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1.
Int J Mol Sci ; 22(2)2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33445756

RESUMO

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and affects over 6 million people worldwide. Development of new drugs to treat this disease remains a priority since those currently available have variable efficacy and frequent adverse effects, especially during the long regimens required for treating the chronic stage of the disease. T. cruzi modulates the host cell-metabolism to accommodate the cell cytosol into a favorable growth environment and acquire nutrients for its multiplication. In this study we evaluated the specific anti-T. cruzi activity of nine bio-energetic modulator compounds. Notably, we identified that 17-DMAG, which targets the ATP-binding site of heat shock protein 90 (Hsp90), has a very high (sub-micromolar range) selective inhibition of the parasite growth. This inhibitory effect was also highly potent (IC50 = 0.27 µmol L-1) against the amastigote intracellular replicative stage of the parasite. Moreover, molecular docking results suggest that 17-DMAG may bind T. cruzi Hsp90 homologue Hsp83 with good affinity. Evaluation in a mouse model of chronic T. cruzi infection did not show parasite growth inhibition, highlighting the difficulties encountered when going from in vitro assays onto preclinical drug developmental stages.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/metabolismo , Animais , Biomarcadores , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/química , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Camundongos , Conformação Molecular , Relação Estrutura-Atividade , Tripanossomicidas/química
2.
Trends Parasitol ; 37(3): 214-225, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33436314

RESUMO

Trypanosoma cruzi, the protozoan agent of Chagas' disease, displays a complex population structure made up of multiple strains showing a diverse ecoepidemiological distribution. Parasite genetic variability may be associated with disease outcome, hence stressing the need to develop methods for T. cruzi typing in vivo. Serological typing methods that exploit the presence of host antibodies raised against polymorphic parasite antigens emerge as an appealing approach to address this issue. These techniques are robust, simple, cost-effective, and are not curtailed by methodological/biological limitations intrinsic to available genotyping methods. Here, we critically assess the progress towards T. cruzi serotyping and discuss the opportunity provided by high-throughput immunomics to improve this field.


Assuntos
Parasitologia/métodos , Testes Sorológicos/normas , Trypanosoma cruzi/classificação , Animais , Doença de Chagas/parasitologia , Humanos , Testes Sorológicos/economia , Testes Sorológicos/tendências , Especificidade da Espécie , Trypanosoma cruzi/imunologia
3.
PLoS Negl Trop Dis ; 14(12): e0008932, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33332357

RESUMO

BACKGROUND: Chagas disease is a neglected zoonosis of growing concern in the southern US, caused by the parasite Trypanosoma cruzi. We genotyped parasites in a large cohort of PCR positive dogs to shed light on parasite transmission cycles and assess potential relationships between parasite diversity and serological test performance. METHODOLOGY/PRINCIPAL FINDINGS: We used a metabarcoding approach based on deep sequencing of T. cruzi mini-exon marker to assess parasite diversity. Phylogenetic analysis of 178 sequences from 40 dogs confirmed the presence of T. cruzi discrete typing unit (DTU) TcI and TcIV, as well as TcII, TcV and TcVI for the first time in US dogs. Infections with multiple DTUs occurred in 38% of the dogs. These data indicate a greater genetic diversity of T. cruzi than previously detected in the US. Comparison of T. cruzi sequence diversity indicated that highly similar T. cruzi strains from these DTUs circulate in hosts and vectors in Louisiana, indicating that they are involved in a shared T. cruzi parasite transmission cycle. However, TcIV and TcV were sampled more frequently in vectors, while TcII and TcVI were sampled more frequently in dogs. CONCLUSIONS/SIGNIFICANCE: These observations point to ecological host-fitting being a dominant mechanism involved in the diversification of T. cruzi-host associations. Dogs with negative, discordant or confirmed positive T. cruzi serology harbored TcI parasites with different mini-exon sequences, which strongly supports the hypothesis that parasite genetic diversity is a key factor affecting serological test performance. Thus, the identification of conserved parasite antigens should be a high priority for the improvement of current serological tests.


Assuntos
Doença de Chagas/veterinária , Éxons/genética , Variação Genética , Trypanosoma cruzi/genética , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Doença de Chagas/transmissão , Estudos de Coortes , Cães , Genótipo , Humanos , Louisiana/epidemiologia , Filogenia , Testes Sorológicos/veterinária , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/fisiologia , Zoonoses
4.
PLoS Negl Trop Dis ; 14(12): e0008969, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33347472

RESUMO

CD8 T cells are regarded as pivotal players in both immunoprotection and immunopathology following Trypanosoma cruzi infection. Previously, we demonstrated the expansion of CD8+ T lymphocytes in the spleen of T. cruzi-infected mice under treatment with benznidazole (N-benzyl-2-nitroimidazole acetamide; Bz), a drug available for clinical therapy. This finding underlies the concept that the beneficial effects of Bz on controlling acute T. cruzi infection are related to a synergistic process between intrinsic trypanocidal effect and indirect triggering of the active immune response. In the present study, we particularly investigated the effect of Bz treatment on the CD8+ T cell subset following T. cruzi infection. Herein we demonstrated that, during acute T. cruzi infection, Bz treatment reduces and abbreviates the parasitemia, but maintains elevated expansion of CD8+ T cells. Within this subset, a remarkable group of CD8low cells was found in both Bz-treated and non-treated infected mice. In Bz-treated mice, early pathogen control paralleled the lower frequency of recently activated CD8low cells, as ascertained by CD69 expression. However, the CD8low subset sustains significant levels of CD44highCD62Llow and CD62LlowT-bethigh effector memory T cells, in both Bz-treated and non-treated infected mice. These CD8low cells also comprise the main group of spontaneous interferon (IFN)-γ-producing CD8+ T cells. Interestingly, following in vitro anti-CD3/CD28 stimulation, CD8+ T cells from Bz-treated T. cruzi-infected mice exhibited higher frequency of IFN-γ+ cells, which bear mostly a CD8low phenotype. Altogether, our results point to the marked presence of CD8low T cells that arise during acute T. cruzi infection, with Bz treatment promoting their significant expansion along with a potential effector program for high IFN-γ production.


Assuntos
Doença de Chagas/tratamento farmacológico , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Doença Aguda , Animais , Linfócitos T CD8-Positivos/imunologia , Doença de Chagas/parasitologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Baço/imunologia , Trypanosoma cruzi/genética
5.
Exp Parasitol ; 218: 108012, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33011239

RESUMO

Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in almost all countries of Latin America. In Brazil, oral infection is becoming the most important mechanism of transmission of the disease in several regions of the country. The gastrointestinal tract is the gateway for the parasite through this route of infection, however, little is known about the involvement of these organs related to oral route. In this sense, the present study evaluated the impact of oral infection on the digestive tract in mice infected by Berenice-78 (Be-78) T. cruzi strain, in comparison with the intraperitoneal route of infection. In this work, the intraperitoneal route group showed a peak of parasitemia similar to the oral route group, however the mortality rate among the orally infected animals was higher when compared to intraperitoneal route. By analyzing the frequency of blood cell populations, differences were mainly observed in CD4+ T lymphocytes, and not in CD8+, presenting an earlier reduction in the number of CD4+ T cells, which persisted for a longer period, in the animals of the oral group when compared with the intraperitoneal group. Animals infected by oral route presented a higher tissue parasitism and inflammatory infiltrate in stomach, duodenum and colon on the 28th day after infection. Therefore, these data suggest that oral infection has a different profile of parasitological and immune responses compared to intraperitoneal route, being the oral route more virulent and with greater tissue parasitism in organs of the gastrointestinal tract evaluated during the acute phase.


Assuntos
Doença de Chagas/patologia , Trato Gastrointestinal/patologia , Trato Gastrointestinal/parasitologia , Trypanosoma cruzi/patogenicidade , Administração Oral , Análise de Variância , Animais , Doença de Chagas/mortalidade , Doença de Chagas/parasitologia , Colo/parasitologia , Colo/patologia , Duodeno/parasitologia , Duodeno/patologia , Imunofenotipagem , Masculino , Camundongos , Monócitos/patologia , Parasitemia/mortalidade , Parasitemia/parasitologia , Estômago/parasitologia , Estômago/patologia , Taxa de Sobrevida
6.
BMC Infect Dis ; 20(1): 743, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33036559

RESUMO

BACKGROUND: Chagas disease is a zoonotic infection caused by the parasite Trypanosoma cruzi, which affects an estimated 8-11 million people globally. Chagas disease is almost always associated with poverty in rural areas and disproportionately impacts immigrants from Latin America living in the United States. Approximately 20-30% of people who are infected with Chagas disease will develop a chronic form of the infection that can be fatal if left untreated. Chagas disease is vastly underestimated in the United States, often goes undiagnosed and is not well understood by most U.S. healthcare providers. One of the most important ways at reducing barriers to improving diagnostics of Chagas disease in the U.S. is giving healthcare providers the most up-to-date information and access to leading experts. METHODS: An online webinar was conducted for healthcare providers, veterinarians and public health professionals using Chagas disease expert panelists. Pre and post tests were administered to participants (n = 57) to determine the efficacy in raising awareness and to determine key focus areas for improving knowledge. A Wilcoxon rank-sum was used for non-parametric variables equivalent and for questions that assessed knowledge the McNemar's Chi-Square test was used. RESULTS: There were statistically significant learning increases in multiple categories including transmission (p = <.001), clinical presentation (p = 0.016), diagnostics (p = <.001), and treatment (p = <.001). CONCLUSION: Providing easily accessible learning opportunities using validated testing and evaluations should be further developed for rural healthcare providers in the U.S. as well as healthcare providers serving under represented populations such as immigrants. There is a clear lack of knowledge and awareness surrounding Chagas disease in the United States and just by raising awareness and providing education on the topic, lives will be saved.


Assuntos
Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde/educação , Trypanosoma cruzi , Animais , Doença de Chagas/parasitologia , Educação em Veterinária , Emigrantes e Imigrantes , Feminino , Humanos , Aprendizagem , Masculino , Pobreza , Estados Unidos/epidemiologia , Zoonoses/diagnóstico
7.
Exp Parasitol ; 217: 107962, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32763249

RESUMO

Trypanosoma cruzi is a parasitic protozoan that infects various species of domestic and wild animals, triatomine bugs and humans. It is the etiological agent of American trypanosomiasis, also known as Chagas Disease, which affects about 17 million people in Latin America and is emerging elsewhere in the world. Iron (Fe) is a crucial micronutrient for almost all cells, acting as a cofactor for several metabolic enzymes. T. cruzi has a high requirement for Fe, using heminic and non-heminic Fe for growth and differentiation. Fe occurs in the oxidized (Fe3+) form in aerobic environments and needs to be reduced to Fe2+ before it enters cells. Fe-reductase, located in the plasma membranes of some organisms, catalyzes the Fe3+⇒ Fe2+ conversion. In the present study we found an amino acid sequence in silico that allowed us to identify a novel 35 kDa protein in T. cruzi with two transmembrane domains in the C-terminal region containing His residues that are conserved in the Ferric Reductase Domain Superfamily and are required for catalyzing Fe3+ reduction. Accordingly, we named this protein TcFR. Intact epimastigotes from the T. cruzi DM28c strain reduced the artificial Fe3+-containing substrate potassium ferricyanide in a cell density-dependent manner, following Michaelis-Menten kinetics. The TcFR activity was more than eightfold higher in a plasma membrane-enriched fraction than in whole homogenates, and this increase was consistent with the intensity of the 35 kDa band on Western blotting images obtained using anti-NOX5 raised against the human antigen. Immunofluorescence experiments demonstrated TcFR on the parasite surface. That TcFR is part of a catalytic complex allowing T. cruzi to take up Fe from the medium was confirmed by experiments in which DM28c was assayed after culturing in Fe-depleted medium: (i) proliferation during the stationary growth phase was five times slower; (ii) the relative expression of TcFR (qPCR) was 50% greater; (iii) intact cells had 120% higher Fe-reductase activity. This ensemble of results indicates that TcFR is a conserved enzyme in T. cruzi, and its catalytic properties are modulated in order to respond to external Fe fluctuations.


Assuntos
FMN Redutase/metabolismo , Ferro/metabolismo , Trypanosoma cruzi/enzimologia , Sequência de Aminoácidos , Animais , Western Blotting , Membrana Celular/enzimologia , Doença de Chagas/parasitologia , Colorimetria , FMN Redutase/análise , FMN Redutase/química , Imunofluorescência , Humanos , Filogenia , Distribuição de Poisson , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Trypanosoma cruzi/classificação , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismo , Regulação para Cima
8.
PLoS One ; 15(8): e0237180, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750094

RESUMO

BACKGROUND: Chagas disease, caused by the intracellular parasite Trypanosoma cruzi, is one of the most important parasitological infections in the Americas. It is estimated to infect approximately 6 million people from mostly low income countries in Latin America, although recent infections have been reported in southern US states. Several studies have described an extensive genetic diversity among T. cruzi isolates throughout its geographic distribution in the American continent. This diversity has been correlated with the pathology developed during an infection. However, due to a lack of a single reliable test, current diagnosis practices of the disease are not straightforward since several different tests are applied. The use of current genomic sequence data allows for the selection of molecular markers (MM) that have the ability to identify the Discrete Typing Unit (DTU) of T. cruzi in a given infection, without the need of any sequencing reaction. METHODOLOGY/PRINCIPAL FINDINGS: Applying three criteria on the genomic sequencing data of four different phylogenetic lineages of T. cruzi, we designed several molecular tests that can be used for the molecular typing of the parasite. The criteria used were: (1) single-copy orthologs of T. cruzi, (2) T. cruzi unique loci, and (3) T. cruzi polymorphic loci. All criteria combined allowed for the selection of 15 MM, 12 of which were confirmed to be functional and replicable in the laboratory with sylvatic samples. Furthermore, one MM produced distinct polymerase chain reaction (PCR) amplicon sizes among distinct T. cruzi DTUs, allowing the use of a AFLP-PCR test to distinguish DTUs I, II/IV, V and VI. Whereas two MM can differentiate DTUs I, II, IV and V/VI out of the six current DTUs with a PCR-RFLP test. CONCLUSIONS/SIGNIFICANCE: The designed molecular tests provide a practical and inexpensive molecular typing test for the majority of DTUs of T. cruzi, excluding the need to perform any sequencing reaction. This provides the scientific community with an additional specific, quick and inexpensive test that can enhance the understanding of the correlation between the DTU of T. cruzi and the pathology developed during the infection.


Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados/métodos , Doença de Chagas/diagnóstico , Polimorfismo de Fragmento de Restrição/genética , Trypanosoma cruzi/genética , Doença de Chagas/parasitologia , DNA de Protozoário/genética , Loci Gênicos , Variação Genética , Genoma de Protozoário/genética , Humanos , Tipagem Molecular/métodos , Filogenia , Polimorfismo de Nucleotídeo Único
9.
Mem Inst Oswaldo Cruz ; 115: e200214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32725060

RESUMO

BACKGROUND Chagas disease, resulting from Trypanosoma cruzi infections, continues to be a health concern mainly in Latin American countries where the parasite is endemic. The laboratory diagnosis of a chronic infection is determined through serological assays for antibodies against T. cruzi and several tests are available that differ in key components, formats and methodologies. To date, no single test meets the criteria of a gold standard. The situation is further complicated by the difficulties associated with performance comparisons between different immunoassays or methodologies executed at different times and geographical areas. OBJECTIVE To improve the diagnosis of Chagas disease, the WHO coordinated the development of two International Biological Reference Standards for antibodies against anti-T. cruzi: NIBSC 09/186 and NIBSC 09/188 that respectively represent geographical regions with the highest prevalence of TcII and TcI lineages of the parasite. METHODS The principle goal of this study was to verify the behavior of these standards when assayed by several commercially available serological tests that employ different methods to capture and detect human anti-T. cruzi antibodies. FINDINGS AND MAIN CONCLUSIONS The results reinforce the recommendation that these standards be considered for performance evaluations of commercialised immunoassays and should be an integral step in the development of new test components or assay paradigms.


Assuntos
Doença de Chagas/diagnóstico , Testes Sorológicos/normas , Trypanosoma cruzi/isolamento & purificação , Anticorpos Antiprotozoários/sangue , Doença de Chagas/parasitologia , Humanos , Imunoensaio/métodos , Padrões de Referência , Testes Sorológicos/métodos , Trypanosoma cruzi/imunologia , Organização Mundial da Saúde
10.
Life Sci ; 257: 118067, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32652140

RESUMO

Although renin-angiotensin system (RAS) imbalance is manifested in cardiomyopathies with different etiologies, the impact of RAS effectors on Chagas cardiomyopathy and skeletal myositis is poorly understood. Given that diminazene aceturate (DMZ) shares trypanocidal, angiotensin-converting enzyme 2 (ACE2) and angiotensin-(1-7) stimulatory effects, we investigated the impact of DMZ on cardiomyocytes infection in vitro, renin-angiotensin system, Chagas cardiomyopathy and skeletal myositis in vivo. Cardiomyocytes and T. cruzi were used to evaluate DMZ toxicity in vitro. The impact of 20-days DMZ treatment (1 mg/kg) was also investigated in uninfected and T. cruzi-infected mice as follows: control uninfected and untreated, uninfected treated with DMZ, infected untreated and infected treated with DMZ. DMZ had low toxicity on cardiomyocytes, induced dose-dependent antiparasitic activity on T. cruzi trypomastigotes, and reduced parasite load but not infection rates in cardiomyocytes. DMZ increased ACE2 activity and angiotensin-(1-7) plasma levels but exerted no interference on angiotensin-converting enzyme (ACE) activity, ACE, ACE2 and angiotensin II levels in uninfected and infected mice. DMZ treatment also reduced IFN-γ and IL-2 circulating levels but was ineffective in attenuating parasitemia, MCP-1, IL-10, anti-T. cruzi IgG, nitrite/nitrate and malondialdehyde production, myocarditis and skeletal myositis compared to infected untreated animals. As the antiparasitic effect of DMZ in vitro did not manifest in vivo, this drug exhibited limited relevance to the treatment of Chagas disease. Although DMZ is effective in upregulating angiotensin-(1-7) levels, this molecule does not act as a potent modulator of T. cruzi infection, which can establish heart and skeletal muscle parasitism, lipid oxidation and inflammatory damage, even in the presence of high concentrations of this RAS effector.


Assuntos
Cardiomiopatia Chagásica/tratamento farmacológico , Doença de Chagas/tratamento farmacológico , Diminazena/análogos & derivados , Miócitos Cardíacos/efeitos dos fármacos , Sistema Renina-Angiotensina/efeitos dos fármacos , Angiotensina I/metabolismo , Animais , Linhagem Celular , Cardiomiopatia Chagásica/parasitologia , Doença de Chagas/parasitologia , Diminazena/administração & dosagem , Diminazena/farmacologia , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Miocardite/tratamento farmacológico , Miocardite/parasitologia , Miócitos Cardíacos/parasitologia , Miosite/tratamento farmacológico , Miosite/parasitologia , Fragmentos de Peptídeos/metabolismo , Ratos , Tripanossomicidas/administração & dosagem , Tripanossomicidas/farmacologia
11.
Am J Trop Med Hyg ; 103(3): 967-969, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32602437

RESUMO

In the United States, Chagas disease is diagnosed in less than 1% of the estimated > 300,000 people who have the disease. However, the actual prevalence remains unknown, and these estimates may be wide of the mark (too high or too low). The greater part of those living with the disease acquired the infection in an endemic region of Latin America, but autochthonous transmission in the United States is increasingly being described. These cases are considered rare, and the transmission routes are largely unknown. Although triatomines or "kissing bugs" harbor Trypanosoma cruzi in North America, most autochthonous cases are presumed rather than confirmed exposures to naturally infected kissing bugs. Public knowledge of Chagas is growing, and efforts are underway to provide greater awareness, but what are the risk factors for human transmission of Chagas disease in the United States?


Assuntos
Doença de Chagas/epidemiologia , Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Doença de Chagas/parasitologia , Transmissão de Doença Infecciosa , Humanos , América Latina/epidemiologia , Prevalência , Trypanosoma cruzi/patogenicidade , Incerteza , Estados Unidos/epidemiologia
12.
Parasitol Res ; 119(10): 3517-3522, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32617725

RESUMO

The parasite-vector interaction of Chagas disease is still poorly understood and the understanding of this relationship can help in the development of new strategies to control Trypanosoma cruzi transmission, which is the etiological agent of this disease. Considering the need to know if T. cruzi can cause some pathology in the reproductive system of the Chagas disease vectors, we investigated the spermatogenesis of Triatoma infestans infected by T. cruzi through histological and cytogenetic analysis. Trypanosoma cruzi Bolivia strain infection was not pathogenic for the reproductive system of T. infestans, because all the analyzed males had normal spermatogenesis, with all phases (spermatocytogenesis, meiosis and spermiogenesis) happening without any change. Thus, we demonstrated that the presence of T. cruzi Bolivia strain does not have influence in the spermatogenesis of T. infestans and we suggest that the influences on reproductive system observed for other species were a result of the action of the parasite on gametogenesis of females.


Assuntos
Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Espermatogênese/fisiologia , Triatoma/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Doença de Chagas/parasitologia , Interações Hospedeiro-Parasita , Insetos Vetores/fisiologia , Masculino , Triatoma/fisiologia
13.
PLoS Negl Trop Dis ; 14(6): e0008414, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32574175

RESUMO

Chemokine receptor type 3 (CXCR3) plays an important role in CD8+ T cells migration during intracellular infections, such as Trypanosoma cruzi. In addition to chemotaxis, CXCR3 receptor has been described as important to the interaction between antigen-presenting cells and effector cells. We hypothesized that CXCR3 is fundamental to T. cruzi-specific CD8+ T cell activation, migration and effector function. Anti-CXCR3 neutralizing antibody administration to acutely T. cruzi-infected mice decreased the number of specific CD8+ T cells in the spleen, and those cells had impaired in activation and cytokine production but unaltered proliferative response. In addition, anti-CXCR3-treated mice showed decreased frequency of CD8+ T cells in the heart and numbers of plasmacytoid dendritic cells in spleen and lymph node. As CD8+ T cells interacted with plasmacytoid dendritic cells during infection by T. cruzi, we suggest that anti-CXCR3 treatment lowers the quantity of plasmacytoid dendritic cells, which may contribute to impair the prime of CD8+ T cells. Understanding which molecules and mechanisms guide CD8+ T cell activation and migration might be a key to vaccine development against Chagas disease as those cells play an important role in T. cruzi infection control.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Doença de Chagas/imunologia , Quimiocinas/metabolismo , Células Dendríticas/imunologia , Ativação Linfocitária/imunologia , Receptores CXCR3/metabolismo , Trypanosoma cruzi/imunologia , Animais , Movimento Celular , Doença de Chagas/parasitologia , Citoplasma/metabolismo , Citoplasma/parasitologia , Modelos Animais de Doenças , Feminino , Coração , Controle de Infecções , Camundongos , Camundongos Endogâmicos C57BL , Baço/imunologia
14.
PLoS Negl Trop Dis ; 14(6): e0008311, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32497037

RESUMO

BACKGROUND: Trypanosoma cruzi has a high genetic and biological diversity and has been subdivided into seven genetic lineages, named TcI-TcVI and TcBat. DTUs TcI-TcII-TcV and TcVI are agents of ChD in different regions of Latin America. Due to population movements, the disease is an emergent global public health problem. Thus, the aim of this study was to quantify the parasitic load and identify the presence of T. cruzi DTUs in 101 Latin American immigrants with chronic ChD, residing in Barcelona, Spain. METHODOLOGY / PRINCIPAL FINDINGS: 5ml of peripheral blood were collected in guanidine/EDTA from each patient for DNA extraction, quantification of the parasitic load and genotyping. A great variation of the parasitic load of the patients was verified: from 0.001 to 22.2 T. cruzi DNA (fg) / Blood DNA (ng). In patients from Bolivia the parasitic load was 3.76±4.43 T. cruzi DNA (fg) / Blood DNA (ng) (mean ± SD), in patients of other countries was 0.95±1.38 T. cruzi DNA (fg) / Blood DNA (ng). No statistically significant difference was observed in the parasitic load between patients with the indeterminate and cardiac forms of ChD (p = 0,57). Parasite genotyping was performed by multilocus conventional PCR. In patients from Bolivia there was a nearly equal prevalence of DTUs TcV (27/77), TcII/TcV/TcVI (26/77), and TcII/TcVI (22/77). TcVI was detected in only 2 samples (2/77). A higher prevalence of TcII/TcVI (19/24) was verified in patients of other countries, with low prevalence of TcII/TcV/TcVI (4/24) and TcV (1/24). CONCLUSIONS/SIGNIFICANCE: In this study, low/medium parasitic load was found in all patients evaluated. Our data corroborate previous conclusions indicating that patients from the Bolivia, living in Spain, are predominantly infected by TcV, and TcVI DTUs. On the other hand, in Non-Bolivians patients TcII/TcVI predominated. Surprisingly, in our cohort of 101 patients no infection by TcI DTU was observed.


Assuntos
Doença de Chagas/etnologia , Doença de Chagas/parasitologia , DNA de Protozoário/genética , Emigrantes e Imigrantes , Trypanosoma cruzi/classificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bolívia/etnologia , Feminino , Variação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Carga Parasitária , Análise de Sequência de DNA , Espanha/epidemiologia , Trypanosoma cruzi/isolamento & purificação , Adulto Jovem
15.
Exp Parasitol ; 216: 107932, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32535113

RESUMO

Neglected tropical diseases, such as Chagas disease caused by the protozoa Trypanosoma cruzi, affect millions of people worldwide but lack effective treatments that are accessible to the entire population, especially patients with the debilitating chronic phase. The recognition of host cells, invasion and its intracellular replicative success are essential stages for progression of the parasite life cycle and the development of Chagas disease. It is predicted that programmed cell death pathways (apoptosis) would be activated in infected cells, either via autocrine secretion or mediated by cytotoxic immune cells. This process should play a key role in resolving infections by hindering the evolutionary success of the parasite. In this research, we performed assays to investigate the role of the lectin galectin-3 (Gal3) in parasite-host signaling pathways. Using cells with endogenous levels of Gal3 compared to Gal3-deficient cells (induced by RNA interference), we demonstrated that T. cruzi mediated the survival pathways and the subverted apoptosis through Gal3 promoting a pro-survival state in infected cells. Infected Gal3-depleted cells showed increased activation of caspase 3 and pro-apoptotic targets, such as poly (ADP-ribose) polymerase (PARP), and lower accumulation of anti-apoptotic proteins, such as c-IAP1, survivin and XIAP. During the early stages of infection, Gal3 translocates from the cytoplasm to the nucleus and must act in survival pathways. In a murine model of experimental infection, Gal3 knockout macrophages showed lower infectivity and viability. In vivo infection revealed a lower parasitemia and longer survival and an increased spleen cellularity in Gal3 knockout mice with consequences on the percentage of T lymphocytes (CD4+ CD11b+) and macrophages. In addition, cytokines such as IL-2, IL-4, IL-6 and TNF-α are increased in Gal3 knockout mice when compared to wild type genotype. These data demonstrate a Gal3-mediated complex interplay in the host cell, keeping infected cells alive long enough for infection and intracellular proliferation of new parasites. However, a continuous knowledge of these signaling pathways should contribute to a better understanding the mechanisms of cell death subversion that are promoted by protozoans in the pathophysiology of neglected diseases such as Chagas disease.


Assuntos
Apoptose/fisiologia , Doença de Chagas/parasitologia , Galectina 3/fisiologia , Trypanosoma cruzi/fisiologia , Análise de Variância , Animais , Western Blotting , Caspase 3/análise , Sobrevivência Celular , Doença de Chagas/mortalidade , Chlorocebus aethiops , Colorimetria , Citocinas/sangue , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imunofluorescência , Galectina 3/análise , Galectina 3/genética , Células HeLa , Humanos , Imunofenotipagem , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Parasitemia/mortalidade , Parasitemia/parasitologia , Fenótipo , Baço/patologia , Células Vero
16.
Exp Parasitol ; 215: 107931, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32464222

RESUMO

Chagas disease is a public health problem in America. Its parasite, Trypanosoma cruzi, presents different discrete typing units (DTUs), colonizes organs of mammalian hosts in chronic infections, and presents tropism for particular organs in experimental infections. We evaluated T. cruzi tropism towards organs on the naturally infected rodent Octodon degus, identifying the parasites' DTUs, by means of conventional PCR and hybridization. Almost all the analyzed organs presented T. cruzi. More than 42% of the tested oesophagus, skin, skeletal muscle, brain and intestine showed T. cruzi DNA. Other nine types of organs were infected in over 15%. These results suggest that there is some tropism by T. cruzi in chronically infected O. degus. DTU TcV was present in 92.5% of infected organs with identified DTUs; this DTU is frequently reported in human infections in the Southern Cone of South America. Few organs showed mixed DTU infections. This is one of the few reports on the outcome of chronic natural T. cruzi-infection in wild mammal hosts exposed to naturally infected vectors.


Assuntos
Doença de Chagas/veterinária , Octodon/parasitologia , Doenças dos Roedores/patologia , Doenças dos Roedores/parasitologia , Animais , Animais Selvagens , Doença de Chagas/parasitologia , Doença de Chagas/patologia , DNA de Protozoário/isolamento & purificação , Feminino , Masculino , Trypanosoma cruzi/classificação , Trypanosoma cruzi/genética
17.
Am J Trop Med Hyg ; 103(1): 428-436, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32458775

RESUMO

Trypanosoma cruzi is the etiological agent of Chagas disease that infects more than seven million people in Latin America. The parasite is transmitted by triatomine insects, of which some species are often associated with palms. The establishment of oil palm plantations (Elaeis guineensis) in the Orinoco region (Colombia) has been rapidly growing, possibly constituting a new environment for the establishment and increase in triatomine populations. In this study, the potential of Rhodnius prolixus to colonize E. guineensis plantations and maintain T. cruzi transmission was assessed. Fieldwork was conducted in two areas located in the department of Casanare for sampling E. guineensis and Attalea butyracea palms, sampling for triatomines to determine their abundance and prevalence of T. cruzi infection. To assess T. cruzi transmission potential in the area, sylvatic and domestic mammals were sampled. Results showed that palm infestation with triatomines was higher in A. butyracea than in E. guineensis palms and T. cruzi infection in triatomines varied between habitats for one study area, but was constant in the other site. Trypanosoma cruzi-infected mammals in the E. guineensis plantations were mainly generalist rodents, suggesting that these mammals could have an important role in T. cruzi transmission in plantations. In conclusion, E. guineensis plantations in the Orinoco region are suitable habitats for R. prolixus and T. cruzi transmission.


Assuntos
Arecaceae , Doença de Chagas/veterinária , Insetos Vetores/parasitologia , Rhodnius/parasitologia , Animais , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Doença de Chagas/transmissão , Quirópteros/parasitologia , Colômbia/epidemiologia , Cães/parasitologia , Florestas , Gambás/parasitologia , Óleo de Palmeira , Roedores/parasitologia , Sus scrofa/parasitologia , Trypanosoma cruzi
19.
Int J Mol Sci ; 21(5)2020 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-32121441

RESUMO

Unicellular eukaryotes of the Trypanosomatidae family include human and animal pathogens that belong to the Trypanosoma and Leishmania genera. Diagnosis of the diseases they cause requires the sampling of body fluids (e.g., blood, lymph, peritoneal fluid, cerebrospinal fluid) or organ biopsies (e.g., bone marrow, spleen), which are mostly obtained through invasive methods. Body fluids or appendages can be alternatives to these invasive biopsies but appropriateness remains poorly studied. To further address this question, we perform a systematic review on clues evidencing the presence of parasites, genetic material, antibodies, and antigens in body secretions, appendages, or the organs or proximal tissues that produce these materials. Paper selection was based on searches in PubMed, Web of Science, WorldWideScience, SciELO, Embase, and Google. The information of each selected article (n = 333) was classified into different sections and data were extracted from 77 papers. The presence of Trypanosomatidae parasites has been tracked in most of organs or proximal tissues that produce body secretions or appendages, in naturally or experimentally infected hosts. The meta-analysis highlights the paucity of studies on human African trypanosomiasis and an absence on animal trypanosomiasis. Among the collected data high heterogeneity in terms of the I2 statistic (100%) is recorded. A high positivity is recorded for antibody and genetic material detection in urine of patients and dogs suffering leishmaniasis, and of antigens for leishmaniasis and Chagas disease. Data on conjunctival swabs can be analyzed with molecular methods solely for dogs suffering canine visceral leishmaniasis. Saliva and hair/bristles showed a pretty good positivity that support their potential to be used for leishmaniasis diagnosis. In conclusion, our study pinpoints significant gaps that need to be filled in order to properly address the interest of body secretion and hair or bristles for the diagnosis of infections caused by Leishmania and by other Trypanosomatidae parasites.


Assuntos
Leishmania/isolamento & purificação , Trypanosoma/isolamento & purificação , Trypanosomatina/isolamento & purificação , Animais , Doença de Chagas/diagnóstico , Doença de Chagas/parasitologia , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Cães , Humanos , Leishmania/patogenicidade , Leishmaniose/diagnóstico , Leishmaniose/parasitologia , Trypanosoma/patogenicidade , Trypanosomatina/patogenicidade , Tripanossomíase Africana/diagnóstico , Tripanossomíase Africana/parasitologia , Tripanossomíase Africana/veterinária
20.
PLoS Negl Trop Dis ; 14(3): e0008007, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32196491

RESUMO

Investigations into intracellular replication and differentiation of Trypanosoma cruzi within the mammalian host have been restricted by limitations in our ability to detect parasitized cells throughout the course of infection. We have overcome this problem by generating genetically modified parasites that express a bioluminescent/fluorescent fusion protein. By combining in vivo imaging and confocal microscopy, this has enabled us to routinely visualise murine infections at the level of individual host cells. These studies reveal that intracellular parasite replication is an asynchronous process, irrespective of tissue location or disease stage. Furthermore, using TUNEL assays and EdU labelling, we demonstrate that within individual infected cells, replication of both mitochondrial (kDNA) and nuclear genomes is not co-ordinated within the parasite population, and that replicating amastigotes and non-replicating trypomastigotes can co-exist in the same cell. Finally, we report the presence of distinct non-canonical morphological forms of T. cruzi in the mammalian host. These appear to represent transitional forms in the amastigote to trypomastigote differentiation process. Therefore, the intracellular life-cycle of T. cruzi in vivo is more complex than previously realised, with potential implications for our understanding of disease pathogenesis, immune evasion and drug development. Dissecting the mechanisms involved will be an important experimental challenge.


Assuntos
Doença de Chagas/parasitologia , Replicação do DNA , Estágios do Ciclo de Vida , Trypanosoma cruzi/crescimento & desenvolvimento , Animais , Modelos Animais de Doenças , Feminino , Genes Reporter , Microscopia Intravital/métodos , Camundongos SCID , Microscopia Confocal/métodos , Coloração e Rotulagem/métodos , Trypanosoma cruzi/genética
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