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Jan Van Den Abbeele - One of the best experts on this subject based on the ideXlab platform.
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The Tsetse Fly Displays an Attenuated Immune Response to Its Secondary Symbiont, Sodalis glossinidius.
Frontiers in microbiology, 2019Co-Authors: Katrien Trappeniers, Jan Van Den Abbeele, Irina Matetovici, Linda De VooghtAbstract:Sodalis glossinidius, a vertically transmitted facultative symbiont of the Tsetse Fly, is a bacterium in the early/intermediate state of its transition toward symbiosis, representing an important model for investigating how the insect host immune defense response is regulated to allow endosymbionts to establish a chronic infection within their hosts without being eliminated. In this study, we report on the establishment of a Tsetse Fly line devoid of S. glossinidius only, allowing us to experimentally investigate i) the complex immunological interactions between a single bacterial species and its host, ii) how the symbiont population is kept under control, and iii) the impact of the symbiont on the vector competence of the Tsetse Fly to transmit the sleeping sickness parasite. Comparative transcriptome analysis showed no difference in the expression of genes involved in innate immune processes between symbiont-harbouring (GmmSod+) and S. glossinidius-free (GmmSod-) flies. Re-exposure of (GmmSod-) flies to the endosymbiotic bacterium resulted in a moderate immune response, whereas exposure to pathogenic E. coli or to a close non-insect associated relative of S. glossinidius, i.e. S. praecaptivus, resulted in full immune activation. We also showed that S. glossinidius densities are not affected by experimental activation or suppression of the host immune system, indicating that S. glossinidius is resistant to mounted immune attacks and that the host immune system does not play a major role in controlling S. glossinidius proliferation. Finally, we demonstrate that the absence or presence of S. glossinidius in the Tsetse Fly does not alter its capacity to mount an immune response to pathogens nor does it affect the Fly’s susceptibility towards trypanosome infection.
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Innate immunity in the Tsetse Fly (Glossina), vector of African trypanosomes
Developmental and comparative immunology, 2019Co-Authors: Irina Matetovici, Linda De Vooght, Jan Van Den AbbeeleAbstract:Tsetse flies (Glossina sp.) are medically and veterinary important vectors of African trypanosomes, protozoan parasites that cause devastating diseases in humans and livestock in sub-Saharan Africa. These flies feed exclusively on vertebrate blood and harbor a limited diversity of obligate and facultative bacterial commensals. They have a well-developed innate immune system that plays a key role in protecting the Fly against invading pathogens and in modulating the Fly's ability to transmit African trypanosomes. In this review, we brieFly summarize our current knowledge on the Tsetse Fly innate immune system and its interaction with the bacterial commensals and the trypanosome parasite.
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Tsetse Fly tolerance to T. brucei infection: transcriptome analysis of trypanosome-associated changes in the Tsetse Fly salivary gland.
BMC genomics, 2016Co-Authors: Irina Matetovici, Guy Caljon, Jan Van Den AbbeeleAbstract:For their transmission, African trypanosomes rely on their blood feeding insect vector, the Tsetse Fly (Glossina sp.). The ingested Trypanosoma brucei parasites have to overcome a series of barriers in the Tsetse Fly alimentary tract to finally develop into the infective metacyclic forms in the salivary glands that are transmitted to a mammalian host by the Tsetse bite. The parasite population in the salivary gland is dense with a significant number of trypanosomes tightly attached to the epithelial cells. Our current knowledge on the impact of the infection on the salivary gland functioning is very limited. Therefore, this study aimed to gain a deeper insight into the global gene expression changes in the salivary glands of Glossina morsitans morsitans in response to an infection with the T. brucei parasite. A detailed whole transcriptome comparison of midgut-infected Tsetse with and without a mature salivary gland infection was performed to study the impact of a trypanosome infection on different aspects of the salivary gland functioning and the mechanisms that are induced in this tissue to tolerate the infection i.e. to control the negative impact of the parasite presence. Moreover, a transcriptome comparison with age-matched uninfected flies was done to see whether gene expression in the salivary glands is already affected by a trypanosome infection in the Tsetse midgut. By a RNA-sequencing (RNA-seq) approach we compared the whole transcriptomes of flies with a T. brucei salivary gland/midgut infection versus flies with only a midgut infection or versus non-infected flies, all with the same age and feeding history. More than 7500 salivary gland transcripts were detected from which a core group of 1214 differentially expressed genes (768 up- and 446 down-regulated) were shared between the two transcriptional comparisons. Gene Ontology enrichment analysis and detailed gene expression comparisons showed a diverse impact at the gene transcript level. Increased expression was observed for transcripts encoding for proteins involved in immunity (like several genes of the Imd-signaling pathway, serine proteases, serpins and thioester-containing proteins), detoxification of reactive species, cell death, cytoskeleton organization, cell junction and repair. Decreased expression was observed for transcripts encoding the major secreted proteins such as 5'-nucleotidases, adenosine deaminases and the nucleic acid binding proteins Tsals. Moreover, expression of some gene categories in the salivary glands were found to be already affected by a trypanosome midgut infection, before the parasite reaches the salivary glands. This study reveals that the T. brucei population in the Tsetse salivary gland has a negative impact on its functioning and on the integrity of the gland epithelium. Our RNA-seq data suggest induction of a strong local tissue response in order to control the epithelial cell damage, the ROS intoxication of the cellular environment and the parasite infection, resulting in the Fly tolerance to the infection. The modified expression of some gene categories in the Tsetse salivary glands by a trypanosome infection at the midgut level indicate a putative anticipatory response in the salivary glands, before the parasite reaches this tissue.
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Description of a nanobody-based competitive immunoassay to detect Tsetse Fly exposure.
PLoS neglected tropical diseases, 2015Co-Authors: Guy Caljon, Shahid Hussain, Lieve Vermeiren, Jan Van Den AbbeeleAbstract:Tsetse flies are the main vectors of human and animal African trypanosomes. The Tsal proteins in Tsetse Fly saliva were previously identified as suitable biomarkers of bite exposure. A new competitive assay was conceived based on nanobody (Nb) technology to ameliorate the detection of anti-Tsal antibodies in mammalian hosts. A camelid-derived Nb library was generated against the Glossina morsitans morsitans sialome and exploited to select Tsal specific Nbs. One of the three identified Nb families (family III, TsalNb-05 and TsalNb-11) was found suitable for anti-Tsal antibody detection in a competitive ELISA format. The competitive ELISA was able to detect exposure to a broad range of Tsetse species (G. morsitans morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes) and did not cross-react with the other hematophagous insects (Stomoxys calcitrans and Tabanus yao). Using a collection of plasmas from Tsetse-exposed pigs, the new test characteristics were compared with those of the previously described G. m. moristans and rTsal1 indirect ELISAs, revealing equally good specificities (> 95%) and positive predictive values (> 98%) but higher negative predictive values and hence increased sensitivity (> 95%) and accuracy (> 95%). We have developed a highly accurate Nb-based competitive immunoassay to detect specific anti-Tsal antibodies induced by various Tsetse Fly species in a range of hosts. We propose that this competitive assay provides a simple serological indicator of Tsetse Fly presence without the requirement of test adaptation to the vertebrate host species. In addition, the use of monoclonal Nbs for antibody detection is innovative and could be applied to other Tsetse Fly salivary biomarkers in order to achieve a multi-target immunoprofiling of hosts. In addition, this approach could be broadened to other pathogenic organisms for which accurate serological diagnosis remains a bottleneck.
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description of a nanobody based competitive immunoassay to detect Tsetse Fly exposure
PLOS Neglected Tropical Diseases, 2015Co-Authors: Guy Caljon, Shahid Hussain, Lieve Vermeiren, Jan Van Den AbbeeleAbstract:Background Tsetse flies are the main vectors of human and animal African trypanosomes. The Tsal proteins in Tsetse Fly saliva were previously identified as suitable biomarkers of bite exposure. A new competitive assay was conceived based on nanobody (Nb) technology to ameliorate the detection of anti-Tsal antibodies in mammalian hosts.
Guy Caljon - One of the best experts on this subject based on the ideXlab platform.
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Tsetse Fly tolerance to T. brucei infection: transcriptome analysis of trypanosome-associated changes in the Tsetse Fly salivary gland.
BMC genomics, 2016Co-Authors: Irina Matetovici, Guy Caljon, Jan Van Den AbbeeleAbstract:For their transmission, African trypanosomes rely on their blood feeding insect vector, the Tsetse Fly (Glossina sp.). The ingested Trypanosoma brucei parasites have to overcome a series of barriers in the Tsetse Fly alimentary tract to finally develop into the infective metacyclic forms in the salivary glands that are transmitted to a mammalian host by the Tsetse bite. The parasite population in the salivary gland is dense with a significant number of trypanosomes tightly attached to the epithelial cells. Our current knowledge on the impact of the infection on the salivary gland functioning is very limited. Therefore, this study aimed to gain a deeper insight into the global gene expression changes in the salivary glands of Glossina morsitans morsitans in response to an infection with the T. brucei parasite. A detailed whole transcriptome comparison of midgut-infected Tsetse with and without a mature salivary gland infection was performed to study the impact of a trypanosome infection on different aspects of the salivary gland functioning and the mechanisms that are induced in this tissue to tolerate the infection i.e. to control the negative impact of the parasite presence. Moreover, a transcriptome comparison with age-matched uninfected flies was done to see whether gene expression in the salivary glands is already affected by a trypanosome infection in the Tsetse midgut. By a RNA-sequencing (RNA-seq) approach we compared the whole transcriptomes of flies with a T. brucei salivary gland/midgut infection versus flies with only a midgut infection or versus non-infected flies, all with the same age and feeding history. More than 7500 salivary gland transcripts were detected from which a core group of 1214 differentially expressed genes (768 up- and 446 down-regulated) were shared between the two transcriptional comparisons. Gene Ontology enrichment analysis and detailed gene expression comparisons showed a diverse impact at the gene transcript level. Increased expression was observed for transcripts encoding for proteins involved in immunity (like several genes of the Imd-signaling pathway, serine proteases, serpins and thioester-containing proteins), detoxification of reactive species, cell death, cytoskeleton organization, cell junction and repair. Decreased expression was observed for transcripts encoding the major secreted proteins such as 5'-nucleotidases, adenosine deaminases and the nucleic acid binding proteins Tsals. Moreover, expression of some gene categories in the salivary glands were found to be already affected by a trypanosome midgut infection, before the parasite reaches the salivary glands. This study reveals that the T. brucei population in the Tsetse salivary gland has a negative impact on its functioning and on the integrity of the gland epithelium. Our RNA-seq data suggest induction of a strong local tissue response in order to control the epithelial cell damage, the ROS intoxication of the cellular environment and the parasite infection, resulting in the Fly tolerance to the infection. The modified expression of some gene categories in the Tsetse salivary glands by a trypanosome infection at the midgut level indicate a putative anticipatory response in the salivary glands, before the parasite reaches this tissue.
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description of a nanobody based competitive immunoassay to detect Tsetse Fly exposure
PLOS Neglected Tropical Diseases, 2015Co-Authors: Guy Caljon, Shahid Hussain, Lieve Vermeiren, Jan Van Den AbbeeleAbstract:Background Tsetse flies are the main vectors of human and animal African trypanosomes. The Tsal proteins in Tsetse Fly saliva were previously identified as suitable biomarkers of bite exposure. A new competitive assay was conceived based on nanobody (Nb) technology to ameliorate the detection of anti-Tsal antibodies in mammalian hosts.
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Description of a nanobody-based competitive immunoassay to detect Tsetse Fly exposure.
PLoS neglected tropical diseases, 2015Co-Authors: Guy Caljon, Shahid Hussain, Lieve Vermeiren, Jan Van Den AbbeeleAbstract:Tsetse flies are the main vectors of human and animal African trypanosomes. The Tsal proteins in Tsetse Fly saliva were previously identified as suitable biomarkers of bite exposure. A new competitive assay was conceived based on nanobody (Nb) technology to ameliorate the detection of anti-Tsal antibodies in mammalian hosts. A camelid-derived Nb library was generated against the Glossina morsitans morsitans sialome and exploited to select Tsal specific Nbs. One of the three identified Nb families (family III, TsalNb-05 and TsalNb-11) was found suitable for anti-Tsal antibody detection in a competitive ELISA format. The competitive ELISA was able to detect exposure to a broad range of Tsetse species (G. morsitans morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes) and did not cross-react with the other hematophagous insects (Stomoxys calcitrans and Tabanus yao). Using a collection of plasmas from Tsetse-exposed pigs, the new test characteristics were compared with those of the previously described G. m. moristans and rTsal1 indirect ELISAs, revealing equally good specificities (> 95%) and positive predictive values (> 98%) but higher negative predictive values and hence increased sensitivity (> 95%) and accuracy (> 95%). We have developed a highly accurate Nb-based competitive immunoassay to detect specific anti-Tsal antibodies induced by various Tsetse Fly species in a range of hosts. We propose that this competitive assay provides a simple serological indicator of Tsetse Fly presence without the requirement of test adaptation to the vertebrate host species. In addition, the use of monoclonal Nbs for antibody detection is innovative and could be applied to other Tsetse Fly salivary biomarkers in order to achieve a multi-target immunoprofiling of hosts. In addition, this approach could be broadened to other pathogenic organisms for which accurate serological diagnosis remains a bottleneck.
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delivery of a functional anti trypanosome nanobody in different Tsetse Fly tissues via a bacterial symbiont sodalis glossinidius
Microbial Cell Factories, 2014Co-Authors: Linda De Vooght, Guy Caljon, Jan Van Den Abbeele, Karina De RidderAbstract:Background Sodalis glossinidius, a vertically transmitted microbial symbiont of the Tsetse Fly, is currently considered as a potential delivery system for anti-trypanosomal components that reduce or eliminate the capability of the Tsetse Fly host to transmit parasitic trypanosomes, an approach also known as paratransgenesis. An essential step in developing paratransgenic Tsetse is the stable colonization of adult flies and their progeny with recombinant Sodalis bacteria, expressing trypanocidal effector molecules in tissues where the parasite resides.
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Delivery of a functional anti-trypanosome Nanobody in different Tsetse Fly tissues via a bacterial symbiont, Sodalis glossinidius
Microbial cell factories, 2014Co-Authors: Linda De Vooght, Guy Caljon, Karina De Ridder, Jan Van Den AbbeeleAbstract:Sodalis glossinidius, a vertically transmitted microbial symbiont of the Tsetse Fly, is currently considered as a potential delivery system for anti-trypanosomal components that reduce or eliminate the capability of the Tsetse Fly host to transmit parasitic trypanosomes, an approach also known as paratransgenesis. An essential step in developing paratransgenic Tsetse is the stable colonization of adult flies and their progeny with recombinant Sodalis bacteria, expressing trypanocidal effector molecules in tissues where the parasite resides. In this study, Sodalis was tested for its ability to deliver functional anti-trypanosome nanobodies (Nbs) in Glossina morsitans morsitans. We characterized the in vitro and in vivo stability of recombinant Sodalis (recSodalis) expressing a potent trypanolytic nanobody, i.e. Nb_An46. We show that recSodalis is competitive with WT Sodalis in in vivo conditions and that Tsetse flies transiently cleared of their endogenous WT Sodalis population can be successfully repopulated with recSodalis at high densities. In addition, vertical transmission to the offspring was observed. Finally, we demonstrated that recSodalis expressed significant levels (ng range) of functional Nb_An46 in different Tsetse Fly tissues, including the midgut where an important developmental stage of the trypanosome parasite occurs. We demonstrated the proof-of-concept that the Sodalis symbiont can be genetically engineered to express and release significant amounts of functional anti-trypanosome Nbs in different tissues of the Tsetse Fly. The application of this innovative concept of using pathogen-targeting nanobodies delivered by insect symbiotic bacteria could be extended to other vector-pathogen systems.
Serap Aksoy - One of the best experts on this subject based on the ideXlab platform.
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the population genomics of multiple Tsetse Fly glossina fuscipes fuscipes admixture zones in uganda
Molecular Ecology, 2019Co-Authors: Norah P. Saarman, Serap Aksoy, Kirstin Dion, Robert Opiro, Chaz Hyseni, Richard Echodu, Elizabeth A Opiyo, Thomas Johnson, Adalgisa CacconeAbstract:Understanding the mechanisms that enforce, maintain or reverse the process of speciation is an important challenge in evolutionary biology. This study investigates the patterns of divergence and discusses the processes that form and maintain divergent lineages of the Tsetse Fly Glossina fuscipes fuscipes in Uganda. We sampled 251 flies from 18 sites spanning known genetic lineages and the four admixture zones between them. We apply population genomics, hybrid zone and approximate Bayesian computation to the analysis of three types of genetic markers: 55,267 double-digest restriction site-associated DNA (ddRAD) SNPs to assess genome-wide admixture, 16 microsatellites to provide continuity with published data and accurate biogeographic modelling, and a 491-bp fragment of mitochondrial cytochrome oxidase I and II to infer maternal inheritance patterns. Admixture zones correspond with regions impacted by the reorganization of Uganda's river networks that occurred during the formation of the West African Rift system over the last several hundred thousand years. Because Tsetse Fly population distributions are defined by rivers, admixture zones likely represent both old and new regions of secondary contact. Our results indicate that older hybrid zones contain mostly parental types, while younger zones contain variable hybrid types resulting from multiple generations of interbreeding. These findings suggest that reproductive barriers are nearly complete in the older admixture zones, while nearly absent in the younger admixture zones. Findings are consistent with predictions of hybrid zone theory: Populations in zones of secondary contact transition rapidly from early to late stages of speciation or collapse all together.
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Transcriptome Profiling of Trypanosoma brucei Development in the Tsetse Fly Vector Glossina morsitans.
PloS one, 2016Co-Authors: Amy F. Savage, Serap Aksoy, Nikolay G. Kolev, Joseph B. Franklin, Aurélien Vigneron, Christian TschudiAbstract:African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals, have a complex digenetic life cycle between a mammalian host and an insect vector, the blood-feeding Tsetse Fly. Although the importance of the insect vector to transmit the disease was first realized over a century ago, many aspects of trypanosome development in Tsetse have not progressed beyond a morphological analysis, mainly due to considerable challenges to obtain sufficient material for molecular studies. Here, we used high-throughput RNA-Sequencing (RNA-Seq) to profile Trypanosoma brucei transcript levels in three distinct tissues of the Tsetse Fly, namely the midgut, proventriculus and salivary glands. Consistent with current knowledge and providing a proof of principle, transcripts coding for procyclin isoforms and several components of the cytochrome oxidase complex were highly up-regulated in the midgut transcriptome, whereas transcripts encoding metacyclic VSGs (mVSGs) and the surface coat protein brucei alanine rich protein or BARP were extremely up-regulated in the salivary gland transcriptome. Gene ontology analysis also supported the up-regulation of biological processes such as DNA metabolism and DNA replication in the proventriculus transcriptome and major changes in signal transduction and cyclic nucleotide metabolism in the salivary gland transcriptome. Our data highlight a small repertoire of expressed mVSGs and potential signaling pathways involving receptor-type adenylate cyclases and members of a surface carboxylate transporter family, called PADs (Proteins Associated with Differentiation), to cope with the changing environment, as well as RNA-binding proteins as a possible global regulators of gene expression.
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TonB-dependent heme iron acquisition in the Tsetse Fly symbiont Sodalis glossinidius
Applied and environmental microbiology, 2015Co-Authors: Gili Hrusa, Brian L. Weiss, Serap Aksoy, William Farmer, Taylor Applebaum, Jose Santinni Roma, Lauren Szeto, Laura Runyen-janeckyAbstract:Sodalis glossinidius is an intra- and extracellular symbiont of the Tsetse Fly (Glossina sp.), which feeds exclusively on vertebrate blood. S. glossinidius resides in a wide variety of Tsetse tissues and may encounter environments that differ dramatically in iron content. The Sodalis chromosome encodes a putative TonB-dependent outer membrane heme transporter (HemR) and a putative periplasmic/inner membrane ABC heme permease system (HemTUV). Because these gene products mediate iron acquisition processes by other enteric bacteria, we characterized their regulation and physiological role in the Sodalis/Tsetse system. Our results show that the hemR and tonB genes are expressed by S. glossinidius in the Tsetse Fly. Furthermore, transcription of hemR in Sodalis is repressed in a high-iron environment by the iron-responsive transcriptional regulator Fur. Expression of the S. glossinidius hemR and hemTUV genes in an Escherichia coli strain unable to use heme as an iron source stimulated growth in the presence of heme or hemoglobin as the sole iron source. This stimulation was dependent on the presence of either the E. coli or Sodalis tonB gene. Sodalis tonB and hemR mutant strains were defective in their ability to colonize the gut of Tsetse flies that lacked endogenous symbionts, while wild-type S. glossinidius proliferated in this same environment. Finally, we show that the Sodalis HemR protein is localized to the bacterial membrane and appears to bind hemin. Collectively, this study provides strong evidence that TonB-dependent, HemR-mediated iron acquisition is important for the maintenance of symbiont homeostasis in the Tsetse Fly, and it provides evidence for the expression of bacterial high-affinity iron acquisition genes in insect symbionts.
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Tissue distribution and transmission routes for the Tsetse Fly endosymbionts
Journal of Invertebrate Pathology, 2013Co-Authors: Séverine Balmand, Serap Aksoy, Claudia Lohs, Abdelaziz HeddiAbstract:The Tsetse Fly Glossina is the vector of the protozoan Trypanosoma brucei spp., which causes Human and Animal African Trypanosomiasis in sub-Saharan African countries. To supplement their unbalanced vertebrate bloodmeal diet, flies permanently harbor the obligate bacterium Wigglesworthia glossinidia, which resides in bacteriocytes in the midgut bacteriome organ as well as in milk gland organ. Tsetse flies also harbor the secondary facultative endosymbionts (S-symbiont) Sodalis glossinidius that infects various tissues and Wolbachia that infects germ cells. Tsetse flies display viviparous reproductive biology where a single embryo hatches and completes its entire larval development in utero and receives nourishments in the form of milk secreted by mother's accessory glands (milk glands). To analyze the precise tissue distribution of the three endosymbiotic bacteria and to infer the way by which each symbiotic partner is transmitted from parent to progeny, we conducted a Fluorescence In situ Hybridization (FISH) study to survey bacterial spatial distribution across the Fly tissues. We show that bacteriocytes are mono-infected with Wigglesworthia, while both Wigglesworthia and Sodalis are present in the milk gland lumen. Sodalis was further seen in the uterus, spermathecae, fat body, milk and intracellular in the milk gland cells. Contrary to Wigglesworthia and Sodalis, Wolbachia were the only bacteria infecting oocytes, trophocytes, and embryos at early embryonic stages. Furthermore, Wolbachia were not seen in the milk gland and in the fat body. This work further highlights the diversity of symbiont interactions in multipartner associations and supports two maternal routes of symbiont inheritance in the Tsetse Fly: Wolbachia through oocytes, and, Wigglesworthia and Sodalis by means of milk gland bacterial infection at early post-embryonic stages. Copyright (c) International Atomic Energy Agency 2013. Published by Elsevier Inc. All Rights Reserved.
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Tissue distribution and transmission routes for the Tsetse Fly endosymbionts.
Journal of invertebrate pathology, 2012Co-Authors: Séverine Balmand, Serap Aksoy, Claudia Lohs, Abdelaziz HeddiAbstract:The Tsetse Fly Glossina is the vector of the protozoan Trypanosoma brucei spp., which causes Human and Animal African Trypanosomiasis in sub-Saharan African countries. To supplement their unbalanced vertebrate bloodmeal diet, flies permanently harbor the obligate bacterium Wigglesworthia glossinidia, which resides in bacteriocytes in the midgut bacteriome organ as well as in milk gland organ. Tsetse flies also harbor the secondary facultative endosymbionts (S-symbiont) Sodalis glossinidius that infects various tissues and Wolbachia that infects germ cells. Tsetse flies display viviparous reproductive biology where a single embryo hatches and completes its entire larval development in utero and receives nourishments in the form of milk secreted by mother's accessory glands (milk glands). To analyze the precise tissue distribution of the three endosymbiotic bacteria and to infer the way by which each symbiotic partner is transmitted from parent to progeny, we conducted a Fluorescence In situ Hybridization (FISH) study to survey bacterial spatial distribution across the Fly tissues. We show that bacteriocytes are mono-infected with Wigglesworthia, while both Wigglesworthia and Sodalis are present in the milk gland lumen. Sodalis was further seen in the uterus, spermathecae, fat body, milk and intracellular in the milk gland cells. Contrary to Wigglesworthia and Sodalis, Wolbachia were the only bacteria infecting oocytes, trophocytes, and embryos at early embryonic stages. Furthermore, Wolbachia were not seen in the milk gland and in the fat body. This work further highlights the diversity of symbiont interactions in multipartner associations and supports two maternal routes of symbiont inheritance in the Tsetse Fly: Wolbachia through oocytes, and, Wigglesworthia and Sodalis by means of milk gland bacterial infection at early post-embryonic stages.
Abdelaziz Heddi - One of the best experts on this subject based on the ideXlab platform.
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Tissue distribution and transmission routes for the Tsetse Fly endosymbionts
Journal of Invertebrate Pathology, 2013Co-Authors: Séverine Balmand, Serap Aksoy, Claudia Lohs, Abdelaziz HeddiAbstract:The Tsetse Fly Glossina is the vector of the protozoan Trypanosoma brucei spp., which causes Human and Animal African Trypanosomiasis in sub-Saharan African countries. To supplement their unbalanced vertebrate bloodmeal diet, flies permanently harbor the obligate bacterium Wigglesworthia glossinidia, which resides in bacteriocytes in the midgut bacteriome organ as well as in milk gland organ. Tsetse flies also harbor the secondary facultative endosymbionts (S-symbiont) Sodalis glossinidius that infects various tissues and Wolbachia that infects germ cells. Tsetse flies display viviparous reproductive biology where a single embryo hatches and completes its entire larval development in utero and receives nourishments in the form of milk secreted by mother's accessory glands (milk glands). To analyze the precise tissue distribution of the three endosymbiotic bacteria and to infer the way by which each symbiotic partner is transmitted from parent to progeny, we conducted a Fluorescence In situ Hybridization (FISH) study to survey bacterial spatial distribution across the Fly tissues. We show that bacteriocytes are mono-infected with Wigglesworthia, while both Wigglesworthia and Sodalis are present in the milk gland lumen. Sodalis was further seen in the uterus, spermathecae, fat body, milk and intracellular in the milk gland cells. Contrary to Wigglesworthia and Sodalis, Wolbachia were the only bacteria infecting oocytes, trophocytes, and embryos at early embryonic stages. Furthermore, Wolbachia were not seen in the milk gland and in the fat body. This work further highlights the diversity of symbiont interactions in multipartner associations and supports two maternal routes of symbiont inheritance in the Tsetse Fly: Wolbachia through oocytes, and, Wigglesworthia and Sodalis by means of milk gland bacterial infection at early post-embryonic stages. Copyright (c) International Atomic Energy Agency 2013. Published by Elsevier Inc. All Rights Reserved.
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Tissue distribution and transmission routes for the Tsetse Fly endosymbionts.
Journal of invertebrate pathology, 2012Co-Authors: Séverine Balmand, Serap Aksoy, Claudia Lohs, Abdelaziz HeddiAbstract:The Tsetse Fly Glossina is the vector of the protozoan Trypanosoma brucei spp., which causes Human and Animal African Trypanosomiasis in sub-Saharan African countries. To supplement their unbalanced vertebrate bloodmeal diet, flies permanently harbor the obligate bacterium Wigglesworthia glossinidia, which resides in bacteriocytes in the midgut bacteriome organ as well as in milk gland organ. Tsetse flies also harbor the secondary facultative endosymbionts (S-symbiont) Sodalis glossinidius that infects various tissues and Wolbachia that infects germ cells. Tsetse flies display viviparous reproductive biology where a single embryo hatches and completes its entire larval development in utero and receives nourishments in the form of milk secreted by mother's accessory glands (milk glands). To analyze the precise tissue distribution of the three endosymbiotic bacteria and to infer the way by which each symbiotic partner is transmitted from parent to progeny, we conducted a Fluorescence In situ Hybridization (FISH) study to survey bacterial spatial distribution across the Fly tissues. We show that bacteriocytes are mono-infected with Wigglesworthia, while both Wigglesworthia and Sodalis are present in the milk gland lumen. Sodalis was further seen in the uterus, spermathecae, fat body, milk and intracellular in the milk gland cells. Contrary to Wigglesworthia and Sodalis, Wolbachia were the only bacteria infecting oocytes, trophocytes, and embryos at early embryonic stages. Furthermore, Wolbachia were not seen in the milk gland and in the fat body. This work further highlights the diversity of symbiont interactions in multipartner associations and supports two maternal routes of symbiont inheritance in the Tsetse Fly: Wolbachia through oocytes, and, Wigglesworthia and Sodalis by means of milk gland bacterial infection at early post-embryonic stages.
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Interspecific Transfer of Bacterial Endosymbionts between Tsetse Fly Species: Infection Establishment and Effect on Host Fitness
Applied and environmental microbiology, 2006Co-Authors: Brian L. Weiss, Rosa Mouchotte, Rita V. M. Rio, Abdelaziz Heddi, Serap AksoyAbstract:Tsetse flies (Glossina spp.) can harbor up to three distinct species of endosymbiotic bacteria that exhibit unique modes of transmission and evolutionary histories with their host. Two mutualist enterics, Wigglesworthia and Sodalis, are transmitted maternally to Tsetse flies' intrauterine larvae. The third symbiont, from the genus Wolbachia, parasitizes developing oocytes. In this study, we determined that Sodalis isolates from several Tsetse Fly species are virtually identical based on a phylogenetic analysis of their ftsZ gene sequences. Furthermore, restriction fragment-length polymorphism analysis revealed little variation in the genomes of Sodalis isolates from Tsetse Fly species within different subgenera (Glossina fuscipes fuscipes and Glossina morsitans morsitans). We also examined the impact on host fitness of transinfecting G. fuscipes fuscipes and G. morsitans morsitans flies with reciprocal Sodalis strains. Tsetse flies cleared of their native Sodalis symbionts were successfully repopulated with the Sodalis species isolated from a different Tsetse Fly species. These transinfected flies effectively transmitted the novel symbionts to their offspring and experienced no detrimental fitness effects compared to their wild-type counterparts, as measured by longevity and fecundity. Quantitative PCR analysis revealed that transinfected flies maintained their Sodalis populations at densities comparable to those in flies harboring native symbionts. Our ability to transinfect Tsetse flies is indicative of Sodalis ' recent evolutionary history with its Tsetse Fly host and demonstrates that this procedure may be used as a means of streamlining future paratransgenesis experiments.
Marc Coosemans - One of the best experts on this subject based on the ideXlab platform.
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Functional analysis of the twin-arginine translocation pathway in Sodalis glossinidius, a bacterial symbiont of the Tsetse Fly.
Applied and environmental microbiology, 2010Co-Authors: Linda De Vooght, Guy Caljon, Marc Coosemans, Jan Van Den AbbeeleAbstract:This study demonstrates a functional twin-arginine (Tat) translocation pathway present in the Tsetse Fly symbiont Sodalis glossinidius and its potential to export active heterologous proteins to the periplasm. Functionality was demonstrated using green fluorescent protein (GFP) fused to the Tat signal peptide of Escherichia coli trimethylamine N-oxide reductase (TorA).
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Identification of a Tsetse Fly Salivary Protein with Dual Inhibitory Action on Human Platelet Aggregation
PloS one, 2010Co-Authors: Guy Caljon, Karin De Ridder, Marc Coosemans, Patrick De Baetselier, Jan Van Den AbbeeleAbstract:Tsetse flies (Glossina sp.), the African trypanosome vectors, rely on anti-hemostatic compounds for efficient blood feeding. Despite their medical importance, very few salivary proteins have been characterized and functionally annotated. Here we report on the functional characterisation of a 5'nucleotidase-related (5'Nuc) saliva protein of the Tsetse Fly Glossina morsitans morsitans. This protein is encoded by a 1668 bp cDNA corresponding at the genomic level with a single-copy 4 kb gene that is exclusively transcribed in the Tsetse salivary gland tissue. The encoded 5'Nuc protein is a soluble 65 kDa glycosylated compound of Tsetse saliva with a dual anti-hemostatic action that relies on its combined apyrase activity and fibrinogen receptor (GPIIb/IIIa) antagonistic properties. Experimental evidence is based on the biochemical and functional characterization of recombinant protein and on the successful silencing of the 5'nuc translation in the salivary gland by RNA interference (RNAi). Refolding of a 5'Nuc/SUMO-fusion protein yielded an active apyrase enzyme with K(m) and V(max) values of 43+/-4 microM and 684+/-49 nmol Pi/min xmg for ATPase and 49+/-11 microM and 177+/-37 nmol Pi/min xmg for the ADPase activity. In addition, recombinant 5'Nuc was found to bind to GPIIb/IIIa with an apparent K(D) of 92+/-25 nM. Consistent with these features, 5'Nuc potently inhibited ADP-induced thrombocyte aggregation and even caused disaggregation of ADP-triggered human platelets. The importance of 5'Nuc for the Tsetse Fly hematophagy was further illustrated by specific RNAi that reduced the anti-thrombotic activities in saliva by approximately 50% resulting in a disturbed blood feeding process. These data show that this 5'nucleotidase-related apyrase exhibits GPIIb/IIIa antagonistic properties and represents a key thromboregulatory compound of Tsetse Fly saliva.
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Identification of a functional Antigen5-related allergen in the saliva of a blood feeding insect, the Tsetse Fly.
Insect biochemistry and molecular biology, 2009Co-Authors: Guy Caljon, Katleen Broos, Ine De Goeyse, Karin De Ridder, Jeremy M Sternberg, Marc Coosemans, Patrick De Baetselier, Yves Guisez, Jan Van Den AbbeeleAbstract:Our previous screening of a Glossina morsitans morsitans lamdagt11 salivary gland expression library with serum of a Tsetse Fly exposed rabbit identified a cDNA encoding Tsetse Antigen5 (TAg5, 28.9 kDa), a homologue of Antigen5 sting venom allergens. Recombinant TAg5 was produced in Sf9 cells in order to assess its immunogenic properties in humans. Plasma from a patient that previously exhibited anaphylactic reactions against Tsetse Fly bites contained circulating anti-TAg5 and anti-saliva IgEs. In a significant proportion of plasma samples of African individuals, TAg5 and saliva binding IgEs (respectively 56 and 65%) can be detected. Saliva, harvested from flies that were subjected to TAg5- specific RNA interference (RNAi), displayed significantly reduced IgE binding potential. Allergenic properties of TAg5 and Tsetse Fly saliva were further illustrated in immunized mice, using an immediate cutaneous hypersensitivity and passive cutaneous anaphylaxis assay. Collectively, TAg5 was illustrated to be a Tsetse Fly salivary allergen, demonstrating that Antigen5-related proteins are represented as functional allergens not only in stinging but also in blood feeding insects.
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The Glossina morsitans Tsetse Fly saliva: general characteristics and identification of novel salivary proteins.
Insect biochemistry and molecular biology, 2007Co-Authors: J. Van Den Abbeele, Guy Caljon, Jean-françois Dierick, Lotte N. Moens, K. De Ridder, Marc CoosemansAbstract:The Tsetse Fly (Glossina spp.) is an obligate blood-sucking insect that transmits different human-pathogenic and livestock threatening trypanosome species in Africa. To obtain more insight in the Tsetse salivary function, some general aspects of the Tsetse Fly saliva and its composition were studied. Direct pH and protein content measurements revealed a moderately alkaline (pH approximately 8.0) salivary environment with approximately 4.3 microg soluble proteins per gland and a constant representation of the major saliva proteins throughout the blood-feeding cycle. Although major salivary genes are constitutively expressed, upregulation of salivary protein synthesis within 48 h after the blood meal ensures complete protein replenishment from day 3 onwards. Screening of a non-normalised Glossina morsitans morsitans lambdagt11 salivary gland expression library with serum from a saliva-immunized rabbit identified three full-length cDNAs encoding for novel salivary proteins with yet unknown functions: a 8.3 kDa glycine/glutamate-rich protein (G. morsitans morsitans salivary gland protein Gmmsgp1), a 12.0 kDa proline-rich protein (Gmmsgp2), and a 97.4 kDa protein composed of a metallophosphoesterase/5'nucleotidase region with a glutamate/aspartate/asparagines-rich region (Gmmsgp3).
