1
|
Neves EGA, Koh CC, Souza-Silva TG, Passos LSA, Silva ACC, Velikkakam T, Villani F, Coelho JS, Brodskyn CI, Teixeira A, Gollob KJ, Nunes MDCP, Dutra WO. T-Cell Subpopulations Exhibit Distinct Recruitment Potential, Immunoregulatory Profile and Functional Characteristics in Chagas versus Idiopathic Dilated Cardiomyopathies. Front Cardiovasc Med 2022; 9:787423. [PMID: 35187122 PMCID: PMC8847602 DOI: 10.3389/fcvm.2022.787423] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/10/2022] [Indexed: 11/13/2022] Open
Abstract
Chronic Chagas cardiomyopathy (CCC) is one of the deadliest cardiomyopathies known and the most severe manifestation of Chagas disease, which is caused by infection with the parasite Trypanosoma cruzi. Idiopathic dilated cardiomyopathies (IDC) are a diverse group of inflammatory heart diseases that affect the myocardium and are clinically similar to CCC, often causing heart failure and death. While T-cells are critical for mediating cardiac pathology in CCC and IDC, the mechanisms underlying T-cell function in these cardiomyopathies are not well-defined. In this study, we sought to investigate the phenotypic and functional characteristics of T-cell subpopulations in CCC and IDC, aiming to clarify whether the inflammatory response is similar or distinct in these cardiomyopathies. We evaluated the expression of systemic cytokines, determined the sources of the different cytokines, the expression of their receptors, of cytotoxic molecules, and of molecules associated with recruitment to the heart by circulating CD4+, CD8+, and CD4-CD8- T-cells from CCC and IDC patients, using multiparameter flow cytometry combined with conventional and unsupervised machine-learning strategies. We also used an in silico approach to identify the expression of genes that code for key molecules related to T-cell function in hearts of patient with CCC and IDC. Our data demonstrated that CCC patients displayed a more robust systemic inflammatory cytokine production as compared to IDC. While CD8+ T-cells were highly activated in CCC as compared to IDC, CD4+ T-cells were more activated in IDC. In addition to differential expression of functional molecules, these cells also displayed distinct expression of molecules associated with recruitment to the heart. In silico analysis of gene transcripts in the cardiac tissue demonstrated a significant correlation between CD8 and inflammatory, cytotoxic and cardiotropic molecules in CCC transcripts, while no correlation with CD4 was observed. A positive correlation was observed between CD4 and perforin transcripts in hearts from IDC but not CCC, as compared to normal tissue. These data show a clearly distinct systemic and local cellular response in CCC and IDC, despite their similar cardiac impairment, which may contribute to identifying specific immunotherapeutic targets in these diseases.
Collapse
Affiliation(s)
- Eula G. A. Neves
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Carolina C. Koh
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Thaiany G. Souza-Silva
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Lívia Silva Araújo Passos
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Brigham and Womens Hospital, Harvard University, Boston, MA, United States
| | - Ana Carolina C. Silva
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Teresiama Velikkakam
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Fernanda Villani
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Minas Gerais State University, Divinópolis, Brazil
| | - Janete Soares Coelho
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Ezequiel Dias Foundation, Belo Horizonte, Brazil
| | - Claudia Ida Brodskyn
- Gonçalo Moniz Research Center, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, Brazil
| | - Andrea Teixeira
- Rene Rachou Institute, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
| | - Kenneth J. Gollob
- Hospital Israelita Albert Einstein, São Paulo, Brazil
- Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, INCT-DT, Salvador, Brazil
| | - Maria do Carmo P. Nunes
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Walderez O. Dutra
- Department of Morphology, Cell-Cell Interactions Laboratory, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, INCT-DT, Salvador, Brazil
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| |
Collapse
|
2
|
Neves EGA, Koh CC, Padilha da Silva JL, Passos LSA, Villani FNA, Dos Santos JSC, Menezes CAS, Silva VR, Tormin JPAS, Evangelista GFB, Carvalho ATD, Rocha MODC, Nascimento B, Gollob KJ, Nunes MDCP, Dutra WO. Systemic cytokines, chemokines and growth factors reveal specific and shared immunological characteristics in infectious cardiomyopathies. Cytokine 2021; 148:155711. [PMID: 34592495 DOI: 10.1016/j.cyto.2021.155711] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 09/07/2021] [Accepted: 09/13/2021] [Indexed: 12/17/2022]
Abstract
Heart disease is a major cause of death worldwide. Chronic Chagas cardiomyopathy (CCC) caused by infection with Trypanosoma cruzi leading to high mortality in adults, and rheumatic heart disease (RHD), resulting from infection by Streptococcus pyogenes affecting mainly children and young adults, are amongst the deadliest heart diseases in low-middle income countries. Despite distinct etiology, the pathology associated with both diseases is a consequence of inflammation. Here we compare systemic immune profile in patients with these cardiopathies, to identify particular and common characteristics in these infectious heart diseases. We evaluated the expression of 27 soluble factors, employing single and multivariate analysis combined with machine-learning approaches. We observed that, while RHD and CCC display higher levels of circulating mediators than healthy individuals, CCC is associated with stronger immune activation as compared to RHD. Despite distinct etiologies, univariate analysis showed that expression of TNF, IL-17, IFN-gamma, IL-4, CCL4, CCL3, CXCL8, CCL11, CCL2, PDGF-BB were similar between CCC and RHD, consistent with their inflammatory nature. Network analysis revealed common inflammatory pathways between CCC and RHD, while highlighting the broader reach of the inflammatory response in CCC. The final multivariate model showed a 100% discrimination power for the combination of the cytokines IL-12p70, IL-1Ra, IL-4, and IL-7 between CCC and RHD groups. Thus, while clear immunological distinctions were identified between CCC and RHD, similarities indicate shared inflammatory pathways in these infectious heart diseases. These results contribute to understanding the pathogenesis of CCC and RHD and may impact the design of immune-based therapies for these and other inflammatory cardiopathies that may also share immunological characteristics.
Collapse
Affiliation(s)
- Eula G A Neves
- Cell-cell Interactions Laboratory, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Carolina C Koh
- Cell-cell Interactions Laboratory, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Lívia S A Passos
- Cell-cell Interactions Laboratory, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - Cristiane A S Menezes
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vicente R Silva
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Julia P A S Tormin
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | - Manoel Otávio da Costa Rocha
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Bruno Nascimento
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Kenneth John Gollob
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, INCT-DT, Salvador, BA, Brazil
| | - Maria do Carmo P Nunes
- Graduate Program in Infectology and Tropical Medicine, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Walderez O Dutra
- Cell-cell Interactions Laboratory, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, INCT-DT, Salvador, BA, Brazil.
| |
Collapse
|
3
|
De Bona E, Lidani KCF, Bavia L, Omidian Z, Gremski LH, Sandri TL, de Messias Reason IJ. Autoimmunity in Chronic Chagas Disease: A Road of Multiple Pathways to Cardiomyopathy? Front Immunol 2018; 9:1842. [PMID: 30127792 PMCID: PMC6088212 DOI: 10.3389/fimmu.2018.01842] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/26/2018] [Indexed: 12/26/2022] Open
Abstract
Chagas disease (CD), a neglected tropical disease caused by the protozoan Trypanosoma cruzi, affects around six million individuals in Latin America. Currently, CD occurs worldwide, becoming a significant public health concern due to its silent aspect and high morbimortality rate. T. cruzi presents different escape strategies which allow its evasion from the host immune system, enabling its persistence and the establishment of chronic infection which leads to the development of chronic Chagas cardiomyopathy (CCC). The potent immune stimuli generated by T. cruzi persistence may result in tissue damage and inflammatory response. In addition, molecular mimicry between parasites molecules and host proteins may result in cross-reaction with self-molecules and consequently in autoimmune features including autoantibodies and autoreactive cells. Although controversial, there is evidence demonstrating a role for autoimmunity in the clinical progression of CCC. Nevertheless, the exact mechanism underlying the generation of an autoimmune response in human CD progression is unknown. In this review, we summarize the recent findings and hypotheses related to the autoimmune mechanisms involved in the development and progression of CCC.
Collapse
Affiliation(s)
- Elidiana De Bona
- Laboratory of Molecular Immunopathology, Department of Clinical Pathology, Federal University of Paraná, Curitiba, Brazil
| | - Kárita Cláudia Freitas Lidani
- Laboratory of Molecular Immunopathology, Department of Clinical Pathology, Federal University of Paraná, Curitiba, Brazil
| | - Lorena Bavia
- Laboratory of Molecular Immunopathology, Department of Clinical Pathology, Federal University of Paraná, Curitiba, Brazil
| | - Zahra Omidian
- Department of Pathology, Division of Immunology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | | | - Thaisa Lucas Sandri
- Laboratory of Molecular Immunopathology, Department of Clinical Pathology, Federal University of Paraná, Curitiba, Brazil.,Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Iara J de Messias Reason
- Laboratory of Molecular Immunopathology, Department of Clinical Pathology, Federal University of Paraná, Curitiba, Brazil
| |
Collapse
|
4
|
Bonney KM, Engman DM. Autoimmune pathogenesis of Chagas heart disease: looking back, looking ahead. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1537-47. [PMID: 25857229 DOI: 10.1016/j.ajpath.2014.12.023] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/21/2014] [Accepted: 12/23/2014] [Indexed: 01/14/2023]
Abstract
Chagas heart disease is an inflammatory cardiomyopathy that develops in approximately one-third of individuals infected with the protozoan parasite Trypanosoma cruzi. Since the discovery of T. cruzi by Carlos Chagas >100 years ago, much has been learned about Chagas disease pathogenesis; however, the outcome of T. cruzi infection is highly variable and difficult to predict. Many mechanisms have been proposed to promote tissue inflammation, but the determinants and the relative importance of each have yet to be fully elucidated. The notion that some factor other than the parasite significantly contributes to the development of myocarditis was hypothesized by the first physician-scientists who noted the conspicuous absence of parasites in the hearts of those who succumbed to Chagas disease. One of these factors-autoimmunity-has been extensively studied for more than half a century. Although questions regarding the functional role of autoimmunity in the pathogenesis of Chagas disease remain unanswered, the development of autoimmune responses during infection clearly occurs in some individuals, and the implications that this autoimmunity may be pathogenic are significant. In this review, we summarize what is known about the pathogenesis of Chagas heart disease and conclude with a view of the future of Chagas disease diagnosis, pathogenesis, therapy, and prevention, emphasizing recent advances in these areas that aid in the management of Chagas disease.
Collapse
Affiliation(s)
- Kevin M Bonney
- Department of Pathology, Northwestern University, Chicago, Illinois; Department of Microbiology-Immunology, Northwestern University, Chicago, Illinois
| | - David M Engman
- Department of Pathology, Northwestern University, Chicago, Illinois; Department of Microbiology-Immunology, Northwestern University, Chicago, Illinois; Department of Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, Illinois.
| |
Collapse
|
5
|
Abstract
The scarcity of Trypanosoma cruzi in inflammatory lesions of chronic Chagas disease led early investigators to suggest that tissue damage had an autoimmune nature. In spite of parasite persistence in chronic Chagas disease, several reports indicate that inflammatory tissue damage may not be correlated to the local presence of T. cruzi. A significant number of reports have described autoantibodies and self-reactive T cells, often cross-reactive with T. cruzi antigens, both in patients and in animal models. Evidence for a direct pathogenetic role of autoimmunity was suggested by the development of lesions after immunization with T. cruzi antigens or passive transfer of lymphocytes from infected animals, and the amelioration of chronic myocarditis in animals made tolerant to myocardial antigens. Autoimmune and T. cruzi-specific innate or adaptative responses are not incompatible or mutually exclusive, and it is likely that a combination of both is involved in the pathogenesis of chronic Chagas disease cardiomyopathy. The association between persistent infection and autoimmune diseases-such as multiple sclerosis or diabetes mellitus-suggests that post-infectious autoimmunity may be a frequent finding. Here, we critically review evidence for autoimmune phenomena and their possible pathogenetic role in human Chagas disease and animal models, with a focus on chronic Chagas disease cardiomyopathy.
Collapse
|
6
|
Montalvão F, Almeida GM, Silva EM, Borges VM, Vasconcellos R, Takiya CM, Lopes MF, Nunes MP, DosReis GA. Apoptotic lymphocytes treated with IgG from Trypanosoma cruzi infection increase TNF-alpha secretion and reduce parasite replication in macrophages. Eur J Immunol 2010; 40:417-25. [PMID: 19950177 DOI: 10.1002/eji.200939606] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Phagocytic removal of apoptotic lymphocytes exacerbates replication of Trypanosoma cruzi in macrophages. We investigated the presence of Ab against apoptotic lymphocytes in T. cruzi infection and the role of these Ab in parasite replication. Both control and chagasic serum contained IgG Ab that opsonized apoptotic lymphocytes. Treatment of apoptotic lymphocytes with purified IgG from chagasic, but not control serum, reduced T. cruzi replication in macrophages. The protective effect of chagasic IgG depended on Fcgamma receptors, as demonstrated by the requirement for the intact Fc portion of IgG, and the effect could be abrogated by treating macrophages with an anti-CD16/CD32 Fab fragment. Chagasic IgG displayed increased reactivity against a subset of apoptotic cell Ag, as measured by flow cytometry and immunoblot analyses. Apoptotic lymphocytes treated with chagasic IgG, but not control IgG, increased production of TNF-alpha, while decreasing production of TGF-beta1 by infected macrophages. Increased control of parasite replication required TNF-alpha production. Previous immunization with apoptotic cells or injection of apoptotic cells opsonized with chagasic IgG reduced parasitemia in infected mice. These results indicate that Ab raised against apoptotic cells could play a protective role in control of T. cruzi replication by macrophages.
Collapse
Affiliation(s)
- Fabricio Montalvão
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Cunha-Neto E, Bilate AM, Hyland KV, Fonseca SG, Kalil J, Engman DM. Induction of cardiac autoimmunity in Chagas heart disease: A case for molecular mimicry. Autoimmunity 2009; 39:41-54. [PMID: 16455581 DOI: 10.1080/08916930500485002] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Up to 18 million of individuals are infected by the protozoan parasite Trypanosoma cruzi in Latin America, one third of whom will develop chronic Chagas disease cardiomyopathy (CCC) up to 30 years after infection. Cardiomyocyte destruction is associated with a T cell-rich inflammatory infiltrate and fibrosis. The presence of such lesions in the relative scarcity of parasites in the heart, suggested that CCC might be due, in part, to a postinfectious autoimmune process. Over the last two decades, a significant amount of reports of autoimmune and molecular mimicry phenomena have been described in CCC. The authors will review the evidence in support of an autoimmune basis for CCC pathogenesis in humans and experimental animals, with a special emphasis on molecular mimicry as a fundamental mechanism of autoimmunity.
Collapse
Affiliation(s)
- Edecio Cunha-Neto
- Heart Institute (InCor), Laboratory of Immunology, São Paulo, Brazil.
| | | | | | | | | | | |
Collapse
|
8
|
Abstract
The apparent discrepancy between the intensity of inflammatory reaction and scarce number of parasites in chronic chagasic myocarditis prompt several investigators to hypothesize that an autoimmune process was involved in the pathogenesis of Chagas disease. Here, we recapitulate diverse molecular and cellular mechanisms of innate and acquired immunity involved in the control of parasite replication and in the build up of myocarditis observed during infection with Trypanosoma cruzi. In addition, we review the immunoregulatory mechanisms responsible for preventing excessive immune response elicited by this protozoan parasite. Ongoing studies in this research area may provide novel therapeutic strategies that could enhance the immunoprotective response while preventing the deleterious parasite-elicited responses observed during Chagas disease.
Collapse
Affiliation(s)
- Denise Golgher
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, and René Research Center, Oswaldo Cruz Foundation, Belo Horizonte, MG, Brazil
| | | |
Collapse
|
9
|
Pérez-Escobar M, Cevallos AM, Espinoza B, Espinosa N, Martínez I, Hernández R. Trypanosoma cruzi ribosomal protein S4: characterization of its coding locus, analysis of transcripts, and antigenicity of the protein. Mem Inst Oswaldo Cruz 2007; 102:473-9. [PMID: 17612768 DOI: 10.1590/s0074-02762007005000031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 03/07/2007] [Indexed: 01/23/2023] Open
Abstract
Two allelic genomic fragments containing ribosomal protein S4 encoding genes (rpS4) from Trypanosoma cruzi (CL-Brener strain) were isolated and characterized. One allele comprises two complete tandem repeats of a sequence encoding an rpS4 gene. In the other, only one rpS4 gene is found. Sequence comparison to the accessed data in the genome project database reveals that our two-copy allele corresponds to a variant haplotype. However, the deduced aminoacid sequence of all the gene copies is identical. The rpS4 transcripts processing sites were determined by comparison of genomic sequences with published cDNA data. The obtained sequence data demonstrates that rpS4 genes are expressed in epimastigotes, amastigotes, and trypomastigotes. A recombinant version of rpS4 was found to be an antigenic: it was recognized by 62.5% of the individuals with positive serology for T. cruzi and by 93.3% of patients with proven chronic chagasic disease.
Collapse
Affiliation(s)
- Mariana Pérez-Escobar
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, D. F., 04510, México
| | | | | | | | | | | |
Collapse
|
10
|
Obwaller A, Duchêne M, Walochnik J, Wiedermann G, Auer H, Aspöck H. Association of autoantibodies against small nuclear ribonucleoproteins (snRNPs) with symptomatic Toxocara canis infestation. Parasite Immunol 2004; 26:327-33. [PMID: 15679629 DOI: 10.1111/j.0141-9838.2004.00716.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several studies have demonstrated the occurrence of autoantibodies in the course of infestations with helminth parasites and a number of target proteins have been identified. Sera from patients suffering from toxocarosis, a disease caused by the parasitic roundworm Toxocara canis, and from healthy individuals were tested for autoantibodies by immunofluorescence and immunoblot assays using HEp-2 cells as antigen. A considerable proportion of the sera from patients with toxocarosis-associated symptoms were autoantibody-positive, with a speckled staining pattern in the immunofluorescence test (62%) and with anti-snRNP reactivity in the immunoblot assay (98%). In contrast, significantly fewer sera from asymptomatic individuals scored positive in these assays (18% in the immunofluorescence test, P < 0.005; 24% in the immunoblot, P < 0.005). Although the causative link between Toxocara infestation and the occurrence of autoantibodies is still unclear, our results show that increased amounts of autoantibodies are associated with clinical symptoms of inflammation. Thus a serum test for autoantibodies in toxocarosis patients might be a valuable gatekeeper assay for the decision for or against anti-inflammatory treatment.
Collapse
Affiliation(s)
- Andreas Obwaller
- Department of Medical Parasitology, Clinical Institute of Hygiene and Medical Microbiology, Medical University of Vienna, Austria
| | | | | | | | | | | |
Collapse
|
11
|
Bosetto MC, Peixoto MS, de Castro LIR, Cicarelli RMB. Presence of autoantibodies against HeLa small nuclear ribonucleoproteins in chagasic and non-chagasic cardiac patients. Braz J Med Biol Res 2004; 37:37-45. [PMID: 14689042 DOI: 10.1590/s0100-879x2004000100006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We detected anti-human small nuclear ribonucleoprotein (snRNP) autoantibodies in chagasic patients by different immunological methods using HeLa snRNPs. ELISA with Trypanosoma cruzi total lysate antigen or HeLa human U small nuclear ribonucleoproteins (UsnRNPs) followed by incubation with sera from chronic chagasic and non-chagasic cardiac patients was used to screen and compare serum reactivity. Western blot analysis using a T. cruzi total cell extract was also performed in order to select some sera for Western blot and immunoprecipitation assays with HeLa nuclear extract. ELISA showed that 73 and 95% of chronic chagasic sera reacted with HeLa UsnRNPs and T. cruzi antigens, respectively. The Western blot assay demonstrated that non-chagasic cardiac sera reacted with high molecular weight proteins present in T. cruzi total extract, probably explaining the 31% reactivity found by ELISA. However, these sera reacted weakly with HeLa UsnRNPs, in contrast to the chagasic sera, which showed autoantibodies with human Sm (from Stefanie Smith, the first patient in whom this activity was identified) proteins (B/B', D1, D2, D3, E, F, and G UsnRNP). Immunoprecipitation reactions using HeLa nuclear extracts confirmed the reactivity of chagasic sera and human UsnRNA/RNPs, while the other sera reacted weakly only with U1snRNP. These findings agree with previously reported data, thus supporting the idea of the presence of autoimmune antibodies in chagasic patients. Interestingly, non-chagasic cardiac sera also showed reactivity with T. cruzi antigen and HeLa UsnRNPs, which suggests that individuals with heart disease of unknown etiology may develop autoimmune antibodies at any time. The detection of UsnRNP autoantibodies in chagasic patients might contribute to our understanding of how they develop upon initial T. cruzi infection.
Collapse
Affiliation(s)
- M C Bosetto
- Departamento de Ciências Biológicas, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP, Brasil
| | | | | | | |
Collapse
|
12
|
Soares MB, Pontes-De-Carvalho L, Ribeiro-Dos-Santos R. The pathogenesis of Chagas' disease: when autoimmune and parasite-specific immune responses meet. AN ACAD BRAS CIENC 2001; 73:547-59. [PMID: 11743602 DOI: 10.1590/s0001-37652001000400008] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chagas' disease is a major health problem in Latin America, where it constitutes one of the leading causes of heart failure. About one fourth of Trypanosoma cruzi-infected individuals develop chronic chagasic cardiomyopathy (CChC), the most severe form of the disease. CChC is histologically characterized by the presence of multifocal inflammatory infiltrates in the heart, composed mainly by mononuclear cells, usually adhered to myocytes and leading to myocytolysis, and frequently by interstitial fibrosis. The pathogenesis of CChC is still unclear, despite intense investigations both in human beings and in animal models of the disease. Although tissue parasitism is rare in the chronic phase of infection, an immune response targeted to persistent parasites or parasite antigens is suggested, by some authors, as the pathogenic mechanism of CChC. Other researchers affirm that the lack of correlation between tissue parasitism and intensity of inflammation suggests, along with the presence of autoreactive immune responses, that CChC results from the action of an autoimmune response. Herein we review reports from the literature and our own data, which together indicate, on one hand, the participation of parasite-specific immune responses and, on the other hand, clearly demonstrate the participation of heart-specific immune responses in the pathogenesis of CChC. Moreover, multiple factors may determine whether an individual in the indeterminate form of the disease will develop CChC. The mechanisms by which T. cruzi breaks immunological tolerance to heart antigens are also discussed.
Collapse
Affiliation(s)
- M B Soares
- Laboratório de Imunofarmacologia, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, BA, Brazil
| | | | | |
Collapse
|