ABSTRACT
The comprehension of the pathogenesis of Trypanosoma cruzi-elicited myocarditis is crucial to delineate new therapeutic strategies aiming to ameliorate the inflammation that leads to heart dysfunction, without hampering parasite control. The augmented expression of CCL5/RANTES and CCL3/MIP-1alpha, and their receptor CCR5, in the heart of T. cruzi-infected mice suggests a role for CC-chemokines and their receptors in the pathogenesis of T. cruzi-elicited myocarditis. Herein, we discuss our recent results using a CC-chemokine receptor inhibitor (Met-RANTES), showing the participation of CC-chemokines in T. cruzi infection and unraveling CC-chemokine receptors as an attractive therapeutic target for further evaluation in Chagas disease.
Subject(s)
Chagas Cardiomyopathy/drug therapy , Chemokine CCL5/analogs & derivatives , Chemokines, CC/metabolism , Myocarditis/drug therapy , Receptors, Chemokine/antagonists & inhibitors , Trypanosoma cruzi , Animals , CD4-CD8 Ratio , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Chagas Cardiomyopathy/immunology , Chagas Cardiomyopathy/metabolism , Chemokine CCL5/therapeutic use , Chemotaxis, Leukocyte/immunology , Mice , Mice, Inbred C3H , Myocarditis/immunology , Myocarditis/metabolism , Myocarditis/parasitology , Trypanosoma cruzi/immunologyABSTRACT
The comprehension of the pathogenesis of Trypanosoma cruzi-elicited myocarditis is crucial to delineate new therapeutic strategies aiming to ameliorate the inflammation that leads to heart dysfunction, without hampering parasite control. The augmented expression of CCL5/RANTES and CCL3/MIP-1alpha, and their receptor CCR5, in the heart of T. cruzi-infected mice suggests a role for CC-chemokines and their receptors in the pathogenesis of T. cruzi-elicited myocarditis. Herein, we discuss our recent results using a CC-chemokine receptor inhibitor (Met-RANTES), showing the participation of CC-chemokines in T. cruzi infection and unraveling CC-chemokine receptors as an attractive therapeutic target for further evaluation in Chagas disease.
Subject(s)
Animals , Mice , Chagas Cardiomyopathy/drug therapy , /analogs & derivatives , Chemokines, CC/metabolism , Myocarditis/drug therapy , Receptors, Chemokine/antagonists & inhibitors , Trypanosoma cruzi , /immunology , /immunology , Chagas Cardiomyopathy/immunology , Chagas Cardiomyopathy/metabolism , /therapeutic use , Chemotaxis, Leukocyte/immunology , Myocarditis/immunology , Myocarditis/metabolism , Myocarditis/parasitology , Trypanosoma cruzi/immunologyABSTRACT
Several lines of evidence have shown that Trypanosoma cruzi interacts with host extracellular matrix (ECM) components producing breakdown products that play an important role in parasite mobilization and infectivity. Parasite-released antigens also modulate ECM expression that could participate in cell-cell and/or cell-parasite interactions. Increased expression of ECM components has been described in the cardiac tissue of chronic chagasic patients and diverse target tissues including heart, thymus, central nervous system and skeletal muscle of experimentally T. cruzi-infected mice. ECM components may adsorb parasite antigens and cytokines that could contribute to the establishment and perpetuation of inflammation. Furthermore, T. cruzi-infected mammalian cells produce cytokines and chemokines that not only participate in the control of parasitism but also contribute to the establishment of chronic inflammatory lesions in several target tissues and most frequently lead to severe myocarditis. T. cruzi-driven cytokines and chemokines may also modulate VCAM-1 and ICAM-1 adhesion molecules on endothelial cells of target tissues and play a key role in cell recruitment, especially of activated VLA-4+LFA-1+CD8+ T lymphocytes, resulting in a predominance of this cell population in the inflamed heart, central nervous system and skeletal muscle. The VLA-4+-invading cells are surrounded by a fine network of fibronectin that could contribute to cell anchorage, activation and effector functions. Since persistent "danger signals" triggered by the parasite and its antigens are required for the establishment of inflammation and ECM alterations, therapeutic interventions that control parasitism and selectively modulate cell migration improve ECM abnormalities, paving the way for the development of new therapeutic strategies improving the prognosis of T. cruzi-infected individuals
Subject(s)
Animals , Humans , Mice , Cell Adhesion Molecules , Chagas Cardiomyopathy , Extracellular Matrix , Monocyte Chemoattractant Proteins , Chagas Cardiomyopathy , Chronic Disease , Extracellular Matrix , Host-Parasite Interactions , Severity of Illness IndexABSTRACT
Several lines of evidence have shown that Trypanosoma cruzi interacts with host extracellular matrix (ECM) components producing breakdown products that play an important role in parasite mobilization and infectivity. Parasite-released antigens also modulate ECM expression that could participate in cell-cell and/or cell-parasite interactions. Increased expression of ECM components has been described in the cardiac tissue of chronic chagasic patients and diverse target tissues including heart, thymus, central nervous system and skeletal muscle of experimentally T. cruzi-infected mice. ECM components may adsorb parasite antigens and cytokines that could contribute to the establishment and perpetuation of inflammation. Furthermore, T. cruzi-infected mammalian cells produce cytokines and chemokines that not only participate in the control of parasitism but also contribute to the establishment of chronic inflammatory lesions in several target tissues and most frequently lead to severe myocarditis. T. cruzi-driven cytokines and chemokines may also modulate VCAM-1 and ICAM-1 adhesion molecules on endothelial cells of target tissues and play a key role in cell recruitment, especially of activated VLA-4+LFA-1+CD8+ T lymphocytes, resulting in a predominance of this cell population in the inflamed heart, central nervous system and skeletal muscle. The VLA-4+-invading cells are surrounded by a fine network of fibronectin that could contribute to cell anchorage, activation and effector functions. Since persistent "danger signals" triggered by the parasite and its antigens are required for the establishment of inflammation and ECM alterations, therapeutic interventions that control parasitism and selectively modulate cell migration improve ECM abnormalities, paving the way for the development of new therapeutic strategies improving the prognosis of T. cruzi-infected individuals.
Subject(s)
Cell Adhesion Molecules/physiology , Chagas Cardiomyopathy/parasitology , Chemotactic Factors/physiology , Extracellular Matrix/parasitology , Trypanosoma cruzi/physiology , Animals , Chagas Cardiomyopathy/pathology , Chronic Disease , Extracellular Matrix Proteins/metabolism , Host-Parasite Interactions , Humans , Inflammation/metabolism , Inflammation/parasitology , Mice , Severity of Illness IndexABSTRACT
It has been proposed that antigens released by Trypanosoma cruzi sensitize vertebrate cells leading to their destruction by the immune response raised against the parasite. Here, we characterized antigens released by trypomastigotes of T. cruzi that bind to non-infected cells and investigated biological consequences of this adsorption. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of antigens released by [(35)S]-methionine-labeled parasites revealed the presence of polypeptides mainly ranging from 85 to 170 kDa that were specifically recognized by sera from chronically T. cruzi infected rabbits. Polypeptides of 85-110 and 160-170 kDa bound to non-infected epithelial, fibroblast and muscle mammalian cell lines, which thus became targets for anti-T. cruzi antibody binding. Cysteine-proteinase, but not trans-sialidase, was detected among the cell-bound antigens, and purified cysteine-proteinase was adsorbed to non-infected cells. Immunoelectron microscopic studies showed that parasite antigens were mainly released as membrane vesicles that adhered to membrane microvilli and were internalized by mammalian cells. We provide evidence that adsorption of parasite antigens induced an increase in expression of extracellular matrix (ECM) components (fibronectin, laminin and type I collagen) by sensitized cells. Thus, our data reinforce the idea that in vivo T. cruzi released antigens might be involved in the establishment of inflammation, sensitizing non-infected host cells and triggering an immune response against parasite antigens. Further, our data showed that antigen sensitization modulates biological cell functions as ECM expression that could mediate cell-cell or parasite-host cell interactions, contributing to the establishment of inflammation.
