scholarly journals Treatment with Benznidazole during the Chronic Phase of Experimental Chagas' Disease Decreases Cardiac Alterations

2005 ◽  
Vol 49 (4) ◽  
pp. 1521-1528 ◽  
Author(s):  
Simone Garcia ◽  
Carolina O. Ramos ◽  
Juliana F. V. Senra ◽  
Fabio Vilas-Boas ◽  
Maurício M. Rodrigues ◽  
...  

ABSTRACT Chagas' disease, caused by Trypanosoma cruzi infection, is one of the main causes of death due to heart failure in Latin American countries. Benznidazole, the chemotherapeutic agent most often used for the treatment of chagasic patients, is highly toxic and has limited efficacy, especially in the chronic phase of the disease. In the present study we used a mouse model of chronic Chagas' disease to investigate the effects of benznidazole treatment during the chronic phase on disease progression. The hearts of benznidazole-treated mice had decreased parasitism and myocarditis compared to the hearts of untreated chagasic mice. Both groups of Trypanosoma cruzi-infected mice had significant alterations in their electrocardiograms compared to those of the healthy mice. However, untreated mice had significantly higher cardiac conduction disturbances than benznidazole-treated mice, including intraventricular conduction disturbances, atrioventricular blocks, and extrasystoles. The levels of antibodies against T. cruzi antigens (epimastigote extract, P2β, and trans-sialidase) as well as antibodies against peptides of the second extracellular loops of β1-adrenergic and M2-muscarinic cardiac receptors were also lower in the sera from benznidazole-treated mice than in the sera from untreated mice. These results demonstrate that treatment with benznidazole in the chronic phase of infection prevents the development of severe chronic cardiomyopathy, despite the lack of complete parasite eradication. In addition, our data highlight the role of parasite persistence in the development of chronic Chagas' disease and reinforce the importance of T. cruzi elimination in order to decrease or prevent the development of severe chagasic cardiomyopathy.

1987 ◽  
Vol 82 (4) ◽  
pp. 531-536 ◽  
Author(s):  
Luiz Eduardo Ramirez ◽  
Zigman Brener

In order to investigate the value of the rabbit as an experimental model for Chagas' disease, 72 animals have been inoculated by intraperitoneal and conjunctival route with bloodstream forms, vector-derived metacyclic trypomastigotes and tissue culture trypomastigotes of Trypanosoma cruzi strains Y, CL and Ernane. In 95.6% of the animals trypomastigotes had been detected at the early stages of infection by fresh blood examination. The course of parasitemia at the acute phase was strongly influenced by the parasite strain and route of inoculation. At the chronic phase parasites had been recovered by xenodiagnosis and/or hemoculture in 40% of the examined animals. The xenodiagnosis studies have shown selective interactions between the T. cruzi strains and the four species of vectors used, inducing significant variability in the results. The data herein present are consistent with the parasitological requirements established for a suitable model for chronic Chagas' disease.


Author(s):  
Nadjania Saraiva de Lira Silva ◽  
Cristina Mary Orikaza ◽  
Fabiana Rodrigues de Santana ◽  
Luana Aguiar dos Santos ◽  
Bruno Ramos Salu ◽  
...  

Chagas’ disease is a parasitosis caused by Trypanosoma cruzi, which affects approximately 8 million people worldwide. The balance between pro- and anti-inflammatory cytokines produced during immunological responses contributes to disease prognosis and progression. Parasite tissue persistence can induce chronic inflammatory stimuli, which can cause long-term tissue injury and fibrosis. Chronic Chagas’ patients exhibit increased levels of interleukin (IL)-9, an important cytokine in the regulation of inflammatory and fibrogenic processes. Data on the role of IL-9 in other pathologies are sometimes contradictory, and few studies have explored this cytokine’s influence in Chagas’ disease pathology. Hence, the aim of this study was to evaluate the role of IL-9 in the progression of T. cruzi infection in vivo and in vitro. In vitro infection demonstrated that IL-9 reduced the number of infected cells and decreased the multiplication of intracellular amastigotes in both C2C12 myoblasts and bone marrow-derived macrophages. In myoblasts, the increased production of nitric oxide (NO) was essential for reduced parasite multiplication, whereas macrophage responses resulted in increased IL-6 and reduced TGF-β levels, indicating that parasite growth restriction mechanisms induced by IL-9 were cell-type specific. Experimental infection of BALB/c mice with T. cruzi trypomastigotes of the Y strain implicated a major role of IL-9 during the chronic phase, as increased Th9 and Tc9 cells were detected among splenocytes; higher levels of IL-9 in these cell populations and increased cardiac IL-9 levels were detected compared to those of uninfected mice. Moreover, rIL9 treatment decreased serum IL-12, IL-6, and IL-10 levels and cardiac TNF-α levels, possibly attempting to control the inflammatory response. IL-9 neutralization increased cardiac fibrosis, synthesis of collagens I and III, and mastocyte recruitment in BALB/c heart tissue during the chronic phase. In conclusion, our data showed that IL-9 reduced the invasion and multiplication of T. cruzi in vitro, in both myoblasts and macrophages, favoring disease control through cell-specific mechanisms. In vivo, IL-9 was elevated during experimental chronic infection in BALB/c mice, and this cytokine played a protective role in the immunopathological response during this phase by controlling cardiac fibrosis and proinflammatory cytokine production.


Parasitology ◽  
2013 ◽  
Vol 140 (7) ◽  
pp. 917-927 ◽  
Author(s):  
ROMINA FAURO ◽  
SILVINA LO PRESTI ◽  
CAROLINA BAZAN ◽  
ALEJANDRA BAEZ ◽  
MARIANA STRAUSS ◽  
...  

SUMMARYChagas infection is a major endemic disease affecting Latin American countries. The persistence ofTrypanosoma cruzigenerates a chronic inflammatory reactivity that induces an immune response directed to the host's tissues. The effectiveness of the treatment in the chronic phase is still unsatisfactory due, amongst other reasons, to the collateral effects of the drugs used. We investigated the effect of clomipramine, a tricyclic antidepressant that, when used as a treatment ofT. cruzi-chronically infected mice, inhibits trypanothione reductase, an exclusive and vital enzyme ofT. cruzi. Clomipramine improved survival (P<0·05) by diminishing the parasite intensity as demonstrated by PCR studies in the heart and skeletal muscle, and significantly prevented the evolution to fibrosis of the inflammatory infiltrates. Clomipramine could be a good candidate for the treatment of chronic Chagas disease.


Cells ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 200 ◽  
Author(s):  
Bruna Pinto ◽  
Nayara Medeiros ◽  
Tereza Fontes-Cal ◽  
Isabela Naziazeno ◽  
Rodrigo Correa-Oliveira ◽  
...  

Chagas disease, caused by Trypanosoma cruzi, is a potentially life-threatening tropical disease endemic to Latin American countries that affects approximately 8 million people. In the chronic phase of the disease, individuals are classified as belonging to the indeterminate clinical form or to the cardiac and/or digestive forms when clinical symptoms are apparent. The relationship between monocytes and lymphocytes may be an important point to help clarify the complexity that surrounds the clinical symptoms of the chronic phase of Chagas disease. The co-stimulatory signals are essential to determining the magnitude of T cell response to the antigen. The signals are known to determine the regulation of subsequent adaptive immune response. However, little is known about the expression and function of these molecules in Chagas disease. Therefore, this review aims to discuss the possible role of main pathways of co-stimulatory molecule-receptor interactions in this pathology that could be crucial to understand the disease dynamics.


2011 ◽  
Vol 19 (2) ◽  
pp. 167-173 ◽  
Author(s):  
M. Carmen Thomas ◽  
Ana Fernández-Villegas ◽  
Bartolomé Carrilero ◽  
Concepción Marañón ◽  
Daniel Saura ◽  
...  

ABSTRACTNowadays, the techniques available for chronic Chagas' disease diagnosis are very sensitive; however, they do not allow discrimination of the patient's clinical stages of the disease. The present paper describes that three out of the five different repeats contained in theTrypanosoma cruziTcCA-2 membrane protein (3972-FGQAAAGDKPPP, 6303-FGQAAAGDKPAP, and 3973-FGQAAAGDKPSL) are recognized with high sensitivity (>90%) by sera from chronic Chagas' disease patients and that they are not recognized by sera from patients in the acute phase of the disease. A total of 133 serum samples from chagasic patients and 50 serum samples from healthy donors were tested. In addition, sera from 15 patients with different autoimmune diseases, 43 serum samples from patients suffering an infectious disease other than Chagas' disease, and 38 serum samples from patients with nonchagasic cardiac disorders were also included in this study. The residue 3973 peptide shows a specificity of >98%, as it is not recognized by individuals with autoimmune and inflammatory processes or by patients with a nonchagasic cardiomyopathy. Remarkably, the levels of antibody against the 3973 epitope detected by the sera from Chagas' disease patients in the symptomatic chronic phase, involving cardiac or digestive alterations, are higher than those detected by the sera from Chagas' disease patients in the indeterminate phase of the disease. It is suggested that the diagnostic technique described could also be used to indicate the degree of pathology. The amino acids F, Q, and DKP located in the peptide at positions 1, 3, and 8 to 10, respectively, are essential to conform to the immunodominant antigenic epitope.


2019 ◽  
Vol 26 (36) ◽  
pp. 6519-6543 ◽  
Author(s):  
Adriana Egui ◽  
Paola Lasso ◽  
Elena Pérez-Antón ◽  
M. Carmen Thomas ◽  
Manuel Carlos López

Chagas disease courses with different clinical phases and has a variable clinical presentation and progression. The acute infection phase mostly exhibits a non-specific symptomatology. In the absence of treatment, the acute phase is followed by a chronic phase, which is initially asymptomatic. This chronic asymptomatic phase of the disease is characterized by a fragile balance between the host’s immune response and the parasite replication. The loss of this balance is crucial for the progression of the sickness. The virulence and tropism of the T. cruzi infecting strain together to the inflammation processes in the cardiac tissue are the main factors for the establishment and severity of the cardiomyopathy. The efficacy of treatment in chronic Chagas disease patients is controversial. However, several studies carried out in chronic patients demonstrated that antiparasitic treatment reduces parasite load in the bloodstream and leads to an improvement in the immune response against the Trypanosoma cruzi parasite. The present review is mainly focused on the cellular patterns associated to the clinical status and the evolution of the disease in chronic patients, as well as the effectiveness of the treatment related to T. cruzi infection control. Therefore, an emphasis is placed on the dynamics of specific-antigens T cell subpopulations, their memory and activation phenotypes, their functionality and their contribution to pathogenesis or disease control, as well as their association with risk of congenital transmission of the parasite.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Marcela Hernández-Torres ◽  
Rogério Silva do Nascimento ◽  
Monica Cardozo Rebouças ◽  
Alexandra Cassado ◽  
Kely Catarine Matteucci ◽  
...  

AbstractChagas disease is a life-threatening disorder caused by the protozoan parasite Trypanosoma cruzi. Parasite-specific antibodies, CD8+ T cells, as well as IFN-γ and nitric oxide (NO) are key elements of the adaptive and innate immunity against the extracellular and intracellular forms of the parasite. Bim is a potent pro-apoptotic member of the Bcl-2 family implicated in different aspects of the immune regulation, such as negative selection of self-reactive thymocytes and elimination of antigen-specific T cells at the end of an immune response. Interestingly, the role of Bim during infections remains largely unidentified. To explore the role of Bim in Chagas disease, we infected WT, Bim+/−, Bim−/− mice with trypomastigotes forms of the Y strain of T. cruzi. Strikingly, our data revealed that Bim−/− mice exhibit a delay in the development of parasitemia followed by a deficiency in the control of parasite load in the bloodstream and a decreased survival compared to WT and Bim+/− mice. At the peak of parasitemia, peritoneal macrophages of Bim−/− mice exhibit decreased NO production, which correlated with a decrease in the pro-inflammatory Small Peritoneal Macrophage (SPM) subset. A similar reduction in NO secretion, as well as in the pro-inflammatory cytokines IFN-γ and IL-6, was also observed in Bim−/− splenocytes. Moreover, an impaired anti-T. cruzi CD8+ T-cell response was found in Bim−/− mice at this time point. Taken together, our results suggest that these alterations may contribute to the establishment of a delayed yet enlarged parasitic load observed at day 9 after infection of Bim−/− mice and place Bim as an important protein in the control of T. cruzi infections.


2017 ◽  
Vol 11 (7) ◽  
pp. e0005796 ◽  
Author(s):  
Ingebourg Georg ◽  
Alejandro Marcel Hasslocher-Moreno ◽  
Sergio Salles Xavier ◽  
Marcelo Teixeira de Holanda ◽  
Eric Henrique Roma ◽  
...  

2004 ◽  
Vol 37 (6) ◽  
pp. 454-459
Author(s):  
Adriano Gomes Silva ◽  
Elisangela Paula Silveira-Lacerda ◽  
Jair Pereira Cunha-Júnior ◽  
Maria Aparecida de Souza ◽  
Silvio Favoreto Junior

Trypanosoma cruzi trypomastigotes excrete-secrete a complex mixture of antigenic molecules. This antigenic mixture denominated trypomastigote excreted-secreted antigens contains a 150-160 kDa band that shows excellent performance in Chagas' disease diagnosis by immunoblotting. The present study partially characterized by two-dimensional gel electrophoresis the immunoreactivity against the 150-160kDa protein using sera samples from chagasic patients in different phases of the disease. Trypomastigote excreted-secreted antigen preparations were subjected to high-resolution two-dimensional (2D) gel electrophoresis followed by immunoblotting with sera from chagasic and non-chagasic patients. The 150-160kDa protein presented four isoforms with isoelectric focusing ranging from 6.2 to 6.7. The four isoforms were recognized by IgM from acute phase and IgG from chronic phase sera of chagasic patients. The 150-160kDa isoform with IF of approximately 6.4 became the immunodominant spot with the progression of the disease. No cross-reactivity was observed with non-chagasic or patients infected with Leishmania sp. In this study we provide basic knowledge that supports the validation of trypomastigote excreted-secreted antigens for serological diagnosis of Chagas' disease.


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