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Central nervous system alterations was described in Chagas disease in both human and experimental models, leading to meningoencephalitis, stroke and cognitive impairment. Recently, our group demonstrated that acute infection by Trypanossoma cruzi leads to cerebral microvasculophaty in mice with endothelial dysfunction, capillary rarefaction, increased rolling and leukocyte adhesion. Only benznidazole and nifurtimox are available for clinical treatment, they have an efficiency of 80% in the acute phase and less than 20% in chronic phase. However, the effect of these drugs on brain microcirculation has not yet been evaluated. We hypothesized that early treatment with benznidazole could protect brain microcirculation during acute experimental Chagas disease. Swiss Webster mice were inoculated with 10 4 trypomastigotes forms of T. cruzi, and after 24 h they were treated with 50 or 100 mg/kg/day of benznidazole for 14 consecutive days. In untreated infected mice, we observed cerebral microvascular rarefaction, increase in leukocyte rolling and adhesion, reduced cerebral blood flow, and increased CD3+ and F4-80+ cells in brain tissue. Early treatment with benznidazole at 100 mg/kg/day and 50 mg/kg/day prevented the occurrence of the alterations mentioned. Here, we show that BZ is able to protect the microcirculation and reduced brain inflammation in acute experimental Chagas disease., (© 2022. The Author(s).)

Chronic Chagasic cardiomyopathy (CCC), a progressive inflammatory and fibrosing disease, is the most prominent clinical form of Chagas disease, a neglected tropical disease caused by Trypanosoma cruzi infection. During CCC, the parasite remains inside the cardiac cells, leading to tissue damage, involving extensive inflammatory response and irregular fibrosis. Among the fibrogenic factors is transforming growth factor-β (TGF-β), a key cytokine controlling extracellular matrix synthesis and degradation. TGF-β is involved in CCC onset and progression, with increased serum levels and activation of its signaling pathways in the cardiac tissue, which crucially contributes to fibrosis. Inhibition of the TGF-β signaling pathway attenuates T. cruzi infection and prevents cardiac damage in an experimental model of acute Chagas disease. The aim of this study was to investigate the effect of TGF-β neutralization on T. cruzi infection in both in vitro and in vivo pre-clinical models, using the 1D11 monoclonal antibody. To this end, primary cultures of cardiac cells were infected with T. cruzi trypomastigote forms and treated with 1D11. For in vivo studies, 1D11 was administered in different schemes for acute and chronic phase models (Swiss mice infected with 10 4 parasites from the Y strain and C57BL/6 mice infected with 10 2 parasites from the Colombian strain, respectively). Here we show that the addition of 1D11 to cardiac cells greatly reduces cardiomyocyte invasion by T. cruzi and the number of parasites per infected cell. In both acute and chronic experimental models, T. cruzi infection altered the electrical conduction, decreasing the heart rate, increasing the PR interval and the P wave duration. The treatment with 1D11 reduced cardiac fibrosis and reversed electrical abnormalities improving cardiac performance. Taken together, these data further support the major role of the TGF-β signaling pathways in T. cruzi -infection and their biological consequences on parasite/host interactions. The therapeutic effects of the 1D11 antibody are promising and suggest a new possibility to treat cardiac fibrosis in the chronic phase of Chagas' heart disease by TGF-β neutralization., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer CC declared a shared affiliation with the authors RF, ES, WD, RA, and MW to the handling editor at the time of review., (Copyright © 2022 Ferreira, de Souza, Vilar-Pereira, Degrave, Abreu, Meuser-Batista, Ferreira, Ledbeter, Barker, Bailly, Feige, Lannes-Vieira, de Araújo-Jorge and Waghabi.)

Transforming growth factor beta (TGF-β) is deeply involved on the pathogenesis of Chagas disease. Our group has been investigating the participation of this pleiotropic cytokine in different aspects of Chagas disease over the last 20 years. Important observations have been made, such as: (i) the ability of Trypanosoma cruzi in activating latent TGF-β; (ii) the potential involvement of TGF-β pathway on T. cruzi invasion of host cells; (iii) association of TGF-β with parasite intracellular replication; (iv) cardiac fibrosis development and maintenance; (v) disruption of Connexin-43 plaque structures and (vi) inflammation and immune response. In this perspective article we intend to discuss the advances of the potential use of new therapies targeting TGF-β to treat the cardiac alterations of Chagas disease-affected patients.

CD8 T cells are regarded as pivotal players in both immunoprotection and immunopathology following Trypanosoma cruzi infection. Previously, we demonstrated the expansion of CD8+ T lymphocytes in the spleen of T. cruzi-infected mice under treatment with benznidazole (N-benzyl-2-nitroimidazole acetamide; Bz), a drug available for clinical therapy. This finding underlies the concept that the beneficial effects of Bz on controlling acute T. cruzi infection are related to a synergistic process between intrinsic trypanocidal effect and indirect triggering of the active immune response. In the present study, we particularly investigated the effect of Bz treatment on the CD8+ T cell subset following T. cruzi infection. Herein we demonstrated that, during acute T. cruzi infection, Bz treatment reduces and abbreviates the parasitemia, but maintains elevated expansion of CD8+ T cells. Within this subset, a remarkable group of CD8low cells was found in both Bz-treated and non-treated infected mice. In Bz-treated mice, early pathogen control paralleled the lower frequency of recently activated CD8low cells, as ascertained by CD69 expression. However, the CD8low subset sustains significant levels of CD44highCD62Llow and CD62LlowT-bethigh effector memory T cells, in both Bz-treated and non-treated infected mice. These CD8low cells also comprise the main group of spontaneous interferon (IFN)-γ-producing CD8+ T cells. Interestingly, following in vitro anti-CD3/CD28 stimulation, CD8+ T cells from Bz-treated T. cruzi-infected mice exhibited higher frequency of IFN-γ+ cells, which bear mostly a CD8low phenotype. Altogether, our results point to the marked presence of CD8low T cells that arise during acute T. cruzi infection, with Bz treatment promoting their significant expansion along with a potential effector program for high IFN-γ production., Competing Interests: The authors have declared that no competing interests exist.

TGF-β involvement in Chagas disease cardiomyopathy has been clearly demonstrated. The TGF-β signaling pathway is activated in the cardiac tissue of chronic phase patients and is associated with an increase in extracellular matrix protein expression. The aim of this study was to investigate the effect of GW788388, a selective inhibitor of TβR1/ALK5, on cardiac function in an experimental model of chronic Chagas' heart disease. To this end, C57BL/6 mice were infected with Trypanosoma cruzi (102 parasites from the Colombian strain) and treated orally with 3mg/kg GW788388 starting at 120 days post-infection (dpi), when 100% of the infected mice show cardiac damage, and following three distinct treatment schedules: i) single dose; ii) one dose per week; or iii) three doses per week during 30 days. The treatment with GW788388 improved several cardiac parameters: reduced the prolonged PR and QTc intervals, increased heart rate, and reversed sinus arrhythmia, and atrial and atrioventricular conduction disorders. At 180 dpi, 30 days after treatment interruption, the GW3x-treated group remained in a better cardiac functional condition. Further, GW788388 treatment reversed the loss of connexin-43 enriched intercellular plaques and reduced fibrosis of the cardiac tissue. Inhibition of the TGF-β signaling pathway reduced TGF-β/pSmad2/3, increased MMP-9 and Sca-1, reduced TIMP-1/TIMP-2/TIMP-4, and partially restored GATA-6 and Tbox-5 transcription, supporting cardiac recovery. Moreover, GW788388 administration did not modify cardiac parasite load during the infection but reduced the migration of CD3+ cells to the heart tissue. Altogether, our data suggested that the single dose schedule was not as effective as the others and treatment three times per week during 30 days seems to be the most effective strategy. The therapeutic effects of GW788388 are promising and suggest a new possibility to treat cardiac fibrosis in the chronic phase of Chagas' heart disease by TGF-β inhibitors., Competing Interests: The authors have declared that no competing interests exist.

Transforming growth factor beta (TGF-β) cytokine is involved in Chagas disease establishment and progression. Since Trypanosoma cruzi can modulate host cell receptors, we analysed the TGF-β receptor type II (TβRII) expression and distribution during T. cruzi - cardiomyocyte interaction. TβRII immunofluorescent staining revealed a striated organization in cardiomyocytes, which was co-localized with vinculin costameres and enhanced (38%) after TGF-β treatment. Cytochalasin D induced a decrease of 45·3% in the ratio of cardiomyocytes presenting TβRII striations, demonstrating an association of TβRII with the cytoskeleton. Western blot analysis showed that cytochalasin D significantly inhibited Smad 2 phosphorylation and fibronectin stimulation after TGF-β treatment in cardiomyocytes. Trypanosoma cruzi infection elicited a decrease of 79·8% in the frequency of cardiomyocytes presenting TβRII striations, but did not interfere significantly in its expression. In addition, T. cruzi-infected cardiomyocytes present a lower response to exogenous TGF-β, showing no enhancement of TβRII striations and a reduction of phosphorylated Smad 2, with no significant difference in TβRII expression when compared to uninfected cells. Together, these results suggest that the co-localization of TβRII with costameres is important in activating the TGF-β signalling cascade, and that T. cruzi-derived cytoskeleton disorganization could result in altered or low TGF-β response in infected cardiomyocytes.

Aggression is defined as the act in which an individual intentionally harms or injures another of their own species. Antipsychotics are a form of treatment used in psychiatric routine. They have been used for decades in treatment of patients with aggressive behavior. Haloperidol and risperidone promote the control of psychiatric symptoms, through their respective mechanisms of action. Experimental models are obtained by behavioral, genetic, and pharmacological manipulations, and use a reduced number of animals. In this context, we applied the model of spontaneous aggression (MSA), originating the presence of highly aggressive mice (AgR) when reassembled in adulthood. We administered haloperidol and risperidone in escalating doses, for ten consecutive days. Using positive and negative control groups, we evaluated the effectiveness of these drugs and the reversal of the aggressive behavior, performing the tail suspension test (TST) and open field test (OFT) on 10th day of treatment and 10 days after its discontinuation. The results showed that both antipsychotic drugs were effective in AgR and reversed the aggressive phenotype, reducing the number of attacks by AgR and the extent of lesions in the subordinate mice (AgD) exposed to the pattern of aggressive behavior (PAB) of the aggressors. This conclusion is based on the reduction in the animals' motor and exploratory activity, and on the reversal of patterns of aggressive behavior. The association between the MSA and experiments with other therapeutic protocols and different antipsychotics can be an important methodology in the study of aggressive behavior in psychiatric patients., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Heart disease progression occurs in 30% of patients with chronic Trypanosoma cruzi infection. Supplementation with selenium (Se) in animal model of T. cruzi infection produced promising results. There is evidence that patients with Chagas heart disease have lower Se levels than healthy individuals and patients with T. cruzi infection without of cardiac disease. The aim of this investigation is to estimate the effect of Se treatment on prevention of heart disease progression in patients with chagasic cardiopathy., Methods: The Selenium Treatment and Chagasic Cardiopathy trial is a superiority, double-blind, placebo-controlled, randomized clinical trial. The eligibility criteria are as follows: (1) a Chagas disease diagnosis confirmed by serology; (2) segmental, mild or moderate global left ventricular systolic dysfunction; and (3) age between 18 and 65 years. The exclusion criteria are as follows: (1) pregnancy, (2) diabetes mellitus, (3) tobacco use, (4) alcohol abuse, (5) evidence of nonchagasic heart disease, (6) depression, (7) dysphagia with evidence of food residues in the esophagus, (8) dysphagia with weight loss higher than 15% of usual weight in the last four months and/or (9) conditions that may result in low protocol adherence. The intervention will be 100 μg of sodium selenite once daily for 365 consecutive days compared to placebo. The following are the primary outcomes to be measured: (1) the trajectories of the left ventricular ejection fraction in the follow-up period; (2) reduction of heart disease progression rates, with progression defined as a 10% decrease in left ventricular ejection fraction; and (3) rate of hospital admissions attributable to dysrhythmia, heart failure or stroke due to Chagas disease. One hundred thirty patients will be randomly allocated into either the intervention or placebo group at a ratio of 1:1. The sequence allocation concealment and blinding were planned to be conducted with the strategy of numbered boxes. Both patients and health-care providers will remain blinded to the intervention groups during the 5 years of follow-up., Discussion: If Se treatment reduces the progression of Chagas cardiopathy, the inclusion of this micronutrient in the daily diet can improve the therapeutic regimen for this neglected tropical disease at low cost., Trial Registration: Clinical Trials.gov ID: NCT00875173 (registered 20 October 20 2008).

This article looks to the objects and physical environments destined to teaching and research in health from a different perspective. It addresses the communication between the designers and the people that use their projects and investigates in which ways the designer can contribute to a positive transformation of the state of mind of the users of teaching and health environments, taking into account the reaction of people to the products and environments, especially manifestations of pleasure and well-being. The article presents a pilot edition of an instrument for sensitization and data collection in form of a workshop called "Environment, Creation and Pleasure".

This article describes the collective construction of a research instrument (interview guideline) for investigating the knowledge of chagasic patients attended at the Chagas Disease Reference Center of the Oswaldo Cruz Foundation. A multi-professional team worked sequentially on six versions of the guideline for semi-structured interviews. The instrument aims collecting data for a qualitative approach to concepts and perceptions of the patients from the perspective of the human relationships in the context of life and health. It detects the individual experiences regarding the diseasing process, the knowledge about the disease (and the infection), the emotions, reactions, and affections. Some theoretical aspects were discussed based on sociological and anthropological practices used in public health actions. We performed a complete interview with a patient for testing and adjusting the instrument. The interview guideline was tested and showed to be a suitable instrument for investigating the knowledge of chagasic patients, covering many subjective and cognitive aspects. This knowledge can be a useful contribution to the development of strategies, actions and information material aimed at improving and humanizing the care delivered to Chagas disease patients.

Fas/Fas ligand (Fas-L) engagement, a potent inducer of apoptosis, is also important for cellular activation, regulation of effector and chemotactic activity, and secretion of chemokines and cytokines. We evaluated the relevance of Fas/Fas-L in the regulation of myocarditis induced by Trypanosoma cruzi infection and observed that in Fas-L(-/-) mice (gld/gld), cardiac infiltration was significantly reduced, accordingly showing less cardiomyocyte destruction. Fluorescence-activated cell sorting analysis of cardiac inflammatory cells showed higher numbers of CD8(+) T cells in BALB/c compared with gld/gld mice but similar levels of lymphocyte function-associated antigen-1, intercellular adhesion molecule, CD2, and CD69 expression; MAC-1(+) myeloid cells and mast cells were increased in BALB/c mice, whereas gld/gld mice exhibited an enrichment of CD4(+/low) T cells. Intracellular labeling of cytokines revealed no clear cardiac skewing of Th1 or Th2 responses, but we found a higher number of interleukin-10(+) cells in gld/gld mice and a deficient expression of vascular cell adhesion molecule-1 on cardiac endothelial cells in gld/gld mice. Finally, we found a population of CD3(+) but CD4/CD8 double negative cardiac T cells in both groups of infected mice, but down-regulation of some adhesion molecules and surface receptors was only observed in gld/gld mice, indicating a targeted T-cell population mostly affected by the lack of Fas-L engagement. These results point to a role for myocarditis regulation by Fas/Fas-L beyond its possible direct relevance in cellular death.

It is well established that activating-type Fc receptors for immunoglobulin G (FcgammaR), such as FcgammaRI and FcgammaRIII, are essential for inducing inflammatory responses. On the other hand, a unique inhibitory FcgammaR, FcgammaRIIB, inhibits intracellular signaling upon engagement of immunoglobulin G-immune complexes, suppressing inflammation and autoimmunity. The expression of FcgammaRIIB on B lymphocytes, natural killer cells, macrophages, mast cells, and a number of other cell types has been demonstrated for many years. However, the expression on T lymphocytes is probably restricted to activated cells in a narrow window of time. The controversy regarding the FcgammaR expression on T lymphocytes is attributable to considerable heterogeneity of cellular subpopulations and activation stages during immune responses in vivo. We addressed here this question by using mice experimentally infected with Trypanosoma cruzi, and we found an increase in the CD8(+) FcgammaR(+) population but not in the CD4(+) FcgammaR(+) population. Moreover, CD8(+) FcgammaR(+) T cells predominantly composed the cardiac inflammatory infiltration induced by the infection. These results indicate a novel pattern of FcgammaR expression on T cells in a pathological situation, and possible functional roles of this phenomenon are discussed.

Alpha-Macroglobulins (AM) are protease inhibitors with important roles in inflammation and in immunomodulation that behave as acute-phase proteins in many experimental models. In the present work the levels of AM in the plasma of outbred Swiss albino mice acutely infected with Trypanosoma cruzi were studied. The results showed that increased levels of AM were present in the majority of the infected mice and that AM levels increased independently of the rise in parasitaemia. There was a high degree of heterogeneity in the intensity of the modulation of AM levels as well as in the kinetics of AM synthesis. This heterogeneity was related neither with the intensity of infection nor with the sex of the host. No correlation between AM levels and survival to the acute phase could be observed in the outbred mice. The consequence of such a heterogeneity is unclear, although AM as immunoregulatory molecules could play a role in the development of the symptoms of the chronic phase of Chagas' disease.

The effect of mild enzyme (trypsin, neuraminidase) treatment, periodate treatment and addition of carbohydrates (mono, di-, and polysaccharides) on the ingestion of Trypanosoma cruzi epimastigotes and trypomastigotes by mouse macrophages was studied. Trypsin treatment did not interfere with the ingestion of epimastigotes but did, however, increase the ingestion of trypomastigotes by mouse peritoneal macrophages. Neuraminidase and periodate treatment of the parasites increased the uptake of epi- and trypomastigote forms. The neuraminidase effect was partially blocked by galactose or N-acetylgalactosamine. Galactose, mannose, fucose, N-acetylglucosamine, and N-acetylgalactosamine had an influence on the ingestion of T. cruzi by macrophages. This effect was dependent on the strain of parasite tested, and the medium used to cultivate the epimastigotes. The results obtained, in conjunction with the work of others, suggest that glycoproteins and/or glycolipids on the parasite and/or macrophage surface are involved in the T. cruzi-macrophage interaction.

The effect of incubation with lectins of the macrophages or two evolutive stages of Trypanosoma cruzi (noninfective epimastigotes and infective trypomastigotes) on the ingestion of the parasites by mouse peritoneal macrophages was studied. Lectins which bind to residues of mannose (Lens culinaris, LCA), N-acetyl-D-glucosamine or N-acetylneuraminic acid (Triticum vulgaris, WGA), beta-D-galactose (Ricinus communis, RCA), N-acetyl-D-galactosamine (Phaseolus vulgaris, PHA; Dolichos biflorus, DBA; and Wistaria floribunda, WFA), fucose (Lotus tetragonolobus, LTA), and N-acetylneuraminic acid (Limulus polyphemus, LPA) were used. By lectin blockage we concluded that, alpha-D-mannose-like, beta-D-galactose and N-acetyl-D-galactosamine (PHA, reagent) residues, located on the macrophage's surface are required for both epi- and trypomastigote uptake, while N-acetylneuraminic acid and fucose residues, impede trypomastigote ingestion but do not interfere with epimastigote interiorization. Macrophages' N-acetyl-D-glucosamine residues are required for epimastigote uptake. On the other hand, from the T. cruzi surface, mannose residues prevent ingestion of epi- and trypomastigotes. Galactose residues participate in endocytosis of trypomastigotes, but hinder epimastigote interiorization. Exposed N-acetyl-D-glucosamine residues are required for uptake of the two evolutive forms. N-acetylneuraminic acid residues on the trypomastigote membrane prevent their endocytosis by macrophages. These results together with those reported previously showing the effect of monosaccharides on the T. cruzi-macrophage interaction, indicate that (a) sugar residues located on the parasite and on macrophage surface play some role in the process of recognition of T. cruzi, (b) different macrophage carbohydrate-containing receptors are involved in the recognition of epimastigotes and trypomastigotes forms of T. cruzi, (c) N-acetylneuraminic acid residues located on the surface of trypomastigotes or macrophages impede the interaction of the parasite with these host cells, and suggest that (d) sugar-binding proteins located on the macrophage surface participate in the recognition of beta-D-galactose and N-acetyl-D-galactosamine residues located on the surface of trypomastigotes and exposed after blockage or splitting off of N-acetylneuraminic acid residues. Some lectins which bind to macrophages and block the ingestion of parasites did not interfere with their adhesion.

Chicken macrophages, obtained by cultivation of blood monocytes, were infected with epimastigote and bloodstream trypomastigote forms of Trypanosoma cruzi strain Y. The percentage of macrophages containing parasites within parasitophorous vacuoles and of flagellates attached to cell surfaces was determined. By incubation of the macrophages at 4 degrees C or in the presence of cytochalasin B it was possible to dissociate the attachment from the internalization phases in the process of infection of macrophages. Both treatments had a marked effect on the internalization of epimastigote and trypomastigote forms. Cytochalasin B treatment and placement of the macrophages at 4 degrees C before infection inhibited this process by about 99 and 96%, respectively. These results suggest that endocytosis is the principal mechanism of internalization of T. cruzi by macrophages. They show also that epimastigote and trypomastigote forms of T. cruzi have a different rate of adhesion to the macrophage surface.