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Silvester E, Szoor B, Ivens A, Awuah-Mensah G, Gadelha C, Wickstead B, Matthews KR. A conserved trypanosomatid differentiation regulator controls substrate attachment and morphological development in Trypanosoma congolense. PLoS Pathog 2024; 20:e1011889. [PMID: 38408115 PMCID: PMC10919850 DOI: 10.1371/journal.ppat.1011889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 03/07/2024] [Accepted: 02/08/2024] [Indexed: 02/28/2024] Open
Abstract
Trypanosomatid parasites undergo developmental regulation to adapt to the different environments encountered during their life cycle. In Trypanosoma brucei, a genome wide selectional screen previously identified a regulator of the protein family ESAG9, which is highly expressed in stumpy forms, a morphologically distinct bloodstream stage adapted for tsetse transmission. This regulator, TbREG9.1, has an orthologue in Trypanosoma congolense, despite the absence of a stumpy morphotype in that parasite species, which is an important cause of livestock trypanosomosis. RNAi mediated gene silencing of TcREG9.1 in Trypanosoma congolense caused a loss of attachment of the parasites to a surface substrate in vitro, a key feature of the biology of these parasites that is distinct from T. brucei. This detachment was phenocopied by treatment of the parasites with a phosphodiesterase inhibitor, which also promotes detachment in the insect trypanosomatid Crithidia fasciculata. RNAseq analysis revealed that TcREG9.1 silencing caused the upregulation of mRNAs for several classes of surface molecules, including transferrin receptor-like molecules, immunoreactive proteins in experimental bovine infections, and molecules related to those associated with stumpy development in T. brucei. Depletion of TcREG9.1 in vivo also generated an enhanced level of parasites in the blood circulation consistent with reduced parasite attachment to the microvasculature. The morphological progression to insect forms of the parasite was also perturbed. We propose a model whereby TcREG9.1 acts as a regulator of attachment and development, with detached parasites being adapted for transmission.
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Affiliation(s)
- Eleanor Silvester
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth laboratories, Charlotte Auerbach Road, Edinburgh, United Kingdom
| | - Balazs Szoor
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth laboratories, Charlotte Auerbach Road, Edinburgh, United Kingdom
| | - Alasdair Ivens
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth laboratories, Charlotte Auerbach Road, Edinburgh, United Kingdom
| | - Georgina Awuah-Mensah
- Medical School, Centre for Genetics and Genomics, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Catarina Gadelha
- Medical School, Centre for Genetics and Genomics, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Bill Wickstead
- Medical School, Centre for Genetics and Genomics, School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Keith R. Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth laboratories, Charlotte Auerbach Road, Edinburgh, United Kingdom
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Larcombe SD, Briggs EM, Savill N, Szoor B, Matthews KR. The developmental hierarchy and scarcity of replicative slender trypanosomes in blood challenges their role in infection maintenance. Proc Natl Acad Sci U S A 2023; 120:e2306848120. [PMID: 37824530 PMCID: PMC10589647 DOI: 10.1073/pnas.2306848120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/30/2023] [Indexed: 10/14/2023] Open
Abstract
The development of Trypanosoma brucei in its mammalian host is marked by a distinct morphological change as replicative "slender" forms differentiate into cell cycle arrested "stumpy" forms in a quorum-sensing-dependent manner. Although stumpy forms dominate chronic infections at the population level, the proportion of replicative parasites at the individual cell level and the irreversibility of arrest in the bloodstream are unclear. Here, we experimentally demonstrate that developmental cell cycle arrest is definitively irreversible in acute and chronic infections in mice. Furthermore, analysis of replicative capacity and single-cell transcriptome profiling reveal a temporal hierarchy, whereby cell cycle arrest and appearance of a reversible stumpy-like transcriptome precede irreversible commitment and morphological change. Unexpectedly, we show that proliferating parasites are exceptionally scarce in the blood after infections are established. This challenges the ability of bloodstream trypanosomes to sustain infection by proliferation or antigenic variation, these parasites instead being overwhelmingly adapted for transmission.
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Affiliation(s)
- Stephen D. Larcombe
- School of Biological Sciences, Ashworth laboratories, Institute for Immunology and Infection Research, University of Edinburgh, EdinburghEH9 3FL, United Kingdom
| | - Emma M. Briggs
- School of Biological Sciences, Ashworth laboratories, Institute for Immunology and Infection Research, University of Edinburgh, EdinburghEH9 3FL, United Kingdom
- College of Medical, Veterinary and Life Sciences, School of Infection and Immunity, Wellcome Centre for Integrative Parasitology, University of Glasgow, GlasgowG12 8TA, United Kingdom
| | - Nick Savill
- School of Biological Sciences, Ashworth laboratories, Institute for Immunology and Infection Research, University of Edinburgh, EdinburghEH9 3FL, United Kingdom
| | - Balazs Szoor
- School of Biological Sciences, Ashworth laboratories, Institute for Immunology and Infection Research, University of Edinburgh, EdinburghEH9 3FL, United Kingdom
| | - Keith R. Matthews
- School of Biological Sciences, Ashworth laboratories, Institute for Immunology and Infection Research, University of Edinburgh, EdinburghEH9 3FL, United Kingdom
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Ruberto I, Szoor B, Clark R, Matthews KR. Investigating mammalian tyrosine phosphatase inhibitors as potential 'piggyback' leads to target Trypanosoma brucei transmission. Chem Biol Drug Des 2014; 81:291-301. [PMID: 23066974 DOI: 10.1111/cbdd.12079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
African trypanosomiasis is a neglected tropical disease affecting humans and animals across 36 sub-Saharan African countries. We have investigated the potential to exploit a 'piggyback' approach to inhibit Trypanosoma brucei transmission by targeting the key developmental regulator of transmission, T. brucei protein tyrosine phosphatase 1. This strategy took advantage of the extensive investment in inhibitors for human protein tyrosine phosphatase 1B, a key target for pharmaceutical companies for the treatment of obesity and diabetes. Structural predictions for human and trypanosome tyrosine phosphatases revealed the overall conservation of important functional motifs, validating the potential for exploiting cross specific compounds. Thereafter, nineteen inhibitors were evaluated; seventeen from a protein tyrosine phosphatase 1B-targeted inhibitor library and two from literature analysis - oleanolic acid and suramin, the latter of which is a front line drug against African trypanosomiasis. The compounds tested displayed similar inhibitory activities against the human and trypanosome enzymes, mostly behaving as noncompetitive inhibitors. However, their activity against T. brucei in culture was low, necessitating further chemical modification to improve their efficacy and specificity. Nonetheless, the results validate the potential to explore a 'piggyback' strategy targeting T. brucei protein tyrosine phosphatase 1 through exploiting the large pharmacological investment in therapies for obesity targeting protein tyrosine phosphatase 1B.
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Affiliation(s)
- Irene Ruberto
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, Institute of Immunology and Infection Research, University of Edinburgh, King's Building, West Mains Road, Edinburgh EH9 3JT, UK
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Rico E, Rojas F, Mony BM, Szoor B, Macgregor P, Matthews KR. Bloodstream form pre-adaptation to the tsetse fly in Trypanosoma brucei. Front Cell Infect Microbiol 2013; 3:78. [PMID: 24294594 PMCID: PMC3827541 DOI: 10.3389/fcimb.2013.00078] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/24/2013] [Indexed: 12/04/2022] Open
Abstract
African trypanosomes are sustained in the bloodstream of their mammalian hosts by their extreme capacity for antigenic variation. However, for life cycle progression, trypanosomes also must generate transmission stages called stumpy forms that are pre-adapted to survive when taken up during the bloodmeal of the disease vector, tsetse flies. These stumpy forms are rather different to the proliferative slender forms that maintain the bloodstream parasitaemia. Firstly, they are non proliferative and morphologically distinct, secondly, they show particular sensitivity to environmental cues that signal entry to the tsetse fly and, thirdly, they are relatively robust such that they survive the changes in temperature, pH and proteolytic environment encountered within the tsetse midgut. These characteristics require regulated changes in gene expression to pre-adapt the parasite and the use of environmental sensing mechanisms, both of which allow the rapid initiation of differentiation to tsetse midgut procyclic forms upon transmission. Interestingly, the generation of stumpy forms is also regulated and periodic in the mammalian blood, this being governed by a density-sensing mechanism whereby a parasite-derived signal drives cell cycle arrest and cellular development both to optimize transmission and to prevent uncontrolled parasite multiplication overwhelming the host. In this review we detail recent developments in our understanding of the molecular mechanisms that underpin the production of stumpy forms in the mammalian bloodstream and their signal perception pathways both in the mammalian bloodstream and upon entry into the tsetse fly. These discoveries are discussed in the context of conserved eukaryotic signaling and differentiation mechanisms. Further, their potential to act as targets for therapeutic strategies that disrupt parasite development either in the mammalian bloodstream or upon their transmission to tsetse flies is also discussed.
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Affiliation(s)
- Eva Rico
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh Edinburgh, UK
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Kirchner J, Vissi E, Gross S, Szoor B, Rudenko A, Alphey L, White-Cooper H. Drosophila Uri, a PP1alpha binding protein, is essential for viability, maintenance of DNA integrity and normal transcriptional activity. BMC Mol Biol 2008; 9:36. [PMID: 18412953 PMCID: PMC2346476 DOI: 10.1186/1471-2199-9-36] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Accepted: 04/15/2008] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Protein phosphatase 1 (PP1) is involved in diverse cellular processes, and is targeted to substrates via interaction with many different protein binding partners. PP1 catalytic subunits (PP1c) fall into PP1alpha and PP1beta subfamilies based on sequence analysis, however very few PP1c binding proteins have been demonstrated to discriminate between PP1alpha and PP1beta. RESULTS URI (unconventional prefoldin RPB5 interactor) is a conserved molecular chaperone implicated in a variety of cellular processes, including the transcriptional response to nutrient signalling and maintenance of DNA integrity. We show that Drosophila Uri binds PP1alpha with much higher affinity than PP1beta, and that this ability to discriminate between PP1c forms is conserved to humans. Most Uri is cytoplasmic, however we found some protein associated with active RNAPII on chromatin. We generated a uri loss of function allele, and show that uri is essential for viability in Drosophila. uri mutants have transcriptional defects, reduced cell viability and differentiation in the germline, and accumulate DNA damage in their nuclei. CONCLUSION Uri is the first PP1alpha specific binding protein to be described in Drosophila. Uri protein plays a role in transcriptional regulation. Activity of uri is required to maintain DNA integrity and cell survival in normal development.
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Affiliation(s)
- Jasmin Kirchner
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
| | - Emese Vissi
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
| | - Sascha Gross
- Abbott Laboratories, Global Pharmaceutical Regulatory Affairs, Abbott Park, IL 60064-6157, USA
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
| | - Balazs Szoor
- Institute of Immunology and Infection Research, University of Edinburgh, EH9 3JT, UK
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
| | - Andrey Rudenko
- Harvard University, FAS Molecular & Cell Biology, Sherman Fairchild Biochemistry Bldg, 7 Divinity Ave, Cambridge MA, 02138, USA
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
| | - Luke Alphey
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
| | - Helen White-Cooper
- Department of Zoology, University of Oxford, South Parks Rd, Oxford, OX1 3PS. UK
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