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Faral-Tello P, Greif G, Romero S, Cabrera A, Oviedo C, González T, Libisch G, Arévalo AP, Varela B, Verdes JM, Crispo M, Basmadjián Y, Robello C. Trypanosoma cruzi Isolates Naturally Adapted to Congenital Transmission Display a Unique Strategy of Transplacental Passage. Microbiol Spectr 2023; 11:e0250422. [PMID: 36786574 PMCID: PMC10100920 DOI: 10.1128/spectrum.02504-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 01/12/2023] [Indexed: 02/15/2023] Open
Abstract
Chagas disease is mainly transmitted by vertical transmission (VT) in nonendemic areas and in endemic areas where vector control programs have been successful. For the present study, we isolated natural Trypanosoma cruzi strains vertically transmitted through three generations and proceeded to study their molecular mechanism of VT using mice. No parasitemia was detected in immunocompetent mice, but the parasites were able to induce an immune response and colonize different organs. VT experiments revealed that infection with different strains did not affect mating, pregnancy, or resorption, but despite low parasitemia, VT strains reached the placenta and resulted in higher vertical transmission rates than strains of either moderate or high virulence. While the virulent strain modulated more than 2,500 placental genes, VT strains modulated 150, and only 29 genes are shared between them. VT strains downregulated genes associated with cell division and replication and upregulated immunomodulatory genes, leading to anti-inflammatory responses and tolerance. The virulent strain stimulated a strong proinflammatory immune response, and this molecular footprint correlated with histopathological analyses. We describe a unique placental response regarding the passage of T. cruzi VT isolates across the maternal-fetal interphase, challenging the current knowledge derived mainly from studies of laboratory-adapted or highly virulent strains. IMPORTANCE The main findings of this study are that we determined that there are Trypanosoma cruzi strains adapted to transplacental transmission and completely different from the commonly used laboratory reference strains. This implies a specific strategy for the vertical transmission of Chagas disease. It is impressive that the strains specialized for vertical transmission modify the gene expression of the placenta in a totally different way than the reference strains. In addition, we describe isolates of T. cruzi that cannot be transmitted transplacentally. Taken together, these results open up new insights into the molecular mechanisms of this insect vector-independent transmission form.
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Affiliation(s)
- Paula Faral-Tello
- Laboratorio de Interacciones Hospedero Patógeno/UBM, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Gonzalo Greif
- Laboratorio de Interacciones Hospedero Patógeno/UBM, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Selva Romero
- Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Andrés Cabrera
- Laboratorio de Interacciones Hospedero Patógeno/UBM, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Unidad de Microbiología, Instituto de Patobiología, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
| | - Cristina Oviedo
- Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Telma González
- Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Gabriela Libisch
- Laboratorio de Interacciones Hospedero Patógeno/UBM, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Ana Paula Arévalo
- Laboratory Animal Biotechnology Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Belén Varela
- Unidad de Patología, Departamento de Patobiología, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
| | - José Manuel Verdes
- Unidad de Patología, Departamento de Patobiología, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
| | - Martina Crispo
- Laboratory Animal Biotechnology Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Yester Basmadjián
- Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Carlos Robello
- Laboratorio de Interacciones Hospedero Patógeno/UBM, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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2
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Eligio García L, Crisóstomo Vázquez MDP, Maravelez Acosta VA, Soria Guerrero M, Cortés Campos A, Jiménez Cardoso E. Trypanosoma cruzi Antigenic Proteins Shared with Acute Lymphoblastic Leukemia and Neuroblastoma. Pharmaceuticals (Basel) 2022; 15:1421. [PMID: 36422551 PMCID: PMC9693088 DOI: 10.3390/ph15111421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/04/2022] [Accepted: 11/10/2022] [Indexed: 02/19/2024] Open
Abstract
Background. Research studies indicate that immunization with protein extracts of Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, prevents the appearance of tumors in 60% of mice injected with the murine lung carcinoma tumor line. The molecular basis of this process is unknown, although the presence of specific antigens in tumor cells and on the surface of T. cruzi suggests an antiparasitic immune response, with an effective cross-reaction against cancer cells, hence the importance to identify the antigens involved and determine their potential as target cells in anticancer therapy. Aim. This study aimed to determine the presence of antigenic proteins of T. cruzi shared with acute lymphoblastic leukemia and neuroblastoma cells. Material and methods. To achieve this, polyclonal antibodies against T. cruzi were developed in rabbits, and reactivity was determined with protein extracts of acute lymphoblastic leukemia cells and neuroblastoma. The immunodetection of five different strains of T. cruzi against anti-T. cruzi polyclonal antibodies was also performed. Conclusion. The study allows the knowledge of the immunological interactions between cancer and parasites to be expanded and, therefore, contributes to the design of more and better projects that improve the therapeutic strategies applied in oncology.
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Affiliation(s)
| | | | | | | | | | - Enedina Jiménez Cardoso
- Laboratorio de Investigación en Parasitología, Hospital Infantil de México Federico Gómez (HIMFG), Dr. Márquez 162. Col Doctores, Cuauhtémoc, México City 06720, Mexico
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3
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De Souza W, Barrias ES. May the epimastigote form of Trypanosoma cruzi be infective? Acta Trop 2020; 212:105688. [PMID: 32888934 DOI: 10.1016/j.actatropica.2020.105688] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/24/2020] [Accepted: 08/31/2020] [Indexed: 10/23/2022]
Abstract
For many years it has been considered that there are three basic developmental stages of Trypanosoma cruzi: Epimastigote (Epi), Amastigote (Ama) and Trypomastigote (Typo). Epi and Ama are able to divide while Trypo does not divide. Epi are not infective while Ama and Trypo are able to infect host cells. Here we review the available data for the epimastigote form. Taken together the data show that (a) there are intermediate forms between epimastigotes and trypomastigotes in axenic cultures as well as between amastigote and trypomastigote forms within the cells (both in vitro and in vivo), and (c) that the intermediate forms, here designated as "Transitional Epimastigote", most of the time considered as epimastigotes, are able to infect cells. The recognition of the existence of this stage is of practical importance for those work with T. cruzi. Many laboratories working only with T. cruzi in axenic cultures usually consider to work with nonpathogenic cultures. This attitude needs to be changed requiring special care by those working with this protozoan to avoid accidental infections in the laboratory. In view of these observation a new scheme for the life cycle of T. cruzi is proposed.
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Parthasarathy A, Kalesh K. Defeating the trypanosomatid trio: proteomics of the protozoan parasites causing neglected tropical diseases. RSC Med Chem 2020; 11:625-645. [PMID: 33479664 PMCID: PMC7549140 DOI: 10.1039/d0md00122h] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022] Open
Abstract
Mass spectrometry-based proteomics enables accurate measurement of the modulations of proteins on a large scale upon perturbation and facilitates the understanding of the functional roles of proteins in biological systems. It is a particularly relevant methodology for studying Leishmania spp., Trypanosoma cruzi and Trypanosoma brucei, as the gene expression in these parasites is primarily regulated by posttranscriptional mechanisms. Large-scale proteomics studies have revealed a plethora of information regarding modulated proteins and their molecular interactions during various life processes of the protozoans, including stress adaptation, life cycle changes and interactions with the host. Important molecular processes within the parasite that regulate the activity and subcellular localisation of its proteins, including several co- and post-translational modifications, are also accurately captured by modern proteomics mass spectrometry techniques. Finally, in combination with synthetic chemistry, proteomic techniques facilitate unbiased profiling of targets and off-targets of pharmacologically active compounds in the parasites. This provides important data sets for their mechanism of action studies, thereby aiding drug development programmes.
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Affiliation(s)
- Anutthaman Parthasarathy
- Rochester Institute of Technology , Thomas H. Gosnell School of Life Sciences , 85 Lomb Memorial Dr , Rochester , NY 14623 , USA
| | - Karunakaran Kalesh
- Department of Chemistry , Durham University , Lower Mount Joy, South Road , Durham DH1 3LE , UK .
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5
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Kessler RL, Contreras VT, Marliére NP, Aparecida Guarneri A, Villamizar Silva LH, Mazzarotto GACA, Batista M, Soccol VT, Krieger MA, Probst CM. Recently differentiated epimastigotes fromTrypanosoma cruziare infective to the mammalian host. Mol Microbiol 2017; 104:712-736. [DOI: 10.1111/mmi.13653] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2017] [Indexed: 12/31/2022]
Affiliation(s)
| | - Víctor Tulio Contreras
- Laboratorio de Protozoología, Centro de Biología Molecular de Parásitos, Facultad Ciencias de la Salud; Universidad de Carabobo; Valencia Venezuela
| | - Newmar Pinto Marliére
- Vector Behavior and Pathogen Interaction Group; Centro de Pesquisas René Rachou, Fiocruz; Belo Horizonte Minas Gerais Brazil
| | - Alessandra Aparecida Guarneri
- Vector Behavior and Pathogen Interaction Group; Centro de Pesquisas René Rachou, Fiocruz; Belo Horizonte Minas Gerais Brazil
| | | | | | | | - Vanete Thomaz Soccol
- Programa de Pós-Graduação em Processos Biotecnológicos e Biotecnologia, Centro Politécnico; Universidade Federal do Paraná; Curitiba PR Brazil
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Cooper C, Clode PL, Peacock C, Thompson RCA. Host-Parasite Relationships and Life Histories of Trypanosomes in Australia. ADVANCES IN PARASITOLOGY 2016; 97:47-109. [PMID: 28325373 DOI: 10.1016/bs.apar.2016.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Trypanosomes constitute a group of flagellate protozoan parasites responsible for a number of important, yet neglected, diseases in both humans and livestock. The most significantly studied include the causative agents of African sleeping sickness (Trypanosoma brucei) and Chagas disease (Trypanosoma cruzi) in humans. Much of our knowledge about trypanosome host-parasite relationships and life histories has come from these two human pathogens. Recent investigations into the diversity and life histories of wildlife trypanosomes in Australia highlight that there exists a great degree of biological and behavioural variation within and between trypanosomes. In addition, the genetic relationships between some Australian trypanosomes show that they are unexpectedly more closely related to species outside Australia than within it. These findings have led to a growing focus on the importance of understanding parasites occurring naturally in wildlife to (1) better document parasite biodiversity, (2) determine evolutionary relationships and degree of host specificity, (3) understand host-parasite interactions and the role of parasites in the natural ecosystem and (4) identify biosecurity issues of emerging disease in both wildlife and human populations. Here we review what is known about the diversity, life histories, host-parasite interactions and evolutionary relationships of trypanosomes in Australian wildlife. In this context, we focus upon the genetic proximity of key Australian species to the pathogenic T. cruzi and discuss similarities in their biology and behaviour that present a potential risk of human disease transmission by Australian vectors and wildlife.
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Affiliation(s)
- C Cooper
- The University of Western Australia, Crawley, WA, Australia
| | - P L Clode
- The University of Western Australia, Crawley, WA, Australia
| | - C Peacock
- The University of Western Australia, Crawley, WA, Australia; Telethon Kids Institute, Subiaco, WA, Australia
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7
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Colonization of Rhodnius prolixus gut by Trypanosoma cruzi involves an extensive parasite killing. Parasitology 2016; 143:434-43. [PMID: 26818093 DOI: 10.1017/s0031182015001857] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, is ingested by triatomines during their bloodmeal on an infected mammal. Aiming to investigate the development and differentiation of T. cruzi inside the intestinal tract of Rhodnius prolixus at the beginning of infection we fed insects with cultured epimastigotes and blood trypomastigotes from infected mice to determine the amount of recovered parasites after ingestion. Approximately 20% of the ingested parasites was found in the insect anterior midgut (AM) 3 h after feeding. Interestingly, a significant reduction (80%) in the numbers of trypomastigotes was observed after 24 h of infection suggesting that parasites were killed in the AM. Moreover, few parasites were found in that intestinal portion after 96 h of infection. The evaluation of the numbers of parasites in the posterior midgut (PM) at the same periods showed a reduced parasite load, indicating that parasites were not moving from the AM. Additionally, incubation of blood trypomastigotes with extracts from R. prolixus AMs revealed that components of this tissue could induce significant death of T. cruzi. Finally, we observed that differentiation from trypomastigotes to epimastigotes is not completed in the AM; instead we suggest that trypomastigotes change to intermediary forms before their migration to the PM, where differentiation to epimastigotes takes place. The present work clarifies controversial points concerning T. cruzi development in insect vector, showing that parasite suffers a drastic decrease in population size before epimastigonesis accomplishment in PM.
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8
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Kostygov AY, Grybchuk-Ieremenko A, Malysheva MN, Frolov AO, Yurchenko V. Molecular revision of the genus Wallaceina. Protist 2014; 165:594-604. [PMID: 25113831 DOI: 10.1016/j.protis.2014.07.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 07/01/2014] [Accepted: 07/02/2014] [Indexed: 11/17/2022]
Abstract
This work is focused on the molecular revision of the genus Wallaceina established in the very twilight of the classical morphotype-based approach to classification of the Trypanosomatidae. The genus was erected due to the presence of a unique variant of endomastigotes. In molecular phylogenetic studies four described species of Wallaceina were shown to be extremely close to each other and to some other undescribed isolates clustered within Leishmaniinae clade, while three recently included species formed a separate clade. Our results of morphological and molecular phylogenetic analyses demonstrated that all Leishmaniinae-bound wallaceinas are just different isolates of the same species that we rename back to Crithidia brevicula Frolov, Malysheva, 1989. To accommodate former Wallaceina spp. phylogenetically distant from the genus Crithidia, we propose a new generic name Wallacemonas Kostygov et Yurchenko, 2014.
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Affiliation(s)
- Alexei Yu Kostygov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg, 199034, Russia
| | - Anastasiia Grybchuk-Ieremenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Marina N Malysheva
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg, 199034, Russia
| | - Alexander O Frolov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg, 199034, Russia
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic; Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice (Budweis), Czech Republic.
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9
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Abstract
Trypanosoma cruzi is the causal agent of Chagas' disease, a debilitating disorder affecting millions of people in several countries. A flagellated protozoan parasite, T. cruzi has a complex life cycle that involves infecting an insect and a mammalian host. During its life cycle, the parasite undergoes several kinds of stress, prominent among which is heat stress. To deal with this environmental challenge, molecular chaperones and proteases, also known as heat shock proteins (HSPs), are induced as part of the stress response. Several families of HSPs are synthesized by T. cruzi, including members of the major HSP classes such as HSP70, HSP90, HSP100, HSP40, chaperonins and small HSPs, and these proteins show conserved and unique features. In this review we describe these proteins and the corresponding gene expression patterns and discuss their relevance to the biology of the parasite.
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Affiliation(s)
- Turán P Urményi
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil,
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10
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de los Milagros Cámara M, Bouvier LA, Miranda MR, Reigada C, A. Pereira C. Laboratory techniques to obtain different forms of Trypanosoma cruzi: applications to wild-type and genetically modified parasites. Folia Parasitol (Praha) 2013; 60:406-10. [DOI: 10.14411/fp.2013.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ferreira ER, Bonfim-Melo A, Mortara RA, Bahia D. Trypanosoma cruzi extracellular amastigotes and host cell signaling: more pieces to the puzzle. Front Immunol 2012; 3:363. [PMID: 23264776 PMCID: PMC3525110 DOI: 10.3389/fimmu.2012.00363] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/12/2012] [Indexed: 11/13/2022] Open
Abstract
Among the different infective stages that Trypanosoma cruzi employs to invade cells, extracellular amastigotes (EAs) have recently gained attention by our group. This is true primarily because these amastigotes are able to infect cultured cells and animals, establishing a sustainable infective cycle. EAs are thus an excellent means of adaptation and survival for T. cruzi, whose different infective stages each utilize unique mechanisms for attachment and penetration. Here we discuss some features of host cell invasion by EAs and the associated host cell signaling events that occur as part of the process.
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Affiliation(s)
- Eden R Ferreira
- Disciplina de Parasitologia, Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo São Paulo, SP, Brazil
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12
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Minning TA, Weatherly DB, Atwood J, Orlando R, Tarleton RL. The steady-state transcriptome of the four major life-cycle stages of Trypanosoma cruzi. BMC Genomics 2009; 10:370. [PMID: 19664227 PMCID: PMC2907688 DOI: 10.1186/1471-2164-10-370] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 08/07/2009] [Indexed: 12/20/2022] Open
Abstract
Background Chronic chagasic cardiomyopathy is a debilitating and frequently fatal outcome of human infection with the protozoan parasite, Trypanosoma cruzi. Microarray analysis of gene expression during the T. cruzi life-cycle could be a valuable means of identifying drug and vaccine targets based on their appropriate expression patterns, but results from previous microarray studies in T. cruzi and related kinetoplastid parasites have suggested that the transcript abundances of most genes in these organisms do not vary significantly between life-cycle stages. Results In this study, we used whole genome, oligonucleotide microarrays to globally determine the extent to which T. cruzi regulates mRNA relative abundances over the course of its complete life-cycle. In contrast to previous microarray studies in kinetoplastids, we observed that relative transcript abundances for over 50% of the genes detected on the T. cruzi microarrays were significantly regulated during the T. cruzi life-cycle. The significant regulation of 25 of these genes was confirmed by quantitative reverse-transcriptase PCR (qRT-PCR). The T. cruzi transcriptome also mirrored published protein expression data for several functional groups. Among the differentially regulated genes were members of paralog clusters, nearly 10% of which showed divergent expression patterns between cluster members. Conclusion Taken together, these data support the conclusion that transcript abundance is an important level of gene expression regulation in T. cruzi. Thus, microarray analysis is a valuable screening tool for identifying stage-regulated T. cruzi genes and metabolic pathways.
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Affiliation(s)
- Todd A Minning
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA.
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Ramos FP, Araripe JR, Urményi TP, Silva R, Cunha e Silva NL, Leite Fontes CF, da Silveira JF, Rondinelli E. Characterization of RAB-like4, the first identified RAB-like protein from Trypanosoma cruzi with GTPase activity. Biochem Biophys Res Commun 2005; 333:808-17. [PMID: 15975556 DOI: 10.1016/j.bbrc.2005.05.183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Accepted: 05/26/2005] [Indexed: 11/25/2022]
Abstract
RAB proteins, which belong to the RAS superfamily, regulate exocytic and endocytic pathways of eukaryotic cells, controlling vesicle docking and fusion. Few RAB proteins have been identified in parasites. Molecular markers for cellular compartments are important to studies concerning about the protein traffic in Trypanosoma cruzi, the causal agent of Chagas disease. In this work, we describe the characterization of TcRABL4, the first RAB-like gene identified in T. cruzi (GenBank Accession No.: ), present as a single-copy gene. TcRABL4 contains all five consensus RAB motifs but lacks cysteine residues at the C terminus, which are essential to isoprenylation, an absolute prerequisite for membrane association of these proteins. TcRABL4 is a functional GTPase that is able to bind and hydrolyze GTP, and its gene is transcribed as a single 1.2 kb mRNA in epimastigotes. TcRABL4 appears to be differentially regulated in the three cell forms of the parasite, and the protein is not associated to membranes, unlike other RAB proteins. It is possible that TcRABL4 may be a member of a novel family of small GTPases.
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Affiliation(s)
- Fabiane Pereira Ramos
- Laboratório de Metabolismo Macromolecular Firmino Torres de Castro, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, Rio de Janeiro 21949-900, Brazil
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Araripe JR, Ramos FP, Cunha e Silva NL, Urményi TP, Silva R, Leite Fontes CF, da Silveira JF, Rondinelli E. Characterization of a RAB5 homologue in Trypanosoma cruzi. Biochem Biophys Res Commun 2005; 329:638-45. [PMID: 15737633 DOI: 10.1016/j.bbrc.2005.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Indexed: 11/30/2022]
Abstract
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.
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Affiliation(s)
- Júlia Rolão Araripe
- Laboratório de Metabolismo Macromolecular Firmino Torres de Castro, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, Rio de Janeiro 21949-900, Brazil
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15
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Weatherly DB, Atwood JA, Minning TA, Cavola C, Tarleton RL, Orlando R. A Heuristic method for assigning a false-discovery rate for protein identifications from Mascot database search results. Mol Cell Proteomics 2005; 4:762-72. [PMID: 15703444 DOI: 10.1074/mcp.m400215-mcp200] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MS/MS and database searching has emerged as a valuable technology for rapidly analyzing protein expression, localization, and post-translational modifications. The probability-based search engine Mascot has found widespread use as a tool to correlate tandem mass spectra with peptides in a sequence database. Although the Mascot scoring algorithm provides a probability-based model for peptide identification, the independent peptide scores do not correlate with the significance of the proteins to which they match. Herein, we describe a heuristic method for organizing proteins identified at a specified false-discovery rate using Mascot-matched peptides. We call this method PROVALT, and it uses peptide matches from a random database to calculate false-discovery rates for protein identifications and reduces a complex list of peptide matches to a nonredundant list of homologous protein groups. This method was evaluated using Mascot-identified peptides from a Trypanosoma cruzi epimastigote whole-cell lysate, which was separated by multidimensional LC and analyzed by MS/MS. PROVALT was then compared with the two traditional methods of protein identification when using Mascot, the single peptide score and cumulative protein score methods, and was shown to be superior to both in regards to the number of proteins identified and the inclusion of lower scoring nonrandom peptide matches.
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Affiliation(s)
- D Brent Weatherly
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA
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16
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Gomes GG, Peter Urményi T, Rondinelli E, Williams N, Silva R. TcRRMs and Tcp28 genes are intercalated and differentially expressed in Trypanosoma cruzi life cycle. Biochem Biophys Res Commun 2004; 322:985-92. [PMID: 15336561 DOI: 10.1016/j.bbrc.2004.08.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Indexed: 10/26/2022]
Abstract
The identification and characterization of RNA binding proteins in Trypanosoma cruzi are particularly relevant as they play key roles in the regulatory mechanisms of gene expression. In this work, we have identified coding sequences for the proteins, named TcRRM1 and TcRRM2, in the EST database generated by the T. cruzi genomic initiative. TcRRM1 and TcRRM2 contain two RNA binding domains (RRM) and are very similar to two Trypanosoma brucei RNA binding proteins previously reported, Tbp34 and Tbp37, and to a not yet annotated ORF in Leishmania major genome project. The T. cruzi RRM genes are organized in tandem, alternating with copies of Tcp28, a gene of unknown function. However, TcRRM transcript accumulation is higher in the spheromastigote stage, while Tcp28 transcripts accumulate more in the trypomastigote stage suggesting developmental regulation.
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17
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Eickhoff CS, Eckmann L, Hoft DF. Differential interleukin-8 and nitric oxide production in epithelial cells induced by mucosally invasive and noninvasive Trypanosoma cruzi trypomastigotes. Infect Immun 2003; 71:5394-7. [PMID: 12933891 PMCID: PMC187333 DOI: 10.1128/iai.71.9.5394-5397.2003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trypanosoma cruzi metacyclic trypomastigotes (MT), but not blood form trypomastigotes (BFT), are highly mucosally infective. We investigated the abilities of MT and BFT to induce inflammation and/or intracellular killing activity within mucosal epithelia. BFT, but not MT, induced marked increases in interleukin-8, GRO-alpha, MCP-1, and nitric oxide production in HeLa and AGS cells, despite similar infectivities. MT may avoid induction of inflammation as an important biological mechanism facilitating mucosal invasion.
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Affiliation(s)
- C S Eickhoff
- Department of Internal Medicine, Saint Louis University Health Sciences Center, St. Louis, Missouri, USA
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18
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Navarro MC, De Lima AR, Askue J, Contreras VT. Morphological comparison of axenic amastigogenesis of trypomastigotes and metacyclic forms of Trypanosoma cruzi. Mem Inst Oswaldo Cruz 2003; 98:83-91. [PMID: 12700866 DOI: 10.1590/s0074-02762003000100012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Amastigogenesis occurs first when metacyclic trypomastigotes from triatomine urine differentiate into amastigotes inside mammalian host cells and a secondary process when tissue-derived trypomastigotes invade new cells and differentiate newly to amastigotes. Using scanning electron microscopy, we compared the morphological patterns manifested by trypomastigotes and metacyclic forms of Trypanosoma cruzi during their axenic-transformation to amastigotes in acidic medium at 37 C. We show here that in culture MEMTAU medium, secondary and primary axenic amastigogenesis display different morphologies. As already described, we also observed a high differentiation rate of trypomastigotes into amastigotes. Conversely, the transformation rate of in vitro-induced-metacyclic trypomastigotes to amastigotes was significantly slower and displayed distinct patterns of transformation that seem environment-dependent. Morphological comparisons of extracelullar and intracellular amastigotes showed marked similarities, albeit some differences were also detected. SDS-PAGE analyses of protein and glycoprotein from primary and axenic extracelullar amastigotes showed similarities in glycopeptide profiles, but variations between their proteins demonstrated differences in their respective macromolecular constitutions. The data indicate that primary and axenic secondary amastigogenesis of T. cruzi may be the result of different developmental processes and suggest that the respective intracellular mechanisms driving amastigogenesis may not be the same.
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Affiliation(s)
- María C Navarro
- Laboratorio de Protozoolog a, Centro BioMolP, Facultad de Ciencias de la Salud, Universidad de Carabobo, Valencia, Estado Carabobo, Venezuela
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19
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Contreras VT, Navarro MC, De Lima AR, Arteaga R, Duran F, Askue J, Franco Y. Production of amastigotes from metacyclic trypomastigotes of Trypanosoma cruzi. Mem Inst Oswaldo Cruz 2002; 97:1213-20. [PMID: 12563492 DOI: 10.1590/s0074-02762002000800025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Attempts to recreate all the developmental stages of Trypanosoma cruzi in vitro have thus far been met with partial success. It is possible, for instance, to produce trypomastigotes in tissue culture and to obtain metacyclic trypomastigotes in axenic conditions. Even though T. cruzi amastigotes are known to differentiate from trypomastigotes and metacyclic trypomastigotes, it has only been possible to generate amastigotes in vitro from the tissue-culture-derived trypomastigotes. The factors and culture conditions required to trigger the transformation of metacyclic trypomastigotes into amastigotes are as yet undetermined. We show here that pre-incubation of metacyclic trypomastigotes in culture (MEMTAU) medium at 37 degrees C for 48 h is sufficient to commit the parasites to the transformation process. After 72 h of incubation in fresh MEMTAU medium, 90% of the metacyclic parasites differentiate into forms that are morphologically indistinguishable from normal amastigotes. SDS-PAGE, Western blot and PAABS analyses indicate that the transformation of axenic metacyclic trypomastigotes to amastigotes is associated with protein, glycoprotein and antigenic modifications. These data suggest that (a) T. cruzi amastigotes can be obtained axenically in large amounts from metacyclic trypomastigotes, and (b) the amastigotes thus obtained are morphological, biological and antigenically similar to intracellular amastigotes. Consequently, this experimental system may facilitate a direct, in vitro assessment of the mechanisms that enable T. cruzi metacyclic trypomastigotes to transform into amastigotes in the cells of mammalian hosts.
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Affiliation(s)
- Víctor T Contreras
- Laboratorio de Protozoolog a, Centro BioMolP, Facultad de Ciencias de la Salud, Universidad de Carabobo, Valencia, Carabobo, Venezuela.
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20
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Graefe SEB, Wiesgigl M, Gaworski I, Macdonald A, Clos J. Inhibition of HSP90 in Trypanosoma cruzi induces a stress response but no stage differentiation. EUKARYOTIC CELL 2002; 1:936-43. [PMID: 12477794 PMCID: PMC138760 DOI: 10.1128/ec.1.6.936-943.2002] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The 90-kDa heat shock proteins (HSP90) are important in the regulation of numerous intracellular processes in eukaryotic cells. In particular, HSP90 has been shown to be involved in the control of the cellular differentiation of the protozoan parasite Leishmania donovani. We investigated the role of HSP90 in the related parasite Trypanosoma cruzi by inhibiting its function using geldanamycin (GA). GA induced a dose-dependent increase in heat shock protein levels and a dose-dependent arrest of proliferation. Epimastigotes were arrested in G(1) phase of the cell cycle, but no stage differentiation occurred. Blood form trypomastigotes showed conversion towards spheromastigote-like forms when they were cultivated with GA, but differentiation into epimastigotes was permanently blocked. We conclude that, similar to leishmanial HSP90, functional HSP90 is essential for cell division in T. cruzi and serves as a feedback inhibitor in the cellular stress response. In contrast to L. donovani cells, however, T. cruzi cells treated with GA do not begin to differentiate into relevant life cycle stages.
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Affiliation(s)
- Sebastian E B Graefe
- Department of Medical Microbiology and Immunology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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21
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Leal ST, Araripe JR, Urményi TP, Cross GA, Rondinelli E. Trypanosoma cruzi: cloning and characterization of a RAB7 gene. Exp Parasitol 2000; 96:23-31. [PMID: 11038317 DOI: 10.1006/expr.2000.4549] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The small monomeric GTP-binding proteins of the RAB subfamily are key regulatory elements of the machinery that controls membrane traffic in eukaryotic cells. These proteins have been localized to many different intracellular organelles, on both endocytic and exocytic compartments, suggesting that each step of vesicular traffic can involve a specific RAB protein. The presence of conserved amino acid domains in these proteins has allowed the cloning of their genes from several organisms, including yeast, plants, humans, and parasites. In this work we describe the identification, cloning, and characterization of a RAB7 gene homologue in Trypanosoma cruzi (TcRAB7). Our data indicate that this gene is present as a single copy in the T. cruzi genome, located on a 2.25-Mb chromosomal DNA. TcRAB7 is expressed in T. cruzi epimastigotes, metacyclic trypomastigotes, and spheromastigotes. We established transformed cell lines that express two versions of an epitope-tagged TcRAB7 protein: one wild type (pTAG) and one deleted at the C-terminal cysteines (pDeltaCXC). Wild-type TcRAB7 protein (pTAG) appears to be localized exclusively in the membrane fraction, while the mutated TcRAB7 protein (pDeltaCXC) loses the ability to associate with the membrane, showing only cytosolic localization. Also, we produced the recombinant TcRAB7 protein and demonstrated that it binds GTP. The identification of exo- and endocytic machinery components in T. cruzi and their function would provide specific markers of these subcellular compartments, thereby unveiling important aspects of vesicular traffic in this parasite.
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Affiliation(s)
- S T Leal
- Instituto de Biofísica Carlos Chagas Filho, CCS, UFRJ, Rio de Janeiro, RJ, 21949-900, Brazil
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22
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Affiliation(s)
- P S Doyle
- Department of Pathology, University of California, San Francisco, San Francisco, California 94121, USA
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23
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Teixeira SM, Otsu K, Hill KL, Kirchhoff LV, Donelson JE. Expression of a marker for intracellular Trypanosoma cruzi amastigotes in extracellular spheromastigotes. Mol Biochem Parasitol 1999; 98:265-70. [PMID: 10080394 DOI: 10.1016/s0166-6851(98)00158-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- S M Teixeira
- Department of Internal Medicine, University of Iowa, 52245, USA
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24
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Nozaki T, Cross GA. Effects of 3' untranslated and intergenic regions on gene expression in Trypanosoma cruzi. Mol Biochem Parasitol 1995; 75:55-67. [PMID: 8720175 DOI: 10.1016/0166-6851(95)02512-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of 3' untranslated regions (UTR) and intergenic regions (INT), from various Trypanosoma cruzi stage-specific and constitutive genes, on the expression of the reporter firefly luciferase gene (luc), were studied using stable episomal transformation. The 3' UTR influenced luciferase expression by changing the steady-state level and/or the translation efficiency of luc mRNA. Glycoprotein 72 gene (gp72), glycoprotein 85 gene (gp85) or amastin gene (ama) 3' UTR decreased the luc mRNA level 6- to 14-fold, compared to the glyceraldehyde 1-phosphate dehydrogenase gene (gapdh) 3' UTR, in epimastigotes. Luciferase activity decreased in parallel with the luc mRNA level in transformants utilizing the gp85 or ama 3' UTR, whereas luc mRNA containing the gp72 3' UTR showed approximately 5-fold higher translation efficiency than luc mRNA containing a minimal 3' UTR. In amastigotes, the inhibitory effect of the ama 3' UTR observed in other life cycle stages was abolished and luciferase expression was stimulated 16-fold. The overall stage-specific difference mediated by the ama 3' UTR, between epimastigotes and amastigotes, was approximately 100-fold. INT, which was expected to influence polyadenylation efficiency, of gapdh, gp72, or heat shock protein 60 gene inserted after gapdh 3' UTR increased luc mRNA 2- to 8-fold, whereas gp85 INT slightly decreased luc mRNA. By separating effects attributable to the 3' UTR and INT, this study shows the effects of 3' UTR on RNA levels and translational efficiency in T. cruzi.
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Affiliation(s)
- T Nozaki
- Laboratory of Molecular Parasitology, Rockefeller University, New York, NY 10021, USA
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25
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Lima MT, Lenzi HL, Gattass CR. Negative tissue parasitism in mice injected with a noninfective clone of Trypanosoma cruzi. Parasitol Res 1995; 81:6-12. [PMID: 7724515 DOI: 10.1007/bf00932410] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Trypanosoma cruzi is a heterogeneous population of parasites as shown by differences between strains and cloned stock from the same strain. Herein we present evidence of the noninfectivity of CL-14, a clone derived from the CL strain of T. cruzi. In a previous paper we reported the absence of parasitemia and mortality in mice injected with metacyclic trypomastigotes of this clone. To investigate further this lack of infectivity we did and extensive histopathological analysis in mice at different intervals after i.p. (5 and 15 days as well as 1, 4, and 12 months) or i.v. (5 and 30 days) injection of trypomastigotes. In spite of a systematic search in all tissues and organs of the animals, no parasite or significant pathological change was detected in any of the tissue sections. These data suggest the inability of this clone to mediate infection and/or cause pathological alterations in vivo.
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Affiliation(s)
- M T Lima
- Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brasil
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26
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Batista JA, Teixeira SM, Donelson JE, Kirchhoff LV, de Sá CM. Characterization of a Trypanosoma cruzi poly(A)-binding protein and its genes. Mol Biochem Parasitol 1994; 67:301-12. [PMID: 7870134 DOI: 10.1016/0166-6851(94)00133-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have characterized the biochemical properties of a 66-kDa poly(A)-binding protein (PABP1) in the protozoan Trypanosoma cruzi and isolated two classes of cDNAs encoding the protein. In concordance, Southern blots showed the presence of 2 gene copies. The two cDNA classes differ in the length of adenosine-rich segments in the 5' untranslated region and in point changes scattered throughout the sequence, but their 1650-bp open reading frames encode identical proteins. A single mRNA of 5.5 kb was detected, indicating that the noncoding regions are unusually long. Both the mRNA and the protein are constitutively expressed in all stages of T. cruzi life cycle. The biochemical properties and sequence comparisons show that the T. cruzi PABP1 is similar to the PABP1 of other eukaryotic organisms. These results indicate that PABP1 has been conserved throughout eukaryotic evolution.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Protozoan/immunology
- Antigens, Protozoan/analysis
- Base Sequence
- Chromatography, Affinity
- DNA, Protozoan/analysis
- Gene Expression
- Genes, Protozoan
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Poly(A)-Binding Proteins
- RNA, Messenger/biosynthesis
- RNA-Binding Proteins/biosynthesis
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/isolation & purification
- Receptors, Cytoplasmic and Nuclear/biosynthesis
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/isolation & purification
- Sequence Homology, Amino Acid
- Trypanosoma cruzi/genetics
- Trypanosoma cruzi/metabolism
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Affiliation(s)
- J A Batista
- Departamento de Biologia Celular, Universidade de Brasilia, Brazil
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27
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Oliveira MM, Rocha ED, Rondinelli E, Arnholdt AV, Scharfstein J. Signal transduction in Trypanosoma cruzi: opposite effects of adenylcyclase and phospholipase C systems in growth control. Mol Cell Biochem 1993; 124:91-9. [PMID: 8232289 DOI: 10.1007/bf00929200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Fetal calf serum (FCS), which is mitogenic for the pathogenic protozoa T. cruzi, inhibits cAMP production in basal and forskolin-stimulated epimastigotes. It also activates phosphoinositides hydrolysis yielding diacylglycerol and inositol phosphates (Ins-P). Ins-P production is enhanced by AlF4-, GTP or beta-gamma-methylene-GTP, thus implying G proteins mediation in the phenomenon. An enzyme with phospholipase C activity which may be involved in the phospholipid metabolism was partially characterized.
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Affiliation(s)
- M M Oliveira
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
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28
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Lima MT, Jansen AM, Rondinelli E, Gattass CR. Trypanosoma cruzi: properties of a clone isolated from CL strain. Parasitol Res 1991; 77:77-81. [PMID: 1899726 DOI: 10.1007/bf00934390] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BALB/c mice injected i.p. with 2 x 10(6) metacyclic forms of CL-14, a clone isolated from the CL strain of Trypanosoma cruzi, did not show parasitemia as evaluated by direct blood microscopy examination, hemoculture and xenodiagnosis. Moreover, new-born mice (1-2 days old) injected with culture- or insect-derived CL-14 trypomastigotes also displayed negative parasitemia. No mortality was observed in either group of animals. However, despite this apparent non-infectivity, mice injected with clone 14 developed high resistance against a lethal challenge with virulent trypomastigotes. All challenged mice survived and the parasitemia was negative. These results indicate that clone 14 is a very good antigen for the study of acquired immunity in T. cruzi infection and, therefore, a potential candidate for the development of a vaccine against this parasite.
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Affiliation(s)
- M T Lima
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Brazil
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29
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de Carvalho EF, de Castro FT, Rondinelli E, Soares CM, Carvalho JF. HSP 70 gene expression in Trypanosoma cruzi is regulated at different levels. J Cell Physiol 1990; 143:439-44. [PMID: 2193034 DOI: 10.1002/jcp.1041430306] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The level of HSP 70 mRNA is altered in Trypanosoma cruzi cells incubated at supra-optimal temperatures: the total amount of this RNA per cell is increased at 37 degrees C, and slightly decreased at 40 degrees C relative to its level at 29 degrees C. However, its amount is greater in the polysomes at either temperature. The relative increase of this RNA is larger in the polysomes fraction than it is in the total RNA. In addition the level of HSP 70 protein in heat-shocked cells is greater than would be expected from the recruitment of HSP 70 mRNA in the polysomal fraction. Taken together the data are interpreted as indicating that at 37 degrees C and 40 degrees C the HSP 70 gene regulation in T. cruzi involves both the selective accumulation of the HSP 70 mRNA in the polysomes and its preferential translation. At 37 degrees C, in addition, an increase in the total amount of this template is observed in the cells.
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30
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Eperon S, McMahon-Pratt D. Extracellular amastigote-like forms of Leishmania panamensis and L. braziliensis. II. Stage- and species-specific monoclonal antibodies. THE JOURNAL OF PROTOZOOLOGY 1989; 36:510-8. [PMID: 2478699 DOI: 10.1111/j.1550-7408.1989.tb01087.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Immunochemical evidence, employing monoclonal antibodies, shows that the forms of L. braziliensis complex axenically grown at elevated temperature are amastigote-like. The monoclonal antibodies were raised against membrane proteins of amastigote-like forms, strains of both L. panamensis (WR442) and L. braziliensis (M5052), which were grown axenically. The specificities of these antibodies were examined by indirect radioimmune binding assay, indirect immunofluorescent assay and Western blot analyses. Two distinct groups of monoclonal antibodies were obtained and their specificities were consistent with the 3 methods used. Four antibodies are specific for the species L. panamensis and react with both developmental stages. Six antibodies specifically recognize amastigote-like forms grown at elevated temperature and intracellular amastigotes of both L. panamensis (WR442) and L. braziliensis (M5052). These monoclonal antibodies do not bind to promastigotes of these species, nor to promastigotes of any other species of Leishmania. Therefore these antibodies are specific for amastigotes of L. panamensis (WR442) and L. braziliensis (M5052), and suggest that immunochemically both amastigote forms (culture and macrophage) are developmentally very close, if not identical. The molecules associated with the amastigote-specific antigenic determinants consist of a Mr 12-kD component and a heterogeneous component (Mr from 50 kD to greater than 200 kD); these molecules appear to be identical for both amastigote-like forms and amastigotes isolated from macrophages.
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Affiliation(s)
- S Eperon
- Yale University School of Medicine, Department of Epidemiology and Public Health, New Haven, Connecticut 06510
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31
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Eperon S, McMahon-Pratt D. Extracellular cultivation and morphological characterization of amastigote-like forms of Leishmania panamensis and L. braziliensis. THE JOURNAL OF PROTOZOOLOGY 1989; 36:502-10. [PMID: 2810145 DOI: 10.1111/j.1550-7408.1989.tb01086.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Two strains of the Leishmania braziliensis complex have been adapted to grow extracellularly at elevated temperature as amastigote-like forms in a cell-free medium. These parasites can be serially cultivated and maintained at 32 degrees C for L. panamensis (WR442; L. braziliensis panamensis) and at 28 degrees C for L. braziliensis (M5052; L. braziliensis braziliensis). Several observations are presented that the forms adapted at elevated temperature are amastigote-like. Morphologically, the amastigote-like organisms appear rounded to ovoid and are immotile and smaller than promastigotes; the flagellum of the amastigote-like forms does not extend beyond the flagellar pocket. In comparison, the promastigotes are very elongated, with a nucleus at mid-cell length and a very long flagellum. By electron microscopy, the short flagellum of the amastigote-like form is within a distended flagellar pocket; the 9 + 2 axonemal configuration is present but the paraxial rod is not observed. By contrast, the flagellum of the promastigote has a paraxial rod which extends from the axosome level. In addition, these amastigote-like forms of Leishmania are able to infect, to survive and to divide within the macrophage cell line J774.
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Affiliation(s)
- S Eperon
- Yale University School of Medicine, Department of Epidemiology and Public Health, New Haven, Connecticut 06510
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32
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Soares CM, de Carvalho EF, Urményi TP, Carvalho JF, de Castro FT, Rondinelli E. Alpha- and beta-tubulin mRNAs of Trypanosoma cruzi originate from a single multicistronic transcript. FEBS Lett 1989; 250:497-502. [PMID: 2666161 DOI: 10.1016/0014-5793(89)80784-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The cluster of alternated alpha- and beta-tubulin genes in the genome of Trypanosoma cruzi was shown to be transcribed into a single RNA molecule which upon processing gives rise to the mature alpha- and beta-tubulin mRNAs. This conclusion was based on: (i) nuclear RNA species with the same molecular mass hybridize to both alpha- and beta-tubulin cDNA probes; (ii) S1 nuclease assay of the clustered tubulin genes has shown protected DNA fragments of the same size and of greater molecular mass than that corresponding to the mRNAs, hybridizable to both alpha- and beta-tubulin cDNA probes; (iii) beta-tubulin hybrid selected RNA is still able to hybridize to alpha-tubulin probe.
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Affiliation(s)
- C M Soares
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
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