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Tahir Aleem M, Munir F, Shakoor A, Ud Din Sindhu Z, Gao F. Advancement in the development of DNA vaccines against Trypanosoma brucei and future perspective. Int Immunopharmacol 2024; 140:112847. [PMID: 39088922 DOI: 10.1016/j.intimp.2024.112847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/22/2024] [Accepted: 07/29/2024] [Indexed: 08/03/2024]
Abstract
Trypanosomes are the extracellular protozoan parasites that cause human African trypanosomiasis disease in humans and nagana disease in animals. Tsetse flies act as a vector for the transmission of the disease in African countries. Animals infected with these parasites become useless or workless, and if not treated, disease can be fatal. There are many side effects associated with old treatments and some of them result in death in 5% of cases. There is a major surface glycoprotein in the parasite known as variant surface glycoprotein. The immune system of the host develops antibodies against this antigen but due to antigenic variation, parasites evade the immune response. Currently, no vaccine is available that provides complete protection. In murine models, only partial protection was observed using certain antigens. In order to develop vaccines against trypanosomes, molecular biology and immunology tools have been used. Immunization is the sole method for the control of disease because the eradication of the vector from endemic areas is an impossible task. Genetic vaccines can carry multiple genes encoding different antigens of the same parasite or different parasites. DNA immunization induces the activation of both cellular immune response and humoral immune response along with the generation of memory. This review highlights the importance of DNA vaccines and advances in the development of DNA vaccines against T. brucei.
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Affiliation(s)
- Muhammad Tahir Aleem
- Department of Pharmacology, Shantou University Medical College, Shantou 515041, China; Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, Cleveland, OH 44115, USA.
| | - Furqan Munir
- Department of Parasitology, Faculty of Veterinary Science, University of Agriculture, Faisalabad 38040, Pakistan
| | - Amna Shakoor
- Department of Anatomy, Faculty of Veterinary Science, University of Agriculture, Faisalabad 9, 38040, Pakistan
| | - Zia Ud Din Sindhu
- Department of Parasitology, Faculty of Veterinary Science, University of Agriculture, Faisalabad 38040, Pakistan
| | - Fenfei Gao
- Department of Pharmacology, Shantou University Medical College, Shantou 515041, China.
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Chi Y, Mukiibi R, Zhang H, Zhang H, Li W, Robledo D, Chen S, Li Y. Transcriptome Analysis Reveals the Immunosuppression in Tiger Pufferfish ( Takifugu rubripes) under Cryptocaryon irritans Infection. Animals (Basel) 2024; 14:2058. [PMID: 39061520 PMCID: PMC11273842 DOI: 10.3390/ani14142058] [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: 06/19/2024] [Revised: 07/10/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
The tiger pufferfish (Takifugu rubripes), also known as fugu, has recently suffered from severe C. irritans infections under aquaculture environment, yet the underlying immune mechanisms against the parasite remain poorly understood. In this study, we conducted a comprehensive transcriptome analysis of the gill tissue from infected and uninfected fish using PacBio long-read (one pooled sample each for seriously infected and healthy individuals, respectively) and Illumina short-read (three pools for mildly infected, seriously infected, and healthy individuals, respectively) RNA sequencing technologies. After aligning sequence data to fugu's reference genome, 47,307 and 34,413 known full-length transcripts were identified and profiled in healthy and infected fish, respectively. Similarly, we identified and profiled 1126 and 803 novel genes that were obtained from healthy and infected fish, respectively. Interestingly, we found a decrease in the number of alternative splicing (AS) events and long non-coding RNAs (lncRNAs) after infection with C. irritans, suggesting that they may be involved in the regulation of the immune response in fugu. There were 687 and 1535 differentially expressed genes (DEGs) in moderately and heavily infected fish, respectively, compared to uninfected fish. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that immune-related DEGs in the two comparison groups were mainly enriched in cytokine-cytokine receptor interactions, ECM-receptor interactions, T-cell receptor signaling pathways, Th1 and Th2 cell differentiation, and Th17 cell differentiation pathways. Further analysis revealed that a large number of immune-related genes were downregulated in infected fish relative to uninfected ones, such as CCR7, IL7R, TNFRSF21, CD4, COL2A1, FOXP3B, and ITGA8. Our study suggests that C. irritans is potentially a highly efficient parasite that may disrupt the defense mechanisms of fugu against it. In addition, in combination of short-read RNA sequencing and previous genome-wide association analyses, we identified five key genes (NDUFB6, PRELID1, SMOX, SLC25A4, and DENND1B) that might be closely associated with C. irritans resistance. This study not only provides valuable resources of novel genic transcripts for further research, but also provides new insights into the immune mechanisms underlying C. irritans infection response in farmed fugu.
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Affiliation(s)
- Yong Chi
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China;
| | - Robert Mukiibi
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh EH25 9RG, UK; (R.M.); (D.R.)
| | - Hongxiang Zhang
- Tangshan Haidu Seafood Co., Ltd., Tangshan 063506, China; (H.Z.); (H.Z.); (W.L.)
- Fishery Research Institute, Tangshan Academy of Agricultural Sciences, Tangshan 063001, China
| | - Haien Zhang
- Tangshan Haidu Seafood Co., Ltd., Tangshan 063506, China; (H.Z.); (H.Z.); (W.L.)
| | - Weidong Li
- Tangshan Haidu Seafood Co., Ltd., Tangshan 063506, China; (H.Z.); (H.Z.); (W.L.)
| | - Diego Robledo
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh EH25 9RG, UK; (R.M.); (D.R.)
- Department of Genetics, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - Songlin Chen
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China;
| | - Yangzhen Li
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China;
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh EH25 9RG, UK; (R.M.); (D.R.)
- Tangshan Haidu Seafood Co., Ltd., Tangshan 063506, China; (H.Z.); (H.Z.); (W.L.)
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Brühlmann F, Perry C, Griessen C, Gunasekera K, Reymond JL, Naguleswaran A, Rottenberg S, Woods K, Olias P. TurboID mapping reveals the exportome of secreted intrinsically disordered proteins in the transforming parasite Theileria annulata. mBio 2024; 15:e0341223. [PMID: 38747635 PMCID: PMC11237503 DOI: 10.1128/mbio.03412-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 04/15/2024] [Indexed: 06/13/2024] Open
Abstract
Theileria annulata is a tick-transmitted apicomplexan parasite that gained the unique ability among parasitic eukaryotes to transform its host cell, inducing a fatal cancer-like disease in cattle. Understanding the mechanistic interplay between the host cell and malignant Theileria species that drives this transformation requires the identification of responsible parasite effector proteins. In this study, we used TurboID-based proximity labeling, which unbiasedly identified secreted parasite proteins within host cell compartments. By fusing TurboID to nuclear export or localization signals, we biotinylated proteins in the vicinity of the ligase enzyme in the nucleus or cytoplasm of infected macrophages, followed by mass spectrometry analysis. Our approach revealed with high confidence nine nuclear and four cytosolic candidate parasite proteins within the host cell compartments, eight of which had no orthologs in non-transforming T. orientalis. Strikingly, all eight of these proteins are predicted to be highly intrinsically disordered proteins. We discovered a novel tandem arrayed protein family, nuclear intrinsically disordered proteins (NIDP) 1-4, featuring diverse functions predicted by conserved protein domains. Particularly, NIDP2 exhibited a biphasic host cell-cycle-dependent localization, interacting with the EB1/CD2AP/CLASP1 parasite membrane complex at the schizont surface and the tumor suppressor stromal antigen 2 (STAG2), a cohesion complex subunit, in the host nucleus. In addition to STAG2, numerous NIDP2-associated host nuclear proteins implicated in various cancers were identified, shedding light on the potential role of the T. annulata exported protein family NIDP in host cell transformation and cancer-related pathways.IMPORTANCETurboID proximity labeling was used to identify secreted proteins of Theileria annulata, an apicomplexan parasite responsible for a fatal, proliferative disorder in cattle that represents a significant socio-economic burden in North Africa, central Asia, and India. Our investigation has provided important insights into the unique host-parasite interaction, revealing secreted parasite proteins characterized by intrinsically disordered protein structures. Remarkably, these proteins are conspicuously absent in non-transforming Theileria species, strongly suggesting their central role in the transformative processes within host cells. Our study identified a novel tandem arrayed protein family, with nuclear intrinsically disordered protein 2 emerging as a central player interacting with established tumor genes. Significantly, this work represents the first unbiased screening for exported proteins in Theileria and contributes essential insights into the molecular intricacies behind the malignant transformation of immune cells.
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Affiliation(s)
- Francis Brühlmann
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
| | - Carmen Perry
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
| | | | - Kapila Gunasekera
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, Bern, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, Bern, Switzerland
| | | | - Sven Rottenberg
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
| | - Kerry Woods
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
| | - Philipp Olias
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
- Institute of Veterinary Pathology, Justus Liebig University, Giessen, Germany
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Prevalence of Bovine Trypanosomosis and Its Associated Risk Factor in Hawa Galan District, Kelem Wollega Zone of Ethiopia. Vet Med Int 2021; 2021:4531586. [PMID: 34950445 PMCID: PMC8692041 DOI: 10.1155/2021/4531586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/15/2021] [Indexed: 11/27/2022] Open
Abstract
An analytical cross-sectional study was performed between November 2015 and April 2016 at Hawa Galan woreda, Kelem Wollega Zone, Oromia Region, Ethiopia, to estimate the proportion of cattle with trypanosomosis and to evaluate the elements associated with the prevalence of bovine trypanosomosis. A haemoparasitological examination of the Buffy coat method was implemented to determine the proportion of trypanosomosis-positive cattle. A study population of 428 bovines was randomly selected from three peasant associations (PAs) and tested for the presence of the disease. Findings of the laboratory results indicate that among all animals tested at the study time, 26 (6%) animals were positive for the disease. Among the positive results, the proportion of trypanosome species was Trypanosoma congolense 18 (69.3%) and Trypanosoma vivax 8 (30.7%). The prevalence at the selected PAs was 12.5%, 3.8%, and 3% for Lemlem, Madawalkituma, and Ifajiru, respectively. From this finding, the relationship has a statistically significant variation (P < 0.05) among peasant associations and body condition state, and the proportion was significantly greater (P < 0.05) in animals categorized under poor body condition score. The relationships between age and sex of cattle show no statistically significant variation among them (P > 0.05). This study indicates that the proportion of trypanosomosis was greater in anemic (PCV<24%) cattle than nonanemic (PCV≥24%). Therefore, based on this finding, the proportion of bovine trypanosomosis is evident that can cause a major effect on the health of cattle in the study population in the study area. So, effective control methods could be applied to decrease the disease and its related economic loss.
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Rahnama M, Wang B, Dostart J, Novikova O, Yackzan D, Yackzan A, Bruss H, Baker M, Jacob H, Zhang X, Lamb A, Stewart A, Heist M, Hoover J, Calie P, Chen L, Liu J, Farman ML. Telomere Roles in Fungal Genome Evolution and Adaptation. Front Genet 2021; 12:676751. [PMID: 34434216 PMCID: PMC8381367 DOI: 10.3389/fgene.2021.676751] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/28/2021] [Indexed: 11/27/2022] Open
Abstract
Telomeres form the ends of linear chromosomes and usually comprise protein complexes that bind to simple repeated sequence motifs that are added to the 3′ ends of DNA by the telomerase reverse transcriptase (TERT). One of the primary functions attributed to telomeres is to solve the “end-replication problem” which, if left unaddressed, would cause gradual, inexorable attrition of sequences from the chromosome ends and, eventually, loss of viability. Telomere-binding proteins also protect the chromosome from 5′ to 3′ exonuclease action, and disguise the chromosome ends from the double-strand break repair machinery whose illegitimate action potentially generates catastrophic chromosome aberrations. Telomeres are of special interest in the blast fungus, Pyricularia, because the adjacent regions are enriched in genes controlling interactions with host plants, and the chromosome ends show enhanced polymorphism and genetic instability. Previously, we showed that telomere instability in some P. oryzae strains is caused by novel retrotransposons (MoTeRs) that insert in telomere repeats, generating interstitial telomere sequences that drive frequent, break-induced rearrangements. Here, we sought to gain further insight on telomeric involvement in shaping Pyricularia genome architecture by characterizing sequence polymorphisms at chromosome ends, and surrounding internalized MoTeR loci (relics) and interstitial telomere repeats. This provided evidence that telomere dynamics have played historical, and likely ongoing, roles in shaping the Pyricularia genome. We further demonstrate that even telomeres lacking MoTeR insertions are poorly preserved, such that the telomere-adjacent sequences exhibit frequent presence/absence polymorphism, as well as exchanges with the genome interior. Using TERT knockout experiments, we characterized chromosomal responses to failed telomere maintenance which suggested that much of the MoTeR relic-/interstitial telomere-associated polymorphism could be driven by compromised telomere function. Finally, we describe three possible examples of a phenomenon known as “Adaptive Telomere Failure,” where spontaneous losses of telomere maintenance drive rapid accumulation of sequence polymorphism with possible adaptive advantages. Together, our data suggest that telomere maintenance is frequently compromised in Pyricularia but the chromosome alterations resulting from telomere failure are not as catastrophic as prior research would predict, and may, in fact, be potent drivers of adaptive polymorphism.
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Affiliation(s)
- Mostafa Rahnama
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Baohua Wang
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States.,State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jane Dostart
- Department of Biological Sciences, Eastern Kentucky University, Richmond, KY, United States
| | - Olga Novikova
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Daniel Yackzan
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Andrew Yackzan
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Haley Bruss
- Department of Biological Sciences, Eastern Kentucky University, Richmond, KY, United States
| | - Maray Baker
- Department of Biological Sciences, Eastern Kentucky University, Richmond, KY, United States
| | - Haven Jacob
- Department of Biological Sciences, Eastern Kentucky University, Richmond, KY, United States
| | - Xiaofei Zhang
- Department of Computer Sciences, University of Kentucky, Lexington, KY, United States
| | - April Lamb
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Alex Stewart
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Melanie Heist
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Joey Hoover
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Patrick Calie
- Department of Biological Sciences, Eastern Kentucky University, Richmond, KY, United States
| | - Li Chen
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
| | - Jinze Liu
- Department of Computer Sciences, University of Kentucky, Lexington, KY, United States
| | - Mark L Farman
- Department of Plant Pathology, University of Kentucky, Lexington, KY, United States
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Silva Pereira S, Jackson AP, Figueiredo LM. Evolution of the variant surface glycoprotein family in African trypanosomes. Trends Parasitol 2021; 38:23-36. [PMID: 34376326 DOI: 10.1016/j.pt.2021.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 01/22/2023]
Abstract
An intriguing and remarkable feature of African trypanosomes is their antigenic variation system, mediated by the variant surface glycoprotein (VSG) family and fundamental to both immune evasion and disease epidemiology within host populations. Recent studies have revealed that the VSG repertoire has a complex evolutionary history. Sequence diversity, genomic organization, and expression patterns are species-specific, which may explain other variations in parasite virulence and disease pathology. Evidence also shows that we may be underestimating the extent to what VSGs are repurposed beyond their roles as variant antigens, establishing a need to examine VSG functionality more deeply. Here, we review sequence variation within the VSG gene family, and highlight the many opportunities to explore their likely diverse contributions to parasite survival.
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Affiliation(s)
- Sara Silva Pereira
- Instituto de Medicina Molecular - João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Andrew P Jackson
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Luísa M Figueiredo
- Instituto de Medicina Molecular - João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
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Single-Cell RNA Sequencing Reveals that the Switching of the Transcriptional Profiles of Cysteine-Related Genes Alters the Virulence of Entamoeba histolytica. mSystems 2020; 5:5/6/e01095-20. [PMID: 33361325 PMCID: PMC7762796 DOI: 10.1128/msystems.01095-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Studies on the trophozoite of Entamoeba histolytica suggested this organism could accumulate polyploid cells in its proliferative phase and differentiate its cell cycle from that of other eukaryotes. Therefore, a single-cell sequencing technique was used to study the switching of the RNA transcription profiles of single amoebic trophozoites. Entamoeba histolytica is an intestinal protozoan that causes human amoebic colitis and extraintestinal abscesses. Virulence variation is observed in the pathogenicity of E. histolytica trophozoites, but the detailed mechanism remains unclear. Here, a single trophozoite was cultured alone, and the progeny of the trophozoites of each generation were subjected to single-cell RNA sequencing (scRNA-seq) to study the transcriptional profiles of trophozoites. The scRNA-seq analysis indicated the importance of sulfur metabolism and the proteasome pathway in pathogenicity, whereas the isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis did not identify the bulk trophozoites. The trophozoite improved the synthesis of cysteine under cysteine-deficient conditions but downregulated the expression of the intermediate subunit of the lectin of E. histolytica trophozoites and retained the expression of the heavy subunit of lectin, resulting in decreased amoebic phagocytosis and cytotoxicity. The variation in the transmembrane kinase gene family might be critical in regulating the proteasome pathway. Thus, the scRNA-seq technique provided an improved understanding of the biological characteristics and the mechanism of virulence variation of amoebic trophozoites. IMPORTANCE Studies on the trophozoite of Entamoeba histolytica suggested this organism could accumulate polyploid cells in its proliferative phase and differentiate its cell cycle from that of other eukaryotes. Therefore, a single-cell sequencing technique was used to study the switching of the RNA transcription profiles of single amoebic trophozoites. We separated individual trophozoites from axenic cultured trophozoites, CHO cell-incubated trophozoites, and in vivo trophozoites. We found important changes in the sulfur and cysteine metabolism in pathogenicity. The trophozoites strategically regulated the expression of the cysteine-rich protein-encoding genes under cysteine-deficient conditions, thereby decreasing amoebic phagocytosis and cytotoxicity. The single-cell sequencing technique shows evident advantages in comparison with the isobaric tags for relative and absolute quantitation (iTRAQ) proteomic technology (bulk trophozoite level) and reveals the regulation strategy of trophozoites in the absence of exogenous cysteine. This regulation strategy may be the mechanism of virulence variation of amoebic trophozoites.
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Gerem B, Hamid M, Assefa A. Prevalence and Associated Risk Factors of Trypanosoma evansi in Camels in Ethiopia Based on Parasitological Examinations. Vet Med Int 2020; 2020:6172560. [PMID: 32908662 PMCID: PMC7474376 DOI: 10.1155/2020/6172560] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 11/22/2022] Open
Abstract
Camel trypanosomosis (surra), caused by Trypanosoma evansi , is a life-threatening disease with negative impacts on health, production, and working efficiency of camels in different camel-rearing areas of the world, including Ethiopia. A cross-sectional study was carried out from November 2016 to May 2017 to determine the prevalence of camel trypanosomosis (surra) and assess the associated potential risk factors in Dubti and Asayita districts of Afar region, Ethiopia. Blood samples were collected from 200 camels. Wet film and Giemsa-stained blood smears were used for the detection of trypanosomes. Out of 200 examined, 9(4.5%) were positive for Trypanosoma evansi. The higher prevalence of the disease was observed in Dubti (6.97%) than in Asayita (2.63%) districts. Highest infection was observed in the age group >4 years old camels (7.47%), followed by <4 years old camels (1.07%). Previously aborted camels were found at higher risk (P=0.03; OR = 5.11, 95% CI = 1.174-22.317) than camels without an abortion history. There was no statistically significant difference in between body condition categories and herd size of camels with the occurrence of the disease (X 2 = 3.839; P=0.147 and X 2 = 0.718; P=0.698), respectively. The result of the current study revealed that camel trypanosomosis is substantially prevalent in the study area, indicating the need for designing control and prevention strategies.
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Affiliation(s)
- Bekalu Gerem
- Abergelle District Agricultural Office, Abergele, Ethiopia
| | - Muhammed Hamid
- College of Veterinary Medicine, Samara University, P.O. Box 132, Samara, Ethiopia
| | - Ayalew Assefa
- Sekota Dryland Agricultural Research Center, Sekota, Ethiopia
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Evaluation of the Immunoprotective Potential of Recombinant Paraflagellar Rod Proteins of Trypanosoma evansi in Mice. Vaccines (Basel) 2020; 8:vaccines8010084. [PMID: 32059486 PMCID: PMC7157580 DOI: 10.3390/vaccines8010084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 01/24/2020] [Accepted: 01/27/2020] [Indexed: 12/15/2022] Open
Abstract
Trypanosomosis, caused by Trypanosoma evansi, is an economically significant disease of livestock. Systematic antigenic variation by the parasite has undermined prospects for the development of a protective vaccine that targets the immunodominant surface antigens, encouraging exploration of alternatives. The paraflagellar rod (PFR), constituent proteins of the flagellum, are prominent non-variable vaccine candidates for T. evansi owing to their strategic location. Two major PFR constituent proteins, PFR1 (1770bp) and PFR2 (1800bp), were expressed using Escherichia coli. Swiss albino mice were immunized with the purified recombinant TePFR1 (89KDa) and TePFR2 (88KDa) proteins, as well as with the mix of the combined proteins at equimolar concentrations, and subsequently challenged with virulent T. evansi. The PFR-specific humoral response was assessed by ELISA. Cytometric bead-based assay was used to measure the cytokine response and flow cytometry for quantification of the cytokines. The recombinant TePFR proteins induced specific humoral responses in mice, including IgG1 followed by IgG2a and IgG2b. A balanced cytokine response induced by rTePFR 1 and 2 protein vaccination associated with extended survival and improved control of parasitemia following lethal challenge. The observation confirms the immunoprophylactic potential of the covert antigens of T. evansi.
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Vesteg M, Hadariová L, Horváth A, Estraño CE, Schwartzbach SD, Krajčovič J. Comparative molecular cell biology of phototrophic euglenids and parasitic trypanosomatids sheds light on the ancestor of Euglenozoa. Biol Rev Camb Philos Soc 2019; 94:1701-1721. [PMID: 31095885 DOI: 10.1111/brv.12523] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 01/23/2023]
Abstract
Parasitic trypanosomatids and phototrophic euglenids are among the most extensively studied euglenozoans. The phototrophic euglenid lineage arose relatively recently through secondary endosymbiosis between a phagotrophic euglenid and a prasinophyte green alga that evolved into the euglenid secondary chloroplast. The parasitic trypanosomatids (i.e. Trypanosoma spp. and Leishmania spp.) and the freshwater phototrophic euglenids (i.e. Euglena gracilis) are the most evolutionary distant lineages in the Euglenozoa phylogenetic tree. The molecular and cell biological traits they share can thus be considered as ancestral traits originating in the common euglenozoan ancestor. These euglenozoan ancestral traits include common mitochondrial presequence motifs, respiratory chain complexes containing various unique subunits, a unique ATP synthase structure, the absence of mitochondria-encoded transfer RNAs (tRNAs), a nucleus with a centrally positioned nucleolus, closed mitosis without dissolution of the nuclear membrane and nucleoli, a nuclear genome containing the unusual 'J' base (β-D-glucosyl-hydroxymethyluracil), processing of nucleus-encoded precursor messenger RNAs (pre-mRNAs) via spliced-leader RNA (SL-RNA) trans-splicing, post-transcriptional gene silencing by the RNA interference (RNAi) pathway and the absence of transcriptional regulation of nuclear gene expression. Mitochondrial uridine insertion/deletion RNA editing directed by guide RNAs (gRNAs) evolved in the ancestor of the kinetoplastid lineage. The evolutionary origin of other molecular features known to be present only in either kinetoplastids (i.e. polycistronic transcripts, compaction of nuclear genomes) or euglenids (i.e. monocistronic transcripts, huge genomes, many nuclear cis-spliced introns, polyproteins) is unclear.
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Affiliation(s)
- Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, 974 01, Banská Bystrica, Slovakia
| | - Lucia Hadariová
- Biotechnology and Biomedicine Center of the Academy of Sciences and Charles University in Vestec (BIOCEV), 252 50, Vestec, Czech Republic.,Department of Parasitology, Faculty of Science, Charles University in Prague, 128 44, Prague, Czech Republic
| | - Anton Horváth
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15, Bratislava, Slovakia
| | - Carlos E Estraño
- Department of Biological Sciences, University of Memphis, Memphis, TN, 38152-3560, USA
| | - Steven D Schwartzbach
- Department of Biological Sciences, University of Memphis, Memphis, TN, 38152-3560, USA
| | - Juraj Krajčovič
- Department of Biology, Faculty of Natural Sciences, University of ss. Cyril and Methodius, 917 01, Trnava, Slovakia
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Moreno CJG, Temporão A, Torres T, Sousa Silva M. Trypanosoma brucei Interaction with Host: Mechanism of VSG Release as Target for Drug Discovery for African Trypanosomiasis. Int J Mol Sci 2019; 20:ijms20061484. [PMID: 30934540 PMCID: PMC6471236 DOI: 10.3390/ijms20061484] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/05/2019] [Accepted: 03/07/2019] [Indexed: 01/18/2023] Open
Abstract
The protozoan Trypanosoma brucei, responsible for animal and human trypanosomiasis, has a family of major surface proteases (MSPs) and phospholipase-C (PLC), both involved in some mechanisms of virulence during mammalian infections. During parasitism in the mammalian host, this protozoan is exclusively extracellular and presents a robust mechanism of antigenic variation that allows the persistence of infection. There has been incredible progress in our understanding of how variable surface glycoproteins (VSGs) are organised and expressed, and how expression is switched, particularly through recombination. The objective of this manuscript is to create a reflection about the mechanisms of antigenic variation in T. brucei, more specifically, in the process of variable surface glycoprotein (VSG) release. We firstly explore the mechanism of VSG release as a potential pathway and target for the development of anti-T. brucei drugs.
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Affiliation(s)
- Cláudia Jassica Gonçalves Moreno
- Programa de Pós-graduação em Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal 59064-741, Brazil.
| | - Adriana Temporão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2775-412 Oeiras, Portugal.
| | - Taffarel Torres
- Centro de Ciências Biológicas e da Saúde, Universidade Federal Rural de Semi-árido, Mossoró 59625-900, Brazil.
| | - Marcelo Sousa Silva
- Programa de Pós-graduação em Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal 59064-741, Brazil.
- Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal 59012-570, Brazil.
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, 1349-008 Lisbon, Portugal.
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Active Essential Oils and Their Components in Use against Neglected Diseases and Arboviruses. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6587150. [PMID: 30881596 PMCID: PMC6387720 DOI: 10.1155/2019/6587150] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/06/2018] [Indexed: 12/21/2022]
Abstract
The term neglected diseases refers to a group of infections caused by various classes of pathogens, including protozoa, viruses, bacteria, and helminths, most often affecting impoverished populations without adequate sanitation living in close contact with infectious vectors and domestic animals. The fact that these diseases were historically not considered priorities for pharmaceutical companies made the available treatments options obsolete, precarious, outdated, and in some cases nonexistent. The use of plants for medicinal, religious, and cosmetic purposes has a history dating back to the emergence of humanity. One of the principal fractions of chemical substances found in plants are essential oils (EOs). EOs consist of a mixture of volatile and hydrophobic secondary metabolites with marked odors, composed primarily of terpenes and phenylpropanoids. They have great commercial value and were widely used in traditional medicine, by phytotherapy practitioners, and in public health services for the treatment of several conditions, including neglected diseases. In addition to the recognized cytoprotective and antioxidative activities of many of these compounds, larvicidal, insecticidal, and antiparasitic activities have been associated with the induction of oxidative stress in parasites, increasing levels of nitric oxide in the infected host, reducing parasite resistance to reactive oxygen species, and increasing lipid peroxidation, ultimately leading to serious damage to cell membranes. The hydrophobicity of these compounds also allows them to cross the membranes of parasites as well as the blood-brain barrier, collaborating in combat at the second stage of several of these infections. Based on these considerations, the aim of this review was to present an update of the potential of EOs, their fractions, and their chemical constituents, against some neglected diseases, including American and African trypanosomiasis, leishmaniasis, and arboviruses, specially dengue.
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Kuriakose SM, Singh R, Uzonna JE. Host Intracellular Signaling Events and Pro-inflammatory Cytokine Production in African Trypanosomiasis. Front Immunol 2016; 7:181. [PMID: 27242788 PMCID: PMC4872169 DOI: 10.3389/fimmu.2016.00181] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/27/2016] [Indexed: 12/21/2022] Open
Abstract
Pathogens, such as bacteria, viruses, and parasites, possess specific molecules or proteins that are recognized by several host innate immune receptors, leading to the activation of several intracellular signaling molecules and pathways. The magnitude and quality of these events significantly affect the outcome of infection. African trypanosomes, including Trypanosoma congolense, are capable of manipulating the host immune response, including the activity of macrophages, which are the key immune cells that contribute to the immunopathogenesis of African trypanosomiasis. Although it is known that immune hyperactivation and excessive pro-inflammatory cytokine production are the hallmarks of African trypanosomiasis, the mechanisms through which these events are triggered are poorly defined. However, it is known that macrophages may play a significant role in these processes, because phagocytosis of trypanosomes by macrophages initiates intracellular signal transduction cascades that lead to the release of pro-inflammatory cytokines and alteration in cell function. This review highlights recent progress in our understanding of the innate immune receptors, signaling pathways, and transcription factors involved in T. congolense-induced pro-inflammatory cytokine production in macrophages. It will reveal the existence of complex signaling events through which the parasite modulates the host immune response, thus identifying novel targets that could aid in designing strategies to effectively control the disease.
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Affiliation(s)
- Shiby M Kuriakose
- Department of Immunology, Faculty of Health Sciences, University of Manitoba , Winnipeg, MB , Canada
| | - Rani Singh
- Department of Immunology, Faculty of Health Sciences, University of Manitoba , Winnipeg, MB , Canada
| | - Jude E Uzonna
- Department of Immunology, Faculty of Health Sciences, University of Manitoba , Winnipeg, MB , Canada
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Yaro M, Munyard KA, Stear MJ, Groth DM. Combatting African Animal Trypanosomiasis (AAT) in livestock: The potential role of trypanotolerance. Vet Parasitol 2016; 225:43-52. [PMID: 27369574 DOI: 10.1016/j.vetpar.2016.05.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/29/2016] [Accepted: 05/01/2016] [Indexed: 01/09/2023]
Abstract
African Animal Trypanosomiasis (AAT) is endemic in at least 37 of the 54 countries in Africa. It is estimated to cause direct and indirect losses to the livestock production industry in excess of US$ 4.5 billion per annum. A century of intervention has yielded limited success, owing largely to the extraordinary complexity of the host-parasite interaction. Trypanotolerance, which refers to the inherent ability of some African livestock breeds, notably Djallonke sheep, N'Dama cattle and West African Dwarf goats, to withstand a trypanosomiasis challenge and still remain productive without any form of therapy, is an economically sustainable option for combatting this disease. Yet trypanotolerance has not been adequately exploited in the fight against AAT. In this review, we describe new insights into the genetic basis of trypanotolerance and discuss the potential of exploring this phenomenon as an integral part of the solution for AAT, particularly, in the context of African animal production systems.
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Affiliation(s)
- M Yaro
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - K A Munyard
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - M J Stear
- Institute of Biodiversity, Animal Health and Comparative Medicine, Glasgow University, Garscube Estate, Bearsden Road, Glasgow G61 1QH, UK
| | - D M Groth
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
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Alves LGA, Scariot DB, Guimarães RR, Nakamura CV, Mendes RS, Ribeiro HV. Transient Superdiffusion and Long-Range Correlations in the Motility Patterns of Trypanosomatid Flagellate Protozoa. PLoS One 2016; 11:e0152092. [PMID: 27007779 PMCID: PMC4805249 DOI: 10.1371/journal.pone.0152092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/08/2016] [Indexed: 12/21/2022] Open
Abstract
We report on a diffusive analysis of the motion of flagellate protozoa species. These parasites are the etiological agents of neglected tropical diseases: leishmaniasis caused by Leishmania amazonensis and Leishmania braziliensis, African sleeping sickness caused by Trypanosoma brucei, and Chagas disease caused by Trypanosoma cruzi. By tracking the positions of these parasites and evaluating the variance related to the radial positions, we find that their motions are characterized by a short-time transient superdiffusive behavior. Also, the probability distributions of the radial positions are self-similar and can be approximated by a stretched Gaussian distribution. We further investigate the probability distributions of the radial velocities of individual trajectories. Among several candidates, we find that the generalized gamma distribution shows a good agreement with these distributions. The velocity time series have long-range correlations, displaying a strong persistent behavior (Hurst exponents close to one). The prevalence of “universal” patterns across all analyzed species indicates that similar mechanisms may be ruling the motion of these parasites, despite their differences in morphological traits. In addition, further analysis of these patterns could become a useful tool for investigating the activity of new candidate drugs against these and others neglected tropical diseases.
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Affiliation(s)
- Luiz G. A. Alves
- Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, United States of America
- National Institute of Science and Technology for Complex Systems, CNPq, Rio de Janeiro, RJ, 22290-180, Brazil
- * E-mail:
| | - Débora B. Scariot
- Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil
| | - Renato R. Guimarães
- Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil
- National Institute of Science and Technology for Complex Systems, CNPq, Rio de Janeiro, RJ, 22290-180, Brazil
| | - Celso V. Nakamura
- Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil
| | - Renio S. Mendes
- Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil
- National Institute of Science and Technology for Complex Systems, CNPq, Rio de Janeiro, RJ, 22290-180, Brazil
| | - Haroldo V. Ribeiro
- Departamento de Física, Universidade Estadual de Maringá, Maringá, PR, 87020-900, Brazil
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Recombination and Diversification of the Variant Antigen Encoding Genes in the Malaria Parasite Plasmodium falciparum. Microbiol Spectr 2016; 2. [PMID: 26104446 DOI: 10.1128/microbiolspec.mdna3-0022-2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The most severe form of human malaria is caused by the protozoan parasite Plasmodium falciparum. These parasites invade and replicate within the circulating red blood cells of infected individuals leading to numerous disease manifestations, including severe anemia, altered circulation, and tissue inflammation. Malaria parasites are also known for their ability to maintain a chronic infection through antigenic variation, the ability to systematically alter the antigens displayed on the surface of infected cells and thereby avoid clearance by the host's antibody response. The genome of P. falciparum includes several large, multicopy gene families that encode highly variable forms of the surface proteins that are the targets of host immunity. Alterations in expression of genes within these families are responsible for antigenic variation. This process requires the continuous generation of new antigenic variants within these gene families, and studies have shown that new variants arise through extensive recombination and gene conversion events between family members. Malaria parasites possess an unusual complement of DNA repair pathways, thus the study of recombination between variant antigen encoding genes provides a unique view into the evolution of mobile DNA in an organism distantly related to the more closely studied model eukaryotes.
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Maharana BR, Tewari AK, Singh V. An overview on kinetoplastid paraflagellar rod. J Parasit Dis 2015; 39:589-95. [PMID: 26688619 PMCID: PMC4675581 DOI: 10.1007/s12639-014-0422-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 01/13/2014] [Indexed: 01/23/2023] Open
Abstract
Kinetoplastids, the evolutionary ancient organisms exhibit a rich and diverse biology which epitomizes many of the fascinating topics of recent interest and study. These organisms possess a multifunctional organelle, the flagellum containing a canonical 9 + 2 axoneme which is involved in vital roles, viz. parasite cell division, morphogenesis, motility and immune evasion. Since Antony Van Leeuwenhoek's innovative explanation of 'little legs' helping the movements of microbes in 1975, this biological nanomachine has captured the thoughts of scientists. The core structure of kinetoplastid flagellum is embroidered with a range of extra-axonemal structures such as paraflagellar rod (PFR), a large lattice like structure which extends alongside the axoneme from the flagellar pocket to the flagellar tip. The coding sequences for significant components of PFR are highly conserved throughout the Kinetoplastida and Euglenida. The high order organization and restricted evolutionary distribution of the PFR components and structure makes the PFR a particularly valuable therapeutic and prophylactic target. This review focuses on the recent developments in identification of ultra structural components of PFR in order to understand the function of this intriguing organelle and devising strategies for therapeutic interventions.
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Affiliation(s)
- B. R. Maharana
- />Department of Veterinary Parasitology, College of Veterinary Science and Animal Husbandry, Junagadh Agricultural University, Junagadh, 362001 Gujarat India
| | - A. K. Tewari
- />Division of Veterinary Parasitology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243122 Uttar Pradesh India
| | - Veer Singh
- />Department of Veterinary Parasitology, College of Veterinary Science and Animal Husbandry, Sardar Krushinagar Dantiwada Agricultural University, Sardarkrushinagar, 3855006 Gujarat India
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Pena AC, Pimentel MR, Manso H, Vaz-Drago R, Pinto-Neves D, Aresta-Branco F, Rijo-Ferreira F, Guegan F, Pedro Coelho L, Carmo-Fonseca M, Barbosa-Morais NL, Figueiredo LM. Trypanosoma brucei histone H1 inhibits RNA polymerase I transcription and is important for parasite fitness in vivo. Mol Microbiol 2014; 93:645-63. [PMID: 24946224 PMCID: PMC4285223 DOI: 10.1111/mmi.12677] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2014] [Indexed: 11/30/2022]
Abstract
Trypanosoma brucei is a unicellular parasite that causes sleeping sickness in humans. Most of its transcription is constitutive and driven by RNA polymerase II. RNA polymerase I (Pol I) transcribes not only ribosomal RNA genes, but also protein-encoding genes, including variant surface glycoproteins (VSGs) and procyclins. In T. brucei, histone H1 (H1) is required for VSG silencing and chromatin condensation. However, whether H1 has a genome-wide role in transcription is unknown. Here, using RNA sequencing we show that H1 depletion changes the expression of a specific cohort of genes. Interestingly, the predominant effect is partial loss of silencing of Pol I loci, such as VSG and procyclin genes. Labelling of nascent transcripts with 4-thiouridine showed that H1 depletion does not alter the level of labelled Pol II transcripts. In contrast, the levels of 4sU-labelled Pol I transcripts were increased by two- to sixfold, suggesting that H1 preferentially blocks transcription at Pol I loci. Finally, we observed that parasites depleted of H1 grow almost normally in culture but they have a reduced fitness in mice, suggesting that H1 is important for host-pathogen interactions.
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Affiliation(s)
- Ana C Pena
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Edifício Egas Moniz, 1649-028, Lisboa, Portugal
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Artemisinins: Pharmacological actions beyond anti-malarial. Pharmacol Ther 2014; 142:126-39. [DOI: 10.1016/j.pharmthera.2013.12.001] [Citation(s) in RCA: 309] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/26/2013] [Indexed: 12/23/2022]
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Mochabo KM, Zhou M, Suganuma K, Kawazu SI, Suzuki Y, Inoue N. Expression, immunolocalization and serodiagnostic value of Tc38630 protein from Trypanosoma congolense. Parasitol Res 2013; 112:3357-63. [PMID: 23820607 DOI: 10.1007/s00436-013-3515-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 06/19/2013] [Indexed: 11/25/2022]
Abstract
Animal African trypanosomosis is a serious constraint to livestock sector development in sub-Saharan Africa. The disease, mainly caused by Trypanosoma congolense, has a limitation in its diagnosis and treatment. There is urgent need for a simple, rapid detection technique to replace the few available serological tests that are of variable sensitivity and specificity. Currently, there is a promising use of recombinant proteins to improve on the trypanosome lysate to detect antibodies. In this respect, we have identified a stage-specific gene that is relatively highly expressed in metacyclic and blood trypomastigotes of T. congolense. According to previously obtained differential protein expression data, the gene TcIL3000.0.38630 (1,236 bp) is by 8.5 times more expressed in metacyclic and blood trypomastigotes than in procyclic trypomastigotes and epimastigotes. The same stage specific expression pattern was shown in Western blot analysis. In addition, in confocal laser scanning microscopy the Tc38630 protein was present in the cytosol and on the cell surface of metacyclic and blood trypomastigotes. Through bioinformatics, the Tc38630 had N-terminal signal sequence, hydrophilic extracellular domain, single transmembrane alpha-helix and short cytoplasmic domain, which is characteristic of the Trypanosoma brucei invariant surface glycoprotein. However, unlike T. brucei invariant surface glycoprotein, the Tc38630 existed as a single copy gene with a probable allelic polymorphism at the Nar I restriction site. The recombinant Tc38630-based ELISA detected antibodies against Tc38630 as early as 7 days post infection in experimentally infected mouse model. Taken together, our results suggest that the Tc38630 is a novel potential diagnostic antigen of Animal African trypanosomosis.
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Affiliation(s)
- Kennedy Miyoro Mochabo
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11, Inada, Obihiro, Hokkaido, 080-8555, Japan
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Translation of human African trypanosomiasis biomarkers towards field application. TRANSLATIONAL PROTEOMICS 2013. [DOI: 10.1016/j.trprot.2013.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Ali JAM, Creek DJ, Burgess K, Allison HC, Field MC, Mäser P, De Koning HP. Pyrimidine salvage in Trypanosoma brucei bloodstream forms and the trypanocidal action of halogenated pyrimidines. Mol Pharmacol 2012. [PMID: 23188714 DOI: 10.1124/mol.112.082321] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
African trypanosomes are capable of both pyrimidine biosynthesis and salvage of preformed pyrimidines from the host. However, uptake of pyrimidines in bloodstream form trypanosomes has not been investigated, making it difficult to judge the relative importance of salvage and synthesis or to design a pyrimidine-based chemotherapy. Detailed characterization of pyrimidine transport activities in bloodstream form Trypanosoma brucei brucei found that these cells express a high-affinity uracil transporter (designated TbU3) that is clearly distinct from the procyclic pyrimidine transporters. This transporter had low affinity for uridine and 2'deoxyuridine and was the sole pyrimidine transporter expressed in these cells. In addition, thymidine was taken up inefficiently through a P1-type nucleoside transporter. Of importance, the anticancer drug 5-fluorouracil was an excellent substrate for TbU3, and several 5-fluoropyrimidine analogs were investigated for uptake and trypanocidal activity; 5F-orotic acid, 5F-2'deoxyuridine displayed activity in the low micromolar range. The metabolism and mode of action of these analogs was determined using metabolomic assessments of T. brucei clonal lines adapted to high levels of these pyrimidine analogs, and of the sensitive parental strains. The analysis showed that 5-fluorouracil is incorporated into a large number of metabolites but likely exerts toxicity through incorporation into RNA. 5F-2'dUrd and 5F-2'dCtd are not incorporated into nucleic acids but act as prodrugs by inhibiting thymidylate synthase as 5F-dUMP. We present the most complete model of pyrimidine salvage in T. brucei to date, supported by genome-wide profiling of the predicted pyrimidine biosynthesis and conversion enzymes.
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Affiliation(s)
- Juma A M Ali
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
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Affinity is an important determinant of the anti-trypanosome activity of nanobodies. PLoS Negl Trop Dis 2012; 6:e1902. [PMID: 23166849 PMCID: PMC3499403 DOI: 10.1371/journal.pntd.0001902] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 10/01/2012] [Indexed: 02/03/2023] Open
Abstract
Background The discovery of Nanobodies (Nbs) with a direct toxic activity against African trypanosomes is a recent advancement towards a new strategy against these extracellular parasites. The anti-trypanosomal activity relies on perturbing the highly active recycling of the Variant-specific Surface Glycoprotein (VSG) that occurs in the parasite's flagellar pocket. Methodology/Principal Findings Here we expand the existing panel of Nbs with anti-Trypanosoma brucei potential and identify four categories based on their epitope specificity. We modified the binding properties of previously identified Nanobodies Nb_An05 and Nb_An33 by site-directed mutagenesis in the paratope and found this to strongly affect trypanotoxicity despite retention of antigen-targeting properties. Affinity measurements for all identified anti-trypanosomal Nbs reveal a strong correlation between trypanotoxicity and affinity (KD), suggesting that it is a crucial determinant for this activity. Half maximal effective (50%) affinity of 57 nM was calculated from the non-linear dose-response curves. In line with these observations, Nb humanizing mutations only preserved the trypanotoxic activity if the KD remained unaffected. Conclusions/Significance This study reveals that the binding properties of Nanobodies need to be compatible with achieving an occupancy of >95% saturation of the parasite surface VSG in order to exert an anti-trypanosomal activity. As such, Nb-based approaches directed against the VSG target would require binding to an accessible, conserved epitope with high affinity. Nanobodies, antigen binding fragments derived from a non-conventional class of antibodies in camelids, were previously shown to exert a direct activity against African trypanosomes without the need of a toxin. Their mode-of-action relies on interference with the highly active recycling of the Variant-specific Surface Glycoprotein (VSG) that occurs in the flagellar pocket of the parasite. By expanding the panel of anti-trypanosomal Nanobodies and by modification of their binding properties through site-directed mutagenesis, we have been able to show a strong correlation between their trypanotoxic activity and affinity for the cognate antigen. From these studies it was calculated that the parasite surface saturation needs to exceed 95% in order to achieve this anti-trypanosomal effect of Nanobodies, which can be considered as a critical cut-off value for future Nanobody-based or other small molecule drug approaches against the VSG target.
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Effect of adjuvants on the humoral immune response to congopain in mice and cattle. BMC Vet Res 2012; 8:63. [PMID: 22621378 PMCID: PMC3532191 DOI: 10.1186/1746-6148-8-63] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 04/27/2012] [Indexed: 12/05/2022] Open
Abstract
Background We investigated several adjuvants for their effects on the humoral immune response in both mice and cattle using the central domain of congopain (C2), the major cysteine protease of Trypanosoma congolense, as a model for developing a vaccine against animal trypanosomosis. The magnitude and sustainability of the immune response against C2 and the occurrence of a booster effect of infection, an indirect measure of the presence of memory cells, were determined by ELISA, while spectrofluorometry was used to determine and measure the presence of enzyme-inhibiting antibodies. Results Mice immunized with recombinant C2 in TiterMax™, Adjuphos™, purified saponin Quil A™ or Gerbu™ showed the best response according to the evaluation criteria and the latter three were chosen for the cattle vaccination study. The cattle were challenged with T. congolense four and a half months after the last booster. Cattle immunized with recombinant C2 in purified saponin Quil A™ showed the best antibody response according to the measured parameters. Conclusions We identified purified saponin Quil A™ as a good adjuvant for immunizations with C2. The results from this study will be useful in future attempts to develop an effective anti-disease vaccine against African trypanosomosis.
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Seke Etet PF, Mahomoodally MF. New insights in staging and chemotherapy of African trypanosomiasis and possible contribution of medicinal plants. ScientificWorldJournal 2012; 2012:343652. [PMID: 22593674 PMCID: PMC3349134 DOI: 10.1100/2012/343652] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 11/16/2011] [Indexed: 11/17/2022] Open
Abstract
Human African trypanosomiasis (HAT) is a fatal if untreated fly-borne neuroinflammatory disease caused by protozoa of the species Trypanosoma brucei (T.b.). The increasing trend of HAT cases has been reversed, but according to WHO experts, new epidemics of this disease could appear. In addition, HAT is still a considerable burden for life quality and economy in 36 sub-Saharan Africa countries with 15-20 million persons at risk. Following joined initiatives of WHO and private partners, the fight against HAT was re-engaged, resulting in considerable breakthrough. We present here what is known at this day about HAT etiology and pathogenesis and the new insights in the development of accurate tools and tests for disease staging and severity monitoring in the field. Also, we elaborate herein the promising progresses made in the development of less toxic and more efficient trypanocidal drugs including the potential of medicinal plants and related alternative drug therapies.
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Affiliation(s)
- Paul F Seke Etet
- Department of Neurological Sciences (DNNMMS), University of Verona, Via Delle Grazie 8, 37134 Verona, Italy
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Coustou V, Plazolles N, Guegan F, Baltz T. Sialidases play a key role in infection and anaemia in Trypanosoma congolense animal trypanosomiasis. Cell Microbiol 2012; 14:431-45. [PMID: 22136727 DOI: 10.1111/j.1462-5822.2011.01730.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Animal African trypanosomiasis is a major constraint to livestock productivity and has an important impact on millions of people in developing African countries. This parasitic disease, caused mainly by Trypanosoma congolense, results in severe anaemia leading to animal death. In order to characterize potential targets for an anti-disease vaccine, we investigated a multigenic trans-sialidase family (TcoTS) in T. congolense. Sialidase and trans-sialidase activities were quantified for the first time, as well as the tightly regulated TcoTS expression pattern throughout the life cycle. Active enzymes were expressed in bloodstream form parasites and released into the blood during infection. Using genetic tools, we demonstrated a significant correlation between TcoTS silencing and impairment of virulence during experimental infection with T. congolense. Reduced TcoTS expression affected infectivity, parasitaemia and pathogenesis development. Immunization-challenge experiments using recombinant TcoTS highlighted their potential protective use in an anti-disease vaccine.
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Affiliation(s)
- Virginie Coustou
- Univ. de Bordeaux, Microbiologie fondamentale et Pathogénicité, Bordeaux, France.
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Weirather JL, Wilson ME, Donelson JE. Mapping of VSG similarities in Trypanosoma brucei. Mol Biochem Parasitol 2011; 181:141-52. [PMID: 22079099 DOI: 10.1016/j.molbiopara.2011.10.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 10/19/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
Abstract
The protozoan parasite Trypanosoma brucei switches its variant surface glycoprotein (VSG) to subvert its mammalian hosts' immune responses. The T. brucei genome contains as many as 1600 VSG genes (VSGs), but most are silent noncoding pseudogenes. Only one functional VSG, located in a telomere-linked expression site, is transcribed at a time. Silent VSGs are copied into a VSG expression site through gene conversion. Truncated gene conversion events can generate new mosaic VSGs with segments of sequence identity to other VSGs. To examine the VSG family sub-structure within which these events occur, we combined the available VSG sequences and annotations with scripted BLAST searches to map the relationships among VSGs in the T. brucei genome. Clusters of related VSGs were visualized in 2- and 3-dimensions for different N- and C-terminal regions. Five types of N-termini (N1-N5) were observed, within which gene recombinational events are likely to occur, often with fully-coding 'functional' or 'atypical'VSGs centrally located between more dissimilar VSGs. Members of types N1, N3 and N4 are most closely related in the middle of the N-terminal region, whereas type N2 members are more similar near the N-terminus. Some preference occurs in pairing between specific N- and C-terminal types. Statistical analyses indicated no overall tendency for more related VSGs to be located closer in the genome than less related VSGs, although exceptions were noted. Many potential mosaic gene formation events within each N-terminal type were identified, contrasted by only one possible mosaic gene formation between N-terminal types (N1 and N2). These data suggest that mosaic gene formation is a major contributor to the overall VSG diversity, even though gene recombinational events between members of different N-terminal types occur only rarely.
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Affiliation(s)
- Jason L Weirather
- Interdisciplinary Program in Genetics, University of Iowa, Iowa City, IA 52240, USA
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Schauer R, Kamerling JP. The Chemistry and Biology of Trypanosomal trans-Sialidases: Virulence Factors in Chagas Disease and Sleeping Sickness. Chembiochem 2011; 12:2246-64. [DOI: 10.1002/cbic.201100421] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Indexed: 11/10/2022]
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Loveless BC, Mason JW, Sakurai T, Inoue N, Razavi M, Pearson TW, Boulanger MJ. Structural characterization and epitope mapping of the glutamic acid/alanine-rich protein from Trypanosoma congolense: defining assembly on the parasite cell surface. J Biol Chem 2011; 286:20658-65. [PMID: 21471223 PMCID: PMC3121512 DOI: 10.1074/jbc.m111.218941] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/10/2011] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma congolense is an African trypanosome that causes serious disease in cattle in Sub-Saharan Africa. The four major life cycle stages of T. congolense can be grown in vitro, which has led to the identification of several cell-surface molecules expressed on the parasite during its transit through the tsetse vector. One of these, glutamic acid/alanine-rich protein (GARP), is the first expressed on procyclic forms in the tsetse midgut and is of particular interest because it replaces the major surface coat molecule of bloodstream forms, the variant surface glycoprotein (VSG) that protects the parasite membrane, and is involved in antigenic variation. Unlike VSG, however, the function of GARP is not known, which necessarily limits our understanding of parasite survival in the tsetse. Toward establishing the function of GARP, we report its three-dimensional structure solved by iodide phasing to a resolution of 1.65 Å. An extended helical bundle structure displays an unexpected and significant degree of homology to the core structure of VSG, the only other major surface molecule of trypanosomes to be structurally characterized. Immunofluorescence microscopy and immunoaffinity-tandem mass spectrometry were used in conjunction with monoclonal antibodies to map both non-surface-disposed and surface epitopes. Collectively, these studies enabled us to derive a model describing the orientation and assembly of GARP on the surface of trypanosomes. The data presented here suggest the possible structure-function relationships involved in replacement of the bloodstream form VSG by GARP as trypanosomes differentiate in the tsetse vector after a blood meal.
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Affiliation(s)
- Bianca C. Loveless
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada and
| | - Jeremy W. Mason
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada and
| | - Tatsuya Sakurai
- the National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Noboru Inoue
- the National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
| | - Morteza Razavi
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada and
| | - Terry W. Pearson
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada and
| | - Martin J. Boulanger
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada and
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Eyford BA, Sakurai T, Smith D, Loveless B, Hertz-Fowler C, Donelson JE, Inoue N, Pearson TW. Differential protein expression throughout the life cycle of Trypanosoma congolense, a major parasite of cattle in Africa. Mol Biochem Parasitol 2011; 177:116-25. [PMID: 21354217 PMCID: PMC3820035 DOI: 10.1016/j.molbiopara.2011.02.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/07/2011] [Accepted: 02/13/2011] [Indexed: 01/24/2023]
Abstract
Trypanosoma congolense is an important pathogen of livestock in Africa. To study protein expression throughout the T. congolense life cycle, we used culture-derived parasites of each of the three main insect stages and bloodstream stage parasites isolated from infected mice, to perform differential protein expression analysis. Three complete biological replicates of all four life cycle stages were produced from T. congolense IL3000, a cloned parasite that is amenable to culture of major life cycle stages in vitro. Cellular proteins from each life cycle stage were trypsin digested and the resulting peptides were labeled with isobaric tags for relative and absolute quantification (iTRAQ). The peptides were then analyzed by tandem mass spectrometry (MS/MS). This method was used to identify and relatively quantify proteins from the different life cycle stages in the same experiment. A search of the Wellcome Trust's Sanger Institute's semi-annotated T. congolense database was performed using the MS/MS fragmentation data to identify the corresponding source proteins. A total of 2088 unique protein sequences were identified, representing 23% of the ∼9000 proteins predicted for the T. congolense proteome. The 1291 most confidently identified proteins were prioritized for further study. Of these, 784 yielded annotated hits while 501 were described as "hypothetical proteins". Six proteins showed no significant sequence similarity to any known proteins (from any species) and thus represent new, previously uncharacterized T. congolense proteins. Of particular interest among the remainder are several membrane molecules that showed drastic differential expression, including, not surprisingly, the well-studied variant surface glycoproteins (VSGs), invariant surface glycoproteins (ISGs) 65 and 75, congolense epimastigote specific protein (CESP), the surface protease GP63, an amino acid transporter, a pteridine transporter and a haptoglobin-hemoglobin receptor. Several of these surface disposed proteins are of functional interest as they are necessary for survival of the parasites.
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Affiliation(s)
- Brett A. Eyford
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Tatsuya Sakurai
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Derek Smith
- UVic-Genome BC Proteomics Centre, Vancouver Island Technology Park, Victoria, British Columbia V8Z 7X8, Canada
| | - Bianca Loveless
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | | | - John E. Donelson
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Noboru Inoue
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
| | - Terry W. Pearson
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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Njiru ZK, Gitonga PK, Ndungu K. The typing of Trypanosoma evansi isolates using mobile genetic element (MGE) PCR. Parasitol Res 2011; 108:1583-7. [PMID: 21287202 DOI: 10.1007/s00436-010-2246-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 12/22/2010] [Indexed: 11/29/2022]
Abstract
The mobile genetic element PCR (MGE-PCR) is a simple and sensitive technique that can be used to detect genetic variability in Trypanosoma brucei ssp. To investigate the reliability of MGE-PCR in genotyping Trypanosoma evansi, stocks that were isolated directly from camels and after their respective passage in mice were analyzed. Construction of a dendrogram using the MGE-PCR banding profiles revealed a clear distinction between T. evansi and T. brucei, as well as discriminating the T. evansi strains (T. evansi with minicircle types B and A). A minor host-dependent clustering shows a genetic difference of <15%. Changes in the banding profiles were observed after serial passage of T. evansi type B in mice, while those of T. evansi type A were identical. It is apparent that significant random insertion mobile element positional variation occurs when T. evansi isolates are introduced into a new host, a factor that needs to be considered when MGE-PCR is used to determine genetic variation in T. evansi isolates that have different host origins.
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Affiliation(s)
- Z K Njiru
- School of Veterinary Sciences, University of Queensland, Inner Ring Road, Gatton, 4343, Australia.
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Vilchez Larrea SC, Alonso GD, Schlesinger M, Torres HN, Flawiá MM, Fernández Villamil SH. Poly(ADP-ribose) polymerase plays a differential role in DNA damage-response and cell death pathways in Trypanosoma cruzi. Int J Parasitol 2010; 41:405-16. [PMID: 21185298 DOI: 10.1016/j.ijpara.2010.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 11/05/2010] [Indexed: 12/20/2022]
Abstract
Poly(ADP-ribosyl)ation is a post-translational modification of proteins. Poly(ADP-ribose) polymerase (PARP) and poly(ADP-ribose) glycohydrolase (PARG) are the enzymes responsible for poly(ADP-ribose) (PAR) polymer metabolism and are present in most higher eukaryotes. The best understood role of PARP is the maintenance of genomic integrity either via promotion of DNA repair at low levels of genotoxic stress or via promotion of cell death at higher levels of damage. The unicellular eukaryote Trypanosoma cruzi, as opposed to humans and other organisms, has only one PARP (TcPARP) and one PARG (TcPARG). In the present study we show that under different DNA-damaging agents (H(2)O(2) or UV-C radiation) TcPARP is activated and translocated from the cytosol to the nucleus, while TcPARG always shows a nuclear localisation. Parasites in the presence of PARP or PARG inhibitors, as well as parasites over-expressing either TcPARP or TcPARG, suggested that PAR metabolism could be involved in different phases of cell growth, even in the absence of DNA damage. We also believe that we provide the first reported evidence that different proteins could be poly(ADP-ribosyl)ated in response to different stimuli, leading to different cell death pathways.
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Affiliation(s)
- Salomé C Vilchez Larrea
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Vuelta de Obligado 2490, Ciudad Autónoma de Buenos Aires, 1428 Buenos Aires, Argentina
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Leroux AE, Maugeri DA, Opperdoes FR, Cazzulo JJ, Nowicki C. Comparative studies on the biochemical properties of the malic enzymes from Trypanosoma cruzi and Trypanosoma brucei. FEMS Microbiol Lett 2010; 314:25-33. [PMID: 21105905 DOI: 10.1111/j.1574-6968.2010.02142.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Comparative studies showed that, like Trypanosoma cruzi, Trypanosoma brucei exhibits functional cytosolic and mitochondrial malic enzymes (MEs), which are specifically linked to NADP. Kinetic studies provided evidence that T. cruzi and T. brucei MEs display similarly high affinities towards NADP(+) and are also almost equally efficient in catalyzing the production of NADPH. Nevertheless, in contrast to the cytosolic ME from T. cruzi, which is highly activated by l-aspartate (over 10-fold), the T. brucei homologue is slightly more active (50%) in the presence of this amino acid. In T. brucei, both isozymes appear to be clearly more abundant in the insect stage, although they can be immunodetected in the bloodstream forms. By contrast, in T. cruzi the expression of the mitochondrial ME seems to be clearly upregulated in amastigotes, whereas the cytosolic isoform appears to be more abundant in the insect stages of the parasite. It might be hypothesized that in those environments where glucose is very low or absent, these pathogens depend on NADP-linked dehydrogenases such as the MEs for NADPH production, as in those conditions the pentose phosphate pathway cannot serve as a source of essential reducing power.
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Affiliation(s)
- Alejandro E Leroux
- Instituto de Química y Fisicoquímica Biológica IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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Nibret E, Wink M. Trypanocidal and antileukaemic effects of the essential oils of Hagenia abyssinica, Leonotis ocymifolia, Moringa stenopetala, and their main individual constituents. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2010; 17:911-20. [PMID: 20359874 DOI: 10.1016/j.phymed.2010.02.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 01/27/2010] [Accepted: 02/24/2010] [Indexed: 05/17/2023]
Abstract
Essential oils from three Ethiopian medicinal plants; Hagenia abyssinica (Rosaceae), Leonotis ocymifolia (Lamiaceae), and Moringa stenopetala (Moringaceae) were investigated for their chemical composition, trypanocidal, and cytotoxic activities. Twenty components were identified from the essential oil of H. abyssinica female flowers, ledol (58.57%) being the principal volatile oil component. Sixty-eight components were identified from the essential oil of L. ocymifolia aerial part, caryophyllene oxide (12.06%) being the major component. The essential oil of M. stenopetala seeds was dominated by isothiocyanates; benzyl isothiocyanate (54.30%) and isobutyl isothiocyanate (16.37%) were the major components. The trypanocidal (Trypanosoma b. brucei) and antileukaemic (HL-60) effects of the three essential oils were studied. The oil of M. stenopetala seeds and its main compound, benzyl isothiocyanate showed the most potent trypanocidal activities with IC(50) values of 5.03 μg/ml and 1.20 μg/ml, respectively. The oils of H. abyssinica and L. ocymifolia exhibited trypanocidal activities with IC(50) values of 42.30 μg/ml and 15.41 μg/ml, respectively. Individual components (28 compounds) of the essential oils bearing different functional groups were also studied for their structure-activity relationships using trypanosomes and human leukaemia cells. Cinnamaldehyde (IC(50)=2.93 μg/ml) (a representative for aldehydes), nerolidol (IC(50)=15.78 μg/ml) (an alcohol), cedrene (IC(50)=4.07 μg/ml) (a hydrocarbon), benzyl isothiocyanate (IC(50)=1.20 μg/ml) (a representative for mustard oils), 1,8-cineole (IC(50)=83.15 μg/ml) (an ether), safrole (IC(50)=18.40 μg/ml) (aromatics with allyl and/or methoxy side chains), carvone (IC(50)=12.94μg/ml) (a ketone), styrene oxide (IC(50)=3.76 μg/ml) (an epoxide) and carvacrol (IC(50)=11.25 μg/ml) (a phenol) showed the most potent trypanocidal activities from their respective groups. Of all essential oil components tested, carvone (selectivity index (SI)=17.46) and styrene oxide (SI=19.92) showed good selective indices for the parasite with minimal toxicity on the human leukaemia cells. These compounds could therefore serve as lead structures for the development of trypanocidal agents with higher potency.
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Affiliation(s)
- E Nibret
- Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
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Boulangé AF, Khamadi SA, Pillay D, Coetzer THT, Authié E. Production of congopain, the major cysteine protease of Trypanosoma (Nannomonas) congolense, in Pichia pastoris reveals unexpected dimerisation at physiological pH. Protein Expr Purif 2010; 75:95-103. [PMID: 20828616 DOI: 10.1016/j.pep.2010.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 09/01/2010] [Accepted: 09/01/2010] [Indexed: 11/17/2022]
Abstract
African animal trypanosomosis (nagana) is arguably the most important parasitic disease affecting livestock in sub-Saharan Africa. Since none of the existing control measures are entirely satisfactory, vaccine development is being actively pursued. However, due to antigenic variation, the quest for a conventional vaccine has proven elusive. As a result, we have sought an alternative 'anti-disease vaccine approach', based on congopain, a cysteine protease of Trypanosoma congolense, which was shown to have pathogenic effects in vivo. Congopain was initially expressed as a recombinant protein in bacterial and baculovirus expression systems, but both the folding and yield obtained proved inadequate. Hence alternative expression systems were investigated, amongst which Pichia pastoris proved to be the most suitable. We report here the expression of full length, and C-terminal domain-truncated congopain in the methylotrophic yeast P. pastoris. Differences in yield were observed between full length and truncated proteins, the full length producing 2-4 mg of protein per litre of culture, while the truncated form produced 20-30 mg/l. The protease was produced as a proenzyme, but underwent spontaneous activation when acidified (pH <5). To investigate whether this activation was due to autolysis, we produced an inactive mutant (active site Cys→Ala) by site-directed mutagenesis. The mutant form was produced at a much higher rate, up to 100mg/l culture, as a proenzyme. It did not undergo spontaneous cleavage of the propeptide when subjected to acidic pH suggesting an autocatalytic process of activation for congopain. These recombinant proteins displayed a very unusual feature for cathepsin L-like proteinases, i.e. complete dimerisation at pH >6, and by reversibly monomerising at acidic pH <5. This attribute is of utmost importance in the context of an anti-disease vaccine, given that the epitopes recognised by the sera of trypanosome-infected trypanotolerant cattle appear dimer-specific.
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Affiliation(s)
- Alain F Boulangé
- UMR 17 IRD-CIRAD Trypanosomes, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France. ,
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Nibret E, Ashour ML, Rubanza CD, Wink M. Screening of some Tanzanian medicinal plants for their trypanocidal and cytotoxic activities. Phytother Res 2010; 24:945-7. [PMID: 19957246 DOI: 10.1002/ptr.3066] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The objective of the present study was to evaluate in vitro antitrypanosomal and cytotoxic activities of crude extracts of 20 traditionally used medicinal plants of Tanzania. A total of 40 extracts (dichloromethane and methanol) were screened for antiproliferative activity of bloodstream form of T. b. brucei and human leukaemia HL-60 cell. Inhibition of cell proliferation was assessed using resazurin as vital stain. Of the 40 extracts tested, the dichloromethane extract from bark of Warburgia salutaris (Canellaceae) exhibited the most potent antitrypanosomal activity with an IC(50) value of 10.68 microg/ml. A dichloromethane extract from Lannea stuhlmannii (Anacardiaceae) was found to be the most cytotoxic extract against HL-60 (IC(50) = 27.15 microg/ml). Out of the 20 plants tested, 5 plants exhibited trypanocidal activity with IC(50) values below 20 microg/ml. These 5 plants: Entandrophragma bussei (Meliaceae), Securidaca longepedunculata (Polygalaceae), Warburgia salutaris (Canellaceae), Zanha africana (Sapindaceae) and Zanthoxylum chalybeum (Rutaceae) could therefore serve as sources of lead compounds for treatment of trypanosomiasis.
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Affiliation(s)
- Endalkachew Nibret
- Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, Heidelberg, Germany
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Jia Y, Zhao X, Zou J, Suo X. Trypanosoma evansi: identification and characterization of a variant surface glycoprotein lacking cysteine residues in its C-terminal domain. Exp Parasitol 2010; 127:100-6. [PMID: 20599437 DOI: 10.1016/j.exppara.2010.06.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 06/19/2010] [Accepted: 06/29/2010] [Indexed: 12/17/2022]
Abstract
African trypanosomes are flagellated unicellular parasites which proliferate extracellularly in the mammalian host blood-stream and tissue spaces. They evade the hosts' antibody-mediated lyses by sequentially changing their variant surface glycoprotein (VSG). VSG tightly coats the entire parasite body, serving as a physical barrier. In Trypanosoma brucei and the closely related species Trypanosoma evansi, Trypanosoma equiperdum, each VSG polypeptide can be divided into N- and C-terminal domains, based on cysteine distribution and sequence homology. N-terminal domain, the basis of antigenic variation, is hypervariable and contains all the exposed epitopes; C-terminal domain is relatively conserved and a full set of four or eight cysteines were generally observed. We cloned two genes from two distinct variants of T. evansi, utilizing RT-PCR with VSG-specific primers. One contained a VSG type A N-terminal domain followed a C-terminal domain lacking cysteine residues. To confirm that this gene is expressed as a functional VSG, the expression and localization of the corresponding gene product were characterized using Western blotting and immunofluorescent staining of living trypanosomes. Expression analysis showed that this protein was highly expressed, variant-specific, and had a ubiquitous cellular surface localization. All these results indicated that it was expressed as a functional VSG. Our finding showed that cysteine residues in VSG C-terminal domain were not essential; the conserved C-terminal domain generally in T. brucei like VSGs would possibly evolve for regulating the VSG expression.
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Affiliation(s)
- Yonggen Jia
- Parasitology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
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Gohil S, Kats LM, Sturm A, Cooke BM. Recent insights into alteration of red blood cells by Babesia bovis: moovin' forward. Trends Parasitol 2010; 26:591-9. [PMID: 20598944 DOI: 10.1016/j.pt.2010.06.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 06/07/2010] [Accepted: 06/08/2010] [Indexed: 10/19/2022]
Abstract
Over the past decade or so, our understanding of the biology of apicomplexan parasites has increased dramatically, particularly in the case of malaria. Notable achievements are the availability of complete genome sequences, transcriptome and proteome profiles and the establishment of in vitro transfection techniques for asexual-stage malaria parasites. Interestingly, despite their major economic importance and striking similarities with malaria, Babesia parasites have been relatively ignored, but change is on the horizon. Here, we bring together recent work on Babesia bovis parasites which are beginning to unravel the molecular mechanisms that underlie the pathogenesis of babesiosis and highlight some opportunities and challenges that lie ahead.
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Affiliation(s)
- Sejal Gohil
- Department of Microbiology, Monash University, Victoria, Australia
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40
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Wheeler RJ. The trypanolytic factor-mechanism, impacts and applications. Trends Parasitol 2010; 26:457-64. [PMID: 20646962 DOI: 10.1016/j.pt.2010.05.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 05/19/2010] [Accepted: 05/20/2010] [Indexed: 11/25/2022]
Abstract
The Trypanosoma brucei subspecies T. brucei brucei is non-human infective due to susceptibility to lysis by trypanolytic factor (TLF) in human serum. Reviewed here are the advances which have revealed apolipoprotein L1 (ApoL1), found in high density lipoprotein, as the lysis-inducing component of TLF, the means of uptake via haptoglobin-related protein receptor and the mechanism of resistance in T. b. rhodesiense via its serum resistance-associated (SRA) protein. The first practical steps to application of these discoveries are now in progress; transgenic animals expressing either baboon or minimally truncated human ApoL1 show resistance to both T. b. brucei and T. b. rhodesiense. This has major implications for treatment and prevention of human and animal African trypanosomiasis.
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Affiliation(s)
- Richard J Wheeler
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK.
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Nibret E, Wink M. Volatile components of four Ethiopian Artemisia species extracts and their in vitro antitrypanosomal and cytotoxic activities. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2010; 17:369-374. [PMID: 19683909 DOI: 10.1016/j.phymed.2009.07.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 06/24/2009] [Accepted: 07/20/2009] [Indexed: 05/28/2023]
Abstract
Artemisia species are one of the many traditional medicinal plants of Ethiopia used for the treatment of infectious and non-infectious health problems. In the present study, eight extracts prepared from leaves and aerial parts of four Artemisia species (Artemisia absinthium, A. abyssinica, A. afra, and A. annua) growing in Ethiopia were tested in vitro against bloodstream forms of Trypanosoma brucei brucei. The most active extract was the dichloromethane extract from aerial parts of A. abyssinica with an IC(50) value of 19.13 microg/ml. A selectivity index (SI) of 8.24 was obtained with HL-60 cells treated with the same extract. Artemisinin, the best known antimalarial compound from A. annua showed antitrypanosomal activity with an IC(50) value of 35.91 microg/ml and with a selectivity index of 2.44. The dichloromethane extracts of the four species were further investigated for their volatile components using GLC/MS. Camphor was detected in the four species and was found to be the principal compound (38.73%) of A. absinthium extract. Octa-3,5-diene-2,7-dione, 4,5-dihydroxy was detected in three species except in A. afra and was present as the main volatile component (54.95%) of A. abyssinica. Epoxylinalool was detected only in A. afra and was the principal component (29.10%) of dichloromethane extract of the plant. Deoxyqinghaosu was only present in A. annua and absent in the other three Artemisia species. Deoxyqinghaosu was the principal volatile component (20.44%) of the dichloromethane extract of A. annua. In conclusion, the dichloromethane extract from aerial part of A. abyssinica should be considered for further study for the treatment of trypanosomiasis.
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Affiliation(s)
- Endalkachew Nibret
- Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
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Carvalho JA, Rodgers J, Atouguia J, Prazeres DMF, Monteiro GA. DNA vaccines: a rational design against parasitic diseases. Expert Rev Vaccines 2010; 9:175-91. [PMID: 20109028 DOI: 10.1586/erv.09.158] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Parasitic diseases are one of the most devastating causes of morbidity and mortality worldwide. Although immunization against these infections would be an ideal solution, the development of effective vaccines has been hampered by specific challenges posed by parasitic pathogens. Plasmid-based DNA vaccines may prove to be promising immunization tools in this area because vectors can be designed to integrate several antigens from different stages of the parasite life cycle or different subspecies; vaccines, formulations and immunization protocols can be tuned to match the immune response that offers protective immunity; and DNA vaccination is an affordable platform for developing countries. Partial and full protective immunity have been reported following DNA vaccination against the most significant parasitic diseases in the world.
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Affiliation(s)
- Joana A Carvalho
- Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
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Tan C, Hsia RC, Shou H, Carrasco JA, Rank RG, Bavoil PM. Variable expression of surface-exposed polymorphic membrane proteins in in vitro-grown Chlamydia trachomatis. Cell Microbiol 2010; 12:174-87. [PMID: 19811502 PMCID: PMC3073146 DOI: 10.1111/j.1462-5822.2009.01389.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hypothesized variable expression of polymorphic membrane proteins (PmpA-PmpI) in Chlamydia trachomatis-infected patients was tested by examination of the expression of each Pmp subtype in in vitro-grown C. trachomatis. A panel of monospecific polyclonal and monoclonal antibodies was used to demonstrate surface exposure of Pmps of each subtype by differential immunofluorescence (IF) with and without prior detergent permeabilization of paraformaldehyde-fixed inclusions and for selected Pmps by immunogold labelling. Although specific transcript was detected for each pmp gene late in development, IF experiments with Pmp subtype-specific antibodies reveal that a number of inclusions in a single infection do not express Pmps of a given subtype. Coexpression experiments suggest that pmp genes are shut off independently from one another in non-expressing inclusions, i.e. different inclusions are switched off for different Pmps. Overall, these studies establish the existence of an efficient shutoff mechanism independently affecting the expression of each member of the pmp gene family in in vitro-grown C. trachomatis. Like other paralogous gene families of bacterial pathogens, the pmp gene family of C. trachomatis may serve the critical dual function of a highly adaptable virulence factor also providing antigenic diversity in the face of the host adaptive immune response.
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Affiliation(s)
- Chun Tan
- Department of Microbial Pathogenesis, University of Maryland Dental School, 650 West Baltimore Street, Baltimore, MD 21201
| | - Ru-ching Hsia
- Department of Microbial Pathogenesis, University of Maryland Dental School, 650 West Baltimore Street, Baltimore, MD 21201
| | - Huizhong Shou
- Department of Microbial Pathogenesis, University of Maryland Dental School, 650 West Baltimore Street, Baltimore, MD 21201
| | - Jose A. Carrasco
- Department of Microbial Pathogenesis, University of Maryland Dental School, 650 West Baltimore Street, Baltimore, MD 21201
| | - Roger G. Rank
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences and Arkansas Children's Hospital Research Institute, 1120 Marshall St., Little Rock, AR, 72202, USA
| | - Patrik M. Bavoil
- Department of Microbial Pathogenesis, University of Maryland Dental School, 650 West Baltimore Street, Baltimore, MD 21201
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Weir W, Karagenç T, Baird M, Tait A, Shiels BR. Evolution and diversity of secretome genes in the apicomplexan parasite Theileria annulata. BMC Genomics 2010; 11:42. [PMID: 20082698 PMCID: PMC2826314 DOI: 10.1186/1471-2164-11-42] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 01/18/2010] [Indexed: 11/21/2022] Open
Abstract
Background Little is known about how apicomplexan parasites have evolved to infect different host species and cell types. Theileria annulata and Theileria parva invade and transform bovine leukocytes but each species favours a different host cell lineage. Parasite-encoded proteins secreted from the intracellular macroschizont stage within the leukocyte represent a critical interface between host and pathogen systems. Genome sequencing has revealed that several Theileria-specific gene families encoding secreted proteins are positively selected at the inter-species level, indicating diversification between the species. We extend this analysis to the intra-species level, focusing on allelic diversity of two major secretome families. These families represent a well-characterised group of genes implicated in control of the host cell phenotype and a gene family of unknown function. To gain further insight into their evolution and function, this study investigates whether representative genes of these two families are diversifying or constrained within the T. annulata population. Results Strong evidence is provided that the sub-telomerically encoded SVSP family and the host-nucleus targeted TashAT family have evolved under contrasting pressures within natural T. annulata populations. SVSP genes were found to possess atypical codon usage and be evolving neutrally, with high levels of nucleotide substitutions and multiple indels. No evidence of geographical sub-structuring of allelic sequences was found. In contrast, TashAT family genes, implicated in control of host cell gene expression, are strongly conserved at the protein level and geographically sub-structured allelic sequences were identified among Tunisian and Turkish isolates. Although different copy numbers of DNA binding motifs were identified in alleles of TashAT proteins, motif periodicity was strongly maintained, implying conserved functional activity of these sites. Conclusions This analysis provides evidence that two distinct secretome genes families have evolved under contrasting selective pressures. The data supports current hypotheses regarding the biological role of TashAT family proteins in the management of host cell phenotype that may have evolved to allow adaptation of T. annulata to a specific host cell lineage. We provide new evidence of extensive allelic diversity in representative members of the enigmatic SVSP gene family, which supports a putative role for the encoded products in subversion of the host immune response.
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Affiliation(s)
- William Weir
- Division of Veterinary Infection and Immunity, University of Glasgow, Faculty of Veterinary Medicine, Institute of Comparative Medicine, Bearsden Road, Glasgow, Scotland, G61 1QH, UK.
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Nibret E, Sporer F, Asres K, Wink M. Antitrypanosomal and cytotoxic activities of pyrrolizidine alkaloid-producing plants of Ethiopia. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.61.06.0014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Objectives
The objective was to determine the in-vitro effect of extracts from 19 Ethiopian plant species and four pure pyrrolizidine alkaloids on bloodstream forms of Trypanosoma brucei brucei and human leukaemia HL-60 cells.
Methods
Crude plant extracts were prepared using methanol and dichloromethane. The alkaloidal extracts from Solanecio angulatus flowers were prepared with and without zinc reduction using the acid-base extraction method. Cell proliferation inhibitory activity of the extracts and compounds was assessed using Alamarblue.
Key findings
The most active extract was the dichloromethane extract of Solanecio angulatus flowers, with an IC50 value of 12.17 μg/ml. The best selectivity index (SI > 41.08) was obtained for the same extract determined with HL-60 cells. The reduced alkaloidal extract prepared from S. angulatus flowers and after acid-base extraction showed more antitrypanosomal activity than unreduced alkaloidal extract with an IC50 value of 14.35 μg/ml and with a selectivity index of 12.23.
The second most active extract was the dichloromethane extract of Crotalaria phillipsiae twigs with an IC50 value of 12.67 μg/ml and a selectivity index of 34.35. Most of the other extracts tested showed moderate antitrypanosomal activities to variable extents. Among the four pure pyrrolizidine alkaloids tested, senecionine showed moderate antitrypanosomal activity with an IC50 value of 41.78 μg/ml.
Conclusions
Solanecio angulatus (flowers) and Crotalaria phillipsiae (twigs) could serve as sources of novel trypanocidal compounds for the treatment of trypanosomiasis.
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Affiliation(s)
- Endalkachew Nibret
- Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, Im Neuenheimer Feld 364, 69120, Heidelberg, Germany
| | - Frank Sporer
- Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, Im Neuenheimer Feld 364, 69120, Heidelberg, Germany
| | - Kaleab Asres
- Department of Pharmacognosy, School of Pharmacy, Addis Ababa University, Ethiopia
| | - Michael Wink
- Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, Im Neuenheimer Feld 364, 69120, Heidelberg, Germany
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Complexity of the MSG gene family of Pneumocystis carinii. BMC Genomics 2009; 10:367. [PMID: 19664205 PMCID: PMC2743713 DOI: 10.1186/1471-2164-10-367] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 08/07/2009] [Indexed: 11/17/2022] Open
Abstract
Background The relationship between the parasitic fungus Pneumocystis carinii and its host, the laboratory rat, presumably involves features that allow the fungus to circumvent attacks by the immune system. It is hypothesized that the major surface glycoprotein (MSG) gene family endows Pneumocystis with the capacity to vary its surface. This gene family is comprised of approximately 80 genes, which each are approximately 3 kb long. Expression of the MSG gene family is regulated by a cis-dependent mechanism that involves a unique telomeric site in the genome called the expression site. Only the MSG gene adjacent to the expression site is represented by messenger RNA. Several P. carinii MSG genes have been sequenced, which showed that genes in the family can encode distinct isoforms of MSG. The vast majority of family members have not been characterized at the sequence level. Results The first 300 basepairs of MSG genes were subjected to analysis herein. Analysis of 581 MSG sequence reads from P. carinii genomic DNA yielded 281 different sequences. However, many of the sequence reads differed from others at only one site, a degree of variation consistent with that expected to be caused by error. Accounting for error reduced the number of truly distinct sequences observed to 158, roughly twice the number expected if the gene family contains 80 members. The size of the gene family was verified by PCR. The excess of distinct sequences appeared to be due to allelic variation. Discounting alleles, there were 73 different MSG genes observed. The 73 genes differed by 19% on average. Variable regions were rich in nucleotide differences that changed the encoded protein. The genes shared three regions in which at least 16 consecutive basepairs were invariant. There were numerous cases where two different genes were identical within a region that was variable among family members as a whole, suggesting recombination among family members. Conclusion A set of sequences that represents most if not all of the members of the P. carinii MSG gene family was obtained. The protein-changing nature of the variation among these sequences suggests that the family has been shaped by selection for protein variation, which is consistent with the hypothesis that the MSG gene family functions to enhance phenotypic variation among the members of a population of P. carinii.
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Helm JR, Hertz-Fowler C, Aslett M, Berriman M, Sanders M, Quail MA, Soares MB, Bonaldo MF, Sakurai T, Inoue N, Donelson JE. Analysis of expressed sequence tags from the four main developmental stages of Trypanosoma congolense. Mol Biochem Parasitol 2009; 168:34-42. [PMID: 19559733 DOI: 10.1016/j.molbiopara.2009.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 06/15/2009] [Accepted: 06/16/2009] [Indexed: 10/20/2022]
Abstract
Trypanosoma congolense is one of the most economically important pathogens of livestock in Africa. Culture-derived parasites of each of the three main insect stages of the T. congolense life cycle, i.e., the procyclic, epimastigote and metacyclic stages, and bloodstream stage parasites isolated from infected mice, were used to construct stage-specific cDNA libraries and expressed sequence tags (ESTs or cDNA clones) in each library were sequenced. Thirteen EST clusters encoding different variant surface glycoproteins (VSGs) were detected in the metacyclic library and 26 VSG EST clusters were found in the bloodstream library, 6 of which are shared by the metacyclic library. Rare VSG ESTs are present in the epimastigote library, and none were detected in the procyclic library. ESTs encoding enzymes that catalyze oxidative phosphorylation and amino acid metabolism are about twice as abundant in the procyclic and epimastigote stages as in the metacyclic and bloodstream stages. In contrast, ESTs encoding enzymes involved in glycolysis, the citric acid cycle and nucleotide metabolism are about the same in all four developmental stages. Cysteine proteases, kinases and phosphatases are the most abundant enzyme groups represented by the ESTs. All four libraries contain T. congolense-specific expressed sequences not present in the Trypanosoma brucei and Trypanosoma cruzi genomes. Normalized cDNA libraries were constructed from the metacyclic and bloodstream stages, and found to be further enriched for T. congolense-specific ESTs. Given that cultured T. congolense offers an experimental advantage over other African trypanosome species, these ESTs provide a basis for further investigation of the molecular properties of these four developmental stages, especially the epimastigote and metacyclic stages for which it is difficult to obtain large quantities of organisms. The T. congolense EST databases are available at: http://www.sanger.ac.uk/Projects/T_congolense/EST_index.shtml. The sequence data have been submitted to EMBL under the following accession numbers: FN263376-FN292969.
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Affiliation(s)
- Jared R Helm
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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O'Gorman GM, Park SDE, Hill EW, Meade KG, Coussens PM, Agaba M, Naessens J, Kemp SJ, MacHugh DE. Transcriptional profiling of cattle infected with Trypanosoma congolense highlights gene expression signatures underlying trypanotolerance and trypanosusceptibility. BMC Genomics 2009; 10:207. [PMID: 19409086 PMCID: PMC2685408 DOI: 10.1186/1471-2164-10-207] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Accepted: 05/01/2009] [Indexed: 11/14/2022] Open
Abstract
Background African animal trypanosomiasis (AAT) caused by tsetse fly-transmitted protozoa of the genus Trypanosoma is a major constraint on livestock and agricultural production in Africa and is among the top ten global cattle diseases impacting on the poor. Here we show that a functional genomics approach can be used to identify temporal changes in host peripheral blood mononuclear cell (PBMC) gene expression due to disease progression. We also show that major gene expression differences exist between cattle from trypanotolerant and trypanosusceptible breeds. Using bovine long oligonucleotide microarrays and real time quantitative reverse transcription PCR (qRT-PCR) validation we analysed PBMC gene expression in naïve trypanotolerant and trypanosusceptible cattle experimentally challenged with Trypanosoma congolense across a 34-day infection time course. Results Trypanotolerant N'Dama cattle displayed a rapid and distinct transcriptional response to infection, with a ten-fold higher number of genes differentially expressed at day 14 post-infection compared to trypanosusceptible Boran cattle. These analyses identified coordinated temporal gene expression changes for both breeds in response to trypanosome infection. In addition, a panel of genes were identified that showed pronounced differences in gene expression between the two breeds, which may underlie the phenomena of trypanotolerance and trypanosusceptibility. Gene ontology (GO) analysis demonstrate that the products of these genes may contribute to increased mitochondrial mRNA translational efficiency, a more pronounced B cell response, an elevated activation status and a heightened response to stress in trypanotolerant cattle. Conclusion This study has revealed an extensive and diverse range of cellular processes that are altered temporally in response to trypanosome infection in African cattle. Results indicate that the trypanotolerant N'Dama cattle respond more rapidly and with a greater magnitude to infection compared to the trypanosusceptible Boran cattle. Specifically, a subset of the genes analyzed by real time qRT-PCR, which display significant breed differences, could collectively contribute to the trypanotolerance trait in N'Dama.
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Affiliation(s)
- Grace M O'Gorman
- Animal Genomics Laboratory, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD College of Life Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
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Vaughan AM, O'Neill MT, Tarun AS, Camargo N, Phuong TM, Aly ASI, Cowman AF, Kappe SHI. Type II fatty acid synthesis is essential only for malaria parasite late liver stage development. Cell Microbiol 2008; 11:506-20. [PMID: 19068099 PMCID: PMC2688669 DOI: 10.1111/j.1462-5822.2008.01270.x] [Citation(s) in RCA: 288] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Intracellular malaria parasites require lipids for growth and replication. They possess a prokaryotic type II fatty acid synthesis (FAS II) pathway that localizes to the apicoplast plastid organelle and is assumed to be necessary for pathogenic blood stage replication. However, the importance of FAS II throughout the complex parasite life cycle remains unknown. We show in a rodent malaria model that FAS II enzymes localize to the sporozoite and liver stage apicoplast. Targeted deletion of FabB/F, a critical enzyme in fatty acid synthesis, did not affect parasite blood stage replication, mosquito stage development and initial infection in the liver. This was confirmed by knockout of FabZ, another critical FAS II enzyme. However, FAS II-deficient Plasmodium yoelii liver stages failed to form exo-erythrocytic merozoites, the invasive stage that first initiates blood stage infection. Furthermore, deletion of FabI in the human malaria parasite Plasmodium falciparum did not show a reduction in asexual blood stage replication in vitro. Malaria parasites therefore depend on the intrinsic FAS II pathway only at one specific life cycle transition point, from liver to blood.
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