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Freitas NEM, Habib FL, Santos EF, Silva ÂAO, Fontes ND, Leony LM, Sampaio DD, de Almeida MC, Dantas-Torres F, Santos FLN. Technological advances in the serological diagnosis of Chagas disease in dogs and cats: a systematic review. Parasit Vectors 2022; 15:343. [PMID: 36167575 PMCID: PMC9516836 DOI: 10.1186/s13071-022-05476-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/10/2022] [Indexed: 11/12/2022] Open
Abstract
Background Chagas disease (CD) is caused by Trypanosoma cruzi, which is transmitted mainly through the feces/urine of infected triatomine bugs. The acute phase lasts 2–3 months and is characterized by high parasitemia and nonspecific symptoms, whereas the lifelong chronic phase features symptoms affecting the heart and/or digestive tract occurring in 30–40% of infected individuals. As in humans, cardiac abnormalities are observed in T. cruzi-infected dogs and cats. We reviewed the technological advances in the serological diagnosis of CD in dogs and cats. Methods A review of the published literature during the last 54 years (1968–2022) on the epidemiology, clinical features, diagnosis, treatment and prevention of CD in dogs and cats was conducted. Results Using predefined eligibility criteria for a search of the published literature, we retrieved and screened 436 publications. Of these, 84 original studies were considered for inclusion in this review. Dogs and cats are considered as sentinels, potentially indicating an active T. cruzi transmission and thus the risk for human infection. Although dogs and cats are reputed to be important for maintaining the T. cruzi domestic transmission cycle, there are no commercial tests to detect past or active infections in these animals. Most published research on CD in dogs and cats have used in-house serological tests prepared with native and/or full-length recombinant antigens, resulting in variable diagnostic performance. In recent years, chimeric antigens have been used to improve the diagnosis of chronic CD in humans with encouraging results. Some of them have high performance values (> 95%) and extremely low cross-reactivity rates for Leishmania spp., especially the antigens IBMP-8.1 to IBMP-8.4. The diagnostic performance of IBMP antigens was also investigated in dogs, showing high diagnostic performance with negligible cross-reactivity with anti-Leishmania infantum antibodies. Conclusions The development of a commercial immunodiagnostic tool to identify past or active T. cruzi infections in dogs and cats is urgently needed. The use of chimeric recombinant T. cruzi antigens may help to fill this gap and is discussed in this review. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05476-4.
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Affiliation(s)
- Natália Erdens Maron Freitas
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil
| | - Fernanda Lopes Habib
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil
| | - Emily Ferreira Santos
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil
| | - Ângelo Antônio Oliveira Silva
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil
| | - Natália Dantas Fontes
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil
| | - Leonardo Maia Leony
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil
| | - Daniel Dias Sampaio
- Brazil's Family Health Strategy, Municipal Health Department, Tremedal City Hall, Bahia, Tremedal, Brazil
| | - Marcio Cerqueira de Almeida
- Pathology and Molecular Biology Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Salvador, Bahia, Brazil
| | - Filipe Dantas-Torres
- Laboratory of Immunoparasitology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, Pernambuco, Brazil
| | - Fred Luciano Neves Santos
- Advanced Health Public Laboratory, Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Waldemar Falcão Street, 121, Candeal, Bahia, Salvador, 40296-710, Brazil. .,Integrated Translational Program in Chagas Disease From Fiocruz (Fio-Chagas), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
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Bontempi I, Fleitas P, Poato A, Vicco M, Rodeles L, Prochetto E, Cabrera G, Beluzzo B, Arias D, Racca A, Guerrero S, Marcipar I. Trans-sialidase overcomes many antigens to be used as a vaccine candidate against Trypanosoma cruzi. Immunotherapy 2018; 9:555-565. [PMID: 28595515 DOI: 10.2217/imt-2017-0009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AIM The development of vaccines against Trypanosoma cruzi remains in an exploratory stage. Despite several antigen candidates have been evaluated, a comparison among the performance of the immunogens cannot be carried out because the available reports differ in formulations and infection model. In this work, we compared the protective capacity of seven T. cruzi antigens in the same model of five new antigens and two well-established candidates. Materials & methods: We evaluated highly immunogenic proteins that contain tandem repeats (FRA [flagelar repetitive protein], Tc3, Tc6); enzymes involved in metabolic pathways critical for parasite survival (cytosolic tryparedoxin peroxidase and tryparedoxin peroxidase); and enzymes involved in parasite invasion (trans-sialidase [TS] and cruzipain). All these antigens were formulated with Freund's adjuvant and protection against the parasite infection was assessed in BALB/c mice. RESULTS Tc3, cytosolic tryparedoxin peroxidase, cruzipain and TS showed the best outcome after infection in survival level and parasitemia. According to these data, these groups were also assessed using the ISCOMATRIX™ adjuvant which is being used in clinical trials. CONCLUSION Taken together, our results showed that the TS overcomes the performance of other antigens when the same model is employed, confirming that TS is a promising antigen that could be used as a vaccine against T. cruzi.
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Affiliation(s)
- Ivan Bontempi
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Pedro Fleitas
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Alexia Poato
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Miguel Vicco
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina.,Facultad de Ciencias Médicas, Universidad Nacional del Litoral, Argentina
| | - Luz Rodeles
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina.,Facultad de Ciencias Médicas, Universidad Nacional del Litoral, Argentina
| | - Estefania Prochetto
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Gabriel Cabrera
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Bruno Beluzzo
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Diego Arias
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Argentina
| | - Andrea Racca
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - Sergio Guerrero
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Argentina
| | - Iván Marcipar
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
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Soares AKDA, Neves PAF, Cavalcanti MDGADM, Marinho SM, Oliveira WD, Souza JRD, Lorena VMBD, Gomes YDM. Expression of co-stimulatory molecules CD80 and CD86 is altered in CD14 + HLA-DR + monocytes from patients with Chagas disease following induction by Trypanosoma cruzi recombinant antigens. Rev Soc Bras Med Trop 2016; 49:632-636. [PMID: 27812661 DOI: 10.1590/0037-8682-0149-2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/22/2016] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION The relationships between monocytes and lymphocytes through MHC class II molecules and costimulatory, are of utmost importance for the production of an efficient immune response. In this work, we assessed the expression of surface molecules CD80 and CD86 on CD14+HLA-DR+ monocytes from patients with Chagas disease. METHODS: The study population consisted of 31 patients with chronic clinical forms of Chagas disease. Patient blood samples were cultured in the presence of recombinant cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA). RESULTS: We found considerable differences in the expression profile of surface molecules involved in antigen presentation. CONCLUSIONS: CRA and FRA may contribute to host immune response evasion by Trypanozoma cruzi.
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Affiliation(s)
| | | | - Maria da Glória Aureliano de Melo Cavalcanti
- Pronto-Socorro Cardiológico de Pernambuco (PROCAPE) - Universidade de Pernambuco, Recife Pernambuco, Brazil.,Programa Integrado de Doença de Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sílvia Martins Marinho
- Pronto-Socorro Cardiológico de Pernambuco (PROCAPE) - Universidade de Pernambuco, Recife Pernambuco, Brazil.,Programa Integrado de Doença de Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wilson de Oliveira
- Pronto-Socorro Cardiológico de Pernambuco (PROCAPE) - Universidade de Pernambuco, Recife Pernambuco, Brazil.,Programa Integrado de Doença de Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Joelma Rodrigues de Souza
- Departamento de Fisiologia e Patologia, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil
| | - Virginia Maria Barros de Lorena
- Centro de Pesquisas Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Pernambuco, Brazil.,Programa Integrado de Doença de Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Yara de Miranda Gomes
- Centro de Pesquisas Aggeu Magalhães, Fundação Oswaldo Cruz, Recife, Pernambuco, Brazil.,Programa Integrado de Doença de Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
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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: 63] [Impact Index Per Article: 7.9] [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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5
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Santos FLN, Celedon PAF, Zanchin NIT, Brasil TDAC, Foti L, de Souza WV, Silva ED, Gomes YDM, Krieger MA. Performance Assessment of Four Chimeric Trypanosoma cruzi Antigens Based on Antigen-Antibody Detection for Diagnosis of Chronic Chagas Disease. PLoS One 2016; 11:e0161100. [PMID: 27517281 PMCID: PMC4982698 DOI: 10.1371/journal.pone.0161100] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/31/2016] [Indexed: 11/18/2022] Open
Abstract
The performance of serologic tests in chronic Chagas disease diagnosis largely depends on the type and quality of the antigen preparations that are used for detection of anti-Trypanosoma cruzi antibodies. Whole-cell T. cruzi extracts or recombinant proteins have shown variation in the performance and cross-reactivity. Synthetic chimeric proteins comprising fragments of repetitive amino acids of several different proteins have been shown to improve assay performances to detect Chagasic infections. Here, we describe the production of four chimeric T. cruzi proteins and the assessment of their performance for diagnostic purposes. Circular Dichroism spectra indicated the absence of well-defined secondary structures, while polydispersity evaluated by Dynamic Light Scattering revealed only minor aggregates in 50 mM carbonate-bicarbonate (pH 9.6), demonstrating that it is an appropriate buffering system for sensitizing microplates. Serum samples from T. cruzi-infected and non-infected individuals were used to assess the performance of these antigens for detecting antibodies against T. cruzi, using both enzyme-linked immunosorbent assay and a liquid bead array platform. Performance parameters (AUC, sensitivity, specificity, accuracy and J index) showed high diagnostic accuracy for all chimeric proteins for detection of specific anti-T. cruzi antibodies and differentiated seropositive individuals from those who were seronegative. Our data suggest that these four chimeric proteins are eligible for phase II studies.
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Affiliation(s)
| | | | - Nilson Ivo Tonin Zanchin
- Molecular Biology Institute of Paraná, Curitiba, PR, Brazil
- Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil
| | | | - Leonardo Foti
- Molecular Biology Institute of Paraná, Curitiba, PR, Brazil
- Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil
| | | | | | | | - Marco Aurélio Krieger
- Molecular Biology Institute of Paraná, Curitiba, PR, Brazil
- Carlos Chagas Institute, FIOCRUZ-PR, Curitiba, PR, Brazil
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6
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Albareda MC, Laucella SA. Modulation of Trypanosoma cruzi-specific T-cell responses after chemotherapy for chronic Chagas disease. Mem Inst Oswaldo Cruz 2015; 110:414-21. [PMID: 25993507 PMCID: PMC4489479 DOI: 10.1590/0074-02760140386] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 03/20/2015] [Indexed: 01/07/2023] Open
Abstract
The aim of this review is to describe the contributions of the knowledge of T-cell responses to the understanding of the physiopathology and the responsiveness to etiological treatment during the chronic phase of Chagas disease. T-helper (Th)1 and interleukin (IL)-10 Trypanosoma cruzi-specific T-cells have been linked to the asymptomatic phase or to severe clinical forms of the disease, respectively or vice versa, depending on the T. cruzi antigen source, the patient's location and the performed immunological assays. Parasite-specific T-cell responses are modulated after benznidazole (BZ) treatment in chronically T. cruzi-infected subjects in association with a significant decrease in T. cruzi-specific antibodies. Accumulating evidence has indicated that treatment efficacy during experimental infection with T. cruzi results from the combined action of BZ and the activation of appropriate immune responses in the host. However, strong support of this interaction in T. cruzi-infected humans remains lacking. Overall, the quality of T-cell responses might be a key factor in not only disease evolution, but also chemotherapy responsiveness. Immunological parameters are potential indicators of treatment response regardless of achievement of cure. Providing tools to monitor and provide early predictions of treatment success will allow the development of new therapeutic options.
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7
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Floridia-Yapur N, Vega-Benedetti AF, Rumi MM, Ragone P, Lauthier JJ, Tomasini N, d'Amato AMA, Lopez-Quiroga I, Diosque P, Marcipar I, Nasser JR, Cimino RO. Evaluation of recombinant antigens of Trypanosoma cruzi to diagnose infection in naturally infected dogs from Chaco region, Argentina. Parasite Immunol 2015; 36:694-9. [PMID: 25201522 DOI: 10.1111/pim.12144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 09/03/2014] [Indexed: 11/28/2022]
Abstract
Dogs are considered the main mammal reservoir of Trypanosoma cruzi in domiciliary environments. Consequently, accurate detection of T. cruzi infection in canine populations is epidemiologically relevant. Here, we analysed the utility of the T. cruzi recombinant antigens FRA, SAPA, CP1, Ag1 and a SAPA/TSSA VI mixture, in an ELISA format. We used a positive control group of sera obtained from 38 dogs from the Chaco region in Argentina with positive homogenate-ELISA reaction, all of them also positive by xenodiagnosis and/or PCR. The negative group included 19 dogs from a nonendemic area. Sensitivity, specificity, area under the curve (AUC) of the receiver operating charactheristic (ROC) curve and Kappa index were obtained to compare the diagnostic efficiency of the tests. The SAPA/TSSA VI had the highest performance, with a sensitivity of 94.7% and an AUC ROC of 0.99 that indicates high accuracy. Among individual antigens, SAPA-ELISA yielded the highest sensitivity (86.8%) and AUC ROC (0.96), whereas FRA-ELISA was the least efficient test (sensitivity = 36.8%; AUC ROC = 0.53). Our results showed that the use of SAPA/TSSA VI in ELISAs could be a useful tool to study dogs naturally infected with T. cruzi in endemic areas.
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Affiliation(s)
- N Floridia-Yapur
- Cátedra de Química Biológica, Facultad de Ciencias Naturales, Universidad Nacional de Salta, Salta, Argentina; Instituto de Investigaciones de Enfermedades Tropicales, Sede Regional Orán, Universidad Nacional de Salta (IIET), Salta, Argentina
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de Moura Braz SC, de Melo AS, da Glória Aureliano de Melo Cavalca M, Martins SM, de Oliveira W, da Silva ED, Ferreira AGP, de Lorena VMB, de Miranda Gomes Y. Increase in the Expression of CD4 + CD25+ Lymphocytic T Cells in the Indeterminate Clinical Form of Human Chagas Disease After Stimulation With Recombinant Antigens of Trypanosoma cruzi. J Clin Immunol 2014; 34:991-8. [DOI: 10.1007/s10875-014-0092-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 08/26/2014] [Indexed: 12/22/2022]
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de Melo AS, de Lorena VMB, de Moura Braz SC, Docena C, de Miranda Gomes Y. IL-10 and IFN-γ gene expression in chronic Chagas disease patients after in vitro stimulation with recombinant antigens of Trypanosoma cruzi. Cytokine 2012; 58:207-12. [PMID: 22325340 DOI: 10.1016/j.cyto.2012.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 12/07/2011] [Accepted: 01/15/2012] [Indexed: 02/07/2023]
Abstract
Along with several other aspects of Chagas disease, the mechanisms responsible for the different clinical outcomes observed in chronic infected individuals have not yet been clarified. It is believed that the host immune response to the parasite plays an important role in the development of the pathology. Therefore, the aim of this study was to evaluate the relationship between IL-10 and IFN-γ gene expression profile, after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with Trypanosoma cruzi recombinant antigens CRA (cytoplasmatic repetitive antigen) and FRA (flagellar repetitive antigen), and the clinical forms of chronic Chagas disease. Twenty patients with the cardiac form of the disease (CARD), of whom 10 had the mild cardiac form (CARD 1) and 10 the severe cardiac form (CARD 2), and 20 patients with the indeterminate form (IND), were selected at the Chagas Disease Unit of the Oswaldo Cruz University Hospital, University of Pernambuco, Recife, Pernambuco, Brazil. The PBMCs of these individuals were cultured in the presence of CRA or FRA for 3 days and IL-10 and IFN-γ gene expression was evaluated by detection of its messenger RNA using Real Time Quantitative PCR. Although no significant difference was observed between the groups of individuals studied, we found that most patients with IND displayed high levels of IFN-γ gene expression, while the majority of patients with CARD 1 presented high levels of IL-10. The results of this study thus highlight the important role that inflammatory cytokines play in patients with the IND group controlling for parasite replication, and that anti-inflammatory cytokines play in determining susceptibility to progression to symptomatic clinical forms of the disease.
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Affiliation(s)
- Adriene Siqueira de Melo
- Laboratório de Imunoparasitologia, Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães/CPqAM, Fundação Oswaldo Cruz/Fiocruz, Recife, PE, Brazil
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10
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Galetović A, Souza RT, Santos MRM, Cordero EM, Bastos IMD, Santana JM, Ruiz JC, Lima FM, Marini MM, Mortara RA, da Silveira JF. The repetitive cytoskeletal protein H49 of Trypanosoma cruzi is a calpain-like protein located at the flagellum attachment zone. PLoS One 2011; 6:e27634. [PMID: 22096606 PMCID: PMC3214072 DOI: 10.1371/journal.pone.0027634] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 10/20/2011] [Indexed: 12/27/2022] Open
Abstract
Background Trypanosoma cruzi has a single flagellum attached to the cell body by a network of specialized cytoskeletal and membranous connections called the flagellum attachment zone. Previously, we isolated a DNA fragment (clone H49) which encodes tandemly arranged repeats of 68 amino acids associated with a high molecular weight cytoskeletal protein. In the current study, the genomic complexity of H49 and its relationships to the T. cruzi calpain-like cysteine peptidase family, comprising active calpains and calpain-like proteins, is addressed. Immunofluorescence analysis and biochemical fractionation were used to demonstrate the cellular location of H49 proteins. Methods and Findings All of H49 repeats are associated with calpain-like sequences. Sequence analysis demonstrated that this protein, now termed H49/calpain, consists of an amino-terminal catalytic cysteine protease domain II, followed by a large region of 68-amino acid repeats tandemly arranged and a carboxy-terminal segment carrying the protease domains II and III. The H49/calpains can be classified as calpain-like proteins as the cysteine protease catalytic triad has been partially conserved in these proteins. The H49/calpains repeats share less than 60% identity with other calpain-like proteins in Leishmania and T. brucei, and there is no immunological cross reaction among them. It is suggested that the expansion of H49/calpain repeats only occurred in T. cruzi after separation of a T. cruzi ancestor from other trypanosomatid lineages. Immunofluorescence and immunoblotting experiments demonstrated that H49/calpain is located along the flagellum attachment zone adjacent to the cell body. Conclusions H49/calpain contains large central region composed of 68-amino acid repeats tandemly arranged. They can be classified as calpain-like proteins as the cysteine protease catalytic triad is partially conserved in these proteins. H49/calpains could have a structural role, namely that of ensuring that the cell body remains attached to the flagellum by connecting the subpellicular microtubule array to it.
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Affiliation(s)
- Alexandra Galetović
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
- Laboratorio de Bioquímica, Departamento Biomédico, Universidad de Antofagasta, Antofagasta, Chile
| | - Renata T. Souza
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | | | - Esteban M. Cordero
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Izabela M. D. Bastos
- Departamento de Biologia Celular, Instituto de Biologia, Universidade de Brasilia, Brasilia, Brasil
| | - Jaime M. Santana
- Departamento de Biologia Celular, Instituto de Biologia, Universidade de Brasilia, Brasilia, Brasil
| | - Jeronimo C. Ruiz
- Centro de Pesquisa René Rachou (CPqRR), FIOCRUZ, Belo Horizonte, Minas Gerais, Brasil
| | - Fabio M. Lima
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Marjorie M. Marini
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Renato A. Mortara
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - José Franco da Silveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
- * E-mail:
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Vasconcelos RH, Azevedo EA, Cavalcanti MG, Silva ED, Ferreira AG, Morais CN, Gomes YM. Immunoglobulin M antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi in chronic chagasic patients. Hum Immunol 2011; 72:402-5. [DOI: 10.1016/j.humimm.2011.02.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 02/03/2011] [Accepted: 02/22/2011] [Indexed: 11/29/2022]
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12
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Lorena VMB, Lorena IMB, Braz SCM, Melo AS, Melo MFAD, Melo MGAC, Silva ED, Ferreira AGP, Morais CNL, Costa VMA, Correa-Oliveira R, Gomes YM. Cytokine Levels in Serious Cardiopathy of Chagas Disease After In Vitro Stimulation with Recombinant Antigens from Trypanosoma cruzi. Scand J Immunol 2010; 72:529-39. [DOI: 10.1111/j.1365-3083.2010.02462.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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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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Vasconcelos RH, Amaral FN, Cavalcanti MG, Silva ED, Ferreira AG, Morais CN, Gomes YM. Increased levels of IgA antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi differentiate digestive forms of Chagas disease. Hum Immunol 2010; 71:964-7. [DOI: 10.1016/j.humimm.2010.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2010] [Revised: 07/05/2010] [Accepted: 07/12/2010] [Indexed: 11/30/2022]
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15
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Gomes YM, Lorena VMB, Luquetti AO. Diagnosis of Chagas disease: what has been achieved? What remains to be done with regard to diagnosis and follow up studies? Mem Inst Oswaldo Cruz 2010; 104 Suppl 1:115-21. [PMID: 19753466 DOI: 10.1590/s0074-02762009000900017] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 06/03/2009] [Indexed: 11/22/2022] Open
Abstract
In the acute phase and in the chronic forms of Chagas disease, the etiological diagnosis may be performed by detection of the parasite using direct or indirect parasitological methods and by the presence of antibodies in the serum by way of serological tests. Several techniques are easily available, ranging from the simplest wet smear preparation to immuno-enzymatic assays with recombinant antigens that will meet most diagnostic needs. Other tests under evaluation include a molecular test using polymerase chain reaction, which has shown promising results and may be used as a confirmatory test both in the acute and chronic phases of the disease. Better rapid tests are needed for diagnosis, some of which are already under evaluation. Additionally, there is a need for tools that can identify patients cured shortly after specific treatment. Other needs include a marker for prognosis and early diagnosis of congenital transmission.
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Affiliation(s)
- Yara M Gomes
- Laboratório de Imunoparasitologia, Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães-Fiocruz, Recife, PE, Brasil.
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16
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Comparison of recombinant Trypanosoma cruzi peptide mixtures versus multiepitope chimeric proteins as sensitizing antigens for immunodiagnosis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:899-905. [PMID: 19339486 DOI: 10.1128/cvi.00005-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The aim of this work was to determine the best strategy to display antigens (Ags) on immunochemical devices to improve test selectivity and sensitivity. We comparatively evaluated five Trypanosoma cruzi antigenic recombinant peptides, chose the three more sensitive ones, built up chimeras bearing these selected Ags, and systematically compared by enzyme-linked immunosorbent assay the performance of the assortments of those peptides with that of the multiepitope constructions bearing all those peptides lineally fused. The better-performing Ags that were compared included peptides homologous to the previously described T. cruzi flagellar repetitive Ag (here named RP1), shed acute-phase Ag (RP2), B13 (RP5), and the chimeric recombinant proteins CP1 and CP2, bearing repetitions of RP1-RP2 and RP1-RP2-RP5, respectively. The diagnostic performances of these Ags were assessed for discrimination efficiency by the formula +OD/cutoff value (where +OD is the mean optical density value of the positive serum samples tested), in comparison with each other either alone, in mixtures, or as peptide-fused chimeras and with total parasite homogenate (TPH). The discrimination efficiency values obtained for CP1 and CP2 were 25% and 52% higher, respectively, than those of their individual-Ag mixtures. CP2 was the only Ag that showed enhanced discrimination efficiency between Chagas' disease-positive and -negative samples, compared with TPH. This study highlights the convenience of performing immunochemical assays using hybrid, single-molecule, chimeric Ags instead of peptide mixtures. CP2 preliminary tests rendered 98.6% sensitivity when evaluated with a 141-Chagas' disease-positive serum sample panel and 99.4% specificity when assessed with a 164-Chagas' disease-negative serum sample panel containing 15 samples from individuals infected with Leishmania spp.
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17
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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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18
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Rocha GM, Miranda K, Weissmüller G, Bisch PM, de Souza W. Ultrastructure of Trypanosoma cruzi revisited by atomic force microscopy. Microsc Res Tech 2008; 71:133-9. [PMID: 17992694 DOI: 10.1002/jemt.20535] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Most advances in atomic force microscopy (AFM) have been accomplished in recent years. Previous attempts to use AFM to analyze the organization of pathogenic protozoa did not significantly contribute with new structural information. In this work, we introduce a new perspective to the study of the ultrastructure of the epimastigote form of Trypanosoma cruzi by AFM. Images were compared with those obtained using field emission scanning electron microscopy of critical point dried cells and transmission electron microscopy of negative stained detergent-extracted and air-dried cells. AFM images of epimastigote forms showed a flagellum furrow separating the axoneme from the paraflagellar rod (PFR) present from the emergence of the flagellar pocket to the tip of the flagellum. At high magnification, a row of periodically organized structures, which probably correspond to the link between the axoneme, the PFR and the flagellar membrane were seen along the furrow. In the origin of the flagellum, two basal bodies were identified. Beyond the basal bodies, small periodically arranged protrusions, positioned at 400 nm from the flagellar basis were seen. This structure was formed by nine substructures distributed around the flagellar circumference and may correspond to the flagellar necklace. Altogether, our results demonstrate the importance of the application of AFM in the structural characterization of the surface components and cytoskeleton on protozoan parasites.
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Affiliation(s)
- Gustavo Miranda Rocha
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho s/n, 21941-902, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
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19
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Verçosa A, Lorena V, Carvalho C, Melo M, Cavalcanti M, Silva E, Ferreira A, Pereira V, Souza W, Gomes Y. Chagas' disease: IgG isotypes against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens of Trypanosoma cruzi in chronic Chagasic patients. J Clin Lab Anal 2007; 21:271-6. [PMID: 17847109 PMCID: PMC6649189 DOI: 10.1002/jcla.20186] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The wide range of clinical Chagas' disease manifestations, of which heart involvement is the most significant, because of its characteristics, frequency and consequences, and lack of treatment and cure, justify research in this area. Specific immunoglobulin G (IgG) antibody subclasses have been associated with human Chagas' disease. Thus, in this study, the profile of IgG subclasses against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive T. cruzi-specific antigens was correlated with cardiac (CARD, n=33), cardiodigestive (CD, n=7), and indeterminate (IND, n=20) forms of Chagas' disease by indirect enzyme-linked immunosorbent assay (ELISA). IgG subclasses were detected in almost all Chagas patients studied. Nevertheless, only specific IgG2 isotype FRA was found with a significant statistical difference in CARD patients when compared to IND patients. This result suggests the potential use of this isotype for prognostic purposes, for monitoring the progression of chronic Chagas' disease, and for predicting the risk of CARD damage. This is important information, as it could help physicians to evaluate and manage the treatment of their patients. However, a follow-up study is necessary to confirm our result.
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Affiliation(s)
- A.F.A. Verçosa
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
| | - V.M.B. Lorena
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
| | - C.L. Carvalho
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
| | - M.F.A.D. Melo
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
| | - M.G.A. Cavalcanti
- Hospital Oswaldo Cruz (HUOC)/Universidade de Pernambuco (UPE), Recife‐PE, Brazil
| | - E.D. Silva
- Bio‐Manguinhos/Fiocruz, Rio de Janeiro‐RJ, Brazil
| | | | - V.R.A. Pereira
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
| | - W.V. Souza
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
| | - Y.M. Gomes
- Centro de Pesquisas Aggeu Magalhães (CPqAM)/Fiocruz, Recife‐PE, Brazil
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20
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Casais R, Prieto M, Balseiro A, Solano P, Parra F, Martín Alonso JM. Identification and heterologous expression of a Sarcoptes scabiei cDNA encoding a structural antigen with immunodiagnostic potential. Vet Res 2007; 38:435-50. [PMID: 17506973 DOI: 10.1051/vetres:2007007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Accepted: 12/20/2006] [Indexed: 11/14/2022] Open
Abstract
The mite Sarcoptes scabiei causes sarcoptic mange (or scabies), a disease of considerable human and veterinary significance. An S. scabiei cDNA clone of about 2 kb was isolated from a S. scabiei var. hominis expression library by immunological screening using blood serum from a naturally infected chamois (Rupicapra rupicapra). The nucleotide sequence of the identified cDNA contains an open reading frame of 1930 bp that encodes a 642 amino acid polypeptide. This polypeptide shows tandem repeats of a glycine-serine rich 20 residue sequence followed by a unique C-terminal glutamate rich 54 residue sequence. The cDNA or the deduced polypeptide did not show significant similarities to any of the sequences in the databases. A carboxyl-terminal fragment of this polypeptide (residues 380 to 642) was efficiently expressed in Escherichia coli as a fusion with Glutathione S-transferase and then was used to produce a specific antiserum. The antigen encoded by the cDNA was located at the integument of the mite's epidermis and the cavities surrounding its vital organs. Western blot analysis of mite extracts using the specific antiserum against the recombinant protein identified antigens larger that 60 kDa indicating that the isolated cDNA did not contain the full ORF. Moreover, we designed a diagnostic assay based on the carboxyl-terminal fragment of the antigen for the identification of infected animals.
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Affiliation(s)
- Rosa Casais
- Servicio Regional de Investigación y Desarrollo Agroalimentario, Laboratorio de Sanidad Animal, Jove, Gijón, Asturias, Spain
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21
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de Souza W. Macro, micro and nano domains in the membrane of parasitic protozoa. Parasitol Int 2007; 56:161-70. [PMID: 17347028 DOI: 10.1016/j.parint.2007.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 01/30/2007] [Accepted: 02/01/2007] [Indexed: 11/20/2022]
Abstract
The structural organization of the plasma membrane of eukaryotic cells is briefly revised taking into consideration the organization of proteins and lipids and the concept of microdomains, lipid rafts and detergent resistant membranes. The biochemical data available concerning the presence of microdomains in parasitic protozoa is reviewed and emphasis is given on the identification of special domains recognized by morphological approaches, especially with the use of the freeze-fracture technique.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-900, Rio de Janeiro, RJ, Brazil.
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22
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Borges JD, Assis GFMD, Gomes LV, Dias JCP, Pinto IDM, Martins-Filho OA, Torres RM, Viñas PA, Bahia MT, Machado-Coelho GLL, Lana MD. Seroprevalence of Chagas disease in schoolchildren from two municipalities of Jequitinhonha Valley, Minas Gerais, Brazil; six years following the onset of epidemiological surveillance. Rev Inst Med Trop Sao Paulo 2006; 48:81-6. [PMID: 16699629 DOI: 10.1590/s0036-46652006000200005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Six years after the beginning of the epidemiological surveillance of Chagas disease in Berilo and José Gonçalves de Minas, Jequitinhonha Valley, MG, Brazil, a serological inquiry was performed to observe whether the transmission of this endemy was occurring in this area. A randomized sample of 1,412 children seven to 14 years old, was screened. Six asymptomatic children were found to be positive, leading to 0.4% of prevalence. Hemoculture confirmed infection in five out of the six positive cases. Additional epidemiological investigation revealed important antecedents, such as disease reports in relatives and predisposing ecological and housing conditions. Our results demonstrated similar seroprevalence (0.4%) in schoolchildren, ranging from seven to 14 years old, and that were observed six years ago (0.2%) for children 0-9 year-old. Thus, considering the constant presence of Panstrogylus megistus in the peridomicile these findings emphasize the need of continuous improved epidemiological surveillance of Chagas disease in this region.
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Affiliation(s)
- Jaila Dias Borges
- Instituto de Ciências Exatas e Biológicas, UFOP, Ouro Preto, MG, Brazil
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23
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Bisaggio DFR, Campanati L, Pinto RCV, Souto-Padrón T. Effect of suramin on trypomastigote forms of Trypanosoma cruzi: changes on cell motility and on the ultrastructure of the flagellum-cell body attachment region. Acta Trop 2006; 98:162-75. [PMID: 16716244 DOI: 10.1016/j.actatropica.2006.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2005] [Revised: 03/24/2006] [Accepted: 04/12/2006] [Indexed: 10/24/2022]
Abstract
Suramin has been previously reported to inhibit distinct cell enzymes and to affect the synthesis and distribution of cytoskeleton proteins. Our study indicates that prolonged incubation of Trypanosoma cruzi infected-LLC-MK2 cells in the presence of 500 microM suramin during the intracellular development of the parasite caused morphological changes on trypomastigote forms characterized by a partial or complete detachment of the flagellum from the cell body, besides an accentuated decrease on parasite motility. Immunofluorescence analysis of the region of adhesion between the cell body and the flagellum on trypomastigotes obtained from suramin-treated host cells after the completion of cell cycle did not show any difference in the localization of FAZ antigens recognized by 4D9 and L3B2 monoclonal antibodies despite the presence of a detached flagellum. On the other hand, suramin caused a significant increase on the phenotypic expression of FRA antigen, which was observed throughout the surface of trypomastigotes. Cytochemical localization of cationized ferritin in trypomastigotes obtained from suramin-treated host cells showed that anionic particles gained access to the space between the cell and flagellar membranes, as well as to the flagellar pocket, indicating an alteration on extracellular components of the region of adhesion between the cell body and the flagellum.
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Affiliation(s)
- Danielle F R Bisaggio
- Instituto de Microbiologia Professor Paulo de Góes, CCS, Bloco I, Universidade Federal do Rio de Janeiro, Ilha do Fundão, CEP 21941-590, Rio de Janeiro, RJ, Brazil
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24
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Rocha GM, Brandão BA, Mortara RA, Attias M, de Souza W, Carvalho TMU. The flagellar attachment zone of Trypanosoma cruzi epimastigote forms. J Struct Biol 2006; 154:89-99. [PMID: 16414276 DOI: 10.1016/j.jsb.2005.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Revised: 11/16/2005] [Accepted: 11/22/2005] [Indexed: 10/25/2022]
Abstract
The flagellar attachment zone (FAZ) is an adhesion region of Trypanosoma cruzi epimastigote forms where the flagellum emerges from the flagellar pocket and remains attached to the cell body. This region shows a junctional complex which is formed by a linear series of apposed macular structures that are separated by amorphous material and clusters of intramembranous particles. Two protein groups appear to be important in the FAZ region: a membrane glycoprotein of 72kDa and several high molecular weight proteins. To gain a better understanding of the FAZ region, we compared wild-type Y strain T. cruzi epimastigotes with a mutant cell in which the 72-kDa surface glycoprotein (Gp72), involved in cell body-flagellum adhesion, had been deleted by target gene replacement. Using immunofluorescence confocal microscopy and electron microscopy techniques to analyze the FAZ region the results suggest that, in the absence of Gp72, other proteins involved in the formation of FAZ remain concentrated in the flagellar pocket region. The analysis of a 3-D reconstruction model of wild-type epimastigotes showed that the endoplasmic reticulum and mitochondrion are in intimate association with FAZ, in contrast to the null mutant cells where the endoplasmic reticulum was not visualized.
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Affiliation(s)
- Gustavo Miranda Rocha
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, Bloco G, llha do Fundão, Rio de Janeiro, RJ 21949-900, Brazil
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25
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Ersfeld K, Barraclough H, Gull K. Evolutionary Relationships and Protein Domain Architecture in an Expanded Calpain Superfamily in Kinetoplastid Parasites. J Mol Evol 2005; 61:742-57. [PMID: 16315106 DOI: 10.1007/s00239-004-0272-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Accepted: 07/08/2005] [Indexed: 11/27/2022]
Abstract
Employing whole-genome analysis we have characterized a large family of genes coding for calpain-related proteins in three kinetoplastid parasites. We have defined a total of 18 calpain-like sequences in Trypanosoma brucei, 27 in Leishmania major, and 24 in Trypanosoma cruzi. Sequence characterization revealed a well-conserved protease domain in most proteins, although residues critical for catalytic activity were frequently altered. Many of the proteins contain a novel N-terminal sequence motif unique to kinetoplastids. Furthermore, 24 of the sequences contain N-terminal fatty acid acylation motifs indicating association of these proteins with intracellular membranes. This extended family of proteins also includes a group of sequences that completely lack a protease domain but is specifically related to other kinetoplastid calpain-related proteins by a highly conserved N-terminal domain and by genomic organization. All sequences lack the C-terminal calmodulin-related calcium-binding domain typical of most mammalian calpains. Our analysis emphasizes the highly modular structure of calpains and calpain-like proteins, suggesting that they are involved in diverse cellular functions. The discovery of this surprisingly large family of calpain-like proteins in lower eukaryotes that combines novel and conserved sequence modules contributes to our understanding of the evolution of this abundant protein family.
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Affiliation(s)
- Klaus Ersfeld
- Department of Biological Sciences, University of Hull, Hull, HU6 7RX, UK.
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26
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Pereira VRA, Lorena VMB, Da Silva APG, Coutinho EM, Silvas ED, Ferreira AGP, Miranda P, Krieger MA, Goldenberg S, Soares MBP, Correa-Oliveira R, Gomes YM. Immunization with cytoplasmic repetitive antigen and flagellar repetitive antigen of Trypanosoma cruzi stimulates a cellular immune response in mice. Parasitology 2005; 129:563-70. [PMID: 15552401 DOI: 10.1017/s0031182004006043] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In previous studies, we demonstrated that CRA and FRA recombinant proteins, used for diagnosis of Chagas' disease, elicited a humoral immune response in susceptible and resistant mice. To understand better the immune response to these proteins, we have evaluated, the cellular immune response in CRA- and in FRA-immunized BALB/c and C57BL/6 mice. A specific cellular lymphoproliferative response was observed in both strains of mice. Spleen cell cultures mainly from CRA-immunized C57BL/6 and FRA-immunized BALB/c mice produced high levels of IFN-y, indicating the induction of a Type 1 immune response. Regarding the T cell subsets, CD4+ T cells were the major source of IFN-y in CRA- and FRA-immunized mice. These results suggest that CRA and FRA are important immunogens in inducing a Type 1 immune response and that they may be considered as potential vaccine antigens.
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Affiliation(s)
- V R A Pereira
- Centro de Pesquisas Aggeu Magalhães/FIOCRUZ, Recife, PE, Brazil
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27
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Marcipar IS, Olivares ML, Robles L, Dekanty A, Marcipar A, Silber AM. The diagnostic performance of recombinant Trypanosoma cruzi ribosomal P2beta protein is influenced by its expression system. Protein Expr Purif 2004; 34:1-7. [PMID: 14766295 DOI: 10.1016/j.pep.2003.11.022] [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] [Received: 04/23/2003] [Revised: 10/24/2003] [Indexed: 10/26/2022]
Abstract
In the present work, we have determined the effect of expression vectors and their corresponding host bacteria on the antigenic performance of Trypanosoma cruzi P2beta (TcP2beta) full-length recombinant protein. The gene encoding the TcP2beta ribosomal protein was cloned in pMAL-c2 and pET-32a vectors that allow the expression of high levels of soluble fusion proteins. A panel of 32 positive and 32 negative sera was assayed with the purified proteins expressed using pMal-c2 (TcP2beta-MBP) and pET-32a (TcP2beta-TRX) vectors and with MBP and TRX purified from pMAL-c2 and pET-32a vectors, respectively. The antigenic behavior of each TcP2beta recombinant protein differed in the diagnostic performance in terms of DI(+) (93.7 for TcP2beta-MBP vs 100% for TcP2beta-TRX), in DI(-) (90.5 for TcP2beta-MBP vs 100% for TcP2beta-TRX) and in cross-reaction with negative sera. To determine if the higher reactivity of expressed pMAL-c2 protein was due to folding during protein expression or to a steric effect related to the protein adsorption at the titration plate, the reactivity of sera against soluble proteins was assessed by ELISA inhibition assays. As each soluble protein preserved its level of reactivity, we concluded that differences in reactivity were due to intrinsic characteristics of the proteins and not to differences in patterns of adsorption to the plates.
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Affiliation(s)
- Iván S Marcipar
- Instituto de Tecnología Biológica (INTEBIO), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina.
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28
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Diniz FB, Ueta RR, Pedrosa AMDC, Areias MDC, Pereira VRA, Silva ED, da Silva JG, Ferreira AGP, Gomes YM. Impedimetric evaluation for diagnosis of Chagas’ disease: antigen–antibody interactions on metallic eletrodes. Biosens Bioelectron 2003; 19:79-84. [PMID: 14568706 DOI: 10.1016/s0956-5663(03)00213-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A polypeptide chain formed by recombinant antigens, cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) (CF-Chimera) of Trypanosoma cruzi, was adsorbed on gold and platinum electrodes and investigated by electrochemical impedance spectroscopy on phosphate buffer saline solutions (PBS) containing a redox couple. It was found that the adsorption is strongly sensitive to the oxide layer on the electrode surface. In the majority of the experiments the antigens retained their activity as observed through their interaction with sera from chronic chagasic patients. The results expressed in terms of the charge transfer resistance across the interface, indicate the viability of using the impedance methodology for the development of a biosensor for serological diagnosis of Chagas' disease.
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Affiliation(s)
- Flamarion B Diniz
- Laboratório de Eletroquímica, Departamento de Química Fundamental, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE, Brazil.
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29
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Pereira VRA, Lorena VMB, Verçosa AFA, Silva ED, Ferreira AGP, Montarroyos UR, Silva APG, Gomes YM. Antibody isotype responses in Balb/c mice immunized with the cytoplasmic repetitive antigen and flagellar repetitive antigen of Trypanosoma cruzi. Mem Inst Oswaldo Cruz 2003; 98:823-5. [PMID: 14595462 DOI: 10.1590/s0074-02762003000600019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the present report we analyzed the levels of IgG1, IgG2a, IgG2b and IgG3 isotypes from Balb/c mice immunized with cytoplasmic repetitive antigen (CRA), and flagellar repetitive antigen (FRA) of Trypanosoma cruzi. The immunization was done by subcutaneous route three times (20 days apart) and the analysis was performed 14 days after each treatment. CRA-immunized mice produced high levels of all IgG isotypes, mainly IgG3 and IgG1. FRA-immunization elicited only high levels of IgG1.
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Affiliation(s)
- Valéria R A Pereira
- Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães-Fiocruz, 50670-420 Recife, PE, Brasil
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30
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Gadelha AAM, Verçosa AFA, Lorena VMB, Nakazawa M, Carvalho AB, Souza WV, Ferreira AGP, Silva ED, Krieger MA, Goldenberg S, Gomes YM. Chagas' disease diagnosis: comparative analysis of recombinant ELISA with conventional ELISA and the haemagglutination test. Vox Sang 2003; 85:165-70. [PMID: 14516446 DOI: 10.1046/j.1423-0410.2003.00340.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVES Serological screening for Chagas' disease in the blood banks of South America is carried out by using two different assays that generally show a high number of inconclusive results. To establish a combination of two tests that can minimize the number of inconclusive results, we compared a recombinant enzyme-linked immunosorbent assay (ELISA) with two conventional tests. MATERIALS AND METHODS Serum samples from chagasic patients (n = 112), from non-chagasic individuals (n = 143) and from patients with other diseases (n = 32) were tested using three assays: recombinant ELISA (Rec-ELISA); conventional ELISA (Con-ELISA); and the indirect haemagglutination (IHA) test. RESULTS When we evaluated the data by matching the Rec-ELISA and the IHA test, 52 inconclusive results were obtained. When Rec-ELISA and Con-ELISA were matched, only four inconclusive results were observed. CONCLUSIONS Our investigation indicates that the use of two ELISAs with different antigen preparations provides an effective test combination for blood bank screening of Chagas' disease.
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Affiliation(s)
- A A M Gadelha
- Centro de Pesquisas Aggeu Magalhães/FIOCRUZ, Recife, PE, Brazil
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31
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Pereira VRA, de Lorena VMB, Nakazawa M, da Silva APG, Montarroyos U, Correa-Oliveira R, Gomes YDM. Evaluation of the immune response to CRA and FRA recombinant antigens of Trypanosoma cruzi in C57BL/6 mice. Rev Soc Bras Med Trop 2003; 36:435-40. [PMID: 12937718 DOI: 10.1590/s0037-86822003000400001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Humoral and cellular immune responses were evaluated in 44 C57BL/6 mice immunized with the Trypanosoma cruzi recombinant antigens CRA and FRA. Both antigens induced cutaneous immediate-type hypersensitivity response. The levels of IgG1, IgG2a, IgG2b and IgG3 were high in CRA immunized mice. IgG3 was the predominant isotype. Although no difference in antibody levels was observed in FRA-immunized mice when compared to control mice, both antigens were able to induce lymphoproliferation in immunized mice. Significant differences were observed between incorporation of [ H]- thymidine by spleen cell stimulated in vitro with CRA or FRA and the control group. These results suggest that CRA and FRA could be involved in mechanisms of resistance to Trypanosoma cruzi infection.
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32
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Silva ED, Pereira VR, Gomes JA, Lorena VMB, Cançado JR, Ferreira AG, Krieger MA, Goldenberg S, Correa‐Oliveira R, Gomes YM. Use of the EIE-recombinant-Chagas-biomanguinhos kit to monitor cure of human Chagas' disease. J Clin Lab Anal 2002; 16:132-6. [PMID: 11968049 PMCID: PMC6807848 DOI: 10.1002/jcla.10028] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We used the EIE-Recombinant-Chagas-Biomanguinhos kit (EIE-Rec kit) developed by the Oswaldo Cruz Foundation, Brazil, to monitor cure of chagasic patients who were treated during the acute phase of T. cruzi infection. Treated patients were previously studied by parasitological and serological tests and classified as cured patients (CP) (n = 10), dissociated patients (DP) (n = 6), and noncured patients (NCP) (n = 6). When sera of these patients were assayed by EIE-Rec kit all sera from NCP and all sera from CP showed positive and negative reactions, respectively. These results were in full agreement with those obtained previously by the classical tests. Two DP showed a positive reaction; the remaining four displayed a negative reaction, similar to that observed in sera from nonchagasic (NCh) individuals, and could therefore be considered CP. Our results suggest that the EIE-Rec kit could be used to monitor the efficacy of Chagas' disease treatment.
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Affiliation(s)
| | | | | | | | - Joaquim R. Cançado
- Faculdade de Medicina, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Marco Aurélio Krieger
- Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, RJ, Brazil
- Instituto de Biologia Molecular do Paraná, Curitiba, PR, Brazil
| | - Samuel Goldenberg
- Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, RJ, Brazil
- Instituto de Biologia Molecular do Paraná, Curitiba, PR, Brazil
| | | | - Yara M. Gomes
- Centro de Pesquisas Aggeu Magalhães/Fiocruz, Recife, PE, Brazil
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33
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Nakazawa M, Rosa DS, Pereira VR, Moura MO, Furtado VC, Souza WV, Barros MN, Abath FG, Gomes YM. Excretory-secretory antigens of Trypanosoma cruzi are potentially useful for serodiagnosis of chronic Chagas' disease. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2001; 8:1024-7. [PMID: 11527823 PMCID: PMC96191 DOI: 10.1128/cdli.8.5.1024-1027.2001] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The reactivities of sera from chronic chagasic patients against the trypomastigote excreted-secreted antigens (TESA) of Trypanosoma cruzi strains with different biodemes were analyzed by TESA-blot and TESA-enzyme-linked immunosorbent assay (ELISA). Although both tests presented high sensitivity and specificity, TESA-ELISA is more appropriate for screening a larger number of samples.
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Affiliation(s)
- M Nakazawa
- Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães/FIOCRUZ, Hospital Universitário Oswaldo Cruz/UPE, CEP 50670-420 Recife-PE, Brazil
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34
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Gomes YM, Pereira VR, Nakazawa M, Rosa DS, Barros MD, Ferreira AG, Silva ED, Ogatta SF, Krieger MA, Goldenberg S. Serodiagnosis of chronic Chagas infection by using EIE-Recombinant-Chagas-Biomanguinhos kit. Mem Inst Oswaldo Cruz 2001; 96:497-501. [PMID: 11391421 DOI: 10.1590/s0074-02762001000400009] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A kit based on an enzyme immunoassay, EIE-Recombinant-Chagas-Biomanguinhos, developed by the Oswaldo Cruz Foundation, was evaluated for the serodiagnosis of chronic Chagas disease. Evaluation was performed with 368 serum samples collected from individuals living in an endemic area for Chagas disease: 131 patients in the chronic phase with confirmed clinical, epidemiological, and serological diagnosis (indirect immunofluorescence, indirect hemagglutination or enzyme-linked immunosorbent assay) and 237 nonchagasic seronegative individuals were considered negative control. The EIE-Recombinant-Chagas-Biomanguinhos kit showed high sensitivity, 100% (CI 95%: 96.4-100%) and high specificity, 100% (CI 95%: 98-100%). The data obtained were in full agreement with clinical and conventional serology data. In addition, no cross-reaction was observed with sera from patients with cutaneous (n=14) and visceral (n=3) leishmaniasis. However, when these sera were tested by conventional serological assays for Chagas disease, cross-reactions were detected in 14.3% and 33.3% of the patients with cutaneous and visceral leishmaniasis, respectively. No cross-reactions were observed when sera from nonchagasic seronegative patients bearing other infectious disease (syphilis, n=8; HTLV, n=8; HCV, n=7 and HBV, n=12) were tested. In addition, sera of patients with inconclusive results for Chagas disease by conventional serology showed results in agreement with clinical evaluation, when tested by the kit. These results are relevant and indicate that the referred kit provides a safe immunodiagnosis of Chagas disease and could be used in blood bank screening.
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Affiliation(s)
- Y M Gomes
- Departamento de Imunologia, Centro de Pesquisas Aggeu Magalhães, Fiocruz, Recife, PE, 50670-420, Brasil
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35
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Streit JA, Recker TJ, Donelson JE, Wilson ME. BCG expressing LCR1 of Leishmania chagasi induces protective immunity in susceptible mice. Exp Parasitol 2000; 94:33-41. [PMID: 10631078 DOI: 10.1006/expr.1999.4459] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular immune responses are required for protective immunity against Leishmania chagasi. Immunization strategies using live intracellular bacteria (e.g., bacille-Calmette Guerin strain of Mycobacterium bovis) expressing recombinant antigens can induce cellular immune responses to these antigens. Previous studies demonstrated that the L. chagasi antigen LCR1 stimulates IFN-gamma production from T cells of infected BALB/c mice, and immunization with recombinant LCR1 partially protects against L. chagasi infection. To determine whether live bacteria could enhance the immunization potential of LCR1, we engineered BCG expressing LCR1 (BCG-LCR1). Subcutaneous immunization with BCG-LCR1, but not with BCG containing plasmid only (BCG-pMV261), elicited better protective immunity against L. chagasi infection than LCR1 protein alone. BCG-LCR1 administered intraperitoneally did not protect. Splenocytes from mice immunized s.c. with either BCG-LCR1 or BCG-pMV261 and then infected with L. chagasi promastigotes had increased antigen-induced IFN-gamma and reduced IL-10 production compared to splenocytes of control mice. We propose that BCG-LCR1 promotes a Th1-type protective immune response, and it may be a useful component of a Leishmania vaccine.
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Affiliation(s)
- J A Streit
- Department of Internal Medicine, 300D EMRB, University of Iowa, Iowa City 52242, USA
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36
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Santos MR, Lorenzi H, Porcile P, Carmo MS, Schijman A, Brandão A, Araya JE, Gomes HB, Chiurillo MA, Ramirez JL, Degrave WM, Levin MJ, da Silveira JF. Physical mapping of a 670-kb region of chromosomes XVI and XVII from the human protozoan parasite Trypanosoma cruzi encompassing the genes for two immunodominant antigens. Genome Res 1999; 9:1268-76. [PMID: 10613849 PMCID: PMC311010 DOI: 10.1101/gr.9.12.1268] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
As part of the Trypanosoma cruzi Genome Initiative, we have mapped a large portion of the chromosomal bands XVI (2.3 Mb) and XVII (2.6 Mb) containing the highly repetitive and immunodominant antigenic gene families h49 and jl8. Restriction mapping of the isolated chromosomal bands and hybridization with chromosome specific gene probes showed that genes h49 and jl8 are located in a pair of size-polymorphic homologous chromosomes. To construct the integrated map of the chromosomes harboring the h49 and jl8 loci, we used YAC, cosmid, and lambda phage overlapping clones, and long range restriction analysis using a variety of probes (i.e., known gene sequences, ESTs, polymorphic repetitive sequences, anonymous sequences, STSs generated from the YAC ends). The total length covered by the YAC contig was approximately 670 kb, and its map agreed and was complementary to the one obtained by long-range restriction fragment analysis. Average genetic marker spacing in a 105 kb region around h49 and jl8 genes was estimated to be 6.2 kb/marker. We have detected some polymorphism in the H49/JL8 antigens-encoding chromosomes, affecting also the coding regions. The physical map of this region, together with the isolation of specific chromosome markers, will contribute in the global effort to sequence the nuclear genome of this parasite.
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Affiliation(s)
- M R Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, UNIFESP, Rua Botucatu 862, CEP 04023-062, S. Paulo, Brasil
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37
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Abstract
Species of the trypanosomatid parasite genera Trypanosoma and Leishmania exhibit a particular range of cell shapes that are defined by their internal cytoskeletons. The cytoskeleton is characterized by a subpellicular corset of microtubules that are cross-linked to each other and to the plasma membrane. Trypanosomatid cells possess an extremely precise organization of microtubules and filaments, with some of their organelles, such as the mitochondria, kinetoplasts, basal bodies, and flagella, present as single copies in each cell. The duplication of these structures and changes in their position during life cycle differentiations provide markers and insight into events involved in determining cell form and division. We have a rapidly increasing catalog of these structures, their molecular cytology, and their ontogeny. The current sophistication of available molecular genetic techniques for use in these organisms has allowed a new functional analysis of the cytoskeleton, including functions that are intrinsic to the proliferation and pathogenicity of these parasites.
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Affiliation(s)
- K Gull
- School of Biological Sciences, University of Manchester, United Kingdom.
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38
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Bhatia A, Daifalla NS, Jen S, Badaro R, Reed SG, Skeiky YA. Cloning, characterization and serological evaluation of K9 and K26: two related hydrophilic antigens of Leishmania chagasi. Mol Biochem Parasitol 1999; 102:249-61. [PMID: 10498181 DOI: 10.1016/s0166-6851(99)00098-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We report here the molecular cloning and characterization of two related hydrophilic antigens of Leishmania chagasi. These two antigens have predicted molecular weights of approximately 9 and 26 kDa and detect antibodies in sera of patients with kala-azar (k). Thus, to maintain consistency with nomenclature of the previously described 39 kDa diagnostic antigen of L. chagasi (k39 [1]), these antigens are being referred to as k9 and k26. A significant difference between k9 and k26 is the presence of 11 copies of a 14 amino acid repeat in the open reading frame of k26. The region flanking the repeats of k26 shares a 69% identity with the open reading frame of k9. The recombinant proteins encoded by both antigens are very hydrophilic and show aberrant migration on SDS PAGE. Results of Southern blot analysis reveal that k9 and k26 are conserved to varying degrees among various Leishmania species. Interestingly, the repeat region of k26 is specific to L. chagasi and L. donovani while the flanking region is conserved among several other species. Transcript levels of k26 are significantly upregulated in the amastigote stage of the parasite. Our results show that recombinant K26 is specific in detecting antibodies in infection sera from visceral leishmaniasis (VL) patients. Thus rK26 may complement rK39 in a more accurate diagnosis of VL in the old and the new world.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/metabolism
- Base Sequence
- Blotting, Southern
- Cloning, Molecular
- Gene Expression Regulation, Developmental
- Genes, Protozoan
- Humans
- Leishmania/genetics
- Leishmania/growth & development
- Leishmania/immunology
- Leishmania major/genetics
- Leishmania major/immunology
- Leishmaniasis, Visceral/diagnosis
- Molecular Sequence Data
- Open Reading Frames/genetics
- Rabbits
- Recombinant Proteins/immunology
- Sequence Analysis, DNA
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Affiliation(s)
- A Bhatia
- Corixa Corporation, Seattle, WA 98104, USA
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39
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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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40
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Pinho RT, Pedrosa RC, Costa-Martins P, Castello-Branco LR. Saliva ELISA: a method for the diagnosis of chronic Chagas disease in endemic areas. Acta Trop 1999; 72:31-8. [PMID: 9924959 DOI: 10.1016/s0001-706x(98)00075-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An indirect enzyme linked immunosorbent assay (ELISA) was applied to saliva to detect chronic infection by Trypanosoma cruzi in humans. Saliva samples from 114 Chagas' disease chronically infected individuals, characterized by three serological tests and clinical evaluation and from 100 healthy controls were tested for T. cruzi specific IgG antibodies. At dilution of 1 in 2, specific antibodies were detected in saliva samples from 103 of 114 samples from infected patients and 5 of 100 controls (sensitivity 90.4%, specificity 95%). There was no significant correlation between the antibody titre and cardiac or gastrointestinal tract disease. This assay possesses some advantages over other methods as saliva collection is non-invasive, requires no special equipment and whole saliva gave reproducible results. Although serology remains the gold standard for T. cruzi infection, these results suggest that T. cruzi specific salivary antibody detection may provide a screening diagnostic test and contribute to epidemiological studies of chronic trypanosomiasis infection in endemic areas.
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Affiliation(s)
- R T Pinho
- Departamento de Imunologia, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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41
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Masuda MO, Levin M, De Oliveira SF, Dos Santos Costa PC, Bergami PL, Dos Santos Almeida NA, Pedrosa RC, Ferrari I, Hoebeke J, Campos de Carvalho AC. Functionally active cardiac antibodies in chronic Chagas' disease are specifically blocked by Trypanosoma cruzi antigens. FASEB J 1998; 12:1551-8. [PMID: 9806764 DOI: 10.1096/fasebj.12.14.1551] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Antibodies of chronic chagasic patients have been shown to interfere with electric and mechanical activities of cardiac embryonic myocytes in culture and with whole mammalian hearts. A mechanism proposed for this effect involves interaction of the antibodies with G-protein-linked membrane receptors, thus leading to activation of beta adrenergic and muscarinic receptors; more specifically, IgG of chagasic patients would interact with the negatively charged regions of the second extracellular loop of these receptors. We performed competition experiments to test this hypothesis. We evaluated the effect of sera/IgG from patients previously known to depress electrogenesis and/or atrioventricular conduction in isolated rabbit hearts after incubation with live and lysed parasites, the peptide corresponding to the second extracellular loop (O2) of the M2 receptor, and different peptides derived from two ribosomal proteins of T. cruzi: P0 and P2beta. Our results indicate that 1) the antigenic factor inducing the functionally active IgGs in the chagasic patients is probably an intracellular T. cruzi antigen; 2) IgG/serum is interacting with the O2 region of the M2 receptor in the rabbit heart; and 3) the negative charges present in the ribosomal proteins of T. cruzi are important in mediating the interaction between the patients' serum/IgG and the receptor.
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Affiliation(s)
- M O Masuda
- Instituto de Biofisica Carlos Chagas Filho, CCS, UFRJ, Brazil
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42
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Pereira CM, Yamauchi LM, Levin MJ, da Silveira JF, Castilho BA. Mapping of B cell epitopes in an immunodominant antigen of Trypanosoma cruzi using fusions to the Escherichia coli LamB protein. FEMS Microbiol Lett 1998; 164:125-31. [PMID: 9675858 DOI: 10.1111/j.1574-6968.1998.tb13077.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The JL8 protein antigen from Trypanosoma cruzi, a dominant immunogen in man, has been characterized as containing tandem amino acid repeats. Here, we describe the use of the LamB protein of Escherichia coli as a carrier of JL8 derived sequences in order to map the immunodominant B cell epitopes in this antigen. Five different sequences of JL8 were inserted in the LamB protein and the JL8-LamB fusion proteins were tested by ELISA with human chronic chagasic sera. The fusion carrying the sequence AEKQKAAEATKVAE was recognized by most sera. This protein was also capable of inhibiting the binding of human chagasic antibodies to GST-JL8 in competitive ELISA suggesting that it contains an immunodominant B cell epitope of JL8.
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Affiliation(s)
- C M Pereira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, UNIFESP, São Paulo, Brazil
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43
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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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44
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Woodward R, Carden MJ, Gull K. Immunological characterization of cytoskeletal proteins associated with the basal body, axoneme and flagellum attachment zone of Trypanosoma brucei. Parasitology 1995; 111 ( Pt 1):77-85. [PMID: 7609993 DOI: 10.1017/s0031182000064623] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The monoclonal antibody BS7, raised to bovine sperm flagellum cytoskeletal antigens in a previous study, is here reported to detect flagellum-associated structures in Trypanosoma brucei and Crithidia fasciculata. Immunoblotting showed that BS7 cross-reacts with several cytoskeletal T. brucei proteins but phosphatase treatment did not diminish this complex immunoblot reactivity. To characterize further the cross-reactive proteins recognized in T. brucei-cytoskeletons by BS7 each was excised from preparative gels and used as an immunogen for antiserum production. Two proteins, with apparent sizes around 43 and 47 kDa, produced antisera shown to be monospecific by immunoblotting total T. brucei flagellum preparations. Each of these detected the basal body-associated immunofluorescence in T. brucei. Identification of the smaller, 43 kDa, component as a basal body-associated product was supported by the behaviour of a second monoclonal antibody, BBA4, which was also shown to detect the T. brucei basal body complex by immunofluorescence and immunoblots the 43 kDa polypeptide. These observations reveal new components of the trypanosome cytoskeleton. Also, they provide a further example of an immunological approach for identification of interesting, rare components of the T. brucei cytoskeleton starting from a complex mixture of proteins.
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Affiliation(s)
- R Woodward
- Research School of Biosciences, Biological Laboratory, University of Kent, Canterbury
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45
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Wilson ME, Young BM, Andersen KP, Weinstock JV, Metwali A, Ali KM, Donelson JE. A recombinant Leishmania chagasi antigen that stimulates cellular immune responses in infected mice. Infect Immun 1995; 63:2062-9. [PMID: 7729921 PMCID: PMC173265 DOI: 10.1128/iai.63.5.2062-2069.1995] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cellular immune mechanisms resulting in gamma interferon production are critical for protection against visceral leishmaniasis. Antigens stimulating T-cell responses are likely present in the intracellular amastigote form of the parasite, since this is the form found in a mammalian host. To identify T-cell antigens of Leishmania chagasi, the parasite causing South American visceral leishmaniasis, we used a double antibody-T-cell technique to screen an amastigote cDNA library. One cDNA selected (Lcr1) encodes an antigen that stimulated proliferation of splenic T lymphocytes from infected mice that were either resistant (C3H.HeJ) or susceptible (BALB/c) to L. chagasi infection. The Lcr1 cDNA contains four highly divergent 201-bp repeats homologous to the 204-bp repeat of a Trypanosoma cruzi flagellar antigen gene. Results are consistent with a single copy of the Lcr1 gene producing an mRNA of > 10 kb and a protein of > 200 kDa. Recombinant Lcr1, cloned adjacent to polyhistidine and purified on a nickel affinity column, stimulated gamma interferon but not interleukin-4 (IL-4), IL-5, or IL-10 secretion by T-cell-enriched splenocytes from either susceptible or resistant mice during L. chagasi infection. Immunization with Lcr1 partially protected BALB/c mice against challenge with L. chagasi, indicating the utility of the double screening approach in selecting relevant T-cell antigens.
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Affiliation(s)
- M E Wilson
- Department of Internal Medicine, University of Iowa, Iowa City 52242, USA
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46
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Cotrim PC, Paranhos-Baccala G, Santos MR, Mortensen C, Cano MI, Jolivet M, Camargo ME, Mortara RA, Da Silveira JF. Organization and expression of the gene encoding an immunodominant repetitive antigen associated to the cytoskeleton of Trypanosoma cruzi. Mol Biochem Parasitol 1995; 71:89-98. [PMID: 7630386 DOI: 10.1016/0166-6851(95)00036-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have studied the genomic organization and expression of the gene encoding a high molecular mass (300 kDa) repetitive antigen associated with the cytoskeleton of Trypanosoma cruzi. Protease digestion of the native protein, restriction analysis of genomic DNA and sequencing of genomic and cDNA clones indicated that most of the protein is built up by tandemly arranged, nearly identical repeats of 68 amino acids. The gene size was estimated to be approx. 9.4 kb based on the sizes of the transcript and the native protein. The nucleotide sequence conservation among the repeats indicates that selective sequence homogenization, presumably through gene conversion, maintained the amino-acid sequence conservation. Two duplicated allelic forms of this gene were mapped in fragments of about 20 kb. In some strains an additional allele was located in a fragment of 9.4 kb. Our results suggest that this repetitive antigen is a structural protein which could be involved in the attachment of the flagellum to the cell body.
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Affiliation(s)
- P C Cotrim
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, São Paulo, Brazil
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47
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Imboden M, Müller N, Hemphill A, Mattioli R, Seebeck T. Repetitive proteins from the flagellar cytoskeleton of African trypanosomes are diagnostically useful antigens. Parasitology 1995; 110 ( Pt 3):249-58. [PMID: 7724233 DOI: 10.1017/s0031182000080835] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Trypanosome infection of mammalian hosts leads, within days, to a strong early response against a small, distinct number of parasite proteins. One of these proteins is the variable surface glycoprotein (VSG). Most of the others are apparently non-variable, intracellular trypanosome proteins. Two of these antigens I2 and I17 are now characterized at the molecular level. Both exhibit a highly repetitive amino acid sequence organization, but they show no sequence similarity either to each other or to any other proteins known to date. Preliminary serological analyses indicate that both allow the early, sensitive and specific detection of infections with different species of trypanosomatids, making them interesting candidates for the development of diagnostic tools for trypanosomiasis detection.
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Affiliation(s)
- M Imboden
- Institute of General Microbiology, University of Bern, Switzerland
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48
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Woodward R, Carden MJ, Gull K. Molecular characterisation of a novel, repetitive protein of the paraflagellar rod in Trypanosoma brucei. Mol Biochem Parasitol 1994; 67:31-9. [PMID: 7838181 DOI: 10.1016/0166-6851(94)90093-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A partial cDNA clone, termed 5.20, was isolated from a lambda-gt11 phage expression library using a complex antiserum to the T. brucei cytoskeleton. Antisera against the fusion protein product of this 5.20 cDNA recognized a closely-spaced polypeptide doublet of high molecular weight (ca. 180-200 kDa) on immunoblots of T. brucei cytoskeletal preparations. Immunogold labelling suggested the 5.20 protein is intracellular and localized along the entire length of the paraflagellar rod. This pattern is similar to that generated with a monoclonal antibody, ROD1, which recognizes a high molecular weight protein doublet indistinguishable from that detected by 5.20-specific antisera. ROD1 recognizes mammalian spectrin, but the use of specific anti-spectrin antibodies for immunoblotting did not support ideas that 5.20 encodes spectrin or that spectrin can be specifically detected in T. brucei by such methods. Moreover, the sequence of the 5.20 cDNA insert bears little similarity, either in its nucleotide or predicted amino acid sequence to other known proteins and appears to be a unique cytoskeletal protein characterized especially by sequential amino acid sequence repetitiveness. The location of this novel protein suggests it may be responsible for providing either paraflagellar rod-membrane links or for organizing the more abundant paraflagellar rod structural proteins.
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Affiliation(s)
- R Woodward
- Research School of Biosciences, University of Kent at Canterbury, UK
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49
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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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50
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Frasch AC. Trans-sialidase, SAPA amino acid repeats and the relationship between Trypanosoma cruzi and the mammalian host. Parasitology 1994; 108 Suppl:S37-44. [PMID: 8084653 DOI: 10.1017/s0031182000075703] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
During invasion of multicellular organisms, protozoan parasites expose functional molecules that become targets for the host immune response. Recent research on Trypanosoma cruzi, the agent of Chagas' disease, suggests a new model of how the parasite might deal with this problem. Several antigens of T. cruzi have tandemly repeated amino acid motifs in molecules with as yet unknown functions. In two cases, these repeats are in molecules with a defined structure or function. Both proteins are implicated in the invasion of host-cells by the parasite. One of these is the core protein of a putative mucin-like glycoprotein that has Thr/Pro-rich repeats which, by themselves, might define the structure of a highly O-glycosylated molecule. The other protein is SAPA/trans-sialidase/neuraminidase, a molecule able to transfer sialic acid, that has so far only been described in trypanosomes. The amino acid repeats present in SAPA/transsialidase/neuraminidase are unrelated to the enzymic activity and constitute an immunodominant C-terminal domain. The N-terminal domain of SAPA/trans-sialidase/neuraminidase controls the enzymic activity since a recombinant molecule lacking the repeats conserves trans-sialidase activity. That both domains are functionally independent is also indicated by experiments that show that antibodies directed against the amino acid repeats are unable to inhibit trans-sialidase activity. A large number of proteins having trans-sialidase related sequences but lacking enzymic activity are also present in the surface membrane of the parasite. The immunodominant SAPA/trans-sialidase/neuraminidase repeats, together with the complex network of cross-reacting epitopes present in related but enzymatically inactive proteins might contribute to the delay in mounting an effective antibody response.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A C Frasch
- Instituto de investigaciones Bioquímicas Fundación Campomar, Buenos Aires, Argentina
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