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Maurilio J. Soares - One of the best experts on this subject based on the ideXlab platform.
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the terpenic diamine gib24 inhibits the growth of trypanosoma cruzi Epimastigotes and intracellular amastigotes with proteomic analysis of drug resistant Epimastigotes
Chemico-Biological Interactions, 2020Co-Authors: Camila Maria Oliveira De Azeredo, Mauricio Frota Saraiva, Maristela Ribeiro De Oliveira, Gisele Barbosa, Mauro V De Almeida, Marcus V N De Souza, Maurilio J. SoaresAbstract:Abstract The effect of N-geranyl-ethane-1,2-diamine dihydochloride (GIB24), a synthetic diamine, was assayed against different developmental forms of the parasitic protozoan Trypanosoma cruzi (strain Dm28c). The compound was effective against culture epimastigote forms (IC50/24h = 5.64 μM; SI = 16.4) and intracellular amastigotes (IC50/24h = 12.89 μM; SI = 7.18), as detected by the MTT methodology and by cell counting, respectively. Incubation of Epimastigotes for 6h with 6 μM GIB24 (IC50/24h value) resulted in significant dissipation of the mitochondrial membrane potential, prior to permeabilization of the plasma membrane. Rounded Epimastigotes with cell size reduction were observed by scanning electron microscopy. These morpho-physiological changes induced by GIB24 suggest an incidental death process. Treatment of infected Vero cells did not prevent the intracellular amastigotes from completing the intracellular cycle. However, there was a decrease in the number of released parasites, increasing the ratio amastigotes/trypomastigotes. Proteomic analysis of 15 μM GIB24 resistant Epimastigotes indicated that the compound acts mainly on mitochondrial components involved in the Krebs cycle and in maintaining the oxidative homeostasis of the parasites. Our data suggest that GIB24 is active against the main morphological forms of T. cruzi.
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in vitro biological evaluation of eight different essential oils against trypanosoma cruzi with emphasis on cinnamomum verum essential oil
BMC Complementary and Alternative Medicine, 2014Co-Authors: Camila Maria Oliveira De Azeredo, Thalita Gilda Santos, Beatriz Helena Sales L N Maia, Maurilio J. SoaresAbstract:Essential oils (EOs) are complex mixtures of secondary metabolites from various plants. It has been shown that several EOs, or their constituents, have inhibitory activity against trypanosomatid protozoa. Thus, we analyzed the biological activity of different EOs on Trypanosoma cruzi, as well as their cytotoxicity on Vero cells. The following EOs were evaluated on T. cruzi epimastigote forms: Cinnamomum verum, Citrus limon, Cymbopogon nardus, Corymbia citriodora, Eucalyptus globulus, Eugenia uniflora, Myrocarpus frondosus, and Rosmarinus officinalis. Inhibitory activity against T. cruzi (IC50/24 h) and cytotoxicity against Vero cells (CC50/24 h) were evaluated by the MTT assay. The EO of C. verum was selected for further evaluation against trypomastigotes and intracellular amastigotes, as well as on parasite metacyclogenesis. Constituents of C. verum EO were identified by GC-MS. One-way ANOVA statistical analysis was performed with GraphPad version 5.01. Cinnamomum verum EO was the most effective against T. cruzi Epimastigotes (IC50/24 h = 24.13 μg/ml), followed by Myrocarpus frondosus (IC50/24 h = 60.87 μg/ml) and Eugenia uniflora (IC50/24 h = 70 μg/ml). The EOs of C. citriodora, E. globulus, and R. officinalis showed no activity at concentrations up to 300 μg/ml. Incubation of T. cruzi metacyclic trypomastigotes and intracellular amastigotes with C. verum EO resulted in IC50/24 h values of 5.05 μg/ml and 20 μg/ml, respectively. Therefore, trypomastigotes are more susceptible than Epimastigotes, with selectivity index (SI) about 4.7-fold higher (9.78 and 2.05, respectively). Analysis of C. verum EO by GC–MS showed mainly (E)-cinnamaldehyde (81.52%) and eugenol (16.68%). C. verum essential oil is effective against T. cruzi (Epimastigotes, trypomastigotes and amastigotes) and interferes with the parasite differentiation process in vitro. Thus, it represents a strong candidate for further studies to improve its activity on pathogenic trypanosomatids.
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in vitro effects of citral on trypanosoma cruzi metacyclogenesis
Memorias Do Instituto Oswaldo Cruz, 2010Co-Authors: Josiane Cardoso, Maurilio J. SoaresAbstract:Citral, the main constituent of lemongrass (Cymbopogon citratus) essential oil, was added to Trypanosoma cruzi cultures grown in TAU3AAG medium to observe the effect on the epimastigote-to-trypomastigote differentiation process (metacyclogenesis). Our results showed that citral (20 μg/mL) did not affect epimastigote viability or inhibit the differentiation process. Concentrations higher than 60 μg/mL, however, led to 100% cell death (both epimastigote and trypomastigote forms). Although Epimastigotes incubated with 30 μg/mL citral were viable and able to adhere to the substrate, we observed around 50% inhibition in metacyclogenesis, with a calculated concentration that inhibited metacyclogenesis by 50% after 24 h (IC50/24 h) of about 31 μg/mL. Treatment with 30 μg/mL citral did not hinder epimastigote multiplication because epimastigote growth resumed when treated cells were transferred to a drug-free liver infusion tryptose culture medium. Metacyclogenesis was almost totally abolished at 40 μg/mL after 24 h of incubation. Furthermore, the metacyclic trypomastigotes obtained in vitro were similarly susceptible to citral, with an IC50/24 h, concentration that killed 50% of the cells after 24 h, of about 24.5 μg/mL. Therefore, citral appears to be a good candidate as an inhibitory drug for further studies analyzing the T. cruzi metacyclogenesis process.
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transferrin uptake may occur through detergent resistant membrane domains at the cytopharynx of trypanosoma cruzi epimastigote forms
Memorias Do Instituto Oswaldo Cruz, 2007Co-Authors: Jose R Correa, Camila Vargas, Georgia Correa Atella, Maurilio J. SoaresAbstract:Uptake of transferrin by epimastigote forms of the protozoan Trypanosoma cruzi occurs mainly through a cytostome/ cytopharynx, via uncoated endocytic vesicles that bud off from the bottom of the cytopharynx. We have here examined whether detergent-resistant membrane (DRM) domains might be involved in this process. Purified whole cell membrane fractions were assayed for cholesterol levels and used in dot blot analyses. Detergent-resistant membrane markers (cholera B toxin and anti-flotillin-1 antibody) presented positive reaction by dot blots in cholesterol-rich/ protein-poor membrane sub-fractions. The positive dot blot fraction was submitted to lipid composition analysis, showing composition similar to that of raft fractions described for other eukaryotic cells. Immunofluorescence assays allowed the localization of punctual positive signal for flotillin-1, matching the precise cytostome/ cytopharynx location. These data were confirmed by immunofluorescence assays with the co-localization of flotillin-1 and the transferrin uptake site. Our data suggest that DRM domains occur and are integrated at the cytostome/ cytopharynx of T. cruzi Epimastigotes, being the main route for transferrin uptake.
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trypanosoma cruzi activity of essential oils from achillea millefolium l syzygium aromaticum l and ocimum basilicum l on Epimastigotes and trypomastigotes
Experimental Parasitology, 2007Co-Authors: Giani F Santoro, Maria Das Gracas Cardoso, Luiz Gustavo De Lima Guimaraes, Lidiany Z Mendonca, Maurilio J. SoaresAbstract:Trypanocidal activity of clove (Syzygium aromaticum L.), basil (Ocimum basilicum L.) and yarrow (Achillea millefolium L.) essential oils and some of their constituents (eugenol and linalool) was investigated on Trypanosoma cruzi epimastigote and bloodstream trypomastigote forms. Steam distillation was used to isolate the essential oils, with chemical analyses performed by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The IC(50) (concentration that inhibits 50% parasite growth) of the oils and constituents upon T. cruzi was determined by cell counting in a Neubauer chamber. Cell morphology alterations were observed by scanning and transmission electron microscopy. Treatment with oils and constituents demonstrated that they inhibit parasite growth, with clove essential being the most effective one (IC(50)=99.5 microg/ml for Epimastigotes and 57.5 microg/ml for trypomastigotes). Ultrastructural alterations were observed mainly in the nucleus.
Giuseppe Palmisano - One of the best experts on this subject based on the ideXlab platform.
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comprehensive glycoprofiling of the epimastigote and trypomastigote stages of trypanosoma cruzi
Journal of Proteomics, 2017Co-Authors: Maria Júlia M. Alves, Rebeca Kawahara, Rosa Viner, Eliciane Cevolani Mattos, Martin R. Larsen, Morten Thaysenandersen, Walter Colli, Giuseppe PalmisanoAbstract:Abstract Trypanosoma cruzi , the protozoan that causes Chagas disease, has a complex life cycle involving insect and mammalian hosts and distinct developmental stages. During T. cruzi developmental stages, glycoproteins play important role in the host-parasite interaction, such as cellular recognition, host cell invasion and adhesion, and immune evasion. In this study, comprehensive glycoprofiling analysis was performed in the epimastigote and trypomastigote stages of T. cruzi using two glycopeptide enrichment strategies, lectin-based and hydrophilic interaction liquid chromatography, followed by high resolution LC-MS/MS. Following deglycosylation, a total of 1306 N -glycosylation sites in NxS/T/C motifs were identified from 690 T. cruzi glycoproteins. Among them, 170 and 334 glycoproteins were exclusively identified in Epimastigotes and trypomastigotes, respectively. Besides, global site-specific characterization of the N - and O -linked glycan heterogeneity in the two life stages of T. cruzi was achieved by intact glycopeptide analysis, revealing 144/466 unique N -linked and 10/97 unique O -linked intact glycopeptides in Epimastigotes/trypomastigotes, respectively. Conclusively, this study documents the significant T. cruzi stage-specific expression of glycoproteins that can help to better understand the T. cruzi phenotype and response caused by the interaction with different hosts during its complex life cycle. Biological significance Chagas disease caused by the protozoan Trypanosoma cruzi is a neglected disease which affects millions of people especially in Latin America. The absence of efficient drugs and vaccines against Chagas disease stimulates the search for novel targets. Glycoproteins are very attractive therapeutic candidate targets since they mediate key processes in the host-parasite interaction, such as cellular recognition, host cell invasion and adhesion, and immune evasion. This study aimed to provide an in depth characterization of the N -linked and O -linked glycoproteome of two T. cruzi life stages: Epimastigotes and trypomastigotes. Mass spectrometry-based proteomics showed interesting stage-specific glycoproteome signatures that are valuable to better understand the importance of protein glycosylation in Epimastigotes and trypomastigotes and to expand the repertoire of potential therapeutic targets against Chagas disease.
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comprehensive glycoprofiling of the epimastigote and trypomastigote stages of trypanosoma cruzi
Journal of Proteomics, 2017Co-Authors: Maria Júlia Manso Alves, Rebeca Kawahara, Rosa Viner, Eliciane Cevolani Mattos, Martin R. Larsen, Morten Thaysenandersen, Walter Colli, Giuseppe PalmisanoAbstract:Trypanosoma cruzi, the protozoan that causes Chagas disease, has a complex life cycle involving insect and mammalian hosts and distinct developmental stages. During T. cruzi developmental stages, glycoproteins play important role in the host-parasite interaction, such as cellular recognition, host cell invasion and adhesion, and immune evasion. In this study, comprehensive glycoprofiling analysis was performed in the epimastigote and trypomastigote stages of T. cruzi using two glycopeptide enrichment strategies, lectin-based and hydrophilic interaction liquid chromatography, followed by high resolution LC-MS/MS. Following deglycosylation, a total of 1306 N-glycosylation sites in NxS/T/C motifs were identified from 690 T. cruzi glycoproteins. Among them, 170 and 334 glycoproteins were exclusively identified in Epimastigotes and trypomastigotes, respectively. Besides, global site-specific characterization of the N- and O-linked glycan heterogeneity in the two life stages of T. cruzi was achieved by intact glycopeptide analysis, revealing 144/466 unique N-linked and 10/97 unique O-linked intact glycopeptides in Epimastigotes/trypomastigotes, respectively. Conclusively, this study documents the significant T. cruzi stage-specific expression of glycoproteins that can help to better understand the T. cruzi phenotype and response caused by the interaction with different hosts during its complex life cycle.
Mario Steindel - One of the best experts on this subject based on the ideXlab platform.
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trypanocidal activity of coumarins and styryl 2 pyrones from polygala sabulosa a w bennett polygalaceae
Revista Brasileira De Farmacognosia-brazilian Journal of Pharmacognosy, 2008Co-Authors: Moacir Geraldo Pizzolatti, Beatriz G Mendes, Anildo Cunha, Cristian Soldi, Adolfo H Koga, Iriane Eger, Edmundo C Grisard, Mario SteindelAbstract:Bioactivity of fractions and compounds obtained from Polygala sabulosa against Trypanosoma cruzi epimastigote, blood trypomastigote and amastigote forms were evaluated in vitro. Dichloromethane and ethyl acetate fractions showed a strong trypanocidal activity on Epimastigotes (IC50 < 10.4 µg/mL). Chromatographic analysis by TLC of these fractions confirmed the presence of previously described compounds (dihydrostyryl-2-pyrones, styryl-2-pyrones and 6-methoxy-7-prenyloxycoumarin). The dichloromethane fraction was fractioned by silica gel column chromatography to afford the compound α-spinasterol and the ethyl acetate fraction yielded apigenin, quercetin and a quercetin-3-O-glucoside, being the first description for the Polygala genus. 4-Methoxy-6-(11,12-methylenedioxy-14-methoxydihydrostyryl)-2-pyrone, 4-methoxy-6-(11,12-dimethoxystyryl)-2-pyrone, 6-methoxy-7-prenyloxycoumarin and quercetin-3-O-glucoside showed a weak activity against blood trypomastigotes (IC50 < 1008.6 µg/mL). The prenylated coumarin was the most active compound against both epimastigote and trypomastigote forms, IC50 10.5 and 88.2 µg/mL, respectively. The hemolytic activity and cell toxicity of each active compound was also assessed. Furthermore, 4-methoxy-6-(11,12-methylenedioxy-14-methoxydihydrostyryl)-2-pyrone and 6-methoxy-7-prenyloxycoumarin reduced 4 times the T. cruzi infection rate for Vero cells at 100 and 50 µg/mL, respectively. These results show for the first time active compounds against T. cruzi in P. sabulosa.
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penetration of the salivary glands of rhodnius domesticus neiva pinto 1923 hemiptera reduviidae by trypanosoma rangeli tejera 1920 protozoa kinetoplastida
Parasitology Research, 2005Co-Authors: Rosane M. S. Meirelles, Andrea Henriquespons, Maurilio J. Soares, Mario SteindelAbstract:Penetration of the heteroxenous protozoan Trypanosoma rangeli into the salivary glands of its invertebrate host Rhodnius domesticus has been investigated here using different approaches. Electron microscopy showed that Epimastigotes coming from the insect hemocoel cross the basal lamina that surrounds the salivary glands and penetrate through the gland cells cytoplasm. After reaching the gland lumen, epimastigote forms remain adhered to the gland cell microvilli by their flagella, while metacyclic trypomastigotes are found swimming free in the saliva. Analysis by flow cytometry, western blotting and hemolytic activity allowed to demonstrate the presence in T. rangeli of a hemolytic molecule with antigenic cross-reactivity with murine perforin, which could be used by the parasites to reach the salivary gland lumen. This molecule, which we named as rangelysin, has 120 kDa molecular weight, is able to induce hemolysis only in acidic pH, and is produced by both trypomastigote and epimastigote forms.
Walter Colli - One of the best experts on this subject based on the ideXlab platform.
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comprehensive glycoprofiling of the epimastigote and trypomastigote stages of trypanosoma cruzi
Journal of Proteomics, 2017Co-Authors: Maria Júlia M. Alves, Rebeca Kawahara, Rosa Viner, Eliciane Cevolani Mattos, Martin R. Larsen, Morten Thaysenandersen, Walter Colli, Giuseppe PalmisanoAbstract:Abstract Trypanosoma cruzi , the protozoan that causes Chagas disease, has a complex life cycle involving insect and mammalian hosts and distinct developmental stages. During T. cruzi developmental stages, glycoproteins play important role in the host-parasite interaction, such as cellular recognition, host cell invasion and adhesion, and immune evasion. In this study, comprehensive glycoprofiling analysis was performed in the epimastigote and trypomastigote stages of T. cruzi using two glycopeptide enrichment strategies, lectin-based and hydrophilic interaction liquid chromatography, followed by high resolution LC-MS/MS. Following deglycosylation, a total of 1306 N -glycosylation sites in NxS/T/C motifs were identified from 690 T. cruzi glycoproteins. Among them, 170 and 334 glycoproteins were exclusively identified in Epimastigotes and trypomastigotes, respectively. Besides, global site-specific characterization of the N - and O -linked glycan heterogeneity in the two life stages of T. cruzi was achieved by intact glycopeptide analysis, revealing 144/466 unique N -linked and 10/97 unique O -linked intact glycopeptides in Epimastigotes/trypomastigotes, respectively. Conclusively, this study documents the significant T. cruzi stage-specific expression of glycoproteins that can help to better understand the T. cruzi phenotype and response caused by the interaction with different hosts during its complex life cycle. Biological significance Chagas disease caused by the protozoan Trypanosoma cruzi is a neglected disease which affects millions of people especially in Latin America. The absence of efficient drugs and vaccines against Chagas disease stimulates the search for novel targets. Glycoproteins are very attractive therapeutic candidate targets since they mediate key processes in the host-parasite interaction, such as cellular recognition, host cell invasion and adhesion, and immune evasion. This study aimed to provide an in depth characterization of the N -linked and O -linked glycoproteome of two T. cruzi life stages: Epimastigotes and trypomastigotes. Mass spectrometry-based proteomics showed interesting stage-specific glycoproteome signatures that are valuable to better understand the importance of protein glycosylation in Epimastigotes and trypomastigotes and to expand the repertoire of potential therapeutic targets against Chagas disease.
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comprehensive glycoprofiling of the epimastigote and trypomastigote stages of trypanosoma cruzi
Journal of Proteomics, 2017Co-Authors: Maria Júlia Manso Alves, Rebeca Kawahara, Rosa Viner, Eliciane Cevolani Mattos, Martin R. Larsen, Morten Thaysenandersen, Walter Colli, Giuseppe PalmisanoAbstract:Trypanosoma cruzi, the protozoan that causes Chagas disease, has a complex life cycle involving insect and mammalian hosts and distinct developmental stages. During T. cruzi developmental stages, glycoproteins play important role in the host-parasite interaction, such as cellular recognition, host cell invasion and adhesion, and immune evasion. In this study, comprehensive glycoprofiling analysis was performed in the epimastigote and trypomastigote stages of T. cruzi using two glycopeptide enrichment strategies, lectin-based and hydrophilic interaction liquid chromatography, followed by high resolution LC-MS/MS. Following deglycosylation, a total of 1306 N-glycosylation sites in NxS/T/C motifs were identified from 690 T. cruzi glycoproteins. Among them, 170 and 334 glycoproteins were exclusively identified in Epimastigotes and trypomastigotes, respectively. Besides, global site-specific characterization of the N- and O-linked glycan heterogeneity in the two life stages of T. cruzi was achieved by intact glycopeptide analysis, revealing 144/466 unique N-linked and 10/97 unique O-linked intact glycopeptides in Epimastigotes/trypomastigotes, respectively. Conclusively, this study documents the significant T. cruzi stage-specific expression of glycoproteins that can help to better understand the T. cruzi phenotype and response caused by the interaction with different hosts during its complex life cycle.
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trypanosoma cruzi characterization of an intracellular epimastigote like form
Experimental Parasitology, 1999Co-Authors: M Almeidadefaria, Edna Freymuller, Walter Colli, Maria Júlia M. AlvesAbstract:Abstract Almeida-de-Faria, M., Freymuller, E., Colli, W., and Alves, M. J. M. 1999. Trypanosoma cruzi: Characterization of an intracellular epimastigote-like form. Experimental Parasitology92, 263–274. A detailed study of transient epimastigote-like forms as intermediates in the differentiation of Trypanosoma cruzi amastigotes to trypomastigotes inside the host cell cytoplasm was undertaken using the CL-14 clone grown in cells maintained at 33°C. Several parameters related to these forms have been compared with Epimastigotes and other stages of the parasite. Consequently, the designation of intracellular Epimastigotes is proposed for these forms. Despite being five times shorter (5.4 ± 0.7 μm) than the extracellular epimastigote (25.2 ± 2.1 μm), the overall morphology of the intracellular epimastigote is very similar to a bona fide epimastigote, when cell shape, position, and general aspect of organelles are compared by transmission electron microscopy. Epimastigotes from both sources are lysed by human complement and bind to DEAE–cellulose, in contrast to amastigotes and trypomastigote forms. A monoclonal antibody (3C5) reacts with both Epimastigotes either isolated from axenic media or intracellular and very faintly with amastigotes, but not with trypomastigotes. Some differences of a quantitative nature are apparent between the two epimastigote forms when reactivities with lectins or stage-specific antibodies are compared, revealing the transient nature of the intracellular epimastigote. The epitope recognized by 3C5 monoclonal antibody reacts slightly more intensely with extracellular than with intracellular Epimastigotes, as detected by immunoelectron microscopy. Also a very faint reaction of the intracellular Epimastigotes was observed with monoclonal antibody 2C2, an antibody which recognizes a glycoprotein specific for the amastigote stage. Biological parameters as growth curves in axenic media and inhability to invade nonphagocytic tissue-cultured cells are similar in the Epimastigotes from both origins. It is proposed that the epimastigote-like forms are an obligatory transitional stage in the transformation of amastigotes to trypomastigotes with a variable time of permanency in the host cell cytoplasm depending on environmental conditions.
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galactofuranose containing glycoconjugates of epimastigote and trypomastigote forms of trypanosoma cruzi
Molecular and Biochemical Parasitology, 1993Co-Authors: Denise B Golgher, Thais Soutopadron, Walter Colli, Bianca ZingalesAbstract:Abstract Antiserum to LPPG, a lipopeptidophosphoglycan originally described on the surface of Trypanosoma cruzi Epimastigotes of the Y strain, and antibodies to furanoic galactose (gal f ) were obtained in rabbits. A micromethod for the extraction and purification of LPPG from a limited amount of parasites is described. Analysis by Western blots of the purified glycoconjugate probed with both antisera confirmed the presence of gal f -containing LPPG-like molecules in 10 different strains and clones of T. cruzi . An analogous approach indicated that trypomastigotes also contain LPPG-like components. Quantitation experiments allowed to calculate an average value of 1.0 × 10 7 LPPG molecules per epimastigote cell and 0.16 × 10 7 LPPG-like molecules per trypomastigote cell. Immunoelectron microscopy has shown a homogeneous distribution of LPPG on the surface of Epimastigotes. The trypomastigote population, however, is highly heterogeneous with no more than 15% of the parasites being labeled by the anti-LPPG serum. Intense labeling has also been found in vesicles inside the epimastigote and trypomastigote forms. The distribution of gal f epitopes among glycoconjugates of Epimastigotes and trypomastigotes was further investigated. It was shown that gal f units in Epimastigotes are bound to low molecular mass compounds which co-migrate with LPPG whereas in trypomastigotes they have been found in both low molecular mass LPPG-like molecules and glycoproteins of 80–90 kDa. Direct chemical evidence for the presence of gal f residues in the N -linked oligosaccharide chains of these surface glycoproteins has been obtained. Finally, the natural antigenicity of LPPG and gal f in chronic Chagas' disease was investigated. It was found that all chronic chagasic sera investigated recognize this glycoconjugate and that an important part of such recognition can be attributed to gal f residues. Furthermore, no correlation among reactivity to LPPG, strain zymodeme and clinical forms of the disease was found.
Wendy Gibson - One of the best experts on this subject based on the ideXlab platform.
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shape shifting trypanosomes flagellar shortening followed by asymmetric division in trypanosoma congolense from the tsetse proventriculus
PLOS Pathogens, 2018Co-Authors: Lori Peacock, Mick Bailey, Christopher Kay, Wendy GibsonAbstract:Trypanosomatids such as Leishmania and Trypanosoma are digenetic, single-celled, parasitic flagellates that undergo complex life cycles involving morphological and metabolic changes to fit them for survival in different environments within their mammalian and insect hosts. According to current consensus, asymmetric division enables trypanosomatids to achieve the major morphological rearrangements associated with transition between developmental stages. Contrary to this view, here we show that the African trypanosome Trypanosoma congolense, an important livestock pathogen, undergoes extensive cell remodelling, involving shortening of the cell body and flagellum, during its transition from free-swimming proventricular forms to attached Epimastigotes in vitro. Shortening of the flagellum was associated with accumulation of PFR1, a major constituent of the paraflagellar rod, in the mid-region of the flagellum where it was attached to the substrate. However, the PFR1 depot was not essential for attachment, as it accumulated several hours after initial attachment of proventricular trypanosomes. Detergent and CaCl2 treatment failed to dislodge attached parasites, demonstrating the robust nature of flagellar attachment to the substrate; the PFR1 depot was also unaffected by these treatments. Division of the remodelled proventricular trypanosome was asymmetric, producing a small daughter cell. Each mother cell went on to produce at least one more daughter cell, while the daughter trypanosomes also proliferated, eventually resulting in a dense culture of Epimastigotes. Here, by observing the synchronous development of the homogeneous population of trypanosomes in the tsetse proventriculus, we have been able to examine the transition from proventricular forms to attached Epimastigotes in detail in T. congolense. This transition is difficult to observe in vivo as it happens inside the mouthparts of the tsetse fly. In T. brucei, this transition is achieved by asymmetric division of long trypomastigotes in the proventriculus, yielding short Epimastigotes, which go on to colonise the salivary glands. Thus, despite their close evolutionary relationship and shared developmental route within the vector, T. brucei and T. congolense have evolved different ways of accomplishing the same developmental transition from proventricular form to attached epimastigote.
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the life cycle of trypanosoma nannomonas congolense in the tsetse fly
Parasites & Vectors, 2012Co-Authors: Lori Peacock, Simon Cook, Vanessa Ferris, Mick Bailey, Wendy GibsonAbstract:The tsetse-transmitted African trypanosomes cause diseases of importance to the health of both humans and livestock. The life cycles of these trypanosomes in the fly were described in the last century, but comparatively few details are available for Trypanosoma (Nannomonas) congolense, despite the fact that it is probably the most prevalent and widespread pathogenic species for livestock in tropical Africa. When the fly takes up bloodstream form trypanosomes, the initial establishment of midgut infection and invasion of the proventriculus is much the same in T. congolense and T. brucei. However, the developmental pathways subsequently diverge, with production of infective metacyclics in the proboscis for T. congolense and in the salivary glands for T. brucei. Whereas events during migration from the proventriculus are understood for T. brucei, knowledge of the corresponding developmental pathway in T. congolense is rudimentary. The recent publication of the genome sequence makes it timely to re-investigate the life cycle of T. congolense. Experimental tsetse flies were fed an initial bloodmeal containing T. congolense strain 1/148 and dissected 2 to 78 days later. Trypanosomes recovered from the midgut, proventriculus, proboscis and cibarium were fixed and stained for digital image analysis. Trypanosomes contained in spit samples from individually caged flies were analysed similarly. Mensural data from individual trypanosomes were subjected to principal components analysis. Flies were more susceptible to infection with T. congolense than T. brucei; a high proportion of flies infected with T. congolense established a midgut and subsequent proboscis infection, whereas many T. brucei infections were lost in the migration from foregut to salivary glands. In T. congolense, trypomastigotes ceased division in the proventriculus and became uniform in size. The trypanosomes retained trypomastigote morphology during migration via the foregut to the mouthparts and we confirmed that the trypomastigote-epimastigote transition occurred in the proboscis. We found no equivalent to the asymmetric division stage in T. brucei that mediates transition of proventricular trypomastigotes to Epimastigotes. In T. congolense extremely long Epimastigotes with remarkably elongated posterior ends were observed in both the proboscis and cibarium; no difference was found in the developmental stages in these two organs. Dividing trypomastigotes and Epimastigotes were recovered from the proboscis, some of which were in transition from trypomastigote to epimastigote and vice versa. It remains uncertain whether these morphological transitions are mediated by cell division, since we also found non-dividing cells with a variously positioned, juxta-nuclear kinetoplast. We have presented a detailed description of the life cycle of T. congolense in its tsetse fly vector. During development in the fly T. congolense shares a common migratory pathway with its close relative T. brucei, culminating in the production of small metacyclic trypanosomes that can be inoculated with the saliva. Despite this outward similarity in life cycle, the transitional developmental stages in the foregut and mouthparts are remarkably different in the two trypanosome species.