Authors: Girard, Magalí Celeste; Acevedo, Gonzalo Raúl; López, Lucía; Ossowski, Micaela Soledad; Piñeyro, María Dolores; Grosso, Juan Pedro; Fernández, Marisa Mariel; Hernández Vasquez, Yolanda; Robello, Carlos; Gomez, Karina Andrea
Publication Date: 2018.
Language: English.
Abstract:
Trypanosoma cruzi, the aetiological agent of Chagas disease, has a highly efficient detoxification system to deal with the oxidative burst imposed by its host. One of the antioxidant enzymes involved is the cytosolic tryparedoxin peroxidase (c-TXNPx), which catalyses the reduction to hydrogen peroxide, small-chain organic hydroperoxides and peroxynitrite. This enzyme is present in all parasite stages, and its overexpression renders parasites more resistant to the oxidative defences of macrophages, favouring parasite survival. This work addressed the study of the specific humoral and cellular immune response triggered by c-TXNPx in human natural infection. Thus, sera and peripheral blood mononuclear cells (PBMC) were collected from chronically infected asymptomatic and cardiac patients, and non-infected individuals. Results showed that levels of IgG antibodies against c-TXNPx were low in sera from individuals across all groups. B-cell epitope prediction limited immunogenicity to a few, small regions on the c-TXNPx sequence. At a cellular level, PBMC from asymptomatic and cardiac patients proliferated and secreted interferon-γ after c-TXNPx stimulation, compared with mock control. However, only proliferation was higher in asymptomatic patients compared with cardiac and non-infected individuals. Furthermore, asymptomatic patients showed an enhanced frequency of CD19 + CD69 + cells upon exposure to c-TXNPx. Overall, our results show that c-TXNPx fails to induce a strong immune response in natural infection, being measurable only in those patients without any clinical symptoms. The low impact of c-TXNPx in the human immune response could be strategic for parasite survival, as it keeps this crucial antioxidant enzyme activity safe from the mechanisms of adaptive immune response.
Author affiliation: Girard, Magalí Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina
Author affiliation: Acevedo, Gonzalo Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina
Author affiliation: López, Lucía. Instituto Pasteur de Montevideo; Uruguay
Author affiliation: Ossowski, Micaela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina
Author affiliation: Piñeyro, María Dolores. Instituto Pasteur de Montevideo; Uruguay. Universidad de la República; Uruguay
Author affiliation: Grosso, Juan Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina
Author affiliation: Fernández, Marisa Mariel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Author affiliation: Hernández Vasquez, Yolanda. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina
Author affiliation: Robello, Carlos. Instituto Pasteur de Montevideo; Uruguay. Universidad de la República; Uruguay
Author affiliation: Gomez, Karina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Pedersen, Lasse E.; Patch, Jared R.; Kenney, Mary; Glabman, Raisa A.; Nielsen, Morten; Jungersen, Gregers; Buus, Soren; Golde, William T.
Publication Date: 2016.
Language: English.
Abstract:
The immune response to the highly acute foot-and-mouth disease virus (FMDV) is routinely reported as a measure of serum antibody. However, a critical effector function of immune responses combating viral infection of mammals is the cytotoxic T lymphocyte (CTL) response mediated by virus specific CD8 expressing T cells. This immune mechanism arrests viral spread by killing virus infected cells before new, mature virus can develop. We have previously shown that infection of swine by FMDV results in a measurable CTL response and have correlated CTL killing of virus-infected cells with specific class I major histocompatibility complex (MHC) tetramer staining. We also showed that a modified replication defective human adenovirus 5 vector expressing the FMDV structural proteins (Ad5-FMDV-T vaccine) targets the induction of a CD8+ CTL response with a minimal humoral response. In this report, we show that the specificity of the CD8+ T cell response to Ad5-FMDV-T varies between cohorts of genetically identical animals. Further, we demonstrate epitope specificity of CD8+ T cells expands following multiple immunizations with this vaccine.
Author affiliation: Pedersen, Lasse E.. United States Department of Agriculture. Agricultural Research Service; Argentina. Technical University of Denmark; Dinamarca
Author affiliation: Patch, Jared R.. United States Department of Agriculture. Agricultural Research Service; Argentina. University of Vermont; Estados Unidos
Author affiliation: Kenney, Mary. United States Department of Agriculture. Agricultural Research Service; Argentina
Author affiliation: Glabman, Raisa A.. United States Department of Agriculture. Agricultural Research Service; Argentina. University of Vermont; Estados Unidos
Author affiliation: Nielsen, Morten. Technical University of Denmark; Dinamarca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentina
Author affiliation: Jungersen, Gregers. Technical University of Denmark; Dinamarca
Author affiliation: Buus, Soren. Universidad de Copenhagen; Dinamarca
Author affiliation: Golde, William T.. United States Department of Agriculture. Agricultural Research Service; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Braendstrup, Peter; Mortensen, Bo Kok; Justesen, Sune; Østerby, Thomas; Rasmussen, Michael; Hansen, Andreas Martin; Christiansen, Claus Bohn; Hansen, Morten Bagge; Nielsen, Morten; Vindeløv, Lars; Buus, Søren; Stryhn, Anette
Publication Date: 2014.
Language: English.
Abstract:
Human cytomegalovirus (HCMV) is an important human pathogen. It is a leading cause of congenital infection and a leading infectious threat to recipients of solid organ transplants as well as of allogeneic hematopoietic cell transplants. Moreover, it has recently been suggested that HCMV may promote tumor development. Both CD4+ and CD8+ T cell responses are important for long-term control of the virus, and adoptive transfer of HCMV-specific T cells has led to protection from reactivation and HCMV disease. Identification of HCMV-specific T cell epitopes has primarily focused on CD8+ T cell responses against the pp65 phosphoprotein. In this study, we have focused on CD4+ and CD8+ T cell responses against the immediate early 1 and 2 proteins (IE1 and IE2). Using overlapping peptides spanning the entire IE1 and IE2 sequences, peripheral blood mononuclear cells from 16 healthy, HLA-typed, donors were screened by ex vivo IFN-γ ELISpot and in vitro intracellular cytokine secretion assays. The specificities of CD4+ and CD8+ T cell responses were identified and validated by HLA class II and I tetramers, respectively. Eighty-one CD4+ and 44 CD8+ T cell responses were identified representing at least seven different CD4 epitopes and 14 CD8 epitopes restricted by seven and 11 different HLA class II and I molecules, respectively, in total covering 91 and 98% of the Caucasian population, respectively. Presented in the context of several different HLA class II molecules, two epitope areas in IE1 and IE2 were recognized in about half of the analyzed donors. These data may be used to design a versatile anti-HCMV vaccine and/or immunotherapy strategy.
Author affiliation: Braendstrup, Peter. Universidad de Copenhagen; Dinamarca
Author affiliation: Mortensen, Bo Kok. Universidad de Copenhagen; Dinamarca
Author affiliation: Justesen, Sune. Universidad de Copenhagen; Dinamarca
Author affiliation: Østerby, Thomas. Universidad de Copenhagen; Dinamarca
Author affiliation: Rasmussen, Michael. Universidad de Copenhagen; Dinamarca
Author affiliation: Hansen, Andreas Martin. Universidad de Copenhagen; Dinamarca
Author affiliation: Christiansen, Claus Bohn. Copenhagen University Hospital; Dinamarca
Author affiliation: Hansen, Morten Bagge. Copenhagen University Hospital; Dinamarca
Author affiliation: Nielsen, Morten. Technical University of Denmark; Dinamarca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentina
Author affiliation: Vindeløv, Lars. Copenhagen University Hospital; Dinamarca
Author affiliation: Buus, Søren. Universidad de Copenhagen; Dinamarca
Author affiliation: Stryhn, Anette. Universidad de Copenhagen; Dinamarca
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Publication Date: 2016.
Language: English.
Abstract:
Pan-specific prediction of receptor–ligand interaction is conventionally done using machine-learning methods that integrates information about both receptor and ligand primary sequences. To achieve optimal performance using machine learning, dealing with overfitting and data redundancy is critical. Most often so-called ligand clustering methods have been used to deal with these issues in the context of pan-specific receptor–ligand predictions, and the MHC system the approach has proven highly effective for extrapolating information from a limited set of receptors with well characterized binding motifs, to others with no or very limited experimental characterization. The success of this approach has however proven to depend strongly on the similarity of the query molecule to the molecules with characterized specificity using in the machine-learning process. Here, we outline an alternative strategy with the aim of altering this and construct data sets optimal for training of pan-specific receptor–ligand predictions focusing on receptor similarity rather than ligand similarity. We show that this receptor clustering method consistently in benchmarks covering affinity predictions, MHC ligand and MHC epitope identification perform better than the conventional ligand clustering method on the alleles with remote similarity to the training set.
Author affiliation: Mattsson, Andreas Holm. Technical University of Denmark; Dinamarca. Evaxion Biotech; Dinamarca
Author affiliation: Kringelum, J.V.. Evaxion Biotech; Dinamarca
Author affiliation: Garde, C.. Universidad de Copenhagen; Dinamarca
Author affiliation: Nielsen, Morten. Technical University of Denmark; Dinamarca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Murphy, J. Patrick; Konda, Prathyusha; Kowalewski, Daniel J.; Schuster, Heiko; Clements, Derek; Kim, Youra; Cohen, Alejandro M.; Sharif, Tanveer; Nielsen, Morten; Stevanovic, Stefan; Lee, Patrick W.; Gujar, Shashi
Publication Date: 2017.
Language: English.
Abstract:
Class I major histocompatibility complex (MHC-I)-bound peptide ligands dictate the activation and specificity of CD8+ T cells and thus are important for devising T-cell immunotherapies. In recent times, advances in mass spectrometry (MS) have enabled the precise identification of these MHC-I peptides, wherein MS spectra are compared against a reference proteome. Unfortunately, matching these spectra to reference proteome databases is hindered by inflated search spaces attributed to a lack of enzyme restriction in the searches, limiting the efficiency with which MHC ligands are discovered. Here we offer a solution to this problem whereby we developed a targeted database search approach and accompanying tool SpectMHC, that is based on a priori-predicted MHC-I peptides. We first validated the approach using MS data from two different allotype-specific immunoprecipitates for the C57BL/6 mouse background. We then developed allotype-specific HLA databases to search previously published MS data sets of human peripheral blood mononuclear cells (PBMCs). This targeted search strategy improved peptide identifications for both mouse and human ligandomes by greater than 2-fold and is superior to traditional "no enzyme" searches of reference proteomes. Our targeted database search promises to uncover otherwise missed novel T-cell epitopes of therapeutic potential.
Author affiliation: Murphy, J. Patrick. Dalhousie University Halifax; Canadá
Author affiliation: Konda, Prathyusha. Dalhousie University Halifax; Canadá
Author affiliation: Kowalewski, Daniel J.. University of Tübingen; Alemania. Immatics Biotechnologies GmbH; Alemania
Author affiliation: Schuster, Heiko. University of Tübingen; Alemania. Immatics Biotechnologies GmbH; Alemania
Author affiliation: Clements, Derek. Dalhousie University Halifax; Canadá
Author affiliation: Kim, Youra. Dalhousie University Halifax; Canadá
Author affiliation: Cohen, Alejandro M.. Dalhousie University Halifax; Canadá
Author affiliation: Sharif, Tanveer. Dalhousie University Halifax; Canadá
Author affiliation: Nielsen, Morten. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Technical University of Denmark; Dinamarca
Author affiliation: Stevanovic, Stefan. University of Tübingen; Alemania
Author affiliation: Lee, Patrick W.. Dalhousie University Halifax; Canadá
Author affiliation: Gujar, Shashi. Dalhousie University Halifax; Canadá
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Abstract:
Multiple factors determine the ability of a peptide to elicit a cytotoxic T cell lymphocyte response. Binding to a major histocompatibility complex class I (MHC-I) molecule is one of the most essential factors, as no peptide can become a T cell epitope unless presented on the cell surface in complex with an MHC-I molecule. As such, peptide-MHC (pMHC) binding affinity predictors are currently the premier methods for T cell epitope prediction, and these prediction methods have been shown to have high predictive performances in multiple studies. However, not all MHC-I binders are T cell epitopes, and multiple studies have investigated what additional factors are important for determining the immunogenicity of a peptide. A recent study suggested that pMHC stability plays an important role in determining if a peptide can become a T cell epitope. Likewise, a T cell propensity model has been proposed for identifying MHC binding peptides with amino acid compositions favoring T cell receptor interactions. In this study, we investigate if improved accuracy for T cell epitope discovery can be achieved by integrating predictions for pMHC binding affinity, pMHC stability, and T cell propensity. We show that a weighted sum approach allows pMHC stability and T cell propensity predictions to enrich pMHC binding affinity predictions. The integrated model leads to a consistent and significant increase in predictive performance and we demonstrate how this can be utilized to decrease the experimental workload of epitope screens. The final method, NetTepi, is publically available at www.cbs.dtu.dk/services/NetTepi
Author affiliation: Trolle, Thomas. Technical University Of Denmark; Dinamarca
Author affiliation: Nielsen, Morten. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Costa, Joana; Marani, Mariela Mirta; Grazina, Liliana; Villa, Caterina; Meira, Liliana; Oliveira, M. Beatriz P.P.; Leite, José R.S.A.; Mafra, Isabel
Publication Date: 2017.
Language: English.
Abstract:
The introduction of genes isolated from different Bacillus thuringiensis strains to express Cry-type toxins in transgenic crops is a common strategy to confer insect resistance traits. This work intended to extensively in silico analyse Cry1A(b)16 protein for the identification of peptide markers for the biorecognition of transgenic crops. By combining two different strategies based on several bioinformatic tools for linear epitope prediction, a set of seven peptides was successfully selected as potential Cry1A(b)16 immunogens. For the prediction of conformational epitopes, Cry1A(b)16 models were built on the basis of three independent templates of homologue proteins of Cry1A(a) and Cry1A(c) using an integrated approach. PcH_736-746 and PcH_876-886 peptides were selected as the best candidates, being synthesised and used for the production of polyclonal antibodies. To the best of our knowledge, this is the first attempt of selecting and defining linear peptides as immunogenic markers of Cry1A(b)-type toxins in transgenic maize.
Author affiliation: Costa, Joana. Universidad de Porto; Portugal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina
Author affiliation: Marani, Mariela Mirta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina. Universidad de Porto; Portugal
Author affiliation: Grazina, Liliana. Universidad de Porto; Portugal
Author affiliation: Villa, Caterina. Universidad de Porto; Portugal
Author affiliation: Meira, Liliana. Universidad de Porto; Portugal
Author affiliation: Oliveira, M. Beatriz P.P.. Universidad de Porto; Portugal
Author affiliation: Leite, José R.S.A.. Universidade do Brasília; Brasil. Universidade Federal Do Piaui;
Author affiliation: Mafra, Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina. Universidad de Porto; Portugal
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Publication Date: 2016.
Language: English.
Abstract:
Despite human parainfluenza type 3 viruses (HPIV3) are one of the leading causes of acute lower respiratory tract infections in children under five, there is no licensed vaccine and there is limited current information on the molecular characteristics of regional and global circulating strains. The aim of this study was to describe the molecular characterization of HPIV3 circulating in Buenos Aires. We performed a genetic and phylogenetic analysis of the HN glycoprotein gene. Between 2009 and 2013, 124 HPIV3 positive samples taken from hospitalized pediatric patients were analyzed. Four new genetic lineages were described. Among them, C1c and C3d lineages showed local circulation patterns, whereas C3e and C3f comprised sequences from very distant countries. Despite the diversity of the described genotypes, C3a and C3d predominated over the others, the latter was present during the first years of the study and it was progressively replaced by C3a. Molecular analyses showed 28 non-synonymous substitutions, of these 13 were located in potentially predicted B-cell epitopes. Taking together, the emergence of genetic lineages and the information of the molecular characteristics of HN protein may contribute to the general knowledge of HPIV3 molecular epidemiology for future vaccine development and antiviral therapies.
Author affiliation: Goya, Stephanie. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños ; Argentina
Author affiliation: Mistchenko, Alicia Susana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños ; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina
Author affiliation: Viegas, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños ; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Obara, Isaiah; Nielsen, Morten; Jeschek, Marie; Nijhof, Ard; Mazzoni, Camila J.; Svitek, Nicholas; Steinaa, Lucilla; Awino, Elias; Olds, Cassandra; Jabbar, Ahmed; Clausen, Peter Henning; Bishop, Richard P.
Publication Date: 2016.
Language: English.
Abstract:
There is strong evidence that the immunity induced by live vaccination for control of the protozoan parasite Theileria parva is mediated by class I MHC-restricted CD8+ T cells directed against the schizont stage of the parasite that infects bovine lymphocytes. The functional competency of class I MHC genes is dependent on the presence of codons specifying certain critical amino acid residues that line the peptide binding groove. Compared with European Bos taurus in which class I MHC allelic polymorphisms have been examined extensively, published data on class I MHC transcripts in African taurines in T. parva endemic areas is very limited. We utilized the multiplexing capabilities of 454 pyrosequencing to make an initial assessment of class I MHC allelic diversity in a population of Ankole cattle. We also typed a population of exotic Holstein cattle from an African ranch for class I MHC and investigated the extent, if any, that their peptide-binding motifs overlapped with those of Ankole cattle. We report the identification of 18 novel allelic sequences in Ankole cattle and provide evidence of positive selection for sequence diversity, including in residues that predominantly interact with peptides. In silico functional analysis resulted in peptide binding specificities that were largely distinct between the two breeds. We also demonstrate that CD8+ T cells derived from Ankole cattle that are seropositive for T. parva do not recognize vaccine candidate antigens originally identified in Holstein and Boran (Bos indicus) cattle breeds.
Author affiliation: Obara, Isaiah. Freie Universität Berlin; Alemania
Author affiliation: Nielsen, Morten. Technical University of Denmark; Dinamarca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina
Author affiliation: Jeschek, Marie. Berlin Center for Genomics in Biodiversity Research; Alemania
Author affiliation: Nijhof, Ard. Freie Universität Berlin; Alemania
Author affiliation: Mazzoni, Camila J.. Berlin Center for Genomics in Biodiversity Research; Alemania. Evolutionary Genetics; Alemania
Author affiliation: Svitek, Nicholas. International Livestock Research Institute; Kenia
Author affiliation: Steinaa, Lucilla. International Livestock Research Institute; Kenia
Author affiliation: Awino, Elias. International Livestock Research Institute; Kenia
Author affiliation: Olds, Cassandra. International Livestock Research Institute; Kenia
Author affiliation: Jabbar, Ahmed. Freie Universität Berlin; Alemania
Author affiliation: Clausen, Peter Henning. Freie Universität Berlin; Alemania
Author affiliation: Bishop, Richard P.. International Livestock Research Institute; Kenia
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Carmona, Santiago Javier; Nielsen, Morten; Schafer Nielsen, Morten; Mucci, Juan Sebastián; Altech, J; Balouz, Virginia; Tekiel, Valeria Sonia; Frasch, Alberto Carlos C.; Campetella, Oscar Eduardo; Buscaglia, Carlos Andres; Aguero, Fernan
Publication Date: 2015.
Language: English.
Abstract:
Complete characterization of antibody specificities associated to natural infections is expected to provide a rich source of serologic biomarkers with potential applications in molecular diagnosis, follow-up of chemotherapeutic treatments, and prioritization of targets for vaccine development. Here, we developed a highly-multiplexed platform based on next-generation high-density peptide microarrays to map these specificities in Chagas Disease, an exemplar of a human infectious disease caused by the protozoan Trypanosoma cruzi. We designed a high-density peptide microarray containing more than 175,000 overlapping 15mer peptides derived from T. cruzi proteins. Peptides were synthesized in situ on microarray slides, spanning the complete length of 457 parasite proteins with fully overlapped 15mers (1 residue shift). Screening of these slides with antibodies purified from infected patients and healthy donors demonstrated both a high technical reproducibility as well as epitope mapping consistency when compared with earlier low-throughput technologies. Using a conservative signal threshold to classify positive (reactive) peptides we identified 2,031 disease-specific peptides and 97 novel parasite antigens, effectively doubling the number of known antigens and providing a tenfold increase in the number of fine mapped antigenic determinants for this disease. Finally, further analysis of the chip data showed that optimizing the amount of sequence overlap of displayed peptides can increase the protein space covered in a single chip by at least ~3 fold without sacrificing sensitivity. In conclusion, we show the power of high-density peptide chips for the discovery of pathogen-specific linear B-cell epitopes from clinical samples, thus setting the stage for high-throughput biomarker discovery screenings and proteome-wide studies of immune responses against pathogens.
Author affiliation: Carmona, Santiago Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Nielsen, Morten. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Schafer Nielsen, Morten. Schafer-N ApS; Dinamarca
Author affiliation: Mucci, Juan Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Altech, J. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños ; Argentina
Author affiliation: Balouz, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Tekiel, Valeria Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Frasch, Alberto Carlos C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Campetella, Oscar Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Buscaglia, Carlos Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Author affiliation: Aguero, Fernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina
Keywords: High-density peptide microarrays; Next-generation peptide microarrays; Tiling peptide arrays; High-throughput serology assays; Antigen discovery; Epitope discovery; B-cell epitopes; Antigenic determinants; Immune responses; Humoral responses; Chronic infections; Human infectious diseases; Chagas Disease; Trypanosoma cruzi; Salud Ocupacional; Ciencias de la Salud; CIENCIAS MÉDICAS Y DE LA SALUD.
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas