-deleted virus replicated efficiently in the olfactory epithelium. However...

Characterization of a discontinuous epitope of the human immunodeficiency virus (HIV) core protein p24 by epitope excision and differential chemical modification followed by mass spectrometric peptide mapping analysis.

Hochleitner, E. O.; Borchers, C.; Parker, C.; Bienstock, R. J.; Tomer, K. B.
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /03/2000 Português
Relevância na Pesquisa
26.9%
A combination of epitope excision, epitope extraction, and differential chemical modification followed by mass spectrometric peptide mapping was used for the characterization of a discontinuous epitope that is recognized by the mouse anti-HIV-p24 monoclonal antibody 5E2.A3. In epitope excision, the protein is first bound to an immobilized antibody and then digested with proteolytic enzymes. In epitope extraction, the protein is first digested and subsequently allowed to react with the antibody. After epitope excision of the p24-5E2.A3 complex with endoproteinase Lys-C, a large fragment remained affinity bound corresponding to amino acids 1-158 of HIV-p24 (fragment 1-158). Further digestion, however, resulted in loss of affinity. Moreover, no affinity-bound fragments were observed after an epitope extraction experiment. These data from the epitope excision and extraction experiments suggest that the epitope is discontinuous. For the further characterization of the epitope, amino groups in the epitope-containing fragment were acetylated in both the affinity bound and free states followed by mass spectrometric analysis. Two successive acetylation reactions were performed: (1) the first used a low molar excess of acetic anhydride, and (2) the second...

Heterologous Epitope-Scaffold Prime∶Boosting Immuno-Focuses B Cell Responses to the HIV-1 gp41 2F5 Neutralization Determinant

Guenaga, Javier; Dosenovic, Pia; Ofek, Gilad; Baker, David; Schief, William R.; Kwong, Peter D.; Karlsson Hedestam, Gunilla B.; Wyatt, Richard T.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 26/01/2011 Português
Relevância na Pesquisa
26.87%
The HIV-1 envelope glycoproteins (Env) gp120 and gp41 mediate entry and are the targets for neutralizing antibodies. Within gp41, a continuous epitope defined by the broadly neutralizing antibody 2F5, is one of the few conserved sites accessible to antibodies on the functional HIV Env spike. Recently, as an initial attempt at structure-guided design, we transplanted the 2F5 epitope onto several non-HIV acceptor scaffold proteins that we termed epitope scaffolds (ES). As immunogens, these ES proteins elicited antibodies with exquisite binding specificity matching that of the 2F5 antibody. These novel 2F5 epitope scaffolds presented us with the opportunity to test heterologous prime∶boost immunization strategies to selectively boost antibody responses against the engrafted gp41 2F5 epitope. Such strategies might be employed to target conserved but poorly immunogenic sites on the HIV-1 Env, and, more generally, other structurally defined pathogen targets. Here, we assessed ES prime∶boosting by measuring epitope specific serum antibody titers by ELISA and B cell responses by ELISpot analysis using both free 2F5 peptide and an unrelated ES protein as probes. We found that the heterologous ES prime∶boosting immunization regimen elicits cross-reactive humoral responses to the structurally constrained 2F5 epitope target...

‘Multi-Epitope-Targeted’ Immune-Specific Therapy for a Multiple Sclerosis-Like Disease via Engineered Multi-Epitope Protein Is Superior to Peptides

Kaushansky, Nathali; Kerlero de Rosbo, Nicole; Zilkha-Falb, Rina; Yosef-Hemo, Reut; Cohen, Lydia; Ben-Nun, Avraham
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 29/11/2011 Português
Relevância na Pesquisa
26.89%
Antigen-induced peripheral tolerance is potentially one of the most efficient and specific therapeutic approaches for autoimmune diseases. Although highly effective in animal models, antigen-based strategies have not yet been translated into practicable human therapy, and several clinical trials using a single antigen or peptidic-epitope in multiple sclerosis (MS) yielded disappointing results. In these clinical trials, however, the apparent complexity and dynamics of the pathogenic autoimmunity associated with MS, which result from the multiplicity of potential target antigens and “epitope spread”, have not been sufficiently considered. Thus, targeting pathogenic T-cells reactive against a single antigen/epitope is unlikely to be sufficient; to be effective, immunospecific therapy to MS should logically neutralize concomitantly T-cells reactive against as many major target antigens/epitopes as possible. We investigated such “multi-epitope-targeting” approach in murine experimental autoimmune encephalomyelitis (EAE) associated with a single (“classical”) or multiple (“complex”) anti-myelin autoreactivities, using cocktail of different encephalitogenic peptides vis-a-vis artificial multi-epitope-protein (designated Y-MSPc) encompassing rationally selected MS-relevant epitopes of five major myelin antigens...

Conservation Analysis of Dengue Virus T-cell Epitope-Based Vaccine Candidates Using Peptide Block Entropy

Olsen, Lars Rønn; Zhang, Guang Lan; Keskin, Derin Benerci; Reinherz, Ellis Leonard; Brusic, Vladimir
Fonte: Frontiers Research Foundation Publicador: Frontiers Research Foundation
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.59%
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 of broadly covering antigens. Since T-cell epitopes are recognized as peptides rather than individual residues, this method is based on calculating the information content of blocks of peptides from a multiple sequence alignment of homologous proteins rather than using the information content of individual residues. The block entropy analysis provides broad coverage of variant antigens. We applied the block entropy analysis method to the proteomes of the four serotypes of dengue virus (DENV) and found 1,551 blocks of 9-mer peptides, which cover 99% of available sequences with five or fewer unique peptides. 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. In total, 457 subunit peptides that encompass the diversity of all sequenced DENV strains of which 333 are T-cell epitope candidates.

A Series of N-terminal Epitope Tagged Hdh Knock-In Alleles Expressing Normal and Mutant Huntingtin: Their Application to Understanding the Effect of Increasing the Length of Normal Huntingtin’s Polyglutamine Stretch on CAG140 Mouse Model Pathogenesis

Zheng, Shuqiu; Ghitani, Nima; Liu, Jeh-Ping; Zeitlin, Scott O; Blackburn, Jessica S
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.59%
Background: Huntington’s disease (HD) is an autosomal dominant neurodegenerative disease that is caused by the expansion of a polyglutamine (polyQ) stretch within Huntingtin (htt), the protein product of the HD gene. Although studies in vitro have suggested that the mutant htt can act in a potentially dominant negative fashion by sequestering wild-type htt into insoluble protein aggregates, the role of the length of the normal htt polyQ stretch, and the adjacent proline-rich region (PRR) in modulating HD mouse model pathogenesis is currently unknown. Results: We describe the generation and characterization of a series of knock-in HD mouse models that express versions of the mouse HD gene (Hdh) encoding N-terminal hemaglutinin (HA) or 3xFlag epitope tagged full-length htt with different polyQ lengths (HA7Q-, 3xFlag7Q-, 3xFlag20Q-, and 3xFlag140Q-htt) and substitution of the adjacent mouse PRR with the human PRR (3xFlag20Q- and 3xFlag140Q-htt). Using co-immunoprecipitation and immunohistochemistry analyses, we detect no significant interaction between soluble full-length normal 7Q- htt and mutant (140Q) htt, but we do observe N-terminal fragments of epitope-tagged normal htt in mutant htt aggregates. When the sequences encoding normal mouse htt’s polyQ stretch and PRR are replaced with non-pathogenic human sequence in mice also expressing 140Q-htt...

Immune response to enzyme replacement therapy: single epitope control of antigen distribution from circulation

Glaros, E.; Turner, C.; Parkinson, E.; Hopwood, J.; Brooks, D.
Fonte: Academic Press Inc Elsevier Science Publicador: Academic Press Inc Elsevier Science
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
Relevância na Pesquisa
36.59%
Immune response to replacement therapy has been reported for a range of therapeutic strategies being developed for the treatment of patients with genetic disease. The potential problem of immune response to enzyme replacement therapy has been investigated in alpha-L-iduronidase immunized rats, representing a model of the lysosomal storage disorder Hurler syndrome (alpha-L-iduronidase deficiency). The antibody response to alpha-L-iduronidase showed that the positional location of antibody reactivity was similar for different immunized rats, but the precise linear sequence epitopes identified, varied between rats. A monoclonal antibody reacting to an epitope in close proximity to one high antigenicity site on alpha-L-iduronidase was used to reproduce the in vivo effect of altered enzyme tissue distribution, previously observed in immunized rats infused with alpha-L-iduronidase. The study demonstrated that during an immune response, antibody reacting to a single epitope could partially control the tissue distribution of antigen from circulation.; Glaros, Elias N ; Turner, Chris T ; Parkinson, Emma J ; Hopwood, John J ; Brooks, Doug A

Epitope analysis of the FanC subunit protein of the K99 (F5) fimbriae of enterotoxigenic Escherichia coli using a recombinant fusion technique

Ogunniyi, A.; Kotlarski, I.; Morona, R.; Manning, P.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
Relevância na Pesquisa
36.59%
We have used a recombinant approach to characterise the B- and T-cell epitopes of FanC, the major subunit polypeptide of K99 (F5) fimbriae of enterotoxigenic Escherichia coli strains. This involved the fusion of FanC and its carboxy-terminal truncated derivatives to a reporter, the E. coli alkaline phosphatase (PhoA), generating stable, recombinant fusions. The B-cell epitopes of FanC were characterised by Western blotting of FanC::PhoA fusion proteins with a polyclonal mouse antiserum directed against K99 fimbrial antigen, and with a panel of monoclonal antibodies generated to the K99 antigen. An attempt to characterise the T-cell epitopes of the fimbrial subunit was made by standard in vitro T-cell proliferation assay. Our results suggest that the B-cell epitopes of FanC are likely to be continuous, with a potentially immunodominant epitope at the carboxy-terminus. However, T-cell proliferation assays with the FanC::PhoA fusion proteins did not indicate any immunodominant T-cell epitope(s). We hypothesise that fusion of FanC peptides to PhoA had resulted in altered folding of the peptides for antibody and T-cell recognition, highlighting the potential problems and drawbacks of the recombinant fusion technique in defining the epitopes of certain proteins.; Abiodun D Ogunniyi...

Linear B-cell epitope mapping using enzyme-linked immunosorbent assay for libraries of overlapping synthetic peptides

Heuzenroeder, M.; Barton, M.; Vanniasinkam, T.; Phumoonna, T.
Fonte: Humana Press Publicador: Humana Press
Tipo: Parte de Livro
Publicado em //2009 Português
Relevância na Pesquisa
36.59%
The aim of this chapter is to provide a strategy for mapping linear antibody epitopes of protein antigens in order to discover candidates for vaccines or diagnostic tests. A set of overlapping peptides was designed and synthesised based upon a known amino acid sequence of the target protein, virulence-associated protein A (VapA) of the bacterium Rhodococcus equi, an important pulmonary pathogen in foals. The peptides were biotinylated and used in an ELISA to screen immune sera from foals. These biotinylated peptides were coated directly onto micro titre plates that had been pre-coated with NeutrAvidin™. A linear B-cell epitope was identified by a universal recognition of sera to the synthetic peptides which corresponds to a particular fragment of the VapA protein.; Michael W. Heuzenroeder, Mary D. Barton, Thiru Vanniasinkam and Tongted Phumoonna

New approaches to in silico design of epitope-based vaccines; Neue Ansätze zum computergestützten Entwurf epitopbasierter Impfstoffe

Toussaint, Nora Christina
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
Relevância na Pesquisa
36.84%
Traditional trial-and-error based approaches to vaccine design have been remarkably successful. One of the major successes was the eradication of smallpox in the 1970s. However, there are still many diseases for which no viable vaccine could be found, HIV infection and cancer being among the most prominent examples. Here, new, rationally designed types of vaccines, as, e.g., epitope-based vaccines (EVs) are a promising alternative. Due to their manifold advantages and their applicability in personalized medicine EVs have recently been attracting significant interest. EVs make use of target-specific immunogenic peptides, i.e., epitopes, to trigger an immune response. In this thesis we propose new approaches to the in silico design of EVs. Given a set of target antigens, the first step in EV design is the discovery of candidate epitopes. Computational approaches to epitope discovery comprise major histocompatibility complex (MHC) binding prediction and T-cell reactivity prediction. The key problem in MHC binding prediction is the lack of experimental data for the vast majority of known allelic MHC variants. We present two support vector machine (SVM)-based approaches to overcome this problem. The first approach improves the predictive power of SVMs for alleles with little experimental binding data. The second approach — for the first time — allows predictions for all known MHC variants by exploiting structural similarities between different MHC molecules. The key problem in T-cell reactivity prediction are the complex dependencies of T-cell reactivity on the host proteome. We present the first approach that takes these dependencies into account. Our method markedly outperforms previously proposed approaches...

Decidualized and pre-decidualized normal endometrial stromal cells produce more O-linked N-acetylglucosamine containing epitope H than non-decidualized normal endometrial stromal cells

Polyzos, P.T.; Arvanitis, L.; Charchanti, A.; Galani, V.; Havaki, S.; Kallioras, V.; Nakou, María; Faros, E.G.; Marinos, E.; Sgantzos, M.; Kittas, C.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
Relevância na Pesquisa
36.91%
The epitope H contains an O-linked Nacetylglucosamine residue in a specific conformation and/or environment recognized by the monoclonal antibody H (mAbH). mAbH stains two bands with Mr x10-3 of 209 and 62 in lysates of cultured rat astrocytes. In addition, in extracts of cultured MCF-7 breast carcinoma cell line cells it stains cytokeratin 8 and five polypeptides originating from Triton X-100-soluble (Mr x10-3 of 232, 67 and 37) and from the Triton X-100- insoluble (Mr x10-3 of 51 and 50) fractions, respectively. In our previous studies we used the mAbH to investigate by immunostaining the expression of the epitope H in normal human brains, human brains with a variety of lesions, astrocytic tumors, infiltrating ductal breast carcinomas, fibroadenomas, and mitochondria-rich normal, metaplastic and neoplastic cells. In order to gain further insight into the expression patterns of the epitope H in human tissues we used the mAbH to investigate the immunohistochemical expression of the epitope H in normal human endometrium, including 30 cases of proliferative endometrium, 30 cases of early secretory endometrium, 30 cases of mid secretory endometrium, 30 cases of late secretory endometrium and 30 cases of decidual tissues. The main results were the following: 1) The decidual stromal cells presented in all cases high cytoplasmic expression of the epitope H; 2) The predecidual stromal cells presented in all cases of late secretory endometrium significant cytoplasmic expression of the epitope H ranging from moderate to high expression; 3) The non pre-decidual stromal cells of the functional endometrial layer presented in all cases insignificant cytoplasmic expression of the epitope H ranging from null to low expression; 4) The stromal cells of the basal layer of the endometrium and decidua did not express the epitope H in any case; 5) The endometrial stromal granulocytes did not express the epitope H in any case and 6) The blood vessel wall cells (endothelial and smooth muscle) of the endometrium through the whole duration of the menstrual cycle and of the decidua presented high cytoplasmic expression of the epitope H. It is concluded that decidualized and predecidualized human normal endometrial stromal cells show increased expression of the O-linked Nacetylglucosamine containing epitope H compared to non-decidualized endometrial stromal cells. These findings suggest that the expression of the epitope H may be under positive progesteronic control in normal human endometrium. Further investigation of the antigens bearing the epitope H might help to gain further insight into the histophysiology and the pathology of human endometrium.

Induction of protective T-helper 1 immune responses against Echinococcus granulosus in mice by a multi-T-cell epitope antigen based on five proteins

Esmaelizad,Majid; Ahmadian,Gholamreza; Aghaiypour,Khosrow; Shamsara,Mehdi; Paykari,Habibellah; Tebianian,Majid
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 Português
Relevância na Pesquisa
36.59%
In this study, we designed an experiment to predict a potential immunodominant T-cell epitope and evaluate the protectivity of this antigen in immunised mice. The T-cell epitopes of the candidate proteins (EgGST, EgA31, Eg95, EgTrp and P14-3-3) were detected using available web-based databases. The synthesised DNA was subcloned into the pET41a+ vector and expressed in Escherichia coli as a fusion to glutathione-S-transferase protein (GST). The resulting chimeric protein was then purified by affinity chromatography. Twenty female C57BL/6 mice were immunised with the antigen emulsified in Freund's adjuvant. Mouse splenocytes were then cultured in Dulbecco's Modified Eagle's Medium in the presence of the antigen. The production of interferon-γ was significantly higher in the immunised mice than in the control mice (> 1,300 pg/mL), but interleukin (IL)-10 and IL-4 production was not statistically different between the two groups. In a challenge study in which mice were infected with 500 live protoscolices, a high protectivity level (99.6%) was demonstrated in immunised BALB/C mice compared to the findings in the control groups [GST and adjuvant (Adj) ]. These results demonstrate the successful application of the predicted T-cell epitope in designing a vaccine against Echinococcus granulosus in a mouse model.

Single epitope multiple staining to detect ultralow frequency B cells

Townsend, S E; Goodnow, Christopher; Cornall, Richard J
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.47%
Here we describe a method for detecting ultralow frequency target cells from within a high background of irrelevant cells by a novel method, single epitope multiple staining (SEMS). Samples of murine splenocytes were seeded with a low number of splenocyte

Induction of neutralizing antibodies against mutalysin-II from Lachesis muta muta Snake Venom Elicited by a conformational B-cell epitope predicted by Blue Star Sting data base.

MACHADO-DE-ÁVILA, R. A.; VELLOSO, M.; OLIVEIRA, D.; STRANSKY, S.; FLOR-SÁ, A.; SCHNEIDER, F. S.; NESHICH, G.; CHÁVEZ-OLÓRTEGUI, C.
Fonte: Immunome Research, v. 11, n. 1, Mar. 2015. Publicador: Immunome Research, v. 11, n. 1, Mar. 2015.
Tipo: Artigo em periódico indexado (ALICE) Formato: Não paginado.
Português
Relevância na Pesquisa
36.47%
Mutalysin-II, from Lachesis muta muta snake venom, is an endopeptidase with hemorrhagic activity. To identify a conformational epitope we used Blue Star Sting, the latest version of the web based Sting Millenium Suite, as alternative computational analysis tool to select and design peptides. Pre-selected cut-off values of the accessibility and hydrophilicity parameters were used to select amino acid residues as potential conformational epitopes. A peptide (P117-Y116-C115-Q194-C195-L197-N198-K199-P200-Y5-L48) was manually drawn on Swiss-PDB-Viewer package and synthesized by Fmoc-synthesis. Immunization of rabbits with this peptide induced antibodies that recognized Mutalysin-II and protected against the hemorrhagic factors present in Lachesis venom. The Sting Millennium Suite was able to predict conformational epitopes in this class of proteins. Three amino acids (K199, Y5 and L48) were identified as essential in the interaction between the peptide and the neutralizing antibodies.; 2015