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Zuma AA, Dos Santos Barrias E, de Souza W. Basic Biology of Trypanosoma cruzi. Curr Pharm Des 2021; 27:1671-1732. [PMID: 33272165 DOI: 10.2174/1381612826999201203213527] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 10/01/2020] [Accepted: 10/08/2020] [Indexed: 11/22/2022]
Abstract
The present review addresses basic aspects of the biology of the pathogenic protozoa Trypanosoma cruzi and some comparative information of Trypanosoma brucei. Like eukaryotic cells, their cellular organization is similar to that of mammalian hosts. However, these parasites present structural particularities. That is why the following topics are emphasized in this paper: developmental stages of the life cycle in the vertebrate and invertebrate hosts; the cytoskeleton of the protozoa, especially the sub-pellicular microtubules; the flagellum and its attachment to the protozoan body through specialized junctions; the kinetoplast-mitochondrion complex, including its structural organization and DNA replication; glycosome and its role in the metabolism of the cell; acidocalcisome, describing its morphology, biochemistry, and functional role; cytostome and the endocytic pathway; the organization of the endoplasmic reticulum and Golgi complex; the nucleus, describing its structural organization during interphase and division; and the process of interaction of the parasite with host cells. The unique characteristics of these structures also make them interesting chemotherapeutic targets. Therefore, further understanding of cell biology aspects contributes to the development of drugs for chemotherapy.
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Affiliation(s)
- Aline A Zuma
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho - Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Emile Dos Santos Barrias
- Laboratorio de Metrologia Aplicada a Ciencias da Vida, Diretoria de Metrologia Aplicada a Ciencias da Vida - Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho - Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Castro Machado F, Bittencourt-Cunha P, Malvezzi AM, Arico M, Radio S, Smircich P, Zoltner M, Field MC, Schenkman S. EIF2α phosphorylation is regulated in intracellular amastigotes for the generation of infective Trypanosoma cruzi trypomastigote forms. Cell Microbiol 2020; 22:e13243. [PMID: 32597009 DOI: 10.1111/cmi.13243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/13/2022]
Abstract
Trypanosomatids regulate gene expression mainly at the post-transcriptional level through processing, exporting and stabilising mRNA and control of translation. In most eukaryotes, protein synthesis is regulated by phosphorylation of eukaryotic initiation factor 2 (eIF2) at serine 51. Phosphorylation halts overall translation by decreasing availability of initiator tRNAmet to form translating ribosomes. In trypanosomatids, the N-terminus of eIF2α is extended with threonine 169 the homologous phosphorylated residue. Here, we evaluated whether eIF2α phosphorylation varies during the Trypanosoma cruzi life cycle, the etiological agent of Chagas' disease. Total levels of eIF2α are diminished in infective and non-replicative trypomastigotes compared with proliferative forms from the intestine of the insect vector or amastigotes from mammalian cells, consistent with decreased protein synthesis reported in infective forms. eIF2α phosphorylation increases in proliferative intracellular forms prior to differentiation into trypomastigotes. Parasites overexpressing eIF2αT169A or with an endogenous CRISPR/Cas9-generated eIF2αT169A mutation were created and analysis revealed alterations to the proteome, largely unrelated to the presence of μORF in epimastigotes. eIF2αT169A mutant parasites produced fewer trypomastigotes with lower infectivity than wild type, with increased levels of sialylated mucins and oligomannose glycoproteins, and decreased galactofuranose epitopes and the surface protease GP63 on the cell surface. We conclude that eIF2α expression and phosphorylation levels affect proteins relevant for intracellular progression of T. cruzi.
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Affiliation(s)
- Fabricio Castro Machado
- Departmento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Paula Bittencourt-Cunha
- Departmento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Amaranta Muniz Malvezzi
- Departmento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Mirella Arico
- Departmento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Santiago Radio
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay.,Laboratory of Molecular Interactions, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Pablo Smircich
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay.,Laboratory of Molecular Interactions, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Martin Zoltner
- Drug Discovery and Evaluation, Centre for Research of Pathogenicity and Virulence of Parasites, Charles University, Prague, Czech Republic
| | - Mark C Field
- Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, UK.,Institute of Parasitology, Czech Academy of Sciences, Prague, Czech Republic
| | - Sergio Schenkman
- Departmento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Rios L, Campos EE, Menon R, Zago MP, Garg NJ. Epidemiology and pathogenesis of maternal-fetal transmission of Trypanosoma cruzi and a case for vaccine development against congenital Chagas disease. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165591. [PMID: 31678160 PMCID: PMC6954953 DOI: 10.1016/j.bbadis.2019.165591] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/12/2019] [Accepted: 09/25/2019] [Indexed: 12/11/2022]
Abstract
Trypanos o ma cruzi (T. cruzi or Tc) is the causative agent of Chagas disease (CD). It is common for patients to suffer from non-specific symptoms or be clinically asymptomatic with acute and chronic conditions acquired through various routes of transmission. The expecting women and their fetuses are vulnerable to congenital transmission of Tc. Pregnant women face formidable health challenges because the frontline antiparasitic drugs, benznidazole and nifurtimox, are contraindicated during pregnancy. However, it is worthwhile to highlight that newborns can be cured if they are diagnosed and given treatment in a timely manner. In this review, we discuss the pathogenesis of maternal-fetal transmission of Tc and provide a justification for the investment in the development of vaccines against congenital CD.
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Affiliation(s)
- Lizette Rios
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - E Emanuel Campos
- Instituto de Patología Experimental, Universidad Nacional de Salta - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina
| | - Ramkumar Menon
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX, USA
| | - M Paola Zago
- Instituto de Patología Experimental, Universidad Nacional de Salta - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina.
| | - Nisha J Garg
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
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Inhibition of Host Cell Lysosome Spreading by Trypanosoma cruzi Metacyclic Stage-Specific Surface Molecule gp90 Downregulates Parasite Invasion. Infect Immun 2017; 85:IAI.00302-17. [PMID: 28607099 PMCID: PMC5563561 DOI: 10.1128/iai.00302-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/01/2017] [Indexed: 11/20/2022] Open
Abstract
Successful infection by Trypanosoma cruzi, the agent of Chagas' disease, is critically dependent on host cell invasion by metacyclic trypomastigote (MT) forms. Two main metacyclic stage-specific surface molecules, gp82 and gp90, play determinant roles in target cell invasion in vitro and in oral T. cruzi infection in mice. The structure and properties of gp82, which is highly conserved among T. cruzi strains, are well known. Information on gp90 is still rather sparse. Here, we attempted to fill that gap. gp90, purified from poorly invasive G strain MT and expressing gp90 at high levels, inhibited HeLa cell lysosome spreading and the gp82-mediated internalization of a highly invasive CL strain MT expressing low levels of a diverse gp90 molecule. A recombinant protein containing the conserved C-terminal domain of gp90 exhibited the same properties as the native G strain gp90: it counteracted the host cell lysosome spreading induced by recombinant gp82 and exhibited an inhibitory effect on HeLa cell invasion by CL strain MT. Assays to identify the gp90 sequence associated with the property of downregulating MT invasion, using synthetic peptides spanning the gp90 C-terminal domain, revealed the sequence GVLYTADKEW. These data, plus the findings that lysosome spreading was induced upon HeLa cell interaction with CL strain MT, but not with G strain MT, and that in mixed infection CL strain MT internalization was inhibited by G strain MT, suggest that the inhibition of target cell lysosome spreading is the mechanism by which the gp90 molecule exerts its downregulatory role.
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Clemente TM, Cortez C, Novaes ADS, Yoshida N. Surface Molecules Released by Trypanosoma cruzi Metacyclic Forms Downregulate Host Cell Invasion. PLoS Negl Trop Dis 2016; 10:e0004883. [PMID: 27483135 PMCID: PMC4970754 DOI: 10.1371/journal.pntd.0004883] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/07/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The question whether metacylic trypomastigote (MT) forms of different T. cruzi strains differentially release surface molecules, and how they affect host cell invasion, remains to be fully clarified. We addressed that question using T. cruzi strains that differ widely in the ability to invade cells. METHODOLOGY/PRINCIPAL FINDINGS Metacyclic forms were incubated at 37°C for 1 h in complete D10 medium or in nutrient-deprived PBS containing Ca2+ and Mg2+ (PBS++). The conditioned medium (CM), collected after parasite centrifugation, was used for cell invasion assays and Western blot analysis, using monoclonal antibodies directed to gp82 and gp90, the MT surface molecules that promote and negatively regulate invasion, respectively. CM of poorly invasive G strain (G-CM) contained high amounts of gp90 and gp82, either in vesicles or as soluble molecules. CM of highly invasive CL strain (CL-CM) contained gp90 and gp82 at very low levels. HeLa cells were incubated for 1 h with CL strain MT in D10, in absence or in the presence of G-CM or CL-CM. Parasite invasion was significantly inhibited by G-CM, but not by CL-CM. As G strain MT invasion rate in D10 is very low, assays with this strain were performed in PBS++, which induces invasion-promoting lysosome-spreading. G-CM, but not CL-CM, significantly inhibited G strain internalization, effect that was counteracted by preincubating G-CM with an anti-gp90 monoclonal antibody or anti-gp82 polyclonal antibody that do not recognize live MT. G strain CM generated in PBS++ contained much lower amounts of gp90 and gp82 as compared to CM produced in D10, and exhibited lower inhibitory effect on host cell invasion. CONCLUSION/SIGNIFICANCE Our data suggest that the surface molecules spontaneously released by MT impair parasite-host cell interaction, gp82 presumably competing with the molecule expressed on MT surface for the host cell receptor, and gp90 further contributing to down modulate invasion.
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Affiliation(s)
- Tatiana Mordente Clemente
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brasil
| | - Cristian Cortez
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brasil
| | | | - Nobuko Yoshida
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brasil
- * E-mail:
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Bayer-Santos E, Cunha-e-Silva NL, Yoshida N, Franco da Silveira J. Expression and cellular trafficking of GP82 and GP90 glycoproteins during Trypanosoma cruzi metacyclogenesis. Parasit Vectors 2013; 6:127. [PMID: 23634710 PMCID: PMC3652755 DOI: 10.1186/1756-3305-6-127] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/23/2013] [Indexed: 11/25/2022] Open
Abstract
Background The transformation of noninfective epimastigotes into infective metacyclic trypomastigotes (metacyclogenesis) is a fundamental step in the life cycle of Trypanosoma cruzi, comprising several morphological and biochemical changes. GP82 and GP90 are glycoproteins expressed at the surface of metacyclic trypomastigote, with opposite roles in mammalian cell invasion. GP82 is an adhesin that promotes cell invasion, while GP90 acts as a negative regulator of parasite internalization. Our understanding of the synthesis and intracellular trafficking of GP82 and GP90 during metacyclogenesis is still limited. Therefore, we decided to determine whether GP82 and GP90 are expressed only in fully differentiated metacyclic forms or they start to be expressed in intermediate forms undergoing differentiation. Methods Parasite populations enriched in intermediate forms undergoing differentiation were analyzed by quantitative real-time PCR, Western blot, flow cytometry and immunofluorescence to assess GP82 and GP90 expression. Results We found that GP82 and GP90 mRNAs and proteins are expressed in intermediate forms and reach higher levels in fully differentiated metacyclic forms. Surprisingly, GP82 and GP90 presented distinct cellular localizations in intermediate forms compared to metacyclic trypomastigotes. In intermediate forms, GP82 is localized in organelles at the posterior region and colocalizes with cruzipain, while GP90 is localized at the flagellar pocket region. Conclusions This study discloses new aspects of protein expression and trafficking during T. cruzi differentiation by showing that the machinery involved in GP82 and GP90 gene expression starts to operate early in the differentiation process and that different secretion pathways are responsible for delivering these glycoproteins toward the cell surface.
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Affiliation(s)
- Ethel Bayer-Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
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Cortez C, Martins RM, Alves RM, Silva RC, Bilches LC, Macedo S, Atayde VD, Kawashita SY, Briones MRS, Yoshida N. Differential infectivity by the oral route of Trypanosoma cruzi lineages derived from Y strain. PLoS Negl Trop Dis 2012; 6:e1804. [PMID: 23056658 PMCID: PMC3464286 DOI: 10.1371/journal.pntd.0001804] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 07/18/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Diversity of T. cruzi strains is a central problem in Chagas disease research because of its correlation with the wide range of clinical manifestations and the biogeographical parasite distribution. The role played by parasite microdiversity in Chagas disease epidemiology is still debatable. Also awaits clarification whether such diversity is associated with the outcome of oral T. cruzi infection, responsible for frequent outbreaks of acute Chagas disease. METHODS AND FINDINGS We addressed the impact of microdiversity in oral T. cruzi infection, by comparative analysis of two strains, Y30 and Y82, both derived from Y strain, a widely used experimental model. Network genealogies of four nuclear genes (SSU rDNA, actin, DHFR-TS, EF1α) revealed that Y30 is closely related to Discrete Typing Unit TcII while Y82 is more closely related to TcVI, a group containing hybrid strains. Nevertheless, excepting one A-G transition at position 1463, Y30 and Y82 SSU rDNAs were identical. Y82 strain, expressing the surface molecule gp82, infected mice orally more efficiently than Y30, which expresses a related gp30 molecule. Both molecules are involved in lysosome exocytosis-dependent host cell invasion, but exhibit differential gastric mucin-binding capacity, a property critical for parasite migration toward the gastric mucosal epithelium. Upon oral infection of mice, the number of Y30 and Y82 parasites in gastric epithelial cells differed widely. CONCLUSIONS We conclude that metacyclic forms of gp82-expressing Y82 strain, closely related to TcVI, are better adapted than Y30 strain (TcII) to traverse the stomach mucous layer and establish oral route infection. The efficiency to infect target cell is the same because gp82 and gp30 strains have similar invasion-promoting properties. Unknown is whether differences in Y30 and Y82 are natural parasite adaptations or a product of lab-induced evolution by differential selection along the 60 years elapsed since the Y strain isolation.
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Affiliation(s)
- Cristian Cortez
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Rafael M. Martins
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
- Unité de Biologie des Interactions Hôte-Parasite, Institut Pasteur, Paris, France
| | - Renan M. Alves
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Richard C. Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Luciana C. Bilches
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Silene Macedo
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Vanessa D. Atayde
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
- McGill University Health Centre, Montréal, Quebec, Canada
| | - Silvia Y. Kawashita
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
- Superintendência da Polícia Técnico-Científica, São Paulo, Brazil
| | - Marcelo R. S. Briones
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Nobuko Yoshida
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
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Martins RM, Alves RM, Macedo S, Yoshida N. Starvation and rapamycin differentially regulate host cell lysosome exocytosis and invasion by Trypanosoma cruzi metacyclic forms. Cell Microbiol 2011; 13:943-54. [PMID: 21501360 DOI: 10.1111/j.1462-5822.2011.01590.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular mechanisms of host cell invasion by T. cruzi metacyclic trypomastigotes (MT), the developmental forms that initiate infection in the mammalian host, are only partially understood. Here we aimed at further identifying the target cell components involved in signalling cascades leading to MT internalization, and demonstrate for the first time the participation of mammalian target of rapamycin (mTOR). Treatment of human epithelial HeLa cells with mTOR inhibitor rapamycin reduced lysosomal exocytosis and MT invasion. Downregulation of phosphatidylinositol 3-kinase and protein kinase C also impaired exocytosis and MT internalization. The recombinant protein based on gp82, the MT surface molecule that mediates cell adhesion/invasion, induced exocytosis in HeLa cells. Such an effect has not previously been attributed to any T. cruzi surface molecule. Rapamycin treatment diminished gp82 binding as well. Cell invasion assays under conditions that promoted lysosome exocytosis, such as 1 h incubation in starvation medium PBS(++) , increased MT invasion, whereas pre-starvation of cells for 1-2 h had an opposite effect. In contrast to MT, invasion of tissue culture trypomastigotes (TCT) increased upon host cell pre-starvation or treatment with rapamycin, a novel finding that discloses quite distinctive features of the two infective forms in a key process for infection.
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Affiliation(s)
- Rafael Miyazawa Martins
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Rua Botucatu 862, São Paulo, Brazil
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Goldenberg S, Ávila AR. Aspects of Trypanosoma cruzi stage differentiation. ADVANCES IN PARASITOLOGY 2011; 75:285-305. [PMID: 21820561 DOI: 10.1016/b978-0-12-385863-4.00013-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Trypanosoma cruzi alternates between different morphological and functional types during its life cycle. Since the discovery of this parasite at the beginning of the twentieth century, efforts have been made to determine the basis of its pathogenesis in the course of Chagas disease and its biochemical constituents. There has also been work to develop tools and strategies for prophylaxis of the important disease caused by these parasites which affects millions of people in Latin America. The identification of axenic conditions allowing T. cruzi growth and differentiation has led to the identification and characterization of stage-specific antigens as well as a better characterization of the biological properties and biochemical particularities of each individual developmental stage. The recent availability of genomic data should pave the way to new progress in our knowledge of the biology and pathogenesis of T. cruzi. This review addresses the differentiation and major stage-specific antigens of T. cruzi and attempts to describe the complexity of the parasite and of the disease it causes.
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Yoshida N. Molecular mechanisms of Trypanosoma cruzi infection by oral route. Mem Inst Oswaldo Cruz 2010; 104 Suppl 1:101-7. [PMID: 19753464 DOI: 10.1590/s0074-02762009000900015] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 03/08/2009] [Indexed: 11/22/2022] Open
Abstract
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.
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Affiliation(s)
- Nobuko Yoshida
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
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Alves MJM, Colli W. Role of the gp85/trans-sialidase superfamily of glycoproteins in the interaction of Trypanosoma cruzi with host structures. Subcell Biochem 2008; 47:58-69. [PMID: 18512341 DOI: 10.1007/978-0-387-78267-6_4] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Invasion of mammalian cells by T. cruzi trypomastigotes is a multi-step and complex process involving several adhesion molecules, signaling events and proteolytic activities. From the blood to the cell target in different tissues the parasite has to interact with different cells and the extracellular matrix (ECM). The review focus on the role of the gp85/ trans-sialidase superfamily members in the interaction of the parasite with the host cell, particularly with ECM components, with emphasis on the significant variability among the ligands and receptors involved. Use of the SELEX technique to evolve nuclease-resistant RNA aptamers for receptor identification is briefly discussed.
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Affiliation(s)
- Maria Júlia M Alves
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, Brazil.
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Cortez M, Silva MR, Neira I, Ferreira D, Sasso GRS, Luquetti AO, Rassi A, Yoshida N. Trypanosoma cruzi surface molecule gp90 downregulates invasion of gastric mucosal epithelium in orally infected mice. Microbes Infect 2005; 8:36-44. [PMID: 16153873 DOI: 10.1016/j.micinf.2005.05.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Revised: 05/06/2005] [Accepted: 05/23/2005] [Indexed: 11/24/2022]
Abstract
Experiments were performed to elucidate why Trypanosoma cruzi isolates 573 and 587 differ widely in their efficiency to infect gastric mucosal epithelium when administered orally to mice. These isolates have the same surface profile and a similar capacity to enter host cells in vitro. Metacyclic forms of isolates 573 and 587 and the control CL isolate expressed similar levels of gp82, which is a cell invasion-promoting molecule. Expression of gp90, a molecule that downregulates cell invasion, was lower in the CL isolate. Consistent with this profile, approximately threefold fewer parasites of isolates 573 and 587 entered epithelial HeLa cells, as compared to the CL isolate. No difference in the rate of intracellular parasite replication was observed between isolates. When given orally to mice, metacyclic forms of isolate 573, like the CL isolate, produced high parasitemia (>10(6) parasites per ml at the peak), killing approximately 40% of animals, whereas infection with isolate 587 resulted in low parasitemia (<10(5) parasites per ml), with zero mortality. On the fourth day post-inoculation, tissue sections of the mouse stomach stained with hematoxylin and eosin showed a four to sixfold higher number of epithelial cells infected with isolate 573 or CL than with isolate 587. The rate of intracellular parasite development was similar in all isolates. Mimicking in vivo infection, parasites were treated with pepsin at acidic pH and then assayed for their ability to enter HeLa cells or explanted gastric epithelial cells. Pepsin extensively digested gp90 from isolate 573 and significantly increased invasion of both cells, but had minor effect on gp90 or infectivity of isolates 587 and CL. The profile of g82 digestion was similar in isolates 573 and 587, with partial degradation to a approximately 70 kDa fragment, which preserved the target cell binding domain as well as the region involved in gastric mucin adhesion. Gp82 from CL isolate was resistant to pepsin. Assays with parasites recovered from the mouse stomach 2 h after oral infection showed an extensive digestion of gp90 and increased infectivity of isolate 573, but not of isolate 587 or CL. Our data indicate that T. cruzi infection in vitro does not always correlate with in vivo infection because host factors may act on parasites, modulating their infectivity, as is the case of pepsin digestion of isolate 573 gp90.
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Affiliation(s)
- Mauro Cortez
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, R. Botucatu, 862- 6 andar, 04023-062 São Paulo, SP, Brazil
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do Carmo MS, dos Santos MRM, Cano MI, Araya JE, Yoshida N, da Silveira JF. Expression and genome-wide distribution of the gene family encoding a 90 kDa surface glycoprotein of metacyclic trypomastigotes of Trypanosoma cruzi. Mol Biochem Parasitol 2002; 125:201-6. [PMID: 12467988 DOI: 10.1016/s0166-6851(02)00212-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Mirian Silva do Carmo
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, UNIFESP, Rua Botucatu 862, CEP 04023-062 Sao Paulo, Brazil
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Carmo MS, Santos MR, Cummings LM, Araya JE, Yamauchi LM, Yoshida N, Mortara RA, Franco da Silveira J. Isolation and characterisation of genomic and cDNA clones coding for a serine-, alanine-, and proline-rich protein of Trypanosoma cruzi. Int J Parasitol 2001; 31:259-64. [PMID: 11226452 DOI: 10.1016/s0020-7519(00)00170-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We report here the isolation and characterisation of genomic and cDNA clones encoding a Serine-, Alanine-, and Proline-rich protein (SAP) of Trypanosoma cruzi metacyclic trypomastigotes. The deduced peptides translated from these clones were characterised by a high content of residues of alanine, proline, serine, glycine, valine, and threonine distributed in several repeats: P(2-4), S(2-3), A(2-3), AS, SA, PA, AP, SP, PS, and TP. The repeats are partially homologous to the serine-, alanine-, and proline-containing motifs of Leishmania major and Leishmania mexicana proteophosphoglycans. Genes coding for SAP are part of a polymorphic family whose members are linked to members of gp85/sialidase and mucin-like gene families. This is consistent with the hypothesis that this genetic organisation could be a means by which T. cruzi co-ordinates the expression of major surface proteins.
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Affiliation(s)
- M S Carmo
- Escola Paulista de Medicina, UNIFESP, Departamento de Microbiologia, Imunologia e Parasitologia, R. Botucatu, 862, CEP 04023-062, S. Paulo, Brazil
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15
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Málaga S, Yoshida N. Targeted reduction in expression of Trypanosoma cruzi surface glycoprotein gp90 increases parasite infectivity. Infect Immun 2001; 69:353-9. [PMID: 11119524 PMCID: PMC97890 DOI: 10.1128/iai.69.1.353-359.2001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A previous study had shown that the expression of gp90, a stage-specific surface glycoprotein of Trypanosoma cruzi metacyclic trypomastigotes, is inversely correlated with the parasite's ability to invade mammalian cells. By using antisense oligonucleotides complementary to a region of the gp90 gene implicated in host cell adhesion, we investigated whether the selective inhibition of gp90 synthesis affected the capacity of metacyclic forms to enter target cells. Parasites were incubated for 24 h with 20 microM PS1, a phosphorothioate oligonucleotide based on a sequence of the gp90 coding strand; PS2, the antisense counterpart of PS1; or PO2, the unmodified version of PS2 containing phosphodiester linkages, and the expression of surface molecules was analyzed by flow cytometry and immunoblotting using specific monoclonal antibodies. PS2 but not PS1 or PO2 inhibited the expression of gp90. Inhibition by PS2 was dose dependent. Northern blot analysis revealed that steady-state gp90 mRNA levels were diminished in PS2-treated parasites compared to untreated controls. Treatment with PS2 did not affect the expression of other metacyclic stage surface glycoproteins involved in parasite-host cell interaction, such as gp82 and the mucin-like gp35/50. Expression of gp90 was also inhibited by other phosphorothioate oligonucleotides targeted to the gp90 gene (PS4, PS5, PS6, and PS7) but not by PS3, with the same base composition as PS2 but a mismatched sequence. Parasites treated with PS2, PS4, or PS5 entered HeLa cells in significantly higher numbers than untreated controls, whereas the invasive capacity of PS1- and PS3-treated parasites was unchanged, confirming the inverse association between infectivity and gp90 expression.
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Affiliation(s)
- S Málaga
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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16
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Colli W, Alves MJ. Relevant glycoconjugates on the surface of Trypanosoma cruzi. Mem Inst Oswaldo Cruz 2000; 94 Suppl 1:37-49. [PMID: 10677690 DOI: 10.1590/s0074-02761999000700004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- W Colli
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil.
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17
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Carmo MS, Araya JE, Ramirez MI, Boscardin S, Cano MI, Baida RP, Ruiz RC, Santos MR, Chiurillo MA, Ramirez JL, Yoshida N, Silveira JF. Organization and expression of a multigene family encoding the surface glycoproteins of Trypanosoma cruzi metacyclic trypomastigotes involved in the cell invasion. Mem Inst Oswaldo Cruz 2000; 94 Suppl 1:169-71. [PMID: 10677708 DOI: 10.1590/s0074-02761999000700022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- M S Carmo
- Departamento de Micro, Imuno e Parasitologia, Escola Paulista de Medicina, Unifesp, São Paulo, Brasil
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18
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Santos MR, Lorenzi H, Porcile P, Carmo MS, Schijman A, Brandão A, Araya JE, Gomes HB, Chiurillo MA, Ramirez JL, Degrave WM, Levin MJ, da Silveira JF. Physical mapping of a 670-kb region of chromosomes XVI and XVII from the human protozoan parasite Trypanosoma cruzi encompassing the genes for two immunodominant antigens. Genome Res 1999; 9:1268-76. [PMID: 10613849 PMCID: PMC311010 DOI: 10.1101/gr.9.12.1268] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
As part of the Trypanosoma cruzi Genome Initiative, we have mapped a large portion of the chromosomal bands XVI (2.3 Mb) and XVII (2.6 Mb) containing the highly repetitive and immunodominant antigenic gene families h49 and jl8. Restriction mapping of the isolated chromosomal bands and hybridization with chromosome specific gene probes showed that genes h49 and jl8 are located in a pair of size-polymorphic homologous chromosomes. To construct the integrated map of the chromosomes harboring the h49 and jl8 loci, we used YAC, cosmid, and lambda phage overlapping clones, and long range restriction analysis using a variety of probes (i.e., known gene sequences, ESTs, polymorphic repetitive sequences, anonymous sequences, STSs generated from the YAC ends). The total length covered by the YAC contig was approximately 670 kb, and its map agreed and was complementary to the one obtained by long-range restriction fragment analysis. Average genetic marker spacing in a 105 kb region around h49 and jl8 genes was estimated to be 6.2 kb/marker. We have detected some polymorphism in the H49/JL8 antigens-encoding chromosomes, affecting also the coding regions. The physical map of this region, together with the isolation of specific chromosome markers, will contribute in the global effort to sequence the nuclear genome of this parasite.
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Affiliation(s)
- M R Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, UNIFESP, Rua Botucatu 862, CEP 04023-062, S. Paulo, Brasil
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19
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Ruiz RC, Favoreto S, Dorta ML, Oshiro ME, Ferreira AT, Manque PM, Yoshida N. Infectivity of Trypanosoma cruzi strains is associated with differential expression of surface glycoproteins with differential Ca2+ signalling activity. Biochem J 1998; 330 ( Pt 1):505-11. [PMID: 9461549 PMCID: PMC1219166 DOI: 10.1042/bj3300505] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mammalian cell invasion assays, using metacyclic trypomastigotes of Trypanosoma cruzi G and CL strains, showed that the CL strain enters target cells in several-fold higher numbers as compared with the G strain. Analysis of expression of surface glycoproteins in metacyclic forms of the two strains by iodination, immunoprecipitation and FACS, revealed that gp90, undetectable in the CL strain, is one of the major surface molecules in the G strain, that expression of gp82 is comparable in both strains and that gp35/50 is expressed at lower levels in the CL strain. Purified gp90 and gp35/50 bound more efficiently than gp82 to cultured HeLa cells. However, the intensity of the Ca2+ response triggered in HeLa cells by gp82 was significantly higher than that induced by gp35/50 or gp90. Most of the Ca2+ signalling activity of the metacyclic extract towards HeLa cells was due to gp82 and was inhibitable by gp82-specific monoclonal antibody 3F6. Ca2+ mobilization was also triggered in metacyclic trypomastigotes by host-cell components; it was mainly gp82-mediated and more intense in the CL than in the G strain. We propose that expression of gp90 and gp35/50 at high levels impairs binding of metacyclic forms to host cells through productive gp82-mediated interaction, which leads to the target-cell and parasite Ca2+ mobilization required for invasion. Analysis of metacyclic forms of eight additional T. cruzi strains corroborated the inverse correlation between infectivity and expression of gp90 and gp35/50.
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Affiliation(s)
- R C Ruiz
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, R. Botucatu, 862-6 andar, 04023-062, S-ao Paulo, S.P., Brazil
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20
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Santos MR, Cano MI, Schijman A, Lorenzi H, Vázquez M, Levin MJ, Ramirez JL, Brandão A, Degrave WM, da Silveira JF. The Trypanosoma cruzi genome project: nuclear karyotype and gene mapping of clone CL Brener. Mem Inst Oswaldo Cruz 1997; 92:821-8. [PMID: 9580491 DOI: 10.1590/s0074-02761997000600018] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
By using improved pulsed field gel electrophoresis conditions, the molecular karyotype of the reference clone CL Brener selected for Trypanosoma cruzi genome project was established. A total of 20 uniform chromosomal bands ranging in size from 0.45 to 3.5 Megabase pairs (Mbp) were resolved in a single run. The weighted sum of the chromosomal bands was approximately 87 Mbp. Chromoblots were hybridized with 39 different homologous probes, 13 of which identified single chromosomes. Several markers showed linkage and four different linkage groups were identified, each comprising two markers. Densitometric analysis suggests that most of the chromosomal bands contain two or more chromosomes representing either homologous chromosomes and/or heterologous chromosomes with similar sizes.
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Affiliation(s)
- M R Santos
- Universidade Federal de São Paulo (UNIFESP-EPM), Brasil
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21
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Ferrari I, Lorenzi H, Santos MR, Brandariz S, Requena JM, Schijman A, Vázquez M, da Silveira JF, Ben-Dov C, Medrano C, Ghío S, López Bergami P, Cano I, Zingales B, Urmenyi TP, Rondinelli E, González A, Cortes A, Lopez MC, Thomas MC, Alonso C, Ramírez JL, Chiurrillo MA, Aldao RR, Levin MJ. Towards the physical map of the Trypanosoma cruzi nuclear genome: construction of YAC and BAC libraries of the reference clone T. cruzi CL-Brener. Mem Inst Oswaldo Cruz 1997; 92:843-52. [PMID: 9566217 DOI: 10.1590/s0074-02761997000600021] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease.
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Affiliation(s)
- I Ferrari
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI, CONICET, FCYEN-UBA), Buenos Aires, Argentina
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22
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Lesénéchal M, Duret L, Cano MI, Mortara RA, Jolivet M, Camargo ME, da Silveira JF, Paranhos-Baccalà G. Cloning and characterization of a gene encoding a novel immunodominant antigen of Trypanosoma cruzi. Mol Biochem Parasitol 1997; 87:193-204. [PMID: 9247930 DOI: 10.1016/s0166-6851(97)00068-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A Trypanosoma cruzi genomic expression library was screened with a pool of sera obtained from chronic chagasic patients. The recombinant antigen (Tc40) isolated from this library reacted with a large number of serum samples of chronic chagasic patients, suggesting that the presence of anti-Tc40 antibodies may be specifically associated to Chagas' disease. The full-length sequence of the Tc40 gene was determined after isolation of genomic and cDNA clones. The Tc40 cDNA includes a large open reading frame (2745 bp-long) that encodes a polypeptide of 100 kDa without any homology with previously described T. cruzi sequences. In contrast with other T. cruzi antigens whose immunodominant B-cell epitopes are composed by amino acid repetitive motifs, Tc40 does not show any amino acid repetition. Antibodies against the Tc40 recombinant protein reacted with three native polypeptides of 100, 41 and 38 kDa which are tightly associated with membranes or cytoskeleton and expressed in all developmental stages of the parasite life cycle. A transcript of 3.9-kb was detected in Northern blot analysis which is large enough to encode a 100 kDa polypeptide. Tc40 genes were mapped on a chromosomal band of 1.1 Mbp and in a few copies per haploid genome in the G strain.
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Affiliation(s)
- M Lesénéchal
- Unité Mixte CNRS-bio Mérieux, Ecole Normale Supéríeure de Lyon, France
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23
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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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24
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Jazin EE, Bontempi EJ, Sanchez DO, Aslund L, Henriksson J, Frasch AC, Pettersson U. Trypanosoma cruzi exoantigen is a member of a 160 kDa gene family. Parasitology 1995; 110 ( Pt 1):61-9. [PMID: 7845713 DOI: 10.1017/s0031182000081051] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
During the chronic stage of Chagas disease a 160 kDa antigen appears in the blood of patients and remains detectable many years after the onset of the disease. This antigen is secreted by the trypomastigote form of the parasite while it is undetectable in the epimastigote form. We report here that the chronic 160 kDa exoantigen is encoded by a gene family (CEA 160 family). We describe the cloning and partial nucleotide sequence of a gene (CEA 160-1) belonging to the CEA160 family. Comparison of the gene sequence with other sequences present in the databases revealed homologies with several Trypanosoma cruzi surface antigens. Highest amino acid identity (59%) was with members of a family containing epitopes that mimic nervous tissues (Van Voorhis et al. 1993). Another related group (18-22% amino acid identity) comprises proteins of 85 or 160 kDa sharing an amino acid motif that is conserved among bacterial neuraminidases (Fouts et al. 1991; Pollevick et al. 1991; Kahn et al. 1991; Takle & Cross, 1991; Franco et al. 1993). The amino acid identities with the different antigens were not homogeneously distributed. Regions of higher identity (40-60%) were grouped in the central region of each protein.
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Affiliation(s)
- E E Jazin
- Department of Medical Genetics, Biomedical Center, Uppsala, Sweden
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25
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Araya JE, Cano MI, Yoshida N, da Silveira JF. Cloning and characterization of a gene for the stage-specific 82-kDa surface antigen of metacyclic trypomastigotes of Trypanosoma cruzi. Mol Biochem Parasitol 1994; 65:161-9. [PMID: 7935622 DOI: 10.1016/0166-6851(94)90124-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have cloned and sequenced a cDNA clone coding for a metacyclic trypomastigote-specific surface glycoprotein with a molecular mass of 82 kDa (MTS-gp82). By immunoblotting and immunoprecipitation, antibodies against the recombinant protein recognized an 82-kDa protein of metacyclic trypomastigotes, without any detectable reaction towards amastigotes, epimastigotes or tissue culture-derived trypomastigotes. The insert of the MTS-gp82 cDNA clone strongly hybridized with a single 2.2-kb metacyclic trypomastigote mRNA, suggesting that the steady-state levels of mRNAs for MTS-gp82 are developmentally regulated. MTS-gp82 is encoded by a multigene family whose members are distributed in several chromosomes. Sequence analysis revealed 40-56% identity at amino acid level between MTS-gp82 and members of Trypanosoma cruzi gp85/sialidase family (TSA-1, Tt34c1, SA85-1.1). MTS-gp82 showed several amino acid motifs that are characteristic of gp85/sialidase family, such as the Asp box (SxDxGxTW), the subterminal (VTVxNVFLYNR) motif and the putative GPI-anchor sequence. On the basis of its structural features, the MTS-gp82 gene could be included in the T. cruzi gp85/sialidase family, but constituting a distinct group which is preferentially expressed in metacyclic trypomastigotes.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Protozoan/genetics
- Genes, Protozoan
- Glycoproteins/genetics
- Molecular Sequence Data
- Molecular Weight
- Multigene Family
- Neuraminidase/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- Sequence Homology, Amino Acid
- Trypanosoma cruzi/genetics
- Trypanosoma cruzi/growth & development
- Trypanosoma cruzi/immunology
- Variant Surface Glycoproteins, Trypanosoma
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Affiliation(s)
- J E Araya
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, São Paulo, Brazil
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