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Sample records for cruzi circulante post-terapia

  1. Characterization of Trypanosoma cruzi telomerase.

    PubMed

    Campelo, Riward; Galindo, Maria Mercedes; Ramirez, Jose Luis

    2011-12-01

    High telomerase activity is always associated with actively dividing cells, however the detection of this activity in dividing Leishmania and Trypanosoma cruzi cells has always been disappointingly low. Recently, we have found that Leishmania major telomerase activity can be activated by heat, which combined with dilutions of the nuclear extracts produced an increase in activity comparable to cancer cells. Here we examined whether T. cruzi telomerase shares the same physicochemical properties of primer specificity and overall features of the L. major. Our studies revealed that no telomerase inhibitory factors were present in the nuclear lysates of T. cruzi however the enzyme was activated by heat and was very resilient to heat denaturation. We also showed the extension primer specificity, susceptibility to RNase-A and RNase-H digestion, and the effect of telomerase inhibitors.

  2. Protein geranylgeranyltransferase-I of Trypanosoma cruzi

    PubMed Central

    Yokoyama, Kohei; Gillespie, John R.; Van Voorhis, Wesley C.; Buckner, Frederick S.; Gelb, Michael H.

    2008-01-01

    Protein geranylgeranyltransferase type I (PGGT-I) and protein farnesyltransferase (PFT) occur in many eukaryotic cells. Both consist of two subunits, the common αsubunit and a distinct β subunit. In the gene database of protozoa Trypanosoma cruzi, the causative agent of Chagas' disease, a putative protein that consists of 401 amino acids with ∼20% amino acid sequence identity to the PGGT-I β of other species was identified, cloned, and characterized. Multiple sequence alignments show that the T. cruzi ortholog contains all three of the zinc-binding residues and several residues uniquely conserved in the β subunit of PGGT-I. Co-expression of this protein and the α subunit of T. cruzi PFT in Sf9 insect cells yielded a dimeric protein that forms a tight complex selectively with [3H]geranylgeranyl pyrophosphate, indicating a key characteristic of a functional PGGT-I. Recombinant T. cruzi PGGT-I ortholog showed geranylgeranyltransferase activity with distinct specificity toward the C-terminal CaaX motif of protein substrates compared to that of the mammalian PGGT-I and T. cruzi PFT. Most of the CaaX-containing proteins with X=Leu are good substrates of T. cruzi PGGT-I, and those with X=Met are substrates for both T. cruzi PFT and PGGT-I, whereas unlike mammalian PGGT-I, those with X=Phe are poor substrates for T. cruzi PGGT-I. Several candidates for T. cruzi PGGT-I or PFT substrates containing the C-terminal CaaX motif are found in the T. cruzi gene database. Among five C-terminal peptides of those tested, a peptide of a Ras-like protein ending with CVLL was selectively geranylgeranylated by T. cruzi PGGT-I. Other peptides with CTQQ (Tcj2 DNAJ protein), CAVM (TcPRL-1 protein tyrosine phosphatase), CHFM (a small GTPase like protein), and CQLF (TcRho1 GTPase) were specific substrates for T. cruzi PFT but not for PGGT-I. The mRNA and protein of the T. cruzi PGGT-I β ortholog were detected in three life-cycle stages of T. cruzi. Cytosol fractions from

  3. Nuclear structure of Trypanosoma cruzi.

    PubMed

    Schenkman, Sergio; Pascoalino, Bruno dos Santos; Nardelli, Sheila C

    2011-01-01

    The presence of nucleus in living organisms characterizes the Eukaryote domain. The nucleus compartmentalizes the genetic material surrounded by a double membrane called nuclear envelope. The nucleus has been observed since the advent of the light microscope, and sub-compartments such as nucleoli, diverse nuclear bodies and condensed chromosomes have been later recognized, being part of highly organized and dynamic structure. The significance and function of such organization has increased with the understanding of transcription, replication, DNA repair, recombination processes. It is now recognized as consequence of adding complexity and regulation in more complex eukaryotic cells. Here we provide a description of the actual stage of knowledge of the nuclear structure of Trypanosoma cruzi. As an early divergent eukaryote, it presents unique and/or reduced events of DNA replication, transcription and repair as well as RNA processing and transport to the cytosol. Nevertheless, it shows peculiar structure changes accordingly to the cell cycle and stage of differentiation. T. cruzi proliferates only as epimastigote and amastigote stages, and when these forms differentiate in trypomastigote forms, their cell cycle is arrested. This arrested stage is capable of invading mammalian cells and of surviving harsh conditions, such as the gut of the insect vector and mammalian macrophages. Transcription and replication decrease during transformation in trypomastigotes implicating large alterations in the nuclear structure. Recent evidences also suggest that T. cruzi nucleus respond to oxidative and nutritional stresses. Due to the phylogenetic proximity with other well-known trypanosomes, such as Trypanosoma brucei and Leishmania major, they are expected to have similar nuclear organization, although differences are noticed due to distinct life cycles, cellular organizations and the specific adaptations for surviving in different host environments. Therefore, the general

  4. Immunotherapy of Trypanosoma cruzi infections.

    PubMed

    Chamond, N; Coatnoan, N; Minoprio, P

    2002-10-01

    The protozoan parasite Trypanosoma cruzi, causative agent of Chagas' disease, is transmitted to man and other mammals by triatominae insects, or 'kissing bugs'. Since its discovery in 1909, by Carlos Chagas, this parasite has been the object of several publications in the domains of immunology, cellular biology and of control gene organization, regulation and expression. Although much progress has been made concerning prophylaxis of Chagas' disease, particularly vector eradication, additional cases of infection and disease development still occur every day throughout the world. Whilst infection was largely limited in the past to vector transmission in endemic areas of Latin America, its impact has increased in terms of congenital and blood transmission, transplants and recrudescence following immunosuppressive states. Reports on new insect vectors adapted to the parasite and domestic animals infected in more developed countries, emphasize the continuing worldwide public health issue. Therapy against this parasite is limited and cure is subjected to several criteria, such as susceptibility of the parasite strain, age of the host and stage of the disease. The ability of Trypanosoma cruzi to induce important and various host immune system dysfunctions makes the development of effective vaccines a laborious and complex task. These considerations strengthen the latent significance of Chagas' disease and encourage the search for new preventive procedures and the research on rational vaccines.

  5. Bestatin Induces Specific Changes in Trypanosoma cruzi Dipeptide Pool

    PubMed Central

    Creek, Darren J.; Faral-Tello, Paula; Barrett, Michael P.

    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. PMID:25712359

  6. Trypanosoma cruzi Infection in Neotropical Wild Carnivores (Mammalia: Carnivora): At the Top of the T. cruzi Transmission Chain

    PubMed Central

    Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; de Lima, Juliane Saab; Cheida, Carolina Carvalho; Lemos, Frederico Gemesio; de Azevedo, Fernanda Cavalcanti; Arrais, Ricardo Corassa; Bilac, Daniele; Herrera, Heitor Miraglia; Mourão, Guilherme; Jansen, Ana Maria

    2013-01-01

    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 can be

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

    PubMed

    Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; de Lima, Juliane Saab; Cheida, Carolina Carvalho; Lemos, Frederico Gemesio; de Azevedo, Fernanda Cavalcanti; Arrais, Ricardo Corassa; Bilac, Daniele; Herrera, Heitor Miraglia; Mourão, Guilherme; Jansen, Ana Maria

    2013-01-01

    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 can be

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

    PubMed

    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.

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

    PubMed

    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.

  10. Trypanosoma cruzi expresses diverse repetitive protein antigens.

    PubMed Central

    Hoft, D F; Kim, K S; Otsu, K; Moser, D R; Yost, W J; Blumin, J H; Donelson, J E; Kirchhoff, L V

    1989-01-01

    We screened a Trypanosoma cruzi cDNA expression library with human and rabbit anti-T. cruzi sera and identified cDNA clones that encode polypeptides containing tandemly arranged repeats which are 6 to 34 amino acids in length. The peptide repeats encoded by these cDNAs varied markedly in sequence, copy number, and location relative to the polyadenylation site of the mRNAs from which they were derived. The repeats were specific for T. cruzi, but in each case the sizes of the corresponding mRNAs and the total number of repeat copies encoded varied considerably among different isolates of the parasite. Expression of the peptide repeats was not stage specific. One of the peptide repeats occurred in a protein with an Mr of greater than 200,000 and one was in a protein of Mr 75,000 to 105,000. The frequent occurrence and diversity of these peptide repeats suggested that they may play a role in the ability of the parasite to evade immune destruction in its invertebrate and mammalian hosts, but the primary roles of these macromolecules may be unrelated to the host-parasite relationship. Images PMID:2659529

  11. Human Trypanosoma cruzi infection and seropositivity in dogs, Mexico.

    PubMed

    Estrada-Franco, Jose G; Bhatia, Vandanajay; Diaz-Albiter, Hector; Ochoa-Garcia, Laucel; Barbabosa, Alberto; Vazquez-Chagoyan, Juan C; Martinez-Perez, Miguel A; Guzman-Bracho, Carmen; Garg, Nisha

    2006-04-01

    We used 5 diagnostic tests in a cross-sectional investigation of the prevalence of Trypanosoma cruzi in Tejupilco municipality, State of Mexico, Mexico. Our findings showed a substantial prevalence of immunoglobulin G (IgG) and IgM antibodies to T. cruzi in human (n = 293, IgG 2.05%, IgM 5.5%, both 7.1%) and dog (n = 114, IgG 15.8%, IgM 11.4%, both 21%) populations. We also found antibodies to T. cruzi (n = 80, IgG 10%, IgM 15%, both 17.5%) in dogs from Toluca, an area previously considered free of T. cruzi. Our data demonstrate the need for active epidemiologic surveillance programs in these regions. A direct correlation (r2 = 0.955) of seropositivity between humans and dogs suggests that seroanalysis in dogs may help identify the human prevalence of T. cruzi infection in these areas.

  12. Human Trypanosoma cruzi Infection and Seropositivity in Dogs, Mexico

    PubMed Central

    Estrada-Franco, Jose G.; Bhatia, Vandanajay; Diaz-Albiter, Hector; Ochoa-Garcia, Laucel; Barbabosa, Alberto; Vazquez-Chagoyan, Juan C.; Martinez-Perez, Miguel A.; Guzman-Bracho, Carmen

    2006-01-01

    We used 5 diagnostic tests in a cross-sectional investigation of the prevalence of Trypanosoma cruzi in Tejupilco municipality, State of Mexico, Mexico. Our findings showed a substantial prevalence of immunoglobulin G (IgG) and IgM antibodies to T. cruzi in human (n = 293, IgG 2.05%, IgM 5.5%, both 7.1%) and dog (n = 114, IgG 15.8%, IgM 11.4%, both 21%) populations. We also found antibodies to T. cruzi (n = 80, IgG 10%, IgM 15%, both 17.5%) in dogs from Toluca, an area previously considered free of T. cruzi. Our data demonstrate the need for active epidemiologic surveillance programs in these regions. A direct correlation (r2 = 0.955) of seropositivity between humans and dogs suggests that seroanalysis in dogs may help identify the human prevalence of T. cruzi infection in these areas. PMID:16704811

  13. Trypanosoma cruzi and Chagas' Disease in the United States

    PubMed Central

    Bern, Caryn; Kjos, Sonia; Yabsley, Michael J.; Montgomery, Susan P.

    2011-01-01

    Summary: Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and causes potentially life-threatening disease of the heart and gastrointestinal tract. The southern half of the United States contains enzootic cycles of T. cruzi, involving 11 recognized triatomine vector species. The greatest vector diversity and density occur in the western United States, where woodrats are the most common reservoir; other rodents, raccoons, skunks, and coyotes are also infected with T. cruzi. In the eastern United States, the prevalence of T. cruzi is highest in raccoons, opossums, armadillos, and skunks. A total of 7 autochthonous vector-borne human infections have been reported in Texas, California, Tennessee, and Louisiana; many others are thought to go unrecognized. Nevertheless, most T. cruzi-infected individuals in the United States are immigrants from areas of endemicity in Latin America. Seven transfusion-associated and 6 organ donor-derived T. cruzi infections have been documented in the United States and Canada. As improved control of vector- and blood-borne T. cruzi transmission decreases the burden in countries where the disease is historically endemic and imported Chagas' disease is increasingly recognized outside Latin America, the United States can play an important role in addressing the altered epidemiology of Chagas' disease in the 21st century. PMID:21976603

  14. Interferon-Gamma Promotes Infection of Astrocytes by Trypanosoma cruzi

    PubMed Central

    Silva, Rafael Rodrigues; Mariante, Rafael M.; Silva, Andrea Alice; dos Santos, Ana Luiza Barbosa; Roffê, Ester; Santiago, Helton; Gazzinelli, Ricardo Tostes; Lannes-Vieira, Joseli

    2015-01-01

    The inflammatory cytokine interferon-gamma (IFNγ) is crucial for immunity against intracellular pathogens such as the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease (CD). IFNγ is a pleiotropic cytokine which regulates activation of immune and non-immune cells; however, the effect of IFNγ in the central nervous system (CNS) and astrocytes during CD is unknown. Here we show that parasite persists in the CNS of C3H/He mice chronically infected with the Colombian T. cruzi strain despite the increased expression of IFNγ mRNA. Furthermore, most of the T. cruzi-bearing cells were astrocytes located near IFNγ+ cells. Surprisingly, in vitro experiments revealed that pretreatment with IFNγ promoted the infection of astrocytes by T. cruzi increasing uptake and proliferation of intracellular forms, despite inducing increased production of nitric oxide (NO). Importantly, the effect of IFNγ on T. cruzi uptake and growth is completely blocked by the anti-tumor necrosis factor (TNF) antibody Infliximab and partially blocked by the inhibitor of nitric oxide synthesis L-NAME. These data support that IFNγ fuels astrocyte infection by T. cruzi and critically implicate IFNγ-stimulated T. cruzi-infected astrocytes as sources of TNF and NO, which may contribute to parasite persistence and CNS pathology in CD. PMID:25695249

  15. Virulence factors of Trypanosoma cruzi: who is who?

    PubMed

    Osorio, Luis; Ríos, Isabel; Gutiérrez, Bessy; González, Jorge

    2012-12-01

    The aim of this review is to gather the current knowledge of Trypanosoma cruzi's virulence factors described to date in an integrative way, relating these with the parasite's life cycle and trying to elucidate their importance in each process. Several aspects relevant for the parasite's survival, such as invasion, resistance to oxidative damage, escape from the phagolysosomal vacuole and differentiation, among others, will be discussed. However, there is still a lot to learn about what virulence really means in T. cruzi and which parasite molecules are absolutely required to make T. cruzi one of the most successful pathogens to invade, survive and persist in a mammalian host.

  16. Subcellular proteomics of Trypanosoma cruzi reservosomes

    PubMed Central

    Sant’Anna, Celso; Nakayasu, Ernesto S.; Pereira, Miria G.; Lourenço, Daniela; de Souza, Wanderley; Almeida, Igor C.; Cunha-e-Silva, Narcisa L.

    2009-01-01

    Reservosomes are the endpoint of the endocytic pathway in Trypanosoma cruzi epimastigotes. These organelles have the particular ability to concentrate proteins and lipids obtained from medium together with the main proteolytic enzymes originated from the secretory pathway, being at the same time a storage organelle and the main site of protein degradation. Subcellular proteomics have been extensively used for profiling organelles in different cell types. Here, we combine cell fractionation and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify reservosome-resident proteins. Starting from a purified reservosome fraction, we established a protocol to isolate reservosome membranes. Transmission electron microscopy was applied to confirm the purity of the fractions. To achieve a better coverage of identified proteins we analyzed the fractions separately and combined the results. LC-MS/MS analysis identified in total 709 T. cruzi-specific proteins; of these, 456 had predicted function and 253 were classified as hypothetical proteins. We could confirm the presence of most of the proteins validated by previous work and identify new proteins from different classes such as enzymes, proton pumps, transport proteins and others. The definition of the reservosome protein profile is a good tool to assess their molecular signature, identify molecular markers, and understand their relationship with different organelles. PMID:19288526

  17. Phosphatidylinositol kinase activities in Trypanosoma cruzi epimastigotes.

    PubMed

    Gimenez, Alba Marina; Gesumaría, María Celeste; Schoijet, Alejandra C; Alonso, Guillermo D; Flawiá, Mirtha M; Racagni, Graciela E; Machado, Estela E

    2015-01-01

    Phosphatidylinositol (PtdIns) metabolism through phosphatidylinositol kinase (PIKs) activities plays a central role in different signaling pathways. In Trypanosoma cruzi, causative agent of Chagas disease, PIKs have been proposed as target for drug design in order to combat this pathogen. In this work, we studied the classes of PI4K, PIPK and PI3K that could participate in signaling pathways in T. cruzi epimastigote forms. For this reason, we analyzed their enzymatic parameters and detailed responses to avowed kinase inhibitors (adenosine, sodium deoxycholate, wortmannin and LY294002) and activators (Ca(2+), phosphatidic acid, spermine and heparin). Our results suggest the presence and activity of a class III PI4K, a class I PIPK, a class III PI3K previously described (TcVps34) and a class I PI3K. Class I PI3K enzyme, here named TcPI3K, was cloned and expressed in a bacterial system, and their product was tested for kinase activity. The possible participation of TcPI3K in central cellular events of the parasite is also discussed.

  18. Immune Evasion Strategies of Trypanosoma cruzi

    PubMed Central

    Flávia Nardy, Ana; Freire-de-Lima, Célio Geraldo; Morrot, Alexandre

    2015-01-01

    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. PMID:26240832

  19. Interaction of Trypanosoma cruzi adenylate cyclase with liver regulatory factors.

    PubMed Central

    Eisenschlos, C; Flawiá, M M; Torruella, M; Torres, H N

    1986-01-01

    Trypanosoma cruzi adenylate cyclase catalytic subunits may interact with regulatory factors from rat liver membranes, reconstituting heterologous systems which are catalytically active in assay mixtures containing MgATP. The systems show stimulatory responses to glucagon and guanosine 5'-[beta gamma-imido]triphosphate (p[NH]ppG) or fluoride. Reconstitution was obtained by three different methods: fusion of rat liver membranes (pretreated with N-ethylmaleimide) to T. cruzi membranes; interaction of detergent extracts of rat liver membranes with T. cruzi membranes; or interaction of purified preparations of T. cruzi adenylate cyclase and of liver membrane factors in phospholipid vesicles. The liver factors responsible for the guanine nucleotide effect were characterized as the NS protein. Data also indicate that reconstitution requires the presence of a membrane substrate. PMID:2947568

  20. [Trypanosoma cruzi: transport of essential metabolites acquired from the host].

    PubMed

    Pereira, Claudio A; Carrillo, Carolina; Miranda, Mariana R; Bouvier, León A; Cánepa, Gaspar E

    2008-01-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, a disease endemic not only in Argentina but also in all of Latin America. 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 amino acid 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.

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

    PubMed

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

    PubMed Central

    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

  3. Sarcocystis cruzi infection in wood bison (Bison bison athabascae).

    PubMed

    Calero-Bernal, Rafael; Verma, Shiv K; Seaton, C Tom; Sinnett, David; Ball, Erin; Dunams, Detiger; Rosenthal, Benjamin M; Dubey, Jitender P

    2015-05-30

    Endangered wood bison (Bison bison athabascae) is the largest terrestrial mammal in the American continent. Animal health is an important issue in their conservation, and Sarcocystis cruzi may be a cause of clinical disease in Bovidae. Hearts of eight wood bison from Alaska, USA were examined for sarcocysts by histology, transmission electron microscopy, pepsin digestion, and molecularly. Sarcocystis bradyzoites were found in pepsin digests of all eight and sarcocysts were found in histologic sections of myocardium of four bison. Sarcocysts were thin-walled and ultrastructurally consistent with S. cruzi. Characterization of DNA obtained from lysis of pepsin liberated bradyzoites by PCR-RFLP and subsequent phylogenetic analyses matched with that previously reported for S. cruzi infecting cattle in the USA. Collectively, data indicate that wood bison is a natural intermediate host for S. cruzi.

  4. Trypanosoma cruzi meningoencephalitis in a patient with acquired immunodeficiency syndrome.

    PubMed

    Yasukawa, Kosuke; Patel, Shital M; Flash, Charlene A; Stager, Charles E; Goodman, Jerry C; Woc-Colburn, Laila

    2014-07-01

    As a result of global migration, a significant number of people with Trypanosoma cruzi infection now live in the United States, Canada, many countries in Europe, and other non-endemic countries. Trypanosoma cruzi meningoencephalitis is a rare cause of ring-enhancing lesions in patients with acquired immunodeficiency syndrome (AIDS) that can closely mimic central nervous system (CNS) toxoplasmosis. We report a case of CNS Chagas reactivation in an AIDS patient successfully treated with benznidazole and antiretroviral therapy in the United States.

  5. Inositolphosphoceramide Metabolism in Trypanosoma cruzi as Compared to other Trypanosomatids

    PubMed Central

    DE LEDERKREMER, ROSA M.; AGUSTI, ROSALÍA; DOCAMPO, ROBERTO

    2012-01-01

    Chagas disease is caused by Trypanosoma cruzi and is endemic to North, Central and South American countries. Current therapy against this disease is only partially effective and produces adverse side effects. Studies on the metabolic pathways of T. cruzi, in particular those with no equivalent in mammalian cells, might identify targets for the development of new drugs. Ceramide is metabolized to inositolphosphoceramide (IPC) in T. cruzi and other kinetoplastid protists whereas in mammals it is mainly incorporated into sphingomyelin. In T. cruzi, in contrast to Trypanosoma brucei and Leishmania spp., IPC functions as lipid anchor constituent of glycoproteins and free glycosylinositolphospholipids (GIPLs). Inhibition of IPC and GIPLs biosynthesis impairs differentiation of trypomastigotes into the intracellular amastigote forms. The gene encoding IPC synthase in T. cruzi has been identified and the enzyme has been expressed in a cell-free system. The enzyme involved in IPC degradation and the remodelases responsible for the incorporation of ceramide into free GIPLs or into the glycosylphosphatidyl inositols (GPIs) anchoring glycoproteins, and in fatty acid modifications of these molecules of T. cruzi have been understudied. IPC metabolism and remodeling could be exploited as targets for Chagas disease chemotherapy. PMID:21332877

  6. Seroprevalence of Trypanosoma cruzi in raccoons from Tennessee.

    PubMed

    Maloney, Jenny; Newsome, Anthony; Huang, Junjun; Kirby, Jordona; Kranz, Melissa; Wateska, Angela; Dunlap, Brett; Yabsley, Michael J; Dunn, John R; Jones, Timothy F; Moncayo, Abelardo C

    2010-04-01

    Trypanosoma cruzi is the etiologic agent of Chagas' disease. Autochthonous human and canine transmission of T. cruzi has been documented in Tennessee, but little is known about its ecology, including the prevalence of T. cruzi among wildlife in Tennessee. Serum samples from 706 raccoons (Procyon lotor) from 10 counties in the Ridge and Valley and Blue Ridge Mountains ecoregions of eastern Tennessee were tested for antibodies reactive with T. cruzi using the indirect fluorescent antibody assay. Two hundred six (29.2%) samples were seropositive, with 9 counties yielding positive samples (range 14.6-63.6%). Significantly more raccoons from rural habitats (35.1%) were found positive for T. cruzi exposure than were those from suburban habitats (23.1%, P < 0.001). Land cover class was not associated with seropositivity status (P = 0.441), even though deciduous forest was the most common site from where raccoons were trapped and the most common site of positive raccoons in rural areas (42%). Interestingly, age was positively associated with seropositivity. Raccoons older than 1 yr (adults) were 40.1% seropositive compared to 12.2% of those less than 1 yr (juveniles; P < 0.001). Female adults were significantly more likely to be exposed to T. cruzi than were male adult raccoons (P < 0.001). No significant seroprevalence difference was seen among male and female juveniles. This study contributes to understanding the dynamics of T. cruzi exposure within raccoon populations in Tennessee. The importance of habitat (rural vs. suburban) and microhabitat (dens) in risk of exposure to these populations is also discussed.

  7. Transcriptional and phenotypical heterogeneity of Trypanosoma cruzi cell populations

    PubMed Central

    Seco-Hidalgo, Víctor; De Pablos, Luis Miguel; Osuna, Antonio

    2015-01-01

    Trypanosoma cruzi has a complex life cycle comprising pools of cell populations which circulate among humans, vectors, sylvatic reservoirs and domestic animals. Recent experimental evidence has demonstrated the importance of clonal variations for parasite population dynamics, survival and evolution. By limiting dilution assays, we have isolated seven isogenic clonal cell lines derived from the Pan4 strain of T. cruzi. Applying different molecular techniques, we have been able to provide a comprehensive characterization of the expression heterogeneity in the mucin-associated surface protein (MASP) gene family, where all the clonal isogenic populations were transcriptionally different. Hierarchical cluster analysis and sequence comparison among different MASP cDNA libraries showed that, despite the great variability in MASP expression, some members of the transcriptome (including MASP pseudogenes) are conserved, not only in the life-cycle stages but also among different strains of T. cruzi. Finally, other important aspects for the parasite, such as growth, spontaneous metacyclogenesis or excretion of different catabolites, were also compared among the clones, demonstrating that T. cruzi populations of cells are also phenotypically heterogeneous. Although the evolutionary strategy that sustains the MASP expression polymorphism remains unknown, we suggest that MASP clonal variability and phenotypic heterogeneities found in this study might provide an advantage, allowing a rapid response to environmental pressure or changes during the life cycle of T. cruzi. PMID:26674416

  8. Trypanosoma cruzi: modification of macrophage function during infection

    PubMed Central

    1977-01-01

    Infection of mice with Trypanosoma cruzi and subsequent intraperitoneal challenge with heat-killed trypanosomes elicits peritoneal macrophages which display in vitro microbicidal activity against trypomastigotes of T. cruzi. These cells also display other activated properties including rapid spreading, intense membrane activity, secretion of high levels of plasminogen activator, and ingestion mediated by the C3 receptor. An intravenous infection with BCG, followed by an intraperitoneal challenge with mycobacterial antigens brings about macrophages with similar properties. These criteria of macrophage activation were compared in normal and BCG- or T. cruzi-immune mice, with or without an intraperitoneal challenge with specific or unrelated antigens. Trypanocidal activity is displayed by both BCG- and T. cruzi-immune macrophages after intraperitoneal challenge with either antigen. Resident-immune macrophages from both T. cruzi- and BCG-infected mice show a trypanostatic, rather than trypanocidal activity. Macrophages from noninfected mice, challenged with the same antigens, show neither trypanostatic nor trypanocidal activity. Increased secretion of plasminogen activator shows a definite immunological specificity. Challenge with the specific antigen induces the appearance of macrophages secreting high levels of plasminogen activator, while unrelated antigens induce much smaller levels. Noninfected mice challenged with the same antigens do not display any enchancement in secretion. In contrast, increased spreading and phagocytosis mediated by the complement receptor are also displayed by cells from noninfected mice challenged with any of the agents tested. PMID:327012

  9. Editing the Trypanosoma cruzi genome with zinc finger nucleases.

    PubMed

    Burle-Caldas, Gabriela Assis; Grazielle-Silva, Viviane; Soares-Simões, Melissa; Schumann Burkard, Gabriela; Roditi, Isabel; DaRocha, Wanderson Duarte; Teixeira, Santuza M

    2017-03-01

    Gene function studies in Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, have been hindered by the lack of efficient genetic manipulation protocols. In most organisms, insertion and deletion of DNA fragments in the genome are dependent on the generation of double-stranded DNA break (DSB) and repair. By inducing a site-specific DSB, zinc finger nucleases (ZFNs) have proven to be useful to enhance gene editing in many cell types. Using a pair of ZFNs targeted to the T. cruzi gp72 gene, we were able to generate gp72 knockout parasites with improved efficiency compared to the conventional gene knockout protocol. We also provide evidence that, in T. cruzi, repair of DSBs generated by ZFNs occurs primarily by the homologous recombination pathway.

  10. [Congenital transmission of Trypanosoma cruzi infection in Argentina].

    PubMed

    Sosa-Estani, Sergio

    2005-01-01

    Congenital transmission of Trypanosoma cruzi infection in Argentina has being increasing its relative importance with control of vectorial and transfusional transmission growth. It is for this reason that vertical transmission is seen, in the future, as a continuous source of infected newborns, even with vectorial and transfusional transmission completely controlled. Preventing vertical transmission of T.cruzi is not possible, but it can be precociously detected, permitting mother and child to be incorporated into the medical attention system, and so allowing the newbornś treatment with practically 100% efficacy. It is estimated that between 800 and 1700 children infected with T. cruzi by congenital transmission are born in Argentina, per year. The implementation of an early strategy of detection for an effective and opportune treatment acquires great relevance as a Public Health measure.

  11. Aspirin treatment exacerbates oral infections by Trypanosoma cruzi.

    PubMed

    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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:26975994

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

    PubMed

    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.

  14. Potent Anti-Trypanosoma cruzi Activities of Oxidosqualene Cyclase Inhibitors

    PubMed Central

    Buckner, Frederick S.; Griffin, John H.; Wilson, Aaron J.; Van Voorhis, Wesley C.

    2001-01-01

    Trypanosoma cruzi is the protozoan agent that causes Chagas' disease, a major health problem in Latin America. Better drugs are needed to treat infected individuals. The sterol biosynthesis pathway is a potentially excellent target for drug therapy against T. cruzi. In this study, we investigated the antitrypanosomal activities of a series of compounds designed to inhibit a key enzyme in sterol biosynthesis, oxidosqualene cyclase. This enzyme converts 2,3-oxidosqualene to the tetracyclic product, lanosterol. The lead compound, N-(4E,8E)-5,9, 13-trimethyl-4,8, 12-tetradecatrien-1-ylpyridinium, is an electron-poor aromatic mimic of a monocyclized transition state or high-energy intermediate formed from oxidosqualene. This compound and 27 related compounds were tested against mammalian-stage T. cruzi, and 12 inhibited growth by 50% at concentrations below 25 nM. The lead compound was shown to cause an accumulation of oxidosqualene and decreased production of lanosterol and ergosterol, consistent with specific inhibition of the oxidosqualene cyclase. The data demonstrate potent anti-T. cruzi activity associated with inhibition of oxidosqualene cyclase. PMID:11257036

  15. Distinct phosphatase activity profiles in two strains of Trypanosoma cruzi.

    PubMed

    Morales-Neto, R; Hulshof, L; Ferreira, C V; Gadelha, F R

    2009-12-01

    Phosphorylation of parasite proteins plays a key role in the process of cell invasion by Trypanosoma cruzi, the etiologic agent of Chagas' disease. In this sense, characterization of parasite kinases and phosphatases could open new possibilities for the rational design of chemotherapeutic agents for the treatment of Chagas' disease. In this work, we analyzed phosphatase activities in T. cruzi homogenates from 2 strains belonging to different lineages and with different resistance to oxidative stress. Tulahuen 2 cells (Lineage I) showed higher phosphatase activities and specificity constants when compared to the Y strain (Lineage II). Tulahuen 2 had an optimum phosphatase activity at pH 4.0 and the Y strain at pH 7.0. In both cases, neutral–basic, but not acid, phosphatase activities were increased in the presence of Mg2+. Although calcium had an inhibitory effect at a pH of 7.0 and 8.0 in the Y strain, this inhibition was restricted to pH 8.0 in the other strain. Different substrates and acid phosphotyrosine and alkaline phosphatase inhibitors exhibited distinct effects on the phosphatase activity of both strains. Our results provide a better understanding of T. cruzi phosphatases and reinforce the notion of heterogeneity among T. cruzi populations.

  16. Autochthonous Transmission of Trypanosoma Cruzi in Southern California

    PubMed Central

    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

  17. Comparative studies confirm natural infections of buffaloes by Sarcocystis cruzi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Controversy exists concerning whether cattle and water buffalo sustain infections with cysts distinct arrays species in the genus Sarcocystis. In particular, morphologically similar parasites have been alternately ascribed to S. cruzi or to S. levinei, depending on their occurrence in cattle and wa...

  18. Nitric oxide-releasing polymeric nanoparticles against Trypanosoma cruzi

    NASA Astrophysics Data System (ADS)

    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

  19. Prevention of transfusional Trypanosoma cruzi infection in Latin America.

    PubMed

    Schmunis, G A

    1999-01-01

    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 300 individuals in

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

    PubMed

    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. The potential of canine sentinels for reemerging Trypanosoma cruzi transmission

    PubMed Central

    Neyra, Ricardo Castillo; Chu, Lily Chou; Quispe-Machaca, Victor; Ancca-Juarez, Jenny; Malaga Chavez, Fernando S.; Mazuelos, Milagros Bastos; Naquira, Cesar; Bern, Caryn; Gilman, Robert H.; Levy, Michael Z.

    2015-01-01

    Background Chagas disease, a vector-borne disease transmitted by triatomine bugs and caused by the parasite Trypanosoma cruzi, affects millions of people in the Americas. In Arequipa, Peru, indoor residual insecticide spraying campaigns are routinely conducted to eliminate Triatoma infestans, the only vector in this area. Following insecticide spraying, there is risk of vector return and reinitiation of parasite transmission. Dogs are important reservoirs of T. cruzi and may play a role in reinitiating transmission in previously sprayed areas. Dogs may also serve as indicators of reemerging transmission. Methods We conducted a cross-sectional serological screening to detect T. cruzi antibodies in dogs, in conjunction with an entomological vector collection survey at the household level, in a disease endemic area that had been treated with insecticide 13 years prior. Spatial clustering of infected animals and vectors was assessed using Ripley’s K statistic, and the odds of being seropositive for dogs proximate to infected colonies was estimated with multivariate logistic regression. Results There were 106 triatomine-infested houses (41.1%), and 45 houses infested with T. cruzi-infected triatomine insects (17.4%). Canine seroprevalence in the area was 12.3% (n=154); all seropositive dogs were 9 months old or older. We observed clustering of vectors carrying the parasite, but no clustering of seropositive dogs. The age- and sex-adjusted odds ratio between seropositivity to T. cruzi and proximity to an infected triatomine (≤50m) was 5.67 (95% CI: 1.12 – 28.74; p=0.036). Conclusions Targeted control of reemerging transmission can be achieved by improved understanding of T. cruzi in canine populations. Our results suggest that dogs may be useful sentinels to detect re-initiation of transmission following insecticide treatment. Integration of canine T. cruzi blood sampling into existing interventions for zoonotic disease control (e.g. rabies vaccination programs

  2. Differentiation of Trypanosoma cruzi I (TcI) and T. cruzi II (TcII) genotypes using genes encoding serine carboxypeptidases.

    PubMed

    de Araújo, Catarina Andréa Chaves; Mayer, Christoph; Waniek, Peter Josef; Azambuja, Patricia; Jansen, Ana Maria

    2016-11-01

    The parasite Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) can be classified based on biochemical and molecular markers, into six lineages or discrete typing units (DTUs), T. cruzi I-VI (TcI-VI), from which TcI and TcII are the parental genotypes. Trying to understand the dispersion of the subpopulations of T. cruzi in nature and its complex transmission cycles, the serine carboxypeptidase genes of T. cruzi were used as a molecular marker in the present study. DTUs of 25 T. cruzi isolates derived from different hosts and from different regions of Brazil were classified. Using specific primers, the complete serine carboxypeptidase open reading frame of 1401 bp was sequenced. The obtained data shows significant differences in the sequences of TcI and TcII. The analysis of the T. cruzi significantly different serine carboxypeptidase genes allowed distinguishing between the parental DTUs TcI to TcII and the hybrid DTU TcVI which grouped within the latter branch. The sequence diversity within the T. cruzi subpopulations was rather low. The analysis using the genes encoding proteases seems to be an interesting approach for the reconstruction of the origin and genotype evolution of T. cruzi.

  3. Induction of Resistance to Azole Drugs in Trypanosoma cruzi

    PubMed Central

    Buckner, Frederick S.; Wilson, Aaron J.; White, Theodore C.; Van Voorhis, Wesley C.

    1998-01-01

    Trypanosoma cruzi is the protozoan parasite that causes Chagas’ disease, a frequently fatal illness affecting the heart and gastrointestinal systems. An estimated 16 million to 18 million people in Latin America and 50,000 to 100,000 people in the United States are infected with this pathogen. Treatment options for T. cruzi infections are suboptimal due to the toxicities and limited effectiveness of the available drugs. Azole antimicrobial agents have been discovered to have antitrypanosomal activity by inhibition of ergosterol synthesis. The triazole itraconazole was recently shown to produce a parasitologic cure rate of 53% in chronically infected patients (W. Apt et al., Am. J. Trop. Med. Hyg. 59:133–138, 1998), a result which may lead to more use of this family of drugs for the treatment of T. cruzi infections. In the experiments reported on here, resistance to azoles was induced in vitro by serial passage of mammalian-stage parasites in the presence of fluconazole for 4 months. These parasites were cross resistant to the other azoles, ketoconazole, miconazole, and itraconazole. They remained susceptible to benznidazole and amphotericin B. The azole-resistant phenotype was stable for more than 2 months of in vitro serial passage without fluconazole. In addition, the parasites resisted treatment in mice receiving ketoconazole. The rapid development of azole resistance in T. cruzi in vitro suggests that resistance to azole drugs has the potential to occur in patients and may pose an impediment to the progress being made in the treatment of T. cruzi infection. PMID:9835521

  4. Role of iron in Trypanosoma cruzi infection of mice.

    PubMed Central

    Lalonde, R G; Holbein, B E

    1984-01-01

    The role of iron in experimental infection of mice with Trypanosoma cruzi was investigated. B6 mice had a transient parasitemia and a transient anemia, both of maximal intensity 28 d after the inoculation of T. cruzi. There was a biphasic hypoferremic host response to infection with T. cruzi with the peak hypoferremia also occurring 28 d after inoculation of the parasite. The mortality rate from infection was increased from 23% in phosphate-buffered saline-treated B6 mice to 50% in a group of B6 mice receiving iron-dextran (P less than or equal to 0.025), whereas depletion of iron stores with the iron chelator desferrioxamine B and an iron-deficient diet provided complete protection of B6 mice (P less than or equal to 0.05). The mortality rate in the highly susceptible C3H strain was reduced from 100% in the control group to 45% (P less than or equal to 0.025) in the iron-depleted group. The tissue iron stores were altered in mice receiving either iron-dextran or desferrioxamine B and an iron-deficient diet. In vitro, T. cruzi was shown to require both a heme and a nonheme iron source for an optimal growth rate. The effects of iron excess or depletion on the outcome of infection with T. cruzi correlated both with the growth requirements of the parasite for iron and with the availability of intracellular iron. Thus, it was suggested that the hypoferremic response, by sequestering iron within intracellular stores, potentially enhanced the pathogenicity of the intracellular parasites. Furthermore, the in vivo effects of iron excess and depletion correlated with an effect of iron on the growth rate and pathogenicity of the parasite. PMID:6421877

  5. Targeted Screening Strategies to Detect Trypanosoma cruzi Infection in Children

    PubMed Central

    Levy, Michael Z.; Kawai, Vivian; Bowman, Natalie M.; Waller, Lance A.; Cabrera, Lilia; Pinedo-Cancino, Viviana V.; Seitz, Amy E.; Steurer, Frank J.; Cornejo del Carpio, Juan G.; Cordova-Benzaquen, Eleazar; Maguire, James H.; Gilman, Robert H.; Bern, Caryn

    2007-01-01

    Background Millions of people are infected with Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Anti-trypanosomal drug therapy can cure infected individuals, but treatment efficacy is highest early in infection. Vector control campaigns disrupt transmission of T. cruzi, but without timely diagnosis, children infected prior to vector control often miss the window of opportunity for effective chemotherapy. Methods and Findings We performed a serological survey in children 2–18 years old living in a peri-urban community of Arequipa, Peru, and linked the results to entomologic, spatial and census data gathered during a vector control campaign. 23 of 433 (5.3% [95% CI 3.4–7.9]) children were confirmed seropositive for T. cruzi infection by two methods. Spatial analysis revealed that households with infected children were very tightly clustered within looser clusters of households with parasite-infected vectors. Bayesian hierarchical mixed models, which controlled for clustering of infection, showed that a child's risk of being seropositive increased by 20% per year of age and 4% per vector captured within the child's house. Receiver operator characteristic (ROC) plots of best-fit models suggest that more than 83% of infected children could be identified while testing only 22% of eligible children. Conclusions We found evidence of spatially-focal vector-borne T. cruzi transmission in peri-urban Arequipa. Ongoing vector control campaigns, in addition to preventing further parasite transmission, facilitate the collection of data essential to identifying children at high risk of T. cruzi infection. Targeted screening strategies could make integration of diagnosis and treatment of children into Chagas disease control programs feasible in lower-resource settings. PMID:18160979

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

    PubMed

    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.

  7. The characterization of anti-T. cruzi activity relationships between ferrocenyl, cyrhetrenyl complexes and ROS release.

    PubMed

    Echeverría, César; Romero, Valentina; Arancibia, Rodrigo; Klahn, Hugo; Montorfano, Ignacio; Armisen, Ricardo; Borgna, Vincenzo; Simon, Felipe; Ramirez-Tagle, Rodrigo

    2016-08-01

    Trypanosoma cruzi (T. cruzi) is the parasite that causes Chagas disease. Nifurtimox is the most used drug against the T. cruzi, this drug increases intermediaries nitro group, being mainly responsible for the high toxicity component, for this reason it is important to study new organic compounds and thus improve therapeutic strategies against Chagas disease. The electronic effects of ferrocenyl and cyrhetrenyl fragments were investigated by DFT calculation. A close correlation was found between HOMO-LUMO gap of nitro radical NO 2 (-) with the experimental reduction potential found for nitro group and IC50 of two forms the T. cruzi (epimastigote and trypomastigote). The IC50 on human hepatoma cells is higher for both compounds compared to IC50 demonstrated in the two forms the T. cruzi, and additionally show reactive oxygen species release. The information obtained in this paper could generate two new drugs with anti-T. cruzi activity, but additional studies are needed.

  8. Trypanosoma cruzi: variability of stocks from Colombia determined by molecular karyotype and minicircle Southern blot analysis.

    PubMed

    Triana, Omar; Ortiz, Sylvia; Dujardin, Jean-Claude; Solari, Aldo

    2006-05-01

    Nineteen Trypanosoma cruzi stocks, most of them of wild origin, and four Trypanosoma rangeli stocks from Colombia were analysed by molecular karyotype analysis with cloned DNA cruzipain as the probe. Another 27 cloned stocks of T. cruzi from different geographic areas of South America were used as reference for T. cruzi lineages. Phenetic analysis of chromosome size polymorphism demonstrated a great variability of Colombian T. cruzi stocks, suggesting that most belong to lineage I, although two of them belong to lineage II. The 2 lineage II T. cruzi, 17 T. cruzi lineage I, and 3 T. rangeli stocks from Colombia were studied further by Southern blot analysis with a panel of kinetoplast DNA minicircle probes. Hybridisation results indicate that the two T. cruzi II stocks are genetically distant from each other and from T. cruzi lineages IIb, IId, and IIe from Chile. Finally, T. cruzi minicircle probes do not cross-hybridise in any stringency condition tested with T. rangeli minicircles, a clear indication that these parasites can be easily distinguished by this method.

  9. Recent, independent and anthropogenic origins of Trypanosoma cruzi hybrids.

    PubMed

    Lewis, Michael D; Llewellyn, Martin S; Yeo, Matthew; Acosta, Nidia; Gaunt, Michael W; Miles, Michael A

    2011-10-01

    The single celled eukaryote Trypanosoma cruzi, a parasite transmitted by numerous species of triatomine bug in the Americas, causes Chagas disease in humans. T. cruzi generally reproduces asexually and appears to have a clonal population structure. However, two of the six major circulating genetic lineages, TcV and TcVI, are TcII-TcIII inter-lineage hybrids that are frequently isolated from humans in regions where chronic Chagas disease is particularly severe. Nevertheless, a prevalent view is that hybridisation events in T. cruzi were evolutionarily ancient and that active recombination is of little epidemiological importance. We analysed genotypes of hybrid and non-hybrid T. cruzi strains for markers representing three distinct evolutionary rates: nuclear GPI sequences (n = 88), mitochondrial COII-ND1 sequences (n = 107) and 28 polymorphic microsatellite loci (n = 35). Using Maximum Likelihood and Bayesian phylogenetic approaches we dated key evolutionary events in the T. cruzi clade including the emergence of hybrid lineages TcV and TcVI, which we estimated to have occurred within the last 60,000 years. We also found evidence for recent genetic exchange between TcIII and TcIV and between TcI and TcIV. These findings show that evolution of novel recombinants remains a potential epidemiological risk. The clearly distinguishable microsatellite genotypes of TcV and TcVI were highly heterozygous and displayed minimal intra-lineage diversity indicative of even earlier origins than sequence-based estimates. Natural hybrid genotypes resembled typical meiotic F1 progeny, however, evidence for mitochondrial introgression, absence of haploid forms and previous experimental crosses indicate that sexual reproduction in T. cruzi may involve alternatives to canonical meiosis. Overall, the data support two independent hybridisation events between TcII and TcIII and a recent, rapid spread of the hybrid progeny in domestic transmission cycles concomitant with, or as a

  10. Electron Microscopy Analysis of the Nucleolus of Trypanosoma cruzi

    NASA Astrophysics Data System (ADS)

    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.

  11. Trypanosoma cruzi in Persons without Serologic Evidence of Disease, Argentina

    PubMed Central

    Basquiera, Ana L.; Sembaj, Adela; Aguerri, Ana M.; Reyes, María E.; Omelianuk, Mirtha; Fernández, Ruth A.; Enders, Julio; Palma, Atilio; Barral, José Moreno; Madoery, Roberto J.

    2003-01-01

    Current diagnosis of chronic Chagas disease relies on serologic detection of specific immunoglobulin G against Trypanosoma cruzi. However, the presence of parasites detected by polymerase chain reaction (PCR) in patients without positive conventional serologic testing has been observed. We determined the prevalence and clinical characteristics of persons with seronegative results for T. cruzi DNA detected by PCR in a population at high risk for chronic American trypanosomiasis. We studied a total of 194 persons from two different populations: 110 patients were recruited from an urban cardiology clinic, and 84 persons were nonselected citizens from a highly disease-endemic area. Eighty (41%) of persons had negative serologic findings; 12 (15%) had a positive PCR. Three patients with negative serologic findings and positive PCR results had clinical signs and symptoms that suggested Chagas cardiomyopathy. This finding challenges the current recommendations for Chagas disease diagnosis, therapy, and blood transfusion policies. PMID:14720396

  12. Trypanosoma cruzi: susceptibility in mice carrying mutant gene lpr (lymphoproliferation).

    PubMed

    Boyer, M H; Hoff, R; Kipnis, T L; Murphy, E D; Roths, J B

    1983-03-01

    There is evidence that autoimmune aberrations may contribute to the immunopathological consequences of Chagas' disease and because of this we sought to determine whether four inbred strains of mice bearing the single autosomal recessive gene, lpr (lymphoproliferation), which controls certain autoimmune manifestations, are particularly susceptible to acute infection with the Y strain of Trypanosoma cruzi. MRL/MpJ-lpr/lpr, C57Bl/6J-lpr/lpr, AKR/J-lpr/lpr, C3H/HeJ-lpr/lpr showed parasitaemias 2-10 times higher when compared to their congenic partners. Mortality was significantly higher in three of the four lpr strains. The results indicate that a single autosomal recessive gene which is associated with autoimmunity can influence susceptibility to acute T. cruzi infection in mice.

  13. The inositol phosphate/diacylglycerol signalling pathway in Trypanosoma cruzi.

    PubMed Central

    Docampo, R; Pignataro, O P

    1991-01-01

    Using [32P]Pi and [3H]inositol as precursors, we have detected the presence of phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, and their derivatives inositol phosphate, inositol 1,4-bisphosphate and inositol 1,4,5-trisphosphate respectively, in Trypanosoma cruzi epimastigotes. Using digitonin-permeabilized cells it was possible to detect a stimulation in the formation of inositol 1,4,5-trisphosphate and inositol 1,4-bisphosphate as well as an increased generation of diacylglycerol in the presence of 1 mM-CaCl2. These results are consistent with the operation of a functional inositol phosphate/diacylglycerol pathway in T. cruzi, and constitute the first demonstration of the presence and activation of this pathway in a parasitic protozoan. These results also indicate that this pathway is conserved during evolution from lower to higher eukaryotic organisms. Images Fig. 1. PMID:2025225

  14. Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

    PubMed Central

    Silva-Neto, Mário A. C.; Carneiro, Alan B.; Silva-Cardoso, Livia; Atella, Georgia C.

    2012-01-01

    Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease. PMID:22132309

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

    PubMed

    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.

  16. Repertoire, Genealogy and Genomic Organization of Cruzipain and Homologous Genes in Trypanosoma cruzi, T. cruzi-Like and Other Trypanosome Species

    PubMed Central

    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

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

    PubMed

    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

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

    PubMed

    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.

  19. The detection of phosphonolipids in the protozoan Trypanosoma cruzi

    PubMed Central

    Ferguson, Michael A. J.; Allen, Anthony K.; Snary, David

    1982-01-01

    2-Aminoethylphosphonate was detected in the acid hydrolysates of the phosphonolipids and the lipopeptidophosphoglycan of Trypanosoma cruzi, the causative agent of Chagas' disease. This finding represents the first evidence of phosphonolipids in a zooflagellate. By comparison, no phosphonolipids were detected in Trypanosama brucei, indicating that phosphonolipids are not a ubiquitous feature of the Order Kinetoplastidia. ImagesFig. 1.Fig. 2.Fig. 3. PMID:6758765

  20. Characterisation of the fumarate hydratase repertoire in Trypanosoma cruzi.

    PubMed

    de Pádua, Ricardo A P; Kia, Ali Martin; Filho, Antonio José Costa; Wilkinson, Shane R; Nonato, M Cristina

    2017-03-27

    Nifurtimox and benznidazole represent the only treatments options available targeting Chagas disease, the most important parasitic infection in the Americas. However, use of these is problematic as they are toxic and ineffective against the more severe stages of the disease. In this work, we used a multidisciplinary approach to characterise the fumarases from Trypanosoma cruzi, the causative agent of Chagas Disease. We showed this trypanosome expresses cytosolic and mitochondrial fumarases that via an iron-sulfur cluster mediate the reversible conversion of fumarate to S-malate. Based on sequence, biochemical properties and co-factor binding, both T. cruzi proteins share characteristics with class I fumarases, enzymes found in bacteria and some other protozoa but absent from humans, that possess class II isoforms instead. Gene disruption suggested that although the cytosolic or mitochondrial fumarase activities are individually dispensable their combined activity is essential for parasite viability. Finally, based on the mechanistic differences with the human (host) fumarase, we designed and validated a selective inhibitor targeting the parasite enzyme. This study showed that T. cruzi fumarases should be exploited as targets for the development of new chemotherapeutic interventions against Chagas disease.

  1. Imidazolium compounds are active against all stages of Trypanosoma cruzi.

    PubMed

    Faral-Tello, Paula; Liang, Mary; Mahler, Graciela; Wipf, Peter; Robello, Carlos

    2014-03-01

    Imidazolium salts are best known for their applications in organic synthesis as room-temperature ionic liquids, or as precursors of stable carbenes, but they also show important biological properties such as anti-oxidative effects, induction of mitochondrial membrane permeabilisation and inhibition of the infection cycle of Plasmodium falciparum. For these reasons, and since chemotherapy for Chagas disease is inefficient, the aim of this study was to test the use of imidazolium compounds against the kinetoplastid haemoflagellate aetiological agent for this disease, namely Trypanosoma cruzi. The results show that five of the tested compounds are more effective than the reference drug benznidazole against the epimastigote and trypomastigote forms of T. cruzi. Moreover, intracellular amastigotes were also affected by the compounds, which showed lower toxicity in host cells. Transmission electron microscopy analysis demonstrated that the tested agents induced alterations of the kinetoplast and particularly of the mitochondria, leading to extraordinary swelling of the organelle. These results further demonstrate that the test agents with the best profile are those bearing symmetrical bulky substituents at N(1) and N(3), displaying promising activity against all forms of T. cruzi, interesting selectivity indexes and exceptional activity at low doses. Accordingly, these agents represent promising candidates for the treatment of Chagas disease.

  2. Characterization of a RAB5 homologue in Trypanosoma cruzi.

    PubMed

    Araripe, Júlia Rolão; Ramos, Fabiane Pereira; Cunha e Silva, Narcisa Leal; Urményi, Turán Péter; Silva, Rosane; Leite Fontes, Carlos Frederico; da Silveira, José Franco; Rondinelli, Edson

    2005-04-08

    RAB proteins are small GTPases involved in exocytic and endocytic pathways of eukaryotic cells, controlling vesicle docking and fusion. RABs show a remarkable specificity in subcellular localization, so they can be used as molecular markers for studying protein trafficking in Trypanosoma cruzi, the causal agent of Chagas' disease. RAB5 is a component of early endosomes. It has been identified in kinetoplastids such as Trypanosoma brucei and Leishmania donovani. In this work, we describe the characterization of the complete coding sequence of a RAB5 gene homologue in T. cruzi (TcRAB5, GenBank Accession No. AY730667). It is present as a single copy gene, located at chromosomal bands XIII and XIV. TcRAB5 shares the highest degrees of similarity (71%) and identity (63%) with Trypanosoma brucei rhodesiense RAB5a and contains all five characteristic RAB motifs. TcRAB5 is transcribed as a single 1.5kb mRNA in epimastigotes. Its transcript was also detected in the other two forms of the parasite, metacyclic trypomastigotes and spheromastigotes. The recombinant TcRAB5 protein was able to bind and hydrolyze GTP. The identification of proteins involved in T. cruzi endo- and exocytic pathways may generate cellular compartment markers, an invaluable tool to better understand the vesicular transport in this parasite.

  3. Geographical distribution of Trypanosoma cruzi genotypes in Venezuela.

    PubMed

    Carrasco, Hernán J; Segovia, Maikell; Llewellyn, Martin S; Morocoima, Antonio; Urdaneta-Morales, Servio; Martínez, Cinda; Martínez, Clara E; Garcia, Carlos; Rodríguez, Marlenes; Espinosa, Raul; de Noya, Belkisyolé A; Díaz-Bello, Zoraida; Herrera, Leidi; Fitzpatrick, Sinead; Yeo, Matthew; Miles, Michael A; Feliciangeli, M Dora

    2012-01-01

    Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI - TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela.

  4. Molecular mechanisms of Trypanosoma cruzi infection by oral route.

    PubMed

    Yoshida, Nobuko

    2009-07-01

    Frequent reports on outbreaks of acute Chagas' disease by ingestion of food contaminated with parasites from triatomine insects illustrate the importance of this mode of transmission. Studies on oral Trypanosoma cruzi infection in mice have indicated that metacyclic trypomastigotes invade the gastric mucosal epithelium. A key molecule in this process is gp82, a stage-specific surface glycoprotein that binds to both gastric mucin and to target epithelial cells. By triggering Ca2+ signalling, gp82 promotes parasite internalisation. Gp82 is relatively resistant to peptic digestion at acidic pH, thus preserving the properties critical for oral infection. The infection process is also influenced by gp90, a metacyclic stage-specific molecule that negatively regulates the invasion process. T. cruzi strains expressing high gp90 levels invade cells poorly in vitro. However, their infectivity by oral route varies considerably due to varying susceptibilities of different gp90 isoforms to peptic digestion. Parasites expressing pepsin-susceptible gp90 become highly invasive against target cells upon contact with gastric juice. Such is the case of a T. cruzi isolate from an acute case of orally acquired Chagas' disease; the gp90 from this strain is extensively degraded upon short period of parasite permanence in the gastric milieu. If such an exacerbation of infectivity occurs in humans, it may be responsible for the severity of Chagas' disease reported in outbreaks of oral infection.

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

    PubMed

    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.

  6. Antimicrobial activity of synthetic bornyl benzoates against Trypanosoma cruzi

    PubMed Central

    Corrêa, P R C; Miranda, R R S; Duarte, L P; Silva, G D F; Filho, S A Vieira; Okuma, A A; Carazza, F; Morgado-Díaz, J A; Pinge-Filho, P; Yamauchi, L M; Nakamura, C V; Yamada-Ogatta, S F

    2012-01-01

    We report here for the first time the in vitro effects of (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2.2.1]heptan-2-yl-3′,4′,5′-trimethoxy benzoate (1) and (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2.2.1]heptan-2-yl benzoate (2) on the growth and ultrastructure of Trypanosoma cruzi. These two synthetic compounds exerted an antiproliferative effect on the epimastigote forms of the parasite. The ICs50/72h of two synthetic L-bornyl benzoates, 1 and 2, was 10.1 and 12.8 μg/ml, respectively. Both compounds were more selective against epimastigotes than HEp-2 cells. Ultrastructural analysis revealed intense cytoplasmic vacuolization and the appearance of cytoplasmic materials surrounded by membranes. The treatment of peritoneal macrophages with compounds 1 and 2 caused a significant decrease in the number of T. cruzi-infected cells. L-Bornyl benzoate derivatives may serve as a potential source for the development of more effective and safer chemotherapeutic agents against T. cruzi infections. PMID:22943546

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27502971

  10. Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

    PubMed Central

    Carrasco, Hernán J.; Segovia, Maikell; Llewellyn, Martin S.; Morocoima, Antonio; Urdaneta-Morales, Servio; Martínez, Cinda; Martínez, Clara E.; Garcia, Carlos; Rodríguez, Marlenes; Espinosa, Raul; de Noya, Belkisyolé A.; Díaz-Bello, Zoraida; Herrera, Leidi; Fitzpatrick, Sinead; Yeo, Matthew; Miles, Michael A.; Feliciangeli, M. Dora

    2012-01-01

    Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela. PMID:22745843

  11. Gene Discovery through Expressed Sequence Tag Sequencing in Trypanosoma cruzi

    PubMed Central

    Verdun, Ramiro E.; Di Paolo, Nelson; Urmenyi, Turan P.; Rondinelli, Edson; Frasch, Alberto C. C.; Sanchez, Daniel O.

    1998-01-01

    Analysis of expressed sequence tags (ESTs) constitutes a useful approach for gene identification that, in the case of human pathogens, might result in the identification of new targets for chemotherapy and vaccine development. As part of the Trypanosoma cruzi genome project, we have partially sequenced the 5′ ends of 1,949 clones to generate ESTs. The clones were randomly selected from a normalized CL Brener epimastigote cDNA library. A total of 14.6% of the clones were homologous to previously identified T. cruzi genes, while 18.4% had significant matches to genes from other organisms in the database. A total of 67% of the ESTs had no matches in the database, and thus, some of them might be T. cruzi-specific genes. Functional groups of those sequences with matches in the database were constructed according to their putative biological functions. The two largest categories were protein synthesis (23.3%) and cell surface molecules (10.8%). The information reported in this paper should be useful for researchers in the field to analyze genes and proteins of their own interest. PMID:9784549

  12. Blood viscosity changes in experimentally Trypanosoma cruzi-infected rats.

    PubMed

    Berra, H H; Piaggio, E; Revelli, S S; Luquita, A

    2005-01-01

    Microcirculatory alterations would explain focal lesions found in Chagas' cardiomyopathy. Trypanosoma cruzi (T. cruzi) infection induces host blood properties modifications and defensive responses capable of producing blood hyperviscosity, an ischemic risk factor able to affect microvascular blood flow. We studied whole blood viscosity (eta(b)) and plasmatic and cellular factors influencing it in rats, 7 and 14 days after experimental infection with T. cruzi. Increased plasma viscosity (eta(p)) was found in infected versus control rats and it was correlated with high blood parasite levels at 7 days and enhanced gamma-globulin fraction concentration at 14 days. The hematocrit, mean corpuscular volume (MCV) and eta(b) were higher in 14 days infected rats vs. 7 days and control animals. Also, electron microscopy observation showed morphological changes in red blood cells (RBC) at 7 and 14 days post-infection, with increased proportion of echinocyte and stomatocyte shapes transformation. In our rat model of Chagas' disease, BPL, increased plasmatic protein concentration, enhanced MCV and RBC shapes transformation would determine blood hyperviscosity, cause of microvascular blood flow abnormalities.

  13. Trypanosoma cruzi infection: a review with emphasis on cutaneous manifestations

    PubMed Central

    Hemmige, Vagish; Tanowitz, Herbert; Sethi, Aisha

    2013-01-01

    Chagas disease, an infection caused by the protozoan Trypanosoma cruzi and transmitted by the Reduuvid insect vector, remains a major cause of morbidity in Central and South America over a century after its discovery in 1909. Though major advances in preventing the spread of this disease have been made in recent decades, millions of individuals remain chronically infected due to prior exposure to T. cruzi and are at risk for future complications from the disease. Dermatologic manifestations of acute infection may include localized swelling at the site of inoculation (chagoma), conjunctivitis (Romaña’s sign), and a generalized morbilliform eruption (schizotrypanides). Reactivation of quiescent infection in immunocompromised hosts due to the acquired immunodeficiency syndrome or organ transplantation can present with fever and skin lesions including panniculitis. The wide-spread emigration of chronic carriers of T. cruzi to North America, Europe, and Australia makes it imperative that dermatologists worldwide be familiar with this entity to ensure proper diagnosis and treatment. PMID:22515575

  14. Likely Autochthonous Transmission of Trypanosoma cruzi to Humans, South Central Texas, USA

    PubMed Central

    Gunter, Sarah M.; Murray, Kristy O.; Gorchakov, Rodion; Beddard, Rachel; Rossmann, Susan N.; Montgomery, Susan P.; Rivera, Hilda; Brown, Eric L.; Aguilar, David; Widman, Lawrence E.

    2017-01-01

    Chagas disease, caused by Trypanosoma cruzi, is a major neglected tropical disease affecting the Americas. The epidemiology of this disease in the United States is incomplete. We report evidence of likely autochthonous vectorborne transmission of T. cruzi and health outcomes in T. cruzi–seropositive blood donors in south central Texas, USA. PMID:28221110

  15. Tc45, a dimorphic Trypanosoma cruzi immunogen with variable chromosomal localization, is calreticulin.

    PubMed

    Aguillón, J C; Ferreira, L; Pérez, C; Colombo, A; Molina, M C; Wallace, A; Solari, A; Carvallo, P; Galindo, M; Galanti, N; Orn, A; Billetta, R; Ferreira, A

    2000-01-01

    We demonstrate that Tc45, a polypeptide described as an immunogenetically restricted Trypanosoma cruzi antigen in mice, is calreticulin, a dimorphic molecule encoded by genes with variable chromosomal distribution. Previously we showed that IgG from A.SW (H2s) mice immunized with T. cruzi trypomastigotes or epimastigotes and sera from infected humans recognize Tc45, a 45 kD parasite polypeptide. Herein we describe the cloning, sequencing, and expression of the Tc45 gene. A 98% homology in the deduced amino acid sequence was found with a T. cruzi calreticulin-like molecule and 41% with Leishmania donovani and human calreticulin. In the T. cruzi CL Brener clone and in the Tulahuén strain, the gene is located in two and four chromosomes, respectively. Calreticulin was detected in several T. cruzi clones, in the Tulahuén strain, and in T. rangeli, displaying alternative 43 and 46 kD forms.

  16. Molecular phylogeny of Trypanosoma cruzi from Central America (Guatemala) and a comparison with South American strains.

    PubMed

    Iwagami, M; Higo, H; Miura, S; Yanagi, T; Tada, I; Kano, S; Agatsuma, T

    2007-12-01

    Molecular phylogenetic analysis was carried out for 21 strains of Trypanosoma cruzi, nine of which were obtained from Guatemala and 12 from South America. Phylogenetic trees were constructed using the nucleotide sequences of two nuclear gene regions, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and trypanothione reductase (TR), and contiguous portions of two mitochondrial genes, cytochrome oxidase subunit II (COII) and reduced nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1). Possible genetic exchange between the rather divergent lineages of T. cruzi II from South America was suggested in the trees of the two nuclear genes. T. cruzi I strains obtained from Guatemala and Colombia were identical in all the genes examined, but other T. cruzi I isolates from South America were rather polymorphic in the DHFR-TS and mitochondrial genes. No genetic exchange was identified between T. cruzi I populations from Central and South America in the present study.

  17. Gastric invasion by Trypanosoma cruzi and induction of protective mucosal immune responses.

    PubMed Central

    Hoft, D F; Farrar, P L; Kratz-Owens, K; Shaffer, D

    1996-01-01

    Trypanosoma cruzi is an intracellular parasite transmitted from a reduviid insect vector to humans by exposure of mucosal surfaces to infected insect excreta. We have used an oral challenge murine model that mimics vector-borne transmission to study T. cruzi mucosal infection. Although gastric secretions have microbicidal activity against most infectious pathogens, we demonstrate that T. cruzi can invade and replicate in the gastric mucosal epithelium. In addition, gastric mucosal invasion appears to be the unique portal of entry for systemic T. cruzi infection after oral challenge. The mucosal immune responses stimulated by T. cruzi gastric infection are protective against a secondary mucosal parasite challenge. This protective mucosal immunity is associated with increased numbers of lymphocytes that secrete parasite-specific immunoglobulin A. Our results document the first example of systemic microbial invasion through gastric mucosa and suggest the feasibility of a mucosal vaccine designed to prevent infection with this important human pathogen. PMID:8751932

  18. Prevalence of antibodies to Leishmania infantum and Trypanosoma cruzi in wild canids from South Carolina.

    PubMed

    Rosypal, Alexa C; Tidwell, Richard R; Lindsay, David S

    2007-08-01

    Wild canids are reservoir hosts for Leishmania infantum and Trypanosoma cruzi. The present study examined the prevalence of antibodies to these zoonotic parasites in a population of wild canids from a nonagricultural setting in South Carolina. Sera from 26 gray foxes (Urocyon cinereoargenteus) and 2 coyotes (Canis latrans) were examined for antibodies to L. infantum and T. cruzi using the indirect immunofluorescent antibody test and commercially available parasite-specific immunochromatigraphic strip assays. Antibodies to L. infantum were not detected by either assay in gray foxes or coyotes. Two (8%) of 26 gray foxes were positive in both the T. cruzi immunofluorescent antibody and strip assays. Antibodies to T. cruzi were not detected in coyotes. Results from this study indicate that wild canids are exposed to T. cruzi, but not L. infantum. in this geographic region.

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

    PubMed

    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

  20. Trypanosoma cruzi as an effective cancer antigen delivery vector

    PubMed Central

    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.

    2011-01-01

    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. PMID:22114198

  1. Role of placental barrier integrity in infection by Trypanosoma cruzi.

    PubMed

    Díaz-Luján, C; Triquell, M F; Castillo, C; Hardisson, D; Kemmerling, U; Fretes, R E

    2016-12-01

    American trypanosomiasis has long been a neglected disease endemic in LatinAmerica, but congenital transmission has now spread Chagas disease to cause a global health problem. As the early stages of the infection of placental tissue and the vertical transmission by Trypanosoma cruzi are still not well understood, it is important to investigate the relevance of the first structure of the placental barrier in chorionic villi infection by T. cruzi during the initial stage of the infection. Explants of human chorionic villi from healthy pregnant women at term were denuded of their syncytiotrophoblast and co-cultured for 3h, 24h and 96h with 800,000 trypomastigotes (simulating acute infection). T. cruzi infected cells were identified by immunohistochemistry for cytokeratin-7 (+cytotrophoblast) and CD68 (+macrophages), and the infection was quantified. In placental tissue, the parasite load was analyzed by qPCR and microscopy, and the motile trypomastigotes were quantified in culture supernatant. In denuded chorionic villous, the total area occupied by the parasite (451.23μm(2), 1.33%) and parasite load (RQ: 87) was significantly higher (p<0.05) than in the entire villous (control) (5.98μm(2), 0.016%) (RQ:1) and with smaller concentration of nitric oxide. Stromal non-macrophage cells were infected as well as cytotrophoblasts and some macrophages, but with significant differences being observed. The parasite quantity in the culture supernatant was significantly higher (p<0.05) in denuded culture explants from 96h of culture. Although the human complete chorionic villi limited the infection, the detachment of the first structure of the placenta barrier (syncytiotrophoblast) increased both the infection of the villous stroma and the living trypomastigotes in the culture supernatant. Therefore structural and functional alterations to chorionic villi placental barrier reduce placental defenses and may contribute to the vertical transmission of Chagas.

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

    PubMed

    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.

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

    PubMed

    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.

  4. Quantitative Proteomic and Phosphoproteomic Analysis of Trypanosoma cruzi Amastigogenesis*

    PubMed Central

    Queiroz, Rayner M. L.; Charneau, Sébastien; Mandacaru, Samuel C.; Schwämmle, Veit; Lima, Beatriz D.; Roepstorff, Peter; Ricart, Carlos A. O.

    2014-01-01

    Chagas disease is a tropical neglected disease endemic in Latin America caused by the protozoan Trypanosoma cruzi. The parasite has four major life stages: epimastigote, metacyclic trypomastigote, bloodstream trypomastigote, and amastigote. The differentiation from infective trypomastigotes into replicative amastigotes, called amastigogenesis, takes place in vivo inside mammalian host cells after a period of incubation in an acidic phagolysosome. This differentiation process can be mimicked in vitro by incubating tissue-culture-derived trypomastigotes in acidic DMEM. Here we used this well-established differentiation protocol to perform a comprehensive quantitative proteomic and phosphoproteomic analysis of T. cruzi amastigogenesis. Samples from fully differentiated forms and two biologically relevant intermediate time points were Lys-C/trypsin digested, iTRAQ-labeled, and multiplexed. Subsequently, phosphopeptides were enriched using a TiO2 matrix. Non-phosphorylated peptides were fractionated via hydrophilic interaction liquid chromatography prior to LC-MS/MS analysis. LC-MS/MS and bioinformatics procedures were used for protein and phosphopeptide quantitation, identification, and phosphorylation site assignment. We were able to identify regulated proteins and pathways involved in coordinating amastigogenesis. We also observed that a significant proportion of the regulated proteins were membrane proteins. Modulated phosphorylation events coordinated by protein kinases and phosphatases that are part of the signaling cascade induced by incubation in acidic medium were also evinced. To our knowledge, this work is the most comprehensive quantitative proteomics study of T. cruzi amastigogenesis, and these data will serve as a trustworthy basis for future studies, and possibly for new potential drug targets. PMID:25225356

  5. Polyamine depletion inhibits the autophagic response modulating Trypanosoma cruzi infectivity

    PubMed Central

    Vanrell, María C.; Cueto, Juan A.; Barclay, Jeremías J.; Carrillo, Carolina; Colombo, María I.; Gottlieb, Roberta A.; Romano, Patricia S.

    2013-01-01

    Autophagy is a cell process that in normal conditions serves to recycle cytoplasmic components and aged or damaged organelles. The autophagic pathway has been implicated in many physiological and pathological situations, even during the course of infection by intracellular pathogens. Many compounds are currently used to positively or negatively modulate the autophagic response. Recently it was demonstrated that the polyamine spermidine is a physiological inducer of autophagy in eukaryotic cells. We have previously shown that the etiological agent of Chagas disease, the protozoan parasite Trypanosoma cruzi, interacts with autophagic compartments during host cell invasion and that preactivation of autophagy significantly increases host cell colonization by this parasite. In the present report we have analyzed the effect of polyamine depletion on the autophagic response of the host cell and on T. cruzi infectivity. Our data showed that depleting intracellular polyamines by inhibiting the biosynthetic enzyme ornithine decarboxylase with difluoromethylornithine (DFMO) suppressed the induction of autophagy in response to starvation or rapamycin treatment in two cell lines. This effect was associated with a decrease in the levels of LC3 and ATG5, two proteins required for autophagosome formation. As a consequence of inhibiting host cell autophagy, DFMO impaired T. cruzi colonization, indicating that polyamines and autophagy facilitate parasite infection. Thus, our results point to DFMO as a novel autophagy inhibitor. While other autophagy inhibitors such as wortmannin and 3-methyladenine are nonspecific and potentially toxic, DFMO is an FDA-approved drug that may have value in limiting autophagy and the spread of the infection in Chagas disease and possibly other pathological settings. PMID:23697944

  6. Proteomic Analysis of Trypanosoma cruzi Response to Ionizing Radiation Stress

    PubMed Central

    Vieira, Helaine Graziele Santos; Grynberg, Priscila; Bitar, Mainá; Pires, Simone da Fonseca; Hilário, Heron Oliveira; Macedo, Andrea Mara; Machado, Carlos Renato; de Andrade, Hélida Monteiro; Franco, Glória Regina

    2014-01-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is extremely resistant to ionizing radiation, enduring up to 1.5 kGy of gamma rays. Ionizing radiation can damage the DNA molecule both directly, resulting in double-strand breaks, and indirectly, as a consequence of reactive oxygen species production. After a dose of 500 Gy of gamma rays, the parasite genome is fragmented, but the chromosomal bands are restored within 48 hours. Under such conditions, cell growth arrests for up to 120 hours and the parasites resume normal growth after this period. To better understand the parasite response to ionizing radiation, we analyzed the proteome of irradiated (4, 24, and 96 hours after irradiation) and non-irradiated T. cruzi using two-dimensional differential gel electrophoresis followed by mass spectrometry for protein identification. A total of 543 spots were found to be differentially expressed, from which 215 were identified. These identified protein spots represent different isoforms of only 53 proteins. We observed a tendency for overexpression of proteins with molecular weights below predicted, indicating that these may be processed, yielding shorter polypeptides. The presence of shorter protein isoforms after irradiation suggests the occurrence of post-translational modifications and/or processing in response to gamma radiation stress. Our results also indicate that active translation is essential for the recovery of parasites from ionizing radiation damage. This study therefore reveals the peculiar response of T. cruzi to ionizing radiation, raising questions about how this organism can change its protein expression to survive such a harmful stress. PMID:24842666

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

    PubMed Central

    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

  8. Trypanosoma cruzi infection in B-cell-deficient rats.

    PubMed Central

    Rodriguez, A M; Santoro, F; Afchain, D; Bazin, H; Capron, A

    1981-01-01

    The effect of neonatally initiated injections of anti-mu rabbit antiserum on immunity of rats against Trypanosoma cruzi infection was investigated in vivo. Anti-mu treatment resulted in a loss of immunoglobulin M (IgM) and IgG2a synthesis and, subsequently, of antibody production. These rats so treated were shown to be significantly more susceptible to the acute phase of the infection than the control rats treated with normal rabbit serum, as measured by increased parasitemia and mortality. These results indicate the essential role of antibodies, probably in association with complement or effector cells or both, in immunity to acute Chagas' disease. PMID:6783543

  9. Recruitment and endo-lysosomal activation of TLR9 in dendritic cells infected with Trypanosoma cruzi.

    PubMed

    Bartholomeu, Daniella C; Ropert, Catherine; Melo, Mariane B; Parroche, Peggy; Junqueira, Caroline F; Teixeira, Santuza M R; Sirois, Cherilyn; Kasperkovitz, Pia; Knetter, Cathrine F; Lien, Egil; Latz, Eicke; Golenbock, Douglas T; Gazzinelli, Ricardo T

    2008-07-15

    TLR9 is critical in parasite recognition and host resistance to experimental infection with Trypanosoma cruzi. However, no information is available regarding nucleotide sequences and cellular events involved on T. cruzi recognition by TLR9. In silico wide analysis associated with in vitro screening of synthetic oligonucleotides demonstrates that the retrotransposon VIPER elements and mucin-like glycoprotein (TcMUC) genes in the T. cruzi genome are highly enriched for CpG motifs that are immunostimulatory for mouse and human TLR9, respectively. Importantly, infection with T. cruzi triggers high levels of luciferase activity under NF-kappaB-dependent transcription in HEK cells cotransfected with human TLR9, but not in control (cotransfected with human MD2/TLR4) HEK cells. Further, we observed translocation of TLR9 to the lysosomes during invasion/uptake of T. cruzi parasites by dendritic cells. Consistently, potent proinflammatory activity was observed when highly unmethylated T. cruzi genomic DNA was delivered to the endo-lysosomal compartment of host cells expressing TLR9. Thus, together our results indicate that the unmethylated CpG motifs found in the T. cruzi genome are likely to be main parasite targets and probably become available to TLR9 when parasites are destroyed in the lysosome-fused vacuoles during parasite invasion/uptake by phagocytes.

  10. Is the Antitumor Property of Trypanosoma cruzi Infection Mediated by Its Calreticulin?

    PubMed Central

    Ramírez-Toloza, Galia; Abello, Paula; Ferreira, Arturo

    2016-01-01

    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. PMID:27462315

  11. Organ donor screening practices for Trypanosoma cruzi infection among US Organ Procurement Organizations.

    PubMed

    Schwartz, B S; Paster, M; Ison, M G; Chin-Hong, P V

    2011-04-01

    Donor-derived Trypanosoma cruzi infection in solid organ transplant recipients is associated with significant morbidity and mortality. Little is known about T. cruzi screening practices among U.S. organ procurement organizations (OPOs). We distributed a questionnaire to all U.S. OPO directors, requesting data on T. cruzi screening strategies, laboratory methods, number of donors screened, disposition of organs from positive donors and attitudes toward screening. Fifty-eight (100%) U.S. OPOs responded to the survey. Donor screening began in 2002 and is presently performed by 11 (19%) OPOs. Among screening OPOs, four screen all donors and seven use a risk-based strategy. Three different T. cruzi serology tests are used for donor screening. During 2008, 9/993 (0.9%) donors screened positive by a T. cruzi screening test, 6/9 (66%) had confirmatory tests performed and 4/6 (66%) had positive confirmatory tests. These results led to the nonuse of five donors and 17 organs. Five organs from three seropositive donors were transplanted in 2008 without recognized disease transmission. Variability of T. cruzi donor screening strategies, laboratory methods and disposition of organs from positive donors currently exists. Further research is needed to identify the risk of donor-derived T. cruzi infections to help inform the best screening strategy.

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

    PubMed

    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.

  13. Utility of recombinant flagellar calcium-binding protein for serodiagnosis of Trypanosoma cruzi infection.

    PubMed Central

    Godsel, L M; Tibbetts, R S; Olson, C L; Chaudoir, B M; Engman, D M

    1995-01-01

    The protozoan Trypanosoma cruzi is the causative agent of Chagas' disease, a major public health problem in Latin America and of growing concern in the United States as the number of infected immigrants increases. There is currently no testing of U.S. blood products for T. cruzi infection, and the best tests available, although highly sensitive, are not of high enough specificity to be useful for widespread screening of the blood supply in this country. Among the parasite antigens detected by sera of infected humans and mice, those in the range of 24 to 26 kDa are particularly reactive. With an aim of developing a sensitive, specific, recombinant antigen-based serologic test for T. cruzi infection, we used two antibody reagents specific for these 24- to 26-kDa antigens to isolate cDNA clones from a T. cruzi expression library. One clone was found to encode a previously characterized T. cruzi antigen, a 24-kDa flagellar calcium-binding protein (FCaBP). Recombinant FCaBP was found to be a sensitive, specific reagent for distinguishing T. cruzi-infected individuals from uninfected persons, and it therefore could potentially be used for screening purposes, especially if combined with other recombinant T. cruzi antigens that have similarly high degrees of diagnostic sensitivity and specificity. PMID:7559952

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

    PubMed Central

    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.

    2011-01-01

    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 neighboring rural areas with different histories of transmission and vector control in northern Argentina. Lineage II predominated among the 99 isolates characterized and lineage I among the six isolates obtained from sylvatic mammals. Trypanosoma 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. PMID:18585717

  15. The increase in mannose receptor recycling favors arginase induction and Trypanosoma cruzi survival in macrophages.

    PubMed

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

    2011-01-01

    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 intracellular

  16. Identification and Functional Analysis of Trypanosoma cruzi Genes That Encode Proteins of the Glycosylphosphatidylinositol Biosynthetic Pathway

    PubMed Central

    Cardoso, Mariana S.; Junqueira, Caroline; Trigueiro, Ricardo C.; Shams-Eldin, Hosam; Macedo, Cristiana S.; Araújo, Patrícia R.; Gomes, Dawidson A.; Martinelli, Patrícia M.; Kimmel, Jürgen; Stahl, Philipp; Niehus, Sebastian; Schwarz, Ralph T.; Previato, José O.; Mendonça-Previato, Lucia; Gazzinelli, Ricardo T.; Teixeira, Santuza M. R.

    2013-01-01

    Background Trypanosoma cruzi is a protist parasite that causes Chagas disease. Several proteins that are essential for parasite virulence and involved in host immune responses are anchored to the membrane through glycosylphosphatidylinositol (GPI) molecules. In addition, T. cruzi GPI anchors have immunostimulatory activities, including the ability to stimulate the synthesis of cytokines by innate immune cells. Therefore, T. cruzi genes related to GPI anchor biosynthesis constitute potential new targets for the development of better therapies against Chagas disease. Methodology/Principal Findings In silico analysis of the T. cruzi genome resulted in the identification of 18 genes encoding proteins of the GPI biosynthetic pathway as well as the inositolphosphorylceramide (IPC) synthase gene. Expression of GFP fusions of some of these proteins in T. cruzi epimastigotes showed that they localize in the endoplasmic reticulum (ER). Expression analyses of two genes indicated that they are constitutively expressed in all stages of the parasite life cycle. T. cruzi genes TcDPM1, TcGPI10 and TcGPI12 complement conditional yeast mutants in GPI biosynthesis. Attempts to generate T. cruzi knockouts for three genes were unsuccessful, suggesting that GPI may be an essential component of the parasite. Regarding TcGPI8, which encodes the catalytic subunit of the transamidase complex, although we were able to generate single allele knockout mutants, attempts to disrupt both alleles failed, resulting instead in parasites that have undergone genomic recombination and maintained at least one active copy of the gene. Conclusions/Significance Analyses of T. cruzi sequences encoding components of the GPI biosynthetic pathway indicated that they are essential genes involved in key aspects of host-parasite interactions. Complementation assays of yeast mutants with these T. cruzi genes resulted in yeast cell lines that can now be employed in high throughput screenings of drugs against this

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

    PubMed

    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.

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

    PubMed Central

    Zingales, Bianca; Miles, Michael A; Moraes, Carolina B; Luquetti, Alejandro; Guhl, Felipe; Schijman, Alejandro G; Ribeiro, Isabela

    2014-01-01

    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. PMID:25317712

  19. 5-Nitro-2-furyl derivative actives against Trypanosoma cruzi: preliminary in vivo studies.

    PubMed

    Cabrera, Eliana; Murguiondo, Mariana González; Arias, Marelina González; Arredondo, Carolina; Pintos, Cristina; Aguirre, Gabriela; Fernández, Marcelo; Basmadjián, Yester; Rosa, Raquel; Pacheco, José Pedro; Raymondo, Stella; Di Maio, Rossanna; González, Mercedes; Cerecetto, Hugo

    2009-10-01

    Ten 5-nitro-2-furyl derivatives, with good to excellent in vitro anti-Trypanosoma cruzi activity, and nifurtimox were tested oral and intraperitoneally on healthy animals for its acute toxicity on murine models. According to animals' survival percentage, organ histological results, biochemical and haematological findings, three new derivatives, with toxicity like nifurtimox, were selected to test in vivo as antichagasic agents. Clearly, dependences between chemical structure and both acute toxicity and in vivo anti-T. cruzi activity were observed. 4-Hexyl-1-[3-(5-nitro-2-furyl)-2-propenylidene]semicarbazide displayed good profile as anti-T. cruzi agent and better acute toxicity profile than nifurtimox.

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

    PubMed

    Zingales, Bianca; Miles, Michael A; Moraes, Carolina B; Luquetti, Alejandro; Guhl, Felipe; Schijman, Alejandro G; Ribeiro, Isabela

    2014-09-01

    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.

  1. Phospholipid and glycolipid composition of acidocalcisomes of Trypanosoma cruzi.

    PubMed

    Salto, María Laura; Kuhlenschmidt, Theresa; Kuhlenschmidt, Mark; de Lederkremer, Rosa M; Docampo, Roberto

    2008-04-01

    Highly purified acidocalcisomes from Trypanosoma cruzi epimastigotes were obtained by differential centrifugation and iodixanol gradient ultracentrifugation. Lipid analysis of acidocalcisomes revealed the presence of low amounts of 3beta-hydroxysterols and predominance of phospholipids. Alkylacyl phosphatidylinositol (16:0/18:2), diacyl phosphatidylinositol (18:0/18:2), diacyl phosphatidylcholine (16:0/18:2; 16:1/18:2; 16:2/18:2; 18:1/18:2 and 18:2/18:2), and diacyl phosphatidylethanolamine (16:0/18:2 and 16:1/18:2) were the only phospholipids characterized by electrospray ionization-mass spectrometry (ESI-MS). Incubation of epimastigotes with [(3)H]-mannose and isolation of acidocalcisomes allowed the detection of a glycoinositolphospholipid (GIPL) in these organelles. The sugar content of the acidocalcisomal GIPL was similar to that of the GIPL present in a microsomal fraction but the amount of galactofuranose and inositol with respect to the other monosaccharides was lower, suggesting a different chemical structure. Taken together, these results indicate that acidocalcisomes of T. cruzi have a distinct lipid and carbohydrate composition.

  2. Perspectives on Trypanosoma cruzi-induced heart disease (Chagas disease)

    PubMed Central

    Tanowitz, Herbert B.; Machado, Fabiana S.; Jelicks, Linda A.; Shirani, Jamshid; Campos de Carvalho, Antonio C.; Spray, David C.; Factor, Stephen M.; Kirchhoff, Louis V.; Weiss, Louis M.

    2009-01-01

    Chagas disease is caused by the parasite Trypanosoma cruzi it is the most common cause of heart disease in endemic areas of Latin America. The year 2009 marks the 100th anniversary of the discovery of T. cruzi infection and Chagas disease by the Brazilian physician Carlos Chagas. Chagasic cardiomyopathy develops in from 10 to 30 percent of persons who are chronically infected with this parasite. Echocardiography and magnetic resonance imaging are important modalities in the evaluation and prognosis of individuals with chagasic heart disease. The etiology of chagasic heart disease likely is multifactorial. Parasite persistence, autoimmunity, and microvascular abnormalities have been studied extensively as possible pathogenic mechanisms. Experimental studies suggest that alterations in cardiac gap junctions may be etiologic in the pathogenesis of conduction abnormalities. The diagnosis of chronic Chagas disease is made by serology. The treatment of this infection has shortcomings that need to be addressed. Cardiac transplantation and bone marrow stem cell therapy for persons with Chagas disease have received increasing research attention in recent years. PMID:19410685

  3. Trypanosoma cruzi: adaptation to its vectors and its hosts

    PubMed Central

    Noireau, François; Diosque, Patricio; Jansen, Ana Maria

    2009-01-01

    American trypanosomiasis is a parasitic zoonosis that occurs throughout Latin America. The etiological agent, Trypanosoma cruzi, is able to infect almost all tissues of its mammalian hosts and spreads in the environment in multifarious transmission cycles that may or not be connected. This biological plasticity, which is probably the result of the considerable heterogeneity of the taxon, exemplifies a successful adaptation of a parasite resulting in distinct outcomes of infection and a complex epidemiological pattern. In the 1990s, most endemic countries strengthened national control programs to interrupt the transmission of this parasite to humans. However, many obstacles remain to the effective control of the disease. Current knowledge of the different components involved in elaborate system that is American trypanosomiasis (the protozoan parasite T. cruzi, vectors Triatominae and the many reservoirs of infection), as well as the interactions existing within the system, is still incomplete. The Triatominae probably evolve from predatory reduvids in response to the availability of vertebrate food source. However, the basic mechanisms of adaptation of some of them to artificial ecotopes remain poorly understood. Nevertheless, these adaptations seem to be associated with a behavioral plasticity, a reduction in the genetic repertoire and increasing developmental instability. PMID:19250627

  4. Structural analysis of inositol phospholipids from Trypanosoma cruzi epimastigote forms.

    PubMed Central

    Bertello, L E; Gonçalvez, M F; Colli, W; de Lederkremer, R M

    1995-01-01

    Inositol phospholipids (IPL) from epimastigote forms of Trypanosoma cruzi have been investigated by metabolic labelling with [3H]palmitic acid and by GLC-MS analysis of the lipids obtained from non-labelled parasites. The IPL fraction was separated into phosphatidylinositol (PI) and inositol-phosphoceramide subfractions, the latter accounting for 80-85% of the total IPL. The neutral lipids released from the IPLs by PI-specific phospholipase C (PI-PLC) from Bacillus thuringiensis were analysed by silica-gel and reverse-phase TLC for the radioactive lipids and by GLC-MS for the non-radioactive samples. Ceramides containing dihydrosphingosine and sphingosine with C16:0 and C18:0 fatty acids were identified. The main component in the [3H]palmitic acid-labelled ceramides was palmitoyldihydrospingosine, while in the non-labelled sample the ceramides contained mainly sphingosine. This could reflect partial uptake of phospholipid from the medium. The PI contain both alkylacyl- and diacyl-glycerol lipids, with the ether lipid being more abundant. The latter was identified as 1-O-hexadecylglycerol esterified by C18:2 and C18:1 fatty acids. Interestingly, the same lipid had been identified in the anchor of the 1G7 glycoprotein of T. cruzi metacyclic forms. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 PMID:7646454

  5. Structural characterization of NETNES glycopeptide from Trypanosoma cruzi.

    PubMed

    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.

  6. Trypanosoma cruzi Calreticulin Topographical Variations in Parasites Infecting Murine Macrophages.

    PubMed

    González, Andrea; Valck, Carolina; Sánchez, Gittith; Härtel, Steffen; Mansilla, Jorge; Ramírez, Galia; Fernández, María Soledad; Arias, José Luis; Galanti, Norbel; Ferreira, Arturo

    2015-05-01

    Trypanosoma cruzi calreticulin (TcCRT), a 47-kDa chaperone, translocates from the endoplasmic reticulum to the area of flagellum emergence. There, it binds to complement components C1 and mannan-binding lectin (MBL), thus acting as a main virulence factor, and inhibits the classical and lectin pathways. The localization and functions of TcCRT, once the parasite is inside the host cell, are unknown. In parasites infecting murine macrophages, polyclonal anti-TcCRT antibodies detected TcCRT mainly in the parasite nucleus and kinetoplast. However, with a monoclonal antibody (E2G7), the resolution and specificity of the label markedly improved, and TcCRT was detected mainly in the parasite kinetoplast. Gold particles, bound to the respective antibodies, were used as probes in electron microscopy. This organelle may represent a stopover and accumulation site for TcCRT, previous its translocation to the area of flagellum emergence. Finally, early during T. cruzi infection and by unknown mechanisms, an important decrease in the number of MHC-I positive host cells was observed.

  7. Trypanosoma cruzi Calreticulin Topographical Variations in Parasites Infecting Murine Macrophages

    PubMed Central

    González, Andrea; Valck, Carolina; Sánchez, Gittith; Härtel, Steffen; Mansilla, Jorge; Ramírez, Galia; Fernández, María Soledad; Arias, José Luis; Galanti, Norbel; Ferreira, Arturo

    2015-01-01

    Trypanosoma cruzi calreticulin (TcCRT), a 47-kDa chaperone, translocates from the endoplasmic reticulum to the area of flagellum emergence. There, it binds to complement components C1 and mannan-binding lectin (MBL), thus acting as a main virulence factor, and inhibits the classical and lectin pathways. The localization and functions of TcCRT, once the parasite is inside the host cell, are unknown. In parasites infecting murine macrophages, polyclonal anti-TcCRT antibodies detected TcCRT mainly in the parasite nucleus and kinetoplast. However, with a monoclonal antibody (E2G7), the resolution and specificity of the label markedly improved, and TcCRT was detected mainly in the parasite kinetoplast. Gold particles, bound to the respective antibodies, were used as probes in electron microscopy. This organelle may represent a stopover and accumulation site for TcCRT, previous its translocation to the area of flagellum emergence. Finally, early during T. cruzi infection and by unknown mechanisms, an important decrease in the number of MHC-I positive host cells was observed. PMID:25758653

  8. Retrospective distribution of Trypanosoma cruzi I genotypes in Colombia.

    PubMed

    León, Cielo M; Hernández, Carolina; Montilla, Marleny; Ramírez, Juan David

    2015-05-01

    Trypanosoma cruzi is the aetiological agent of Chagas disease, which affects approximately eight million people in the Americas. This parasite exhibits genetic variability, with at least six discrete typing units broadly distributed in the American continent. T. cruzi I (TcI) shows remarkable genetic diversity; a genotype linked to human infections and a domestic cycle of transmission have recently been identified, hence, this strain was named TcIDom. The aim of this work was to describe the spatiotemporal distribution of TcI subpopulations across humans, insect vectors and mammalian reservoirs in Colombia by means of molecular typing targeting the spliced leader intergenic region of mini-exon gene. We analysed 101 TcI isolates and observed a distribution of sylvatic TcI in 70% and TcIDom in 30%. In humans, the ratio was sylvatic TcI in 60% and TcIDom in 40%. In mammal reservoirs, the distribution corresponded to sylvatic TcI in 96% and TcIDom in 4%. Among insect vectors, sylvatic TcI was observed in 48% and TcIDom in 52%. In conclusion, the circulation of TcIDom is emerging in Colombia and this genotype is still adapting to the domestic cycle of transmission. The epidemiological and clinical implications of these findings are discussed herein.

  9. An in vivo role for Trypanosoma cruzi calreticulin in antiangiogenesis.

    PubMed

    Molina, María C; Ferreira, Viviana; Valck, Carolina; Aguilar, Lorena; Orellana, Juana; Rojas, Alvaro; Ramirez, Galia; Billetta, Rosario; Schwaeble, Wilhelm; Lemus, David; Ferreira, Arturo

    2005-04-01

    Angiogenesis leads to neovascularization from existing blood vessels. It is associated with tumor growth and metastasis and is regulated by pro- and antiangiogenic molecules, some of them currently under clinical trials for cancer treatment. During the last few years we have cloned, sequenced and expressed a Trypanosoma cruzi calreticulin gene (TcCRT). Its product, TcCRT, a 45 kDa protein, is more than 50% identical to human CRT (HuCRT). TcCRT, present on the surface of trypomastigotes, binds both C1q and mannan binding lectin and inhibits the classical activation pathway of human complement. Since TcCRT is highly homologous to a functional antiangiogenic fragment from HuCRT (aa 120-180), recombinant (r) and native (n) TcCRT were tested in their antiangiogenic effects, in the chick embryonic chorioallantoid membrane (CAM) assay. Both proteins mediated highly significant antiangiogenic effects in the in vivo CAM assay. This effect was further substantiated in experiments showing that the plasmid construct pSecTag/TcCRT also displayed significant antiangiogenic properties, as compared to the empty vector. Most likely, the fact that antiangiogenic substances act preferentially on growing neoplasic tissues, but not on already established tumors, is due to their effects on emerging blood vessels. The results shown here indicate that TcCRT, like its human counterpart, has antiangiogenic properties. These properties may explain, at least partly, the reported antineoplasic effect of experimental T. cruzi infection.

  10. Retrospective distribution of Trypanosoma cruzi I genotypes in Colombia

    PubMed Central

    León, Cielo M; Hernández, Carolina; Montilla, Marleny; Ramírez, Juan David

    2015-01-01

    Trypanosoma cruzi is the aetiological agent of Chagas disease, which affects approximately eight million people in the Americas. This parasite exhibits genetic variability, with at least six discrete typing units broadly distributed in the American continent. T. cruzi I (TcI) shows remarkable genetic diversity; a genotype linked to human infections and a domestic cycle of transmission have recently been identified, hence, this strain was named TcIDom. The aim of this work was to describe the spatiotemporal distribution of TcI subpopulations across humans, insect vectors and mammalian reservoirs in Colombia by means of molecular typing targeting the spliced leader intergenic region of mini-exon gene. We analysed 101 TcI isolates and observed a distribution of sylvatic TcI in 70% and TcIDom in 30%. In humans, the ratio was sylvatic TcI in 60% and TcIDom in 40%. In mammal reservoirs, the distribution corresponded to sylvatic TcI in 96% and TcIDom in 4%. Among insect vectors, sylvatic TcI was observed in 48% and TcIDom in 52%. In conclusion, the circulation of TcIDom is emerging in Colombia and this genotype is still adapting to the domestic cycle of transmission. The epidemiological and clinical implications of these findings are discussed herein. PMID:25946157

  11. Clonal population structure of Colombian sylvatic Trypanosoma cruzi.

    PubMed

    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.

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

    PubMed

    da Silva, Rosiane V; Malvezi, Aparecida D; Augusto, Leonardo da Silva; Kian, Danielle; Tatakihara, Vera Lúcia H; Yamauchi, Lucy M; Yamada-Ogatta, Sueli F; Rizzo, Luiz V; Schenkman, Sergio; Pinge-Filho, Phileno

    2013-01-01

    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.

  13. Seroprevalence of Trypanosoma cruzi in stray and pet dogs in Grenada, West Indies.

    PubMed

    Chikweto, A; Kumthekar, S; Chawla, P; Tiwari, K P; Perea, L M; Paterson, T; Sharma, R N

    2014-06-01

    American trypanosomiasis (Chagas disease) caused by the protozoan parasite Trypanosoma cruzi is endemic to parts of South America and the Caribbean. Infected dogs are important in the epidemiology of the parasite as they can play a role in the transmission of the parasite to humans. A total of 399 dog sera (242 stray and 157 pet dogs) were examined for T. cruzi infection; using a qualitative immunochromatographic dipstick test, based on recombinant antigens specific for American trypanosomiasis (Trypanosoma detect rapid test; InBios international, Inc., Seattle, Washington). Overall seroprevalence for T. cruzi was estimated at 10.5% (95% confidence interval: 7.5% to 13.5%); with stray dogs being significantly more affected (p<0.05, χ2). Results from this study indicate that dogs in Grenada are moderately exposed to T. cruzi compared to other areas in the region.

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

    PubMed Central

    Paes, Marcia Cristina; Cosentino-Gomes, Daniela; de Souza, Cíntia Fernandes; Nogueira, Natália Pereira de Almeida; Meyer-Fernandes, José Roberto

    2011-01-01

    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. PMID:22007287

  15. Differentiation of Trypanosoma cruzi and Trypanosoma rangeli of Colombia using minicircle hybridization tests.

    PubMed

    Botero, Adriana; Ortiz, Sylvia; Muñoz, Sergio; Triana, Omar; Solari, Aldo

    2010-11-01

    Although Trypanosoma rangeli is harmless for humans, it is a serious problem since it may be confused with diagnosis of Trypanosoma cruzi, the etiologic agent of Chagas disease. Both parasites overlap geographically, share antigenic protein, and are able to infect the same Triatominae vector and vertebrate host, including human. Our objective was to differentiate T. cruzi and T. rangeli isolates from Colombia based on polymerase chain reaction (PCR) amplification of the minicircles followed by appropriate hybridization tests with selected DNA probes and restriction fragment length polymorphism (RFLP) analysis. We worked with highly characterized T. cruzi and T. rangeli isolates from different biologic origins and geographic areas of Colombia, and they were analyzed by RFLP and PCR amplification of variable region of minicircles and Southern blot analysis. Our results and experimental conditions demonstrate the usefulness of PCR amplification of the minicircles followed by Southern blot analysis to differentiate T. cruzi from T. rangeli, which can be highly important to improve diagnosis of Chagas disease.

  16. Familial Analysis of Seropositivity to Trypanosoma cruzi and of Clinical Forms of Chagas Disease

    PubMed Central

    Silva-Grecco, Roseane L.; Balarin, Marly A. S.; Correia, Dalmo; Prata, Aluízio; Rodrigues, Virmondes

    2010-01-01

    A cross-sectional study was carried out in Água Comprida, MG, Brazil, a region previously endemic to Chagas disease whose vectorial transmission was interrupted around 20 year ago. A total of 998 individuals were examined for anti-Trypanosoma cruzi antibodies. Seropositivity was observed in 255 subjects (25.5%), and 743 subjects were negative. Forty-one families with 5–80 individuals with similar environmental conditions were selected for familial analysis. In 15 families, seropositivity to T. cruzi was observed in > 50% of individuals. The segregation analysis confirmed family aggregation for the seropositivity to the T. cruzi. Heart commitment was the major clinical form observed, and in six families, > 50% of the individuals display cardiopathy that may be attributed to T. cruzi infection. Our results support the hypothesis that there is a family aggregation for the seropositivity but without the effect of one major gene. PMID:20064994

  17. Trypanosoma cruzi parasites fight for control of the JAK-STAT pathway by disarming their host

    PubMed Central

    Stahl, Philipp; Schwarz, Ralph T; Debierre-Grockiego, Françoise; Meyer, Thomas

    2014-01-01

    The zoonotic Chagas’ disease is caused by infections with the hemoflagellate Trypanosoma cruzi (T. cruzi) which is endemic in Latin America. Despite recent advances in our understanding of the pathogenesis of the disease, the underlying molecular processes involved in host-parasite interactions are only poorly understood. In particular, the mechanisms for parasite persistence in host cells remain largely unknown. Cytokine-driven transcription factors from the family of STAT (signal transducer and activator of transcription) proteins appear to play a central role in the fight against T. cruzi infection. However, amastigotes proliferating in the cytoplasm of infected host cells develop effective strategies to circumvent the attack executed by STAT proteins. This review highlights the interactions between T. cruzi parasites and human host cells in terms of cytokine signaling and, in particular, discusses the impact of STATs on the balance between parasite invasion and clearance. PMID:26413423

  18. Prevalence of antibody to Trypanosoma cruzi in pregnant Hispanic women in Houston.

    PubMed

    Di Pentima, M C; Hwang, L Y; Skeeter, C M; Edwards, M S

    1999-06-01

    We assessed the seroprevalence of antibodies to Trypanosoma cruzi among pregnant Hispanic women in Houston. Sera from 2,107 Hispanic and 1,658 non-Hispanic subjects were tested by ELISA for the presence of antibodies to T. cruzi. Twenty-two (0.6%) of 3,765 subjects had sera that were reactive. Seroreactivity was confirmed by hemagglutination assay. Eleven subjects had reactive sera, giving a confirmed seroprevalence of 0.3% (95% CI, 0-1%). Nine sera from Hispanic and two from non-Hispanic women were positive by hemagglutination assay, for a prevalence of 0.4% and 0.1%, respectively, during pregnancy. On the basis of these seroreactivity data, transplacental transmission of T. cruzi could occur in the continental United States. Screening for antibodies to T. cruzi during pregnancy would provide the potential for early intervention in congenital Chagas' disease.

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

    PubMed

    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.

  20. Regional Variation in the Correlation of Antibody and T-Cell Responses to Trypanosoma cruzi

    PubMed Central

    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

    2014-01-01

    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. PMID:24710614

  1. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development.

    PubMed

    Cueto, Juan Agustín; Vanrell, María Cristina; Salassa, Betiana Nebaí; Nola, Sébastien; Galli, Thierry; Colombo, María Isabel; Romano, Patricia Silvia

    2016-12-19

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development.

  2. First case of natural infection in pigs. Review of Trypanosoma cruzi reservoirs in Mexico.

    PubMed

    Salazar-Schettino, P M; Bucio, M I; Cabrera, M; Bautista, J

    1997-01-01

    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.

  3. Evidence for Trypanosoma cruzi in adipose tissue in human chronic Chagas disease

    PubMed Central

    Ferreira, Adaliene Versiani Matos; Segatto, Marcela; Menezes, Zélia; Macedo, Andréa Mara; Gelape, Cláudio; de Oliveira Andrade, Luciana; Nagajyothi, Fnu; Scherer, Philipp E.; Teixeira, Mauro Martins; Tanowitz, Herbert B.

    2013-01-01

    Trypanosoma cruzi the cause of Chagas disease persists in tissues of infected experimental animals and humans. Here we demonstrate the persistence of the parasite in adipose tissue from of three of 10 elderly seropositive patients with chronic chagasic heart disease. Nine control patients had no parasites in the fat. We also demonstrate that T. cruzi parasitizes primary adipocytes in vitro. Thus, in humans as in mice the parasite may persist in adipose tissue for decades and become a reservoir of infection. PMID:21726660

  4. Evidence for Trypanosoma cruzi in adipose tissue in human chronic Chagas disease.

    PubMed

    Ferreira, Adaliene Versiani Matos; Segatto, Marcela; Menezes, Zélia; Macedo, Andréa Mara; Gelape, Cláudio; de Oliveira Andrade, Luciana; Nagajyothi, Fnu; Scherer, Philipp E; Teixeira, Mauro Martins; Tanowitz, Herbert B

    2011-11-01

    Trypanosoma cruzi the cause of Chagas disease persists in tissues of infected experimental animals and humans. Here we demonstrate the persistence of the parasite in adipose tissue from of three of 10 elderly seropositive patients with chronic chagasic heart disease. Nine control patients had no parasites in the fat. We also demonstrate that T. cruzi parasitizes primary adipocytes in vitro. Thus, in humans as in mice the parasite may persist in adipose tissue for decades and become a reservoir of infection.

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

    PubMed

    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.

  6. Epidemiological survey of Trypanosoma cruzi infection in domestic owned cats from the tropical southeast of Mexico.

    PubMed

    Jiménez-Coello, M; Acosta-Viana, K Y; Guzman-Marin, E; Gomez-Rios, A; Ortega-Pacheco, A

    2012-09-01

    American trypanosomiasis is an infectious disease of importance for public health and caused by the protozoa Trypanosoma cruzi mainly transmitted by triatomine bugs. The precise role of cats in the peridomestic transmission of T. cruzi and the mechanism by which cats become infected remain uncertain. The objective of this work was to determine the prevalence of T. cruzi infection in domestic cats from an urban area of tropical Mexico by serological and molecular methods and evaluate associated risk factors. A total of 220 domestic cats from Merida Yucatan, Mexico, were studied. Animals older than 3 months were blood sampled. Serum and DNA were obtained. Specific T. cruzi IgG antibodies were detected using a commercial indirect ELISA with an anti-cat antibody HRP labelled. Positive cases were confirmed by Western blot (WB). Polymerase chain reaction (PCR) was also performed using the primers TC1 and TC2. From the 220 cats, 8.6% had antibodies against T. cruzi using ELISA test and later confirmed by WB. In 75 cats (34%), the sequence of ADNk of T. cruzi was amplified. The bad-regular body condition was the only risk factor associated with PCR positive to T.cruzi (P < 0.001). In Mexico, there are no previous epidemiological reports that demonstrate the importance of the cat as a reservoir of T. cruzi. Few individuals were identified with a serological response because they were probably at an early stage of infection or antibodies were not detected because they could be immunocompromised (FIV, FeLV or others). It is necessary to monitor PCR-positive patients and conduct further studies for better understanding of the epidemiology and pathogenesis of Chagas disease in domestic cats.

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

    PubMed

    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.

  8. Influence of saccharides and sodium chloride on growth and differentiation of Trypanosoma cruzi.

    PubMed

    Adroher, F J; Lupiáñez, J A; Osuna, A

    1988-01-01

    The influence of saccharides, especially glucose and fructose, on the metacyclogenesis and growth of Trypanosoma cruzi has been investigated. In the absence of glucose and fructose in the media, both the percentage of metacyclic forms and the growth increased significantly. Furthermore, the addition of NaCl to the medium without monosaccharides strongly increased the formation of metacyclic forms. Presence of NaCl and absence of monosaccharides showed a synergic effect on differentiation of T. cruzi.

  9. Vector Surveillance to Determine Species Composition and Occurrence of Trypanosoma cruzi Infection at Three Military Installations in San Antonio, Texas

    DTIC Science & Technology

    2012-01-01

    protozoan Trypanosoma cruzi Chagas, which was identifi ed by the Brazilian physician Carlos R. J. Chagas in 1909.1 It is a serious disease that mainly...ABSTRACT Chagas disease, also known as American trypanosomiasis, is caused by the hemofl agellate protozoan Trypano- soma cruzi which is transmitted by...Chagas disease, also known as American trypanosomiasis, is caused by the hemofl agellate protozoan Trypanosoma cruzi which is transmitted by blood

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Household risk factors for Trypanosoma cruzi seropositivity in two geographic regions of Ecuador.

    PubMed

    Black, Carla L; Ocaña, Sofia; Riner, Diana; Costales, Jaime A; Lascano, Mauricio S; Davila, Santiago; Arcos-Teran, Laura; Seed, J Richard; Grijalva, Mario J

    2007-02-01

    Few studies on the relationship between environmental factors and Trypanosoma cruzi transmission have been conducted in Ecuador. We conducted a cross-sectional study of household risk factors for T. cruzi seropositivity in 2 distinct geographical regions of Ecuador. Exposure information was collected via household surveys, and subjects were tested for serological evidence of T. cruzi infection. In total, 3,286 subjects from 997 households were included. In the coastal region, factors associated with seropositivity were living in a house with a palm roof (odds ratio [OR] = 2.63, 95% confidence interval, [1.61. 4.27]), wood walls (OR = 5.75 [2.04, 16.18]), or cane walls (OR = 2.81 11.31, 6.04]), and the presence of firewood in the peridomicile (OR = 2.48 [1.54, 4.01]). Accumulation of trash outside the home was associated with a reduced risk of seropositivity (OR = 0.25 [0.12, 0.51]). In the Andean region, living in a house with adobe walls was the only factor predictive of T. cruzi seropositivity. In conclusion, risk factors for T. cruzi transmission in Ecuador varied by geographic region, probably because of differing behavior of the triatomine vector species in each region. An understanding of the transmission dynamics of T. cruzi in a particular area is necessary for the development of effective Chagas disease control strategies in those areas.

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

    PubMed

    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.

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

    PubMed Central

    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

  14. Do commercial serologic tests for Trypanosoma cruzi infection detect Mexican strains in women and newborns?

    PubMed

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

    2011-04-01

    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.

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

    PubMed

    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.

  16. Trypanosoma cruzi Survival following Cold Storage: Possible Implications for Tissue Banking

    PubMed Central

    Martin, Diana L.; Goodhew, Brook; Czaicki, Nancy; Foster, Kawanda; Rajbhandary, Srijana; Hunter, Shawn; Brubaker, Scott A.

    2014-01-01

    While Trypanosoma cruzi, the etiologic agent of Chagas disease, is typically vector-borne, infection can also occur through solid organ transplantation or transfusion of contaminated blood products. The ability of infected human cells, tissues, and cellular and tissue-based products (HCT/Ps) to transmit T. cruzi is dependent upon T. cruzi surviving the processing and storage conditions to which HCT/Ps are subjected. In the studies reported here, T. cruzi trypomastigotes remained infective 24 hours after being spiked into blood and stored at room temperature (N = 20); in 2 of 13 parasite-infected cultures stored 28 days at 4°C; and in samples stored 365 days at −80°C without cryoprotectant (N = 28), despite decreased viability compared to cryopreserved parasites. Detection of viable parasites after multiple freeze/thaws depended upon the duration of frozen storage. The ability of T. cruzi to survive long periods of storage at +4 and −80°C suggests that T. cruzi-infected tissues stored under these conditions are potentially infectious. PMID:24759837

  17. Heme modulates Trypanosoma cruzi bioenergetics inducing mitochondrial ROS production.

    PubMed

    Nogueira, Natália P; Saraiva, Francis M S; Oliveira, Matheus P; Mendonça, Ana Paula M; Inacio, Job D F; Almeida-Amaral, Elmo E; Menna-Barreto, Rubem F; Laranja, Gustavo A T; Torres, Eduardo J Lopes; Oliveira, Marcus F; Paes, Marcia C

    2017-03-29

    Trypanosoma cruzi is the causative agent of Chagas disease and has a single mitochondrion, an organelle responsible for ATP production and the main site for the formation of reactive oxygen species (ROS). T. cruzi is an obligate intracellular parasite with a complex life cycle that alternates between vertebrate and invertebrate hosts, therefore the development of survival strategies and morphogenetic adaptations to deal with the various environments is mandatory. Over the years our group has been studying the vector-parasite interactions using heme as a physiological oxidant molecule that triggered epimastigote proliferation however, the source of ROS induced by heme remained unknown. In the present study we demonstrate the involvement of heme in the parasite mitochondrial metabolism, decreasing oxygen consumption leading to increased mitochondrial ROS and membrane potential. First, we incubated epimastigotes with carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), an uncoupler of oxidative phosphorylation, which led to decreased ROS formation and parasite proliferation, even in the presence of heme, correlating mitochondrial ROS and T. cruzi survival. This hypothesis was confirmed after the mitochondria-targeted antioxidant ((2-(2,2,6,6 Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (MitoTEMPO) decreased both heme-induced ROS and epimastigote proliferation. Furthermore, heme increased the percentage of tetramethylrhodamine methyl ester (TMRM) positive parasites tremendously-indicating the hyperpolarization and increase of potential of the mitochondrial membrane (ΔΨm). Assessing the mitochondrial functional metabolism, we observed that in comparison to untreated parasites, heme-treated epimastigotes decreased their oxygen consumption, and increased the complex II-III activity. These changes allowed the electron flow into the electron transport system, even though the complex IV (cytochrome c oxidase) activity decreased

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

    PubMed

    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.

  19. Beta-interferon inhibits cell infection by Trypanosoma cruzi

    NASA Technical Reports Server (NTRS)

    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.

  20. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

    PubMed Central

    Lantos, Andrés B.; Carlevaro, Giannina; Araoz, Beatriz; Ruiz Diaz, Pablo; Camara, María de los Milagros; Buscaglia, Carlos A.; Bossi, Mariano; Yu, Hai; Chen, Xi; Bertozzi, Carolyn R.; Mucci, Juan; Campetella, Oscar

    2016-01-01

    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(1,3)Galactosyl 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 soluble form. PMID

  1. Succinate-dependent metabolism in Trypanosoma cruzi epimastigotes.

    PubMed

    Denicola-Seoane, A; Rubbo, H; Prodanov, E; Turrens, J F

    1992-08-01

    Trypanosoma cruzi epimastigotes permeabilized with digitonin (65 micrograms (mg protein)-1) to measure mitochondrial respiration were exposed to different substrates. Although none of the NADH-dependent substrates stimulated respiration, succinate supported not only oxygen consumption but also oxidative phosphorylation (respiratory control ratio of 1.9 +/- 0.3) indicating that the mitochondria were coupled. The rate of NADH-dependent oxygen consumption by membrane fractions (9.4 +/- 0.7 nmol min-1 (mg protein)-1) was reduced by 50% upon addition of catalase indicating that the electrons from NADH oxidation reduced oxygen to H2O2. NADH-dependent H2O2 production (16 +/- 1 nmol min-1 (mg protein)-1) was confirmed using cytochrome c peroxidase. This activity was inhibited by fumarate by 70%, suggesting a competition between fumarate and oxygen for the electrons from NADH, probably at the fumarate reductase level. The respiratory chain inhibitor antimycin blocked both respiration by intact cells and succinate-dependent cytochrome c by isolated membranes. No inhibition by antimycin was observed when NADH replaced succinate as an electron donor, indicating that the electrons from NADH oxidation reduced cytochrome c through a different route. Malonate blocked not only succinate-cytochrome c reductase and fumarate reductase, but also intact cell motility. These results suggest that succinate has a central role in the intermediate metabolism of i. cruzi, as it may be used for respiration or excreted to the extracellular space under anaerobic conditions. In addition, 2 potential sources of H2O2 were tentatively identified as: (a) the enzyme fumarate reductase; and (b) a succinate-dependent site, which may be the semiquinone form of Coenzyme Q9, as in mammalian mitochondria.

  2. Identification of Contractile Vacuole Proteins in Trypanosoma cruzi

    PubMed Central

    Park, Miyoung; Martins, Vicente P.; Atwood, James; Moles, Kristen; Collins, Dalis; Rohloff, Peter; Tarleton, Rick; Moreno, Silvia N. J.; Orlando, Ron; Docampo, Roberto

    2011-01-01

    Contractile vacuole complexes are critical components of cell volume regulation and have been shown to have other functional roles in several free-living protists. However, very little is known about the functions of the contractile vacuole complex of the parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, other than a role in osmoregulation. Identification of the protein composition of these organelles is important for understanding their physiological roles. We applied a combined proteomic and bioinfomatic approach to identify proteins localized to the contractile vacuole. Proteomic analysis of a T. cruzi fraction enriched for contractile vacuoles and analyzed by one-dimensional gel electrophoresis and LC-MS/MS resulted in the addition of 109 newly detected proteins to the group of expressed proteins of epimastigotes. We also identified different peptides that map to at least 39 members of the dispersed gene family 1 (DGF-1) providing evidence that many members of this family are simultaneously expressed in epimastigotes. Of the proteins present in the fraction we selected several homologues with known localizations in contractile vacuoles of other organisms and others that we expected to be present in these vacuoles on the basis of their potential roles. We determined the localization of each by expression as GFP-fusion proteins or with specific antibodies. Six of these putative proteins (Rab11, Rab32, AP180, ATPase subunit B, VAMP1, and phosphate transporter) predominantly localized to the vacuole bladder. TcSNARE2.1, TcSNARE2.2, and calmodulin localized to the spongiome. Calmodulin was also cytosolic. Our results demonstrate the utility of combining subcellular fractionation, proteomic analysis, and bioinformatic approaches for localization of organellar proteins that are difficult to detect with whole cell methodologies. The CV localization of the proteins investigated revealed potential novel roles of these organelles in phosphate metabolism

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

    PubMed

    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.

  4. Transcriptome and Functional Genomics Reveal the Participation of Adenine Phosphoribosyltransferase in Trypanosoma cruzi Resistance to Benznidazole.

    PubMed

    García-Huertas, Paola; Mejía-Jaramillo, Ana María; González, Laura; Triana Chávez, Omar

    2017-03-09

    Currently, the only available treatments for Trypanosoma cruzi are benznidazole (Bz) and nifurtimox (Nfx). The mechanisms of action and resistance to these drugs in this parasite are not complete known. In order to identify differentially expressed transcripts between sensitive and resistant parasites, a massive pyrosequencing of the T. cruzi transcriptome was carried out. Additionally, the 2D gel electrophoresis profile of sensitive and resistant parasites was analyzed and the data were supported with functional genomics. The results showed 133 differentially expressed genes in resistant parasites. The transcriptome analysis revealed the regulation of different genes with several functions and metabolic pathways, which could suggest that resistance in T. cruzi is a multigenic process. Additionally, using transcriptomics, one gene, adenine phosphoribosyltransferase (APRT), was found to be down-regulated in the resistant parasites and its expression profile was confirmed by 2D electrophoresis analysis. The role of this gene in the resistance to Bz was confirmed overexpressing it in sensitive and resistant parasites. Interestingly, both parasites became more sensitive to Bz and H2 O2 . This is the first RNA-seq study to identify regulated genes in T. cruzi associated with Bz resistance and to show the role of APRT in T. cruzi resistance. Although T. cruzi regulation is mainly post-transcriptional, the transcriptome analysis, supported by 2D gel analysis and functional genomic, provides an overall idea of the expression profiles of genes under resistance conditions. These results contribute essential information to further the understanding of the mechanisms of action and resistance to Bz in T. cruzi. This article is protected by copyright. All rights reserved.

  5. Mammalian cell invasion by closely related Trypanosoma species T. dionisii and T. cruzi.

    PubMed

    Maeda, Fernando Yukio; Cortez, Cristian; Alves, Renan Melatto; Yoshida, Nobuko

    2012-02-01

    Protozoan parasites of the genus Trypanosoma can infect virtually all mammalian species. Within this genus, Trypanosoma dionisii from bats and Trypanosoma cruzi that causes Chagas' disease, belonging to the subgenus Schizotrypanum, can invade mammalian cells. The mechanisms of cell invasion by T. dionisii are poorly understood. To address that question, metacyclic trypomastigotes (MT) and human epithelial HeLa cells were used. Similarly to genetically divergent T. cruzi strains G (TcI) and CL (TcVI), associated, respectively with marsupial and human infections, T. dionisii infectivity increased under nutritional stress, a condition that induces host cell lysosome exocytosis required for parasite internalization. For efficient internalization, T. dionisii depended on MT protein tyrosine kinase (PTK) and Ca(2+) mobilization from acidocalcisomes, whereas T. cruzi strains also relied on phosphatidylinositol 3-kinase (PI3K), protein kinase C (PKC) and Ca(2+) released from thapsigargin-sensitive compartments. T. dionisii-induced signaling in host cells implicated PKC and Ca(2+) mobilized from thapsigargin-sensitive stores, like T. cruzi, but without PI3K involvement. Unlike T. cruzi, T. dionisii metacyclic forms did not use l-proline as source of energy required for internalization. Molecules related to T. cruzi surface glycoproteins involved in MT-host cell interaction were undetectable in T. dionisii. The difference in the surface profile of the two species was also inferred from the susceptibility of T. dionisii metacyclic forms to complement-mediated lysis, as opposed to complete resistance of T. cruzi. In summary, the two Trypanosoma species display distinct surface profiles but invade host cells through a common mechanism involving lysosome mobilization to the site of parasite entry.

  6. The Ly49E Receptor Inhibits the Immune Control of Acute Trypanosoma cruzi Infection

    PubMed Central

    Filtjens, Jessica; Coltel, Nicolas; Cencig, Sabrina; Taveirne, Sylvie; Van Ammel, Els; Van Acker, Aline; Kerre, Tessa; Matthys, Patrick; Taghon, Tom; Vandekerckhove, Bart; Carlier, Yves; Truyens, Carine; Leclercq, Georges

    2016-01-01

    The protozoan parasite Trypanosoma cruzi circulates in the blood upon infection and invades various 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-infection. 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. PMID:27891126

  7. Mexican Trypanosoma cruzi T. cruzi I strains with different degrees of virulence induce diverse humoral and cellular immune responses in a murine experimental infection model.

    PubMed

    Espinoza, B; Rico, T; Sosa, S; Oaxaca, E; Vizcaino-Castillo, A; Caballero, M L; Martínez, I

    2010-01-01

    It is has been shown that the majority of T. cruzi strains isolated from Mexico belong to the T. cruzi I (TCI). The immune response produced in response to Mexican T. cruzi I strains has not been well characterized. In this study, two Mexican T. cruzi I strains were used to infect Balb/c mice. The Queretaro (TBAR/MX/0000/Queretaro)(Qro) strain resulted in 100% mortality. In contrast, no mortality was observed in mice infected with the Ninoa (MHOM/MX/1994/Ninoa) strain. Both strains produced extended lymphocyte infiltrates in cardiac tissue. Ninoa infection induced a diverse humoral response with a higher variety of immunoglobulin isotypes than were found in Qro-infected mice. Also, a stronger inflammatory TH1 response, represented by IL-12p40, IFNgamma, RANTES, MIG, MIP-1beta, and MCP-1 production was observed in Qro-infected mice when compared with Ninoa-infected mice. We propose that an exacerbated TH1 immune response is a likely cause of pathological damage observed in cardiac tissue and the primary cause of death in Qro-infected mice.

  8. Mexican Trypanosoma cruzi T. cruzi I Strains with Different Degrees of Virulence Induce Diverse Humoral and Cellular Immune Responses in a Murine Experimental Infection Model

    PubMed Central

    Espinoza, B.; Rico, T.; Sosa, S.; Oaxaca, E.; Vizcaino-Castillo, A.; Caballero, M. L.; Martínez, I.

    2010-01-01

    It is has been shown that the majority of T. cruzi strains isolated from Mexico belong to the T. cruzi I (TCI). The immune response produced in response to Mexican T. cruzi I strains has not been well characterized. In this study, two Mexican T. cruzi I strains were used to infect Balb/c mice. The Queretaro (TBAR/MX/0000/Queretaro)(Qro) strain resulted in 100% mortality. In contrast, no mortality was observed in mice infected with the Ninoa (MHOM/MX/1994/Ninoa) strain. Both strains produced extended lymphocyte infiltrates in cardiac tissue. Ninoa infection induced a diverse humoral response with a higher variety of immunoglobulin isotypes than were found in Qro-infected mice. Also, a stronger inflammatory TH1 response, represented by IL-12p40, IFNγ, RANTES, MIG, MIP-1β, and MCP-1 production was observed in Qro-infected mice when compared with Ninoa-infected mice. We propose that an exacerbated TH1 immune response is a likely cause of pathological damage observed in cardiac tissue and the primary cause of death in Qro-infected mice. PMID:20396398

  9. Genetic Variability and Phylogenetic Relationships within Trypanosoma cruzi I Isolated in Colombia Based on Miniexon Gene Sequences

    PubMed Central

    Herrera, Claudia; Guhl, Felipe; Falla, Alejandra; Fajardo, Anabella; Montilla, Marleny; Adolfo Vallejo, Gustavo; Bargues, M. Dolores

    2009-01-01

    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. PMID:20798881

  10. Trans-Sialidase Inhibition Assay Detects Trypanosoma cruzi Infection in Different Wild Mammal Species

    PubMed Central

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

    2013-01-01

    Abstract 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. PMID:23930975

  11. Molecular characterization and intracellular distribution of the alpha 5 subunit of Trypanosoma cruzi 20S proteasome.

    PubMed

    Gutiérrez, Bessy; Osorio, Luis; Motta, María Cristina M; Huima-Byron, Telervo; Erdjument-Bromage, Heydeie; Muñoz, Christian; Sagua, Hernán; Mortara, Renato A; Echeverría, Alex; Araya, Jorge E; González, Jorge

    2009-12-01

    Three different monoclonal antibodies were produced against Trypanosona cruzi proteasomes. These antibodies were shown to react with a single 27-kDa band on immunoblots of purified proteasomes. Using a 7E5 monoclonal antibody (IgG1) that recognized the alpha5 subunit of protozoan protease we have studied the intracellular distribution of the T. cruzi 20S proteasome. Contrary to all cell types described to date, T. cruzi 20S proteasome was found not only in the cytoplasm and nucleus but also in the kinetoplast. As revealed by confocal microscopy, the reactivity of monoclonal antibody 7E5 was highly specific for protozoan proteasome because the antibody recognized only the proteasomes from parasites and not those from the mammalian host in T. cruzi infected cells. These findings were confirmed by immunoblots or immunoprecipitations, followed by chymotrypsin-like activity detection in kinetoplasts isolated by differential centrifugation and sucrose density gradients. Proteasome 20S was present in all T. cruzi stages and only slight differences in terms of relative abundance were found. The potential role of the proteasome in kinetoplast remodeling remains to be determined.

  12. From genome screening to creation of vaccine against Trypanosoma cruzi by use of immunoinformatics.

    PubMed

    Teh-Poot, Christian; Tzec-Arjona, Evelyn; Martínez-Vega, Pedro; Ramirez-Sierra, Maria Jesus; Rosado-Vallado, Miguel; Dumonteil, Eric

    2015-01-15

    Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and activation of CD8(+) T cells is crucial for a protective immune response. Therefore, the identification of antigens with major histocompatibility complex class I epitopes is a crucial step for vaccine development against T. cruzi. Our aim was to identify novel antigens and epitopes by immunoinformatics analysis of the parasite proteome (12 969 proteins) and to validate their immunotherapeutic potential in infected mice. We identified 172 predicted epitopes, using NetMHC and RANKPEP. The corresponding protein sequences were reanalyzed to generate a consensus prediction, and 26 epitopes were selected for in vivo validation. The interferon γ (IFN-γ) recall response of splenocytes from T. cruzi-infected mice confirmed that 10 of 26 epitopes (38%) induced IFN-γ production. The immunotherapeutic potential of a mixture of all 10 peptides was evaluated in infected mice. The therapeutic vaccine was able to control T. cruzi infection, as evidenced by reduced parasitemia, cardiac tissue inflammation, and parasite burden and increased survival. These findings illustrate the benefits of this approach for the rapid development of a vaccine against pathogens with large genomes. The identified peptides and the proteins from which they are derived are excellent candidates for the development of a vaccine against T. cruzi.

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

    PubMed Central

    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

  14. Purification and characterization of an 80-kilodalton Trypanosoma cruzi urinary antigen.

    PubMed Central

    Corral, R S; Orn, A; Freilij, H L; Bergman, T; Grinstein, S

    1989-01-01

    A Trypanosoma cruzi antigen eliminated in the urine of experimentally infected dogs was detected by enzyme-linked immunosorbent assay between 9 and 28 days after infection. The parasite urinary antigen (UAg) was purified by affinity chromatography with polyclonal antibodies to T. cruzi. The eluate of the antibody column was subjected to high-performance liquid chromatography and showed a single peak of A280. This antigen was the only parasite component found in the urine of infected dogs during the course of acute T. cruzi infection. Antigen characterization was performed by two-dimensional gel electrophoresis, lectin affinity chromatography, proteolytic digestion, and Western blotting (immunoblotting). The isolated UAg exhibited a relative molecular size of 80 kilodaltons (kDa), an isoelectric point of 6.2 to 6.8, binding to concanavalin A, and sensitivity to trypsin. The parasite antigen was electroeluted from polyacrylamide gels and subjected to acid hydrolysis and amino acid analysis by reverse-phase high-performance liquid chromatography. The 80-kDa glycoprotein was recognized by serum antibodies from a wide variety of T. cruzi-infected hosts. The UAg proved to be a highly antigenic component present in different strains of T. cruzi. This 80-kDa polypeptide resembles one of the parasite antigens previously found in the urine of patients with acute Chagas' disease. Images PMID:2643616

  15. Identification of major Trypanosoma cruzi antigenic determinants in chronic Chagas' heart disease.

    PubMed

    Levin, M J; Mesri, E; Benarous, R; Levitus, G; Schijman, A; Levy-Yeyati, P; Chiale, P A; Ruiz, A M; Kahn, A; Rosenbaum, M B

    1989-11-01

    To identify Trypanosoma cruzi target antigens in overt Chagas' heart disease, a parasite lambda gt11 cDNA library was screened with the serum of a patient with a severe chagasic heart involvement (JL). Using a phage dot array immunoassay, 5 highly antigenic clones, JL1, JL5, JL7, JL8, and JL9, were probed with sera from clinically characterized T. cruzi infected subjects. The correlation of cloned T. cruzi antigen recognition with the clinical status of the subjects led to the identification of a recombinant antigen, JL5, that reacted predominantly with sera from patients with Chagas' heart disease. The antigenic determinant of the JL5 recombinant was a small 35 amino acid peptide. The nucleotide and the deduced amino acid sequence, together with other experimental data, allowed identification as the C-terminal portion of a T. cruzi P ribosomal protein. The C-terminal undecapeptide in JL5, EDDDMGFGLFD, was highly homologous to the same region of the human P protein SD(D/E)DMGFGLFD. The latter sequence has been identified as the P protein epitope in systemic lupus erythematosus (SLE). Positive SLE sera reacted with the JL5 recombinant phage, suggesting that the T. cruzi P protein might induce antibodies with a similar specificity to that of P antibodies in SLE.

  16. Glyceraldehyde 3-phosphate dehydrogenase-telomere association correlates with redox status in Trypanosoma cruzi.

    PubMed

    Pariona-Llanos, Ricardo; Pavani, Raphael Souza; Reis, Marcelo; Noël, Vincent; Silber, Ariel Mariano; Armelin, Hugo Aguirre; Cano, Maria Isabel Nogueira; Elias, Maria Carolina

    2015-01-01

    Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a classical metabolic enzyme involved in energy production and plays a role in additional nuclear functions, including transcriptional control, recognition of misincorporated nucleotides in DNA and maintenance of telomere structure. Here, we show that the recombinant protein T. cruzi GAPDH (rTcGAPDH) binds single-stranded telomeric DNA. We demonstrate that the binding of GAPDH to telomeric DNA correlates with the balance between oxidized and reduced forms of nicotinamide adenine dinucleotides (NAD+/NADH). We observed that GAPDH-telomere association and NAD+/NADH balance changed throughout the T. cruzi life cycle. For example, in replicative epimastigote forms of T. cruzi, which show similar intracellular concentrations of NAD+ and NADH, GAPDH binds to telomeric DNA in vivo and this binding activity is inhibited by exogenous NAD+. In contrast, in the T. cruzi non-proliferative trypomastigote forms, which show higher NAD+ concentration, GAPDH was absent from telomeres. In addition, NAD+ abolishes physical interaction between recombinant GAPDH and synthetic telomere oligonucleotide in a cell free system, mimicking exogenous NAD+ that reduces GAPDH-telomere interaction in vivo. We propose that the balance in the NAD+/NADH ratio during T. cruzi life cycle homeostatically regulates GAPDH telomere association, suggesting that in trypanosomes redox status locally modulates GAPDH association with telomeric DNA.

  17. Glyceraldehyde 3-Phosphate Dehydrogenase-Telomere Association Correlates with Redox Status in Trypanosoma cruzi

    PubMed Central

    Pariona-Llanos, Ricardo; Pavani, Raphael Souza; Reis, Marcelo; Noël, Vincent; Silber, Ariel Mariano; Armelin, Hugo Aguirre; Cano, Maria Isabel Nogueira; Elias, Maria Carolina

    2015-01-01

    Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a classical metabolic enzyme involved in energy production and plays a role in additional nuclear functions, including transcriptional control, recognition of misincorporated nucleotides in DNA and maintenance of telomere structure. Here, we show that the recombinant protein T. cruzi GAPDH (rTcGAPDH) binds single-stranded telomeric DNA. We demonstrate that the binding of GAPDH to telomeric DNA correlates with the balance between oxidized and reduced forms of nicotinamide adenine dinucleotides (NAD+/NADH). We observed that GAPDH-telomere association and NAD+/NADH balance changed throughout the T. cruzi life cycle. For example, in replicative epimastigote forms of T. cruzi, which show similar intracellular concentrations of NAD+ and NADH, GAPDH binds to telomeric DNA in vivo and this binding activity is inhibited by exogenous NAD+. In contrast, in the T. cruzi non-proliferative trypomastigote forms, which show higher NAD+ concentration, GAPDH was absent from telomeres. In addition, NAD+ abolishes physical interaction between recombinant GAPDH and synthetic telomere oligonucleotide in a cell free system, mimicking exogenous NAD+ that reduces GAPDH-telomere interaction in vivo. We propose that the balance in the NAD+/NADH ratio during T. cruzi life cycle homeostatically regulates GAPDH telomere association, suggesting that in trypanosomes redox status locally modulates GAPDH association with telomeric DNA. PMID:25775131

  18. Epidemiology of American Tegumentary Leishmaniasis and Trypanosoma cruzi Infection in the Northwestern Argentina

    PubMed Central

    Hoyos, Carlos L.; Cajal, Silvana P.; Juarez, Marisa; Marco, Jorge D.; Alberti D'Amato, Anahí M.; Cayo, Melina; Torrejón, Irma; Cimino, Rubén O.; Diosque, Patricio; Nasser, Julio R.

    2016-01-01

    Background. Endemic areas of tegumentary leishmaniasis (TL) in Salta, Argentina, present some overlap zones with the geographical distribution of Chagas disease, with mixed infection cases being often detected. Objectives. The purpose of this study was to determine the magnitude of Leishmania sp. infection and potential associated risk factors, the serologic prevalence of T. cruzi, and the presence of T. cruzi-Leishmania sp. mixed infection in a region of the northwest of Argentina. Methods. Cross-sectional studies were conducted to detect TL prevalence and T. cruzi seroprevalence. A case-control study was conducted to examine leishmaniasis risk factors. Results. Prevalence of TL was 0.17%, seroprevalence of T. cruzi infection was 9.73%, and mixed infection proportion—within the leishmaniasic patients group—was 16.67%. The risk factors associated with TL transmission were sex, age, exposure to bites at work, staying outdoors more than 10 hours/day, bathing in the river, and living with people who had lesions or were infected during the study. Discussion. The endemic pattern of TL seems to involve exposure of patients to vectors in wild as well as peridomestic environment. Cases of T. cruzi infection are apparently due to migration. Therefore, a careful epidemiological surveillance is necessary due to the contraindication of antimonial administration to chagasic patients. PMID:27777950

  19. Antiparasitic evaluation of betulinic acid derivatives reveals effective and selective anti-Trypanosoma cruzi inhibitors.

    PubMed

    Meira, Cássio Santana; Barbosa-Filho, José Maria; Lanfredi-Rangel, Adriana; Guimarães, Elisalva Teixeira; Moreira, Diogo Rodrigo Magalhães; Soares, Milena Botelho Pereira

    2016-07-01

    Betulinic acid is a pentacyclic triterpenoid with several biological properties already described, including antiparasitic activity. Here, the anti-Trypanosoma cruzi activity of betulinic acid and its semi-synthetic amide derivatives (BA1-BA8) was investigated. The anti-Trypanosoma cruzi activity and selectivity were enhanced in semi-synthetic derivatives, specially on derivatives BA5, BA6 and BA8. To understand the mechanism of action underlying betulinic acid anti-T. cruzi activity, we investigated ultrastructural changes by electron microscopy. Ultrastructural studies showed that trypomastigotes incubated with BA5 had membrane blebling, flagella retraction, atypical cytoplasmic vacuoles and Golgi cisternae dilatation. Flow cytometry analysis showed that parasite death is mainly caused by necrosis. Treatment with derivatives BA5, BA6 or BA8 reduced the invasion process, as well as intracellular parasite development in host cells, with a potency and selectivity similar to that observed in benznidazole-treated cells. More importantly, the combination of BA5 and benznidazole revealed synergistic effects on trypomastigote and amastigote forms of T. cruzi. In conclusion, we demonstrated that BA5 compound is an effective and selective anti-T. cruzi agent.

  20. Trypanosoma cruzi infection in captive Neotropical primates in the Brazilian Amazon.

    PubMed

    Bahia, Michele; de Nazaré Leite Barros, Flávia; Magalhães-Matos, Paulo Cesar; de Souza Gonçalves, Thamirys; Chiesorin Neto, Laerzio; Oliveira Faria, Diogo Cesar Lagroteria; Aparecida Romeiro, Sandra; Barros Monteiro, Frederico Ozanan; Góes-Cavalcante, Gustavo; Scofield, Alessandra

    2017-02-01

    The aim of this study was to detect the infection by Trypanosoma cruzi in captive Neotropical primates in the Brazilian Amazon. From February 2013 to July 2014, 112 blood samples were collected from Neotropical primates from the Amazonas, Amapá, and Pará States, north of Brazil. The subjects belonged to the families Cebidae (N = 59), Atelidae (N = 41), Callitrichidae (N = 5), Pitheciidae (N = 4), and Aotidae (N = 3). Blood smears also were examined for the presence of trypomastigotes by optical microscopy. For the detection of T. cruzi DNA, a Nested-PCR with primers TCZ1/TCZ2 and TCZ3/TCZ4 was performed. T. cruzi DNA was detected in 12.5% (14/112) of Neotropical primates examined. Positive samples were detected in 16%, 12.5%, and 11.11% of the different species of primates sampled from the Amapá, Pará, and Amazonas states, respectively. The analysis of the blood smears did not reveal trypomastigote forms of T. cruzi. In conclusion, Neotropical primates kept in captivity were infected by T. cruzi in the studied areas. We recommend that a health management protocol be put into place to prevent the transmission of infectious agents among captive populations, captive and wild populations, and between NHPs and the technicians who handle these animals.

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

    PubMed Central

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

    2015-01-01

    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 hodnius 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. PMID:26560985

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

    PubMed

    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.

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

    PubMed

    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.

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

    SciTech Connect

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

    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.

  5. Activities of Psilostachyin A and Cynaropicrin against Trypanosoma cruzi In Vitro and In Vivo

    PubMed Central

    da Silva, Cristiane França; Batista, Denise da Gama Jaen; De Araújo, Julianna Siciliano; Batista, Marcos Meuser; Lionel, Jessica; de Souza, Elen Mello; Hammer, Erica Ripoll; da Silva, Patricia Bernardino; De Mieri, Maria; Adams, Michael; Zimmermann, Stefanie; Hamburger, Matthias; Brun, Reto; Schühly, Wolfgang

    2013-01-01

    In vitro and in vivo activities against Trypanosoma cruzi were evaluated for two sesquiterpene lactones: psilostachyin A and cynaropicrin. Cynaropicrin had previously been shown to potently inhibit African trypanosomes in vivo, and psilostachyin A had been reported to show in vivo effects against T. cruzi, albeit in another test design. In vitro data showed that cynaropicrin was more effective than psilostachyin A. Ultrastructural alterations induced by cynaropicrin included shedding events, detachment of large portions of the plasma membrane, and vesicular bodies and large vacuoles containing membranous structures, suggestive of parasite autophagy. Acute toxicity studies showed that one of two mice died at a cynaropicrin dose of 400 mg/kg of body weight given intraperitoneally (i.p.). Although no major plasma biochemical alterations could be detected, histopathology demonstrated that the liver was the most affected organ in cynaropicrin-treated animals. Although cynaropicrin was as effective as benznidazole against trypomastigotes in vitro, the treatment (once or twice a day) of T. cruzi-infected mice (up to 50 mg/kg/day cynaropicrin) did not suppress parasitemia or protect against mortality induced by the Y and Colombiana strains. Psilostachyin A (0.5 to 50 mg/kg/day given once a day) was not effective in the acute model of T. cruzi infection (Y strain), reaching 100% animal mortality. Our data demonstrate that although it is very promising against African trypanosomes, cynaropicrin does not show efficacy compared to benznidazole in acute mouse models of T. cruzi infection. PMID:23939901

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

    PubMed

    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.

  7. Emerging Chagas disease: trophic network and cycle of transmission of Trypanosoma cruzi from palm trees in the Amazon.

    PubMed Central

    Teixeira, A. R.; Monteiro, P. S.; Rebelo, J. M.; Argañaraz, E. R.; Vieira, D.; Lauria-Pires, L.; Nascimento, R.; Vexenat, C. A.; Silva, A. R.; Ault, S. K.; Costa, J. M.

    2001-01-01

    A trophic network involving molds, invertebrates, and vertebrates, ancestrally adapted to the palm tree (Attalaea phalerata) microhabitat, maintains enzootic Trypanosoma cruzi infections in the Amazonian county Paço do Lumiar, state of Maranhão, Brazil. We assessed seropositivity for T. cruzi infections in the human population of the county, searched in palm trees for the triatomines that harbor these infections, and gathered demographic, environmental, and socioeconomic data. Rhodnius pictipes and R. neglectus in palm-tree frond clefts or in houses were infected with T. cruzi (57% and 41%, respectively). Human blood was found in 6.8% of R. pictipes in houses, and 9 of 10 wild Didelphis marsupialis had virulent T. cruzi infections. Increasing human population density, rain forest deforestation, and human predation of local fauna are risk factors for human T. cruzi infections. PMID:11266300

  8. Aromatic glycosyl disulfide derivatives: evaluation of their inhibitory activities against Trypanosoma cruzi.

    PubMed

    Gutiérrez, Bessy; Muñoz, Christian; Osorio, Luis; Fehér, Krisztina; Illyés, Tünde-Zita; Papp, Zsuzsa; Kumar, Ambati Ashok; Kövér, Katalin E; Sagua, Hernán; Araya, Jorge E; Morales, Patricio; Szilágyi, László; González, Jorge

    2013-06-15

    Aromatic oligovalent glycosyl disulfides and some diglycosyl disulfides were tested against three different Trypanosoma cruzi strains. Di-(β-D-galactopyranosyl-dithiomethylene) benzenes 2b and 4b proved to be the most active derivatives against all three strains of cell culture-derived trypomastigotes with IC50 values ranging from 4 to 11 μM at 37 °C. The inhibitory activities were maintained, although somewhat lowered, at a temperature of 4 °C as well. Three further derivatives displayed similar activities against at least one of the three strains. Low cytotoxicities of the active compounds, tested on confluent HeLa, Vero and peritoneal macrophage cell cultures, resulted in significantly higher selectivity indices (SI) than that of the reference drug benznidazole. Remarkably, several molecules of the tested panel strongly inhibited the parasite release from T. cruzi infected HeLa cell cultures suggesting an effect against the intracellular development of T. cruzi amastigotes as well.

  9. The natural compounds piperovatine and piperlonguminine induce autophagic cell death on Trypanosoma cruzi.

    PubMed

    Veiga-Santos, Phercyles; Desoti, Vânia Cristina; Miranda, Nathielle; Ueda-Nakamura, Tânia; Dias-Filho, Benedito Prado; Silva, Sueli Oliveira; Cortez, Diogenes Aparício Garcia; de Mello, João Carlos Palazzo; Nakamura, Celso Vataru

    2013-03-01

    The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Our group has been attempting to find alternative drugs isolated from natural products as a potential source of pharmacological agents against Trypanosoma cruzi. Here, we demonstrate the antitrypanosomal activity of the amides piperovatine and piperlonguminine isolated from Piper ovatum against epimastigotes and intracellular amastigotes. We also investigated the mechanisms of action of these compounds on extracellular amastigote and epimastigote forms of T. cruzi. These amides showed low toxicity to LLCMK(2) mammalian cells. By using transmission and scanning electron microscopy, we observed that the compounds caused severe alterations in T. cruzi. These alterations were mainly located in plasma membrane and mitochondria. Furthermore, the study of treated parasites labeled with Rh123, PI and MDC corroborate with our TEM data. These mitochondrial dysfunctions induced by the amides might trigger biochemical alterations that lead to cell death. Altogether, our data evidence a possible autophagic process.

  10. Trypanosoma cruzi: characterization of reinfection and search for tissue tropism in hamsters (Mesocricetus auratus).

    PubMed

    Cabrine-Santos, M; Lages Silva, E; Chapadeiro, E; Ramírez, L E

    2001-11-01

    Tissue tropism, the role of reinfection in the development of Chagas' disease, and the selection of subpopulations of Trypanosoma cruzi were evaluated in hamsters inoculated with the VIC strain of T. cruzi. Adult allogeneic male hamsters were inoculated once or reinoculated by the intraperitoneal route up to four times with 2000 blood trypomastigotes. Animals were studied by blood culture, histopathology, immunohistochemistry, and molecular techniques (PCR and low-stringency single specific primer-PCR). Homogeneity of the T. cruzi population observed in different tissues suggests that selective tropism of the VIC strain extends only to various muscle tissues in hamsters and that reinfection is not a factor in the development of the inflammatory processes, although it may aggravate it, possibly due to an increase in tissue parasitism, which might induce autoimmune mechanisms. Reinfection did not induce selection of subpopulations in the tissue or in the blood.

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

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

    PubMed Central

    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

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

    PubMed

    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.

  15. Trypanosoma cruzi trans-sialidase as a drug target against Chagas disease (American trypanosomiasis).

    PubMed

    Miller, Bill R; Roitberg, Adrian E

    2013-10-01

    Chagas disease (or American trypanosomiasis) is a deadly tropical disease that affects millions of people worldwide, primarily in rural regions of South America. Trypanosoma cruzi, the parasitic cause of Chagas disease, possesses a membrane-anchored trans-sialidase enzyme that transfers sialic acids from the host cell surface to the parasitic cell surface, allowing T. cruzi to effectively evade the host's immune system. This enzyme has no analogous human counterpart and thus has become an interesting drug target to combat the parasite. Recent computational efforts have improved our knowledge about the enzyme's structure, dynamics and catalyzed reaction. Many compounds have been tested against trans-sialidase activity, but no strong inhibitors have been identified yet. The current lack of drugs for Chagas disease necessitates more R&D into the design and discovery of strong inhibitors of T. cruzi trans-sialidase.

  16. An automatic algorithm for the detection of Trypanosoma cruzi parasites in blood sample images.

    PubMed

    Soberanis-Mukul, Roger; Uc-Cetina, Víctor; Brito-Loeza, Carlos; Ruiz-Piña, Hugo

    2013-12-01

    Chagas disease is a tropical parasitic disease caused by the flagellate protozoan Trypanosoma cruzi (T. cruzi) and currently affecting large portions of the Americas. One of the standard laboratory methods to determine the presence of the parasite is by direct visualization in blood smears stained with some colorant. This method is time-consuming, requires trained microscopists and is prone to human mistakes. In this article we propose a novel algorithm for the automatic detection of T. cruzi parasites, in microscope digital images obtained from peripheral blood smears treated with Wright's stain. Our algorithm achieved a sensitivity of 0.98 and specificity of 0.85 when evaluated against a dataset of 120 test images. Experimental results show the versatility of the method for parasitemia determination.

  17. Gene expression and molecular modeling of the HSP104 chaperone of Trypanosoma cruzi.

    PubMed

    Campos, R A; da Silva, M L; da Costa, G V; Bisch, P M; Peralta, J M; Silva, R; Rondinelli, E; Urményi, T P

    2012-08-06

    Heat shock protein (HSP) 104 is a highly conserved molecular chaperone that catalyzes protein unfolding, disaggregation and degradation under stress conditions. We characterized HSP104 gene structure and expression in Trypanosoma cruzi, a protozoan parasite that causes Chagas' disease. The T. cruzi HSP104 is an 869 amino-acid protein encoded by a single-copy gene that has the highest sequence similarity (76%) with that of T. brucei and the lowest (23%) with that of the human protein. HSP104 transcripts were detected at room temperature, and levels increased after incubation at 37° or 40°C. The HSP104 protein was found at low levels in non-heat-shocked cells, and accumulated continuously up to 24 h at elevated temperatures. We developed a predicted structural model of hexameric T. cruzi HSP104, which showed some conserved features.

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

    PubMed Central

    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

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

    PubMed Central

    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

  20. Phylogenetic character mapping of proteomic diversity shows high correlation with subspecific phylogenetic diversity in Trypanosoma cruzi

    PubMed Central

    Telleria, Jenny; Biron, David G.; Brizard, Jean-Paul; Demettre, Edith; Séveno, Martial; Barnabé, Christian; Ayala, Francisco J.; Tibayrenc, Michel

    2010-01-01

    We performed a phylogenetic character mapping on 26 stocks of Trypanosoma cruzi, the parasite responsible for Chagas disease, and 2 stocks of the sister taxon T. cruzi marinkellei to test for possible associations between T. cruzi–subspecific phylogenetic diversity and levels of protein expression, as examined by proteomic analysis and mass spectrometry. We observed a high level of correlation (P < 10−4) between genetic distance, as established by multilocus enzyme electrophoresis, and proteomic dissimilarities estimated by proteomic Euclidian distances. Several proteins were found to be specifically associated to T. cruzi phylogenetic subdivisions (discrete typing units). This study explores the previously uncharacterized links between infraspecific phylogenetic diversity and gene expression in a human pathogen. It opens the way to searching for new vaccine and drug targets and for identification of specific biomarkers at the subspecific level of pathogens. PMID:21059959

  1. Role of Trypanosoma cruzi Trans-sialidase on the Escape from Host Immune Surveillance

    PubMed Central

    Nardy, Ana F. F. R.; Freire-de-Lima, Celio G.; Pérez, Ana R.; Morrot, Alexandre

    2016-01-01

    Chagas disease is caused by the flagellate protozoan Trypanosoma cruzi, affecting millions of people throughout Latin America. The parasite dampens host immune response causing modifications in diverse lymphoid compartments, including the thymus. T. cruzi trans-sialidase (TS) seems to play a fundamental role in such immunopathological events. This unusual enzyme catalyses the transference of sialic acid molecules from host glycoconjugates to acceptor molecules placed on the parasite surface. TS activity mediates several biological effects leading to the subversion of host immune system, hence favoring both parasite survival and the establishment of chronic infection. This review summarizes current findings on the roles of TS in the immune response during T. cruzi infection. PMID:27047464

  2. Trypanosoma cruzi, the Causal Agent of Chagas Disease: Boundaries between Wild and Domestic Cycles in Venezuela

    PubMed Central

    Herrera, Leidi

    2014-01-01

    Trypanosoma cruzi the etiological agent of American Trypanosomiasis or Chagas disease (ChD) is transmitted by triatomines vectors between mammals including man. T. cruzi has existed for circa 150 Ma in the Americas and nearly 10 million people are currently infected. The overlap between wild and domestic ecotopes where T. cruzi circulates is increasing. Host–parasite interactions have been determined by infection patterns in these cycles, all under natural or laboratorial conditions. This mini-review describes specific parasite niches, such as plant communities or biological corridors between domestic and wild landscapes, in order to help identify risk factors for ChD and define the boundaries between wild and domestic transmission cycles, with an emphasis on research undertaken in Venezuela. PMID:25506587

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

    PubMed

    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.

  4. A shuttle vector which facilitates the expression of transfected genes in Trypanosoma cruzi and Leishmania.

    PubMed Central

    Kelly, J M; Ward, H M; Miles, M A; Kendall, G

    1992-01-01

    A Trypanosoma cruzi expression vector has been constructed using sequences derived from the flanking regions of the glyceraldehyde 3-phosphate dehydrogenase (gGAPDH) genes. The neomycin phosphotransferase (neor) gene was incorporated as a selectable marker. Using electroporation we have introduced this vector into both T. cruzi and Leishmania cells and conferred G418 resistance. Transformation is mediated by large extrachromosomal circular elements composed of head-to-tail tandem repeats of the vector. The transformed phenotype is stable for at least 6 months in the absence of G418 and can be maintained during passage through the T. cruzi life-cycle. Foreign genes inserted into an expression site within the vector (pTEX) can be expressed at high levels in transformed cells. To our knowledge this paper describes the first trypanosome shuttle vector and the first vector which functions in both trypanosomes and Leishmania. Images PMID:1324472

  5. Cyclic AMP-dependent protein kinase activity in Trypanosoma cruzi.

    PubMed Central

    Ulloa, R M; Mesri, E; Esteva, M; Torres, H N; Téllez-Iñón, M T

    1988-01-01

    A cyclic AMP-dependent protein kinase activity from epimastigote forms of Trypanosoma cruzi was characterized. Cytosolic extracts were chromatographed on DEAE-cellulose columns, giving two peaks of kinase activity, which were eluted at 0.15 M- and 0.32 M-NaCl respectively. The second activity peak was stimulated by nanomolar concentrations of cyclic AMP. In addition, a cyclic AMP-binding protein co-eluted with the second kinase activity peak. Cyclic AMP-dependent protein kinase activity was further purified by gel filtration, affinity chromatography on histone-agarose and cyclic AMP-agarose, as well as by chromatography on CM-Sephadex. The enzyme ('holoenzyme') could be partially dissociated into two different components: 'catalytic' and 'regulatory'. The 'regulatory' component had specific binding for cyclic AMP, and it inhibited phosphotransferase activity of the homologous 'catalytic component' or of the 'catalytic subunit' from bovine heart. Cyclic AMP reversed these inhibitions. A 'holoenzyme preparation' was phosphorylated in the absence of exogenous phosphate acceptor and analysed by polyacrylamide-gel electrophoresis. A 56 kDa band was phosphorylated. The same preparation was analysed by Western blotting, by using polyclonal antibodies to the regulatory subunits of protein kinases type I or II. Both antibodies reacted with the 56 kDa band. Images Fig. 7. Fig. 8. PMID:2848508

  6. Cell-substrate adhesion during Trypanosoma cruzi differentiation

    PubMed Central

    1988-01-01

    The transformation of Trypanosoma cruzi epimastigotes to the mammal infective metacyclic trypomastigotes (metacyclogenesis) can be performed in vitro under chemically defined conditions. Under these conditions, differentiating epimastigotes adhere to a surface before their transformation into metacyclic trypomastigotes. Scanning and transmission electron microscopy of adhered and non-adhered parasites during the metacyclogenesis process show that only epimastigotes and few transition forms are found in the first population, whereas metacyclic trypomastigotes are exclusively found in the cell culture supernatant. PAGE analysis of the [35S]methionine metabolic labeling products of adhered and non-adhered parasites shows that although most of the polypeptides are conserved, adhered parasites express specifically four polypeptides in the range of 45-50 kD with an isoelectric point of 4.8. These proteins might be involved in the adhesion process and are recognized by an antiserum against total adhered parasite proteins. This antiserum also recognized a group of 45- 50 kD in the iodine-radiolabeled surface proteins of differentiating cells, providing direct evidence that these components are indeed surface antigens. The results suggest that epimastigotes must adhere to a substrate before their transformation to metacyclic trypomastigotes, being released to the medium as the metacyclogenesis process is accomplished. This could correspond to the process naturally occurring within the triatomine invertebrate host. PMID:3283152

  7. Murine models susceptibility to distinct Trypanosoma cruzi I genotypes infection.

    PubMed

    León, Cielo M; Montilla, Marleny; Vanegas, Ricardo; Castillo, Maria; Parra, Edgar; Ramírez, Juan David

    2017-04-01

    Chagas disease is a complex zoonosis that affects around 8 million people worldwide. This pathology is caused by Trypanosoma cruzi, a kinetoplastid parasite that shows tremendous genetic diversity evinced in six distinct Discrete Typing Units (TcI-TcVI) including a recent genotype named as TcBat and associated with anthropogenic bats. TcI presents a broad geographical distribution and has been associated with chronic cardiomyopathy. Recent phylogenetic studies suggest the existence of two genotypes (Domestic (TcIDom) and sylvatic TcI) within TcI. The understanding of the course of the infection in different mouse models by these two genotypes is not yet known. Therefore, we infected 126 animals (ICR-CD1, National Institute of Health (NIH) and Balb/c) with two TcIDom strains and one sylvatic strain for a follow-up period of 60 days. We quantified the parasitaemia, immune response and histopathology observing that the maximum day of parasitaemia was achieved at day 21 post-infection. Domestic strains showed higher parasitaemia than the sylvatic strain in the three mouse models; however in the survival curves Balb/c mice were less susceptible to infection compared with NIH and ICR-CD1. Our results suggest that the genetic background plays a fundamental role in the natural history of the infection and the sympatric TcI genotypes have relevant implications in disease pathogenesis.

  8. Trypanosoma cruzi: histopathology of endocrine system in immunocompromised mice.

    PubMed Central

    Calabrese, K. S.; Lagrange, P. H.; da Costa, S. C.

    1994-01-01

    Naturally immunocompromised athymic mice, neonatal mice and adult outbred OFI mice treated with the immunosuppressive agents cyclophosphamide (CY), dexamethasone (DM) and indomethacin (IM) were infected with trypomastigotes of Trypanosoma cruzi Y and CL strains. 10(4) parasites were used, except in the case of IM treatment, where mice received 10(3) trypomastigotes in one group and 10(5) in another. The course of parasitaemia, tissue distribution of amastigotes and time of mortality were compared with an infected thymus intact control group. Neonate and indomethacin treated mice presented the same pattern of parasitaemia. Death occurred as early as 9-10 days after infection. A single dose of CY 200 mg/kg given 5 days after infection enhanced the parasitaemia and increased the number of parasites in the tissues. All groups were similar in terms of colonization of the endocrine system by parasites and the adrenals showed the highest density of amastigotes nests. The thyroid gland (analysed only in neonates) showed intense amastigote accumulation. Colonization of the ovary was observed with amastigotes in both the theca interna and in the stroma. The testes (also examined only in the neonate) showed that the interstitial cells, the tunica albuginea of the seminiferous tubules and the loose connective tissue were infected. Athymic nude mice showed the most intense parasite colonization of the islets of Langerhans. Images Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:7734334

  9. Trypanosoma cruzi Gene Expression in Response to Gamma Radiation

    PubMed Central

    Grynberg, Priscila; Passos-Silva, Danielle Gomes; Mourão, Marina de Moraes; Hirata Jr, Roberto; Macedo, Andrea Mara; Machado, Carlos Renato; Bartholomeu, Daniella Castanheira; Franco, Glória Regina

    2012-01-01

    Trypanosoma cruzi is an organism highly resistant to ionizing radiation. Following a dose of 500 Gy of gamma radiation, the fragmented genomic DNA is gradually reconstructed and the pattern of chromosomal bands is restored in less than 48 hours. Cell growth arrests after irradiation but, while DNA is completely fragmented, RNA maintains its integrity. In this work we compared the transcriptional profiles of irradiated and non-irradiated epimastigotes at different time points after irradiation using microarray. In total, 273 genes were differentially expressed; from these, 160 were up-regulated and 113 down-regulated. We found that genes with predicted functions are the most prevalent in the down-regulated gene category. Translation and protein metabolic processes, as well as generation of precursor of metabolites and energy pathways were affected. In contrast, the up-regulated category was mainly composed of obsolete sequences (which included some genes of the kinetoplast DNA), genes coding for hypothetical proteins, and Retrotransposon Hot Spot genes. Finally, the tyrosyl-DNA phosphodiesterase 1, a gene involved in double-strand DNA break repair process, was up-regulated. Our study demonstrated the peculiar response to ionizing radiation, raising questions about how this organism changes its gene expression to manage such a harmful stress. PMID:22247781

  10. The role of sigmodontine rodents as sylvatic hosts of Trypanosoma cruzi in the Argentinean Chaco.

    PubMed

    Orozco, M Marcela; Piccinali, Romina V; Mora, Matías S; Enriquez, Gustavo F; Cardinal, M Victoria; Gürtler, Ricardo E

    2014-03-01

    The role of rodents in the sylvatic transmission of Trypanosoma cruzi has seldom been investigated using parasitological and molecular methods. We assessed the occurrence of T. cruzi in wild small rodents from Pampa del Indio, in the Argentinean Chaco, and identified the taxonomic status of positive rodents by sequencing a fragment of cytochrome b gene (cytb) and performing BLAST searches and phylogenetic analyses. A total of 176 Sigmodontinae rodents was captured in six surveys using 5425 trap-nights in a wide range of sylvatic habitats between 2009 and 2011. Host infection was determined by xenodiagnosis and by polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR) from blood samples. None of the 176 rodents examined was xenodiagnosis-positive. The prevalence of infection determined by kDNA-PCR from blood samples was 16.2% (95% confidence interval, 10.1-21.9%). Half of the infections detected by kDNA-PCR were confirmed by nuclear satellite DNA-PCR or by kDNA-PCR of the rectal contents of xenodiagnostic bugs. The 24 positive specimens were assigned to eight species, providing the first records of T. cruzi in Akodon montensis, Akodon toba, Graomys chacoensis, and Oligoryzomys chacoensis. The occurrence of T. cruzi infection in Oligoryzomys nigripes, Calomys callosus, Necromys lasiurus and Oecomys sp. (most probably Oecomys mamorae) from the Gran Chaco is also reported for the first time. Although sigmodontine rodents were frequently infected, the intensity of bug rectal infection with T. cruzi was below the detection limit of xenodiagnosis (subpatent infectiousness to bugs), indicating they had a low reservoir host competence.

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

    SciTech Connect

    Buarque, Diego S.; Spindola, Leticia M.N.; Martins, Rafael M.; Braz, Gloria R.C.; Tanaka, Aparecida S.

    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.

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

    PubMed Central

    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

  13. Virulence of Trypanosoma cruzi in Açai ( Euterpe oleraceae Martius) Pulp following Mild Heat Treatment.

    PubMed

    Barbosa, Rodrigo Labello; Pereira, Karen Signori; Dias, Viviane Liotti; Schmidt, Flávio Luis; Alves, Delma Pegolo; Guaraldo, Ana Maria Aparecida; Passos, Luiz Augusto Corrêa

    2016-10-01

    Outbreaks of acute Chagas disease (ACD) in northern Brazil can be caused by the ingestion of unprocessed açai pulp contaminated with Trypanosoma cruzi . The aim of this study was to determine the minimum thermal process required to inactivate T. cruzi in açai pulp. Trypomastigotes (100,000) of T. cruzi Y strain were added to 0.15 M NaCl or açai pulp and continuously mixed while being heat treated at 37 to 49°C for up to 1 h. When necessary, parasites were separated from açai pulp by forced sieving. Inocula were administrated intraperitoneally in inbred immunodeficient C.B-17-Prkdc(scid)/Pas Unib mice, and the recipients were monitored for parasitemia and mortality. Mice received prophylactic antibiotic therapy by using cephalexin to prevent bacterial infection from the açai pulp. T. cruzi retained its virulence in 0.15 M NaCl and açai pulp at 44 ± 0.1°C for 10 min and at 43 ± 0.1°C for 20 min, respectively, causing ACD and death in mice up to 24 days after infection. Incubation of açai pulp inoculum above 43°C for 20 min neutralized T. cruzi virulence, thereby preventing ACD and death in murine recipients. The heating of açai pulp above 43°C for 20 min is a practical and effective measure to prevent foodborne ACD caused by T. cruzi .

  14. Trypanosoma cruzi evades the protective role of interferon-gamma-signaling in parasite-infected cells.

    PubMed

    Stahl, Philipp; Ruppert, Volker; Schwarz, Ralph T; Meyer, Thomas

    2014-01-01

    The protozoan parasite Trypanosoma cruzi is responsible for the zoonotic Chagas disease, a chronic and systemic infection in humans and warm-blooded animals typically leading to progressive dilated cardiomyopathy and gastrointestinal manifestations. In the present study, we report that the transcription factor STAT1 (signal transducer and activator of transcription 1) reduces the susceptibility of human cells to infection with T. cruzi. Our in vitro data demonstrate that interferon -γ (IFNγ) pre-treatment causes T. cruzi-infected cells to enter an anti-parasitic state through the activation of the transcription factor STAT1. Whereas stimulation of STAT1-expressing cells with IFNγ significantly impaired intracellular replication of parasites, no protective effect of IFNγ was observed in STAT1-deficient U3A cells. The gene encoding indoleamine 2, 3-dioxygenase (ido) was identified as a STAT1-regulated target gene engaged in parasite clearance. Exposure of cells to T. cruzi trypomastigotes in the absence of IFNγ resulted in both sustained tyrosine and serine phosphorylation of STAT1 and its increased DNA binding. Furthermore, we found that in response to T. cruzi the total amount of intracellular STAT1 increased in an infectious dose-dependent manner, both at the mRNA and protein level. While STAT1 activation is a potent strategy of the host in the fight against the invading pathogen, amastigotes replicating intracellularly antagonize this pathway by specifically promoting the dephosphorylation of STAT1 serine 727, thereby partially circumventing its protective effects. These findings point to the crucial role of the IFNγ/STAT1 signal pathway in the evolutionary combat between T. cruzi parasites and their host.

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

    PubMed

    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.

  16. Galectin-1 Prevents Infection and Damage Induced by Trypanosoma cruzi on Cardiac Cells

    PubMed Central

    Benatar, Alejandro F.; García, Gabriela A.; Bua, Jacqeline; Cerliani, Juan P.; Postan, Miriam; Tasso, Laura M.; Scaglione, Jorge; Stupirski, Juan C.; Toscano, Marta A.

    2015-01-01

    Background Chronic Chagas cardiomyopathy caused by Trypanosoma cruzi is the result of a pathologic process starting during the acute phase of parasite infection. Among different factors, the specific recognition of glycan structures by glycan-binding proteins from the parasite or from the mammalian host cells may play a critical role in the evolution of the infection. Methodology and Principal Findings Here we investigated the contribution of galectin–1 (Gal–1), an endogenous glycan-binding protein abundantly expressed in human and mouse heart, to the pathophysiology of T. cruzi infection, particularly in the context of cardiac pathology. We found that exposure of HL–1 cardiac cells to Gal–1 reduced the percentage of infection by two different T. cruzi strains, Tulahuén (TcVI) and Brazil (TcI). In addition, Gal–1 prevented exposure of phosphatidylserine and early events in the apoptotic program by parasite infection on HL–1 cells. These effects were not mediated by direct interaction with the parasite surface, suggesting that Gal–1 may act through binding to host cells. Moreover, we also observed that T. cruzi infection altered the glycophenotype of cardiac cells, reducing binding of exogenous Gal–1 to the cell surface. Consistent with these data, Gal–1 deficient (Lgals1-/-) mice showed increased parasitemia, reduced signs of inflammation in heart and skeletal muscle tissues, and lower survival rates as compared to wild-type (WT) mice in response to intraperitoneal infection with T. cruzi Tulahuén strain. Conclusion/Significance Our results indicate that Gal–1 modulates T. cruzi infection of cardiac cells, highlighting the relevance of galectins and their ligands as regulators of host-parasite interactions. PMID:26451839

  17. Congenital transmission of Trypanosoma cruzi in Argentina, Honduras, and Mexico: study protocol

    PubMed Central

    2013-01-01

    Background Trypanosoma cruzi has been divided into Discrete Typing Units I and non-I (II-VI). T. cruzi I is predominant in Mexico and Central America, while non-I is predominant in most of South America, including Argentina. Little is known about congenital transmission of T. cruzi I. The specific aim of this study is to determine the rate of congenital transmission of T. cruzi I compared to non-I. Methods/design We are conducting a prospective study to enroll at delivery, 10,000 women in Argentina, 7,500 women in Honduras, and 13,000 women in Mexico. We are measuring transmitted maternal T. cruzi antibodies by performing two rapid tests in cord blood (Stat-Pak, Chembio, Medford, New York, and Trypanosoma Detect, InBios, Seattle, Washington). If at least one of the results is positive, we are identifying infants who are congenitally infected by performing parasitological examinations on cord blood and at 4–8 weeks, and serological follow-up at 10 months. Serological confirmation by ELISA (Wiener, Rosario, Argentina) is performed in cord and maternal blood, and at 10 months. We also are performing T. cruzi standard PCR, real-time quantitative PCR and genotyping on maternal venous blood and on cord blood, and serological examinations on siblings. Data are managed by a Data Center in Montevideo, Uruguay. Data are entered online at the sites in an OpenClinica data management system, and digital pictures of data forms are sent to the Data Center for quality control. Weekly reports allow for rapid feedback to the sites. Trial registration Observational study with ClinicalTrials.gov Identifier NCT01787968 PMID:24119247

  18. Evasion of the Immune Response by Trypanosoma cruzi during Acute Infection

    PubMed Central

    Cardoso, Mariana S.; Reis-Cunha, João Luís; Bartholomeu, Daniella C.

    2016-01-01

    Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical disease that affects millions of people mainly in Latin America. To establish a life-long infection, T. cruzi must subvert the vertebrate host’s immune system, using strategies that can be traced to the parasite’s life cycle. Once inside the vertebrate host, metacyclic trypomastigotes rapidly invade a wide variety of nucleated host cells in a membrane-bound compartment known as the parasitophorous vacuole, which fuses to lysosomes, originating the phagolysosome. In this compartment, the parasite relies on a complex network of antioxidant enzymes to shield itself from lysosomal oxygen and nitrogen reactive species. Lysosomal acidification of the parasitophorous vacuole is an important factor that allows trypomastigote escape from the extremely oxidative environment of the phagolysosome to the cytoplasm, where it differentiates into amastigote forms. In the cytosol of infected macrophages, oxidative stress instead of being detrimental to the parasite, favors amastigote burden, which then differentiates into bloodstream trypomastigotes. Trypomastigotes released in the bloodstream upon the rupture of the host cell membrane express surface molecules, such as calreticulin and GP160 proteins, which disrupt initial and key components of the complement pathway, while others such as glycosylphosphatidylinositol-mucins stimulate immunoregulatory receptors, delaying the progression of a protective immune response. After an immunologically silent entry at the early phase of infection, T. cruzi elicits polyclonal B cell activation, hypergammaglobulinemia, and unspecific anti-T. cruzi antibodies, which are inefficient in controlling the infection. Additionally, the coexpression of several related, but not identical, epitopes derived from trypomastigote surface proteins delays the generation of T. cruzi-specific neutralizing antibodies. Later in the infection, the establishment of an anti-T. cruzi

  19. Evidence for the existence of an Ns-type regulatory protein in Trypanosoma cruzi membranes.

    PubMed Central

    Eisenschlos, C D; Paladini, A A; Molina y Vedia, L; Torres, H N; Flawiá, M M

    1986-01-01

    The existence of a GTP-binding protein of the Ns type in Trypanosoma cruzi was explored. Epimastigote membranes were labelled by cholera toxin in the presence of [adenine-14C]NAD+. After SDS/polyacrylamide-gel electrophoresis of extracted membrane proteins, a single labelled polypeptide band of apparent Mr approx. 45,000 was detected. Epimastigote cells were treated with N-ethylmaleimide and electrofused to lymphoma S49 cells lacking the Ns protein. Evidence indicates that in such electrofusion-generated cell hybrids a heterologous adenylate cyclase system was reconstituted with the Ns protein provided by T. cruzi epimastigotes. Images Fig. 2. PMID:3099761

  20. Trypanosoma cruzi: TcRAB7 protein is localized at the Golgi apparatus in epimastigotes.

    PubMed

    Araripe, Júlia R; Cunha e Silva, Narcisa L; Leal, Simone T; de Souza, Wanderley; Rondinelli, Edson

    2004-08-20

    In mammalian cells, the Rab7 protein is a key element of late endocytic membrane traffic. Several results suggest that it is involved in the transport from early to late endosome or from late endosome to lysosome. We have previously characterized a Rab7 gene homologue (TcRAB7) in Trypanosoma cruzi. Now, using an affinity-purified antibody specific to TcRAB7 protein we have determined that it is localized at the Golgi apparatus of the parasite. Our results indicate that the T. cruzi Rab7 homologue may function in a different route than its counterparts in mammalian cells.

  1. First description of Trypanosoma cruzi human infection in Esmeraldas province, Ecuador.

    PubMed

    Guevara, Ángel; Moreira, Juan; Criollo, Hipatia; Vivero, Sandra; Racines, Marcia; Cevallos, Varsovia; Prandi, Rosanna; Caicedo, Cynthia; Robinzon, Francisco; Anselmi, Mariella

    2014-08-06

    Chagas disease was described in Ecuador in 1930 in the province of Guayas and thereafter in various provinces. Triatomine were reported in the province of Esmeraldas but no human infection has been described. Here we report the first evidence that the disease does exist in the province of Esmeraldas. In indigenous Awá communities located in the northwest jungle of the Esmeraldas province, 144 individuals were tested using ELISA and PCR for T.cruzi of which 5 (3.47%) were positive. Twenty eight triatomine were collected, 27 were Triatoma dispar and 1 Pastrongylus rufotuberculatus, T.cruzi was detected in 11 (42.3%) of 26 insects.

  2. Trypanosoma cruzi alkaline 2-DE: Optimization and application to comparative proteome analysis of flagellate life stages

    PubMed Central

    Magalhães, Adriana D; Charneau, Sébastien; Paba, Jaime; Guércio, Rafael AP; Teixeira, Antonio RL; Santana, Jaime M; Sousa, Marcelo V; Ricart, Carlos AO

    2008-01-01

    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 biological traits of T. cruzi life

  3. Membrane traffic and synaptic cross-talk during host cell entry by Trypanosoma cruzi

    PubMed Central

    Butler, Claire E; Tyler, Kevin M

    2012-01-01

    It is widely accepted that Trypanosoma cruzi can exploit the natural exocytic response of the host to cell damage, utilizing host cell lysosomes as important effectors. It is, though, increasingly clear that the parasite also exploits endocytic mechanisms which allow for incorporation of plasma membrane into the parasitophorous vacuole. Further, that these endocytic mechanisms are involved in cross-talk with the exocytic machinery, in the recycling of vesicles and in the manipulation of the cytoskeleton. Here we review the mechanisms by which T. cruzi exploits features of the exocytic and endocytic pathways in epithelial and endothelial cells and the evidence for cross-talk between these pathways. PMID:22646288

  4. Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA

    PubMed Central

    Shender, Lisa A.; Lewis, Michael D.; Rejmanek, Daniel; Mazet, Jonna A. K.

    2016-01-01

    Background Trypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US) may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections. Methodology/Principle Findings We conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles) and northern (Vallecito) California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs), revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes) were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans. Conclusions/Significance Triatoma protracta populations

  5. Influence of electrolytes and non-electrolytes on growth and differentiation of Trypanosoma cruzi.

    PubMed

    Osuna, A; Adroher, F J; Lupiáñez, J A

    1990-05-01

    The influence of electrolytes and non-electrolytes, especially NaCl and sorbitol, on the metacyclogenesis and growth of Trypanosoma cruzi has been studied. The addition of 50 or 100 mEq/l NaCl to the culture media significantly increased the development of metacyclic forms. Other electrolytes and non-electrolytes had no effect on epimastigote-metacyclic differentiation. The growth rate was never modified to any extent. The influence of sodium concentration, osmotic pressure, among other factors, are discussed. Electrophoresis showed proteins bands which could be related either to the adaptation of T. cruzi to the new culture media or to the initiation of differentiation processes.

  6. The ecology of the Trypanosoma cruzi transmission cycle: Dispersion of zymodeme 3 (Z3) in wild hosts from Brazilian biomes.

    PubMed

    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.

  7. Distribution and pathogenicity of Trypanosoma cruzi isolated from peridomestic populations of Triatoma infestans and Triatoma guasayana from rural western Argentina

    PubMed Central

    Lauricella, Marta A; Stariolo, Raúl L; Riarte, Adelina R; Segura, Elsa L; Gürtler, Ricardo E

    2011-01-01

    We assessed the distribution of Trypanosoma cruzi infection in peridomestic triatomines collected manually at a district-wide scale in rural villages around Olta, western Argentina, and typed the isolated strains according to their pathogenicity to laboratory mice. Of 1623 triatomines examined, only 14 (0.9%) were infected with T. cruzi based on microscopical examination of feces. The prevalence of T. cruzi infection was 0.8% in Triatoma infestans, 2.3% in T. guasayana, and nil in T. garciabesi, T. platensis, and T. eratyrusiformis. Local transmission occurred in kitchens, store-rooms and goat corrals or nearby, though at very low levels. T. cruzi was detected by at least one parasitological method in 11 (79%) of 14 microscope-positive bugs. Hemoculture was the most sensitive method (67%) followed by culture of organ homogenates, histopathology or xenodiagnosis of inoculated suckling mice (55-58%), and culture of microscope-positive bug feces (46%). The evidence suggests that most of the isolated T. cruzi strains would be myotropic type III. Our study establishes for the first time that peridomestic, microscope-positive T. guasayana nymphs were actually infected with T. cruzi, and may be implicated as a putative secondary vector of T. cruzi in domestic or peridomestic sites. PMID:16021298

  8. Trypanosoma cruzi infection and benznidazole therapy independently stimulate oxidative status and structural pathological remodeling of the liver tissue in mice.

    PubMed

    Novaes, Rômulo Dias; Santos, Eliziária C; Cupertino, Marli C; Bastos, Daniel S S; Oliveira, Jerusa M; Carvalho, Thaís V; Neves, Mariana M; Oliveira, Leandro L; Talvani, André

    2015-08-01

    This study used a murine model of Chagas disease to investigate the isolated and combined impact of Trypanosoma cruzi infection and benznidazole (BZ) therapy on liver structure and function. Male C57BL/6 mice were challenged with T. cruzi and BZ for 15 days. Serum levels of cytokines and hepatic enzymes, liver oxidative stress, morphology, collagen, and glycogen content were monitored. Separately, T. cruzi infection and BZ treatment resulted in a pro-oxidant status and hepatic reactive damage. Concurrently, both T. cruzi infection and BZ treatment induced upregulation of antioxidant enzymes and pathological reorganization of the liver parenchyma and stroma. T. cruzi infection increased serum levels of Th1 cytokines, which were reduced by BZ in both infected and non-infected animals. BZ also induced functional organ damage, increasing serum levels of liver enzymes. When combined, T. cruzi infection and BZ therapy elicited intense hepatic reactive damage that was not compensated by antioxidant enzymatic reaction, subsequently culminating in more severe morphofunctional hepatic injury. Taken together, these findings indicate that during specific treatment of Chagas disease, hepatic pathology may be a result of an interaction between BZ metabolism and specific mechanisms activated during the natural course of T. cruzi infection, rather than an isolated toxic effect of BZ on liver structure and function.

  9. Mouse macrophage galactose-type lectin (mMGL) is critical for host resistance against Trypanosoma cruzi infection.

    PubMed

    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.

  10. Frequency of IFNγ-producing T cells correlates with seroreactivity and activated T cells during canine Trypanosoma cruzi infection

    PubMed Central

    2014-01-01

    Vaccines to prevent Trypanosoma cruzi infection in humans or animals are not available, and in many settings, dogs are an important source of domestic infection for the insect vector. Identification of infected canines is crucial for evaluating peridomestic transmission dynamics and parasite control strategies. As immune control of T. cruzi infection is dependent on humoral and cell-mediated immune responses, we aimed to define a serodiagnostic assay and T cell phenotypic markers for identifying infected dogs and studying the canine T. cruzi-specific immune response. Plasma samples and peripheral blood mononuclear cells (PBMCs) were obtained from forty-two dogs living in a T. cruzi-endemic region. Twenty dogs were known to be seropositive and nine seronegative by conventional serologic tests two years prior to our study. To determine canine seroreactivity, we tested sera or plasma samples in a multiplex bead array against eleven recombinant T. cruzi proteins. Ninety-four percent (17/18) of dogs positive by multiplex serology were initially positive by conventional serology. The frequency of IFNγ-producing cells in PBMCs responding to T. cruzi correlated to serological status, identifying 95% of multiplex seropositive dogs. Intracellular staining identified CD4+ and CD8+ T cell populations as the sources of T. cruzi lysate-induced IFNγ. Low expression of CCR7 and CD62L on CD4+ and CD8+ T cells suggested a predominance of effector/effector memory T cells in seropositive canines. These results are the first, to our knowledge, to correlate T. cruzi-specific antibody responses with T cell responses in naturally infected dogs and validate these methods for identifying dogs exposed to T. cruzi. PMID:24456537

  11. Comparison of the infectivity of Trypanosoma cruzi insect-derived metacyclic trypomastigotes after mucosal and cutaneous contaminative challenges

    PubMed Central

    Eickhoff, Christopher Steven; Dunn, Brian Anthony; Sullivan, Nicole Lea; Hoft, Daniel Fredric

    2013-01-01

    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. PMID:23828001

  12. Identification and detection of Trypanosoma cruzi by using a DNA amplification fingerprint obtained from the ribosomal intergenic spacer.

    PubMed Central

    González, N; Galindo, I; Guevara, P; Novak, E; Scorza, J V; Añez, N; Da Silveira, J F; Ramírez, J L

    1994-01-01

    We designed a PCR assay targeted on repeated elements of the ribosomal intergenic spacer which produces highly polymorphic DNA band patterns for different strains of Trypanosoma cruzi. By labeling the PCR products with digoxigenin and by chemiluminescence detection, we improved the assay sensitivity by three orders of magnitude to get T. cruzi strain fingerprints in feces of the trypanosome-infected triatomine bug vector. We also developed a capture assay for the digoxigenin-labeled PCR products that allowed us to detect T. cruzi in triatomine bug vector feces and in human serum samples with a solid support. Images PMID:8126172

  13. OBSERVATIONS ON THE RESPIRATION OF TRYPANOSOMA CRUZI IN CULTURE

    PubMed Central

    von Brand, Theodor; Johnson, Eleanor M.; Rees, Charles W.

    1946-01-01

    1. The oxygen consumption of cultural forms of Trypanosoma cruzi decreases in intensity with increasing age of the cultures; no correlation with any other factor studied could be established. 2. The respiratory quotient was high for the first 10 days, i.e. as long as the population increased; with the onset of a decline in numbers, the R.Q. began to drop. It is believed that the flagellates consume in the beginning predominantly sugar and later predominantly protein. Observations on the pH of the cultures bear out this view. 3. The oxygen consumption was independent of the oxygen tension over a wide range of tensions. 4. The oxygen consumption increased in the temperature range 13° to 40°C., while a temperature of 44°C. proved to be lethal. Upon application of Arrhenius' equation, two straight lines, intersecting at about 28°C., resulted. The µ values were 23,980 and 5275 for the lower and higher temperature range respectively. 5. Of the oxidase inhibitors tested, strong inhibition of the oxygen consumption was achieved with azide, cyanide, and hydrogen sulfide. Pyrophosphate had no influence at all. There is some probability that cytochrome oxidase is the chief oxidase present. 6. The strongest inhibitory influence due to dehydrogenase inhibitors was observed with propyl carbamate and high concentrations of ethyl carbamate. 7. A small fraction of the oxygen consumption, about 10 per cent, may be due to substances with sulfhydryl groups, as indicated by a slight but distinct inhibition due to dilute iodoacetate and to arsenite. PMID:19873484

  14. Trypanosoma cruzi induces cellular proliferation in the trophoblastic cell line BeWo.

    PubMed

    Droguett, Daniel; Carrillo, Ileana; Castillo, Christian; Gómez, Fresia; Negrete, Miguel; Liempi, Ana; Muñoz, Lorena; Galanti, Norbel; Maya, Juan Diego; Kemmerling, Ulrike

    2017-02-01

    Congenital transmission of Trypanosoma cruzi (T. cruzi) is partially responsible for the progressive globalization of Chagas disease. During congenital transmission the parasite must cross the placental barrier where the trophoblast, a continuous renewing epithelium, is the first tissue in contact with the parasite. The trophoblast turnover implies cellular proliferation, differentiation and apoptotic cell death. The epithelial turnover is considered part of innate immunity. We previously demonstrated that T. cruzi induces cellular differentiation and apoptosis in this tissue. Here we demonstrate that T. cruzi induces cellular proliferation in a trophoblastic cell line. We analyzed the cellular proliferation in BeWo cells by determining DNA synthesis by BrdU incorporation assays, mitotic index, cell cycle analysis by flow cytometry, as well as quantification of nucleolus organizer regions by histochemistry and expression of the proliferation markers PCNA and Ki67 by Western blotting and/or immunofluorescence. Additionally, we determined the ERK1/2 MAPK pathway activation by the parasite by Western blotting.

  15. Nitrofuran drugs as common subversive substrates of Trypanosoma cruzi lipoamide dehydrogenase and trypanothione reductase.

    PubMed

    Blumenstiel, K; Schöneck, R; Yardley, V; Croft, S L; Krauth-Siegel, R L

    1999-12-01

    Lipoamide dehydrogenase (LipDH), trypanothione reductase (TR), and glutathione reductase (GR) catalyze the NAD(P)H-dependent reduction of disulfide substrates. TR occurs exclusively in trypanosomatids which lack a GR. Besides their physiological reactions, the flavoenzymes catalyze the single-electron reduction of nitrofurans with the concomitant generation of superoxide anions. Here, we report on the interaction of clinically used antimicrobial nitrofurans with LipDH and TR from Trypanosoma cruzi, the causative agent of Chagas' disease (South American trypanosomiasis), in comparison to mammalian LipDH and GR. The compounds were studied as inhibitors and as subversive substrates of the enzymes. None of the nitrofurans inhibited LipDH, although they did interfere with the disulfide reduction of TR and GR. When the compounds were studied as substrates, T. cruzi LipDH showed a high rate of nitrofuran reduction and was even more efficient than its mammalian counterpart. Several derivatives were also effective subversive substrates of TR, but the respective reaction with human GR was negligible. Nifuroxazide, nifuroxime, and nifurprazine proved to be the most promising derivatives since they were redox-cycled by both T. cruzi LipDH and TR and had pronounced antiparasitic effects in cultures of T. cruzi and Trypanosoma brucei. The results suggest that those nitrofuran derivatives which interact with both parasite flavoenzymes should be revisited as trypanocidal drugs.

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

    SciTech Connect

    Chou, Bin; Hiromatsu, Kenji; Hisaeda, Hajime; Duan, Xuefeng; Imai, Takashi; Murata, Shigeo; Tanaka, Keiji; Himeno, Kunisuke

    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.

  17. Cavia porcellus as a Model for Experimental Infection by Trypanosoma cruzi

    PubMed Central

    Castro-Sesquen, Yagahira E.; Gilman, Robert H.; Yauri, Verónica; Angulo, Noelia; Verastegui, Manuela; Velásquez, Daniel E.; Sterling, Charles R.; Martin, Diana; Bern, Caryn

    2011-01-01

    The guinea pig (Cavia porcellus) is a natural reservoir for Trypanosoma cruzi but has seldom been used as an experimental infection model. We developed a guinea pig infection model for acute and chronic Chagas disease. Seventy-two guinea pigs were inoculated intradermally with 104 trypomastigotes of T. cruzi strain Y (experimental group); 18 guinea pigs were used as control group. Eight animals from the experimental group and two from the control group were sacrificed 5, 15, 20, 25, 40, 55, 115, 165, and 365 days after inoculation. During the acute phase (15 to 55 days), we observed parasitemia (with a peak on day 20) and positive IgM and IgG Western blots with anti-shed acute-phase antigen bands. The cardiac tissue showed vasculitis, necrosis (on days 40 to 55), moderate to severe inflammation, and abundant amastigote nests. Smaller numbers of amastigote nests were also present in kidney, brain, and other organs. In the early chronic phase (115 to 165 days), parasitemia disappeared and anti–T. cruzi IgG antibodies were still detectable. In cardiac tissue, the number of amastigote nests and the grade of inflammation decreased. In the chronic phase (365 days), the cardiac tissue showed vasculitis and fibrosis; detectable parasite DNA was associated with higher grades of inflammation. The experimental T. cruzi infection model in guinea pigs shows kinetics and pathologic changes similar to those of the human disease. PMID:21703410

  18. ORAL TRANSMISSION OF TRYPANOSOMA CRUZI WITH OPPOSING EVIDENCE FOR THE THEORY OF CARNIVORY

    PubMed Central

    Ellis, Angela E.; Yabsley, Michael J.

    2010-01-01

    We present the first demonstration of oral transmission of Trypanosoma cruzi to raccoons (Procyon lotor), a natural reservoir host in the United States, by ingestion of trypomastigotes and infected bugs, but not infected tissue. To investigate an alternative, non-vector–based transmission method, we tested the hypothesis that raccoons scavenging on infected hosts results in patent infection. Macerated tissue from selected organs infected with amastigote stages of T. cruzi was orally administered to experimental groups of raccoons (n = 2/group) at 2, 12, or 24 hr after collection of the tissue samples. Additionally, raccoons (n = 1) in control groups were inoculated intravenously or per os with trypomastigotes. To further elucidate transmission routes of T. cruzi to raccoons, infected Rhodnius prolixus were fed to raccoons (n = 2). Raccoons did not become infected after ingestion of amastigote-infected tissues as evidenced by negative polymerase chain reaction results from blood and tissue, lack of seroconversion, and negative parasitemias. However, per os transmission can occur by ingestion of the infective trypomastigote stage or infected reduviid bugs. We conclude from these findings that oral transmission of T. cruzi may be a route of infection for wildlife in sylvatic cycles, but the scavenging behavior of animals is not likely a significant transmission route. PMID:18763853

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

    PubMed Central

    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

  20. Fibronectin-Degrading Activity of Trypanosoma cruzi Cysteine Proteinase Plays a Role in Host Cell Invasion

    PubMed Central

    Maeda, Fernando Yukio; Cortez, Cristian; Izidoro, Mario Augusto; Juliano, Luiz

    2014-01-01

    Trypanosoma cruzi, the agent of Chagas disease, binds to diverse extracellular matrix proteins. Such an ability prevails in the parasite forms that circulate in the bloodstream and contributes to host cell invasion. Whether this also applies to the insect-stage metacyclic trypomastigotes, the developmental forms that initiate infection in the mammalian host, is not clear. Using T. cruzi CL strain metacyclic forms, we investigated whether fibronectin bound to the parasites and affected target cell invasion. Fibronectin present in cell culture medium bound to metacyclic forms and was digested by cruzipain, the major T. cruzi cysteine proteinase. G strain, with negligible cruzipain activity, displayed a minimal fibronectin-degrading effect. Binding to fibronectin was mediated by gp82, the metacyclic stage-specific surface molecule implicated in parasite internalization. When exogenous fibronectin was present at concentrations higher than cruzipain can properly digest, or fibronectin expression was stimulated by treatment of epithelial HeLa cells with transforming growth factor beta, the parasite invasion was reduced. Treatment of HeLa cells with purified recombinant cruzipain increased parasite internalization, whereas the treatment of parasites with cysteine proteinase inhibitor had the opposite effect. Metacyclic trypomastigote entry into HeLa cells was not affected by anti-β1 integrin antibody but was inhibited by anti-fibronectin antibody. Overall, our results have indicated that the cysteine proteinase of T. cruzi metacyclic forms, through its fibronectin-degrading activity, is implicated in host cell invasion. PMID:25267835

  1. Trypanosoma cruzi Infection Is Enhanced by Vector Saliva through Immunosuppressant Mechanisms Mediated by Lysophosphatidylcholine▿

    PubMed Central

    Mesquita, Rafael D.; Carneiro, Alan Brito; Bafica, André; Gazos-Lopes, Felipe; Takiya, Christina M.; Souto-Padron, Thaís; Vieira, Danielle P.; Ferreira-Pereira, Antônio; Almeida, Igor C.; Figueiredo, Rodrigo T.; Porto, Bárbara N.; Bozza, Marcelo T.; Graça-Souza, Aurélio V.; Lopes, Angela H. C. S.; Atella, Geórgia C.; Silva-Neto, Mário A. C.

    2008-01-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, is transmitted by bug feces deposited on human skin during a blood meal. However, parasite infection occurs through the wound produced by insect mouthparts. Saliva of the Triatominae bug Rhodnius prolixus is a source of lysophosphatidylcholine (LPC). Here, we tested the role of both triatomine saliva and LPC on parasite transmission. We show that vector saliva is a powerful inducer of cell chemotaxis. A massive number of inflammatory cells were found at the sites where LPC or saliva was inoculated into the skin of mice. LPC is a known chemoattractant for monocytes, but neutrophil recruitment induced by saliva is LPC independent. The preincubation of peritoneal macrophages with saliva or LPC increased fivefold the association of T. cruzi with these cells. Moreover, saliva and LPC block nitric oxide production by T. cruzi-exposed macrophages. The injection of saliva or LPC into mouse skin in the presence of the parasite induces an up-to-sixfold increase in blood parasitemia. Together, our data suggest that saliva of the Triatominae enhances T. cruzi transmission and that some of its biological effects are attributed to LPC. This is a demonstration that a vector-derived lysophospholipid may act as an enhancing factor of Chagas disease. PMID:18794282

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

    PubMed

    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.

  3. Trypanosoma cruzi: desferrioxamine decreases mortality and parasitemia in infected mice through a trypanostatic effect.

    PubMed

    Arantes, Jerusa Marilda; Francisco, Amanda Fortes; de Abreu Vieira, Paula Melo; Silva, Maisa; Araújo, Márcio Sobreira Silva; de Carvalho, Andréa Teixeira; Pedrosa, Maria Lúcia; Carneiro, Cláudia Martins; Tafuri, Washington Luiz; Martins-Filho, Olindo Assis; Elói-Santos, Silvana Maria

    2011-08-01

    Desferrioxamine (DFO) is a potent iron chelator that is also known to modulate inflammation and act as an efficient antioxidant under normal conditions and under oxidative stress. Many in vitro and in vivo studies have shown the efficacy of DFO in the treatment of viral, bacterial and protozoan infections. DFO is known to reduce the intensity of Trypanosoma cruzi infections in mice even during a course of therapy that is not effective in maintaining anaemia or low iron levels. To further clarify these findings, we investigated the action of DFO on mouse T. cruzi infection outcomes and the direct impact of DFO on parasites. Infected animals treated with DFO (5 mg/animal/day) for 35 days, beginning 14 days prior to infection, presented lower parasitemia and lower cumulative mortality rate. No significant effect was observed on iron metabolism markers, erythrograms, leukograms or lymphocyte subsets. In the rapid method for testing in vivo T. cruzi susceptibility, DFO also induced lower parasitemia. In regard to its direct impact on parasites, DFO slightly inhibited the growth of amastigotes and trypomastigotes in fibroblast culture. Trypan blue staining showed no effects of DFO on parasite viability, and only minor apoptosis in trypomastigotes was observed. Nevertheless, a clear decrease in parasite mobility was detected. In conclusion, the beneficial actions of DFO on mice T. cruzi infection seem to be independent of host iron metabolism and free of significant haematological side effects. Through direct action on the parasite, DFO has more effective trypanostatic than trypanocidal properties.

  4. Strain-specific protective immunity following vaccination against experimental Trypanosoma cruzi infection.

    PubMed

    Haolla, Filipe A; Claser, Carla; de Alencar, Bruna C G; Tzelepis, Fanny; de Vasconcelos, José Ronnie; de Oliveira, Gabriel; Silvério, Jaline C; Machado, Alexandre V; Lannes-Vieira, Joseli; Bruna-Romero, Oscar; Gazzinelli, Ricardo T; dos Santos, Ricardo Ribeiro; Soares, Milena B P; Rodrigues, Mauricio M

    2009-09-18

    Immunisation with Amastigote Surface Protein 2 (asp-2) and trans-sialidase (ts) genes induces protective immunity in highly susceptible A/Sn mice, against infection with parasites of the Y strain of Trypanosoma cruzi. Based on immunological and biological strain variations in T. cruzi parasites, our goal was to validate our vaccination results using different parasite strains. Due to the importance of the CD8(+) T cells in protective immunity, we initially determined which strains expressed the immunodominant H-2K(k)-restricted epitope TEWETGQI. We tested eight strains, four of which elicited immune responses to this epitope (Y, G, Colombian and Colombia). We selected the Colombian and Colombia strains for our studies. A/Sn mice were immunised with different regimens using both T. cruzi genes (asp-2 and ts) simultaneously and subsequently challenged with blood trypomastigotes. Immune responses before the challenge were confirmed by the presence of specific antibodies and peptide-specific T cells. Genetic vaccination did not confer protective immunity against acute infection with a lethal dose of the Colombian strain. In contrast, we observed a drastic reduction in parasitemia and a significant increase in survival, following challenge with an otherwise lethal dose of the Colombia strain. In many surviving animals with late-stage chronic infection, we observed alterations in the heart's electrical conductivity, compared to naive mice. In summary, we concluded that immunity against T. cruzi antigens, similar to viruses and bacteria, may be strain-specific and have a negative impact on vaccine development.

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

    PubMed Central

    Risso, Marikena G.; Sartor, Paula A.; Burgos, Juan M.; Briceño, Luis; Rodríguez, Eva M.; Guhl, Felipe; Chavez, Omar Triana; Espinoza, Berta; Monteón, Victor M.; Russomando, Graciela; Schijman, Alejandro G.; Bottasso, Oscar A.; Leguizamón, Maria Susana

    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 frequency of TSSA II recognition was observed in Colombia, Venezuela, and Mexico (northern region of Latin America). In Argentina and Paraguay (southern region), immunophenotyping confirmed the already reported TCII (TcII to TcVI) dominance. The lineage distribution between these regions showed significant difference but not among countries within them (except for Colombia and Venezuela). TSSA-WB shows TCII emergence in the northern region where TCI was reported as dominant or even as the unique T. cruzi lineage infecting humans. PMID:21212206

  6. Rhodnius prolixus Life History Outcomes Differ when Infected with Different Trypanosoma cruzi I Strains

    PubMed Central

    Peterson, Jennifer K.; Graham, Andrea L.; Dobson, Andrew P.; Chávez, Omar Triana

    2015-01-01

    The effect of a parasite on the life history of its vector is important for understanding and predicting disease transmission. Chagas disease agent Trypanosoma cruzi is a generalist parasite that is diverse across scales from its genetic diversity to the 100s of mammal and vector species it infects. Its vertebrate hosts show quite variable responses to infection, however, to date there are no studies looking at how T. cruzi variability might result in variable outcomes in its invertebrate host. Therefore, we investigated the effect of different T. cruzi I strains on Rhodnius prolixus survival and development. We found significant variation between insects infected with different strains, with some strains having no effect, as compared with uninfected insects, and others with significantly lower survival and development. We also found that different variables had varying importance between strains, with the effect of time postinfection and the blood:weight ratio of the infective meal significantly affecting the survival of insects infected with some strains, but not others. Our results suggest that T. cruzi can be pathogenic not only to its vertebrate hosts but also to its invertebrate hosts. PMID:26078316

  7. In Vitro and In Vivo Biological Effects of Novel Arylimidamide Derivatives against Trypanosoma cruzi

    PubMed Central

    Timm, Bruno Lisboa; da Silva, Patrícia Bernadino; Batista, Marcos Meuser; da Silva, Francisca Hildemagna Guedes; da Silva, Cristiane França; Tidwell, Richard R.; Patrick, Donald A.; Jones, Susan Kilgore; Bakunov, Stanislav A.; Bakunova, Svetlana M.

    2014-01-01

    Chagas disease (CD), a neglected tropical disease caused by Trypanosoma cruzi, remains a serious public health problem in several Latin American countries. The available chemotherapies for CD have limited efficacy and exhibit undesirable side effects. Aromatic diamidines and arylimidamides (AIAs) have shown broad-spectrum activity against intracellular parasites, including T. cruzi. Therefore, our aim was to evaluate the biological activity of eight novel AIAs (16DAP002, 16SAB079, 18SAB075, 23SMB022, 23SMB026, 23SMB054, 26SMB070, and 27SMB009) against experimental models of T. cruzi infection in vitro and in vivo. Our data show that none of the compounds induced a loss of cellular viability up to 32 μM. Two AIAs, 18SAB075 and 16DAP002, exhibited good in vitro activity against different parasite strains (Y and Tulahuen) and against the two relevant forms of the parasite for mammalian hosts. Due to the excellent selective indexes of 18SAB075, this AIA was moved to in vivo tests for acute toxicity and parasite efficacy; nontoxic doses (no-observed-adverse-effect level [NOAEL], 50 mg/kg) were employed in the tests for parasite efficacy. In experimental models of acute T. cruzi infection, 18SAB075 reduced parasitemia levels only up to 50% and led to 40% protection against mortality (at 5 mg/kg of body weight), being less effective than the reference drug, benznidazole. PMID:24752263

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

    PubMed

    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.

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

    PubMed Central

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

    1986-01-01

    We have studied 15 gene loci coding for enzymes in 121 Trypanosoma cruzi stocks from a wide geographic range--from the United States 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. We 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. We 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. PMID:3510428

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

    PubMed Central

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

    2012-01-01

    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. PMID:22943545

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

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    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.

  14. 2,3-DIPHENYL-1,4-NAPHTHOQUINONE: A POTENTIAL CHEMOTHERAPEUTIC AGENT AGAINST TRYPANOSOMA CRUZI

    PubMed Central

    Ramos, Enrique I.; Garza, Kristine M.; Krauth-Siegel, R. L.; Bader, Julia; Martinez, Luiz E.; Maldonado, Rosa A.

    2010-01-01

    Chagas disease, caused by Trypanosoma cruzi, is a wide spread infection in Latin America. Currently, only 2 partially effective and highly toxic drugs, i.e., benznidazole and nifurtimox, are available for the treatment of this disease and several efforts are underway in the search for better chemotherapeutic agents. Here, we have determined the trypanocidal activity of 2,3-diphenyl-1,4-naphthoquinone (DPNQ), a novel quinone derivative. In vitro, DPNQ was highly cytotoxic at a low, micromolar concentration (LD50 = 2.5 μM) against epimastigote, cell-derived trypomastigote, and intracellular amastigote forms of T. cruzi, but not against mammalian cells (LD50 = 130 μM). In vivo studies on the murine model of Chagas disease revealed that DPNQ-treated animals (3 doses of 10 mg/kg/day) showed a significant delay in parasitemia peak and higher (up to 60%) survival rate 70 days post-infection, when compared to control group (infected, untreated). We also observed a 2-fold decrease in the parasitemia between the control group (infected, untreated) and the treated group (infected, treated). No apparent drug toxicity effects were noticed in the control group (uninfected, treated). In addition, we determined that DPNQ is the first competitive inhibitor of T. cruzi lipoamide dehydrogenase (TcLipDH) thus far described. Our results indicate that DPNQ is a promising chemotherapeutic agent against T. cruzi. PMID:18788881

  15. Proteomics in Trypanosoma cruzi - Localization of Novel Proteins to Various Organelles

    PubMed Central

    Ferella, Marcela; Nilsson, Daniel; Darban, Hamid; Rodrigues, Claudia; Bontempi, Esteban J; Docampo, Roberto; Andersson, Björn

    2009-01-01

    The completion of the genome sequence of Trypanosoma cruzi has been followed by several studies of protein expression, with the long-term aim to obtain a complete picture of the parasite proteome. We report a proteomic analysis of an organellar cell fraction from T. cruzi CL Brener epimastigotes. A total of 396 proteins were identified by LC-MS/MS. Of these, 138 were annotated as hypothetical in the genome databases and the rest could be assigned to several metabolic and biosynthetic pathways, transport, and structural functions. Comparative analysis with a whole cell proteome study resulted in the validation of the expression of 173 additional proteins. Of these, 38 proteins previously reported in other stages were not found in the only large-scale study of the total epimastigote stage proteome. A selected set of identified proteins was analyzed further to investigate gene copy number, sequence variation, transmembrane domains and targeting signals. The genes were cloned and the proteins expressed with a c-myc epitope tag in T. cruzi epimastigotes. Immunofluorescence microscopy revealed the localization of these proteins in different cellular compartments, such as endoplasmic reticulum, acidocalcisome, mitochondrion, and putative cytoplasmic transport or delivery vesicles. The results demonstrate that the use of enriched subcellular fractions allows the detection of T. cruzi proteins that are undetected by whole cell proteomic methods. PMID:18546153

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

    PubMed

    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.

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

    PubMed Central

    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

  18. The Role of the Trypanosoma cruzi TcNRBD1 Protein in Translation

    PubMed Central

    Oliveira, Camila; Carvalho, Paulo Costa; Goldenberg, Samuel

    2016-01-01

    The regulation of gene expression in trypanosomatids occurs mainly at the post-transcriptional level. Despite the importance of this type of control in Trypanosoma cruzi, few RNA binding proteins have been characterized. The RRM domain (RNA Recognition Motif) is one of the most abundant domains found in RNA-binding proteins in higher eukaryotes. Proteins containing the RRM domain are involved in the majority of post-transcriptional processes regulating gene expression. In this work, we aimed to characterize the protein TcNRBD1 from T. cruzi. TcNRBD1 is an RNA-binding protein that contains 2 RRM domains and is the ortholog of the P34 and P37 proteins from Trypanosoma brucei. The TcNRBD1 protein is expressed in all developmental stages of T. cruzi, and its localization pattern is concentrated at the perinuclear region. TcNRBD1 is associated with polysomes and with the 80S monosomes. Furthermore, sequencing of the mRNAs bound to TcNRBD1 allowed the identification of several transcripts that encode ribosomal proteins. Immunoprecipitation assays followed by mass spectrometry showed that the protein complexes with several ribosomal proteins from both the 40S and 60S subunits. In summary, the results indicate that TcNRBD1 is associated with different parts of the translation process, either by regulating mRNAs that encode ribosomal proteins or by acting in some step of ribosome assembly in T. cruzi. PMID:27760165

  19. Molecular identification and genotyping of Trypanosoma cruzi DNA in autochthonous Chagas disease patients from Texas, USA.

    PubMed

    Garcia, Melissa N; Burroughs, Hadley; Gorchakov, Rodion; Gunter, Sarah M; Dumonteil, Eric; Murray, Kristy O; Herrera, Claudia P

    2017-04-01

    The parasitic protozoan Trypanosoma cruzi, the causative agent of Chagas disease, is widely distributed throughout the Americas, from the southern United States (US) to northern Argentina, and infects at least 6 million people in endemic areas. Much remains unknown about the dynamics of T. cruzi transmission among mammals and triatomine vectors in sylvatic and peridomestic eco-epidemiological cycles, as well as of the risk of transmission to humans in the US. Identification of T. cruzi DTUs among locally-acquired cases is necessary for enhancing our diagnostic and clinical prognostic capacities, as well as to understand parasite transmission cycles. Blood samples from a cohort of 15 confirmed locally-acquired Chagas disease patients from Texas were used for genotyping T. cruzi. Conventional PCR using primers specific for the minicircle variable region of the kinetoplastid DNA (kDNA) and the highly repetitive genomic satellite DNA (satDNA) confirmed the presence of T. cruzi in 12/15 patients. Genotyping was based on the amplification of the intergenic region of the miniexon gene of T. cruzi and sequencing. Sequences were analyzed by BLAST and phylogenetic analysis by Maximum Likelihood method allowed the identification of non-TcI DTUs infection in six patients, which corresponded to DTUs TcII, TcV or TcVI, but not to TcIII or TcIV. Two of these six patients were also infected with a TcI DTU, indicating mixed infections in those individuals. Electrocardiographic abnormalities were seen among patients with single non-TcI and mixed infections of non-TcI and TcI DTUs. Our results indicate a greater diversity of T. cruzi DTUs circulating among autochthonous human Chagas disease cases in the southern US, including for the first time DTUs from the TcII-TcV-TcVI group. Furthermore, the DTUs infecting human patients in the US are capable of causing Chagasic cardiac disease, highlighting the importance of parasite detection in the population.

  20. Interaction with host factors exacerbates Trypanosoma cruzi cell invasion capacity upon oral infection.

    PubMed

    Covarrubias, Charles; Cortez, Mauro; Ferreira, Daniele; Yoshida, Nobuko

    2007-12-01

    Outbreaks of severe acute Chagas' disease acquired by oral infection, leading to death in some cases, have occurred in recent years. Using the mouse model, we investigated the basis of such virulence by analyzing a Trypanosoma cruzi isolate, SC, from a patient with severe acute clinical symptoms, who was infected by oral route. It has previously been shown that, upon oral inoculation into mice, T. cruzi metacyclic trypomastigotes invade the gastric mucosal epithelium by engaging the stage-specific surface glycoprotein gp82, whereas the surface molecule gp90 functions as a down-modulator of cell invasion. We found that, when orally inoculated into mice, metacyclic forms of the SC isolate, which express high levels of gp90, produced high parasitemias and high mortality, in sharp contrast with the reduced infectivity in vitro. Upon recovery from the mouse stomach 1h after oral inoculation, the gp90 molecule of the parasites was completely degraded, and their entry into HeLa cells, as well as into Caco-2 cells, was increased. The gp82 molecule was more resistant to digestive action of the gastric juice. Host cell invasion of SC isolate metacyclic trypomastigotes was augmented in the presence of gastric mucin. No alteration in infectivity was observed in T. cruzi strains CL and G which were used as references and which express gp90 molecules resistant to degradation by gastric juice. Taken together, our findings suggest that the exacerbation of T. cruzi infectivity, such as observed upon interaction of the SC isolate with the mouse stomach components, may be responsible for the severity of acute Chagas' disease that has been reported in outbreaks of oral T. cruzi infection.

  1. Trypanosoma cruzi infection by oral route: how the interplay between parasite and host components modulates infectivity.

    PubMed

    Yoshida, Nobuko

    2008-06-01

    Trypanosoma cruzi infection by oral route constitutes the most important mode of transmission in some geographical regions, as illustrated by reports on microepidemics and outbreaks of acute Chagas' disease acquired by ingestion of food contaminated with parasites from triatomine insects. In the mouse model, T. cruzi metacyclic trypomastigotes invade the gastric mucosal epithelium, a unique portal of entry for systemic infection. High efficiency of metacyclic forms in establishing infection by oral route is associated with expression of gp82, a stage-specific surface molecule that binds to gastric mucin and to epithelial cells. Gp82 promotes parasite entry by triggering the signaling cascades leading to intracellular Ca(2+) mobilization. T. cruzi strains deficient in gp82 can effectively invade cells in vitro, by engaging the Ca(2+) signal-inducing surface glycoprotein gp30. However, they are poorly infective in mice by oral route because gp30 has low affinity for gastric mucin. Metacyclic forms also express gp90, a stage-specific surface glycoprotein that binds to host cells and acts as a negative regulator of invasion. T. cruzi strains expressing gp90 at high levels, in addition to gp82 and gp30, are all poor cell invaders in vitro. Notwithstanding, their infectivity by oral route may vary because, unlike gp82 and gp30, which resist degradation by pepsin in the gastric milieu, the gp90 isoforms of different strains have varying susceptibility to peptic digestion. For instance, in a T. cruzi isolate, derived from an acute case of Chagas' disease acquired by oral route, gp90 is extensively degraded by gastric juice in the mouse stomach and this renders the parasite highly invasive towards target cells. If such an exacerbation of infectivity occurs in humans, it may be responsible for the severity of the disease reported in outbreaks of oral infection.

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

    PubMed

    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.

  3. Anatomical route of invasion and protective mucosal immunity in Trypanosoma cruzi conjunctival infection.

    PubMed

    Giddings, O K; Eickhoff, C S; Smith, T J; Bryant, L A; Hoft, D F

    2006-10-01

    Trypanosoma cruzi is a protozoan parasite that can initiate mucosal infection after conjunctival exposure. The anatomical route of T. cruzi invasion and spread after conjunctival parasite contamination remains poorly characterized. In the present work we have identified the sites of initial invasion and replication after contaminative conjunctival challenges with T. cruzi metacyclic trypomastigotes using a combination of immunohistochemical and real-time PCR confirmatory techniques in 56 mice between 3 and 14 days after challenge. Our results demonstrate that the predominant route of infection involves drainage of parasites through the nasolacrimal duct into the nasal cavity. Initial parasite invasion occurs within the ductal and respiratory epithelia. After successive waves of intracellular replication and cell-to-cell spread, parasites drain via local lymphatic channels to lymph nodes and then disseminate through the blood to distant tissues. This model of conjunctival challenge was used to identify immune responses associated with protection against mucosal infection. Preceding mucosal infection induces mucosal immunity, resulting in at least 50-fold reductions in recoverable tissue parasite DNA in immune mice compared to controls 10 days after conjunctival challenge (P < 0.05). Antigen-specific gamma interferon production by T cells was increased at least 100-fold in cells harvested from immune mice (P < 0.05). Mucosal secretions containing T. cruzi-specific secretory immunoglobulin A harvested from immune mice were shown to protect against mucosal parasite infection (P < 0.05), demonstrating that mucosal antibodies can play a role in T. cruzi immunity. This model provides an important tool for detailed studies of mucosal immunity necessary for the development of mucosal vaccines.

  4. Metabolic Signatures of Triatomine Vectors of Trypanosoma cruzi Unveiled by Metabolomics

    PubMed Central

    Antunes, Luis Caetano M.; Han, Jun; Pan, Jingxi; Moreira, Carlos J. C.; Azambuja, Patrícia; Borchers, Christoph H.; Carels, Nicolas

    2013-01-01

    Chagas disease is a trypanosomiasis whose causative agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous insects known as triatomines and affects a large proportion of South America. The digestive tract of the insect vectors in which T. cruzi develops constitutes a dynamic environment that affects the development of the parasite. Thus, we set out to investigate the chemical composition of the triatomine intestinal tract through a metabolomics approach. We performed Direct Infusion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry on fecal samples of three triatomine species (Rhodnius prolixus, Triatoma infestans, Panstrongylus megistus) fed with rabbit blood. We then identified groups of metabolites whose frequencies were either uniform in all species or enriched in each of them. By querying the Human Metabolome Database, we obtained putative identities of the metabolites of interest. We found that a core group of metabolites with uniform frequencies in all species represented approximately 80% of the molecules detected, whereas the other 20% varied among triatomine species. The uniform core was composed of metabolites of various categories, including fatty acids, steroids, glycerolipids, nucleotides, sugars, and others. Nevertheless, the metabolic fingerprint of triatomine feces differs depending on the species considered. The variable core was mainly composed of prenol lipids, amino acids, glycerolipids, steroids, phenols, fatty acids and derivatives, benzoic acid and derivatives, flavonoids, glycerophospholipids, benzopyrans, and quinolines. Triatomine feces constitute a rich and varied chemical medium whose constituents are likely to affect T. cruzi development and infectivity. The complexity of the fecal metabolome of triatomines suggests that it may affect triatomine vector competence for specific T. cruzi strains. Knowledge of the chemical environment of T. cruzi in its invertebrate host is likely to

  5. Association of Trypanosoma cruzi infection with risk factors and electrocardiographic abnormalities in northeast Mexico

    PubMed Central

    2014-01-01

    Background American trypanosomiasis is a major disease and public health issue, caused by the protozoan parasite Trypanosoma cruzi. The prevalence of T. cruzi has not been fully documented, and there are few reports of this issue in Nuevo Leon. The aim of this study was to update the seroprevalence rate of T. cruzi infection, including an epidemiological analysis of the risk factors associated with this infection and an electrocardiographic (ECG) evaluation of those infected. Methods Sera from 2,688 individuals from 10 municipalities in the state of Nuevo Leon, Mexico, were evaluated using an enzyme-linked immunosorbent assay and an indirect hemagglutination assay. An ECG case–control study was performed in subjects seropositive for T. cruzi and the results were matched by sex and age to seronegative residents of the same localities. A univariate analysis with χ2 and Fisher’s exact tests was used to determine the association between seropositivity and age (years), sex, and ECG changes. A multivariate analysis was then performed to calculate the odd ratios between T. cruzi seropositivity and the risk factors. Results The seropositive rate was 1.93% (52/2,688). In the ECG study, 22.85% (8/35) of the infected individuals exhibited ECG abnormalities. Triatoma gerstaeckeri was the only vector reported. The main risk factors were ceiling construction material (P ≤ 0.0024), domestic animals (P ≤ 0.0001), and living in rural municipalities (P ≤ 0.0025). Conclusions These findings demonstrate a 10-fold higher prevalence of Chagas disease than previously reported (0.2%), which implies a serious public health threat in northeastern Mexico. The epidemiological profile established in this study differs from that found in the rest of Mexico, where human populations live in close proximity to domiciliary triatomines. PMID:24580840

  6. The Prevalence of Chagas Heart Disease in a Central Bolivian Community Endemic for Trypanosoma Cruzi

    PubMed Central

    Yager, Jessica E.; Lozano Beltran, Daniel F.; Torrico, Faustino; Gilman, Robert H.; Bern, Caryn

    2015-01-01

    Background Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population. Objectives and Methods Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or ECG consistent with cardiac abnormalities were also scheduled for echocardiography. Results and conclusions Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% versus 0 for complete right bundle branch block and 10.4% versus 1.9% for any bundle branch block; p=0.008 and p<0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure. Though almost one third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease. PMID:26407509

  7. Changes in Trypanosoma cruzi-specific immune responses following treatment: surrogate markers of treatment efficacy

    PubMed Central

    Laucella, Susana A.; Mazliah, Damián Pérez; Bertocchi, Graciela; Alvarez, María G.; Cooley, Gretchen; Viotti, Rodolfo; Albareda, María C.; Lococo, Bruno; Postan, Miriam; Armenti, Alejandro; Tarleton, Rick L.

    2009-01-01

    Background As many as 20 million people are living with Trypanosoma cruzi infection in Latin American, yet few receive any treatment. The major limitation in developing and evaluating potential new drugs for their efficacy is the lack of reliable tests to assess parasite burden and elimination. Methods Adults volunteers with chronic T. cruzi infection were evaluated clinically and stratified according to the Kuschnir classification. Individuals in group 0 and group 1 clinical status were treated with 5 mg benznidazole/kg/day for 30 days. The changes in T. cruzi-specific T cell and antibody responses, as well as in clinical status, were measured periodically over the 3-5 year follow-up period and compared to pre-treatment conditions and to an untreated control group. Results The frequency of peripheral IFN- g-producing T cells specific for T. cruzi declined as early as 12 months after BZ treatment and subsequently became undetectable in a substantial proportion of treated subjects. Addtionally decreases in antibody responses to a pool of recombinant T. cruzi proteins also declined in many of these same subjects. The shift to negative IFN- g T cell responses was highly associated with an early increase in IFN- g-producing T cells with phenotypic features of effector/effector memory cells in a subset of subjects. Benznidazole treatment also resulted in an increase in naïve and early differentiated memory-like CD8+ T cells in a majority of subjects. Conclusions BZ treatment during chronic Chagas disease has a substantial impact on parasite-specific immune response that is likely to be indicative of treatment efficacy and cure. PMID:19877967

  8. Trypanosome species, including Trypanosoma cruzi, in sylvatic and peridomestic bats of Texas, USA.

    PubMed

    Hodo, Carolyn L; Goodwin, Chloe C; Mayes, Bonny C; Mariscal, Jacqueline A; Waldrup, Kenneth A; Hamer, Sarah A

    2016-12-01

    In contrast to other mammalian reservoirs, many bat species migrate long-distances and have the potential to introduce exotic pathogens to new areas. Bats have long been associated with blood-borne protozoal trypanosomes of the Schizotrypanum subgenus, which includes the zoonotic parasite Trypanosoma cruzi, agent of Chagas disease. Another member of the subgenus, Trypanosoma dionisii, infects bats of Europe and South America, and genetic similarities between strains from the two continents suggest transcontinental movement of this parasite via bats. Despite the known presence of diverse trypanosomes in bats of Central and South America, and the presence of T. cruzi-infected vectors and wildlife in the US, the role of bats in maintaining and dispersing trypanosomes in the US has not yet been reported. We collected hearts and blood from 8 species of insectivorous bats from 30 counties across Texas. Using PCR and DNA sequencing, we tested 593 bats for trypanosomes and found 1 bat positive for T. cruzi (0.17%), 9 for T. dionisii (1.5%), and 5 for Blastocrithidia spp. (0.8%), a group of insect trypanosomes. The T. cruzi-infected bat was carrying TcI, the strain type associated with human disease in the US. In the T. dionisii-infected bats, we detected three unique variants associated with the three infected bat species. These findings represent the first report of T. cruzi in a bat in the US, of T. dionisii in North America, and of Blastocrithidia spp. in mammals, and underscore the importance of bats in the maintenance of trypanosomes, including agents of human and animal disease, across broad geographic locales.

  9. Kongenitale Chagas. Einfluss einer Trypanosoma Cruzi-Infektion auf die Embryonalentwicklung bei Traechtigen Maeusen (Congenital Chagas Diseases. Effect of ’Trypanosoma cruzi’ Infection on Embryogeny in Gravid Mice),

    DTIC Science & Technology

    Congenital Chagas’ disease in man and animals entailing abortion , premature delivery and deformation has been reported in the literature, although...the effect of T. cruzi infection on the fetal development of mice has been investigated after inoculating three different strains of T. cruzi in...in either early death or retarded growth of the embryos and fetuses, although trypanosomes were not demonstrable in injured fetuses (however

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

    PubMed Central

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

    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. Domestic dogs, free from T. cruziinfection, received three immunisations with fixed T. rangeliepimastigotes. Dogs were not challenged with T. cruzi, but they were left in their environment. This immunisation induced antibodies againstT. cruzi for more than three years in dogs in their natural habitat, while control dogs remained serologically negative. PMID:27074257

  11. Subtelomeric I-SceI-Mediated Double-Strand Breaks Are Repaired by Homologous Recombination in Trypanosoma cruzi

    PubMed Central

    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

  12. Subtelomeric I-SceI-Mediated Double-Strand Breaks Are Repaired by Homologous Recombination in Trypanosoma cruzi.

    PubMed

    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.

  13. Effect of elevated environmental temperature on the antibody response of mice to Trypanosoma cruzi during the acute phase of infection.

    PubMed Central

    Dimock, K A; Davis, C D; Kuhn, R E

    1991-01-01

    When held at 36 degrees C, Trypanosoma cruzi-infected C3H mice survive an otherwise lethal infection with significantly decreased parasitemia levels and enhanced immune responsiveness. Treatment of T. cruzi-infected mice with the immunosuppressive agent cyclophosphamide indicated that the positive effects of increased environmental temperature were primarily due to enhancement of immunity. A parasite-specific, enzyme-linked immunosorbent assay and immunoblot analysis were used to examine the effect of elevated environmental temperature on the production of anti-T. cruzi antibodies. Both the reactivity and diversity of anti-T. cruzi antibodies were found to be lower in infected mice held at 36 degrees C than in infected mice held at room temperature. However, reactivity and diversity could be enhanced by vaccination with culture forms of the parasite. Images PMID:1937796

  14. Trypanosoma cruzi and myoid cells from seminiferous tubules: interaction and relation with fibrous components of extracellular matrix in experimental Chagas' disease

    PubMed Central

    Carvalho, Luiz Otávio Pereira; Abreu-Silva, Ana Lucia; Hardoim, Daiana de Jesús; Tedesco, Roberto Carlos; Mendes, Verônica Gonçalves; da Costa, Sylvio Celso Gonçalves; Calabrese, Kátia da Silva

    2009-01-01

    The main transmission route of Trypanosoma cruzi is by triatomine bugs. However, T. cruzi is also transmitted through blood transfusion, organ transplantation, ingestion of contaminated food or fluids, or is congenital. Sexual transmission, although suggested since the discovery of Chagas’ disease, has remained unproven. Sexual transmission would require T. cruzi to be located at the testes and ovaries. Here we investigated whether T. cruzi is present in the gonads of mice infected with 104 T. cruzi trypomastigotes from the CL strain. Fourteen days after experimental infection, histopathological examination showed alterations in the extracellular matrix of the lamina propria of the seminiferous tubules. Furthermore, amastigotes were present in seminiferous tubules, within myoid cells, and in the adjacencies of the basal compartment. These results indicate that T. cruzi is able to reach seminiferous tubule lumen, thus suggesting that Chagas’ disease could potentially be transmitted through sexual intercourse. Complementary studies are required to demonstrate that Chagas’ disease can be transmitted by coitus. PMID:19200251

  15. Prevalence and Transmission of Trypanosoma cruzi in People of Rural Communities of the High Jungle of Northern Peru

    PubMed Central

    Alroy, Karen A.; Huang, Christine; Gilman, Robert H.; Quispe-Machaca, Victor R.; Marks, Morgan A.; Ancca-Juarez, Jenny; Hillyard, Miranda; Verastegui, Manuela; Sanchez, Gerardo; Cabrera, Lilia; Vidal, Elisa; Billig, Erica M. W.; Cama, Vitaliano A.; Náquira, César; Bern, Caryn; Levy, Michael Z.

    2015-01-01

    Background Vector-borne transmission of Trypanosoma cruzi is seen exclusively in the Americas where an estimated 8 million people are infected with the parasite. Significant research in southern Peru has been conducted to understand T. cruzi infection and vector control, however, much less is known about the burden of infection and epidemiology in northern Peru. Methodology A cross-sectional study was conducted to estimate the seroprevalence of T. cruzi infection in humans (n=611) and domestic animals [dogs (n=106) and guinea pigs (n=206)] in communities of Cutervo Province, Peru. Sampling and diagnostic strategies differed according to species. An entomological household study (n=208) was conducted to identify the triatomine burden and species composition, as well as the prevalence of T. cruzi in vectors. Electrocardiograms (EKG) were performed on a subset of participants (n=90 T. cruzi infected participants and 170 age and sex-matched controls). The seroprevalence of T. cruzi among humans, dogs, and guinea pigs was 14.9% (95% CI: 12.2 – 18.0%), 19.8% (95% CI: 12.7- 28.7%) and 3.3% (95% CI: 1.4 – 6.9%) respectively. In one community, the prevalence of T. cruzi infection was 17.2% (95% CI: 9.6 - 24.7%) among participants < 15 years, suggesting recent transmission. Increasing age, positive triatomines in a participant's house, and ownership of a T. cruzi positive guinea pig were independent correlates of T. cruzi infection. Only one species of triatomine was found, Panstrongylus lignarius, formerly P. herreri. Approximately forty percent (39.9%, 95% CI: 33.2 - 46.9%) of surveyed households were infested with this vector and 14.9% (95% CI: 10.4 - 20.5%) had at least one triatomine positive for T. cruzi. The cardiac abnormality of right bundle branch block was rare, but only identified in seropositive individuals. Conclusions Our research documents a substantial prevalence of T. cruzi infection in Cutervo and highlights a need for greater attention and vector

  16. An improved general approach for cloning and characterizing telomeres: the protozoan parasite Trypanosoma cruzi as model organism.

    PubMed

    Chiurillo, Miguel Angel; Santos, Marcia R M; Franco Da Silveira, Jose; Ramírez, Jose Luis

    2002-07-10

    We here describe a general strategy for cloning and characterizing telomeric and sub-telomeric regions of the human protozoan parasite Trypanosoma cruzi. The use of a bacterial artificial chromosome vector and a telomeric adaptor produced stable telomeric recombinant clones with inserts ranging from 5 to 25 kb. Analysis of these recombinants provided unique landmarks for chromosomal mapping and sequencing and enabled us to derive a more accurate picture of T. cruzi telomeric organization.

  17. Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil.

    PubMed

    Brito, Veruska Nogueira de; Almeida, Arleana do Bom Parto Ferreira de; Nakazato, Luciano; Duarte, Rosemere; Souza, Cladson de Oliveira; Sousa, Valéria Régia Franco

    2014-11-01

    Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.

  18. Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil.

    PubMed

    Brito, Veruska Nogueira de; Almeida, Arleana do Bom Parto Ferreira de; Nakazato, Luciano; Duarte, Rosemere; Souza, Cladson de Oliveira; Sousa, Valéria Régia Franco

    2014-10-14

    Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.

  19. Ecological diversity of Trypanosoma cruzi transmission in the Amazon basin. The main scenaries in the Brazilian Amazon.

    PubMed

    Coura, J R; Junqueira, A C V

    2015-11-01

    The ecological diversity of Trypanosoma cruzi transmission in the Brazilian Amazon region is directly interlinked with the parasite's extensive reservoir, composed of 33 species of wild mammals within the following orders: Marsupialia, Chiroptera, Rodentia, Xenarthra, Carnivora and Primates; and of 16 species of wild triatomines, of which ten may be infected with T. cruzi. Four scenarios for the diversity of T. cruzi transmission in the Brazilian Amazon region are evident: (i) T. cruzi transmission between vectors and wild mammals, which is characterized as a wild enzooty encompassing the entire Amazon basin; (ii) accidental T. cruzi transmission from vectors and wild mammals to humans, when they invade the wild ecotope or when these vectors and wild mammals invade human homes; (iii) occupational Chagas disease among piassava (Leopoldinia piassaba) palm fiber gatherers, transmitted by the vector Rhodnius brethesi, for which these palm trees are the specific ecotope; (IV) oral T. cruzi transmission to humans through food contamination, particularly in juices from plants such as assai, which today is considered to be endemic in the Brazilian Amazon region, with more than 1500 cases notified.

  20. Replication Protein A Presents Canonical Functions and Is Also Involved in the Differentiation Capacity of Trypanosoma cruzi.

    PubMed

    Pavani, Raphael Souza; da Silva, Marcelo Santos; Fernandes, Carlos Alexandre Henrique; Morini, Flavia Souza; Araujo, Christiane Bezerra; Fontes, Marcos Roberto de Mattos; Sant'Anna, Osvaldo Augusto; Machado, Carlos Renato; Cano, Maria Isabel; Fragoso, Stenio Perdigão; Elias, Maria Carolina

    2016-12-01

    Replication Protein A (RPA), the major single stranded DNA binding protein in eukaryotes, is composed of three subunits and is a fundamental player in DNA metabolism, participating in replication, transcription, repair, and the DNA damage response. In human pathogenic trypanosomatids, only limited studies have been performed on RPA-1 from Leishmania. Here, we performed in silico, in vitro and in vivo analysis of Trypanosoma cruzi RPA-1 and RPA-2 subunits. Although computational analysis suggests similarities in DNA binding and Ob-fold structures of RPA from T. cruzi compared with mammalian and fungi RPA, the predicted tridimensional structures of T. cruzi RPA-1 and RPA-2 indicated that these molecules present a more flexible tertiary structure, suggesting that T. cruzi RPA could be involved in additional responses. Here, we demonstrate experimentally that the T. cruzi RPA complex interacts with DNA via RPA-1 and is directly related to canonical functions, such as DNA replication and DNA damage response. Accordingly, a reduction of TcRPA-2 expression by generating heterozygous knockout cells impaired cell growth, slowing down S-phase progression. Moreover, heterozygous knockout cells presented a better efficiency in differentiation from epimastigote to metacyclic trypomastigote forms and metacyclic trypomastigote infection. Taken together, these findings indicate the involvement of TcRPA in the metacyclogenesis process and suggest that a delay in cell cycle progression could be linked with differentiation in T. cruzi.

  1. Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil

    PubMed Central

    de Brito, Veruska Nogueira; de Almeida, Arleana do Bom Parto Ferreira; Nakazato, Luciano; Duarte, Rosemere; Souza, Cladson de Oliveira; Sousa, Valéria Régia Franco

    2014-01-01

    Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals. PMID:25410993

  2. [Reactivity of GST-SAPA antigen of Trypanosoma cruzi against sera from patients with Chagas disease and leishmaniasis].

    PubMed

    Gil, José; Cimino, Rubén; López Quiroga, Inés; Cajal, Silvana; Acosta, Norma; Juarez, Marisa; Zacca, Rosa; Orellana, Viviana; Krolewiecki, Alejandro; Diosque, Patricio; Nasser, Julio

    2011-01-01

    Serologic diagnosis of Trypanosoma cruzi infection is important due to the limited sensitivity of direct parasitologic methods for diagnosis in the indeterminate and chronic phases of disease. SAPA antigen has been used in several studies and has been shown to be a good marker for use in the diagnosis of T. cruzi infection. Chagas disease and leishmaniasis are endemic in northern Salta with overlapping zones of transmission, which frequently leads to T. cruzi-Leishmania spp. mixed infections. Diagnosis is complicated by the fact that there is significant cross-reactivity when non-specific antigens are used. We evaluated the reactivity of GST-SAPA antigen in the ELISA test (ELISA-SAPA) against sera from persons infected with T. cruzi (n = 154), leishmaniasis (n = 66), mixed infections (29), and healthy controls (n = 28) using commercial ELISA and IHA kits as reference tests. For ELISA-SAPA the sensitivity, specificity and kappa index were calculated for detection of T. cruzi infection. Among sera from patients infected with leishmaniasis, 30.5% of co-infections were detected. ELISA-SAPA sensitivity was 97.1% (confidence interval 95%: 94.5-99.9), specificity was 100% (confidence interval 95%: 99.4-100), and kappa index was 96% (confidence interval 95%: 93-99%), for detection of T. cruzi infection. Sensitivity, specificity and kappa indices have shown a high efficiency of ELISA-SAPA.

  3. Performance Assessment of Four Chimeric Trypanosoma cruzi Antigens Based on Antigen-Antibody Detection for Diagnosis of Chronic Chagas Disease

    PubMed Central

    Zanchin, Nilson Ivo Tonin; Brasil, Tatiana de Arruda Campos; Foti, Leonardo; de Souza, Wayner Vieira; Silva, Edmilson Domingos; Gomes, Yara de Miranda; Krieger, Marco Aurélio

    2016-01-01

    The performance of serologic tests in chronic Chagas disease diagnosis largely depends on the type and quality of the antigen preparations that are used for detection of anti-Trypanosoma cruzi antibodies. Whole-cell T. cruzi extracts or recombinant proteins have shown variation in the performance and cross-reactivity. Synthetic chimeric proteins comprising fragments of repetitive amino acids of several different proteins have been shown to improve assay performances to detect Chagasic infections. Here, we describe the production of four chimeric T. cruzi proteins and the assessment of their performance for diagnostic purposes. Circular Dichroism spectra indicated the absence of well-defined secondary structures, while polydispersity evaluated by Dynamic Light Scattering revealed only minor aggregates in 50 mM carbonate-bicarbonate (pH 9.6), demonstrating that it is an appropriate buffering system for sensitizing microplates. Serum samples from T. cruzi-infected and non-infected individuals were used to assess the performance of these antigens for detecting antibodies against T. cruzi, using both enzyme-linked immunosorbent assay and a liquid bead array platform. Performance parameters (AUC, sensitivity, specificity, accuracy and J index) showed high diagnostic accuracy for all chimeric proteins for detection of specific anti-T. cruzi antibodies and differentiated seropositive individuals from those who were seronegative. Our data suggest that these four chimeric proteins are eligible for phase II studies. PMID:27517281

  4. Genetically different isolates of Trypanosoma cruzi elicit different infection dynamics in raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana).

    PubMed

    Roellig, Dawn M; Ellis, Angela E; Yabsley, Michael J

    2009-12-01

    Trypanosoma cruzi is a genetically and biologically diverse species. In the current study we determined T. cruzi infection dynamics in two common North American reservoirs, Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor). Based on previous molecular and culture data from naturally-exposed animals, we hypothesised that raccoons would have a longer patent period than opossums, and raccoons would be competent reservoirs for both genotypes T. cruzi I (TcI) and TcIIa, while opossums would only serve as hosts for TcI. Individuals (n=2 or 3) of each species were inoculated with 1x10(6) culture-derived T. cruzi trypomastigotes of TcIIa (North American (NA) - raccoon), TcI (NA - opossum), TcIIb (South American - human), or both TcI and TcIIa. Parasitemias in opossums gradually increased and declined rapidly, whereas parasitemias peaked sooner in raccoons and they maintained relatively high parasitemia for 5weeks. Raccoons became infected with all three T. cruzi strains, while opossums only became infected with TcI and TcIIb. Although opossums were susceptible to TcIIb, infection dynamics were dramatically different compared with TcI. Opossums inoculated with TcIIb seroconverted, but parasitemia duration was short and only detectable by PCR. In addition, raccoons seroconverted sooner (3-7days post inoculation) than opossums (10days post inoculation). These data suggest that infection dynamics of various T. cruzi strains can differ considerably in different wildlife hosts.

  5. Geographical structuring of Trypanosoma cruzi populations from Chilean Triatoma infestans triatomines and their genetic relationship with other Latino American counterparts

    PubMed Central

    Venegas, J; Rojas, T; DÍaz, F; Miranda, S; Jercic, M I; González, C; Coñoepán, W; Pichuantes, S; RodrÍguez, J; Gajardo, M; Sánchez, G

    2011-01-01

    In order to obtain more information about the population structure of Chilean Trypanosoma cruzi, and their genetic relationship with other Latino American counterparts, we performed the study of T. cruzi samples detected in the midgut content of Triatoma infestans insects from three endemic regions of Chile. The genetic characteristics of these samples were analysed using microsatellite markers and PCR conditions that allow the detection of predominant T. cruzi clones directly in triatomine midgut content. Population genetic analyses using the Fisher’s exact method, analysis of molecular variance (AMOVA) and the determination of FST showed that the northern T. cruzi population sample was genetically differentiated from the two southern population counterparts. Further analysis showed that the cause of this genetic differentiation was the asymmetrical distribution of TcIII T. cruzi predominant clones. Considering all triatomines from the three regions, the most frequent predominant lineages were TcIII (38%), followed by TcI (34%) and hybrid (8%). No TcII lineage was observed along the predominant T. cruzi clones. The best phylogenetic reconstruction using the shared allelic genetic distance was concordant with the population genetic analysis and tree topology previously described studying foreign samples. The correlation studies showed that the lineage TcIII from the III region was genetically differentiated from the other two, and this differentiation was correlated with geographical distance including Chilean and mainly Brazilian samples. It will be interesting to investigate whether this geographical structure may be related with different clinical manifestation of Chagas disease. PMID:22325822

  6. Replication Protein A Presents Canonical Functions and Is Also Involved in the Differentiation Capacity of Trypanosoma cruzi

    PubMed Central

    Pavani, Raphael Souza; da Silva, Marcelo Santos; Fernandes, Carlos Alexandre Henrique; Morini, Flavia Souza; Araujo, Christiane Bezerra; Fontes, Marcos Roberto de Mattos; Sant’Anna, Osvaldo Augusto; Machado, Carlos Renato; Cano, Maria Isabel; Fragoso, Stenio Perdigão; Elias, Maria Carolina

    2016-01-01

    Replication Protein A (RPA), the major single stranded DNA binding protein in eukaryotes, is composed of three subunits and is a fundamental player in DNA metabolism, participating in replication, transcription, repair, and the DNA damage response. In human pathogenic trypanosomatids, only limited studies have been performed on RPA-1 from Leishmania. Here, we performed in silico, in vitro and in vivo analysis of Trypanosoma cruzi RPA-1 and RPA-2 subunits. Although computational analysis suggests similarities in DNA binding and Ob-fold structures of RPA from T. cruzi compared with mammalian and fungi RPA, the predicted tridimensional structures of T. cruzi RPA-1 and RPA-2 indicated that these molecules present a more flexible tertiary structure, suggesting that T. cruzi RPA could be involved in additional responses. Here, we demonstrate experimentally that the T. cruzi RPA complex interacts with DNA via RPA-1 and is directly related to canonical functions, such as DNA replication and DNA damage response. Accordingly, a reduction of TcRPA-2 expression by generating heterozygous knockout cells impaired cell growth, slowing down S-phase progression. Moreover, heterozygous knockout cells presented a better efficiency in differentiation from epimastigote to metacyclic trypomastigote forms and metacyclic trypomastigote infection. Taken together, these findings indicate the involvement of TcRPA in the metacyclogenesis process and suggest that a delay in cell cycle progression could be linked with differentiation in T. cruzi. PMID:27984589

  7. Survey of Feral Swine ( Sus scrofa ) Infection with the Agent of Chagas Disease ( Trypanosoma cruzi ) in Texas, 2013-14.

    PubMed

    Comeaux, Juliette M; Curtis-Robles, Rachel; Lewis, Barbara C; Cummings, Kevin J; Mesenbrink, Brian T; Leland, Bruce R; Bodenchuk, Michael J; Hamer, Sarah A

    2016-07-01

    : Feral swine ( Sus scrofa ) are an invasive species and reservoir of numerous zoonotic pathogens in the US, and Texas leads the nation in the estimated population size of feral hogs. Texas also harbors enzootic transmission cycles of the protozoan parasite Trypanosoma cruzi , agent of Chagas disease. Given previous evidence that swine can serve as reservoirs of T. cruzi in Latin America and new evidence of triatomines (kissing bugs) feeding on swine in Texas, we measured the prevalence of T. cruzi infection in feral swine in Texas. From 2013 to 2014, we sampled blood and/or cardiac tissue from 78 feral swine across 14 Texas counties (seven with and seven without prior documentation of kissing bug occurrence) and used PCR and histopathology to detect T. cruzi infection. We determined an overall infection prevalence of 6% (3 of 54) based on PCR evaluation of cardiac tissue, and no blood samples were positive (n=72). All three positive pigs were from counties where kissing bugs are documented. No T. cruzi amastigotes were noted on histopathology (n=54). Sarcocysts were observed in 10 (18%) of the samples, five of which also had mild focal areas of degeneration and inflammatory cell infiltration. Eco-epidemiologic investigations can provide an assessment of contributions of feral hogs to maintenance of T. cruzi across a landscape to help protect human and animal health.

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

    SciTech Connect

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

    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

  9. Treatment Success in Trypanosoma cruzi Infection Is Predicted by Early Changes in Serially Monitored Parasite-Specific T and B Cell Responses

    PubMed Central

    Cooley, Gretchen; Albareda, María C.; Viotti, Rodolfo; Perez-Mazliah, Damián E.; Lococo, Bruno; Castro Eiro, Melisa; Laucella, Susana A.; Tarleton, Rick L.

    2016-01-01

    Background Chagas disease is the highest impact parasitic disease in Latin America. We have proposed that changes in Trypanosoma cruzi-specific immune responses might serve as surrogate indicators of treatment success. Herein, we addressed in a long-term follow-up study whether cure achieved after treatment can be predicted by changes in non-conventional indexes of anti-parasite serological and T cell activities. Methodology/Principal Findings T. cruzi-specific T cell responses, as measured by interferon-γ ELISPOT and T. cruzi-specific antibodies assessed by ELISA, hemagglutination and immunofluorescence tests as well as by a multiplex assay incorporating 14 recombinant T. cruzi proteins were measured in 33 patients at 48–150 months post-benznidazole treatment. Cure — as assessed by conventional serological tests — was associated with an early decline in T. cruzi-specific IFN-γ-producing T cells and in antibody titers measured by the multiplex serological assay. Changes in the functional status and potential of T. cruzi-specific T cells, indicative of reduced antigen stimulation, provided further evidence of parasitological cure following benznidazole treatment. Patients showing a significant reduction in T. cruzi-specific antibodies had higher pre-therapy levels of T. cruzi-specific IFN-γ- producing T cells compared to those with unaltered humoral responses post-treatment. Conclusions/Significance Monitoring of appropriate immunological responses can provide earlier and robust measures of treatment success in T. cruzi infection. PMID:27128444

  10. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico

    PubMed Central

    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

  11. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico.

    PubMed

    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

  12. Developmental and reproductive patterns of Triatoma brasiliensis infected with Trypanosoma cruzi under laboratory conditions.

    PubMed

    Oliveira, Tiago G; Carvalho-Costa, Filipe A; Gomes, Taís F; Sarquis, Otília; Sposina, Ricardo; Lima, Marli M

    2010-12-01

    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.

  13. Antibody profiles induced by Trypanosoma cruzi in chagasic patients with previous or current exposure to mycobacteria.

    PubMed

    Peverengo, Luz; Prochetto, Estefanía; Rodeles, Luz; Valenzuela, Ignacio; Marcipar, Iván Sergio; Bottasso, Oscar; Vicco, Miguel Hernán

    2016-12-01

    Since the immune response mounted by the host to a particular microorganism might be influenced by the acquired immunological experience due to previous contact with other microorganisms, we performed a cross-sectional study to explore the pattern of Trypanosoma cruzi infection-related antibodies in T. cruzi-seropositive individuals presenting concomitant tuberculosis, or the antecedent of BCG vaccination. Sampled individuals were grouped as follows: patients with Chagas disease, not vaccinated with BCG, who further developed pulmonary tuberculosis; individuals with Chagas disease, BCG-vaccinated; and subjects with Chagas disease, presenting neither BCG scar nor tuberculosis disease. Non-vaccinated individuals or without tuberculosis, presented the highest values of anti-PH (P < 0.001), anti-FRA (P < 0.001), anti-p2β (P = 0.0023) and anti-B13 (P < 0.001) antibodies. The present findings constitute the first demonstration of the potential influence of concomitant tuberculosis on Chagas disease.

  14. Attenuated Salmonella sp. as a DNA Delivery System for Trypanosoma cruzi Antigens.

    PubMed

    Bivona, Augusto E; Cerny, Natacha; Alberti, Andrés Sánchez; Cazorla, Silvia I; Malchiodi, Emilio L

    2016-01-01

    Chagas disease is an important neglected disease affecting thousands of people in the Americas. Novel strategies for prophylactic and therapeutic vaccines against the etiological agent, the intracellular protozoan Trypanosoma cruzi, are urgently needed. Vaccines based on attenuated virus and bacteria as a foreign DNA delivery system represent a strong advantage over naked DNA-based vaccines. Here we describe the use of attenuated Salmonella carrying a eukaryotic expression plasmid encoding a T. cruzi antigen. The main advantages of the methodology are the oral administration of the Salmonella-based vaccine and the induction of a strong humoral and cell-mediated immune response at both mucosal and systemic level, favored by the adjuvant effect elicited by the bacteria pathogen-associated molecular patterns.

  15. Proteomic analysis of Trypanosoma cruzi developmental stages using isotope-coded affinity tag reagents.

    PubMed

    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.

  16. Experimental and Mathematical-Modeling Characterization of Trypanosoma cruzi Epimastigote Motility

    PubMed Central

    Arias-del-Angel, Jorge A.; Dévora-Canales, Diego; Manning-Cela, Rebeca G.; Santana-Solano, Jesús; Santillán, Moisés

    2015-01-01

    The present work is aimed at characterizing the motility of parasite T. cruzi in its epimastigote form. To that end, we recorded the trajectories of two strains of this parasite (a wild-type strain and a stable transfected strain, which contains an ectopic copy of LYT1 gene and whose motility is known to be affected). We further extracted parasite trajectories from the recorded videos, and statistically analysed the following trajectory-step features: step length, angular change of direction, longitudinal and transverse displacements with respect to the previous step, and mean square displacement. Based on the resulting observations, we developed a mathematical model to simulate parasite trajectories. The fact that the model predictions closely match most of the experimentally observed parasite-trajectory characteristics, allows us to conclude that the model is an accurate description of T. cruzi motility. PMID:26544863

  17. Nutritional Status Driving Infection by Trypanosoma cruzi: Lessons from Experimental Animals

    PubMed Central

    Malafaia, Guilherme; Talvani, André

    2011-01-01

    This paper reviews the scientific knowledge about protein-energy and micronutrient malnutrition in the context of Chagas disease, especially in experimental models. The search of articles was conducted using the electronic databases of SciELO (Scientific Electronic Library Online), PubMed and MEDLINE published between 1960 and March 2010. It was possible to verify that nutritional deficiencies (protein-energy malnutrition and micronutrient malnutrition) exert a direct effect on the infection by T. cruzi. However, little is known about the immunological mechanisms involved in the relationship “nutritional deficiencies and infection by T. cruzi”. A hundred years after the discovery of Chagas disease many aspects of this illness still require clarification, including the effects of nutritional deficiencies on immune and pathological mechanisms of T. cruzi infection. PMID:21577255

  18. Surface charge of trypanosoma cruzi. Binding of cationized ferritin and measurement of cellular electrophoretic mobility.

    PubMed

    De Souza, W; Arguello, C; Martinez-Paloma, A; Trissl, D; Gonzáles-Robles, A; Chiari, E

    1977-08-01

    The surface charge of epimastigote and trypomastigote forms of Trypanosoma cruzi was evaluated by means of binding of cationized ferritin to the cell surface as visualized by electron microscopy, and by direct measurements of the cellular microelectrophoretic mobility (EPM). Epimastigote forms had a mean EPM of -0.52 micrometer-s-1-V-1-cm and were lightly labeled with cationized ferritin. In contrast, bloodstream trypomastigotes had a much higher EPM (-1.14), and the surface was heavily labeled with cationized ferritin. When trypomastigotes from staionary phase cultures were isolated on DEAE cellulose columns, the mean EPM was found to be significantly lower (-0.63), and labeling with cationized ferritin decreased. With a mixed population containing epimastigote, trypomastigote, and intermediate forms, EPM values ranging between -0.70 to -1.14 were found. From these observations we conclude that there is a definite increase in negative surface charge during development from epi- to trypomastigote forms of T. cruzi.

  19. Antiheart antibody-dependent cytotoxicity in the sera of mice chronically infected with Trypanosoma cruzi.

    PubMed Central

    Laguens, R P; Meckert, P C; Chambó, J G

    1988-01-01

    Sera of mice chronically infected with Trypanosoma cruzi contain antibodies that bind to the surface of living adult syngeneic heart muscle cells. In a syngeneic system, with nonadherent spleen mononuclear cells as effector cells and cardiocytes as targets, antibody-dependent cytotoxicity (ADCC), revealed by the liberation of creatine phosphokinase from damaged cardiocytes, was observed after incorporation of serum samples from infected mice. Target damage was decreased after absorption with syngeneic myocardium, but absorption with T. cruzi epimastigotes or trypomastigotes or with syngeneic skeletal muscle had no effect on ADCC. No complement-dependent lysis against heart muscle cells was detected in the same serum samples. These observations indicate that serum from chronically chagasic mice contain antibodies that bind to the surface of living adult syngeneic cardiocytes and are able to exert ADCC, suggesting that they could play a role in the pathogenesis of the heart damage that occurs in Chagas' disease. Images PMID:3126153

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

    PubMed

    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.

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

    PubMed

    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.

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

    SciTech Connect

    Sugiyama, Shigeru; Tokuoka, Keiji; Uchiyama, Nahoko; Okamoto, Naoki; Okano, Yousuke; Matsumura, Hiroyoshi; Inaka, Koji; Urade, Yoshihiro; Inoue, Tsuyoshi

    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.

  3. Protein preparation, crystallization and preliminary X-ray analysis of Trypanosoma cruzi nucleoside diphosphate kinase 1.

    PubMed

    Gómez Barroso, J A; Pereira, H; Miranda, M; Pereira, C; Garratt, R C; Aguilar, C F

    2010-07-01

    The flagellated protozoan parasite Trypanosoma cruzi is the aetiological agent of Chagas disease. Nucleoside diphosphate kinases (NDPKs) are enzymes that are involved in energy management and nucleoside balance in the cell. T. cruzi TcNDPK1, a canonical isoform, was overexpressed in Escherichia coli as an N-terminally poly-His-tagged fusion protein and crystallized. Crystals grew after 72 h in 0.2 M MgCl(2), 20% PEG 3350. Data were collected to 3.5 A resolution using synchrotron X-ray radiation at the National Synchrotron Light Laboratory (Campinas, Brazil). The crystals belonged to the trigonal space group P3, with unit-cell parameters a = b = 127.84, c = 275.49 A. Structure determination is under way and will provide relevant information that may lead to the first step in rational drug design for the treatment of Chagas disease.

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

    PubMed Central

    Sartor, Paula A.; Cardinal, Martha V.; Orozco, Marcela M.; Gürtler, Ricardo E.; 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 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. PMID:21471302

  5. Perforin-expressing cytotoxic cells contribute to chronic cardiomyopathy in Trypanosoma cruzi infection

    PubMed Central

    Silverio, Jaline Coutinho; de-Oliveira-Pinto, Luzia Maria; da Silva, Andréa Alice; de Oliveira, Gabriel Melo; Lannes-Vieira, Joseli

    2010-01-01

    Understanding the dual participation of the immune response in controlling the invader and at the same time causing tissue damage might contribute to the design of effective new vaccines and therapies for Chagas disease. Perforin, a cytolytic protein product of killer cells, is involved in resistance to acute Trypanosoma cruzi infection. However, the contribution of perforin in parasite control and chronic chagasic cardiomyopathy is unclear. Perforin-positive cells were detected in the heart tissue during the acute and chronic phases of infection of C57BL/6 mice inoculated with low dose (102 parasites) of the Colombian T. cruzi strain. This protocol led to acute phase survival in both wild-type and perforin null (pfp−/−) mice lineages. During the chronic infection, parasitism and inducible nitric oxide synthase (iNOS) as well as interleukin (IL)-4+ and, mainly, interferon (IFN)-γ+ cells were more elevated in the heart tissue of pfp−/− mice. Higher levels of circulating NO and anti-parasite immunoglobulin (Ig)G2c and IgG3, paralleled by a prominent frequency of IFN-γ+ and IL-10+ splenocytes, were present in pfp−/−-infected mice. Therefore, although the perforin-dependent pathway plays a role, it is not crucial for anti-T. cruzi immunity and acute phase survival of mice infected with a low inoculum. Further, perforin deficiency resulted in lower activity of creatine kinase-muscle brain isoform (CK-MB) isoenzyme in serum and a more restricted connexin 43 loss, both of which are markers of the cardiomyocyte lesion. Moreover, perforin deficiency hampered the development of severe electrocardiographic abnormalities. Hence, our results corroborate that perforin-bearing cytotoxic cells might contribute to cardiomyocyte lesion and heart dysfunction during chronic T. cruzi infection, shedding light on immunopathogenesis of chronic chagasic cardiomyopathy. PMID:19878357

  6. Effect of ionizing radiation exposure on Trypanosoma cruzi ubiquitin-proteasome system.

    PubMed

    Cerqueira, Paula G; Passos-Silva, Danielle G; Vieira-da-Rocha, João P; Mendes, Isabela Cecilia; de Oliveira, Karla A; Oliveira, Camila F B; Vilela, Liza F F; Nagem, Ronaldo A P; Cardoso, Joseane; Nardelli, Sheila C; Krieger, Marco A; Franco, Glória R; Macedo, Andrea M; Pena, Sérgio D J; Schenkman, Sérgio; Gomes, Dawidson A; Guerra-Sá, Renata; Machado, Carlos R

    2017-03-01

    In recent years, proteasome involvement in the damage response induced by ionizing radiation (IR) became evident. However, whether proteasome plays a direct or indirect role in IR-induced damage response still unclear. Trypanosoma cruzi is a human parasite capable of remarkable high tolerance to IR, suggesting a highly efficient damage response system. Here, we investigate the role of T. cruzi proteasome in the damage response induced by IR. We exposed epimastigotes to high doses of gamma ray and we analyzed the expression and subcellular localization of several components of the ubiquitin-proteasome system. We show that proteasome inhibition increases IR-induced cell growth arrest and proteasome-mediated proteolysis is altered after parasite exposure. We observed nuclear accumulation of 19S and 20S proteasome subunits in response to IR treatments. Intriguingly, the dynamic of 19S particle nuclear accumulation was more similar to the dynamic observed for Rad51 nuclear translocation than the observed for 20S. In the other hand, 20S increase and nuclear translocation could be related with an increase of its regulator PA26 and high levels of proteasome-mediated proteolysis in vitro. The intersection between the opposed peaks of 19S and 20S protein levels was marked by nuclear accumulation of both 20S and 19S together with Ubiquitin, suggesting a role of ubiquitin-proteasome system in the nuclear protein turnover at the time. Our results revealed the importance of proteasome-mediated proteolysis in T. cruzi IR-induced damage response suggesting that proteasome is also involved in T. cruzi IR tolerance. Moreover, our data support the possible direct/signaling role of 19S in DNA damage repair. Based on these results, we speculate that spatial and temporal differences between the 19S particle and 20S proteasome controls proteasome multiple roles in IR damage response.

  7. The Effectiveness of Natural Diarylheptanoids against Trypanosoma cruzi: Cytotoxicity, Ultrastructural Alterations and Molecular Modeling Studies

    PubMed Central

    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

  8. Crystal structure of Trypanosoma cruzi tyrosine aminotransferase: substrate specificity is influenced by cofactor binding mode.

    PubMed Central

    Blankenfeldt, W.; Nowicki, C.; Montemartini-Kalisz, M.; Kalisz, H. M.; Hecht, H. J.

    1999-01-01

    The crystal structure of tyrosine aminotransferase (TAT) from the parasitic protozoan Trypanosoma cruzi, which belongs to the aminotransferase subfamily Igamma, has been determined at 2.5 A resolution with the R-value R = 15.1%. T. cruzi TAT shares less than 15% sequence identity with aminotransferases of subfamily Ialpha but shows only two larger topological differences to the aspartate aminotransferases (AspATs). First, TAT contains a loop protruding from the enzyme surface in the larger cofactor-binding domain, where the AspATs have a kinked alpha-helix. Second, in the smaller substrate-binding domain, TAT has a four-stranded antiparallel beta-sheet instead of the two-stranded beta-sheet in the AspATs. The position of the aromatic ring of the pyridoxal-5'-phosphate cofactor is very similar to the AspATs but the phosphate group, in contrast, is closer to the substrate-binding site with one of its oxygen atoms pointing toward the substrate. Differences in substrate specificities of T. cruzi TAT and subfamily Ialpha aminotransferases can be attributed by modeling of substrate complexes mainly to this different position of the cofactor-phosphate group. Absence of the arginine, which in the AspATs fixes the substrate side-chain carboxylate group by a salt bridge, contributes to the inability of T. cruzi TAT to transaminate acidic amino acids. The preference of TAT for tyrosine is probably related to the ability of Asn17 in TAT to form a hydrogen bond to the tyrosine side-chain hydroxyl group. PMID:10595543

  9. Production of MMP-9 and inflammatory cytokines by Trypanosoma cruzi-infected macrophages.

    PubMed

    de Pinho, Rosa Teixeira; da Silva, Wellington Seguins; de Castro Côrtes, Luzia Monteiro; da Silva Vasconcelos Sousa, Periela; de Araujo Soares, Renata Oliveira; Alves, Carlos Roberto

    2014-12-01

    Matrix metalloproteinases (MMPs) constitute a large family of Zn(2+) and Ca(2+) dependent endopeptidases implicated in tissue remodeling and chronic inflammation. MMPs also play key roles in the activation of growth factors, chemokines and cytokines produced by many cell types, including lymphocytes, granulocytes, and, in particular, activated macrophages. Their synthesis and secretion appear to be important in a number of physiological processes, including the inflammatory process. Here, we investigated the interaction between human and mouse macrophages with T. cruzi Colombian and Y strains to characterize MMP-9 and cytokine production in this system. Supernatants and total extract of T. cruzi infected human and mouse macrophages were obtained and used to assess MMP-9 profile and inflammatory cytokines. The presence of metalloproteinase activity was determined by zymography, enzyme-linked immunosorbent assay and immunoblotting assays. The effect of cytokines on MMP-9 production in human macrophages was verified by previous incubation of cytokines on these cells in culture, and analyzed by zymography. We detected an increase in MMP-9 production in the culture supernatants of T. cruzi infected human and mouse macrophages. The addition of IL-1β or TNF-α to human macrophage cultures increased MMP-9 production. In contrast, MMP-9 production was down-modulated when human macrophage cultures were treated with IFN-γ or IL-4 before infection. Human macrophages infected with T. cruzi Y or Colombian strains produced increased levels of MMP-9, which was related to the production of cytokines such as IL-1β, TNF-α and IL-6.

  10. Combined Treatment of Heterocyclic Analogues and Benznidazole upon Trypanosoma cruzi In Vivo

    PubMed Central

    Batista, Denise da Gama Jaén; Batista, Marcos Meuser; de Oliveira, Gabriel Melo; Britto, Constança Carvalho; Rodrigues, Ana Carolina Mondaine; Stephens, Chad E.; Boykin, David W.; Soeiro, Maria de Nazaré Correia

    2011-01-01

    Chagas disease caused by Trypanosoma cruzi is an important cause of mortality and morbidity in Latin America but no vaccines or safe chemotherapeutic agents are available. Combined therapy is envisioned as an ideal approach since it may enhance efficacy by acting upon different cellular targets, may reduce toxicity and minimize the risk of drug resistance. Therefore, we investigated the activity of benznidazole (Bz) in combination with the diamidine prodrug DB289 and in combination with the arylimidamide DB766 upon T. cruzi infection in vivo. The oral treatment of T.cruzi-infected mice with DB289 and Benznidazole (Bz) alone reduced the number of circulating parasites compared with untreated mice by about 70% and 90%, respectively. However, the combination of these two compounds decreased the parasitemia by 99% and protected against animal mortality by 100%, but without providing a parasitological cure. When Bz (p.o) was combined with DB766 (via ip route), at least a 99.5% decrease in parasitemia levels was observed. DB766+Bz also provided 100% protection against mice mortality while Bz alone provided about 87% protection. This combined therapy also reduced the tissular lesions induced by T. cruzi infection: Bz alone reduced GPT and CK plasma levels by about 12% and 78% compared to untreated mice group, the combination of Bz with DB766 resulted in a reduction of GPT and CK plasma levels of 56% and 91%. Cure assessment through hemocultive and PCR approaches showed that Bz did not provide a parasitological cure, however, DB766 alone or associated with Bz cured ≥13% of surviving animals. PMID:21814568

  11. Host Cell Poly(ADP-Ribose) Glycohydrolase Is Crucial for Trypanosoma cruzi Infection Cycle

    PubMed Central

    Vilchez Larrea, Salomé C.; Schlesinger, Mariana; Kevorkian, María L.; Flawiá, Mirtha M.; Alonso, Guillermo D.; Fernández Villamil, Silvia H.

    2013-01-01

    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. PMID:23776710

  12. Host cell poly(ADP-ribose) glycohydrolase is crucial for Trypanosoma cruzi infection cycle.

    PubMed

    Vilchez Larrea, Salomé C; Schlesinger, Mariana; Kevorkian, María L; Flawiá, Mirtha M; Alonso, Guillermo D; Fernández Villamil, Silvia H

    2013-01-01

    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.

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

    PubMed

    Planer, Joseph D; Hulverson, Matthew A; Arif, Jennifer A; Ranade, Ranae M; Don, Robert; Buckner, Frederick S

    2014-07-01

    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.

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

    PubMed

    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

  15. Trypanosoma cruzi Response to Sterol Biosynthesis Inhibitors: Morphophysiological Alterations Leading to Cell Death

    PubMed Central

    Kessler, Rafael Luis; Soares, Maurilio José; Probst, Christian Macagnan; Krieger, Marco Aurélio

    2013-01-01

    The protozoan parasite Trypanosoma cruzi displays similarities to fungi in terms of its sterol lipid biosynthesis, as ergosterol and other 24-alkylated sterols are its principal endogenous sterols. The sterol pathway is thus a potential drug target for the treatment of Chagas disease. We describe here a comparative study of the growth inhibition, ultrastructural and physiological changes leading to the death of T. cruzi cells following treatment with the sterol biosynthesis inhibitors (SBIs) ketoconazole and lovastatin. We first calculated the drug concentration inhibiting epimastigote growth by 50% (EC50/72 h) or killing all cells within 24 hours (EC100/24 h). Incubation with inhibitors at the EC50/72 h resulted in interesting morphological changes: intense proliferation of the inner mitochondrial membrane, which was corroborated by flow cytometry and confocal microscopy of the parasites stained with rhodamine 123, and strong swelling of the reservosomes, which was confirmed by acridine orange staining. These changes to the mitochondria and reservosomes may reflect the involvement of these organelles in ergosterol biosynthesis or the progressive autophagic process culminating in cell lysis after 6 to 7 days of treatment with SBIs at the EC50/72 h. By contrast, treatment with SBIs at the EC100/24 h resulted in rapid cell death with a necrotic phenotype: time-dependent cytosolic calcium overload, mitochondrial depolarization and reservosome membrane permeabilization (RMP), culminating in cell lysis after a few hours of drug exposure. We provide the first demonstration that RMP constitutes the “point of no return” in the cell death cascade, and propose a model for the necrotic cell death of T. cruzi. Thus, SBIs trigger cell death by different mechanisms, depending on the dose used, in T. cruzi. These findings shed new light on ergosterol biosynthesis and the mechanisms of programmed cell death in this ancient protozoan parasite. PMID:23383204

  16. Trypanosoma cruzi: Entry into Mammalian Host Cells and Parasitophorous Vacuole Formation

    PubMed Central

    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

  17. Interferon-γ-Induced Nitric Oxide Causes Intrinsic Intestinal Denervation in Trypanosoma cruzi-Infected Mice

    PubMed Central

    Arantes, Rosa M.E.; Marche, Homero H.F.; Bahia, Maria T.; Cunha, Fernando Q.; Rossi, Marcos A.; Silva, João S.

    2004-01-01

    In this study, the role of nitric oxide (NO) in neuronal destruction during acute-phase Trypanosoma cruzi infection was evaluated in male C57BL/6 (WT, wild-type) mice and knockout mice [inducible nitric oxide synthase (iNOS)−/− and interferon (IFN)−/−]. Selected animals were infected by intraperitoneal injection of 100 trypomastigote forms of the Y strain of T. cruzi. Others were injected intraperitoneally with an equal volume of saline solution and served as controls. Our findings support those of previous studies regarding myenteric denervation in acute-phase T. cruzi infection. In addition, we clearly demonstrate that, despite the fact that parasite nests and similar inflammatory infiltrate in the intestinal wall were more pronounced in infected iNOS−/− mice than in infected WT mice, the former presented no reduction in myenteric plexus neuron numbers. Neuronal nerve profile expression, as revealed by the general nerve marker PGP 9.5, was preserved in all knockout animals. Infected IFN−/− mice suffered no significant neuronal loss and there was no inflammatory infiltrate in the intestinal wall. On days 5 and 10 after infection, iNOS activity was greater in infected WT mice than in controls, whereas iNOS activity in infected knockout mice remained unchanged. These findings clearly demonstrate that neuronal damage does not occur in NO-impaired infected knockout mice, regardless of whether inflammatory infiltrate is present (iNOS−/−) or absent (IFN−/−). In conclusion, our observations strongly indicate that myenteric denervation in acute-phase T. cruzi infection is because of IFN-γ-elicited NO production resulting from iNOS activation in the inflammatory foci along the intestinal wall. PMID:15039223

  18. Identification of Trypanosoma cruzi Discrete Typing Units (DTUs) in Latin-American migrants in Barcelona (Spain).

    PubMed

    Abras, Alba; Gállego, Montserrat; Muñoz, Carmen; Juiz, Natalia A; Ramírez, Juan Carlos; Cura, Carolina I; Tebar, Silvia; Fernández-Arévalo, Anna; Pinazo, María-Jesús; de la Torre, Leonardo; Posada, Elizabeth; Navarro, Ferran; Espinal, Paula; Ballart, Cristina; Portús, Montserrat; Gascón, Joaquim; Schijman, Alejandro G

    2017-04-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is divided into six Discrete Typing Units (DTUs): TcI-TcVI. We aimed to identify T. cruzi DTUs in Latin-American migrants in the Barcelona area (Spain) and to assess different molecular typing approaches for the characterization of T. cruzi genotypes. Seventy-five peripheral blood samples were analyzed by two real-time PCR methods (qPCR) based on satellite DNA (SatDNA) and kinetoplastid DNA (kDNA). The 20 samples testing positive in both methods, all belonging to Bolivian individuals, were submitted to DTU characterization using two PCR-based flowcharts: multiplex qPCR using TaqMan probes (MTq-PCR), and conventional PCR. These samples were also studied by sequencing the SatDNA and classified as type I (TcI/III), type II (TcII/IV) and type I/II hybrid (TcV/VI). Ten out of the 20 samples gave positive results in the flowcharts: TcV (5 samples), TcII/V/VI (3) and mixed infections by TcV plus TcII (1) and TcV plus TcII/VI (1). By SatDNA sequencing, we classified the 20 samples, 19 as type I/II and one as type I. The most frequent DTU identified by both flowcharts, and suggested by SatDNA sequencing in the remaining samples with low parasitic loads, TcV, is common in Bolivia and predominant in peripheral blood. The mixed infection by TcV-TcII was detected for the first time simultaneously in Bolivian migrants. PCR-based flowcharts are very useful to characterize DTUs during acute infection. SatDNA sequence analysis cannot discriminate T. cruzi populations at the level of a single DTU but it enabled us to increase the number of characterized cases in chronically infected patients.

  19. Frequent House Invasion of Trypanosoma cruzi-Infected Triatomines in a Suburban Area of Brazil

    PubMed Central

    Ribeiro Jr., Gilmar; Gurgel-Gonçalves, Rodrigo; Reis, Renato Barbosa; dos Santos, Carlos Gustavo Silva; Amorim, Alekhine; Andrade, Sônia Gumes; Reis, Mitermayer G.

    2015-01-01

    Background 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. Methodology/Principal Findings 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). Conclusions/Significance 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. PMID:25909509

  20. Influence of Parasite Load on Renal Function in Mice Acutely Infected with Trypanosoma cruzi

    PubMed Central

    Parreira, Ricardo Cambraia; Miguel, Renata Botelho; de Paula Rogerio, Alexandre; Oliveira, Carlo Jose Freire; Chica, Javier Emilio Lazo

    2013-01-01

    Background Chagas disease is a neglected tropical disease caused by Trypanosoma cruzi. Despite the vast number of studies evaluating the pathophysiological mechanisms of the disease, the influence of parasite burden on kidney lesions remains unclear. Thus, the main goal of this work was to evaluate the effect of T. cruzi infection on renal function and determine whether there was a correlation between parasite load and renal injury using an acute experimental model of the disease. Methodology/Principal Findings Low, medium and high parasite loads were generated by infecting C57BL/6 mice with 300 (low), 3,000 (medium) or 30,000 (high) numbers of “Y” strain trypomastigotes. We found that mice infected with T. cruzi trypomastigotes show increased renal injury. The infection resulted in reduced urinary excretion and creatinine clearance. We also observed a marked elevation in the ratio of urine volume to kidney and body weight, blood urea nitrogen, chloride ion, nitric oxide, pro- and anti-inflammatory cytokines and the number of leukocytes in the blood and/or renal tissues of infected mice. Additionally, we observed the presence of the parasite in the cortical/medullary and peri-renal region, an increase of inflammatory infiltrate and of vascular permeability of the kidney. Overall, most renal changes occurred mainly in animals infected with high parasitic loads. Conclusions/Significance These data demonstrate that T. cruzi impairs kidney function, and this impairment is more evident in mice infected with high parasitic loads. Moreover, these data suggest that, in addition to the extensively studied cardiovascular effects, renal injury should be regarded as an important indicator for better understanding the pan-infectivity of the parasite and consequently for understanding the disease in experimental models. PMID:23951243

  1. Frequency of the Congenital Transmission of Trypanosoma cruzi: A Systematic Review and Meta-Analysis

    PubMed Central

    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

  2. Digestion of human immunoglobulin G by the major cysteine proteinase (cruzipain) from Trypanosoma cruzi.

    PubMed

    Bontempi, E; Cazzulo, J J

    1990-08-01

    The major cysteine proteinase (cruzipain) from Trypanosoma cruzi was able to digest human IgG, as shown by polyacrylamide gel electrophoresis in the presence of SDS, and by gel filtration on a Superose 12 column, in a FPLC system. The Fab fragment of IgG was only slightly degraded, but Fc was extensively hydrolyzed to small peptides. The results suggest that cruzipain might be involved in the defense mechanisms of the parasite against the immune response of the host.

  3. Expression and the Peculiar Enzymatic Behavior of the Trypanosoma cruzi NTH1 DNA Glycosylase

    PubMed Central

    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

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

    PubMed Central

    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

  5. The Effectiveness of Natural Diarylheptanoids against Trypanosoma cruzi: Cytotoxicity, Ultrastructural Alterations and Molecular Modeling Studies.

    PubMed

    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

    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.

  6. Farnesyl Diphosphate Synthase Localizes to the Cytoplasm of Trypanosoma cruzi and T.brucei

    PubMed Central

    Ferella, Marcela; Li, Zhu-Hong; Andersson, Björn; Docampo, Roberto

    2008-01-01

    The farnesyl diphosphate synthase (FPPS) has previously been characterized in trypanosomes as an essential enzyme for their survival and as the target for bisphosphonates, drugs that are effective both in vitro and in vivo against these parasites. Enzymes from the isoprenoid pathway have been assigned to different compartments in eukaryotes, including trypanosomatids. We here report that FPPS localizes to the cytoplasm of both Trypanosoma cruzi and T. brucei, and is not present in other organelles such as the mitochondria and glycosomes. PMID:18406406

  7. Longitudinal studies of the immune response of Colombian patients infected with Trypanosoma cruzi and T. rangeli.

    PubMed

    Hudson, L; Guhl, F; de Sanchez, N; Bridge, D; Jaramillo, C A; Young, A

    1988-06-01

    Two groups of patients were examined for anti-Trypanosoma cruzi antibodies by immunofluorescence and ELISA (i) inhabitants of the village and surrounding rural area of Tibu, Norte de Santander, Columbia (n = 327) and (ii) employees of the Empresa Colombiana de Petroleos (ECOPETROL, n = 849). The latter group had a lower rate of positive serology (12 as compared to 29%) but the distributions of antibody titres were very similar in the two groups. A total of 119 serum samples (37 village and 82 ECOPETROL, including 25 seronegative controls) were analysed for their ability to immunoprecipitate the 7 major polypeptides of T. cruzi trypomastigotes of Mr greater than 72 kDa. Although 10 sera from positive patients showed no immunoprecipitation, all of the remaining positive sera contained antibodies which reacted with the 150, 90 and 85 kDa polypeptides. When the T. cruzi immunofluorescence positive, immunoprecipitation negative sera were retested by ELISA using GP90, all were negative thus suggesting that the patients had had a misdiagnosed T. rangeli infection. The new diagnosis was confirmed by immunofluorescence and ELISA with T. rangeli epimastigotes. Longitudinal studies were carried out on 19 patients from the ECOPETROL group for up to 3.5 years. Five seropositive patients showed a change in their anti-trypomastigote immunoprecipitation profiles over this period; one by loss of a previously recognized high molecular weight band and four others by conversion from a negative to a positive immunoprecipitation profile. These latter patients presented initially with uncomplicated T. rangeli infection but then acquired a T. cruzi superinfection. These patients represent the nucleus of a group in which prospective studies will identify the effect of T. rangeli infection on the course of subsequent South American trypanosomiasis and Chagas' disease.

  8. Long-term reduction of Trypanosoma cruzi infection in sylvatic mammals following deforestation and sustained vector surveillance in northwestern Argentina.

    PubMed

    Ceballos, L A; Cardinal, M V; Vazquez-Prokopec, G M; Lauricella, M A; Orozco, M M; Cortinas, R; Schijman, A G; Levin, M J; Kitron, U; Gürtler, R E

    2006-07-01

    Long-term variations in the dynamics and intensity of sylvatic transmission of Trypanosoma cruzi were investigated around eight rural villages in the semiarid Argentine Chaco in 2002-2004 and compared to data collected locally in 1984-1991. Of 501 wild mammals from 13 identified species examined by xenodiagnosis, only 3 (7.9%) of 38 Didelphis albiventris opossums and 1 (1.1%) of 91 Conepatus chinga skunks were infected by T. cruzi. The period prevalence in opossums was four-fold lower in 2002-2004 than in 1984-1991 (32-36%). The infection prevalence of skunks also decreased five-fold from 4.1-5.6% in 1984-1991 to 1.1% in 2002-2004. Infection in opossums increased with age and from summer to spring in both study periods. The force of infection per 100 opossum-months after weaning declined more than six-fold from 8.2 in 1988-1991 to 1.2 in 2002-2004. Opossums were mainly infected by T. cruzi lineage I and secondarily by lineage IId in 1984-1991, and only by T. cruzi I in 2002-2004; skunks were infected by T. cruzi IId in 1984-1991 and by IIc in 2002-2004. The striking decline of T. cruzi infection in opossums and skunks occurred in parallel to community-wide insecticide spraying followed by selective sprays leading to very low densities of infected Triatoma infestans in domestic and peridomestic habitats since 1992; to massive deforestation around one of the villages or selective extraction of older trees, and apparent reductions in opossum abundance jointly with increases in foxes and skunks. These factors may underlie the dramatic decrease of T. cruzi infection in wild reservoir hosts.

  9. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae): Aspects of the ecology of parasite-vector interactions.

    PubMed

    Falcão de Oliveira, Everton; Oshiro, Elisa Teruya; Fernandes, Wagner de Souza; Murat, Paula Guerra; Medeiros, Márcio José de; Souza, Alda Izabel; Oliveira, Alessandra Gutierrez de; Galati, Eunice Aparecida Bianchi

    2017-02-01

    Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial capacity for L. infantum

  10. Biological characterization of Trypanosoma cruzi stocks from domestic and sylvatic vectors in Sierra Nevada of Santa Marta, Colombia.

    PubMed

    Téllez-Meneses, Jair; Mejía-Jaramillo, Ana María; Triana-Chávez, Omar

    2008-10-01

    Sierra Nevada of Santa Marta is one of the most endemic regions of Chagas disease in Colombia. In this study, we compared the biological behavior and genetic features of Trypanosoma cruzi stocks that were isolated from domestic and sylvatic insects in this area. Rhodnius prolixus (from domestic environments) and Triatoma dimidiata (from sylvatic, peridomestic and domestic environments) are the most important vectors in this region. Genetic characterization showed that all stocks corresponded to T. cruzi I, but LSSP-PCR analyses indicated that some genotypes were present in both environments. Biological characterization in vitro showed a low growth rate in sylvatic T. cruzi stocks and in some domestic T. cruzi stocks, possibly indicating the presence of stocks with similar behavior in both transmission cycles. In parallel, in vivo behavioral analysis also indicated that T. cruzi stocks are variable and this species did not show a correlation between the environments where they were isolated. In addition, all stocks demonstrated a low mortality rate and histopathological lesions in heart, skeletal muscle and colon tissue. Moreover, our data indicated that experimentally infected chagasic mice displayed a relation between their myocardial inflammation intensity, parasitism tissue and parasite load using the qPCR. In conclusion, our results indicate that the T. cruzi stocks present in SNSM have similar biological behavior and do not show a correlation with the different transmission cycles. This could be explained by the complex transmission dynamics of T. cruzi in Sierra Nevada of Santa Marta, where hosts, vectors (e.g., T. dimidiata) and reservoirs circulate in both environments due to the close contact between the two transmission cycles, favoring environment overlapping. This knowledge is an important key to understanding the epidemiology and pathology of Chagas disease in this Colombian region. Furthermore, our findings could be of significant use in the design of

  11. Desing and synthesis of potent anti-Trypanosoma cruzi agents new thiazoles derivatives which induce apoptotic parasite death.

    PubMed

    da Silva, Elany Barbosa; Oliveira E Silva, Dayane Albuquerque; Oliveira, Arsênio Rodrigues; da Silva Mendes, Carlos Henrique; Dos Santos, Thiago André Ramos; da Silva, Aline Caroline; de Castro, Maria Carolina Acioly; Ferreira, Rafaela Salgado; Moreira, Diogo Rodrigo Magalhães; Cardoso, Marcos Veríssimo de Oliveira; de Simone, Carlos Alberto; Pereira, Valéria Rêgo Alves; Leite, Ana Cristina Lima

    2017-04-21

    Chagas disease, caused by the kinetoplastid protozoan parasite Trypanosoma cruzi, remains a relevant cause of illness and premature death and it is estimated that 6 million to 7 million people are infected worldwide. Although chemotherapy options are limited presenting serious problems, such as low efficacy and high toxicity. T. cruzi is susceptible to thiazoles, making this class of compounds appealing for drug development. Previously, thiazoles resulted in an increase in anti-T. cruzi activity in comparison to thiosemicarbazones. Here, we report the structural planning, synthesis and anti-T. cruzi evaluation of new thiazoles derivatives (3a-m and 4a-m), designed from molecular hybridization associated with non-classical bioisosterism. By varying substituents attached to the phenyl and thiazole rings, substituents were observed to retain, enhance or greatly increase their anti-T. cruzi activity, in comparison to the corresponding thiosemicarbazones. In most cases, electron-withdrawing substituents, such as bromine, 3,4-dichloro and nitro groups, greatly increased antiparasitic activity. Specifically, new thiazoles were identified that inhibit the epimastigote proliferation and were toxic for trypomastigotes without affecting macrophages viability. These compounds were also 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 molecules induce apoptosis. In conclusion, except for compounds 3h and 3k, all thiazoles derivatives evaluated exhibited higher cytotoxic activity against the trypomastigote forms than the reference medicament benznidazole, without affecting macrophages viability. Compounds 4d and 4k were highlights, CC50 = 1.2 e 1.6 μM, respectively. Mechanistically, these compounds do not inhibit the cruzain, but induce T. cruzi cell death by an apoptotic process, being considered a good starting

  12. A Kazal-type inhibitor is modulated by Trypanosoma cruzi to control microbiota inside the anterior midgut of Rhodnius prolixus.

    PubMed

    Soares, Tatiane S; Buarque, Diego S; Queiroz, Bruna R; Gomes, Cícera M; Braz, Glória R C; Araújo, Ricardo N; Pereira, Marcos H; Guarneri, Alessandra A; Tanaka, Aparecida S

    2015-05-01

    The triatomine insect, Rhodnius prolixus, is a vector of Trypanosoma cruzi, a protozoan parasite that causes Chagas disease. The parasite must overcome immune response and microbiota to develop inside the midgut of triatomines. In this study, we expressed, purified and characterized a Kazal-type inhibitor from the midgut of R. prolixus, named RpTI, which may be involved in microbiota - T. cruzi interactions. The qPCR showed that the RpTI transcript was primarily expressed in tissues from the intestinal tract and that it was upregulated in the anterior midgut after T. cruzi infection. A 315-bp cDNA fragment encoding the mature protein was cloned into the pPIC9 vector and expressed in Pichia pastoris system. Recombinant RpTI (rRpTI) was purified on a trypsin-Sepharose column and had a molecular mass of 11.5 kDa as determined by SDS-PAGE analysis. This protein inhibited trypsin (Ki = 0.42 nM), whereas serine proteases from the coagulation cascade were not inhibited. Moreover, trypanocidal assays revealed that rRpTI did not interfere in the viability of T. cruzi trypomastigotes. The RpTI transcript was also knocked down by RNA interference prior to infection of R. prolixus with T. cruzi. The amount of T. cruzi in the anterior midgut was significantly lower in RpTI knockdown insects compared to the non-silenced groups. We also verified that the bacterial load is higher in the anterior midgut of silenced and infected R. prolixus compared to non-silenced and infected insects. Our results suggest that T. cruzi infection increases the expression of RpTI to mediate microbiota modulation and is important for parasite immediately after infection with R. prolixus.

  13. The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina

    PubMed Central

    Alvarado-Otegui, J.A.; Ceballos, L.A.; Orozco, M.M.; Enriquez, G.F.; Cardinal, M.V.; Cura, C.; Schijman, A.G.; Kitron, U.; Gürtler, R.E.

    2012-01-01

    Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species was captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively. PMID:22771688

  14. Unequivocal Identification of Subpopulations in Putative Multiclonal Trypanosoma cruzi Strains by FACs Single Cell Sorting and Genotyping

    PubMed Central

    Valadares, Helder Magno Silva; Pimenta, Juliana Ramos; Segatto, Marcela; Veloso, Vanja Maria; Gomes, Mônica Lúcia; Chiari, Egler; Gollob, Kenneth John; Bahia, Maria Terezinha; de Lana, Marta; Franco, Glória Regina; Machado, Carlos Renato; Pena, Sérgio Danilo Junho; Macedo, Andréa Mara

    2012-01-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and current conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (FACS) was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations – Silvio X10 cl1 (TcI) and Esmeraldo cl3 (TcII) – and three naturally occurring strains, one isolated from a vector (A316A R7) and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality. PMID:22802979

  15. Unequivocal identification of subpopulations in putative multiclonal Trypanosoma cruzi strains by FACs single cell sorting and genotyping.

    PubMed

    Valadares, Helder Magno Silva; Pimenta, Juliana Ramos; Segatto, Marcela; Veloso, Vanja Maria; Gomes, Mônica Lúcia; Chiari, Egler; Gollob, Kenneth John; Bahia, Maria Terezinha; de Lana, Marta; Franco, Glória Regina; Machado, Carlos Renato; Pena, Sérgio Danilo Junho; Macedo, Andréa Mara

    2012-01-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and current conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (FACS) was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations--Silvio X10 cl1 (TcI) and Esmeraldo cl3 (TcII)--and three naturally occurring strains, one isolated from a vector (A316A R7) and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality.

  16. Ecological Connectivity of Trypanosoma cruzi Reservoirs and Triatoma pallidipennis Hosts in an Anthropogenic Landscape with Endemic Chagas Disease

    PubMed Central

    Ramsey, Janine M.; Gutiérrez-Cabrera, Ana E.; Salgado-Ramírez, Liliana; Peterson, A. Townsend; Sánchez-Cordero, Victor; Ibarra-Cerdeña, Carlos N.

    2012-01-01

    Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats. PMID:23049923

  17. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae): Aspects of the ecology of parasite-vector interactions

    PubMed Central

    Murat, Paula Guerra; de Medeiros, Márcio José; Souza, Alda Izabel; de Oliveira, Alessandra Gutierrez

    2017-01-01

    Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis–infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis–infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial capacity for L

  18. Automated High-Content Assay for Compounds Selectively Toxic to Trypanosoma cruzi in a Myoblastic Cell Line

    PubMed Central

    Alonso-Padilla, Julio; Cotillo, Ignacio; Presa, Jesús L.; Cantizani, Juan; Peña, Imanol; Bardera, Ana I.; Martín, Jose J.; Rodriguez, Ana

    2015-01-01

    Background Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, represents a very important public health problem in Latin America where it is endemic. Although mostly asymptomatic at its initial stage, after the disease becomes chronic, about a third of the infected patients progress to a potentially fatal outcome due to severe damage of heart and gut tissues. There is an urgent need for new drugs against Chagas disease since there are only two drugs available, benznidazole and nifurtimox, and both show toxic side effects and variable efficacy against the chronic stage of the disease. Methodology/Principal Findings Genetically engineered parasitic strains are used for high throughput screening (HTS) of large chemical collections in the search for new anti-parasitic compounds. These assays, although successful, are limited to reporter transgenic parasites and do not cover the wide T. cruzi genetic background. With the aim to contribute to the early drug discovery process against Chagas disease we have developed an automated image-based 384-well plate HTS assay for T. cruzi amastigote replication in a rat myoblast host cell line. An image analysis script was designed to inform on three outputs: total number of host cells, ratio of T. cruzi amastigotes per cell and percentage of infected cells, which respectively provides one host cell toxicity and two T. cruzi toxicity readouts. The assay was statistically robust (Z´ values >0.6) and was validated against a series of known anti-trypanosomatid drugs. Conclusions/Significance We have established a highly reproducible, high content HTS assay for screening of chemical compounds against T. cruzi infection of myoblasts that is amenable for use with any T. cruzi strain capable of in vitro infection. Our visual assay informs on both anti-parasitic and host cell toxicity readouts in a single experiment, allowing the direct identification of compounds selectively targeted to the parasite. PMID:25615687

  19. Long-Term Immunity to Trypanosoma cruzi in the Absence of Immunodominant trans-Sialidase-Specific CD8+ T Cells

    PubMed Central

    Rosenberg, Charles S.; Zhang, Weibo; Bustamante, Juan M.

    2016-01-01

    Trypanosoma cruzi infection drives the expansion of remarkably focused CD8+ T cell responses targeting epitopes encoded by variant trans-sialidase (TS) genes. Infection of C57BL/6 mice with T. cruzi results in up to 40% of all CD8+ T cells committed to recognition of the dominant TSKB20 and subdominant TSKB18 TS epitopes. However, despite this enormous response, these mice fail to clear T. cruzi infection and subsequently develop chronic disease. One possible reason for the failure to cure T. cruzi infection is that immunodomination by these TS-specific T cells may interfere with alternative CD8+ T cell responses more capable of complete parasite elimination. To address this possibility, we created transgenic mice that are centrally tolerant to these immunodominant epitopes. Mice expressing TSKB20, TSKB18, or both epitopes controlled T. cruzi infection and developed effector CD8+ T cells that maintained an activated phenotype. Memory CD8+ T cells from drug-cured TSKB-transgenic mice rapidly responded to secondary T. cruzi infection. In the absence of the response to TSKB20 and TSKB18, immunodominance did not shift to other known subdominant epitopes despite the capacity of these mice to expand epitope-specific T cells specific for the model antigen ovalbumin expressed by engineered parasites. Thus, CD8+ T cell responses tightly and robustly focused on a few epitopes within variant TS antigens appear to neither contribute to, nor detract from, the ability to control T. cruzi infection. These data also indicate that the relative position of an epitope within a CD8+ immunodominance hierarchy does not predict its importance in pathogen control. PMID:27354447

  20. Identification of Three Classes of Heteroaromatic Compounds with Activity against Intracellular Trypanosoma cruzi by Chemical Library Screening

    PubMed Central

    Bettiol, Esther; Samanovic, Marie; Murkin, Andrew S.; Raper, Jayne; Buckner, Frederick; Rodriguez, Ana

    2009-01-01

    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 β-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC50: 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 IC50 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. PMID:19238193

  1. Long-term reduction of Trypanosoma cruzi infection in sylvatic mammals following deforestation and sustained vector surveillance in northwestern Argentina

    PubMed Central

    Ceballos, L.A.; Cardinal, M.V.; Vazquez-Prokopec, G.M.; Lauricella, M.A.; Orozco, M.M.; Cortinas, R.; Schijman, A.G.; Levin, M.J.; Kitron, U.; Gürtler, R.E.

    2007-01-01

    Long-term variations in the dynamics and intensity of sylvatic transmission of Trypanosoma cruzi were investigated around eight rural villages in the semiarid Argentine Chaco in 2002–2004 and compared to data collected locally in 1984–1991. Of 501 wild mammals from 13 identified species examined by xenodiagnosis, only 3 (7.9%) of 38 Didelphis albiventris opossums and 1 (1.1%) of 91 Conepatus chinga skunks were infected by T. cruzi. The period prevalence in opossums was four-fold lower in 2002–2004 than in 1984–1991 (32–36%). The infection prevalence of skunks also decreased five-fold from 4.1–5.6% in 1984–1991 to 1.1% in 2002–2004. Infection in opossums increased with age and from summer to spring in both study periods. The force of infection per 100 opossum-months after weaning declined more than six-fold from 8.2 in 1988–1991 to 1.2 in 2002–2004. Opossums were mainly infected by T. cruzi lineage I and secondarily by lineage IId in 1984–1991, and only by T. cruzi I in 2002–2004; skunks were infected by T. cruzi IId in 1984–1991 and by IIc in 2002–2004. The striking decline of T. cruzi infection in opossums and skunks occurred in parallel to community-wide insecticide spraying followed by selective sprays leading to very low densities of infected Triatoma infestans in domestic and peridomestic habitats since 1992; to massive deforestation around one of the villages or selective extraction of older trees, and apparent reductions in opossum abundance jointly with increases in foxes and skunks. These factors may underlie the dramatic decrease of T. cruzi infection in wild reservoir hosts. PMID:16839513

  2. The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina.

    PubMed

    Alvarado-Otegui, J A; Ceballos, L A; Orozco, M M; Enriquez, G F; Cardinal, M V; Cura, C; Schijman, A G; Kitron, U; Gürtler, R E

    2012-10-01

    Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species were captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively.

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

    SciTech Connect

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

    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. The C-terminal region of Trypanosoma cruzi MASPs is antigenic and secreted via exovesicles

    PubMed Central

    De Pablos, Luis Miguel; Díaz Lozano, Isabel María; Jercic, Maria Isabel; Quinzada, Markela; Giménez, Maria José; Calabuig, Eva; Espino, Ana Margarita; Schijman, Alejandro Gabriel; Zulantay, Inés; Apt, Werner; Osuna, Antonio

    2016-01-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected and emerging tropical disease, endemic to South America and present in non-endemic regions due to human migration. The MASP multigene family is specific to T. cruzi, accounting for 6% of the parasite’s genome and plays a key role in immune evasion. A common feature of MASPs is the presence of two conserved regions: an N-terminal region codifying for signal peptide and a C-terminal (C-term) region, which potentially acts as GPI-addition signal peptide. Our aim was the analysis of the presence of an immune response against the MASP C-term region. We found that this region is highly conserved, released via exovesicles (EVs) and has an associated immune response as revealed by epitope affinity mapping, IFA and inhibition of the complement lysis assays. We also demonstrate the presence of a fast IgM response in Balb/c mice infected with T. cruzi. Our results reveal the presence of non-canonical secreted peptides in EVs, which can subsequently be exposed to the immune system with a potential role in evading immune system targets in the parasite. PMID:27270330

  5. Chagas' disease: reactivity against homologous tissues induced by different strains of Trypanosoma cruzi.

    PubMed

    Tekiel, V S; Mirkin, G A; Gonzalez Cappa, S M

    1997-11-01

    We have previously reported that the mechanisms of neuromyopathic damage induced by Trypanosoma cruzi are mediated by T cells and are parasite-strain dependent. In the present study our aim was to determine whether the humoral response against muscle and nervous system is also parasite-strain dependent. Of the sera from mice infected with RA and CA-I. T. cruzi strains, 93% reacted against antigens of the nervous system (sciatic nerve, spinal cord and brain). No differences in the ability to recognize heart antigens were found between RA (48%) and CA-I (63%) antisera. Reactivity against skeletal muscle was only relevant in anti-CA-I sera at 270 days post-infection. Each of the antisera assayed in Western blots developed a particular antigenic pattern, but 3 antigens in the nervous system of molecular weight 48, 60 and 70 kDa were detected by 42, 28 and 23% of the sera, respectively. On the other hand, deposits of IgG were observed at the interstitial matrix in sciatic nerve and as endomisial and sarcolemmal patterns in skeletal muscle by IFAT for both RA and CA-I antisera. Absorption of sera with parasite antigens did not abolish the autoreactivity. Our results suggest that major serum autoreactivity from T. cruzi-infected mice is not parasite-strain dependent and does not arise from molecular mimicry.

  6. How Trypanosoma cruzi handles cell cycle arrest promoted by camptothecin, a topoisomerase I inhibitor.

    PubMed

    Zuma, Aline Araujo; Mendes, Isabela Cecília; Reignault, Lissa Catherine; Elias, Maria Carolina; de Souza, Wanderley; Machado, Carlos Renato; Motta, Maria Cristina M

    2014-02-01

    The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease, which affects approximately 8 million people in Latin America. This parasite contains a single nucleus and a kinetoplast, which harbors the mitochondrial DNA (kDNA). DNA topoisomerases act during replication, transcription and repair and modulate DNA topology by reverting supercoiling in the DNA double-strand. In this work, we evaluated the effects promoted by camptothecin, a topoisomerase I inhibitor that promotes protozoan proliferation impairment, cell cycle arrest, ultrastructure alterations and DNA lesions in epimastigotes of T. cruzi. The results showed that inhibition of cell proliferation was reversible only at the lowest drug concentration (1μM) used. The unpacking of nuclear heterochromatin and mitochondrion swelling were the main ultrastructural modifications observed. Inhibition of parasite proliferation also led to cell cycle arrest, which was most likely caused by nuclear DNA lesions. Following camptothecin treatment, some of the cells restored their DNA, whereas others entered early apoptosis but did not progress to late apoptosis, indicating that the protozoa stay alive in a "senescence-like" state. This programmed cell death may be associated with a decrease in mitochondrial membrane potential and an increase in the production of reactive oxygen species. Taken together, these results indicate that the inhibition of T. cruzi proliferation is related to events capable of affecting cell cycle, DNA organization and mitochondrial activity.

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

    PubMed Central

    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. PMID:28377930

  8. Proteomic analysis of Trypanosoma cruzi secretome: characterization of two populations of extracellular vesicles and soluble proteins.

    PubMed

    Bayer-Santos, Ethel; Aguilar-Bonavides, Clemente; Rodrigues, Silas Pessini; Cordero, Esteban Maurício; Marques, Alexandre Ferreira; Varela-Ramirez, Armando; Choi, Hyungwon; Yoshida, Nobuko; da Silveira, José Franco; Almeida, Igor C

    2013-02-01

    Microorganisms use specialized systems to export virulence factors into host cells. Secretion of effector proteins into the extracellular environment has been described in Trypanosoma cruzi; however, a comprehensive proteomic analysis of the secretome and the secretion mechanisms involved remain elusive. Here, we present evidence that T. cruzi releases proteins associated with vesicles that are formed by at least two different mechanisms. Transmission electron microscopy showed larger vesicles budding from the plasma membrane of noninfective epimastigotes and infective metacyclic trypomastigotes, as well as smaller vesicles within the flagellar pocket of both forms. Parasite conditioned culture supernatant was fractionated and characterized by morphological, immunochemical, and proteomic analyses. Three fractions were obtained by differential ultracentrifugation: the first enriched in larger vesicles resembling ectosomes, the second enriched in smaller vesicles resembling exosomes, and a third fraction enriched in soluble proteins not associated with extracellular vesicles. Label-free quantitative proteomic analysis revealed a rich collection of proteins involved in metabolism, signaling, nucleic acid binding, and parasite survival and virulence. These findings support the notion that T. cruzi uses different secretion pathways to excrete/secrete proteins. Moreover, our results suggest that metacyclic forms may use extracellular vesicles to deliver cargo into host cells.

  9. Eco-epidemiological aspects of Trypanosoma cruzi, Trypanosoma rangeli and their vector (Rhodnius pallescens) in Panama.

    PubMed

    Vasquez, Ana Maria de; Samudio, Franklyn E; Saldaña, Azael; Paz, Hector M; Calzada, José E

    2004-01-01

    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.

  10. Domestic dogs and cats as sources of Trypanosoma cruzi infection in rural northwestern Argentina.

    PubMed

    Gürtler, R E; Cecere, M C; Lauricella, M A; Cardinal, M V; Kitron, U; Cohen, J E

    2007-01-01

    The reservoir capacity of domestic cats and dogs for Trypanosoma cruzi infection and the host-feeding patterns of domestic Triatoma infestans were assessed longitudinally in 2 infested rural villages in north-western Argentina. A total of 86 dogs and 38 cats was repeatedly examined for T. cruzi infection by serology and/or xenodiagnosis. The composite prevalence of infection in dogs (60%), but not in cats, increased significantly with age and with the domiciliary density of infected T. infestans. Dogs and cats had similarly high forces of infection, prevalence of infectious hosts (41-42%), and infectiousness to bugs at a wide range of infected bug densities. The infectiousness to bugs of seropositive dogs declined significantly with increasing dog age and was highly aggregated. Individual dog infectiousness to bugs was significantly autocorrelated over time. Domestic T. infestans fed on dogs showed higher infection prevalence (49%) than those fed on cats (39%), humans (38%) or chickens (29%) among 1085 bugs examined. The basic reproduction number of T. cruzi in dogs was at least 8.2. Both cats and dogs are epidemiologically important sources of infection for bugs and householders, dogs nearly 3 times more than cats.

  11. Nuclear Compartmentalization Contributes to Stage-Specific Gene Expression Control in Trypanosoma cruzi

    PubMed Central

    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

  12. Ultrastructural and physiological changes induced by different stress conditions on the human parasite Trypanosoma cruzi.

    PubMed

    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.

  13. Antagonic activities of Trypanosoma cruzi metacaspases affect the balance between cell proliferation, death and differentiation.

    PubMed

    Laverrière, M; Cazzulo, J J; Alvarez, V E

    2012-08-01

    Metacaspases are distant relatives of animal caspases present in plants, fungi and protozoa. At variance with caspases, metacaspases exhibit stringent specificity for basic amino-acid residues and are absolutely dependent on millimolar concentrations of calcium. In the protozoan parasite Trypanosoma cruzi, metacaspases have been suggested to be involved in an apoptosis-like phenomenon upon exposure of the parasite to fresh human serum (FHS). Nuclear relocalization of metacaspases was observed after FHS treatment and overexpression of metacaspase-5 led to enhanced sensitivity to this stimulus. Here we report some biochemical properties of T. cruzi metacaspases. Performing fluorescent-activated cell sorting (FACS) analysis of epimastigotes inducibly overexpressing metacaspase-3, we demonstrate a role for this metacaspase in cell cycle progression, protection of epimastigotes from naturally occurring cell death and differentiation to infective metacyclic trypomastigotes. We also show that regulation of metacaspase-3 activity is important for cell cycle completion inside the mammalian host. On the other hand, inducible overexpression of metacaspase-5 lacking its C-terminal domain caused an apoptotic-like response. These results suggest that the two T. cruzi metacaspases could play an important role in the life cycle and bring to light the close relationship between cell division, death and differentiation in this ancient unicellular eukaryote.

  14. Trypanosoma cruzi: experimental parasitism in the central nervous system of albino mice.

    PubMed

    Morocoima, Antonio; Socorro, Grace; Avila, Régulo; Hernández, Ana; Merchán, Solángel; Ortiz, Diana; Primavera, Gabriela; Chique, José; Herrera, Leidi; Urdaneta-Morales, Servio

    2012-11-01

    Trypanosoma cruzi causes a pan-infection, Chagas disease, in American mammals through fecal transmission by triatomine insects, resulting in an acute phase parasitemia with intracellularity mainly in the myocells and cells of the central nervous system (CNS).The parasites, due to the immune response, then decrease in number, characteristic of the life-long chronicity of the disease. We infected a mouse model with isolates obtained from reservoirs and vectors from rural and urban endemic areas in Venezuela. Intracellular proliferation and differentiation of the parasite in astrocytes, microglia, neurons, endothelial cells of the piarachnoid, cells of the Purkinje layer, and spinal ganglion cells, as well as extracellularly in the neuropil, were evaluated during the acute phase. Damages were identified as meningoencephalitis, astrocytosis, reactive microglia, acute neuronal degeneration by central chromatolysis, endothelial cell hyperplasia, edema of the neuropil, and satellitosis. This is the first time that satellitosis has been reported from a mammal infected with T. cruzi. Intracellular T. cruzi and inflammatory infiltrates were found in cardiac and skeletal myocytes and liver cells. No parasitism or alterations to the CNS were observed in the chronic mice, although they did show myocarditis and myocitis with extensive infiltrates. Our results are discussed in relation to hypotheses that deny the importance of the presence of tissue parasites versus the direct relationship between these and the damages produced during the chronic phase of Chagas disease. We also review the mechanisms proposed as responsible for the nervous phase of this parasitosis.

  15. Effects of camptothecin derivatives and topoisomerase dual inhibitors on Trypanosoma cruzi growth and ultrastructure

    PubMed Central

    2014-01-01

    Background Trypanosoma cruzi is the etiological agent of Chagas’ disease that is an endemic disease in Latin America and affects about 8 million people. This parasite belongs to the Trypanosomatidae family which contains a single mitochondrion with an enlarged region, named kinetoplast that harbors the mitochondrial DNA (kDNA). The kinetoplast and the nucleus present a great variety of essential enzymes involved in DNA replication and topology, including DNA topoisomerases. Such enzymes are considered to be promising molecular targets for cancer treatment and for antiparasitic chemotherapy. In this work, the proliferation and ultrastructure of T. cruzi epimastigotes were evaluated after treatment with eukaryotic topoisomerase I inhibitors, such as topotecan and irinotecan, as well as with dual inhibitors (compounds that block eukaryotic topoisomerase I and topoisomerase II activities), such as baicalein, luteolin and evodiamine. Previous studies have shown that such inhibitors were able to block the growth of tumor cells, however most of them have never been tested on trypanosomatids. Results Considering the effects of topoisomerase I inhibitors, our results showed that topotecan decreased cell proliferation and caused unpacking of nuclear heterochromatin, however none of these alterations were observed after treatment with irinotecan. The dual inhibitors baicalein and evodiamine decreased cell growth; however the nuclear and kinetoplast ultrastructures were not affected. Conclusions Taken together, our data showed that camptothecin is more efficient than its derivatives in decreasing T. cruzi proliferation. Furthermore, we conclude that drugs pertaining to a certain class of topoisomerase inhibitors may present different efficiencies as chemotherapeutical agents. PMID:24917086

  16. The C-terminal region of Trypanosoma cruzi MASPs is antigenic and secreted via exovesicles.

    PubMed

    De Pablos, Luis Miguel; Díaz Lozano, Isabel María; Jercic, Maria Isabel; Quinzada, Markela; Giménez, Maria José; Calabuig, Eva; Espino, Ana Margarita; Schijman, Alejandro Gabriel; Zulantay, Inés; Apt, Werner; Osuna, Antonio

    2016-06-08

    Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected and emerging tropical disease, endemic to South America and present in non-endemic regions due to human migration. The MASP multigene family is specific to T. cruzi, accounting for 6% of the parasite's genome and plays a key role in immune evasion. A common feature of MASPs is the presence of two conserved regions: an N-terminal region codifying for signal peptide and a C-terminal (C-term) region, which potentially acts as GPI-addition signal peptide. Our aim was the analysis of the presence of an immune response against the MASP C-term region. We found that this region is highly conserved, released via exovesicles (EVs) and has an associated immune response as revealed by epitope affinity mapping, IFA and inhibition of the complement lysis assays. We also demonstrate the presence of a fast IgM response in Balb/c mice infected with T. cruzi. Our results reveal the presence of non-canonical secreted peptides in EVs, which can subsequently be exposed to the immune system with a potential role in evading immune system targets in the parasite.

  17. New scenarios of Trypanosoma cruzi transmission in the Orinoco region of Colombia

    PubMed Central

    Rendón, Lina María; Guhl, Felipe; Cordovez, Juan Manuel; Erazo, Diana

    2015-01-01

    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. PMID:25830543

  18. New scenarios of Trypanosoma cruzi transmission in the Orinoco region of Colombia.

    PubMed

    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.

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

    PubMed

    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 (p<0.0001-0.01) and a discrete lymphomonocytic infiltrate in cardiac and skeletal muscles was present. In the chronic phase, the histological view was normal. In contrast, control group revealed amastigote nests and typical histopathological alterations compatible with chagasic myocarditis, endocarditis and pericarditis. These results, together with previous works in our laboratory, show that T. rangeli induces immunoprotection in three species of animals: mice, guinea 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.

  20. The endless race between Trypanosoma cruzi and host immunity: lessons for and beyond Chagas disease.

    PubMed

    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.

  1. Melatonin and zinc treatment: distinctive modulation of cytokine production in chronic experimental Trypanosoma cruzi infection.

    PubMed

    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.

  2. Swimming against the current: genetic vaccination against Trypanosoma cruzi infection in mice.

    PubMed

    Rodrigues, Mauricio M; de Alencar, Bruna C; Claser, Carla; Tzelepis, Fanny; Silveira, Eduardo L; Haolla, Filipe A; Dominguez, Mariana R; Vasconcelos, José Ronnie

    2009-07-01

    Vaccines have had an unquestionable impact on public health during the last century. The most likely reason for the success of vaccines is the robust protective properties of specific antibodies. However, antibodies exert a strong selective pressure and many microorganisms, such as the obligatory intracellular parasite Trypanosoma cruzi, have been selected to survive in their presence. Although the host develops a strong immune response to T. cruzi, they do not clear the infection and instead progress to the chronic phase of the disease. Parasite persistence during the chronic phase of infection is now considered the main factor contributing to the chronic symptoms of the disease. Based on this finding, containment of parasite growth and survival may be one method to avoid the immunopathology of the chronic phase. In this context, vaccinologists have looked over the past 20 years for other immune effector mechanisms that could eliminate these antibody-resistant pathogens. We and others have tested the hypothesis that non-antibody-mediated cellular immune responses (CD4+ Th1 and CD8+ Tc1 cells) to specific parasite antigens/genes expressed by T. cruzi could indeed be used for the purpose of vaccination. This hypothesis was confirmed in different mouse models, indicating a possible path for vaccine development.

  3. Human infection with Trypanosoma cruzi in Nasca, Peru: a seroepidemiological survey.

    PubMed

    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.

  4. Trypanosoma cruzi strain TcI is associated with chronic Chagas disease in the Brazilian Amazon

    PubMed Central

    2014-01-01

    Background Chagas disease in the Amazon region is considered an emerging anthropozoonosis with a predominance of the discrete typing units (DTUs) TcI and TcIV. These DTUs are responsible for cases of acute disease associated with oral transmission. Chronic disease cases have been detected through serological surveys. However, the mode of transmission could not be determined, or any association of chronic disease with a specific T. cruzi DTU’s. The aim of this study was to characterize Trypanosoma cruzi in patients with chronic Chagas disease in the State of Amazonas, Brazil. Methods Blood culture and xenodiagnosis were performed in 36 patients with positive serology for Chagas disease who participated in a serological survey performed in urban and rural areas of Manaus, Amazonas. DNA samples were extracted from the feces of triatomines used for xenodiagnosis, and the nontranscribed spacer of the mini-exon gene and the mitochondrial gene cytochrome oxidase subunit II (COII) were amplified by PCR and sequenced. Results Blood culture and xenodiagnosis were negative in 100% of samples; however, molecular techniques revealed that in 13 out of 36 (36%) fecal samples from xenodiagnosis, T. cruzi was characterized as the DTU TcI, and different haplotypes were identified within the same DTU. Conclusion The DTU TcI, which is mainly associated with acute cases of Chagas disease in the Amazon region, is also responsible for chronic infection in patients from a region in the State of Amazonas. PMID:24916362

  5. Mechanisms of Infectivity and Evasion Derived from Microvesicles Cargo Produced by Trypanosoma cruzi

    PubMed Central

    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

  6. Biological activity of the azlactone derivative EPA-35 against Trypanosoma cruzi.

    PubMed

    de Azeredo, Camila Maria Oliveira; Ávila, Eloah Pereira; Pinheiro, Danielle Lobo Justo; Amarante, Giovanni Wilson; Soares, Maurilio José

    2017-02-01

    Chagas disease, caused by Trypanosoma cruzi, affects six to seven million people worldwide. Treatment is based on benznidazole, producing several side effects and debatable efficacy, highlighting the need for new alternative drugs. We investigated the activity of four C-4 functionalized azlactone derivatives (EPA-27, EPA-35, EPA-63 and EPA-91) as potential T. cruzi inhibitors. Screening with epimastigotes indicated EPA-35 as the best compound (IC50/24 h: 33 μM). This compound was 14.1 times more potent against intracellular amastigotes (IC50/24 h: 2.34 μM). Treatment of infected Vero cells for 72 h (up to 30 μM EPA-35) resulted in a dose-dependent decrease in number of trypomastigotes and amastigotes released in the supernatant, but the amastigote/trypomastigote ratio remained constant, indicating that amastigote growth was disturbed, but cell differentiation was unaffected. Analysis of treated epimastigotes by flow cytometry indicated that the plasma membrane remained intact, but there was a significant decrease in mitochondrial membrane potential. The pattern of cell distribution in the cell cycle stages (G1, G2, M) was unaltered in treated epimastigotes, indicating a trypanocidal rather than a trypanostatic activity. Scanning electron microscopy and flow cytometry showed epimastigotes with a round shape and decrease in cell size. Taken together, our data indicate that the EPA-35 is effective against T. cruzi. Synthetic transformation of EPA-35 into other derivatives may provide promising compounds for further evaluation against this parasite.

  7. Trypanosoma cruzi: Role of δ-Amastin on Extracellular Amastigote Cell Invasion and Differentiation

    PubMed Central

    Cruz, Mário C.; Souza-Melo, Normanda; da Silva, Claudio Vieira; DaRocha, Wanderson Duarte; Bahia, Diana; Araújo, Patrícia R.; Teixeira, Santuza R.; Mortara, Renato A.

    2012-01-01

    Trypanosoma cruzi is a protozoan parasite that comprises different phylogenetic groups and is the causative agent of Chagas’ disease. Different T. cruzi strains present differences in infectivity in in vitro and in vivo experimental models, which are likely related to the expression of different virulence factors. Amastin is a surface glycoprotein abundantly expressed on the intracellular mammalian amastigote form of the parasite. In this study, we showed that a highly infective strain (G strain) of extracellular amastigote (EA) invasive forms expressed reduced RNA levels of amastin compared to a less infective strain (CL). The treatment of HeLa cells with recombinant δ-amastin reduced infectivity of EA forms. However, the ectopic expression of δ-amastin accelerated amastigote differentiation into trypomastigotes. Corroborating the virulence behavior in association with amastin expression, the EAs overexpressing amastin were precociously and robustly observed in the liver of susceptible mouse strains (A/JUnib), whereas parasitemia was never detected in in vivo assays. This is the first report on the regulatory role of amastin in the course of both in vitro and in vivo T. cruzi infection. PMID:23272170

  8. Diet regulates liver autophagy differentially in murine acute Trypanosoma cruzi infection.

    PubMed

    Lizardo, Kezia; Almonte, Vanessa; Law, Calvin; Aiyyappan, Janeesh Plakkal; Cui, Min-Hui; Nagajyothi, Jyothi F

    2017-02-01

    Chagas disease is a tropical parasitic disease caused by the protozoan Trypanosoma cruzi, which affects about ten million people in its endemic regions of Latin America. After the initial acute stage of infection, 60-80% of infected individuals remain asymptomatic for several years to a lifetime; however, the rest develop the debilitating symptomatic stage, which affects the nervous system, digestive system, and heart. The challenges of Chagas disease have become global due to immigration. Despite well-documented dietary changes accompanying immigration, as well as a transition to a western style diet in the Chagas endemic regions, the role of host metabolism in the pathogenesis of Chagas disease remains underexplored. We have previously used a mouse model to show that host diet is a key factor regulating cardiomyopathy in Chagas disease. In this study, we investigated the effect of a high-fat diet on liver morphology and physiology, lipid metabolism, immune signaling, energy homeostasis, and stress responses in the murine model of acute T. cruzi infection. Our results indicate that in T. cruzi-infected mice, diet differentially regulates several liver processes, including autophagy, a stress response mechanism, with corresponding implications for human Chagas disease patients.

  9. Benznidazole Biotransformation and Multiple Targets in Trypanosoma cruzi Revealed by Metabolomics

    PubMed Central

    Trochine, Andrea; Creek, Darren J.; Faral-Tello, Paula; Barrett, Michael P.; Robello, Carlos

    2014-01-01

    Background The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn. Methodology/Principal findings Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, γ-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected. Conclusions/significance Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi. PMID:24853684

  10. Domestic dogs and cats as sources of Trypanosoma cruzi infection in rural northwestern Argentina

    PubMed Central

    GÜRTLER, R. E.; CECERE, M. C.; LAURICELLA, M. A.; CARDINAL, M. V.; KITRON, U.; COHEN, J. E.

    2009-01-01

    SUMMARY The reservoir capacity of domestic cats and dogs for Trypanosoma cruzi infection and the host-feeding patterns of domestic Triatoma infestans were assessed longitudinally in 2 infested rural villages in north-western Argentina. A total of 86 dogs and 38 cats was repeatedly examined for T. cruzi infection by serology and/or xenodiagnosis. The composite prevalence of infection in dogs (60%), but not in cats, increased significantly with age and with the domiciliary density of infected T. infestans. Dogs and cats had similarly high forces of infection, prevalence of infectious hosts (41–42%), and infectiousness to bugs at a wide range of infected bug densities. The infectiousness to bugs of seropositive dogs declined significantly with increasing dog age and was highly aggregated. Individual dog infectiousness to bugs was significantly autocorrelated over time. Domestic T. infestans fed on dogs showed higher infection prevalence (49%) than those fed on cats (39%), humans (38%) or chickens (29%) among 1085 bugs examined. The basic reproduction number of T. cruzi in dogs was at least 8·2. Both cats and dogs are epidemiologically important sources of infection for bugs and householders, dogs nearly 3 times more than cats. PMID:17032467

  11. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection

    PubMed Central

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  12. Mechanisms of Infectivity and Evasion Derived from Microvesicles Cargo Produced by Trypanosoma cruzi.

    PubMed

    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.

  13. A novel stage-specific glycosomal nucleoside diphosphate kinase from Trypanosoma cruzi.

    PubMed

    Los Milagros Camara, Maria de; Bouvier, Leon; Reigada, Chantal; Digirolamo, Fabio A; Saye, Melisa; Pereira, Claudio A

    2017-02-17

    Nucleoside diphosphate kinases (NDPK) are key enzymes involved in the intracellular nucleotide maintenance in all living organisms, especially in trypanosomatids which are unable to synthesise purines de novo. Four putative NDPK isoforms were identified in the Trypanosoma cruzi Chagas, 1909 genome but only two of them were characterised so far. In this work, we studied a novel isoform from T. cruzi called TcNDPK3. This enzyme presents an atypical N-terminal extension similar to the DM10 domains. In T. cruzi, DM10 sequences targeted other NDPK isoform (TcNDPK2) to the cytoskeleton, but TcNDPK3 was localised in glycosomes despite lacking a typical peroxisomal targeting signal. In addition, TcNDPK3 was found only in the bloodstream trypomastigotes where glycolytic enzymes are very abundant. However, TcNDPK3 mRNA was also detected at lower levels in amastigotes suggesting regulation at protein and mRNA level. Finally, 33 TcNDPK3 gene orthologs were identified in the available kinetoplastid genomes. The characterisation of new glycosomal enzymes provides novel targets for drug development to use in therapies of trypanosomatid associated diseases.

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

    PubMed Central

    de Morais, Carlos Gustavo Vieira; Castro Lima, Ana Karina; dos Santos, Rosiane Freire; Da-Silva, Silvia Amaral Gonçalves; Dutra, Patrícia Maria Lourenço

    2015-01-01

    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. PMID:26090399

  15. Use of trans-Sialidase Inhibition Assay in a Population Serologically Negative for Trypanosoma cruzi but at a High Risk of Infection

    PubMed Central

    Leguizamón, María S.; Russomando, Graciela; Rojas de Arias, Antonieta; Samudio, Margarita; Cabral, Margarita; González-Cappa, Stella Maris; Frasch, Alberto Carlos C.; Campetella, Oscar

    1998-01-01

    trans-Sialidase inhibition assay (TIA) was employed in a population at high risk of Trypanosoma cruzi infection. From 20 serum samples that were negative by conventional serologic and parasitologic assays, 18 (90%) were reactive in TIA, providing further evidence of the higher sensitivity of TIA and suggesting that the actual prevalence of T. cruzi infection might be underestimated. PMID:9521153

  16. Decoding the Anti-Trypanosoma cruzi Action of HIV Peptidase Inhibitors Using Epimastigotes as a Model

    PubMed Central

    Sangenito, Leandro S.; Menna-Barreto, Rubem F. S.; d′Avila-Levy, Claudia M.; Branquinha, Marta H.

    2014-01-01

    Background Aspartic peptidase inhibitors have shown antimicrobial action against distinct microorganisms. Due to an increase in the occurrence of Chagas' disease/AIDS co-infection, we decided to explore the effects of HIV aspartic peptidase inhibitors (HIV-PIs) on Trypanosoma cruzi, the etiologic agent of Chagas' disease. Methodology and Principal Findings HIV-PIs presented an anti-proliferative action on epimastigotes of T. cruzi clone Dm28c, with IC50 values ranging from 0.6 to 14 µM. The most effective inhibitors, ritonavir, lopinavir and nelfinavir, also had an anti-proliferative effect against different phylogenetic T. cruzi strains. The HIV-PIs induced some morphological alterations in clone Dm28c epimastigotes, as reduced cell size and swollen of the cellular body. Transmission electron microscopy revealed that the flagellar membrane, mitochondrion and reservosomes are the main targets of HIV-PIs in T. cruzi epimastigotes. Curiously, an increase in the epimastigote-into-trypomastigote differentiation process of clone Dm28c was observed, with many of these parasites presenting morphological alterations including the detachment of flagellum from the cell body. The pre-treatment with the most effective HIV-PIs drastically reduced the interaction process between epimastigotes and the invertebrate vector Rhodnius prolixus. It was also noted that HIV-PIs induced an increase in the expression of gp63-like and calpain-related molecules, and decreased the cruzipain expression in epimastigotes as judged by flow cytometry and immunoblotting assays. The hydrolysis of a cathepsin D fluorogenic substrate was inhibited by all HIV-PIs in a dose-dependent manner, showing that the aspartic peptidase could be a possible target to these drugs. Additionally, we verified that ritonavir, lopinavir and nelfinavir reduced drastically the viability of clone Dm28c trypomastigotes, causing many morphological damages. Conclusions and Significance The results contribute to understand

  17. Chagas Cardiomyopathy Manifestations and Trypanosoma cruzi Genotypes Circulating in Chronic Chagasic Patients

    PubMed Central

    Ramírez, Juan David; Guhl, Felipe; Rendón, Lina María; Rosas, Fernando; Marin-Neto, Jose A.; Morillo, Carlos A.

    2010-01-01

    Chagas disease caused by Trypanosoma cruzi is a complex disease that is endemic and an important problem in public health in Latin America. The T. cruzi parasite is classified into six discrete taxonomic units (DTUs) based on the recently proposed nomenclature (TcI, TcII, TcIII, TcIV, TcV and TcVI). The discovery of genetic variability within TcI showed the presence of five genotypes (Ia, Ib, Ic, Id and Ie) related to the transmission cycle of Chagas disease. In Colombia, TcI is more prevalent but TcII has also been reported, as has mixed infection by both TcI and TcII in the same Chagasic patient. The objectives of this study were to determine the T. cruzi DTUs that are circulating in Colombian chronic Chagasic patients and to obtain more information about the molecular epidemiology of Chagas disease in Colombia. We also assessed the presence of electrocardiographic, radiologic and echocardiographic abnormalities with the purpose of correlating T. cruzi genetic variability and cardiac disease. Molecular characterization was performed in Colombian adult chronic Chagasic patients based on the intergenic region of the mini-exon gene, the 24Sα and 18S regions of rDNA and the variable region of satellite DNA, whereby the presence of T.cruzi I, II, III and IV was detected. In our population, mixed infections also occurred, with TcI-TcII, TcI-TcIII and TcI-TcIV, as well as the existence of the TcI genotypes showing the presence of genotypes Ia and Id. Patients infected with TcI demonstrated a higher prevalence of cardiac alterations than those infected with TcII. These results corroborate the predominance of TcI in Colombia and show the first report of TcIII and TcIV in Colombian Chagasic patients. Findings also indicate that Chagas cardiomyopathy manifestations are more correlated with TcI than with TcII in Colombia. PMID:21152056

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

    PubMed

    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%) (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.

  19. Trypanocide Treatment of Women Infected with Trypanosoma cruzi and Its Effect on Preventing Congenital Chagas

    PubMed Central

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

    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 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. PMID:25411847

  20. Prevalence of Trypanosoma cruzi's Discrete Typing Units in a cohort of Latin American migrants in Spain.

    PubMed

    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

  1. Relationships between altitude, triatomine (Triatoma dimidiata) immune response and virulence of Trypanosoma cruzi, the causal agent of Chagas' disease.

    PubMed

    DE Fuentes-Vicente, J A; Cabrera-Bravo, M; Enríquez-Vara, J N; Bucio-Torres, M I; Gutiérrez-Cabrera, A E; Vidal-López, D G; Martínez-Ibarra, J A; Salazar-Schettino, P M; Córdoba-Aguilar, A

    2017-03-01

    Little is known about how the virulence of a human pathogen varies in the environment it shares with its vector. This study focused on whether the virulence of Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae), the causal agent of Chagas' disease, is related to altitude. Accordingly, Triatoma dimidiata (Hemiptera: Reduviidae) specimens were collected at three different altitudes (300, 700 and 1400 m a.s.l.) in Chiapas, Mexico. The parasite was then isolated to infect uninfected T. dimidiata from the same altitudes, as well as female CD-1 mice. The response variables were phenoloxidase (PO) activity, a key insect immune response, parasitaemia in mice, and amastigote numbers in the heart, oesophagus, gastrocnemius and brain of the rodents. The highest levels of PO activity, parasitaemia and amastigotes were found for Tryp. cruzi isolates sourced from 700 m a.s.l., particularly in the mouse brain. A polymerase chain reaction-based analysis indicated that all Tryp. cruzi isolates belonged to a Tryp. cruzi I lineage. Thus, Tryp. cruzi from 700 m a.s.l. may be more dangerous than sources at other altitudes. At this altitude, T. dimidiata is more common, apparently because the conditions are more beneficial to its development. Control strategies should focus activity at altitudes around 700 m a.s.l., at least in relation to the region of the present study sites.

  2. Intraspecies Variation in Trypanosoma cruzi GPI-Mucins: Biological Activities and Differential Expression of α-Galactosyl Residues

    PubMed Central

    Soares, Rodrigo P.; Torrecilhas, Ana C.; Assis, Rafael R.; Rocha, Marcele N.; Moura e Castro, Felipe A.; Freitas, Gustavo F.; Murta, Silvane M.; Santos, Sara L.; Marques, Alexandre F.; Almeida, Igor C.; Romanha, Alvaro J.

    2012-01-01

    The glycosylphosphatidylinositol (GPI)-anchored mucins of Trypanosoma cruzi trypomastigotes play an important immunomodulatory role during the course of Chagas disease. Here, some biological activities of tGPI-mucins from four T. cruzi isolates, including benznidazole-susceptible (BZS-Y), benznidazole-resistant (BZR-Y), CL, and Colombiana, were evaluated. GPI-mucins were able to differentially trigger the production of interleukin-12 and nitric oxide in BALB/c macrophages and modulate LLC-MK2 cell invasion. The significance of these variations was assessed after analysis of the terminal α-galactosyl residues. Enzymatic treatment with α-galactosidase indicated a differential expression of O-linked α-galactosyl residues among the strains, with higher expression of this sugar in BZS-Y and BZR-Y T. cruzi populations followed by Colombiana and CL. Unweighted pair group method analysis of the carbohydrate anchor profile and biological parameters allowed the clustering of two groups. One group includes Y and CL strains (T. cruzi II and VI), and the other group is represented by Colombiana strain (T. cruzi I). PMID:22764297

  3. Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease

    PubMed Central

    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. PMID:26465748

  4. Impairment in natural killer cells editing of immature dendritic cells by infection with a virulent Trypanosoma cruzi population.

    PubMed

    Batalla, Estela I; Pino Martínez, Agustina M; Poncini, Carolina V; Duffy, Tomás; Schijman, Alejandro G; González Cappa, Stella M; Alba Soto, Catalina D

    2013-01-01

    Early interactions between natural killer (NK) and dendritic cells (DC) shape the immune response at the frontier of innate and adaptive immunity. Activated NK cells participate in maturation or deletion of DCs that remain immature. We previously demonstrated that infection with a high virulence (HV) population of the protozoan parasite Trypanosoma cruzi downmodulates DC maturation and T-cell activation capacity. Here, we evaluated the role of NK cells in regulating the maturation level of DCs. Shortly after infection with HV T. cruzi, DCs in poor maturation status begin to accumulate in mouse spleen. Although infection induces NK cell cytotoxicity and cytokine production, NK cells from mice infected with HV T. cruzi exhibit reduced ability to lyse and fail to induce maturation of bone marrow-derived immature DCs (iDCs). NK-mediated lysis of iDCs is restored by in vitro blockade of the IL-10 receptor during NK-DC interaction or when NK cells are obtained from T. cruzi-infected IL-10 knockout mice. These results suggest that infection with a virulent T. cruzi strain alters NK cell-mediated regulation of the adaptive immune response induced by DCs. This regulatory circuit where IL-10 appears to participate might lead to parasite persistence but can also limit the induction of a vigorous tissue-damaging T-cell response.

  5. Proteomic and bioinformatic analysis of Trypanosoma cruzi chemotherapy and potential drug targets: new pieces for an old puzzle.

    PubMed

    Sadok Menna-Barreto, Rubem Figueiredo; Belloze, Kele Teixeira; Perales, Jonas; Silva-Jr, Floriano Paes

    2014-03-01

    Chagas disease is endemic in Latin America and is caused by the protozoan hemoflagellate parasite Trypanosoma cruzi. Nowadays, it has also been disseminated to non-endemic countries due to the ease of global mobility. The nitroheterocycle benznidazole is currently used to treat this neglected tropical disease, although this drug causes severe side effects and has limited efficacy during the chronic phase of the disease. Proteomics and bioinformatics have recently become powerful tools in the identification of new drug targets. In the last decade, proteomic profiles of different T. cruzi forms under distinct experimental conditions were assessed. These reports have pointed to many potential drug targets, with ergosterol biosynthesis-related proteins and redox system enzymes being the most promising candidates. Nevertheless, the majority of the compounds active against T. cruzi still have unclear mechanisms of action, and most proteomic efforts have studied epimastigotes (the non-clinically relevant insect form of the parasite). Additional analyses with the clinically relevant parasite forms should be performed to identify proteins that actually bind drugs active against T. cruzi. Nonetheless, due to the known technical hurdles in generating such experimental data, bioinformatic approaches that integrate currently available data to generate additional knowledge will also be useful. Here, we review T. cruzi proteomics and describe the main chemoproteomic methods and their application to the identification of trypanosomatid drug targets. Finally, we discuss the potential benefits of more extensively integrating all proteomic data with other molecular databases via bioinformatic analyses to develop novel, viable strategies for alternative treatments of Chagas disease.

  6. Microcavia australis (Caviidae, Rodentia), a new highly competent host of Trypanosoma cruzi I in rural communities of northwestern Argentina.

    PubMed

    Cecere, M Carla; Cardinal, Marta V; Arrabal, Juan P; Moreno, Claudio; Gürtler, Ricardo E

    2015-02-01

    Rodents are well-known hosts of Trypanosoma cruzi but little is known on the role of some caviomorph rodents. We assessed the occurrence and prevalence of T. cruzi infection in Microcavia australis ("southern mountain, desert or small cavy") and its infectiousness to the vector Triatoma infestans in four rural communities of Tafí del Valle department, northwestern Argentina. Parasite detection was performed by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR) from blood samples. A total of 51 cavies was captured in traps set up along cavy paths in peridomestic dry-shrub fences located between 25 and 85 m from the nearest domicile. We document the first record of M. australis naturally infected by T. cruzi. Cavies presented a very high prevalence of infection (46.3%; 95% confidence interval, CI=33.0-59.6%). Only one (4%) of 23 cavies negative by xenodiagnosis was found infected by kDNA-PCR. TcI was the only discrete typing unit identified in 12 cavies with a positive xenodiagnosis. The infectiousness to T. infestans of cavies positive by xenodiagnosis or kDNA-PCR was very high (mean, 55.8%; CI=48.4-63.1%) and exceeded 80% in 44% of the hosts. Cavies are highly-competent hosts of T. cruzi in peridomestic habitats near human dwellings in rural communities of Tucumán province in northwestern Argentina.

  7. Cell-specific Activation of Nuclear Factor-κB by the Parasite Trypanosoma cruzi Promotes Resistance to Intracellular Infection

    PubMed Central

    Hall, Belinda S.; Tam, Winnie; Sen, Ranjan; Pereira, Miercio E. A.

    2000-01-01

    The transcription factor nuclear factor-κB (NF-κB) is central to the innate and acquired immune response to microbial pathogens, coordinating cellular responses to the presence of infection. Here we demonstrate a direct role for NF-κB activation in controlling intracellular infection in nonimmune cells. Trypanosoma cruzi is an intracellular parasite of mammalian cells with a marked preference for infection of myocytes. The molecular basis for this tissue tropism is unknown. Trypomastigotes, the infectious stage of T. cruzi, activate nuclear translocation and DNA binding of NF-κB p65 subunit and NF-κB-dependent gene expression in epithelial cells, endothelial cells, and fibroblasts. Inactivation of epithelial cell NF-κB signaling by inducible expression of the inhibitory mutant IκBaM significantly enhances parasite invasion. T. cruzi do not activate NF-κB in cells derived from skeletal, smooth, or cardiac muscle, despite the ability of these cells to respond to tumor necrosis factor-α with NF-κB activation. The in vitro infection level in these muscle-derived cells is more than double that seen in the other cell types tested. Therefore, the ability of T. cruzi to activate NF-κB correlates inversely with susceptibility to infection, suggesting that NF-κB activation is a determinant of the intracellular survival and tissue tropism of T. cruzi. PMID:10637298

  8. Bottlenecks in domestic animal populations can facilitate the emergence of Trypanosoma cruzi, the aetiological agent of Chagas disease

    PubMed Central

    Levy, Michael Z.; Tustin, Aaron; Castillo-Neyra, Ricardo; Mabud, Tarub S.; Levy, Katelyn; Barbu, Corentin M.; Quispe-Machaca, Victor R.; Ancca-Juarez, Jenny; Borrini-Mayori, Katty; Naquira-Velarde, Cesar; Ostfeld, Richard S.

    2015-01-01

    Faeces-mediated transmission of Trypanosoma cruzi (the aetiological agent of Chagas disease) by triatomine insects is extremely inefficient. Still, the parasite emerges frequently, and has infected millions of people and domestic animals. We synthesize here the results of field and laboratory studies of T. cruzi transmission conducted in and around Arequipa, Peru. We document the repeated occurrence of large colonies of triatomine bugs (more than 1000) with very high infection prevalence (more than 85%). By inoculating guinea pigs, an important reservoir of T. cruzi in Peru, and feeding triatomine bugs on them weekly, we demonstrate that, while most animals quickly control parasitaemia, a subset of animals remains highly infectious to vectors for many months. However, we argue that the presence of these persistently infectious hosts is insufficient to explain the observed prevalence of T. cruzi in vector colonies. We posit that seasonal rains, leading to a fluctuation in the price of guinea pig food (alfalfa), leading to annual guinea pig roasts, leading to a concentration of vectors on a small subpopulation of animals maintained for reproduction, can propel T. cruzi through vector colonies and create a considerable force of infection for a pathogen whose transmission might otherwise fizzle out. PMID:26085582

  9. Bottlenecks in domestic animal populations can facilitate the emergence of Trypanosoma cruzi, the aetiological agent of Chagas disease.

    PubMed

    Levy, Michael Z; Tustin, Aaron; Castillo-Neyra, Ricardo; Mabud, Tarub S; Levy, Katelyn; Barbu, Corentin M; Quispe-Machaca, Victor R; Ancca-Juarez, Jenny; Borrini-Mayori, Katty; Naquira-Velarde, Cesar; Ostfeld, Richard S

    2015-07-07

    Faeces-mediated transmission of Trypanosoma cruzi (the aetiological agent of Chagas disease) by triatomine insects is extremely inefficient. Still, the parasite emerges frequently, and has infected millions of people and domestic animals. We synthesize here the results of field and laboratory studies of T. cruzi transmission conducted in and around Arequipa, Peru. We document the repeated occurrence of large colonies of triatomine bugs (more than 1000) with very high infection prevalence (more than 85%). By inoculating guinea pigs, an important reservoir of T. cruzi in Peru, and feeding triatomine bugs on them weekly, we demonstrate that, while most animals quickly control parasitaemia, a subset of animals remains highly infectious to vectors for many months. However, we argue that the presence of these persistently infectious hosts is insufficient to explain the observed prevalence of T. cruzi in vector colonies. We posit that seasonal rains, leading to a fluctuation in the price of guinea pig food (alfalfa), leading to annual guinea pig roasts, leading to a concentration of vectors on a small subpopulation of animals maintained for reproduction, can propel T. cruzi through vector colonies and create a considerable force of infection for a pathogen whose transmission might otherwise fizzle out.

  10. Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease.

    PubMed

    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.

  11. Validation of N-myristoyltransferase as Potential Chemotherapeutic Target in Mammal-Dwelling Stages of Trypanosoma cruzi

    PubMed Central

    Herrera, Linda J.; Brand, Stephen; Santos, Andres; Nohara, Lilian L.; Harrison, Justin; Norcross, Neil R.; Thompson, Stephen; Smith, Victoria; Lema, Carolina; Varela-Ramirez, Armando; Gilbert, Ian H.; Almeida, Igor C.; Maldonado, Rosa A.

    2016-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance Taken together, our data point out to the potential use of NMT inhibitors as anti-T. cruzi chemotherapy. PMID:27128971

  12. Pre-Columbian Chagas disease in Brazil: Trypanosoma cruzi I in the archaeological remains of a human in Peruaçu Valley, Minas Gerais, Brazil.

    PubMed

    Fernandes, Alexandre; Iñiguez, Alena M; Lima, Valdirene S; Souza, Sheila M F Mendonça de; Ferreira, Luiz Fernando; Vicente, Ana Carolina P; Jansen, Ana M

    2008-08-01

    We evaluated the presence and distribution of Trypanosoma cruzi DNA in a mummy presenting with megacolon that was dated as approximately 560 +/- 40 years old. The mummy was from the Peruaçu Valley in the state of Minas Gerais, Brazil. All samples were positive for T. cruzi minicircle DNA, demonstrating the presence and broad dissemination of the parasite in this body. From one sample, a mini-exon gene fragment was recovered and characterized by sequencing and was found to belong to the T. cruzi I genotype. This finding suggests that T. cruzi I infected humans during the pre-Columbian times and that, in addition to T. cruzi infection, Chagas disease in Brazil most likely preceded European colonization.

  13. Incidence of trypanosoma cruzi infection among children following domestic reinfestation after insecticide spraying in rural northwestern Argentina.

    PubMed

    Gürtler, Ricardo E; Cecere, María C; Lauricella, Marta A; Petersen, Rosario M; Chuit, Roberto; Segura, Elsa L; Cohen, Joel E

    2005-07-01

    Following increasing reinfestation with Triatoma infestans after insecticide spraying, the household incidence of infection with Trypanosoma cruzi in children was positively related to the domestic abundance of infected T. infestans and the presence or proportion of infected dogs or cats in Amamá, a rural village in northwestern Argentina. Seven (12.1%) children seronegative for antibodies to T. cruzi at baseline, with no history of travel or blood transfusion, seroconverted after three years. Six incident cases lived in houses heavily infested with T. infestans, with high proportions of bugs infected with T. cruzi and having fed on humans or dogs. The remaining incident case occurred under a very light domestic infestation detected only at the endpoint, and most bugs had fed on humans. Dogs had a 17 times greater force of infection than children (4.3% per year). Sustained vector surveillance is crucially needed in high-risk areas for Chagas disease such as the Gran Chaco.

  14. Experimental chemotherapy of Trypanosoma cruzi infection: persistence of parasite antigens and positive serology in parasitologically cured mice.

    PubMed Central

    Andrade, S. G.; Freitas, L. A.; Peyrol, S.; Pimentel, A. R.; Sadigursky, M.

    1991-01-01

    Mice infected with Trypanosoma cruzi, but parasitologically cured after specific chemotherapy, continued to exhibit positive indirect immunofluorescence serological tests 3-6 months after the therapy. Treatment of trypanosome antigens with monospecific antisera produced in rabbits, and examination by immunoelectron-microscopy following peroxidase labelling disclosed the presence of membrane deposits in cell processes in the spleens of the mice. Similar deposits were observed in the external membranes of T. cruzi amastigotes in the spleens of acutely infected mice, but not in normal control mice. No reaction occurred in tissues not previously treated with the monospecific anti-T. cruzi serum. Positive cells in treated and cured mice, as well as in the not cured or untreated control mice, were located in germinal centres of the splenic white pulp and presented long and branching cytoplasmic processes, which are indicative of dendritic cells of the lymphoid follicles of the spleen. Images Fig. 1 Fig. 2 Fig. 3 PMID:1907221

  15. Early Diagnosis of Congenital Trypanosoma cruzi Infection, Using Shed Acute Phase Antigen, in Ushuaia, Tierra del Fuego, Argentina

    PubMed Central

    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. PMID:20064996

  16. A high throughput analysis of cytokines and chemokines expression during the course of Trypanosoma cruzi experimental oral infection.

    PubMed

    Rodrigues, Adele A; Notário, Ana Flávia O; Teixeira, Thaise L; e Silva, Rebecca T; Quintal, Amanda P N; Alves, Rosiane N; Brígido, Paula C; Siqueira, Carla S; Martins, Flávia A; Machado, Fabrício C; Clemente, Tatiana M; da Silva, Aline A; Borges, Bruna C; Teixeira, Samuel C; dos Santos, Marlus A; da Silva, Claudio V

    2016-05-01

    Trypanosoma cruzi has high biological and biochemical diversity and variable tissue tropism. Here we aimed to verify the kinetics of cytokine and chemokine in situ secretion in animals infected with two distinct T. cruzi strains after oral inoculation. Also, we investigated parasite migration, residence and pathological damage in stomach, heart and spleen. Our results showed that host immune response against T. cruzi infection is an intricate phenomenon that depends on the parasite strain, on the infected organ and on the time point of the infection. We believe that a wide comprehension of host immune response will potentially provide basis for the development of immunotherapeutic strategies in order to clear parasitism and minimize tissue injury. In this context, we find that KC poses as a possible tool to be used.

  17. Between a bug and a hard place: Trypanosoma cruzi genetic diversity and the clinical outcomes of Chagas disease

    PubMed Central

    Messenger, Louisa A; Miles, Michael A; Bern, Caryn

    2015-01-01

    Over the last 30 years, concomitant with successful transnational disease control programs across Latin America, Chagas disease has expanded from a neglected, endemic parasitic infection of the rural poor to an urbanized chronic disease, and now a potentially emergent global health problem. Trypanosoma cruzi infection has a highly variable clinical course, ranging from complete absence of symptoms to severe and often fatal cardiovascular and/or gastrointestinal manifestations. To date, few correlates of clinical disease progression have been identified. Elucidating a putative role for T. cruzi strain diversity in Chagas disease pathogenesis is complicated by the scarcity of parasites in clinical specimens and the limitations of our contemporary genotyping techniques. This article systematically reviews the historical literature, given our current understanding of parasite genetic diversity, to evaluate the evidence for any association between T. cruzi genotype and chronic clinical outcome, risk of congenital transmission or reactivation and orally transmitted outbreaks. PMID:26162928

  18. INCIDENCE OF TRYPANOSOMA CRUZI INFECTION AMONG CHILDREN FOLLOWING DOMESTIC REINFESTATION AFTER INSECTICIDE SPRAYING IN RURAL NORTHWESTERN ARGENTINA

    PubMed Central

    GÜRTLER, RICARDO E.; CECERE, MARÍA C.; LAURICELLA, MARTA A.; PETERSEN, ROSARIO M.; CHUIT, ROBERTO; SEGURA, ELSA L.; COHEN, JOEL E.

    2005-01-01

    Following increasing reinfestation with Triatoma infestans after insecticide spraying, the household incidence of infection with Trypanosoma cruzi in children was positively related to the domestic abundance of infected T. infestans and the presence or proportion of infected dogs or cats in Amamá, a rural village in northwestern Argentina. Seven (12.1%) children seronegative for antibodies to T. cruzi at baseline, with no history of travel or blood transfusion, seroconverted after three years. Six incident cases lived in houses heavily infested with T. infestans, with high proportions of bugs infected with T. cruzi and having fed on humans or dogs. The remaining incident case occurred under a very light domestic infestation detected only at the endpoint, and most bugs had fed on humans. Dogs had a 17 times greater force of infection than children (4.3% per year). Sustained vector surveillance is crucially needed in high-risk areas for Chagas disease such as the Gran Chaco. PMID:16014842

  19. Trypanosoma cruzi: Biological characterization of a isolate from an endemic area and its susceptibility to conventional drugs

    PubMed Central

    Grosso, Noelia L.; Bua, Jacqueline; Perrone, Alina E.; Gonzalez, Mariela N.; Bustos, Patricia L.; Postan, Miriam; Fichera, Laura E.

    2010-01-01

    We describe some biological and molecular characteristics of a Trypanosoma cruzi isolate derived from a Triatomine captured in Nicaragua. PCR based typification showed that this isolate, named Nicaragua, belonged to the lineage Tc I. Nicaragua infected culture cells were treated with allopurinol, showing different behaviour according to the cellular compartment, being cardiomyocyte primary cultures more resistant to this drug. The course of the infection in a mice experimental model and its susceptibility to benznidazole and allopurinol was analysed. In benznidazole treatment, mice reverted the high lethal effect of parasites during the acute infection, however, a few parasites were detected in the heart of 88 % of mice one year post-infection. Since Trypanosoma cruzi is a heterogeneous species population it is important to study and characterize different parasites actually circulating in humans in endemic areas. In this work we show that T. cruzi Nicaragua isolate, is sensitive to early benznidazole treatment. PMID:20493848

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

    PubMed

    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.

  1. Differential Pattern of Infection of Sylvatic Nymphs and Domiciliary Adults of Triatoma infestans with Trypanosoma cruzi Genotypes in Chile

    PubMed Central

    Bacigalupo, Antonella; Segovia, Verónica; García, Alejandro; Botto-Mahan, Carezza; Ortiz, Sylvia; Solari, Aldo; Acuna-Retamar, Mariana; Torres-Pérez, Fernando; Cattan, Pedro E.

    2012-01-01

    In Chile, the main vector of Chagas disease, Triatoma infestans, is under control after insecticide spraying. However, it has been found colonizing wild habitats. This study evaluated Trypanosoma cruzi infection of sylvatic and domiciliary T. infestans and identified their parasite genotypes. The sample studied was composed mainly of T. infestans sylvatic nymphs and domiciliary adults from a semi-urban area with human dwellings under vector control surveillance. Results showed prevalences of 57.7% in nymphs and 68.6% in adults. Hybridization tests showed a major T. cruzi lineage (TcI) circulating in sylvatic (93.3%) and domiciliary (100%) T. infestans. TcII, TcV, and TcVI were also detected, mainly in nymphs, suggesting differential adaptation of T. cruzi lineages among instars. We also discuss the origin of domiciliary individuals of T. infestans and the risk of human infection by triatomines of sylvatic foci that invade houses despite vector control programs. PMID:22802439

  2. A novel protein phosphatase 2A (PP2A) is involved in the transformation of human protozoan parasite Trypanosoma cruzi.

    PubMed Central

    González, Jorge; Cornejo, Alberto; Santos, Marcia R M; Cordero, Esteban M; Gutiérrez, Bessy; Porcile, Patricio; Mortara, Renato A; Sagua, Hernán; Da Silveira, José Franco; Araya, Jorge E

    2003-01-01

    Here we provide evidence for a critical role of PP2As (protein phosphatase 2As) in the transformation of Trypanosoma cruzi. In axenic medium at pH 5.0, trypomastigotes rapidly transform into amastigotes, a process blocked by okadaic acid, a potent PP2A inhibitor, at concentrations as low as 0.1 microM. 1-Norokadaone, an inactive okadaic acid analogue, did not affect the transformation. Electron microscopy studies indicated that okadaic acid-treated trypomastigotes had not undergone ultrastructural modifications, reinforcing the idea that PP2A inhibits transformation. Using a microcystin-Sepharose affinity column we purified the native T. cruzi PP2A. The enzyme displayed activity against 32P-labelled phosphorylase a that was inhibited in a dose-dependent manner by okadaic acid. The protein was also submitted to MS and, from the peptides obtained, degenerate primers were used to clone a novel T. cruzi PP2A enzyme by PCR. The isolated gene encodes a protein of 303 amino acids, termed TcPP2A, which displayed a high degree of homology (86%) with the catalytic subunit of Trypanosoma brucei PP2A. Northern-blot analysis revealed the presence of a major 2.1-kb mRNA hybridizing in all T. cruzi developmental stages. Southern-blot analysis suggested that the TcPP2A gene is present in low copy number in the T. cruzi genome. These results are consistent with the mapping of PP2A genes in two chromosomal bands by pulsed-field gel electrophoresis and chromoblot hybridization. Our studies suggest that in T. cruzi PP2A is important for the complete transformation of trypomastigotes into amastigotes during the life cycle of this protozoan parasite. PMID:12737627

  3. Trypanosoma cruzi has not lost its S-adenosylmethionine decarboxylase: characterization of the gene and the encoded enzyme.

    PubMed Central

    Persson, K; Aslund, L; Grahn, B; Hanke, J; Heby, O

    1998-01-01

    All attempts to identify ornithine decarboxylase in the human pathogen Trypanosoma cruzi have failed. The parasites have instead been assumed to depend on putrescine uptake and S-adenosylmethionine decarboxylase (AdoMetDC) for their synthesis of the polyamines spermidine and spermine. We have now identified the gene encoding AdoMetDC in T. cruzi by PCR cloning, with degenerate primers corresponding to conserved amino acid sequences in AdoMetDC proteins of other trypanosomatids. The amplified DNA fragment was used as a probe to isolate the complete AdoMetDC gene from a T. cruzi genomic library. The AdoMetDC gene was located on chromosomes with a size of approx. 1.4 Mbp, and contained a coding region of 1110 bp, specifying a sequence of 370 amino acid residues. The protein showed a sequence identity of only 25% with human AdoMetDC, the major differences being additional amino acids present in the terminal regions of the T. cruzi enzyme. As expected, a higher sequence identity (68-72%) was found in comparison with trypanosomatid AdoMetDCs. When the coding region was expressed in Escherichia coli, the recombinant protein underwent autocatalytic cleavage, generating a 33-34 kDa alpha subunit and a 9 kDa beta subunit. The encoded protein catalysed the decarboxylation of AdoMet (Km 0.21 mM) and was stimulated by putrescine but inhibited by the polyamines, weakly by spermidine and strongly by spermine. Methylglyoxal-bis(guanylhydrazone) (MGBG), a potent inhibitor of human AdoMetDC, was a poor inhibitor of the T. cruzi enzyme. This differential sensitivity to MGBG suggests that the two enzymes are sufficiently different to warrant the search for compounds that might interfere with the progression of Chagas' disease by selectively inhibiting T. cruzi AdoMetDC. PMID:9677309

  4. Regulation of Trypanosoma cruzi infection in mice by gamma interferon and interleukin 10: role of NK cells.

    PubMed Central

    Cardillo, F; Voltarelli, J C; Reed, S G; Silva, J S

    1996-01-01

    Gamma interferon (IFN-gamma) plays an important role in experimental Trypanosoma cruzi infections, presumably by controlling the early replication of parasites in host macrophages. In this work, we show that NK cells represent an important cell type responsible for the production of most of the IFN-gamma in the early stage of T. cruzi infection and that the in vivo treatment of mice with anti-NK1.1 monoclonal antibody made resistant animals susceptible to the infection. Through in vitro experiments, we demonstrate that normal splenocytes from euthymic or athymic nude mice cultivated for 48 h with live T. cruzi trypomastigotes produced elevated levels of IFN-gamma. In addition, NK-depleted splenocytes show a drastic reduction of IFN-gamma production in response to live T. cruzi trypomastigotes. We also demonstrated that IFN-gamma production is dependent on a factor secreted by adherent cells. Supernatants of spleen cells from athymic nude mice are able to induce IFN-gamma production by normal splenocytes when cultured with trypomastigotes. The addition of anti-interleukin-10 to these cultures resulted in a marked increase in IFN-gamma production. On the other hand, the absence of NK cells led to an increased secretion of interleukin-10 upon in vitro stimulation with T. cruzi. Taken together, these results suggest that NK cells are the major source of IFN-gamma that could be involved in limiting the replication of T. cruzi in host macrophages during the early acute phase of the infection. PMID:8557330

  5. [Prevalence of positive serology to Trypanosoma cruzi in patients with clinical diagnosis of dilated myocardiopathy in the state of Campeche].

    PubMed

    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.

  6. Massive screening yields novel and selective Trypanosoma cruzi triosephosphate isomerase dimer-interface-irreversible inhibitors with anti-trypanosomal activity.

    PubMed

    Alvarez, Guzmán; Aguirre-López, Beatriz; Varela, Javier; Cabrera, Mauricio; Merlino, Alicia; López, Gloria V; Lavaggi, María Laura; Porcal, Williams; Di Maio, Rossanna; González, Mercedes; Cerecetto, Hugo; Cabrera, Nallely; Pérez-Montfort, Ruy; de Gómez-Puyou, Marieta Tuena; Gómez-Puyou, Armando

    2010-12-01

    Triosephosphate isomerase from Trypanosoma cruzi (TcTIM), an enzyme in the glycolytic pathway that exhibits high catalytic rates of glyceraldehyde-3-phosphate- and dihydroxyacetone-phosphate-isomerization only in its dimeric form, was screened against an in-house chemical library containing nearly 230 compounds belonging to different chemotypes. After secondary screening, twenty-six compounds from eight different chemotypes were identified as screening positives. Four compounds displayed selectivity for TcTIM over TIM from Homo sapiens and, concomitantly, in vitro activity against T. cruzi.

  7. Immunization with Hexon Modified Adenoviral Vectors Integrated with gp83 Epitope Provides Protection against Trypanosoma cruzi Infection

    PubMed Central

    Gu, Linlin; Krendelchtchikova, Valentina; Nde, Pius N.; Pratap, Siddharth; Lima, Maria F.; Villalta, Fernando; Matthews, Qiana L.

    2014-01-01

    Background Trypanosoma cruzi is the causative agent of Chagas disease. Chagas disease is an endemic infection that affects over 8 million people throughout Latin America and now has become a global challenge. The current pharmacological treatment of patients is unsuccessful in most cases, highly toxic, and no vaccines are available. The results of inadequate treatment could lead to heart failure resulting in death. Therefore, a vaccine that elicits neutralizing antibodies mediated by cell-mediated immune responses and protection against Chagas disease is necessary. Methodology/Principal Findings The “antigen capsid-incorporation” strategy is based upon the display of the T. cruzi epitope as an integral component of the adenovirus' capsid rather than an encoded transgene. This strategy is predicted to induce a robust humoral immune response to the presented antigen, similar to the response provoked by native Ad capsid proteins. The antigen chosen was T. cruzi gp83, a ligand that is used by T. cruzi to attach to host cells to initiate infection. The gp83 epitope, recognized by the neutralizing MAb 4A4, along with His6 were incorporated into the Ad serotype 5 (Ad5) vector to generate the vector Ad5-HVR1-gp83-18 (Ad5-gp83). This vector was evaluated by molecular and immunological analyses. Vectors were injected to elicit immune responses against gp83 in mouse models. Our findings indicate that mice immunized with the vector Ad5-gp83 and challenged with a lethal dose of T. cruzi trypomastigotes confer strong immunoprotection with significant reduction in parasitemia levels, increased survival rate and induction of neutralizing antibodies. Conclusions/Significance This data demonstrates that immunization with adenovirus containing capsid-incorporated T. cruzi antigen elicits a significant anti-gp83-specific response in two different mouse models, and protection against T. cruzi infection by eliciting neutralizing antibodies mediated by cell-mediated immune responses

  8. High-Resolution Molecular Typing of Trypanosoma cruzi in 2 Large Outbreaks of Acute Chagas Disease in Colombia.

    PubMed

    Hernández, Carolina; Vera, Mauricio Javier; Cucunubá, Zulma; Flórez, Carolina; Cantillo, Omar; Buitrago, Luz Stella; González, Marina Stella; Ardila, Susanne; Dueñas, Liliana Zuleta; Tovar, Rubén; Forero, Luis Fernando; Ramírez, Juan David

    2016-10-15

    Oral transmission of Trypanosoma cruzi has gained relevance because of its association with high morbidity and lethality rates. This transmission route is responsible for maintaining the infection of the parasite in sylvatic cycles, and human cases have been associated mainly with the consumption of food contaminated with triatomine feces or didelphid secretions. Several ecological changes allow the intrusion of sylvatic reservoirs and triatomines to the domestic environments with subsequent food contamination. Here, high-resolution molecular tools were used to detect and genotype T. cruzi across humans, reservoirs, and insect vectors in 2 acute outbreaks of presumptive oral transmission in eastern Colombia.

  9. Putative Role of the Aldo-Keto Reductase from Trypanosoma cruzi in Benznidazole Metabolism

    PubMed Central

    Garavaglia, Patricia Andrea; Laverrière, Marc; Cannata, Joaquín J. B.

    2016-01-01

    Benznidazole (Bz), the drug used for treatment of Chagas' disease (caused by the protozoan Trypanosoma cruzi), is activated by a parasitic NADH-dependent type I nitroreductase (NTR I). However, several studies have shown that other enzymes are involved. The aim of this study was to evaluate whether the aldo-keto reductase from T. cruzi (TcAKR), a NADPH-dependent oxido-reductase previously described by our group, uses Bz as the substrate. We demonstrated that both recombinant and native TcAKR enzymes reduce Bz by using NADPH, but not NADH, as a cofactor. TcAKR-overexpressing epimastigotes showed higher NADPH-dependent Bz reductase activity and a 50% inhibitory concentration (IC50) value for Bz 1.8-fold higher than that of the controls, suggesting that TcAKR is involved in Bz detoxification instead of activation. To understand the role of TcAKR in Bz metabolism, we studied TcAKR expression and NADPH/NADH-dependent Bz reductase activities in two T. cruzi strains with differential susceptibility to Bz: CL Brener and Nicaragua. Taking into account the results obtained with TcAKR-overexpressing epimastigotes, we expected the more resistant strain, Nicaragua, to have higher TcAKR levels than CL Brener. However, the results were the opposite. CL Brener showed 2-fold higher TcAKR expression and 5.7-fold higher NADPH-Bz reduction than the Nicaragua strain. In addition, NADH-dependent Bz reductase activity, characteristic of NTR I, was also higher in CL Brener than in Nicaragua. We conclude that although TcAKR uses Bz as the substrate, TcAKR activity is not a determinant of Bz resistance in wild-type strains and may be overcome by other enzymes involved in Bz activation, such as NADPH- and NADH-dependent reductases. PMID:26856844

  10. Genetic Profiling of the Isoprenoid and Sterol Biosynthesis Pathway Genes of Trypanosoma cruzi

    PubMed Central

    Cosentino, Raúl O.; Agüero, Fernán

    2014-01-01

    In Trypanosoma cruzi the isoprenoid and sterol biosynthesis pathways are validated targets for chemotherapeutic intervention. In this work we present a study of the genetic diversity observed in genes from these pathways. Using a number of bioinformatic strategies, we first identified genes that were missing and/or were truncated in the T. cruzi genome. Based on this analysis we obtained the complete sequence of the ortholog of the yeast ERG26 gene and identified a non-orthologous homolog of the yeast ERG25 gene (sterol methyl oxidase, SMO), and we propose that the orthologs of ERG25 have been lost in trypanosomes (but not in Leishmanias). Next, starting from a set of 16 T. cruzi strains representative of all extant evolutionary lineages, we amplified and sequenced ∼24 Kbp from 22 genes, identifying a total of 975 SNPs or fixed differences, of which 28% represent non-synonymous changes. We observed genes with a density of substitutions ranging from those close to the average (∼2.5/100 bp) to some showing a high number of changes (11.4/100 bp, for the putative lathosterol oxidase gene). All the genes of the pathway are under apparent purifying selection, but genes coding for the sterol C14-demethylase, the HMG-CoA synthase, and the HMG-CoA reductase have the lowest density of missense SNPs in the panel. Other genes (TcPMK, TcSMO-like) have a relatively high density of non-synonymous SNPs (2.5 and 1.9 every 100 bp, respectively). However, none of the non-synonymous changes identified affect a catalytic or ligand binding site residue. A comparative analysis of the corresponding genes from African trypanosomes and Leishmania shows similar levels of apparent selection for each gene. This information will be essential for future drug development studies focused on this pathway. PMID:24828104

  11. Distribution of Trypanosoma cruzi discrete typing units in Bolivian migrants in Spain.

    PubMed

    Perez-Molina, José A; Poveda, Cristina; Martinez-Perez, Angela; Guhl, Felipe; Monge-Maillo, Begoña; Fresno, Manuel; López-Velez, Rogelio; Ramírez, Juan D; Girones, Nuria

    2014-01-01

    Chagas disease is caused by the protozoan Trypanosoma cruzi. This parasite is transmitted to humans mainly through the faeces of infected triatomine "kissing" bugs, by blood transfusions or organ donation from infected donors, and can be transmitted from mother to child. This disease is endemic in the Americas, where Bolivia has up to 28.8% prevalence in general population. Increased migration to Europe has made it emerge in countries where it was previously unknown, being Spain the second country in number of patients after the United States. T. cruzi is an organism with a rich genetic diversity, what has been grouped into six discrete typing units (DTUs). Some authors have linked these DTUs either to specific geographical distribution or to the different clinical presentations. Nevertheless little is known about its distribution in migrant populations. Our aim was to describe the T. cruzi strains isolated from a population of chronically infected Bolivian patients attending our clinic in Madrid. Thirty-three consecutive 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 epidemiological/clinical data and the different DTUs were tested. Twenty-seven out of thirty-three patients had their DTU detected. Mean age was 36 years (IQR 31-43.3) and 23 were women (76.7%). The median time since arrival to Spain was 60 months (IQR 43-81). The most common DTU were TcV, TcIV and TcI. Four patients had cardiac involvement: 2 had TcV and 2 could not have their DTU determined. TcIII was not isolated from any patient. DTUs distribution in migrant population seems to be similar to that observed in the patients' countries of origin.

  12. Temporizin and Temporizin-1 Peptides as Novel Candidates for Eliminating Trypanosoma cruzi

    PubMed Central

    Calabrese, Kátia S.; Hardoim, Daiane J.; Taniwaki, Noemi; Alves, Luiz A.; De Simone, Salvatore G.

    2016-01-01

    Tropical diseases caused by parasitic infections continue to cause socioeconomic distress worldwide. Among these, Chagas disease has become a great concern because of globalization. Caused by Trypanosoma cruzi, there is an increasing need to discover new, more effective methods to manage infections that minimize disease onset. Antimicrobial peptides represent a possible solution to this challenge. As effector molecules of the innate immune response against pathogens, they are the first line of defense found in all multi-cellular organisms. In amphibians, temporins are a large family of antimicrobial peptides found in skin secretions. Their functional roles and modes of action present unique properties that indicate possible candidates for therapeutic applications. Here, we investigated the trypanocide activity of temporizin and temporizin-1. Temporizin is an artificial, hybrid peptide containing the N-terminal region of temporin A, the pore-forming region of gramicidin and a C-terminus consisting of alternating leucine and lysine. Temporizin-1 is a modification of temporizin with a reduction in the region responsible for insertion into membranes. Their activities were evaluated in a cell permeabilization assay by flow cytometry, an LDH release assay, electron microscopy, an MTT assay and patch clamp experiments. Both temporizin and temporizin-1 demonstrated toxicity against T. cruzi with temporizin displaying slightly more potency. At concentrations up to 100 μg/ ml, both peptides exhibited low toxicity in J774 cells, a macrophage lineage cell line, and no toxicity was observed in mouse primary peritoneal macrophages. In contrast, the peptides showed some toxicity in rat adenoma GH3 cells and Jurkat human lymphoma cells with temporizin-1 displaying lower toxicity. In summary, a shortened form of the hybrid temporizin peptide, temporizin-1, was efficient at killing T. cruzi and it has low toxicity in wild-type mammalian cells. These data suggest that temporizin-1

  13. Characterization of TcCYC6 from Trypanosoma cruzi, a gene with homology to mitotic cyclins.

    PubMed

    Di Renzo, María Agostina; Laverrière, Marc; Schenkman, Sergio; Wehrendt, Diana Patricia; Tellez-Iñón, María Teresa; Potenza, Mariana

    2016-06-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is a protozoan parasite with a life cycle that alternates between replicative and non-replicative forms, but the components and mechanisms that regulate its cell cycle are poorly described. In higher eukaryotes, cyclins are proteins that activate cyclin-dependent kinases (CDKs), by associating with them along the different stages of the cell cycle. These cyclin-CDK complexes exert their role as major modulators of the cell cycle by phosphorylating specific substrates. For the correct progression of the cell cycle, the mechanisms that regulate the activity of cyclins and their associated CDKs are diverse and must be controlled precisely. Different types of cyclins are involved in specific phases of the eukaryotic cell cycle, preferentially activating certain CDKs. In this work, we characterized TcCYC6, a putative coding sequence of T. cruzi which encodes a protein with homology to mitotic cyclins. The overexpression of this sequence, fused to a tag of nine amino acids from influenza virus hemagglutinin (TcCYC6-HA), showed to be detrimental for the proliferation of epimastigotes in axenic culture and affected the cell cycle progression. In silico analysis revealed an N-terminal segment similar to the consensus sequence of the destruction box, a hallmark for the degradation of several mitotic cyclins. We experimentally determined that the TcCYC6-HA turnover decreased in the presence of proteasome inhibitors, suggesting that TcCYC6 degradation occurs via ubiquitin-proteasome pathway. The results obtained in this study provide first evidence that TcCYC6 expression and degradation are finely regulated in T. cruzi.

  14. Trypanosoma cruzi in the Chicken Model: Chagas-Like Heart Disease in the Absence of Parasitism

    PubMed Central

    Teixeira, Antonio R. L.; Gomes, Clever; Nitz, Nadjar; Sousa, Alessandro O.; Alves, Rozeneide M.; Guimaro, Maria C.; Cordeiro, Ciro; Bernal, Francisco M.; Rosa, Ana C.; Hejnar, Jiri; Leonardecz, Eduardo; Hecht, Mariana M.

    2011-01-01

    Background The administration of anti-trypanosome nitroderivatives curtails Trypanosoma cruzi infection in Chagas disease patients, but does not prevent destructive lesions in the heart. This observation suggests that an effective treatment for the disease requires understanding its pathogenesis. Methodology/Principal Findings To understand the origin of clinical manifestations of the heart disease we used a chicken model system in which infection can be initiated in the egg, but parasite persistence is precluded. T. cruzi inoculation into the air chamber of embryonated chicken eggs generated chicks that retained only the parasite mitochondrial kinetoplast DNA minicircle in their genome after eight days of gestation. Crossbreeding showed that minicircles were transferred vertically via the germ line to chicken progeny. Minicircle integration in coding regions was shown by targeted-primer thermal asymmetric interlaced PCR, and detected by direct genomic analysis. The kDNA-mutated chickens died with arrhythmias, shortness of breath, cyanosis and heart failure. These chickens with cardiomyopathy had rupture of the dystrophin and other genes that regulate cell growth and differentiation. Tissue pathology revealed inflammatory dilated cardiomegaly whereby immune system mononuclear cells lyse parasite-free target heart fibers. The heart cell destruction implicated a thymus-dependent, autoimmune; self-tissue rejection carried out by CD45+, CD8γδ+, and CD8α lymphocytes. Conclusions/Significance These results suggest that genetic alterations resulting from kDNA integration in the host genome lead to autoimmune-mediated destruction of heart tissue in the absence of T. cruzi parasites. PMID:21468314

  15. Different genotypes of Trypanosoma cruzi produce distinctive placental environment genetic response in chronic experimental infection.

    PubMed

    Juiz, Natalia Anahí; Solana, María Elisa; Acevedo, Gonzalo Raúl; Benatar, Alejandro Francisco; Ramirez, Juan Carlos; da Costa, Priscilla Almeida; Macedo, Andrea Mara; Longhi, Silvia Andrea; Schijman, Alejandro G

    2017-03-01

    Congenital infection of Trypanosoma cruzi allows transmission of this parasite through generations. Despite the problematic that this entails, little is known about the placenta environment genetic response produced against infection. We performed functional genomics by microarray analysis in C57Bl/6J mice comparing placentas from uninfected animals and from animals infected with two different T. cruzi strains: K98, a clone of the non-lethal myotropic CA-I strain (TcI), and VD (TcVI), isolated from a human case of congenital infection. Analysis of networks by GeneMANIA of differentially expressed genes showed that "Secretory Granule" was a pathway down-regulated in both infected groups, whereas "Innate Immune Response" and "Response to Interferon-gamma" were pathways up-regulated in VD infection but not in K98. Applying another approach, the GSEA algorithm that detects small changes in predetermined gene sets, we found that metabolic processes, transcription and macromolecular transport were down-regulated in infected placentas environment and some pathways related to cascade signaling had opposite regulation: over-represented in VD and down-regulated in K98 group. We also have found a stronger tropism to the placental organ by VD strain, by detection of parasite DNA and RNA, suggesting living parasites. Our study is the first one to describe in a murine model the genetic response of placental environment to T. cruzi infection and suggests the development of a strong immune response, parasite genotype-dependent, to the detriment of cellular metabolism, which may contribute to control infection preventing the risk of congenital transmission.

  16. Altered Distribution of Peripheral Blood Memory B Cells in Humans Chronically Infected with Trypanosoma cruzi

    PubMed Central

    Fernández, Esteban R.; Olivera, Gabriela C.; Quebrada Palacio, Luz P.; González, Mariela N.; Hernandez-Vasquez, Yolanda; Sirena, Natalia María; Morán, María L.; Ledesma Patiño, Oscar S.; Postan, Miriam

    2014-01-01

    Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans. PMID:25111833

  17. Evidence of substantial recombination among Trypanosoma cruzi II strains from Minas Gerais.

    PubMed

    Baptista, Rodrigo de Paula; D'Ávila, Daniella Alchaar; Segatto, Marcela; do Valle, Ítalo Faria; Franco, Glória Regina; Valadares, Helder Magno Silva; Gontijo, Eliane Dias; Galvão, Lúcia Maria da Cunha; Pena, Sérgio Danilo Junho; Chiari, Egler; Machado, Carlos Renato; Macedo, Andréa Mara

    2014-03-01

    Due to the scarcity of evidence of sexuality in Trypanosoma cruzi, the causative agent of Chagas disease, it has been general accepted that the parasite reproduction is essentially clonal with infrequent genetic recombination. This assumption is mainly supported by indirect evidence, such as Hardy-Weinberg imbalances, linkage disequilibrium and a strong correlation between independent sets of genetic markers of T. cruzi populations. However, because the analyzed populations are usually isolated from different geographic regions, the possibility of population substructuring as generating these genetic marker imbalances cannot be eliminated. To investigate this possibility, we firstly compared the allele frequencies and haplotype networks using seven different polymorphic loci (two from mitochondrial and five from different nuclear chromosomes) in two groups of TcII strains: one including isolates obtained from different regions in Latin America and the other including isolates obtained only from patients of the Minas Gerais State in Brazil. Our hypothesis was that if the population structure is essentially clonal, Hardy-Weinberg disequilibrium and a sharp association between the clusters generated by analyzing independent markers should be observed in both strain groups, independent of the geographic origin of the samples. The results demonstrated that the number of microsatellite loci in linkage disequilibrium decreased from 4 to 1 when only strains from Minas Gerais were analyzed. Moreover, we did not observed any correlation between the clusters when analyzing the nuclear and mitochondrial loci, suggesting independent inheritance of these markers among the Minas Gerais strains. Besides, using a second subset of five physically linked microsatellite loci and the Minas Gerais strains, we could also demonstrate evidence of homologous recombination roughly proportional to the relative distance among them. Taken together, our results do not support a clonal population

  18. Ecological, Social and Biological Risk Factors for Continued Trypanosoma cruzi Transmission by Triatoma dimidiata in Guatemala

    PubMed Central

    Bustamante, Dulce M.; De Urioste-Stone, Sandra M.; Juárez, José G.; Pennington, Pamela M.

    2014-01-01

    Background Chagas disease transmission by Triatoma dimidiata persists in Guatemala and elsewhere in Central America under undefined ecological, biological and social (eco-bio-social) conditions. Methodology Eco-bio-social risk factors associated with persistent domiciliary infestation were identified by a cross-sectional survey and qualitative participatory methods. Quantitative and qualitative data were generated regarding Trypanosoma cruzi reservoirs and triatomine hosts. Blood meal analysis and infection of insects, dogs and rodents were determined. Based on these data, multimodel inference was used to identify risk factors for domestic infestation with the greatest relative importance (>0.75). Principal Findings Blood meal analysis showed that 64% of 36 bugs fed on chickens, 50% on humans, 17% on dogs; 24% of 34 bugs fed on Rattus rattus and 21% on Mus musculus. Seroprevalence among 80 dogs was 37%. Eight (17%) of 46 M. musculus and three (43%) of seven R. rattus from households with infected triatomines were infected with T. cruzi Distinct Typing Unit I. Results from interviews and participatory meetings indicated that vector control personnel and some householders perceived chickens roosting and laying eggs in the house as bug infestation risk factors. House construction practices were seen as a risk factor for bug and rodent infestation, with rodents being perceived as a pest by study participants. Multimodel inference showed that house infestation risk factors of high relative importance are dog density, mouse presence, interior wall plaster condition, dirt floor, tile roofing and coffee tree presence. Conclusions/Significance Persistent house infestation is closely related to eco-bio-social factors that maintain productive T. dimidiata habitats associated with dogs, chickens and rodents. Triatomine, dog and rodent infections indicate active T. cruzi transmission. Integrated vector control methods should include actions that consider the role of

  19. Vesicles from different Trypanosoma cruzi strains trigger differential innate and chronic immune responses

    PubMed Central

    Nogueira, Paula M.; Ribeiro, Kleber; Silveira, Amanda C. O.; Campos, João H.; Martins-Filho, Olindo A.; Bela, Samantha R.; Campos, Marco A.; Pessoa, Natalia L.; Colli, Walter; Alves, Maria J. M.; Soares, Rodrigo P.; Torrecilhas, Ana Claudia

    2015-01-01

    Trypomastigote forms of Trypanosoma cruzi, the causative agent of Chagas Disease, shed extracellular vesicles (EVs) enriched with glycoproteins of the gp85/trans-sialidase (TS) superfamily and other α-galactosyl (α-Gal)-containing glycoconjugates, such as mucins. Here, purified vesicles from T. cruzi strains (Y, Colombiana, CL-14 and YuYu) were quantified according to size, intensity and concentration. Qualitative analysis revealed differences in their protein and α-galactosyl contents. Later, those polymorphisms were evaluated in the modulation of immune responses (innate and in the chronic phase) in C57BL/6 mice. EVs isolated from YuYu and CL-14 strains induced in macrophages higher levels of proinflammatory cytokines (TNF-α and IL-6) and nitric oxide via TLR2. In general, no differences were observed in MAPKs activation (p38, JNK and ERK 1/2) after EVs stimulation. In splenic cells derived from chronically infected mice, a different modulation pattern was observed, where Colombiana (followed by Y strain) EVs were more proinflammatory. This modulation was independent of the T. cruzi strain used in the mice infection. To test the functional importance of this modulation, the expression of intracellular cytokines after in vitro exposure was evaluated using EVs from YuYu and Colombiana strains. Both EVs induced cytokine production with the appearance of IL-10 in the chronically infected mice. A high frequency of IL-10 in CD4+ and CD8+ T lymphocytes was observed. A mixed profile of cytokine induction was observed in B cells with the production of TNF-α and IL-10. Finally, dendritic cells produced TNF-α after stimulation with EVs. Polymorphisms in the vesicles surface may be determinant in the immunopathologic events not only in the early steps of infection but also in the chronic phase. PMID:26613751

  20. Proliferation and Differentiation of Trypanosoma cruzi inside Its Vector Have a New Trigger: Redox Status

    PubMed Central

    Nogueira, Natália P.; Saraiva, Francis M. S.; Sultano, Pedro E.; Cunha, Paula R. B. B.; Laranja, Gustavo A. T.; Justo, Graça A.; Sabino, Kátia C. C.; Coelho, Marsen G. P.; Rossini, Ana; Atella, Georgia C.; Paes, Marcia C.

    2015-01-01

    Trypanosoma cruzi proliferate and differentiate inside different compartments of triatomines gut that is the first environment encountered by T. cruzi. Due to its complex life cycle, the parasite is constantly exposed to reactive oxygen species (ROS). We tested the influence of the pro-oxidant molecules H2O2 and the superoxide generator, Paraquat, as well as, metabolism products of the vector, with distinct redox status, in the proliferation and metacyclogenesis. These molecules are heme, hemozoin and urate. We also tested the antioxidants NAC and GSH. Heme induced the proliferation of epimastigotes and impaired the metacyclogenesis. β-hematin, did not affect epimastigote proliferation but decreased parasite differentiation. Conversely, we show that urate, GSH and NAC dramatically impaired epimastigote proliferation and during metacyclogenesis, NAC and urate induced a significant increment of trypomastigotes and decreased the percentage of epimastigotes. We also quantified the parasite loads in the anterior and posterior midguts and in the rectum of the vector by qPCR. The treatment with the antioxidants increased the parasite loads in all midgut sections analyzed. In vivo, the group of vectors fed with reduced molecules showed an increment of trypomastigotes and decreased epimastigotes when analyzed by differential counting. Heme stimulated proliferation by increasing the cell number in the S and G2/M phases, whereas NAC arrested epimastigotes in G1 phase. NAC greatly increased the percentage of trypomastigotes. Taken together, these data show a shift in the triatomine gut microenvironment caused by the redox status may also influence T. cruzi biology inside the vector. In this scenario, oxidants act to turn on epimastigote proliferation while antioxidants seem to switch the cycle towards metacyclogenesis. This is a new insight that defines a key role for redox metabolism in governing the parasitic life cycle. PMID:25671543

  1. Proliferation and differentiation of Trypanosoma cruzi inside its vector have a new trigger: redox status.

    PubMed

    Nogueira, Natália P; Saraiva, Francis M S; Sultano, Pedro E; Cunha, Paula R B B; Laranja, Gustavo A T; Justo, Graça A; Sabino, Kátia C C; Coelho, Marsen G P; Rossini, Ana; Atella, Georgia C; Paes, Marcia C

    2015-01-01

    Trypanosoma cruzi proliferate and differentiate inside different compartments of triatomines gut that is the first environment encountered by T. cruzi. Due to its complex life cycle, the parasite is constantly exposed to reactive oxygen species (ROS). We tested the influence of the pro-oxidant molecules H2O2 and the superoxide generator, Paraquat, as well as, metabolism products of the vector, with distinct redox status, in the proliferation and metacyclogenesis. These molecules are heme, hemozoin and urate. We also tested the antioxidants NAC and GSH. Heme induced the proliferation of epimastigotes and impaired the metacyclogenesis. β-hematin, did not affect epimastigote proliferation but decreased parasite differentiation. Conversely, we show that urate, GSH and NAC dramatically impaired epimastigote proliferation and during metacyclogenesis, NAC and urate induced a significant increment of trypomastigotes and decreased the percentage of epimastigotes. We also quantified the parasite loads in the anterior and posterior midguts and in the rectum of the vector by qPCR. The treatment with the antioxidants increased the parasite loads in all midgut sections analyzed. In vivo, the group of vectors fed with reduced molecules showed an increment of trypomastigotes and decreased epimastigotes when analyzed by differential counting. Heme stimulated proliferation by increasing the cell number in the S and G2/M phases, whereas NAC arrested epimastigotes in G1 phase. NAC greatly increased the percentage of trypomastigotes. Taken together, these data show a shift in the triatomine gut microenvironment caused by the redox status may also influence T. cruzi biology inside the vector. In this scenario, oxidants act to turn on epimastigote proliferation while antioxidants seem to switch the cycle towards metacyclogenesis. This is a new insight that defines a key role for redox metabolism in governing the parasitic life cycle.

  2. Host Life History Strategy, Species Diversity, and Habitat Influence Trypanosoma cruzi Vector Infection in Changing Landscapes

    PubMed Central

    Gottdenker, Nicole L.; Chaves, Luis Fernando; Calzada, José E.; Saldaña, Azael; Carroll, C. Ronald

    2012-01-01

    Background Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. Methodology/Principal Findings R. pallescens vectors (N = 643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site. Conclusions/Significance In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially

  3. Ecology of Trypanosoma cruzi I genotypes across Rhodnius prolixus captured in Attalea butyracea palms.

    PubMed

    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 across 59 individuals. The results showed that all the insects were infected with TcI; 28.57% were sylvatic TcI, 12.38% TcIDom and 15,24% mixed infections (TcIDom/sylvatic TcI). Statistical analysis showed a similar behavior between TcIDom and mixed infections in the mid-point and at the crown of the palm, being more frequent in the crown, while sylvatic TcI does not seem to have a specific association with any of the sampled areas. These findings are consistent with other studies showing high mobility of the insect vector between different ecotopes, increasing the need to develop improvements in the programs of disease control.

  4. Alternative Method for the Mass Rearing of Lutzomyia (Lutzomyia) cruzi (Diptera: Psychodidae) in a Laboratory Setting.

    PubMed

    Oliveira, E F; Fernandes, W S; Oshiro, E T; Oliveira, A G; Galati, E A B

    2015-09-01

    The understanding of the transmission dynamics of Leishmania spp. Ross as well as the epidemiology and spread of leishmaniasis is related to parasite-vector-host interactions. These interactions can be studied using specimens of a sand fly population reared in the laboratory, exposing individuals to experimental infection for the investigation of vector competence and parameters of the vectorial capacity of the species. The present study sought to describe an alternative method for the implantation of a Lutzomyia (Lutzomyia) cruzi colony with wild specimens captured in the municipality of Corumbá, Brazil. With Method 1, engorged females were individualized for oviposition. The eggs were transferred to an acrylic petri dish with a layer of plaster on the bottom, on which food was placed after hatching of the first larvae. With Method 2, females were kept in groups for oviposition in containers, in which soil and food were placed on their bottom for the larvae. In addition, the exposure time of the larvae to light was reduced in comparison with Method 1. With Method 2, a significantly greater number of specimens of Lu. cruzi was obtained. The ratio between the number of emerged adults and the females followed for oviposition was 0.42 with Method 1 and 2.75 with Method 2. The optimization of the rearing conditions for Lu. cruzi will enable the establishment of a colony providing a sufficient number of specimens to develop experimental infection by Leishmania as well as vectorial competence and some parameters of the vectorial capacity of this sand fly.

  5. Prevalence of antibody to Trypanosoma cruzi in three populations in Belize.

    PubMed

    Jaramillo, R; Bryan, J P; Schur, J; Pan, A A

    1997-09-01

    Cross-sectional studies were conducted to determine the prevalence of antibody to Trypanosoma cruzi, the agent of Chagas' disease among three populations in Belize. Specimens were tested using a second-generation enzyme-linked immunoassay (EIA). Confirmatory testing with three single-antigen EIAs and a radioimmunoprecipitation assay (RIPA) were performed. Five (0.5%) of 962 blood donors at the Belize City Hospital were reactive including four (6%) of 65 donors from countries known to be endemic for Chagas' disease and one (0.1%) of 861 from Belize (P < 0.001). Among 467 healthy members of the Belize Defense Force, none were reactive. The third group included workers and families primarily from other Central American countries living on a banana plantation in a rural area of the country. Twenty-seven (6.1%) of 442 sera were reactive. The prevalence was 5.3% of 75 < 15 years of age, 4.2% of 236 15-34 years of age, and 9.7% of 124 > or = 35 years of age (P = 0.11, by chi-square for trend). The prevalence was similar in males (6.7% of 280) and females (5.8% of 154). The prevalence of those born in Belize (4 of 56, 7.1%) was similar with that of those born in El Salvador (9 of 110, 8.2%), Guatemala (6 of 117, 5.1%), and Honduras (8 of 129, 6.2%). Of the four persons with reactive sera who were born in Belize, the immigrant mother of one was also reactive, suggesting possible congenital transmission. Among 31 sera repeatedly reactive by EIA to T. cruzi that were further studied, 22 (71%) were reactive by at least two of three single-antigen confirmatory EIAs and 29 (94%) by RIPA. Additional studies should focus on the epidemiology of T. cruzi and ways to reduce risk of transfusion-related infections in Belize.

  6. Different genotypes of Trypanosoma cruzi produce distinctive placental environment genetic response in chronic experimental infection

    PubMed Central

    Juiz, Natalia Anahí; Solana, María Elisa; Acevedo, Gonzalo Raúl; Benatar, Alejandro Francisco; Ramirez, Juan Carlos; da Costa, Priscilla Almeida; Macedo, Andrea Mara; Longhi, Silvia Andrea

    2017-01-01

    Congenital infection of Trypanosoma cruzi allows transmission of this parasite through generations. Despite the problematic that this entails, little is known about the placenta environment genetic response produced against infection. We performed functional genomics by microarray analysis in C57Bl/6J mice comparing placentas from uninfected animals and from animals infected with two different T. cruzi strains: K98, a clone of the non-lethal myotropic CA-I strain (TcI), and VD (TcVI), isolated from a human case of congenital infection. Analysis of networks by GeneMANIA of differentially expressed genes showed that “Secretory Granule” was a pathway down-regulated in both infected groups, whereas “Innate Immune Response” and “Response to Interferon-gamma” were pathways up-regulated in VD infection but not in K98. Applying another approach, the GSEA algorithm that detects small changes in predetermined gene sets, we found that metabolic processes, transcription and macromolecular transport were down-regulated in infected placentas environment and some pathways related to cascade signaling had opposite regulation: over-represented in VD and down-regulated in K98 group. We also have found a stronger tropism to the placental organ by VD strain, by detection of parasite DNA and RNA, suggesting living parasites. Our study is the first one to describe in a murine model the genetic response of placental environment to T. cruzi infection and suggests the development of a strong immune response, parasite genotype-dependent, to the detriment of cellular metabolism, which may contribute to control infection preventing the risk of congenital transmission. PMID:28273076

  7. Differential energetic metabolism during Trypanosoma cruzi differentiation. II. Hexokinase, phosphofructokinase and pyruvate kinase.

    PubMed

    Adroher, F J; Osuna, A; Lupiáñez, J A

    1990-04-18

    The activities of hexokinase (ATP:hexose-6-phosphate transferase, E.C. 2.7.1.1), phosphofructokinase (ATP:fructose-6-phosphate 1-phosphotransferase, E.C.2.7.1.11) and pyruvate kinase (ATP:pyruvate transferase, E.C. 2.7.1.40), and their kinetic behaviour in two morphological forms of Trypanosoma cruzi (epimastigotes and metacyclic trypomastigotes) have been studied. The kinetic responses of the three enzymes to their respective substrates were normalized to hyperbolic forms on a velocity versus substrate concentration plots. Hexokinase and phosphofructokinase showed a higher activity in epimastigotes than in metacyclics, whereas pyruvate kinase had similar activity in both forms of the parasite. The specific activity of hexokinase from epimastigotes was 102.00 mUnits/mg of protein and the apparent Km value for glucose was 35.4 microM. Metacyclic forms showed a specific activity of 55.25 mUnits/mg and a Km value of 46.3 microM. The kinetic parameters (specific activity and Km for fructose 6-phosphate) of phosphofructokinase for epimastigotes were 42.60 mUnits/mg and 0.31 mM and for metacyclics 13.97 mUnits/mg and 0.16 mM, respectively. On the contrary, pyruvate kinase in both forms of T. cruzi did not show significant differences in its kinetic parameters. The specific activity in epimastigotes was 37.00 mUnits/mg and the Km for phosphoenolpyruvate was 0.47 mM, whereas in metacyclics these values were 42.94 mUnits/mg and 0.46 mM, respectively. The results presented in this work, clearly demonstrate a quantitative change in the glycolytic pathway of both culture forms of T. cruzi.

  8. Proinflammatory and Cytotoxic Effects of Hexadecylphosphocholine (Miltefosine) against Drug-Resistant Strains of Trypanosoma cruzi

    PubMed Central

    Saraiva, Victor B.; Gibaldi, Daniel; Previato, José O.; Mendonça-Previato, Lucia; Bozza, Marcelo T.; Freire-de-Lima, Célio G.; Heise, Norton

    2002-01-01

    The increased resistance of the protozoan parasite Trypanosoma cruzi to nitro derivatives is one of the major problems for the successful treatment of Chagas' disease. In the present study, we have tested the effects of 1-O-hexadecylphosphocholine (miltefosine) against strains of T. cruzi that are partially resistant (strain Y) and highly resistant (strain Colombiana) to the drugs in clinical use. As expected, epimastigotes of strain Colombiana showed higher levels of resistance to benznidazole than those of strain Y. However, the level of resistance to miltefosine was the same for both strains. This alkylphospholipid was also extremely toxic against intracellular amastigotes of both strains. This ether-lipid analogue induced in a dose-dependent manner the production of tumor necrosis factor alpha and nitric oxide (NO) radicals by infected and noninfected macrophages, suggesting that miltefosine may activate macrophages in vitro. Nevertheless, the cytotoxic effect of miltefosine against intracellular amastigotes was independent of the amount of NO produced by the infected macrophages since the same dose-response curves for miltefosine were observed when the NO production was blocked by the NO synthase inhibitor NG-monomethyl-l-arginine monoacetate. Preliminary in vivo studies with BALB/c mice infected with strain Y indicated that oral miltefosine promoted survival and reduced the parasitemia to levels comparable to those observed when benznidazole was used. Four months after treatment, no parasites were detected in the blood or spleen tissue sections maintained in culture. Together, these results support the hypothesis that miltefosine may be used for the treatment of Chagas' disease, including cases caused by resistant strains of T. cruzi. PMID:12384352

  9. Rhenium(I) tricarbonyl compounds of bioactive thiosemicarbazones: Synthesis, characterization and activity against Trypanosoma cruzi.

    PubMed

    Rodríguez Arce, Esteban; Machado, Ignacio; Rodríguez, Belén; Lapier, Michel; Zúñiga, María Carolina; Maya, Juan Diego; Olea Azar, Claudio; Otero, Lucía; Gambino, Dinorah

    2017-05-01

    American Trypanosomiasis is a chronic infection discovered and described in 1909 by the Brazilian scientist Carlos Chagas. It is caused by the protozoan parasite Trypanosoma cruzi. Although it affects about 10million people in Latin America, the current chemotherapy is still inadequate. The discovery of new drugs is urgently needed. Our group is focused on the development of prospective metal-based drugs mainly based on bioactive ligands and pharmacologically interesting metal ions. In this work three new rhenium(I) tricarbonyl compounds fac-[Re(I)(CO)3Br(HL)] where HL=5-nitrofuryl containing thiosemicarbazones were synthesized and fully characterized in solution and in the solid state. The in vitro evaluation of the compounds on T. cruzi trypomastigotes (Dm28c strain) showed that the Re(I) compounds are 8 to 15 times more active than the reference drug Nifurtimox and show a 4 to 17 fold increase in activity in respect to the free (HL) ligands. Obtained compounds also show good selectivity indexes (IC50 endothelial cells Ea.hy926/IC50 T. cruzi (Dm28c tripomastigotes)). (1)H NMR and MS studies, performed with time, showed that the fac-[Re(CO)3Br(HL)] species convert into the dimers [Re2(CO)6(L)2] in solution. Crystal structure of [Re(I)2(CO)6(L2)2], the product of complexes' dimerization, was solved. Related to the mechanism of action, the studied compounds do not generate radical oxygen species in the parasite (as 5-nitrofuryl derived thiosemicarbazones do) probably due to the unfavorable nitro reduction potential of the generated dimeric species. On the contrary, the compounds produce a decrease of the oxygen consumption rate of the parasites, maybe inhibiting their mitochondrial respiration.

  10. Putative Role of the Aldo-Keto Reductase from Trypanosoma cruzi in Benznidazole Metabolism.

    PubMed

    Garavaglia, Patricia Andrea; Laverrière, Marc; Cannata, Joaquín J B; García, Gabriela Andrea

    2016-05-01

    Benznidazole (Bz), the drug used for treatment of Chagas' disease (caused by the protozoan Trypanosoma cruzi), is activated by a parasitic NADH-dependent type I nitroreductase (NTR I). However, several studies have shown that other enzymes are involved. The aim of this study was to evaluate whether the aldo-keto reductase from T. cruzi (TcAKR), a NADPH-dependent oxido-reductase previously described by our group, uses Bz as the substrate. We demonstrated that both recombinant and native TcAKR enzymes reduce Bz by using NADPH, but not NADH, as a cofactor. TcAKR-overexpressing epimastigotes showed higher NADPH-dependent Bz reductase activity and a 50% inhibitory concentration (IC50) value for Bz 1.8-fold higher than that of the controls, suggesting that TcAKR is involved in Bz detoxification instead of activation. To understand the role of TcAKR in Bz metabolism, we studied TcAKR expression and NADPH/NADH-dependent Bz reductase activities in two T. cruzi strains with differential susceptibility to Bz: CL Brener and Nicaragua. Taking into account the results obtained with TcAKR-overexpressing epimastigotes, we expected the more resistant strain, Nicaragua, to have higher TcAKR levels than CL Brener. However, the results were the opposite. CL Brener showed 2-fold higher TcAKR expression and 5.7-fold higher NADPH-Bz reduction than the Nicaragua strain. In addition, NADH-dependent Bz reductase activity, characteristic of NTR I, was also higher in CL Brener than in Nicaragua. We conclude that although TcAKR uses Bz as the substrate, TcAKR activity is not a determinant of Bz resistance in wild-type strains and may be overcome by other enzymes involved in Bz activation, such as NADPH- and NADH-dependent reductases.

  11. Towards a new strategy for the diagnosis of congenital Trypanosoma cruzi infection.

    PubMed

    Abras, Alba; Muñoz, Carmen; Ballart, Cristina; Berenguer, Pere; Llovet, Teresa; Herrero, Mercedes; Tebar, Silvia; Pinazo, María-Jesús; Posada, Elizabeth; Martí, Carmen; Fumadó, Victoria; Bosch, Jordi; Coll, Oriol; Juncosa, Teresa; Ginovart, Gemma; Armengol, Josep; Gascón, Joaquim; Portús, Montserrat; Gállego, Montserrat

    2017-02-15

    The immigration of Latin American women of childbearing age has spread the congenital transmission of Chagas disease to non-endemic areas, and the disease is now a worldwide problem. Some European health authorities have implemented screening programs to prevent vertical transmission, but the lack of a uniform protocol calls for the urgent establishment of a new strategy, common for all laboratories. Our aims were (i) to analyze the trend of passive IgG antibodies in the newborn by means of five serological tests for the diagnosis and follow-up of congenital Trypanosoma cruzi infection, (ii) to assess the utility of these techniques for diagnosing a congenital transmission, and (iii) to propose a strategy for a prompt, efficient and cost-effective diagnosis of T. cruzi infection. In non-infected newborns, a continuous decreasing trend of passive IgG antibodies was observed, but none of the serological assays seroreverted in all the infants before 12 months. From 12 months onwards, serological tests achieved negative results in all the samples analyzed, with the exception of the highly sensitive chemiluminescent microparticle immunoassay (CMIA). In contrast, in congenitally infected infants, the antibody decline was only detected after treatment initiation. In order to improve the diagnosis of congenital T. cruzi infection, we propose a new strategy involving fewer tests that allows significant cost savings. The protocol could start 1 month after birth with a parasitological test and/or a PCR. If negative, a serological test would be carried out at 9 months, which if positive, would be followed by another at around 12 months for confirmation.

  12. Distantiae Transmission of Trypanosoma cruzi: A New Epidemiological Feature of Acute Chagas Disease in Brazil

    PubMed Central

    Xavier, Samanta Cristina das Chagas; Roque, André Luiz Rodrigues; Bilac, Daniele; de Araújo, Vitor Antônio Louzada; Neto, Sócrates Fraga da Costa; Lorosa, Elias Seixas; da Silva, Luiz Felipe Coutinho Ferreira; Jansen, Ana Maria

    2014-01-01

    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”. PMID:24854494

  13. A Cytoplasmic New Catalytic Subunit of Calcineurin in Trypanosoma cruzi and Its Molecular and Functional Characterization

    PubMed Central

    Orrego, Patricio R.; Olivares, Héctor; Cordero, Esteban M.; Bressan, Albert; Cortez, Mauro; Sagua, Hernán; Neira, Ivan; González, Jorge; da Silveira, José Franco; Yoshida, Nobuko; Araya, Jorge E.

    2014-01-01

    Parasitological cure for Chagas disease is considered extremely difficult to achieve because of the lack of effective chemotherapeutic agents against Trypanosoma cruzi at different stages of infection. There are currently only two drugs available. These have several limitations and can produce serious side effects. Thus, new chemotherapeutic targets are much sought after. Among T. cruzi components involved in key processes such as parasite proliferation and host cell invasion, Ca2+-dependent molecules play an important role. Calcineurin (CaN) is one such molecule. In this study, we cloned a new isoform of the gene coding for CL strain catalytic subunit CaNA (TcCaNA2) and characterized it molecularly and functionally. There is one copy of the TcCaNA2 gene per haploid genome. It is constitutively transcribed in all T. cruzi developmental forms and is localized predominantly in the cytosol. In the parasite, TcCaNA2 is associated with CaNB. The recombinant protein TcCaNA2 has phosphatase activity that is enhanced by Mn2+/Ni2+. The participation of TcCaNA2 in target cell invasion by metacyclic trypomastigotes was also demonstrated. Metacyclic forms with reduced TcCaNA2 expression following treatment with morpholino antisense oligonucleotides targeted to TcCaNA2 invaded HeLa cells at a lower rate than control parasites treated with morpholino sense oligonucleotides. Similarly, the decreased expression of TcCaNA2 following treatment with antisense morpholino oligonucleotides partially affected the replication of epimastigotes, although to a lesser extent than the decrease in expression following treatment with calcineurin inhibitors. Our findings suggest that the calcineurin activities of TcCaNA2/CaNB and TcCaNA/CaNB, which have distinct cellular localizations (the cytoplasm and the nucleus, respectively), may play a critical role at different stages of T. cruzi development, the former in host cell invasion and the latter in parasite multiplication. PMID:24498455

  14. Immune Protection against Trypanosoma cruzi Induced by TcVac4 in a Canine Model

    PubMed Central

    Aparicio-Burgos, José E.; Zepeda-Escobar, José A.; de Oca-Jimenez, Roberto Montes; Estrada-Franco, José G.; Barbabosa-Pliego, Alberto; Ochoa-García, Laucel; Alejandre-Aguilar, Ricardo; Rivas, Nancy; Peñuelas-Rivas, Giovanna; Val-Arreola, Margarita; Gupta, Shivali; Salazar-García, Felix; Garg, Nisha J.; Vázquez-Chagoyán, Juan C.

    2015-01-01

    Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GM-CSF-encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs. We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines. PMID:25853654

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

    PubMed Central

    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

  16. Trypanothione Reductase: A Target for the Development of Anti-Trypanosoma cruzi drugs.

    PubMed

    Vázquez, Karina; Paulino, Margot; Salas, Cristian O; Zarate-Ramos, Juan J; Vera, Brenda; Rivera, Gildardo

    2017-03-15

    Chagas disease or American trypanosomiasis is a major parasitic disease in Latin America with treatment available via two drugs: nifurtimox and benznidazole. These two treatments are ineffective in the chronic phase of the disease. Therefore, there is a need for the development of new, efficient and safe drugs for the treatment of these diseases. With this goal, one of the promising targets proposed is the trypanothione reductase (TR), a key enzyme important in the metabolism of Trypanosoma cruzi. In this review, we analyze the importance of TR as a drug target, as well as their compounds inhibitors reported in the last decade as potential therapeutic agents for Chagas disease.

  17. Overview of DNA Repair in Trypanosoma cruzi, Trypanosoma brucei, and Leishmania major

    PubMed Central

    Passos-Silva, Danielle Gomes; Rajão, Matheus Andrade; Nascimento de Aguiar, Pedro Henrique; Vieira-da-Rocha, João Pedro; Machado, Carlos Renato; Furtado, Carolina

    2010-01-01

    A wide variety of DNA lesions arise due to environmental agents, normal cellular metabolism, or intrinsic weaknesses in the chemical bonds of DNA. Diverse cellular mechanisms have evolved to maintain genome stability, including mechanisms to repair damaged DNA, to avoid the incorporation of modified nucleotides, and to tolerate lesions (translesion synthesis). Studies of the mechanisms related to DNA metabolism in trypanosomatids have been very limited. Together with recent experimental studies, the genome sequencing of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, has revealed interesting features of the DNA repair mechanism in these protozoan parasites, which will be reviewed here. PMID:20976268

  18. Long-term preservation of blood samples for diagnosis of Trypanosoma cruzi infection.

    PubMed

    Pérez, A C; Cura, E; Subías, E; Lansetti, J C; Segura, E L

    1990-03-01

    Feasability and suitability for field research of a whole-blood preservation method was evaluated through the screening of anti-Trypanosoma cruzi antibodies in 1209 samples under different conditions. Antibody reactivity of paired samples from preserved capillary blood (CBP) and sera from venous blood (VBS) were studied by specific techniques. Over 96% concordance was found on indoor studies carried out with samples without storage or after 15 or 30 days preservation of CBP at 37 degrees C and VBS at -20 degrees C. Outdoor studies performed at field conditions, achieved a 92.1% concordance.

  19. Soulamarin Isolated from Calophyllum brasiliense (Clusiaceae) Induces Plasma Membrane Permeabilization of Trypanosoma cruzi and Mytochondrial Dysfunction

    PubMed Central

    Rea, Alexandre; Tempone, Andre G.; Pinto, Erika G.; Mesquita, Juliana T.; Rodrigues, Eliana; Silva, Luciana Grus M.; Sartorelli, Patricia; Lago, João Henrique G.

    2013-01-01

    Chagas disease is caused by the parasitic protozoan Trypanosoma cruzi. It has high mortality as well as morbidity rates and usually affects the poorer sections of the population. The development of new, less harmful and more effective drugs is a promising research target, since current standard treatments are highly toxic and administered for long periods. Fractioning of methanol (MeOH) extract of the stem bark of Calophyllum brasiliense (Clusiaceae) resulted in the isolation of the coumarin soulamarin, which was characterized by one- and two-dimensional 1H- and 13C NMR spectroscopy as well as ESI mass spectrometry. All data obtained were consistent with a structure of 6-hydroxy-4-propyl-5-(3-hydroxy-2-methyl-1-oxobutyl)-6″,6″-dimethylpyrane-[2″,3″:8,7]-benzopyran-2-one for soulamarin. Colorimetric MTT assays showed that soulamarin induces trypanocidal effects, and is also active against trypomastigotes. Hemolytic activity tests showed that soulamarin is unable to induce any observable damage to erythrocytes (cmax. = 1,300 µM). The lethal action of soulamarin against T. cruzi was investigated by using amino(4-(6-(amino(iminio)methyl)-1H-indol-2-yl)phenyl)methaniminium chloride (SYTOX Green and 1H,5H,11H,15H-Xantheno[2,3,4-ij:5,6,7-i′j′]diquinolizin-18-ium, 9-[4-(chloromethyl)phenyl]-2,3,6,7,12,13,16,17-octahydro-chloride (MitoTracker Red) as fluorimetric probes. With the former, soulamarin showed dose-dependent permeability of the plasma membrane, relative to fully permeable Triton X-100-treated parasites. Spectrofluorimetric and fluorescence microscopy with the latter revealed that soulamarin also induced a strong depolarization (ca. 97%) of the mitochondrial membrane potential. These data demonstrate that the lethal action of soulamarin towards T. cruzi involves damages to the plasma membrane of the parasite and mitochondrial dysfunction without the additional generation of reactive oxygen species, which may have also contributed to the death of

  20. Trypanosoma cruzi TcI and TcII transmission among wild carnivores, small mammals and dogs in a conservation unit and surrounding areas, Brazil.

    PubMed

    Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; Arrais, Ricardo Corassa; Santos, Jean Pierre; Lima, Valdirene dos Santos; Xavier, Samanta Cristina das Chagas; Cordeir-Estrela, Pedro; D'Andrea, Paulo Sérgio; Jansen, Ana Maria

    2013-02-01

    Aiming to better understand the ecological aspects of Trypanosoma cruzi transmission cycles, wild carnivores, small mammals and dogs were examined for T. cruzi infection in the Serra da Canastra National Park region, Brazil. Isolates were genotyped using mini-exon gene and PCR-RFLP (1f8 and H3) genomic targets. Trypanosoma cruzi transmission was well established in the area and occurred in both wild and peridomestic environments. Dog seroprevalence was 29·4% (63/214) and TcI and TcII genotypes, besides mixed infections were observed. Only TcI was detected in wild mammals. Marsupials displayed lower relative abundance, but a high prevalence of positive haemocultures (4/22), whereas rodents displayed positive haemocultures (9/113) mainly in the abundant Akodon montensis and Cerradomys subflavus species. The felid Leopardus pardalis was the only carnivore to display positive haemoculture and was captured in the same region where the small mammal prevalence of T. cruzi infection was high. Two canid species, Chrysocyon brachyurus and Cerdocyon thous, were serologically positive for T. cruzi infection (4/8 and 8/39, respectively), probably related to their capacity to exploit different ecological niches. Herein, dog infection not only signals T. cruzi transmission but also the genotypes present. Distinct transmission strategies of the T. cruzi genotypes are discussed.

  1. Structures of dihydrofolate reductase-thymidylate synthase of Trypanosoma cruzi in the folate-free state and in complex with two antifolate drugs, trimetrexate and methotrexate

    SciTech Connect

    Senkovich, Olga; Schormann, Norbert; Chattopadhyay, Debasish

    2010-11-22

    The flagellate protozoan parasite Trypanosoma cruzi is the pathogenic agent of Chagas disease (also called American trypanosomiasis), which causes approximately 50 000 deaths annually. The disease is endemic in South and Central America. The parasite is usually transmitted by a blood-feeding insect vector, but can also be transmitted via blood transfusion. In the chronic form, Chagas disease causes severe damage to the heart and other organs. There is no satisfactory treatment for chronic Chagas disease and no vaccine is available. There is an urgent need for the development of chemotherapeutic agents for the treatment of T. cruzi infection and therefore for the identification of potential drug targets. The dihydrofolate reductase activity of T. cruzi, which is expressed as part of a bifunctional enzyme, dihydrofolate reductase-thymidylate synthase (DHFR-TS), is a potential target for drug development. In order to gain a detailed understanding of the structure-function relationship of T. cruzi DHFR, the three-dimensional structure of this protein in complex with various ligands is being studied. Here, the crystal structures of T. cruzi DHFR-TS with three different compositions of the DHFR domain are reported: the folate-free state, the complex with the lipophilic antifolate trimetrexate (TMQ) and the complex with the classical antifolate methotrexate (MTX). These structures reveal that the enzyme is a homodimer with substantial interactions between the two TS domains of neighboring subunits. In contrast to the enzymes from Cryptosporidium hominis and Plasmodium falciparum, the DHFR and TS active sites of T. cruzi lie on the same side of the monomer. As in other parasitic DHFR-TS proteins, the N-terminal extension of the T. cruzi enzyme is involved in extensive interactions between the two domains. The DHFR active site of the T. cruzi enzyme shows subtle differences compared with its human counterpart. These differences may be exploited for the development of

  2. Effect of treatment with cyclophosphamide in low doses upon the onset of delayed type hypersensitivity in mice chronically infected with Trypanosoma cruzi: involvement of heart interstitial dendritic cells.

    PubMed

    Thé, Torriceli Souza; Portella, Renata Siqueira; Guerreiro, Marcos Lázaro; Andrade, Sonia Gumes

    2013-09-01

    Acute infection with Trypanosoma cruzi results in intense myocarditis, which progresses to a chronic, asymptomatic indeterminate form. The evolution toward this chronic cardiac form occurs in approximately 30% of all cases of T. cruzi infection. Suppression of delayed type hypersensitivity (DTH) has been proposed as a potential explanation of the indeterminate form. We investigated the effect of cyclophosphamide (CYCL) treatment on the regulatory mechanism of DTH and the participation of heart interstitial dendritic cells (IDCs) in this process using BALB/c mice chronically infected with T. cruzi. One group was treated with CYCL (20 mg/kg body weight) for one month. A DTH skin test was performed by intradermal injection of T. cruzi antigen (3 mg/mL) in the hind-footpad and measured the skin thickness after 24 h, 48 h and 72 h. The skin test revealed increased thickness in antigen-injected footpads, which was more evident in the mice treated with CYCL than in those mice that did not receive treatment. The thickened regions were characterised by perivascular infiltrates and areas of necrosis. Intense lesions of the myocardium were present in three/16 cases and included large areas of necrosis. Morphometric evaluation of lymphocytes showed a predominance of TCD8 cells. Heart IDCs were immunolabelled with specific antibodies (CD11b and CD11c) and T. cruzi antigens were detected using a specific anti-T. cruzi antibody. Identification of T. cruzi antigens, sequestered in these cells using specific anti-T. cruzi antibodies was done, showing a significant increase in the number of these cells in treated mice. These results indicate that IDCs participate in the regulatory mechanisms of DTH response to T. cruzi infection.

  3. First finding of Trypanosoma cruzi II in vampire bats from a district free of domestic vector-borne transmission in Northeastern Argentina.

    PubMed

    Argibay, Hernán D; Orozco, M Marcela; Cardinal, M Victoria; Rinas, Miguel A; Arnaiz, María; Mena Segura, Carlos; Gürtler, Ricardo E

    2016-09-01

    Establishing the putative links between sylvatic and domestic transmission cycles of Trypanosoma cruzi, the etiological agent of Chagas disease, is of public health relevance. We conducted three surveys to assess T. cruzi infection in wild mammals from a rural and a preserved area in Misiones Province, Northeastern Argentina, which had recently been declared free of vector- and blood-borne transmission of human T. cruzi infection. A total of 200 wild mammals were examined by xenodiagnosis (XD) and/or polymerase chain reaction (PCR) amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). The overall prevalence of T. cruzi infection was 8%. Nine (16%) of 57 Didelphis albiventris opossums and two (7%) of 29 Desmodus rotundus vampire bats were positive by both XD and kDNA-PCR. Additionally, one D. rotundus positive for T. cruzi by kDNA-PCR tested positive by satellite-DNA-PCR (SAT-DNA-PCR). The T. cruzi-infected bats were captured indoors and in the yard of a vacant dwelling. All D. albiventris were infected with TcI and both XD-positive D. rotundus by TcII. Fifty-five opossum cubs within the marsupium were negative by XD. The mean infectiousness to the vector was 62% in D. albiventris and 50% in D. rotundus. Mice experimentally infected with a parasite isolate from a vampire bat displayed lesions typically caused by T. cruzi. Our study documents the presence of the genotype TcII in a sylvatic host for the first time in Argentina, and the occurrence of two transmission cycles of T. cruzi in a district free of domestic vector-borne transmission.

  4. Possible Differences in the Effects of Trypanosoma cruzi on Blood Cells and Serum Protein of Two Wildlife Reservoirs.

    PubMed

    Martínez-Hernández, Fernando; López-Díaz, Osvaldo; Bello-Bedoy, Rafael; Villalobos, Guiehdani; Muñoz-García, Claudia I; Alejandre-Aguilar, Ricardo; Córdoba-Aguilar, Alex; Gutiérrez-Cabrera, Ana E; Suzán, Gerardo; Villanueva-García, Claudia; Gama-Campillo, Lilia M; Díaz-Negrete, Mariela T; Rendón-Franco, Emilio

    2016-11-01

    A key step in the dynamics of vector-borne diseases is the role of seasonality. Trypanosoma cruzi is a protozoan that causes Chagas disease. Some wild mammals are considered natural hosts, yet not all mammals show the same response to infection. We explored the effect of T. cruzi on blood parameters in two mammal carnivores, coati (Nasua narica) and raccoon (Procyon lotor), that were naturally infected in summer and winter seasons. The study was carried out in the Zoological Park "Parque Museo de la Venta," in Southeastern Mexico. Blood samples were collected in summer and winter from 2010 to 2013. Parasite infection was assessed by PCR from whole blood, and a complete hemogram was determined by traditional manual methods. We found that both species had the same T. cruzi I lineage. For coatis, mean corpuscular volume, mean corpuscular hemoglobin, and monocytes were dependent of season, while eosinophils and plasma proteins were significantly different, but with no season effect. For raccoon, erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin, and monocytes were dependent of season. These results and a previous study that indicated interspecific differences in parasitemia in both species suggest that raccoon is a better reservoir than coati. Such a different interspecific response implies that animals do not contribute equally to maintain T. cruzi parasites in the ecosystem. Such inequality differs according to season.

  5. Higher seroprevalence of Trypanosoma cruzi infection in dogs than in humans in an urban area of Campeche, Mexico.

    PubMed

    Balan, Luis Ucan; Yerbes, Isai Medina; Piña, Miguel Angel Novelo; Balmes, Javier; Pascual, Alberto; Hernández, Oscar; Lopez, Ruth; Monteón, Victor

    2011-07-01

    The reservoir capacity of dogs for Trypanosoma cruzi infection was analyzed in the city of Campeche, an urban town located in the Yucatan peninsula in Mexico. The city is inhabited by ~96,000 dogs and ~168,000 humans; Triatoma dimidiata is the only recognized vector. In the present study, we sampled 262 dogs (148 stray dogs and 114 pet dogs) and 2800 young people (ranging in age between 15 and 20 years old) and tested for T. cruzi antibodies by enzyme-linked immunosorbent assay, Indirect Immunofluorescence, and Western blotting serological assays. Seroprevalence in stray dogs was twice higher than in pet dogs (9.5% vs. 5.3%) with general seroprevalence of 7.6%. In humans, the observed seroprevalence was 76 times lower than in dogs (0.1% vs. 7.6%, respectively). Western blotting analysis showed that dogs' antibodies recognized different T. cruzi antigenic patterns than those for humans. In conclusion, T. cruzi infection in Campeche, Mexico, represents a low potential risk to inhabitants but deserves vigilance.

  6. Physalin B inhibits Trypanosoma cruzi infection in the gut of Rhodnius prolixus by affecting the immune system and microbiota.

    PubMed

    Castro, Daniele P; Moraes, Caroline S; Gonzalez, Marcelo S; Ribeiro, Ivone M; Tomassini, Therezinha C B; Azambuja, Patrícia; Garcia, Eloi S

    2012-12-01

    Physalin B is a natural secosteroidal, extracted from the Solanaceae plant, Physalis angulata, and it presents immune-modulator effects on the bloodsucking bug, Rhodnius prolixus. In this work, R. prolixus was treated with physalin B at a concentration of 1 mg/ml of blood meal (oral application), or 20 ng/insect (applied topically) or 57 ng/cm(2) of filter paper (contact treatment), and infected with Trypanosoma cruzi Dm28c clone (2×10(6) epimastigotes/insect). The three types of applications significantly decreased the number of T. cruzi Dm28c in the gut comparing with the non-treated infected insects (controls). All groups of infected insects treated with physalin B had higher numbers of bacterial microbiota in the gut than the non-treated controls infected with T. cruzi. We observed that the infected physalin B insects with topical and contact treatments had a lower antibacterial activity in the gut when compared with control infected insects. Furthermore, infected insects with the physalin B oral treatment produced higher levels of nitrite and nitrate in the gut than control infected insects. These results demonstrate that physalin B decreases the T. cruzi transmission by inhibiting the parasite development in the insect vector R. prolixus. Herein the importance of physalin B modulation on the immune system and microbiota population in terms of parasite development and transmission are discussed.

  7. Detection of Trypanosoma cruzi and T. rangeli Infections from Rhodnius pallescens Bugs by Loop-Mediated Isothermal Amplification (LAMP)

    PubMed Central

    Thekisoe, Oriel M. M.; Rodriguez, Carol V.; Rivas, Francisco; Coronel-Servian, Andrea M.; Fukumoto, Shinya; Sugimoto, Chihiro; Kawazu, Shin-Ichiro; Inoue, Noboru

    2010-01-01

    We have developed two loop-mediated isothermal amplification (LAMP) assays for specific detection of Trypanosoma cruzi and Trypanosoma rangeli based on the 18S ribosomal RNA (rRNA) and the small nucleolar RNA (snoRNA) genes, respectively. The detection limit of the assays is 100 fg and 1 pg for T. cruzi and T. rangeli, respectively, with reactions conducted in 60 minutes. The two LAMP assays were used in detection of T. cruzi and T. rangeli infections in comparison with polymerase chain reaction (PCR) for DNA samples extracted from Rhodnius pallescens bugs collected from palm trees in Panama. Out of a total of 52 DNA samples from R. pallescens bugs 17 (33%) and 14 (27%) were T. cruzi-positive by LAMP and PCR, respectively, while, 7 (13%) and 4 (8%) were T. rangeli-positive by LAMP and PCR, respectively. Further evaluation of these LAMP assays is needed, especially with specimens collected from human patients as well as blood kept for transfusion purposes. PMID:20439966

  8. Deficiency in Mannose-Binding Lectin-Associated Serine Protease-2 Does Not Increase Susceptibility to Trypanosoma cruzi Infection

    PubMed Central

    Ribeiro, Carolina H.; Lynch, Nicholas J.; Stover, Cordula M.; Ali, Youssif M.; Valck, Carolina; Noya-Leal, Francisca; Schwaeble, Wilhelm J.; Ferreira, Arturo

    2015-01-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, a chronic illness affecting 10 million people around the world. The complement system plays an important role in fighting microbial infections. The recognition molecules of the lectin pathway of complement activation, mannose-binding lectin (MBL), ficolins, and CL-11, bind to specific carbohydrates on pathogens, triggering complement activation through MBL-associated serine protease-2 (MASP-2). Previous in vitro work showed that human MBL and ficolins contribute to T. cruzi lysis. However, MBL-deficient mice are only moderately compromised in their defense against the parasite, as they may still activate the lectin pathway through ficolins and CL-11. Here, we assessed MASP-2-deficient mice, the only presently available mouse line with total lectin pathway deficiency, for a phenotype in T. cruzi infection. Total absence of lectin pathway functional activity did not confer higher susceptibility to T. cruzi infection, suggesting that it plays a minor role in the immune response against this parasite. PMID:25548381

  9. A lytic monoclonal antibody to Trypanosoma cruzi bloodstream trypomastigotes which recognizes an epitope expressed in tissues affected in Chagas' disease.

    PubMed Central

    Zwirner, N W; Malchiodi, E L; Chiaramonte, M G; Fossati, C A

    1994-01-01

    It has been suggested that molecular mimicry between the antigens of Trypanosoma cruzi and the host could have a role in the onset of the chronic stage of Chagas' disease. In this article, we report on a monoclonal antibody (MAb), CAK20.12 (immunoglobulin G2b), which reacts with a polypeptidic epitope of a 150-kDa antigen expressed on the surface of several strains of T. cruzi. This MAb also causes lysis of bloodstream trypomastigotes. Serum samples from 30 of 30 patients with chronic and 11 of 13 patients with acute Chagas' disease present specific antibodies to this antigen. MAb CAK20.12 reacts, by indirect immunofluorescence, with human and syngeneic murine striated muscle tissue, with the smooth muscle layer of cardiac arteries, with the lamina muscularis mucosae and the external striated muscle layer of the esophagus, and with the smooth muscle cells of the colon from normal syngeneic mice. Reactivity with the small intestine was very weak, and no reactivity with ventricle or atrium tissue was detected. Adsorption with an antigenic fraction from normal murine striated muscle or from T. cruzi epimastigotes confirmed that MAb CAK20.12 recognizes a common epitope present in parasites and host tissues. MAb CAK20.12, lytic for the infective form of T. cruzi, recognizes an epitope expressed in striated and smooth muscle cells of the host tissues affected in the chronic stage of Chagas' disease. Images PMID:7514576

  10. Seroprevalence of Trypanosoma cruzi Infection in Schoolchildren and in Pregnant Women from an Amazonian Region in Orellana Province, Ecuador

    PubMed Central

    Vargas, Caty Carrera; Narváez, Alberto Orlando; Aroca, Jenny Muzzio; Shiguango, Gonzalo; Robles, Luiggi Martini; Herrera, Claudia; Dumonteil, Eric

    2015-01-01

    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. PMID:26283751

  11. Alternative activation and increase of Trypanosoma cruzi survival in murine macrophages stimulated by cruzipain, a parasite antigen.

    PubMed

    Stempin, Cinthia; Giordanengo, Laura; Gea, Susana; Cerbán, Fabio

    2002-10-01

    We studied the macrophage (Mo) activation pathways through Mo interaction with immunogenic Trypanosoma cruzi antigens as cruzipain (Cz) and R13. J774 cells, peritoneal and spleen Mo from normal mice, were used. Although Mo classic activation was observed in the presence of lipopolysaccharide, evaluated through nitric oxide (NO) and interleukin (IL)-12 production, Cz and R13 did not activate Mo in this way. To study the alternative pathway, we examined the arginase activity in Mo cultured with Cz. An increase of arginase activity was detected in all Mo sources assayed. An increase of IL-10 and transforming growth factor-beta in culture supernatants from Mo stimulated with Cz was observed. The study of expression of B7.1 and B7.2 in spleen Mo revealed that Cz induces preferential expression of B7.2. In vitro studies revealed that Cz stimulated J774 cells and then, infected with trypomastigotes of T. cruzi, developed a higher number of intracellular parasites than unstimulated infected Mo. Thus, Cz favors the perpetuation of T. cruzi infection. In addition, a down-regulation of inducible NO synthase was observed in J774 cells stimulated with Cz. These results suggest that Cz interaction with Mo could modulate the immune response generated against T. cruzi through the induction of a preferential metabolic pathway in Mo.

  12. CHICKEN COOPS, Triatoma dimidiata INFESTATION AND ITS INFECTION WITH Trypanosoma cruzi IN A RURAL VILLAGE OF YUCATAN, MEXICO

    PubMed Central

    KOYOC-CARDEÑA, Edgar; MEDINA-BARREIRO, Anuar; ESCOBEDO-ORTEGÓN, Francisco Javier; RODRÍGUEZ-BUENFIL, Jorge Carlos; BARRERA-PÉREZ, Mario; REYES-NOVELO, Enrique; CHABLÉ-SANTOS, Juan; SELEM-SALAS, Celia; VAZQUEZ-PROKOPEC, Gonzalo; MANRIQUE-SAIDE, Pablo

    2015-01-01

    This study longitudinally investigated the association between Triatoma dimidiata infestation, triatomine infection with Trypanosoma cruzi and household/backyard environmental characteristics in 101 homesteads in Molas and Yucatan, Mexico, between November 2009 (rainy season) and May 2010 (dry season). Logistic regression models tested the associations between insect infestation/infection and potential household-level risk factors. A total of 200 T. dimidiata were collected from 35.6% of the homesteads, mostly (73%) from the peridomicile. Of all the insects collected, 48% were infected with T. cruzi. Infected insects were collected in 31.6% of the homesteads (54.1% and 45.9% intra- and peridomiciliary, respectively). Approximately 30% of all triatomines collected were found in chicken coops. The presence of a chicken coop in the backyard of a homestead was significantly associated with both the odds of finding T. dimidiata (OR = 4.10, CI 95% = 1.61-10.43, p = 0.003) and the presence of triatomines infected with T. cruzi (OR = 3.37, CI 95% = 1.36-8.33, p = 0.006). The results of this study emphasize the relevance of chicken coops as a putative source of T. dimidiata populations and a potential risk for T. cruzi transmission. PMID:26200970

  13. 1,4-Diamino-2-butanone, a putrescine analogue, promotes redox imbalance in Trypanosoma cruzi and mammalian cells.

    PubMed

    Soares, Chrislaine O; Colli, Walter; Bechara, Etelvino J H; Alves, Maria Julia M

    2012-12-15

    The putrescine analogue 1,4-diamino-2-butanone (DAB) is highly toxic to various microorganisms, including Trypanosoma cruzi. Similar to other α-aminocarbonyl metabolites, DAB exhibits pro-oxidant properties. DAB undergoes metal-catalyzed oxidation yielding H(2)O(2), NH(4)(+) ion, and a highly toxic α-oxoaldehyde. In vitro, DAB decreases mammalian cell viability associated with changes in redox balance. Here, we aim to clarify the DAB pro-oxidant effects on trypomastigotes and on intracellular T. cruzi amastigotes. DAB (0.05-5 mM) exposure in trypomastigotes, the infective stage of T. cruzi, leads to a decline in parasite viability (IC(50)c.a. 0.2 mM DAB; 4 h incubation), changes in morphology, thiol redox imbalance, and increased TcSOD activity. Medium supplementation with catalase (2.5 μM) protects trypomastigotes against DAB toxicity, while host cell invasion by trypomastigotes is hampered by DAB. Additionally, intracellular amastigotes are susceptible to DAB toxicity. Furthermore, pre-treatment with 100-500 μM buthionine sulfoximine (BSO) of LLC-MK2 potentiates DAB cytotoxicity, whereas 5 mM N-acetyl-cysteine (NAC) protects cells from oxidative stress. Together, these data support the hypothesis that redox imbalance contributes to DAB cytotoxicity in both T. cruzi and mammalian host cells.

  14. Trypanosoma cruzi seroprevalence in pregnant women and screening by PCR and microhaematocrit in newborns from Guanajuato, Mexico.

    PubMed

    Montes-Rincón, Laura Mayela; Galaviz-Silva, Lucio; González-Bravo, Francisco Ernesto; Molina-Garza, Zinnia Judith

    2016-12-01

    Chagas disease is caused by an infection with the protozoan hemoflagellate Trypanosoma cruzi, and it is a major endemic health problem in Latin America. The congenital route is one of the main non-vectorial pathways of transmission, which can arise either in the chronic or acute phase of maternal infection. Serological screening of T. cruzi infection was performed in 520 pregnant women and newborns at the Hospital General Regional de León, Guanajuato, Mexico, between 2014 and 2015. Anti-T. cruzi antibodies were detected in 20 mothers (4%) by ELISA and HIA with four PCR-positive newborn cases. Risk factors were identified according to an epidemiological survey, and the most significant (P<0.050) factors associated with T. cruzi infection were the building materials of dwellings, the presence of pets and dwellings located in rural areas. This study constitutes the first systematic study on congenital Chagas disease and the epidemiological risk factors in Guanajuato. Our results represent the probability of an incidence of 770 cases per 100,000 births during a period of 12 months, with a vertical transmission rate by 0.8%, which highlights the necessity to establish reliable serological and PCR tests in pregnant women to prevent vertical transmission. However, it is also important to follow-up the newborns from seropositive mothers for one year, which is necessary, as many children yielded negative results.

  15. Morphological and Phylogenetic Description of Trypanosoma noyesi sp. nov.: An Australian Wildlife Trypanosome within the T. cruzi Clade.

    PubMed

    Botero, Adriana; Cooper, Crystal; Thompson, Craig K; Clode, Peta L; Rose, Karrie; Thompson, R C Andrew

    2016-11-01

    A number of trypanosome isolates from Australian marsupials are within the clade containing the human pathogen Trypanosoma cruzi. Trypanosomes within this clade are thought to have diverged from a common ancestral bat trypanosome. Here, we characterise Trypanosoma noyesi sp. nov. isolated from the critically endangered woylie (Bettongia pencillata) using phylogenetic inferences from three gene regions (18S rDNA, gGAPDH, and CytB) coupled with morphological and behavioural observations in vitro. We also investigated potential vectors and the presence of T. noyesi in the grey-headed flying fox (Pteropus poliocephalus). Phylogenetic analysis revealed T. noyesi and similar genotypes grouped at the periphery of the T. cruzi clade. T. noyesi is morphologically distinct both from other species of Australian trypanosomes and those within the T. cruzi clade. Although trypanosomes were not observed in the digestive tract of ectoparasites and biting flies collected from T. noyesi infected marsupials, tabanid and biting midges tested positive for T. noyesi DNA, indicating they are vector candidates. Tissues from flying foxes were negative for T. noyesi. This study provides novel information on the morphology and genetic variability of an Australian trypanosome within the T. cruzi clade.

  16. Effects of specific treatment on parasitological and histopathological parameters in mice infected with different Trypanosoma cruzi clonal genotypes.

    PubMed

    Toledo, M J O; Bahia, M T; Veloso, V M; Carneiro, C M; Machado-Coelho, G L L; Alves, C F; Martins, H R; Cruz, R E; Tafuri, W L; Lana, M

    2004-06-01

    The goal of this study was to verify the effect of specific treatment on parasitological and histopathological parameters in mice experimentally infected with different Trypanosoma cruzi clonal genotypes. Twenty cloned stocks were selected, representative of the whole phylogenetic diversity of the protozoan and belonging to the clonal genotypes 19 and 20 (T. cruzi I) and 39 and 32 (T. cruzi II). The stocks were inoculated in 40 BALB/c mice divided into four groups: (i) treated with benznidazole, (ii) treated with itraconazole and (iii and iv) untreated control groups (NT) for each drug, respectively. Seven parameters related to parasitaemia curves and histopathological lesions were analysed. Four during the acute phase (AP) and three during both the AP and chronic phase (CP) of infection. Statistical comparison between benznidazole-treated and NT groups for the biological parameters showed significant differences for all genotypes. Benznidazole treatment led to lower patent period, maximum of parasitaemia, day of maximum parasitaemia and area under the parasitaemia curve for all genotypes analysed. Percentage of positive haemoculture during AP and CP was lower for genotypes 19 and 32. Tissue parasitism (TP) and inflammatory process (IP) during AP were lower for genotypes 19 and 32, respectively. In general, itraconazole treatment induced a smaller reduction in these same parameters between treated and NT animals in relation to benznidazole treatment. Our results indicate that phylogenetic divergence among T. cruzi clonal genotypes must be taken in account in chemotherapy and studies dealing with all aspects of the parasite and the disease.

  17. New Sylvatic Hosts of Trypanosoma cruzi and Their Reservoir Competence in the Humid Chaco of Argentina: A Longitudinal Study

    PubMed Central

    Orozco, M. Marcela; Enriquez, Gustavo F.; Alvarado-Otegui, Julián A.; Cardinal, M. Victoria; Schijman, Alejandro G.; Kitron, Uriel; Gürtler, Ricardo E.

    2013-01-01

    A four-year longitudinal study of the structure of sylvatic transmission cycles of Trypanosoma cruzi, reservoir host competence and parasite discrete typing units was conducted in a disturbed rural area of the humid Chaco in Argentina. Among 190 mammals examined by xenodiagnosis and polymerase chain reaction amplification, the composite prevalence of infection was substantially higher in Dasypus novemcinctus armadillos (57.7%) and Didelphis albiventris opossums (38.1%) than in Euphractus sexcinctus (20.0%), Tolypeutes matacus (12.5%), and Chaetophractus vellerosus (6.3%) armadillos. Trypanosoma cruzi was detected for the first time in Thylamys pusilla small opossums and in two unidentified small rodents. Infection was spatially aggregated only in armadillos. All Didelphis were infected with T. cruzi I and all armadillo species were infected with T. cruzi III, implying two distinct sylvatic cycles with no inputs from the domestic cycle. Dasypus armadillos and Didelphis opossums were much more infectious to vectors than other armadillos, small opossums, or rodents. PMID:23530075

  18. The role of selenium in intestinal motility and morphology in a murine model of Typanosoma cruzi infection

    PubMed Central

    de Souza, Andréa Pereira; Sieberg, Ryan; Li, Hua; Cahill, Hannah R.; Zhao, Dazhi; Araújo-Jorge, Tania C.; Tanowitz, Herbert B.

    2010-01-01

    Infection with Trypanosoma cruzi causes mega-syndromes of the gastrointestinal (GI) tract in humans and animals. In the present study, we employed magnetic resonance imaging to non-invasively monitor the effect of selenium supplementation on alterations in the GI tract of T. cruzi-infected mice. CD1 mice infected with T. cruzi (Brazil strain) exhibited dilatation of the intestines similar to that we recently reported in infected C57Bl/6 mice. The average intestine lumen diameter increased by 65% and the increase was reduced to 29% in mice supplemented with 2 ppm selenium in the drinking water. When supplemented with 3 ppm selenium in chow the lumen diameter was also significantly reduced although the difference between the infected and infected supplemented mice was smaller. Intestinal motility in infected mice fed with selenium-enriched chow was increased compared with infected mice fed with normal unsupplemented chow and was not significantly different from intestinal motility in uninfected mice. We suggest that Se may be used to modulate the inflammatory, immunological, and/or antioxidant responses involved in intestinal disturbances caused by T. cruzi infection. PMID:20195635

  19. Trypanosoma cruzi Immune Response Modulation Decreases Microbiota in Rhodnius prolixus Gut and Is Crucial for Parasite Survival and Development

    PubMed Central

    Castro, Daniele P.; Moraes, Caroline S.; Gonzalez, Marcelo S.; Ratcliffe, Norman A.; Azambuja, Patrícia; Garcia, Eloi S.

    2012-01-01

    Trypanosoma cruzi in order to complete its development in the digestive tract of Rhodnius prolixus needs to overcome the immune reactions and microbiota trypanolytic activity of the gut. We demonstrate that in R. prolixus following infection with epimastigotes of Trypanosoma cruzi clone Dm28c and, in comparison with uninfected control insects, the midgut contained (i) fewer bacteria, (ii) higher parasite numbers, and (iii) reduced nitrite and nitrate production and increased phenoloxidase and antibacterial activities. In addition, in insects pre-treated with antibiotic and then infected with Dm28c, there were also reduced bacteria numbers and a higher parasite load compared with insects solely infected with parasites. Furthermore, and in contrast to insects infected with Dm28c, infection with T. cruzi Y strain resulted in a slight decreased numbers of gut bacteria but not sufficient to mediate a successful parasite infection. We conclude that infection of R. prolixus with the T. cruzi Dm28c clone modifies the host gut immune responses to decrease the microbiota population and these changes are crucial for the parasite development in the insect gut. PMID:22574189

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

    PubMed

    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.

  1. Human leucocyte antigen-G (HLA-G) and its murine functional homolog Qa2 in the Trypanosoma cruzi Infection.

    PubMed

    Dias, Fabrício C; Mendes-Junior, Celso T; Silva, Maria C; Tristão, Fabrine S M; Dellalibera-Joviliano, Renata; Moreau, Philippe; 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.

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

    PubMed Central

    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

  3. Molecular characterization of the short interspersed repetitive element SIRE in the six discrete typing units (DTUs) of Trypanosoma cruzi.

    PubMed

    Pavia, Paula X; Thomas, M Carmen; López, Manuel C; Puerta, Concepción J

    2012-10-01

    Repetitive sequences constitute an important proportion of the Trypanosoma cruzi genome; hence, they have been used as molecular markers and as amplification targets to identify the parasite presence via PCR. In this study, a molecular characterization of the SIRE repetitive element was performed in the six discrete typing units (DTUs) of T. cruzi. The results evidenced that this element, located in multiple chromosomes, was interspersed in the genome of all DTUs of the parasite. The presence of several motifs implicated in element insertion, duplication, and functionality suggests that SIRE could be an active element in the parasite genome. Of interest, there were SIRE specific Alu I fragments that allowed to discriminate DTU I from the others DTUs. Moreover, an UPGMA phenetic tree constructed from fragment sharing Southern blot data showed that T. cruzi I isolates conform a cluster separated from the T. cruzi II-VI isolates. When the relative number of SIRE copies was determined, a variation from 105 to 2,000 copies per haploid genome was observed among the different isolates without kept a DTU-relationship. In all, these findings suggest that SIRE sequence is a good target for parasite DNA amplification.

  4. Effects of complement depletion in experimental chagas disease: immune lysis of virulent blood forms of Trypanosoma cruzi.

    PubMed Central

    Budzko, D B; Pizzimenti, M C; Kierszenbaum, F

    1975-01-01

    In mice infected with virulent blood (trypomastigote) forms of Trypanosoma cruzi, complement depletion with cobra venom factor caused a marked exacerbation of the disease evidenced by significantly increased parasitemia levels and early mortality as compared with those of untreated infected animals. The effect was greater in mice receiving cobra venom factor on day 7 postinfection, i.e., at the time when the parasites had had time to localize and multiply in the tissues and appeared in the circulation in appreciable numbers. The possibility that complement participates in host defense against T. cruzi infection through a mechanism involving immune lysis was explored in vitro. T. cruzi trypomastigotes were found to undergo immune lysis in sera of patients with chronic Chagas' disease, in sera of immunized mice, and in solutions containing both immune mouse gamma globulin and a source of active complement. This phenomenon failed to take place either in the absence of complement or after complement inactivation by heat or utilizing complement inactivators. The lytic capacity of heated sera was restored by the addition of active complement to the system. During the immune lysis of T. cruzi blood forms, complement was activated in human sera via both the classical and the alternate pathways. In mouse sera, activation followed at least the alternate pathway. PMID:46840

  5. Seroprevalence of Trypanosoma cruzi Infection in Schoolchildren and in Pregnant Women from an Amazonian Region in Orellana Province, Ecuador.

    PubMed

    Carrera Vargas, Caty; Narváez, Alberto Orlando; Muzzio Aroca, Jenny; Shiguango, Gonzalo; Robles, Lu