Organotypic endothelial adhesion molecules are key for Trypanosoma brucei tropism and virulence

Trypanosoma brucei is responsible for lethal diseases in humans and cattle in Sub-Saharan Africa. These extracellular parasites extravasate from the blood circulation into several tissues. The importance of the vasculature in tissue tropism is poorly understood. Using intravital imaging and bioluminescence, we found that gonadal white adipose tissue and pancreas are the two main parasite reservoirs. We show that reservoir establishment happens before vascular permeability is compromised, suggesting that extravasation is an active mechanism. Blocking endothelial surface adhesion molecules (E-selectin, P-selectins, or ICAM2) significantly reduced extravascular parasite load in all organs and delayed host lethality. Remarkably, blocking CD36 had a specific effect on adipose tissue tropism that was sufficient to delay lethality, suggesting that establishment of the adipose tissue reservoir is necessary for parasite virulence. This works demonstrates the importance of the vasculature in a T. brucei infection and identifies organ-specific adhesion molecules as key players for tissue tropism.

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Antioxidants promote establishment of trypanosome infections in tsetse

Parasitology ◽

10.1017/s0031182007002247 ◽

2007 ◽

Vol 134 (6) ◽

pp. 827-831 ◽

Cited By ~ 72

Author(s):

E. T. MacLEOD ◽

I. MAUDLIN ◽

A. C. DARBY ◽

S. C. WELBURN

Keyword(s):

Reactive Oxygen Species ◽

Cell Death ◽

Trypanosoma Brucei ◽

Sub Saharan Africa ◽

Tsetse Flies ◽

Oxygen Species ◽

Infection Rates ◽

Trypanosoma Brucei Brucei ◽

Sub Saharan ◽

Cyclical Transmission

SUMMARYEfficient, cyclical transmission of trypanosomes through tsetse flies is central to maintenance of human sleeping sickness and nagana across sub-Saharan Africa. Infection rates in tsetse are normally very low as most parasites ingested with the fly bloodmeal die in the fly gut, displaying the characteristics of apoptotic cells. Here we show that a range of antioxidants (glutathione, cysteine, N-acetyl-cysteine, ascorbic acid and uric acid), when added to the insect bloodmeal, can dramatically inhibit cell death of Trypanosoma brucei brucei in tsetse. Both L- and D-cysteine invoked similar effects suggesting that inhibition of trypanosome death is not dependent on protein synthesis. The present work suggests that antioxidants reduce the midgut environment protecting trypanosomes from cell death induced by reactive oxygen species.

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Salivarian Trypanosomes Have Adopted Intricate Host-Pathogen Interaction Mechanisms that Ensure Survival in Plain Sight of the Adaptive Immune System

Pathogens ◽

10.3390/pathogens10060679 ◽

2021 ◽

Vol 10 (6) ◽

pp. 679

Author(s):

Stefan Magez ◽

Joar Esteban Pinto Torres ◽

Seoyeon Oh ◽

Magdalena Radwanska

Keyword(s):

Immune System ◽

Trypanosoma Brucei ◽

Adaptive Immune System ◽

Sub Saharan Africa ◽

Survival Strategies ◽

Mechanical Transmission ◽

Sub Saharan ◽

Animal Trypanosomiasis ◽

Host Parasite ◽

Treatment And Diagnosis

Salivarian trypanosomes are extracellular parasites affecting humans, livestock and game animals. Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense are human infective sub-species of T. brucei causing human African trypanosomiasis (HAT—sleeping sickness). The related T. b. brucei parasite lacks the resistance to survive in human serum, and only inflicts animal infections. Animal trypanosomiasis (AT) is not restricted to Africa, but is present on all continents. T. congolense and T. vivax are the most widespread pathogenic trypanosomes in sub-Saharan Africa. Through mechanical transmission, T. vivax has also been introduced into South America. T. evansi is a unique animal trypanosome that is found in vast territories around the world and can cause atypical human trypanosomiasis (aHT). All salivarian trypanosomes are well adapted to survival inside the host’s immune system. This is not a hostile environment for these parasites, but the place where they thrive. Here we provide an overview of the latest insights into the host-parasite interaction and the unique survival strategies that allow trypanosomes to outsmart the immune system. In addition, we review new developments in treatment and diagnosis as well as the issues that have hampered the development of field-applicable anti-trypanosome vaccines for the implementation of sustainable disease control.

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Organotypic Endothelial Adhesion Molecules are Key For Trypanosoma Brucei Tropism and Virulence

SSRN Electronic Journal ◽

10.2139/ssrn.3821966 ◽

2021 ◽

Author(s):

Mariana De Niz ◽

Daniela Bras ◽

Mafalda Pedro ◽

Ana Margarida Nascimento ◽

Claudio Franco ◽

...

Keyword(s):

Adhesion Molecules ◽

Trypanosoma Brucei ◽

Endothelial Adhesion Molecules

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Faculty Opinions recommendation of Organotypic endothelial adhesion molecules are key for Trypanosoma brucei tropism and virulence.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.740845419.793590372 ◽

2021 ◽

Author(s):

Cynthia He

Keyword(s):

Adhesion Molecules ◽

Trypanosoma Brucei ◽

Endothelial Adhesion Molecules

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Proteomics and theTrypanosoma bruceicytoskeleton: advances and opportunities

Parasitology ◽

10.1017/s0031182012000443 ◽

2012 ◽

Vol 139 (9) ◽

pp. 1168-1177 ◽

Cited By ~ 10

Author(s):

NEIL PORTMAN ◽

KEITH GULL

Keyword(s):

Life Cycle ◽

Trypanosoma Brucei ◽

Cell Biology ◽

Molecular Composition ◽

Etiological Agent ◽

Sub Saharan Africa ◽

Parasitic Disease ◽

Cell Cycles ◽

Sub Saharan ◽

High Level

SUMMARYTrypanosoma bruceiis the etiological agent of devastating parasitic disease in humans and livestock in sub-saharan Africa. The pathogenicity and growth of the parasite are intimately linked to its shape and form. This is in turn derived from a highly ordered microtubule cytoskeleton that forms a tightly arrayed cage directly beneath the pellicular membrane and numerous other cytoskeletal structures such as the flagellum. The parasite undergoes extreme changes in cellular morphology during its life cycle and cell cycles which require a high level of integration and coordination of cytoskeletal processes. In this review we will discuss the role that proteomics techniques have had in advancing our understanding of the molecular composition of the cytoskeleton and its functions. We then consider future opportunities for the application of these techniques in terms of addressing some of the unanswered questions of trypanosome cytoskeletal cell biology with particular focus on the differences in the composition and organisation of the cytoskeleton through the trypanosome life-cycle.

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Mechanisms of Arsenical and Diamidine Uptake and Resistance in Trypanosoma brucei

Eukaryotic Cell ◽

10.1128/ec.2.5.1003-1008.2003 ◽

2003 ◽

Vol 2 (5) ◽

pp. 1003-1008 ◽

Cited By ~ 138

Author(s):

Enock Matovu ◽

Mhairi L. Stewart ◽

Federico Geiser ◽

Reto Brun ◽

Pascal Mäser ◽

...

Keyword(s):

Trypanosoma Brucei ◽

Drug Sensitivity ◽

Sleeping Sickness ◽

Drug Uptake ◽

Sub Saharan Africa ◽

Parental Line ◽

Adenosine Transport ◽

Sub Saharan ◽

High Level

ABSTRACT Sleeping sickness, caused by Trypanosoma brucei spp., has become resurgent in sub-Saharan Africa. Moreover, there is an alarming increase in treatment failures with melarsoprol, the principal agent used against late-stage sleeping sickness. In T. brucei, the uptake of melarsoprol as well as diamidines is thought to be mediated by the P2 aminopurine transporter, and loss of P2 function has been implicated in resistance to these agents. The trypanosomal gene TbAT1 has been found to encode a P2-type transporter when expressed in yeast. Here we investigate the role of TbAT1 in drug uptake and drug resistance in T. brucei by genetic knockout of TbAT1. Tbat1-null trypanosomes were deficient in P2-type adenosine transport and lacked adenosine-sensitive transport of pentamidine and melaminophenyl arsenicals. However, the null mutants were only slightly resistant to melaminophenyl arsenicals and pentamidine, while resistance to other diamidines such as diminazene was more pronounced. Nevertheless, the reduction in drug sensitivity might be of clinical significance, since mice infected with tbat1-null trypanosomes could not be cured with 2 mg of melarsoprol/kg of body weight for four consecutive days, whereas mice infected with the parental line were all cured by using this protocol. Two additional pentamidine transporters, HAPT1 and LAPT1, were still present in the null mutant, and evidence is presented that HAPT1 may be responsible for the residual uptake of melaminophenyl arsenicals. High-level arsenical resistance therefore appears to involve the loss of more than one transporter.

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Novel protein candidates for serodiagnosis of African animal trypanosomosis: Evaluation of the diagnostic potential of lysophospholipase and glycerol kinase from Trypanosoma brucei

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009985 ◽

2021 ◽

Vol 15 (12) ◽

pp. e0009985

Author(s):

Magamba Tounkara ◽

Alain Boulangé ◽

Magali Thonnus ◽

Frédéric Bringaud ◽

Adrien Marie Gaston Bélem ◽

...

Keyword(s):

Trypanosoma Brucei ◽

Sub Saharan Africa ◽

Tsetse Flies ◽

African Countries ◽

Human Form ◽

Novel Proteins ◽

Diagnostic Potential ◽

Sub Saharan ◽

Better Than ◽

Novel Protein

African trypanosomosis, a parasitic disease caused by protozoan parasites transmitted by tsetse flies, affects both humans and animals in sub-Saharan Africa. While the human form (HAT) is now limited to foci, the animal form (AAT) is widespread and affects the majority of sub-Saharan African countries, and constitutes a real obstacle to the development of animal breeding. The control of AAT is hampered by a lack of standardized and easy-to used diagnosis tools. This study aimed to evaluate the diagnostic potential of TbLysoPLA and TbGK proteins from Trypanosoma brucei brucei for AAT serodiagnosis in indirect ELISA using experimental and field sera, individually, in combination, and associated with the BiP C-terminal domain (C25) from T. congolense. These novel proteins were characterized in silico, and their sequence analysis showed strong identities with their orthologs in other trypanosomes (more than 60% for TbLysoPLA and more than 82% for TbGK). TbLysoPLA displays a low homology with cattle (<35%) and Piroplasma (<15%). However, TbGK shares more than 58% with cattle and between 45–55% with Piroplasma. We could identify seven predicted epitopes on TbLysoPLA sequence and 14 potential epitopes on TbGK. Both proteins were recombinantly expressed in Escherichia coli. Their diagnostic potential was evaluated by ELISA with sera from cattle experimentally infected with T. congolense and with T.b. brucei, sera from cattle naturally infected with T. congolense, T. vivax and T.b. brucei. Both proteins used separately had poor diagnostic performance. However, used together with the BiP protein, they showed 60% of sensitivity and between 87–96% of specificity, comparable to reference ELISA tests. In conclusion, we showed that the performance of the protein combinations is much better than the proteins tested individually for the diagnosis of AAT.

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Highly Localized Enrichment of Trypanosoma brucei Parasites Using Dielectrophoresis

Micromachines ◽

10.3390/mi11060625 ◽

2020 ◽

Vol 11 (6) ◽

pp. 625

Author(s):

Devin Keck ◽

Callie Stuart ◽

Josie Duncan ◽

Emily Gullette ◽

Rodrigo Martinez-Duarte

Keyword(s):

Rural Communities ◽

Trypanosoma Brucei ◽

Serological Test ◽

A Priori ◽

Sub Saharan Africa ◽

Field Gradients ◽

High Enrichment ◽

Vector Borne ◽

Sub Saharan

Human African trypanosomiasis (HAT), also known as sleeping sickness, is a vector-borne neglected tropical disease endemic to rural sub-Saharan Africa. Current methods of early detection in the affected rural communities generally begin with general screening using the card agglutination test for trypanosomiasis (CATT), a serological test. However, the gold standard for confirmation of trypanosomiasis remains the direct observation of the causative parasite, Trypanosoma brucei. Here, we present the use of dielectrophoresis (DEP) to enrich T. brucei parasites in specific locations to facilitate their identification in a future diagnostic assay. DEP refers to physical movement that can be selectively induced on the parasites when exposing them to electric field gradients of specific magnitude, phase and frequency. The long-term goal of our work is to use DEP to selectively trap and enrich T. brucei in specific locations while eluting all other cells in a sample. This would allow for a diagnostic test that enables the user to characterize the presence of parasites in specific locations determined a priori instead of relying on scanning a sample. In the work presented here, we report the characterization of the conditions that lead to high enrichment, 780% in 50 s, of the parasite in specific locations using an array of titanium microelectrodes.

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Transcriptional differentiation of Trypanosoma brucei during in vitro acquisition of resistance to acoziborole

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009939 ◽

2021 ◽

Vol 15 (11) ◽

pp. e0009939

Author(s):

Pieter C. Steketee ◽

Federica Giordani ◽

Isabel M. Vincent ◽

Kathryn Crouch ◽

Fiona Achcar ◽

...

Keyword(s):

Trypanosoma Brucei ◽

Morphological Changes ◽

Protozoan Parasite ◽

Resistant Cell ◽

Resistant Cell Line ◽

Surface Proteins ◽

Sub Saharan Africa ◽

Cross Resistance ◽

Sub Saharan

Subspecies of the protozoan parasite Trypanosoma brucei are the causative agents of Human African Trypanosomiasis (HAT), a debilitating neglected tropical disease prevalent across sub-Saharan Africa. HAT case numbers have steadily decreased since the start of the century, and sustainable elimination of one form of the disease is in sight. However, key to this is the development of novel drugs to combat the disease. Acoziborole is a recently developed benzoxaborole, currently in advanced clinical trials, for treatment of stage 1 and stage 2 HAT. Importantly, acoziborole is orally bioavailable, and curative with one dose. Recent studies have made significant progress in determining the molecular mode of action of acoziborole. However, less is known about the potential mechanisms leading to acoziborole resistance in trypanosomes. In this study, an in vitro-derived acoziborole-resistant cell line was generated and characterised. The AcoR line exhibited significant cross-resistance with the methyltransferase inhibitor sinefungin as well as hypersensitisation to known trypanocides. Interestingly, transcriptomics analysis of AcoR cells indicated the parasites had obtained a procyclic- or stumpy-like transcriptome profile, with upregulation of procyclin surface proteins as well as differential regulation of key metabolic genes known to be expressed in a life cycle-specific manner, even in the absence of major morphological changes. However, no changes were observed in transcripts encoding CPSF3, the recently identified protein target of acoziborole. The results suggest that generation of resistance to this novel compound in vitro can be accompanied by transcriptomic switches resembling a procyclic- or stumpy-type phenotype.

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