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Bhattacharyya T, Murphy N, Miles MA. Diversity of Chagas disease diagnostic antigens: Successes and limitations. PLoS Negl Trop Dis 2024; 18:e0012512. [PMID: 39352878 PMCID: PMC11444392 DOI: 10.1371/journal.pntd.0012512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2024] Open
Abstract
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, remains a public health issue in endemic regions of the Americas, and is becoming globalised due to migration. In the chronic phase, 2 accordant serological tests are required for diagnosis. In addition to "in-house" assays, commercial tests are available (principally ELISA and rapid diagnostic tests). Herein, we discuss the discovery era of defined T. cruzi serological antigens and their utilisation in commercialised tests. A striking feature is the re-discovery of the same antigens from independent studies, and their overlapping use among commonly reported commercial serological tests. We also consider reports of geographical variation in assay sensitivity and areas for refinement including applications to congenital diagnosis, treatment monitoring, and lineage-specific antigens.
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Affiliation(s)
- Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, United Kingdom
| | - Niamh Murphy
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, United Kingdom
| | - Michael A. Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, United Kingdom
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Dias ER, Durans AM, Succar BB, Pinto LALT, Lechuga GC, Miguez MG, Figueira-Mansur J, Argondizzo APC, Bernardo AR, Diniz RL, Esteves GS, Silva ED, Morel CM, Borges-Pereira J, De-Simone SG, Junqueira ACV, Provance DW. A Multi-Epitope Protein for High-Performance Serodiagnosis of Chronic Chagas Disease in ELISA and Lateral Flow Platforms. Int J Mol Sci 2024; 25:9811. [PMID: 39337297 PMCID: PMC11432030 DOI: 10.3390/ijms25189811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2024] [Revised: 09/03/2024] [Accepted: 09/04/2024] [Indexed: 09/30/2024] Open
Abstract
We developed a protein to rapidly and accurately diagnose Chagas disease, a life-threatening illness identified by the WHO as a critical worldwide public health risk. Limitations in present day serological tests are complicating the current health situation and contributing to most infected persons being unaware of their condition and therefore untreated. To improve diagnostic testing, we developed an immunological mimic of the etiological agent, Trypanosoma cruzi, by combining ten pathogen-specific epitopes within the beta-barrel protein structure of Thermal Green Protein. The resulting multi-epitope protein, DxCruziV3, displayed high specificity and sensitivity as the antibody capture reagent in an ELISA platform with an analytical sensitivity that exceeds WHO recommendations. Within an immunochromatographic platform, DxCruziV3 showed excellent performance for the point of application diagnosis in a region endemic for multiple diseases, the municipality of Barcelos in the state of Amazonas, Brazil. In total, 167 individuals were rapidly tested using whole blood from a finger stick. As recommended by the Brazilian Ministry of Health, venous blood samples were laboratory tested by conventional assays for comparison. Test results suggest utilizing DxCruziV3 in different assay platforms can confidently diagnose chronic infections by T. cruzi. Rapid and more accurate results will benefit everyone but will have the most noticeable impact in resource-limited rural areas where the disease is endemic.
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Affiliation(s)
- Evandro R Dias
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Tropical Medicine Graduate Program (Stricto Sensu), Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Epidemiologia e Sistemática Molecular, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Doenças Parasitarias, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Andressa M Durans
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Epidemiologia e Sistemática Molecular, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Barbara B Succar
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Epidemiologia e Sistemática Molecular, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Luiz André L T Pinto
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Guilherme C Lechuga
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Epidemiologia e Sistemática Molecular, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Mariana G Miguez
- Laboratório de Tecnologia Recombinante, Institute of Technology in Immunobiology, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Janaina Figueira-Mansur
- Laboratório de Tecnologia Recombinante, Institute of Technology in Immunobiology, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Ana P C Argondizzo
- Laboratório de Tecnologia Recombinante, Institute of Technology in Immunobiology, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Aline R Bernardo
- Laboratório de Reativos em Diagnóstico, Institute of Technology in Immunobiology, Rio de Janeiro 21040-361, RJ, Brazil
| | - Rafaela L Diniz
- Laboratório de Reativos em Diagnóstico, Institute of Technology in Immunobiology, Rio de Janeiro 21040-361, RJ, Brazil
| | - Gabriela S Esteves
- Laboratório de Tecnologia Recombinante, Institute of Technology in Immunobiology, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Edimilson D Silva
- Laboratório de Reativos em Diagnóstico, Institute of Technology in Immunobiology, Rio de Janeiro 21040-361, RJ, Brazil
| | - Carlos M Morel
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - José Borges-Pereira
- Laboratório de Doenças Parasitarias, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - Salvatore G De-Simone
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Epidemiologia e Sistemática Molecular, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Science and Biotechnology Graduate Program, Department of Molecular and Cellular Biology, Biology Institute, Fluminense Federal University, Niterói 24020-141, RJ, Brazil
| | - Angela C V Junqueira
- Tropical Medicine Graduate Program (Stricto Sensu), Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Doenças Parasitarias, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
| | - David William Provance
- Center for Technological Development in Health, National Institute of Science and Technology for Innovation in Neglected Population Diseases, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
- Laboratório de Epidemiologia e Sistemática Molecular, Oswaldo Cruz Institute, Oswald Cruz Foundation, Rio de Janeiro 21040-361, RJ, Brazil
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Ribeiro AJ, Silva KA, Lopes LDS, Resende CAA, Couto CAP, Gandra IB, Pereira IAG, Barcelos ICDS, Pereira SP, Xavier SR, Tavares GDSV, Machado JM, Da Paz MC, Chávez-Fumagalli MA, Coelho EAF, Giunchetti RC, Chaves AT, Dutra WO, Gonçalves AAM, Galdino AS. The use of peptides for immunodiagnosis of human Chagas disease. Amino Acids 2024; 56:35. [PMID: 38698213 PMCID: PMC11065921 DOI: 10.1007/s00726-024-03394-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 04/10/2024] [Indexed: 05/05/2024]
Abstract
Chagas disease, caused by the protozoa Trypanosoma cruzi, continues to be a serious public health problem in Latin America, worsened by the limitations in its detection. Given the importance of developing new diagnostic methods for this disease, the present review aimed to verify the number of publications dedicated to research on peptides that demonstrate their usefulness in serodiagnosis. To this end, a bibliographic survey was conducted on the PubMed platform using the keyword "peptide" or "epitope" combined with "Chagas disease" or "Trypanosoma cruzi"; "diagno*" or "serodiagnosis" or "immunodiagnosis", without period restriction. An increasing number of publications on studies employing peptides in ELISA and rapid tests assays was verified, which confirms the expansion of research in this field. It is possible to observe that many of the peptides tested so far originate from proteins widely used in the diagnosis of Chagas, and many of them are part of commercial tests developed. In this sense, as expected, promising results were obtained for several peptides when tested in ELISA, as many of them exhibited sensitivity and specificity values above 90%. Furthermore, some peptides have been tested in several studies, confirming their diagnostic potential. Despite the promising results observed, it is possible to emphasize the need for extensive testing of peptides, using different serological panels, in order to confirm their potential. The importance of producing an effective assay capable of detecting the clinical stages of the disease, as well as new immunogenic antigens that enable new serological diagnostic tools for Chagas disease, is evident.
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Affiliation(s)
- Anna Julia Ribeiro
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Kamila Alves Silva
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Lucas da Silva Lopes
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Carlos Ananias Aparecido Resende
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Carolina Alves Petit Couto
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Isadora Braga Gandra
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Isabela Amorim Gonçalves Pereira
- Programa de Pós-Graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30130-100, Brazil
| | - Isabelle Caroline Dos Santos Barcelos
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Sabrina Paula Pereira
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Sandra Rodrigues Xavier
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Grasiele de Sousa Viera Tavares
- Programa de Pós-Graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30130-100, Brazil
| | - Juliana Martins Machado
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Mariana Campos Da Paz
- Laboratório de Bioativos e Nanobiotecnologia, Universidade Federal de São João Del-Rei, Divinópolis, MG, 35501-296, Brazil
| | - Miguel Angel Chávez-Fumagalli
- Computational Biology and Chemistry Research Group, Vicerrectorado de Investigación, Universidad Católica de Santa María, Arequipa, 04000, Peru
| | - Eduardo Antonio Ferraz Coelho
- Programa de Pós-Graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30130-100, Brazil
| | - Rodolfo Cordeiro Giunchetti
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, e Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais (INCT-DT), Belo Horizonte, MG, 31270-901, Brazil
| | - Ana Thereza Chaves
- Programa de Pós-Graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 30130-100, Brazil
| | - Walderez Ornelas Dutra
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, e Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais (INCT-DT), Belo Horizonte, MG, 31270-901, Brazil
| | - Ana Alice Maia Gonçalves
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil
| | - Alexsandro Sobreira Galdino
- Laboratório de Biotecnologia de Microrganismos, Universidade Federal de São João Del-Rei, Divinópolis, e Instituto Nacional de Ciência e Tecnologia em Biotecnologia Industrial (INCT-BI), Divinópolis, MG, 35501-296, Brazil.
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Effect of the Tc13Tul antigen from Trypanosoma cruzi on splenocytes from naïve mice. Parasitology 2020; 147:1114-1123. [PMID: 32466805 DOI: 10.1017/s0031182020000864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, releases factors, including antigens from the trans-sialidase (TS) superfamily, which modulate the host immune responses. Tc13 antigens belong to group IV of TSs and are characterized by C-terminal EPKSA repeats. Here, we studied the effect of the Tc13 antigen from the Tulahuén strain, Tc13Tul, on primary cultures of splenocytes from naïve BALB/c mice. Recombinant Tc13Tul increased the percentage of viable cells and induced B (CD19+) lymphocyte proliferation. Tc13Tul stimulation also induced secretion of non-specific IgM and interferon-γ (IFN-γ). The same effects were induced by Tc13Tul on splenocytes from naïve C3H/HeJ mice. In vivo administration of Tc13Tul to naïve BALB/c mice increased non-specific IgG in sera. In addition, in vitro cultured splenocytes from Tc13Tul-inoculated mice secreted a higher basal level of non-specific IgM than controls and the in vitro Tc13Tul stimulation of these cells showed an enhanced effect on IgM and IFN-γ secretion. Our results indicate that Tc13Tul may participate in the early immunity in T. cruzi infection by favouring immune system evasion through B-cell activation and non-specific Ig secretion. In contrast, as IFN-γ is an important factor involved in T. cruzi resistance, this may be considered a Tc13Tul effect in favour of the host.
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Leishmania infantum recombinant kinesin degenerated derived repeat (rKDDR): A novel potential antigen for serodiagnosis of visceral leishmaniasis. PLoS One 2019; 14:e0211719. [PMID: 30703138 PMCID: PMC6355020 DOI: 10.1371/journal.pone.0211719] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 01/18/2019] [Indexed: 01/08/2023] Open
Abstract
Visceral leishmaniasis (VL) or kala-azar, the most severe form of leishmaniasis, can lead to death if not properly diagnosed and treated. Correct identification of infected patients and reservoirs is vital for controlling the spread of leishmaniasis. Current diagnostic kits for leishmaniasis show high sensitivity and specificity, but can also result in false negatives and cross reactions with related parasitic infections. New diagnostic methods with greater accuracy are urgently needed for diagnosis of leishmaniasis. In this study, we aimed to uncover a new highly effective antigen for the diagnosis of visceral leishmaniasis in dogs and humans, aiming to improve the accuracy compared with those of current methods of diagnosis. Initially, in-silico epitope prediction analyses identified several potential B-cell epitopes in the repetitive region of Leishmania infantum kinesin, which co-localized with predicted structural disordered regions, suggesting high potential for antigenicity. Based on this analysis, 8.5 genomic motifs, which encode the repetitive sequence of 39 degenerate amino acids, were selected for recombinant expression. BLASTn analysis of this repetitive region indicated that it is absent in the T. cruzi parasite, which is closely related to Leishmania, indicating the specificity of this region. This potentially antigenic protein, named recombinant kinesin degenerated derived repeat (rKDDR), was recombinantly expressed in Escherichia coli BL21-Star using the pET28a-TEV expression vector. We then evaluated the performance of rKDDR in correctly diagnosing Leishmania infection and compared this new assay with currently used diagnostic tests for leishmaniasis. rKDDR showed greater sensitivity and specificity in correctly diagnosing leishmaniasis both in human (sensitivity 92.86% and specificity 100%) and canine (sensitivity 88.54% and specificity 97.30%) sera compared with those of rK39 (human: sensitivity 90.48% and specificity 97.92%; canine: sensitivity 78.13% and specificity 90.09%). In addition, the rKDDR-ELISA outperformed the EIE-LVC kit, which is the serologic kit recommended by the Brazilian Ministry of Health for the diagnosis of canine visceral leishmaniasis. These results indicate that rKDDR is a highly promising candidate for diagnosis of visceral leishmaniasis, and is more accurate than the currently used gold-standard antigens.
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Panesso-Gómez S, Pavia P, Rodríguez-Mantilla IE, Lasso P, Orozco LA, Cuellar A, Puerta CJ, Mendoza de Molano B, González JM. Trypanosoma cruzi Detection in Colombian Patients with a Diagnosis of Esophageal Achalasia. Am J Trop Med Hyg 2018; 98:717-723. [PMID: 29405099 PMCID: PMC5930867 DOI: 10.4269/ajtmh.17-0417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Achalasia is a motility disorder of the esophagus that might be secondary to a chronic Trypanosoma cruzi infection. Several studies have investigated esophageal achalasia in patients with Chagas disease (CD) in Latin America, but no related studies have been performed in Colombia. The goals of the present study were to determine the presence of anti-T. cruzi antibodies in patients with esophageal achalasia who visited a referral hospital in Bogotá, Colombia, and to detect the presence of the parasite and its discrete typing units (DTUs). This cross-sectional study was conducted in adult patients (18-65 years old) who were previously diagnosed with esophageal achalasia and from whom blood was drawn to assess antibodies against T. cruzi using four different serological tests. Trypanosoma cruzi DNA was detected by conventional polymerase chain reaction (cPCR) and quantitative polymerase chain reaction (qPCR). In total, 38 patients, with an average age of 46.6 years (standard deviation of ±16.2) and comprising 16 men and 22 women, were enrolled. Five (13.15%) patients were found to be positive for anti-T. cruzi antibodies by indirect immunofluorescence assay (IFA), and two patients who were negative according to IFA were reactive by both enzyme-linked immunosorbent assay and immunoblot (5.3%). Parasite DNA was detected in two of these seven patients by cPCR and in one of these by qPCR. The parasite DTU obtained was TcI. In summary, this study identified T. cruzi in Colombian patients with esophageal achalasia, indicating that digestive compromise could also be present in patients with chronic CD.
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Affiliation(s)
- Santiago Panesso-Gómez
- Grupo de Ciencias Básicas Médicas, School of Medicine, Universidad de Los Andes, Bogotá, Colombia
| | - Paula Pavia
- Scientific Research Unit, Hospital Militar Central, Bogotá, Colombia
| | | | - Paola Lasso
- Laboratorio de Parasitología Molecular, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Luis A Orozco
- Gastrocenter, Investigación y Desarrollo Sistemas Clínicos, Bogotá, Colombia
| | - Adriana Cuellar
- Grupo de Inmunobiología y Biología Celular, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Concepción J Puerta
- Laboratorio de Parasitología Molecular, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Belén Mendoza de Molano
- Gastroenterology Section, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - John M González
- Grupo de Ciencias Básicas Médicas, School of Medicine, Universidad de Los Andes, Bogotá, Colombia
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Mucci J, Carmona SJ, Volcovich R, Altcheh J, Bracamonte E, Marco JD, Nielsen M, Buscaglia CA, Agüero F. Next-generation ELISA diagnostic assay for Chagas Disease based on the combination of short peptidic epitopes. PLoS Negl Trop Dis 2017; 11:e0005972. [PMID: 28991925 PMCID: PMC5648266 DOI: 10.1371/journal.pntd.0005972] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/19/2017] [Accepted: 09/18/2017] [Indexed: 01/22/2023] Open
Abstract
Chagas Disease, caused by the protozoan Trypanosoma cruzi, is a major health and economic problem in Latin America for which no vaccine or appropriate drugs for large-scale public health interventions are yet available. Accurate diagnosis is essential for the early identification and follow up of vector-borne cases and to prevent transmission of the disease by way of blood transfusions and organ transplantation. Diagnosis is routinely performed using serological methods, some of which require the production of parasite lysates, parasite antigenic fractions or purified recombinant antigens. Although available serological tests give satisfactory results, the production of reliable reagents remains laborious and expensive. Short peptides spanning linear B-cell epitopes have proven ideal serodiagnostic reagents in a wide range of diseases. Recently, we have conducted a large-scale screening of T. cruzi linear B-cell epitopes using high-density peptide chips, leading to the identification of several hundred novel sequence signatures associated to chronic Chagas Disease. Here, we performed a serological assessment of 27 selected epitopes and of their use in a novel multipeptide-based diagnostic method. A combination of 7 of these peptides were finally evaluated in ELISA format against a panel of 199 sera samples (Chagas-positive and negative, including sera from Leishmaniasis-positive subjects). The multipeptide formulation displayed a high diagnostic performance, with a sensitivity of 96.3% and a specificity of 99.15%. Therefore, the use of synthetic peptides as diagnostic tools are an attractive alternative in Chagas’ disease diagnosis. Chagas disease, caused by the parasite Trypanosoma cruzi, is a life-long and debilitating illness of major significance throughout Latin America, and an emergent threat to global public health. Diagnostic tests are key tools to support disease surveillance, and to ultimately help stop transmission of the parasite. However currently available diagnostic methods have several limitations. Identification of novel biomarkers with improved diagnostic characteristics is a main priority. Recently, we conducted a large-scale screening looking for new T. cruzi antigens using short peptides displayed on a solid support at high-density. This led to the identification of several hundred novel antigenic epitopes. In this work we validated the serodiagnostic performance of 27 of these against an extended panel of human serum samples. Based on this analysis, we developed a proof-of-principle multiplex diagnostic kit by combining different validated reactive peptides. Overall, our data support the applicability of high-density peptide microarrays for the rapid identification and mapping epitopes that could be readily translated into novel and useful tools for diagnosis of Chagas disease.
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Affiliation(s)
- Juan Mucci
- Instituto de Investigaciones Biotecnológicas (IIB)–Instituto Tecnológico de Chascomús (INTECH), Universidad Nacional de San Martín (UNSAM)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires, Argentina
| | - Santiago J. Carmona
- Instituto de Investigaciones Biotecnológicas (IIB)–Instituto Tecnológico de Chascomús (INTECH), Universidad Nacional de San Martín (UNSAM)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires, Argentina
| | - Romina Volcovich
- Servicio de Parasitología y Chagas, Hospital de Niños Ricardo Gutierrez, Ciudad Autónoma de Buenos Aires, Argentina
| | - Jaime Altcheh
- Servicio de Parasitología y Chagas, Hospital de Niños Ricardo Gutierrez, Ciudad Autónoma de Buenos Aires, Argentina
| | - Estefanía Bracamonte
- Instituto de Patología Experimental, Facultad de Ciencias de la Salud, Universidad Nacional de Salta (UNSa)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina
| | - Jorge D. Marco
- Instituto de Patología Experimental, Facultad de Ciencias de la Salud, Universidad Nacional de Salta (UNSa)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina
| | - Morten Nielsen
- Instituto de Investigaciones Biotecnológicas (IIB)–Instituto Tecnológico de Chascomús (INTECH), Universidad Nacional de San Martín (UNSAM)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires, Argentina
- Department of Bio and Health Informatics, Technical University of Denmark, DK Lyngby, Denmark
| | - Carlos A. Buscaglia
- Instituto de Investigaciones Biotecnológicas (IIB)–Instituto Tecnológico de Chascomús (INTECH), Universidad Nacional de San Martín (UNSAM)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires, Argentina
| | - Fernán Agüero
- Instituto de Investigaciones Biotecnológicas (IIB)–Instituto Tecnológico de Chascomús (INTECH), Universidad Nacional de San Martín (UNSAM)–Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires, Argentina
- * E-mail:
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Balouz V, Agüero F, Buscaglia CA. Chagas Disease Diagnostic Applications: Present Knowledge and Future Steps. ADVANCES IN PARASITOLOGY 2016; 97:1-45. [PMID: 28325368 PMCID: PMC5363286 DOI: 10.1016/bs.apar.2016.10.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chagas disease, caused by the protozoan Trypanosoma cruzi, is a lifelong and debilitating illness of major significance throughout Latin America and an emergent threat to global public health. Being a neglected disease, the vast majority of Chagasic patients have limited access to proper diagnosis and treatment, and there is only a marginal investment into R&D for drug and vaccine development. In this context, identification of novel biomarkers able to transcend the current limits of diagnostic methods surfaces as a main priority in Chagas disease applied research. The expectation is that these novel biomarkers will provide reliable, reproducible and accurate results irrespective of the genetic background, infecting parasite strain, stage of disease, and clinical-associated features of Chagasic populations. In addition, they should be able to address other still unmet diagnostic needs, including early detection of congenital T. cruzi transmission, rapid assessment of treatment efficiency or failure, indication/prediction of disease progression and direct parasite typification in clinical samples. The lack of access of poor and neglected populations to essential diagnostics also stresses the necessity of developing new methods operational in point-of-care settings. In summary, emergent diagnostic tests integrating these novel and tailored tools should provide a significant impact on the effectiveness of current intervention schemes and on the clinical management of Chagasic patients. In this chapter, we discuss the present knowledge and possible future steps in Chagas disease diagnostic applications, as well as the opportunity provided by recent advances in high-throughput methods for biomarker discovery.
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Affiliation(s)
- Virginia Balouz
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, B 1650 HMP, Buenos Aires, Argentina
| | - Fernán Agüero
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, B 1650 HMP, Buenos Aires, Argentina
| | - Carlos A. Buscaglia
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, B 1650 HMP, Buenos Aires, Argentina
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Multi-epitope proteins for improved serological detection of Trypanosoma cruzi infection and Chagas Disease. Diagn Microbiol Infect Dis 2015; 84:191-6. [PMID: 26658314 DOI: 10.1016/j.diagmicrobio.2015.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/02/2015] [Accepted: 11/07/2015] [Indexed: 11/24/2022]
Abstract
We previously reported that tandem repeat (TR) proteins from Trypanosoma cruzi could serve as targets of the antibody response and be useful as diagnostic indicators. To optimize reagents for detecting T. cruzi infection we evaluated individual TR proteins and identified several that were recognized by the majority of Chagas patient's sera collected from individuals form Brazil. We then produced novel, recombinant fusion proteins to combine the reactive TR proteins into a single diagnostic product. Direct comparison of the antibody response of serum samples that were readily detected by the established fusion antigen used in commercial detection of Chagas disease, TcF, revealed strong responses to TcF43 and TcF26 proteins. While the TcF43 and TcF26 antigens enhanced detection and strength of signal, they did not compromise the specificity of detection compared to that obtained with TcF. Finally, it was apparent by testing against a panel of 84 serum samples assembled on the basis of moderate or weak reactivity against TcF (mostly signal:noise <5) that TcF43 and TcF26 could more strongly detected by many of the sera that had low TcF antibody levels. Taken together, these data indicate that TcF43 and TcF26 could be used to enhance the detection of T. cruzi infection as well as supporting a diagnosis of Chagas disease.
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Mapping antigenic motifs in the trypomastigote small surface antigen from Trypanosoma cruzi. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:304-12. [PMID: 25589551 DOI: 10.1128/cvi.00684-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The trypomastigote small surface antigen (TSSA) is a mucin-like molecule from Trypanosoma cruzi, the etiological agent of Chagas disease, which displays amino acid polymorphisms in parasite isolates. TSSA expression is restricted to the surface of infective cell-derived trypomastigotes, where it functions as an adhesin and engages surface receptors on the host cell as a prerequisite for parasite internalization. Previous results have established TSSA-CL, the isoform encoded by the CL Brener clone, as an appealing candidate for use in serology-based diagnostics for Chagas disease. Here, we used a combination of peptide- and recombinant protein-based tools to map the antigenic structure of TSSA-CL at maximal resolution. Our results indicate the presence of different partially overlapping B-cell epitopes clustering in the central portion of TSSA-CL, which contains most of the polymorphisms found in parasite isolates. Based on these results, we assessed the serodiagnostic performance of a 21-amino-acid-long peptide that spans TSSA-CL major antigenic determinants, which was similar to the performance of the previously validated glutathione S-transferase (GST)-TSSA-CL fusion molecule. Furthermore, the tools developed for the antigenic characterization of the TSSA antigen were also used to explore other potential diagnostic applications of the anti-TSSA humoral response in Chagasic patients. Overall, our present results provide additional insights into the antigenic structure of TSSA-CL and support this molecule as an excellent target for molecular intervention in Chagas disease.
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Use of an enzyme-linked immunosorbent assay that utilizes the Tc13Tul antigen of Trypanosoma cruzi to monitor patients after treatment with benznidazole. Diagn Microbiol Infect Dis 2013; 76:197-205. [DOI: 10.1016/j.diagmicrobio.2013.02.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 01/19/2013] [Accepted: 02/07/2013] [Indexed: 11/22/2022]
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12
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Recombinant vaccine displaying the loop-neutralizing determinant from protective antigen completely protects rabbits from experimental inhalation anthrax. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:341-9. [PMID: 23283638 DOI: 10.1128/cvi.00612-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We previously showed that a multiple antigenic peptide (MAP) vaccine displaying amino acids (aa) 304 to 319 from the 2β2-2β3 loop of protective antigen was capable of protecting rabbits from an aerosolized spore challenge with Bacillus anthracis Ames strain. Antibodies to this sequence, referred to as the loop-neutralizing determinant (LND), are highly potent at neutralizing lethal toxin yet are virtually absent in rabbit and human protective antigen (PA) antiserum. While the MAP vaccine was protective against anthrax, it contains a single heterologous helper T cell epitope which may be suboptimal for stimulating an outbred human population. We therefore engineered a recombinant vaccine (Rec-LND) containing two tandemly repeated copies of the LND fused to maltose binding protein, with enhanced immunogenicity resulting from the p38/P4 helper T cell epitope from Schistosoma mansoni. Rec-LND was found to be highly immunogenic in four major histocompatibility complex (MHC)-diverse strains of mice. All (7/7) rabbits immunized with Rec-LND developed high-titer antibody, 6 out of 7 developed neutralizing antibody, and all rabbits were protected from an aerosolized spore challenge of 193 50% lethal doses (LD(50)) of the B. anthracis Ames strain. Survivor serum from Rec-LND-immunized rabbits revealed significantly increased neutralization titers and specific activity compared to prechallenge levels yet lacked PA or lethal factor (LF) antigenemia. Control rabbits immunized with PA, which were also completely protected, appeared sterilely immune, exhibiting significant declines in neutralization titer and specific activity compared to prechallenge levels. We conclude that Rec-LND may represent a prototype anthrax vaccine for use alone or potentially combined with PA-containing vaccines.
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Diagnostic peptide discovery: prioritization of pathogen diagnostic markers using multiple features. PLoS One 2012; 7:e50748. [PMID: 23272069 PMCID: PMC3522711 DOI: 10.1371/journal.pone.0050748] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 10/23/2012] [Indexed: 11/27/2022] Open
Abstract
The availability of complete pathogen genomes has renewed interest in the development of diagnostics for infectious diseases. Synthetic peptide microarrays provide a rapid, high-throughput platform for immunological testing of potential B-cell epitopes. However, their current capacity prevent the experimental screening of complete “peptidomes”. Therefore, computational approaches for prediction and/or prioritization of diagnostically relevant peptides are required. In this work we describe a computational method to assess a defined set of molecular properties for each potential diagnostic target in a reference genome. Properties such as sub-cellular localization or expression level were evaluated for the whole protein. At a higher resolution (short peptides), we assessed a set of local properties, such as repetitive motifs, disorder (structured vs natively unstructured regions), trans-membrane spans, genetic polymorphisms (conserved vs. divergent regions), predicted B-cell epitopes, and sequence similarity against human proteins and other potential cross-reacting species (e.g. other pathogens endemic in overlapping geographical locations). A scoring function based on these different features was developed, and used to rank all peptides from a large eukaryotic pathogen proteome. We applied this method to the identification of candidate diagnostic peptides in the protozoan Trypanosoma cruzi, the causative agent of Chagas disease. We measured the performance of the method by analyzing the enrichment of validated antigens in the high-scoring top of the ranking. Based on this measure, our integrative method outperformed alternative prioritizations based on individual properties (such as B-cell epitope predictors alone). Using this method we ranked 10 million 12-mer overlapping peptides derived from the complete T. cruzi proteome. Experimental screening of 190 high-scoring peptides allowed the identification of 37 novel epitopes with diagnostic potential, while none of the low scoring peptides showed significant reactivity. Many of the metrics employed are dependent on standard bioinformatic tools and data, so the method can be easily extended to other pathogen genomes.
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Freitas LM, dos Santos SL, Rodrigues-Luiz GF, Mendes TAO, Rodrigues TS, Gazzinelli RT, Teixeira SMR, Fujiwara RT, Bartholomeu DC. Genomic analyses, gene expression and antigenic profile of the trans-sialidase superfamily of Trypanosoma cruzi reveal an undetected level of complexity. PLoS One 2011; 6:e25914. [PMID: 22039427 PMCID: PMC3198458 DOI: 10.1371/journal.pone.0025914] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 09/13/2011] [Indexed: 12/20/2022] Open
Abstract
The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.
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Affiliation(s)
- Leandro M. Freitas
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sara Lopes dos Santos
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Tiago A. O. Mendes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Thiago S. Rodrigues
- Centro Federal de Educação Tecnológica de Minas Gerais, Belo Horizonte, Brazil
| | - Ricardo T. Gazzinelli
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Santuza M. R. Teixeira
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ricardo T. Fujiwara
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniella C. Bartholomeu
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- * E-mail:
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Goto Y, Duthie MS, Nguyen TT, Asada M, Kawazu SI, Carter D, Inoue N. Serological characterizations of tandem repeat proteins for detection of African trypanosome infection in cattle. Parasitol Int 2011; 60:538-40. [PMID: 21944942 DOI: 10.1016/j.parint.2011.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/05/2011] [Accepted: 09/07/2011] [Indexed: 12/19/2022]
Abstract
Serological diagnosis is a useful method to detect African trypanosome infection in livestock animals. Currently available serological tests utilize whole parasites or crude antigens, and recombinant antigens may improve reproducibility/standardization and reduce production costs. With a goal of identifying such recombinant proteins, we computationally identified proteins with tandem repeat (TR) domain from the parasite proteomes and evaluated their potential for serological diagnosis of African trypanosome infections in cattle. Among those tested, Tbg4 demonstrated the best performance with 92% sensitivity, followed by TbbGM6 (85%), TcoGM6 (85%), Tbg2 (65%) and Tbg5 (65%). Although further evaluations such as investigating cross-reactivity to other infections are needed, our data indicate the potential of these antigens for detection of African trypanosome infection in cattle.
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Affiliation(s)
- Yasuyuki Goto
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
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Goto Y, Duthie MS, Kawazu SI, Inoue N, Carter D. Biased cellular locations of tandem repeat antigens in African trypanosomes. Biochem Biophys Res Commun 2011; 405:434-8. [PMID: 21241659 PMCID: PMC3042534 DOI: 10.1016/j.bbrc.2011.01.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 01/12/2011] [Indexed: 02/04/2023]
Abstract
Trypanosoma brucei subspecies cause African trypanosomiasis in humans and animals. These parasites possess genes encoding proteins with large tandem repeat (TR) domains as do the other trypanosomatid parasites. We have previously demonstrated that TR protein of Leishmania infantum and Trypanosoma cruzi are often targets of B-cell responses. However, African trypanosomes are susceptible to antibody-mediated immunity, and it may be detrimental for the parasites to have such B-cell antigens on the cell surface. Here we show TR proteins of T. brucei subspecies are also antigenic: recombinant TR proteins of these parasites detect antibodies in sera from mice infected with the parasites by ELISA. Analysis of amino acid sequences revealed that, different from TR proteins of Leishmania species or T. cruzi, the presence of predicted signal peptides, trans-membrane domains and GPI anchor signals in T. brucei TR proteins are significantly lower than those of the whole proteome. Many of the T. brucei TR proteins are specific in the species or conserved only in the closely related species, as is the same case for Leishmania major and T. cruzi. These results suggest that, despite their sharing some common characteristics, such abundance in large TR domains and immunological dominance, TR genes have evolved independently among the trypanosomatid parasites.
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Affiliation(s)
- Yasuyuki Goto
- Laboratory of Molecular Immunology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
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In vivo infection by Trypanosoma cruzi: the conserved FLY domain of the gp85/trans-sialidase family potentiates host infection. Parasitology 2010; 138:481-92. [PMID: 21040619 DOI: 10.1017/s0031182010001411] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Trypanosoma cruzi is a protozoan parasite that infects vertebrates, causing in humans a pathological condition known as Chagas' disease. The infection of host cells by T. cruzi involves a vast collection of molecules, including a family of 85 kDa GPI-anchored glycoproteins belonging to the gp85/trans-sialidase superfamily, which contains a conserved cell-binding sequence (VTVXNVFLYNR) known as FLY, for short. Herein, it is shown that BALB/c mice administered with a single dose (1 μg/animal, intraperitoneally) of FLY-synthetic peptide are more susceptible to infection by T. cruzi, with increased systemic parasitaemia (2-fold) and mortality. Higher tissue parasitism was observed in bladder (7·6-fold), heart (3-fold) and small intestine (3·6-fold). Moreover, an intense inflammatory response and increment of CD4+ T cells (1·7-fold) were detected in the heart of FLY-primed and infected animals, with a 5-fold relative increase of CD4+CD25+FoxP3+ T (Treg) cells. Mice treated with anti-CD25 antibodies prior to infection, showed a decrease in parasitaemia in the FLY model employed. In conclusion, the results suggest that FLY facilitates in vivo infection by T. cruzi and concurs with other factors to improve parasite survival to such an extent that might influence the progression of pathology in Chagas' disease.
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Hernández P, Heimann M, Riera C, Solano M, Santalla J, Luquetti AO, Beck E. Highly effective serodiagnosis for Chagas' disease. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1598-604. [PMID: 20668136 PMCID: PMC2952994 DOI: 10.1128/cvi.00489-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 01/26/2009] [Accepted: 07/06/2010] [Indexed: 11/20/2022]
Abstract
Many proteins of Trypanosoma cruzi, the causative agent of Chagas' disease, contain characteristic arrays of highly repetitive immunogenic amino acid motifs. Diagnostic tests using these motifs in monomeric or dimeric form have proven to provide markedly improved specificity compared to conventional tests based on crude parasite extracts. However, in many cases the available tests still suffer from limited sensitivity. In this study we produced stable synthetic genes with maximal codon variability for the four diagnostic antigens, B13, CRA, TcD, and TcE, each containing between three and nine identical amino acid repeats. These genes were combined by linker sequences encoding short proline-rich peptides, giving rise to a 24-kDa fusion protein which was used as a novel diagnostic antigen in an enzyme-linked immunosorbent assay setup. Validation of the assay with a large number of well-characterized patient sera from Bolivia and Brazil revealed excellent diagnostic performance. The high sensitivity of the new test may allow future studies to use blood collected by finger prick and dried on filter paper, thus dramatically reducing the costs and effort for the detection of T. cruzi infection.
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Affiliation(s)
- Pilar Hernández
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
| | - Michael Heimann
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
| | - Cristina Riera
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
| | - Marco Solano
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
| | - José Santalla
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
| | - Alejandro O. Luquetti
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
| | - Ewald Beck
- University of Giessen, Institute of Biochemistry, Friedrichstrasse 24, D-35392 Giessen, Germany, Universidad de Barcelona, Laboratory of Parasitology, Avenida Diagonal, 08028 Barcelona, Spain, SEDES, Servicio Departmental de Salud, Cochabamba, Bolivia, INLASA, Laboratory of Parasitology, La Paz, Bolivia, Universidade Federal de Goiás, Instituto de Patologia Tropical e Saúde Pública, Caixa Postal 1031, 74000-970 Goiania, Brazil
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Pattabhi S, Whittle J, Mohamath R, El-Safi S, Moulton GG, Guderian JA, Colombara D, Abdoon AO, Mukhtar MM, Mondal D, Esfandiari J, Kumar S, Chun P, Reed SG, Bhatia A. Design, development and evaluation of rK28-based point-of-care tests for improving rapid diagnosis of visceral leishmaniasis. PLoS Negl Trop Dis 2010; 4. [PMID: 20856856 PMCID: PMC2939046 DOI: 10.1371/journal.pntd.0000822] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 08/16/2010] [Indexed: 12/01/2022] Open
Abstract
Background Visceral leishmaniasis (VL) is diagnosed by microscopic confirmation of the parasite in bone marrow, spleen or lymph node aspirates. These procedures are unsuitable for rapid diagnosis of VL in field settings. The development of rK39-based rapid diagnostic tests (RDT) revolutionized diagnosis of VL by offering high sensitivity and specificity in detecting disease in the Indian subcontinent; however, these tests have been less reliable in the African subcontinent (sensitivity range of 75–85%, specificity of 70–92%). We have addressed limitations of the rK39 with a new synthetic polyprotein, rK28, followed by development and evaluation of two new rK28-based RDT prototype platforms. Methodology/Principal Findings Evaluation of 62 VL-confirmed sera from Sudan provided sensitivities of 96.8% and 93.6% (95% CI = K28: 88.83–99.61%; K39: 84.30–98.21%) and specificities of 96.2% and 92.4% (95% CI = K28: 90.53–98.95%; K39: 85.54–96.65%) for rK28 and rK39, respectively. Of greater interest was the observation that individual VL sera with low rK39 reactivity often had much higher rK28 reactivity. This characteristic of the fusion protein was exploited in the development of rK28 rapid tests, which may prove to be crucial in detecting VL among patients with low rK39 antibody levels. Evaluation of two prototype lateral flow-based rK28 rapid tests on 53 VL patients in Sudan and 73 VL patients in Bangladesh provided promisingly high sensitivities (95.9% [95% CI = 88.46–99.1 in Sudan and 98.1% [95% CI = 89.93–99.95%] in Bangladesh) compared to the rK39 RDT (sensitivities of 86.3% [95% CI = 76.25–93.23%] in Sudan and 88.7% [95% CI = 76.97–95.73%] in Bangladesh). Conclusions/Significance Our study compares the diagnostic accuracy of rK39 and rK28 in detecting active VL cases and our findings indicate that rK28 polyprotein has great potential as a serodiagnostic tool. A new rK28-based RDT will prove to be a valuable asset in simplifying VL disease confirmation at the point-of-care. Visceral Leishmaniasis caused by Leishmania donovani is endemic in several parts of South Asia, East Africa, South and Central America. It is a vector-borne disease transmitted by bites of infected sand flies and often fatal in the absence of chemotherapy. Timely diagnosis is an essential first step in providing proper patient care and in controlling transmission. VL diagnosis in East Africa and Latin America are currently based on microscopic confirmation of parasites in tissue aspirates. The Kalazar Detect rapid test is widely used as a confirmatory test in India with very high accuracy, but sensitivity issues have severely limited its usefulness in the African sub-continent. Direct Agglutination Test is another confirmatory test used widely in East Africa and offers high sensitivity but is not field-friendly. We report on the design of a novel synthetic fusion protein capable of sequestering antibodies against three different Leishmania donovani antigens and the development of point-of-care tests for improving VL diagnosis. We believe the ease of use of these rapid tests and their high accuracy in detecting VL cases could make them useful as a first-line test, thereby eliminating the need for painful biopsies and ensuring better patient care.
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Affiliation(s)
- Sowmya Pattabhi
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Jacqueline Whittle
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Raodoh Mohamath
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Sayda El-Safi
- Department of Microbiology and Parasitology, Faculty of Medicine, Khartoum University, Khartoum, Sudan
| | - Garner G. Moulton
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Jeffrey A. Guderian
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Danny Colombara
- Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington, United States of America
| | - Asem O. Abdoon
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Maowia M. Mukhtar
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Dinesh Mondal
- Laboratory Sciences Division, International Centre for Diarrhoeal Diseases Research, Dhaka, Bangladesh
| | - Javan Esfandiari
- Chembio Diagnostic Systems, Inc., Medford, New York, United States of America
| | - Shailendra Kumar
- Chembio Diagnostic Systems, Inc., Medford, New York, United States of America
| | - Peter Chun
- Ease-Medtrend, Shanghai, People's Republic of China
| | - Steven G. Reed
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Ajay Bhatia
- Infectious Disease Research Institute, Seattle, Washington, United States of America
- * E-mail:
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Goto Y, Carter D, Guderian J, Inoue N, Kawazu SI, Reed SG. Upregulated expression of B-cell antigen family tandem repeat proteins by Leishmania amastigotes. Infect Immun 2010; 78:2138-45. [PMID: 20160013 PMCID: PMC2863543 DOI: 10.1128/iai.01102-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/10/2009] [Accepted: 02/10/2010] [Indexed: 12/18/2022] Open
Abstract
Proteins with tandem repeat (TR) domains have been found in various protozoan parasites, and they are often targets of B-cell responses. Through systematic analyses of whole proteomes, we recently demonstrated that two trypanosomatid parasites, Leishmania infantum and Trypanosoma cruzi, are rich in antigenic proteins with large TR domains. However, the reason that these proteins are antigenic was unclear. Here, by performing molecular, immunological, and bioinformatic characterizations of Leishmania TR proteins, we found two possible factors affecting the antigenicity of these proteins; one factor is their fundamental composition as TR proteins, and the other is regulation of their expression by parasites. Enzyme-linked immunosorbent assays (ELISAs) using recombinant proteins revealed that the copy number of the repeat affects the affinity of binding between antigens and antibodies, as expected based on thermodynamic binding kinetics. Other than containing TR domains, the TR proteins do not share characteristics, such as sequence similarity or biased cellular location predicted by the presence of a signal sequence(s) and/or a transmembrane domain(s). However, the TR proteome contained a higher percentage of proteins upregulated in amastigotes than the whole proteome, and upregulated expression of a TR protein seemed to affect its antigenicity. These results indicate that Leishmania parasites actively utilize the TR protein family for parasitism in mammalian hosts.
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Affiliation(s)
- Yasuyuki Goto
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
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21
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Alvarez MG, Postan M, Weatherly DB, Albareda MC, Sidney J, Sette A, Olivera C, Armenti AH, Tarleton RL, Laucella SA. HLA Class I-T cell epitopes from trans-sialidase proteins reveal functionally distinct subsets of CD8+ T cells in chronic Chagas disease. PLoS Negl Trop Dis 2008; 2:e288. [PMID: 18846233 PMCID: PMC2565697 DOI: 10.1371/journal.pntd.0000288] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 08/06/2008] [Indexed: 11/23/2022] Open
Abstract
Background Previously, we identified a set of HLA-A020.1-restricted trans-sialidase peptides as targets of CD8+ T cell responses in HLA-A0201+ individuals chronically infected by T. cruzi. Methods and Findings Herein, we report the identification of peptides encoded by the same trans-sialidase gene family that bind alleles representative of the 6 most common class I HLA-supertypes. Based on a combination of bioinformatic predictions and HLA-supertype considerations, a total of 1001 epitopes predicted to bind to HLA A01, A02, A03, A24, B7 and B44 supertypes was selected. Ninety-six supertype-binder epitopes encoded by multiple trans-sialidase genes were tested for the ability to stimulate a recall CD8+ T cell response in the peripheral blood from subjects with chronic T. cruzi infection regardless the HLA haplotype. An overall hierarchy of antigenicity was apparent, with the A02 supertype peptides being the most frequently recognized in the Chagas disease population followed by the A03 and the A24 supertype epitopes. CD8+ T cell responses to promiscuous epitopes revealed that the CD8+ T cell compartment specific for T. cruzi displays a functional profile with T cells secreting interferon-γ alone as the predominant pattern and very low prevalence of single IL-2-secreting or dual IFN-γ/IL-2 secreting T cells denoting a lack of polyfunctional cytokine responses in chronic T. cruzi infection. Conclusions This study identifies a set of T. cruzi peptides that should prove useful for monitoring immune competence and changes in infection and disease status in individuals with chronic Chagas disease. At present, 16–20 million people in Central and South America are infected with Trypanosoma cruzi, the causative agent of Chagas disease in humans. The primary clinical consequence of the infection is a cardiomyopathy, which manifests in approximately 30% of infected individuals, many years after the initial infection. Our work in Chagas disease patients began as an effort to assess the range and specificity of antigens that were recognized by T cells, in particular CD8+ T cells, in individuals with long-term infections with Trypanosoma cruzi. Trans-sialidase proteins from T. cruzi are major surface and released proteins that are targets of humoral and cellular immune responses. We previously, identified a set of trans-sialidase peptides that were recognized by a very low frequency of chronically T. cruzi-infected subjects. Based on bioinformatic predictions, herein we report the identification of new trans-sialidase epitopes that are recognized by a higher proportion of T. cruzi-infected people. The functional profile of T cells specific for these peptides is characteristic of an infection with long term stimulation of the immune system, with high levels of IFN-γ-secreting T cells and low levels of IL-2 production. This set of T. cruzi peptides should prove useful for monitoring immune competence and changes in infection and disease status in individuals with chronic Chagas disease.
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Affiliation(s)
- María G. Alvarez
- Hospital Interzonal General de Agudos “Eva Perón”, San Martín, Provincia de Buenos Aires, Argentina
| | - Miriam Postan
- Instituto Nacional de Parasitología “Dr. Mario Fatala Chabén”, Buenos Aires, Argentina
| | - D. Brent Weatherly
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - María C. Albareda
- Instituto Nacional de Parasitología “Dr. Mario Fatala Chabén”, Buenos Aires, Argentina
| | - John Sidney
- La Jolla Institute of Allergy and Immunology, La Jolla, California, United States of America
| | - Alessandro Sette
- La Jolla Institute of Allergy and Immunology, La Jolla, California, United States of America
| | - Carina Olivera
- Instituto Nacional de Parasitología “Dr. Mario Fatala Chabén”, Buenos Aires, Argentina
| | - Alejandro H. Armenti
- Hospital Interzonal General de Agudos “Eva Perón”, San Martín, Provincia de Buenos Aires, Argentina
| | - Rick L. Tarleton
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Susana A. Laucella
- Instituto Nacional de Parasitología “Dr. Mario Fatala Chabén”, Buenos Aires, Argentina
- * E-mail:
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22
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Abstract
Proteins with tandem repeat (TR) domains have been found in various protozoan parasites, often acting as targets of B-cell responses. However, the extent of the repeats within Trypanosoma cruzi, the causative agent of Chagas' disease, has not been examined well. Here, we present a systematic survey of the TR genes found in T. cruzi, in comparison with other organisms. Although the characteristics of TR genes varied from organism to organism, the presence of genes having large TR domains was unique to the trypanosomatids examined, including T. cruzi. Sequence analyses of T. cruzi TR genes revealed their divergency; they do not share such characteristics as sequence similarity or biased cellular location predicted by the presence of a signal sequence or transmembrane domain(s). In contrast, T. cruzi TR proteins seemed to possess significant antigenicity. A number of previously characterized T. cruzi antigens were detected by this computational screening, and several of those antigens contained a large TR domain. Further analyses of the T. cruzi genome demonstrated that previously uncharacterized TR proteins in this organism may also be immunodominant. Taken together, T. cruzi is rich in large TR domain-containing proteins with immunological significance; it is worthwhile further analyzing such characteristics of TR proteins as the copy number and consensus sequence of the repeats to determine whether they might contribute to the biological variability of T. cruzi strains with regard to induced immunological responses, host susceptibility, disease outcomes, and pathogenicity.
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23
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Evaluation of immune responses raised againstTc13 antigens ofTrypanosoma cruziin the outcome of murine experimental infection. Parasitology 2007; 135:347-57. [DOI: 10.1017/s0031182007003873] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYWe have previously reported that genetic immunization withTc13Tul antigen ofTrypanosoma cruzi, the aetiological agent of Chagas' disease, triggers harmful effects and non-protective immune responses. In order to confirm the role ofTc13 antigens duringT. cruziinfection, herein we studied the humoral and cellular immune responses to theTc13Tul molecule and its EPKSA C-terminal portion in BALB/cT. cruzi-infected mice or mice immunized with recombinantTc13Tul. Analysis of the antibody response showed that B-cell epitopes that stimulate a sustained IgM production along the infection and high levels of IgG in the acute phase are mainly located at theTc13 N- and C-terminal domains, respectively. DTH assays showed that T-cell epitopes are mainly at theTc13 N-terminal segment and that they do not elicit an efficient memory response. RecombinantTc13Tul did not induce IFN-γ secretion in either infected or immunized mice. However, a putative CD8+Tc13Tul-derived peptide was found to elicit IFN-γ production in chronically infected animals. Immunization with recombinantTc13Tul did not induce pathology in tissues and neither did it protect against the infection. Our results show that in the outcome ofT. cruziinfection theTc13 family protein mainly triggers non-protective immune responses.
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24
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Goto Y, Coler RN, Reed SG. Bioinformatic identification of tandem repeat antigens of the Leishmania donovani complex. Infect Immun 2006; 75:846-51. [PMID: 17088350 PMCID: PMC1828517 DOI: 10.1128/iai.01205-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
With large amounts of parasite gene sequence available, additional bioinformatic tools to screen these sequences for identifying genes encoding antigens are needed. Proteins containing tandem repeat (TR) domains are often B-cell antigens, and antibody responses toward TR domains of the proteins are dominant in human infected with certain parasites. We hypothesized that antigens of serological significance could be identified with a search for TR domains. Here we show the result of bioinformatic screening of the gene sequence database of the parasitic protozoan Leishmania infantum. Of 8,191 genes scanned, 64 genes contained TR domains. Of the 64 genes, 22 encoded previously characterized antigens; the remaining 42 genes were previously uncharacterized. By using sera from Sudanese visceral leishmaniasis patients, we confirmed that the TR domains of LinJ11.0070, LinJ25.1100, LinJ27.0400, and LinJ29.0110, which were from the 42 uncharacterized proteins, are also antigenic. The results suggest the validity of this approach for identifying leishmanial antigens of serological significance.
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Affiliation(s)
- Yasuyuki Goto
- Infectious Disease Research Institute, 1124 Columbia St, Suite 400, Seattle, WA 98104, USA
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25
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Shadomy SV, Waring SC, Martins-Filho OA, Oliveira RC, Chappell CL. Combined use of enzyme-linked immunosorbent assay and flow cytometry to detect antibodies to Trypanosoma cruzi in domestic canines in Texas. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2004; 11:313-9. [PMID: 15013981 PMCID: PMC371209 DOI: 10.1128/cdli.11.2.313-319.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Canines may be sentinels and/or reservoirs for human Trypanosoma cruzi exposures. This study adapted a method originally designed for human diagnostics to detect serum immunoglobulin G to T. cruzi in canines. The method combined an enzyme-linked immunosorbent assay (ELISA) for screening and flow cytometry detection of anti-live trypomastigote antibodies (ALTA) for confirmation. The assays were optimized by using known positive and negative control canine sera, and cutoff values were established. The ELISA and ALTA assay easily distinguished between reactive (positive controls) and nonreactive (negative controls) sera and were used to test sera collected in a cross-sectional seroprevalence survey of 356 domestic canines from Harris County, Tex., and the surrounding area. Fifty-three (14.9%) of 356 asymptomatic canines in the survey were positive by ELISA, and 5 (1.4%) were confirmed positive with the ALTA assay, with an additional 4 (1.1%) canines classified as "suspect positive." Thus, the overall prevalence of T. cruzi antibodies in this population was 2.6%. This is the first U.S. study to use the combination of ELISA and ALTA to detect serum antibodies to T. cruzi and the first report of the prevalence of T. cruzi infection in domestic canines in the Houston, Tex. (Harris County), region. Our results demonstrate that the combination of ELISA and ALTA has been successfully adapted for use in testing canines for serological evidence of T. cruzi infection. Seroprevalence survey results suggest that T. cruzi antibody-positive domestic canines in the peridomestic setting are present in the Houston, Tex., region and further suggest that T. cruzi is enzootic in the region.
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Affiliation(s)
- Sean V Shadomy
- Center for Infectious Diseases, The University of Texas Health Science Center at Houston School of Public Health, Houston, Texas 77030, USA
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26
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Joensen L, Borda E, Kohout T, Perry S, García G, Sterin-Borda L. Trypanosoma cruzi antigen that interacts with the beta1-adrenergic receptor and modifies myocardial contractile activity. Mol Biochem Parasitol 2003; 127:169-77. [PMID: 12672526 DOI: 10.1016/s0166-6851(03)00003-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Previously, we have demonstrated that plasma membranes from the parasite Trypanosoma cruzi (T. cruzi) recognize and adhere to host cells through parasite surface attachment molecules that have affinity for beta(1)-adrenergic receptors (beta(1)-ARs) on target organs. In this report we identify a parasite protein that not only interacts with beta(1)-ARs, but also displays beta-agonist-like activity. We demonstrate that a recombinant maltose binding protein fusion of Tc13 Tul (MBP-Tc13 Tul), a member of the T. cruzi antigen 13 family of surface antigen proteins, competes for binding sites with the beta-adrenergic receptor antagonist [125I]-CYP on membranes purified both from CHO cells expressing human beta(1)-ARs and from rat atria. The competition is prevented by pre-treating MBP-Tc13 Tul with antibodies directed against the EPKSA repeat domain of Tc13 Tul, implicating this portion of the molecule in binding to the beta(1)-AR. Furthermore, MBP-Tc13 Tul activates rat myocardial beta(1)-ARs, resulting in synthesis of cyclic adenosine monophosphate (cAMP) and an increase in cardiac contractility. These biological effects are selectively suppressed by the beta(1)-AR antagonist atenolol, by a synthetic peptide corresponding to the second extracellular loop of the human beta(1)-AR, and by the anti-EPKSA repeat antibodies. These results imply that the Tc13 Tul cell-surface antigen of T. cruzi plays a central role in misregulating the beta(1)-AR following parasite infection, and may be a causative factor of dysautonomic syndrome described in Chagas' disease.
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Affiliation(s)
- Lilian Joensen
- Argentine National Parasitology Institute "Dr. Mario Fatala Chaben", ANLIS "Dr. Carlos G. Malbrán", University of Buenos Aires, Buenos Aires, Argentina
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27
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García GA, Joensen LG, Búa J, Ainciart N, Perry SJ, Ruiz AM. Trypanosoma cruzi: molecular identification and characterization of new members of the Tc13 family. Description of the interaction between the Tc13 antigen from Tulahuén strain and the second extracellular loop of the beta(1)-adrenergic receptor. Exp Parasitol 2003; 103:112-9. [PMID: 12880587 DOI: 10.1016/s0014-4894(03)00087-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Trypanosoma cruzi Tc13 antigens belong to the trans-sialidase superfamily. Their sequences have been described only partially and, up to now, their physiological activity has not been elucidated. Here we present two new members of this family from the Tulahuén strain (Tc13 Tul) and the CL Brener clone (Tc13 CL), being the latter the first Tc13 sequence fully described. Alignment of all Tc13 sequences allowed us to define two sub-families that differ in the number of repeats and the presence or absence of the GPI addition site. Chromoblots demonstrate that Tc13 antigens are mainly located in chromosome III and its homologous. Pull down assays suggest that recombinant MBP-Tc13 Tul interacts with the second extracellular loop of the beta(1)-adrenergic receptor. This is the first evidence that a Tc13 antigen acts as a ligand interacting with a neurotransmitter receptor. These observations might add some light to the development of chagasic pathology.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/metabolism
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Antigens, Surface/metabolism
- Base Sequence
- Glycoproteins
- Humans
- Molecular Sequence Data
- Neuraminidase/chemistry
- Neuraminidase/genetics
- Neuraminidase/metabolism
- Receptors, Adrenergic, beta-1/chemistry
- Receptors, Adrenergic, beta-1/metabolism
- Restriction Mapping
- Sequence Alignment
- Sequence Analysis, DNA
- Trypanosoma cruzi/classification
- Trypanosoma cruzi/enzymology
- Trypanosoma cruzi/genetics
- Trypanosoma cruzi/immunology
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Affiliation(s)
- Gabriela A García
- Dr. Mario Fatala Chabén National Institute of Parasitology (ANLIS/Malbrán), Paseo Colón 568, (1063) Buenos Aires, Argentina.
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28
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da Silveira JF, Umezawa ES, Luquetti AO. Chagas disease: recombinant Trypanosoma cruzi antigens for serological diagnosis. Trends Parasitol 2001; 17:286-91. [PMID: 11378036 DOI: 10.1016/s1471-4922(01)01897-9] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Diagnosis of individuals infected by Trypanosoma cruzi is performed mainly by serological tests using crude antigens, which might crossreact with other infections. In the past ten years, many recombinant T. cruzi proteins and synthetic peptides have been described, and some are already on the market. Managers of laboratories and blood banks need to make decisions on a cost-benefit basis whether to include these new-generation tests. Here, we indicate antigens that are likely to prove most useful.
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Affiliation(s)
- J F da Silveira
- Dept Micro, Imuno e Parasitologia da Escola Paulista de Medicina, UNIFESP, Rua Botucatu 862, CEP 04023-062, São Paulo, Brazil
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29
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Burns JM, Adeeku EK, Belk CC, Dunn PD. An unusual tryptophan-rich domain characterizes two secreted antigens of Plasmodium yoelii-infected erythrocytes. Mol Biochem Parasitol 2000; 110:11-21. [PMID: 10989141 DOI: 10.1016/s0166-6851(00)00252-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Previously, we reported the characterization of pypAg-1, a novel protective membrane protein of Plasmodium yoelii-infected erythrocytes. Immunization studies indicated that pypAg-1 contained at least two protective epitopes. One of these determinants was associated with the N-terminal portion of pypAg-1, that also included a 220 amino acid domain unusually rich in tryptophan residues. Using sera from mice immunized against P. yoelii, we have identified a second related antigen, pypAg-3. The pypag-3 cDNA encodes a 43 kDa blood-stage protein that is also characterized by the presence of a 220 residue tryptophan-rich domain. Of particular interest, sequence comparisons revealed that 24 tryptophan residues are positionally conserved between pypAg-1 and pypAg-3. Otherwise, the two antigens share limited sequence similarity. Full-length recombinant pypAg-3 was expressed, purified and used to produce a high titer polyclonal rabbit antiserum. As with pypAg-1, immunofluorescence studies showed that pypAg-3 is expressed in the cytoplasm and associated with the membrane of P. yoelii infected erythrocytes. In addition, pypAg-1 and pypAg-3 appear to be secreted proteins, as both were detected in culture supernatants of P. yoelii-infected erythrocytes. Finally, metabolically labeled pypAg-1 and pypAg-3 secreted from parasitized cells bind to the surface of uninfected, normal mouse erythrocytes. As such, the conservation of the unusual tryptophan-rich domain between two blood-stage malarial proteins with similar biological properties suggests that it may be important for protein export and/or function.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/metabolism
- Cloning, Molecular
- DNA, Complementary
- DNA, Protozoan/genetics
- Erythrocytes/metabolism
- Erythrocytes/parasitology
- Fluorescent Antibody Technique, Indirect
- Malaria/parasitology
- Membrane Proteins/chemistry
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Membrane Proteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Plasmodium yoelii/genetics
- Plasmodium yoelii/immunology
- Plasmodium yoelii/metabolism
- Polymerase Chain Reaction
- Protein Structure, Tertiary
- Protozoan Proteins
- Rabbits
- Sequence Analysis, DNA
- Tryptophan/chemistry
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Affiliation(s)
- J M Burns
- Department of Microbiology, Meharry Medical College, 1005 D.B. Todd Blvd., Nashville, TN 37208, USA.
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30
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Oelemann WM, Vanderborght BO, Verissimo Da Costa GC, Teixeira MG, Borges-Pereira J, De Castro JA, Coura JR, Stoops E, Hulstaert F, Zrein M, Peralta JM. A recombinant peptide antigen line immunoassay optimized for the confirmation of Chagas' disease. Transfusion 1999; 39:711-7. [PMID: 10413278 DOI: 10.1046/j.1537-2995.1999.39070711.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The transfusion of contaminated blood has become the major route of transmission for Chagas' disease in Brazil. Current screening tests are insensitive and yield conflicting results, while confirmatory assays do not exist. A line immunoassay (INNO-LIA Chagas Ab [INNO-LIA]) combining relevant, immunodominant recombinant and synthetic antigens on a single nylon membrane strip was evaluated for the serologic confirmation of Chagas' disease. STUDY DESIGN AND METHODS Sera from 1062 patients and healthy residents of four Brazilian regions endemic for Chagas' disease were used for test optimization. The established confirmation algorithm was evaluated with an independent set of positive (n = 75) and negative (n = 148) samples. RESULTS In the optimization phase, without an established comparative gold standard, the results with the INNO-LIA were compared with those obtained in four other screening assays. In the validation phase, the INNO-LIA showed a sensitivity of 100 percent (95% CI, 95.21-100) and a specificity of 99.32 percent (95% CI, 96.29-99.98) for well-characterized sera. Moreover, its specificity reached 100 percent with a set of 40 sera obtained from patients with documented leishmaniasis. The interpretation criteria defined in this study indicated that the INNO-LIA accurately detected the presence of antibodies to various specific antigens of Trypanosoma cruzi. CONCLUSION The INNO-LIA Chagas Ab assay may become the first commercial assay to reliably confirm the presence of antibodies to T. cruzi.
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Affiliation(s)
- W M Oelemann
- Institute of Microbiology and the Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Brazil.
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31
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Burns JM, Adeeku EK, Dunn PD. Protective immunization with a novel membrane protein of Plasmodium yoelii-infected erythrocytes. Infect Immun 1999; 67:675-80. [PMID: 9916076 PMCID: PMC96372 DOI: 10.1128/iai.67.2.675-680.1999] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/1998] [Accepted: 11/11/1998] [Indexed: 11/20/2022] Open
Abstract
Immunization with a particulate fraction of blood-stage antigens was shown previously to protect mice against Plasmodium yoelii malaria. To identify antigens inducing the protective response, sera from immunized mice were used to screen a P. yoelii cDNA expression library. Sequence analysis of one 2.6-kb cDNA clone indicated that the identified gene, pypag-1, encoded a novel plasmodial antigen. Two nonoverlapping regions of pypag-1 were expressed in Escherichia coli. The first recombinant antigen, pAg-1N, contained the N-terminal 337 residues, which included a putative transmembrane domain and a region relatively rich in tryptophan residues. The second recombinant antigen, pAg-1C, contained the remaining C-terminal 211 residues, which included 31 copies of a 5-amino-acid degenerative repeat. Immunoblot studies using rabbit antiserum raised against recombinant pAg-1N showed that the native pypAg-1 protein migrated at approximately 98 kDa, considerably slower than its predicted molecular mass of 66 kDa. Immunofluorescence studies localized the expression of the native pypAg-1 protein both to the cytoplasm and at the surface of P. yoelii-infected erythrocytes. Immunization with either pAg-1N or pAg-1C induced a four- to sevenfold reduction in P. yoelii blood-stage parasitemia. As such, pypAg-1 appears to contain at least two distinct protective epitopes. To our knowledge, this is the first characterization of a protective antigen of P. yoelii that is associated with the erythrocyte membrane.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/isolation & purification
- Base Sequence
- Cloning, Molecular
- DNA, Protozoan
- Disease Models, Animal
- Erythrocytes/immunology
- Gene Expression
- Immunoblotting
- Malaria/prevention & control
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/isolation & purification
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Membrane Proteins/isolation & purification
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Plasmodium yoelii/genetics
- Plasmodium yoelii/immunology
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/isolation & purification
- Rabbits
- Sequence Analysis, DNA
- Vaccination
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Vaccines, Synthetic/isolation & purification
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Affiliation(s)
- J M Burns
- Department of Microbiology, Meharry Medical College, Nashville, Tennessee 37208, USA.
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32
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Chico M, Sandoval C, Guevara A, Calvopiña M, Cooper PJ, Reed SG, Guderian RH. Chagas disease in Ecuador: evidence for disease transmission in an Indigenous population in the Amazon region. Mem Inst Oswaldo Cruz 1997; 92:317-20. [PMID: 9332593 DOI: 10.1590/s0074-02761997000300002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Two well-defined synthetic peptides TcD and PEP2 were used in a sero-epidemiological study for the detection of Trypanosoma cruzi infections in an indigenous group in the Amazon region of Ecuador. Of the 18 communities studied along the Rio Napo, province of Napo, 15 (83.3%) were found to be positive for T. cruzi infection. Of the 1,011 individuals examined 61 (6.03%) resulted positive. A prevalence of infection of 4.8% was found in children aged 1-5 years. The prevalence of infection increased with age, with adults 50 years or older showing a maximum prevalence of 18.8%. Autochthonous transmission of T. cruzi is present among this isolated indigenous population.
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Affiliation(s)
- M Chico
- Departamento de Investigaciones Clínicas, Hospital Vozandes, HCJB, Quito, Ecuador
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Gomes YM. PCR and sero-diagnosis of chronic Chagas' disease. Biotechnological advances. Appl Biochem Biotechnol 1997; 66:107-19. [PMID: 9248034 DOI: 10.1007/bf02788756] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In the acute phase of Chagas' disease, when the parasitemia is high, diagnosis can be easily made using conventional parasitological methods. During the chronic phase, due to the low parasitemia, diagnosis is performed mainly by immunological methods. Conventional serological techniques are limited by cross-reactivity with other parasitic diseases, non-standardization of reagents, and the diversity of technical procedures. Methods are being developed to improve the sensitivity and specificity of diagnosis using molecular approaches. PCR-based detection systems and the use of recombinant antigens in ELISA are the most promising.
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Affiliation(s)
- Y M Gomes
- Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães-FIOCRUZ, Cidade Universitária, Recife-PE, Brazil
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Abstract
Gastrointestinal dysfunction is a major problem for many patients with chronic Chagas' disease, as are cardiac dysrhythmias and cardiomyopathy. The underlying anatomic abnormality in these patients is a denervation of the gastrointestinal tract. This process of nerve destruction usually develops insidiously over many years, and it is highly variable in terms of its extent in individual patients as well as in the segments of the gastrointestinal tract that are most affected. Megaesophagus is the most common manifestation of gastrointestinal Chagas disease, and mechanical dilation of the esophageal sphincter or surgery in advanced cases usually give satisfactory relief of symptoms. Megacolon, particularly of the sigmoid segment, is also common in patients with chronic T. cruzi infections, and its presence can be complicated by fecal impaction or sigmoid volvulus. Patients with advanced megacolon who have resections of the sigmoid colon and most of the rectum generally do well postoperatively.
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Affiliation(s)
- L V Kirchhoff
- Division of Infectious Diseases, University of Iowa, Iowa City, USA
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35
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Scotto d'Abusco AS, De Santo C, Menna T, Coscia MR, Oreste U, Geller-Bernstein C, Ruffilli A. Characterization of a dominant antigenic determinant of Par o I encoded by recombinant DNA. Clin Exp Allergy 1996; 26:223-31. [PMID: 8835131 DOI: 10.1111/j.1365-2222.1996.tb00083.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The pollens from Parietaria judaica and Parietaria officinalis are a major cause of pollinosis in Europe. Par o I (13.5 kDa) and Par j I (12 kDa), the major allergens from these species, are highly crossreactive. METHODS We have immunoscreened a P. judaica pollen cDNA expression library with a rabbit antiserum specific for Par j I and with a serum pool from allergic patients. An immunopositive clone containing a 26 bp insert was further characterized. The insert sequence was determined and the beta-galactosidase fusion protein was partially purified by electroelution from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. RESULTS This fusion protein specifically and extensively inhibited Par o I and Par j I binding of a rabbit antiserum and of a serum pool obtained from allergic patients. The antifusion-protein antiserum obtained in a rabbit (anti 6a) specifically precipitated radioiodinated purified Par o I in the double antibody radioimmunoassay (DARIA) and competed with antibodies of sera from allergic patients for the binding to Parietaria pollen extract allergens by enzyme linked immunosorbent assay (ELISA). We investigated the prevalence of antibody response towards the 6a epitope in patients naturally sensitized to Parietaria. The presence of 6a specific IgE antibodies was assessed in the sera of 33 patients using inhibition assays. All sera had antibodies with this specificity: the extensive percentage of inhibition reached suggested that they dominated individual ab response. CONCLUSION In conclusion, the antibody response induced by natural exposure to the pollen of Parietaria appears to be higly focused on a single linear antigenic determinant of the major allergens which may play a relevant role in the development of clinical allergy. This report is, to our knowledge, the first description of a dominant linear epitope of a major allergen.
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Affiliation(s)
- A S Scotto d'Abusco
- International Institute of Genetics and Biophysics, National Research Council, Naples, Italy
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36
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Taibi A, Guevara-Espinoza A, Schöneck R, Yahiaoui B, Ouaissi A. Improved specificity of Trypanosoma cruzi identification by polymerase chain reaction using an oligonucleotide derived from the amino-terminal sequence of a Tc24 protein. Parasitology 1995; 111 ( Pt 5):581-90. [PMID: 8559591 DOI: 10.1017/s0031182000077064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In the present study, the diagnostic value of Trypanosoma cruzi recombinant protein (Tc24) was examined. Although antibodies against Tc24 were detected during natural and experimental T. cruzi infections, specificity studies revealed that sera from T. rangeli-infected mice also recognized to some extent Tc24 protein. In addition, sera from Tc24-immunized mice reacted against a 21 kDa polypeptide in T. rangeli extracts. Detailed analysis of the antibody response against 20-40 peptide localized in the Tc24 amino-terminal domain suggests that this sequence is not expressed by T. rangeli 21 kDa antigen. Therefore, the PCR reaction using oligonucleotides corresponding to a 20-26 peptide clearly demonstrated the specificity of the oligoprobes for T. cruzi identification. Positive signals were also found when using blood samples from T. cruzi-infected mice. Taken together, these results suggest that the PCR-based 20-26 assay may be useful in the specific diagnosis of Chagas' disease.
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Affiliation(s)
- A Taibi
- Centre d'Immunologie et de Biologie Parasitaire, Unité INSERM U415, Institut Pasteur, Lille, France
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37
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Dillon DC, Day CH, Whittle JA, Magill AJ, Reed SG. Characterization of a Leishmania tropica antigen that detects immune responses in Desert Storm viscerotropic leishmaniasis patients. Proc Natl Acad Sci U S A 1995; 92:7981-5. [PMID: 7644524 PMCID: PMC41270 DOI: 10.1073/pnas.92.17.7981] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A chronic debilitating parasitic infection, viscerotropic leishmaniasis (VTL), has been described in Operation Desert Storm veterans. Diagnosis of this disease, caused by Leishmania tropica, has been difficult due to low or absent specific immune responses in traditional assays. We report the cloning and characterization of two genomic fragments encoding portions of a single 210-kDa L. tropica protein useful for the diagnosis of VTL in U.S. military personnel. The recombinant proteins encoded by these fragments, recombinant (r) Lt-1 and rLt-2, contain a 33-amino acid repeat that reacts with sera from Desert Storm VTL patients and with sera from L. tropica-infected patients with cutaneous leishmaniasis. Antibody reactivities to rLt-1 indicated a bias toward IgG2 in VTL patient sera. Peripheral blood mononuclear cells from VTL patients produced interferon gamma, but not interleukin 4 or 10, in response to rLt-1. No cytokine production was observed in response to parasite lysate. The results indicate that specific leishmanial antigens may be used to detect immune responses in VTL patients with chronic infections.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Protozoan/blood
- Antigens, Protozoan/immunology
- Base Sequence
- Cells, Cultured
- DNA, Protozoan/chemistry
- Genes, Protozoan
- Humans
- Immunoblotting
- Immunoglobulin G/blood
- Interferon-gamma/biosynthesis
- Interleukin-10/analysis
- Interleukin-4/analysis
- Leishmania tropica/genetics
- Leishmania tropica/immunology
- Leishmania tropica/isolation & purification
- Leishmaniasis, Cutaneous/diagnosis
- Leishmaniasis, Cutaneous/immunology
- Leishmaniasis, Cutaneous/parasitology
- Leishmaniasis, Visceral/diagnosis
- Leishmaniasis, Visceral/immunology
- Leishmaniasis, Visceral/parasitology
- Lymphocytes/immunology
- Middle East
- Military Personnel
- Molecular Sequence Data
- Open Reading Frames
- Recombinant Proteins/immunology
- Repetitive Sequences, Nucleic Acid
- United States/ethnology
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Affiliation(s)
- D C Dillon
- Infectious Disease Research Institute, Seattle, WA 98104, USA
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38
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Nedved ML, Gottlieb PA, Moe GR. CD and DNA binding studies of a proline repeat-containing segment of the replication arrest protein Tus. Nucleic Acids Res 1994; 22:5024-30. [PMID: 7800495 PMCID: PMC523773 DOI: 10.1093/nar/22.23.5024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Tus is a sequence-specific DNA binding protein that regulates its own transcription and can arrest Escherichia coli replication when bound to Ter sites on the chromosome. In order to identify segments of Tus that may be involved in DNA binding interactions we have analyzed the Tus amino acid sequence with respect to secondary structure motifs and similarity to other protein sequences. A twenty amino acid segment containing several basic residues and a proline repeat motif with a periodicity of five residues was identified. The motif was common to several other nucleic acid binding proteins, including histone H1-3, Xenopus laevis ribosomal protein L1, and the single-stranded DNA binding protein (DBP) from adenovirus. A 22 amino acid peptide, TPPI, having a sequence similar to the Tus segment binds non-specifically and non-cooperatively to double- and single-stranded DNA with a binding constant of 1.5 +/- 0.2 x 10(6) M-1. The estimated binding site size was 4.3 +/- 0.5 base pairs. Circular dichroism studies indicated that the peptide was a random coil in buffer but adopted a helical structure in 50% trifluroethanol and in sodium dodecyl sulfate at concentrations above the critical micellar concentration. Several helical models of the TPPI sequence were constructed graphically and minimized. One of them, an amphiphilic, left-handed, 5.1(19) helical model was best able to account for the observed structural properties of TPPI in the presence of structure-promoting additives.
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Affiliation(s)
- M L Nedved
- Department of Chemistry and Biochemistry, University of Delaware, Newark 19716
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39
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Skeiky YA, Benson DR, Elwasila M, Badaro R, Burns JM, Reed SG. Antigens shared by Leishmania species and Trypanosoma cruzi: immunological comparison of the acidic ribosomal P0 proteins. Infect Immun 1994; 62:1643-51. [PMID: 7513304 PMCID: PMC186375 DOI: 10.1128/iai.62.5.1643-1651.1994] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Patients with visceral leishmaniasis produce high levels of immunoglobulin, but the specificities of antibodies produced are not well characterized. In an effort to identify leishmania antigens that are specific to Leishmania species or are cross-reactive with other parasitic protozoa, we have cloned and characterized full-length genomic and cDNA clones encoding a Leishmania chagasi acidic ribosomal antigen, LcP0, recognized during human infections. The protein is homologous to the Trypanosoma cruzi and human ribosomal proteins TcP0 and HuP0, respectively. Unlike most higher eukaryotes, but similar to TcP0, LcP0 has a C-terminal heptapeptide sequence resembling those of the archaebacterial acidic (P-like) proteins. The highly charged C-terminal acidic domain of LcP0 contains a serine residue typically found in most eukaryotes but lacking in all T. cruzi P proteins we have characterized thus far. L. chagasi-infected individuals as well as those with T. cruzi infections have antibodies cross-reactive with recombinant LcP0 and TcP0 as well as HuP0. However, the properties of anti-P0 antibodies in T. cruzi and L. chagasi infection sera are quite different. Through the use of synthetic peptides, we showed that while T. cruzi infection anti-TcP0 antibodies are exclusively directed against the C-terminal domain of TcP0, L. chagasi infection sera contain antibodies reactive with epitopes other than the C-terminal sequence of LcP0. Thus, anti-LcP0 antibodies in L. chagasi infection sera represent the first characterized deviation from the restricted immunodominant C-terminal epitope involved in the generation of anti-P0 antibodies following infection or autoimmune diseases.
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Affiliation(s)
- Y A Skeiky
- Infectious Disease Research Institute, Seattle, Washington 98109
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40
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Peralta JM, Teixeira MG, Shreffler WG, Pereira JB, Burns JM, Sleath PR, Reed SG. Serodiagnosis of Chagas' disease by enzyme-linked immunosorbent assay using two synthetic peptides as antigens. J Clin Microbiol 1994; 32:971-4. [PMID: 8027352 PMCID: PMC267164 DOI: 10.1128/jcm.32.4.971-974.1994] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
An enzyme-linked immunosorbent assay (ELISA) was developed for detecting antibodies against Trypanosoma cruzi. Two synthetic T. cruzi peptides, TcD and PEP2, were used. The specificity and sensitivity of the peptide ELISA were determined with 260 serum samples from individuals living in an area in which Chagas' disease is endemic. ELISAs were performed with the peptides singly or in combination. The evaluation of these tests showed that 168 (93.8%) of 179 serum samples from T. cruzi-infected patients were positive when TcD peptide was used as antigen; 164 (91.6%) samples were positive with PEP2, and 178 (99.4%) samples were positive when the two peptides were combined. Thus, the sensitivity of the ELISA using the two peptides exceeded 99%. The specificity was evaluated by using a panel of 118 serum samples that included samples from 81 individuals living in an area of endemicity with negative serology for Chagas' disease and from 37 patients from areas in which T. cruzi was not endemic but with other pathologies, such as leishmaniasis, tuberculosis, and leprosy. Only two false-positive serum samples were found in this group of individuals, giving a test specificity of more than 98%. Because these peptides can be synthesized and are very stable at room temperature, the use of such reagents can improve the standardization and reproducibility of ELISAs for the serodiagnosis of T. cruzi infection.
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Affiliation(s)
- J M Peralta
- Instituto de Microbiologia, UFRJ, Rio de Janerio, Brazil
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41
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42
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Klein BS, Hogan LH, Jones JM. Immunologic recognition of a 25-amino acid repeat arrayed in tandem on a major antigen of Blastomyces dermatitidis. J Clin Invest 1993; 92:330-7. [PMID: 8326001 PMCID: PMC293603 DOI: 10.1172/jci116571] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A 120-kD glycoprotein antigen abundantly expressed on Blastomyces dermatitidis yeasts is a target of cellular and humoral immune responses in human infection. To investigate the antigen and immune response more carefully at the molecular level, we screened an expression library from B. dermatitidis to identify clones that encode this antigen, designated WI-1. A 942-bp cDNA was isolated by immunologic screening with polyclonal, rabbit anti-WI-1 antiserum. Northern hybridization analysis showed that the cDNA hybridized to yeast message approximately equal to 3.9 kb. DNA and deduced protein sequence analysis of the clone demonstrated a 25-amino acid repeat arrayed in tandem, present in 4.5 copies near the 5' end, and rich in predicted antigenic epitopes. Further analysis showed strong homology in these tandem repeats with invasin, an adhesin of Yersiniae. Cloned cDNA was used to express a 30-kD fusion protein strongly recognized in western blots by rabbit anti-WI-1 antiserum, and by sera from all 35 blastomycosis patients studied. The fusion protein product of subcloned cDNA encoding only the tandem repeat also was strongly recognized in western blots by sera from the 35 blastomycosis patients, but not by sera from 10 histoplasmosis and 5 coccidioidomycosis patients. An antigen-inhibition radioimmunoassay showed that the tandem repeat alone completely eliminated rabbit and human anti-WI-1 antibody binding to radiolabeled native WI-1. From these results, we conclude that the 25-amino acid repeat of WI-1 displays an immunodominant B cell epitope, and that the carboxyl-terminus of the molecule exhibits an architecture that may promote adhesion of Blastomyces yeasts to host cells or extracellular matrix proteins and ultimately provide a clearer picture of the molecular pathogenesis of blastomycosis.
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Affiliation(s)
- B S Klein
- Department of Pediatrics, University of Wisconsin Medical School, Madison
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Smulian AG, Theus SA, Denko N, Walzer PD, Stringer JR. A 55 kDa antigen of Pneumocystis carinii: analysis of the cellular immune response and characterization of the gene. Mol Microbiol 1993; 7:745-53. [PMID: 8469116 DOI: 10.1111/j.1365-2958.1993.tb01165.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Rat-derived Pneumocystis carinii contains a major antigen complex of 45-55 kDa. The fusion protein of a cDNA encoding the 3' portion of the 55kDa antigen, which had previously been shown to be recognized by serum antibodies of exposed subjects, was investigated for its ability to stimulate a cellular immune response. Rats exposed to P. carinii via the environment exhibited a vigorous proliferative response to the antigen whereas unexposed rats did not. The full-length cDNA for a 55kDa antigen was cloned and found to contain a 1245bp open reading frame capable of encoding a 414-amino-acid peptide. The gene encoding this protein contained a single 39bp intron and transcribed a 1.45kb RNA message. The cloning and characterization of the 55kDa antigen gene will allow production of the specific immunological reagents necessary to characterize this molecule and study its role in the biology and pathogenesis of P. carinii.
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Affiliation(s)
- A G Smulian
- Veterans Affairs Medical Center, Cincinnati, Ohio 45220
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44
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Burns JM, Shreffler WG, Benson DR, Ghalib HW, Badaro R, Reed SG. Molecular characterization of a kinesin-related antigen of Leishmania chagasi that detects specific antibody in African and American visceral leishmaniasis. Proc Natl Acad Sci U S A 1993; 90:775-9. [PMID: 8421715 PMCID: PMC45748 DOI: 10.1073/pnas.90.2.775] [Citation(s) in RCA: 273] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We report the cloning of a Leishmania chagasi antigen gene and an evaluation of leishmaniasis patient antibody responses to the recombinant protein, rK39. rK39 contains a 39-amino acid repeat that is part of a 230-kDa protein predominant in L. chagasi tissue amastigotes. Sequence analyses showed this protein, LcKin, to be related to the kinesin superfamily of motor proteins. Southern blot analyses demonstrated LcKin-related sequences in seven species of Leishmania, with conservation of the repeat between L. chagasi and Leishmania donovani. Serological evaluation revealed that 98% (56 of 57) of Brazilian and 100% (52 of 52) of Sudanese visceral leishmaniasis patients have high antibody levels to the rK39 repeat. Detectable anti-K39 antibody was virtually absent in cutaneous and mucosal leishmaniasis patients and in individuals infected with Trypanosoma cruzi. The data show that rK39 may replace crude parasite antigens as a basis for serological diagnosis of visceral leishmaniasis.
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Affiliation(s)
- J M Burns
- Seattle Biomedical Research Institute, WA 98109
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Abstract
Chagas' disease, caused by Trypanosoma cruzi, is an important cause of morbidity in many countries in Latin America. The important modes of transmission are by the bite of the reduviid bug and blood transfusion. The organism exists in three morphological forms: trypomastigotes, amastigotes, and epimastigotes. The mechanism of transformation and differentiation is currently being explored, and signal transduction pathways of the parasites may be involved in this process. Parasite adherence to and invasion of host cells is a complex process involving complement, phospholipase, penetrin, neuraminidase, and hemolysin. Two clinical forms of the disease are recognized, acute and chronic. During the acute stage pathological damage is related to the presence of the parasite, whereas in the chronic stage few parasites are found. In recent years the roles of tumor necrosis factor, gamma interferon, and the interleukins in the pathogenesis of this infection have been reported. The common manifestations of chronic cardiomyopathy are arrhythmias and thromboembolic events. Autoimmune, neurogenic, and microvascular factors may be important in the pathogenesis of the cardiomyopathy. The gastrointestinal tract is another important target, and "mega syndromes" are common manifestations. The diagnosis and treatment of this infection are active areas of investigation. New serological and molecular biological techniques have improved the diagnosis of chronic infection. Exacerbations of T. cruzi infection have been reported for patients receiving immuno-suppressive therapy and for those with AIDS.
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Affiliation(s)
- H B Tanowitz
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York
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Skeiky YA, Benson DR, Parsons M, Elkon KB, Reed SG. Cloning and expression of Trypanosoma cruzi ribosomal protein P0 and epitope analysis of anti-P0 autoantibodies in Chagas' disease patients. J Exp Med 1992; 176:201-11. [PMID: 1377223 PMCID: PMC2119278 DOI: 10.1084/jem.176.1.201] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Chagas' disease, caused by the intracellular protozoan parasite Trypanosoma cruzi, is a major cause of heart failure in endemic areas. Antigenic mimicry by T. cruzi antigens sharing epitopes with host macromolecules has been implicated in the pathogenesis which is thought to have a significant autoimmune component. We report herein on the cloning and characterization of a full-length cDNA from a T. cruzi expression library encoding a protein, TcP0, that is homologous to the human 38-kD ribosomal phosphoprotein HuP0. The T. cruzi P0 protein shows a clustering of residues that are evolutionarily conserved in higher eukaryotes. This includes an alanine- and glycine-rich region adjacent to a highly charged COOH terminus. This "hallmark" domain is the basis of the crossreactivity of the highly immunogenic eukaryotic P protein family. We found that T. cruzi-infected individuals have antibodies reacting with host (self) P proteins, as well as with recombinant TcP0. Deletion of the six carboxy-terminal amino acids abolished the reactivity of the T. cruzi infection sera with TcP0. This is similar to the specificity of anti-P autoantibodies described for a subset of patients with systemic lupus erythematosus (SLE) (Elkon, K., E. Bonfa, R. Llovet, W. Danho, H. Weissbach, and N. Brot. 1988. Proc. Natl. Acad. Sci. USA. 85:5186). These results suggest that T. cruzi P proteins may contribute to the development of autoreactive antibodies in Chagas' disease, and that the underlying mechanisms of anti-P autoantibody may be similar in Chagas' and SLE patients. This study represents the first definitive report of the cloning of a full-length T. cruzi antigen that mimics a characterized host homologue in structure, function, and shared antigenicity.
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Affiliation(s)
- Y A Skeiky
- Seattle Biomedical Research Institute, Washington 98109
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47
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New nucleotide sequence data on the EMBL File Server. Nucleic Acids Res 1992; 20:2905-27. [PMID: 1614890 PMCID: PMC336956 DOI: 10.1093/nar/20.11.2905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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