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Rachid MA, Teixeira AL, Barcelos LS, Machado CRS, Chiari E, Tanowitz HB, Camargos ERS, Teixeira MM. Role of endothelin receptors in the control of central nervous system parasitism in Trypanosoma cruzi infection in rats. J Neuroimmunol 2010; 220:64-8. [PMID: 20116865 DOI: 10.1016/j.jneuroim.2010.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 12/02/2009] [Accepted: 01/12/2010] [Indexed: 10/19/2022]
Abstract
Endothelin has been implicated in the pathogenesis of experimental and human Chagas disease. In the present study, we investigated whether the treatment with bosentan, an antagonist of both ET(A)/ET(B) endothelin receptors, modified parasite load and inflammation in the central nervous system (CNS) of Trypanosomacruzi-infected rats. The cerebellum was the most affected region in the CNS with marked parasitism and inflammation. Treatment with bosentan enhanced parasitemia and CNS parasitism, but control of infection was eventually attained. There was also an increase in the levels of the cytokines TNF-alpha, IL-10, IFN-gamma, CCL2/MCP-1, CCL3/MIP-1alpha and CCL5/RANTES in the brain of infected animals at days 9, 13 and 18 after infection. Overall, bosentan has some effects on the expression of certain cytokines and this may be related to the initial enhanced parasite load. Altogether, our data suggest that endothelin action via ET(A) and ET(B) receptors may play a role in the initial resistance of the CNS to T. cruzi infection in rats.
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Affiliation(s)
- Milene A Rachid
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270901, Belo Horizonte, MG, Brazil.
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Nagib PRA, Dutra WO, Chiari E, Machado CRS. Trypanosoma cruzi: populations bearing opposite virulence induce differential expansion of circulating CD3+CD4-CD8- T cells and cytokine serum levels in young and adult rats. Exp Parasitol 2007; 116:366-74. [PMID: 17399706 DOI: 10.1016/j.exppara.2007.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 02/03/2007] [Accepted: 02/09/2007] [Indexed: 11/30/2022]
Abstract
The JG strain is the least virulent while the CL-Brener clone is one of the most virulent Trypanosoma cruzi populations in young rats. In this study, we determined that the parasitemia peak values in CL-Brener clone-infected adult rats were 50-fold lower than in young rats and that mortality was null as compared to 45% death in young rats. Low parasitemia, milder and sustained myocarditis and myositis characterized JG infections. CL-Brener clone caused a significantly higher production of pro-inflammatory cytokines and higher expansion of CD3(+)CD4(-)CD8(-), double-negative (DN) T cells, during the acute phase in both adult and young rats. DN T cell frequencies correlated with IFN-gamma levels. These findings may explain the higher inflammation and fast acute phase resolution in CL-Brener infection. In young rats, IL-10 levels were similar in both infections. The IL-10/IFN-gamma ratio was higher in JG acute infection in accordance with the milder inflammation and parasite persistence leading to a chronic phase. In conclusion, virulence and pathogenicity depend on T. cruzi ability to induce expansion of DN T cells and production of specific cytokines.
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Affiliation(s)
- Patrícia R A Nagib
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, MG, Brazil
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3
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Rachid MA, Camargos ERS, Barcellos L, Marques CA, Chiari E, Huang H, Tanowitz HB, Teixeira MM, Machado CRS. Blockade of endothelin ETA/ETB receptors favors a role for endothelin during acute Trypanosoma cruzi infection in rats. Microbes Infect 2006; 8:2113-9. [PMID: 16844401 DOI: 10.1016/j.micinf.2006.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Revised: 03/08/2006] [Accepted: 03/27/2006] [Indexed: 11/29/2022]
Abstract
Endothelin has been implicated in the pathogenesis of experimental and human Chagas' disease (American trypanosomiasis). In the present study, we tested the effect of bosentan, an antagonist of both ET(A) and ET(B) endothelin receptors, on parasitemia, histopathology (heart and diaphragm), heart levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-10, interferon (IFN)-gamma, CCL2, CCL3 and CCL5, and the serum levels of nitrate/nitrite (NOx). Bosentan treatment was accompanied by a significant increase in parasitemia and tissue parasitism or inflammation. In vehicle-treated rats, Trypanosoma cruzi infection increased the cardiac levels of TNF-alpha, IFN-gamma and IL-10, at day 9 post inoculation, and the TNF-alpha remained elevated until day 13. The infection also caused a significant increase in the cardiac levels of the chemokines CCL2 (9, 13 and 18 days) and CCL3 (13 and 18 days). Bosentan-treatment had no significant effect on the infection-associated increase in IFN-gamma and chemokine concentrations. There was a lower increase in IL-10 at day 9 and this was mirrored by a greater increase of TNF-alpha at day 13, in comparison with vehicle-treated rats. These latter findings correlated well with the enhanced inflammatory process in hearts of bosentan-treated infected rats. Bosentan treatment reduced the infection-associated increase in NOx serum concentration. Altogether, our data suggest that ET action on ET(A) and ET(B) receptors may play a role in the initial control of T. cruzi infection in rats probably by interfering in NO production.
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Affiliation(s)
- Milene A Rachid
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil
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Neves SRS, Machado CRS, Pinto AMT, Borges AHD, Cunha FQ, Camargos ERS. Macrophage populations and cardiac sympathetic denervation during L-NAME-induced hypertension in rats. Histol Histopathol 2006; 21:803-12. [PMID: 16691532 DOI: 10.14670/hh-21.803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rat model of hypertension induced by prolonged treatment with Nomega-nitro-L-arginine methyl ester (L-NAME) has been extensively used. However, the effects on cardiac autonomic innervation are unknown. Here, the cardiac sympathetic innervation is analyzed in parallel with myocardial lesions and leukocyte infiltration during L-NAME (40 mg/Kg body weight/day, orally) treatment. The occurrence of cardiomyocyte hypertrophy, a controversial matter, is also addressed. Degenerating cardiomyocytes and focal inflammation occurred one day after treatment. Inflammatory lesions became gradually more frequent until day 7. At day 14 fibroblast-like cells were outstanding. Interstitial and perivascular connective tissue increased from day 28 on. In the left ventricle, cardiomyocyte hypertrophy occurred only around the damaged area during the first 14 days. After 28 days, it became more widespread. In the right ventricle, the hypertrophic cardiomyocytes were restricted to damaged areas. Significant reduction of the noradrenergic nerve terminals occurred from day 3 to 28. The area occupied by ED1+ (hematogenous) macrophages increased until day 7, and dropped to control levels by day 10. ED2+ (resident) macrophages increased from day 3 to 7 and remained higher than control values up to day 77. Animals receiving both L- NAME and aminoguanidine (AG), an inducible nitric oxide synthase (iNOS) inhibitor (65 mg/Kg body weight/day, orally), showed significant decrease in the nitrite serum levels, sympathetic denervation and macrophage infiltration at day 7. No denervation was detectable at day 14 of double treatment, using subcutaneous AG. Our findings favor a role for ED1+ macrophages and iNOS in the hypertension-induced denervation process.
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Affiliation(s)
- S R S Neves
- Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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Maldonado IRSC, Ferreira ML, Camargos ERS, Chiari E, Machado CRS. Skeletal muscle regeneration and Trypanosoma cruzi-induced myositis in rats. Histol Histopathol 2004; 19:85-93. [PMID: 14702175 DOI: 10.14670/hh-19.85] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although Chagas' disease is known to provoke severe acute myositis, information on muscle regeneration is missing. The current paper shows that during T. cruzi infection in rats, skeletal muscle parasitism and the consequent inflammatory process are higher in muscle with a high proportion of type-I myofibres (soleus and diaphragm). Immunohistochemistry showed an acute inflammatory process characterized by ED1+ and ED2+ macrophages, CD8+ lymphocytes, and NK cells. Parasite-nest rupture provoked segmental degeneration of myofibres followed by regeneration. These phenomena were observed at both light and transmission electron microscopy levels. Myofibre regeneration involved activation of satellite cells assessed by the expression of MyoD, a muscle-specific transcription factor. Ultrastructural evidence of fusion of myoblast-like cells with the intact segment of degenerating fibres has been provided. At the chronic phase no signs of fibrosis were found, but sparse and small inflammatory foci were found. Our results argue against the relevant participation of autoimmunity phenomena in both acute and chronic phases and furnish a new view for explaining histopathological findings in human patient muscles.
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Affiliation(s)
- I R S C Maldonado
- Departament of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Minas Gerais, Brazil
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Camargos ERS, Rocha LLV, Rachid MA, Almeida AP, Ferreira AJ, Teixeira AL, Chiari E, Barton M, Teixeira MM, Machado CRS. Protective role of ETA endothelin receptors during the acute phase of Trypanosoma cruzi infection in rats. Microbes Infect 2004; 6:650-6. [PMID: 15158772 DOI: 10.1016/j.micinf.2004.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2003] [Accepted: 03/02/2004] [Indexed: 01/01/2023]
Abstract
Chagas' disease, caused by Trypanosoma cruzi, has an acute phase characterized by blood-circulating trypomastigotes and amastigote proliferation in several cell types, especially muscle cells. In the chronic phase, around 70% of infected people are asymptomatic (latent form). The remainder develop chagasic cardiomyopathy and/or digestive syndromes. There is evidence for aggravation of the chronic cardiac pathology by endothelin-mediated vasoconstriction. Holtzman rats have proven to be a good model for Chagas' disease acute phase and latent chronic phase. Now, we investigate the effects of prolonged treatment with an endothelin ET(A) receptor antagonist, BSF 461314, during the acute phase on parasitemia, coronary flow, tissue parasitism and the inflammatory process. Using isolated heart in Langendorff's preparation, endothelial dysfunction was observed only in non-treated infected animals. Histoquantitative analyses carried out in heart and diaphragm showed higher tissue parasitism and/or inflammatory process in BSF 461314-treated animals. Our data indicate that endothelin ET(A) receptors contribute to the initial mechanisms of parasite control. Impairment of the endothelium-dependent vasodilatation favors hazardous effects. However, blocking endothelin ET(A) receptors can prevent the latter.
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Affiliation(s)
- Elizabeth R S Camargos
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Av. Antonio Carlos 6627, P.O. Box 486, CEP: 31270-901 Belo Horizonte, MG, Brazil
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Silva GC, Nagib PRA, Chiari E, van Rooijen N, Machado CRS, Camargos ERS. Peripheral macrophage depletion reduces central nervous system parasitism and damage in Trypanosoma cruzi-infected suckling rats. J Neuroimmunol 2004; 149:50-8. [PMID: 15020064 DOI: 10.1016/j.jneuroim.2003.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2003] [Revised: 12/09/2003] [Accepted: 12/10/2003] [Indexed: 11/22/2022]
Abstract
We aim at investigating the role of blood born macrophages on the brain reaction to Trypanosoma cruzi infection in suckling rats. This infection provoked the appearance of numerous ED1(+) cells in the neural parenchyma and increased the amount of meningeal and perivascular ED2(+) macrophages. CD8(+) and NKR(+) cells also occurred. Parenchymal blood vessels showed strong ICAM-1 and decreased occludin immunoreactivities. Selective depletion of peripheral macrophages by clodronate liposomes decreased tissue parasitism, nodular lesions, ICAM-1 upregulation and leukocyte infiltration. Occludin immunoreactivity remained as in uninfected animals. Our results indicate a role for blood-born macrophages in both parasite invasion and brain reaction. Microglia activation cannot be discarded.
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Affiliation(s)
- Grace C Silva
- Department of Morphology, Federal University of Minas Gerais, Av. Antonio Carlos, 6627, 31270.901 Belo Horizonte, Minas Gerais, Brazil
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Franco DJ, Vago AR, Chiari E, Meira FCA, Galvão LMC, Machado CRS. Trypanosoma cruzi: mixture of two populations can modify virulence and tissue tropism in rat. Exp Parasitol 2003; 104:54-61. [PMID: 12932760 DOI: 10.1016/s0014-4894(03)00119-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In rats, CL-Brener clone caused high mortality, severe acute myocarditis, and myositis that subsided completely in surviving animals. Accordingly, no parasite kDNA could be amplified in several organs after 4 months. The monoclonal JG strain caused null mortality, acute predominantly focal myocarditis, discrete and focal myositis, and a chronic phase with sparse inflammatory foci. Double infection with both Trypanosoma cruzi populations turned mortality very low or null. At the end of the acute phase, the heart exhibited only JG strain kDNA (LSSP-PCR), while skeletal muscles and rectum exhibited only CL-Brener kDNA. Molecular and histopathological findings were accordant. In double infection chronic phase, JG strain remains in heart and appeared in organs previously parasitized by CL-Brener clone. Understanding the virulence and histotropism shifts now described could be important to clarify the variable clinical course and epidemiological peculiarities of Chagas' disease.
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Affiliation(s)
- Deila J Franco
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil
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Santos AAD, Chiarini-Garcia H, Oliveira KR, Machado CRS. Development of different mast cell types in the opossum Didelphis albiventris. Anat Embryol (Berl) 2003; 206:239-45. [PMID: 12592575 DOI: 10.1007/s00429-002-0293-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/06/2002] [Indexed: 11/27/2022]
Abstract
Previous studies have disclosed three types of mast cell in opossums: connective tissue (CTMC), mucosal (MMC), and lymphatic sinus (LSMC). In contrast to most opossum lymph nodes, the mesenteric lymph node is virtually devoid of LSMC, displaying medullary cord CTMC. The present study aimed to describe the development of these mast cell populations. Toluidine blue staining and a histochemical method for demonstrating heparin allowed the identification of immature and mature mast cells. Immature CTMC devoid of detectable heparin were rare until postnatal day 10. Mature CTMC filled with heparin-containing granules became numerous by day 30 to day 40. In the ileum, despite the presence of mature CTMC in the submucosa and mucosa (villus base), immature mast cells first appeared in the villus core by day 65 and adult features were apparent by day 100. In LSMC-containing lymph nodes, immature mast cells were found in lymphatic sinuses by day 10. Clear signs of LSMC differentiation were observed from day 20. Compared with the 10-day value, the mean diameter of cytoplasmic granules at day 40 had doubled and that at day 110 had tripled. In the mesenteric lymph nodes, immature mast cells differentiated into lymphatic sinus CTMC-like cells. After day 80, most of them were located in medullary cords. Weaning and complete maturation of mucosa preceded the differentiation of MMC. In lymph nodes, LSMC differentiation occurred in parallel with the development of the medullary region and deep cortex units.
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Affiliation(s)
- Ana Alice D Santos
- Department of Morphology, Federal University of Uberlândia, PO Box 593-38400-066, Uberlândia, MG, Brazil
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Martinelli PM, Camargos ERS, Morel G, Tavares CAP, Nagib PRA, Machado CRS. Rat heart GDNF: effect of chemical sympathectomy. Histochem Cell Biol 2002; 118:337-43. [PMID: 12376830 DOI: 10.1007/s00418-002-0452-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2002] [Indexed: 11/24/2022]
Abstract
Developmental studies indicate a role for GDNF in survival of motor, autonomic, and sensory neurons. However, no study attempted to demonstrate its participation in autonomic nerve regeneration. In this work, chemical sympathectomy by 6-hydroxydopamine provided the model for assessing heart GDNF expression during denervation and axonal regrowth. A glyoxylic acid-based histochemical technique evaluated the noradrenergic innervation. ELISA determined GDNF levels after concentrating heart homogenates. Light and ultrastructural in situ hybridization and immunocytochemistry were used for identifying cells expressing GDNF mRNA and protein. In control rats, the GDNF cardiac levels were significantly higher in 37-day-old animals in comparison with those aging 60 days. In sympathectomized rats, GDNF cardiac levels were significantly higher 7 days after sympathectomy and dropped to control levels at day 30. GDNF mRNA was expressed in atrial and ventricular myocytes from normal and sympathectomized rats. GDNF immunoreactivity occurred on atrial granules and quantitative analysis in electron micrographs confirmed ELISA-obtained data. In ventricular myocytes gold particles occurred sparsely. These findings constitute the first evidence for GDNF synthesis by cardiomyocytes and postulate a role for this factor soon after cardiac sympathetic denervation, probably in nerve regeneration. In atrial myocytes, GDNF is probably secreted by regulated pathway.
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Affiliation(s)
- Patricia M Martinelli
- Department of Morphology, Institute of Biological Sciences (ICB), Federal University of Minas Gerais (UFMG), 31270-901 Belo Horizonte, MG, Brazil
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Camargos ERS, Machado CRS, Teixeira AL, Rocha LLV, Ferreira AJ, Almeida AP, Barton M, Teixeira MM. Role of endothelin during experimental Trypanosoma cruzi infection in rats. Clin Sci (Lond) 2002; 103 Suppl 48:64S-67S. [PMID: 12193056 DOI: 10.1042/cs103s064s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Chagas' disease is caused by the intracellular protozoan Trypanosoma cruzi. Here we have investigated the role of endothelin-1 in T. cruzi acute infection in rats, using the orally active ET(A) receptor antagonist BSF-461314. Treatment with BSF-461314 markedly increased parasitaemia, but animals managed to control the infection by day 15. Histopathological analysis of heart tissue at the end of the acute phase showed greater numbers of parasite nests in BSF-461314-treated animals. The perfusion of isolated rat hearts from infected animals with bradykinin failed to induce an increase, and actually reduced, coronary blood flow. Pretreatment with BSF-461314 prevented changes in coronary flow induced by T. cruzi infection. Together these results demonstrate that endothelin-1, through ET(A) receptor activation, contributes to the protective immune response against acute T. cruzi infection. Moreover, these data suggest that endothelin-1 is a mediator of impaired endothelium-dependent vasomotion in the coronary microcirculation associated with acute T. cruzi infection.
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Affiliation(s)
- Elizabeth R S Camargos
- Department of Morphology, Instituto de Ciências Biológicas, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, Minas Gerais, Brazil
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Andrade LO, Machado CRS, Chiari E, Pena SDJ, Macedo AM. Trypanosoma cruzi: role of host genetic background in the differential tissue distribution of parasite clonal populations. Exp Parasitol 2002; 100:269-75. [PMID: 12128054 DOI: 10.1016/s0014-4894(02)00024-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, has quite a variable clinical presentation, ranging from asymptomatic to severe chronic cardiac and/or gastrointestinal disease. The reason for that is not completely understood, but both parasite and host genetic traits are certainly involved. Recently, we have demonstrated clinically and experimentally that the genetic variability of T. cruzi is one of the determinants of the pattern of tissue involvement in Chagas' disease. We then decided to turn our attention to the role of host genetic background. To study this, we compared the infection of four lineages of mice [three inbred (BALB/c, DBA-2, and c57Black/6) and one outbred (Swiss)] with two T. cruzi clonal populations, the Col1.7G2 clone and the JG monoclonal strain. The tissue distribution of T. cruzi strains was identical for BALB/c and DBA-2 mice, but very different in C57BL/6 (H-2(b)) and outbred Swiss mice. This result clearly demonstrates the importance of host genetic aspects in the process. Since BALB/c and DBA-2 have the same H-2 haplotype (H-2(d)) and C57BL/6 does not (H-2(b)), it is possible that MHC variability may be involved in influencing the tissue distribution of involvement in experimental Chagas' disease of the mouse.
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Affiliation(s)
- Luciana O Andrade
- Departamento de Bioquìmica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901 MG, Brazil
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