WorldWideScience

Sample records for acute trypanosoma cruzi

  1. The Ly49E receptor inhibits the immune control of acute Trypanosoma cruzi infection

    Directory of Open Access Journals (Sweden)

    Jessica Filtjens

    2016-11-01

    Full Text Available The protozoan parasite Trypanosoma cruzi (T. cruzi circulates in the blood upon infection and invades a variety of cells. Parasites intensively multiply during the acute phase of infection and persist lifelong at low levels in tissues and blood during the chronic phase. Natural killer (NK and NKT cells play an important role in the immune control of T. cruzi infection, mainly by releasing the cytokine IFN-γ that activates the microbicidal action of macrophages and other cells and shapes a protective type 1 immune response. The mechanisms by which immune cells are regulated to produce IFN-γ during T. cruzi infection are still incompletely understood. Here, we show that urokinase plasminogen activator (uPA is induced early upon T. cruzi infection, and remains elevated until day 20 post inoculation. We previously demonstrated that the inhibitory receptor Ly49E, which is expressed, among others, on NK and NKT cells, is triggered by uPA. Therefore, we compared wild type (WT to Ly49E knockout (KO mice for their control of experimental T. cruzi infection. Our results show that young, i.e. 4- and 6-week-old, Ly49E KO mice control the infection better than WT mice, indicated by a lower parasite load and less cachexia. The beneficial effect of Ly49E depletion is more obvious in 4-week-old male than in female mice and weakens in 8-week-old mice. In young mice, the lower T. cruzi parasitemia in Ly49E KO mice is paralleled by higher IFN-γ production compared to their WT controls. Our data indicate that Ly49E receptor expression inhibits the immune control of T. cruzi infection. This is the first demonstration that the inhibitory Ly49E receptor can interfere with the immune response to a pathogen in vivo.

  2. Oral exposure to Phytomonas serpens attenuates thrombocytopenia and leukopenia during acute infection with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Rosiane V da Silva

    Full Text Available Mice infected with Trypanosoma cruzi, the agent of Chagas disease, rapidly develop anemia and thrombocytopenia. These effects are partially promoted by the parasite trans-sialidase (TS, which is shed in the blood and depletes sialic acid from the platelets, inducing accelerated platelet clearance and causing thrombocytopenia during the acute phase of disease. Here, we demonstrate that oral immunization of C57BL/6 mice with Phytomonas serpens, a phytoflagellate parasite that shares common antigens with T. cruzi but has no TS activity, reduces parasite burden and prevents thrombocytopenia and leukopenia. Immunization also reduces platelet loss after intraperitoneal injection of TS. In addition, passive transfer of immune sera raised in mice against P. serpens prevented platelet clearance. Thus, oral exposure to P. serpens attenuates the progression of thrombocytopenia induced by TS from T. cruzi. These findings are not only important for the understanding of the pathogenesis of T. cruzi infection but also for developing novel approaches of intervention in Chagas disease.

  3. The Acute Phase of Trypanosoma cruzi Infection Is Attenuated in 5-Lipoxygenase-Deficient Mice

    Directory of Open Access Journals (Sweden)

    Adriana M. C. Canavaci

    2014-01-01

    Full Text Available In the present work we examine the contribution of 5-lipoxygenase- (5-LO- derived lipid mediators to immune responses during the acute phase of Trypanosoma cruzi infection in 5-LO gene knockout (5-LO−/− mice and wild-type (WT mice. Compared with WT mice, the 5-LO−/− mice developed less parasitemia/tissue parasitism, less inflammatory cell infiltrates, and a lower mortality. This resistance of 5-LO−/− mice correlated with several differences in the immune response to infection, including reduced PGE2 synthesis; sustained capacity of splenocytes to produce high levels of interleukin (IL-12 early in the infection; enhanced splenocyte production of IL-1β, IL-6, and IFN-γ; rapid T-cell polarization to secrete high quantities of IFN-γ and low quantities of IL-10; and greater numbers of CD8+CD44highCD62Llow memory effector T cells at the end of the acute phase of infection. The high mortality in WT mice was associated with increased production of LTB4/LTC4, T cell bias to produce IFN-γ, high levels of serum nitrite, and marked protein extravasation into the peritoneal cavity, although survival was improved by treatment with a cys-LT receptor 1 antagonist. These data also provide evidence that 5-LO-derived mediators negatively affect host survival during the acute phase of T. cruzi infection.

  4. Distantiae transmission of Trypanosoma cruzi: a new epidemiological feature of acute Chagas disease in Brazil.

    Directory of Open Access Journals (Sweden)

    Samanta Cristina das Chagas Xavier

    2014-05-01

    Full Text Available BACKGROUND: The new epidemiological scenario of orally transmitted Chagas disease that has emerged in Brazil, and mainly in the Amazon region, needs to be addressed with a new and systematic focus. Belém, the capital of Pará state, reports the highest number of acute Chagas disease (ACD cases associated with the consumption of açaí juice. METHODOLOGY/PRINCIPAL FINDINGS: The wild and domestic enzootic transmission cycles of Trypanosoma cruzi were evaluated in the two locations (Jurunas and Val-de Cães that report the majority of the autochthonous cases of ACD in Belém city. Moreover, we evaluated the enzootic cycle on the three islands that provide most of the açaí fruit that is consumed in these localities. We employed parasitological and serological tests throughout to evaluate infectivity competence and exposure to T. cruzi. In Val-de-Cães, no wild mammal presented positive parasitological tests, and 56% seroprevalence was observed, with low serological titers. Three of 14 triatomines were found to be infected (TcI. This unexpected epidemiological picture does not explain the high number of autochthonous ACD cases. In Jurunas, the cases of ACD could not be autochthonous because of the absence of any enzootic cycle of T. cruzi. In contrast, in the 3 island areas from which the açaí fruit originates, 66.7% of wild mammals and two dogs displayed positive hemocultures, and 15.6% of triatomines were found to be infected by T. cruzi. Genotyping by mini-exon gene and PCR-RFLP (1f8/Akw21I targeting revealed that the mammals and triatomines from the islands harbored TcI and Trypanosoma rangeli in single and mixed infections. CONCLUSION/SIGNIFICANCE: These findings show that cases of Chagas disease in the urban area of Belém may be derived from infected triatomines coming together with the açaí fruits from distant islands. We term this new epidemiological feature of Chagas disease as "Distantiae transmission".

  5. Global metabolomic profiling of acute myocarditis caused by Trypanosoma cruzi infection.

    Directory of Open Access Journals (Sweden)

    Núria Gironès

    2014-11-01

    Full Text Available Chagas disease is caused by Trypanosoma cruzi infection, being cardiomyopathy the more frequent manifestation. New chemotherapeutic drugs are needed but there are no good biomarkers for monitoring treatment efficacy. There is growing evidence linking immune response and metabolism in inflammatory processes and specifically in Chagas disease. Thus, some metabolites are able to enhance and/or inhibit the immune response. Metabolite levels found in the host during an ongoing infection could provide valuable information on the pathogenesis and/or identify deregulated metabolic pathway that can be potential candidates for treatment and being potential specific biomarkers of the disease. To gain more insight into those aspects in Chagas disease, we performed an unprecedented metabolomic analysis in heart and plasma of mice infected with T. cruzi. Many metabolic pathways were profoundly affected by T. cruzi infection, such as glucose uptake, sorbitol pathway, fatty acid and phospholipid synthesis that were increased in heart tissue but decreased in plasma. Tricarboxylic acid cycle was decreased in heart tissue and plasma whereas reactive oxygen species production and uric acid formation were also deeply increased in infected hearts suggesting a stressful condition in the heart. While specific metabolites allantoin, kynurenine and p-cresol sulfate, resulting from nucleotide, tryptophan and phenylalanine/tyrosine metabolism, respectively, were increased in heart tissue and also in plasma. These results provide new valuable information on the pathogenesis of acute Chagas disease, unravel several new metabolic pathways susceptible of clinical management and identify metabolites useful as potential specific biomarkers for monitoring treatment and clinical severity in patients.

  6. Absence of Fas-L aggravates renal injury in acute Trypanosoma cruzi infection

    Directory of Open Access Journals (Sweden)

    Gabriel Melo de Oliveira

    2009-12-01

    Full Text Available Trypanosoma cruzi infection induces diverse alterations in immunocompetent cells and organs, myocarditis and congestive heart failure. However, the physiological network of disturbances imposed by the infection has not been addressed thoroughly. Regarding myocarditis induced by the infection, we observed in our previous work that Fas-L-/- mice (gld/gld have very mild inflammatory infiltration when compared to BALB/c mice. However, all mice from both lineages die in the early acute phase. Therefore, in this work we studied the physiological connection relating arterial pressure, renal function/damage and cardiac insufficiency as causes of death. Our results show that a broader set of dysfunctions that could be classified as a cardio/anaemic/renal syndrome is more likely responsible for cardiac failure and death in both lineages. However, gld/gld mice had very early glomerular deposition of IgM and a more intense renal inflammatory response with reduced renal filtration, which is probably responsible for the premature death in the absence of significant myocarditis in gld/gld.

  7. The CC Chemokine Receptor 5 Is Important in Control of Parasite Replication and Acute Cardiac Inflammation following Infection with Trypanosoma cruzi

    OpenAIRE

    2006-01-01

    Infection of susceptible mice with the Colombiana strain of Trypanosoma cruzi results in an orchestrated expression of chemokines and chemokine receptors within the heart that coincides with parasite burden and cellular infiltration. CC chemokine receptor 5 (CCR5) is prominently expressed during both acute and chronic disease, suggesting a role in regulating leukocyte trafficking and accumulation within the heart following T. cruzi infection. To better understand the functional role of CCR5 a...

  8. Serodiagnosis of Chronic and Acute Chagas' Disease with Trypanosoma cruzi Recombinant Proteins: Results of a Collaborative Study in Six Latin American Countries

    Science.gov (United States)

    Umezawa, Eufrosina S.; Luquetti, Alejandro O.; Levitus, Gabriela; Ponce, Carlos; Ponce, Elisa; Henriquez, Diana; Revollo, Susana; Espinoza, Bertha; Sousa, Octavio; Khan, Baldip; da Silveira, José Franco

    2004-01-01

    An enzyme-linked immunosorbent assay to diagnose Chagas' disease by a serological test was performed with Trypanosoma cruzi recombinant antigens (JL8, MAP, and TcPo). High sensitivity (99.4%) and specificity (99.3%) were obtained when JL8 was combined with MAP (JM) and tested with 150 serum samples from chagasic and 142 nonchagasic individuals. Moreover, JM also diagnosed 84.2% of patients in the acute phase of T. cruzi infection. PMID:14715803

  9. Early molecular diagnosis of acute Chagas disease after transplantation with organs from Trypanosoma cruzi-infected donors.

    Science.gov (United States)

    Cura, C I; Lattes, R; Nagel, C; Gimenez, M J; Blanes, M; Calabuig, E; Iranzo, A; Barcan, L A; Anders, M; Schijman, A G

    2013-12-01

    Organ transplantation (TX) is a novel transmission modality of Chagas disease. The results of molecular diagnosis and characterization of Trypanosoma cruzi acute infection in naïve TX recipients transplanted with organs from infected deceased donors are reported. Peripheral blood and cerebrospinal fluid samples from the TX recipients of organs from infected donors were prospectively and sequentially studied for detection of T. cruzi by means of kinetoplastid DNA polymerase chain reaction (kDNA-PCR). In positive blood samples, a PCR algorithm for identification of T. cruzi Discrete Typing Units (DTUs) and quantitative real-time PCR (qPCR) to quantify parasitic loads were performed. Minicircle signatures of T. cruzi infecting populations were also analyzed using restriction fragment length polymorphism (RFLP)-PCR. Eight seronegative TX recipients from four infected donors were studied. In five, the infection was detected at 68.4 days post-TX (36-98 days). In one case, it was transmitted to two of three TX recipients. The comparison of the minicircle signatures revealed nearly identical RFLP-PCR profiles, confirming a common source of infection. The five cases were infected by DTU TcV. This report reveals the relevance of systematic monitoring of TX recipients using PCR strategies in order to provide an early diagnosis allowing timely anti-trypanosomal treatment.

  10. Role of CCL3/MIP-1alpha and CCL5/RANTES during acute Trypanosoma cruzi infection in rats.

    Science.gov (United States)

    Roffê, Ester; Oliveira, Fabiano; Souza, Adriano L S; Pinho, Vanessa; Souza, Danielle G; Souza, Patrícia R S; Russo, Remo C; Santiago, Helton C; Romanha, Alvaro J; Tanowitz, Herbert B; Valenzuela, Jesus G; Teixeira, Mauro M

    2010-08-01

    Chagas' disease is caused by Trypanosoma cruzi infection and is characterized by chronic fibrogenic inflammation and heart dysfunction. Chemokines are produced during infection and drive tissue inflammation. In rats, acute infection is characterized by intense myocarditis and regression of inflammation after control of parasitism. We investigated the role of CCL3 and CCL5 during infection by using DNA vaccination encoding for each chemokine separately or simultaneously. MetRANTES treatment was used to evaluate the role of CCR1 and CCR5, the receptors for CCL3 and CCL5. Vaccination with CCL3 or CCL5 increased heart parasitism and decreased local IFN-gamma production, but did not influence intensity of inflammation. Simultaneous treatment with both plasmids or treatment with MetRANTES enhanced cardiac inflammation, fibrosis and parasitism. In conclusion, chemokines CCL3 and CCL5 are relevant, but not essential, for control of T. cruzi infection in rats. On the other hand, combined blockade of these chemokines or their receptors enhanced tissue inflammation and fibrosis, clearly contrasting with available data in murine models of T. cruzi infection. These data reinforce the important role of chemokines during T. cruzi infection but suggest that caution must be taken when expanding the therapeutic modulation of the chemokine system in mice to the human infection.

  11. Limited Ability of Posaconazole To Cure both Acute and Chronic Trypanosoma cruzi Infections Revealed by Highly Sensitive In Vivo Imaging.

    Science.gov (United States)

    Francisco, Amanda Fortes; Lewis, Michael D; Jayawardhana, Shiromani; Taylor, Martin C; Chatelain, Eric; Kelly, John M

    2015-08-01

    The antifungal drug posaconazole has shown significant activity against Trypanosoma cruzi in vitro and in experimental murine models. Despite this, in a recent clinical trial it displayed limited curative potential. Drug testing is problematic in experimental Chagas disease because of difficulties in demonstrating sterile cure, particularly during the chronic stage of infection when parasite burden is extremely low and tissue distribution is ill defined. To better assess posaconazole efficacy against acute and chronic Chagas disease, we have exploited a highly sensitive bioluminescence imaging system which generates data with greater accuracy than other methods, including PCR-based approaches. Mice inoculated with bioluminescent T. cruzi were assessed by in vivo and ex vivo imaging, with cyclophosphamide-induced immunosuppression used to enhance the detection of relapse. Posaconazole was found to be significantly inferior to benznidazole as a treatment for both acute and chronic T. cruzi infections. Whereas 20 days treatment with benznidazole was 100% successful in achieving sterile cure, posaconazole failed in almost all cases. Treatment of chronic infections with posaconazole did however significantly reduce infection-induced splenomegaly, even in the absence of parasitological cure. The imaging-based screening system also revealed that adipose tissue is a major site of recrudescence in mice treated with posaconazole in the acute, but not the chronic stage of infection. This in vivo screening model for Chagas disease is predictive, reproducible and adaptable to diverse treatment schedules. It should provide greater assurance that drugs are not advanced prematurely into clinical trial.

  12. The MASP family of Trypanosoma cruzi: changes in gene expression and antigenic profile during the acute phase of experimental infection.

    Directory of Open Access Journals (Sweden)

    Sara Lopes dos Santos

    Full Text Available BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas disease, a debilitating illness that affects millions of people in the Americas. A major finding of the T. cruzi genome project was the discovery of a novel multigene family composed of approximately 1,300 genes that encode mucin-associated surface proteins (MASPs. The high level of polymorphism of the MASP family associated with its localization at the surface of infective forms of the parasite suggests that MASP participates in host-parasite interactions. We speculate that the large repertoire of MASP sequences may contribute to the ability of T. cruzi to infect several host cell types and/or participate in host immune evasion mechanisms. METHODS: By sequencing seven cDNA libraries, we analyzed the MASP expression profile in trypomastigotes derived from distinct host cells and after sequential passages in acutely infected mice. Additionally, to investigate the MASP antigenic profile, we performed B-cell epitope prediction on MASP proteins and designed a MASP-specific peptide array with 110 putative epitopes, which was screened with sera from acutely infected mice. FINDINGS AND CONCLUSIONS: We observed differential expression of a few MASP genes between trypomastigotes derived from epithelial and myoblast cell lines. The more pronounced MASP expression changes were observed between bloodstream and tissue-culture trypomastigotes and between bloodstream forms from sequential passages in acutely infected mice. Moreover, we demonstrated that different MASP members were expressed during the acute T. cruzi infection and constitute parasite antigens that are recognized by IgG and IgM antibodies. We also found that distinct MASP peptides could trigger different antibody responses and that the antibody level against a given peptide may vary after sequential passages in mice. We speculate that changes in the large repertoire of MASP antigenic peptides during an infection may contribute to

  13. Effects of repetitive stress during the acute phase of Trypanosoma cruzi infection on chronic Chagas' disease in rats.

    Science.gov (United States)

    Caetano, Leony Cristina; Brazão, Vânia; Filipin, Marina Del Vecchio; Santello, Fabricia Helena; Caetano, Luana Naiara; Toldo, Miriam Paula Alonso; Caldeira, Jerri C; do Prado, José Clóvis

    2009-03-01

    The effect of repetitive stress during acute infection with Trypanosoma cruzi (T. cruzi) on the chronic phase of ensuing Chagas' disease was the focus of this investigation. The aim of this study was to evaluate in Wistar rats the influence of repetitive stress during the acute phase of infection (7 days) with the Y strain of T. cruzi on the chronic phase of the infection (at 180 days). Exposure to ether vapor for 1 min twice a day was used as a stressor. Repetitive stress enhanced the number of circulating parasites and cardiac tissue disorganization, from a moderate to a severe diffuse mononuclear inflammatory process and the presence of amastigote burden in the cardiac fibers. Immunological parameters revealed that repetitive stress triggered a reduced concanavalin A induced splenocyte proliferation in vitro with major effects on the late chronic phase. Serum interleukin-12 concentration decreased in both stressed and infected rats in the early phase of infection although it was higher on 180 days post-infection. These results suggest that repetitive stress can markedly impair the host's immune system and enhance the pathological process during the chronic phase of Chagas' disease.

  14. Circulating Trypanosoma cruzi populations differ from those found in the tissues of the same host during acute experimental infection.

    Science.gov (United States)

    Lo Presti, M Silvina; Esteves, Blanca H; Moya, Diego; Bazán, P Carolina; Strauss, Mariana; Báez, Alejandra L; Pizzi, Rogelio; Quispe Ricalde, M Antonieta; Valladares, Basilio; Rivarola, H Walter; Paglini-Oliva, Patricia A

    2014-05-01

    We evaluated the presence and distribution of two Trypanosoma cruzi natural isolates in blood, heart, skeletal muscle, liver, and spleen tissues in the acute phase of the experimental infection (35 days postinfection) in order to determine if the populations present in blood were different to those found in the tissues of the same host. Thirty mice were infected with 50 forms of each isolate or with a combination of them. Presence and molecular characterization of the parasites in the host tissues were determined by specific PCR. Cardiac and skeletal muscle alterations were analyzed by histological studies. T. cruzi variability in the host tissues was analyzed through RFLP studies. Both isolates used consisted of a mixture of two T. cruzi lineages. Specific PCRs were positive for most of the samples from the 3 groups analyzed. Cardiac and skeletal muscle sections from the groups infected with one isolate presented mild to moderate inflammatory infiltrates; the group infected with both isolates showed severe inflammatory infiltrates and the presence of amastigote nests in both tissues. Different parasite populations were found in circulation and in the tissues from the same host. These results are important for patients with high probability of mixed infections in endemic areas and contribute to the knowledge of parasite/host interactions.

  15. Curcumin Enhances the Anti-Trypanosoma cruzi Activity of Benznidazole-Based Chemotherapy in Acute Experimental Chagas Disease.

    Science.gov (United States)

    Novaes, Rômulo Dias; Sartini, Marcus Vinicius Pessoa; Rodrigues, João Paulo Ferreira; Gonçalves, Reggiani Vilela; Santos, Eliziária Cardoso; Souza, Raquel Lopes Martins; Caldas, Ivo Santana

    2016-06-01

    Although curcumin can increase the effectiveness of drugs against malaria, combination therapies using the molecule have never been investigated in Chagas disease (ChD). Therefore, we evaluated the efficacy of curcumin as a complementary strategy to benznidazole (Bz)-based chemotherapy in mice acutely infected with Trypanosoma cruzi Eighty-four 12-week-old Swiss mice were equally randomized into seven groups: uninfected (NI), T. cruzi infected and untreated (INF), infected and treated with 100 mg/kg of body weight Bz (B100), 50 mg/kg Bz (B50), 100 mg/kg curcumin (C100), 100 mg/kg Bz plus 100 mg/kg curcumin (B100 plus C100), and 50 mg/kg Bz plus 100 mg/kg curcumin (B50 plus C100). After microscopic identification of blood trypomastigotes (4 days after inoculation), both drugs were administered by gavage once a day for 20 days. Curcumin showed limited antiparasitic, anti-inflammatory, and antioxidant effects when administered alone. When curcumin and Bz were combined, there was a drastic reduction in parasitemia, parasite load, mortality, anti-T. cruzi IgG reactivity, circulating levels of cytokines (gamma interferon [IFN-γ], interleukin 4 [IL-4], and MIP1-α), myocardial inflammation, and morphological and oxidative cardiac injury; these results exceeded the isolated effects of Bz. The combination of Bz and curcumin was also effective at mitigating liver toxicity triggered by Bz, increasing the parasitological cure rate, and preventing infection recrudescence in noncured animals, even when the animals were treated with 50% of the recommended therapeutic dose of Bz. By limiting the toxic effects of Bz and enhancing its antiparasitic efficiency, the combination of the drug with curcumin may be a relevant therapeutic strategy that is possibly better tolerated in ChD treatment than Bz-based monotherapy.

  16. Nitroheterocyclic drugs cure experimental Trypanosoma cruzi infections more effectively in the chronic stage than in the acute stage

    Science.gov (United States)

    Francisco, Amanda Fortes; Jayawardhana, Shiromani; Lewis, Michael D.; White, Karen L.; Shackleford, David M.; Chen, Gong; Saunders, Jessica; Osuna-Cabello, Maria; Read, Kevin D.; Charman, Susan A.; Chatelain, Eric; Kelly, John M.

    2016-01-01

    The insect-transmitted protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, and infects 5–8 million people in Latin America. Chagas disease is characterised by an acute phase, which is partially resolved by the immune system, but then develops as a chronic life-long infection. There is a consensus that the front-line drugs benznidazole and nifurtimox are more effective against the acute stage in both clinical and experimental settings. However, confirmative studies have been restricted by difficulties in demonstrating sterile parasitological cure. Here, we describe a systematic study of nitroheterocyclic drug efficacy using highly sensitive bioluminescence imaging of murine infections. Unexpectedly, we find both drugs are more effective at curing chronic infections, judged by treatment duration and therapeutic dose. This was not associated with factors that differentially influence plasma drug concentrations in the two disease stages. We also observed that fexinidazole and fexinidazole sulfone are more effective than benznidazole and nifurtimox as curative treatments, particularly for acute stage infections, most likely as a result of the higher and more prolonged exposure of the sulfone derivative. If these findings are translatable to human patients, they will have important implications for treatment strategies. PMID:27748443

  17. Immune Evasion Strategies of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Ana Flávia Nardy

    2015-01-01

    Full Text Available Microbes have evolved a diverse range of strategies to subvert the host immune system. The protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, provides a good example of such adaptations. This parasite targets a broad spectrum of host tissues including both peripheral and central lymphoid tissues. Rapid colonization of the host gives rise to a systemic acute response which the parasite must overcome. The parasite in fact undermines both innate and adaptive immunity. It interferes with the antigen presenting function of dendritic cells via an action on host sialic acid-binding Ig-like lectin receptors. These receptors also induce suppression of CD4+ T cells responses, and we presented evidence that the sialylation of parasite-derived mucins is required for the inhibitory effects on CD4 T cells. In this review we highlight the major mechanisms used by Trypanosoma cruzi to overcome host immunity and discuss the role of parasite colonization of the central thymic lymphoid tissue in chronic disease.

  18. Cyclooxygenase-2 and Prostaglandin E2 Signaling through Prostaglandin Receptor EP-2 Favor the Development of Myocarditis during Acute Trypanosoma cruzi Infection.

    Directory of Open Access Journals (Sweden)

    Néstor A Guerrero

    Full Text Available Inflammation plays an important role in the pathophysiology of Chagas disease, caused by Trypanosoma cruzi. Prostanoids are regulators of homeostasis and inflammation and are produced mainly by myeloid cells, being cyclooxygenases, COX-1 and COX-2, the key enzymes in their biosynthesis from arachidonic acid (AA. Here, we have investigated the expression of enzymes involved in AA metabolism during T. cruzi infection. Our results show an increase in the expression of several of these enzymes in acute T. cruzi infected heart. Interestingly, COX-2 was expressed by CD68+ myeloid heart-infiltrating cells. In addition, infiltrating myeloid CD11b+Ly6G- cells purified from infected heart tissue express COX-2 and produce prostaglandin E2 (PGE2 ex vivo. T. cruzi infections in COX-2 or PGE2-dependent prostaglandin receptor EP-2 deficient mice indicate that both, COX-2 and EP-2 signaling contribute significantly to the heart leukocyte infiltration and to the release of chemokines and inflammatory cytokines in the heart of T. cruzi infected mice. In conclusion, COX-2 plays a detrimental role in acute Chagas disease myocarditis and points to COX-2 as a potential target for immune intervention.

  19. The CC chemokine receptor 5 is important in control of parasite replication and acute cardiac inflammation following infection with Trypanosoma cruzi.

    Science.gov (United States)

    Hardison, Jenny L; Wrightsman, Ruth A; Carpenter, Philip M; Kuziel, William A; Lane, Thomas E; Manning, Jerry E

    2006-01-01

    Infection of susceptible mice with the Colombiana strain of Trypanosoma cruzi results in an orchestrated expression of chemokines and chemokine receptors within the heart that coincides with parasite burden and cellular infiltration. CC chemokine receptor 5 (CCR5) is prominently expressed during both acute and chronic disease, suggesting a role in regulating leukocyte trafficking and accumulation within the heart following T. cruzi infection. To better understand the functional role of CCR5 and its ligands with regard to both host defense and/or disease, CCR5(-/-) mice were infected with T. cruzi, and the disease severity was evaluated. Infected CCR5(-/-) mice develop significantly higher levels of parasitemia (P < or = 0.05) and cardiac parasitism (P < or = 0.01) during acute infection that correlated with reduced survival. Further, we show that CCR5 is essential for directing the migration of macrophages and T cells to the heart early in acute infection with T. cruzi. In addition, data are provided demonstrating that CCR5 does not play an essential role in maintaining inflammation in the heart during chronic infection. Collectively, these studies clearly demonstrate that CCR5 contributes to the control of parasite replication and the development of a protective immune response during acute infection but does not ultimately participate in maintaining a chronic inflammatory response within the heart.

  20. Trypanosoma cruzi Infection and Host Lipid Metabolism

    OpenAIRE

    2014-01-01

    Trypanosoma cruzi is the causative agent of Chagas disease. Approximately 8 million people are thought to be affected worldwide. Several players in host lipid metabolism have been implicated in T. cruzi-host interactions in recent research, including macrophages, adipocytes, low density lipoprotein (LDL), low density lipoprotein receptor (LDLR), and high density lipoprotein (HDL). All of these factors are required to maintain host lipid homeostasis and are intricately connected via several me...

  1. Amastigotes forms of Trypanosoma cruzi detected in a renal allograft

    Directory of Open Access Journals (Sweden)

    CARVALHO Maria Fernanda C.

    1997-01-01

    Full Text Available Trypanosoma cruzi, the causative agent of Chagas?disease assumes two distinct forms in vertebrate hosts: circulating trypomastigote and tissular amastigote. This latter form infects predominantly the myocardium, smooth and skeletal muscle, and central nervous system. The present work describes for the first time the detection of amastigote forms of T. cruzi in the renal parenchyma of a kidney graft recipient one month after transplantation. The patient was serologically negative for Chagas?disease and received no blood transfusion prior to transplant. The cadaver donor was from an endemic area for Chagas?disease. The recipient developed the acute form of the disease with detection of amastigote forms of T. cruzi in the renal allograft biopsy and circulating trypomastigote forms. The present report demonstrates that T. cruzi can infect the renal parenchyma. This mode of transmission warrants in endemic areas of Chagas?disease

  2. The cell surface of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Wanderley de Souza

    1984-01-01

    Full Text Available The cell surface of trypanosomatids is formed by the plasma membrane and a layer of sub-pellicular microtubules which are connected to the plasma membrane. The plasma membrane is composed by proteins, lipids and carbohydrates which form the glycocalix. In this paper we will review briefly aspects related to the organization of the cell surface of Trypanosoma cruzi.

  3. Early diagnosis of congenital Trypanosoma cruzi infection, using shed acute phase antigen, in Ushuaia, Tierra del Fuego, Argentina.

    Science.gov (United States)

    Mallimaci, María Cristina; Sosa-Estani, Sergio; Russomando, Graciela; Sanchez, Zunilda; Sijvarger, Carina; Alvarez, Isabel Marcela; Barrionuevo, Lola; Lopez, Carlos; Segura, Elsa Leonor

    2010-01-01

    Chagas' disease, or American trypanosomiasis, is caused by the protozoan parasite Trypanasoma cruzi. It is estimated that 15,000 new cases of congenital T. cruzi transmission occur in the Americas each year. The aim of this study was to estimate the rate of congenital T. cruzi infection in infants born to infected women living in Ushuaia, Argentina, as well to assess a serologic test using Shed Acute Phase Antigen (SAPA) for a timely diagnosis of congenital infection. The rate of congenital infection among children in the study was 4.4% (3/68). Our results show that for infants younger than 30 days of age, matched blood samples from mother and infant were capable of identifying congenital transmission of infection using an enzyme-linked immunosorbent assay with SAPA. For infants older than 3 months, congenital infection could be ruled out using the same procedure.

  4. Dogs infected with the blood trypomastigote form of Trypanosoma cruzi display an increase expression of cytokines and chemokines plus an intense cardiac parasitism during acute infection.

    Science.gov (United States)

    de Souza, Sheler Martins; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Reis, Levi Eduardo Soares; da Silva Fonseca, Kátia; Nogueira, Nívia Carolina; Reis, Alexandre Barbosa; Tafuri, Washington Luiz; Carneiro, Cláudia Martins

    2014-03-01

    The recent increase in immigration of people from areas endemic for Chagas disease (Trypanosoma cruzi) to the United States and Europe has raised concerns about the transmission via blood transfusion and organ transplants in these countries. Infection by these pathways occurs through blood trypomastigotes (BT), and these forms of T. cruzi are completely distinct of metacyclic trypomastigotes (MT), released by triatomine vector, in relation to parasite-host interaction. Thus, research comparing infection with these different infective forms is important for explaining the potential impacts on the disease course. Here, we investigated tissue parasitism and relative mRNA expression of cytokines, chemokines, and chemokine receptors in the heart during acute infection by MT or BT forms in dogs. BT-infected dogs presented a higher cardiac parasitism, increased relative mRNA expression of pro-inflammatory and immunomodulatory cytokines and of the chemokines CCL3/MIP-1α, CCL5/RANTES, and the chemokine receptor CCR5 during the acute phase of infection, as compared to MT-infected dogs. These results suggest that infection with BT forms may lead to an increased immune response, as revealed by the cytokines ratio, but this kind of immune response was not able to control the cardiac parasitism. Infection with the MT form presented an increase in the relative mRNA expression of IL-12p40 as compared to that of IL-10 or TGF-β1. Correlation analysis showed increased relative mRNA expression of IFN-γ as well as IL-10, which may be an immunomodulatory response, as well as an increase in the correlation of CCL5/RANTES and its CCR5 receptor. Our findings revealed a difference between inoculum sources of T. cruzi, as vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase, which may influence immunopathological aspects of Chagas disease.

  5. Diagnosis of congenital Trypanosoma cruzi infection: A serologic test using Shed Acute Phase Antigen (SAPA) in mother-child binomial samples.

    Science.gov (United States)

    Volta, Bibiana J; Russomando, Graciela; Bustos, Patricia L; Scollo, Karenina; De Rissio, Ana M; Sánchez, Zunilda; Cardoni, Rita L; Bua, Jacqueline

    2015-07-01

    Chagas congenital infection is an important health problem in endemic and non-endemic areas in which Trypanosoma cruzi-infected women can transmit the parasite to their offspring. In this study, we evaluated the antibody levels against the T. cruzi Shed Acute Phase Antigen (SAPA) in 91 binomial samples of seropositive pregnant women and their infected and non-infected children by ELISA. In 70 children without congenital T. cruzi transmission, the titers of anti-SAPA antibodies were lower than those of their seropositive mothers. In contrast, 90.5% of 21 congenitally infected children, at around 1 month of age, showed higher anti-SAPA antibody levels than their mothers. Subtracting the SAPA-ELISA mother OD value to the SAPA-ELISA child OD allowed efficient detection of most T. cruzi congenitally infected children immediately after birth, when total anti-parasite antibodies transferred during pregnancy are still present in all children born to seropositive women. A positive correlation was observed between parasitemia levels in mothers and infants evaluated by quantitative DNA amplification and anti-SAPA antibody titers by ELISA. As SAPA serology has proved to be very efficient to detect T. cruzi infection in mother-child binomial samples, it could be of extreme help for early diagnosis of newborns, in maternities and hospitals where DNA amplification is not available. This prompt diagnosis may prevent drop out of the long-term follow-up for future diagnosis and may ensure early trypanocidal treatment, which has proved to be efficient to cure infants with congenital Chagas disease.

  6. Differential expression of microRNAs in thymic epithelial cells from Trypanosoma cruzi acutely-infected mice: putative role in thymic atrophy.

    Directory of Open Access Journals (Sweden)

    Leandra eLinhares-Lacerda

    2015-08-01

    Full Text Available A common feature seen in acute infections is a severe atrophy of the thymus. This occurs in the murine model of acute Chagas disease. Moreover, in thymuses from Trypanosoma cruzi acutely infected mice, thymocytes exhibit an increase in the density of fibronectin and laminin integrin-type receptors, with an increase in migratory response ex-vivo. Thymic epithelial cells (TEC play a major role in the intrathymic T cell differentiation. To date, the consequences of molecular changes promoted by parasite infection upon thymus have not been elucidated. Considering the importance of microRNA for gene expression regulation, 85 microRNAs were analyzed in TEC from T. cruzi acutely infected mice. The infection significantly modulated 29 miRNAs and modulation of 9 was also dependent whether TEC sorted out from the thymus exhibited cortical or medullary phenotype. In silico analysis revealed that these miRNAs may control target mRNAs known to be responsible for chemotaxis, cell adhesion and cell death. Considering that we sorted TEC in the initial phase of thymocyte loss, it is conceivable that changes in TEC miRNA expression profile are functionally related to thymic atrophy, providing new clues to better understanding the mechanisms of the thymic involution seen in experimental Chagas disease.

  7. Altered thymocyte migration during experimental acute Trypanosoma cruzi infection: combined role of fibronectin and the chemokines CXCL12 and CCL4.

    Science.gov (United States)

    Mendes-da-Cruz, Daniella Arêas; Silva, João Santana; Cotta-de-Almeida, Vinícius; Savino, Wilson

    2006-06-01

    We previously showed migration disturbances in the thymus during experimental infection with Trypanosoma cruzi, the causative agent of Chagas disease. These changes were related to the enhanced expression of extracellular matrix ligands and receptors, leading to the escape of immature cells to the periphery. Here, we analyzed the expression and role of selected chemokines (CXCL12 and CCL4) and their receptors (CXCR4 and CCR5) in regulating thymocyte migration in conjunction with extracellular matrix during acute T. cruzi infection. We found increased chemokine deposition in the thymus of infected mice when compared to controls, accompanied by enhanced co-localization with fibronectin as well as up-regulated surface expression of CXCR4 and CCR5 in thymocytes. We also noticed altered thymocyte migration towards the chemokines analyzed. Such an enhancement was even more prominent when fibronectin was added as a haptotatic stimulus in combination with a given chemokine. Our findings suggest that thymocyte migration results from a combined action of chemokines and extracellular matrix (ECM), which can be altered during pathological conditions such as T. cruzi infection, and may be at the origin of the changes in the T cell repertoire seen in this pathological process.

  8. Differential impact of metacyclic and blood trypomastigotes on parasitological, serological and phenotypic features triggered during acute Trypanosoma cruzi infection in dogs.

    Science.gov (United States)

    Carneiro, Cláudia Martins; Martins-Filho, Olindo Assis; Reis, Alexandre Barbosa; Veloso, Vanja Maria; Araújo, Flávio Marcos Gomes; Bahia, Maria Terezinha; de Lana, Marta; Machado-Coelho, George Luiz Lins; Gazzinelli, Giovanni; Correa-Oliveira, Rodrigo; Tafuri, Washington Luiz

    2007-02-01

    A detailed follow-up investigation of the major parasitological, serological and phenotypic features in dogs experimentally infected with metacyclic (MT) and blood (BT) trypomastigotes of Trypanosoma cruzi strain Berenice-78, typifying vectorial and transfusional transmission of human Chagas disease, has been conducted. Although there were no changes with respect to the window of patent-parasitaemia, significant differences between MT- and BT-infected dogs in both the prepatent period (days 23 and 19, respectively) and the day of maximum parasitaemia (days 26 and 22, respectively) were recorded. A progressive enhancement in the level of T. cruzi-specific antibodies accompanied infection by both MT and BT forms, although higher IgG titres developed on days 14 and 21 following infection with MT forms. Higher Thy-1(+)/CD21(+) and lower CD4(+)/CD8(+) cell ratios, occasioned by increased levels of Thy-1(+) and CD8(+) T-cells and reduced frequencies of CD4(+) T-cells and CD21(+) B-lymphocytes, were observed in both MT- and BT-infected animals. The reduced frequency of CD14(+) leukocytes was revealed as the most relevant phenotypic feature intrinsic to T. cruzi infection independent of inoculum source. BT-specific phenotypic features included an early reduction in the percentage of circulating CD21(+) and CD14(+) leukocytes, together with a higher Thy-1(+)/CD21(+) cell ratio on day 42. On the other hand, higher levels of CD8(+) T-cells, together with a lower CD4(+)/CD8(+) cell ratio on day 28, were characteristic of MT infection. These findings emphasise the importance of inoculum source and suggest that vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during acute Chagas disease.

  9. Bestatin Induces Specific Changes in Trypanosoma cruzi Dipeptide Pool

    OpenAIRE

    2015-01-01

    Proteases and peptidases in Trypanosoma cruzi are considered potential targets for antichagasic chemotherapy. We monitored changes in low-mass metabolites in T. cruzi epimastigotes treated with bestatin, a dipeptide metalloaminopeptidase inhibitor. After treatment, multiple dipeptides were shown to be increased, confirming in situ inhibition of the leucine aminopeptidase of T. cruzi (LAPTc) and probably other peptidases.

  10. Inducible suicide vector systems for Trypanosoma cruzi.

    Science.gov (United States)

    Ma, Yanfen; Weiss, Louis M; Huang, Huan

    2015-06-01

    Chagas disease caused by Trypanosoma cruzi is a major neglected tropical parasitic disease. The pathogenesis of this infection remains disputable. There is no suitable vaccine for the prevention. Attenuated live vaccines can provide strong protection against infection; however, there are the concerns about latent infection or reversion to virulence in such attenuated strains. A method to induce T. cruzi death would provide a critical tool for research into the pathophysiological mechanisms and provide a novel design of safe live attenuated vaccines. We established effective inducible systems for T. cruzi employing the degradation domain based on the Escherichia coli dihydrofolate reductase (ecDHFR). The DHFR degradation domain (DDD) can be stabilized by trimethoprim-lactate and can be used to express detrimental or toxic proteins. T. cruzi lines with Alpha-toxin, Cecropin A and GFP under the control of DDD with a hemagglutinin tag (HA) were developed. Interestingly, amastigotes bearing GFP-DDDHA, Alpha-toxin-DDDHA, Cecropin A-DDDHA and DDDHA all resulted in inducible cell death with these fusions, indicating that DDDHA protein is also detrimental to amastigotes. Furthermore, these strains were attenuated in mouse experiments producing no pathological changes and inoculation with these DDDHA strains in mice provided strong protection against lethal wild type infection.

  11. Trypanosoma cruzi, cancer and the Cold War.

    Science.gov (United States)

    Krementsov, Nikolai

    2009-07-01

    In the summer of 1946, the international community of cancer researchers was inspired by the announcement that two Soviet scientists, Nina Kliueva and Grigorii Roskin, had discovered anticancer properties in culture extracts made from the South American protozoan, Trypanosoma cruzi, and had produced a preparation--named after its discoverers KR--which showed clear therapeutic effects on cancer patients. Research teams from various countries enthusiastically pursued the promising new line of investigation. The story of the rise and fall of interest in the anticancer properties of T. cruzi in different countries suggests that during the second half of the twentieth century, the Cold War competition between the superpowers played an important role in shaping the research agendas of cancer studies.

  12. Chronic experimental infection by Trypanosoma cruzi in Cebus apella monkeys

    Directory of Open Access Journals (Sweden)

    A. Riarte

    1995-12-01

    Full Text Available Twenty young male Cebus apella monkeys were infected with CAl Trypanosoma cruzi strain and reinfected with CA l or Tulahuen T.cruzi strains, with different doses and parasite source. Subpatent parasitemia was usually demonstrated in acute and chronic phases. Patent parasitemia was evident in one monkey in the acute phase and in four of them in the chronic phase after re-inoculations with high doses of CAl strain. Serological conversion was observed in all monkeys; titers were low, regardless of the methods used to investigate anti-T. cruzi specific antibodies. Higher titers were induced only when re-inoculations were perfomed with the virulent Tulahuén strain or high doses of CAl strain. Clinical electrocardiographic and ajmaline test evaluations did not reveal changes between infected and control monkeys. Histopathologically, cardiac lesions were always characterized by focal or multifocal mononuclear infiltrates and/or isolated fibrosis, as seen during the acute and chronic phases; neither amastigote nests nor active inflammation and fibrogenic processes characteristic of human acute and chronic myocarditis respectively, were observed. These morphological aspects more closely resemble those found in the "indeterminate phase" and contrast with the more diffuse and progressive pattern of the human chagasic myocarditis. All monkeys survived and no mortality was observed.

  13. The Trypanosoma cruzi protease cruzain mediates immune evasion.

    Directory of Open Access Journals (Sweden)

    Patricia S Doyle

    2011-09-01

    Full Text Available Trypanosoma cruzi is the causative agent of Chagas' disease. Novel chemotherapy with the drug K11777 targets the major cysteine protease cruzain and disrupts amastigote intracellular development. Nevertheless, the biological role of the protease in infection and pathogenesis remains unclear as cruzain gene knockout failed due to genetic redundancy. A role for the T. cruzi cysteine protease cruzain in immune evasion was elucidated in a comparative study of parental wild type- and cruzain-deficient parasites. Wild type T. cruzi did not activate host macrophages during early infection (<60 min and no increase in ∼P iκB was detected. The signaling factor NF-κB P65 colocalized with cruzain on the cell surface of intracellular wild type parasites, and was proteolytically cleaved. No significant IL-12 expression occurred in macrophages infected with wild type T. cruzi and treated with LPS and BFA, confirming impairment of macrophage activation pathways. In contrast, cruzain-deficient parasites induced macrophage activation, detectable iκB phosphorylation, and nuclear NF-κB P65 localization. These parasites were unable to develop intracellularly and survive within macrophages. IL 12 expression levels in macrophages infected with cruzain-deficient T. cruzi were comparable to LPS activated controls. Thus cruzain hinders macrophage activation during the early (<60 min stages of infection, by interruption of the NF-κB P65 mediated signaling pathway. These early events allow T. cruzi survival and replication, and may lead to the spread of infection in acute Chagas' disease.

  14. Quantitative Proteomic and Phosphoproteomic Analysis of Trypanosoma cruzi Amastigogenesis

    DEFF Research Database (Denmark)

    Queiroz, Rayner M L; Charneau, Sebastien; Mandacaru, Samuel C;

    2014-01-01

    Chagas disease is a tropical neglected disease endemic in Latin America and it is caused by the protozoan Trypanosoma cruzi. The parasite has four major life stages: epimastigote, metacyclic trypomastigote, bloodstream trypomastigote and amastigote. The differentiation from infective trypomastigo......Chagas disease is a tropical neglected disease endemic in Latin America and it is caused by the protozoan Trypanosoma cruzi. The parasite has four major life stages: epimastigote, metacyclic trypomastigote, bloodstream trypomastigote and amastigote. The differentiation from infective...

  15. Detection of Trypanosoma cruzi by Polymerase Chain Reaction.

    Science.gov (United States)

    Márquez, María Elizabeth; Concepción, Juan Luis; González-Marcano, Eglys; Mondolfi, Alberto Paniz

    2016-01-01

    American Trypanosomiasis (Chagas disease) is an infectious disease caused by the hemoflagellate parasite Trypanosoma cruzi which is transmitted by reduviid bugs. T. cruzi infection occurs in a broad spectrum of reservoir animals throughout North, Central, and South America and usually evolves into an asymptomatic chronic clinical stage of the disease in which diagnosis is often challenging. This chapter describes the application of polymerase chain reaction (PCR) for the detection of Trypanosoma cruzi DNA including protocols for sample preparation, DNA extraction, and target amplification methods.

  16. Immunopathological Aspects of Experimental Trypanosoma cruzi Reinfections

    Directory of Open Access Journals (Sweden)

    Juliana Reis Machado

    2014-01-01

    Full Text Available Chagas disease is caused by Trypanosoma cruzi infection. Besides the host-related factors, such as immune response and genetic background, the parasite, strain, and occurrences of reinfection episodes, may influence disease outcome. Our results demonstrate that both the primary infection and the reinfection with the Colombiana strain are connected with lower survival rate of the mice. After reinfection, parasitaemia is approximately ten times lower than in primary infected animals. Only Colombiana, Colombiana/Colombiana, and Y/Colombiana groups presented amastigote nests in cardiac tissue. Moreover, the mice infected and/or reinfected with the Colombiana strain had more T. cruzi nests, more intense inflammatory infiltrate, and higher in situ expression of TNF-α and IFN-γ than Y strain. Antigen-stimulated spleen cells from infected and/or reinfected animals produced higher levels of TNF-α, IFN-γ, and IL-10. Our results reinforce the idea that Chagas disease outcome is influenced by the strain of the infective parasite, being differentially modulated during reinfection episodes. It highlights the need of control strategies involving parasite strain characterization in endemic areas for Chagas disease.

  17. The flagellar adenylate kinases of Trypanosoma cruzi.

    Science.gov (United States)

    Camara, María de los Milagros; Bouvier, León A; Miranda, Mariana R; Pereira, Claudio A

    2015-01-01

    Adenylate kinases (ADK) are key enzymes involved in cell energy management. Trypanosomatids present the highest number of variants in a single cell in comparison with the rest of the living organisms. In this work, we characterized two flagellar ADKs from Trypanosoma cruzi, called TcADK1 and TcADK4, which are also located in the cell cytosol. Interestingly, TcADK1 presents a stage-specific expression. This variant was detected in epimastigotes cells, and was completely absent in trypomastigotes and amastigotes, while TcADK4 is present in the major life cycle stages of T. cruzi. Both variants are also regulated, in opposite ways, along the parasite growth curve suggesting that their expression depends on the intra- and extracellular conditions. Both, TcADK1 and TcADK4 present N-terminal extension that could be responsible for their subcellular localization. The presence of ADK variants in the flagellum would be critical for the provision of energy in a process of high ATP consumption such as cell motility.

  18. Flagellar Motility of Trypanosoma cruzi Epimastigotes

    Directory of Open Access Journals (Sweden)

    G. Ballesteros-Rodea

    2012-01-01

    Full Text Available The hemoflagellate Trypanosoma cruzi is the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known about T. cruzi motility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

  19. Differential gene expression during Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    Marco Aurelio Krieger

    1999-09-01

    Full Text Available The transformation of epimastigotes into metacyclic trypomastigotes involves changes in the pattern of expressed genes, resulting in important morphological and functional differences between these developmental forms of Trypanosoma cruzi. In order to identify and characterize genes involved in triggering the metacyclogenesis process and in conferring to metacyclic trypomastigotes their stage specific biological properties, we have developed a method allowing the isolation of genes specifically expressed when comparing two close related cell populations (representation of differential expression or RDE. The method is based on the PCR amplification of gene sequences selected by hybridizing and subtracting the populations in such a way that after some cycles of hybridization-amplification genes specific to a given population are highly enriched. The use of this method in the analysis of differential gene expression during T. cruzi metacyclogenesis (6 hr and 24 hr of differentiation and metacyclic trypomastigotes resulted in the isolation of several clones from each time point. Northern blot analysis showed that some genes are transiently expressed (6 hr and 24 hr differentiating cells, while others are present in differentiating cells and in metacyclic trypomastigotes. Nucleotide sequencing of six clones characterized so far showed that they do not display any homology to gene sequences available in the GeneBank.

  20. The Uptake of GABA in Trypanosoma cruzi.

    Science.gov (United States)

    Galvez Rojas, Robert L; Ahn, Il-Young; Suárez Mantilla, Brian; Sant'Anna, Celso; Pral, Elizabeth Mieko Furusho; Silber, Ariel Mariano

    2015-01-01

    Gamma aminobutyric acid (GABA) is widely known as a neurotransmitter and signal transduction molecule found in vertebrates, plants, and some protozoan organisms. However, the presence of GABA and its role in trypanosomatids is unknown. Here, we report the presence of intracellular GABA and the biochemical characterization of its uptake in Trypanosoma cruzi, the etiological agent of Chagas' disease. Kinetic parameters indicated that GABA is taken up by a single transport system in pathogenic and nonpathogenic forms. Temperature dependence assays showed a profile similar to glutamate transport, but the effect of extracellular cations Na(+) , K(+) , and H(+) on GABA uptake differed, suggesting a different uptake mechanism. In contrast to reports for other amino acid transporters in T. cruzi, GABA uptake was Na(+) dependent and increased with pH, with a maximum activity at pH 8.5. The sensitivity to oligomycin showed that GABA uptake is dependent on ATP synthesis. These data point to a secondary active Na(+) /GABA symporter energized by Na(+) -exporting ATPase. Finally, we show that GABA occurs in the parasite's cytoplasm under normal culture conditions, indicating that it is regularly taken up from the culture medium or synthesized through an still undescribed metabolic pathway.

  1. Tumor necrosis factor-α regulates glucocorticoid synthesis in the adrenal glands of Trypanosoma cruzi acutely-infected mice. the role of TNF-R1.

    Directory of Open Access Journals (Sweden)

    Silvina R Villar

    Full Text Available Adrenal steroidogenesis is under a complex regulation involving extrinsic and intrinsic adrenal factors. TNF-α is an inflammatory cytokine produced in response to tissue injury and several other stimuli. We have previously demonstrated that TNF-R1 knockout (TNF-R1(-/- mice have a dysregulated synthesis of glucocorticoids (GCs during Trypanosoma cruzi acute infection. Since TNF-α may influence GCs production, not only through the hypothalamus-pituitary axis, but also at the adrenal level, we now investigated the role of this cytokine on the adrenal GCs production. Wild type (WT and TNF-R1(-/- mice undergoing acute infection (Tc-WT and Tc-TNF-R1(-/- groups, displayed adrenal hyperplasia together with increased GCs levels. Notably, systemic ACTH remained unchanged in Tc-WT and Tc-TNF-R1(-/- compared with uninfected mice, suggesting some degree of ACTH-independence of GCs synthesis. TNF-α expression was increased within the adrenal gland from both infected mouse groups, with Tc-WT mice showing an augmented TNF-R1 expression. Tc-WT mice showed increased levels of P-p38 and P-ERK compared to uninfected WT animals, whereas Tc-TNF-R1(-/- mice had increased p38 and JNK phosphorylation respect to Tc-WT mice. Strikingly, adrenal NF-κB and AP-1 activation during infection was blunted in Tc-TNF-R1(-/- mice. The accumulation of mRNAs for steroidogenic acute regulatory protein and cytochrome P450 were significantly increased in both Tc-WT and Tc-TNF-R1(-/- mice; being much more augmented in the latter group, which also had remarkably increased GCs levels. TNF-α emerges as a potent modulator of steroidogenesis in adrenocortical cells during T. cruzi infection in which MAPK pathways, NF-κB and AP-1 seem to play a role in the adrenal synthesis of pro-inflammatory cytokines and enzymes regulating GCs synthesis. These results suggest the existence of an intrinsic immune-adrenal interaction involved in the dysregulated synthesis of GCs during murine Chagas

  2. Dehydroepiandrosterone increases resistance to experimental infection by Trypanosoma cruzi.

    Science.gov (United States)

    Santos, Carla Domingues; Toldo, Míriam Paula Alonso; Santello, Fabrícia Helena; Filipin, Marina Del Vecchio; Brazão, Vânia; do Prado Júnior, José Clóvis

    2008-05-31

    Dehydroepiandrosterone (DHEA) enhances immune responses against a wide range of viral, bacterial, and parasitic pathogens. In a previous study, we reported that administration of DHEA significantly decreased the numbers of blood parasites in Trypanosoma cruzi experimental infection. The present study was undertaken to determine the effectiveness of DHEA in reducing the severity of acute phase T. cruzi infection of male and female Wistar rats. Animals were treated subcutaneously with 40 mg/kg body weight/day of DHEA. The concentration of nitric oxide (NO) was determined in spleen peritoneal cavity. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were determined in the sera of uninfected and infected animals. DHEA treatment augments NO production for both sexes after in vitro LPS treatment for uninfected animals. Infection triggered enhanced NO levels although not significant. IL-2 and IFN-gamma were detectable in higher concentrations in treated and infected rats of both genders when compared to untreated controls. These data suggest that DHEA may have a potent immunoregulatory function that can affect the course of T. cruzi infection.

  3. An in vitro iron superoxide dismutase inhibitor decreases the parasitemia levels of Trypanosoma cruzi in BALB/c mouse model during acute phase

    Science.gov (United States)

    Olmo, Francisco; Urbanová, Kristína; Rosales, Maria Jose; Martín-Escolano, Ruben; Sánchez-Moreno, Manuel; Marín, Clotilde

    2015-01-01

    In order to identify new compounds to treat Chagas disease during the acute phase with higher activity and lower toxicity than the reference drug benznidazole (Bz), two hydroxyphthalazine derivative compounds were prepared and their trypanocidal effects against Trypanosoma cruzi were evaluated by light microscopy through the determination of IC50 values. Cytotoxicity was determined by flow cytometry assays against Vero cells. In vivo assays were performed in BALB/c mice, in which the parasitemia levels were quantified by fresh blood examination; the assignment of a cure was determined by reactivation of blood parasitemia levels after immunosuppression. The mechanism of action was elucidated at metabolic and ultra-structural levels, by 1H NMR and TEM studies. Finally, as these compounds are potentially capable of causing oxidative damage in the parasites, the study was completed, by assessing their activity as potential iron superoxide dismutase (Fe-SOD) inhibitors. High-selectivity indices observed in vitro were the basis of promoting one of the tested compounds to in vivo assays. The tests on the murine model for the acute phase of Chagas disease showed better parasitemia inhibition values than those found for Bz. Compound 2 induced a remarkable decrease in the reactivation of parasitemia after immunosuppression. Compound 2 turned out to be a great inhibitor of Fe-SOD. The high antiparasitic activity and low toxicity together with the modest costs for the starting materials render this compound an appropriate molecule for the development of an affordable anti-Chagas agent. PMID:26236582

  4. Sexual transmission of Trypanosoma cruzi in murine model.

    Science.gov (United States)

    Ribeiro, Marcelle; Nitz, Nadjar; Santana, Camilla; Moraes, Aline; Hagström, Luciana; Andrade, Rafael; Rios, Adriano; Sousa, Alessandro; Dallago, Bruno; Gurgel-Gonçalves, Rodrigo; Hecht, Mariana

    2016-03-01

    Trypanosoma cruzi is mainly transmitted by blood-sucking triatomines, but other routes also have epidemiological importance, such as blood transfusion and congenital transmission. Although the possibility of sexual transmission of T. cruzi has been suggested since its discovery, few studies have been published on this subject. We investigated acquisition of T. cruzi by sexual intercourse in an experimental murine model. Male and female mice in the chronic phase of Chagas disease were mated with naive partners. Parasitological, serological and molecular tests demonstrated the parasites in tissues and blood of partners. These results confirm the sexual transmission of T. cruzi in mice.

  5. Trypanosoma cruzi screening in Texas blood donors, 2008-2012.

    Science.gov (United States)

    Garcia, M N; Woc-Colburn, L; Rossmann, S N; Townsend, R L; Stramer, S L; Bravo, M; Kamel, H; Beddard, R; Townsend, M; Oldham, R; Bottazzi, M E; Hotez, P J; Murray, K O

    2016-04-01

    Chagas disease is an important emerging disease in Texas that results in cardiomyopathy in about 30% of those infected with the parasite Trypanosoma cruzi. Between the years 2008 and 2012, about 1/6500 blood donors were T. cruzi antibody-confirmed positive. We found older persons and minority populations, particularly Hispanic, at highest risk for screening positive for T. cruzi antibodies during routine blood donation. Zip code analysis determined that T. cruzi is associated with poverty. Chagas disease has a significant disease burden and is a cause of substantial economic losses in Texas.

  6. Papel do óxido nítrico no desenvolvimento de lesões cardíacas na fase aguda da infecção experimental pelo Trypanosoma cruzi Role of nitric oxide in the development of cardiac lesions during the acute phase of experimental infection by Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Cláudia Renata Bibiano Borges

    2009-04-01

    Full Text Available A doença de Chagas é causada pelo Trypanosoma cruzi e o coração é o órgão mais acometido. O óxido nítrico apresenta importante ação anti-Trypanosoma, porém, com pouca evidência de seu papel no mecanismo de lesão tecidual. O objetivo deste estudo foi analisar a contribuição do óxido nítrico no desenvolvimento da inflamação e da fibrose cardíaca na fase aguda da infecção experimental por cepas Y e Colombiana do Trypanosoma cruzi. A inflamação foi significativamente maior nos animais infectados pela cepa Colombiana, comparada com os infectados com a cepa Y, tanto nos animais C57BL/6 (3,98x1,87%; p=0,004 quanto nos animais C57BL/6 deficientes na sintase do óxido nítrico induzível (3,99x2,4%; p=0,013. O parasitismo cardíaco dos animais C57BL/6 deficientes na sintase do óxido nítrico induzível infectados pela cepa Colombiana foi significativamente maior que o destes mesmos animais infectados com a cepa Y (2,78x0,17 ninhos/mm²; p=0,004 assim como, os animais C57BL/6 infectados com a cepa Colombiana (2,78x1,33 ninhos/mm²; p=0,006 ou cepa Y (2,78x0,53 ninhos/mm²; p=0,005. Os dados reforçam o papel do óxido nítrico no controle do parasitismo e sugerem seu papel na proteção tecidual, controlando a inflamação e potencialmente diminuindo lesões cardíacas durante a fase aguda na doença de Chagas experimental.Chagas disease is caused by Trypanosoma cruzi and the heart is the organ most affected. Nitric oxide has notable anti-Trypanosoma action, but with little evidence regarding its role in the mechanism for tissue injury. The objective of this study was to analyze the contribution of nitric oxide towards the development of inflammation and cardiac fibrosis during the acute phase of experimental infection by Y and Colombian strains of Trypanosoma cruzi. The inflammation was significantly more intense in animals infected with the Colombian strain, compared with those infected with the Y strain, both in C57BL/6

  7. Growth hormones therapy in immune response against Trypanosoma cruzi.

    Science.gov (United States)

    Frare, Eduardo Osório; Santello, Fabricia Helena; Caetano, Leony Cristina; Caldeira, Jerri C; Toldo, Míriam Paula Alonso; Prado, José Clóvis do

    2010-04-01

    Growth hormone (GH) is an important hypophyseal hormone that is primarily involved in body growth and metabolism. In mammals, control of Trypanosoma cruzi parasitism during the acute phase of infection is considered to be critically dependent on direct macrophage activation by cytokines. To explore the possibility that GH might be effective in the treatment of Chagas' disease, we investigated its effects on the course of T. cruzi infection in rats, focusing our analyses on its influences on parasitemia, NO, TNF-alpha and IFN-gamma concentration and on histopathological alterations and parasite burden in heart tissue. T. cruzi-infected male Wistar rats were intraperitoneally treated with 5 ng/10 g body weight/day of GH. Animals treated with GH showed a significant reduction in the number of blood trypomastigotes during the acute phase of infection compared with untreated animals (P<0.05). For all experimental days (7, 14 and 21 post infection) of the acute phase, infected and GH treated animals reached higher concentrations of TNF-alpha, IFN-gamma and nitric oxide as compared to untreated and infected counterparts (P<0.05) Histopathological observations of heart tissue revealed that GH administration also resulted in fewer and smaller amastigote burdens, and less inflammatory infiltrate and tissue disorganization, indicating a reduced parasitism of this tissue. These results show that GH can be considered as an immunomodulator substance for controlling parasite replication and combined with the current drug used may represent in the future a new therapeutic tool to reduce the harmful effects of Chagas' disease.

  8. EPIDEMIOLOGÍA MOLECULAR DE TRYPANOSOMA CRUZI

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2013-01-01

    Full Text Available La enfermedad de Chagas causada por el parásito Trypanosoma cruzi es una zoonosis compleja, ampliamente distribuida en el continente americano. La infección puede ser adquirida a través de las heces de insectos triatominos, transfusión de sangre, trasplante de órganos, vía oral, por transmisión congénita y por accidentes de laboratorio. El completo entendimiento de la etiología y epidemiología de la enfermedad de Chagas a través de su distribución geográfica es complejo y permanece bajo intensa investigación hasta la actualidad. Los recientes estudios sobre la variabilidad genética del parásito han dado nuevas luces de los diferentes escenarios de los ciclos de transmisión de la enfermedad y su patogénesis en humanos. El propósito principal para la caracterización molecular de T.cruzi y sus múltiples genotipos está dirigido hacia su asociación con la clínica y la patogenesis de la enfermedad, así como al esclarecimiento de los diferentes escenarios de transmisión y los aspectos coevolutivos relacionados con reservorios e insectos vectores. La caracterización molecular de los diferentes aislamientos a partir de humanos, insectos y reservorios, ha permitido identificar la amplia variabilidad genética del parásito, abriendo nuevos caminos hacia la búsqueda de nuevos blancos terapéuticos y pruebas diagnósticas más específicas que contribuyan a mitigar la enfermedad de Chagas.

  9. Predominance of Trypanosoma cruzi I among Panamanian sylvatic isolates.

    Science.gov (United States)

    Samudio, Franklyn; Ortega-Barría, Eduardo; Saldaña, Azael; Calzada, Jose

    2007-02-01

    Trypanosoma cruzi is throughout Panama, which is in agreement with the widespread of the sylvatic vectors implicated in the transmission. Eco-epidemiological changes in some regions of the country have led to a successful dissemination of the palm-tree Attalea butyracea and a possible adaptation of the primary vector of Chagas' disease to human settlements. These facts might increase both vector-human contact and human infection with different potentials T. cruzi genotypes and make therefore necessary a study to disclose Panamanian T. cruzi make-up. In this study, 71 T. cruzi isolates from Rhodnius pallescens were analyzed using mini-exon gene and sequence-characterized amplified region markers. The analyzed strains were T. cruzi lineage I. This finding along with prior results indicates that T. cruzi I is the principal genotype circulating in both sylvatic and domestic/peridomestic cycles and consequently responsible for the disease in the country.

  10. Mother-to-Child Transmission of Trypanosoma cruzi.

    Science.gov (United States)

    Gebrekristos, Hirut T; Buekens, Pierre

    2014-09-01

    Among the world's most neglected tropical diseases, Chagas disease is vector-borne and caused by Trypanosoma cruzi. T cruzi infection is endemic to South and Central America as well as Mexico. Due to population migration, T cruzi is increasingly becoming a public health problem in nonendemic settings. Success with vector control strategies has led to a relative increase in the burden attributable to congenital transmission of T cruzi. In endemic settings, approximately 5% of infected pregnant women transmit to their offspring. Congenital T cruzi infection is generally asymptomatic and parasitological and serological testing is required for diagnosis. This review highlights research gaps with a focus on (1) improving screening, diagnostic, and treatment options and (2) designing epidemiologic studies to understand risk factors for congenital T cruzi.

  11. Genitourinary changes in hamsters infected and reinfected with Trypanosoma cruzi

    OpenAIRE

    Cabrine-Santos Marlene; Santos Vitorino Modesto dos; Lima Marcus Aurelho; Abreu Marta Elena Araújo de; Lages-Silva Eliane; Ramírez Luís Eduardo

    2003-01-01

    Authors describe genitourinary changes in male hamsters infected and reinfected with Trypanosoma cruzi. Changes in genital organs have been described in human and in experimental chagasic infection. Genital dysfunctions in chronic chagasic patients affect ejaculation, libido and sexual potency, and testis biopsies may show arrested maturation of germ cells, oligozoospermia and azoospermia. Sixty-five male hamsters were inoculated and reinoculated with 2x10³ trypomastigotes of T. cruzi VIC str...

  12. Comparative pathogenicity in Swiss mice of Trypanosoma cruzi IV from northern Brazil and Trypanosoma cruzi II from southern Brazil.

    Science.gov (United States)

    Meza, Sheila Karina Lüders; Kaneshima, Edilson Nobuyoshi; Silva, Sueli de Oliveira; Gabriel, Maristela; de Araújo, Silvana Marques; Gomes, Mônica Lúcia; Monteiro, Wuelton Marcelo; Barbosa, Maria das Graças Vale; Toledo, Max Jean de Ornelas

    2014-11-01

    The geographical heterogeneity of Chagas disease (ChD) is mainly caused by genetic variability of the etiological agent Trypanosoma cruzi. Our hypothesis was that the pathogenicity for mice may vary with the genetic lineage (or Discrete Typing Unit - DTU) of the parasite. To test this hypothesis, parasitological and histopathological evaluations were performed in mice inoculated with strains belonging to the DTU T. cruzi IV (TcIV) from the State of Amazonas (northern Brazil), or the DTU T. cruzi II (TcII) from the State of Paraná (southern Brazil). Groups of 10 Swiss mice were inoculated with eight strains of TcIV obtained from acute cases (7) from two outbreaks of orally acquired ChD, and from the triatomine Rhodnius robustus (1) from Amazonas; and three strains of TcII obtained from chronic patients in Paraná. We evaluated the pre-patent period, patent period, maximum peak of parasitemia, day of maximum peak of parasitemia, area under the parasitemia curve, inflammatory process, and tissue parasitism in the acute phase. TcIV was less virulent than TcII, and showed significantly (p < 0.005) lower parasitemia levels. Although the levels of tissue parasitism did not differ statistically, mice infected with TcIV displayed significantly (p < 0.001) fewer inflammatory processes than mice infected with TcII. This supported the working hypothesis, since TcIV from Amazonas was less pathogenic than TcII from Paraná; and agreed with the lower severity of human cases of ChD in the Amazon region.

  13. Infecção por Trypanosoma cruzi em candidatos a doador de sangue Trypanosoma cruzi infection in blood donors

    Directory of Open Access Journals (Sweden)

    Ana M. Bonametti

    1998-12-01

    Full Text Available INTRODUÇÃO: A transmissão transfusional da tripanossomíase americana tem-se reduzido no Brasil, com a progressiva ampliação do controle de qualidade do sangue. Nesse sentido, realizou-se pesquisa para avaliar a atual soro-prevalência da infecção por Trypanosoma cruzi em candidatos a doador de sangue em Londrina, Paraná (Brasil, e comparar essa taxa com a encontrada em candidatos a doador estudados em 1958 e 1975, na mesma cidade. MÉTODO: Estudo transversal para determinação da soroprevalência. O imuno-diagnóstico de infecção por Trypanosoma cruzi foi realizado através das técnicas imunoenzimática (ELISA e imunofluorescência indireta. RESULTADOS E CONCLUSÃO: A taxa de soroprevalência encontrada foi de 1,3%. Foi detectada tendência de queda temporal da taxa de positividade dos testes sorológicos para o diagnóstico de infecção por Trypanosoma cruzi nos bancos de sangue do município estudado nos anos de 1958, 1975 e 1995.INTRODUCTION: Transmission of American trypanossomiasis by transfusion has been reduced by expansion of control measures of blood quality in Brazil. A research project was, therefore, undertaken to evaluate soropositivity for Trypanosoma cruzi infection on blood donors and to compare this rate with those found in 1958 and 1975 in blood banks. METHOD: A transversal study was carried out on blood donors in Londrina, Paraná, Brazil. ELISA and Immunofluorescence were the serological test techniques used in the diagnosis of Trypanosoma cruzi infection. RESULTS AND CONCLUSION: A serumprevalence rate of 1.3% was found with a tendency for positive serum findings for Trypanosoma cruzi infection on blood donors to decrease over Aime (1958, 1975, and 1995.

  14. Molecular characterization of human Trypanosoma cruzi isolates from endemic areas in Panama

    Directory of Open Access Journals (Sweden)

    Octavio E Sousa

    2006-06-01

    Full Text Available The present work provides information on Trypanosoma cruzi genotype circulating in endemic areas of Chagas disease in Panama. A total of 26 crude stocks of T. cruzi, isolated from the blood of persons with different clinical profiles of Chagas disease were collected and crio-conserved until used. Most of the stocks had been characterized by means of isoenzyme electrophoresis on cellulose acetate membranes. The clinical profiles of infected persons included 9 (34.6% asymptomatic and 17 acute (65.4% including 5 (19.2% fatal cases, 2 under 5 years old and 3 adults. A multiplex-PCR assay based on the amplification of the non-transcribed spacer of the mini-exon gene was performed. All stocks of T. cruzi included in the study were found to correspond to Tc I group. This result supports the predominance of T. cruzi-I in the transmission cycles affecting the human population in the Republic of Panama.

  15. Interactions between Trypanosoma cruzi secreted proteins and host cell signaling pathways

    Directory of Open Access Journals (Sweden)

    Renata Watanabe Costa

    2016-03-01

    Full Text Available Chagas disease is one of the prevalent neglected tropical diseases, affecting at least 6-7 million individuals in Latin America. It is caused by the protozoan parasite Trypanosoma cruzi (T. cruzi, which is transmitted to vertebrate hosts by blood-sucking insects. After infection, the parasite invades and multiplies in the myocardium, leading to acute myocarditis that kills around 5% of untreated individuals. T. cruzi secretes proteins that manipulate multiple host cell signaling pathways to promote host cell invasion. The primary secreted lysosomal peptidase in T. cruzi is cruzipain, which has been shown to modulate the host immune response. Cruzipain hinders macrophage activation during the early stages of infection by interrupting the NF-kB P65 mediated signaling pathway. This allows the parasite to survive and replicate, and may contribute to the spread of infection in acute Chagas disease. Another secreted protein P21, which is expressed in all of the developmental stages of T. cruzi, has been shown to modulate host phagocytosis signaling pathways. The parasite also secretes soluble factors that exert effects on host extracellular matrix, such as proteolytic degradation of collagens. Finally, secreted phospholipase A from T. cruzi contributes to lipid modifications on host cells and concomitantly activates the PKC signaling pathway. Here we present a brief review of the interaction between secreted proteins from T. cruzi and the host cells, emphasizing the manipulation of host signaling pathways during invasion.

  16. Trypanosoma cruzi tubulin eliminated in the urine of the infected host.

    Science.gov (United States)

    Bertot, G M; Corral, R S; Fresno, M; Rodríguez, C; Katzin, A M; Grinstein, S

    1998-06-01

    In previous studies we have identified and characterized an 80-kDa Trypanosoma cruzi urinary antigen (UAg) eliminated during acute infection. Polyclonal antibodies raised against this antigen revealed by western blotting and immunoprecipitation analyses showed the existence of another antigenic component of 50-55 kDa in the UAg preparation. The antiserum was also used for screening of a T. cruzi expression library. Sequencing of inserts from selected cDNA clones showed high homology with the 3' end of the T.cruzi beta-tubulin gene sequence encoding for the C-terminus of the protein. The presence of T. cruzi tubulin in the UAg was confirmed by immunoprecipitation of a 50-55-kDa protein from 125I-labeled UAg with monoclonal antibodies (MAbs) to human alpha/beta-tubulin. Interestingly, MAbs recognized radiolabeled T. cruzi tubulin eliminated in the urine of infected mice 24 hr postinoculation of [35S]methionine-labeled viable trypomastigotes. Tubulin found in the urine proved to be of T. cruzi origin because this protein could not be identified in urinary specimens from uninfected animals or mice acutely infected with Leishmania infantum or Toxoplasma gondii. We conclude that tubulin is one of the parasite antigens eliminated in the urine of T. cruzi-infected hosts. This finding may be used to develop a noninvasive procedure for early diagnosis of Chagas' disease.

  17. Autochthonous Transmission of Trypanosoma Cruzi in Southern California

    Science.gov (United States)

    Hernandez, Salvador; Flores, Carmen A.; Viana, Gracia M.; Sanchez, Daniel R.; Traina, Mahmoud I.

    2016-01-01

    Trypanosoma cruzi usually infects humans via triatomine insects in Latin America. Vector-borne transmission in the United States is exceedingly rare. We describe (1) the first case of probable autochthonous transmission reported in California in more than 30 years and (2) the first ever reported case in the greater Los Angeles area. PMID:28018928

  18. Trypanosoma cruzi: avirulence of the PF strain to Callithrix marmosets

    Directory of Open Access Journals (Sweden)

    Humberto Menezes

    1981-06-01

    Full Text Available Callithrix jacchus geoffroy marmosets (HumBol. 1812 were injected once subcutaneously with 10.000 parasites/g body weight and followed for a period of six months. The PF strain of Trypanosoma cruzi was used. Follow-up was done through blood cultures, xenodiagnosis, serological tests, and ECG. A small number of normaI animais served as control.

  19. Infecção tripla por Trypanosoma cruzi, Plasmodium vivax e P. falciparum: relato de caso Triple infection by Trypanosoma cruzi, Plasmodium vivax and P. falciparum: case report

    Directory of Open Access Journals (Sweden)

    Andrea Silvestre Lobão Costa

    2012-12-01

    Full Text Available O presente registro acerca da identificação de infecção aguda de dois plasmódios e um Trypanosoma constitui evento raro. Pré-escolar, sexo feminino, 5 anos de idade, apresentou síndrome febril; foi submetida a exame de gota espessa no qual foram identificadas formas assexuadas e sexuadas de Plasmodium vivax e P. falciparum, respectivamente, além de tripomastigotas sanguíneos de Trypanosoma cruzi. No peridomicílio, foram encontrados insetos da espécie Rhodnius sp. Os autores reforçam a importância dos estudos dos ciclos peridomiciliares de T. cruzi em ambientes silvestres na Amazônia e discutem a importância da estratégia de vigilância continuada de Trypanosomas spp. nos exames de gota espessa.This report describes a rare case of acute infection caused by two Plasmodia and one Trypanosoma. 5 year-old female patient attending kindergarten presented persistent fever syndrome. She was submitted to thick smear exam, in which asexual and sexual forms of Plasmodium vivax and P. falciparum were detected, respectively, as well as trypomastigotes of Trypanosoma cruzi. Rhodnius sp. triatomines were found in the vicinity. The authors reinforce the importance of investigating the domiciliary cycles of T. cruzi in the Amazon region. Moreover, we discuss the importance of continuous monitoring of Trypanosomas spp. in thick smear exams.

  20. Bed Bugs (Cimex lectularius) as Vectors of Trypanosoma cruzi

    Science.gov (United States)

    Salazar, Renzo; Castillo-Neyra, Ricardo; Tustin, Aaron W.; Borrini-Mayorí, Katty; Náquira, César; Levy, Michael Z.

    2015-01-01

    Populations of the common bed bug, Cimex lectularius, have recently undergone explosive growth. Bed bugs share many important traits with triatomine insects, but it remains unclear whether these similarities include the ability to transmit Trypanosoma cruzi, the etiologic agent of Chagas disease. Here, we show efficient and bidirectional transmission of T. cruzi between hosts and bed bugs in a laboratory environment. Most bed bugs that fed on experimentally infected mice acquired the parasite. A majority of previously uninfected mice became infected after a period of cohabitation with exposed bed bugs. T. cruzi was also transmitted to mice after the feces of infected bed bugs were applied directly to broken host skin. Quantitative bed bug defecation measures were similar to those of important triatomine vectors. Our findings suggest that the common bed bug may be a competent vector of T. cruzi and could pose a risk for vector-borne transmission of Chagas disease. PMID:25404068

  1. Bed bugs (Cimex lectularius) as vectors of Trypanosoma cruzi.

    Science.gov (United States)

    Salazar, Renzo; Castillo-Neyra, Ricardo; Tustin, Aaron W; Borrini-Mayorí, Katty; Náquira, César; Levy, Michael Z

    2015-02-01

    Populations of the common bed bug, Cimex lectularius, have recently undergone explosive growth. Bed bugs share many important traits with triatomine insects, but it remains unclear whether these similarities include the ability to transmit Trypanosoma cruzi, the etiologic agent of Chagas disease. Here, we show efficient and bidirectional transmission of T. cruzi between hosts and bed bugs in a laboratory environment. Most bed bugs that fed on experimentally infected mice acquired the parasite. A majority of previously uninfected mice became infected after a period of cohabitation with exposed bed bugs. T. cruzi was also transmitted to mice after the feces of infected bed bugs were applied directly to broken host skin. Quantitative bed bug defecation measures were similar to those of important triatomine vectors. Our findings suggest that the common bed bug may be a competent vector of T. cruzi and could pose a risk for vector-borne transmission of Chagas disease.

  2. Isolation and characterization of paraflagellar proteins from Trypanosoma cruzi.

    Science.gov (United States)

    Saborio, J L; Manuel Hernandez, J; Narayanswami, S; Wrightsman, R; Palmer, E; Manning, J

    1989-03-05

    Two different Trypanosoma cruzi polypeptides, with masses of 70 and 68 kDa were purified and characterized in this work. These two polypeptides designated PAR 1 and PAR 2, respectively, co-purified during each step of the isolation procedure and were found to be located exclusively in T. cruzi flagella by indirect immunofluorescence. A pre-embedding immunoelectron microscopy procedure, with a gold-tagged secondary antibody, permitted direct identification of PAR 2 as a component of the T. cruzi paraflagellar rod. PAR 1 and PAR 2 were found to be immunologically distinct and showed no cross-reactivity with actin, tubulin, intermediate filament proteins, or other proteins present in mammalian cells. The results presented indicate that PAR 1 and PAR 2 are the major components of T. cruzi paraflagellar filaments, and that these filaments have no counterpart in mammalian cells.

  3. Interactions between Trypanosoma cruzi Secreted Proteins and Host Cell Signaling Pathways

    Science.gov (United States)

    Watanabe Costa, Renata; da Silveira, Jose F.; Bahia, Diana

    2016-01-01

    Chagas disease is one of the prevalent neglected tropical diseases, affecting at least 6–7 million individuals in Latin America. It is caused by the protozoan parasite Trypanosoma cruzi, which is transmitted to vertebrate hosts by blood-sucking insects. After infection, the parasite invades and multiplies in the myocardium, leading to acute myocarditis that kills around 5% of untreated individuals. T. cruzi secretes proteins that manipulate multiple host cell signaling pathways to promote host cell invasion. The primary secreted lysosomal peptidase in T. cruzi is cruzipain, which has been shown to modulate the host immune response. Cruzipain hinders macrophage activation during the early stages of infection by interrupting the NF-kB P65 mediated signaling pathway. This allows the parasite to survive and replicate, and may contribute to the spread of infection in acute Chagas disease. Another secreted protein P21, which is expressed in all of the developmental stages of T. cruzi, has been shown to modulate host phagocytosis signaling pathways. The parasite also secretes soluble factors that exert effects on host extracellular matrix, such as proteolytic degradation of collagens. Finally, secreted phospholipase A from T. cruzi contributes to lipid modifications on host cells and concomitantly activates the PKC signaling pathway. Here, we present a brief review of the interaction between secreted proteins from T. cruzi and the host cells, emphasizing the manipulation of host signaling pathways during invasion. PMID:27065960

  4. Comparative analysis of the kinomes of three pathogenic trypanosomatids: Leishmania major, Trypanosoma brucei and Trypanosoma cruzi

    OpenAIRE

    Parsons, Marilyn; Worthey, Elizabeth A.; Ward, Pauline N; Mottram, Jeremy C.

    2005-01-01

    Background The trypanosomatids Leishmania major, Trypanosoma brucei and Trypanosoma cruzi cause some of the most debilitating diseases of humankind: cutaneous leishmaniasis, African sleeping sickness, and Chagas disease. These protozoa possess complex life cycles that involve development in mammalian and insect hosts, and a tightly coordinated cell cycle ensures propagation of the highly polarized cells. However, the ways in which the parasites respond to their environment and coordinate intr...

  5. Immunotherapy of Trypanosoma cruzi infection with DNA vaccines in mice.

    Science.gov (United States)

    Dumonteil, Eric; Escobedo-Ortegon, Javier; Reyes-Rodriguez, Norma; Arjona-Torres, Arletty; Ramirez-Sierra, Maria Jesus

    2004-01-01

    The mechanisms involved in the pathology of chronic chagasic cardiomyopathy are still debated, and the controversy has interfered with the development of new treatments and vaccines. Because of the potential of DNA vaccines for immunotherapy of chronic and infectious diseases, we tested if DNA vaccines could control an ongoing Trypanosoma cruzi infection. BALB/c mice were infected with a lethal dose (5 x 10(4) parasites) as a model of acute infection, and then they were treated with two injections of 100 microg of plasmid DNA 1 week apart, beginning on day 5 postinfection. Control mice had high levels of parasitemia and mortality and severe cardiac inflammation, while mice treated with plasmid DNA encoding trypomastigote surface antigen 1 or Tc24 had reduced parasitemia and mild cardiac inflammation and >70% survived the infection. The efficacy of the immunotherapy also was significant when it was delayed until days 10 and 15 after infection. Parasitological analysis of cardiac tissue of surviving mice indicated that most mice still contained detectable parasite kinetoplast DNA but fewer mice contained live parasites, suggesting that there was efficient but not complete parasite elimination. DNA vaccine immunotherapy was also evaluated in CD1 mice infected with a low dose (5 x 10(2) parasites) as a model of chronic infection. Immunotherapy was initiated on day 70 postinfection and resulted in improved survival and reduced cardiac tissue inflammation. These results suggest that DNA vaccines have strong potential for the immunotherapy of T. cruzi infection and may provide new alternatives for the control of Chagas' disease.

  6. Exacerbated Skeletal Muscle Inflammation and Calcification in the Acute Phase of Infection by Mexican Trypanosoma cruzi DTUI Strain

    Directory of Open Access Journals (Sweden)

    Andrea Vizcaíno-Castillo

    2014-01-01

    Full Text Available A murine model was used to study the histopathological aspects and cytokine expression levels in skeletal muscle provoked by the infection with Mexican TcI strains. BALB/c mice were inoculated with the virulent Querétaro strain and the nonvirulent Ninoa strain. Parasite numbers were counted in blood and skeletal muscle at different times post-infection, and real time-PCR expression levels of the cytokines IL-12, IL-4, IL-10, IFN-γ, and TNF-α were evaluated. In the acute phase of infection, a high parasitic load, both in blood and skeletal muscle, was detected. The histopathological analyses showed an exacerbated inflammation and granulomatous-like infiltrate with the Querétaro strain. Interestingly, extensive calcification areas were observed in the skeletal muscle surrounded by inflammatory infiltrates. TNF-α and IL-10 expression exhibited a significant increase at the peak of infection. In summary, Querétaro strain, a Mexican TcI strain, is virulent enough to induce high inflammation and calcification in skeletal muscle of the hind limbs, which could be related to high expression levels of TNF-α.

  7. Trypanosoma cruzi: single cell live imaging inside infected tissues

    Science.gov (United States)

    Ferreira, Bianca Lima; Orikaza, Cristina Mary; Cordero, Esteban Mauricio

    2016-01-01

    Summary Although imaging the live Trypanosoma cruzi parasite is a routine technique in most laboratories, identification of the parasite in infected tissues and organs has been hindered by their intrinsic opaque nature. We describe a simple method for in vivo observation of live single‐cell Trypanosoma cruzi parasites inside mammalian host tissues. BALB/c or C57BL/6 mice infected with DsRed‐CL or GFP‐G trypomastigotes had their organs removed and sectioned with surgical blades. Ex vivo organ sections were observed under confocal microscopy. For the first time, this procedure enabled imaging of individual amastigotes, intermediate forms and motile trypomastigotes within infected tissues of mammalian hosts. PMID:26639617

  8. Genetically attenuated Trypanosoma cruzi parasites as a potential vaccination tool

    OpenAIRE

    2012-01-01

    Chagas disease is the clinical manifestation of the infection produced by the parasite Trypanosoma cruzi. Currently there is no vaccine to prevent this disease and the protection attained with vaccines containing non-replicating parasites is limited. Genetically attenuated trypanosomatid parasites can be obtained by deletion of selected genes. Gene deletion takes advantage of the fact that this parasite can undergo homologous recombination between endogenous and foreign DNA sequences artifici...

  9. Surface antigens of metacyclic trypomastigotes of Trypanosoma cruzi.

    OpenAIRE

    1983-01-01

    The surface antigen makeup of metacyclic trypomastigote forms of strain G of Trypanosoma cruzi, which produce a subpatent infection in mice, differed from those of the virulent strains Y and CL. A 100,000-molecular-weight protein, barely detectable on the Y or CL cell surface, appeared as the main surface antigen of the G metacyclic trypomastigotes. In addition, the G metacyclic forms differed from those of the virulent strains in their susceptibility to complement-mediated immunolysis.

  10. Pure paraflagellar rod protein protects mice against Trypanosoma cruzi infection.

    OpenAIRE

    1995-01-01

    The paraflagellar rod proteins (PAR) purified from Trypanosoma cruzi epimastigotes were shown to protect mice against an otherwise lethal challenge inoculum of 10(3) bloodstream-form trypomastigotes. The injection route used for immunization was shown to have a marked impact on the development of protective immunity. Mice receiving subcutaneous (s.c.) injections of PAR proteins had reduced bloodstream parasitemias and showed 100% survival following challenge. In contrast, mice immunized via t...

  11. Biosynthesis of very long chain fatty acids in Trypanosoma cruzi.

    Science.gov (United States)

    Livore, Verónica I; Uttaro, Antonio D

    2015-01-01

    Trypanosoma brucei and Trypanosoma cruzi showed similar fatty acid (FA) compositions, having a high proportion of unsaturated FAs, mainly 18:2Δ9,12 (23-39%) and 18:1Δ9 (11-17%). C22 polyunsaturated FAs are in significant amounts only in T. brucei (12-20%) but represent a mere 2% of total FAs in T. cruzi. Both species have also similar profiles of medium- and long-chain saturated FAs, from 14:0 to 20:0. Interestingly, procyclic and bloodstream forms of T. brucei lack very long chain FAs (VLCFAs), whereas epimastigotes and trypomastigotes of T. cruzi contain 22:0 (0.1-0.2%), 24:0 (1.5-2%), and 26:0 (0.1-0.2%). This is in agreement with the presence of an additional FA elongase gene (TcELO4) in T. cruzi. TcELO4 was expressed in a Saccharomyces cerevisiae mutant lacking the endogenous ScELO3, rescuing the synthesis of saturated and hydroxylated C26 FAs in the yeast. Expression of TcELO4 also rescued the synthetic lethality of a ScELO2, ScELO3 double mutation, and the VLCFA profile of the transformed yeast was similar to that found in T. cruzi. By identifying TcELO4 as the enzyme responsible for the elongation of FA from 16:0 and 18:0 up to 26:0, with 24:0 being the preferred product, this work completed the characterization of FA elongases in Trypanosoma spp.

  12. Vaccination with Trypanosoma rangeli induces resistance of guinea pigs to virulent Trypanosoma cruzi.

    Science.gov (United States)

    Basso, B; Moretti, E; Fretes, R

    2014-01-15

    Chagas' disease, endemic in Latin America, is spread in natural environments through animal reservoirs, including marsupials, mice and guinea pigs. Farms breeding guinea pigs for food are located in some Latin-American countries with consequent risk of digestive infection. The aim of this work was to study the effect of vaccination with Trypanosoma rangeli in guinea pigs challenged with Trypanosoma cruzi. Animals were vaccinated with fixated epimastigotes of T. rangeli, emulsified with saponin. Controls received only PBS. Before being challenged with T. cruzi, parasitemia, survival rates and histological studies were performed. The vaccinated guinea pigs revealed significantly lower parasitemia than controls (pguinea pigs and dogs. The development of vaccines for use in animals, like domestic dogs and guinea pigs in captivity, opens up new opportunities for preventive tools, and could reduce the risk of infection with T. cruzi in the community.

  13. An iron-binding Trypanosoma cruzi urinary antigen.

    Science.gov (United States)

    Corral, R S; Bertot, G M; Petray, P B; Altcheh, J M; Singh, M; Orn, A; Rapoport, M F; Grinstein, S

    1995-12-01

    An 80-kDa Trypanosoma cruzi urinary antigen (UAg) was affinity-purified from the urine of infected dogs. We demonstrated that UAg is structurally and functionally related to proteins belonging to the transferrin family, as shown by amino acid sequence and iron binding experiments. Nevertheless, monoclonal antibodies raised against UAg specifically and selectively recognized this parasite's circulating antigen. The existence of an 80-kDa T. cruzi antigen co-migrating with UAg could be confirmed when epimastigotes were metabolically labelled with [35S] methionine and then immunoprecipitated with the above mentioned antibodies. We conclude that UAg is an iron-binding T. cruzi component eliminated in the urine of the infected host.

  14. Trypanosoma cruzi and Trypanosoma rangeli: interplay with hemolymph components of Rhodnius prolixus.

    Science.gov (United States)

    Mello, C B; Garcia, E S; Ratcliffe, N A; Azambuja, P

    1995-05-01

    Studies were carried out on the course of infection of Trypanosoma cruzi (clone Dm28c) and Trypanosoma rangeli (clone San Agustin) and their interactions with hemolymph components of Rhodnius prolixus. These parasites when inoculated into the hemocoel of adult R. prolixus (i) had different courses of infection (T. rangeli had high rates of both multiplication and infection and T. cruzi had no division and disappeared soon from the hemolymph); (ii) induced high but no differential increases in lysozyme levels; (iii) failed to induce any other antibacterial activity; (iv) showed similar patterns of hemolymph agglutination activity for erythrocytes and parasites, although there was evidence of limited, unquantifiable, agglutination of T. cruzi; (v) elicited different hemocyte responses with only the T. rangeli infection resulting in significantly increased hemocyte counts; and (vi) did not induce trypanolytic activity. These experiments, unlike previous studies, also showed (i) an interaction of these trypanosomes with the prophenoloxidase-activating system [phenoloxidase (PO) production was spontaneously activated by both parasites but the number of T. cruzi in the hemolymph was directly correlated with PO levels] and (ii) that the elimination of T. cruzi also corresponded to the formation of nodules in the hemolymph. The significance of these results is discussed in relation to the hypothesis that T. rangeli but not T. cruzi has the ability to escape from and perhaps utilize the vector immune system in order to successfully colonize the R. prolixus hemolymph.

  15. Suppressive action of melatonin on the TH-2 immune response in rats infected with Trypanosoma cruzi.

    Science.gov (United States)

    Santello, Fabricia Helena; Frare, Eduardo Osório; dos Santos, Carla Domingues; Caetano, Leony Cristina; Alonso Toldo, Míriam Paula; do Prado, José Clóvis

    2008-10-01

    Control of the acute phase of Trypanosoma cruzi infection is critically dependent on cytokine-mediated macrophage activation to intracellular killing, natural killer (NK) cells, CD4(+) T cells, CD8(+) T cells and B cells. Cell-mediated immunity in T. cruzi infection is also modulated by cytokines, but in addition to parasite-specific responses, autoimmunity can be also triggered. Importantly, cytokines may also play a role in the cell-mediated immunity of infected subjects. Here we studied the role of cytokines in the regulation of innate and adaptive immunity during the acute phase of T. cruzi infection in Wistar rats. Melatonin is an effective regulator of the immune system. Macrophages and T lymphocytes, which have melatonin receptors, are target cells for the immunomodulatory function of melatonin. In this paper melatonin was orally given via two protocols: prior to and concomitant with infection. Both treatments were highly effective against T. cruzi with enhanced action for the concomitant treatment. The data suggest an up-regulation of the TH-1 immune response as all analyzed parameters, interleukin (IL)-4, IL-10, transforming growth factor-beta1 and splenocyte proliferation, displayed reduced levels as compared with the untreated counterparts. However, the direct effects of melatonin on immune cells have not been fully investigated during T. cruzi infection. We conclude that in light of the current results, melatonin exerted important therapeutic benefits through its immune regulatory effects.

  16. Pentamidine exerts in vitro and in vivo anti Trypanosoma cruzi activity and inhibits the polyamine transport in Trypanosoma cruzi.

    Science.gov (United States)

    Díaz, María V; Miranda, Mariana R; Campos-Estrada, Carolina; Reigada, Chantal; Maya, Juan D; Pereira, Claudio A; López-Muñoz, Rodrigo

    2014-06-01

    Pentamidine is an antiprotozoal and fungicide drug used in the treatment of leishmaniasis and African trypanosomiasis. Despite its extensive use as antiparasitic drug, little evidence exists about the effect of pentamidine in Trypanosoma cruzi, the etiological agent of Chagas' disease. Recent studies have shown that pentamidine blocks a polyamine transporter present in Leishmania major; consequently, its might also block these transporters in T. cruzi. Considering that T. cruzi lacks the ability to synthesize putrescine de novo, the inhibition of polyamine transport can bring a new therapeutic target against the parasite. In this work, we show that pentamidine decreases, not only the viability of T. cruzi trypomastigotes, but also the parasite burden of infected cells. In T. cruzi-infected mice pentamidine decreases the inflammation and parasite burden in hearts from infected mice. The treatment also decreases parasitemia, resulting in an increased survival rate. In addition, pentamidine strongly inhibits the putrescine and spermidine transport in T. cruzi epimastigotes and amastigotes. Thus, this study points to reevaluate the utility of pentamidine and introduce evidence of a potential new action mechanism. In the quest of new therapeutic strategies against Chagas disease, the extensive use of pentamidine in human has led to a well-known clinical profile, which could be an advantage over newly synthesized molecules that require more comprehensive trials prior to their clinical use.

  17. Trypanosoma cruzi: Transporte de metabolitos esenciales obtenidos del hospedador Trypanosoma cruzi: Transport of essential metabolites acquired from the host

    Directory of Open Access Journals (Sweden)

    Claudio A. Pereira

    2008-10-01

    Full Text Available El Trypanosoma cruzi es el agente causal de la enfermedad de Chagas, endémica en Argentina y en toda América Latina. Presenta numerosas características metabólicas diferenciales respecto a sus hospedadores insectos y mamíferos. Algunas de estas diferencias fueron consecuencia de millones de años de adaptación al parasitismo en los cuales estos organismos protozoarios reemplazaron, a lo largo de su evolución, muchas rutas metabólicas de biosíntesis por sistemas de transporte de metabolitos desde el hospedador. En esta revisión se describen los avances en el conocimiento de los sistemas de transporte tanto bioquímicos como también de las moléculas involucradas en dichos procesos. Se aborda con especial énfasis los transportadores de aminoácidos y poliaminas de T. cruzi de la familia AAAP (Amino Acid/Auxin Permeases ya que parece ser exclusiva de los tripanosomátidos. Teniendo en cuenta que estas moléculas se encuentran completamente ausentes en mamíferos podrían ser consideradas como potenciales blancos contra el Trypanosoma cruzi.Trypanosoma cruzi is the etiological agent of Chagas disease, a disease endemic not only in Argentina but also in all of Latinamerica. T. cruzi presents several metabolic characteristics which are completely absent in its insect vectors and in mammalian hosts. Some of these differences were acquired after millions of years of adaptation to parasitism, during which this protozoan replaced many biosynthetic routes for transport systems. In the present review, we describe the advances in the knowledge of T. cruzi transport processes and the molecules involved. In particular, we focus on aminoacid and polyamine transporters from the AAAP family (Amino Acid/Auxin Permeases, because they seem to be exclusive transporters from trypanosomatids. Taking into account that these permeases are completely absent in mammals, they could be considered as a potential target against Trypanosoma cruzi.

  18. Incidence of Trypanosoma cruzi Infection in Triatomines Collected at Indio Mountains Research Station

    OpenAIRE

    2015-01-01

    Chagas disease, caused by the parasite Trypanosoma cruzi, is an emerging infectious disease in the United States. In our study, 24 out of 39 triatomines, from the specie Triatoma rubida, were infected with Trypanosoma cruzi. Additionally, only the genotype TcI was characterized among the parasite specimens. Improved knowledge of local epidemiology is needed to prevent transmission of Chagas disease.

  19. Trypanosoma cruzi population dynamics in the Central Ecuadorian Coast.

    Science.gov (United States)

    Costales, Jaime A; Jara-Palacios, Miguel A; Llewellyn, Martin S; Messenger, Louisa A; Ocaña-Mayorga, Sofía; Villacís, Anita G; Tibayrenc, Michel; Grijalva, Mario J

    2015-11-01

    Chagas disease is the most important parasitic disease in Latin America. The causative agent, Trypanosoma cruzi, displays high genetic diversity and circulates in complex transmission cycles among domestic, peridomestic and sylvatic environments. In Ecuador, Rhodnius ecuadoriensis is known to be the major vector species implicated in T. cruzi transmission. However, across vast areas of Ecuador, little is known about T. cruzi genetic diversity in relation to different parasite transmission scenarios. Fifty-eight T. cruzi stocks from the central Ecuadorian coast, most of them derived from R. ecuadoriensis, were included in the study. All of them were genotyped as T. cruzi discrete typing unit I (DTU TcI). Analysis of 23 polymorphic microsatellite loci through neighbor joining and discriminant analysis of principal components yielded broadly congruent results and indicate genetic subdivision between sylvatic and peridomestic transmission cycles. However, both analyses also suggest that any barriers are imperfect and significant gene flow between parasite subpopulations in different habitats exists. Also consistent with moderate partition and residual gene flow between subpopulations, the fixation index (FST) was significant, but of low magnitude. Finally, the lack of private alleles in the domestic/peridomestic transmission cycle suggests the sylvatic strains constitute the ancestral population. The T. cruzi population in the central Ecuadorian coast shows moderate tendency to subdivision according to transmission cycle. However, connectivity between cycles exists and the sylvatic T. cruzi population harbored by R. ecuadoriensis vectors appears to constitute a source from which the parasite invades human domiciles and their surroundings in this region. We discuss the implications these findings have for the planning, implementation and evaluation of local Chagas disease control interventions.

  20. Impact of benznidazole on infection course in mice experimentally infected with Trypanosoma cruzi I, II, and IV.

    Science.gov (United States)

    Gruendling, Ana Paula; Massago, Miyoko; Teston, Ana Paula M; Monteiro, Wuelton M; Kaneshima, Edilson N; Araújo, Silvana M; Gomes, Mônica L; Barbosa, Maria das Graças V; Toledo, Max Jean O

    2015-06-01

    American trypanosomiasis is an emerging zoonosis in the Brazilian Amazon. Studies on benznidazole (BZ) chemotherapy with Trypanosoma cruzi from this region have great relevance, given the different discrete typing units (DTUs) that infect humans in the Amazon and other regions of Brazil. We performed a parasitological, histopathological, and molecular analysis of mice inoculated with strains of T. cruzi I, II, and IV that were BZ-treated during the acute phase of infection. Groups of Swiss mice were inoculated; 13 received oral BZ, whereas the other 13 comprised the untreated controls. Unlike parasitemia, the infectivity and mortality did not vary among the DTUs. Trypanosoma cruzi DNA was detected in all tissues analyzed and the proportion of organs parasitized varied with the parasite DTU. The BZ treatment reduced the most parasitological parameters, tissue parasitism and the inflammatory processes at all infection stages and for all DTUs. However, the number of significant reductions varied according to the DTU and infection phase.

  1. Vaccination of dogs with Trypanosoma rangeli induces antibodies against Trypanosoma cruzi in a rural area of Córdoba, Argentina

    OpenAIRE

    2016-01-01

    Dogs play a major role in the domestic cycle of Trypanosoma cruzi, acting as reservoirs. In a previous work we have developed a model of vaccination of dogs in captivity with nonpathogenic Trypanosoma rangeli epimastigotes, resulting in the production of protective antibodies against T. cruzi, with dramatic decrease of parasitaemia upon challenge with 100,000 virulent forms of this parasite. The aim of this work was to evaluate the immunogenicity of this vaccine in dogs living in a rural area...

  2. Control of Trypanosoma cruzi infection and changes in T-cell populations induced by a therapeutic DNA vaccine in mice.

    Science.gov (United States)

    Zapata-Estrella, Hiatzy; Hummel-Newell, Caroline; Sanchez-Burgos, Gilma; Escobedo-Ortegon, Javier; Ramirez-Sierra, Maria Jesus; Arjona-Torres, Arletty; Dumonteil, Eric

    2006-03-15

    Previous work showed that immunotherapy with a DNA vaccine encoding Trypanosoma cruzi antigen TSA-1 reduced cardiac tissue damage and improved survival in mice when administered during the acute or chronic phases of T. cruzi infection. In the present study, we investigated changes in T-cell populations induced by DNA vaccine immunotherapy. ICR mice were infected with 500 T. cruzi blood trypomastigotes and treated during the acute or chronic phases with two 100 microg doses of DNA vaccine. Analysis of stained splenocytes by flow cytometry indicated that the therapeutic vaccine induced a rapid increase in the number of CD4+ and CD8+ T cells in both the acute and chronic phases. Also, there was a rapid increase in T. cruzi-specific IFNgamma-producing CD8+ T cells following treatment during the chronic phase. The effects of these changes on the control of infection required longer time periods to be detectable but resulted in a reduction in myocarditis and T. cruzi parasite burden in both phases of the infection, as assessed by histopathologic analysis and semi-quantitative PCR detection of T. cruzi in cardiac tissue. These results suggest that DNA vaccines that induce CD8+ T-cells activity and IFNgamma production, would be good candidates for effective therapeutic vaccination against T. cruzi infection.

  3. Aspirin treatment exacerbates oral infections by Trypanosoma cruzi.

    Science.gov (United States)

    Cossentini, Luana Aparecida; Da Silva, Rosiane Valeriano; Yamada-Ogatta, Sueli Fumie; Yamauchi, Lucy Megumi; De Almeida Araújo, Eduardo José; Pinge-Filho, Phileno

    2016-05-01

    Oral transmission of the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease, has been documented in Latin American countries. The reported cases of infection were due to the ingestion of contaminated fresh fruit, juices, or sugar cane juice. There have been few studies on the physiopathology of the disease in oral transmission cases. Gastritis is a common ailment that can be caused by poor dietary habits, intake of alcohol or other gastric irritants, bacterial infection, or by the widespread use of non-steroidal anti-inflammatory drugs (NSAIDs). This study investigated in a mouse model whether gastric mucosal injury, induced by aspirin, would affect the course of disease in animals infected with T. cruzi by the oral route. The CL14 and G strains of T. cruzi, both of low infectivity, were used. To this end, groups of BALB/c mice were treated during 5 days with aspirin (100 mg kg(-1)) before oral infection with T. cruzi metacyclic forms (4 × 10(5) or 5 × 10(7) parasites/mouse). Histological analysis and determination of nitric oxide and TNF-α were performed in gastric samples obtained 5 days after infection. Parasitemia was monitored from the thirteenth day after infection. The results indicate that aspirin treatment of mice injured their gastric mucosa and facilitated invasion by both CL14 and G strains of T. cruzi. Strain CL14 caused more severe infection compared to the G strain, as larger numbers of amastigote nests were found in the stomach and parasitemia levels were higher. Our study is novel in that it shows that gastric mucosal damage caused by aspirin, a commonly used NSAID, facilitates T. cruzi infection by the oral route.

  4. Occurrence of Trypanosoma cruzi in Maryland

    Science.gov (United States)

    Herman, C.M.; Bruce, J.I.

    1962-01-01

    During 1954-1960, 2005 mammals of 18 species collected at the Patuxent Wildlife Research Center, Maryland, were examined for trypanosomes. T. cruzi was found in 10 raccoons between October 31 and November 30. Infection occurred in 2 percent of all raccoons sampled, and in 11.3 percent of the 80 raccoons sampled in November. Examination was by direct smears, stained smears and cultures of heart blood. Although, in previous studies, at least two experimentally infected raccoons exhibited extended parasitemia (14 and 8 weeks), no such continuing parasitemia was observed in the natural infections. No trypanosomes were found in any of the other mammals examined.

  5. Trypanosoma cruzi disrupts thymic homeostasis by altering intrathymic and systemic stress-related endocrine circuitries.

    Directory of Open Access Journals (Sweden)

    Ailin Lepletier

    2013-11-01

    Full Text Available We have previously shown that experimental infection caused by Trypanosoma cruzi is associated with changes in the hypothalamus-pituitary-adrenal axis. Increased glucocorticoid (GC levels are believed to be protective against the effects of acute stress during infection but result in depletion of CD4(+CD8(+ thymocytes by apoptosis, driving to thymic atrophy. However, very few data are available concerning prolactin (PRL, another stress-related hormone, which seems to be decreased during T. cruzi infection. Considering the immunomodulatory role of PRL upon the effects caused by GC, we investigated if intrathymic cross-talk between GC and PRL receptors (GR and PRLR, respectively might influence T. cruzi-induced thymic atrophy. Using an acute experimental model, we observed changes in GR/PRLR cross-activation related with the survival of CD4(+CD8(+ thymocytes during infection. These alterations were closely related with systemic changes, characterized by a stress hormone imbalance, with progressive GC augmentation simultaneously to PRL reduction. The intrathymic hormone circuitry exhibited an inverse modulation that seemed to counteract the GC-related systemic deleterious effects. During infection, adrenalectomy protected the thymus from the increase in apoptosis ratio without changing PRL levels, whereas an additional inhibition of circulating PRL accelerated the thymic atrophy and led to an increase in corticosterone systemic levels. These results demonstrate that the PRL impairment during infection is not caused by the increase of corticosterone levels, but the opposite seems to occur. Accordingly, metoclopramide (MET-induced enhancement of PRL secretion protected thymic atrophy in acutely infected animals as well as the abnormal export of immature and potentially autoreactive CD4(+CD8(+ thymocytes to the periphery. In conclusion, our findings clearly show that Trypanosoma cruzi subverts mouse thymus homeostasis by altering intrathymic and

  6. Early Trypanosoma cruzi Infection Reprograms Human Epithelial Cells

    Directory of Open Access Journals (Sweden)

    María Laura Chiribao

    2014-01-01

    Full Text Available Trypanosoma cruzi, the causative agent of Chagas disease, has the peculiarity, when compared with other intracellular parasites, that it is able to invade almost any type of cell. This property makes Chagas a complex parasitic disease in terms of prophylaxis and therapeutics. The identification of key host cellular factors that play a role in the T. cruzi invasion is important for the understanding of disease pathogenesis. In Chagas disease, most of the focus is on the response of macrophages and cardiomyocytes, since they are responsible for host defenses and cardiac lesions, respectively. In the present work, we studied the early response to infection of T. cruzi in human epithelial cells, which constitute the first barrier for establishment of infection. These studies identified up to 1700 significantly altered genes regulated by the immediate infection. The global analysis indicates that cells are literally reprogrammed by T. cruzi, which affects cellular stress responses (neutrophil chemotaxis, DNA damage response, a great number of transcription factors (including the majority of NFκB family members, and host metabolism (cholesterol, fatty acids, and phospholipids. These results raise the possibility that early host cell reprogramming is exploited by the parasite to establish the initial infection and posterior systemic dissemination.

  7. Identification of novel cyclic nucleotide binding proteins in Trypanosoma cruzi.

    Science.gov (United States)

    Jäger, Adriana V; De Gaudenzi, Javier G; Mild, Jesica G; Mc Cormack, Bárbara; Pantano, Sergio; Altschuler, Daniel L; Edreira, Martin M

    2014-12-01

    Cyclic AMP has been implicated as second messenger in a wide range of cellular processes. In the protozoan parasite Trypanosoma cruzi, cAMP is involved in the development of the parasite's life cycle. While cAMP effectors have been widely studied in other eukaryotic cells, little is known about cAMP's mechanism of action in T. cruzi. To date, only a cAMP-dependent protein kinase A (PKA) has been cloned and characterised in this parasite; however experimental evidence indicates the existence of cAMP-dependent, PKA-independent events. In order to identify new cAMP binding proteins as potential cAMP effectors, we carried out in silico studies using the predicted T. cruzi proteome. Using a combination of search methods 27 proteins with putative cNMP binding domains (CBDs) were identified. Phylogenetic analysis of the CBDs presented a homogeneous distribution, with sequences segregated into two main branches: one containing kinases-like proteins and the other gathering hypothetical proteins with different function or no other known. Comparative modelling of the strongest candidates provides support for the hypothesis that these proteins may give rise to structurally viable cyclic nucleotide binding domains. Pull-down and nucleotide displacement assays strongly suggest that TcCLB.508523.80 could bind cAMP and eventually be a new putative PKA-independent cAMP effector in T. cruzi.

  8. Production of amastigotes from metacyclic trypomastigotes of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Víctor T Contreras

    2002-12-01

    Full Text Available Attempts to recreate all the developmental stages of Trypanosoma cruzi in vitro have thus far been met with partial success. It is possible, for instance, to produce trypomastigotes in tissue culture and to obtain metacyclic trypomastigotes in axenic conditions. Even though T. cruzi amastigotes are known to differentiate from trypomastigotes and metacyclic trypomastigotes, it has only been possible to generate amastigotes in vitro from the tissue-culture-derived trypomastigotes. The factors and culture conditions required to trigger the transformation of metacyclic trypomastigotes into amastigotes are as yet undetermined. We show here that pre-incubation of metacyclic trypomastigotes in culture (MEMTAU medium at 37°C for 48 h is sufficient to commit the parasites to the transformation process. After 72 h of incubation in fresh MEMTAU medium, 90% of the metacyclic parasites differentiate into forms that are morphologically indistinguishable from normal amastigotes. SDS-PAGE, Western blot and PAABS analyses indicate that the transformation of axenic metacyclic trypomastigotes to amastigotes is associated with protein, glycoprotein and antigenic modifications. These data suggest that (a T. cruzi amastigotes can be obtained axenically in large amounts from metacyclic trypomastigotes, and (b the amastigotes thus obtained are morphological, biological and antigenically similar to intracellular amastigotes. Consequently, this experimental system may facilitate a direct, in vitro assessment of the mechanisms that enable T. cruzi metacyclic trypomastigotes to transform into amastigotes in the cells of mammalian hosts.

  9. Proteomic Analysis of Trypanosoma cruzi Epimastigotes Subjected to Heat Shock

    Directory of Open Access Journals (Sweden)

    Deyanira Pérez-Morales

    2012-01-01

    Full Text Available Trypanosoma cruzi is exposed to sudden temperature changes during its life cycle. Adaptation to these variations is crucial for parasite survival, reproduction, and transmission. Some of these conditions may change the pattern of genetic expression of proteins involved in homeostasis in the course of stress treatment. In the present study, the proteome of T. cruzi epimastigotes subjected to heat shock and epimastigotes grow normally was compared by two-dimensional gel electrophoresis followed by mass spectrometry for protein identification. Twenty-four spots differing in abundance were identified. Of the twenty-four changed spots, nineteen showed a greater intensity and five a lower intensity relative to the control. Several functional categories of the identified proteins were determined: metabolism, cell defense, hypothetical proteins, protein fate, protein synthesis, cellular transport, and cell cycle. Proteins involved in the interaction with the cellular environment were also identified, and the implications of these changes are discussed.

  10. Periurban Trypanosoma cruzi-infected Triatoma infestans, Arequipa, Peru.

    Science.gov (United States)

    Levy, Michael Zachary; Bowman, Natalie M; Kawai, Vivian; Waller, Lance A; Cornejo del Carpio, Juan Geny; Cordova Benzaquen, Eleazar; Gilman, Robert H; Bern, Caryn

    2006-09-01

    In Arequipa, Peru, vectorborne transmission of Chagas disease by Triatoma infestans has become an urban problem. We conducted an entomologic survey in a periurban community of Arequipa to identify risk factors for triatomine infestation and determinants of vector population densities. Of 374 households surveyed, triatomines were collected from 194 (52%), and Trypanosoma cruzi-carrying triatomines were collected from 72 (19.3%). Guinea pig pens were more likely than other animal enclosures to be infested and harbored 2.38x as many triatomines. Stacked brick and adobe enclosures were more likely to have triatomines, while wire mesh enclosures were protected against infestation. In human dwellings, only fully stuccoed rooms were protected against infestation. Spatially, households with triatomines were scattered, while households with T. cruzi-infected triatomines were clustered. Keeping small animals in wire mesh cages could facilitate control of T. infestans in this densely populated urban environment.

  11. Electron Microscopy Analysis of the Nucleolus of Trypanosoma cruzi

    Science.gov (United States)

    López-Velázquez, Gabriel; Hernández, Roberto; López-Villaseñor, Imelda; Reyes-Vivas, Horacio; Segura-Valdez, María De L.; Jiménez-García, Luis F.

    2005-08-01

    The nucleolus is the main site for synthesis and processing of ribosomal RNA in eukaryotes. In mammals, plants, and yeast the nucleolus has been extensively characterized by electron microscopy, but in the majority of the unicellular eukaryotes no such studies have been performed. Here we used ultrastructural cytochemical and immunocytochemical techniques as well as three-dimensional reconstruction to analyze the nucleolus of Trypanosoma cruzi, which is an early divergent eukaryote of medical importance. In T. cruzi epimastigotes the nucleolus is a spherical intranuclear ribonucleoprotein organelle localized in a relatively central position within the nucleus. Dense fibrillar and granular components but not fibrillar centers were observed. In addition, nuclear bodies resembling Cajal bodies were observed associated to the nucleolus in the surrounding nucleoplasm. Our results provide additional morphological data to better understand the synthesis and processing of the ribosomal RNA in kinetoplastids.

  12. Novo transmissor silvestre do "Trypanosoma (Schizotrypanum cruzi" (Chagas, 1909

    Directory of Open Access Journals (Sweden)

    F. Nery Guimarães

    1943-06-01

    Full Text Available In nests of opossum (Didelphis aurita, localized in palm-trees of the species Attalea indaya Dr., the authors found a new tritatoma, the description of which is being made by Dr. H. LENT. They verified that this triatoma had been naturally infected by Trypanosoma (Schizotrhypanum cruzy. Two guinea-pigs were subsequently infected by peritoneal inoculation of excrements of this new triatoma. The xenodiagnosis of these guinea-pigs, made with normal nymphas of. T. megistus and T. infestans resulted positive after 25 days. Evidence was obtained of being the opossum (Didelphis one of the sources infection of the new vector, because several specimens of them were found infected, and also a specimen of D. aurita, which contained trypanosomes with the morphology of T. (S. cruzy in the peripheral blood.

  13. Trypanosoma cruzi Experimental Infection Impacts on the Thymic Regulatory T Cell Compartment

    Science.gov (United States)

    González, Florencia Belén; Calmon-Hamaty, Flavia; Nô Seara Cordeiro, Synara; Fernández Bussy, Rodrigo; Spinelli, Silvana Virginia; D'Attilio, Luciano; Bottasso, Oscar; Savino, Wilson; Cotta-de-Almeida, Vinícius; Villar, Silvina Raquel; Pérez, Ana Rosa

    2016-01-01

    The dynamics of regulatory T cells in the course of Trypanosoma cruzi infection is still debated. We previously demonstrated that acute murine T. cruzi infection results in an impaired peripheral CD4+Foxp3+ T cell differentiation due to the acquisition of an abnormal Th1-like phenotype and altered functional features, negatively impacting on the course of infection. Moreover, T. cruzi infection induces an intense thymic atrophy. As known, the thymus is the primary lymphoid organ in which thymic-derived regulatory T cells, known as tTregs, differentiate. Considering the lack of available data about the effect of T. cruzi infection upon tTregs, we examined tTreg dynamics during the course of disease. We confirmed that T. cruzi infection induces a marked loss of tTreg cell number associated to cell precursor exhaustion, partially avoided by glucocorticoid ablation- and IL-2 survival factor depletion. At the same time, tTregs accumulate within the CD4 single-positive compartment, exhibiting an increased Ki-67/Annexin V ratio compared to controls. Moreover, tTregs enhance after the infection the expression of signature markers (CD25, CD62L and GITR) and they also display alterations in the expression of migration-associated molecules (α chains of VLAs and chemokine receptors) such as functional fibronectin-driven migratory disturbance. Taken together, we provide data demonstrating profound alterations in tTreg compartment during acute murine T. cruzi infection, denoting that their homeostasis is significantly affected. The evident loss of tTreg cell number may compromise the composition of tTreg peripheral pool, and such sustained alteration over time may be partially related to the immune dysregulation observed in the chronic phase of the disease. PMID:26745276

  14. Trypanosoma cruzi: dehydroepiandrosterone (DHEA) and immune response during the chronic phase of the experimental Chagas' disease.

    Science.gov (United States)

    Caetano, Leony Cristina; Santello, Fabricia Helena; Del Vecchio Filipin, Marina; Brazão, Vânia; Caetano, Luana Naiara; Toldo, Miriam Paula Alonso; Caldeira, Jerri C; do Prado Júnior, José Clóvis

    2009-07-07

    Dehydroepiandrosterone (DHEA) has long been considered as a precursor for many steroid hormones. It also enhances the immune responses against a wide range of viral, bacterial, and parasitic pathogens. The aims of this work were to evaluate the influences of exogenous DHEA treatment on Wistar rats infected with the Y strain of Trypanosoma cruzi during the acute and its influence on the chronic phase of infection. Animals were subcutaneous treated with 40 mg/kg body weight/day of DHEA. DHEA treatment promoted increased lymphoproliferative responses as well as enhanced concentrations of NO and IL-12. So, we point in the direction that our results validate the utility of the use of DHEA as an alternative therapy candidate against T. cruzi.

  15. AUMENTO DA EXPRESSÃO DE ?-CATENINA E CADERINA NO CORAÇÃO DE CAMUNDONGOS NA FASE AGUDA E CRÔNICA DA INFECÇÃO EXPERIMENTAL POR Trypanosoma cruzi UPREGULATION OF ?-CATENIN AND CADHERIN EXPRESSION IN HEARTS OF MICE IN ACUTE AND CHRONIC PHASE OF EXPERIMENTAL Trypanosoma cruzi infection

    Directory of Open Access Journals (Sweden)

    Tatyane Penha Sales

    2008-12-01

    Full Text Available As proteínas das junções de aderência têm sido associadas ao mecanismo patológico da miocardiopatia chagásica. Objetivando determinar a natureza dessas alterações, infectaram-se dez camundongos machos Swiss Webster com 25 dias de idade por via intraperitoneal com uma cepa tipo III de Trypanosoma cruzi na dose de 1,0 x 104 tripomastigotas/camundongo. Cinco camundongos infectados foram sacrificados no 14° dia (pico de parasitemia de infecção (grupo A e outros cinco camundongos (grupo C três meses após a inoculação, representando a fase crônica da infecção. Inocularam-se dez animais com solução estéril de cloreto de sódio 0,9%, sendo sacrificados no 14° dia (grupo CA e cinco ao final do terceiro mês (grupo CC, para servirem como controles não-infectados. As junções de aderência foram analisadas a partir do lisado total dos corações submetido a western blotting para pan-caderina e β-catenina. A análise do western blotting revelou aumento da expressão de pan-caderina na fase aguda (2,1x ± 0,89, p= 0,048 e crônica (2,1x ± 0,92, p= 0,05 quando comparadas com seus respectivos controles. Em relação à β-catenin, os resultados mostraram o mesmo padrão caracterizado pelo aumento de seus níveis na fase aguda (6,8x ± 4,65, p= 0,047 e crônica (3,65x ± 1,93, p= 0,033 em comparação aos controles. Assim, estes resultados indicam a associação das proteínas de junção de aderência aos eventos patológicos em corações de camundongos infectados por T. cruzi.

    PALAVRAS-CHAVES: Doença de Chagas, junções de aderência, miocardite, western blotting.
    Adherens junctions proteins have also been envolved in pathological mechanism of chagasic myocardiopathy. Aimed to determine the nature of these alterations, ten Swiss Webster male mice, 25 days-old were infected with a Type III strain of Trypanosoma cruzi through intraperitoneal (IP route with 1.0 x 104 trypomastigotes/mouse. Five infected mice were

  16. Genotypic variation among lineages of Trypanosoma cruzi and its geographic aspects.

    Science.gov (United States)

    Higo, Hiroo; Miura, Sachio; Horio, Masahiro; Mimori, Tatsuyuki; Hamano, Shinjiro; Agatsuma, Takeshi; Yanagi, Tetsuo; Cruz-Reyes, Arejandro; Uyema, Norma; Rojas de Arias, A; Matta, Vivian; Akahane, Hiroshige; Hirayama, Kenji; Takeuchi, Tsutomu; Tada, Isao; Himeno, Kunisuke

    2004-12-01

    Isozyme analysis with 18 enzyme loci was conducted on 146 isolates of Trypanosoma cruzi from Mexico, Guatemala, Colombia, Ecuador, Peru, Brazil, Bolivia, Paraguay and Chile. Forty-four different MLGs (groups of isolates with identical multilocus genotypes) were identified and a phylogeny was constructed. The phylogenetic tree consisted of two main groups (T. cruzi I, T. cruzi II), and the latter was further divided into two subgroups (T. cruzi IIa, T. cruzi IIb-e). Evidence of hybridization between different MLGs of T. cruzi II was found, which means that genetic exchanges seem to have occurred in South American T. cruzi. On the other hand, the persistence of characteristic T. cruzi I and T. cruzi II isozyme patterns in single small villages in Bolivia and Guatemala suggested that genetic exchange is very rare between major lineages. A significant difference in genetic diversity was shown between T. cruzi I and T. cruzi II from several indices of population genetics. Two possibilities could explain this genetic variation in the population: differences in evolutionary history and/or different tendencies to exchange genetic material. Broad-scale geographic distributions of T. cruzi I and T. cruzi IIb-e were different; T. cruzi I occurred in Central America and south to Bolivia and Brazil, while T. cruzi IIb-e occurred in the central and southern areas of South America, overlapping with T. cruzi I in Brazil and Bolivia.

  17. Preventive and therapeutic DNA vaccination partially protect dogs against an infectious challenge with Trypanosoma cruzi.

    Science.gov (United States)

    Quijano-Hernández, Israel A; Castro-Barcena, Alejandro; Vázquez-Chagoyán, Juan C; Bolio-González, Manuel E; Ortega-López, Jaime; Dumonteil, Eric

    2013-04-26

    American trypanosomiasis, or Chagas disease, is caused by Trypanosoma cruzi, and a vaccine would greatly improve disease control. While some studies in mice suggest that a vaccine is feasible, limited efficacy has been observed in dogs. We evaluated here the safety and efficacy of a DNA vaccine encoding TSA-1 and Tc24 antigens in a dog model of acute T. cruzi infection. Mongrel dogs were immunized with two doses of 500 μg of DNA vaccine, two weeks apart, and infected with T. cruzi (SylvioX10/4 strain) two weeks after the second vaccine dose. Another group of dogs was infected first and treated with the vaccine. Disease progression was monitored for up to 70 days post-infection. The vaccine did not induce any critical change in blood parameters, nor exacerbation of disease in vaccinated animals. On the contrary, it prevented anemia and a decrease in lymphocyte counts following T. cruzi infection in vaccinated dogs. Both preventive and therapeutic vaccination significantly reduced parasitemia, cardiac inflammation and cardiac parasite burden, and tended to reduce the development of cardiac arrhythmias. These results indicate that a preventive or therapeutic DNA vaccine encoding TSA-1 and Tc24 antigens is safe and may reduce both parasite transmission and the clinical progression of Chagas disease in vaccinated dogs. This DNA vaccine may thus be an excellent veterinary vaccine candidate. These data also further strengthen the feasibility of a Chagas disease vaccine for humans.

  18. Effects of betamethasone on the course of experimentai. Infection with Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Frederico G.C. Abath

    1986-09-01

    Full Text Available In this experiment, the effect of betamethasone administered in the early post- acute infection of mice by Trypanosoma cruzi was studied. This drug was administered during 30 days after the 42nd day of infection in a dose of 0.15 mg/day. The betamethasone treatment did not cause fresh outbreaks of parasitemia and the histopathological findings in the chronic phase were not different from those in the control group. The higher cumulative mortality after treatment in the experimental group was due to superimposed bacterial infections. Outbred albino mice infected with low numbers ofY strain Trypanosoma cruzi trypomastigotes were not suitable models for Chagas' disease, since after 7 months of observation only mild histological lesions developed in all the animais. Prolonged betamethasone treatment of mice infected with low numbers o/Trypanosoma cruzi of the Y strain, during the post-acute phase did not aggravate the course of infection.Foram estudados os efeitos da betametasona administrada na fase pós-aguda imediata de uma infecção pelo T. cruzi em camundongos. O tratamento consistiu de 30 doses diárias de 0,15 mg de betametasona, a partir de 42° dia de infecção, não havendo aparecimento de novos surtos de parasitemia. No tempo de duração do experimento (7 meses não houve diferença entre as lesões histopatológicas dos animais tratados e dos não tratados. O grupo experimental apresentou uma maior mortalidade acumulada no 75º dia de infecção, o que pode ser atribuído a infecções bacterianas associadas. Por outro lado, camundongos albinos "outbred", infectados com baixo inóculo, não se apresentaram como bom modelo de doença de Chagas, já que não desenvolveram lesões importantes nem na fase aguda nem após 7 meses de infecção. Em conclusão, o tratamento imunosupressivo prolongado, após a fase aguda de uma infecção mínima com a cepa Ydo T. cruzi não tem influência sobre o curso da infecção, pelo menos no que tange

  19. Prevention of transfusional Trypanosoma cruzi infection in Latin America

    Directory of Open Access Journals (Sweden)

    Schmunis Gabriel A

    1999-01-01

    Full Text Available Trypanosoma cruzi is a protozoan infection widely spread in Latin America, from Mexico in the north to Argentina and Chile in the south. The second most important way of acquiring the infection is by blood transfusion. Even if most countries of Latin America have law/decree/norms, that make mandatory the screening of blood donors for infectious diseases, including T. cruzi (El Salvador and Nicaragua do not have laws on the subject, there is usually no enforcement or it is very lax. Analysis of published serologic surveys of T. cruzi antibodies in blood donors done in 1993, indicating the number of donors and screening coverage for T. cruzi in ten countries of Central and South America indicated that the probability of receiving a potentially infected transfusion unit in each country varied from 1,096 per 10,000 transfusions in Bolivia, the highest, to 13.02 or 13.86 per 10,000 transfusions in Honduras and Venezuela respectively, where screening coverage was 100%. On the other hand the probability of transmitting a T. cruzi infected unit was 219/10,000 in Bolivia, 24/10,000 in Colombia, 17/10,000 in El Salvador, and around 2-12/10,000 for the seven other countries. Infectivity risks defined as the likelihood of being infected when receiving an infected transfusion unit were assumed to be 20% for T. cruzi. Based on this, estimates of the absolute number of infections induced by transfusion indicated that they were 832, 236, and 875 in Bolivia, Chile and Colombia respectively. In all the other countries varied from seven in Honduras to 85 in El Salvador. Since 1993, the situation has improved. At that time only Honduras and Venezuela screened 100% of donors, while seven countries, Argentina, Colombia, El Salvador, Honduras, Paraguay, Uruguay and Venezuela, did the same in 1996. In Central America, without information from Guatemala, the screening of donors for T. cruzi prevented the transfusion of 1,481 infected units and the potential infection of

  20. Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula.

    Science.gov (United States)

    López-Cancino, Sury Antonio; Tun-Ku, Ezequiel; De la Cruz-Felix, Himmler Keynes; Ibarra-Cerdeña, Carlos Napoleón; Izeta-Alberdi, Amaia; Pech-May, Angélica; Mazariegos-Hidalgo, Carlos Jesús; Valdez-Tah, Alba; Ramsey, Janine M

    2015-11-01

    Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in

  1. Nitric oxide-releasing polymeric nanoparticles against Trypanosoma cruzi

    Science.gov (United States)

    Seabra, A. B.; Kitice, N. A.; Pelegrino, M. T.; Lancheros, C. A. C.; Yamauchi, L. M.; Pinge-Filho, P.; Yamada-Ogatta, S. F.

    2015-05-01

    Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi (T. cruzi), and the disease remains a major health problem in many Latin American countries. Several papers report that the killing of the parasite is dependent on the production of nitric oxide (NO). The endogenous free radical NO is an important cellular signalling molecule that plays a key role in the defense against pathogens, including T. cruzi. As T. cruzi is able to compromise host macrophages decreasing endogenous NO production, the administration of exogenous NO donors represents an interesting strategy to combat Chagas disease. Thus, the aims of this study were to prepare and evaluate the antimicrobial activity of NO-releasing polymeric nanoparticles against T. cruzi. Biocompatible polymeric nanoparticles composed of chitosan/sodium tripolyphosphate(TPP) were prepared and used to encapsulate mercaptosuccinic acid (MSA), which is a thiol-containing molecule. Nitrosation of free thiols (SH) groups of MSA were performed by the addition of equimolar amount of sodium nitrite (NaNO2), leading to the formation of S-nitroso-MSA-containing nanoparticles. These polymeric nanoparticles act as spontaneous NO donors, with free NO release. The results show the formation of nanoparticles with average hydrodynamic diameter ranging from 270 to 500 nm, average of polydispersity index of 0.35, and encapsulation efficiency in the range of 99%. The NO release kinetics from the S-nitroso-MSA-containing nanoparticles showed sustained and controlled NO release over several hours. The microbicidal activity of S-nitroso-MSA-containing nanoparticles was evaluated by incubating NO-releasing nanoparticles (200 - 600 μg/mL) with replicative and non-infective epimastigote, and non-replicative and infective trypomastigote forms of T. cruzi. In addition, a significant decrease in the percentage of macrophage-infected (with amastigotes) and

  2. Effect of scorpion toxin on the enterochromaffin-like cells in normal and Trypanosoma cruzi-infected rats: a morphological study

    Directory of Open Access Journals (Sweden)

    N. H. Toppa

    1989-02-01

    Full Text Available Intravenous injection of scorpion toxin (Tityus serrulatus in normal and Trypanosoma cruzi infected rats did not cause ultrastructural morphologic changes on enterochromaffin-like (ECL cells of the stomach, although it induced a significant increase of the gastric secretion. Our data seem to indicate that gastric ECL cells structure is not affected by stimulation with scorpion toxin or by acute infection with T. cruzi in the rat.

  3. Trypanosoma cruzi infection in neotropical wild carnivores (Mammalia: Carnivora: at the top of the T. cruzi transmission chain.

    Directory of Open Access Journals (Sweden)

    Fabiana Lopes Rocha

    Full Text Available Little is known on the role played by Neotropical wild carnivores in the Trypanosoma cruzi transmission cycles. We investigated T. cruzi infection in wild carnivores from three sites in Brazil through parasitological and serological tests. The seven carnivore species examined were infected by T. cruzi, but high parasitemias detectable by hemoculture were found only in two Procyonidae species. Genotyping by Mini-exon gene, PCR-RFLP (1f8/Akw21I and kDNA genomic targets revealed that the raccoon (Procyon cancrivorus harbored TcI and the coatis (Nasua nasua harbored TcI, TcII, TcIII-IV and Trypanosoma rangeli, in single and mixed infections, besides four T. cruzi isolates that displayed odd band patterns in the Mini-exon assay. These findings corroborate the coati can be a bioaccumulator of T. cruzi Discrete Typing Units (DTU and may act as a transmission hub, a connection point joining sylvatic transmission cycles within terrestrial and arboreal mammals and vectors. Also, the odd band patterns observed in coatis' isolates reinforce that T. cruzi diversity might be much higher than currently acknowledged. Additionally, we assembled our data with T. cruzi infection on Neotropical carnivores' literature records to provide a comprehensive analysis of the infection patterns among distinct carnivore species, especially considering their ecological traits and phylogeny. Altogether, fifteen Neotropical carnivore species were found naturally infected by T. cruzi. Species diet was associated with T. cruzi infection rates, supporting the hypothesis that predator-prey links are important mechanisms for T. cruzi maintenance and dispersion in the wild. Distinct T. cruzi infection patterns across carnivore species and study sites were notable. Musteloidea species consistently exhibit high parasitemias in different studies which indicate their high infectivity potential. Mesocarnivores that feed on both invertebrates and mammals, including the coati, a host that

  4. Life cycle of Trypanosoma cruzi (y strain in mice

    Directory of Open Access Journals (Sweden)

    Pinto Pedro Luiz Silva

    1999-01-01

    Full Text Available Since 1958, we have studied experimental Chagas' disease (CD by subcutaneous inoculation of 1,000 blood forms of Trypanosoma cruzi (Y strain in Balb/C. mice. Evolution of parasitemia remained constant, beginning on the 5th and 6th day of the disease, increasing progressively, achieving a maximum on about the 30th day. After another month, only a few forms were present, and they disappeared from the circulation after the third month, as determined from direct examination of slides and the use of a Neubauer Counting Chamber. These events coincided with the appearance of amastigote nests in the tissues (especially the cardiac ones, starting the first week, and following the Gauss parasitemia curve, but they were not in parallel until the chronic stage. In 1997, we began to note the following changes: Parasites appeared in the circulation during the first week and disappeared starting on the 7th day, and there was a coincident absence of the amastigote nests in the tissues. A careful study verified that young forms in the evolutionary cycle of T. cruzi (epi + amastigotes began to appear alongside the trypomastigotes in the circulation on the 5th and 7th post-inoculation day. At the same time, rounded, oval, and spindle shapes were seen circulating through the capillaries and sinusoids of the tissues, principally of the hematopoietic organs. Stasis occurs because the diameter of the circulating parasites is greater than the vessels, and this makes them more visible. Examination of the sternal bone marrow revealed young cells with elongated forms and others truncated in the shape of a "C" occupying the internal surface of the blood cells that had empty central portions (erythrocytes?. We hypothesize that there could be a loss of virulence or mutation of the Y strain of Trypanosoma cruzi.

  5. Vaccination of dogs with Trypanosoma rangeli induces antibodies against Trypanosoma cruzi in a rural area of Córdoba, Argentina.

    Science.gov (United States)

    Basso, Beatriz; Marini, Vanina; Gauna, Diego; Frias, Maria

    2016-04-01

    Dogs play a major role in the domestic cycle of Trypanosoma cruzi, acting as reservoirs. In a previous work we have developed a model of vaccination of dogs in captivity with nonpathogenic Trypanosoma rangeli epimastigotes, resulting in the production of protective antibodies against T. cruzi, with dramatic decrease of parasitaemia upon challenge with 100,000 virulent forms of this parasite. The aim of this work was to evaluate the immunogenicity of this vaccine in dogs living in a rural area. Domestic dogs, free from T. cruzi infection, received three immunisations with fixed T. rangeli epimastigotes. Dogs were not challenged with T. cruzi, but they were left in their environment. This immunisation induced antibodies against T. cruzi for more than three years in dogs in their natural habitat, while control dogs remained serologically negative.

  6. Heterogeneous infectiousness in guinea pigs experimentally infected with Trypanosoma cruzi.

    Science.gov (United States)

    Castillo-Neyra, Ricardo; Borrini Mayorí, Katty; Salazar Sánchez, Renzo; Ancca Suarez, Jenny; Xie, Sherrie; Náquira Velarde, Cesar; Levy, Michael Z

    2016-02-01

    Guinea pigs are important reservoirs of Trypanosoma cruzi, the causative parasite of Chagas disease, and in the Southern Cone of South America, transmission is mediated mainly by the vector Triatoma infestans. Interestingly, colonies of Triatoma infestans captured from guinea pig corrals sporadically have infection prevalence rates above 80%. Such high values are not consistent with the relatively short 7-8 week parasitemic period that has been reported for guinea pigs in the literature. We experimentally measured the infectious periods of a group of T. cruzi-infected guinea pigs by performing xenodiagnosis and direct microscopy each week for one year. Another group of infected guinea pigs received only direct microscopy to control for the effect that inoculation by triatomine saliva may have on parasitemia in the host. We observed infectious periods longer than those previously reported in a number of guinea pigs from both the xenodiagnosis and control groups. While some guinea pigs were infectious for a short time, other "super-shedders" were parasitemic up to 22 weeks after infection, and/or positive by xenodiagnosis for a year after infection. This heterogeneity in infectiousness has strong implications for T. cruzi transmission dynamics and control, as super-shedder guinea pigs may play a disproportionate role in pathogen spread.

  7. Expanding the tool box for genetic manipulation of Trypanosoma cruzi.

    Science.gov (United States)

    Burle-Caldas, Gabriela de Assis; Grazielle-Silva, Viviane; Laibida, Letícia Adejani; DaRocha, Wanderson Duarte; Teixeira, Santuza Maria Ribeiro

    2015-01-01

    Trypanosoma cruzi is a protozoan parasite that causes Chagas disease, an illness that affects 6-7 million people and for which there is no effective drug therapy or vaccine. The publication of its complete genome sequence allowed a rapid advance in molecular studies including in silico screening of genes involved with pathogenicity as well as molecular targets for the development of new diagnostic methods, drug therapies and prophylactic vaccines. Alongside with in silico genomic analyses, methods to study gene function in this parasite such as gene deletion, overexpression, mutant complementation and reporter gene expression have been largely explored. More recently, the use of genome-wide strategies is producing a shift towards a global perspective on gene function studies, with the examination of the expression and biological roles of gene networks in different stages of the parasite life cycle and under different contexts of host parasite interactions. Here we describe the molecular tools and protocols currently available to perform genetic manipulation of the T. cruzi genome, with emphasis on recently described strategies of gene editing that will facilitate large-scale functional genomic analyses. These new methodologies are long overdue, since more efficient protocols for genetic manipulation in T. cruzi are urgently needed for a better understanding of the biology of this parasite and molecular processes involved with the complex and often harmful, interaction with its human host.

  8. Conservation and divergence within the clathrin interactome of Trypanosoma cruzi.

    Science.gov (United States)

    Kalb, Ligia Cristina; Frederico, Yohana Camila A; Boehm, Cordula; Moreira, Claudia Maria do Nascimento; Soares, Maurilio José; Field, Mark C

    2016-08-09

    Trypanosomatids are parasitic protozoa with a significant burden on human health. African and American trypanosomes are causative agents of Nagana and Chagas disease respectively, and speciated about 300 million years ago. These parasites have highly distinct life cycles, pathologies, transmission strategies and surface proteomes, being dominated by the variant surface glycoprotein (African) or mucins (American) respectively. In African trypanosomes clathrin-mediated trafficking is responsible for endocytosis and post-Golgi transport, with several mechanistic aspects distinct from higher organisms. Using clathrin light chain (TcCLC) and EpsinR (TcEpsinR) as affinity handles, we identified candidate clathrin-associated proteins (CAPs) in Trypanosoma cruzi; the cohort includes orthologs of many proteins known to mediate vesicle trafficking, but significantly not the AP-2 adaptor complex. Several trypanosome-specific proteins common with African trypanosomes, were also identified. Fluorescence microscopy revealed localisations for TcEpsinR, TcCLC and TcCHC at the posterior region of trypomastigote cells, coincident with the flagellar pocket and Golgi apparatus. These data provide the first systematic analysis of clathrin-mediated trafficking in T. cruzi, allowing comparison between protein cohorts and other trypanosomes and also suggest that clathrin trafficking in at least some life stages of T. cruzi may be AP-2-independent.

  9. High throughput screening for anti-Trypanosoma cruzi drug discovery.

    Science.gov (United States)

    Alonso-Padilla, Julio; Rodríguez, Ana

    2014-12-01

    The discovery of new therapeutic options against Trypanosoma cruzi, the causative agent of Chagas disease, stands as a fundamental need. Currently, there are only two drugs available to treat this neglected disease, which represents a major public health problem in Latin America. Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable. Thus, there is an urgent need for new, improved anti-T. cruzi drugs. With the objective to reliably accelerate the drug discovery process against Chagas disease, several advances have been made in the last few years. Availability of engineered reporter gene expressing parasites triggered the development of phenotypic in vitro assays suitable for high throughput screening (HTS) as well as the establishment of new in vivo protocols that allow faster experimental outcomes. Recently, automated high content microscopy approaches have also been used to identify new parasitic inhibitors. These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti-T. cruzi drug entities in the near future, are reviewed here.

  10. High throughput screening for anti-Trypanosoma cruzi drug discovery.

    Directory of Open Access Journals (Sweden)

    Julio Alonso-Padilla

    2014-12-01

    Full Text Available The discovery of new therapeutic options against Trypanosoma cruzi, the causative agent of Chagas disease, stands as a fundamental need. Currently, there are only two drugs available to treat this neglected disease, which represents a major public health problem in Latin America. Both available therapies, benznidazole and nifurtimox, have significant toxic side effects and their efficacy against the life-threatening symptomatic chronic stage of the disease is variable. Thus, there is an urgent need for new, improved anti-T. cruzi drugs. With the objective to reliably accelerate the drug discovery process against Chagas disease, several advances have been made in the last few years. Availability of engineered reporter gene expressing parasites triggered the development of phenotypic in vitro assays suitable for high throughput screening (HTS as well as the establishment of new in vivo protocols that allow faster experimental outcomes. Recently, automated high content microscopy approaches have also been used to identify new parasitic inhibitors. These in vitro and in vivo early drug discovery approaches, which hopefully will contribute to bring better anti-T. cruzi drug entities in the near future, are reviewed here.

  11. In vitro evaluation of the activity of aromatic nitrocompounds against Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Renata B Oliveira

    2003-01-01

    Full Text Available Fourteen compounds were evaluated for their activity against Trypanosoma cruzi blood stream forms at the concentration of 500 µg/ml. Six compounds were active and re-tested at lower concentrations.

  12. Molecular basis of mammalian cell invasion by Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Nobuko Yoshida

    2006-03-01

    Full Text Available Establishment of infection by Trypanosoma cruzi, the agent of Chagas' disease, depends on a series of events involving interactions of diverse parasite molecules with host components. Here we focus on the mechanisms of target cell invasion by metacyclic trypomastigotes (MT and mammalian tissue culture trypomastigotes (TCT. During MT or TCT internalization, signal transduction pathways are activated both in the parasite and the target cell, leading to Ca2+ mobilization. For cell adhesion, MT engage surface glycoproteins, such as gp82 and gp35/50, which are Ca2+ signal-inducing molecules. In T. cruzi isolates that enter host cells in gp82-mediated manner, parasite protein tyrosine kinase as well as phospholipase C are activated, and Ca2+ is released from I P3-sensitive stores, whereas in T. cruzi isolates that attach to target cells mainly through gp35/50, the signaling pathway involving adenylate cyclase appears to be stimulated, with Ca2+ release from acidocalciosomes. In addition, T. cruzi isolate-dependent inhibitory signals, mediated by MT-specific gp90, may be triggered both in the host cell and the parasite. The repertoire of TCT molecules implicated in cell invasion includes surface glycoproteins of gp85 family, with members containing binding sites for laminin and cytokeratin 18, enzymes such as cruzipain, trans-sialidase, and an oligopeptidase B that generates a Ca2+-agonist from a precursor molecule.O estabelecimento da infecção por Trypanosoma cruzi, o agente da doença de Chagas, depende de uma série de eventos envolvendo interações de diversas moléculas do parasita com componentes do hospedeiro. Focalizamos aqui os mecanismos de invasão celular por tripomastigotas metacíclicos (TM e por tripomastigotas de cultura de tecido (TCT. Durante a internalização de TM ou TCT, vias de transdução de sinal são ativadas tanto no parasita como na célula alvo, acarretando a mobilização de Ca2+. Para adesão, TM utiliza as glicoprote

  13. Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera

    OpenAIRE

    1989-01-01

    Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-re...

  14. Functional characterization of 8-oxoguanine DNA glycosylase of Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Carolina Furtado

    Full Text Available The oxidative lesion 8-oxoguanine (8-oxoG is removed during base excision repair by the 8-oxoguanine DNA glycosylase 1 (Ogg1. This lesion can erroneously pair with adenine, and the excision of this damaged base by Ogg1 enables the insertion of a guanine and prevents DNA mutation. In this report, we identified and characterized Ogg1 from the protozoan parasite Trypanosoma cruzi (TcOgg1, the causative agent of Chagas disease. Like most living organisms, T. cruzi is susceptible to oxidative stress, hence DNA repair is essential for its survival and improvement of infection. We verified that the TcOGG1 gene encodes an 8-oxoG DNA glycosylase by complementing an Ogg1-defective Saccharomyces cerevisiae strain. Heterologous expression of TcOGG1 reestablished the mutation frequency of the yeast mutant ogg1(-/- (CD138 to wild type levels. We also demonstrate that the overexpression of TcOGG1 increases T. cruzi sensitivity to hydrogen peroxide (H(2O(2. Analysis of DNA lesions using quantitative PCR suggests that the increased susceptibility to H(2O(2 of TcOGG1-overexpressor could be a consequence of uncoupled BER in abasic sites and/or strand breaks generated after TcOgg1 removes 8-oxoG, which are not rapidly repaired by the subsequent BER enzymes. This hypothesis is supported by the observation that TcOGG1-overexpressors have reduced levels of 8-oxoG both in the nucleus and in the parasite mitochondrion. The localization of TcOgg1 was examined in parasite transfected with a TcOgg1-GFP fusion, which confirmed that this enzyme is in both organelles. Taken together, our data indicate that T. cruzi has a functional Ogg1 ortholog that participates in nuclear and mitochondrial BER.

  15. Optimized multilocus sequence typing (MLST scheme for Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Patricio Diosque

    2014-08-01

    Full Text Available Trypanosoma cruzi, the aetiological agent of Chagas disease possess extensive genetic diversity. This has led to the development of a plethora of molecular typing methods for the identification of both the known major genetic lineages and for more fine scale characterization of different multilocus genotypes within these major lineages. Whole genome sequencing applied to large sample sizes is not currently viable and multilocus enzyme electrophoresis, the previous gold standard for T. cruzi typing, is laborious and time consuming. In the present work, we present an optimized Multilocus Sequence Typing (MLST scheme, based on the combined analysis of two recently proposed MLST approaches. Here, thirteen concatenated gene fragments were applied to a panel of T. cruzi reference strains encompassing all known genetic lineages. Concatenation of 13 fragments allowed assignment of all strains to the predicted Discrete Typing Units (DTUs, or near-clades, with the exception of one strain that was an outlier for TcV, due to apparent loss of heterozygosity in one fragment. Monophyly for all DTUs, along with robust bootstrap support, was restored when this fragment was subsequently excluded from the analysis. All possible combinations of loci were assessed against predefined criteria with the objective of selecting the most appropriate combination of between two and twelve fragments, for an optimized MLST scheme. The optimum combination consisted of 7 loci and discriminated between all reference strains in the panel, with the majority supported by robust bootstrap values. Additionally, a reduced panel of just 4 gene fragments displayed high bootstrap values for DTU assignment and discriminated 21 out of 25 genotypes. We propose that the seven-fragment MLST scheme could be used as a gold standard for T. cruzi typing, against which other typing approaches, particularly single locus approaches or systematic PCR assays based on amplicon size, could be compared.

  16. Trypanosoma cruzi-Trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected Rhodnius prolixus.

    Science.gov (United States)

    Peterson, Jennifer K; Graham, Andrea L; Elliott, Ryan J; Dobson, Andrew P; Triana Chávez, Omar

    2016-08-01

    Trypanosoma cruzi, causative agent of Chagas disease, co-infects its triatomine vector with its sister species Trypanosoma rangeli, which shares 60% of its antigens with T. cruzi. Additionally, T. rangeli has been observed to be pathogenic in some of its vector species. Although T. cruzi-T. rangeli co-infections are common, their effect on the vector has rarely been investigated. Therefore, we measured the fitness (survival and reproduction) of triatomine species Rhodnius prolixus infected with just T. cruzi, just T. rangeli, or both T. cruzi and T. rangeli. We found that survival (as estimated by survival probability and hazard ratios) was significantly different between treatments, with the T. cruzi treatment group having lower survival than the co-infected treatment. Reproduction and total fitness estimates in the T. cruzi and T. rangeli treatments were significantly lower than in the co-infected and control groups. The T. cruzi and T. rangeli treatment group fitness estimates were not significantly different from each other. Additionally, co-infected insects appeared to tolerate higher doses of parasites than insects with single-species infections. Our results suggest that T. cruzi-T. rangeli co-infection could ameliorate negative effects of single infections of either parasite on R. prolixus and potentially help it to tolerate higher parasite doses.

  17. A genomic scale map of genetic diversity in Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Ackermann Alejandro A

    2012-12-01

    Full Text Available Abstract Background Trypanosoma cruzi, the causal agent of Chagas Disease, affects more than 16 million people in Latin America. The clinical outcome of the disease results from a complex interplay between environmental factors and the genetic background of both the human host and the parasite. However, knowledge of the genetic diversity of the parasite, is currently limited to a number of highly studied loci. The availability of a number of genomes from different evolutionary lineages of T. cruzi provides an unprecedented opportunity to look at the genetic diversity of the parasite at a genomic scale. Results Using a bioinformatic strategy, we have clustered T. cruzi sequence data available in the public domain and obtained multiple sequence alignments in which one or two alleles from the reference CL-Brener were included. These data covers 4 major evolutionary lineages (DTUs: TcI, TcII, TcIII, and the hybrid TcVI. Using these set of alignments we have identified 288,957 high quality single nucleotide polymorphisms and 1,480 indels. In a reduced re-sequencing study we were able to validate ~ 97% of high-quality SNPs identified in 47 loci. Analysis of how these changes affect encoded protein products showed a 0.77 ratio of synonymous to non-synonymous changes in the T. cruzi genome. We observed 113 changes that introduce or remove a stop codon, some causing significant functional changes, and a number of tri-allelic and tetra-allelic SNPs that could be exploited in strain typing assays. Based on an analysis of the observed nucleotide diversity we show that the T. cruzi genome contains a core set of genes that are under apparent purifying selection. Interestingly, orthologs of known druggable targets show statistically significant lower nucleotide diversity values. Conclusions This study provides the first look at the genetic diversity of T. cruzi at a genomic scale. The analysis covers an estimated ~ 60% of the genetic diversity present in the

  18. Comprehensive glycoprofiling of the epimastigote and trypomastigote stages of Trypanosoma cruzi

    DEFF Research Database (Denmark)

    Alves, Maria Julia Manso; Kawahara, Rebeca; Viner, Rosa

    2017-01-01

    Trypanosoma cruzi, the protozoan that causes Chagas disease, has a complex life cycle involving insect and mammalian hosts and distinct developmental stages. During T. cruzi developmental stages, glycoproteins play important role in the host-parasite interaction, such as cellular recognition, hos...

  19. Comprehensive proteomic analysis of Trypanosoma cruzi epimastigote cell surface proteins by two complementary methods

    DEFF Research Database (Denmark)

    Queiroz, Rayner M L; Charneau, Sébastien; Motta, Flávia N;

    2013-01-01

    Trypanosoma cruzi is a protozoan that causes Chagas' disease, a neglected infectious illness that affects millions of people, mostly in Latin America. Here, the cell surface subproteome of the T. cruzi epimastigote life form was characterized. In order to prepare samples enriched in epimastigote...

  20. Comparative evaluation of therapeutic DNA vaccines against Trypanosoma cruzi in mice

    OpenAIRE

    2007-01-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health problem in most of Latin America. A key priority is the development of new treatments, due to the poor efficacy of current ones. We report here the comparative evaluation of therapeutic DNA vaccines encoding various T. cruzi antigens. ICR mice infected with 500 parasites intraperitoneally were treated at 5 and 12 days postinfection with 20 mu g of plasmid DNA encoding T. cruzi antigens TSA-1, TS, ASP-...

  1. Purification of extracellular and intracellular amastigotes of Trypanosoma cruzi from mammalian host-infected cells

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Alexandre Marques, Ernesto Nakayasu & Igor Almeida ### Abstract The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, which affects millions of people in Latin America. T. cruzi has a complex life cycle characterized by several developmental forms present in vertebrate and invertebrate hosts. In vertebrate mammalian hosts T. cruzi is found as intracellular amastigotes and bloodstream trypomastigotes. On the other hand, in the intestine of the ...

  2. Cardiac plexus of dogs experimentally infected with Trypanosoma cruzi: inflammatory lesions and quantitative studies

    Directory of Open Access Journals (Sweden)

    Marcelo V. Caliari

    1995-03-01

    Full Text Available Qualitative and quantitative aspects of the superficial and profound cardiac plexus of dogs experimentally infected with Be-62 and Be-78 strains of Trypanosoma cruzi were studied. Animals were autopsied in the acute phase of infection. The inflammatory process, lesions and number of parasites were more intense and frequent in animals infected with the Be-78 strain than in those infected with Be-62. Despite this, no statistically significant differences could be found between the number of neuron bodies in the ganglia of infected and control dogs.Foi realizado estudo qualitativo e quantitativo dos plexos cardíacos superficiais e profundos em cães inoculados com o Trypanosoma cruzi das cepas Be-62 e Be-78 e sacrificados na fase aguda. O processo inflamatório, as lesões e o parasitismo dos plexos foram mais intensos e frequentes nos animais inoculados com a cepa Be-78 do que naqueles inoculados com a cepa Be- 62. Apesar deste fato, não foi verificada diferença estatisticamente significativa entre o número de corpos de neurônio por gânglio dos animais chagásicos e os controles.

  3. Concomitant Benznidazole and Suramin Chemotherapy in Mice Infected with a Virulent Strain of Trypanosoma cruzi.

    Science.gov (United States)

    Santos, Eliziária C; Novaes, Rômulo D; Cupertino, Marli C; Bastos, Daniel S S; Klein, Raphael C; Silva, Eduardo A M; Fietto, Juliana L R; Talvani, André; Bahia, Maria T; Oliveira, Leandro L

    2015-10-01

    Although suramin (Sur) is suggested as a potential drug candidate in the management of Chagas disease, this issue has not been objectively tested. In this study, we examined the applicability of concomitant treatment with benznidazole (Bz) and suramin in mice infected with a virulent strain of Trypanosoma cruzi. Eighty 12-week-old male C57BL/6 mice were equally randomized in eight groups: (i) noninfected mice (negative control) and mice infected with T. cruzi Y strain receiving (ii) no treatment (positive control), (iii) Bz, 100 mg/kg of body weight per day, (iv) Sur, 20 mg/kg/day, and (v to viii) Sur, 20 mg/kg/day, combined with Bz, 100, 50, 25, or 5 mg/kg/day. Bz was administered by gavage, and Sur was administered intraperitoneally. Sur dramatically increased the parasitemia, cardiac content of parasite DNA, inflammation, oxidative tissue damage, and mortality. In response to high parasitic load in cardiac tissue, Sur stimulated the immune system in a manner typical of the acute phase of Chagas disease, increasing tissue levels of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and inducing a preferential IgG2a anti-T. cruzi serum pattern. When Sur and Bz were combined, the infection severity was attenuated, showing a dose-dependent Bz response. Sur therapy had a more harmful effect on the host than on the parasite and reduced the efficacy of Bz against T. cruzi infection. Considering that Sur drastically reinforced the infection evolution, potentiating the inflammatory process and the severity of cardiac lesions, the in vivo findings contradicted the in vitro anti-T. cruzi potential described for this drug.

  4. Activity in vivo of anti-Trypanosoma cruzi compounds selected from a high throughput screening.

    Directory of Open Access Journals (Sweden)

    Grasiella Andriani

    2011-08-01

    Full Text Available Novel technologies that include recombinant pathogens and rapid detection methods are contributing to the development of drugs for neglected diseases. Recently, the results from the first high throughput screening (HTS to test compounds for activity against Trypanosoma cruzi trypomastigote infection of host cells were reported. We have selected 23 compounds from the hits of this HTS, which were reported to have high anti-trypanosomal activity and low toxicity to host cells. These compounds were highly purified and their structures confirmed by HPLC/mass spectrometry. The compounds were tested in vitro, where about half of them confirmed the anti-T. cruzi activity reported in the HTS, with IC50 values lower than 5 µM. We have also adapted a rapid assay to test anti-T. cruzi compounds in vivo using mice infected with transgenic T. cruzi expressing luciferase as a model for acute infection. The compounds that were active in vitro were also tested in vivo using this assay, where we found two related compounds with a similar structure and low in vitro IC50 values (0.11 and 0.07 µM that reduce T. cruzi infection in the mouse model more than 90% after five days of treatment. Our findings evidence the benefits of novel technologies, such as HTS, for the drug discovery pathway of neglected diseases, but also caution about the need to confirm the results in vitro. We also show how rapid methods of in vivo screening based in luciferase-expressing parasites can be very useful to prioritize compounds early in the chain of development.

  5. Proteomic analysis of two Trypanosoma cruzi zymodeme 3 strains.

    Science.gov (United States)

    Kikuchi, Simone A; Sodré, Cátia L; Kalume, Dário E; Elias, Camila G R; Santos, André L S; de Nazaré Soeiro, Maria; Meuser, Marcus; Chapeaurouge, Alex; Perales, Jonas; Fernandes, Octavio

    2010-12-01

    Two Trypanosoma cruzi Z3 strains, designated as 3663 and 4167, were previously isolated from insect vectors captured in the Brazilian Amazon region. These strains exhibited different infection patterns in Vero, C6/36, RAW 264.7 and HEp-2 cell lineages, in which 3663 trypomastigote form was much less infective than 4167 ones. A proteomic approach was applied to investigate the differences in the global patterns of protein expression in these two Z3 strains. Two-dimensional (2D) protein maps were generated and certain spots were identified by mass spectrometry (MS). Our analyses revealed a significant difference in the expression profile of different proteins between strains 3663 and 4167. Among them, cruzipain, an important regulator of infectivity. This data was corroborated by flow cytometry analysis using anti-cruzipain antibody. This difference could contribute to the infectivity profiles observed for each strain by in vitro assay using different cell lines.

  6. Parasite Genome Projects and the Trypanosoma cruzi Genome Initiative

    Directory of Open Access Journals (Sweden)

    Wim Degrave

    1997-11-01

    Full Text Available Since the start of the human genome project, a great number of genome projects on other "model" organism have been initiated, some of them already completed. Several initiatives have also been started on parasite genomes, mainly through support from WHO/TDR, involving North-South and South-South collaborations, and great hopes are vested in that these initiatives will lead to new tools for disease control and prevention, as well as to the establishment of genomic research technology in developing countries. The Trypanosoma cruzi genome project, using the clone CL-Brener as starting point, has made considerable progress through the concerted action of more than 20 laboratories, most of them in the South. A brief overview of the current state of the project is given

  7. Trypanosoma cruzi: orchiectomy and dehydroepiandrosterone therapy in infected rats.

    Science.gov (United States)

    Filipin, Marina Del Vecchio; Brazão, Vânia; Caetano, Leony Cristina; Santello, Fabricia Helena; Toldo, Míriam Paula Alonso; Caetano, Luana Naiara; do Prado, José Clóvis

    2008-11-01

    The ability of gonadal hormones to influence and induce diverse immunological functions during the course of a number of parasitic infections has been extensively studied in the latest decades. Dehydroepiandrosterone and its sulfate are the most abundant steroid hormones secreted by the human adrenal cortex and are considered potent immune-activators. The effects of orchiectomy on the course of Trypanosoma cruzi infection in rats, treated and untreated with DHEA were examined, by comparing blood and cardiac parasitism, macrophage numbers, nitric oxide and IFN-gamma levels. Orchiectomy enhanced resistance against infection with elevated numbers of macrophages, enhanced concentrations of NO and IFN-gamma and reduced amastigote burdens in heart when compared to control animals. DHEA replacement exerted a synergistic effect, up-modulating the immune response. Male sex steroids appear to play fundamental role in determining the outcome of disease, through the regulation and modulation of the activity of the immune response.

  8. Pure paraflagellar rod protein protects mice against Trypanosoma cruzi infection.

    Science.gov (United States)

    Wrightsman, R A; Miller, M J; Saborio, J L; Manning, J E

    1995-01-01

    The paraflagellar rod proteins (PAR) purified from Trypanosoma cruzi epimastigotes were shown to protect mice against an otherwise lethal challenge inoculum of 10(3) bloodstream-form trypomastigotes. The injection route used for immunization was shown to have a marked impact on the development of protective immunity. Mice receiving subcutaneous (s.c.) injections of PAR proteins had reduced bloodstream parasitemias and showed 100% survival following challenge. In contrast, mice immunized via the intraperitoneal (i.p.) route developed parasitemia levels equivalent to those of unimmunized controls and did not survive infection. Western blotting (immunoblotting) demonstrated that sera from both i.p. and s.c. immunized mice reacted specifically with PAR proteins; however, the antibody titer of the i.p. immunized mice was approximately 64-fold greater than that of the s.c. immunized mice, suggesting that the protective response in the s.c. immunized mice is cell mediated rather than humoral.

  9. Beta-interferon inhibits cell infection by Trypanosoma cruzi

    Science.gov (United States)

    Kierszenbaum, F.; Sonnenfeld, G.

    1984-01-01

    Beta interferon has been shown to inhibit the capacity of bloodstream forms of the flagellate Trypanosoma cruzi, the causative agent of Chagas' disease, to associate with and infect mouse peritoneal macrophages and rat heart myoblasts. The inhibitory effect was abrogated in the presence of specific antibodies to the interferon. Pretreatment of the parasites with interferon reduced their infectivity for untreated host cells, whereas pretreament of either type of host cell did not affect the interaction. The effect of interferon on the trypanosomes was reversible; the extent of the inhibitory effect was significantly reduced afer 20 min, and was undetectable after 60 min when macrophages were used as host cells. For the myoblasts, 60 min elapsed before the inhibitory effect began to subside and 120 min elapsed before it became insignificant or undetectable.

  10. Diverse inhibitor chemotypes targeting Trypanosoma cruzi CYP51.

    Directory of Open Access Journals (Sweden)

    Shamila S Gunatilleke

    Full Text Available BACKGROUND: Chagas Disease, a WHO- and NIH-designated neglected tropical disease, is endemic in Latin America and an emerging infection in North America and Europe as a result of population moves. Although a major cause of morbidity and mortality due to heart failure, as well as inflicting a heavy economic burden in affected regions, Chagas Disease elicits scant notice from the pharmaceutical industry because of adverse economic incentives. The discovery and development of new routes to chemotherapy for Chagas Disease is a clear priority. METHODOLOGY/PRINCIPAL FINDINGS: The similarity between the membrane sterol requirements of pathogenic fungi and those of the parasitic protozoon Trypanosoma cruzi, the causative agent of Chagas human cardiopathy, has led to repurposing anti-fungal azole inhibitors of sterol 14α-demethylase (CYP51 for the treatment of Chagas Disease. To diversify the therapeutic pipeline of anti-Chagasic drug candidates we exploited an approach that included directly probing the T. cruzi CYP51 active site with a library of synthetic small molecules. Target-based high-throughput screening reduced the library of ∼104,000 small molecules to 185 hits with estimated nanomolar K(D values, while cross-validation against T. cruzi-infected skeletal myoblast cells yielded 57 active hits with EC(50 <10 µM. Two pools of hits partially overlapped. The top hit inhibited T. cruzi with EC(50 of 17 nM and was trypanocidal at 40 nM. CONCLUSIONS/SIGNIFICANCE: The hits are structurally diverse, demonstrating that CYP51 is a rather permissive enzyme target for small molecules. Cheminformatic analysis of the hits suggests that CYP51 pharmacology is similar to that of other cytochromes P450 therapeutic targets, including thromboxane synthase (CYP5, fatty acid ω-hydroxylases (CYP4, 17α-hydroxylase/17,20-lyase (CYP17 and aromatase (CYP19. Surprisingly, strong similarity is suggested to glutaminyl-peptide cyclotransferase, which is unrelated to CYP

  11. Phthalimido-thiazoles as building blocks and their effects on the growth and morphology of Trypanosoma cruzi.

    Science.gov (United States)

    Gomes, Paulo André Teixeira de Moraes; Oliveira, Arsênio Rodrigues; Cardoso, Marcos Veríssimo de Oliveira; Santiago, Edna de Farias; Barbosa, Miria de Oliveira; de Siqueira, Lucianna Rabelo Pessoa; Moreira, Diogo Rodrigo Magalhães; Bastos, Tanira Matutino; Brayner, Fábio André; Soares, Milena Botelho Pereira; Mendes, Andresa Pereira de Oliveira; de Castro, Maria Carolina Accioly Brelaz; Pereira, Valéria Rego Alves; Leite, Ana Cristina Lima

    2016-03-23

    Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi that affects approximately 6-7 million people worldwide. Benznidazole is the only drug approved for treatment during the acute and asymptomatic chronic phases; however, its efficacy during the symptomatic chronic phase is controversial. The present work reports the synthesis and anti-T. cruzi activities of a novel series of phthalimido-thiazoles. Some of these compounds showed potent inhibition of the trypomastigote form of the parasite at low cytotoxicity concentrations in spleen cells, and the resulting structure-activity relationships are discussed. We also showed that phthalimido-thiazoles induced ultrastructural alterations on morphology, flagellum shortening, chromatin condensation, mitochondria swelling, reservosomes alterations and endoplasmic reticulum dilation. Together, these data revealed, for the first time, a novel series of phthalimido-thiazoles-structure-based compounds with potential effects against T. cruzi and lead-like characteristics against Chagas disease.

  12. Clonal population structure of Colombian sylvatic Trypanosoma cruzi.

    Science.gov (United States)

    Márquez, E; Arcos-Burgos, M; Triana, O; Moreno, J; Jaramillo, N

    1998-12-01

    Isoenzyme variability and evidence of genetic exchange were evaluated in 75 wild stocks of Trypanosoma cruzi obtained from different hosts from 5 geographical regions within the endemic area in Colombia. Cluster analysis of genetic variability was attempted. Thirty-three multilocus enzyme genotypes (clonets) were identified from 75 stocks, 27 of which clustered with zymodeme Z1 and 6 with zymodeme Z3. Two stocks isolated from human infections showed the potential risk to rural communities in Colombia. The stocks exhibited departures from Hardy-Weinberg expectations, including both fixed heterozygote and fixed homozygote demes, where both segregation and recombination were absent. To inspect for population subdivision that might falsely imply clonality in these stocks, Wright's F statistics were calculated. Theta values (Fst) were significantly different from 0 when 33 clonets, 27 Z1-like clonets, and 5 geographical subpopulations were compared; thus, a significant amount of divergence has occurred between and within them. In addition, linkage disequilibrium was detected for most possible pairwise comparisons of loci. In conclusion, the above results all support a scenario of long-term clonal evolution in Colombian sylvatic T. cruzi populations.

  13. Genetically attenuated Trypanosoma cruzi parasites as a potential vaccination tool.

    Science.gov (United States)

    Pérez Brandan, Cecilia; Basombrío, Miguel Ángel

    2012-01-01

    Chagas disease is the clinical manifestation of the infection produced by the parasite Trypanosoma cruzi. Currently there is no vaccine to prevent this disease and the protection attained with vaccines containing non-replicating parasites is limited. Genetically attenuated trypanosomatid parasites can be obtained by deletion of selected genes. Gene deletion takes advantage of the fact that this parasite can undergo homologous recombination between endogenous and foreign DNA sequences artificially introduced in the cells. This approach facilitated the discovery of several unknown gene functions, as well as allowing us to speculate about the potential for genetically attenuated live organisms as experimental immunogens. Vaccination with live attenuated parasites has been used effectively in mice to reduce parasitemia and histological damage, and in dogs, to prevent vector-delivered infection in the field. However, the use of live parasites as immunogens is controversial due to the risk of reversion to a virulent phenotype. Herein, we present our results from experiments on genetic manipulation of two T. cruzi strains to produce parasites with impaired replication and infectivity, and using the mutation of the dhfr-ts gene as a safety device against reversion to virulence.

  14. Immunity and immune modulation in Trypanosoma cruzi infection.

    Science.gov (United States)

    Cardillo, Fabíola; de Pinho, Rosa Teixeira; Antas, Paulo Renato Zuquim; Mengel, José

    2015-12-01

    Chagas disease is caused by the protozoan Trypanosoma cruzi. The parasite reaches the secondary lymphoid organs, the heart, skeletal muscles, neurons in the intestine and esophagus among other tissues. The disease is characterized by mega syndromes, which may affect the esophagus, the colon and the heart, in about 30% of infected people. The clinical manifestations associated with T. cruzi infection during the chronic phase of the disease are dependent on complex interactions between the parasite and the host tissues, particularly the lymphoid system that may either result in a balanced relationship with no disease or in an unbalanced relationship that follows an inflammatory response to parasite antigens and associated tissues in some of the host organs and/or by an autoimmune response to host antigens. This review discusses the findings that support the notion of an integrated immune response, considering the innate and adaptive arms of the immune system in the control of parasite numbers and also the mechanisms proposed to regulate the immune response in order to tolerate the remaining parasite load, during the chronic phase of infection. This knowledge is fundamental to the understanding of the disease progression and is essential for the development of novel therapies and vaccine strategies.

  15. Structural characterization of NETNES glycopeptide from Trypanosoma cruzi.

    Science.gov (United States)

    Chiodi, Carla G; Verli, Hugo

    2013-05-24

    Trypanosoma cruzi is a protozoan, responsible for Chagas disease, that parasites triatomines and some vertebrates, mainly Homo sapiens. In 2010, nearly 10 million people in whole world, most from Latin America, had Chagas disease, which is an illness of high morbidity, low mortality, and serious problems of quality of life. The available treatment has high toxicity and low efficacy at chronic phase. Some of the protozoan antigenic or virulence factors include complex carbohydrate structures that, due to their uniqueness, may constitute potential selective targets for the development of new treatments. One example of such structures is NETNES, a low abundance T. cruzi glycopeptide, comprising 13 amino acid residues, one or two N-glycosylation chains, a GPI anchor and two P-glycosylations. In this context, the current work aims to obtain an atomic model for NETNES, including its glycan chains and membrane attachment, in order to contribute in the characterization of its structure and dynamics. Based on POPC and GPI models built in agreement with experimental data, our results indicate that, in the first third of the simulation, NETNES peptide is very flexible in solution, bending itself between asparagine residues and lying down on some carbohydrates and membrane, exposing amino acid residues and some other glycans, mainly terminal mannoses, to the extracellular medium, remaining in this position until the end of simulations.

  16. Experimental infections in Venezuelan lizards by Trypanosoma cruzi.

    Science.gov (United States)

    Urdaneta-Morales, S; McLure, I

    1981-06-01

    Virulent trypomastigotes of the Y strain of Trypanosoma cruzi were administered to Tropidurus hispidus, Ameiva ameiva, Cnemidophorus lemniscatus, Polychrus marmoratus, and Phyllodactylus ventralis (Sauria). Intraperitoneal and subcutaneous inoculations of lizards with mouse blood or with feces of infected Rhodnius prolixus (Reduviidae, Triatominae), as well as forced ingestion of triturated Rhodnius, produced no parasitaemias detectable either directly or by xenodiagnosis, while control mice became parasitized. Pretreatment with the immunosuppressive drug Fluocinolone acetonide led to establishing patent infections in inoculated lizards. Cryptic infections were established by inoculation of 1 X 10(6) parasites from Davis' medium, or by 95 X 10(3) parasites from lizard tissue culture. Parasites were not seen in tissues. Mice inoculated with blood or tissue homogenates from these lizards became parasitized. Parasites from Davis' medium inoculated into the peritoneal cavity of lizards were capable, to a very low degree, of penetrating the free peritoneal macrophages and changing into amastigotes. The factors possibly responsible for the natural resistance of poikilothermic vertebrates to T. cruzi are discussed.

  17. In vitro effects of citral on Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    Josiane Cardoso

    2010-12-01

    Full Text Available Citral, the main constituent of lemongrass (Cymbopogon citratus essential oil, was added to Trypanosoma cruzi cultures grown in TAU3AAG medium to observe the effect on the epimastigote-to-trypomastigote differentiation process (metacyclogenesis. Our results showed that citral (20 μg/mL did not affect epimastigote viability or inhibit the differentiation process. Concentrations higher than 60 μg/mL, however, led to 100% cell death (both epimastigote and trypomastigote forms. Although epimastigotes incubated with 30 μg/mL citral were viable and able to adhere to the substrate, we observed around 50% inhibition in metacyclogenesis, with a calculated concentration that inhibited metacyclogenesis by 50% after 24 h (IC50/24 h of about 31 μg/mL. Treatment with 30 μg/mL citral did not hinder epimastigote multiplication because epimastigote growth resumed when treated cells were transferred to a drug-free liver infusion tryptose culture medium. Metacyclogenesis was almost totally abolished at 40 μg/mL after 24 h of incubation. Furthermore, the metacyclic trypomastigotes obtained in vitro were similarly susceptible to citral, with an IC50/24 h, concentration that killed 50% of the cells after 24 h, of about 24.5 μg/mL. Therefore, citral appears to be a good candidate as an inhibitory drug for further studies analyzing the T. cruzi metacyclogenesis process.

  18. Trypanosoma cruzi as an effective cancer antigen delivery vector.

    Science.gov (United States)

    Junqueira, Caroline; Santos, Luara I; Galvão-Filho, Bruno; Teixeira, Santuza M; Rodrigues, Flávia G; DaRocha, Wanderson D; Chiari, Egler; Jungbluth, Achim A; Ritter, Gerd; Gnjatic, Sacha; Old, Lloyd J; Gazzinelli, Ricardo T

    2011-12-06

    One of the main challenges in cancer research is the development of vaccines that induce effective and long-lived protective immunity against tumors. Significant progress has been made in identifying members of the cancer testis antigen family as potential vaccine candidates. However, an ideal form for antigen delivery that induces robust and sustainable antigen-specific T-cell responses, and in particular of CD8(+) T lymphocytes, remains to be developed. Here we report the use of a recombinant nonpathogenic clone of Trypanosoma cruzi as a vaccine vector to induce vigorous and long-term T cell-mediated immunity. The rationale for using the highly attenuated T. cruzi clone was (i) the ability of the parasite to persist in host tissues and therefore to induce a long-term antigen-specific immune response; (ii) the existence of intrinsic parasite agonists for Toll-like receptors and consequent induction of highly polarized T helper cell type 1 responses; and (iii) the parasite replication in the host cell cytoplasm, leading to direct antigen presentation through the endogenous pathway and consequent induction of antigen-specific CD8(+) T cells. Importantly, we found that parasites expressing a cancer testis antigen (NY-ESO-1) were able to elicit human antigen-specific T-cell responses in vitro and solid protection against melanoma in a mouse model. Furthermore, in a therapeutic protocol, the parasites expressing NY-ESO-1 delayed the rate of tumor development in mice. We conclude that the T. cruzi vector is highly efficient in inducing T cell-mediated immunity and protection against cancer cells. More broadly, this strategy could be used to elicit a long-term T cell-mediated immunity and used for prophylaxis or therapy of chronic infectious diseases.

  19. Semisolid liver infusion tryptose supplemented with human urine allows growth and isolation of Trypanosoma cruzi and Trypanosoma rangeli clonal lineages

    OpenAIRE

    2016-01-01

    Abstract: INTRODUCTION This work shows that 3% (v/v) human urine (HU) in semisolid Liver Infusion Tryptose (SSL) medium favors the growth of Trypanosoma cruzi and T. rangeli. METHODS Parasites were plated as individual or mixed strains on SSL medium and on SSL medium with 3% human urine (SSL-HU). Isolate DNA was analyzed using polymerase chain reaction (PCR) and pulsed-field gel electrophoresis (PFGE). RESULTS SSL-HU medium improved clone isolation. PCR revealed that T. cruzi strains pr...

  20. Potential Role of Carvedilol in the Cardiac Immune Response Induced by Experimental Infection with Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Aline Luciano Horta

    2017-01-01

    Full Text Available Trypanosoma cruzi causes a cardiac infection characterized by an inflammatory imbalance that could become the inciting factor of the illness. To this end, we evaluated the role of carvedilol, a beta-blocker with potential immunomodulatory properties, on the immune response in C57BL/6 mice infected with VL-10 strain of T. cruzi in the acute phase. Animals (n=40 were grouped: (i not infected, (ii infected, (iii infected + carvedilol, and (iv not infected + carvedilol. We analyzed parameters related to parasitemia, plasma levels of TNF, IL-10, and CCL2, and cardiac histopathology after the administration of carvedilol for 30 days. We did not observe differences in the maximum peaks of parasitemia in the day of their detection among the groups. The plasma TNF was elevated at 60 days of infection in mice treated or not with carvedilol. However, we observed a decreased CCL2 level and increased IL-10 levels in those infected animals treated with carvedilol, which impacted the reduction of the inflammatory infiltration in cardiac tissue. For this experimental model, carvedilol therapy was not able to alter the levels of circulating parasites but modulates the pattern of CCL2 and IL-10 mediators when the VL10 strain of T. cruzi was used in C57BL6 mice.

  1. Potential Role of Carvedilol in the Cardiac Immune Response Induced by Experimental Infection with Trypanosoma cruzi

    Science.gov (United States)

    Horta, Aline Luciano; Leite, Ana Luisa Junqueira; Paula Costa, G.

    2017-01-01

    Trypanosoma cruzi causes a cardiac infection characterized by an inflammatory imbalance that could become the inciting factor of the illness. To this end, we evaluated the role of carvedilol, a beta-blocker with potential immunomodulatory properties, on the immune response in C57BL/6 mice infected with VL-10 strain of T. cruzi in the acute phase. Animals (n = 40) were grouped: (i) not infected, (ii) infected, (iii) infected + carvedilol, and (iv) not infected + carvedilol. We analyzed parameters related to parasitemia, plasma levels of TNF, IL-10, and CCL2, and cardiac histopathology after the administration of carvedilol for 30 days. We did not observe differences in the maximum peaks of parasitemia in the day of their detection among the groups. The plasma TNF was elevated at 60 days of infection in mice treated or not with carvedilol. However, we observed a decreased CCL2 level and increased IL-10 levels in those infected animals treated with carvedilol, which impacted the reduction of the inflammatory infiltration in cardiac tissue. For this experimental model, carvedilol therapy was not able to alter the levels of circulating parasites but modulates the pattern of CCL2 and IL-10 mediators when the VL10 strain of T. cruzi was used in C57BL6 mice.

  2. A human astrocytoma cell line is highly susceptible to infection with Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Juan Camilo Vargas-Zambrano

    2013-04-01

    Full Text Available Astrocytes play a vital role in neuronal protection, homeostasis, vascular interchange and the local immune response. Some viruses and parasites can cross the blood-brain barrier and infect glia. Trypanosoma cruzi, the aetiological agent of Chagas disease, can seriously compromise the central nervous system, mainly in immune-suppressed individuals, but also during the acute phase of the infection. In this report, the infective capacity of T. cruzi in a human astrocyte tumour-derived cell line was studied. Astrocytes exposed to trypomastigotes (1:10 ratio produced intracellular amastigotes and new trypomastigotes emerged by day 4 post-infection (p.i.. At day 6 p.i., 93% of the cells were infected. Using flow cytometry, changes were observed in both the expression of major histocompatibility complex class I and II molecules and the chemokine secretion pattern of astrocytes exposed to the parasite. Blocking the low-density lipoprotein receptor on astrocytes did not reduce parasite intracellular infection. Thus, T. cruzi can infect astrocytes and modulate the immune response during central nervous system infection.

  3. Paraflagellar rod proteins administered with alum and IL-12 or recombinant adenovirus expressing IL-12 generates antigen-specific responses and protective immunity in mice against Trypanosoma cruzi.

    Science.gov (United States)

    Wrightsman, R A; Manning, J E

    2000-01-31

    Successful vaccination of mice against an otherwise lethal challenge with the Peru strain of Trypanosoma cruzi necessitates the induction of a strong cell mediated immune response. Previously, immunization of mice with the paraflagellar rod proteins from Trypanosoma cruzi90% reduction in parasitemia in immunized mice challenged with the bloodstream stage of Trypanosoma cruzi.

  4. Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

    Directory of Open Access Journals (Sweden)

    Nívia Carolina Nogueira-Paiva

    2014-02-01

    Full Text Available Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78 T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.

  5. Ageing is not associated with an altered immune response during Trypanosoma cruzi infection: Ageing and Trypanosoma cruzi infection.

    Science.gov (United States)

    Colato, Rafaela Pravato; Brazão, Vânia; Santello, Fabricia Helena; Toldo, Míriam Paula Alonso; do Vale, Gabriel Tavares; Tirapelli, Carlos Renato; Pereira-da-Silva, Gabriela; do Prado, José Clóvis

    2017-01-25

    The aims of this work were to evaluate the influence of ageing on the magnitude of the immune response in male Wistar rats infected with the Y strain of Trypanosoma cruzi (T. cruzi). Infected young animals displayed enhanced CD4(+) T cells as compared to uninfected counterparts. Ageing also triggered a significant reduction in CD8(+) T cells compared to young and uninfected groups. The percentage of spleen NKT cells was reduced for all groups, regardless of the infection status. Significant decreased B-cells was noted in aged controls and infected animals as compared to young counterparts. A significant decrease in MHC class II (RT1B) expression in all aged animals was observed, whether infected or not. The highest and significant levels of Thiobarbituric Acid Reactive Substances (TBARS) were noted in the aged and infected animals as compared to young-infected ones (16day). Consequently superoxide dismutase (SOD) activity was reduced for both control and infected aged animals. Significant elevation of 8-isoprostane levels was found in aged control and infected animals. Plasma glutathione (GSH) concentration was reduced in aged control animals, as well as, in the young infected animals. NO production was increased in both infected and uninfected aged animals compared to young infected and uninfected animals. Corticosterone levels were elevated in aged animals, whether infected or not. Thus, our results are inedited since the immune response is not worsened by the simple fact of animals being older. Ageing by itself triggered a damaged immune response as well as enhanced reactive oxygen species, when compared to young counterparts, but it did not contribute to impair the immune response of T. cruzi infected and aged rats.

  6. The diversity and expansion of the trans-sialidase gene family is a common feature in Trypanosoma cruzi clade members.

    Science.gov (United States)

    Chiurillo, Miguel Angel; Cortez, Danielle R; Lima, Fábio M; Cortez, Caroline; Ramírez, José Luis; Martins, Andre G; Serrano, Myrna G; Teixeira, Marta M G; da Silveira, José Franco

    2016-01-01

    Trans-sialidase (TS) is a polymorphic protein superfamily described in members of the protozoan genus Trypanosoma. Of the eight TS groups recently described, TS group I proteins (some of which have catalytic activity) are present in the distantly related Trypanosoma brucei and Trypanosoma cruzi phylogenetic clades, whereas other TS groups have only been described in some species belonging to the T. cruzi clade. In the present study we analyzed the repertoire, distribution and phylogenetic relationships of TS genes among species of the T. cruzi clade based on sequence similarity, multiple sequence alignment and tree-reconstruction approaches using TS sequences obtained with the aid of PCR-based strategies or retrieved from genome databases. We included the following representative isolates of the T. cruzi clade from South America: T. cruzi, T. cruzi Tcbat, Trypanosoma cruzi marinkellei, Trypanosoma dionisii, Trypanosoma rangeli and Trypanosoma conorhini. The cloned sequences encoded conserved TS protein motifs Asp-box and VTVxNVxLYNR but lacked the FRIP motif (conserved in TS group I). The T. conorhini sequences were the most divergent. The hybridization patterns of TS probes with chromosomal bands confirmed the abundance of these sequences in species in the T. cruzi clade. Divergence and relationship analysis placed most of the TS sequences in the groups defined in T. cruzi. Further examination of members of TS group II, which includes T. cruzi surface glycoproteins implicated in host cell attachment and invasion, showed that sequences of T. cruzi Tcbat grouped with those of T. cruzi genotype TcI. Our analysis indicates that different members of the T. cruzi clade, with different vertebrate hosts, vectors and pathogenicity, share the extensive expansion and sequence diversification of the TS gene family. Altogether, our results are congruent with the evolutionary history of the T. cruzi clade and represent a contribution to the understanding of the molecular

  7. Trypanosoma cruzi strains and autonomic nervous system pathology in experimental chagas disease

    Directory of Open Access Journals (Sweden)

    Márcia Maria de Souza

    1996-04-01

    Full Text Available Lesions involving the sympathetic (para-vertebral ganglia and para-sympathetic ganglia of intestines (Auerbach plexus and heart (right atrial ganglia were comparatively analyzed in mice infected with either of three different strain types of Trypanosoma cruzi, during acute and chronic infection, in an attempt to understand the influence of parasite strain in causing autonomic nervous system pathology. Ganglionar involvement with neuronal destruction appeared related to inflammation, which most of the times extended from neighboring adipose and cardiac, smooth and striated muscular tissues. Intraganglionic parasitism was exceptional. Inflammation involving peripheral nervous tissue exhibited a focal character and its variability in the several groups examined appeared unpredictable. Although lesions were generally more severe with the Y strain, comparative qualitative study did not allow the conclusion, under the present experimental conditions, that one strain was more pathogenic to the autonomic nervous system than others. No special tropism of the parasites from any strain toward autonomic ganglia was disclosed.

  8. Neuronal changes caused by Trypanosoma cruzi: an experimental model

    Directory of Open Access Journals (Sweden)

    Neide M Moreira

    2011-06-01

    Full Text Available Define an experimental model by evaluating quantitative and morphometric changes in myenteric neurons of the colon of mice infected with Trypanosoma cruzi. Twenty-eight Swiss male mice were distributed into groups: control (CG, n=9 and inoculated with 100 (IG100, n=9 and 1000 (IG1000, n=10 blood trypomastigotes, Y strain-T. cruzi II. Parasitemia was evaluated from 3-25 days post inoculation (dpi with parasites peak of 7.7 × 10(6 and 8.4 × 10(6 trypomastigotes/mL at 8th dpi (p>0.05 in IG100 and IG1000, respectively. Chronic phase of the infection was obtained with two doses of 100mg/Kg/weight and one dose of 250mg/Kg/weight of Benznidazole on 11, 16 and 18 dpi. Three animals from each group were euthanized at 18, 30 and 75 dpi. The colon was stained with Giemsa. The quantitative and morphometric analysis of neurons revealed that the infection caused a decrease of neuronal density on 30th dpi (pDefinir um modelo experimental de avaliação de alterações quantitativas e morfométricas nos neurônios mientéricos do cólon de camundongos infectados pelo Trypanosoma cruzi. Vinte e oito camundongos Swiss machos foram distribuídos nos grupos: controle (GC, n=9 e infectados com 100 (IG100, n=9 e 1000 (IG1000, n=10 tripomastigotas sanguíneos, cepa Y-T. cruzi II. A parasitemia foi avaliada 3-25 dias pós inoculação (dpi, com pico de parasitos de 7,7 × 10(6 e 8,4 × 10(6 tripomastigotas/mL no 8º dpi (p>0,05 em IG100 e IG1000, respectivamente. A fase crônica da infecção foi obtida com duas doses de 100mg/Kg/weight e uma dose de 250mg/Kg/ weight do benznidazol, em 11, 16 e 18 dpi. Três animais de cada grupo foram sacrificados aos 18, 30 e 75 dpi. O cólon foi corado com Giemsa. A análise quantitativa e morfométrica de neurônios revelou que a infecção causou uma diminuição da densidade neuronal no 30º dpi (p<0,05 e 75 dpi (p<0,05 em IG100 e IG1000. A infecção causou morte e hipertrofia neuronal no 75º dpi em IG100 e IG1000 (p<0,05, p

  9. Genetic Vaccination against Experimental Infection with Myotropic Parasite Strains of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Adriano Fernando Araújo

    2014-01-01

    Full Text Available In earlier studies, we reported that a heterologous prime-boost regimen using recombinant plasmid DNA followed by replication-defective adenovirus vector, both containing Trypanosoma cruzi genes encoding trans-sialidase (TS and amastigote surface protein (ASP 2, provided protective immunity against experimental infection with a reticulotropic strain of this human protozoan parasite. Herein, we tested the outcome of genetic vaccination of F1 (CB10XBALB/c mice challenged with myotropic parasite strains (Brazil and Colombian. Initially, we determined that the coadministration during priming of a DNA plasmid containing the murine IL-12 gene improved the immune response and was essential for protective immunity elicited by the heterologous prime-boost regimen in susceptible male mice against acute lethal infections with these parasites. The prophylactic or therapeutic vaccination of resistant female mice led to a drastic reduction in the number of inflammatory infiltrates in cardiac and skeletal muscles during the chronic phase of infection with either strain. Analysis of the electrocardiographic parameters showed that prophylactic vaccination reduced the frequencies of sinus arrhythmia and atrioventricular block. Our results confirmed that prophylactic vaccination using the TS and ASP-2 genes benefits the host against acute and chronic pathologies caused by T. cruzi and should be further evaluated for the development of a veterinary or human vaccine against Chagas disease.

  10. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

    Directory of Open Access Journals (Sweden)

    Andrés B Lantos

    2016-04-01

    Full Text Available Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully

  11. Kinetics of Trypanosoma cruzi destruction in the mouse spleen

    Directory of Open Access Journals (Sweden)

    Zulmira M.S. Cordeiro

    1997-02-01

    Full Text Available Massive destruction of parasitized splenic macrophages was histologically observed at the height of a virulent infection caused by Trypanosoma cruzi (Y strain in the mouse. This was coincident with a sudden drop in parasitemic curve. Most of the animals died at this point, probably due to the liberation of toxic products, such as TNF, following the massive destruction of parasitized cells. However, parasitized-cell destruction indicated the transition from susceptibility to resistance. Although it has been extensively studied in vitro, this study contributes with the morphological counterpart observed in vivo by optical and electron microscopy. When infected animals were specifically treated during early infection transition to chronic phase was immediately observed without splenic parasitism. Animals that apparently recovered from massive cell-destruction in the spleen showed evidences of a rapid restoration of splenic architecture.Um estudo histologico sequenciado mostrou que o parasitismo dos macrófagos esplênicos por uma cepa virulenta (cepa Y do Trypanosoma cruzi tem um curso progressivo, mas chega até um ponto em que todos as células parasitadas são subitamente destruídas. Tal achado coincidiu com uma quéda brusca da curva parasitêmica e com a morte da maioria dos animais, provavelmente devido à liberação de produtos tóxicos (como o TNF pelas células desintegradas. O achado foi interpretado como o auge da transição entre uma fase de susceptibilidade e outra de resistência. Embora esta transição tenha sido bem estudada in vitro, este estudo contribui com os dados do substrato morfológico observados in vivo, através da microscopia ótica e eletrônica. O tratamento específico e supressivo feito na fase inicial da infecção acarreta uma transição imediata para a fase crônica e aí o parasitismo esplênico desaparece completamente. Os animais que aparentemente se recuperaram expontaneamente após a fase de destrui

  12. Functional characterization of NADP-dependent isocitrate dehydrogenase isozymes from Trypanosoma cruzi.

    Science.gov (United States)

    Leroux, Alejandro E; Maugeri, Dante A; Cazzulo, Juan J; Nowicki, Cristina

    2011-05-01

    Trypanosoma cruzi exhibits two putative isocitrate dehydrogenases (IDHs). Both idh genes were cloned and the recombinant enzymes expressed in Escherichia coli. Our results showed that T. cruzi IDHs are strictly dependent on NADP(+) and display apparent affinities towards isocitrate and the coenzyme in the low micromolar range. In T. cruzi, IDHs are cytosolic and mitochondrial enzymes, and there is no evidence for the typical Krebs cycle-related NAD-dependent IDH. Hence, like in Trypanosoma brucei, the Krebs cycle is not a canonical route in T. cruzi. However, the citrate produced in the mitochondrion could be isomerized into isocitrate in the cytosol and the mitochondrion by means of the putative aconitase, which would provide the substrate for both IDHs. The cytosolic IDH is significantly more abundant in amastigotes, cell-derived and metacyclic trypomastigotes than in epimastigotes. This observation fits in well with the expected oxidative burst this pathogen has to face when infecting the mammalian host.

  13. Crystal Structure of Triosephosphate Isomerase from Trypanosoma cruzi in Hexane

    Science.gov (United States)

    Gao, Xiu-Gong; Maldonado, Ernesto; Perez-Montfort, Ruy; Garza-Ramos, Georgina; Tuena de Gomez-Puyou, Marietta; Gomez-Puyou, Armando; Rodriguez-Romero, Adela

    1999-08-01

    To gain insight into the mechanisms of enzyme catalysis in organic solvents, the x-ray structure of some monomeric enzymes in organic solvents was determined. However, it remained to be explored whether the structure of oligomeric proteins is also amenable to such analysis. The field acquired new perspectives when it was proposed that the x-ray structure of enzymes in nonaqueous media could reveal binding sites for organic solvents that in principle could represent the starting point for drug design. Here, a crystal of the dimeric enzyme triosephosphate isomerase from the pathogenic parasite Trypanosoma cruzi was soaked and diffracted in hexane and its structure solved at 2- angstrom resolution. Its overall structure and the dimer interface were not altered by hexane. However, there were differences in the orientation of the side chains of several amino acids, including that of the catalytic Glu-168 in one of the monomers. No hexane molecules were detected in the active site or in the dimer interface. However, three hexane molecules were identified on the surface of the protein at sites, which in the native crystal did not have water molecules. The number of water molecules in the hexane structure was higher than in the native crystal. Two hexanes localized at <4 angstrom from residues that form the dimer interface; they were in close proximity to a site that has been considered a potential target for drug design.

  14. In vitro activity of Etanidazole against the protozoan parasite Trypanosoma cruzi

    OpenAIRE

    Petray, Patricia B.; María J Morilla; Corral, Ricardo S.; Romero, Eder L.

    2004-01-01

    We investigated the in vitro action of an hydrosoluble 2-nitroimidazole, Etanidazole (EZL), against Trypanosoma cruzi, the etiologic agent of Chagas disease. EZL displayed lethal activity against isolated trypomastigotes as well as amastigotes of T. cruzi (RA strain) growing in Vero cells or J774 macrophages, without affecting host cell viability. Although not completely equivalent to Benznidazole (BZL), the reference drug for Chagas chemotherapy, EZL takes advantage in exertingits anti-T. cr...

  15. Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

    OpenAIRE

    Fabbro, Diana L.; Emmaria Danesi; Veronica Olivera; Maria Olenka Codebó; Susana Denner; Cecilia Heredia; Mirtha Streiger; Sergio Sosa-Estani

    2014-01-01

    With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment be...

  16. First Case of Natural Infection in Pigs: Review of Trypanosoma cruzi Reservoirs in Mexico

    Directory of Open Access Journals (Sweden)

    Paz María Salazar-Schettino

    1997-07-01

    Full Text Available An epidemiological research project was performed in the State of Morelos including collection of samples for blood smears and culture, serological tests, and xenodiagnoses from a total of 76 domestic and peridomestic mammals. Two strains of Trypanosoma cruzi were isolated by haemocultures; one from a pig (Sus scrofa, the first case of natural infection reported in Mexico, and the other from a dog (Canis familiaris. This study summarizes current information in Mexico concerning confirmed reservoirs of T. cruzi

  17. Comparing two protocols of DNA extraction of Trypanosoma cruzi cultured in axenic medium

    OpenAIRE

    López, Mariela; Instituto de Investigaciones Biomédicas “Dr. Francisco J. Triana Alonso”, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Escuela de Bioanálisis, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Licenciada en Bioanálisis; Rivera, María G.; Instituto de Investigaciones Biomédicas “Dr. Francisco J. Triana Alonso”, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Licenciada en Bioanálisis.; Viettri, Mercedes; Biomédicas “Dr. Francisco J. Triana Alonso”, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Licenciada en Bioanálisis.; Lares, María; Instituto de Investigaciones Biomédicas “Dr. Francisco J. Triana Alonso”, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Técnico superior universitario en Química.; Morocoima, Antonio; Centro de Medicina Tropical de Oriente, Facultad de Medicina, Universidad de Oriente. Anzoátegui, Venezuela. Médico cirujano, magíster en Parasitología.; Herrera, Leidi; Instituto de Zoología y Ecología Tropical, Facultad de Ciencias, Universidad Central de Venezuela. Caracas, Venezuela. Biólogo, doctora en Ciencias.; Ferrer, Elizabeth; Instituto de Investigaciones Biomédicas “Dr. Francisco J. Triana Alonso”, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Departamento de Parasitología, Facultad de Ciencias de la Salud, Universidad de Carabobo. Maracay, Venezuela. Licenciada en bioanálisis, doctora en Biología Molecular.

    2014-01-01

    Objectives. To compare two extraction protocols of Trypanosoma cruzi DNA for use in DNA amplification of kinetoplast minicircles (kDNA) through the technique of Polymerase Chain Reaction (PCR). Materials and methods. Epimastigotes of T. cruzi were cultured in axenic conditions and masses from 1.5 to 100 x 106 parasites were obtained. DNA extraction was performed using two protocols: extraction with organic solvents (phenol/chloroform), and with resin (Chelex®100), from different parasitic sed...

  18. trans-Sialidase Neutralizing Antibody Detection in Trypanosoma cruzi-Infected Domestic Reservoirs ▿

    OpenAIRE

    Sartor, Paula A.; Cardinal, Martha V.; Orozco, Marcela M; Ricardo E Gürtler; Leguizamón, M. Susana

    2011-01-01

    The detection of Trypanosoma cruzi infection in domestic dogs and cats is relevant to evaluating human transmission risks and the effectiveness of insecticide spraying campaigns. However, the serological assays routinely used are associated with cross-reactivity in sera from mammals infected with Leishmania spp. We used a trans-sialidase inhibition assay (TIA) for T. cruzi diagnosis in serum samples from 199 dogs and 57 cats from areas where these types of infections are endemic. TIA is based...

  19. Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model

    Directory of Open Access Journals (Sweden)

    César Gómez-Hernández

    2011-12-01

    Full Text Available INTRODUCTION: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. METHODS: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD - (random amplified polymorphic DNA. RESULTS: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6 to 10(7 parasites/mL and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. CONCLUSIONS: The Mexican T. cruzi strains are myotrophic and belong to group TcI.

  20. Trypanosoma cruzi Differentiates and Multiplies within Chimeric Parasitophorous Vacuoles in Macrophages Coinfected with Leishmania amazonensis.

    Science.gov (United States)

    Pessoa, Carina Carraro; Ferreira, Éden Ramalho; Bayer-Santos, Ethel; Rabinovitch, Michel; Mortara, Renato Arruda; Real, Fernando

    2016-05-01

    The trypanosomatids Leishmania amazonensis and Trypanosoma cruzi are excellent models for the study of the cell biology of intracellular protozoan infections. After their uptake by mammalian cells, the parasitic protozoan flagellates L. amazonensis and T. cruzi lodge within acidified parasitophorous vacuoles (PVs). However, whereas L. amazonensis develops in spacious, phagolysosome-like PVs that may enclose numerous parasites, T. cruzi is transiently hosted within smaller vacuoles from which it soon escapes to the host cell cytosol. To investigate if parasite-specific vacuoles are required for the survival and differentiation of T. cruzi, we constructed chimeric vacuoles by infection of L. amazonensis amastigote-infected macrophages with T. cruzi epimastigotes (EPIs) or metacyclic trypomastigotes (MTs). These chimeric vacuoles, easily observed by microscopy, allowed the entry and fate of T. cruzi in L. amazonensis PVs to be dynamically recorded by multidimensional imaging of coinfected cells. We found that although T. cruzi EPIs remained motile and conserved their morphology in chimeric vacuoles, T. cruzi MTs differentiated into amastigote-like forms capable of multiplying. These results demonstrate that the large adaptive vacuoles of L. amazonensis are permissive to T. cruzi survival and differentiation and that noninfective EPIs are spared from destruction within the chimeric PVs. We conclude that T. cruzi differentiation can take place in Leishmania-containing vacuoles, suggesting this occurs prior to their escape into the host cell cytosol.

  1. Identification of three classes of heteroaromatic compounds with activity against intracellular Trypanosoma cruzi by chemical library screening.

    Directory of Open Access Journals (Sweden)

    Esther Bettiol

    Full Text Available The development of new drugs against Chagas disease is a priority since the currently available medicines have toxic effects, partial efficacy and are targeted against the acute phase of disease. At present, there is no drug to treat the chronic stage. In this study, we have optimized a whole cell-based assay for high throughput screening of compounds that inhibit infection of mammalian cells by Trypanosoma cruzi trypomastigotes. A 2000-compound chemical library was screened using a recombinant T. cruzi (Tulahuen strain expressing beta-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC(50: 54, 190 and 23 nM, respectively. Each of these three compounds presents a different mechanism of action on intracellular proliferation of T. cruzi amastigotes. CX1 shows strong trypanocidal activity, an essential characteristic for the development of drugs against the chronic stage of Chagas disease where parasites are found intracellular in a quiescent stage. NT1 has a trypanostatic effect, while PCH1 affects parasite division. The three compounds also show high activity against intracellular T. cruzi from the Y strain and against the related kinetoplastid species Leishmania major and L. amazonensis. Characterization of the anti-T. cruzi activity of molecules chemically related to the three library hits allowed the selection of two compounds with IC(50 values of 2 nM (PCH6 and CX2. These values are approximately 100 times lower than those of the medicines used in patients against T. cruzi. These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis.

  2. Genetic immunization elicits antigen-specific protective immune responses and decreases disease severity in Trypanosoma cruzi infection.

    Science.gov (United States)

    Garg, Nisha; Tarleton, Rick L

    2002-10-01

    Immunity to Trypanosoma cruzi requires elicitation of humoral and cell-mediated immune responses to extracellular trypomastigotes and intracellular amastigotes. In this study, the effectiveness of the T. cruzi trans-sialidase family (ts) genes ASP-1, ASP-2, and TSA-1 as genetic vaccines was assessed. Immunization of mice with plasmids encoding ASP-1, ASP-2, or TSA-1 elicited poor antigen-specific cytotoxic-T-lymphocyte (CTL) activity and T. cruzi-specific antibody responses. Codelivery of interleukin-12 and granulocyte-macrophage colony-stimulating factor plasmids with antigen-encoding plasmids resulted in a substantial increase in CTL activity and antibody production and in increased resistance to T. cruzi infection. In pooled results from two to four experiments, 30 to 60% of mice immunized with antigen-encoding plasmids and 60 to 80% of mice immunized with antigen-encoding plasmids plus cytokine adjuvants survived a lethal challenge with T. cruzi. In comparison, 90% of control mice injected with empty plasmid DNA died during the acute phase of infection. However, the pool of three ts genes provided no greater protection than the most effective single gene (ASP-2) either with or without coadministration of cytokine plasmids. Importantly, the extent of tissue parasitism, inflammation, and associated tissue damage in skeletal muscles during the chronic phase of T. cruzi infection in mice immunized with antigen-encoding plasmids plus cytokine adjuvants was remarkably reduced compared to mice immunized with only cytokine adjuvants or empty plasmid DNA. These results identify new vaccine candidates and establish some of the methodologies that might be needed to develop effective vaccine-mediated control of T. cruzi infection. In addition, this work provides the first evidence that prophylactic genetic immunization can prevent the development of Chagas' disease.

  3. Coadministration of cruzipain and GM-CSF DNAs, a new immunotherapeutic vaccine against Trypanosoma cruzi infection.

    Science.gov (United States)

    Cerny, Natacha; Sánchez Alberti, Andrés; Bivona, Augusto E; De Marzi, Mauricio C; Frank, Fernanda M; Cazorla, Silvia I; Malchiodi, Emilio L

    2016-01-01

    Therapeutic vaccine research and development are especially important in Chagas disease considering the characteristics of the chronic infection and the number of people in the Americas living with a parasite infection for decades. We have previously reported the efficacy of attenuated Salmonella enterica (S) carrying plasmid encoding cruzipain (SCz) to protect against Trypanosoma cruzi infection. In the present work we investigated whether Cz DNA vaccine immunotherapy could be effective in controlling an ongoing T. cruzi infection in mice. We here report the intramuscular administration of naked Cz DNA or the oral administration of Salmonella as Cz DNA delivery system as therapeutic vaccines in mice during acute or chronic infection. The coadministration of a plasmid encoding GM-CSF improved vaccine performance, indicating that the stimulation of innate immune cells is needed in the event of an ongoing infection. These therapeutic vaccines were able to address the response to a protective and sustained Th1 biased profile not only against Cz but also against a variety of parasite antigens. The combined therapeutic vaccine during the chronic phase of infection prevents tissue pathology as shown by a reduced level of enzyme activity characteristic of tissue damage and a tissue status compatible with normal tissue. The obtained results suggest that immunotherapy with Cz and GM-CSF DNAs, either alone or in combination with other drug treatments, may represent a promising alternative for Chagas disease therapy.

  4. Role of membrane-bound IgM in Trypanosoma cruzi evasion from immune clearance.

    Science.gov (United States)

    Garcia, I E; Lima, M R; Marinho, C R; Kipnis, T L; Furtado, G C; Alvarez, J M

    1997-04-01

    We have recently described that Trypanosoma cruzi parasites of the reticulotropic Y strain increase their resistance to antibody-induced clearance during their interaction with the vertebrate host immune system. In the present study, we observed that trypomastigotes of the myotropic CL strain isolated from normal host also display an increased resistance to immune clearance when compared to parasites obtained from immunosuppressed donors. Through fluorescence-activated cell sorting analysis, we have observed that the high expression of membrane-bound IgM antibodies on Y and CL trypomastigotes correlates with their enhanced resistance to Ig-induced clearance. Trypomastigotes from normal mice were essentially refractory to the in vitro binding of immunoglobulins, showing that their membrane structures were completely covered by IgM antibodies. These findings suggest that this isotype does not efficiently mediate immune clearance. Moreover, membrane-bound IgM antibodies limited the amount of IgG attached to the parasite and, as a consequence, impaired efficient immune clearance. Through this mechanism, trypomastigotes of T. cruzi could increase their persistence in the bloodstream thus favoring parasite transmission to its hematophagous host vector in the early acute phase of the disease.

  5. Structural design, synthesis and pharmacological evaluation of 4-thiazolidinones against Trypanosoma cruzi.

    Science.gov (United States)

    de Oliveira Filho, Gevanio Bezerra; de Oliveira Cardoso, Marcos Veríssimo; Espíndola, José Wanderlan Pontes; Ferreira, Luiz Felipe Gomes Rebello; de Simone, Carlos Alberto; Ferreira, Rafaela Salgado; Coelho, Pollyanne Lacerda; Meira, Cássio Santana; Magalhaes Moreira, Diogo Rodrigo; Soares, Milena Botelho Pereira; Lima Leite, Ana Cristina

    2015-12-01

    Chagas disease is an infection caused by protozoan Trypanosoma cruzi, which affects approximately 8-10million people worldwide. Benznidazole is the only drug approved for treatment during the acute and asymptomatic chronic phases of Chagas disease; however, it has poor efficacy during the symptomatic chronic phase. Therefore, the development of new pharmaceuticals is needed. Here, we employed the bioisosterism to modify a potent antiparasitic and cruzain-inhibitor aryl thiosemicarbazone (4) into 4-thiazolidinones (7-21). Compounds (7-21) were prepared by using a straightforward synthesis and enabled good to excellent yields. As a chemical elucidation tool, X-ray diffraction of compound (10) revealed the geometry and conformation of this class compounds. The screening against cruzain showed that 4-thiazolidinones were less active than thiosemicarbazone (4). However, the antiparasitic activity in Y strain trypomastigotes and host cell cytotoxicity in J774 macrophages revealed that compounds (10 and 18-21) are stronger and more selective antiparasitic agents than thiosemicarbazone (4). Specifically, compounds (18-20), which carry a phenyl at position N3 of heterocyclic ring, were the most active ones, suggesting that this is a structural determinant for activity. In infected macrophages, compounds (18-20) reduced intracellular amastigotes, whereas Benznidazole did not. In T. cruzi-infected mice treated orally with 100mg/kg of compound (20), a decreased of parasitemia was observed. In conclusion, we demonstrated that the conversation of thiosemicarbazones into 4-thiazolidinones retains pharmacological property while enhances selectivity.

  6. NATURAL INFECTION BY Trypanosoma cruzi IN ONE DOG IN CENTRAL WESTERN BRAZIL: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Arleana do Bom Parto Ferreira de Almeida

    2013-07-01

    Full Text Available SUMMARY It is estimated that about 10 million people are infected with Trypanosoma cruzi worldwide, mostly in Latin America and more than 25 million are at risk of acquiring this infection in endemic areas. Dogs are an important reservoir for this pathogen and thus, considered a risk factor for human populations. This report describes one case of Chagas disease in a dog from Cuiabá, Mato Grosso State, Brazil. The diagnosis was obtained by direct examination of trypomastigote forms in blood smears. Amastigotes forms were visualized in microscopy of the bone marrow, lymph nodes, kidneys, liver and brain. The T. cruzi (ZIII infection was confirmed by Polymerase Chain Reaction, and sequencing. The animal presented multisystemic failure and died. Although acute Chagas disease in humans is not reported in Cuiabá, this is the first report of a canine case in this region. This case represents a warning, to health professionals and authorities, to the possibility of transmission of this zoonosis in Cuiabá.

  7. Human Leucocyte Antigen-G (HLA-G) and Its Murine Functional Homolog Qa2 in the Trypanosoma cruzi Infection

    Science.gov (United States)

    Dias, Fabrício C.; Mendes-Junior, Celso T.; Silva, Maria C.; Tristão, Fabrine S. M.; Dellalibera-Joviliano, Renata; Soares, Edson G.; Menezes, Jean G.; Schmidt, André; Dantas, Roberto O.; Marin-Neto, José A.; Silva, João S.; Donadi, Eduardo A.

    2015-01-01

    Genetic susceptibility factors, parasite strain, and an adequate modulation of the immune system seem to be crucial for disease progression after Trypanosoma cruzi infection. HLA-G and its murine functional homolog Qa2 have well-recognized immunomodulatory properties. We evaluated the HLA-G 3′ untranslated region (3′UTR) polymorphic sites (associated with mRNA stability and target for microRNA binding) and HLA-G tissue expression (heart, colon, and esophagus) in patients presenting Chagas disease, stratified according to the major clinical variants. Further, we investigated the transcriptional levels of Qa2 and other pro- and anti-inflammatory genes in affected mouse tissues during T. cruzi experimental acute and early chronic infection induced by the CL strain. Chagas disease patients exhibited differential HLA-G 3′UTR susceptibility allele/genotype/haplotype patterns, according to the major clinical variant (digestive/cardiac/mixed/indeterminate). HLA-G constitutive expression on cardiac muscle and colonic cells was decreased in Chagasic tissues; however, no difference was observed for Chagasic and non-Chagasic esophagus tissues. The transcriptional levels of Qa2 and other anti and proinflammatory (CTLA-4, PDCD1, IL-10, INF-γ, and NOS-2) genes were induced only during the acute T. cruzi infection in BALB/c and C57BL/6 mice. We present several lines of evidence indicating the role of immunomodulatory genes and molecules in human and experimental T. cruzi infection. PMID:25688175

  8. Human Leucocyte Antigen-G (HLA-G and Its Murine Functional Homolog Qa2 in the Trypanosoma cruzi Infection

    Directory of Open Access Journals (Sweden)

    Fabrício C. Dias

    2015-01-01

    Full Text Available Genetic susceptibility factors, parasite strain, and an adequate modulation of the immune system seem to be crucial for disease progression after Trypanosoma cruzi infection. HLA-G and its murine functional homolog Qa2 have well-recognized immunomodulatory properties. We evaluated the HLA-G 3′ untranslated region (3′UTR polymorphic sites (associated with mRNA stability and target for microRNA binding and HLA-G tissue expression (heart, colon, and esophagus in patients presenting Chagas disease, stratified according to the major clinical variants. Further, we investigated the transcriptional levels of Qa2 and other pro- and anti-inflammatory genes in affected mouse tissues during T. cruzi experimental acute and early chronic infection induced by the CL strain. Chagas disease patients exhibited differential HLA-G 3′UTR susceptibility allele/genotype/haplotype patterns, according to the major clinical variant (digestive/cardiac/mixed/indeterminate. HLA-G constitutive expression on cardiac muscle and colonic cells was decreased in Chagasic tissues; however, no difference was observed for Chagasic and non-Chagasic esophagus tissues. The transcriptional levels of Qa2 and other anti and proinflammatory (CTLA-4, PDCD1, IL-10, INF-γ, and NOS-2 genes were induced only during the acute T. cruzi infection in BALB/c and C57BL/6 mice. We present several lines of evidence indicating the role of immunomodulatory genes and molecules in human and experimental T. cruzi infection.

  9. In vitro cytocidal effect of novel lytic peptides on Plasmodium falciparum and Trypanosoma cruzi.

    Science.gov (United States)

    Jaynes, J M; Burton, C A; Barr, S B; Jeffers, G W; Julian, G R; White, K L; Enright, F M; Klei, T R; Laine, R A

    1988-10-01

    Plasmodium falciparum and Trypanosoma cruzi were killed by two novel lytic peptides (SB-37 and Shiva-1) in vitro. Human erythrocytes infected with P. falciparum, and Vero cells infected with T. cruzi, were exposed to these peptides. The result, in both cases, was a significant decrease in the level of parasite infection. Furthermore, the peptides had a marked cytocidal effect on trypomastigote stages of T. cruzi in media, whereas host eukaryotic cells were unaffected by the treatments. In view of the worldwide prevalence of these protozoan diseases and the lack of completely suitable treatments, lytic peptides may provide new and unique chemotherapeutic agents for the treatment of these infections.

  10. Immunological Identification of Trypanosoma cruzi Lineages in Human Infection Along the Endemic Area

    OpenAIRE

    2011-01-01

    Genotyping studies show a polarized geographic distribution of Trypanosoma cruzi lineages in humans. Here, we assessed their distribution along Latin America through an immunological approach we designated Western blot (WB) assay with Trypomastigote small-surface antigen (TSSA) I and TSSA II (TSSA-WB). These antigens are expressed by T. cruzi I (TCI; now TcI) and T. cruzi II (TCII; reclassified as TcII to TcVI) parasites. TSSA-WB showed good concordance with genotyping tests. An unexpected fr...

  11. Modulation of parasitemia and antibody responce to Trypanosoma cruzy by cyclophosphamide in Calomys callosus (Rodentia, Cricetidae)

    OpenAIRE

    1992-01-01

    Calomys callosus a wild rodent, previously described as harboring Trypanosoma cruzi, has a low susceptibility to infection by this protozoan. Experiments were designed to evaluate the contribution of the immune response to the resistance to T. cruzi infection exhibited by C. calossus. Animals were submitted to injections of high (200 mg/kg body weight) and low (20 mg/kg body weight) doses of cyclophosphamide on days -1 or -1 and +5, and inoculated with 4 x 10³ T. cruzi on day O. Parasitemia, ...

  12. Drug discovery for Chagas disease should consider Trypanosoma cruzi strain diversity

    Directory of Open Access Journals (Sweden)

    Bianca Zingales

    2014-09-01

    Full Text Available This opinion piece presents an approach to standardisation of an important aspect of Chagas disease drug discovery and development: selecting Trypanosoma cruzi strains for in vitro screening. We discuss the rationale for strain selection representing T. cruzi diversity and provide recommendations on the preferred parasite stage for drug discovery, T. cruzi discrete typing units to include in the panel of strains and the number of strains/clones for primary screens and lead compounds. We also consider experimental approaches for in vitro drug assays. The Figure illustrates the current Chagas disease drug-discovery and development landscape.

  13. Experimental transmission of the parasitic flagellates Trypanosoma cruzi and Trypanosoma rangeli between triatomine bugs or mice and captive neotropical bats

    Directory of Open Access Journals (Sweden)

    Maurice E Thomas

    2007-08-01

    Full Text Available Trypanosoma cruzi and Trypanosoma rangeli-like trypanosomes have been found in a variety of neotropical bat species. In this study, bats (Artibeus lituratus, Carollia perspicillata, Desmodus rotundus, Glossophaga soricina, Molossus molossus, Phyllostomus hastatus were maintained under controlled conditions, and experiments were conducted to determine how they might become infected naturally with trypanosomes. All bats were first screened for existing infections by hemoculture and the examination of blood smears, and only apparently uninfected animals were then used in the experiments. Proof was obtained that the triatomine bug Rhodnius prolixus would readily feed upon some of the bats, and two species became infected after being bitten by bugs infected with T. rangeli. Some bats also became infected by ingesting R. prolixus carrying T. cruzi, or following subcutaneous or intragastic inoculation with fecal suspensions of R. prolixus containing T. cruzi. P. hastatus became infected after ingesting mice carrying T. cruzi. All of the bats studied inhabit roosts that may be occupied by triatomine bugs and, with the exception of D. rotundus, all also feed to at least some extent upon insects. These findings provide further evidence of how bats may play significant roles in the epidemiology of T. cruzi and T. rangeli in the New World tropics.

  14. Recrudescence induced by cyclophosphamide of chronic Trypanosoma cruzi infection in mice is influenced by the parasite strain

    Directory of Open Access Journals (Sweden)

    Maria Elizabeth S Pereira

    1996-02-01

    Full Text Available Reactivation of chronic chagasic patients may occur upon use of immunosuppressive drugs related to kidney or heart transplantation or when they are affected by concomitant HIV infection. This recrudescence, however, does not occur in all chagasic patients exposed to immunosuppressive agents. We therefore investigated the influence of Trypanosoma cruzi strains in the recrudescence of the parasitism in mice at the chronic phase treated with cyclophosphamide, an immunosuppressor that blocks lymphocytes DNA synthesis and therefore controls B cells response. A large variation was detected in the percentages of newly established acute phases in the groups of mice inoculated with the different strains. We suggest that reactivation of chronic T. cruzi infections is influenced by the parasite intrinsic characteristics, a phenomenon that might occur in the human disease.

  15. Induction of proinflammatory cytokines and nitric oxide by Trypanosoma cruzi in renal cells.

    Science.gov (United States)

    de Oliveira, Gabriel M; Yoshida, Nobuko; Higa, Elisa M S; Shenkman, Sérgio; Alves, Monique; Staquicini, Daniela; Cascabulho, Cynthia; Schor, Nestor

    2011-08-01

    Chagas disease is typically associated with cardiac involvement. During the acute phase of murine infection with Trypanosoma cruzi, severe acute myocarditis can develop. Prior to cardiac alteration, however, infected mice present with renal inflammatory infiltration causing acute kidney injury due to an ischemia/reperfusion lesion. Thus, the present study was undertaken in order to evaluate whether the parasites or some of their components would directly affect renal cells. As such, this study employed kidney cell lines (mesangial, epithelial, and proximal tubular) that mimic different regions of the renal system. Mesangial cells are more resistant to infection, showing reduced parasite internalization relative to epithelial and proximal tubular cells. Upon infection, mesangial cells produced more nitric oxide, tumor factor necrosis-α, and interferon-γ and showed decreased viability when compared to the other cell lines. These results indicate that the resistance of mesangial cells to infection may be related to the increased expression of nitric oxide and proinflammatory cytokines. Conversely, the high levels of nitric oxide produced by these cells caused impairment of cell integrity and viability. Higher nitric oxide concentrations promote cellular injury and can be involved in the genesis of ischemia/reperfusion lesions in acute kidney injury.

  16. Active transcription and ultrastructural changes during Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    Ludmila R.P. Ferreira

    2008-03-01

    Full Text Available The differentiation of proliferating epimastigote forms of Trypanosoma cruzi , the protozoan parasite that causes Chagas’ disease, into the infective and non-proliferating metacyclic forms can be reproduced in the laboratory by incubating the cells in a chemically-defined medium that mimics the urine of the insect vector. Epimastigotes have a spherical nucleus, a flagellum protruding from the middle of the protozoan cell, and a disk-shaped kinetoplast - an organelle that corresponds to the mitochondrial DNA. Metacyclic trypomastigotes have an elongated shape with the flagellum protruding from the posterior portion of the cell and associated with a spherical kinetoplast. Here we describe the morphological events of this transformation and characterize a novel intermediate stage by three-dimensional reconstruction of electron microscope serial sections. This new intermediate stage is characterized by a kinetoplast compressing an already elongated nucleus, indicating that metacyclogenesis involves active movements of the flagellar structure relative to the cell body. As transcription occurs more intensely in proliferating epimastigotes than in metacyclics, we also examined the presence of RNA polymerase II and measured transcriptional activity during the differentiation process. Both the presence of the enzyme and transcriptional activity remain unchanged during all steps of metacyclogenesis. RNA polymerase II levels and transcriptional activity only decrease after metacyclics are formed. We suggest that transcription is required during the epimastigote-to-metacyclic trypomastigote differentiation process, until the kinetoplast and flagellum reach the posterior position of the parasites in the infective form.A diferenciação de formas epimastigotas (proliferativas do Trypanosoma cruzi, parasita protozoário causador da doença de Chagas, em formas metacíclicas tripomastigotas (infectivas e não proliferativas, pode ser reproduzida em laborat

  17. The genome sequence of Trypanosoma cruzi, etiologic agent of Chagas disease

    NARCIS (Netherlands)

    El-Sayed, NM; Myler, PJ; Bartholomeu, DC; Nilsson, D; Aggarwal, G; Tran, AN; Ghedin, E; Worthey, EA; Delcher, AL; Blandin, G; Westenberger, SJ; Caler, E; Cerqueira, GC; Branche, C; Haas, B; Anupama, A; Arner, E; Aslund, L; Attipoe, P; Bontempi, E; Bringaud, F; Burton, P; Cadag, E; Campbell, DA; Carrington, M; Crabtree, J; Darban, H; da Silveira, JF; de Jong, P; Edwards, K; Englund, PT; Fazelina, G; Feldblyum, T; Ferella, M; Frasch, AC; Gull, K; Horn, D; Hou, LH; Huang, YT; Kindlund, E; Ktingbeil, M; Kluge, S; Koo, H; Lacerda, D; Levin, MJ; Lorenzi, H; Louie, T; Machado, CR; McCulloch, R; McKenna, A; Mizuno, Y; Mottram, JC; Nelson, S; Ochaya, S; Osoegawa, K; Pai, G; Parsons, M; Pentony, M; Pettersson, U; Pop, M; Ramirez, JL; Rinta, J; Robertson, L; Salzberg, SL; Sanchez, DO; Seyler, A; Sharma, R; Shetty, J; Simpson, AJ; Sisk, E; Tammi, MT; Tarteton, R; Teixeira, S; Van Aken, S; Vogt, C; Ward, PN; Wickstead, B; Wortman, J; White, O; Fraser, CM; Stuart, KD; Andersson, B

    2005-01-01

    Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large, fa

  18. The effect of the diterpene 5-epi-icetexone on the cell cycle of Trypanosoma cruzi.

    NARCIS (Netherlands)

    Lozano, E.; Barrera, P.; Tonn, C.; Nieto, M.; Sartor, T.; Sosa, M.A.

    2012-01-01

    Numerous natural compounds have been used against Trypanosoma cruzi, the causative agent of Chagas' disease. Here, we studied the effect of the diterpene 5-epi-icetexone on growth and morphology of parasites synchronized with hydroxyurea, at different periods of time after removal of the nucleotide.

  19. Importation of Hybrid Human-Associated Trypanosoma cruzi Strains of Southern South American Origin, Colombia

    OpenAIRE

    2016-01-01

    We report the characterization of Trypanosoma cruzi of southern South American origin among humans, domestic vectors, and peridomestic hosts in Colombia using high-resolution nuclear and mitochondrial genotyping. Expanding our understanding of the geographic range of lineage TcVI, which is associated with severe Chagas disease, will help clarify risk of human infection for improved disease control.

  20. Galactonolactone oxidoreductase from Trypanosoma cruzi employs a FAD cofactor for the synthesis of vitamin C.

    NARCIS (Netherlands)

    Kudryashova, E.V.; Leferink, N.G.H.; Slot, I.G.M.; Berkel, van W.J.H.

    2011-01-01

    Trypanosoma cruzi, the aetiological agent of Chagas' disease, is unable to salvage vitamin C (l-ascorbate) from its environment and relies on de novo synthesis for its survival. Because humans lack the capacity to synthesize ascorbate, the trypanosomal enzymes involved in ascorbate biosynthesis are

  1. Maxi-circles and mini-circles in kinetoplast DNA from Trypanosoma cruzi.

    NARCIS (Netherlands)

    W. Leon; A.C.C. Frasch; J.H.J. Hoeijmakers (Jan); F. Fase-Fowler; P. Borst (Piet); F. Brunel; J. Davison

    1980-01-01

    textabstractMaxi-circles are a minor component of kinetoplast DNAs from all trypanosomatids studied, but they have not previously been found in Trypanosoma cruzi; We have spread intact kinetoplast DNA from the epimastigotes of strain Y in protein monolayers and analysed the mini-circle networks by e

  2. Cell surface proteome analysis of human-hosted Trypanosoma cruzi life stages

    DEFF Research Database (Denmark)

    Queiroz, Rayner M L; Charneau, Sébastien; Bastos, Izabela M D;

    2014-01-01

    Chagas' disease is a neglected infectious illness, caused by the protozoan Trypanosoma cruzi. It remains a challenging health issue in Latin America, where it is endemic, and so far there is no immunoprophylatic vaccine or satisfactory chemotherapic treatment for its chronic stage. The present work...

  3. Kinetic properties and inhibition of Trypanosoma cruzi 3-hydroxy-3-methylglutaryl CoA reductase

    DEFF Research Database (Denmark)

    Hurtado-Guerrrero, Ramón; Pena Diaz, Javier; Montalvetti, Andrea;

    2002-01-01

    A detailed kinetic analysis of the recombinant soluble enzyme 3-hydroxy-3-methylglutaryl CoA reductase (HMGR) from Trypanosoma cruzi has been performed. The enzyme catalyzes the normal anabolic reaction and the reductant is NADPH. It also catalyzes the oxidation of mevalonate but at a lower propo...

  4. Aspects of resistance to experimental infection with Trypanosoma cruzi; Aspectos da resistencia a infecao experimental com Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Viviane Liotti

    2010-07-01

    Chagas disease, a zoonosis caused by the protozoan Trypanosoma cruzi, has a wide distribution in Latin America and extends from the southern part of the United States to Argentina. A number of 10 million of infected people is estimated and another 25 million exposed to the risk. Although discovered over a century, Chagas disease is still a serious infection that causes great socioeconomic impact, with no effective treatment at the chronic phase and in which, a lack of scientific knowledge can be observed. The main goal of this work was that obtaining and using consomic strain of mice, the resistance could be investigated. Consomic strains were produced by programmed mating, in which the animals were monitored with DNA polymorphic markers, and one of his chromosomes was replaced by his homologue from another strain. As parental, were used, the inbred strains C57BL/6/J Unib with resistant phenotype (donor) and as receiver, the A/JUnib strain, that has a susceptible phenotype. These models were used to produce five consomic strains: for the chromosomes 7 (CSs7), 11 (CSs11), 14 (CSs14), 17 (CSs17) and 19 (CSs19), described by Passos et al. (2003) as important in controlling infection caused by the Y strain of T. cruzi. In experimental testing, the consomics were inoculated intraperitoneally at doses of 10{sup 1}, 10{sup 2}, 10{sup 3} and 10{sup 4} using as control, animals from both parental lines. In all consomics, resistance was higher than that observed in the susceptible parental. In a second protocol, the consomics were mated with scheduled associations and the progenies were challenged with inocula employing increasing doses of trypomastigotes. The resistance observed in this group was also higher than that observed in the parental with susceptible phenotype. The observed results demonstrate that the use of the consomic strains that were produced order to assess the contribution of each chromosome in the resistance, as well as the effects of association between

  5. Trypanosoma cruzi: blood parasitism kinetics and their correlation with heart parasitism intensity during long-term infection of Beagle dogs

    Directory of Open Access Journals (Sweden)

    Vanja M Veloso

    2008-09-01

    Full Text Available The goals of the present study were to evaluate the kinetics of blood parasitism by examination of fresh blood, blood culture (BC and PCR assays and their correlation with heart parasitism during two years of infection in Beagle dogs inoculated with the Be-78, Y and ABC Trypanosoma cruzi strains. Our results showed that the parasite or its kDNA is easily detected during the acute phase in all infected animals. On the other hand, a reduced number of positive tests were verified during the chronic phase of the infection. The frequency of positive tests was correlated with T. cruzi strain. The percentage of positive BC and blood PCR performed in samples from animals inoculated with Be-78 and ABC strains were similar and significantly larger in relation to animals infected with the Y strain.Comparison of the positivity of PCR tests performed using blood and heart tissue samples obtained two years after infection showed two different patterns associated with the inoculated T. cruzi strain: (1 high PCR positivity for both blood and tissue was observed in animals infected with Be-78 or ABC strains; (2 lower and higher PCR positivity for the blood and tissue, respectively, was detected in animals infected with Y strains. These data suggest that the sensitivity of BC and blood PCR was T. cruzi strain dependent and, in contrast, the heart tissue PCR revealed higher sensitivity regardless of the parasite stock.

  6. The population structure of Trypanosoma cruzi: expanded analysis of 54 strains using eight polymorphic CA-repeat microsatellites

    Directory of Open Access Journals (Sweden)

    Riva P Oliveira

    1999-09-01

    Full Text Available Recently we cloned and sequenced the first eight Trypanosoma cruzi polymorphic microsatellite loci and studied 31 clones and strains to obtain valuable information about the population structure of the parasite. We have now studied 23 further strains, increasing from 11 to 31 the number of strains obtained from patients with chronic Chagas disease. This expanded set of 54 strains and clones analyzed with the eight microsatellites markers confirmed the previously observed diploidy, clonal population organization and very high polymorphism of T. cruzi. Moreover, this new study disclosed two new features of the population genetic structure of T. cruzi. The first was the discovery that, similarly to what we had previously shown for strains isolated from insect vectors, mammals and humans with acute disease, isolates from patients in the chronic phase of Chagas disease could also be multiclonal, albeit at a reduced proportion. Second, when we used parsimony to display the genetic relationship among the clonal lineages in an unrooted Wagner network we observed, like before, a good correlation of the tree topography with the classification in three clusters on the basis of single locus analysis of the ribosomal RNA genes. However, a significant new finding was that now the strains belonging to cluster 2 split in two distant sub-clusters. This observation suggests that the evolutionary history of T. cruzi may be more complex than we previously thought.

  7. The isolation and identification of Trypanosoma cruzi from raccoons in Maryland

    Science.gov (United States)

    Walton, B.C.; Bauman, P.M.; Diamond, L.S.; Herman, C.M.

    1958-01-01

    Five raccoons trapped at Patuxent Research Refuge, Laurel, Maryland, were found to have trypanosomes in the blood which were morphologically indistinguishable from Trypanosoma cruzi on stained smears. The organism grew well in culture. It developed and reproduced in Triatoma protracta, T. infestans, T. phyllosoma, and Rhodnius prolixus. Experimental infections were produced in raccoons, opossums, mice, rats, and monkeys by inoculation of blood, culture, and triatome forms. Typical leishmaniform bodies were found in tissue sections of cardiac muscle fibers from naturally and experimentally infected animals. Cross agglutinations carried out with Iiving cultural forms and rabbit antisera demonstrated a close antigenic relationship between the raccoon trypanosome and T. cruzi (Brazil strain). On the basis of (1) morphology, (2) presence of leishmaniform tissue stages, (3) development in triatomes, (4) infectivity to a variety of mammals, (5) culture characteristics, and (6) cross reactions in serological tests, this parasite is considered conspecific with Trypanosoma cruzi (Chagas, 1909), the causative agent of American human trypanosomiasis.

  8. The Chemokines CXCL9 and CXCL10 Promote a Protective Immune Response but Do Not Contribute to Cardiac Inflammation following Infection with Trypanosoma cruzi

    OpenAIRE

    2006-01-01

    The expression of chemokines within the heart during experimental infection of susceptible mice with the Colombiana strain of Trypanosoma cruzi was characterized in an attempt to determine a functional role for these molecules in both host defense and disease. Analysis of chemokine transcripts revealed that CXC chemokine ligand 9 (CXCL9) and CXCL10, as well as CC chemokine ligand 2 (CCL2) and CCL5, were prominently expressed during acute disease, whereas transcripts for CXCL9, CXCL10, and CCL...

  9. A soluble 3-hydroxy-3-methylglutaryl-CoA reductase in the protozoan Trypanosoma cruzi

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Montalvetti, A; Camacho, A;

    1997-01-01

    We report the isolation and characterization of a genomic clone containing the open reading frame sequence for 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase from Trypanosoma cruzi, the causative agent of Chagas' disease. The protozoan gene encoded for a smaller polypeptide than the rest...... sensitive to proteolytic inactivation. Furthermore the enzyme can be efficiently overexpressed in a highly active form by using the expression vector pET-11c. Thus Trypanosoma cruzi HMG-CoA reductase is unique in the sense that it totally lacks the membrane-spanning sequences present in all eukaryotic HMG...... cellular distribution of enzymic activity was investigated after differential centrifugation of Trypanosoma cell extracts. Reductase activity was primarily associated with the cellular soluble fraction because 95% of the total cellular activity was recovered in the supernatant and was particularly...

  10. Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera Trypanosoma cruzi: identificação de antígenos específicos de epimastigotas reconhecidos por soros humanos imunes

    OpenAIRE

    1989-01-01

    Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-re...

  11. Trypanosoma cruzi contains a single detectable uracil-DNA glycosylase and repairs uracil exclusively via short patch base excision repair

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Akbari, Mansour; Sundheim, Ottar;

    2004-01-01

    Enzymes involved in genomic maintenance of human parasites are attractive targets for parasite-specific drugs. The parasitic protozoan Trypanosoma cruzi contains at least two enzymes involved in the protection against potentially mutagenic uracil, a deoxyuridine triphosphate nucleotidohydrolase (...

  12. Regulation and use of the extracellular matrix by Trypanosoma cruzi during early infection

    Directory of Open Access Journals (Sweden)

    Pius N. Nde

    2012-11-01

    Full Text Available Chagas disease, which was once thought to be confined to endemic regions of Latin America, has now gone global becoming a new worldwide challenge. For more than a century since its discovery, it has remained neglected with no effective drugs or vaccines. The mechanisms by which Trypanosoma cruzi regulates and uses the extracellular matrix to invade cells and cause disease are just beginning to be understood. Here we critically review and discuss the regulation of the extracellular matrix (ECM interactome by T. cruzi, the use of the ECM by T. cruzi and analyze the molecular ECM/T. cruzi interphase during the early process of infection. It has been shown that invasive trypomastigote forms of T. cruzi use and modulate components of the ECM during the initial process of infection. Infective trypomastigotes up-regulate the expression of laminin γ-1 (LAMC1 and thrombospondin (THBS1 to facilitate the recruitment of trypomastigotes to enhance cellular infection. Silencing the expression of LAMC1 and THBS1 by stable RNAi dramatically reduces trypanosome infection. T. cruzi gp83, a ligand that mediates the attachment of trypanosomes to cells to initiate infection, up-regulates LAMC1 expression to enhance cellular infection. Infective trypomastigotes use Tc85 to interact with laminin, p45 mucin to interact with LAMC1 through galectin-3 (LGALS3, a human lectin, and calreticulin (TcCRT to interact with TSB1 to enhance cellular infection. Silencing the expression of LGALS3 also reduces cellular infection. Despite the role of the ECM in T. cruzi infection, almost nothing is known about the ECM interactome networks operating in the process of T. cruzi infection and its ligands. Here, we present the first elucidation of the human ECM interactome network regulated by T. cruzi and its gp83 ligand that facilitates cellular infection. The elucidation of the human ECM interactome regulated by T. cruzi and the dissection of the molecular ECM/T. cruzi interphase using

  13. Interactions Between Trypanosoma cruzi the Chagas Disease Parasite and Naturally Infected Wild Mepraia Vectors of Chile.

    Science.gov (United States)

    Campos-Soto, Ricardo; Ortiz, Sylvia; Cordova, Ivan; Bruneau, Nicole; Botto-Mahan, Carezza; Solari, Aldo

    2016-03-01

    Chagas disease, which ranks among the world's most neglected diseases, is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi. Mepraia species are the wild vectors of this parasite in Chile. Host-parasite interactions can occur at several levels, such as co-speciation and ecological host fitting, among others. Thus, we are exploring the interactions between T. cruzi circulating in naturally infected Mepraia species in all areas endemic of Chile. We evaluated T. cruzi infection rates of 27 different haplotypes of the wild Mepraia species and identified their parasite genotypes using minicircle PCR amplification and hybridization tests with genotype-specific DNA probes. Infection rates were lower in northern Chile where Mepraia gajardoi circulates (10-35%); in central Chile, Mepraia spinolai is most abundant, and infection rates varied in space and time (0-55%). T. cruzi discrete typing units (DTUs) TcI, TcII, TcV, and Tc VI were detected. Mixed infections with two or more DTUs are frequently found in highly infected insects. T. cruzi DTUs have distinct, but not exclusive, ecological and epidemiological associations with their hosts. T. cruzi infection rates of M. spinolai were higher than in M. gajardoi, but the presence of mixed infection with more than one T. cruzi DTU was the same. The same T. cruzi DTUs (TcI, TcII, TcV, and TcVI) were found circulating in both vector species, even though TcI was not equally distributed. These results suggest that T. cruzi DTUs are not associated with any of the two genetically related vector species nor with the geographic area. The T. cruzi vectors interactions are discussed in terms of old and recent events. By exploring T. cruzi DTUs present in Mepraia haplotypes and species from northern to central Chile, we open the analysis on these invertebrate host-parasite interactions.

  14. Transcriptome Remodeling in Trypanosoma cruzi and Human Cells during Intracellular Infection.

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2016-04-01

    Full Text Available Intracellular colonization and persistent infection by the kinetoplastid protozoan parasite, Trypanosoma cruzi, underlie the pathogenesis of human Chagas disease. To obtain global insights into the T. cruzi infective process, transcriptome dynamics were simultaneously captured in the parasite and host cells in an infection time course of human fibroblasts. Extensive remodeling of the T. cruzi transcriptome was observed during the early establishment of intracellular infection, coincident with a major developmental transition in the parasite. Contrasting this early response, few additional changes in steady state mRNA levels were detected once mature T. cruzi amastigotes were formed. Our findings suggest that transcriptome remodeling is required to establish a modified template to guide developmental transitions in the parasite, whereas homeostatic functions are regulated independently of transcriptomic changes, similar to that reported in related trypanosomatids. Despite complex mechanisms for regulation of phenotypic expression in T. cruzi, transcriptomic signatures derived from distinct developmental stages mirror known or projected characteristics of T. cruzi biology. Focusing on energy metabolism, we were able to validate predictions forecast in the mRNA expression profiles. We demonstrate measurable differences in the bioenergetic properties of the different mammalian-infective stages of T. cruzi and present additional findings that underscore the importance of mitochondrial electron transport in T. cruzi amastigote growth and survival. Consequences of T. cruzi colonization for the host include dynamic expression of immune response genes and cell cycle regulators with upregulation of host cholesterol and lipid synthesis pathways, which may serve to fuel intracellular T. cruzi growth. Thus, in addition to the biological inferences gained from gene ontology and functional enrichment analysis of differentially expressed genes in parasite and

  15. Testing the efficacy of a multi-component DNA-prime/DNA-boost vaccine against Trypanosoma cruzi infection in dogs.

    Directory of Open Access Journals (Sweden)

    José E Aparicio-Burgos

    Full Text Available BACKGROUND: Trypanosoma cruzi, the etiologic agent of Chagas Disease, is a major vector borne health problem in Latin America and an emerging infectious disease in the United States. METHODS: We tested the efficacy of a multi-component DNA-prime/DNA-boost vaccine (TcVac1 against experimental T. cruzi infection in a canine model. Dogs were immunized with antigen-encoding plasmids and cytokine adjuvants, and two weeks after the last immunization, challenged with T. cruzi trypomastigotes. We measured antibody responses by ELISA and haemagglutination assay, parasitemia and infectivity to triatomines by xenodiagnosis, and performed electrocardiography and histology to assess myocardial damage and tissue pathology. RESULTS: Vaccination with TcVac1 elicited parasite-and antigen-specific IgM and IgG (IgG2>IgG1 responses. Upon challenge infection, TcVac1-vaccinated dogs, as compared to non-vaccinated controls dogs, responded to T. cruzi with a rapid expansion of antibody response, moderately enhanced CD8(+ T cell proliferation and IFN-γ production, and suppression of phagocytes' activity evidenced by decreased myeloperoxidase and nitrite levels. Subsequently, vaccinated dogs controlled the acute parasitemia by day 37 pi (44 dpi in non-vaccinated dogs, and exhibited a moderate decline in infectivity to triatomines. TcVac1-immunized dogs did not control the myocardial parasite burden and electrocardiographic and histopatholgic cardiac alterations that are the hallmarks of acute Chagas disease. During the chronic stage, TcVac1-vaccinated dogs exhibited a moderate decline in cardiac alterations determined by EKG and anatomo-/histo-pathological analysis while chronically-infected/non-vaccinated dogs continued to exhibit severe EKG alterations. CONCLUSIONS: Overall, these results demonstrated that TcVac1 provided a partial resistance to T. cruzi infection and Chagas disease, and provide an impetus to improve the vaccination strategy against Chagas disease.

  16. Mexican Trypanosoma cruzi isolates: in vitro susceptibility of epimastigotes to anti-trypanosoma cruzi drugs and metacyclic forms to complement-mediated lysis.

    Science.gov (United States)

    León-Pérez, Floribeth; Gómez-Garcia, Lorena; Alejandre-Aguilar, R; López, R; Monteón, V M

    2007-01-01

    Trypanosoma cruzi has a clonal organization with an ample array of genetic and phenotypic features and probably anaploid constitution. Consequently, the biological behavior, biochemistry, and molecular attributes may be distinctive for each parasite strain in different geographical regions. As far as we know, there is no published information on the susceptibility of Mexican T. cruzi stocks to anti-T. cruzi drugs such as benznidazole and gentian violet, or on its resistance to complement-mediated lysis. We studied 10 Mexican T. cruzi isolates from different geographical areas, such as the pacific coast (Oaxaca, Guerrero, and Nayarit States), central part of Mexico (Guanajuato State), Gulf of Mexico (Veracruz State), and the Yucatan Peninsula (Campeche State). We searched for the natural resistance to drugs in in vitro assay against the 10 Mexican isolates using epimastigote forms and the complement-mediated lysis using metacyclic trypomastigotes insect-derived in three of them (one for each geographic region). In general, we observed high resistance to benznidazole in all the Mexican isolates tested, but in the complement-mediated lysis test, they showed moderate to high susceptibility. Although it is necessary to expand this study by using trypomastigotes and the intracellular form to verify its biological role, we suggest that Mexican T. cruzi parasites may have a variable susceptibility to antibody-mediated lysis and high resistance to benznidazole.

  17. Regional variation in the correlation of antibody and T-cell responses to Trypanosoma cruzi.

    Science.gov (United States)

    Martin, Diana L; Marks, Morgan; Galdos-Cardenas, Gerson; Gilman, Robert H; Goodhew, Brook; Ferrufino, Lisbeth; Halperin, Anthony; Sanchez, Gerardo; Verastegui, Manuela; Escalante, Patricia; Naquira, Cesar; Levy, Michael Z; Bern, Caryn

    2014-06-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major cause of morbidity and mortality in Central and South America. Geographic variations in the sensitivity of serologic diagnostic assays to T. cruzi may reflect differences in T. cruzi exposure. We measured parasite-specific T-cell responses among seropositive individuals in two populations from South America with widely varying antibody titers against T. cruzi. Antibody titers among seropositive individuals were significantly lower in Arequipa, Peru compared with Santa Cruz, Bolivia. Similarly, the proportion of seropositive individuals with positive T-cell responses was lower in Peru than Bolivia, resulting in overall lower frequencies of interferon-γ (IFNγ)-secreting cells from Peruvian samples. However, the magnitude of the IFNγ response was similar among the IFNγ responders in both locations. These data indicate that immunological discrepancies based on geographic region are reflected in T-cell responses as well as antibody responses.

  18. The Role of Heme and Reactive Oxygen Species in Proliferation and Survival of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Marcia Cristina Paes

    2011-01-01

    Full Text Available Trypanosoma cruzi, the protozoan responsible for Chagas disease, has a complex life cycle comprehending two distinct hosts and a series of morphological and functional transformations. Hemoglobin degradation inside the insect vector releases high amounts of heme, and this molecule is known to exert a number of physiological functions. Moreover, the absence of its complete biosynthetic pathway in T. cruzi indicates heme as an essential molecule for this trypanosomatid survival. Within the hosts, T. cruzi has to cope with sudden environmental changes especially in the redox status and heme is able to increase the basal production of reactive oxygen species (ROS which can be also produced as byproducts of the parasite aerobic metabolism. In this regard, ROS sensing is likely to be an important mechanism for the adaptation and interaction of these organisms with their hosts. In this paper we discuss the main features of heme and ROS susceptibility in T. cruzi biology.

  19. Trypanosoma cruzi-associated cerebrovascular disease: a case-control study in Eastern Colombia.

    Science.gov (United States)

    Leon-Sarmiento, Fidias E; Mendoza, Eder; Torres-Hillera, Martin; Pinto, Neyla; Prada, Janette; Silva, Clara A; Vera, Silvia J; Castillo, Erwin; Valderrama, Vladimir; Prada, Didier G; Bayona-Prieto, Jaime; Garcia, Ingrid

    2004-01-15

    Trypanosoma cruzi infection is a common cause of cardiopathy in South America leading it eventually to an established stroke; however, the association between T. cruzi infection itself and cerebrovascular disease is still unknown. We did a case-control study at Eastern Colombia and found that T. cruzi infection was more frequent and statistically significant in stroke cases (24.4%) than controls (1.9%), (Chi square: 21.72; OR: 16.13; 95% confidence interval (CI): 3.64-71.4; p<0.00001). After removing the seropositive patients with cardiological abnormalities, the significance still remained by multivariate analysis (p<0.05). This is the first case-control study that demonstrated a significant link between this infection and symptomatic cerebrovascular disease, mainly ischemic, regardless of cardiac abnormalities. Therefore, we recommend that patients with stroke must be screened for T. cruzi infection if they currently live or have lived in places where this parasite is considered endemic.

  20. Heterologous expression of a plant arginine decarboxylase gene in Trypanosoma cruzi.

    Science.gov (United States)

    Carrillo, Carolina; Serra, María P; Pereira, Claudio A; Huber, Alejandra; González, Nélida S; Algranati, Israel D

    2004-11-01

    Wild-type Trypanosoma cruzi epimastigotes lack arginine decarboxylase (ADC) enzymatic activity. However, the transformation of these parasites with a recombinant plasmid containing the oat ADC cDNA coding region gave rise to the transient heterologous expression of the enzyme, suggesting the absence of endogenous mechanisms that could inhibit the expression of a hypothetical own ADC gene or the assay used to measure its enzymatic activity. The foreign ADC enzyme expressed in the transgenic T. cruzi was characterized by identification of the products, the stoichiometry of the catalysed reaction, the specific inhibition by alpha-difluoromethylarginine (DFMA) and the study of its metabolic turnover. The half-life of the heterologous ADC activity in T. cruzi was about 150 min. Bioinformatics studies and polymerase chain reaction (PCR) analyses seem to indicate the absence of ADC-like DNA sequences in the wild-type T. cruzi genome.

  1. Genetic diversity of Colombian sylvatic Trypanosoma cruzi isolates revealed by the ribosomal DNA

    Directory of Open Access Journals (Sweden)

    Cuervo Patricia

    2002-01-01

    Full Text Available American trypanosomiasis is a common zoonosis in Colombia and Trypanosoma cruzi presents a wide distribution throughout the country. Although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using Colombian strains. In this study, we amplified the non-transcribed spacer of the mini-gene by PCR, typing the isolates as T. cruzi I, T. cruzi zymodeme 3 or T. rangeli. In addition, the internal transcribed spacers of the ribosomal gene concomitant with the 5.8S rDNA were amplified and submitted to restriction fragment polymorphism analysis. The profiles were analyzed by a numerical methodology generating a phenetic dendrogram that shows heterogeneity among the T. cruzi isolates. This finding suggests a relationship between the complexity of the sylvatic transmission cycle in Colombia and the diversity of the sylvan parasites.

  2. CC-chemokine receptors: a potential therapeutic target for Trypanosoma cruzi-elicited myocarditis.

    Science.gov (United States)

    Marino, A P M P; Silva, A A; Santos, P V A; Pinto, L M O; Gazinelli, R T; Teixeira, M M; Lannes-Vieira, J

    2005-03-01

    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.

  3. CC-chemokine receptors: a potential therapeutic target for Trypanosoma cruzi-elicited myocarditis

    Directory of Open Access Journals (Sweden)

    APMP Marino

    2005-03-01

    Full Text Available 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.

  4. Mechanism of Trypanosoma cruzi Placenta Invasion and Infection: The Use of Human Chorionic Villi Explants

    Directory of Open Access Journals (Sweden)

    Ricardo E. Fretes

    2012-01-01

    Full Text Available Congenital Chagas disease, a neglected tropical disease, endemic in Latin America, is associated with premature labor and miscarriage. During vertical transmission the parasite Trypanosoma cruzi (T. cruzi crosses the placental barrier. However, the exact mechanism of the placental infection remains unclear. We review the congenital transmission of T. cruzi, particularly the role of possible local placental factors that contribute to the vertical transmission of the parasite. Additionally, we analyze the different methods available for studying the congenital transmission of the parasite. In that context, the ex vivo infection with T. cruzi trypomastigotes of human placental chorionic villi constitutes an excellent tool for studying parasite infection strategies as well as possible local antiparasitic mechanisms.

  5. Lipid Bodies: Inflammatory Organelles Implicated in Host-Trypanosoma cruzi Interplay during Innate Immune Responses

    Directory of Open Access Journals (Sweden)

    Heloisa D'Avila

    2012-01-01

    Full Text Available The flagellated protozoa Trypanosoma cruzi is the causal agent of Chagas' disease, a significant public health issue and still a major cause of morbidity and mortality in Latin America. Acute Chagas' disease elicits a strong inflammatory response. In order to control the parasite multiplication, cells of the monocytic lineage are highly mobilized. Monocyte differentiation leads to the formation of phagocytosing macrophages, which are strongly activated and direct host defense. A distinguishing feature of Chagas' disease-triggered macrophages is the presence of increased numbers of distinct cytoplasmic organelles termed lipid bodies or lipid droplets. These organelles are actively formed in response to the parasite and are sites for synthesis and storage of inflammatory mediators. This review covers current knowledge on lipid bodies elicited by the acute Chagas' disease within inflammatory macrophages and discusses the role of these organelles in inflammation. The increased knowledge of lipid bodies in pathogenic mechanisms of infections may not only contribute to the understanding of pathogen-host interactions but may also identify new targets for intervention.

  6. Insight into the exoproteome of the tissue-derived trypomastigote form of trypanosoma cruzi

    DEFF Research Database (Denmark)

    Queiroz, Rayner M L; Ricart, Carlos A O; Machado, Mara O;

    2016-01-01

    The protozoan parasite Trypanosoma cruzi causes Chagas disease, one of the major neglected infectious diseases. It has the potential to infect any nucleated mammalian cell. The secreted/excreted protein repertoire released by T. cruzi trypomastigotes is crucial in host-pathogen interactions...

  7. Inefficient complement system clearance of Trypanosoma cruzi metacyclic trypomastigotes enables resistant strains to invade eukaryotic cells.

    Directory of Open Access Journals (Sweden)

    Igor Cestari

    Full Text Available The complement system is the main arm of the vertebrate innate immune system against pathogen infection. For the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, subverting the complement system and invading the host cells is crucial to succeed in infection. However, little attention has focused on whether the complement system can effectively control T. cruzi infection. To address this question, we decided to analyse: 1 which complement pathways are activated by T. cruzi using strains isolated from different hosts, 2 the capacity of these strains to resist the complement-mediated killing at nearly physiological conditions, and 3 whether the complement system could limit or control T. cruzi invasion of eukaryotic cells. The complement activating molecules C1q, C3, mannan-binding lectin and ficolins bound to all strains analysed; however, C3b and C4b deposition assays revealed that T. cruzi activates mainly the lectin and alternative complement pathways in non-immune human serum. Strikingly, we detected that metacyclic trypomastigotes of some T. cruzi strains were highly susceptible to complement-mediated killing in non-immune serum, while other strains were resistant. Furthermore, the rate of parasite invasion in eukaryotic cells was decreased by non-immune serum. Altogether, these results establish that the complement system recognizes T. cruzi metacyclic trypomastigotes, resulting in killing of susceptible strains. The complement system, therefore, acts as a physiological barrier which resistant strains have to evade for successful host infection.

  8. Immunocytochemical identification of leishmania and Trypanosoma cruzi amastigotes in situ with homologous and heterologous polyclonal antibodies

    Directory of Open Access Journals (Sweden)

    A.J.A. Barbosa

    1991-03-01

    Full Text Available The unlabelled antibody peroxidase-antiperoxidase method was used to study the immunocytochemical properties of Leishmania and Trypanosoma cruzi amastigotes in situ after tissues had been submitted to different fixation procedures. Antisera were obtained from rabbits chronically infected with different strains of T. cruzi or immunized with L. mexicana amazonensis and L. braziliensis guyanensis, and were applied on 5 µm thick sections. T. cruzi antigens were well stained by the three anti-T. cruzi sera and the two anti-heis.hmama.sera at optimum dilution between 1:1,000 and 1:2,000, regardless the parasite strain. Differently, the leishmanial antigens were revealed by Leishmania sera only at low dilutions (between 1:60 -1:160, whereas the anti-T. cruzi sera, at these low dilutions, gave rather weak stainings. Although there is no clear explanation for this immunocytochemical "reverse-monodirectional" cross-reactivity between Leishmania and T. cruzi, the present results show that polyclonal antibodies agains Leishmania species, when used for immunocytochemical detection of these parasites in situ, react more strongly with T. cruzi amastigotes than with the homologous amastigotes.

  9. Aspirin Modulates Innate Inflammatory Response and Inhibits the Entry of Trypanosoma cruzi in Mouse Peritoneal Macrophages

    Directory of Open Access Journals (Sweden)

    Aparecida Donizette Malvezi

    2014-01-01

    Full Text Available The intracellular protozoan parasite Trypanosoma cruzi causes Chagas disease, a serious disorder that affects millions of people in Latin America. Cell invasion by T. cruzi and its intracellular replication are essential to the parasite’s life cycle and for the development of Chagas disease. Here, we present evidence suggesting the involvement of the host’s cyclooxygenase (COX enzyme during T. cruzi invasion. Pharmacological antagonist for COX-1, aspirin (ASA, caused marked inhibition of T. cruzi infection when peritoneal macrophages were pretreated with ASA for 30 min at 37°C before inoculation. This inhibition was associated with increased production of IL-1β and nitric oxide (NO∙ by macrophages. The treatment of macrophages with either NOS inhibitors or prostaglandin E2 (PGE2 restored the invasive action of T. cruzi in macrophages previously treated with ASA. Lipoxin ALX-receptor antagonist Boc2 reversed the inhibitory effect of ASA on trypomastigote invasion. Our results indicate that PGE2, NO∙, and lipoxins are involved in the regulation of anti-T. cruzi activity by macrophages, providing a better understanding of the role of prostaglandins in innate inflammatory response to T. cruzi infection as well as adding a new perspective to specific immune interventions.

  10. Molecular epidemiology of domestic and sylvatic Trypanosoma cruzi infection in rural northwestern Argentina.

    Science.gov (United States)

    Cardinal, Marta V; Lauricella, Marta A; Ceballos, Leonardo A; Lanati, Leonardo; Marcet, Paula L; Levin, Mariano J; Kitron, Uriel; Gürtler, Ricardo E; Schijman, Alejandro G

    2008-11-01

    Genetic diversity of Trypanosoma cruzi populations and parasite transmission dynamics have been well documented throughout the Americas, but few studies have been conducted in the Gran Chaco ecoregion, one of the most highly endemic areas for Chagas disease, caused by T. cruzi. In this study, we assessed the distribution of T. cruzi lineages (identified by PCR strategies) in Triatoma infestans, domestic dogs, cats, humans and sylvatic mammals from two neighbouring rural areas with different histories of transmission and vector control in northern Argentina. Lineage II predominated amongst the 99 isolates characterised and lineage I amongst the six isolates obtained from sylvatic mammals. T. cruzi lineage IIe predominated in domestic habitats; it was found in 87% of 54 isolates from Tr. infestans, in 82% of 33 isolates from dogs, and in the four cats found infected. Domestic and sylvatic cycles overlapped in the study area in the late 1980s, when intense domestic transmission occurred, and still overlap marginally. The introduction of T. cruzi from sylvatic into domestic habitats is likely to occur very rarely in the current epidemiological context. The household distribution of T. cruzi lineages showed that Tr. infestans, dogs and cats from a given house compound shared the same parasite lineage in most cases. Based on molecular evidence, this result lends further support to the importance of dogs and cats as domestic reservoir hosts of T. cruzi. We believe that in Argentina, this is the first time that lineage IIc has been isolated from naturally infected domestic dogs and Tr. infestans.

  11. Is the anti-tumor property of Trypanosoma cruzi infection mediated by its Calreticulin?

    Directory of Open Access Journals (Sweden)

    Galia Andrea Ramírez-Toloza

    2016-07-01

    Full Text Available Eight to 10 million people in 21 endemic countries are infected with Trypanosoma cruzi. However, only 30% of those infected develop symptoms of Chagas’ disease, a chronic, neglected tropical disease worldwide. Similar to other pathogens, T. cruzi has evolved to resist the host immune response. Studies, performed 80 years ago in the Soviet Union, proposed that T. cruzi infects tumor cells with similar capacity to that displayed for target tissues such as cardiac, aortic or digestive. An antagonistic relationship between T. cruzi infection and cancer development was also proposed, but the molecular mechanisms involved have remained largely unknown. Probably, a variety of T. cruzi molecules is involved. This review focuses on how T. cruzi calreticulin (TcCRT, exteriorized from the endoplasmic reticulum, targets the first classical complement component C1 and negatively regulates the Classical Complement activation cascade, promoting parasite infectivity. We propose that this C1-dependent TcCRT-mediated virulence is critical to explain, at least an important part, of the parasite capacity to inhibit tumor development. We will discuss how TcCRT, by directly interacting with venous and arterial endothelial cells, inhibits angiogenesis and tumor growth. Thus, these TcCRT functions not only illustrate T. cruzi interactions with the host immune defensive strategies, but also illustrate a possible co-evolutionary adaptation to privilege a prolonged interaction with its host.

  12. Seroprevalence of Trypanosoma cruzi Among Eleven Potential Reservoir Species from Six States Across the Southern United States

    OpenAIRE

    2010-01-01

    Trypanosoma cruzi, the causative agent of Chagas' disease, is a substantial public health concern in Latin America. Although rare in humans and domestic animals in the United States, T. cruzi is commonly detected in some wildlife species, most commonly raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana). To increase our understanding of the reservoir host species range and geographic distribution, 11 species of mammals from six states spanning the known range of T. cruzi (Ar...

  13. Trypanosoma cruzi: expression of antigenic component 5 among 35 laboratory clones obtained from 18 different isozymic variants

    Directory of Open Access Journals (Sweden)

    Simone F. Breniere

    1987-04-01

    Full Text Available Two monoclonal antibodies anti-component 5 of Trypanosoma cruzi (I-35/115 and II-190/30 were tested in IFA and ELISA respectively against 35 T. cruzi laboratory clones. Among the 35 clones tested, 18 different isozyme patterns were detected. All clones were recognized by both monoclonal antibodies except one clone which did not react with II-190/30. These results support the universal expression of specific component 5 within the taxon T. cruzi.

  14. Genetic Immunization Elicits Antigen-Specific Protective Immune Responses and Decreases Disease Severity in Trypanosoma cruzi Infection

    OpenAIRE

    2002-01-01

    Immunity to Trypanosoma cruzi requires elicitation of humoral and cell-mediated immune responses to extracellular trypomastigotes and intracellular amastigotes. In this study, the effectiveness of the T. cruzi trans-sialidase family (ts) genes ASP-1, ASP-2, and TSA-1 as genetic vaccines was assessed. Immunization of mice with plasmids encoding ASP-1, ASP-2, or TSA-1 elicited poor antigen-specific cytotoxic-T-lymphocyte (CTL) activity and T. cruzi-specific antibody responses. Codelivery of int...

  15. Trans-sialidase inhibition assay detects Trypanosoma cruzi infection in different wild mammal species.

    Science.gov (United States)

    Sartor, Paula A; Ceballos, Leonardo A; Orozco, Marcela M; Cardinal, Marta V; Gürtler, Ricardo E; Leguizamón, María S

    2013-08-01

    The detection of Trypanosoma cruzi infection in mammals is crucial for understanding the eco-epidemiological role of the different species involved in parasite transmission cycles. Xenodiagnosis (XD) and hemoculture (HC) are routinely used to detect T. cruzi in wild mammals. Serological methods are much more limited because they require the use of specific antibodies to immunoglobulins of each mammalian species susceptible to T. cruzi. In this study we detected T. cruzi infection by trans-sialidase (TS) inhibition assay (TIA). TIA is based on the antibody neutralization of a recombinant TS that avoids the use of anti-immunoglobulins. TS activity is not detected in the co-endemic protozoan parasites Leishmania spp and T. rangeli. In the current study, serum samples from 158 individuals of nine wild mammalian species, previously tested by XD, were evaluated by TIA. They were collected from two endemic areas in northern Argentina. The overall TIA versus XD co-reactivity was 98.7% (156/158). All 18 samples from XD-positive mammals were TIA-positive (co-positivity, 100%) and co-negativity was 98.5% (138/140). Two XD-negative samples from a marsupial (Didelphis albiventris) and an edentate (Dasypus novemcinctus) were detected by TIA. TIA could be used as a novel tool for serological detection of Trypanosoma cruzi in a wide variety of sylvatic reservoir hosts.

  16. Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

    Science.gov (United States)

    Fabbro, Diana L; Danesi, Emmaria; Olivera, Veronica; Codebó, Maria Olenka; Denner, Susana; Heredia, Cecilia; Streiger, Mirtha; Sosa-Estani, Sergio

    2014-11-01

    With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment before pregnancy. Their children were studied to detect congenital infection. Among 354 "chronically infected mother-biological child" pairs, 132 were treated women and 222 were untreated women. Among the children born to untreated women, we detected 34 infected with T. cruzi (15.3%), whose only antecedent was maternal infection. Among the 132 children of previously treated women, no infection with T. cruzi was found (0.0%) (pChagas infection was effective in preventing the congenital transmission of Trypanosoma cruzi to their children; it had also a protective effect on the women's clinical evolution and deparasitation could be demonstrated in many treated women after over 10 years of follow up.

  17. [Trypanosoma cruzi in French Guinea: review of accumulated data since 1940].

    Science.gov (United States)

    Raccurt, C P

    1996-01-01

    Between 1939 and 1994, nine cases of Chagas disease have been reported in French Guiana: seven in the acute phase including two that were fatal and two in the chronic phase with cardiac sequellae. A tenth case of transient parasitemia was described but the patient's clinical status was not mentioned. Screening by xenodiagnosis revealed one subclinical infection. Heart disease is a highly specific manifestation of Trypanosoma cruzi infection, this being consistent with the known presence of zymodeme 1 in the sylvatic reservoir and reduviid vectors. The low incidence of positive serology (0.7% in a group of 740 subjects in whom serum samples were tested by indirect immunofluorescence) indicates that the disease is not currently becoming endemic. The main animal reservoirs for infection are small land marsupials (Didelphis marsupialis being the most frequently infected) and edentata especially armadillos (Dasypus novemcinctus). A peridomestic cycle, implicating D. marsupialis and Philander oppossum, plant-eating marsupials, with Rhodnius pictipes as the vector is highly active. Further study is necessary to ascertain another mechanism involving R. prolixus as a vector in dwellings in urban areas. Outbreaks require careful epidemiologic surveillance. French Guiana should no longer be considered as an enzootic area but as an area of risk for sporadic Chagas disease with epidemiologic features similar to those of the disease in dense Amazon forest areas. Appropriate measures must be taken to screen and promptly manage Chagas disease in the population. Special care is needed for concurrent HIV-T. cruzi infection due to the severity of this combination. Preventive measures are also needed to preclude transfusional infection.

  18. Immunoregulatory actions of melatonin and zinc during chronic Trypanosoma cruzi infection.

    Science.gov (United States)

    Brazão, Vânia; Santello, Fabricia Helena; Filipin, Marina Del Vecchio; Azevedo, Angela Palamin; Toldo, Míriam Paula Alonso; de Morais, Fabiana Rossetto; do Prado, José Clóvis

    2015-03-01

    After one century of the discovery of Chagas' disease and the development of an efficient drug with amplitude of actions both in the acute and chronic phase is still a challenge. Alternative immune modulators have been exhaustively used. For that purpose, melatonin and zinc were administered during chronic Trypanosoma cruzi-infected Wistar rats and several endpoints were assessed. Melatonin has a remarkable functional versatility, being associated with important antioxidant, anti-inflammatory, and anti-apoptotic effects. The cross-talk between zinc and the immune system includes its ability to influence the production and signaling of numerous inflammatory cytokines in a variety of cell types. Our study showed that zinc triggered a decrease in the generation of IFN-γ for TCD4(+) cells. Reduced percentage of CD4(+) T cells producing TNF-α was observed in control melatonin or zinc-and-melatonin-treated animals as compared with untreated rats. On the other hand, a significant increase in the percentage of IL-4 from CD4(+) and CD8(+) T lymphocytes producers was observed 60 days after infection, for all zinc-treated animals, whether infected or not. Melatonin and zinc therapies increased the percentages of CD4(+) and CD8(+) T lymphocytes IL-10 producers. CD4(+) CD25(high) Foxp3(+) T cells were also elevated in zinc- and melatonin-treated animals. The modulation of the immune system influenced by these molecules affected cytokine production and the inflammatory process during chronic T. cruzi infection. Elucidation of the interplay between cytokine balance and the pathogenesis of Chagas' disease is extremely relevant not only for the comprehension of the immune mechanisms and clinical forms but, most importantly, also for the implementation of efficient and adequate therapies.

  19. Comparative study of the biological properties of Trypanosoma cruzi I genotypes in a murine experimental model.

    Science.gov (United States)

    Cruz, Lissa; Vivas, Angie; Montilla, Marleny; Hernández, Carolina; Flórez, Carolina; Parra, Edgar; Ramírez, Juan David

    2015-01-01

    Chagas disease is an endemic zoonosis in Latin America and caused by the parasite Trypanosoma cruzi. This kinetoplastid displays remarkable genetic variability, allowing its classification into six Discrete Typing Units (DTUs) from TcI to TcVI. T. cruzi I presents the broadest geographical distribution in the continent and has been associated to severe forms of cardiomyopathies. Recently, a particular genotype associated to human infections has been reported and named as TcIDOM (previously named TcIa-b). This genotype shows to be clonal and adapted to the domestic cycle but so far no studies have determined the biological properties of domestic (TcIDOM) and sylvatic TcI strains (previously named TcIc-e). Hence, the aim of this study was to untangle the biological features of these genotypes in murine models. We infected ICR-CD1 mice with five TcI strains (two domestic, two sylvatic and one natural mixture) and determined the course of infection during 91 days (acute and chronic phase of the disease) in terms of parasitemia, tissue tropism, immune response (IgG titers) and tissue invasion by means of histopathology studies. Statistically significant differences were observed in terms of parasitemia curves and prepatent period between domestic (TcIDOM) and sylvatic strains. There were no differences in terms of IgG antibodies response across the mice infected with the five strains. Regarding the histopathology, our results indicate that domestic strains present higher parasitemias and low levels of histopathological damage. In contrast, sylvatic strains showed lower parasitemias and high levels of histopathological damage. These results highlight the sympatric and behavioral differences of domestic and sylvatic TcI strains; the clinical and epidemiological implications are herein discussed.

  20. Serological survey of Leishmania infantum and Trypanosoma cruzi in dogs from urban areas of Brazil and Colombia

    Science.gov (United States)

    Leishmania infantum and Trypanosoma cruzi are zoonotic parasites that are endemic throughout many parts of Latin America. Infected dogs play an important role in transmission of both parasites to humans. A serological survey of Leishmania and Trypanosoma infection was conducted on 365 dogs from São ...

  1. Trypanosoma cruzi extracellular amastigotes and host cell signaling: more pieces to the puzzle

    Directory of Open Access Journals (Sweden)

    Éden Ramalho Ferreira

    2012-11-01

    Full Text Available Among the different infective stages that Trypanosoma cruzi employs to invade cells, extracellular amastigotes have recently gained attention by our group. This is true primarily because these amastigotes are able to infect cultured cells and animals, establishing a sustainable infective cycle. Extracellular amastigotes are thus an excellent means of adaptation and survival for T. cruzi, whose different infective stages each utilize unique mechanisms for attachment and penetration. Here we discuss some features of host cell invasion by extracellular amastigotes and the associated host cell signaling events that occur as part of the process.

  2. Vaccination with Trypomastigote Surface Antigen 1-Encoding Plasmid DNA Confers Protection against Lethal Trypanosoma cruzi Infection

    OpenAIRE

    1998-01-01

    DNA vaccination was evaluated with the experimental murine model of Trypanosoma cruzi infection as a means to induce antiparasite protective immunity, and the trypomastigote surface antigen 1 (TSA-1), a target of anti-T. cruzi antibody and major histocompatibility complex (MHC) class I-restricted CD8+ cytotoxic T-lymphocyte (CTL) responses, was used as the model antigen. Following the intramuscular immunization of H-2b and H-2d mice with a plasmid DNA encoding an N-terminally truncated TSA-1 ...

  3. Clonagem e caracterização funcional do gene Rad51 de Trypanosoma cruzi

    OpenAIRE

    Carlos Gustavo Regis da Silva

    2002-01-01

    O Trypanosoma cruzi é um parasito pertencente à ordem Kinetoplastida e o agente causador da doença de Chagas. Nesse organismo, é observado um baixo grau de divergência entre alelos. Esse fenômeno é pouco comum em organismos de reprodução clonal como o T. cruzi e ocorre devido a rearranjos gênicos como o processo de recombinação. Esse processo também representa uma das vias de reparo de quebras na dupla fita de DNA. O produto do gene Rad51 é uma das principais proteínas envolvidas nesses proce...

  4. [New sites with Triatominae infected by Trypanosoma cruzi in the Mexican Republic].

    Science.gov (United States)

    Tay Zavala, J; Sánchez Vega, J T; Robert Guerrero, L; Alonso Guerrero, T; Romero-Cabello, R

    1996-01-01

    We report 29 new localities with Triatominae in the Republic of México; these Triatominae belong to 8 different species. Infection by Trypanosoma cruzi in the majority of these localities with high rates of positivity was found. Biological observations concerning the collected Triatominae are given. The necessity of continued work in relation to geographical distribution, ecology, frequency of infection by T. cruzy, and the role played by Triatominae of the Republic of México in the transmission of the infection to the man is stressed.

  5. AFAP-1L1-mediated actin filaments crosslinks hinder Trypanosoma cruzi cell invasion and intracellular multiplication.

    Science.gov (United States)

    de Araújo, Karine Canuto Loureiro; Teixeira, Thaise Lara; Machado, Fabrício Castro; da Silva, Aline Alves; Quintal, Amanda Pifano Neto; da Silva, Claudio Vieira

    2016-10-01

    Host actin cytoskeleton polymerization has been shown to play an important role during Trypanosoma cruzi internalization into mammalian cell. The structure and dynamics of the actin cytoskeleton in cells are regulated by a vast number of actin-binding proteins. Here we aimed to verify the impact of AFAP-1L1, during invasion and multiplication of T. cruzi. Knocking-down AFAP-1L1 increased parasite cell invasion and intracellular multiplication. Thus, we have shown that the integrity of the machinery formed by AFAP-1L1 in actin cytoskeleton polymerization is important to hinder parasite infection.

  6. Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts

    Directory of Open Access Journals (Sweden)

    Tecia Maria Ulisses Carvalho

    2013-01-01

    Full Text Available A significant number of scientific groups working on several countries have made efforts to better understand the process of invasion of several types of host cells by Trypanosoma cruzi, the etiologic agent of Chagas disease. In this mini-review we analyze the two mechanisms of invasion considered to be relevant: active penetration and endocytosis. The term active penetration is considered in view of its original description by Dvorak and co-workers. Taking into consideration all results obtained we conclude that endocytosis, with its many variations, is the only mechanism used by T. cruzi to invade host cells.

  7. DHEA and testosterone therapies in Trypanosoma cruzi-infected rats are associated with thymic changes.

    Science.gov (United States)

    Filipin, Marina Del Vecchio; Caetano, Leony Cristina; Brazão, Vânia; Santello, Fabricia Helena; Toldo, Míriam Paula Alonso; do Prado, José Clóvis

    2010-08-01

    The ability of the gonadal hormones to influence diverse immunological functions during the course of several infections has been extensively studied in the latest decades. Testosterone has a suppressive effect on immune response of vertebrates and increases susceptibility toward numerous parasitic diseases. Dehydroepiandrosterone is an abundant steroid hormone secreted by the human adrenal cortex and it is considered potent immune-activator. In this paper, it was examined the effects of DHEA and testosterone supplementation in the thymic atrophy in rats infected with Trypanosoma cruzi, by comparing blood parasitism, thymocyte proliferation, TNF-alpha and IL-12 levels. Our data point in the direction that DHEA treatment triggered enhanced thymocyte proliferation as compared to its infected counterparts and reduced production of TNF-alpha during the acute phase of infection. Oppositely, the lowest values for cells proliferation and IL-12 concentrations were reached in testosterone-supplied animals. The combined treatment testosterone and DHEA improves the effectiveness of the host's immune response, reducing blood parasites and the immunosuppressive effects of male androgens besides increasing IL-12 concentrations and decreasing TNF-alpha levels.

  8. Trypanosoma cruzi high infectivity in vitro is related to cardiac lesions during long-term infection in Beagledogs

    Directory of Open Access Journals (Sweden)

    Paulo MM Guedes

    2007-03-01

    Full Text Available Trypanosoma cruzi is a hemoflagelate parasite associated with heart dysfunctions causing serious problems in Central and South America. Beagle dogs develop the symptoms of Chagas disease in humans, and could be an important experimental model for better understanding the immunopathogenic mechanisms involved in the chagasic infection. In the present study we investigated the relation among biological factors inherent to the parasite (trypomastigote polymorphism and in vitro infectivity and immunoglobulin production, inflammation, and fibrosis in the heart of Beagle dogs infected with either T. cruzi Y or Berenice-78 strains. In vitro infectivity of Vero cells as well as the extension of cardiac lesions in infected Beagle was higher for Y strain when compared to Berenice-78 strain. These data suggested that in vitro infectivity assays may correlate with pathogenicity in vivo. In fact, animals infected with Y strain, which shows prevalence of slender forms and high infectivity in vitro, presented cardiomegaly, inflammation, and fibrosis in heart area. Concerning the immunoglobulin production, no statistically significant difference was observed for IgA, IgM or IgG levels among T. cruzi infected animals. However, IgA together IgM levels have shown to be a good marker for the acute phase of Chagas disease.

  9. Inhibition of Trypanosoma cruzi growth in vitro by Solanum alkaloids: a comparison with ketoconazole.

    Science.gov (United States)

    Chataing, B; Concepción, J L; Lobatón, R; Usubillaga, A

    1998-02-01

    The glycoalkaloids alpha-chaconine, alpha-solamargine, alpha-solanine, solasonine, sycophantine, and tomatine, as well as the aglycones demissidine, solanidine, solanocapsine, solasodine, tomatidine, and veratrine were tested as growth inhibitors of Trypanosoma cruzi, strain EP, in LIT medium. Their activity was compared with the antifungal ketoconazole. Glycoalkaloids containing alpha-chacotriose showed trypanolytic activity against the epimastigote form and trypanocidal activity against the bloodstream and metacyclic trypomastigote form of Trypanosoma cruzi in culture medium in micromolar concentrations. Ketoconazole showed a lower activity, at the same concentrations of alpha-chaconine and alpha-solamargine. The observations indicate that the initial target of the compound is at the membrane level with a concomitant change in the parasite morphology. Moreover, internal compartments of the parasites were observed to be affected by the drugs, revealing the dissolution of some organelles as mitocondrias and glycosomes.

  10. Preparation, crystallization and preliminary crystallographic analysis of old yellow enzyme from Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Shigeru [Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan); Tokuoka, Keiji [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Uchiyama, Nahoko [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874 (Japan); Okamoto, Naoki; Okano, Yousuke; Matsumura, Hiroyoshi [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Inaka, Koji [Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan); Urade, Yoshihiro [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874 (Japan); Inoue, Tsuyoshi, E-mail: inouet@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan)

    2007-10-01

    Old yellow enzyme from Trypanosoma cruzi, has been crystallized using the hanging-drop vapour-diffusion method. Old yellow enzyme (OYE) is an NADPH oxidoreductase that contains a flavin mononucleotide as a prosthetic group. The OYE from Trypanosoma cruzi, which produces prostaglandin F{sub 2α}, a potent mediator of various physiological and pathological processes, from prostaglandin H2. The protein was recombinantly expressed and purified from Escherichia coli and was crystallized using the hanging-drop vapour-diffusion method. The crystal belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 56.3, b = 78.8, c = 78.8 Å, β = 93.4° and two molecules per asymmetric unit. The crystals were suitable for X-ray crystallographic studies and diffracted to 1.70 Å resolution. A Patterson search method is in progress using the structure of OYE from Pseudomonas putida as a starting model.

  11. Temporal variation in Trypanosoma cruzi lineages from the native rodent Octodon degus in semiarid Chile.

    Science.gov (United States)

    Botto-Mahan, Carezza; Rojo, Gemma; Sandoval-Rodríguez, Alejandra; Peña, Fabiola; Ortiz, Sylvia; Solari, Aldo

    2015-11-01

    Chagas disease is a zoonosis caused by the protozoan parasite Trypanosoma cruzi and transmitted by triatomine insects to several mammalian species acting as reservoir hosts. In the present study, we assess T. cruzi-prevalence and DTU composition of the endemic rodent Octodon degus from a hyper-endemic area of Chagas disease in Chile. Parasite detection is performed by PCR assays on blood samples of individuals captured in the austral summers of 2010-2013. The infection level in rodents differed in the summers of these four years between 18% and 70%. Overall, infected O. degus showed similar T. cruzi-DTU composition (TcI, TcII, TcV and TcVI lineages) among years, corresponding to single and mixed infection, but the relative importance of each DTU changed among years. In 2013, we detected that only three out of the four T. cruzi-DTU found in O. degus were present in the endemic triatomine Mepria spinolai. We suggest that O. degus, an abundant long-lived rodent, is an important native reservoir of T. cruzi in the wild transmission cycle of Chagas disease and it is able to maintain all the T. cruzi-DTUs described in semiarid Chile.

  12. Cloning and expression of transgenes using linear vectors in Trypanosoma cruzi.

    Science.gov (United States)

    Curto, María de Los Ángeles; Lorenzi, Hernán A; Moraes Barros, Roberto R; Souza, Renata T; Levin, Mariano J; Da Silveira, José Franco; Schijman, Alejandro G

    2014-06-01

    The identification of new targets for vaccine and drug development for the treatment of Chagas' disease is dependent on deepening our understanding of the parasite genome. Vectors for genetic manipulation in Trypanosoma cruzi basically include those that remain as circular episomes and those that integrate into the parasite's genome. Artificial chromosomes are alternative vectors to overcome problematic transgene expression often occurring with conventional vectors in this parasite. We have constructed a series of vectors named pTACs (Trypanosome Artificial Chromosomes), all of them carrying telomeric and subtelomeric sequences and genes conferring resistance to different selection drugs. In addition, one pTAC harbours a modified GFP gene (pTAC-gfp), and another one carries the ornithine decarboxilase gene from Crithidia fasciculata (pTAC-odc). We have encountered artificial chromosomes generated from pTACs in transformed T. cruzi epimastigotes for every version of the designed vectors. These extragenomic elements, in approximately 6-8 copies per cell, remained as linear episomes, contained telomeres and persisted after 150 and 60 generations with or without selection drugs, respectively. The linear molecules remained stable through the different T. cruzi developmental forms. Furthermore, derived artificial chromosomes from pTAC-odc could complement the auxotrophy of T. cruzi for polyamines. Our results show that pTACs constitute useful tools for reverse functional genetics in T. cruzi that will contribute to a better understanding of T. cruzi biology.

  13. The trans-sialidase, the major Trypanosoma cruzi virulence factor: Three decades of studies.

    Science.gov (United States)

    Freire-de-Lima, L; Fonseca, L M; Oeltmann, T; Mendonça-Previato, L; Previato, J O

    2015-11-01

    Chagas' disease is a potentially life-threatening disease caused by the protozoan parasite Trypanosoma cruzi. Since the description of Chagas'disease in 1909 extensive research has identified important events in the disease in order to understand the biochemical mechanism that modulates T. cruzi-host cell interactions and the ability of the parasite to ensure its survival in the infected host. Exactly 30 years ago, we presented evidence for the first time of a trans-sialidase activity in T. cruzi (T. cruzi-TS). This enzyme transfers sialic acid from the host glycoconjugates to the terminal β-galactopyranosyl residues of mucin-like molecules on the parasite's cell surface. Thenceforth, many articles have provided convincing data showing that T. cruzi-TS is able to govern relevant mechanisms involved in the parasite's survival in the mammalian host, such as invasion, escape from the phagolysosomal vacuole, differentiation, down-modulation of host immune responses, among others. The aim of this review is to cover the history of the discovery of T. cruzi-TS, as well as some well-documented biological effects encompassed by this parasite's virulence factor, an enzyme with potential attributes to become a drug target against Chagas disease.

  14. Trypanosoma cruzi Infection in an Indigenous Kariña Community in Eastern Venezuela

    Directory of Open Access Journals (Sweden)

    Mariolga Berrizbeitia

    2012-01-01

    Full Text Available We investigated the seroprevalence of Trypanosoma cruzi infection in an indigenous Kariña population in eastern Venezuela. A total of 175 serum samples were collected in the community of Piñantal during February 2009. Interviews targeting socioeconomic and environmental factors associated with the T. cruzi transmission were also conducted. Samples were evaluated using trypomastigote excreted/secreted antigens (TESAs in an ELISA format. TESA-ELISA positive samples were confirmed by indirect haemagglutination (HAI (Wiener. A nonsystematic collection of vectors was also undertaken. T. cruzi seroprevalence was 7.43% according to both assays, and the mean age of infected patients was 48.61±10.40 years (range 34 to 73 years. The vector infection rate was 20.00% (2/10. T. cruzi seropositivity was associated with a history of triatomine bites, the ability to recognize the vector and poor knowledge about Chagas disease, but no associations were found with gender, house type, knowledge of how the disease is transmitted, or the presence of vectors or animals inside dwellings. To our knowledge, this is the first study of the seroprevalence of T. cruzi in an indigenous population in eastern Venezuela. All of the epidemiological variables required for the establishment of active vectorial transmission of T. cruzi were present in this community.

  15. Studying nanotoxic effects of CdTe quantum dots in Trypanosoma cruzi

    Science.gov (United States)

    Stahl, C. V.; Almeida, D. B.; de Thomaz, A. A.; Fontes, A.; Menna-Barreto, R. F. S.; Santos-Mallet, J. R.; Cesar, C. L.; Gomes, S. A. O.; Feder, D.

    2010-02-01

    Many studies have been done in order to verify the possible nanotoxicity of quantum dots in some cellular types. Protozoan pathogens as Trypanosoma cruzi, etiologic agent of Chagas1 disease is transmitted to humans either by blood-sucking triatomine vectors, blood transfusion, organs transplantation or congenital transmission. The study of the life cycle, biochemical, genetics, morphology and others aspects of the T. cruzi is very important to better understand the interactions with its hosts and the disease evolution on humans. Quantum dot, nanocrystals, highly luminescent has been used as tool for experiments in in vitro and in vivo T. cruzi life cycle development in real time. We are now investigating the quantum dots toxicity on T. cruzi parasite cells using analytical methods. In vitro experiments were been done in order to test the interference of this nanoparticle on parasite development, morphology and viability (live-death). Ours previous results demonstrated that 72 hours after parasite incubation with 200 μM of CdTe altered the development of T. cruzi and induced cell death by necrosis in a rate of 34%. QDs labeling did not effect: (i) on parasite integrity, at least until 7 days; (ii) parasite cell dividing and (iii) parasite motility at a concentration of 2 μM CdTe. This fact confirms the low level of cytotoxicity of these QDs on this parasite cell. In summary our results is showing T. cruzi QDs labeling could be used for in vivo cellular studies in Chagas disease.

  16. Autonomic Dysfunction and Risk Factors Associated with Trypanosoma cruzi Infection among Children in Arequipa, Peru

    OpenAIRE

    Bowman, Natalie M.; Kawai, Vivian; Gilman, Robert H.; Bocangel, Cesar; Galdos-Cardenas, Gerson; Cabrera, Lilia; Levy, Michael Z.; Cornejo del Carpio, Juan Geny; Delgado, Freddy; Rosenthal, Lauren; Pinedo-Cancino, Vivian V.; Steurer, Francis; Seitz, Amy E.; Maguire, James H.; Bern, Caryn

    2011-01-01

    Chagas disease affects an estimated 8 million people in Latin America. Infected individuals have 20–30% lifetime risk of developing cardiomyopathy, but more subtle changes in autonomic responses may be more frequent. We conducted a matched case-control study of children in Arequipa, Peru, where triatomine infestation and Trypanosoma cruzi infection are emerging problems. We collected data on home environment, history, physical examination, electrocardiogram, and autonomic testing. Signs of tr...

  17. Evaluation of a Recombinant Trypanosoma cruzi Mucin-Like Antigen for Serodiagnosis of Chagas' Disease ▿

    OpenAIRE

    2011-01-01

    Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and is one of the most important endemic problems in Latin America. Lately, it has also become a health concern in the United States and Europe. Currently, a diagnosis of Chagas' disease and the screening of blood supplies for antiparasite antibodies are achieved by conventional serological tests that show substantial variation in the reproducibility and reliability of their results. In addition, the specificity of these as...

  18. Human infection with Trypanosoma cruzi induces parasite antigen-specific cytotoxic T lymphocyte responses.

    OpenAIRE

    1998-01-01

    Experimental models of Chagas' disease, an infection caused by the intracellular protozoan Trypanosoma cruzi, have demonstrated the crucial immunoprotective role played by CD8(+) T lymphocytes. These cells dominate inflammatory foci in parasitized tissues and their elimination from mice leads to uncontrolled parasite replication and subsequent death of the infected host. A trypomastigote surface antigen, TSA-1, and two amastigote surface molecules, ASP-1 and ASP-2, were recently identified as...

  19. Trypanosoma cruzi: serum antibody reactivity to the parasite antigens in susceptible and resistant mice

    OpenAIRE

    1990-01-01

    The specific antibody responses were compared among susceptible (A/Sn), moderately susceptible (Balb/c) and resistant (C57 BL/lOJ) mice infected with Trypanosoma cruzi (Y strain). Sera obtained during the second week of infection recognized a surface trypomastigote antigen of apparent Mr 80 kDa while displaying complex reactivity to surface epimastigote antigens. Complex trypomastigote antigens recognition was detected around the middle of the third week of infection. No major differences wer...

  20. Molecular and Functional Characterization of a Trypanosoma cruzi Nuclear Adenylate Kinase Isoform

    OpenAIRE

    María de los Milagros Cámara; Bouvier, León A.; Canepa, Gaspar E.; Mariana R Miranda; Pereira, Claudio A.

    2013-01-01

    Trypanosoma cruzi, the etiological agent of Chagas’ disease, is an early divergent eukaryote in which control of gene expression relies mainly in post-transcriptional mechanisms. Transcription levels are globally up and down regulated during the transition between proliferating and non-proliferating life-cycle stages. In this work we characterized a nuclear adenylate kinase isoform (TcADKn) that is involved in ribosome biogenesis. Nuclear adenylate kinases have been recently described in a fe...

  1. Rapid Detection of Trypanosoma cruzi in Human Serum by Use of an Immunochromatographic Dipstick Test ▿

    OpenAIRE

    Reithinger, Richard; Mario J Grijalva; Chiriboga, Rosa F.; Alarcón de Noya, Belkisyolé; Jaime R. Torres; Pavia-Ruz, Norma; MANRIQUE-SAIDE, Pablo; Cardinal, Marta V.; Ricardo E. Gürtler

    2010-01-01

    We evaluated a commercially available immunochromatographic dipstick test to detect Trypanosoma cruzi infection in 366 human serum samples with known serological results from Argentina, Ecuador, Mexico, and Venezuela. One hundred forty-nine of 366 (40.7%) and 171/366 (46.7%) samples tested positive by dipstick and serology, respectively. Dipstick sensitivity was calculated to be 84.8% (range between countries, 77.5 to 95%), and specificity was 97.9% (95.9 to 100%).

  2. Prevalence of Trypanosoma cruzi and Leishmania chagasi infection and risk factors in a Colombian indigenous population

    OpenAIRE

    Augusto CORREDOR ARJONA; ALVAREZ MORENO Carlos Arturo; Carlos Alberto AGUDELO; BUENO,Martha; López, Myriam Consuelo; CÁCERES,Elvia; REYES Patricia; DUQUE BELTRAN,Sofia; GÜALDRON Luis Eduardo; SANTACRUZ Maria Mercedes

    1999-01-01

    This study was carried out in order to obtain base-line data concerning the epidemiology of American Visceral Leishmaniasis and Chagas? Disease in an indigenous population with whom the government is starting a dwelling improvement programme. Information was collected from 242 dwellings (1,440 people), by means of house to house interviews about socio-economic and environmental factors associated with Leishmania chagasi and Trypanosoma cruzi transmission risk. A leishmanin skin test was appli...

  3. Structural Insights into Inhibition of Sterol 14[alpha]-Demethylase in the Human Pathogen Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Lepesheva, Galina I.; Hargrove, Tatiana Y.; Anderson, Spencer; Kleshchenko, Yuliya; Furtak, Vyacheslav; Wawrzak, Zdzislaw; Villalta, Fernando; Waterman, Michael R. (Vanderbilt); (NWU); (Meharry)

    2010-09-02

    Trypanosoma cruzi causes Chagas disease (American trypanosomiasis), which threatens the lives of millions of people and remains incurable in its chronic stage. The antifungal drug posaconazole that blocks sterol biosynthesis in the parasite is the only compound entering clinical trials for the chronic form of this infection. Crystal structures of the drug target enzyme, Trypanosoma cruzi sterol 14{alpha}-demethylase (CYP51), complexed with posaconazole, another antifungal agent fluconazole and an experimental inhibitor, (R)-4{prime}-chloro-N-(1-(2,4-dichlorophenyl)-2-(1H-imid-azol-1-yl)ethyl)biphenyl-4-carboxamide (VNF), allow prediction of important chemical features that enhance the drug potencies. Combined with comparative analysis of inhibitor binding parameters, influence on the catalytic activity of the trypanosomal enzyme and its human counterpart, and their cellular effects at different stages of the Trypanosoma cruzi life cycle, the structural data provide a molecular background to CYP51 inhibition and azole resistance and enlighten the path for directed design of new, more potent and selective drugs to develop an efficient treatment for Chagas disease.

  4. Autonomic dysfunction and risk factors associated with Trypanosoma cruzi infection among children in Arequipa, Peru.

    Science.gov (United States)

    Bowman, Natalie M; Kawai, Vivian; Gilman, Robert H; Bocangel, Cesar; Galdos-Cardenas, Gerson; Cabrera, Lilia; Levy, Michael Z; Cornejo del Carpio, Juan Geny; Delgado, Freddy; Rosenthal, Lauren; Pinedo-Cancino, Vivian V; Steurer, Francis; Seitz, Amy E; Maguire, James H; Bern, Caryn

    2011-01-01

    Chagas disease affects an estimated 8 million people in Latin America. Infected individuals have 20-30% lifetime risk of developing cardiomyopathy, but more subtle changes in autonomic responses may be more frequent. We conducted a matched case-control study of children in Arequipa, Peru, where triatomine infestation and Trypanosoma cruzi infection are emerging problems. We collected data on home environment, history, physical examination, electrocardiogram, and autonomic testing. Signs of triatomine infestation and/or animals sleeping in the child's room and household members with Chagas disease were associated with increased infection risk. Electrocardiogram findings did not differ between cases and controls. However, compared with control children, infected children had blunted autonomic responses by three different measures, the Valsalva maneuver, the cold pressor test, and the orthostatic test. T. cruzi-infected children show autonomic dysfunction, although the prognostic value of this finding is not clear. Sustained vector control programs are essential to decreasing future T. cruzi infections.

  5. In vitro activity of Etanidazole against the protozoan parasite Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Patricia B Petray

    2004-03-01

    Full Text Available We investigated the in vitro action of an hydrosoluble 2-nitroimidazole, Etanidazole (EZL, against Trypanosoma cruzi, the etiologic agent of Chagas disease. EZL displayed lethal activity against isolated trypomastigotes as well as amastigotes of T. cruzi (RA strain growing in Vero cells or J774 macrophages, without affecting host cell viability. Although not completely equivalent to Benznidazole (BZL, the reference drug for Chagas chemotherapy, EZL takes advantage in exertingits anti-T. cruzi activity for longer periods without serious toxic side effects, as those recorded in BZL-treated patients. Our present results encourage further experiments to study in depth the trypanocidal properties of this drug already licensed for use in human cancers.

  6. In vitro activity of Etanidazole against the protozoan parasite Trypanosoma cruzi.

    Science.gov (United States)

    Petray, Patricia B; Morilla, María J; Corral, Ricardo S; Romero, Eder L

    2004-03-01

    We investigated the in vitro action of an hydrosoluble 2-nitroimidazole, Etanidazole (EZL), against Trypanosoma cruzi, the etiologic agent of Chagas disease. EZL displayed lethal activity against isolated trypomastigotes as well as amastigotes of T. cruzi (RA strain) growing in Vero cells or J774 macrophages, without affecting host cell viability. Although not completely equivalent to Benznidazole (BZL), the reference drug for Chagas chemotherapy, EZL takes advantage in exerting its anti-T. cruzi activity for longer periods without serious toxic side effects, as those recorded in BZL-treated patients. Our present results encourage further experiments to study in depth the trypanocidal properties of this drug already licensed for use in human cancers.

  7. Mapping of B-Cell Epitopes in a Trypanosoma cruzi Immunodominant Antigen Expressed in Natural Infections

    Science.gov (United States)

    Lesénéchal, Mylène; Becquart, Laurence; Lacoux, Xavier; Ladavière, Laurent; Baida, Renata C. P.; Paranhos-Baccalà, Glaucia; da Silveira, José Franco

    2005-01-01

    Tc40 is an immunodominant antigen present in natural Trypanosoma cruzi infections. This immunogen was thoroughly mapped by using overlapping amino acid sequences identified by gene cloning and chemical peptide synthesis. To map continuous epitopes of the Tc40 antigen, an epitope expression library was constructed and screened with sera from human chagasic patients. A major, linear B-cell epitope spanning residues 403 to 426 (PAKAAAPPAA) was identified in the central domain of Tc40. A synthetic peptide spanning this region reacted strongly with 89.8% of the serum samples from T. cruzi-infected individuals. This indicates that the main antigenic site is defined by the linear sequence of the peptide rather than a conformation-dependent structure. The major B-cell epitope of Tc40 shares a high degree of sequence identity with T. cruzi ribosomal and RNA binding proteins, suggesting the existence of cross-reactivity among these molecules. PMID:15699429

  8. Autonomic Dysfunction and Risk Factors Associated with Trypanosoma cruzi Infection among Children in Arequipa, Peru

    Science.gov (United States)

    Bowman, Natalie M.; Kawai, Vivian; Gilman, Robert H.; Bocangel, Cesar; Galdos-Cardenas, Gerson; Cabrera, Lilia; Levy, Michael Z.; Cornejo del Carpio, Juan Geny; Delgado, Freddy; Rosenthal, Lauren; Pinedo-Cancino, Vivian V.; Steurer, Francis; Seitz, Amy E.; Maguire, James H.; Bern, Caryn

    2011-01-01

    Chagas disease affects an estimated 8 million people in Latin America. Infected individuals have 20–30% lifetime risk of developing cardiomyopathy, but more subtle changes in autonomic responses may be more frequent. We conducted a matched case-control study of children in Arequipa, Peru, where triatomine infestation and Trypanosoma cruzi infection are emerging problems. We collected data on home environment, history, physical examination, electrocardiogram, and autonomic testing. Signs of triatomine infestation and/or animals sleeping in the child's room and household members with Chagas disease were associated with increased infection risk. Electrocardiogram findings did not differ between cases and controls. However, compared with control children, infected children had blunted autonomic responses by three different measures, the Valsalva maneuver, the cold pressor test, and the orthostatic test. T. cruzi-infected children show autonomic dysfunction, although the prognostic value of this finding is not clear. Sustained vector control programs are essential to decreasing future T. cruzi infections. PMID:21212207

  9. Chagas disease (Trypanosoma cruzi and HIV co-infection in Colombia

    Directory of Open Access Journals (Sweden)

    Carolina Hernández

    2014-09-01

    Full Text Available Chagas disease is a complex zoonotic pathology caused by the kinetoplastid Trypanosoma cruzi. This parasite presents remarkable genetic variability and has been grouped into six discrete typing units (DTUs. The association between the DTUs and clinical outcome remains unknown. Chagas disease and co-infection with HIV/AIDS has been reported widely in Brazil and Argentina. Herein, we present the molecular analyses from a Chagas disease patient with HIV/AIDS co-infection in Colombia who presented severe cardiomyopathy, pleural effusion, and central nervous system involvement. A mixed infection by T. cruzi genotypes was detected. We suggest including T. cruzi in the list of opportunistic pathogens for the management of HIV patients in Colombia. The epidemiological implications of this finding are discussed.

  10. Extensive diversity of Trypanosoma cruzi discrete typing units circulating in Triatoma dimidiata from central Veracruz, Mexico.

    Science.gov (United States)

    Ramos-Ligonio, Angel; Torres-Montero, Jesús; López-Monteon, Aracely; Dumonteil, Eric

    2012-10-01

    Chagas disease (or American trypanosomiasis) is a parasitic disease of major public health importance, caused by Trypanosoma cruzi, which presents extensive genetic diversity. The parasite has been classified into six lineages or discrete typing units (TcI to TcVI) and we performed here the molecular characterization of the strains present in Triatoma dimidiata, the main vector in central Veracruz, Mexico. Unexpectedly, TcI only represented 9/33 strains identified (27%), and we reported for the first time the presence of TcII, TcIII, TcIV and TcV strains in Mexico, at a relatively high frequency (13-27% each). Our observations indicate a much greater diversity of T. cruzi DTUs than previously estimated in at least part of Mexico. These results have important implications for the understanding of the phylogeography of T. cruzi DTUs and the epidemiology of Chagas disease in North America.

  11. ORC1/CDC6 and MCM7 distinct associate with chromatin through Trypanosoma cruzi life cycle.

    Science.gov (United States)

    Calderano, Simone; Godoy, Patricia; Soares, Daiane; Sant'Anna, Osvaldo Augusto; Schenkman, Sergio; Elias, M Carolina

    2014-02-01

    Trypanosoma cruzi alternates between replicative and non-replicative stages. We analyzed the expression of components of the pre-replication machinery TcORC1/CDC6 and TcMCM7 and their interaction with DNA in all T. cruzi stages. TcORC1/CDC6 remains in the nuclear space during all stages of the life cycle and interacts with DNA in the replicative stages; however, it does not bind to DNA in the non-replicative forms. Moreover, TcMCM7 is not present in the non-replicative stages. These data suggest that the lacking of DNA replication during the T. cruzi life cycle may be a consequence of the blocking of TcORC1/CDC6-DNA interaction and of the down regulation of the TcMCM7 expression.

  12. Trypanosoma cruzi infection in offspring born to chagasic C3H/He mice

    Directory of Open Access Journals (Sweden)

    Silvana Marques de Araújo

    1996-04-01

    Full Text Available This study reports the effects of Trypanosoma cruzi infection induced in C3H/He male and female mice born to chagasic mice. An experimental model was established infecting female C3H/He mice with a low virulent T. cruzi clone. In this model, mating, fertilization, pregnancy evolution and delivery was carried out successfully. The offspring was infected at four, six and eigth weeks of age. The results showed that the offspring born to chagasic mothers present decreased resistance to acquired T. cruzi infection. This decreased resistance was expressed by higher levels of parasitaemia and higher mortality rates in offspring born to chagasic mothers than in controls. Age and sex were shown to be important factors of this phenomenon. The results suggest that maternal immune system products can modulate the immune response of the offspring.

  13. Effects of platelet-activating factor on the interaction of Trypanosoma cruzi with Rhodnius prolixus.

    Science.gov (United States)

    Zimmermann, Luciana T; Folly, Evelize; Gomes, Marta T; Alviano, Daniela S; Alviano, Celuta S; Silva-Filho, Fernando C; Atella, Geórgia C; Lopes, Angela H

    2011-06-01

    We investigated the effects of platelet-activating factor (PAF) on the interaction of Trypanosoma cruzi with Rhodnius prolixus. The parasites (epimastigotes) were treated with PAF and/or WEB 2086 (PAF antagonist) for 1 h prior to the interaction experiments. PAF stimulated both in vivo and ex vivo interactions between T. cruzi and R. prolixus while WEB 2086 abrogated these effects. PAF-treated epimastigotes also showed an increase in surface negativity and in the amount of surface sialic acid. Neither of these effects was observed when the epimastigotes were treated with neuraminidase following PAF treatment. In the ex vivo interaction experiments, the number of epimastigotes bound to the midguts of the insects was reduced when the epimastigotes had been treated with neuraminidase. We conclude that PAF modulates the interaction of T. cruzi with R. prolixus by altering the amount of sialyl residues at the surface of the parasite.

  14. The population genetics of Trypanosoma cruzi revisited in the light of the predominant clonal evolution model.

    Science.gov (United States)

    Tibayrenc, Michel; Ayala, Francisco J

    2015-11-01

    Comparing the population structure of Trypanosoma cruzi with that of other pathogens, including parasitic protozoa, fungi, bacteria and viruses, shows that the agent of Chagas disease shares typical traits with many other species, related to a predominant clonal evolution (PCE) pattern: statistically significant linkage disequilibrium, overrepresented multilocus genotypes, near-clades (genetic subdivisions somewhat blurred by occasional genetic exchange/hybridization) and "Russian doll" patterns (PCE is observed, not only at the level of the whole species, but also, within the near-clades). Moreover, T. cruzi population structure exhibits linkage with the diversity of several strongly selected genes, with gene expression profiles, and with some major phenotypic traits. We discuss the evolutionary significance of these results, and their implications in terms of applied research (molecular epidemiology/strain typing, analysis of genes of interest, vaccine and drug design, immunological diagnosis) and of experimental evolution. Lastly, we revisit the long-term debate of describing new species within the T. cruzi taxon.

  15. Circulation of Tc Ia discrete type unit Trypanosoma cruzi in Yucatan Mexico.

    Science.gov (United States)

    Monteón, Victor; Triana-Chávez, Omar; Mejía-Jaramillo, Ana; Pennignton, Pamela; Ramos-Ligonio, Ángel; Acosta, Karla; Lopez, Ruth

    2016-06-01

    The etiologic agent Trypanosoma cruzi (Tc) has been grouped into six discrete type units (DTU I-VI); within DTU-I exists four subgroups defined Ia-Id. In Colombia, the genotype Ia is associated with human infection and domiciliated Rhodnius vector. In the Yucatan Peninsula of Mexico, the main vector involved in T. cruzi transmission is Triatoma dimidiata predominantly via sylvatic and peridomiciliated cycles. In this study, multiple sequence analysis of mini-exon intergenic regions of T. cruzi isolates obtained from T. dimidiata in the Yucatan Peninsula of Mexico revealed they belonged to Tc Ia DTU along with two additional Mexican strains located 1,570 km away from Yucatan. In conclusion Tc Ia circulates in the Yucatan peninsula in T. dimidiata vector and likewise in the northwest region of Mexico.

  16. JVG9, a benzimidazole derivative, alters the surface and cytoskeleton of Trypanosoma cruzi bloodstream trypomastigotes

    Science.gov (United States)

    Díaz-Chiguer, Dylan L; Hernández-Luis, Francisco; Nogueda-Torres, Benjamín; Castillo, Rafael; Reynoso-Ducoing, Olivia; Hernández-Campos, Alicia; Ambrosio, Javier R

    2014-01-01

    Trypanosoma cruzi has a particular cytoskeleton that consists of a subpellicular network of microtubules and actin microfilaments. Therefore, it is an excellent target for the development of new anti-parasitic drugs. Benzimidazole 2-carbamates, a class of well-known broad-spectrum anthelmintics, have been shown to inhibit the in vitro growth of many protozoa. Therefore, to find efficient anti-trypanosomal (trypanocidal) drugs, our group has designed and synthesised several benzimidazole derivatives. One, named JVG9 (5-chloro-1H-benzimidazole-2-thiol), has been found to be effective against T. cruzi bloodstream trypomastigotes under both in vitro and in vivo conditions. Here, we present the in vitro effects observed by laser scanning confocal and scanning electron microscopy on T. cruzi trypomastigotes. Changes in the surface and the distribution of the cytoskeletal proteins are consistent with the hypothesis that the trypanocidal activity of JVG9 involves the cytoskeleton as a target. PMID:25317703

  17. Trypanosoma cruzi: strain selection by diferent schedules of mouse passage of an initially mixed infection

    Directory of Open Access Journals (Sweden)

    Maria P. Deane

    1984-12-01

    Full Text Available From an initial double infection in mice, established by simultaneous and equivalent inocula of bloodstream forms of strains Y and F of Trypanosoma cruzi, two lines were derived by subinoculations: one (W passaged every week, the other (M every month. Through biological and biochemical methods only the Y strain was identified at the end of the 10th and 16th passages of line W and only the F strain at the 2nd and 4th passages of line M. The results illustrate strain selection through laboratory manipulation of initially mixed populations of T. cruzi.De uma infecção inicialmente dupla em camundongo, estabelecida por inóculo simultaneo e equivalente de formas sanguíneas das cepas Y e F de Trypanosoma cruzi, duas linhagens foram originadas por subinoculações: uma (W passada casa semana, a outra (M cada mês. Por métodos biológicos e bioquímicos apenas a cepa Y foi identificada ao fim a 10a. e 16a. passagens da linhagem W e apenas a cepa F na 2a. e 4a.passagens de linhagem M. Os resultados demonstram a seleção de cepas através de manipulação em laboratorio de populações inicialmente mistas de T. cruzi.

  18. Molecular epidemiology of Trypanosoma cruzi and Triatoma dimidiata in costal Ecuador.

    Science.gov (United States)

    Wong, Yim Yan; Sornosa Macias, Karen Jeniffer; Guale Martínez, Doris; Solorzano, Luis F; Ramirez-Sierra, Maria Jesus; Herrera, Claudia; Dumonteil, Eric

    2016-07-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In Ecuador, Triatoma dimidiata and Rhodnius ecuadoriensis are the main vector species, responsible for over half of the cases of T. cruzi infection in the country. T. dimidiata is believed to have been introduced in Ecuador during colonial times, and its elimination from the country is thus believed to be feasible. We investigated here the molecular ecology of T. dimidiata and T. cruzi in costal Ecuador to further guide control efforts. Analysis of the Internal Transcribed Spacer 2 (ITS-2) of 23 specimens from Progreso, Guayas, unambiguously supported the likely importation of T. dimidiata from Central America to Ecuador. The observation of a very high parasite infection rate (54%) and frequent feeding on humans (3/5) confirmed a continued risk of transmission to humans. All genotyped parasites corresponded to TcI DTU and Trypanosoma rangeli was not detected in T. dimidiata. TcI subgroups corresponded to TcIa (25%), and mixed infections with TcIa and TcId (75%). Further studies should help clarify T. cruzi genetic structure in the country, and the possible impact of the introduction of T. dimidiata on the circulating parasite strains. The elevated risk posed by this species warrants continuing efforts for its control, but its apparent mobility between peridomestic and domestic habitats may favor reinfestation following insecticide spraying.

  19. Identification of monoclonal antibodies against the trypomastigote stage of Trypanosoma cruzi by use of iminobiotinylated surface polypeptides.

    Science.gov (United States)

    Beard, C A; Wrightsman, R A; Manning, J E

    1985-08-01

    The surface polypeptides of epimastigotes and tissue culture-derived trypomastigotes of Trypanosoma cruzi have been isolated free of most cytosolic components by use of the 2-iminobiotin-avidin interaction. Polypeptides of the trypomastigote stage obtained by this technique are recognized by serum antibodies from Chagasic patients and T. cruzi-infected mice. These polypeptides have been used as the detecting antigen for the identification of hybridoma cells producing monoclonal antibodies against the surface proteins of the trypomastigote stage of T. cruzi. These experiments document a practical approach for obtaining T. cruzi surface proteins in sufficient quantity and purity for use in immunological studies.

  20. Tigutcystatin, a cysteine protease inhibitor from Triatoma infestans midgut expressed in response to Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Buarque, Diego S.; Spindola, Leticia M.N. [Department of Biochemistry, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, 04044-020 Sao Paulo, SP (Brazil); Martins, Rafael M. [Biology of Host Parasite Interactions Unit, Institute Pasteur, 75015 Paris (France); Braz, Gloria R.C. [Department of Biochemistry, Instituto de Quimica, Universidade Federal do Rio de Janeiro, 21941-909 Rio de Janeiro (Brazil); Tanaka, Aparecida S., E-mail: Tanaka.bioq@epm.br [Department of Biochemistry, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, 04044-020 Sao Paulo, SP (Brazil)

    2011-09-23

    Highlights: {yields} Tigutcystatin inhibits Trypanosoma cruzi cysteine proteases with high specificity. {yields} Tigutcystatin expression is up-regulated in response to T. cruzi infection. {yields} It is the first cysteine proteases inhibitor characterized from a triatomine insect. -- Abstract: The insect Triatoma infestans is a vector of Trypanosoma cruzi, the etiological agent of Chagas disease. A cDNA library was constructed from T. infestans anterior midgut, and 244 clones were sequenced. Among the EST sequences, an open reading frame (ORF) with homology to a cystatin type 2 precursor was identified. Then, a 288-bp cDNA fragment encoding mature cystatin (lacking signal peptide) named Tigutcystatin was cloned fused to a N-terminal His tag in pET-14b vector, and the protein expressed in Escherichia coli strain Rosetta gami. Tigutcystatin purified and cleaved by thrombin to remove His tag presented molecular mass of 11 kDa and 10,137 Da by SDS-PAGE and MALDI-TOF mass spectrometry, respectively. Purified Tigutcystatin was shown to be a tight inhibitor towards cruzain, a T. cruzi cathepsin L-like enzyme (K{sub i} = 3.29 nM) and human cathepsin L (K{sub i} = 3.78 nM). Tissue specific expression analysis showed that Tigutcystatin was mostly expressed in anterior midgut, although amplification in small intestine was also detected by semi quantitative RT-PCR. qReal time PCR confirmed that Tigutcystatin mRNA is significantly up-regulated in anterior midgut when T. infestans is infected with T. cruzi. Together, these results indicate that Tigutcystatin may be involved in modulation of T. cruzi in intestinal tract by inhibiting parasite cysteine proteases, which represent the virulence factors of this protozoan.

  1. Inhibition of HIV-1 replication in human monocyte-derived macrophages by parasite Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Guadalupe Andreani

    Full Text Available BACKGROUND: Cells of monocyte/macrophage lineage are one of the major targets of HIV-1 infection and serve as reservoirs for viral persistence in vivo. These cells are also the target of the protozoa Trypanosoma cruzi, the causative agent of Chagas disease, being one of the most important endemic protozoonoses in Latin America. It has been demonstrated in vitro that co-infection with other pathogens can modulate HIV replication. However, no studies at cellular level have suggested an interaction between T. cruzi and HIV-1 to date. METHODOLOGY/PRINCIPAL FINDINGS: By using a fully replicative wild-type virus, our study showed that T. cruzi inhibits HIV-1 antigen production by nearly 100% (p99% being stronger than HIV-T. cruzi (approximately 90% for BaL and approximately 85% for VSV-G infection. In MDM with established HIV-1 infection, T. cruzi significantly inhibited luciferate activity (p<0.01. By quantifying R-U5 and U5-gag transcripts by real time PCR, our study showed the expression of both transcripts significantly diminished in the presence of trypomastigotes (p<0.05. Thus, T. cruzi inhibits viral post-integration steps, early post-entry steps and entry into MDM. Trypomastigotes also caused a approximately 60-70% decrease of surface CCR5 expression on MDM. Multiplication of T. cruzi inside the MDM does not seem to be required for inhibiting HIV-1 replication since soluble factors secreted by trypomastigotes have shown similar effects. Moreover, the major parasite antigen cruzipain, which is secreted by the trypomastigote form, was able to inhibit viral production in MDM over 90% (p<0.01. CONCLUSIONS/SIGNIFICANCE: Our study showed that T. cruzi inhibits HIV-1 replication at several replication stages in macrophages, a major cell target for both pathogens.

  2. Trypanosoma cruzi: insights into naphthoquinone effects on growth and proteinase activity.

    Science.gov (United States)

    Bourguignon, Saulo C; Cavalcanti, Danielle F B; de Souza, Alessandra M T; Castro, Helena C; Rodrigues, Carlos R; Albuquerque, Magaly G; Santos, Dilvani O; da Silva, Gabriel Gomes; da Silva, Fernando C; Ferreira, Vitor F; de Pinho, Rosa T; Alves, Carlos R

    2011-01-01

    In this study we compared the effects of naphthoquinones (α-lapachone, β-lapachone, nor-β-lapachone and Epoxy-α-lap) on growth of Trypanosoma cruzi epimastigotes forms, and on viability of VERO cells. In addition we also experimentally analyzed the most active compounds inhibitory profile against T. cruzi serine- and cysteine-proteinases activity and theoretically evaluated them against cruzain, the major T. cruzi cysteine proteinase by using a molecular docking approach. Our results confirmed β-lapachone and Epoxy-α-lap with a high trypanocidal activity in contrast to α-lapachone and nor-β-lapachone whereas Epoxy-α-lap presented the safest toxicity profile against VERO cells. Interestingly the evaluation of the active compounds effects against T. cruzi cysteine- and serine-proteinases activities revealed different targets for these molecules. β-Lapachone is able to inhibit the cysteine-proteinase activity of T. cruzi proteic whole extract and of cruzain, similar to E-64, a classical cysteine-proteinase inhibitor. Differently, Epoxy-α-lap inhibited the T. cruzi serine-proteinase activity, similar to PMSF, a classical serine-proteinase inhibitor. In agreement to these biological profiles in the enzymatic assays, our theoretical analysis showed that E-64 and β-lapachone interact with the cruzain specific S2 pocket and active site whereas Epoxy-α-lap showed no important interactions. Overall, our results infer that β-lapachone and Epoxy-α-lap compounds may inhibit T. cruzi epimastigotes growth by affecting T. cruzi different proteinases. Thus the present data shows the potential of these compounds as prototype of protease inhibitors on drug design studies for developing new antichagasic compounds.

  3. Functional characterization of enzymes involved in cysteine biosynthesis and H(2)S production in Trypanosoma cruzi.

    Science.gov (United States)

    Marciano, Daniela; Santana, Marianela; Nowicki, Cristina

    2012-10-01

    Trypanosoma cruzi is expected to synthetize de novo cysteine by different routes, among which the two-step pathway involving serine acetyltransferase and cysteine synthase (CS) is comprised. Also, cystathionine β synthase (CBS) might contribute to the de novo generation of cysteine in addition to catalyze the first step of the reverse transsulfuration route producing cystathionine. However, neither the functionality of CS nor that of cystathionine γ lyase (CGL) has been assessed. Our results show that T. cruzi CS could participate notably more actively than CBS in the de novo synthesis of cysteine. Interestingly, at the protein level T. cruzi CS is more abundant in amastigotes than in epimastigotes. Unlike the mammalian homologues, T. cruzi CGL specifically cleaves cystathionine into cysteine and is unable to produce H(2)S. The expression pattern of T. cruzi CGL parallels that of CBS, which unexpectedly suggests that in addition to the de novo synthesis of cysteine, the reverse transsulfuration pathway could be operative in the mammalian and insect stages. Besides, T. cruzi CBS produces H(2)S by decomposing cysteine or via condensation of cysteine with homocysteine. The latter reaction leads to cystathionine production, and is catalyzed remarkably more efficiently than the breakdown of cysteine. In T. cruzi like in other organisms, H(2)S could exert regulatory effects on varied metabolic processes. Notably, T. cruzi seems to count on stage-specific routes involved in cysteine production, the multiple cysteine-processing alternatives could presumably reflect this parasite's high needs of reducing power for detoxification of reactive oxygen species.

  4. Risk Factors and Screening for Trypanosoma cruzi Infection of Dutch Blood Donors.

    Directory of Open Access Journals (Sweden)

    Ed Slot

    Full Text Available Blood donors unaware of Trypanosoma cruzi infection may donate infectious blood. Risk factors and the presence of T. cruzi antibodies in at-risk Dutch blood donors were studied to assess whether specific blood safety measures are warranted in the Netherlands.Birth in a country endemic for Chagas disease (CEC, having a mother born in a CEC, or having resided for at least six continuous months in a CEC were considered risk factors for T. cruzi infection. From March through September 2013, risk factor questions were asked to all donors who volunteered to donate blood or blood components. Serum samples were collected from donors reporting one or more risk factors, and screened for IgG antibodies to T. cruzi by EIA.Risk factors for T. cruzi infection were reported by 1,426 of 227,278 donors (0.6%. Testing 1,333 at-risk donors, none (0.0%; 95%, CI 0.0-0.4% was seroreactive for IgG antibodies to T. cruzi. A total of 472 donors were born in a CEC; 553 donors reported their mother being born in a CEC; and 1,121 donors reported a long-term stay in a CEC. The vast majority of reported risk factors were related to Suriname and Brazil. Overall, the participants resided for 7,694 years in CECs, which equals 2.8 million overnight stays. Of those, 1.9 million nights were spent in Suriname.Asymptomatic T. cruzi infection appears to be extremely rare among Dutch blood donors. Blood safety interventions to mitigate the risk of T. cruzi transmission by transfusion would be highly cost-ineffective in the Netherlands, and are thus not required.

  5. Repertoire, genealogy and genomic organization of cruzipain and homologous genes in Trypanosoma cruzi, T. cruzi-like and other trypanosome species.

    Science.gov (United States)

    Lima, Luciana; Ortiz, Paola A; da Silva, Flávia Maia; Alves, João Marcelo P; Serrano, Myrna G; Cortez, Alane P; Alfieri, Silvia C; Buck, Gregory A; Teixeira, Marta M G

    2012-01-01

    Trypanosoma cruzi, the agent of Chagas disease, is a complex of genetically diverse isolates highly phylogenetically related to T. cruzi-like species, Trypanosoma cruzi marinkellei and Trypanosoma dionisii, all sharing morphology of blood and culture forms and development within cells. However, they differ in hosts, vectors and pathogenicity: T. cruzi is a human pathogen infective to virtually all mammals whilst the other two species are non-pathogenic and bat restricted. Previous studies suggest that variations in expression levels and genetic diversity of cruzipain, the major isoform of cathepsin L-like (CATL) enzymes of T. cruzi, correlate with levels of cellular invasion, differentiation, virulence and pathogenicity of distinct strains. In this study, we compared 80 sequences of genes encoding cruzipain from 25 T. cruzi isolates representative of all discrete typing units (DTUs TcI-TcVI) and the new genotype Tcbat and 10 sequences of homologous genes from other species. The catalytic domain repertoires diverged according to DTUs and trypanosome species. Relatively homogeneous sequences are found within and among isolates of the same DTU except TcV and TcVI, which displayed sequences unique or identical to those of TcII and TcIII, supporting their origin from the hybridization between these two DTUs. In network genealogies, sequences from T. cruzi clustered tightly together and closer to T. c. marinkellei than to T. dionisii and largely differed from homologues of T. rangeli and T. b. brucei. Here, analysis of isolates representative of the overall biological and genetic diversity of T. cruzi and closest T. cruzi-like species evidenced DTU- and species-specific polymorphisms corroborating phylogenetic relationships inferred with other genes. Comparison of both phylogenetically close and distant trypanosomes is valuable to understand host-parasite interactions, virulence and pathogenicity. Our findings corroborate cruzipain as valuable target for drugs, vaccine

  6. Immunocytochemical identification of leishmania and Trypanosoma cruzi amastigotes in situ with homologous and heterologous polyclonal antibodies

    Directory of Open Access Journals (Sweden)

    A.J.A. Barbosa

    1991-03-01

    Full Text Available The unlabelled antibody peroxidase-antiperoxidase method was used to study the immunocytochemical properties of Leishmania and Trypanosoma cruzi amastigotes in situ after tissues had been submitted to different fixation procedures. Antisera were obtained from rabbits chronically infected with different strains of T. cruzi or immunized with L. mexicana amazonensis and L. braziliensis guyanensis, and were applied on 5 µm thick sections. T. cruzi antigens were well stained by the three anti-T. cruzi sera and the two anti-heis.hmama.sera at optimum dilution between 1:1,000 and 1:2,000, regardless the parasite strain. Differently, the leishmanial antigens were revealed by Leishmania sera only at low dilutions (between 1:60 -1:160, whereas the anti-T. cruzi sera, at these low dilutions, gave rather weak stainings. Although there is no clear explanation for this immunocytochemical "reverse-monodirectional" cross-reactivity between Leishmania and T. cruzi, the present results show that polyclonal antibodies agains Leishmania species, when used for immunocytochemical detection of these parasites in situ, react more strongly with T. cruzi amastigotes than with the homologous amastigotes.O método daperoxidase-antiperoxidase foi utilizado para estudar as propriedades imunocitoquimicas de Leishmanias e de amastigotas do Trypanosoma cruzi, in situ, após os tecidos terem sido submetidos a diferentes tipos de fixação. Anti-soros foram obtidos de coelhos cronicamente infectados com três cepas de T. cruzi ou imunizados com L. mexicana ámazonensis e L. braziliensis guyanensis e aplicados nos cortes histológicos de 5 µm de espessura. Os antígenos de T. cruzi foram corados muito bem pelos três soros anti-T. cruzi e pelos dois soros anti-Leishmania com diluições entre 1:1.000 e 1:2.000. Diferentemente, os antígenos dç Leishmania foram revelados pelos soros anti- Leishmania somente em baixas diluições, ou seja, entre 1:60 e 1:160 enquanto que os soros

  7. Trypanosoma cruzi in dogs: electrocardiographic and echocardiographic evaluation, in Malinalco, State of Mexico

    Directory of Open Access Journals (Sweden)

    González-Vieyra SD

    2011-12-01

    Full Text Available Sandra Díaz González-Vieyra1, Ninfa Ramírez-Durán2, Ángel H Sandoval-Trujillo3, Juan C Vázquez-Chagoyán1, Humberto G Monroy-Salazar1, Alberto Barbabosa-Pliego11Research Center of Advanced Studies in Animal Health, Veterinary Husbandry School, 2Medical and Ambiental Microbiology, Research Center of Advanced Studies in Health Science, School of Medicine, Autonomous University of the State of Mexico, Toluca, Mexico; 3Department of Biological Systems, Metropolitan Autonomous University, Xochimilco, Mexico City, MexicoAbstract: Chagas disease caused by Trypanosoma cruzi is an important public health problem in Latin America. Dogs are considered a risk factor for human Chagas disease, a sentinel for T. cruzi infection in endemic regions and an animal model to study pathological aspects of the disease. The potential use of dogs as indicators of human cardiac pathogenicity of local T. cruzi strains has been studied insufficiently. We studied electrocardiographic (EKG and echocardiographic (ECG alteration frequencies observed in an open population of dogs in Malinalco, Mexico, and determined if such frequencies were statistically associated with T. cruzi infection in dogs. Animals (n = 139 were clinically examined and owners were asked to answer a questionnaire about dogs’ living conditions. Two commercial serological tests (IHA, ELISA were conducted to detect anti-T. cruzi serum antibodies. Significant differences between seropositive and seronegative animals in cardiomyopathic frequencies were detected through EKG and ECG (P < 0.05. Thirty dogs (21.58% were serologically positive to anti-T. cruzi antibodies (to ELISA and IHA assays, of which nine (30% had EKG and/or ECG alterations. From the remaining 104 (78.42% seronegative animals, five (4.5% had EKG and/or ECG abnormalities. Our data support the hypothesis that most EKG and ECG alterations found in dogs from Malinalco could be associated with T. cruzi infection. Considering the dog as a

  8. Prolactin: does it exert an up-modulation of the immune response in Trypanosoma cruzi-infected rats?

    Science.gov (United States)

    Filipin, Marina Del Vecchio; Brazão, Vânia; Santello, Fabricia Helena; Caetano, Leony Cristina; Toldo, Míriam Paula Alonso; do Prado, José Clóvis

    2011-09-27

    During the course of infection by Trypanosoma cruzi, the host immune system is involved in distinct, complex interactions with the endocrine system, and prolactin (PRL) is one of several hormones involved in immunoregulation. Although intensive studies attempting to understand the mechanisms that underlie Chagas' disease have been undertaken, there are still some pieces missing from this complex puzzle. Because data are scarce concerning the role of PRL involvement in Chagas' disease and taking into account the existence of crosstalk between neuroendocrine hormones and the immune system, the current study evaluates a possible up-regulation of the cellular immune response triggered by PRL in T. cruzi-infected rats and the role of PRL in reversing immunosuppression caused by the parasitic infection. The data shown herein demonstrate that PRL induces the proliferation of T lymphocytes, coupled with an activation of macrophages and the production of nitric oxide (NO), leading to a reduction in the number of blood trypomastigotes during the peak of parasitemia. During the acute phase of T. cruzi infection, an enhancement of both CD3+CD4+ and CD3+CD8+ T cell populations were observed in infected groups, with the highest numbers of these T cell subsets found in the infected group treated with PRL. Because NO is a signaling molecule involved in a number of cellular interactions with components of the immune system and the neuroendocrine system, PRL can be considered an alternative hormone able to up-regulate the host's immune system, consequently lowering the pathological effects of a T. cruzi infection.

  9. Evolução da cardiopatia experimentalmente induzida em coelhos infectados com Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Florêncio Figueiredo

    1985-09-01

    Full Text Available Coelhos jovens de ambos os sexos (1-2 meses de idade, outbred, inoculados com tripomastigotas da cepa Colômbia de Trypanosoma cruzi desenvolveram lesões cardíacas, macro e microscópicas, além de características parasitológicas e imunológicas, muito semelhantes às observadas na doença de Chagas humana, tanto na fase aguda como na fase crônica. Na fase aguda a síndrome cardíaca caracteriza-se macroscopicamente por discreta cardiomegalia, com dilatação de câmaras direitas, e miscroscopicamente por miocardite focal pouco acentuada; na fase crônica, por cardiomegalia moderada ou acentuada, com hipertrofia e dilatação de câmaras e adelgaçamento da ponta (aneurisma apical, predominantemente do ventrículo esquerdo, e por miocardite focal, cóm áreas de necrose miocitolítica e degeneração de miocélulas, associadas a infiltrado inflamatório, principalmente composto de linfócitos, e fibrose intersticial. Devido à reprodução de aspectos da doença cardíaca chagásica humana em tempo relativamente curto, à simplicidade, à disponibilidade para múltiplos pesquisadores e ao baixo custo, o modelo representado pelo coelho constitui uma alternativa para estudos dos mecanismos, patologia e tratamento da cardiopatia chagásica.Male and female out bred young rabbits (1-2 months of age inoculated with trypomastigote forms of the Colombia strain of T. cruzi have been shown to develop cardiac pathologic changes, besides parasitologícal and immunological features, very similar to those observed in both acute and chronic phases of Chagas' disease in man. In the acute phase the cardiac syndrome is characterized grossly by slight cardiomegaly, with dilatation of the right chambers and microscopically by discretefocal myocarditis: in the chronic phase, by moderate ormarked cardiomegaly, with hypertrophy and dilatation of all chambers, and thinning of the ventricularapex (apical aneurysm, particularly of the left ventricle, andstriking

  10. MicroRNA Transcriptome Profiling in Heart of Trypanosoma cruzi-Infected Mice: Parasitological and Cardiological Outcomes.

    Directory of Open Access Journals (Sweden)

    Isabela Cunha Navarro

    Full Text Available Chagas disease is caused by the parasite Trypanosoma cruzi, and it begins with a short acute phase characterized by high parasitemia followed by a life-long chronic phase with scarce parasitism. Cardiac involvement is the most prominent manifestation, as 30% of infected subjects will develop abnormal ventricular repolarization with myocarditis, fibrosis and cardiomyocyte hypertrophy by undefined mechanisms. Nevertheless, follow-up studies in chagasic patients, as well as studies with murine models, suggest that the intensity of clinical symptoms and pathophysiological events that occur during the acute phase of disease are associated with the severity of cardiac disease observed during the chronic phase. In the present study we investigated the role of microRNAs (miRNAs in the disease progression in response to T. cruzi infection, as alterations in miRNA levels are known to be associated with many cardiovascular disorders. We screened 641 rodent miRNAs in heart samples of mice during an acute infection with the Colombiana T.cruzi strain and identified multiple miRNAs significantly altered upon infection. Seventeen miRNAs were found significantly deregulated in all three analyzed time points post infection. Among these, six miRNAs had their expression correlated with clinical parameters relevant to the disease, such as parasitemia and maximal heart rate-corrected QT (QTc interval. Computational analyses identified that the gene targets for these six miRNAs were involved in networks and signaling pathways related to increased ventricular depolarization and repolarization times, important factors for QTc interval prolongation. The data presented here will guide further studies about the contribution of microRNAs to Chagas heart disease pathogenesis.

  11. Real-time PCR strategy for parasite quantification in blood and tissue samples of experimental Trypanosoma cruzi infection.

    Science.gov (United States)

    Caldas, Sérgio; Caldas, Ivo Santana; Diniz, Lívia de Figueiredo; Lima, Wanderson Geraldo de; Oliveira, Riva de Paula; Cecílio, Alzira Batista; Ribeiro, Isabela; Talvani, André; Bahia, Maria Terezinha

    2012-09-01

    The lack of an accurate diagnosis has been a serious obstacle to the advancement of the anti-Trypanosoma cruzi chemotherapy and long-term infection can result in different health risks to human. PCRs are alternative methods, more sensitive than conventional parasitological techniques, which due to their low sensitivities are considered unsuitable for these purposes. The aim of this study was to investigate a sensitive diagnostic strategy to quantify blood and cardiac tissues parasites based on real-time PCR tools during acute and chronic phases of murine Chagas disease, as well as to monitor the evolution of infection in those mice under specific treatment. In parallel, fresh blood examination, immunological analysis and quantification of cardiac inflammation were also performed to confront and improve real-time PCR data. Similar profiles of parasitemia curves were observed in both quantification techniques during the acute phase of the infection. In contrast, parasites could be quantified only by real-time PCR at 60 and 120 days of infection. In cardiac tissue, real-time PCR detected T. cruzi DNA in 100% of infected mice, and using this tool a significant Pearson correlation between parasite load in peripheral blood and in cardiac tissue during acute and chronic phases was observed. Levels of serum CCL2, CCL5 and nitric oxide were coincident with parasite load but focal and diffuse mononuclear infiltrates was observed, even with significant (pblood and cardiac muscle at the treatment period, but after the end of chemotherapy an increase of parasitism was detected. Interestingly, inflammatory mediators levels and heart inflammation intensity had similar evolution to the parasite load, in the group of animals treated. Taken together, our data show that real-time PCR strategy used was suitable for studies of murine T. cruzi infection and may prove useful in investigations involving experimental chemotherapy of the disease and the benefits of treatment in relation to

  12. Immunomodulatory effects of zinc and DHEA on the Th-1 immune response in rats infected with Trypanosoma cruzi.

    Science.gov (United States)

    Brazão, Vânia; Santello, Fabricia Helena; Caetano, Leony Cristina; Del Vecchio Filipin, Marina; Toldo, Míriam Paula Alonso; do Prado, José Clóvis

    2010-05-01

    Chagas' disease is considered the sixth most important neglected tropical disease worldwide. Considerable knowledge has been accumulated concerning the role of zinc on cellular immunity. The steroid hormone dehydroepiandrosterone (DHEA) is also known to modulate the immune system. The aims of this paper were to investigate a possible synchronization of their effects on cytokines and NO production and the resistance to Trypanosoma cruzi during the acute phase of infection. It was found that zinc, DHEA or zinc and DHEA supplementation enhanced the immune response, as evidenced by a significant reduction in parasitemia levels. Zinc and DHEA supplementation exerted additive effects on the immune response by elevation of macrophage counts, and by increasing concentrations of IFN-gamma and NO.

  13. Risk factors associated with Trypanosoma cruzi exposure in domestic dogs from a rural community in Panama.

    Science.gov (United States)

    Saldaña, Azael; Calzada, José E; Pineda, Vanessa; Perea, Milixa; Rigg, Chystrie; González, Kadir; Santamaria, Ana Maria; Gottdenker, Nicole L; Chaves, Luis F

    2015-11-01

    Chagas disease, caused by Trypanosoma cruzi infection, is a zoonosis of humans, wild and domestic mammals, including dogs. In Panama, the main T. cruzi vector is Rhodnius pallescens, a triatomine bug whose main natural habitat is the royal palm, Attalea butyracea. In this paper, we present results from three T. cruzi serological tests (immunochromatographic dipstick, indirect immunofluorescence and ELISA) performed in 51 dogs from 24 houses in Trinidad de Las Minas, western Panama. We found that nine dogs were seropositive (17.6% prevalence). Dogs were 1.6 times more likely to become T. cruzi seropositive with each year of age and 11.6 times if royal palms where present in the peridomiciliary area of the dog's household or its two nearest neighbours. Mouse-baited-adhesive traps were employed to evaluate 12 peridomestic royal palms. All palms were found infested with R. pallescens with an average of 25.50 triatomines captured per palm. Of 35 adult bugs analysed, 88.6% showed protozoa flagellates in their intestinal contents. In addition, dogs were five times more likely to be infected by the presence of an additional domestic animal species in the dog's peridomiciliary environment. Our results suggest that interventions focused on royal palms might reduce the exposure to T. cruzi infection.

  14. Human infection with Trypanosoma cruzi induces parasite antigen-specific cytotoxic T lymphocyte responses.

    Science.gov (United States)

    Wizel, B; Palmieri, M; Mendoza, C; Arana, B; Sidney, J; Sette, A; Tarleton, R

    1998-09-01

    Experimental models of Chagas' disease, an infection caused by the intracellular protozoan Trypanosoma cruzi, have demonstrated the crucial immunoprotective role played by CD8(+) T lymphocytes. These cells dominate inflammatory foci in parasitized tissues and their elimination from mice leads to uncontrolled parasite replication and subsequent death of the infected host. A trypomastigote surface antigen, TSA-1, and two amastigote surface molecules, ASP-1 and ASP-2, were recently identified as targets of CD8(+) cytotoxic T lymphocytes (CTL) in T. cruzi-infected mice. Until now, however, there was no evidence for the development of parasite-specific CTL in T. cruzi-infected humans. In this study, human CTL specific for TSA-1-, ASP-1-, and ASP-2-derived peptides were detected in the peripheral blood mononuclear cells from 21 of 24 HLA-A2(+) T. cruzi-infected patients. CTL recognition was antigen specific, A2-restricted, and CD8(+) T cell-dependent. Demonstration of human CTL against T. cruzi and against target molecules identified using the murine model provides important information for the optimal design and evaluation of vaccines to prevent or ameliorate Chagas' disease.

  15. Usefulness of microsatellite typing in population genetic studies of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Macedo Andrea M

    2001-01-01

    Full Text Available Through microsatellite analysis of 53 monoclonal populations of Trypanosoma cruzi, we found a remarkable degree of genetic polymorphism with no single multilocus genotype being observed more than once. The microsatellite profile proved to be stable during 70 generations of the CL Brener clone in culture. The microsatellite profiling presented also high diagnostic sensitivity since DNA amplifications could be achieved with less than 100 fg DNA, corresponding to half parasite total DNA content. Based on these technical attributes the microsatellite assay turns out to be an important tool for direct typing T. cruzi in biological samples. By using this approach we were able to type T. cruzi in feces of artificially infected bugs and in single cells sorted by FACS. The microsatellites have shown to be excellent markers for T. cruzi phylogenetic reconstruction. We used maximum parsimony based on the minimum number of mutational steps to build an unrooted Wagner network, which confirms previous conclusions based on the analysis of the D7 domain of the LSU rDNA gene that T. cruzi is composed by two major groups. We also obtained evidence that strains belonging to rRNA group 2 are subdivided into two genetically distant clusters, and that one of these clusters is more related to rRNA group 1/2. These results suggest different origins for these strains.

  16. Trypanosoma cruzi strains from triatomine collected in Bahia and Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Aline Rimoldi Ribeiro

    2014-04-01

    Full Text Available OBJECTIVE Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01, Triatoma melanocephala (11, T. lenti (94, T. pseudomaculata (02, T. sherlocki (26 and T. sordida (460, and two in cities in Rio Grande do Sul, namely T. circummaculata (11 and T. rubrovaria (115. Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one, T. lenti (one, T. rubrovaria (16 and T. sordida (10. Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.

  17. Synthesis and characterization of potent inhibitors of Trypanosoma cruzi dihydrofolate reductase

    Energy Technology Data Exchange (ETDEWEB)

    Schormann, Norbert; Velu, Sadanandan E.; Murugesan, Srinivasan; Senkovich, Olga; Walker, Kiera; Chenna, Bala C.; Shinkre, Bidhan; Desai, Amar; Chattopadhyay, Debasish (UAB)

    2010-09-17

    Dihydrofolate reductase (DHFR) of the parasite Trypanosoma cruzi (T. cruzi) is a potential target for developing drugs to treat Chagas disease. We have undertaken a detailed structure-activity study of this enzyme. We report here synthesis and characterization of six potent inhibitors of the parasitic enzyme. Inhibitory activity of each compound was determined against T. cruzi and human DHFR. One of these compounds, ethyl 4-(5-[(2,4-diamino-6-quinazolinyl)methyl]amino-2-methoxyphenoxy)butanoate (6b) was co-crystallized with the bifunctional dihydrofolate reductase-thymidylate synthase enzyme of T. cruzi and the crystal structure of the ternary enzyme:cofactor:inhibitor complex was determined. Molecular docking was used to analyze the potential interactions of all inhibitors with T. cruzi DHFR and human DHFR. Inhibitory activities of these compounds are discussed in the light of enzyme-ligand interactions. Binding affinities of each inhibitor for the respective enzymes were calculated based on the experimental or docked binding mode. An estimated 60-70% of the total binding energy is contributed by the 2,4-diaminoquinazoline scaffold.

  18. DO COMMERCIAL SEROLOGIC TESTS FOR TRYPANOSOMA CRUZI INFECTION DETECT MEXICAN STRAINS IN WOMEN AND NEWBORNS?

    Science.gov (United States)

    Gamboa-León, Rubi; Gonzalez-Ramirez, Claudia; Padilla-Raygoza, Nicolas; Sosa-Estani, Sergio; Caamal-Kantun, Alejandra; Buekens, Pierre; Dumonteil, Eric

    2012-01-01

    We sought to determine the serological test that could be used for Trypanosoma cruzi seroprevalence studies in Mexico, where lineage I predominates. In a previous study among pregnant women and their newborns in the states of Yucatan and Guanajuato, we reported a 0.8–0.9% of prevalence for T. cruzi–specific antibodies by Stat-Pak and Wiener ELISA. We have expanded this study here by performing an additional non-commercial ELISA and confirming the seropositives with Western blot, using whole antigens of a local parasite strain. We found a seroprevalence of 0.6% (3/500) in Merida and 0.4% in Guanajuato (2/488). The 5 seropositive umbilical cord samples reacted to both non-commercial ELISA and Western blot tests, and only 1 of the maternal samples was not reactive to non-commercial ELISA. A follow-up of the newborns at 10 mo was performed in Yucatan to determine the presence of T. cruzi antibodies in children as evidence of congenital infection. None of the children was seropositive. One newborn from an infected mother died at 2 wk of age of cardiac arrest, but T. cruzi infection was not confirmed. The T. cruzi seroprevalence data obtained with both commercial tests (Stat-Pak and ELISA Wiener) are similar to those from non-commercial tests using a local Mexican strain of T. cruzi. PMID:21506787

  19. Influence of melatonin therapy and orchiectomy on T cell subsets in male Wistar rats infected with Trypanosoma cruzi.

    Science.gov (United States)

    Santello, Fabricia H; Del Vecchio Filipin, Marina; Caetano, Leony C; Brazão, Vânia; Caetano, Luana N; Dos Santos, Carla D; Alonso Toldo, Míriam P; do Prado, José C

    2009-10-01

    Gonadal steroids exert an important influence on the host immune response during infection. Changes resulting from the absence or replacement of gonadal hormones may represent a distinct evolution of a particular parasite. Taking into account the greater susceptibility of males to parasites, the magnitude of the immune response seems to depend on the interaction of many hormones that will act synergistically with other immune cells. The aims of this research were to evaluate the effects of the luck of male sex hormones due to orchiectomy, and the influence of oral administration of melatonin on the immune response of male Wistar rats infected with the Y strain of Trypanosoma cruzi. The percentage of CD3(+) CD4(+) and CD3(+) CD8(+) lymphocyte T cell subsets were evaluated using flow cytometry and the measurement of IL-2 and IL-12. For all parameters examined, a synergistic action of melatonin and orchiectomy on the host's immune response was observed, promoting an effective response against the parasite during the acute phase of infection. These results offer insight into other possibilities for possibly controlling T. cruzi proliferation through melatonin therapy and also the stimulatory effects on host's immune response triggered by the absence of male gonadal steroids during the acute phase of infection.

  20. Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II Resposta à quimioterapia com benzonidazol de clones isolados da cepa 21SF do Trypanosoma cruzi (biodema Tipo II, Trypanosoma cruzi II

    Directory of Open Access Journals (Sweden)

    Rozália Figueira Campos

    2005-04-01

    Full Text Available Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II. Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days. Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640 and untreated controls (1:160 to 1:640. Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.A suscetibilidade à quimioterapia com o benzonidazol, de 5 clones isolados da cepa 21SF (biodema Tipo II, T. cruzi II, foi investigada. Camundongos suíços foram infectados com a cepa parental e com cada clone e submetidos à quimioterapia com benzonidazol (100mg/k/dia durante 90 dias. Os índices de cura foram avaliados pelos testes de cura parasitológicos. A sorologia foi avaliada para os animais tratados e (de negativo a 1: 640 e para os controles não tratados( 1:160 a 1:640. Os índices de cura variaram de 30% a 100% para os 5 clones sendo de 25% para a cepa parental. Os resultados sugerem que a variabilidade de resposta ao tratamento das populações clonais das cepas Trypanosoma cruzi II é responsável pela grande variação na resposta à quimioterapia com benzonidazol e nifurtimox das cepas deste biodema.

  1. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi.

    Science.gov (United States)

    Sülsen, Valeria P; Puente, Vanesa; Papademetrio, Daniela; Batlle, Alcira; Martino, Virginia S; Frank, Fernanda M; Lombardo, María E

    2016-01-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin accomplished its antiparasitic

  2. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi

    Science.gov (United States)

    Papademetrio, Daniela; Batlle, Alcira; Martino, Virginia S.; Frank, Fernanda M.; Lombardo, María E.

    2016-01-01

    Trypanosoma cruzi is the causative agent of Chagas’ disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin accomplished its

  3. Synergy testing of FDA-approved drugs identifies potent drug combinations against Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Joseph D Planer

    2014-07-01

    Full Text Available An estimated 8 million persons, mainly in Latin America, are infected with Trypanosoma cruzi, the etiologic agent of Chagas disease. Existing antiparasitic drugs for Chagas disease have significant toxicities and suboptimal effectiveness, hence new therapeutic strategies need to be devised to address this neglected tropical disease. Due to the high research and development costs of bringing new chemical entities to the clinic, we and others have investigated the strategy of repurposing existing drugs for Chagas disease. Screens of FDA-approved drugs (described in this paper have revealed a variety of chemical classes that have growth inhibitory activity against mammalian stage Trypanosoma cruzi parasites. Aside from azole antifungal drugs that have low or sub-nanomolar activity, most of the active compounds revealed in these screens have effective concentrations causing 50% inhibition (EC50's in the low micromolar or high nanomolar range. For example, we have identified an antihistamine (clemastine, EC50 of 0.4 µM, a selective serotonin reuptake inhibitor (fluoxetine, EC50 of 4.4 µM, and an antifolate drug (pyrimethamine, EC50 of 3.8 µM and others. When tested alone in the murine model of Trypanosoma cruzi infection, most compounds had insufficient efficacy to lower parasitemia thus we investigated using combinations of compounds for additive or synergistic activity. Twenty-four active compounds were screened in vitro in all possible combinations. Follow up isobologram studies showed at least 8 drug pairs to have synergistic activity on T. cruzi growth. The combination of the calcium channel blocker, amlodipine, plus the antifungal drug, posaconazole, was found to be more effective at lowering parasitemia in mice than either drug alone, as was the combination of clemastine and posaconazole. Using combinations of FDA-approved drugs is a promising strategy for developing new treatments for Chagas disease.

  4. Comparative analysis of the kinomes of three pathogenic trypanosomatids: Leishmania major, Trypanosoma brucei and Trypanosoma cruzi

    OpenAIRE

    Ward Pauline N; Worthey Elizabeth A; Parsons Marilyn; Mottram Jeremy C

    2005-01-01

    Abstract Background The trypanosomatids Leishmania major, Trypanosoma brucei and Trypanosoma cruzi cause some of the most debilitating diseases of humankind: cutaneous leishmaniasis, African sleeping sickness, and Chagas disease. These protozoa possess complex life cycles that involve development in mammalian and insect hosts, and a tightly coordinated cell cycle ensures propagation of the highly polarized cells. However, the ways in which the parasites respond to their environment and coordi...

  5. MDL28170, a calpain inhibitor, affects Trypanosoma cruzi metacyclogenesis, ultrastructure and attachment to Rhodnius prolixus midgut.

    Directory of Open Access Journals (Sweden)

    Vítor Ennes-Vidal

    Full Text Available BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas' disease. During the parasite life cycle, many molecules are involved in the differentiation process and infectivity. Peptidases are relevant for crucial steps of T. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we have investigated the effect of the calpain inhibitor MDL28170 on the attachment of T. cruzi epimastigotes to the luminal midgut surface of Rhodnius prolixus, as well as on the metacyclogenesis process and ultrastructure. MDL28170 treatment was capable of significantly reducing the number of bound epimastigotes to the luminal surface midgut of the insect. Once the cross-reactivity of the anti-Dm-calpain was assessed, it was possible to block calpain molecules by the antibody, leading to a significant reduction in the capacity of adhesion to the insect guts by T. cruzi. However, the antibodies were unable to interfere in metacyclogenesis, which was impaired by the calpain inhibitor presenting a significant reduction in the number of metacyclic trypomastigotes. The calpain inhibitor also promoted a direct effect against bloodstream trypomastigotes. Ultrastructural analysis of epimastigotes treated with the calpain inhibitor revealed disorganization in the reservosomes, Golgi and plasma membrane disruption. CONCLUSIONS/SIGNIFICANCE: The presence of calpain and calpain-like molecules in a wide range of organisms suggests that these proteins could be necessary for basic cellular functions. Herein, we demonstrated the effects of MDL28170 in crucial steps of the T. cruzi life cycle, such as attachment to the insect midgut and metacyclogenesis, as well as in parasite viability and morphology. Together with our previous findings, these results help to shed some light on the functions of T. cruzi calpains. Considering the potential roles of

  6. Vaccination with trypomastigote surface antigen 1-encoding plasmid DNA confers protection against lethal Trypanosoma cruzi infection.

    Science.gov (United States)

    Wizel, B; Garg, N; Tarleton, R L

    1998-11-01

    DNA vaccination was evaluated with the experimental murine model of Trypanosoma cruzi infection as a means to induce antiparasite protective immunity, and the trypomastigote surface antigen 1 (TSA-1), a target of anti-T. cruzi antibody and major histocompatibility complex (MHC) class I-restricted CD8(+) cytotoxic T-lymphocyte (CTL) responses, was used as the model antigen. Following the intramuscular immunization of H-2(b) and H-2(d) mice with a plasmid DNA encoding an N-terminally truncated TSA-1 lacking or containing the C-terminal nonapeptide tandem repeats, the antibody level, CTL response, and protection against challenge with T. cruzi were assessed. In H-2(b) mice, antiparasite antibodies were induced only by immunization with the DNA construct encoding TSA-1 containing the C-terminal repeats. However, both DNA constructs were efficient in eliciting long-lasting CTL responses against the protective H-2Kb-restricted TSA-1515-522 epitope. In H-2(d) mice, inoculation with either of the two TSA-1-expressing vectors effectively generated antiparasite antibodies and primed CTLs that lysed T. cruzi-infected cells in an antigen-specific, MHC class I-restricted, and CD8(+)-T-cell-dependent manner. When TSA-1 DNA-vaccinated animals were challenged with T. cruzi, 14 of 22 (64%) H-2(b) and 16 of 18 (89%) H-2(d) mice survived the infection. The ability to induce significant murine anti-T. cruzi protective immunity by immunization with plasmid DNA expressing TSA-1 provides the basis for the application of this technology in the design of optimal DNA multicomponent anti-T. cruzi vaccines which may ultimately be used for the prevention or treatment of Chagas' disease.

  7. Trypanosoma cruzi extracts elicit protective immune response against chemically induced colon and mammary cancers.

    Science.gov (United States)

    Ubillos, Luis; Freire, Teresa; Berriel, Edgardo; Chiribao, María Laura; Chiale, Carolina; Festari, María Florencia; Medeiros, Andrea; Mazal, Daniel; Rondán, Mariella; Bollati-Fogolín, Mariela; Rabinovich, Gabriel A; Robello, Carlos; Osinaga, Eduardo

    2016-04-01

    Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, has anticancer effects mediated, at least in part, by parasite-derived products which inhibit growth of tumor cells. We investigated whether immunity to T. cruzi antigens could induce antitumor activity, using two rat models which reproduce human carcinogenesis: colon cancer induced by 1,2-dimethylhydrazine (DMH), and mammary cancer induced by N-nitroso-N-methylurea (NMU). We found that vaccination with T. cruzi epimastigote lysates strongly inhibits tumor development in both animal models. Rats immunized with T. cruzi antigens induce activation of both CD4(+) and CD8(+) T cells and splenocytes from these animals showed higher cytotoxic responses against tumors as compared to rats receiving adjuvant alone. Tumor-associated immune responses included increasing number of CD11b/c(+) His48(-) MHC II(+) cells corresponding to macrophages and/or dendritic cells, which exhibited augmented NADPH-oxidase activity. We also found that T. cruzi lysate vaccination developed antibodies specific for colon and mammary rat cancer cells, which were capable of mediating antibody-dependent cellular cytotoxicity (ADCC) in vitro. Anti-T. cruzi antibodies cross-reacted with human colon and breast cancer cell lines and recognized 41/60 (68%) colon cancer and 38/63 (60%) breast cancer samples in a series of 123 human tumors. Our results suggest that T. cruzi antigens can evoke an integrated antitumor response involving both the cellular and humoral components of the immune response and provide novel insights into the understanding of the intricate relationship between parasite infection and tumor growth.

  8. How Trypanosoma cruzi deals with oxidative stress: Antioxidant defence and DNA repair pathways.

    Science.gov (United States)

    Machado-Silva, Alice; Cerqueira, Paula Gonçalves; Grazielle-Silva, Viviane; Gadelha, Fernanda Ramos; Peloso, Eduardo de Figueiredo; Teixeira, Santuza Maria Ribeiro; Machado, Carlos Renato

    2016-01-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is an obligatory intracellular parasite with a digenetic life cycle. Due to the variety of host environments, it faces several sources of oxidative stress. In addition to reactive oxygen species (ROS) produced by its own metabolism, T. cruzi must deal with high ROS levels generated as part of the host's immune responses. Hence, the conclusion that T. cruzi has limited ability to deal with ROS (based on the lack of a few enzymes involved with oxidative stress responses) seems somewhat paradoxical. Actually, to withstand such variable sources of oxidative stress, T. cruzi has developed complex defence mechanisms. This includes ROS detoxification pathways that are distinct from the ones in the mammalian host, DNA repair pathways and specialized polymerases, which not only protect its genome from the resulting oxidative damage but also contribute to the generation of genetic diversity within the parasite population. Recent studies on T. cruzi's DNA repair pathways as mismatch repair (MMR) and GO system suggested that, besides a role associated with DNA repair, some proteins of these pathways may also be involved in signalling oxidative damage. Recent data also suggested that an oxidative environment might be beneficial for parasite survival within the host cell as it contributes to iron mobilization from the host's intracellular storages. Besides contributing to the understanding of basic aspects of T. cruzi biology, these studies are highly relevant since oxidative stress pathways are part of the poorly understood mechanisms behind the mode of action of drugs currently used against this parasite. By unveiling new peculiar aspects of T. cruzi biology, emerging data on DNA repair pathways and other antioxidant defences from this parasite have revealed potential new targets for a much needed boost in drug development efforts towards a better treatment for Chagas disease.

  9. High Trypanosoma cruzi infection prevalence associated with minimal cardiac pathology among wild carnivores in central Texas

    Directory of Open Access Journals (Sweden)

    Rachel Curtis-Robles

    2016-08-01

    Full Text Available Infection with the zoonotic vector-borne protozoal parasite Trypanosoma cruzi causes Chagas disease in humans and dogs throughout the Americas. Despite the recognized importance of various wildlife species for perpetuating Trypanosoma cruzi in nature, relatively little is known about the development of cardiac disease in infected wildlife. Using a cross-sectional study design, we collected cardiac tissue and blood from hunter-donated wildlife carcasses- including raccoon (Procyon lotor, coyote (Canis latrans, gray fox (Urocyon cinereoargenteus, and bobcat (Lynx rufus – from central Texas, a region with established populations of infected triatomine vectors and increasing diagnoses of Chagas disease in domestic dogs. Based on PCR analysis, we found that 2 bobcats (14.3%, 12 coyotes (14.3%, 8 foxes (13.8%, and 49 raccoons (70.0% were positive for T. cruzi in at least one sample (right ventricle, apex, and/or blood clot. Although a histologic survey of right ventricles showed that 21.1% of 19 PCR-positive hearts were characterized by mild lymphoplasmocytic infiltration, no other lesions and no amastigotes were observed in any histologic section. DNA sequencing of the TcSC5D gene revealed that raccoons were infected with T. cruzi strain TcIV, and a single racoon harbored a TcI/TcIV mixed infection. Relative to other wildlife species tested here, our data suggest that raccoons may be important reservoirs of TcIV in Texas and a source of infection for indigenous triatomine bugs. The overall high level of infection in this wildlife community likely reflects high levels of vector contact, including ingestion of bugs. Although the relationship between the sylvatic cycle of T. cruzi transmission and human disease risk in the United States has yet to be defined, our data suggest that hunters and wildlife professionals should take precautions to avoid direct contact with potentially infected wildlife tissues.

  10. Genotyping of Trypanosoma cruzi DTUs and Trypanosoma rangeli genetic groups in experimentally infected Rhodnius prolixus by PCR-RFLP.

    Science.gov (United States)

    Sá, Amanda R N; Dias, Greicy B M; Kimoto, Karen Y; Steindel, Mário; Grisard, Edmundo C; Toledo, Max Jean O; Gomes, Mônica L

    2016-04-01

    The specific detection and genetic typing of trypanosomes that infect humans, mammalian reservoirs, and vectors is crucial for diagnosis and epidemiology. We utilized a PCR-RFLP assay that targeted subunit II of cytochrome oxidase and 24Sα-rDNA to simultaneously detect and discriminate six Trypanosoma cruzi discrete typing units (DTUs) and two genetic groups of Trypanosoma rangeli (KP1+/KP1-) in intestinal contents of experimentally infected Rhodnius prolixus. The PCR assays showed that in 23 of 29 (79.4%) mixed infections with the six T. cruzi DTUs and mixed infections with individual DTUs and/or groups KP1+ and KP1-, both parasites were successfully detected. In six mixed infections that involved TcIII, the TcI, TcII, TcV, and TcVI DTUs predominated to the detriment of TcIII, indicating the selection of genetic groups. Interactions between different genetic groups and vectors may lead to genetic selection over TcIII. The elimination of this DTU by the immune system of the vector appears unlikely because TcIII was present in other mixed infections (TcIII/TcIV and TcIII/KP1+). Both molecular markers used in this study were sensitive and specific, demonstrating their usefulness in a wide geographical area where distinct genotypes of these two species are sympatric. Although the cellular and molecular mechanisms that are involved in parasite-vector interactions are still poorly understood, our results indicate a dynamic selection toward specific T. cruzi DTUs in R. prolixus during mixed genotype infections.

  11. Aspectos ultra-estruturais da forma epimastigota do Trypanosoma cruzi em meio LIT

    Directory of Open Access Journals (Sweden)

    Wanderley de Souza

    1975-06-01

    Full Text Available E feito um estudo da ultra-estrutura da forma epismastigota do Trypanosoma cruzi mantida em meio de cultivo acelular. O núcleo das formas em divisão apresenta um aspecto homogêneo. Microtúbulos intranucleares são observados durante a divisão. No entanto, a membrana nuclear permanece íntegra. O citoplasma apresenta-se com vacúolos de dimensões e aspectos variados. Com o método do ácido periódico-tiosemicarbazida-proteinato de prata, polissacaríáeos e/ou glicoproteínas foram localizados na membrana celular e na membrana que delimita certos vacúolos citoplasmáticos.In this paper the fine structure of the epimastigotes forms of Trypanosoma cruzi maintained in an acellular culture medium, is described. During division the nucleus shows a homogenous structure owing to the dispersion of its chromatin and nucleolar material. Microtubules similar to those of a mitotic spindle in metazoan cells appear, running frorn one pole to the other. During the whole process of division the nuclear membrane remains intact. The cytoplam shows many vacuoles. With the cytochemical method of acid periodic-thiosemicarbazide-silver proteinate, a polysaccharide surface coat is observed on the whole surface membrane system of T. cruzi. A positive re- action is also observed in the membranes of some vacuoles in the cytoplasm of the parasites.

  12. Trypanosoma cruzi: an in vitro cycle of cell differentiation in axenic culture.

    Science.gov (United States)

    Rondinelli, E; Silva, R; Carvalho, J F; de Almeida Soares, C M; de Carvalho, E F; de Castro, F T

    1988-08-01

    The operation of an in vitro cycle of cell differentiation of Trypanosoma cruzi in axenic culture was obtained. When epimastigote forms, grown in LIT medium, were transferred to a modified LIT medium (E. Chiari, 1981, "Diferenciação do Trypanosoma cruzi em cultura." Ph.D. dissertation, Universidade Federal de Minas Gerais, Brazil), metacyclic trypomastigotes were generated. The latter, upon treatment with fresh human serum, and subsequent incubation in LIT medium gave origin to clusters of spheromastigote cells. The spheromastigotes were resistent to lysis mediated by the complement system and possess a morphology shown by optical and electron microscopy to be very similar to spheromastigotes derived from tissues of infected vertebrates. Blood-like trypomastigotes, or epimastigotes, could be obtained from spheromastigotes depending on the incubation conditions: at high serum concentration (55%) at 37 C, blood-like trypomastigotes were generated; by aging or heating (37 C), at low serum concentration (10%), epimastigotes were formed, closing the whole sequence of cell differentiation of T. cruzi. The molecular characterization of the different cell forms by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of metabolic pulse labeled proteins showed that the in vitro differentiated cells were distinct, not only by morphological criteria, but by differential gene expression as well. All the forms described could be obtained in large amounts (6 x 10(7) to 1 x 10(8)/ml), making it possible to perform preparative biochemical, molecular biological, and immunological experiments.

  13. The Dialogue of the Host-Parasite Relationship: Leishmania spp. and Trypanosoma cruzi Infection

    Directory of Open Access Journals (Sweden)

    Carlos Gustavo Vieira de Morais

    2015-01-01

    Full Text Available The intracellular protozoa Leishmania spp. and Trypanosoma cruzi and the causative agents of Leishmaniasis and Chagas disease, respectively, belong to the Trypanosomatidae family. Together, these two neglected tropical diseases affect approximately 25 million people worldwide. Whether the host can control the infection or develops disease depends on the complex interaction between parasite and host. Parasite surface and secreted molecules are involved in triggering specific signaling pathways essential for parasite entry and intracellular survival. The recognition of the parasite antigens by host immune cells generates a specific immune response. Leishmania spp. and T. cruzi have a multifaceted repertoire of strategies to evade or subvert the immune system by interfering with a range of signal transduction pathways in host cells, which causes the inhibition of the protective response and contributes to their persistence in the host. The current therapeutic strategies in leishmaniasis and trypanosomiasis are very limited. Efficacy is variable, toxicity is high, and the emergence of resistance is increasingly common. In this review, we discuss the molecular basis of the host-parasite interaction of Leishmania and Trypanosoma cruzi infection and their mechanisms of subverting the immune response and how this knowledge can be used as a tool for the development of new drugs.

  14. Trypanosoma Cruzi Cyp51 Inhibitor Derived from a Mycobacterium Tuberculosis Screen Hit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chiung-Kuang; Doyle, Patricia S.; Yermalitskaya, Liudmila V.; Mackey, Zachary B.; Ang, Kenny K.H.; McKerrow, James H.; Podust, Larissa M.; (Vanderbilt); (UCSF)

    2009-02-18

    The two front-line drugs for chronic Trypanosoma cruzi infections are limited by adverse side-effects and declining efficacy. One potential new target for Chagas disease chemotherapy is sterol 14{alpha}-demethylase (CYP51), a cytochrome P450 enzyme involved in biosynthesis of membrane sterols. In a screening effort targeting Mycobacterium tuberculosis CYP51 (CYP51{sub Mt}), we previously identified the N-[4-pyridyl]-formamide moiety as a building block capable of delivering a variety of chemotypes into the CYP51 active site. In that work, the binding modes of several second generation compounds carrying this scaffold were determined by high-resolution co-crystal structures with CYP51{sub Mt}. Subsequent assays against the CYP51 orthologue in T. cruzi, CYP51{sub Tc}, demonstrated that two of the compounds tested in the earlier effort bound tightly to this enzyme. Both were tested in vitro for inhibitory effects against T. cruzi and the related protozoan parasite Trypanosoma brucei, the causative agent of African sleeping sickness. One of the compounds had potent, selective anti-T. cruzi activity in infected mouse macrophages. Cure of treated host cells was confirmed by prolonged incubation in the absence of the inhibiting compound. Discrimination between T. cruzi and T. brucei CYP51 by the inhibitor was largely based on the variability (phenylalanine versus isoleucine) of a single residue at a critical position in the active site. CYP51{sub Mt}-based crystal structure analysis revealed that the functional groups of the two tightly bound compounds are likely to occupy different spaces in the CYP51 active site, suggesting the possibility of combining the beneficial features of both inhibitors in a third generation of compounds to achieve more potent and selective inhibition of CYP51{sub Tc}. Enzyme sterol 14{alpha}-demethylase (CYP51) is a well-established target for anti-fungal therapy and is a prospective target for Chagas disease therapy. We previously identified a

  15. Clinical forms of Trypanosoma cruzi infected individuals in the chronic phase of Chagas disease in Puebla, Mexico

    OpenAIRE

    2006-01-01

    In Mexico, despite the relatively high seroprevalence of Trypanosoma cruzi infection in humans in some areas, reported morbidity of Chagas disease is not clear. We determined clinical stage in 71 individuals seropositive to T. cruzi in the state of Puebla, Mexico, an area endemic for Chagas disease with a reported seroprevalence of 7.7%. Diagnosis of Chagas disease was made by two standardized serological tests (ELISA, IHA). Individuals were stratified according to clinical studies. All patie...

  16. Domestic, peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis

    OpenAIRE

    Claudia Mendonça de Bezerra; Luciano Pamplona de Góes Cavalcanti; Rita de Cássia Moreira de Souza; Silvia Ermelinda Barbosa; Samanta Cristina das Chagas Xavier; Ana Maria Jansen; Relrison Dias Ramalho; Liléia Diotaiut

    2014-01-01

    The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and ...

  17. Trypanosoma cruzi trans-sialidase in complex with a neutralizing antibody: structure/function studies towards the rational design of inhibitors.

    Directory of Open Access Journals (Sweden)

    Alejandro Buschiazzo

    2012-01-01

    Full Text Available Trans-sialidase (TS, a virulence factor from Trypanosoma cruzi, is an enzyme playing key roles in the biology of this protozoan parasite. Absent from the mammalian host, it constitutes a potential target for the development of novel chemotherapeutic drugs, an urgent need to combat Chagas' disease. TS is involved in host cell invasion and parasite survival in the bloodstream. However, TS is also actively shed by the parasite to the bloodstream, inducing systemic effects readily detected during the acute phase of the disease, in particular, hematological alterations and triggering of immune cells apoptosis, until specific neutralizing antibodies are elicited. These antibodies constitute the only known submicromolar inhibitor of TS's catalytic activity. We now report the identification and detailed characterization of a neutralizing mouse monoclonal antibody (mAb 13G9, recognizing T. cruzi TS with high specificity and subnanomolar affinity. This mAb displays undetectable association with the T. cruzi superfamily of TS-like proteins or yet with the TS-related enzymes from Trypanosoma brucei or Trypanosoma rangeli. In immunofluorescence assays, mAb 13G9 labeled 100% of the parasites from the infective trypomastigote stage. This mAb also reduces parasite invasion of cultured cells and strongly inhibits parasite surface sialylation. The crystal structure of the mAb 13G9 antigen-binding fragment in complex with the globular region of T. cruzi TS was determined, revealing detailed molecular insights of the inhibition mechanism. Not occluding the enzyme's catalytic site, the antibody performs a subtle action by inhibiting the movement of an assisting tyrosine (Y₁₁₉, whose mobility is known to play a key role in the trans-glycosidase mechanism. As an example of enzymatic inhibition involving non-catalytic residues that occupy sites distal from the substrate-binding pocket, this first near atomic characterization of a high affinity inhibitory molecule

  18. Structural characterization of CYP51 from Trypanosoma cruzi and Trypanosoma brucei bound to the antifungal drugs posaconazole and fluconazole.

    Directory of Open Access Journals (Sweden)

    Chiung-Kuang Chen

    Full Text Available BACKGROUND: Chagas Disease is the leading cause of heart failure in Latin America. Current drug therapy is limited by issues of both efficacy and severe side effects. Trypansoma cruzi, the protozoan agent of Chagas Disease, is closely related to two other major global pathogens, Leishmania spp., responsible for leishmaniasis, and Trypansoma brucei, the causative agent of African Sleeping Sickness. Both T. cruzi and Leishmania parasites have an essential requirement for ergosterol, and are thus vulnerable to inhibitors of sterol 14alpha-demethylase (CYP51, which catalyzes the conversion of lanosterol to ergosterol. Clinically employed anti-fungal azoles inhibit ergosterol biosynthesis in fungi, and specific azoles are also effective against both Trypanosoma and Leishmania parasites. However, modification of azoles to enhance efficacy and circumvent potential drug resistance has been problematic for both parasitic and fungal infections due to the lack of structural insights into drug binding. METHODOLOGY/PRINCIPAL FINDINGS: We have determined the crystal structures for CYP51 from T. cruzi (resolutions of 2.35 A and 2.27 A, and from the related pathogen T. brucei (resolutions of 2.7 A and 2.6 A, co-crystallized with the antifungal drugs fluconazole and posaconazole. Remarkably, both drugs adopt multiple conformations when binding the target. The fluconazole 2,4-difluorophenyl ring flips 180 degrees depending on the H-bonding interactions with the BC-loop. The terminus of the long functional tail group of posaconazole is bound loosely in the mouth of the hydrophobic substrate binding tunnel, suggesting that the major contribution of the tail to drug efficacy is for pharmacokinetics rather than in interactions with the target. CONCLUSIONS/SIGNIFICANCE: The structures provide new insights into binding of azoles to CYP51 and mechanisms of potential drug resistance. Our studies define in structural detail the CYP51 therapeutic target in T. cruzi, and

  19. Biochemical behavior of Trypanosoma cruzi strains isolated from mice submitted to specific chemotherapy

    Directory of Open Access Journals (Sweden)

    Jesila Pinto M. Marretto

    1994-12-01

    Full Text Available To investigate the influence of chemotherapy on the biochemical beha vior of Trypanosoma cruzi strains, three groups of mice were infected with one of three strains of T. cruzi of different biological and isoenzymic patterns (Peruvian, 21 SF and Colombian strains. Each group was subdivided into subgroups: 1 - treated with nifurtimox; 2 - treated with benznidazole and 3 - untreated infected controls. At the end of treatment, that lasted for 90 days, xenodiagnosis, sub inoculation of blood into new born mice and haemoculture were performed as tests of cure. From the positive tests, 22 samples of T. cruzi were isolated from all subgroups. Electrophoretic analysis of the isoenzymes PGM, GP1, ALAT and AS AT failed to show any difference between parasite strains isolated from treated and untreated mice, which indicates that no detectable clonal selection or parasite genetic markers alterations concerning the isoenzymes analysed have been determined by treatment with drugs of recognized antiparasitic effect, suggesting stability of the phenotypic characteristics of the three biological types of T. cruzi strains.Com o objetivo de investigar a influência da quimioterapia no padrão bioquímico de diferentes cepas do Trypanosoma cruzi, três grupos de camundongos foram infectados respectivamente com as cepas Peruana, 21 SF e Colombiana, que correspondem a diferentes padrões biológicos e isoenzimáticos. Cada grupo foi subdividido em subgrupos: 1 - tratados com nifurtimox; 2 - tratados com benzonidazol; 3- controles infectados não tratados. Ao final do tratamento que durou 90 dias, os animais foram submetidos a testes parasitológicos de cura: xenodiagnóstico, subinoculação do sangue em camundongos recém-nascidos e hemocultura em meio Warren. A partir da positivação destes testes, foram isoladas 22 amostras do T. cruzi dos três subgrupos. A análise eletroforética dos extratos enzimáticos obtidos após cultura para as enzimas PGM, GPI, ALAT e

  20. Trypanosoma cruzi Needs a Signal Provided by Reactive Oxygen Species to Infect Macrophages

    Science.gov (United States)

    Goes, Grazielle R.; Rocha, Peter S.; Diniz, Aline R. S.; Aguiar, Pedro H. N.; Machado, Carlos R.; Vieira, Leda Q.

    2016-01-01

    Background During Trypanosoma cruzi infection, macrophages produce reactive oxygen species (ROS) in a process called respiratory burst. Several works have aimed to elucidate the role of ROS during T. cruzi infection and the results obtained are sometimes contradictory. T. cruzi has a highly efficiently regulated antioxidant machinery to deal with the oxidative burst, but the parasite macromolecules, particularly DNA, may still suffer oxidative damage. Guanine (G) is the most vulnerable base and its oxidation results in formation of 8-oxoG, a cellular marker of oxidative stress. Methodology/Principal Findings In order to investigate the contribution of ROS in T. cruzi survival and infection, we utilized mice deficient in the gp91phox (Phox KO) subunit of NADPH oxidase and parasites that overexpress the enzyme EcMutT (from Escherichia coli) or TcMTH (from T. cruzi), which is responsible for removing 8-oxo-dGTP from the nucleotide pool. The modified parasites presented enhanced replication inside murine inflammatory macrophages from C57BL/6 WT mice when compared with control parasites. Interestingly, when Phox KO macrophages were infected with these parasites, we observed a decreased number of all parasites when compared with macrophages from C57BL/6 WT. Scavengers for ROS also decreased parasite growth in WT macrophages. In addition, treatment of macrophages or parasites with hydrogen peroxide increased parasite replication in Phox KO mice and in vivo. Conclusions Our results indicate a paradoxical role for ROS since modified parasites multiply better inside macrophages, but proliferation is significantly reduced when ROS is removed from the host cell. Our findings suggest that ROS can work like a signaling molecule, contributing to T. cruzi growth inside the cells. PMID:27035573

  1. Prevalence of Trypanosoma cruzi and Leishmania chagasi infection and risk factors in a Colombian indigenous population

    Directory of Open Access Journals (Sweden)

    CORREDOR ARJONA Augusto

    1999-01-01

    Full Text Available This study was carried out in order to obtain base-line data concerning the epidemiology of American Visceral Leishmaniasis and Chagas? Disease in an indigenous population with whom the government is starting a dwelling improvement programme. Information was collected from 242 dwellings (1,440 people, by means of house to house interviews about socio-economic and environmental factors associated with Leishmania chagasi and Trypanosoma cruzi transmission risk. A leishmanin skin test was applied to 385 people and 454 blood samples were collected on filter paper in order to detect L. chagasi antibodies by ELISA and IFAT and T. cruzi antibodies by ELISA. T. cruzi seroprevalence was 8.7% by ELISA, L. chagasi was 4.6% and 5.1% by IFAT and ELISA, respectively. ELISA sensitivity and specificity for L. chagasi antibodies were 57% and 97.5% respectively, as compared to the IFAT. Leishmanin skin test positivity was 19%. L. chagasi infection prevalence, being defined as a positive result in the three-immunodiagnostic tests, was 17.1%. Additionally, 2.7% of the population studied was positive to both L. chagasi and T. cruzi, showing a possible cross-reaction. L. chagasi and T. cruzi seropositivity increased with age, while no association with gender was observed. Age (p<0.007, number of inhabitants (p<0.05, floor material (p<0.03 and recognition of vector (p<0.01 were associated with T. cruzi infection, whilst age ( p<0.007 and dwelling improvement (p<0.02 were associated with L. chagasi infection. It is necessary to evaluate the long-term impact of the dwelling improvement programme on these parasitic infections in this community.

  2. Development of an aptamer-based concentration method for the detection of Trypanosoma cruzi in blood.

    Directory of Open Access Journals (Sweden)

    Rana Nagarkatti

    Full Text Available Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8-25 nM range. The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood.

  3. Development of an Aptamer-Based Concentration Method for the Detection of Trypanosoma cruzi in Blood

    Science.gov (United States)

    Nagarkatti, Rana; Bist, Vaibhav; Sun, Sirena; Fortes de Araujo, Fernanda; Nakhasi, Hira L.; Debrabant, Alain

    2012-01-01

    Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8–25 nM range). The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood. PMID:22927983

  4. Implication of CA repeated tracts on post-transcriptional regulation in Trypanosoma cruzi.

    Science.gov (United States)

    Pastro, Lucía; Smircich, Pablo; Pérez-Díaz, Leticia; Duhagon, María Ana; Garat, Beatriz

    2013-08-01

    In Trypanosoma cruzi gene expression regulation mainly relays on post-transcriptional events. Nevertheless, little is known about the signals which control mRNA abundance and functionality. We have previously found that CA repeated tracts (polyCA) are abundant in the vicinity of open reading frames and constitute specific targets for single stranded binding proteins from T. cruzi epimastigote. Given the reported examples of the involvement of polyCA motifs in gene expression regulation, we decided to further study their role in T. cruzi. Using an in silico genome-wide analysis, we identify the genes that contain polyCA within their predicted UTRs. We found that about 10% of T. cruzi genes carry polyCA therein. Strikingly, they are frequently concurrent with GT repeated tracts (polyGT), favoring the formation of a secondary structure exhibiting the complementary polydinucleotides in a double stranded helix. This feature is found in the species-specific family of genes coding for mucine associated proteins (MASPs) and other genes. For those polyCA-containing UTRs that lack polyGT, the polyCA is mainly predicted to adopt a single stranded structure. We further analyzed the functional role of such element using a reporter approach in T. cruzi. We found out that the insertion of polyCA at the 3' UTR of a reporter gene in the pTEX vector modulates its expression along the parasite's life cycle. While no significant change of the mRNA steady state of the reporter gene could be detected at the trypomastigote stage, significant increase in the epimastigote and reduction in the amastigote stage were observed. Altogether, these results suggest the involvement of polyCA as a signal in gene expression regulation in T. cruzi.

  5. Synergistic Effect of Lupenone and Caryophyllene Oxide against Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Glendy Polanco-Hernández

    2013-01-01

    Full Text Available The in vitro trypanocidal activity of a 1 : 4 mixture of lupenone and caryophyllene oxide confirmed a synergistic effect of the terpenoids against epimastigotes forms of T. cruzi (IC50=10.4 μg/mL, FIC = 0.46. In addition, testing of the terpenoid mixture for its capacity to reduce the number of amastigote nests in cardiac tissue and skeletal muscle of infected mice showed a reduction of more than 80% at a dose level of 20.8 mg·kg−1·day−1.

  6. Synergistic Effect of Lupenone and Caryophyllene Oxide against Trypanosoma cruzi

    Science.gov (United States)

    Polanco-Hernández, Glendy; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Rosado, María E.; Guzmán-Marín, Eugenia; Acosta-Viana, Karla Y.; Giménez-Turba, Alberto; Salamanca, Efraín; Peña-Rodríguez, Luis M.

    2013-01-01

    The in vitro trypanocidal activity of a 1 : 4 mixture of lupenone and caryophyllene oxide confirmed a synergistic effect of the terpenoids against epimastigotes forms of T. cruzi (IC50 = 10.4 μg/mL, FIC = 0.46). In addition, testing of the terpenoid mixture for its capacity to reduce the number of amastigote nests in cardiac tissue and skeletal muscle of infected mice showed a reduction of more than 80% at a dose level of 20.8 mg·kg−1·day−1. PMID:23762135

  7. The Increase in Mannose Receptor Recycling Favors Arginase Induction and Trypanosoma Cruzi Survival in Macrophages

    Directory of Open Access Journals (Sweden)

    Vanina V. Garrido, Laura R. Dulgerian, Cinthia C. Stempin, Fabio M. Cerbán

    2011-01-01

    Full Text Available The macrophage mannose receptor (MR is a pattern recognition receptor of the innate immune system that binds to microbial structures bearing mannose, fucose and N-acetylglucosamine on their surface. Trypanosoma cruzi antigen cruzipain (Cz is found in the different developmental forms of the parasite. This glycoprotein has a highly mannosylated C-terminal domain that participates in the host-antigen contact. Our group previously demonstrated that Cz-macrophage (Mo interaction could modulate the immune response against T. cruzi through the induction of a preferential metabolic pathway. In this work, we have studied in Mo the role of MR in arginase induction and in T. cruzi survival using different MR ligands. We have showed that pre-incubation of T. cruzi infected cells with mannose-Bovine Serum Albumin (Man-BSA, MR specific ligand biased nitric oxide (NO/urea balance towards urea production and increased intracellular amastigotes growth. The study of intracellular signals showed that pre-incubation with Man-BSA in T. cruzi J774 infected cells induced down-regulation of JNK and p44/p42 phosphorylation and increased of p38 MAPK phosphorylation. These results are coincident with previous data showing that Cz also modifies the MAPK phosphorylation profile induced by the parasite. In addition, we have showed by confocal microscopy that Cz and Man-BSA enhance MR recycling. Furthermore, we studied MR behavior during T. cruzi infection in vivo. MR was up-regulated in F4/80+ cells from T. cruzi infected mice at 13 and 15 days post infection. Besides, we investigated the effect of MR blocking antibody in T. cruzi infected peritoneal Mo. Arginase activity and parasite growth were decreased in infected cells pre-incubated with anti-MR antibody as compared with infected cells treated with control antibody. Therefore, we postulate that during T. cruzi infection, Cz may contact with MR, increasing MR recycling which leads to arginase activity up-regulation and

  8. Assessing the vulnerability of Brazilian municipalities to the vectorial transmission of Trypanosoma cruzi using multi-criteria decision analysis.

    Science.gov (United States)

    Vinhaes, Márcio Costa; de Oliveira, Stefan Vilges; Reis, Priscilleyne Ouverney; de Lacerda Sousa, Ana Carolina; Silva, Rafaella Albuquerque E; Obara, Marcos Takashi; Bezerra, Cláudia Mendonça; da Costa, Veruska Maia; Alves, Renato Vieira; Gurgel-Gonçalves, Rodrigo

    2014-09-01

    Despite the dramatic reduction in Trypanosoma cruzi vectorial transmission in Brazil, acute cases of Chagas disease (CD) continue to be recorded. The identification of areas with greater vulnerability to the occurrence of vector-borne CD is essential to prevention, control, and surveillance activities. In the current study, data on the occurrence of domiciliated triatomines in Brazil (non-Amazonian regions) between 2007 and 2011 were analyzed. Municipalities' vulnerability was assessed based on socioeconomic, demographic, entomological, and environmental indicators using multi-criteria decision analysis (MCDA). Overall, 2275 municipalities were positive for at least one of the six triatomine species analyzed (Panstrongylus megistus, Triatoma infestans, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma rubrovaria, and Triatoma sordida). The municipalities that were most vulnerable to vector-borne CD were mainly in the northeast region and exhibited a higher occurrence of domiciliated triatomines, lower socioeconomic levels, and more extensive anthropized areas. Most of the 39 new vector-borne CD cases confirmed between 2001 and 2012 in non-Amazonian regions occurred within the more vulnerable municipalities. Thus, MCDA can help to identify the states and municipalities that are most vulnerable to the transmission of T. cruzi by domiciliated triatomines, which is critical for directing adequate surveillance, prevention, and control activities. The methodological approach and results presented here can be used to enhance CD surveillance in Brazil.

  9. A new approach for potential drug target discovery through in silico metabolic pathway analysis using Trypanosoma cruzi genome information

    Directory of Open Access Journals (Sweden)

    Marcelo Alves-Ferreira

    2009-12-01

    Full Text Available The current drug options for the treatment of chronic Chagas disease have not been sufficient and high hopes have been placed on the use of genomic data from the human parasite Trypanosoma cruzi to identify new drug targets and develop appropriate treatments for both acute and chronic Chagas disease. However, the lack of a complete assembly of the genomic sequence and the presence of many predicted proteins with unknown or unsure functions has hampered our complete view of the parasite's metabolic pathways. Moreover, pinpointing new drug targets has proven to be more complex than anticipated and has revealed large holes in our understanding of metabolic pathways and their integrated regulation, not only for this parasite, but for many other similar pathogens. Using an in silicocomparative study on pathway annotation and searching for analogous and specific enzymes, we have been able to predict a considerable number of additional enzymatic functions in T. cruzi. Here we focus on the energetic pathways, such as glycolysis, the pentose phosphate shunt, the Krebs cycle and lipid metabolism. We point out many enzymes that are analogous to those of the human host, which could be potential new therapeutic targets.

  10. Visual genome-wide RNAi screening to identify human host factors required for Trypanosoma cruzi infection.

    Directory of Open Access Journals (Sweden)

    Auguste Genovesio

    Full Text Available The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy.

  11. Genetic Variability and Microdistribution of Triatoma infestans Genotypes and Trypanosoma cruzi Clones in Arequipa Region (Peru

    Directory of Open Access Journals (Sweden)

    Brenière Simone F

    1997-01-01

    Full Text Available The genetic variability of Triatoma infestans and Trypanosoma cruzi populations was studied by isoenzyme analysis in two distinct areas of Arequipa province (Peru; one, Santa Rita de Siguas, being an endemic area for Chagas' disease, the second, Arequipa, recently infected. Analysis of T. infestans genetic variability indicates, (i temporal stability of genotypes found in Santa Rita de Siguas, (ii high genetic differences between Arequipa and Santa Rita de Siguas populations suggesting minor contact between them, (iii multiple origin of the T. infestans population in Arequipa, and (iv poor dispersal capacity of T. infestans: the panmictic unit could be reduce to a house. Parasite isoenzyme analysis was performed in 29 Peruvian stocks of T. cruzi, mainly isolated from bugs taken in a single locality, Santa Rita de Siguas. The results show, (i a high genetic polymorphism, (ii nine different multilocus genotypes were detected and clustered in two different clades, (iii most of the parasite isolates pertained to one of the clade and were genetically similar to those analyzed 12 years before. This sample allowed the study of the mating system of T. cruzi in strict sympatic conditions and gave more strength to the hypothesis of the clonal structure of T. cruzi populations

  12. Genetic variability and microdistribution of Triatoma infestans genotypes and Trypanosoma cruzi clones in Arequipa region (Peru).

    Science.gov (United States)

    Brenière, S F; Lopez, J; Vargas, F; Barnabé, C

    1997-01-01

    The genetic variability of Triatoma infestans and Trypanosoma cruzi populations was studied by isoenzyme analysis in two distinct areas of Arequipa province (Peru); one, Santa Rita de Siguas, being an endemic area for Chagas' disease, the second, Arequipa, recently infected. Analysis of T. infestans genetic variability indicates, (i) temporal stability of genotypes found in Santa Rita de Siguas, (ii) high genetic differences between Arequipa and Santa Rita de Siguas populations suggesting minor contact between them, (iii) multiple origin of the T. infestans population in Arequipa, and (iv) poor dispersal capacity of T. infestans: the panmictic unit could be reduce to a house. Parasite isoenzyme analysis was performed in 29 Peruvian stocks of T. cruzi, mainly isolated from bugs taken in a single locality, Santa Rita de Siguas. The results show, (i) a high genetic polymorphism, (ii) nine different multilocus genotypes were detected and clustered in two different clades, (iii) most of the parasite isolates pertained to one of the clade and were genetically similar to those analyzed 12 years before. This sample allowed the study of the mating system of T. cruzi in strict sympathic conditions and gave more strength to the hypothesis of the clonal structure of T. cruzi populations.

  13. Trypanosoma cruzi calreticulin inhibits the complement lectin pathway activation by direct interaction with L-Ficolin.

    Science.gov (United States)

    Sosoniuk, Eduardo; Vallejos, Gerardo; Kenawy, Hany; Gaboriaud, Christine; Thielens, Nicole; Fujita, Teizo; Schwaeble, Wilhelm; Ferreira, Arturo; Valck, Carolina

    2014-07-01

    Trypanosoma cruzi, the agent of Chagas' disease, the sixth neglected tropical disease worldwide, infects 10-12 million people in Latin America. Differently from T. cruzi epimastigotes, trypomastigotes are complement-resistant and infective. CRPs, T-DAF, sialic acid and lipases explain at least part of this resistance. In vitro, T. cruzi calreticulin (TcCRT), a chaperone molecule that translocates from the ER to the parasite surface: (a) Inhibits the human classical complement activation, by interacting with C1, (b) As a consequence, an increase in infectivity is evident and, (c) It inhibits angiogenesis and tumor growth. We report here that TcCRT also binds to the L-Ficolin collagenous portion, thus inhibiting approximately between 35 and 64% of the human complement lectin pathway activation, initiated by L-Ficolin, a property not shared by H-Ficolin. While L-Ficolin binds to 60% of trypomastigotes and to 24% of epimastigotes, 50% of the former and 4% of the latter display TcCRT on their surfaces. Altogether, these data indicate that TcCRT is a parasite inhibitory receptor for Ficolins. The resulting evasive activities, together with the TcCRT capacity to inhibit C1, with a concomitant increase in infectivity, may represent T. cruzi strategies to inhibit important arms of the innate immune response.

  14. Biochemical behavior of Trypanosoma cruzi strains isolated from mice submitted to specific chemotherapy

    Directory of Open Access Journals (Sweden)

    Jesila Pinto M. Marretto

    1994-12-01

    Full Text Available To investigate the influence of chemotherapy on the biochemical beha vior of Trypanosoma cruzi strains, three groups of mice were infected with one of three strains of T. cruzi of different biological and isoenzymic patterns (Peruvian, 21 SF and Colombian strains. Each group was subdivided into subgroups: 1 - treated with nifurtimox; 2 - treated with benznidazole and 3 - untreated infected controls. At the end of treatment, that lasted for 90 days, xenodiagnosis, sub inoculation of blood into new born mice and haemoculture were performed as tests of cure. From the positive tests, 22 samples of T. cruzi were isolated from all subgroups. Electrophoretic analysis of the isoenzymes PGM, GP1, ALAT and AS AT failed to show any difference between parasite strains isolated from treated and untreated mice, which indicates that no detectable clonal selection or parasite genetic markers alterations concerning the isoenzymes analysed have been determined by treatment with drugs of recognized antiparasitic effect, suggesting stability of the phenotypic characteristics of the three biological types of T. cruzi strains.

  15. Identification of a hyperendemic area for Trypanosoma cruzi infection in central Veracruz, Mexico.

    Science.gov (United States)

    Ramos-Ligonio, Angel; López-Monteon, Aracely; Guzmán-Gómez, Daniel; Rosales-Encina, José Luis; Limón-Flores, Yairh; Dumonteil, Eric

    2010-07-01

    The state of Veracruz, Mexico, is a well-recognized endemic region for Chagas disease, but the geographic distribution of the disease and its magnitude are still poorly documented. We evaluated the seroprevalence of Trypanosoma cruzi infection in the sanitary jurisdictions of Cordoba and Cosamaloapan in central Veracruz. A total of 654 serum samples from 19 rural localities were tested by using four tests: two enzyme-linked immunosorbent assays, an indirect immunofluorescent, and Western blotting. Overall, 110 (16.8%) of 654 samples were positive for T. cruzi by >/= 2 tests (95% confidence interval = 14.2-19.9%). The municipality of Tezonapa in the jurisdiction of Cordoba was identified as a potential hyperendemic region with seroprevalence rates cruzi transmission dynamics in Tezonapa. The magnitude of T. cruzi infection rate in this region calls for the urgent implementation of extensive epidemiologic surveillance and control programs.

  16. Identification of a Hyperendemic Area for Trypanosoma cruzi Infection in Central Veracruz, Mexico

    Science.gov (United States)

    Ramos-Ligonio, Angel; López-Monteon, Aracely; Guzmán-Gómez, Daniel; Rosales-Encina, José Luis; Limón-Flores, Yairh; Dumonteil, Eric

    2010-01-01

    The state of Veracruz, Mexico, is a well-recognized endemic region for Chagas disease, but the geographic distribution of the disease and its magnitude are still poorly documented. We evaluated the seroprevalence of Trypanosoma cruzi infection in the sanitary jurisdictions of Cordoba and Cosamaloapan in central Veracruz. A total of 654 serum samples from 19 rural localities were tested by using four tests: two enzyme-linked immunosorbent assays, an indirect immunofluorescent, and Western blotting. Overall, 110 (16.8%) of 654 samples were positive for T. cruzi by ≥ 2 tests (95% confidence interval = 14.2–19.9%). The municipality of Tezonapa in the jurisdiction of Cordoba was identified as a potential hyperendemic region with seroprevalence rates ≤ 45% in young children. No cases were detected in the jurisdiction of Cosamaloapan. Further studies should help clarify T. cruzi transmission dynamics in Tezonapa. The magnitude of T. cruzi infection rate in this region calls for the urgent implementation of extensive epidemiologic surveillance and control programs. PMID:20595496

  17. Trypanosoma cruzi infection in Elche (Spain): comparison of the seroprevalence in immigrants from Paraguay and Bolivia.

    Science.gov (United States)

    Ramos, José M; Ponce, Yamileth; Gallegos, Ingrid; Flóres-Chávez, María; Cañavate, Carmen; Gutiérrez, Félix

    2012-05-01

    Chagas disease is a global public health problem due to the recent emigration of people from Latin America to other regions, including Europe. The aim of this study is to determine the prevalence of Trypanosoma cruzi infection among Paraguayans and Bolivians living in Elche (Spain), a city located in the Mediterranean Coast of Spain. A cross-sectional study was conducted. Capillary blood samples were obtained through a finger prick, and collected on filter paper. An enzyme-linked immunosorbent assay and indirect immunofluorescence tests were performed to search for anti-T. cruzi IgG antibodies in the filter papers. Thirteen out of 201 participants were infected with T. cruzi in this study, seven out of 73 Bolivians and six out of 128 Paraguayans, corresponding to seroprevalences of 9·59% (95%CI, 4·72-18·5%) and 4·69% (95%CI, 2·17-9·85%), respectively. Palpitation, chest pain, and migration from rural endemic areas were the most common clinical and epidemiological risk factors associated with T. cruzi infection detected in the Paraguayan group. This study highlights that Chagas disease is no longer limited to the Bolivian population living in Spain. It is important to note this wider prevalence and, therefore, not discount Paraguayans in the screening for Chagas disease in Spain. Indeed, this should be considered for all immigrants from Latin America.

  18. Limited antigenic variation in the Trypanosoma cruzi candidate vaccine antigen TSA-1.

    Science.gov (United States)

    Knight, J M; Zingales, B; Bottazzi, M E; Hotez, P; Zhan, B

    2014-12-01

    Chagas disease (American trypanosomiasis caused by Trypanosoma cruzi) is one of the most important neglected tropical diseases in the Western Hemisphere. The toxicities and limited efficacies of current antitrypanosomal drugs have prompted a search for alternative technologies such as a therapeutic vaccine comprised of T. cruzi antigens, including a recombinant antigen encoding the N-terminal 65 kDa portion of Trypomastigote surface antigen-1 (TSA-1). With at least six known genetically distinct T. cruzi lineages, variability between the different lineages poses a unique challenge for the development of broadly effective therapeutic vaccine. The variability across the major lineages in the current vaccine candidate antigen TSA-1 has not previously been addressed. To assess the variation in TSA-1, we cloned and sequenced TSA-1 from several different T. cruzi strains representing three of the most clinically relevant lineages. Analysis of the different alleles showed limited variation in TSA-1 across the different strains and fit with the current theory for the evolution of the different lineages. Additionally, minimal variation in known antigenic epitopes for the HLA-A 02 allele suggests that interlineage variation in TSA-1 would not impair the range and efficacy of a vaccine containing TSA-1.

  19. Differential expression profiles in the midgut of Triatoma infestans infected with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Diego S Buarque

    Full Text Available Chagas disease, or American trypanosomiasis, is a parasitic disease caused by the protozoan Trypanosoma cruzi and is transmitted by insects from the Triatominae subfamily. To identify components involved in the protozoan-vector relationship, we constructed and analyzed cDNA libraries from RNA isolated from the midguts of uninfected and T. cruzi-infected Triatoma infestans, which are major vectors of Chagas disease. We generated approximately 440 high-quality Expressed Sequence Tags (ESTs from each T. infestans midgut cDNA library. The sequences were grouped in 380 clusters, representing an average length of 664.78 base pairs (bp. Many clusters were not classified functionally, representing unknown transcripts. Several transcripts involved in different processes (e.g., detoxification showed differential expression in response to T. cruzi infection. Lysozyme, cathepsin D, a nitrophorin-like protein and a putative 14 kDa protein were significantly upregulated upon infection, whereas thioredoxin reductase was downregulated. In addition, we identified several transcripts related to metabolic processes or immunity with unchanged expressions, including infestin, lipocalins and defensins. We also detected ESTs encoding juvenile hormone binding protein (JHBP, which seems to be involved in insect development and could be a target in control strategies for the vector. This work demonstrates differential gene expression upon T. cruzi infection in the midgut of T. infestans. These data expand the current knowledge regarding vector-parasite interactions for Chagas disease.

  20. New, combined, and reduced dosing treatment protocols cure Trypanosoma cruzi infection in mice.

    Science.gov (United States)

    Bustamante, Juan M; Craft, Julie M; Crowe, Byron D; Ketchie, Sarah A; Tarleton, Rick L

    2014-01-01

    The development of treatment protocols with reduced toxicity and equivalent or improved efficacy for Trypanosoma cruzi infection is a priority. We tested the effectiveness of benznidazole (BZ), nifurtimox (NFX), other prospective drugs in intermittent and combined treatment protocols to cure T. cruzi infection initiated with susceptible and drug-resistant parasite strains. A 40-day course of BZ, NFX, or the oxaborale AN4169 cured 100% of mice, whereas posaconazole (POS), and NTLA-1 (a nitro-triazole) cured approximately 90% and 20% of mice, respectively. Reducing the overall dosage of BZ or NFX by using an intermittent (once every 5 days) schedule or combining 5 daily doses of POS with 7 intermittent doses of BZ also provided approximately 100% cure. T. cruzi strains resistant to BZ were also found to be resistant to other drugs (POS), and extending the time of treatment or combining drugs did not increase cure rates with these isolates. Thus, dosing schedules for anti-T. cruzi compounds should be determined empirically, and compounds targeting different pathways may be combined to yield effective therapies with reduced toxicity. This work also suggests that standard treatment protocols using BZ and NFX may be significantly overdosing patients, perhaps contributing to the adverse events.

  1. Colonization of Rhodnius prolixus gut by Trypanosoma cruzi involves an extensive parasite killing.

    Science.gov (United States)

    Ferreira, Roberta Carvalho; Kessler, Rafael Luis; Lorenzo, Marcelo Gustavo; Paim, Rafaela Magalhães Macedo; Ferreira, Luciana De Lima; Probst, Christian Macagnan; Alves-Silva, Juliana; Guarneri, Alessandra Aparecida

    2016-04-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, is ingested by triatomines during their bloodmeal on an infected mammal. Aiming to investigate the development and differentiation of T. cruzi inside the intestinal tract of Rhodnius prolixus at the beginning of infection we fed insects with cultured epimastigotes and blood trypomastigotes from infected mice to determine the amount of recovered parasites after ingestion. Approximately 20% of the ingested parasites was found in the insect anterior midgut (AM) 3 h after feeding. Interestingly, a significant reduction (80%) in the numbers of trypomastigotes was observed after 24 h of infection suggesting that parasites were killed in the AM. Moreover, few parasites were found in that intestinal portion after 96 h of infection. The evaluation of the numbers of parasites in the posterior midgut (PM) at the same periods showed a reduced parasite load, indicating that parasites were not moving from the AM. Additionally, incubation of blood trypomastigotes with extracts from R. prolixus AMs revealed that components of this tissue could induce significant death of T. cruzi. Finally, we observed that differentiation from trypomastigotes to epimastigotes is not completed in the AM; instead we suggest that trypomastigotes change to intermediary forms before their migration to the PM, where differentiation to epimastigotes takes place. The present work clarifies controversial points concerning T. cruzi development in insect vector, showing that parasite suffers a drastic decrease in population size before epimastigonesis accomplishment in PM.

  2. Visual Genome-Wide RNAi Screening to Identify Human Host Factors Required for Trypanosoma cruzi Infection

    Science.gov (United States)

    de Macedo Dossin, Fernando; Choi, Seo Yeon; Kim, Nam Youl; Kim, Hi Chul; Jung, Sung Yong; Schenkman, Sergio; Almeida, Igor C.; Emans, Neil; Freitas-Junior, Lucio H.

    2011-01-01

    The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy. PMID:21625474

  3. In silico structural characterization of protein targets for drug development against Trypanosoma cruzi.

    Science.gov (United States)

    Lima, Carlyle Ribeiro; Carels, Nicolas; Guimaraes, Ana Carolina Ramos; Tufféry, Pierre; Derreumaux, Philippe

    2016-10-01

    Trypanosoma cruzi is the protozoan pathogen responsible for Chagas disease, which is a major public health problem in tropical and subtropical regions of developing countries and particularly in Brazil. Despite many studies, there is no efficient treatment against Chagas disease, and the search for new therapeutic targets specific to T. cruzi is critical for drug development. Here, we have revisited 41 protein sequences proposed by the analogous enzyme pipeline, and found that it is possible to provide structures for T. cruzi sequences with clear homologs or analogs in H. sapiens and likely associated with trypanothione reductase, cysteine synthase, and ATPase functions, and structures for sequences specific to T. cruzi and absent in H. sapiens associated with 2,4-dienoyl-CoA reductase, and leishmanolysin activities. The implications of our structures refined by atomistic molecular dynamics (monomer or dimer states) in their in vitro environments (aqueous solution or membrane bilayers) are discussed for drug development and suggest that all protein targets, except cysteine synthase, merit further investigation.

  4. Genetic immunization based on the ubiquitin-fusion degradation pathway against Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Bin [Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180 (Japan); Department of Parasitology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan); Hiromatsu, Kenji, E-mail: khiromatsu@fukuoka-u.ac.jp [Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180 (Japan); Hisaeda, Hajime; Duan, Xuefeng; Imai, Takashi [Department of Parasitology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan); Murata, Shigeo; Tanaka, Keiji [Department of Molecular Oncology, The Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613 (Japan); Himeno, Kunisuke [Department of Parasitology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan)

    2010-02-12

    Cytotoxic CD8{sup +} T cells are particularly important to the development of protective immunity against the intracellular protozoan parasite, Trypanosoma cruzi, the etiological agent of Chagas disease. We have developed a new effective strategy of genetic immunization by activating CD8{sup +} T cells through the ubiquitin-fusion degradation (UFD) pathway. We constructed expression plasmids encoding the amastigote surface protein-2 (ASP-2) of T. cruzi. To induce the UFD pathway, a chimeric gene encoding ubiquitin fused to ASP-2 (pUB-ASP-2) was constructed. Mice immunized with pUB-ASP-2 presented lower parasitemia and longer survival period, compared with mice immunized with pASP-2 alone. Depletion of CD8{sup +} T cells abolished protection against T. cruzi in mice immunized with pUB-ASP-2 while depletion of CD4{sup +} T cells did not influence the effective immunity. Mice deficient in LMP2 or LMP7, subunits of immunoproteasomes, were not able to develop protective immunity induced. These results suggest that ubiquitin-fused antigens expressed in antigen-presenting cells were effectively degraded via the UFD pathway, and subsequently activated CD8{sup +} T cells. Consequently, immunization with pUB-ASP-2 was able to induce potent protective immunity against infection of T. cruzi.

  5. Trypanosoma cruzi: Maintenance in Culture Modify Gene and Antigenic Expression of Metacyclic Trypomastigotes

    Directory of Open Access Journals (Sweden)

    Víctor T Contreras

    1998-11-01

    Full Text Available In this study we examined whether the maintenance of Trypanosoma cruzi by long-time in axenic culture produces changes in gene expression and antigenic profiles. The studies were made with a Dm30L-clone from a low-virulent strain and a non-cloned virulent EP-strain of T. cruzi. Both parasites were maintained, for at least seven years, by successive alternate passage triatomine/mouse (triatomine condition, or by serial passage in axenic medium (culture condition. The comparison of the [35S]methionine metabolic labeling products of virulent and non-virulent parasites by 2D-SDS-PAGE, clearly indicates that the expression of metacyclic trypomastigotes (but not of epimastigotes proteins have been altered by laboratory maintenance conditions. Western blot analysis of EP and Dm30L-epimastigotes using a serum anti-epimastigotes revealed that although most of antigens are conserved, four antigens are characteristics of triatomine condition parasites and three other are characteristics of culture condition parasites. Anti-metacyclics serum revealed significative differences in EP- and Dm30L-metacyclic trypomastigotes from triatomine condition. However, avirulent metacyclic forms were antigenically very similar. These results suggest that besides a possible selection of avirulent subpopulation from T. cruzi strains genetically heterogeneous when maintained by long time in axenic culture, changes in virulence might be due to post-translational modifications of the antigens induced by the absence of the natural alternability (vertebrate-invertebrate in the life-cycle of T. cruzi

  6. Natural populations of Trypanosoma cruzi, the agent of Chagas disease, have a complex multiclonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Tibayrenc, M.; Ward, P.; Moya, A.; Ayala, F.J.

    1986-01-01

    The authors have studied 15 gene loci coding for enzymes in 121 Trypanosoma cruzi stocks from a wide geographic range - from the US and Mexico to Chile and southern Brazil. T.cruzi is diploid but reproduction is basically clonal, with very little if any sexuality remaining at present. They have identified 43 different clones by their genetic composition; the same genetic clone is often found in very distant places and in diverse hosts. There is much genetic heterogeneity among the different clones, and they cannot be readily classified into a few discrete groups that might represent natural taxa. These findings imply that the biological and medical characteristics need to be ascertained separately for each natural clone. The evidence indicates that clonal evolution is very ancient in T.cruzi. The authors propose two alternative hypotheses concerning the relationship between the biochemical diversity and the heterogeneity in other biological and medical characteristics of T. cruzi. One hypothesis is that the degree of diversity between strains simply reflects the time elapsed since their last common ancestor. The second hypothesis is that biological and medical heterogeneity is recent and reflects adaptation to different transmission cycles. A decision between the two hypotheses can be reached with appropriate studies, with important medical consequences.

  7. Inhibitory effects of human alpha 2-macroglobulin on Trypanosoma cruzi epimastigote proteinases.

    Science.gov (United States)

    Ramos, A; Remedi, M S; Sánchez, C; Bonacci, G; Vides, M A; Chiabrando, G

    1997-12-01

    The inactivation of Trypanosoma cruzi proteinases by human alpha 2-macroglobulin (alpha 2-M), a major plasma proteinase inhibitor was studied. Evidences regarding the interaction between alpha 2-M and proteolytic enzymes contained in crude cell-free extracts of T. cruzi were derived from electrophoretic and enzymatic assays. The former showed conformational and structural changes occurring in alpha 2-M, as judged by the appearance of transformed 'fast' form on native PAGE; generation of bands of approximately 90 kDa on reduced SDS-PAGE and formation of covalent complexes enzyme-inhibitor on SDS-PAGE. On the other hand, the total proteolytic activity on azocasein dropped significantly in the presence of alpha 2-M, although partial activity was still maintained. The proteinases detected as a double band of 44 and 53 kDa on gelatin SDS-PAGE were also inhibited by alpha 2-M. Results suggest that the study of specific interactions between alpha 2-M and T. cruzi-proteinases, probably with cruzipain, could be biologically important in the fate of T. cruzi-infection and Chagas' disease.

  8. Enhancing effects of gamma interferon on phagocytic cell association with and killing of Trypanosoma cruzi

    Science.gov (United States)

    Wirth, J. J.; Kierszenbaum, F.; Sonnenfeld, G.; Zlotnik, A.

    1985-01-01

    Results are reported from a study of the influence gamma interferon (GIFN) and interleukin 2 (IL2) have on the capability of P388D1 cells and mouse resident peritoneal macrophages (MPM) to attach to the blood-resident parasites Trypanosoma cruzi and kill them. Cultures of trypomastigote forms of the Tulahuen strain of T. cruzi grown in bovine serum were introduced into peritoneal cells of mice, along with P388D1 cells incubated with GIFN, IL2 and both. Control cells were also maintained. Statistical analysis were then performed on data on counts of the number of dead T. Cruzi cells. The GIFN enhanced the interaction of MPM and P388D1 cells with the surface of T. Cruzi, provided the interaction was given over 12 hr to take place. A depression of the cytotoxicity of P388D1 cells was attributed to mediation by H2O2, an effect partially offset by incubation with the lymphokine GIFN.

  9. Electrocardiographic alteration among first degree relatives with serologic evidence of Trypanosoma cruzi infection: a sibship study

    Directory of Open Access Journals (Sweden)

    Julio C. Morini

    1994-09-01

    Full Text Available To analyze whether electrocardiographic alterations (ECGA in patients with antibodies to Trypanosoma cruzi showed a patttern of familial aggregation, a sample of 379 young adults (166 men and 213 women distributed in sibships, were assessed for the presence of anti-T.cruzi antibodies, and subjected to a complete clinical examination and a standard resting electrocardiogram (ECG. Positive T. cruzi serology was detected in 165 individuals, 48 of them showing an abnormal ECG (overall prevalence 29 por cento. One hundred and eleven seropositive individuals were distributed in 45 sibships, each of them constituted by more than one seropositive sib, with ECGA being present in 34 out of these patients. Seropositive subjects with ECGA were detected in 27 sibships. Since the index case within each sibship is counted exactly once, affected individuals selected at random as propositi were extracted to calculate the prevalence of ECGA among first degree relatives of probands. Abnormal ECGs were recorded in 7 out of 45 sibs yielding a prevalence that did not differ from estimations registered in the general population or seropositive sibs. Data from the present sample show no familial aggregation for the occurrence of ECGA in patients with T.cruzi infection.

  10. A α-glycerophosphate dehydrogenase is present in Trypanosoma cruzi glycosomes

    Directory of Open Access Journals (Sweden)

    JL Concepcion

    2001-07-01

    Full Text Available α-glycerophosphate dehydrogenase (α-GPDH-EC.1.1.1.8 has been considered absent in Trypanosoma cruzi in contradiction with all other studied trypanosomatids. After observing that the sole malate dehydrogenase can not maintain the intraglycosomal redox balance, GPDH activity was looked for and found, although in very variable levels, in epimastigotes extracts. GPDH was shown to be exclusively located in the glycosome of T. cruzi by digitonin treatment and isopycnic centrifugation. Antibody against T. brucei GPDH showed that this enzyme seemed to be present in an essentially inactive form at the beginning of the epimastigotes growth. GPDH is apparently linked to a salicylhydroxmic-sensitive glycerophosphate reoxidizing system and plays an essential role in the glycosome redox balance.

  11. The activity of a metronidazole analogue and its β-cyclodextrin complex against Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Marcela Silva Lopes

    2011-12-01

    Full Text Available In this study we prepared an inclusion complex between an iodide analogue of metronidazole (MTZ-I and cyclodextrin (CD to develop a safer and more effective method of treating Trypanosoma cruzi infections. According to our results, MTZ-I and MTZ-I:β-CD were 10 times more active than MTZ, demonstrating that the presence of an iodine atom on the side chain increased the trypanocidal activity while maintaining its cytotoxicity. The selective index shows that MTZ-I was 10 times more active against T. cruzi than it was against mammalian cells. The modification of MTZ side chains provides a promising avenue for the development of new drugs.

  12. Synanthropic rodent reservoirs of Trypanosoma (Schizotrypanum cruzi in the valley of Caracas, Venezuela

    Directory of Open Access Journals (Sweden)

    HERRERA Leidi

    1997-01-01

    Full Text Available Direct blood examination and xenodiagnosis of 47 synanthropic rodents (Rattus rattus, R. norvegicus, Mus musculus captured in the valley of Caracas, Venezuela, revealed trypanosomal infections in 12 R. rattus, 10 with T. lewisi and 2 with T. cruzi. Of the latter the course of parasitemia, the pleomorphism of the bloodstream trypomastigotes, tissue tropism in naturally and experimentally infected rats and mice, host mortality, morphology of fecal parasites in Rhodnius prolixus used for xenodiagnosis, and infectivity of the bug feces for NMRI mice, were all characteristic of Trypanosoma (Schizotrypanum cruzi. One rat, with a patent parasitemia, had numerous nests of amastigotes in cardiac muscle and moderate parasitism of the smooth muscle of the duodenum and of skeletal muscle. Mice inoculated with fecal flagellates from the bugs had moderate tissue tropism in the same organs and also in the colon and pancreas. The possible role of R. rattus in the establishment of foci of Chagas? disease in Caracas is discussed

  13. Genómica del Trypanosoma cruzi. Nuevas oportunidades para tratar el mal de Chagas

    Directory of Open Access Journals (Sweden)

    Jorge A. Huete-Pérez

    2006-12-01

    Full Text Available LA SECUENCIACIÓN DEL GENOMA HUMANO PUBLICADA EN FEBRERO de 2001 ha sido considerada como el hito científico más importante del siglo XX. La secuenciación, cuatro años más tarde, de tres parásitos tripanosmatidas, entre ellos el Trypanosoma cruzi, podría ser también catalogada como uno de los acontecimientos científicos más importantes para la salud publica del continente americano. Aquí se presenta un panorama general sobre los resultados más significativos del estudio geonómico del T. cruzi, se abordan los trabajos realizados por nuestro laboratorio en la Universidad Centroamericana, finalizando con una discusión sobre las perspectivas del uso de la genómica en Nicaragua.

  14. Proteomic analysis of Trypanosoma cruzi developmental stages using isotope-coded affinity tag reagents.

    Science.gov (United States)

    Paba, Jaime; Ricart, Carlos A O; Fontes, Wagner; Santana, Jaime M; Teixeira, Antonio R L; Marchese, Jason; Williamson, Brian; Hunt, Tony; Karger, Barry L; Sousa, Marcelo V

    2004-01-01

    Comparative proteome analysis of developmental stages of the human pathogen Trypanosoma cruzi was carried out by isotope-coded affinity tag technology (ICAT) associated with liquid cromatography-mass spectrometry peptide sequencing (LC-MS/MS). Protein extracts of the protozoan trypomastigote and amastigote stages were labeled with heavy (D8) and light (D0) ICAT reagents and subjected to cation exchange and avidin affinity chromatographies followed by LC-MS/MS analysis. High confidence sequence information and expression levels for 41 T. cruzi polypeptides, including metabolic enzymes, paraflagellar rod components, tubulins, and heat-shock proteins were reported. Twenty-nine proteins displayed similar levels of expression in both forms of the parasite, nine proteins presented higher levels in trypomastigotes, whereas three were more expressed in amastigotes.

  15. Developmental and reproductive patterns of Triatoma brasiliensis infected with Trypanosoma cruzi under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Tiago G Oliveira

    2010-12-01

    Full Text Available The aim of this work was to study the interaction between Trypanosoma cruzi-1 and Triatoma brasiliensis. A group of 1st instar nymphs was initially fed on T. cruzi-infected mice and a control group was fed on uninfected mice. From the second feeding onwards, both groups were otherwise fed on non-infected mice. The resulting adults were grouped in pairs: infected male/uninfected female, uninfected male/infected female, infected male and female and uninfected male/uninfected female. The infection affected only the 1st instar nymphs, which took significantly more time to reach the 2nd instar than uninfected nymphs. The differences in the molting time between the infected and uninfected nymphs from the 2nd to the 5th instars were not statistically significant. Both groups presented similar rates of nymphal mortality and reproductive performance was not significantly affected by infection in any of the treatments.

  16. Binding Mode and Selectivity of Steroids towards Glucose-6-phosphate Dehydrogenase from the Pathogen Trypanosoma cruzi.

    Science.gov (United States)

    Ortiz, Cecilia; Moraca, Francesca; Medeiros, Andrea; Botta, Maurizio; Hamilton, Niall; Comini, Marcelo A

    2016-03-17

    Glucose-6-phosphate dehydrogenase (G6PDH) plays a housekeeping role in cell metabolism by generating reducing power (NADPH) and fueling the production of nucleotide precursors (ribose-5-phosphate). Based on its indispensability for pathogenic parasites from the genus Trypanosoma, G6PDH is considered a drug target candidate. Several steroid-like scaffolds were previously reported to target the activity of G6PDH. Epiandrosterone (EA) is an uncompetitive inhibitor of trypanosomal G6PDH for which its binding site to the enzyme remains unknown. Molecular simulation studies with the structure of Trypanosoma cruzi G6PDH revealed that EA binds in a pocket close to the G6P binding-site and protrudes into the active site blocking the interaction between substrates and hence catalysis. Site directed mutagenesis revealed the important steroid-stabilizing effect of residues (L80, K83 and K84) located on helix α-1 of T. cruzi G6PDH. The higher affinity and potency of 16α-Br EA by T. cruzi G6PDH is explained by the formation of a halogen bond with the hydrogen from the terminal amide of the NADP+-nicotinamide. At variance with the human enzyme, the inclusion of a 21-hydroxypregnane-20-one moiety to a 3β-substituted steroid is detrimental for T. cruzi G6PDH inhibition. The species-specificity of certain steroid derivatives towards the parasite G6PDH and the corresponding biochemically validated binding models disclosed in this work may prove valuable for the development of selective inhibitors against the pathogen's enzyme.

  17. Host cell poly(ADP-ribose glycohydrolase is crucial for Trypanosoma cruzi infection cycle.

    Directory of Open Access Journals (Sweden)

    Salomé C Vilchez Larrea

    Full Text Available Trypanosoma cruzi, etiological agent of Chagas' disease, has a complex life cycle which involves the invasion of mammalian host cells, differentiation and intracellular replication. Here we report the first insights into the biological role of a poly(ADP-ribose glycohydrolase in a trypanosomatid (TcPARG. In silico analysis of the TcPARG gene pointed out the conservation of key residues involved in the catalytic process and, by Western blot, we demonstrated that it is expressed in a life stage-dependant manner. Indirect immunofluorescence assays and electron microscopy using an anti-TcPARG antibody showed that this enzyme is localized in the nucleus independently of the presence of DNA damage or cell cycle stage. The addition of poly(ADP-ribose glycohydrolase inhibitors ADP-HPD (adenosine diphosphate (hydroxymethyl pyrrolidinediol or DEA (6,9-diamino-2-ethoxyacridine lactate monohydrate to the culture media, both at a 1 µM concentration, reduced in vitro epimastigote growth by 35% and 37% respectively, when compared to control cultures. We also showed that ADP-HPD 1 µM can lead to an alteration in the progression of the cell cycle in hydroxyurea synchronized cultures of T. cruzi epimastigotes. Outstandingly, here we demonstrate that the lack of poly(ADP-ribose glycohydrolase activity in Vero and A549 host cells, achieved by chemical inhibition or iRNA, produces the reduction of the percentage of infected cells as well as the number of amastigotes per cell and trypomastigotes released, leading to a nearly complete abrogation of the infection process. We conclude that both, T. cruzi and the host, poly(ADP-ribose glycohydrolase activities are important players in the life cycle of Trypanosoma cruzi, emerging as a promising therapeutic target for the treatment of Chagas' disease.

  18. trans-Sialidase neutralizing antibody detection in Trypanosoma cruzi-infected domestic reservoirs.

    Science.gov (United States)

    Sartor, Paula A; Cardinal, Martha V; Orozco, Marcela M; Gürtler, Ricardo E; Leguizamón, M Susana

    2011-06-01

    The detection of Trypanosoma cruzi infection in domestic dogs and cats is relevant to evaluating human transmission risks and the effectiveness of insecticide spraying campaigns. However, the serological assays routinely used are associated with cross-reactivity in sera from mammals infected with Leishmania spp. We used a trans-sialidase inhibition assay (TIA) for T. cruzi diagnosis in serum samples from 199 dogs and 57 cats from areas where these types of infections are endemic. TIA is based on the antibody neutralization of recombinant trans-sialidase, an enzyme that is not detected in the coendemic Leishmania species or Trypanosoma rangeli parasites. T. cruzi infection was also evaluated by conventional serology (CS) (indirect immunofluorescence, indirect hemagglutination, enzyme-linked immunosorbent assay, and immunochromatographic dipstick test) and xenodiagnosis. Sera from 30 dogs and 15 cats from areas where these organisms are not endemic and 5 dogs with visceral leishmaniasis were found to be nonreactive by TIA and CS. Samples from dogs and cats demonstrated 91 and 95% copositivities between TIA and CS, whereas the conegativities were 98 and 97%, respectively. Sera from xenodiagnosis-positive dogs and cats also reacted by TIA (copositivities of 97 and 83%, respectively). TIA was reactive in three CS-negative samples and was able to resolve results in two cat serum samples that were CS inconclusive. Our study is the first to describe the development of trans-sialidase neutralizing antibodies in naturally infected dogs and cats. High CS conegativity and the absence of trans-sialidase neutralization in dog sera from areas where leishmaniasis is not endemic and from dogs with visceral leishmaniasis support TIA specificity. The TIA may be a useful tool for T. cruzi detection in the main domestic reservoirs.

  19. The Effectiveness of Natural Diarylheptanoids against Trypanosoma cruzi: Cytotoxicity, Ultrastructural Alterations and Molecular Modeling Studies

    Science.gov (United States)

    Sueth-Santiago, Vitor; Moraes, Julliane de B. B.; Sobral Alves, Eliomara Sousa; Vannier-Santos, Marcos André; Freire-de-Lima, Célio G.; Castro, Rosane N.; Mendes-Silva, Gustavo Peron; Del Cistia, Catarina de Nigris; Magalhães, Luma Godoy; Andricopulo, Adriano Defini; Sant´Anna, Carlos Mauricio R.; Decoté-Ricardo, Debora; Freire de Lima, Marco Edilson

    2016-01-01

    Curcumin (CUR) is the major constituent of the rhizomes of Curcuma longa and has been widely investigated for its chemotherapeutic properties. The well-known activity of CUR against Leishmania sp., Trypanosoma brucei and Plasmodium falciparum led us to investigate its activity against Trypanosoma cruzi. In this work, we tested the cytotoxic effects of CUR and other natural curcuminoids on different forms of T. cruzi, as well as the ultrastructural changes induced in epimastigote form of the parasite. CUR was verified as the curcuminoid with more significant trypanocidal properties (IC50 10.13 μM on epimastigotes). Demethoxycurcumin (DMC) was equipotent to CUR (IC50 11.07 μM), but bisdemethoxycurcumin (BDMC) was less active (IC50 45.33 μM) and cyclocurcumin (CC) was inactive. In the experiment with infected murine peritoneal macrophages all diarylheptanoids were more active than the control in the inhibition of the trypomastigotes release. The electron microscopy images showed ultrastructural changes associated with the cytoskeleton of the parasite, indicating tubulin as possible target of CUR in T. cruzi. The results obtained by flow cytometry analysis of DNA content of the parasites treated with natural curcuminoids suggested a mechanism of action on microtubules related to the paclitaxel`s mode of action. To better understand the mechanism of action highlighted by electron microscopy and flow cytometry experiments we performed the molecular docking of natural curcuminoids on tubulin of T. cruzi in a homology model and the results obtained showed that the observed interactions are in accordance with the IC50 values found, since there CUR and DMC perform similar interactions at the binding site on tubulin while BDMC do not realize a hydrogen bond with Lys163 residue due to the absence of methoxyl groups. These results indicate that trypanocidal properties of CUR may be related to the cytoskeletal alterations. PMID:27658305

  20. Frequency of the Congenital Transmission of Trypanosoma cruzi: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Howard, Elizabeth J.; Xiong, Xu; Carlier, Yves; Sosa-Estani, Sergio; Buekens, Pierre

    2014-01-01

    Background Chagas disease is caused by the parasite Trypanosoma cruzi and endemic in much of Latin America. With increased globalization and immigration, it is a risk in any country due in part to congenital transmission. The frequency of congenital transmission is unclear. Objective To assess the frequency of congenital transmission of T. cruzi. Search Strategy PubMed, Journals@Ovid Full Text, EMBASE, CINAHL, Fuente Academica and BIREME databases were searched using seven search terms related to Chagas disease or Trypanosoma cruzi and congenital transmission. Selection Criteria The inclusion criteria were the following: Dutch, English, French, Portuguese or Spanish language; case report, case series or observational study; original data on congenital T. cruzi infection in humans; congenital infection rate reported or it could be derived. This systematic review included 13 case reports/series and 51 observational studies. Data Collection and Analysis Two investigators independently collected data on study characteristics, diagnosis and congenital infection rate. The principal summary measure – the congenital transmission rate – is defined as the number of congenitally infected infants divided by the number of infants born to infected mothers. A random effects model was utilized. Main Results The pooled congenital transmission rate was 4.7% (95% confidence interval: 3.9–5.6%). Endemic countries had a higher rate of congenital transmission compared to non-endemic (5.0% vs. 2.7%). Conclusions Congenital transmission of Chagas disease is a global problem. Overall risk of congenital infection in infants born to infected mothers is about 5%. The congenital mode of transmission requires targeted screening to prevent future cases of Chagas disease. PMID:23924273

  1. Genetic control of responses to Trypanosoma cruzi in mice: multiple genes influencing parasitemia and survival.

    OpenAIRE

    1982-01-01

    Inbred strains of mice can be divided into two groups based on the level of parasitemia which develops after injection with 10(3) trypomastigotes of Trypanosoma cruzi (Peru). Strains which developed parasitemias of greater than 10(7) trypomastigotes per ml by day 17, including C3H/HeJ, BALB/c, and CBA/N mice, were termed high parasitemia strains. Low parasitemia strains, including C57BL/6J and DBA/2J mice, developed parasitemias of less than 5 x 10(6) trypomastigotes per ml by day 17 of infec...

  2. Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts

    Science.gov (United States)

    de Souza, Wanderley; de Carvalho, Tecia M. Ulisses

    2013-01-01

    In the present short review, we analyze past experiments that addressed the interactions of intracellular pathogenic protozoa (Trypanosoma cruzi, Toxoplasma gondii, and Plasmodium) with host cells and the initial use of the term active penetration to indicate that a protozoan “crossed the host cell membrane, penetrating into the cytoplasm.” However, the subsequent use of transmission electron microscopy showed that, for all of the protozoans and cell types examined, endocytosis, classically defined as involving the formation of a membrane-bound vacuole, took place during the interaction process. As a consequence, the recently penetrated parasites are always within a vacuole, designated the parasitophorous vacuole (PV). PMID:23355838

  3. Studies on the virulence and attenuation of Trypanosoma cruzi using immunodeficient animals

    Directory of Open Access Journals (Sweden)

    Basombrío Miguel Ángel

    2000-01-01

    Full Text Available Tissue invasion and pathology by Trypanosoma cruzi result from an interaction between parasite virulence and host immunity. Successive in vivo generations of the parasite select populations with increasing ability to invade the host. Conversely, prolonged in vitro selection of the parasite produces attenuated sublines with low infectivity for mammals. One such subline (TCC clone has been extensively used in our laboratory as experimental vaccine and tested in comparative experiments with its virulent ancestor (TUL. The experiments here reviewed aimed at the use of immunodeficient mice for testing the infectivity of TCC parasites. It has not been possible to obtain virulent, revertant sublines by prolonged passaged in such mice.

  4. Synthesis, cytotoxicity, and anti-Trypanosoma cruzi activity of new chalcones.

    Science.gov (United States)

    Aponte, José C; Verástegui, Manuela; Málaga, Edith; Zimic, Mirko; Quiliano, Miguel; Vaisberg, Abraham J; Gilman, Robert H; Hammond, Gerald B

    2008-10-09

    Synthesis of a cytotoxic dihydrochalcone, first isolated from a traditional Amazonian medicinal plant Iryanthera juruensis Warb (Myristicaceae), followed by a comprehensive SAR analysis of saturated and unsaturated chalcone synthetic intermediates, led to the identification of analogues with selective and significant in vitro anti- Trypanosoma cruzi activity. Further SAR studies were undertaken with the synthesis of 21 new chalcones containing two allyloxy moieties that resulted in the discovery of 2',4'-diallyloxy-6'-methoxy chalcones with improved selectivity against this parasite at concentrations below 25 microM, four of which exhibited a selectivity index greater than 12.

  5. Arginine kinase of the flagellate protozoa Trypanosoma cruzi. Regulation of its expression and catalytic activity.

    Science.gov (United States)

    Alonso, G D; Pereira, C A; Remedi, M S; Paveto, M C; Cochella, L; Ivaldi, M S; Gerez de Burgos, N M; Torres, H N; Flawiá, M M

    2001-06-01

    In epimastigotes of Trypanosoma cruzi, the etiological agent of Chagas' disease, arginine kinase activity increased continuously during the exponential phase of growth. A correlation between growth rate, enzyme-specific activity and enzyme protein was observed. Arginine kinase-specific activity, expressed as a function of enzyme protein, remains roughly constant up to 18 days of culture. In the whole range of the culture time mRNA levels showed minor changes indicating that the enzyme activity is post-transcriptionally regulated. Arginine kinase could be proposed as a modulator of energetic reserves under starvation stress condition.

  6. Bias due to methods of parasite detection when estimating prevalence of infection of Triatoma infestans by Trypanosoma cruzi

    OpenAIRE

    Lardeux, Frédéric; Aliaga, C.; Depickère, Stéphanie

    2016-01-01

    The study aimed to quantify the bias from parasite detection methods in the estimation of the prevalence of infection of Triatoma infestans by Trypanosoma cruzi, the agent of Chagas disease. Three common protocols that detect T. cruzi in a sample of 640 wild-caught T. infestans were compared: (1) the microscopic observation of insect fecal droplets, (2) a PCR protocol targeting mini-exon genes of T. cruzi (MeM-PCR), and (3) a PCR protocol targeting a satellite repeated unit of the parasite. A...

  7. Comparison of the infectivity of Trypanosoma cruzi insect-derived metacyclic trypomastigotes after mucosal and cutaneous contaminative challenges

    Directory of Open Access Journals (Sweden)

    Christopher Steven Eickhoff

    2013-06-01

    Full Text Available Trypanosoma cruzi infects humans when infected triatomine vector excreta contaminate breaks in skin or mucosal surfaces. T. cruzi insect-derived metacyclic trypomastigotes (IMT invade through gastric mucosa after oral challenges without any visible inflammatory changes, while cutaneous and conjunctival infections result in obvious local physical signs. In this study we compared the infectivity of T. cruzi IMT in mice after cutaneous and oral contaminative challenges simulating natural infections. The 50% infective dose (ID50 for oral challenge was 100 fold lower than the ID50for cutaneous challenge, indicating that oral mucosal transmission is more efficient than cutaneous transmission.

  8. Application of core-shell PEGylated CdS/Cd(OH) 2 quantum dots as biolabels of Trypanosoma cruzi parasites

    Science.gov (United States)

    Chaves, C. R.; Fontes, A.; Farias, P. M. A.; Santos, B. S.; de Menezes, F. D.; Ferreira, R. C.; Cesar, C. L.; Galembeck, A.; Figueiredo, R. C. B. Q.

    2008-11-01

    Semiconductor quantum dots are a promising class of materials in the labeling of biological systems. In the present study we show the marking pattern of Trypanosoma cruzi ( T. cruzi) live parasites using PEGylated CdS/Cd(OH) 2 fluorescent nanocrystals. The analysis obtained by confocal fluorescence microscopy and transmission electron microscopy indicates that only the endocytic paths of parasites were labeled. The parasites were alive after the incubation with the CdS/Cd(OH) 2-PEG suspension. Labeling the T. cruzi with quantum dots can help to better understand the endocytosis process and also the cellular differentiation.

  9. Eco-epidemiological aspects of Trypanosoma cruzi, Trypanosoma rangeli and their vector (Rhodnius pallescens in Panama Generalidades do Trypanosoma cruzi, do Trypanosoma rangeli e do seu vetor (Rhodnius pallescens no Panamá

    Directory of Open Access Journals (Sweden)

    Ana Maria de Vasquez

    2004-08-01

    Full Text Available The eco-epidemiology of T. cruzi infection was investigated in the Eastern border of the Panama Canal in Central Panama. Between 1999 and 2000, 1110 triatomines were collected: 1050 triatomines (94.6% from palm trees, 27 (2.4% from periurban habitats and 33 (3.0% inside houses. All specimens were identified as R. pallescens. There was no evidence of vector domiciliation. Salivary glands from 380 R. pallescens revealed a trypanosome natural infection rate of 7.6%, while rectal ampoule content from 373 triatomines was 45%. Isoenzyme profiles on isolated trypanosomes demonstrated that 85.4% (n = 88 were T. cruzi and 14.6% (n = 15 were T. rangeli. Blood meal analysis from 829 R. pallescens demonstrated a zoophilic vector behavior, with opossums as the preferential blood source. Seroprevalence in human samples from both study sites was less than 2%. Our results demonstrate that T. cruzi survives in the area in balanced association with R. pallescens, and with several different species of mammals in their natural niches. However, the area is an imminent risk of infection for its population, consequently it is important to implement a community educational program regarding disease knowledge and control measures.A epidemiologia da infecção do T. cruzi foi investigada na margem oriental do canal do Panamá, na região central da Republica do Panamá. A informação obtida durante o estudo avaliou fatores de risco da doença de Chagas nesta área. Entre 1999 e 2000, 1110 triatomíneos foram coletados: 1050 triatomíneos (94,6% em palmeiras, 27 (2,4% em habitats periurbanos e 33 (3,0% no interior de casas. Todos os espécimens foram identificados como R. pallescens. Não havia nenhuma evidência de domiciliação do vetor. O exame de glândulas salivares de 380 R. pallescens revelaram taxa de infecção natural por Trypanosoma de 7,6%, mas o conteúdo da ampola rectal de 373 triatomíneos mostrou 45% de positividade. Os perfis de isoenzimas em

  10. Transferability of Trypanosoma cruzi from mixed human host infection to Triatoma infestans and from insects to axenic culture.

    Science.gov (United States)

    Ortiz, Sylvia; Zulantay, Inés; Apt, Werner; Saavedra, Miguel; Solari, Aldo

    2015-02-01

    The etiologic agent of Chagas disease is Trypanosoma cruzi, a protozoan whose life cycle involves obligatory passage through vertebrate and invertebrate hosts in a series of stages. The aim of this study was to explore the transferability of mixed discrete typing units (DTUs) of T. cruzi present in chronic chagasic patients when passed through an invertebrate host during xenodiagnosis (XD) and then when transferred to axenic cultures to obtain T. cruzi isolates. DTUs of T. cruzi present in these two hosts and axenic cultures were identified by kDNA PCR amplification and subsequent hybridization with DTU-specific probes. Mixtures of Tc I, Tc II, Tc V and Tc VI DTUs were detected in blood samples. However as a result of XD and axenic cultures it was possible to identify mostly Tc V. We conclude that the transferability of an isolate of T.cruzi derived from mixed DTUs present in human blood depends upon the starved invertebrate host used for xenodiagnosis.

  11. Cell death and serum markers of collagen metabolism during cardiac remodeling in Cavia porcellus experimentally infected with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Yagahira E Castro-Sesquen

    Full Text Available We studied cell death by apoptosis and necrosis in cardiac remodeling produced by Trypanosoma cruzi infection. In addition, we evaluated collagen I, III, IV (CI, CIII and CIV deposition in cardiac tissue, and their relationship with serum levels of procollagen type I carboxy-terminal propeptide (PICP and procollagen type III amino-terminal propeptide (PIIINP. Eight infected and two uninfected guinea pigs were necropsied at seven time points up to one year post-infection. Cell death by necrosis and apoptosis was determined by histopathological observation and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Deposition of cardiac collagen types was determined by immunohistochemistry and serum levels of PICP, PIIINP, and anti-T. cruzi IgG1 and IgG2 by ELISA. IgG2 (Th1 response predominated throughout the course of infection; IgG1 (Th2 response was detected during the chronic phase. Cardiac cell death by necrosis predominated over apoptosis during the acute phase; during the chronic phase, both apoptosis and necrosis were observed in cardiac cells. Apoptosis was also observed in lymphocytes, endothelial cells and epicardial adipose tissue, especially in the chronic phase. Cardiac levels of CI, CIII, CIV increased progressively, but the highest levels were seen in the chronic phase and were primarily due to increase in CIII and CIV. High serum levels of PICP and PIIINP were observed throughout the infection, and increased levels of both biomarkers were associated with cardiac fibrosis (p = 0.002 and p = 0.038, respectively. These results confirm the role of apoptosis in cell loss mainly during the chronic phase and the utility of PICP and PIIINP as biomarkers of fibrosis in cardiac remodeling during T. cruzi infection.

  12. Trypanosoma cruzi alkaline 2-DE: Optimization and application to comparative proteome analysis of flagellate life stages

    Directory of Open Access Journals (Sweden)

    Santana Jaime M

    2008-09-01

    Full Text Available Abstract Background Trypanosoma cruzi, a flagellate protozoan, is the etiological agent of Chagas disease, a chronic illness that causes irreversible damage to heart and digestive tract in humans. Previous 2-DE analyses of T. cruzi proteome have not focused on basic proteins, possibly because of inherent difficulties for optimizing 2-DE in the alkaline pH range. However, T. cruzi wide pH range 2-DE gels have shown few visible spots in the alkaline region, indicating that the parasite either did not have an appreciable amount of alkaline proteins or that these proteins were underrepresented in the 2-DE gels. Results Different IEF conditions using 6–11 pH gradient strips were tested for separation of T. cruzi alkaline proteins. The optimized methodology described here was performed using anodic "paper bridge" sample loading supplemented by increased concentration of DTT and Triton X-100 on Multiphor II (GE Healthcare equipment and an electrode pad embedded in DTT- containing solution near the cathode in order to avoid depletion of reducing agent during IEF. Landmark proteins were identified by peptide mass fingerprinting allowing the production of an epimastigote 2-DE map. Most identified proteins corresponded to metabolic enzymes, especially those related to amino acid metabolism. The optimized 2-DE protocol was applied in combination with the "two-in-one gel" method to verify the relative expression of the identified proteins between samples from epimastigote and trypomastigote life stages. Conclusion High resolution 2-DE gels of T. cruzi life forms were achieved using the optimized methodology and a partial epimastigote alkaline 2-DE map was built. Among 700 protein spots detected, 422 were alkaline with a pI above 7.0. The "two-in-one gel" method simplified the comparative analysis between T. cruzi life stages since it minimized variations in spot migration and silver-stained spot volumes. The comparative data were in agreement with

  13. Mammalian cell invasion and intracellular trafficking by Trypanosoma cruzi infective forms

    Directory of Open Access Journals (Sweden)

    Renato A. Mortara

    2005-03-01

    Full Text Available Trypanosoma cruzi, the etiological agent of Chagas’ disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle and T. cruzi II, linked to the human disease. In the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. Several parasite surface components and some of host cell receptors with which they interact have been identified. Our work focused on how amastigotes, usually found growing in the cytoplasm, can invade mammalian cells with infectivities comparable to that of trypomastigotes. We found differences in cellular responses induced by amastigotes and trypomastigotes regarding cytoskeletal components and actin-rich projections. Extracellularly generated amastigotes of T. cruzi I strains may display greater infectivity than metacyclic trypomastigotes towards cultured cell lines as well as target cells that have modified expression of different classes of cellular components. Cultured host cells harboring the bacterium Coxiella burnetii allowed us to gain new insights into the trafficking properties of the different infective forms of T. cruzi, disclosing unexpected requirements for the parasite to transit between the parasitophorous vacuole to its final destination in the host cell cytoplasm.O agente etiológico da doença de Chagas, Trypanosoma cruzi, ocorre como cepas ou isolados que podem ser agrupados em duas grandes linhagens filogenéticas: T. cruzi I associada ao ciclo silvestre e T. cruzi II ligada à doençahumana. No hospedeiro mamífero o parasita tem que invadir células, e vários estudos relacionam as formas flageladas tripomastigotas neste processo. Diferentes componentes de superfície dos parasitas e alguns dos respectivos receptores foram identificados. Em nosso trabalho temos procurado compreender como amastigotas, que normalmente são encontrados crescendo

  14. Criopreservação de formas de cultura do Trypanosoma cruzi Cryopreservation of Trypanosoma cruzi culture form

    Directory of Open Access Journals (Sweden)

    Lúcia Maria C. Galvão

    1981-09-01

    Full Text Available Formas de cultura de diferentes cepas do T.cruzi foram submetidas a vários processos de criopreservação. As percentagens de recuperação, avaliadas pela motilidade dos parasitas, foram consideradas como adequadas com algumas das técnicas empregadas, variando entre 60 a 80%. A estabilidade das características biológicas do material criopreservado foi investigada através do estudo das curvas de crescimento e diferenciação em meio acelular, infectividade para celulas de cultura de tecido ("Vero", diferenciação intracelular em cultura de tecido assim como infectividade e curso da infecção em animais de laboratório. De um modo geral essas características nao foram significativamente alteradas no material congelado e estocado por diferentes períodos de tempo.A systematic study of the cryopreservation of T. cruzi culture forms was per formed using different parasite strains and freezing methods. The recovery rates with some of the methods as evaluated by motility of the thawed parasites were fairly high (60-80%. The following aspects have been used to investigate the stability of the parasites' biological characteristics atter cryopreservation: growth and differentiation in acelular medium, infectivity to tissue culture "Vero" cells, intracellular differentiation and infectivity to animals. Those characteristics had not been significantly changed by the cryopreservation procedures.

  15. Structural model of a putrescine-cadaverine permease from Trypanosoma cruzi predicts residues vital for transport and ligand binding

    NARCIS (Netherlands)

    Soysa, R.; Venselaar, H.; Poston, J.; Ullman, B.; Hasne, M.P.

    2013-01-01

    The TcPOT1.1 gene from Trypanosoma cruzi encodes a high affinity putrescine-cadaverine transporter belonging to the APC (amino acid/polyamine/organocation) transporter superfamily. No experimental three-dimensional structure exists for any eukaryotic member of the APC family, and thus the structural

  16. Seroprevalence of Trypanosoma cruzi Infection in Schoolchildren and in Pregnant Women from an Amazonian Region in Orellana Province, Ecuador.

    Science.gov (United States)

    Carrera Vargas, Caty; Narváez, Alberto Orlando; Muzzio Aroca, Jenny; Shiguango, Gonzalo; Robles, Luiggi Martini; Herrera, Claudia; Dumonteil, Eric

    2015-10-01

    Chagas disease is a parasitic disease caused by the protozoan parasite Trypanosoma cruzi and about 230,000 persons are estimated to be infected in Ecuador. However, limited studies have been performed in the Amazon region, on the eastern side of the country. We evaluated here the seroprevalence of Trypanosoma cruzi infection in 12 rural villages of the Loreto canton, Orellana Province in schoolchildren aged 5-15 years and in pregnant women. A total of 1,649 blood samples were tested for Trypanosoma cruzi antibodies by enzyme-linked immunosorbent assay and indirect hemaglutination, and discordant samples were tested by indirect immunofluorescence assay. We detected a seroprevalence of anti-Trypanosoma cruzi antibodies of 1.3% in schoolchildren aged 5-15 years, indicating the persistence of a constant and active vectorial transmission in the Loreto County and confirming the need of the implementation of nonconventional vector control. We also observed a seroprevalence of 3.8% in pregnant women, indicating a clear risk of congenital transmission. Further studies should help define this risk more precisely and implement current international guidelines for the diagnosis, treatment, and care of these cases.

  17. Sesquiterpene lactones and the diterpene 5-epi-icetexone affect the intracellular and extracellular stages of Trypanosoma cruzi

    NARCIS (Netherlands)

    Lozano, E.; Barrera, P.; Salinas, R.; Vega, I.; Nieto, M.; Tonn, C.; Kemmerling, U.; Mortara, R.A.; Sosa, M.A.

    2012-01-01

    Chagas disease is a major health problem in Latin America and is caused by the parasitic protozoan Trypanosoma cruzi. Although many drugs have been used to alleviate the disease, these have been ineffective in the chronic phase and have also presented numerous side effects on patients. In this study

  18. The vaccination of human beings with a live avirulent strain of Trypanosoma cruzi: a new series of volunteers

    Directory of Open Access Journals (Sweden)

    Humberto Menezes

    1973-04-01

    Full Text Available Five human volunteers were vaccinated with a live avirulent strain of Trypanosoma cruzi and followed-up for one year. Except for a few cases of questionable results presented by only one Laboratory, ali the other clinicai, parasitological and serological tests remained negative during that period.

  19. Expression, purification and crystallization of Trypanosoma cruzi dihydroorotate dehydrogenase complexed with orotate

    Energy Technology Data Exchange (ETDEWEB)

    Inaoka, Daniel Ken; Takashima, Eizo; Osanai, Arihiro; Shimizu, Hironari [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Nara, Takeshi; Aoki, Takashi [Department of Parasitology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Harada, Shigeharu [Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Kita, Kiyoshi, E-mail: kitak@m.u-tokyo.ac.jp [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2005-10-01

    The Trypanosoma cruzi dihydroorotate dehydrogenase, a key enzyme in pyrimidine de novo biosynthesis and redox homeostasis, was crystallized in complex with its first reaction product, orotate. Dihydroorotate dehydrogenase (DHOD) catalyzes the oxidation of dihydroorotate to orotate, the fourth step and the only redox reaction in the de novo biosynthesis of pyrimidine. DHOD from Trypanosoma cruzi (TcDHOD) has been expressed as a recombinant protein in Escherichia coli and purified to homogeneity. Crystals of the TcDHOD–orotate complex were grown at 277 K by the sitting-drop vapour-diffusion technique using polyethylene glycol 3350 as a precipitant. The crystals diffract to better than 1.8 Å resolution using synchrotron radiation (λ = 0.900 Å). X-ray diffraction data were collected at 100 K and processed to 1.9 Å resolution with 98.2% completeness and an overall R{sub merge} of 7.8%. The TcDHOD crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 67.87, b = 71.89, c = 123.27 Å. The presence of two molecules in the asymmetric unit (2 × 34 kDa) gives a crystal volume per protein weight (V{sub M}) of 2.2 Å{sup 3} Da{sup −1} and a solvent content of 44%.

  20. Digital holographic microscopy for detection of Trypanosoma cruzi parasites in fresh blood mounts

    Science.gov (United States)

    Romero, G. G.; Monaldi, A. C.; Alanís, E. E.

    2012-03-01

    An off-axis holographic microscope, in a transmission mode, calibrated to automatically detect the presence of Trypanosoma cruzi in blood is developed as an alternative diagnosis tool for Chagas disease. Movements of the microorganisms are detected by measuring the phase shift they produce on the transmitted wave front. A thin layer of blood infected by Trypanosoma cruzi parasites is examined in the holographic microscope, the images of the visual field being registered with a CCD camera. Two consecutive holograms of the same visual field are subtracted point by point and a phase contrast image of the resulting hologram is reconstructed by means of the angular spectrum propagation algorithm. This method enables the measurement of phase distributions corresponding to temporal differences between digital holograms in order to detect whether parasites are present or not. Experimental results obtained using this technique show that it is an efficient alternative that can be incorporated successfully as a part of a fully automatic system for detection and counting of this type of microorganisms.

  1. 3-H-[1,2]Dithiole as a New Anti-Trypanosoma cruzi Chemotype: Biological and Mechanism of Action Studies.

    Science.gov (United States)

    Couto, Marcos; Sánchez, Carina; Dávila, Belén; Machín, Valentina; Varela, Javier; Álvarez, Guzmán; Cabrera, Mauricio; Celano, Laura; Aguirre-López, Beatriz; Cabrera, Nallely; de Gómez-Puyou, Marieta Tuena; Gómez-Puyou, Armando; Pérez-Montfort, Ruy; Cerecetto, Hugo; González, Mercedes

    2015-08-12

    The current pharmacological Chagas disease treatments, using Nifurtimox or Benznidazole, show limited therapeutic results and are associated with potential side effects, like mutagenicity. Using random screening we have identified new chemotypes that were able to inhibit relevant targets of the Trypanosoma cruzi. We found 3H-[1,2]dithioles with the ability to inhibit Trypanosoma cruzi triosephosphate isomerase (TcTIM). Herein, we studied the structural modifications of this chemotype to analyze the influence of volume, lipophilicity and electronic properties in the anti-T. cruzi activity. Their selectivity to parasites vs. mammalian cells was also examined. To get insights into a possible mechanism of action, the inhibition of the enzymatic activity of TcTIM and cruzipain, using the isolated enzymes, and the inhibition of membrane sterol biosynthesis and excreted metabolites, using the whole parasite, were achieved. We found that this structural framework is interesting for the generation of innovative drugs for the treatment of Chagas disease.

  2. 3-H-[1,2]Dithiole as a New Anti-Trypanosoma cruzi Chemotype: Biological and Mechanism of Action Studies

    Directory of Open Access Journals (Sweden)

    Marcos Couto

    2015-08-01

    Full Text Available The current pharmacological Chagas disease treatments, using Nifurtimox or Benznidazole, show limited therapeutic results and are associated with potential side effects, like mutagenicity. Using random screening we have identified new chemotypes that were able to inhibit relevant targets of the Trypanosoma cruzi. We found 3H-[1,2]dithioles with the ability to inhibit Trypanosoma cruzi triosephosphate isomerase (TcTIM. Herein, we studied the structural modifications of this chemotype to analyze the influence of volume, lipophilicity and electronic properties in the anti-T. cruzi activity. Their selectivity to parasites vs. mammalian cells was also examined. To get insights into a possible mechanism of action, the inhibition of the enzymatic activity of TcTIM and cruzipain, using the isolated enzymes, and the inhibition of membrane sterol biosynthesis and excreted metabolites, using the whole parasite, were achieved. We found that this structural framework is interesting for the generation of innovative drugs for the treatment of Chagas disease.

  3. Trypanosoma cruzi-elicited CD8+ T cell-mediated myocarditis: chemokine receptors and adhesion molecules as potential therapeutic targets to control chronic inflammation?

    Directory of Open Access Journals (Sweden)

    Joseli Lannes-Vieira

    2003-04-01

    Full Text Available In Chagas disease, during the acute phase, the establishment of inflammatory processes is crucial for Trypanosoma cruzi control in target tissues and for the establishment of host/parasite equilibrium. However, in about 30% of the patients, inflammation becomes progressive, resulting in chronic disease, mainly characterized by myocarditis. Although several hypothesis have been raised to explain the pathogenesis of chagasic myocardiopathy, including the persistence of the parasite and/or participation of autoimmune processes, the molecular mechanisms underlying the establishment of the inflammatory process leading to parasitism control but also contributing to the maintenance of T. cruzi-elicited chronic myocarditis remain unsolved. Trying to shed light on these questions, we have for several years been working with murine models for Chagas disease that reproduce the acute self-resolving meningoencephalitis, the encephalitis resulting of reactivation described in immunodeficient individuals, and several aspects of the acute and chronic myocarditis. In the present review, our results are summarized and discussed under the light of the current literature. Furthermore, rational therapeutic intervention strategies based on integrin-mediated adhesion and chemokine receptor-driven recruitment of leukocytes are proposed to control T. cruzi-elicited unbalanced inflammation.

  4. Estudo dos caracteres de uma amostra boliviana de Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Gentilda K. Funayama

    1974-04-01

    Full Text Available Amostra de T. cruzi, mediante a inoculação em camundongos brancos jovens, foi isolada de fezes de exemplares de T. infestans capturados em Vitichi, Bolívia e denominada amostra Bolívia. Essa amostra, que se comporta de um modo peculiar em reações de aglutinação, segundo Siqueira, Ribeiro e Fernandes, em 1973, mostrou-se patogênica para camundongos, infectando 100% dos animais inoculados, quer com formas metacíclicas de triatomíneos, quer com formas sanguícolas de doadores com infecção aguda. As formas sanguícolas, em camundongos, medem 23,37 μ de comprimento total médio e tem índice nuclear de 0,94. Nos camundongos mortos durante a fase aguda os ninhos de leishmânias são abundantes, sobretudo no coração. A infecção dos camundongos é grave com curto período prepatente, parasitemia elevada e alta taxa de letalidade. A amostra Bolívia confere, aos animais que sobrevivem, alto grau de resistência contra reinfecção pela amostra Y. Cultiva-se bem em meios líquidos (Warren e difásicos (NNN e evolui regularmente em várias espécies de triatomíneos testadas.

  5. Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model Caracterização molecular de cepas mexicanas de Trypanosoma cruzi e seu comportamento no modelo experimental do camundongo

    Directory of Open Access Journals (Sweden)

    César Gómez-Hernández

    2011-12-01

    Full Text Available INTRODUCTION: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. METHODS: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD - (random amplified polymorphic DNA. RESULTS: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6 to 10(7 parasites/mL and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. CONCLUSIONS: The Mexican T. cruzi strains are myotrophic and belong to group TcI.INTRODUÇÃO: Durante muito tempo, foi questionada a importância da doença de Chagas no México onde muitos a consideravam um padecimento exótico. Considerando a grande diversidade genética existente, entre os isolados de Trypanosoma cruzi, a importância da caracterização biológica desses e o escasso número de informações sobre os aspectos clínicos e biológicos da doença de Chagas no México, o objetivo deste trabalho

  6. Protective Role of Acetylsalicylic Acid in Experimental Trypanosoma cruzi Infection: Evidence of a 15-epi-Lipoxin A4-Mediated Effect

    Science.gov (United States)

    Henriquez, Natalia; Faúndez, Mario; Torres, Gloria; Castillo, Christian; Escanilla, Sebastián; Kemmerling, Ulrike; Morello, Antonio; López-Muñoz, Rodrigo A.; Maya, Juan D.

    2013-01-01

    Chagas' disease, produced by Trypanosoma cruzi, affects more than 8 million people, producing approximately 10,000 deaths each year in Latin America. Migration of people from endemic regions to developed countries has expanded the risk of infection, transforming this disease into a globally emerging problem. PGE2 and other eicosanoids contribute to cardiac functional deficits after infection with T. cruzi. Thus, the inhibition of host cyclooxygenase (COX) enzyme emerges as a potential therapeutic target. In vivo studies about the effect of acetylsalicylic acid (ASA) upon T. cruzi infection are controversial, and always report the effect of ASA at a single dose. Therefore, we aimed to analyze the effect of ASA at different doses in an in vivo model of infection and correlate it with the production of arachidonic acid metabolites. ASA decreased mortality, parasitemia, and heart damage in T. cruzi (Dm28c) infected mice, at the low doses of 25 and 50 mg/Kg. However, this effect disappeared when the high ASA doses of 75 and 100 mg/Kg were used. We explored whether this observation was related to the metabolic shift toward the production of 5-lipoxygenase derivatives, and although we did not observe an increase in LTB4 production in infected RAW cells and mice infected, we did find an increase in 15-epi-LXA4 (an ASA-triggered lipoxin). We also found high levels of 15-epi-LXA4 in T. cruzi infected mice treated with the low doses of ASA, while the high ASA doses decreased 15-epi-LXA4 levels. Importantly, 15-epi-LXA4 prevented parasitemia, mortality, and cardiac changes in vivo and restored the protective role in the treatment with a high dose of ASA. This is the first report showing the production of ASA-triggered lipoxins in T. cruzi infected mice, which demonstrates the role of this lipid as an anti-inflammatory molecule in the acute phase of the disease. PMID:23638194

  7. Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

    Directory of Open Access Journals (Sweden)

    Diana L Fabbro

    2014-11-01

    Full Text Available With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment before pregnancy. Their children were studied to detect congenital infection. Among 354 "chronically infected mother-biological child" pairs, 132 were treated women and 222 were untreated women. Among the children born to untreated women, we detected 34 infected with T. cruzi (15.3%, whose only antecedent was maternal infection. Among the 132 children of previously treated women, no infection with T. cruzi was found (0.0% (p<0.05. Among 117 mothers with clinical and serological follow up, 71 had been treated and 46 were untreated. The women were grouped into three groups. Group A: 25 treated before 15 years of age; Group B: 46 treated at 15 or more years of age; Group C: untreated, average age of 29.2 ± 6.2 years at study entry. Follow-up for Groups A, B and C was 16.3 ± 5.8, 17.5 ± 9.2 and 18.6 ± 8.6 years respectively. Negative seroconversion: Group A, 64.0% (16/25; Group B, 32.6% (15/46; Group C, no seronegativity was observed. Clinical electrocardiographic alterations compatible with chagasic cardiomyopathy: Group A 0.0% (0/25; B 2.2% (1/46 and C 15.2% (7/46. The trypanocidal treatment of women with chronic Chagas infection was effective in preventing the congenital transmission of Trypanosoma cruzi to their children; it had also a protective effect on the women's clinical evolution and deparasitation could be demonstrated in many treated women after over 10 years of follow up.

  8. The Trypanosoma cruzi Diamine Transporter Is Essential for Robust Infection of Mammalian Cells.

    Directory of Open Access Journals (Sweden)

    Marie-Pierre Hasne

    Full Text Available Trypanosoma cruzi is incapable of synthesizing putrescine or cadaverine de novo, and, therefore, salvage of polyamines from the host milieu is an obligatory nutritional function for the parasite. A high-affinity diamine transporter (TcPOT1 from T. cruzi has been identified previously that recognizes both putrescine and cadaverine as ligands. In order to assess the functional role of TcPOT1 in intact parasites, a Δtcpot1 null mutant was constructed by targeted gene replacement and characterized. The Δtcpot1 mutant lacked high-affinity putrescine-cadaverine transport capability but retained the capacity to transport diamines via a non-saturable, low-affinity mechanism. Transport of spermidine and arginine was not impacted by the Δtcpot1 lesion. The Δtcpot1 cell line exhibited a significant but not total defect in its ability to subsist in Vero cells, although initial infection rates were not affected by the lesion. These findings reveal that TcPOT1 is the sole high-affinity diamine permease in T. cruzi, that genetic obliteration of TcPOT1 impairs the ability of the parasite to maintain a robust infection in mammalian cells, and that a secondary low-affinity uptake mechanism for this key parasite nutrient is operative but insufficient for optimal infection.

  9. New scenarios of Trypanosoma cruzi transmission in the Orinoco region of Colombia.

    Science.gov (United States)

    Rendón, Lina María; Guhl, Felipe; Cordovez, Juan Manuel; Erazo, Diana

    2015-05-01

    Rhodnius prolixus, a blood-sucking triatomine with domiciliary anthropophilic habits, is the main vector of Chagas disease. The current paradigm of Trypanosoma cruzi transmission in Columbia includes a sylvatic and domiciliary cycle co-existing with domestic and sylvatic populations of reservoirs. The aim of this study is to evaluate the population densities and relative abundance of triatomines and mammals that may be involved in the sylvatic cycle of Chagas disease to clarify the epidemiological scenario in an endemic area in the province of Casanare. Insect vectors on Attalea butyracea palms were captured using both manual searches and bait traps. The capture of mammals was performed using Sherman and Tomahawk traps. We report an infestation index of 88.5% in 148 palms and an index of T. cruzi natural infection of 60.2% in 269 dissected insects and 11.9% in 160 captured mammals. High population densities of triatomines were observed in the sylvatic environment and there was a high relative abundance of reservoirs in the area, suggesting a stable enzootic cycle. We found no evidence of insect domiciliation. Taken together, these observations suggest that eco-epidemiological factors shape the transmission dynamics of T. cruzi, creating diverse scenarios of disease transmission.

  10. Simultaneous stable expression of neomycin phosphotransferase and green fluorescence protein genes in Trypanosoma cruzi.

    Science.gov (United States)

    dos Santos, W G; Buck, G A

    2000-12-01

    The ribosomal RNA (rRNA) gene promoter was used to construct plasmid vectors that simultaneously express multiple exogenous genes in Trypanosoma cruzi. Vector pBSPANEO expresses neomycin phosphotransferase, and pPAGFPAN expresses both green fluorescent protein and neomycin phosphotransferase from a single promoter. Both vectors require the presence of the rRNA promoter for stable transfection; epimastigotes transfected with pPAGFPAN strongly fluoresced due to green fluorescent protein expression. Intact plasmids were rescued from the T. cruzi-transfected population after >8 mo of culture, indicating stable replication of these vectors. Vectors were integrated into the rRNA locus by homologous recombination and into other loci, presumably by illegitimate recombination. Parasites bearing tandem concatamers of plasmids were also found among the transfectants. Transfectants expressing green fluorescent protein showed a bright green fluorescence distributed throughout the cell. Fluorescence was also detected in amastigotes after infection of mammalian cells with transfected parasites, indicating that the rRNA promoter can drive efficient expression of these reporter genes in multiple life-cycle stages of the parasite. Expression of the heterologous genes was detected after passage in mice or in the insect vector. These vectors will be useful for the genetic dissection of T. cruzi biology and pathogenesis.

  11. Cell culture and animal infection with distinct Trypanosoma cruzi strains expressing red and green fluorescent proteins.

    Science.gov (United States)

    Pires, S F; DaRocha, W D; Freitas, J M; Oliveira, L A; Kitten, G T; Machado, C R; Pena, S D J; Chiari, E; Macedo, A M; Teixeira, S M R

    2008-03-01

    Different strains of Trypanosoma cruzi were transfected with an expression vector that allows the integration of green fluorescent protein (GFP) and red fluorescent protein (RFP) genes into the beta-tubulin locus by homologous recombination. The sites of integration of the GFP and RFP markers were determined by pulse-field gel electrophoresis and Southern blot analyses. Cloned cell lines selected from transfected epimastigote populations maintained high levels of fluorescent protein expression even after 6 months of in vitro culture of epimastigotes in the absence of drug selection. Fluorescent trypomastigotes and amastigotes were observed within Vero cells in culture as well as in hearts and diaphragms of infected mice. The infectivity of the GFP- and RFP-expressing parasites in tissue culture cells was comparable to wild type populations. Furthermore, GFP- and RFP-expressing parasites were able to produce similar levels of parasitemia in mice compared with wild type parasites. Cell cultures infected simultaneously with two cloned cell lines from the same parasite strain, each one expressing a distinct fluorescent marker, showed that at least two different parasites are able to infect the same cell. Double-infected cells were also detected when GFP- and RFP-expressing parasites were derived from strains belonging to two distinct T. cruzi lineages. These results show the usefulness of parasites expressing GFP and RFP for the study of various aspects of T. cruzi infection including the mechanisms of cell invasion, genetic exchange among parasites and the differential tissue distribution in animal models of Chagas disease.

  12. New scenarios of Trypanosoma cruzi transmission in the Orinoco region of Colombia

    Directory of Open Access Journals (Sweden)

    Lina María Rendón

    2015-05-01

    Full Text Available Rhodnius prolixus, a blood-sucking triatomine with domiciliary anthropophilic habits, is the main vector of Chagas disease. The current paradigm of Trypanosoma cruzi transmission in Columbia includes a sylvatic and domiciliary cycle co-existing with domestic and sylvatic populations of reservoirs. The aim of this study is to evaluate the population densities and relative abundance of triatomines and mammals that may be involved in the sylvatic cycle of Chagas disease to clarify the epidemiological scenario in an endemic area in the province of Casanare. Insect vectors on Attalea butyracea palms were captured using both manual searches and bait traps. The capture of mammals was performed using Sherman and Tomahawk traps. We report an infestation index of 88.5% in 148 palms and an index of T. cruzi natural infection of 60.2% in 269 dissected insects and 11.9% in 160 captured mammals. High population densities of triatomines were observed in the sylvatic environment and there was a high relative abundance of reservoirs in the area, suggesting a stable enzootic cycle. We found no evidence of insect domiciliation. Taken together, these observations suggest that eco-epidemiological factors shape the transmission dynamics of T. cruzi, creating diverse scenarios of disease transmission.

  13. Melatonin and zinc treatment: distinctive modulation of cytokine production in chronic experimental Trypanosoma cruzi infection.

    Science.gov (United States)

    Brazão, Vânia; Del Vecchio Filipin, Marina; Santello, Fabricia Helena; Caetano, Leony Cristina; Abrahão, Ana Amélia Carraro; Toldo, Míriam Paula Alonso; do Prado, José Clóvis

    2011-12-01

    Melatonin by exhibiting antioxidant, anti-aging, and immunomodulatory properties favorably modulate the immune function, protecting the hosts from several infectious diseases. Zinc is an essential trace element important for the efficiency of the immune system in reason of its widespread role in the activity of enzymes, transcription factors and cytokines. The etiology of Chagas' disease, caused by a protozoan parasite Trypanosoma cruzi, has been the focus of considerable discussion, although chronic phase still remains not fully understood. This study showed that zinc and melatonin treatment did not affect the percentage of both CD4+ and CD8+ T lymphocytes subsets in chronically infected animals. Increased levels of IL-2 and IL-10, as well as, enhanced thymocyte proliferation in T. cruzi infected groups under zinc and melatonin therapy was observed as compared to untreated group. Conversely, during the chronic phase of infection, macrophages counts were reduced in melatonin and zinc-melatonin treated animals. The combined actions of zinc and melatonin have beneficial effects in counteracting parasite-induced immune dysregulation, protecting animals against the harmful actions of chronic T. cruzi infection. Furthermore, our results provide an experimental basis for further studies on the role of immunomodulatory therapies.

  14. Mechanisms of Infectivity and Evasion Derived from Microvesicles Cargo Produced by Trypanosoma cruzi

    Science.gov (United States)

    Borges, Bruna C.; Uehara, Isadora A.; Dias, Laysa O. S.; Brígido, Paula C.; da Silva, Claudio V.; Silva, Marcelo J. B.

    2016-01-01

    Cell invasion by the intracellular protozoans requires interaction of proteins from both the host and the parasite. Many parasites establish chronic infections, showing they have the potential to escape the immune system; for example, Trypanosoma cruzi is an intracellular parasite that causes Chagas disease. Parasite internalization into host cell requires secreted and surface molecules, such as microvesicles. The release of microvesicles and other vesicles, such as exosomes, by different eukaryotic organisms was first observed in the late twentieth century. The characterization and function of these vesicles have recently been the focus of several investigations. In this review, we discuss the release of microvesicles by T. cruzi. The molecular content of these vesicles is composed of several molecules that take place during parasite-host cell interaction and contribute to the parasite-driven mechanism of evasion from the host immune system. These new findings appear to have a profound impact on the comprehension of T. cruzi biology and highlight novel potential strategies for developing more efficient therapeutic approaches. PMID:27921011

  15. Kinetic and molecular characterization of the pyruvate phosphate dikinase from Trypanosoma cruzi.

    Science.gov (United States)

    González-Marcano, Eglys; Acosta, Héctor; Mijares, Alfredo; Concepción, Juan Luis

    2016-06-01

    Trypanosoma cruzi, like other trypanosomatids analyzed so far, can use both glucose and amino acids as carbon and energy source. In these parasites, glycolysis is compartmentalized in glycosomes, authentic but specialized peroxisomes. The major part of this pathway, as well as a two-branched glycolytic auxiliary system, are present in these organelles. The first enzyme of one branch of this auxiliary system is the PPi-dependent pyruvate phosphate dikinase (PPDK) that converts phosphoenolpyruvate (PEP), inorganic pyrophosphate (PPi) and AMP into pyruvate, inorganic phosphate (Pi) and ATP, thus contributing to the ATP/ADP balance within the glycosomes. In this work we cloned, expressed and purified the T. cruzi PPDK. It kinetic parameters were determined, finding KM values for PEP, PPi and AMP of 320, 70 and 17 μM, respectively. Using molecular exclusion chromatography, two native forms of the enzyme were found with estimated molecular weights of 200 and 100 kDa, corresponding to a homodimer and monomer, respectively. It was established that T. cruzi PPDK's specific activity can be enhanced up to 2.6 times by the presence of ammonium in the assay mixture. During growth of epimastigotes in batch culture an apparent decrease in the specific activity of PPDK was observed. However, when its activity is normalized for the presence of ammonium in the medium, no significant modification of the enzyme activity per cell in time was found.

  16. Human infection with Trypanosoma cruzi in Nasca, Peru: a seroepidemiological survey.

    Science.gov (United States)

    Acosta, H M; Ferreira, C S; de Carvalho, M E

    1997-01-01

    We estimated the proportion of seropositivity for infection with Trypanosoma cruzi (Chagas' disease) in a sample of the rural population of the Province of Nasca, Department of Ica, southwestern Peru. Although Triatoma infestans, the only vector species identified in the Department of Ica, is often found in domestic environments, data of the extent of human infection with T. cruzi are scant. This study comprised 446 houses, known to be infested with triatomines, distributed in 19 rural localities. While visiting those houses we collected filter paper bloodspots from 864 occupants (of both sexes, aged one year or over). By means of the indirect fluorescent antibody test (IFAT), we detected anti-T. cruzi IgG antibodies in samples from 178 individuals (20.6%). Seropositivity was significantly more frequent in females (23.8%) than in males (17.5%). Among the 410 individuals in the 1- to 10-year-old age group (47.5% of the population sample), 85 (20.7%) were found seropositive, which is indicative of an early acquisition of the infection. Within this group no significant differences in seropositivity were associated with sex.

  17. Ultrastructural and physiological changes induced by different stress conditions on the human parasite Trypanosoma cruzi.

    Science.gov (United States)

    Pérez-Morales, Deyanira; Hernández, Karla Daniela Rodríguez; Martínez, Ignacio; Agredano-Moreno, Lourdes Teresa; Jiménez-García, Luis Felipe; Espinoza, Bertha

    2017-01-01

    Trypanosoma cruzi is the etiological agent of Chagas disease. The life cycle of this protozoan parasite is digenetic because it alternates its different developmental forms through two hosts, a vector insect and a vertebrate host. As a result, the parasites are exposed to sudden and drastic environmental changes causing cellular stress. The stress response to some types of stress has been studied in T. cruzi, mainly at the molecular level; however, data about ultrastructure and physiological state of the cells in stress conditions are scarce or null. In this work, we analyzed the morphological, ultrastructural, and physiological changes produced on T. cruzi epimastigotes when they were exposed to acid, nutritional, heat, and oxidative stress. Clear morphological changes were observed, but the physiological conditions varied depending on the type of stress. The maintenance of the physiological state was severely affected by heat shock, acidic, nutritional, and oxidative stress. According to the surprising observed growth recovery after damage by stress alterations, different adaptations from the parasite to these harsh conditions were suggested. Particular cellular death pathways are discussed.

  18. Maternal-fetal transmission of Trypanosoma cruzi, a health problem slightly studied in Mexico: case Chiapas

    Directory of Open Access Journals (Sweden)

    Guillermina Campos-Valdez

    2016-05-01

    Full Text Available Objective. To determine the Trypanosoma cruzi infection prevalence in 1125 pregnant women and the transmission frequency to their children from Tapachula and Palenque, Chiapas. Materials and methods. We determined the prevalence by serology tests and the transmission frequency by polymerase chain reaction (PCR and T. cruzi reactivity capacity after 12 months. Results. Total maternal infection prevalence were 23/1 125 (2.04%, 9/600 (1.5% were from Tapachula and 14/525 (2.6% from Palenque. The seropositive women were between 20 and 35 years old, 31.8% have Premature Rapture of Membrane and 9.1% have history of perinatal death. The total percentage of positive newborns by PCR was 9/23 (39.13%, out of those 2/9 (22.2% are from Tapachula and 7/14 (50% from Palenque. The Maternal Fetal transmission frequency was. 2/9 (22.2% in Tapachula and 1/14 (7.14% in Palenque, all positive infants were asynthomatic. Conclusion. The maternal-fetal transmission rate in Chiapas State is variable; the reason could be the maternal immunological status and T. cruzi strain.

  19. The endless race between Trypanosoma cruzi and host immunity: lessons for and beyond Chagas disease.

    Science.gov (United States)

    Junqueira, Caroline; Caetano, Braulia; Bartholomeu, Daniella C; Melo, Mariane B; Ropert, Catherine; Rodrigues, Maurício M; Gazzinelli, Ricardo T

    2010-09-15

    Infection with the protozoan parasite Trypanosoma cruzi, the agent of Chagas disease, is characterised by a variable clinical course - from symptomless cases to severe chronic disease with cardiac and/or gastrointestinal involvement. The variability in disease outcome has been attributed to host responses as well as parasite heterogeneity. In this article, we review studies indicating the importance of immune responses as key determinants of host resistance to T. cruzi infection and the pathogenesis of Chagas disease. Particular attention is given to recent studies defining the role of cognate innate immune receptors and immunodominant CD8+ T cells that recognise parasite components - both crucial for host-parasite interaction and disease outcome. In light of these studies we speculate about parasite strategies that induce a strong and long-lasting T-cell-mediated immunity but at the same time allow persistence of the parasite in the vertebrate host. We also discuss what we have learned from these studies for increasing our understanding of Chagas pathogenesis and for the design of new strategies to prevent the development of Chagas disease. Finally, we highlight recent studies employing a genetically engineered attenuated T. cruzi strain as a vaccine shuttle that elicits potent T cell responses specific to a tumour antigen and protective immunity against a syngeneic melanoma cell line.

  20. Comparative evaluation of therapeutic DNA vaccines against Trypanosoma cruzi in mice.

    Science.gov (United States)

    Sanchez-Burgos, Gilma; Mezquita-Vega, R Gabino; Escobedo-Ortegon, Javier; Ramirez-Sierra, Maria Jesus; Arjona-Torres, Arletty; Ouaissi, Ali; Rodrigues, Mauricio M; Dumonteil, Eric

    2007-08-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health problem in most of Latin America. A key priority is the development of new treatments, due to the poor efficacy of current ones. We report here the comparative evaluation of therapeutic DNA vaccines encoding various T. cruzi antigens. ICR mice infected with 500 parasites intraperitoneally were treated at 5 and 12 days postinfection with 20 microg of plasmid DNA encoding T. cruzi antigens TSA-1, TS, ASP-2-like, Tc52 or Tc24. Treatment with plasmid encoding TS and/or ASP-2-like antigens had no significant effect on parasitemia or survival. Treatment with Tc52 DNA significantly reduced parasitemia, as well as cardiac parasite burden, and improved survival, although myocarditis was not significantly affected. Finally, treatment with plasmids encoding Tc24 and TSA-1 induced the most complete control of disease as evidenced by significant reductions in parasitemia, mortality, myocarditis and heart parasite burden. These data demonstrate that therapeutic vaccine efficacy is dependent on the antigen and suggest that DNA vaccines encoding Tc24, TSA-1, and Tc52 represent the best candidates for further studies of a therapeutic vaccine against Chagas disease.

  1. Optical detection of Trypanosoma cruzi in blood samples for diagnosis purpose

    Science.gov (United States)

    Alanis, Elvio; Romero, Graciela; Alvarez, Liliana; Martinez, Carlos C.; Basombrio, Miguel A.

    2004-10-01

    An optical method for detection of Trypanosoma Cruzi (T. cruzi) parasites in blood samples of mice infected with Chagas disease is presented. The method is intended for use in human blood, for diagnosis purposes. A thin layer of blood infected by T. cruzi parasites, in small concentrations, is examined in an interferometric microscope in which the images of the vision field are taken by a CCD camera and temporarily stored in the memory of a host computer. The whole sample is scanned displacing the microscope plate by means of step motors driven by the computer. Several consecutive images of the same field are taken and digitally processed by means of image temporal differentiation in order to detect if a parasite is eventually present in the field. Each field of view is processed in the same fashion, until the full area of the sample is covered or until a parasite is detected, in which case an acoustical warning is activated and the corresponding image is displayed permitting the technician to corroborate the result visually. A discussion of the reliability of the method as well as a comparison with other well established techniques are presented.

  2. Multi-epitope proteins for improved serological detection of Trypanosoma cruzi infection and Chagas Disease.

    Science.gov (United States)

    Duthie, Malcolm S; Guderian, Jeffery A; Vallur, Aarthy C; Misquith, Ayesha; Liang, Hong; Mohamath, Raodoh; Luquetti, Alejandro O; Carter, Darrick; Tavares, Suelene N B; Reed, Steven G

    2016-03-01

    We previously reported that tandem repeat (TR) proteins from Trypanosoma cruzi could serve as targets of the antibody response and be useful as diagnostic indicators. To optimize reagents for detecting T. cruzi infection we evaluated individual TR proteins and identified several that were recognized by the majority of Chagas patient's sera collected from individuals form Brazil. We then produced novel, recombinant fusion proteins to combine the reactive TR proteins into a single diagnostic product. Direct comparison of the antibody response of serum samples that were readily detected by the established fusion antigen used in commercial detection of Chagas disease, TcF, revealed strong responses to TcF43 and TcF26 proteins. While the TcF43 and TcF26 antigens enhanced detection and strength of signal, they did not compromise the specificity of detection compared to that obtained with TcF. Finally, it was apparent by testing against a panel of 84 serum samples assembled on the basis of moderate or weak reactivity against TcF (mostly signal:noise detected by many of the sera that had low TcF antibody levels. Taken together, these data indicate that TcF43 and TcF26 could be used to enhance the detection of T. cruzi infection as well as supporting a diagnosis of Chagas disease.

  3. Nuclear Compartmentalization Contributes to Stage-Specific Gene Expression Control in Trypanosoma cruzi

    Science.gov (United States)

    Pastro, Lucía; Smircich, Pablo; Di Paolo, Andrés; Becco, Lorena; Duhagon, María A.; Sotelo-Silveira, José; Garat, Beatriz

    2017-01-01

    In the protozoan parasite Trypanosoma cruzi, as in other trypanosomatids, transcription of protein coding genes occurs in a constitutive fashion, producing large polycistronic transcription units. These units are composed of non-functionally related genes which are pervasively processed to yield each mRNA. Therefore, post-transcriptional processes are crucial to regulate gene expression. Considering that nuclear compartmentalization could contribute to gene expression regulation, we comparatively studied the nuclear, cytoplasmic and whole cell transcriptomes of the non-infective epimastigote stage of T. cruzi, using RNA-Seq. We found that the cytoplasmic transcriptome tightly correlates with the whole cell transcriptome and both equally correlate with the proteome. Nonetheless, 1,200 transcripts showed differential abundance between the nuclear and cytoplasmic fractions. For the genes with transcript content augmented in the nucleus, significant structural and compositional differences were found. The analysis of the reported epimastigote translatome and proteome, revealed scarce ribosome footprints and encoded proteins for them. Ontology analyses unveiled that many of these genes are distinctive of other parasite life-cycle stages. Finally, the relocalization of transcript abundance in the metacyclic trypomastigote infective stage was confirmed for specific genes. While gene expression is strongly dependent on transcript steady-state level, we here highlight the importance of the distribution of transcripts abundance between compartments in T. cruzi. Particularly, we show that nuclear compartmentation is playing an active role in the developmental stage determination preventing off-stage expression. PMID:28243589

  4. Genetic Variability and Phylogenetic Relationships within Trypanosoma cruzi I Isolated in Colombia Based on Miniexon Gene Sequences

    Directory of Open Access Journals (Sweden)

    Claudia Herrera

    2009-01-01

    Full Text Available Phylogenetic studies of Trypanosoma cruzi have identified the existence of two groups: T. cruzi I and T. cruzi II. There are aspects that still remain unknown about the genetic variability within the T. cruzi I group. Given its epidemiological importance, it is necessary to have a better understanding of T. cruzi transmission cycles. Our purpose was to corroborate the existence of haplotypes within the T. cruzi I group and to describe the genetic variability and phylogenetic relationships, based on single nucleotide polymorphisms (SNPs found in the miniexon gene intergenic region, for the isolates from different hosts and epidemiological transmission cycles in Colombian regions. 31 T. cruzi isolates were molecularly characterized. Phylogenetic relationships within T. cruzi I isolates showed four haplotype groups (Ia–Id, associated with their transmission cycle. In previous studies, we reported that haplotype Ia is mainly associated with the domestic cycle and domiciliated Rhodnius prolixus. Haplotype Ib is associated with the domestic cycle and peridomestic cycle, haplotype Ic is closely related with the peridomestic cycle, and haplotype Id is strongly associated with the sylvatic cycle. The phylogenetic methodologies applied in this study are tools that bolster the associations among isolates and thus shed light on Chagas disease epidemiology.

  5. Secondary Metabolites from Vietnamese Marine Invertebrates with Activity against Trypanosoma brucei and T. cruzi

    Directory of Open Access Journals (Sweden)

    Nguyen Phuong Thao

    2014-06-01

    Full Text Available Marine-derived natural products from invertebrates comprise an extremely diverse and promising source of the compounds from a wide variety of structural classes. This study describes the discovery of five marine natural products with activity against Trypanosoma species by natural product library screening using whole cell in vitro assays. We investigated the anti-trypanosomal activity of the extracts from the soft corals and echinoderms living in Vietnamese seas. Of the samples screened, the methanolic extracts of several marine organisms exhibited potent activities against cultures of Trypanosoma brucei and T. cruzi (EC50 < 5.0 μg/mL. Among the compounds isolated from these extracts, laevigatol B (1 from Lobophytum crassum and L. laevigatum, (24S-ergost-4-ene-3-one (2 from Sinularia dissecta, astropectenol A (3 from Astropecten polyacanthus, and cholest-8-ene-3β,5α,6β,7α-tetraol (4 from Diadema savignyi showed inhibitory activity against T. brucei with EC50 values ranging from 1.57 ± 0.14 to 14.6 ± 1.36 μM, relative to the positive control, pentamidine (EC50 = 0.015 ± 0.003 μM. Laevigatol B (1 and 5α-cholest-8(14-ene-3β,7α-diol (5 exhibited also significant inhibitory effects on T. cruzi. The cytotoxic activity of the pure compounds on mammalian cells was also assessed and found to be insignificant in all cases. This is the first report on the inhibitory effects of marine organisms collected in Vietnamese seas against Trypanosoma species responsible for neglected tropical diseases.

  6. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozonn cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossum, Didelphis virginiana, from Southern Louisian

    Science.gov (United States)

    We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoan’s of veterinary importance (Neospora caninum, Sarcocystis neurona and Besnoitia darlingi) in a population of North American opossums (Didelphis...

  7. CD8+ T-cells expressing interferon gamma or perforin play antagonistic roles in heart injury in experimental Trypanosoma cruzi-elicited cardiomyopathy.

    Science.gov (United States)

    Silverio, Jaline Coutinho; Pereira, Isabela Resende; Cipitelli, Márcio da Costa; Vinagre, Nathália Ferreira; Rodrigues, Maurício Martins; Gazzinelli, Ricardo Tostes; Lannes-Vieira, Joseli

    2012-01-01

    In Chagas disease, CD8(+) T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8(+) T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC). Here we explored the role of CD8(+) T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8(+) T-cell capacity to produce interferon-gamma (IFNγ) and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8(+) T-cells segregated into IFNγ(+) perforin (Pfn)(neg) or IFNγ(neg)Pfn(+) cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8(+)Pfn(+) cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8(-/-) recipients showed that the CD8(+) cells from infected ifnγ(-/-)pfn(+/+) donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8(+) cells from ifnγ(+/+)pfn(-/-) donors. Moreover, the reconstitution of naïve cd8(-/-) mice with CD8(+) cells from naïve ifnγ(+/+)pfn(-/-) donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ(+) cells accumulation, whereas reconstitution with CD8(+) cells from naïve ifnγ(-/-)pfn(+/+) donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn(+) cells in the cardiac tissue. Our data support a possible antagonist effect of CD8(+)Pfn(+) and CD8(+)IFNγ(+) cells during CCC. CD8(+)IFNγ(+) cells may exert a beneficial role

  8. CD8+ T-Cells Expressing Interferon Gamma or Perforin Play Antagonistic Roles in Heart Injury in Experimental Trypanosoma Cruzi-Elicited Cardiomyopathy

    Science.gov (United States)

    Cipitelli, Márcio da Costa; Vinagre, Nathália Ferreira; Rodrigues, Maurício Martins; Gazzinelli, Ricardo Tostes; Lannes-Vieira, Joseli

    2012-01-01

    In Chagas disease, CD8+ T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8+ T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC). Here we explored the role of CD8+ T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8+ T-cell capacity to produce interferon-gamma (IFNγ) and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8+ T-cells segregated into IFNγ+ perforin (Pfn)neg or IFNγnegPfn+ cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8+Pfn+ cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8−/− recipients showed that the CD8+ cells from infected ifnγ−/−pfn+/+ donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8+ cells from ifnγ+/+pfn−/− donors. Moreover, the reconstitution of naïve cd8−/− mice with CD8+ cells from naïve ifnγ+/+pfn−/− donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ+ cells accumulation, whereas reconstitution with CD8+ cells from naïve ifnγ−/−pfn+/+ donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn+ cells in the cardiac tissue. Our data support a possible antagonist effect of CD8+Pfn+ and CD8+IFNγ+ cells during CCC. CD8+IFNγ+ cells may exert a beneficial role, whereas CD8+Pfn+ may play a detrimental role

  9. CD8+ T-cells expressing interferon gamma or perforin play antagonistic roles in heart injury in experimental Trypanosoma cruzi-elicited cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Jaline Coutinho Silverio

    Full Text Available In Chagas disease, CD8(+ T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8(+ T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC. Here we explored the role of CD8(+ T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8(+ T-cell capacity to produce interferon-gamma (IFNγ and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8(+ T-cells segregated into IFNγ(+ perforin (Pfn(neg or IFNγ(negPfn(+ cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8(+Pfn(+ cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8(-/- recipients showed that the CD8(+ cells from infected ifnγ(-/-pfn(+/+ donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8(+ cells from ifnγ(+/+pfn(-/- donors. Moreover, the reconstitution of naïve cd8(-/- mice with CD8(+ cells from naïve ifnγ(+/+pfn(-/- donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ(+ cells accumulation, whereas reconstitution with CD8(+ cells from naïve ifnγ(-/-pfn(+/+ donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn(+ cells in the cardiac tissue. Our data support a possible antagonist effect of CD8(+Pfn(+ and CD8(+IFNγ(+ cells during CCC. CD8(+IFNγ(+ cells may exert a beneficial role, whereas CD8(+Pfn

  10. Suppression of humoral immunity and lymphocyte responsiveness during experimental trypanosoma cruzi infections Supresión de la inmunidade humoral y de la respuesta linfocitaria durante la infección experimental con Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    José A. O'daly

    1984-04-01

    Full Text Available C3H/He and C57B1/6 mice were inoculated with 500 Trypanosoma cruzi trypomastigotes (Strain Y. During the acute phase infected mice presented parasitemia and enlargement of lymph nodes and spleens and intracellular parasites were observed in the heart. Examinations of cells derived from spleen and lymph nodes showed increased numbers of IgM and IgG-bearing cells. During the peak of splenomegaly, about day 17 post-infections, splenic lymphocytes showed a marked decrease in responsiveness to T and B-cell mitogens, parasite antigens and plaque forming cells (PFC to sheep red blood cells (SRBC. Unfractionated or plastic adherent splenic cells from mice, obtained during the acute phase were able to suppress the response to mitogens by lymphocytes from uninfected mice. During the chronic phase. Disappearance of parasitemia and intracellular parasites in the hearts as well as a decrease in spleen size, was observed. These changes preceded the complete recovery of responsiveness to mitogens and T. cruzi antigens by C57B1/6 splenic lymphocytes. However, this recovery was only partial in the C3H/He mice, known to be more sensitive to T. cruzi infection. Partial recovery of humoral immune response also occurred in both strains of mice during the chronic phase.Ratones C3H/He y C57B1/6 inoculados con 500 tripomastigotes de la cepa Y de T. cruzi muestran durante la fase aguda de la enferme-dad, parasitemia, aumento del bazo y gânglios linfáticos así como parásitos intracelulares en el corazón. Análisis de las células presentes en ganglios linfáticos y bazo presenta aumento de células IgM e IgG. Cuando la esplenomegalia es mayor, alrededor del día 17 postínfección, los linfocitos esplénicos mostraron un descenso marcado en la respuesta a mitógenos de células B y T, antígenos de T. cruzi y células formadoras de placas contra glóbulos rojos de carnero. Células de bazo o células esplénicas adherentes a plástico, obtenidas de ratones durante

  11. Tres especies de triatominos y su importancia como vectores de Trypanosoma Cruzi en México Importance of three vectors of Trypanosoma cruzi in Mexico

    Directory of Open Access Journals (Sweden)

    Paz M. Salazar Schettino

    2005-03-01

    Full Text Available Se presentan observaciones hechas en el campo y en el laboratorio sobre tres vectores de Trypanosoma cruzi: Triatoma barberi, T. pallidipennis y T. dimidiata. Se comparan resultados en relación con sus ecotopos, capacidad vectorial, características biológicas, índices entomológicos y sitios de captura. En relación con sus ecotopos, T. barberi tiene preferencia por el interior del domicilio humano, en paredes, directamente en contacto con las camas; T. pallidipennis, cuando se encuentra dentro de las casas, prefiere pisos y entre la ropa, aunque su principal ecotopo es silvestre; T. dimidiata tiene localización en pisos, especialmente bajo las camas, en el ángulo entre pared y piso; T. barberi y T. dimidiata son atraídas por la luz. Los ciclos de vida fueron de 523, 171 y 510 días, respectivamente para Triatoma barberi, T. pallidipennis y T. dimidiata. La capacidad vectorial se determinó según el tiempo que tarda en defecar durante o después de su ingesta de sangre: T. barberi defeca durante su alimentación, mientras que T. pallidipennis y T. dimidiata lo hacen de 10 a 20 y de 20 a 30 minutos después de iniciado el proceso, respectivamente. Los índices de infección natural fueron de 56.6 para T.barberi, 29 para T. pallidipennis y 15.6 para T. dimidiata. Los índices metaciclogénicos, que indican porcentajes de tripomastigotes metacíclicos en intestino posterior de los vectores fueron en T. barberi 76.6, T. pallidipennis 15 y T. dimidiata 26, con lo que se concluye que la primera especie es el mejor transmisor de T. cruzi en México.Observations made in the field and in the laboratory on three vectors of Trypanosoma cruzi: Triatoma barberi, T. pallidipennis and T. dimidiata are here presented. Results are compared in relation with their ecotopes, vectorial capacity, biological characteristic, entomological indexes and capture places. In relation with their ecotopos T. barberi has preference for the interior of the human home, in

  12. On the tissular parasitism of Trypanosoma cruzi y strain in swiss mice Sobre o parasitismo tecidual da cepa Y do Trypanosoma cruzi em camundongos albinos (Swiss-Webster

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora de Sousa

    1984-12-01

    Full Text Available A review of the tissular parasitism of Trypanosoma cruzi Y strain in Swiss mice was carried out. This strain parasitized preferentially smooth, skeletal and cardiac muscle fibers, with low transitory spleen and liver parasitism, as previously found by some Authors, although differing from other reports. These results can be related to the host genetical constitution and/or the degree of the strain virulence at the time of this study. Furthermore, we discuss that the high macrophagotropism reported for this strain in some instances could be an artificially induced condition resulting from its serial maintenance in mice, either for a longer time and/or by using young animals. The heavy parasitism and inflammation observed in the bladder, pancreas and spermatic duct of some inoculated mice, as well as the testis parasitization, were also noteworthy findings.Através deste trabalho fizemos uma revisão do parasitismo tecidual da cepa Y do Trypanosoma cruzi em camundongos albinos (Swiss-Webster. Esta cepa parasitou preferencialmente as fibras musculares lisas, esqueléticas e cardíacas, sendo baixo e transitório seu parasitismo do baço e fígado, conforme já observado por alguns Autores, embora diferindo de outros achados. Estes resultados podem estar relacionados com o padrão genético do hospedeiro e/ou com o grau de virulência da cepa por ocasião deste estudo. Além do mais, discutimos a possibilidade de que o intenso macrofagotropismo descrito para esta cepa em algumas ocasiões possa ser uma condição artificialmente induzida através de sua manutenção seriada em camundongos por tempo prolongado e/ou pelo uso de animais jovens. Também são dignos de nota, o intenso parasitismo e inflamação da bexiga, pâncreas e canal espermático de alguns animais inoculados, assim como, o encontro de ninhos de amastigotas no testículo.

  13. Frequent house invasion of Trypanosoma cruzi-infected triatomines in a suburban area of Brazil.

    Directory of Open Access Journals (Sweden)

    Gilmar Ribeiro

    2015-04-01

    Full Text Available The demographic transition of populations from rural areas to large urban centers often results in a disordered occupation of forest remnants and increased economic pressure to develop high-income buildings in these areas. Ecological and socioeconomic factors associated with these urban transitions create conditions for the potential transmission of infectious diseases, which was demonstrated for Chagas disease.We analyzed 930 triatomines, mainly Triatoma tibiamaculata, collected in artificial and sylvatic environments (forests near houses of a suburban area of the city of Salvador, Bahia State, Brazil between 2007 and 2011. Most triatomines were captured at peridomiciles. Adult bugs predominated in all studied environments, and nymphs were scarce inside houses. Molecular analyses of a randomly selected sub-sample (n=212 of triatomines showed Trypanosoma cruzi infection rates of 65%, 50% and 56% in intradomestic, peridomestic and sylvatic environments, respectively. We detected the T. cruzi lineages I and II and mixed infections. We also showed that T. tibiamaculata fed on blood from birds (50%, marsupials (38%, ruminants (7% and rodents (5%. The probability of T. cruzi infection was higher in triatomines that fed on marsupial blood (odds ratio (OR = 1.95, 95% confidence interval (CI = 1.22-3.11. Moreover, we observed a protective effect against infection in bugs that fed on bird blood (OR = 0.43, 95% CI = 0.30-0.73.The frequent invasion of houses by infected triatomines indicates a potential risk of T. cruzi transmission to inhabitants in this area. Our results reinforce that continuous epidemiological surveillance should be performed in areas where domestic transmission is controlled but enzootic transmission persists.

  14. La enfermedad del adyuvante en ratas infectadas experimentalmente con Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Silvia Revelli

    1986-06-01

    Full Text Available Se estudió la evolución de la artritis por adyuvante en ratas que habían sido infectadas previamente con Trypanosoma cruzi, con el objeto de evaluar su competencia inmunológica a través de la respuesta artrítica. La artritis por adyuvante se indujo en ratas adultas, endocriadas de ambos sexos, con 0.1 mi de adyuvante completo de Freund en la almohadilla plantar, en 2 lotes: a inyectadas 90 días antes con 1 x 10(6 T. cruzi y b testigos normales simultáneos. Se midieron, la lesión artrítica macroscópicamente con una escala semicuantitativa, y con microscopía óptica la histopatología de la lesión local y la del corazón, a los 180 días post-infecoión. La magnitud de las lesiones artríticas en las ratas con T. cruzi fue significativamente menor (p < 0.001 que la de los testigos, en todo el período. El infiltrado inflamatorio local, formado por linfocitos, plasmocitos y macrófagos fue significativamente menor (p < 0.001 en las ratas chagásicas, con respecto al de los testigos. Se postula que en las ratas que recibieron T. cruzi la respuesta artrítica menor podría deberse a una competición antigénica con los determinantes del parásito o a mecanismos inmunosupresores que interfieren en la producción de la entidad experimental.

  15. Expression and the Peculiar Enzymatic Behavior of the Trypanosoma cruzi NTH1 DNA Glycosylase

    Science.gov (United States)

    Ormeño, Fernando; Barrientos, Camila; Ramirez, Santiago; Ponce, Iván; Valenzuela, Lucía; Sepúlveda, Sofía; Bitar, Mainá; Kemmerling, Ulrike; Machado, Carlos Renato; Cabrera, Gonzalo; Galanti, Norbel

    2016-01-01

    Trypanosoma cruzi, the etiological agent of Chagas’ disease, presents three cellular forms (trypomastigotes, epimastigotes and amastigotes), all of which are submitted to oxidative species in its hosts. However, T. cruzi is able to resist oxidative stress suggesting a high efficiency of its DNA repair machinery.The Base Excision Repair (BER) pathway is one of the main DNA repair mechanisms in other eukaryotes and in T. cruzi as well. DNA glycosylases are enzymes involved in the recognition of oxidative DNA damage and in the removal of oxidized bases, constituting the first step of the BER pathway. Here, we describe the presence and activity of TcNTH1, a nuclear T. cruzi DNA glycosylase. Surprisingly, purified recombinant TcNTH1 does not remove the thymine glycol base, but catalyzes the cleavage of a probe showing an AP site. The same activity was found in epimastigote and trypomastigote homogenates suggesting that the BER pathway is not involved in thymine glycol DNA repair. TcNTH1 DNA-binding properties assayed in silico are in agreement with the absence of a thymine glycol removing function of that parasite enzyme. Over expression of TcNTH1 decrease parasite viability when transfected epimastigotes are submitted to a sustained production of H2O2.Therefore, TcNTH1 is the only known NTH1 orthologous unable to eliminate thymine glycol derivatives but that recognizes and cuts an AP site, most probably by a beta-elimination mechanism. We cannot discard that TcNTH1 presents DNA glycosylase activity on other DNA base lesions. Accordingly, a different DNA repair mechanism should be expected leading to eliminate thymine glycol from oxidized parasite DNA. Furthermore, TcNTH1 may play a role in the AP site recognition and processing. PMID:27284968

  16. Identification of immunodominant epitopes in Trypanosoma cruzi trypomastigote surface antigen-1 protein that mask protective epitopes.

    Science.gov (United States)

    Wrightsman, R A; Dawson, B D; Fouts, D L; Manning, J E

    1994-10-01

    The gene that encodes trypomastigote surface Ag-1 (TSA-1), a major surface Ag of the bloodstream trypomastigote stage of Trypanosoma cruzi, was expressed in a baculovirus expression system. To determine the epitope(s) in TSA-1 that was recognized during T. cruzi infection and after immunization with TSA-1, subregions of the TSA-1 gene were expressed in a bacterial expression system. As seen by Western blotting, both mice and rabbits immunized with recombinant TSA-1 protein, as well as T. cruzi-infected mice, developed strong immune responses to the carboxyl-proximal region of TSA-1, but show no reaction to the amino-proximal portion of TSA-1. When mice were immunized with either recombinant TSA-1 protein or the carboxyl-proximal region of TSA-1, they did not survive challenge with 10(3) bloodstream trypomastigotes. However, 70% of the mice immunized with the amino-proximal portion of TSA-1 survived challenge with 10(3) bloodstream trypomastigotes. Thus, the immune responses elicited by recombinant TSA-1 or the carboxyl-proximal portion of TSA-1 are nonprotective during T. cruzi infection. In contrast, vaccination with the amino proximal region of TSA-1 elicits a protective immune response. These results suggest that responses to immunodominant epitope(s) within the carboxyl-proximal portion of TSA-1 mask epitopes within the amino-proximal portion that are capable of stimulating host-protective immune responses. It is suggested that immunodominant regions in surface molecules such as TSA-1 may provide a mechanism for the parasite to evade the host immune response by directing the response away from epitopes that have the potential to elicit a reaction that is damaging to the parasite.

  17. Variation in antigenic determinants specific to the infective stage of Trypanosoma cruzi.

    Science.gov (United States)

    Wrightsman, R A; Leon, W; Manning, J E

    1986-08-01

    Monoclonal antibodies reactive with the surface antigens of the Peru strain of Trypanosoma cruzi were analyzed by Western blots and immunofluorescence assays to determine their reactivity with three life cycle stages and five strain isolates of T. cruzi. One monoclonal antibody, 7.6, recognized a 68-kilodalton (kDa) polypeptide in Western blots of Peru strain trypomastigotes, epimastigotes, and amastigotes. A 68-kDa polypeptide was also detected by monoclonal antibody 7.6 in trypomastigotes of the CL and Y strains and in the clonal isolates Esmeraldo clone 3 and Silvio X10 clone 1. Positive immunofluorescence results were obtained for all life cycle stages of the five strains that were reacted with monoclonal antibody 7.6, thus indicating that the antigen recognized by monoclonal antibody 7.6 is universally present in all T. cruzi strains tested. In contrast, monoclonal antibody 4.2 reacted with a polypeptide doublet of 90 and 105 kDa in Western blots of Peru strain trypomastigotes, but it did not detect these antigens in epimastigotes or amastigotes. The same polypeptide doublet of 90 and 105 kDa was also detected in Western blots of Y strain trypomastigotes; however, no bands were detected in blots of strain CL or isolate Silvio X10 clone 1 trypomastigotes. In blots of Esmeraldo clone 3 trypomastigotes, a single band of 130 kDa was detected by monoclonal antibody 4.2. In immunofluorescence assays of monoclonal antibody 4.2, positive reactions were obtained only with trypomastigotes of Peru, Y, and Esmeraldo clone 3 strains. Thus, monoclonal antibody 4.2 recognizes a trypomastigote-specific antigen which is not universally present on all strains of T. cruzi.

  18. Trypanosoma cruzi: Entry into Mammalian Host Cells and Parasitophorous Vacuole Formation

    Science.gov (United States)

    Barrias, Emile Santos; de Carvalho, Tecia Maria Ulisses; De Souza, Wanderley

    2013-01-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted to vertebrate hosts by blood-sucking insects. This protozoan is an obligate intracellular parasite. The infective forms of the parasite are the metacyclic trypomastigotes, amastigotes, and bloodstream trypomastigotes. The recognition between the parasite and mammalian host cell, involves numerous molecules present in both cell types, and similar to several intracellular pathogens, T. cruzi is internalized by host cells via multiple endocytic pathways. Morphological studies demonstrated that after the interaction of the infective forms of T. cruzi with phagocytic or non-phagocytic cell types, plasma membrane (PM) protrusions can form, showing similarity with those observed during canonical phagocytosis or macropinocytic events. Additionally, several molecules known to be molecular markers of membrane rafts, macropinocytosis, and phagocytosis have been demonstrated to be present at the invasion site. These events may or may not depend on the host cell lysosomes and cytoskeleton. In addition, after penetration, components of the host endosomal-lysosomal system, such as early endosomes, late endosomes, and lysosomes, participate in the formation of the nascent parasitophorous vacuole (PV). Dynamin, a molecule involved in vesicle formation, has been shown to be involved in the PV release from the host cell PM. This review focuses on the multiple pathways that T. cruzi can use to enter the host cells until complete PV formation. We will describe different endocytic processes, such as phagocytosis, macropinocytosis, and endocytosis using membrane microdomains and clathrin-dependent endocytosis and show results that are consistent with their use by this smart parasite. We will also discuss others mechanisms that have been described, such as active penetration and the process that takes advantage of cell membrane wound repair. PMID:23914186

  19. Trypanosoma cruzi: Entry Into Mammalian Host Cells and Parasitophorous Vacuole Formation

    Directory of Open Access Journals (Sweden)

    Emile Santos Barrias

    2013-08-01

    Full Text Available Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted to vertebrate hosts by blood-sucking insects. This protozoan is an obligate intracellular parasite. The infective forms of the parasite are the metacyclic trypomastigotes, amastigotes and bloodstream trypomastigotes. The recognition between the parasite and mammalian host cell, involves numerous molecules present in both cell types, and similar to several intracellular pathogens, T.cruzi is internalized by host cells via multiple endocytic pathways. Morphological studies demonstrated that after the interaction of the infective forms of T.cruzi with phagocytic or non-phagocytic cell types, plasma membrane protrusions can form, showing similarity with those observed during canonical phagocytosis or macropinocytic events. Additionally, several molecules known to be molecular markers of membrane rafts, macropinocytosis and phagocytosis have been demonstrated to be present at the invasion site. These events may or may not depend on the host cell lysosomes and cytoskeleton. In addition, after penetration, components of the host endosomal-lysosomal system, such as early endosomes, late endosomes and lysosomes, participate in the formation of the nascent parasithophorous vacuole (VP. Dynamin, a molecule involved in vesicle formation, has been shown to be involved in the parasitophorous vacuole release from the host cell plasma membrane. This review focuses on the multiple pathways that T.cruzi can use to enter the host cells until complete VP formation. We will describe different endocytic processes, such as phagocytosis, macropinocytosis, endocytosis using membrane microdomains and clathrin-dependent endocytosis and show results that are consistent with their use by this smart parasite. We will also discuss other mechanisms that have been described, such as active penetration and the process that takes advantage of cell membrane wound repair.

  20. Subtelomeric I-SceI-Mediated Double-Strand Breaks Are Repaired by Homologous Recombination in Trypanosoma cruzi

    Science.gov (United States)

    Chiurillo, Miguel A.; Moraes Barros, Roberto R.; Souza, Renata T.; Marini, Marjorie M.; Antonio, Cristiane R.; Cortez, Danielle R.; Curto, María Á.; Lorenzi, Hernán A.; Schijman, Alejandro G.; Ramirez, José L.; da Silveira, José F.

    2016-01-01

    Trypanosoma cruzi chromosome ends are enriched in surface protein genes and pseudogenes (e.g., trans-sialidases) surrounded by repetitive sequences. It has been proposed that the extensive sequence variability among members of these protein families could play a role in parasite infectivity and evasion of host immune response. In previous reports we showed evidence suggesting that sequences located in these regions are subjected to recombination. To support this hypothesis we introduced a double-strand break (DSB) at a specific target site in a T. cruzi subtelomeric region cloned into an artificial chromosome (pTAC). This construct was used to transfect T. cruzi epimastigotes expressing the I-SceI meganuclease. Examination of the repaired sequences showed that DNA repair occurred only through homologous recombination (HR) with endogenous subtelomeric sequences. Our findings suggest that DSBs in subtelomeric repetitive sequences followed by HR between them may contribute to increased variability in T. cruzi multigene families. PMID:28066363

  1. Subtelomeric I-SceI-Mediated Double-Strand Breaks Are Repaired by Homologous Recombination in Trypanosoma cruzi.

    Science.gov (United States)

    Chiurillo, Miguel A; Moraes Barros, Roberto R; Souza, Renata T; Marini, Marjorie M; Antonio, Cristiane R; Cortez, Danielle R; Curto, María Á; Lorenzi, Hernán A; Schijman, Alejandro G; Ramirez, José L; da Silveira, José F

    2016-01-01

    Trypanosoma cruzi chromosome ends are enriched in surface protein genes and pseudogenes (e.g., trans-sialidases) surrounded by repetitive sequences. It has been proposed that the extensive sequence variability among members of these protein families could play a role in parasite infectivity and evasion of host immune response. In previous reports we showed evidence suggesting that sequences located in these regions are subjected to recombination. To support this hypothesis we introduced a double-strand break (DSB) at a specific target site in a T. cruzi subtelomeric region cloned into an artificial chromosome (pTAC). This construct was used to transfect T. cruzi epimastigotes expressing the I-SceI meganuclease. Examination of the repaired sequences showed that DNA repair occurred only through homologous recombination (HR) with endogenous subtelomeric sequences. Our findings suggest that DSBs in subtelomeric repetitive sequences followed by HR between them may contribute to increased variability in T. cruzi multigene families.

  2. Human infection with Trypanosoma cruzi in Nasca, Peru: A seroepidemiological survey (1

    Directory of Open Access Journals (Sweden)

    Hilda Maria SOLIS ACOSTA

    1997-03-01

    Full Text Available We estimated the proportion of seropositivity for infection with Trypanosoma cruzi (Chagas’ disease in a sample of the rural population of the Province of Nasca, Department of Ica, southwestern Peru. Although Triatoma infestans, the only vector species identified in the Department of Ica, is often found in domestic environments, data of the extent of human infection with T. cruzi are scant. This study comprised 446 houses, known to be infested with triatomines, distributed in 19 rural localities. While visiting those houses we collected filter paper bloodspots from 864 occupants (of both sexes, aged one year or over. By means of the indirect fluorescent antibody test (IFAT, we detected anti-T. cruzi IgG antibodies in samples from 178 individuals (20.6%. Seropositivity was significantly more frequent in females (23.8% than in males (17.5%. Among the 410 individuals in the 1- to 10-year-old age group (47.5% of the population sample, 85 (20.7% were found seropositive, which is indicative of an early acquisition of the infection. Within this group no significant differences in seropositivity were associated with sexInfecção humana por Trypanosoma cruzi em Nasca, Peru: um inquérito soroepidemiológico Estimamos a proporção de positividade sorológica para infecção chagásica em amostra da população rural da Província de Nasca, Departamento de Ica, sudoeste do Peru. Embora Triatoma infestans, o único vetor identificado no Departamento de Ica, seja encontrado freqüentemente em ambientes domésticos, são escassos os dados sobre a infecção de indivíduos humanos por Trypanosoma cruzi. Este estudo compreendeu 446 unidades domiciliares sabidamente infestadas por triatomíneos, distribuídas em 19 localidades. Ao visitá-las colhemos, em papel-filtro, amostras de sangue de 864 pessoas de um ano ou mais de idade, sem seleção por sexo. Por meio da reação de imunofluorescência indireta (RIFI, detectamos anticorpos IgG anti-T. cruzi em

  3. Early Regulation of Profibrotic Genes in Primary Human Cardiac Myocytes by Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Aniekanabassi N Udoko

    2016-01-01

    Full Text Available The molecular mechanisms of Trypanosoma cruzi induced cardiac fibrosis remains to be elucidated. Primary human cardiomyoctes (PHCM exposed to invasive T. cruzi trypomastigotes were used for transcriptome profiling and downstream bioinformatic analysis to determine fibrotic-associated genes regulated early during infection process (0 to 120 minutes. The identification of early molecular host responses to T. cruzi infection can be exploited to delineate important molecular signatures that can be used for the classification of Chagasic patients at risk of developing heart disease. Our results show distinct gene network architecture with multiple gene networks modulated by the parasite with an incline towards progression to a fibrogenic phenotype. Early during infection, T. cruzi significantly upregulated transcription factors including activator protein 1 (AP1 transcription factor network components (including FOSB, FOS and JUNB, early growth response proteins 1 and 3 (EGR1, EGR3, and cytokines/chemokines (IL5, IL6, IL13, CCL11, which have all been implicated in the onset of fibrosis. The changes in our selected genes of interest did not all start at the same time point. The transcriptome microarray data, validated by quantitative Real-Time PCR, was also confirmed by immunoblotting and customized Enzyme Linked Immunosorbent Assays (ELISA array showing significant increases in the protein expression levels of fibrogenic EGR1, SNAI1 and IL 6. Furthermore, phosphorylated SMAD2/3 which induces a fibrogenic phenotype is also upregulated accompanied by an increased nuclear translocation of JunB. Pathway analysis of the validated genes and phospho-proteins regulated by the parasite provides the very early fibrotic interactome operating when T. cruzi comes in contact with PHCM. The interactome architecture shows that the parasite induces both TGF-β dependent and independent fibrotic pathways, providing an early molecular foundation for Chagasic

  4. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico

    Science.gov (United States)

    Sánchez-González, Gilberto; Figueroa-Lara, Alejandro; Elizondo-Cano, Miguel; Wilson, Leslie; Novelo-Garza, Barbara; Valiente-Banuet, Leopoldo; Ramsey, Janine M.

    2016-01-01

    An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico’s national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years of Mexico

  5. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico.

    Science.gov (United States)

    Sánchez-González, Gilberto; Figueroa-Lara, Alejandro; Elizondo-Cano, Miguel; Wilson, Leslie; Novelo-Garza, Barbara; Valiente-Banuet, Leopoldo; Ramsey, Janine M

    2016-03-01

    An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico's national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years of Mexico's mandated

  6. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico.

    Directory of Open Access Journals (Sweden)

    Gilberto Sánchez-González

    2016-03-01

    Full Text Available An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico's national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years

  7. Bisphosphonates inhibit the growth of Trypanosoma brucei, Trypanosoma cruzi, Leishmania donovani, Toxoplasma gondii, and Plasmodium falciparum: a potential route to chemotherapy.

    Science.gov (United States)

    Martin, M B; Grimley, J S; Lewis, J C; Heath, H T; Bailey, B N; Kendrick, H; Yardley, V; Caldera, A; Lira, R; Urbina, J A; Moreno, S N; Docampo, R; Croft, S L; Oldfield, E

    2001-03-15

    We have investigated the effects in vitro of a series of bisphosphonates on the proliferation of Trypanosoma cruzi, Trypanosoma brucei rhodesiense, Leishmania donovani, Toxoplasma gondii, and Plasmodium falciparum. The results show that nitrogen-containing bisphosphonates of the type used in bone resorption therapy have significant activity against parasites, with the aromatic species having in some cases nanomolar or low-micromolar IC(50) activity values against parasite replication (e.g. o-risedronate, IC(50) = 220 nM for T. brucei rhodesiense; risedronate, IC(50) = 490 nM for T. gondii). In T. cruzi, the nitrogen-containing bisphosphonate risedronate is shown to inhibit sterol biosynthesis at a pre-squalene level, most likely by inhibiting farnesylpyrophosphate synthase. Bisphosphonates therefore appear to have potential in treating parasitic protozoan diseases.

  8. The ecology of the Trypanosoma cruzi transmission cycle: Dispersion of zymodeme 3 (Z3) in wild hosts from Brazilian biomes.

    Science.gov (United States)

    Lisboa, Cristiane Varella; Xavier, Samanta Cristina das Chagas; Herrera, Heitor Miraglia; Jansen, Ana Maria

    2009-10-28

    Two main genotypes in Trypanosoma cruzi subpopulations can be distinguished by PCR amplification of sequences from the mini-exon gene non-transcribed spacer, respectively, T. cruzi I (TCI) and T. cruzi II (TCII). This technique is also capable of distinguishing a third assemblage of subpopulations that do not fit in these genotypes and that remain known as zymodeme Z3 (Z3). The distribution pattern as well as the mammalian host range of this latter T. cruzi sublineage still remains unclear. Thus, the intention of our study was to increase the information regarding these aspects. The mini-exon analysis of T. cruzi isolates obtained from sylvatic animals in the Amazon Forest, Atlantic Rainforest, Caatinga and Pantanal showed that prevalence of the Z3 subpopulation in nature was low (15 out of 225 isolates, corresponding to 7%). A higher prevalence of Z3 was observed in the Caatinga (15%) and the Pantanal (12%). Infection by Z3 was observed in mammalian hosts included in Carnivora, Chiroptera, Didelphimorphia, Rodentia and Xernathra. The T. cruzi Z3 subpopulation was observed also in mixed infections (33%) with TCI (n=2) and TCII (n=3). These results demonstrate that T. cruzi Z3 displays a wider distribution and host range than formerly understood as it has been demonstrated to be able infect species included in five orders of mammalian host species dispersed through all forest strata of the four Brazilian biomes evaluated.

  9. Stage and strain specific expression of the tandemly repeated 90 kDa surface antigen gene family in Trypanosoma cruzi.

    Science.gov (United States)

    Beard, C A; Wrightsman, R A; Manning, J E

    1988-04-01

    A recombinant cDNA library constructed in the expression vector lambda gtll using mRNA from the trypomastigote stage of Trypanosoma cruzi was screened with two monoclonal antibodies that have been shown to react with a 105 kDa and a 90 kDa surface antigen in trypomastigotes of the Peru and Y strains of T. cruzi. One recombinant lambda phage, designated Tcc-20, was reactive to both monoclonals. The beta-galactosidase/T. cruzi hybrid protein encoded in Tcc-20 is recognized by the monoclonal antibodies and by serum antibodies from mice infected with strains of T. cruzi which contain the 90 kDa antigen. Antibodies immunoselected from serum of mice infected with the Peru strain by adsorption to Tcc-20 fusion protein react specifically with a 90 kDa polypeptide in trypomastigote but not epimastigote lysates of T. cruzi. The mRNA complementary to the DNA insert in Tcc-20 is present only in those stages and strains of T. cruzi which express the 90 kDa surface antigen. These characteristics are strong evidence that the T. cruzi DNA fragment cloned into Tcc-20 encodes a portion of the 90 kDa surface antigen. The gene(s) which encodes this polypeptide is shown to be present in approximately 20 copies per haploid genome and most, and possibly all, of the copies are found in a tandemly linked multigene family.

  10. Immunofluorescent Antibody Test (IFAT for Trypanosoma cruzi in dogs from urban and rural areas of Pelotas, RS

    Directory of Open Access Journals (Sweden)

    Charlene Nascimento dos Santos

    2015-07-01

    Full Text Available Chagas disease (CD is a zoonosis with the protozoan Trypanosoma cruzi as the causative agent. Dogs are considered the main domestic reservoir for T. cruzi in most Latin American countries and in some areas of the United States. In southern Brazil, despite being an endemic area of the disease, the prevalence in dogs is still unknown. This study aimed to evaluate the frequency of T. cruzi antibodies in dogs from urban and rural areas of Pelotas, RS, Brazil. A total of 227 canine sera were used for serological tests, of which 99 were from urban areas and 128 were from rural areas of Pelotas. Information regarding the environment and the possible risk factors (origin, rural contact, age, breed, confinement and gender to which the dogs were exposed were recorded. Indirect immunofluorescence was used to assess the presence of specific immunoglobulins (IgG anti-T. cruzi in the serum of dogs. Of the 227 sera analyzed, 81 (35.7% exhibited anti-T. cruzi, which represented 34.3% of the dogs from the urban area and 36.7% of the dogs from the rural area. Among the variables analyzed, rural contact and male gender showed an association with seropositivity for T. cruzi. The detection of T. cruzi antibodies in the serum of these dogs emphasizes the need to study trypanosomiasis in this important domestic reservoir of Chagas disease.

  11. Cryptic infections in mice with the Trypanosoma cruzi CL-14 clone Infecções subpatentes em camundongos pelo clone CL-14 do Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    M.A. SOUSA

    1999-05-01

    Full Text Available A infectividade do clone CL-14 do Trypanosoma cruzi para camundongos foi revista utilizando-se como inóculo metacíclicos de cultura em NNN+LIT, pré-incubados ou não com complemento de cobaio. Nos animais inoculados não observamos parasitemia patente, mas a presença do parasito foi confirmada em 30% deles (9/30 através de hemocultivo ou xenodiagnóstico, este examinado aos 100 dias. A positividade das hemoculturas pôde ser evidenciada a partir dos 60 dias quando procederam de camundongos inoculados com metacíclicos tratados com complemento. Nos demais hemocultivos a positividade foi constatada aos 100 dias ou posteriormente. Um reisolado do CL-14 também não determinou parasitemia patente em camundongos até 30 dias após a inoculação. Estes achados são discutidos em relação à proteção imunológica observada em camundongos inoculados com este clone.

  12. Acerca del ciclo evolutivo del Trypanosoma (Schizotrypanum cruzi Chagas 1909, en sus fases tisular y hematica

    Directory of Open Access Journals (Sweden)

    Cecilio Romaña

    1956-06-01

    Full Text Available El autor pasa en revista los trabajos publicados sobre el ciclo evolutivo del Trypanosoma (S. cruzi en el huésped vertebrado, desde el descubrimiento de la enfermedad hasta nuestros días. Luego analiza las ideas de los autores modernos, fundadas en gran parte en las observaciones que ya en 1914 realizaron MAYER y ROCHA LIMA de las cuales participan actualmente ROMAÑA y MEYER, ELKELES y WOOD. Finalmente expressa que a partir de los tripanosomas infectantes los parásitos que penetram en el protoplasma celular pueden seguir dos mecanismos en su evolución hacia cuerpos leishmanioides: 1.º Por "regresión fusiforme" y 2.º por "regresión orbicular"; llegados a la forma leishmanioide los parásitos se multiplican por división binaria, una vez lleno el protoplasma celular, siguen un processo inverso de transformación hacia tripanosoma que puede seguir igualmente dos mecanismos diversos: 1. "progresión fusiforme" y 2.º "progresión orbicular". Estos diversos mecanismos de transformación están esquematizados en la fig. N.º 1 del trabajo.The author reviews published works about the evolutive cycle of the Trypanosoma cruzi in the vertebrate host, from the discovery of the disease to our days. Then, he analyzes the ideas of the modern authors who based themselves on the observations made formerly, in 1914, by MAYER & ROCHA LIMA, ideas that ROMAÑA and MEYER, ELKELES and WOOD agree at the present time. Last, he states that, from the infective trypanosomas, the parasites which enter the cellular protoplasma may follow two systems to perform their evolution up to leishmanioid bodies: 1.] by fusiform regression, 2.º by an orbicular regression. Once the parasites reach the leishmanioid forms, they multiply by binary division. When the celular protoplasm is filled up with the parasites, these follow an inverted transformation up to trypanosoma state, following also two systems; similar to the repression 1.º a fusiform progression, 2.º an

  13. Validation of N-myristoyltransferase as Potential Chemotherapeutic Target in Mammal-Dwelling Stages of Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Linda J Herrera

    2016-04-01

    Full Text Available Trypanosoma cruzi causes Chagas disease, an endemic and debilitating illness in Latin America. Lately, owing to extensive population movements, this neglected tropical disease has become a global health concern. The two clinically available drugs for the chemotherapy of Chagas disease have rather high toxicity and limited efficacy in the chronic phase of the disease, and may induce parasite resistance. The development of new anti-T. cruzi agents is therefore imperative. The enzyme N-myristoyltransferase (NMT has recently been biochemically characterized, shown to be essential in Leishmania major, Trypanosoma brucei, and T. cruzi¸ and proposed as promising chemotherapeutic target in these trypanosomatids.Here, using high-content imaging we assayed eight known trypanosomatid NMT inhibitors, against mammal-dwelling intracellular amastigote and trypomastigote stages and demonstrated that three of them (compounds 1, 5, and 8 have potent anti-proliferative effect at submicromolar concentrations against T. cruzi, with very low toxicity against human epithelial cells. Moreover, metabolic labeling using myristic acid, azide showed a considerable decrease in the myristoylation of proteins in parasites treated with NMT inhibitors, providing evidence of the on-target activity of the inhibitors.Taken together, our data point out to the potential use of NMT inhibitors as anti-T. cruzi chemotherapy.

  14. Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease.

    Science.gov (United States)

    Pinto, C Miguel; Ocaña-Mayorga, Sofía; Tapia, Elicio E; Lobos, Simón E; Zurita, Alejandra P; Aguirre-Villacís, Fernanda; MacDonald, Amber; Villacís, Anita G; Lima, Luciana; Teixeira, Marta M G; Grijalva, Mario J; Perkins, Susan L

    2015-01-01

    The generalist parasite Trypanosoma cruzi has two phylogenetic lineages associated almost exclusively with bats-Trypanosoma cruzi Tcbat and the subspecies T. c. marinkellei. We present new information on the genetic variation, geographic distribution, host associations, and potential vectors of these lineages. We conducted field surveys of bats and triatomines in southern Ecuador, a country endemic for Chagas disease, and screened for trypanosomes by microscopy and PCR. We identified parasites at species and genotype levels through phylogenetic approaches based on 18S ribosomal RNA (18S rRNA) and cytochrome b (cytb) genes and conducted a comparison of nucleotide diversity of the cytb gene. We document for the first time T. cruzi Tcbat and T. c. marinkellei in Ecuador, expanding their distribution in South America to the western side of the Andes. In addition, we found the triatomines Cavernicola pilosa and Triatoma dispar sharing shelters with bats. The comparisons of nucleotide diversity revealed a higher diversity for T. c. marinkellei than any of the T. c. cruzi genotypes associated with Chagas disease. Findings from this study increased both the number of host species and known geographical ranges of both parasites and suggest potential vectors for these two trypanosomes associated with bats in rural areas of southern Ecuador. The higher nucleotide diversity of T. c. marinkellei supports a long evolutionary relationship between T. cruzi and bats, implying that bats are the original hosts of this important parasite.

  15. Role of GP82 in the selective binding to gastric mucin during oral infection with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Daniela I Staquicini

    Full Text Available Oral infection by Trypanosoma cruzi has been the primary cause of recent outbreaks of acute Chagas' diseases. This route of infection may involve selective binding of the metacyclic trypomastigote surface molecule gp82 to gastric mucin as a first step towards invasion of the gastric mucosal epithelium and subsequent systemic infection. Here we addressed that question by performing in vitro and in vivo experiments. A recombinant protein containing the complete gp82 sequence (J18, a construct lacking the gp82 central domain (J18*, and 20-mer synthetic peptides based on the gp82 central domain, were used for gastric mucin binding and HeLa cell invasion assays, or for in vivo experiments. Metacyclic trypomastigotes and J18 bound to gastric mucin whereas J18* failed to bind. Parasite or J18 binding to submaxillary mucin was negligible. HeLa cell invasion by metacyclic forms was not affected by gastric mucin but was inhibited in the presence of submaxillary mucin. Of peptides tested for inhibition of J18 binding to gastric mucin, the inhibitory peptide p7 markedly reduced parasite invasion of HeLa cells in the presence of gastric mucin. Peptide p7*, with the same composition as p7 but with a scrambled sequence, had no effect. Mice fed with peptide p7 before oral infection with metacyclic forms developed lower parasitemias than mice fed with peptide p7*. Our results indicate that selective binding of gp82 to gastric mucin may direct T. cruzi metacyclic trypomastigotes to stomach mucosal epithelium in oral infection.

  16. ADAPTACIÓN DE LA CEPA MUNANTA DE TRYPANOSOMA CRUZI AL CULTIVO IN VITRO EN CÉLULAS VERO

    OpenAIRE

    Velazco Gamboa, Carolina; Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá; Puentes Corredor, Manuel; Instituto de Inmunología - HSJD, Bogotá; Moreno García, Alberto; Instituto de Inmunología - HSJD, Bogotá; Patarroyo Murillo, Manuel Elkin; Instituto de Inmunología - HSJD, Bogotá; Puerta Bula, Concepción; Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá

    2013-01-01

    The importance of obtaining the different stages of Trypanosoma cruzi in order to recognize the antigens involved in the intracellular invasion and replication processes, makes it necessary to adapt these strains to tissue culture, especially considering the high leve! of biological, biochemical and genetic variation, which is found among the strains and clones ofthe parasite. Within the aforementioned context, in this study, the Colombian strain ofT. cruzi, M un anta, was adapted to tissue c...

  17. Seroprevalence of Trypanosoma cruzi among Teenek Amerindian residents of the Huasteca region in San Luis Potosi, Mexico.

    Science.gov (United States)

    Juarez-Tobias, Soledad; Vaughan, Gilberto; Torres-Montoya, Aida; Escobar-Gutierrez, Alejandro

    2009-08-01

    Scarce information on the seroprevalence of Trypanosoma cruzi among Amerindians is available, and the distribution of this disease in Mexican Indian populations is unknown. In this study, the presence of specific antibodies against T. cruzi among Teenek Amerindians in nine different communities located in San Luis Potosi State was analyzed. An average seroprevalence of 6.5% was found in these populations, suggesting that active transmission of disease occurs in this relatively isolated population in Mexico, and therefore, further studies should be conducted to identify risk factor associated to Chagas disease in other isolated populations across the country to determine the prevalence of Chagas disease in Mexican Amerindians.

  18. [Prevalence of positive serology to Trypanosoma cruzi in patients with clinical diagnosis of dilated myocardiopathy in the state of Campeche].

    Science.gov (United States)

    Alducin-Téllez, César; Rueda-Villegas, Enrique; Medina-Yerbes, Isaí; Hernández, Oscar; López, Ruth; Peña-Hernández, Virginia; Monteón, Víctor

    2011-01-01

    The prevalence of chronic Chagas' heart disease as a cause of dilated cardiomyopathy is unknown in the State of Campeche, Mexico. A study was conducted to determine the prevalence of positive serology for Trypanosoma cruzi in patients with clinical diagnosis of dilated cardiomyopathy. Of a total of 127 patients diagnosed with dilated cardiomyopathy, we studied 91 with two positive serological tests for T. cruzi. We identified 14 positive cases for a prevalence of 15 % of chronic Chagas' heart disease. This prevalence is similar to that reported for the rest of the Yucatan Peninsula.

  19. The chemokines CXCL9 and CXCL10 promote a protective immune response but do not contribute to cardiac inflammation following infection with Trypanosoma cruzi.

    Science.gov (United States)

    Hardison, Jenny L; Wrightsman, Ruth A; Carpenter, Philip M; Lane, Thomas E; Manning, Jerry E

    2006-01-01

    The expression of chemokines within the heart during experimental infection of susceptible mice with the Colombiana strain of Trypanosoma cruzi was characterized in an attempt to determine a functional role for these molecules in both host defense and disease. Analysis of chemokine transcripts revealed that CXC chemokine ligand 9 (CXCL9) and CXCL10, as well as CC chemokine ligand 2 (CCL2) and CCL5, were prominently expressed during acute disease, whereas transcripts for CXCL9, CXCL10, and CCL5 remained elevated during chronic infection. Inflammatory macrophages present within the heart were the primary cellular source of these chemokines following T. cruzi infection. Peak chemokine expression levels coincided with increased gamma interferon expression and inflammation within the heart, suggesting a role for these molecules in both host defense and disease. Indeed, simultaneous treatment of T. cruzi-infected mice with neutralizing antibodies specific for CXCL9 and CXCL10 resulted in an increased parasite burden that was sustained out to 50 days p.i. Antibody targeting either CXCL10 or CCL5 did not change either T. cruzi burden within the heart nor attenuate the severity of cardiac inflammation at any time point examined, while targeting CXCL9 in combination with CXCL10 resulted in increased parasite burden. Collectively, these studies imply that CXCL9 and CXCL10 signaling enhances immune responses following parasite infection. However, antibody targeting of CXCL9 and CXCL10, or CXCL10 alone, or CCL5 alone does not directly modulate the inflammatory response within the heart, suggesting that other proinflammatory factors are able to regulate inflammation in this tissue in response to T. cruzi infection.

  20. Anti-Trypanosoma cruzi activity of 10 medicinal plants used in northeast Mexico.

    Science.gov (United States)

    Molina-Garza, Zinnia Judith; Bazaldúa-Rodríguez, Aldo Fabio; Quintanilla-Licea, Ramiro; Galaviz-Silva, Lucio

    2014-08-01

    The aim of this study was to screen the trypanocidal activity of plants used in traditional Mexican medicine for the treatment of various diseases related to parasitic infections. Cultured Trypanosoma cruzi epimastigotes were incubated for 96h with different concentrations of methanolic extracts obtained from Artemisia mexicana, Castela texana, Cymbopogon citratus, Eryngium heterophyllum, Haematoxylum brasiletto, Lippia graveolens, Marrubium vulgare, Persea americana, Ruta chalepensis and Schinus molle. The inhibitory concentration (IC50) was determined for each extract via a colorimetric method. Among the evaluated species, the methanolic extracts of E. heterophyllum, H. brasiletto, M. vulgare and S. molle exhibited the highest trypanocidal activity, showing percentages of growth inhibition between 88 and 100% at a concentration of 150μg/ml. These medicinal plants may represent a valuable source of new bioactive compounds for the therapeutic treatment of trypanosomiasis.

  1. Aspectos ultra-estruturais da forma epimastigota do Trypanosoma cruzi em meio LIT

    Directory of Open Access Journals (Sweden)

    Wanderley de Souza

    1975-06-01

    Full Text Available E feito um estudo da ultra-estrutura da forma epismastigota do Trypanosoma cruzi mantida em meio de cultivo acelular. O núcleo das formas em divisão apresenta um aspecto homogêneo. Microtúbulos intranucleares são observados durante a divisão. No entanto, a membrana nuclear permanece íntegra. O citoplasma apresenta-se com vacúolos de dimensões e aspectos variados. Com o método do ácido periódico-tiosemicarbazida-proteinato de prata, polissacaríáeos e/ou glicoproteínas foram localizados na membrana celular e na membrana que delimita certos vacúolos citoplasmáticos.

  2. Trypanosoma cruzi infection in the Mexican state of Guerrero: a seroepidemiological (ELISA) survey of 20 communities.

    Science.gov (United States)

    Andersson, N; Morales, A; Nava, E; Martinez, E; Rodriguez, I; Young, P; Howard, M K; Miles, M A

    1990-10-01

    The enzyme linked immunosorbent assay (ELISA) was used to analyse 4372 blood samples from residents of 978 households in 20 representative communities in the Mexican state of Guerrero. Seventy-five individuals had very high titres of antibodies against Trypanosoma cruzi. Samples with intermediate optical density values, despite overlapping values with several control positives on a single-well test, did not sustain their positivity at high dilutions. 'Intermediate positives' had a different distribution among the 20 communities to samples sustaining reactivity at high dilutions, indicating possible cross-reactivity with another infectious agent. The finding of seropositive children under the age of 10 years in the Costa Chica, Acapulco and the Tierra Caliente regions, with family clustering of putative cases, indicates that recent transmission must be considered. Very few people interviewed in the 20 communities knew the triatomine bug could transmit a disease.

  3. Screening of Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase enzyme inhibitors

    Directory of Open Access Journals (Sweden)

    Ana C. Leite

    2009-03-01

    Full Text Available The inhibitory activity of crude extracts of Meliaceae and Rutaceae plants on glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH enzyme from Trypanosoma cruzi was evaluated at 100 μg/mL. Forty-six extracts were tested and fifteen of them showed significant inhibitory activity (IA % > 50. The majority of the assayed extracts of Meliaceae plants (Cedrela fissilis, Cipadessa fruticosa and Trichilia ramalhoi showed high ability to inhibit the enzymatic activity. The fractionation of the hexane extract from branches of C. fruticosa led to the isolation of three flavonoids: flavone, 7-methoxyflavone and 3',4',5',5,7-pentamethoxyflavone. The two last compounds showed high ability to inhibit the gGAPDH activity. Therefore, the assayed Meliaceae species could be considered as a promising source of lead compounds against Chagas' disease.

  4. Reversibility of muscle and heart lesions in chronic Trypanosoma cruzi infected mice after late trypanomicidal treatment

    Directory of Open Access Journals (Sweden)

    M. A. Segura

    1994-06-01

    Full Text Available The effect of trypanomicidal treatment upon established histopathological Trypanosoma cruzi induced lesions was studied in Swiss mice. The animals were inoculated with 50 trypomastigotes and infection was allowed to progress without treatment for 99 days. After this period, the animals were divided in three groups, treated for 30 days with either placebo, benznidazole (200 mg/kg/day or nifurtimox (100 mg/kg/day. These treatments induced 94 and 100 (per cent cure rates respectively as detected by xenodiagnosis and reduction of antibody levels. Autopsies and histopathological studies of heart, urinary bladderand skeletal muscle performed on day 312 after infection showed almost complete healing without residual lesions. As long periods were allowed between infection, treatment and autopsy, the results indicate that tissue lesions depend, up to advances stages, on the continuous presence of the parasite.

  5. Metabolites from the leaf extract of Serjania yucatanensis with trypanocidal activity against Trypanosoma cruzi.

    Science.gov (United States)

    Polanco-Hernández, Glendy; Escalante-Erosa, Fabiola; García-Sosa, Karlina; Chan-Bacab, Manuel J; Sagua-Franco, Hernán; González, Jorge; Osorio-Rodríguez, Luis; Peña-Rodríguez, Luis M

    2012-07-01

    The bioassay-guided phytochemical investigation of the leaf extract of Serjania yucatanensis, a woody climbing plant endemic to the Yucatan peninsula, led to the identification of a mixture of a triterpene [lup-20(29)-en-3-one] and an oxygenated sesquiterpene (β-caryophyllene oxide), as that responsible for the originally detected trypanocidal activity in the organic crude extract. Results showed that the mixture of lup-20(29)-en-3-one and β-caryophyllene oxide is active against trypomastigotes of Trypanosoma cruzi (IC(50) =80.3 μg/mL) and inhibits the egress of trypomastigotes from infected Vero cells (when tested at 100 μg/mL) without being cytotoxic.

  6. Assessment of the anti-protozoal activity of crude Carica papaya seed extract against Trypanosoma cruzi.

    Science.gov (United States)

    Jiménez-Coello, Matilde; Guzman-Marín, Eugenia; Ortega-Pacheco, Antonio; Perez-Gutiérrez, Salud; Acosta-Viana, Karla Y

    2013-10-11

    In order to determine the in vivo activity against the protozoan Trypanosoma cruzi, two doses (50 and 75 mg/kg) of a chloroform extract of Carica papaya seeds were evaluated compared with a control group of allopurinol. The activity of a mixture of the three main compounds (oleic, palmitic and stearic acids in a proportion of 45.9% of oleic acid, 24.1% of palmitic and 8.52% of stearic acid previously identified in the crude extract of C. papaya was evaluated at doses of 100, 200 and 300 mg/kg. Both doses of the extracts were orally administered for 28 days. A significant reduction (p papaya extract in comparison with the positive control group (allopurinol 8.5 mg/kg). Parasitemia in animals treated with the fatty acids mixture was also significantly reduced (p papaya (from ripe fruit) are able to reduce the number of parasites from both parasite stages, blood trypomastigote and amastigote (intracellular stage).

  7. Trypanosoma cruzi Epimastigotes Are Able to Manage Internal Cholesterol Levels under Nutritional Lipid Stress Conditions

    Science.gov (United States)

    Pereira, Miria Gomes; Visbal, Gonzalo; Salgado, Leonardo T.; Vidal, Juliana Cunha; Godinho, Joseane L. P.; De Cicco, Nuccia N. T.; Atella, Geórgia C.; de Souza, Wanderley; Cunha-e-Silva, Narcisa

    2015-01-01

    Trypanosoma cruzi epimastigotes store high amounts of cholesterol and cholesteryl esters in reservosomes. These unique organelles are responsible for cellular digestion by providing substrates for homeostasis and parasite differentiation. Here we demonstrate that under nutritional lipid stress, epimastigotes preferentially mobilized reservosome lipid stocks, instead of lipid bodies, leading to the consumption of parasite cholesterol reservoirs and production of ergosterol. Starved epimastigotes acquired more LDL-NBD-cholesterol by endocytosis and distributed the exogenous cholesterol to their membranes faster than control parasites. Moreover, the parasites were able to manage internal cholesterol levels, alternating between consumption and accumulation. With normal lipid availability, parasites esterified cholesterol exhibiting an ACAT-like activity that was sensitive to Avasimibe in a dose-dependent manner. This result also implies that exogenous cholesterol has a role in lipid reservoirs in epimastigotes. PMID:26068009

  8. The effect of Bulgarian propolis against Trypanosoma cruzi and during its interaction with host cells

    Directory of Open Access Journals (Sweden)

    Andréia Pires Dantas

    2006-03-01

    Full Text Available Propolis has shown activity against pathogenic microorganisms that cause diseases in humans and animals. The ethanol (Et-Blg and acetone (Ket-Blg extracts from a Bulgarian propolis, with known chemical compositions, presented similar activity against tissue culture-derived amastigotes. The treatment of Trypanosoma cruzi-infected skeletal muscle cells with Et-Blg led to a decrease of infection and of the intracellular proliferation of amastigotes, while damage to the host cell was observed only at concentration 12.5 times higher than those affecting the parasite. Ultrastructural analysis of the effect of both extracts in epimastigotes revealed that the main targets were the mitochondrion and reservosomes. Et-Blg also affected the mitochondrion-kinetoplast complex in trypomastigotes, offering a potential target for chemotherapeutic agents.

  9. In Vitro and in Vivo Anti-Trypanosoma cruzi Activity of a Novel Nitro-derivative

    Directory of Open Access Journals (Sweden)

    Susana Muelas-Serrano

    2002-06-01

    Full Text Available Nitroarylidenemalononitriles and their cyanoacetamide derivatives with remarkable anti-epimastigote properties, were synthesized attempting to obtain new 3,5-diamino-4-(5'-nitroarylidene-4H-thiadiazine 1,1-dioxide derivatives, which in previous reports had shown anti-Trypanosoma cruzi activity. Tests to evaluate the cytotoxicity of compounds were performed on J774 macrophages. 5-nitro-2-thienyl-malononitrile (5NO2TM, was the only product which maintained a high anti-epimastigote activity at concentrations in which it was no longer cytotoxic, thus it was assayed against intracellular amastigotes. Its anti-amastigote activity was similar to that of nifurtimox. Afterwards in vivo toxicity and anti-chagasic activity were determined. A reduction in parasitemia was observed.

  10. Effects of water deprivation on renal hydroelectrolytic excretion in chronically Trypanosoma cruzi-infected rats

    Directory of Open Access Journals (Sweden)

    T.T. Rosa

    1995-03-01

    Full Text Available The effect of an 8 hour-period of water deprivation on fluid and electrolyte renal excretion was investigated in male Wistar rats infected with the strain São Felipe (12SF of Trypanosoma cruzi, in comparison with age and sex matched non-infected controls. The median percent reductions in the urinary flow (-40% v -63% and excretion ofsodium (-57% v-79% were smaller in chagasic than in control rats, respectively. So, chagasic rats excreted more than controls. On the other hand, the median percent decrement in the clearance of creatinine was higher in chagasic (-51% than in controls (-39%. Thus, chagasic rats showed some disturbed renal hydroelectrolytic responses to water deprivation, expressed by smaller conservation, or higher excretion of water and sodium in association with smaller glomerularfiltration rate. This fact denoted an elevation in the fractional excretion of sodium and water.

  11. Identification of novel Trypanosoma cruzi prolyl oligopeptidase inhibitors by structure-based virtual screening

    Science.gov (United States)

    de Almeida, Hugo; Leroux, Vincent; Motta, Flávia Nader; Grellier, Philippe; Maigret, Bernard; Santana, Jaime M.; Bastos, Izabela Marques Dourado

    2016-12-01

    We have previously demonstrated that the secreted prolyl oligopeptidase of Trypanosoma cruzi (POPTc80) is involved in the infection process by facilitating parasite migration through the extracellular matrix. We have built a 3D structural model where POPTc80 is formed by a catalytic α/β-hydrolase domain and a β-propeller domain, and in which the substrate docks at the inter-domain interface, suggesting a "jaw opening" gating access mechanism. This preliminary model was refined by molecular dynamics simulations and next used for a virtual screening campaign, whose predictions were tested by standard binding assays. This strategy was successful as all 13 tested molecules suggested from the in silico calculations were found out to be active POPTc80 inhibitors in the micromolar range (lowest K i at 667 nM). This work paves the way for future development of innovative drugs against Chagas disease.

  12. The multiple and complex and changeable scenarios of the Trypanosoma cruzi transmission cycle in the sylvatic environment.

    Science.gov (United States)

    Jansen, Ana Maria; Xavier, Samanta C C; Roque, André Luiz R

    2015-11-01

    In this study, we report and discuss the results generated from over 20 years of studies of the Trypanosoma cruzi sylvatic transmission cycle. Our results have uncovered new aspects and reviewed old concepts on issues including reservoirs, true generalist species, association of mammalian species with distinct discrete typing units - DTUs, distribution of T. cruzi genotypes in the wild, mixed infections, and T. cruzi transmission ecology. Using parasitological and serological tests, we examined T. cruzi infection in 7,285 mammalian specimens from nine mammalian orders dispersed all over the Brazilian biomes. The obtained T. cruzi isolates were characterized by mini-exon gene sequence polymorphism and PCR RFLP to identify DTUs. Infection by T. cruzi was detected by serological methods in 20% of the examined animals and isolated from 41% of those infected, corresponding to 8% of all the examined mammals. Each mammal taxon responded uniquely to T. cruzi infection. Didelphis spp. are able to maintain high and long-lasting parasitemias (positive hemocultures) caused by TcI but maintain and rapidly control parasitemias caused by TcII to almost undetectable levels. In contrast, the tamarin species Leontopithecus rosalia and L. chrysomelas maintain long-lasting and high parasitemias caused by TcII similarly to Philander sp. The coati Nasua nasua maintains high parasitemias by both parental T. cruzi DTUs TcI or TcII and by TcII/TcIV (formerly Z3) at detectable levels. Wild and domestic canidae seem to display only a short period of reservoir competence. T. cruzi infection was demonstrated in the wild canid species Cerdocyon thous and Chrysocyon brachyurus, and positive hemoculture was obtained in one hyper carnivore species (Leopardus pardalis), demonstrating that T. cruzi transmission is deeply immersed in the trophic net. T. cruzi DTU distribution in nature did not exhibit any association with a particular biome or habitat. TcI predominates throughout (58% of the T. cruzi

  13. Biotherapic of Trypanosoma cruzi 17d increases apoptosis in experimentally infected mice

    Directory of Open Access Journals (Sweden)

    Silvana Marques de Araújo

    2011-09-01

    Full Text Available Introduction: the mechanism of action of ultradiluted medicines has not yet been established[1,3]. Many basic research studies have focused on isopathic models using in vitro or in vivo designs [4,5]. Recent studies indicate that an ultradiluted (isopathic antigen can transfer signals to the immune system and modulate its response when an organism is challenged against this same antigen [6]. Some studies on experimental infection of mice by T. cruzi identified apoptotic cells and showed that the increase of their number is associated with an increase also in the number of parasites in the blood of the infected animals, while blockage of apoptosis can be the target of therapeutic intervention [7,8]. Aim: to evaluate the development of apoptosis in mice treated with biotherapic of Trypanosoma cruzi in dilution 17d through in situ detection of fragmented DNA. Method: in a blind randomized controlled trial, 36 male Swiss mice age 4 or 8 weeks were distributed in groups control - treated with 7% hydroalcoholic solution(CI-4=9 animals or CI-8=9 animals; and treated with biotherapic 17d (BIOT-4=9 animals or BIOT-8=9 animals. Infection was performed with 1,400 trypomastigotes T. cruzi-strain Y via intraperitoneal. Biotherapic 17d was prepared through the addition of 0.9ml of concentrated T. cruzi (10E+7 trypomastigotes/ml to 9.1 ml of distilled water. The following dilutions were prepared in 86% hydroalcoholic solution until dilution 16d. Dilution 17d was prepared with 7% hydroalcoholic solution. It was performed microbiological control and biological risk in vivo. Treatment: 0.2 ml in 3 consecutive days, oral route, from the moment infection was verified. Animals were sacrificed on the 3rd day of treatment in a chamber saturated with ether. The liver and spleen were removed and fixated in 4% paraformaldehyde for 24 hours and then included in paraffin. Apoptosis was evaluated through DNA fragmentation – TUNEL technique (TdT d

  14. Interactions between 4-aminoquinoline and heme: Promising mechanism against Trypanosoma cruzi.

    Science.gov (United States)

    Lechuga, Guilherme Curty; Borges, Júlio Cesar; Calvet, Claudia Magalhães; de Araújo, Humberto Pinheiro; Zuma, Aline Araujo; do Nascimento, Samara Braga; Motta, Maria Cristina Machado; Bernardino, Alice Maria Rolim; Pereira, Mirian Claudia de Souza; Bourguignon, Saulo Cabral

    2016-12-01

    Chagas disease is a neglected tropical disease caused by the flagellated protozoan Trypanosoma cruzi. The current drugs used to treat this disease have limited efficacy and produce severe side effects. Quinolines, nitrogen heterocycle compounds that form complexes with heme, have a broad spectrum of antiprotozoal activity and are a promising class of new compounds for Chagas disease chemotherapy. In this study, we evaluated the activity of a series of 4-arylaminoquinoline-3-carbonitrile derivatives against all forms of Trypanosoma cruzi in vitro. Compound 1g showed promising activity against epimastigote forms when combined with hemin (IC50<1 μM), with better performance than benznidazole, the reference drug. This compound also inhibited the viability of trypomastigotes and intracellular amastigotes. The potency of 1g in combination with heme was enhanced against epimastigotes and trypomastigotes, suggesting a similar mechanism of action that occurs in Plasmodium spp. The addition of hemin to the culture medium increased trypanocidal activity of analog 1g without changing the cytotoxicity of the host cell, reaching an IC50 of 11.7 μM for trypomastigotes. The mechanism of action was demonstrated by the interaction of compound 1g with hemin in solution and prevention of heme peroxidation. Compound 1g and heme treatment induced alterations of the mitochondrion-kinetoplast complex in epimastigotes and trypomastigotes and also, accumulation of electron-dense deposits in amastigotes as visualized by transmission electron microscopy. The trypanocidal activity of 4-aminoquinolines and the elucidation of the mechanism involving interaction with heme is a neglected field of research, given the parasite's lack of heme biosynthetic pathway and the importance of this cofactor for parasite survival and growth. The results of this study can improve and guide rational drug development and combination treatment strategies.

  15. Interactions between 4-aminoquinoline and heme: Promising mechanism against Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Guilherme Curty Lechuga

    2016-12-01

    Full Text Available Chagas disease is a neglected tropical disease caused by the flagellated protozoan Trypanosoma cruzi. The current drugs used to treat this disease have limited efficacy and produce severe side effects. Quinolines, nitrogen heterocycle compounds that form complexes with heme, have a broad spectrum of antiprotozoal activity and are a promising class of new compounds for Chagas disease chemotherapy. In this study, we evaluated the activity of a series of 4-arylaminoquinoline-3-carbonitrile derivatives against all forms of Trypanosoma cruzi in vitro. Compound 1g showed promising activity against epimastigote forms when combined with hemin (IC50<1 μM, with better performance than benznidazole, the reference drug. This compound also inhibited the viability of trypomastigotes and intracellular amastigotes. The potency of 1g in combination with heme was enhanced against epimastigotes and trypomastigotes, suggesting a similar mechanism of action that occurs in Plasmodium spp. The addition of hemin to the culture medium increased trypanocidal activity of analog 1g without changing the cytotoxicity of the host cell, reaching an IC50 of 11.7 μM for trypomastigotes. The mechanism of action was demonstrated by the interaction of compound 1g with hemin in solution and prevention of heme peroxidation. Compound 1g and heme treatment induced alterations of the mitochondrion-kinetoplast complex in epimastigotes and trypomastigotes and also, accumulation of electron-dense deposits in amastigotes as visualized by transmission electron microscopy. The trypanocidal activity of 4-aminoquinolines and the elucidation of the mechanism involving interaction with heme is a neglected field of research, given the parasite's lack of heme biosynthetic pathway and the importance of this cofactor for parasite survival and growth. The results of this study can improve and guide rational drug development and combination treatment strategies.

  16. Projected future distributions of vectors of Trypanosoma cruzi in North America under climate change scenarios.

    Directory of Open Access Journals (Sweden)

    Miroslava Garza

    2014-05-01

    Full Text Available BACKGROUND: Chagas disease kills approximately 45 thousand people annually and affects 10 million people in Latin America and the southern United States. The parasite that causes the disease, Trypanosoma cruzi, can be transmitted by insects of the family Reduviidae, subfamily Triatominae. Any study that attempts to evaluate risk for Chagas disease must focus on the ecology and biogeography of these vectors. Expected distributional shifts of vector species due to climate change are likely to alter spatial patterns of risk of Chagas disease, presumably through northward expansion of high risk areas in North America. METHODOLOGY/PRINCIPAL FINDINGS: We forecast the future (2050 distributions in North America of Triatoma gerstaeckeri and T. sanguisuga, two of the most common triatomine species and important vectors of Trypanosoma cruzi in the southern United States. Our aim was to analyze how climate change might affect the future shift of Chagas disease in North America using a maximum entropy algorithm to predict changes in suitable habitat based on vector occurrence points and predictive environmental variables. Projections based on three different general circulation models (CCCMA, CSIRO, and HADCM3 and two IPCC scenarios (A2 and B2 were analyzed. Twenty models were developed for each case and evaluated via cross-validation. The final model averages result from all twenty of these models. All models had AUC >0.90, which indicates that the models are robust. Our results predict a potential northern shift in the distribution of T. gerstaeckeri and a northern and southern distributional shift of T. sanguisuga from its current range due to climate change. CONCLUSIONS/SIGNIFICANCE: The results of this study provide baseline information for monitoring the northward shift of potential risk from Chagas disease in the face of climate change.

  17. Trypanosoma cruzi (Chagas' disease agent reduces HIV-1 replication in human placenta

    Directory of Open Access Journals (Sweden)

    Cappa Stella

    2008-07-01

    Full Text Available Abstract Background Several factors determine the risk of HIV mother-to-child transmission (MTCT, such as coinfections in placentas from HIV-1 positive mothers with other pathogens. Chagas' disease is one of the most endemic zoonoses in Latin America, caused by the protozoan Trypanosoma cruzi. The purpose of the study was to determine whether T. cruzi modifies HIV infection of the placenta at the tissue or cellular level. Results Simple and double infections were carried out on a placental histoculture system (chorionic villi isolated from term placentas from HIV and Chagas negative mothers and on the choriocarcinoma BeWo cell line. Trypomastigotes of T. cruzi (VD lethal strain, either purified from mouse blood or from Vero cell cultures, 24 h-supernatants of blood and cellular trypomastigotes, and the VSV-G pseudotyped HIV-1 reporter virus were used for the coinfections. Viral transduction was evaluated by quantification of luciferase activity. Coinfection with whole trypomastigotes, either from mouse blood or from cell cultures, decreased viral pseudotype luciferase activity in placental histocultures. Similar results were obtained from BeWo cells. Supernatants of stimulated histocultures were used for the simultaneous determination of 29 cytokines and chemokines with the Luminex technology. In histocultures infected with trypomastigotes, as well as in coinfected tissues, IL-6, IL-8, IP-10 and MCP-1 production was significantly lower than in controls or HIV-1 transducted tissue. A similar decrease was observed in histocultures treated with 24 h-supernatants of blood trypomastigotes, but not in coinfected tissues. Conclusion Our results demonstrated that the presence of an intracellular pathogen, such as T. cruzi, is able to impair HIV-1 transduction in an in vitro system of human placental histoculture. Direct effects of the parasite on cellular structures as well as on cellular/viral proteins essential for HIV-1 replication might influence

  18. Prevalence of Trypanosoma cruzi's Discrete Typing Units in a cohort of Latin American migrants in Spain.

    Science.gov (United States)

    Martinez-Perez, Angela; Poveda, Cristina; Ramírez, Juan David; Norman, Francesca; Gironés, Núria; Guhl, Felipe; Monge-Maillo, Begoña; Fresno, Manuel; López-Vélez, Rogelio

    2016-05-01

    Chagas disease is caused by the protozoan Trypanosoma cruzi. This is an endemic disease in the Americas, but increased migration to Europe has made it emerge in countries where it was previously unknown, being Spain the second non endemic country in number of patients. T. cruzi is a parasite with a wide genetic diversity, which has been grouped by consensus into 6 Discrete Typing Units (DTUs) affecting humans. Some authors have linked these DTUs either to a specific epidemiological context or to the different clinical presentations. Our main objective was to describe the T. cruzi DTUs identified from a population of chronically infected Latin American migrants attending a reference clinic in Madrid. 149 patients meeting this condition were selected for the study. Molecular characterization was performed by an algorithm that combines PCR of the intergenic region of the mini exon-gene, the 24Sα and 18S regions of rDNA and the variable region of the satellite DNA. A descriptive analysis was performed and associations between geographical/clinical data and the different DTUs were tested. DTUs could be determined in 105 out of 149 patients, 93.3% were from Bolivia, 67.7% were women and median age was 35 years (IQR 29-44). The most common DTU found was TcV (58; 55.2%), followed by TcIV (17; 16.2%), TcII (10; 9.5%) and TcI (4; 3.8%). TcIII and TcVI were not identified from any patient, and 15.2% patients presented mixed infections. In addition, we determined DTUs after treatment in a subset of patients. In 57% patients had different DTUs before and after treatment. DTUs distribution from this study indicates active transmission of T. cruzi is occurring in Bolivia, in both domestic and sylvatic cycles. TcIV was confirmed as a cause of chronic human disease. The current results indicate no correlation between DTU and any specific clinical presentation associated with Chagas disease, nor with geographical origin. Treatment with benznidazole does not always clear T. cruzi

  19. Prevalencia de infeccion humana por Trypanosoma cruzi en bancos de sangre en Venezuela Prevalence of human infections by Trypanosoma cruzi in Venezuelan blood banks

    Directory of Open Access Journals (Sweden)

    Alberto Aché

    1993-10-01

    Full Text Available Las primeras investigaciones realizadas a nivel de bancos de sangre, durante la década 50, indican que la seroprevalencia por infecciones a T. cruzi entre hemodadores fue de 12%. Un estudio posterior, entre 1963-64, efectuado en varios bancos de sangre, así como otros centros, registró una seroprevalencia global de 6.0% (1.1-10.1%. La donación de sangre en Venezuela es gratuita. El control de los bancos de sangre recae en el Departamento de Transfusiones y Bancos de Sangre del Ministerio de Sanidad y Asistencia Social. A partir de 1988, se emplea uniformemente la técnica de ELISA para el diagnóstico de infecciones a T. cruzi en los Bancos de Sangre. La seropositividad promedio interanual, entre 1984-1992, fue de 1.20% (1.09-1.94%. Existen variaciones geográficas entre las localidades de varias entidades federales. Los estados con mayor prevalencia se ubican en las regiones del occidente y centro del país, a saber: Portuguesa, Barinas, Lara, Trujillo, Cojedes y Carabobo. Por las dificultades en obtener tasas de incidencia para el Mal de Chagas, resulta adecuado emplear tasas de prevalencia para uso en salud pública, en función de su mayor estabilidad; y en el caso de Venezuela, dada la severidad menor y una sobrevivencia mayor por esta patologia hoy día. La especificidad, como parámetro de las pruebas serológicas, debería considerarse en función de la baja seroprevalencia detectada a nivel nacional. Convendría emplear varias pruebas diagnósticas en paralelo para buscar un equilibrio entre sensibilidad y especificidad.Primary investigations carried out in blood banks in Venezuela during the 1950s, indicated that overall seroprevalence for Trypanosoma cruzi infection was 12% amongst blood donors. In Venezuela, blood donation is free. All public and private blood banks are controlled by the Ministry of Health. As from 1988 the ELISA technique was uniformly used in blood banks for the detection of T. cruzi infections. Annual median

  20. Trypanosoma cruzi prevalence and clinical forms in blood donor candidates in Brazil Prevalência e formas clínicas de Trypanosoma cruzi em candidatos a doadores de sangue no Brasil

    Directory of Open Access Journals (Sweden)

    H J Silveira

    2003-12-01

    Full Text Available The prevalence and clinical forms of Trypanosoma cruzi were evaluated among blood donor candidates attended at a general hospital in Rio de Janeiro, Brazil, from January 1997 to April 1999. The investigation was done by means of the indirect hemagglutination test and was confirmed via ELISA. Data were collected from clinical examinations, conventional electrocardiogram, chest radiography and echocar-diography. The results showed that despite Trypanosoma cruzi prevalence of 1.17% (128 patients, mainly in males aged 40 years or over, 70.8% of these patients, mainly males aged 19 to 39 years, demonstrated abnormalities that allowed the diagnosis of cardiopathy and/or esophagopathy. This once again corroborates the importance of Trypanosoma cruzi infection in urban centers.A prevalência e a manifestação das formas clinicas de Trypanosoma cruzi foram avaliadas em candidatos a doadores de sangue atendidos em um hospital geral de Nova Iguaçu, Rio de Janeiro, Brasil, no período de janeiro de 1997 a abril de 1999. A pesquisa sorológica foi realizada por meio do teste de hemaglutinação indireta e confirmada pelo ELISA. Os dados foram coletados considerando os exames clínicos, eletrocardiograma convencional, radiografia de tórax e ecocardiografia. Os resultados demonstraram que, apesar da prevalência ser de 1,17% (128 pacientes, principalmente entre homens com idade igual ou superior a 40 anos, 70,8%, principalmente de homens entre 19 e 39 anos, demonstraram alterações que permitiram o diagnóstico de cardiopatias e/ou esofagopatias, ratificando mais uma vez sua importância nos centros urbanos.

  1. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    Energy Technology Data Exchange (ETDEWEB)

    Souza, C.F. [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Carneiro, A.B.; Silveira, A.B. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); Laranja, G.A.T. [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); Silva-Neto, M.A.C. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); INCT, Entomologia Molecular (Brazil); Costa, S.C. Goncalves da [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Paes, M.C., E-mail: mcpaes@uerj.br [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); INCT, Entomologia Molecular (Brazil)

    2009-12-18

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

  2. A novel ABCG-like transporter of Trypanosoma cruzi is involved in natural resistance to benznidazole

    Directory of Open Access Journals (Sweden)

    Bianca Zingales

    2015-05-01

    Full Text Available Benznidazole (BZ is one of the two drugs used for Chagas disease treatment. Nevertheless therapeutic failures of BZ have been reported, which were mostly attributed to variable drug susceptibility among Trypanosoma cruzi strains. ATP-binding cassette (ABC transporters are involved in a variety of translocation processes and some members have been implicated in drug resistance. Here we report the characterisation of the first T. cruzi ABCG transporter gene, named TcABCG1, which is over-expressed in parasite strains naturally resistant to BZ. Comparison of TcABCG1 gene sequence of two TcI BZ-resistant strains with CL Brener BZ-susceptible strain showed several single nucleotide polymorphisms, which determined 11 amino acid changes. CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene. Only in the parasites transfected with TcI genes there was 2-2.6-fold increased abundance of TcABCG1 transporter protein. The analysis in wild type strains also suggests that the level of TcABCG1 transporter is related to BZ natural resistance. The characteristics of untranslated regions of TcABCG1 genes of BZ-susceptible and resistant strains were investigated by computational tools.

  3. Trypanosoma cruzi: Correlations of Biological Aspects of the Life Cycle in Mice and Triatomines

    Directory of Open Access Journals (Sweden)

    Lima Valdirene S

    1999-01-01

    Full Text Available The infection pattern in Swiss mice and Triatomine bugs (Rhodnius neglectus of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically characterized. The clones and the original isolate were in the same zymodeme (Z1 except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice infected with the original stock and one of the clones (F8. All clones and the original isolate infected bugs well while only the original isolate and clones E2 and F3 yielded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade off i.e. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered.

  4. An ecological overview on the factors that drives to Trypanosoma cruzi oral transmission.

    Science.gov (United States)

    de Noya, Belkisyolé Alarcón; González, Oscar Noya

    2015-11-01

    American trypanosomiasis is one of the few native parasites of this continent. As a zoonosis, Trypanosoma cruzi infects about 180 species out of 25 families of mammals. Its regular transmission is through triatomines, which can easily transmit parasites either by the skin route (contamination of mammals skin with their feces) or by oral route (ingestion of food contaminated with complete triatomines or their feces) and additionally through haematogenous via (congenital and transfusional) and by tissues (transplants). The oral route, which seems to be the ancestral form of transmission to wild and domestic mammals, has recently become more important after the success achieved in the control of domicile vectors using residual pesticides. From its initial diagnosis in 1967, tens of oral outbreaks have been diagnosed mostly in the Brazilian Amazon and subsequently in other four countries in South America. Environmental imbalance caused by man through the invasion and deforestation of woodlands, results in reduction of biodiversity of mammals as food source for triatomines, affecting the "dilution effect" of T. cruzi in the nature increasing the risk of human infection. On the other hand, triatomines invade houses looking for new blood sources. One of the consequences of domiciliated triatomines is the food contamination spread, especially in home-made juices, which has been the source of infection of most oral outbreaks. Other biotic and abiotic factors help to explain the recent increase of oral transmission outbreaks of Chagas disease, distributed in nine eco-regions of America.

  5. In vitro antiparasitic activity of new thiosemicarbazones in strains of Trypanosoma cruzi.

    Science.gov (United States)

    Moreno-Rodríguez, Adriana; Salazar-Schettino, Paz María; Bautista, Juan Luis; Hernández-Luis, Francisco; Torrens, Hugo; Guevara-Gómez, Yolanda; Pina-Canseco, Socorro; Torres, Martha Bucio; Cabrera-Bravo, Margarita; Martinez, Cesar Mendoza; Pérez-Campos, Eduardo

    2014-11-24

    In this study thiosemicarbazones derivatives of 5-[(trifluoromethyl)phenylthio]-2-furaldehyde were synthesized and evaluated in terms of their efficiency in challenging the growth of epimastigote forms of Trypanosoma cruzi, the etiological agent of Chagas' disease. A number of compounds were synthesized from 5-bromo-2-furfuraldehyde using nucleophilic aromatic substitution, with a series of trifluoromethyl thiolates, followed by condensation reactions with thiosemicarbazide. Their molecular structures were determined by (1)H, (13)C and (19)F NMR, MS and IR spectroscopy. When tested with T. cruzi, they showed a stronger reaction, similar to nifurtimox and benznidazole, with the 5-[nitro-4-(trifluoromethyl)phenyltio]-2-furaldehyde thiosemicarbazone (compound 4) showing the highest antiparasitic activity. This improved activity may be explained due to the nitro group present in the molecule, which potentiates its activity. The thiosemicarbazone derivatives in this study showed no apoptosis in platelets or monocytes, nor did they induce platelet activation. The trypanocidal activity of these substances represents a good starting point for a medicinal chemistry program aimed at therapy for Chagas' disease.

  6. Standardization of serological tests for detecting anti-Trypanosoma cruzi antibodies in dogs

    Directory of Open Access Journals (Sweden)

    M. A. Lauricella

    1993-09-01

    Full Text Available This paper reports on the standardization of four serological reactions currently used in human serodiagnosis for the detection of anti-Trypanosoma cruzi antibodies in naturally and experimentally infected dogs. Indirect immunofluorescence test (IFAT and hemagglutination test (IHAT were standardized, and complement fixation test (CFT and direct agglutination test (DAT were used for diagnostic confirmation. Four hundred and eighty one mongrel dogs that were studied by xenodiagnosis were used: (1 parasitemic dogs of two localities of endemic area (EA of Santiago del Estero province in Argentina (n = 134; (2 non-parasitemic dogs of the same area (n = 285; (3 dogs experimentally infected with T. cruzi in the patent period (n = 6; (4 non-infected dogs (n = 56 which were born in the city of Buenos Aires (BA, one non-EA for Chagas' disease. For IFAT, parasitemic dogs EA showed 95% of reactive sera. Non parasitemic dogs EA showed 77% of non reactive sera. None sera from BA were reactive for dilutions higher than four. For IHAT, 84% of sera of parasitemic dogs EA showed serological reactivity and among non parasitemic dogs BA, 61% were non reactive, while the remainder showed at most titres of 1/16. The cut-off titres for IFAT and IHAT were 1/16 and 1/32 respectively, and for CFT and DAT 1/1 and 1/128 respectively. Sensitivity for IFAT, IHAT, CF and DAT were 95%, 84%, 97% and 95% respectively.

  7. Nucleotide sequence and transcription of a trypomastigote surface antigen gene of Trypanosoma cruzi.

    Science.gov (United States)

    Fouts, D L; Ruef, B J; Ridley, P T; Wrightsman, R A; Peterson, D S; Manning, J E

    1991-06-01

    In previous studies we identified a 500-bp segment of the gene, TSA-1, which encodes an 85-kDa trypomastigote-specific surface antigen of the Peru strain of Trypanosoma cruzi. TSA-1 was shown to be located at a telomeric site and to contain a 27-bp tandem repeat unit within the coding region. This repeat unit defines a discrete subset of a multigene family and places the TSA-1 gene within this subset. In this study, we present the complete nucleotide sequence of the TSA-1 gene from the Peru strain. By homology matrix analysis, fragments of two other trypomastigote specific surface antigen genes, pTt34 and SA85-1.1, are shown to have extensive sequence homology with TSA-1 indicating that these genes are members of the same gene family as TSA-1. The TSA-1 subfamily was also found to be active in two other strains of T. cruzi, one of which contains multiple telomeric members and one of which contains a single non-telomeric member, suggesting that transcription is not necessarily dependent on the gene being located at a telomeric site. Also, while some of the sequences found in this gene family are present in 2 size classes of poly(A)+ RNA, others appear to be restricted to only 1 of the 2 RNA classes.

  8. Internalization of components of the host cell plasma membrane during infection by Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Carvalho TMU

    1999-01-01

    Full Text Available Epimastigote and trypomastigote forms of Trypanosoma cruzi attach to the macrophage surface and are internalized with the formation of a membrane bounded vacuole, known as the parasitophorous vacuole (PV. In order to determine if components of the host cell membrane are internalized during formation of the PV we labeled the macrophage surface with fluorescent probes for proteins, lipids and sialic acid residues and then allowed the labeled cells to interact with the parasites. The interaction process was interrupted after 1 hr at 37ºC and the distribution of the probes analyzed by confocal laser scanning microscopy. During attachment of the parasites to the macrophage surface an intense labeling of the attachment regions was observed. Subsequently labeling of the membrane lining the parasitophorous vacuole containing epimastigote and trypomastigote forms was seen. Labeling was not uniform, with regions of intense and light or no labeling. The results obtained show that host cell membrane lipids, proteins and sialoglycoconjugates contribute to the formation of the membrane lining the PV containing epimastigote and trypomastigote T. cruzi forms. Lysosomes of the host cell may participate in the process of PV membrane formation.

  9. Resveratrol inhibits Trypanosoma cruzi arginine kinase and exerts a trypanocidal activity.

    Science.gov (United States)

    Valera Vera, Edward A; Sayé, Melisa; Reigada, Chantal; Damasceno, Flávia S; Silber, Ariel M; Miranda, Mariana R; Pereira, Claudio A

    2016-06-01

    Arginine kinase catalyzes the reversible transphosphorylation between ADP and phosphoarginine which plays a critical role in the maintenance of cellular energy homeostasis. Arginine kinase from the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, meets the requirements to be considered as a potential therapeutic target for rational drug design including being absent in its mammalian hosts. In this study a group of polyphenolic compounds was evaluated as potential inhibitors of arginine kinase using molecular docking techniques. Among the analyzed compounds with the lowest free binding energy to the arginine kinase active site (cruzi trypomastigotes bursting from infected CHO K1 cells, with IC50=77μM. Additionally epimastigotes overexpressing arginine kinase were 5 times more resistant to resveratrol compared to controls. Taking into account that: (1) resveratrol is considered as completely nontoxic; (2) is easily accessible due to its low market price; and (3) has as a well-defined target enzyme which is absent in the mammalian host, it is a promising compound as a trypanocidal drug for Chagas disease.

  10. Immunodiagnosis of Trypanosoma cruzi (Chagas' Disease Infection in Naturally Infected Dogs

    Directory of Open Access Journals (Sweden)

    Lauricella MA

    1998-01-01

    Full Text Available This study reports on the standardization of an enzyme-linked immunosorbent assay (ELISA for detecting specific antibodies anti-Trypanosoma cruzi in naturally infected dogs. Sera from 182 mongrel dogs of all ages residing in four rural villages in Santiago del Estero, Argentina, were collected in November 1994 and preserved in buffered neutral glycerin. All sera were tested by indirect hemagglutination test (IHAT, indirect immunofluorescence test (IFAT, and ELISA using the flagellar fraction of T. cruzi as antigen. Dog sera from an area without vectorial transmission were used to calculate ELISA specificity and cut-off value. Eighty-six percent of sera had concordant results for all tests. All sera reactive for IHAT and IFAT were also reactive for ELISA, except in one case. Sera tested by ELISA when diluted 1:200 allowed a clearer division between non-reactive and reactive sera than when 1:100 with greater agreement among serologic techniques. The specificity of ELISA was 96.2%. Among 34 adult dogs with a positive xenodiagnosis, sensitivity was 94% both for ELISA and IFAT. ELISA is the first choice for screening purposes and one of the pair of techniques recommended for diagnostic studies in dog populations

  11. Cruzipain, a major Trypanosoma cruzi antigen, conditions the host immune response in favor of parasite.

    Science.gov (United States)

    Giordanengo, Laura; Guiñazú, Natalia; Stempin, Cinthia; Fretes, Ricardo; Cerbán, Fabio; Gea, Susana

    2002-04-01

    We recently demonstrated that humoral immune response to cruzipain, a major antigen of Trypanosoma cruzi parasite, is implicated in the pathogenesis of experimental Chagas' disease. In the present study, the spleen cell phenotype and the cytokine profile induced by cruzipain in immunized mice were analyzed. The results showed that cruzipain increases the number of spleen cells with large size and granularity. Splenocyte populations with CD19(+), Mac-1(+), Gr-1(+) and CD11c(+) positive surface markers significantly increased in immune mice compared to controls ones. Histological study revealed the presence of high number of megacariocyte and granulocyte-macrophage progenitors, indicating extramedullary hemopoiesis in spleens of immune mice. The finding of high levels of IL-4, IL5 and IL-10 and low levels of IFN-gamma and IL-12 in supernatants of immune cells stimulated with cruzipain indicates a preferential activation of T2 type cells in immune animals. To investigate the role of innate immunity cells, the classical and alternative metabolic pathways of spleen macrophages from immune mice stimulated by cruzipain were also studied. The results showed an increase of urea associated with a decrease of nitrite levels, suggesting that cruzipain up-regulates the arginase way. Therefore, cruzipain leads to T2 type cytokine profile which may enhance the arginase via in the macrophages promoting a susceptible mechanism to infection. Thus, we postulate that during T. cruzi infection, cruzipain could be used by the parasite to spread inside the host.

  12. Chagas' Disease and HIV Co-infection: Genotypic Characterization of the Trypanosoma cruzi Strain

    Directory of Open Access Journals (Sweden)

    Pacheco Raquel S

    1998-01-01

    Full Text Available In the past few years, new aspects of the immunopathology of Chagas' disease have been described in immunosuppressed patients, such as fatal central nervous system lesions related to the reactivation of the parasite. This article is the first description of the genotypic characterization, at the strain level, of Trypanosoma cruzi isolated from a patient with Chagas` disease/AIDS co-infection. The presence of four hypodense lesions was observed in the cranial compute tomographic scan. The diagnosis of AIDS was assessed by the detection of anti-HIV antibodies using enzyme-linked immunosorbent assay (ELISA and Western blot techniques. The CD4+ lymphocyte counts were maintained under 200 cells/mm3 during one year demonstrating the severity of the state of immunosuppression. Chagas' disease was confirmed by serological and parasitological methods. Trypomastigote forms were visualized in a thick blood smear. The parasite isolated is genotypically similar to the CL strain. The paper reinforces that cerebral Chagas' disease can be considered as another potential opportunistic infection in AIDS resulting from the reactivation of a dormant T. cruzi infection acquired years earlier.

  13. A new bianthron glycoside as inhibitor of Trypanosoma cruzi glyceraldehyde 3-phosphate dehydrogenase activity

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Edangelo M.S. de; Silva, Maria G.V. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Analitica e Fisico-Quimica; Wiggers, Helton J.; Montanari, Carlos A. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, (Brazil). Setor de Quimica de Produtos Naturais; Andricopulo, Adriano D. [Universidade de Sao Paulo (USP), Sao Carlos SP (Brazil). Inst. de Fisica

    2009-07-01

    A phytochemical investigation of the ethanolic extract of stalks of Senna martiana Benth. (Leguminoseae), native specie of northeast Brazil, resulted in the isolation and spectroscopic characterization of a new bianthrone glycoside, martianine 1 (10,10'-il-chrysophanol-10-oxi- 10,10'-bi-glucosyl). Its identification was established by HRMS, IR and 2D NMR experiments. The evaluation of martianine trypanocidal activity was carried out against gliceraldehyde 3-phosphate dehydrogenase enzyme from Trypanosoma cruzi. Its inhibitory constant (K{sub i}) is in the low micromolar concentration and it was determined by isothermal titration calorimetry to be 27.3 +-2.47 {mu}mol L{sup -1}. The non-competitive mechanism is asserted to be putative of the mode of action martianine displays against T. cruzi GAPDH. Results show that martianine has a great potential to become new lead molecule by inhibiting this key enzyme and for the development of new drugs against Chagas disease. (author)

  14. Characterization of a 21kDa protein from Trypanosoma cruzi associated with mammalian cell invasion.

    Science.gov (United States)

    da Silva, Claudio V; Kawashita, Silvia Y; Probst, Christian M; Dallagiovanna, Bruno; Cruz, Mário C; da Silva, Erika A; Souto-Padrón, Thaís C B S; Krieger, Marco A; Goldenberg, Samuel; Briones, Marcelo R S; Andrews, Norma W; Mortara, Renato A

    2009-04-01

    Trypanosoma cruzi genomic database was screened for hypothetical proteins that showed high probability of being secreted or membrane anchored and thus, likely involved in host-cell invasion. A sequence that codes for a 21kDa protein that showed high probability of being secreted was selected. After cloning this protein sequence, the results showed that it was a ubiquitous protein and secreted by extracellular amastigotes. The recombinant form (P21-His(6)) adhered to HeLa cells in a dose-dependent manner. Pretreatment of host cells with P21-His(6) inhibited cell invasion by extracellular amastigotes from G and CL strains. On the other hand, when the protein was added to host cells at the same time as amastigotes, an increase in cell invasion was observed. Host-cell pretreatment with P21-His(6) augmented invasion by metacyclic trypomastigotes. Moreover, polyclonal antibody anti-P21 inhibited invasion only by extracellular amastigotes and metacyclic trypomastigotes from G strain. These results suggested that P21 might be involved in T. cruzi cell invasion. We hypothesize that P21 could be secreted in the juxtaposition parasite-host cell and triggers signaling events yet unknown that lead to parasite internalization.

  15. Rab32 is essential for maintaining functional acidocalcisomes, and for growth and infectivity of Trypanosoma cruzi

    Science.gov (United States)

    Niyogi, Sayantanee; Jimenez, Veronica; Girard-Dias, Wendell; de Souza, Wanderley; Miranda, Kildare; Docampo, Roberto

    2015-01-01

    ABSTRACT The contractile vacuole complex (CVC) of Trypanosoma cruzi, the etiologic agent of Chagas disease, collects and expels excess water as a mechanism of regulatory volume decrease after hyposmotic stress; it also has a role in cell shrinking after hyperosmotic stress. Here, we report that, in addition to its role in osmoregulation, the CVC of T. cruzi has a role in the biogenesis of acidocalcisomes. Expression of dominant-negative mutants of the CVC-located small GTPase Rab32 (TcCLB.506289.80) results in lower numbers of less-electron-dense acidocalcisomes, lower content of polyphosphate, lower capacity for acidocalcisome acidification and Ca2+ uptake that is driven by the vacuolar proton pyrophosphatase and the Ca2+-ATPase, respectively, as well as less-infective parasites, revealing the role of this organelle in parasite infectivity. By using fluorescence, electron microscopy and electron tomography analyses, we provide further evidence of the active contact of acidocalcisomes with the CVC, indicating an active exchange of proteins between the two organelles. PMID:25964650

  16. Insight into the exoproteome of the tissue-derived trypomastigote form of Trypanosoma cruzi

    Science.gov (United States)

    Queiroz, Rayner; Ricart, Carlos; Machado, Mara; Bastos, Izabela; Santana, Jaime; Sousa, Marcelo; Roepstorff, Peter; Charneau, Sébastien

    2016-11-01

    The protozoan parasite Trypanosoma cruzi causes Chagas disease, one of the major neglected infectious diseases. It has the potential to infect any nucleated mammalian cell. The secreted/excreted protein repertoire released by T. cruzi trypomastigotes is crucial in host-pathogen interactions. In this study, mammalian tissue culture-derived trypomastigotes (Y strain) were used to characterize the exoproteome of the infective bloodstream life form. Proteins released into the serum-free culture medium after 3h of incubation were harvested and digested with trypsin. NanoLC-MS/MS analysis resulted in the identification of 540 proteins, the largest set of released proteins identified to date in Trypanosome spp. Bioinformatic analysis predicted most identified proteins as secreted, predominantly by non-classical pathways, and involved in host-cell infection. Some proteins possess predicted GPI-anchor signals, these being mostly trans-sialidases, mucin associated surface proteins and surface glycoproteins. Moreover, we enriched phosphopeptides and glycopeptides from tryptic digests. The majority of identified glycoproteins are trans-sialidases and surface glycoproteins involved in host-parasite interaction. Conversely, most identified phosphoproteins have no Gene Ontology classification. The existence of various proteins related to similar functions in the exoproteome likely reflects this parasite’s enhanced mechanisms for adhesion, invasion and internalization of different host-cell types, and escape from immune defences.

  17. Comparison of conventional serology and PCR methods for the routine diagnosis of Trypanosoma cruzi infection

    Directory of Open Access Journals (Sweden)

    Soraia Reda Gilber

    2013-06-01

    Full Text Available Introduction Trypanosoma cruzi, a flagellated protozoan, is the etiologic agent of Chagas disease, and it is estimated that approximately 5 million people in Brazil are infected with this parasite. This work aimed to compare the current diagnostic methods for Chagas disease, including conventional serological (IFAT and ELISA and molecular techniques (PCR, to introduce PCR as an auxiliary technique. Methods A total of 106 chagasic patients were evaluated: 88 from endemic areas of Parana, 6 from São Paulo, 3 from Minas Gerais, 3 from Rio Grande do Sul, 1 from Bahia and 5 from the Santa Catarina T. cruzi outbreak. The samples were analyzed by conventional serological methods (IFAT, ELISA, hemoculture and PCR to confirm Chagas disease. Results When IFAT was used to determine antibody levels, the sensitivity was 81.7% for patients with the cardiac form of the disease and 100% for the other clinical forms. In contrast, ELISA showed 84% sensitivity and 100% specificity. The use of serological and molecular techniques and their implications for the diagnosis of Chagas disease in non-endemics area are discussed. Conclusions PCR constitutes an excellent support methodology for the laboratory diagnosis of Chagas disease due to its high sensitivity and specificity.

  18. Identification of Protein Complex Associated with LYT1 of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    C. Lugo-Caballero

    2013-01-01

    Full Text Available To carry out the intracellular phase of its life cycle, Trypanosoma cruzi must infect a host cell. Although a few molecules have been reported to participate in this process, one known protein is LYT1, which promotes lysis under acidic conditions and is involved in parasite infection and development. Alternative transcripts from a single LYT1 gene generate two proteins with differential functions and compartmentalization. Single-gene products targeted to more than one location can interact with disparate proteins that might affect their function and targeting properties. The aim of this work was to study the LYT1 interaction map using coimmunoprecipitation assays with transgenic parasites expressing LYT1 products fused to GFP. We detected several proteins of sizes from 8 to 150 kDa that bind to LYT1 with different binding strengths. By MS-MS analysis, we identified proteins involved in parasite infectivity (trans-sialidase, development (kDSPs and histones H2A and H2B, and motility and protein traffic (dynein and α- and β-tubulin, as well as protein-protein interactions (TPR-protein and kDSPs and several hypothetical proteins. Our approach led us to identify the LYT1 interaction profile, thereby providing insights into the molecular mechanisms that contribute to parasite stage development and pathogenesis of T. cruzi infection.

  19. Seroprevalence of Trypanosoma cruzi among mothers and children in rural Mayan communities and associated reproductive outcomes.

    Science.gov (United States)

    Gamboa-León, Rubi; Ramirez-Gonzalez, Claudia; Pacheco-Tucuch, Freddy S; O'Shea, Matthew; Rosecrans, Kathryn; Pippitt, Julia; Dumonteil, Eric; Buekens, Pierre

    2014-08-01

    Our objective was to determine the seroprevalence of Trypanosoma cruzi infection among mothers and children in two rural Mayan communities in Yucatan, Mexico and examine sociodemographic characteristics and adverse reproductive outcomes associated with maternal infection. We performed household surveys in the communities of Sudzal and Teya. Mothers were interviewed, and blood samples were obtained to perform rapid tests and enzyme-linked immunosorbent assays (ELISAs). We surveyed 390 mothers and 685 children. The overall seroprevalence was 2.3% among mothers and 0.4% among children. In Sudzal, we found a seroprevalence of 4.4% among mothers and 0.7% in children. In Teya, we found a seroprevalence of 0.9% among mothers and 0.3% among children. Compared with uninfected mothers, seropositive mothers reported more stillbirths (relative risk = 4.7; 95% confidence interval = 2.1-10.4). T. cruzi infection is present in these communities, and infected children indicate active transmission. Seropositivity in mothers is associated with a history of adverse reproductive outcomes.

  20. Genome-wide screening and identification of new Trypanosoma cruzi antigens with potential application for chronic Chagas disease diagnosis.

    Directory of Open Access Journals (Sweden)

    João Luís Reis-Cunha

    Full Text Available The protozoan Trypanosoma cruzi is the etiologic agent of Chagas disease, an infection that afflicts approximately 8 million people in Latin America. Diagnosis of chronic Chagas disease is currently based on serological tests because this condition is usually characterized by high anti-T. cruzi IgG titers and low parasitemia. The antigens used in these assays may have low specificity due to cross reactivity with antigens from related parasite infections, such as leishmaniasis, and low sensitivity caused by the high polymorphism among T. cruzi strains. Therefore, the identification of new T. cruzi-specific antigens that are conserved among the various parasite discrete typing units (DTUs is still required. In the present study, we have explored the hybrid nature of the T. cruzi CL Brener strain using a broad genome screening approach to select new T. cruzi antigens that are conserved among the different parasite DTUs and that are absent in other trypanosomatid species. Peptide arrays containing the conserved antigens with the highest epitope prediction scores were synthesized, and the reactivity of the peptides were tested by immunoblot using sera from C57BL/6 mice chronically infected with T. cruzi strains from the TcI, TcII or TcVI DTU. The two T. cruzi proteins that contained the most promising peptides were expressed as recombinant proteins and tested in ELISA experiments with sera from chagasic patients with distinct clinical manifestations: those infected with T. cruzi from different DTUs and those with cutaneous or visceral leishmaniasis. These proteins, named rTc_11623.20 and rTc_N_10421.310, exhibited 94.83 and 89.66% sensitivity, 98.2 and 94.6% specificity, respectively, and a pool of these 2 proteins exhibited 96.55% sensitivity and 98.18% specificity. This work led to the identification of two new antigens with great potential application in the diagnosis of chronic Chagas disease.

  1. Conformational restriction of aryl thiosemicarbazones produces potent and selective anti-Trypanosoma cruzi compounds which induce apoptotic parasite death.

    Science.gov (United States)

    Magalhaes Moreira, Diogo Rodrigo; de Oliveira, Ana Daura Travassos; Teixeira de Moraes Gomes, Paulo André; de Simone, Carlos Alberto; Villela, Filipe Silva; Ferreira, Rafaela Salgado; da Silva, Aline Caroline; dos Santos, Thiago André Ramos; Brelaz de Castro, Maria Carolina Accioly; Pereira, Valéria Rego Alves; Leite, Ana Cristina Lima

    2014-03-21

    Chagas disease, caused by Trypanosoma cruzi, is a life-threatening infection leading to approximately 12,000 deaths per year. T. cruzi is susceptible to thiosemicarbazones, making this class of compounds appealing for drug development. Previously, the homologation of aryl thiosemicarbazones resulted in an increase in anti-T. cruzi activity in comparison to aryl thiosemicarbazones without a spacer group. Here, we report the structural planning, synthesis and anti-T. cruzi evaluation of new aryl thiosemicarbazones (9a-x), designed as more conformationally restricted compounds. By varying substituents attached to the phenyl ring, substituents were observed to retain, enhance or greatly increase the anti-T. cruzi activity, in comparison to the nonsubstituted derivative. In most cases, hydrophobic and bulky substituents, such as bromo, biphenyl and phenoxyl groups, greatly increased antiparasitic activity. Specifically, thiosemicarbazones were identified that inhibit the epimastigote proliferation and were toxic for trypomastigotes without affecting mouse splenocytes viability. The most potent anti-T. cruzi thiosemicarbazones were evaluated against cruzain. However, inhibition of this enzyme was not observed, suggesting that the compounds work through another mechanism. In addition, examination of T. cruzi cell death showed that these thiosemicarbazones induce apoptosis. In conclusion, the structural design executed within the series of aryl thiosemicarbazones (9a-x) led to the identification of new potent anti-T. cruzi agents, such as compounds (9h) and (9r), which greatly inhibited epimastigote proliferation, and demonstrated a toxicity for trypomastigotes, but not for splenocytes. Mechanistically, these compounds do not inhibit the cruzain, but induce T. cruzi cell death by an apoptotic process.

  2. Mouse macrophage galactose-type lectin (mMGL) is critical for host resistance against Trypanosoma cruzi infection.

    Science.gov (United States)

    Vázquez, Alicia; Ruiz-Rosado, Juan de Dios; Terrazas, Luis I; Juárez, Imelda; Gomez-Garcia, Lorena; Calleja, Elsa; Camacho, Griselda; Chávez, Ana; Romero, Miriam; Rodriguez, Tonathiu; Espinoza, Bertha; Rodriguez-Sosa, Miriam

    2014-01-01

    The C-type lectin receptor mMGL is expressed exclusively by myeloid antigen presenting cells (APC) such as dendritic cells (DC) and macrophages (Mφ), and it mediates binding to glycoproteins carrying terminal galactose and α- or β-N-acetylgalactosamine (Gal/GalNAc) residues. Trypanosoma cruzi (T. cruzi) expresses large amounts of mucin (TcMUC)-like glycoproteins. Here, we show by lectin-blot that galactose moieties are also expressed on the surface of T. cruzi. Male mMGL knockout (-/-) and wild-type (WT) C57BL/6 mice were infected intraperitoneally with 10(4) T. cruzi trypomastigotes (Queretaro strain). Following T. cruzi infection, mMGL-/- mice developed higher parasitemia and higher mortality rates compared with WT mice. Although hearts from T. cruzi-infected WT mice presented few amastigote nests, mMGL-/- mice displayed higher numbers of amastigote nests. Compared with WT, Mφ from mMGL-/- mice had low production of nitric oxide (NO), interleukin (IL)-12 and tumor necrosis factor (TNF)-α in response to soluble T. cruzi antigens (TcAg). Interestingly, upon in vitro T. cruzi infection, mMGL-/- Mφ expressed lower levels of MHC-II and TLR-4 and harbored higher numbers of parasites, even when mMGL-/- Mφ were previously primed with IFN-γ or LPS/IFN-γ. These data suggest that mMGL plays an important role during T. cruzi infection, is required for optimal Mφ activation, and may synergize with TLR-4-induced pathways to produce TNF-α, IL-1β and NO during the early phase of infection.

  3. Experimental evidence of biological interactions among different isolates of Trypanosoma cruzi from the Chaco Region.

    Directory of Open Access Journals (Sweden)

    Paula G Ragone

    Full Text Available Many infectious diseases arise from co-infections or re-infections with more than one genotype of the same pathogen. These mixed infections could alter host fitness, the severity of symptoms, success in pathogen transmission and the epidemiology of the disease. Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits a high biological variability often correlated with its genetic diversity. Here, we developed an experimental approach in order to evaluate biological interaction between three T. cruzi isolates belonging to different Discrete Typing Units (DTUs TcIII, TcV and TcVI. These isolates were obtained from a restricted geographical area in the Chaco Region. Different mixed infections involving combinations of two isolates (TcIII + TcV, TcIII + TcVI and TcV + TcVI were studied in a mouse model. The parameters evaluated were number of parasites circulating in peripheral blood, histopathology and genetic characterization of each DTU in different tissues by DNA hybridization probes. We found a predominance of TcVI isolate in blood and tissues respect to TcIII and TcV; and a decrease of the inflammatory response in heart when the damage of mice infected with TcVI and TcIII + TcVI mixture were compared. In addition, simultaneous presence of two isolates in the same tissue was not detected. Our results show that biological interactions between isolates with different biological behaviors lead to changes in their biological properties. The occurrence of interactions among different genotypes of T. cruzi observed in our mouse model suggests that these phenomena could also occur in natural cycles in the Chaco Region.

  4. Ecology of Trypanosoma cruzi I genotypes across Rhodnius prolixus captured in Attalea butyracea palms.

    Science.gov (United States)

    Poveda, Cristina; Higuera, Adriana; Urbano, Plutarco; Ramírez, Juan David

    2017-04-01

    Trypanosoma cruzi, the agent of Chagas disease exhibits significant genetic diversity. This parasite is divided into six discrete typing units (DTUs) where T. cruzi I (TcI) is the most widespread in the Americas. TcI genotypes have been associated to domestic and sylvatic cycles of transmission (TcIDom and sylvatic TcI). Due to the importance of the enzootic transmission, we determined the frequency of TcI genotypes present in Rhodnius prolixus captured in different regions of the palm A. butyracea to understand the ecology of the disease and the importance of A. butyracea palms as ecotopes of R. prolixus. Forty A. butyracea palms were sampled (base crown, mid-point and crown) capturing 105 individuals identified as R. prolixus by morphological and molecular barcoding. We conducted molecular detection and typing of T. cruzi acr