Oxidative Phosphorylation Is Required for Powering Motility and Development of the Sleeping Sickness Parasite Trypanosoma brucei in the Tsetse Fly Vector

African trypanosomes cause disease in humans and their livestock and are transmitted by tsetse flies. The insect ingests these parasites with its blood meal, but to be transmitted to another mammal, the trypanosome must undergo complex development within the tsetse fly and migrate from the insect's gut to its salivary glands.

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Oxidative phosphorylation is required for powering motility and development of the sleeping sickness parasite Trypanosoma brucei within the tsetse fly vector

10.1101/2021.06.30.450569 ◽

2021 ◽

Author(s):

Caroline E Dewar ◽

Aitor Casas-Sánchez ◽

Constentin Dieme ◽

Aline Crouzols ◽

Lee Haines ◽

...

Keyword(s):

Oxidative Phosphorylation ◽

Trypanosoma Brucei ◽

Atp Synthase ◽

Sleeping Sickness ◽

Tsetse Fly ◽

Tsetse Flies ◽

Respiratory Chain Complexes ◽

Atp Production

The single-celled parasite Trypanosoma brucei causes sleeping sickness in humans and nagana in livestock and is transmitted by hematophagous tsetse flies. Lifecycle progression from mammalian bloodstream form to tsetse midgut form and, subsequently, infective salivary gland form depends on complex developmental steps and migration within different fly tissues. As the parasite colonises the glucose-poor insect midgut, its ATP production is thought to depend on activation of mitochondrial amino acid catabolism via oxidative phosphorylation. This process involves respiratory chain complexes and the F1FO-ATP synthase, and it requires protein subunits of these complexes that are encoded in the parasite's mitochondrial DNA (kinetoplast or kDNA). Here we show that a progressive loss of kDNA-encoded functions correlates with an increasingly impaired ability of T. brucei to initiate and complete its development in the tsetse. First, parasites with a mutated F1FO-ATP synthase with a reduced capacity for oxidative phosphorylation can initiate differentiation from bloodstream to insect form, but they are unable to proliferate in vitro. Unexpectedly, these cells can still colonise the tsetse midgut. However, these parasites exhibit a motility defect and are severely impaired in colonising or migrating to subsequent tsetse tissues. Second, parasites with a fully disrupted F1FO-ATP synthase complex that is completely unable to produce ATP by oxidative phosphorylation can still differentiate to the first insect stage in vitro but die within a few days and cannot establish a midgut infection in vivo. Third, mutant parasites lacking kDNA entirely can initiate differentiation but die within 24 h. Together, these three scenarios show that efficient ATP production via oxidative phosphorylation is not essential for initial colonisation of the tsetse vector, but it is required to power trypanosome migration within the fly.

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Tsetse blood-meal sources, endosymbionts and trypanosome-associations in the Maasai Mara National Reserve, a wildlife-human-livestock interface

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0008267 ◽

2021 ◽

Vol 15 (1) ◽

pp. e0008267

Author(s):

Edward Edmond Makhulu ◽

Jandouwe Villinger ◽

Vincent Owino Adunga ◽

Maamun M. Jeneby ◽

Edwin Murungi Kimathi ◽

...

Keyword(s):

Blood Meal ◽

Glossina Pallidipes ◽

Tsetse Fly ◽

Tsetse Flies ◽

African Buffalo ◽

African Trypanosomiasis ◽

African Trypanosomes ◽

Sodalis Glossinidius ◽

Vertebrate Hosts ◽

Blood Meals

African trypanosomiasis (AT) is a neglected disease of both humans and animals caused by Trypanosoma parasites, which are transmitted by obligate hematophagous tsetse flies (Glossina spp.). Knowledge on tsetse fly vertebrate hosts and the influence of tsetse endosymbionts on trypanosome presence, especially in wildlife-human-livestock interfaces, is limited. We identified tsetse species, their blood-meal sources, and correlations between endosymbionts and trypanosome presence in tsetse flies from the trypanosome-endemic Maasai Mara National Reserve (MMNR) in Kenya. Among 1167 tsetse flies (1136 Glossina pallidipes, 31 Glossina swynnertoni) collected from 10 sampling sites, 28 (2.4%) were positive by PCR for trypanosome DNA, most (17/28) being of Trypanosoma vivax species. Blood-meal analyses based on high-resolution melting analysis of vertebrate cytochrome c oxidase 1 and cytochrome b gene PCR products (n = 354) identified humans as the most common vertebrate host (37%), followed by hippopotamus (29.1%), African buffalo (26.3%), elephant (3.39%), and giraffe (0.84%). Flies positive for trypanosome DNA had fed on hippopotamus and buffalo. Tsetse flies were more likely to be positive for trypanosomes if they had the Sodalis glossinidius endosymbiont (P = 0.0002). These findings point to complex interactions of tsetse flies with trypanosomes, endosymbionts, and diverse vertebrate hosts in wildlife ecosystems such as in the MMNR, which should be considered in control programs. These interactions may contribute to the maintenance of tsetse populations and/or persistent circulation of African trypanosomes. Although the African buffalo is a key reservoir of AT, the higher proportion of hippopotamus blood-meals in flies with trypanosome DNA indicates that other wildlife species may be important in AT transmission. No trypanosomes associated with human disease were identified, but the high proportion of human blood-meals identified are indicative of human African trypanosomiasis risk. Our results add to existing data suggesting that Sodalis endosymbionts are associated with increased trypanosome presence in tsetse flies.

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Surface Sialic Acids Taken from the Host Allow Trypanosome Survival in Tsetse Fly Vectors

Journal of Experimental Medicine ◽

10.1084/jem.20030635 ◽

2004 ◽

Vol 199 (10) ◽

pp. 1445-1450 ◽

Cited By ~ 62

Author(s):

Kisaburo Nagamune ◽

Alvaro Acosta-Serrano ◽

Haruki Uemura ◽

Reto Brun ◽

Christina Kunz-Renggli ◽

...

Keyword(s):

Salivary Gland ◽

Trypanosoma Brucei ◽

Sialic Acids ◽

Sleeping Sickness ◽

Tsetse Fly ◽

Mammalian Host ◽

Tsetse Flies ◽

African Trypanosome ◽

Blood Sucking

The African trypanosome Trypanosoma brucei, which causes sleeping sickness in humans and Nagana disease in livestock, is spread via blood-sucking Tsetse flies. In the fly's intestine, the trypanosomes survive digestive and trypanocidal environments, proliferate, and translocate into the salivary gland, where they become infectious to the next mammalian host. Here, we show that for successful survival in Tsetse flies, the trypanosomes use trans-sialidase to transfer sialic acids that they cannot synthesize from host's glycoconjugates to the glycosylphosphatidylinositols (GPIs), which are abundantly expressed on their surface. Trypanosomes lacking sialic acids due to a defective generation of GPI-anchored trans-sialidase could not survive in the intestine, but regained the ability to survive when sialylated by means of soluble trans-sialidase. Thus, surface sialic acids appear to protect the parasites from the digestive and trypanocidal environments in the midgut of Tsetse flies.

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Basic Biology of Trypanosoma brucei with reference to the development of chemotherapies

Current Pharmaceutical Design ◽

10.2174/1381612827666210119105008 ◽

2021 ◽

Vol 27 ◽

Author(s):

Samuel Dean

Keyword(s):

Trypanosoma Brucei ◽

Late Stage ◽

Antigenic Variation ◽

Molecular Genetic ◽

Sleeping Sickness ◽

Tsetse Fly ◽

Tsetse Flies ◽

African Sleeping Sickness ◽

Stage Disease ◽

Late Stage Disease

: Trypanosoma brucei are protozoan parasites that causes the lethal human disease African sleeping sickness, and the economically devastating disease of cattle, Nagana. African sleeping sickness, or Human African Trypanosomiasis (HAT) threatens 65 million people, and animal trypanosomiasis makes large areas of farmland unusable. There is no vaccine and licenced therapies against the most severe, late-stage disease are toxic, impractical and ineffective. Trypanosomes are transmitted by tsetse flies and HAT is therefore predominantly confined to the tsetse fly belt in subSaharan African. They are exclusively extracellular, and they differentiate between at least seven developmental forms that are highly adapted to host and vector niches. In the mammalian (human) host they inhabit the blood, cerebrospinal fluid (late stage disease), skin and adipose fat. In the tsetse fly vector, they travel from the tsetse midgut to the salivary glands via the ectoperitrophic space and proventriculus. Trypanosomes are evolutionarily divergent compared with most branches of eukaryotic life. Perhaps most famous for their extraordinary mechanisms of monoallelic gene expression and antigenic variation, they have also been investigated because much of their biology is either highly unconventional or extreme. Moreover, in addition to their importance as pathogens, many researchers have been attracted to the field because trypanosomes have some of the most advanced molecular genetic tools and database resources of any model system. The following will cover just some aspects of trypanosome biology and how its divergent biochemistry has been leveraged to develop drugs to treat African Sleeping sickness. It is by no means intended to be a comprehensive survey of trypanosome features. Rather, it is hoped that it will present trypanosomes as one of the most fascinating and tractable systems in which to do discovery biology.

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Positional Dynamics and Glycosomal Recruitment of Developmental Regulators during Trypanosome Differentiation

mBio ◽

10.1128/mbio.00875-19 ◽

2019 ◽

Vol 10 (4) ◽

Cited By ~ 2

Author(s):

Balázs Szöőr ◽

Dorina V. Simon ◽

Federico Rojas ◽

Julie Young ◽

Derrick R. Robinson ◽

...

Keyword(s):

Life Cycle ◽

Trypanosoma Brucei ◽

Tyrosine Phosphatase ◽

Tsetse Fly ◽

Sub Saharan Africa ◽

Metabolic Adaptation ◽

Tsetse Flies ◽

Content Type ◽

African Trypanosomes ◽

Sub Saharan

ABSTRACT Glycosomes are peroxisome-related organelles that compartmentalize the glycolytic enzymes in kinetoplastid parasites. These organelles are developmentally regulated in their number and composition, allowing metabolic adaptation to the parasite’s needs in the blood of mammalian hosts or within their arthropod vector. A protein phosphatase cascade regulates differentiation between parasite developmental forms, comprising a tyrosine phosphatase, Trypanosoma brucei PTP1 (TbPTP1), which dephosphorylates and inhibits a serine threonine phosphatase, TbPIP39, which promotes differentiation. When TbPTP1 is inactivated, TbPIP39 is activated and during differentiation becomes located in glycosomes. Here we have tracked TbPIP39 recruitment to glycosomes during differentiation from bloodstream “stumpy” forms to procyclic forms. Detailed microscopy and live-cell imaging during the synchronous transition between life cycle stages revealed that in stumpy forms, TbPIP39 is located at a periflagellar pocket site closely associated with TbVAP, which defines the flagellar pocket endoplasmic reticulum. TbPTP1 is also located at the same site in stumpy forms, as is REG9.1, a regulator of stumpy-enriched mRNAs. This site provides a molecular node for the interaction between TbPTP1 and TbPIP39. Within 30 min of the initiation of differentiation, TbPIP39 relocates to glycosomes, whereas TbPTP1 disperses to the cytosol. Overall, the study identifies a “stumpy regulatory nexus” (STuRN) that coordinates the molecular components of life cycle signaling and glycosomal development during transmission of Trypanosoma brucei. IMPORTANCE African trypanosomes are parasites of sub-Saharan Africa responsible for both human and animal disease. The parasites are transmitted by tsetse flies, and completion of their life cycle involves progression through several development steps. The initiation of differentiation between blood and tsetse fly forms is signaled by a phosphatase cascade, ultimately trafficked into peroxisome-related organelles called glycosomes that are unique to this group of organisms. Glycosomes undergo substantial remodeling of their composition and function during the differentiation step, but how this is regulated is not understood. Here we identify a cytological site where the signaling molecules controlling differentiation converge before the dispersal of one of them into glycosomes. In combination, the study provides the first insight into the spatial coordination of signaling pathway components in trypanosomes as they undergo cell-type differentiation.

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Tsetse Fly Saliva Accelerates the Onset of Trypanosoma brucei Infection in a Mouse Model Associated with a Reduced Host Inflammatory Response

Infection and Immunity ◽

10.1128/iai.01046-06 ◽

2006 ◽

Vol 74 (11) ◽

pp. 6324-6330 ◽

Cited By ~ 45

Author(s):

Guy Caljon ◽

Jan Van Den Abbeele ◽

Benoît Stijlemans ◽

Marc Coosemans ◽

Patrick De Baetselier ◽

...

Keyword(s):

Trypanosoma Brucei ◽

Inflammatory Responses ◽

Blood Feeding ◽

Immunoglobulin M ◽

Tsetse Fly ◽

Surface Glycoprotein ◽

Tsetse Flies ◽

Feeding Site ◽

African Trypanosomes ◽

Cytokine Tumor Necrosis Factor

ABSTRACT Tsetse flies (Glossina sp.) are the vectors that transmit African trypanosomes, protozoan parasites that cause human sleeping sickness and veterinary infections in the African continent. These blood-feeding dipteran insects deposit saliva at the feeding site that enables the blood-feeding process. Here we demonstrate that tsetse fly saliva also accelerates the onset of a Trypanosoma brucei infection. This effect was associated with a reduced inflammatory reaction at the site of infection initiation (reflected by a decrease of interleukin-6 [IL-6] and IL-12 mRNA) as well as lower serum concentrations of the trypanocidal cytokine tumor necrosis factor. Variant-specific surface glycoprotein-specific antibody isotypes immunoglobulin M (IgM) and IgG2a, implicated in trypanosome clearance, were not suppressed. We propose that tsetse fly saliva accelerates the onset of trypanosome infection by inhibiting local and systemic inflammatory responses involved in parasite control.

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Tsetse blood-meal sources, endosymbionts, and trypanosome infections provide insight into African trypanosomiasis transmission in the Maasai Mara National Reserve, a wildlife-human-livestock interface

10.1101/2020.04.06.027367 ◽

2020 ◽

Cited By ~ 1

Author(s):

Edward Edmond Makhulu ◽

Jandouwe Villinger ◽

Vincent Owino Adunga ◽

Maamun M. Jeneby ◽

Edwin Murungi Kimathi ◽

...

Keyword(s):

Blood Meal ◽

Vector Competence ◽

Glossina Pallidipes ◽

Tsetse Fly ◽

Tsetse Flies ◽

African Buffalo ◽

African Trypanosomiasis ◽

Trypanosome Infection ◽

African Trypanosomes ◽

Blood Meals

AbstractBackgroundAfrican trypanosomiasis (AT) is a neglected disease of both humans and animals caused by Trypanosoma parasites, which are transmitted by obligate hematophagous tsetse flies (Glossina spp.). Understanding of AT transmission is hampered by limited knowledge on interactions of tsetse flies with their vertebrate hosts and the influence of endosymbionts on vector competence, especially in wildlife-human-livestock interfaces. We identified the tsetse species, their blood-meal sources, and the correlation between endosymbiont and trypanosome infection status in the trypanosome-endemic Maasai Mara National Reserve (MMNR) of Kenya.Methodology/Principal FindingsAmong 1167 tsetse flies (1136 Glossina pallidipes, 31 Glossina swynnertoni) collected from 10 sampling sites, 28 (2.4%) were positive by PCR for trypanosomes, majority (17/28) being Trypanosoma vivax. Blood-meal analyses based on high-resolution melting analysis of mitochondrial cytochrome c oxidase 1 and cytochrome b gene PCR products (n = 345) identified humans as the most common vertebrate host (37%), followed by hippopotamus (29.1%), African buffalo (26.3%), elephant (3.39%), and giraffe (0.84%). Trypanosome-infected flies had fed on hippopotamus and buffalo. Additionally, PCR analysis revealed that tsetse flies were more likely to be infected with trypanosomes if they were infected with the Sodalis glossinidius endosymbiont (P = 0.0022 Fisher’s exact test).Conclusions/SignificanceDiverse species of wildlife hosts may contribute to the maintenance of tsetse populations and/or persistent circulation of African trypanosomes in the MMNR. Although the African buffalo is known to be a key reservoir of AT, the higher proportion of hippopotamus blood-meals in trypanosomes-infected flies identified here indicates that other wildlife species may also be important to transmission cycles. No trypanosomes associated with human disease were identified, but the high proportion of human blood-meals identified are indicative of human African trypanosomiasis transmission risk. Furthermore, this work provides data showing that Sodalis endosymbionts can is associated with increased trypanosome infection rates in endemic ecologies.Author summaryHuman and animal African trypanosomiasis are neglected tropical diseases with potential to spread to new areas. Wild animals are important reservoirs for African trypanosomes and crucial in the emergence and re-emergence of AT. Vertebrate host-vector-parasite interactions are integral to trypanosome transmission. We investigated the vertebrate blood-meals and trypanosomes-endosymbionts co-infections in tsetse flies, which have been associated with reservoirs and vector competence, respectively, on AT transmission in Kenya’s Maasai Mara National Reserve. We identified tsetse fly diversity, trypanosome and endosymbiont infection status, and vertebrate blood-meal hosts to infer potential transmission dynamics. We found that Glossina pallidipes was the major tsetse fly vector and that Trypanosoma vivax was the main trypanosome species circulating in the region. Humans, hippopotamus, and buffalo were the most frequented for blood-meals. Buffalo and hippopotamus blood-meals were identified in trypanosome infected flies. Feeding of the flies on both humans and wildlife may potentiate the risk of the human trypanosomiasis in this ecology. Additionally, we found that the endosymbiont Sodalis glossinidius is associated with higher trypanosome infection rates in wild tsetse flies. These findings emphasize the importance of understanding the interaction of tsetse flies with vertebrate blood-meal sources and their endosymbionts in the transmission and control of AT.

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Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v84i1.1412 ◽

2017 ◽

Vol 84 (1) ◽

Cited By ~ 2

Author(s):

Purity K. Gitonga ◽

Kariuki Ndung’u ◽

Grace A. Murilla ◽

Paul C. Thande ◽

Florence N. Wamwiri ◽

...

Keyword(s):

Survival Time ◽

Trypanosoma Brucei ◽

Acute Infection ◽

Glossina Pallidipes ◽

Trypanosoma Congolense ◽

Tsetse Fly ◽

Economic Losses ◽

Entire Group ◽

Tsetse Flies ◽

African Countries

African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4–11) and 4.5 ± 0.2 (range, 4–6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

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History of Sleeping Sickness in East Africa

Clinical Microbiology Reviews ◽

10.1128/cmr.12.1.112 ◽

1999 ◽

Vol 12 (1) ◽

pp. 112-125 ◽

Cited By ~ 56

Author(s):

Geoff Hide

Keyword(s):

East Africa ◽

Molecular Data ◽

Sleeping Sickness ◽

Tsetse Fly ◽

Tsetse Flies ◽

Agricultural Practice ◽

Molecular Approaches ◽

History Of ◽

The Stability ◽

The Right

SUMMARY The history of human sleeping sickness in East Africa is characterized by the appearance of disease epidemics interspersed by long periods of endemicity. Despite the presence of the tsetse fly in large areas of East Africa, these epidemics tend to occur multiply in specific regions or foci rather than spreading over vast areas. Many theories have been proposed to explain this phenomenon, but recent molecular approaches and detailed analyses of epidemics have highlighted the stability of human-infective trypanosome strains within these foci. The new molecular data, taken alongside the history and biology of human sleeping sickness, are beginning to highlight the important factors involved in the generation of epidemics. Specific, human-infective trypanosome strains may be associated with each focus, which, in the presence of the right conditions, can be responsible for the generation of an epidemic. Changes in agricultural practice, favoring the presence of tsetse flies, and the important contribution of domestic animals as a reservoir for the parasite are key factors in the maintenance of such epidemics. This review examines the contribution of molecular and genetic data to our understanding of the epidemiology and history of human sleeping sickness in East Africa.

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Human African trypanosomiasis

Oxford Textbook of Medicine ◽

10.1093/med/9780199204854.003.070810_update_001 ◽

2010 ◽

pp. 1119-1127

Author(s):

August Stich

Keyword(s):

West Africa ◽

East Africa ◽

Trypanosoma Brucei ◽

Human African Trypanosomiasis ◽

Protozoan Parasite ◽

Sleeping Sickness ◽

Tsetse Flies ◽

African Trypanosomiasis ◽

Tropical Africa

Human African trypanosomiasis (HAT, sleeping sickness) is caused by two subspecies of the protozoan parasite Trypanosoma brucei: T. b. rhodesiense is prevalent in East Africa among many wild and domestic mammals; T. b. gambiense causes an anthroponosis in Central and West Africa. The disease is restricted to tropical Africa where it is transmitted by the bite of infected tsetse flies (...

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