1
|
Jayawardhana S, Ward AI, Francisco AF, Lewis MD, Taylor MC, Kelly JM, Olmo F. Benznidazole treatment leads to DNA damage in Trypanosoma cruzi and the persistence of rare widely dispersed non-replicative amastigotes in mice. PLoS Pathog 2023; 19:e1011627. [PMID: 37956215 PMCID: PMC10681306 DOI: 10.1371/journal.ppat.1011627] [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: 08/22/2023] [Revised: 11/27/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
Benznidazole is the front-line drug used to treat infections with Trypanosoma cruzi, the causative agent of Chagas disease. However, for reasons that are unknown, treatment failures are common. When we examined parasites that survived benznidazole treatment in mice using highly sensitive in vivo and ex vivo bioluminescence imaging, we found that recrudescence is not due to persistence of parasites in a specific organ or tissue that preferentially protects them from drug activity. Surviving parasites are widely distributed and located in host cells where the vast majority contained only one or two amastigotes. Therefore, infection relapse does not arise from a small number of intact large nests. Rather, persisters are either survivors of intracellular populations where co-located parasites have been killed, or amastigotes in single/low-level infected cells exist in a state where they are less susceptible to benznidazole. To better assess the nature of parasite persisters, we exposed infected mammalian cell monolayers to a benznidazole regimen that reduces the intracellular amastigote population to <1% of the pre-treatment level. Of host cells that remained infected, as with the situation in vivo, the vast majority contained only one or two surviving intracellular amastigotes. Analysis, based on non-incorporation of the thymidine analogue EdU, revealed these surviving parasites to be in a transient non-replicative state. Furthermore, treatment with benznidazole led to widespread parasite DNA damage. When the small number of parasites which survive in mice after non-curative treatment were assessed using EdU labelling, this revealed that these persisters were also initially non-replicative. A possible explanation could be that triggering of the T. cruzi DNA damage response pathway by the activity of benznidazole metabolites results in exit from the cell cycle as parasites attempt DNA repair, and that metabolic changes associated with non-proliferation act to reduce drug susceptibility. Alternatively, a small percentage of the parasite population may pre-exist in this non-replicative state prior to treatment.
Collapse
Affiliation(s)
- Shiromani Jayawardhana
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alexander I. Ward
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Amanda F. Francisco
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Michael D. Lewis
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Martin C. Taylor
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John M. Kelly
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Francisco Olmo
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| |
Collapse
|
2
|
Ang CW, Lee BM, Jackson CJ, Wang Y, Franzblau SG, Francisco AF, Kelly JM, Bernhardt PV, Tan L, West NP, Sykes ML, Hinton AO, Bolisetti R, Avery VM, Cooper MA, Blaskovich MA. Nitroimidazopyrazinones with Oral Activity against Tuberculosis and Chagas Disease in Mouse Models of Infection. J Med Chem 2022; 65:13125-13142. [DOI: 10.1021/acs.jmedchem.2c00972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chee Wei Ang
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
- School of Science, Monash University Malaysia, Subang Jaya, 47500 Selangor, Malaysia
| | - Brendon M. Lee
- Research School of Chemistry, Australian National University, Sullivans Creek Road, Acton ACT 2601, Australia
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical College, New York, New York 10021, United States
| | - Colin J. Jackson
- Research School of Chemistry, Australian National University, Sullivans Creek Road, Acton ACT 2601, Australia
| | - Yuehong Wang
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Scott G. Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Amanda F. Francisco
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - John M. Kelly
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Paul V. Bernhardt
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Nicholas P. West
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Melissa L. Sykes
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland 4111, Australia
| | - Alexandra O. Hinton
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Raghu Bolisetti
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Vicky M. Avery
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland 4111, Australia
- School of Environment and Science, Griffith University, Nathan, Queensland 4111, Australia
| | - Matthew A. Cooper
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Mark A.T. Blaskovich
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| |
Collapse
|
3
|
Macleod OJS, Cook AD, Webb H, Crow M, Burns R, Redpath M, Seisenberger S, Trevor CE, Peacock L, Schwede A, Kimblin N, Francisco AF, Pepperl J, Rust S, Voorheis P, Gibson W, Taylor MC, Higgins MK, Carrington M. Invariant surface glycoprotein 65 of Trypanosoma brucei is a complement C3 receptor. Nat Commun 2022; 13:5085. [PMID: 36038546 PMCID: PMC9424271 DOI: 10.1038/s41467-022-32728-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
African trypanosomes are extracellular pathogens of mammals and are exposed to the adaptive and innate immune systems. Trypanosomes evade the adaptive immune response through antigenic variation, but little is known about how they interact with components of the innate immune response, including complement. Here we demonstrate that an invariant surface glycoprotein, ISG65, is a receptor for complement component 3 (C3). We show how ISG65 binds to the thioester domain of C3b. We also show that C3 contributes to control of trypanosomes during early infection in a mouse model and provide evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance. Deposition of C3b on pathogen surfaces, such as trypanosomes, is a central point in activation of the complement system. In ISG65, trypanosomes have evolved a C3 receptor which diminishes the downstream effects of C3 deposition on the control of infection. Trypanosomes evade the immune response through antigenic variation of a surface coat containing variant surface glycoproteins (VSG). They also express invariant surface glycoproteins (ISGs), which are less well understood. Here, Macleod et al. show that ISG65 of T. brucei is a receptor for complement component 3. They provide the crystal structure of T. brucei ISG65 in complex with complement C3d and show evidence that ISG65 is involved in reducing trypanosome susceptibility to C3-mediated clearance in vivo.
Collapse
Affiliation(s)
- Olivia J S Macleod
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Alexander D Cook
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Helena Webb
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Mandy Crow
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Roisin Burns
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Maria Redpath
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Stefanie Seisenberger
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Camilla E Trevor
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Lori Peacock
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Angela Schwede
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Nicola Kimblin
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Amanda F Francisco
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Julia Pepperl
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Steve Rust
- Antibody Discovery and Protein Engineering, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Paul Voorheis
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Wendy Gibson
- Bristol Veterinary School and School of Biological Sciences, University of Bristol, Bristol, UK
| | - Martin C Taylor
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK. .,Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.
| |
Collapse
|
4
|
Taylor MC, Ward AI, Olmo F, Francisco AF, Jayawardhana S, Costa FC, Lewis MD, Kelly JM. Bioluminescent:Fluorescent Trypanosoma cruzi Reporter Strains as Tools for Exploring Chagas Disease Pathogenesis and Drug Activity. Curr Pharm Des 2021; 27:1733-1740. [PMID: 33234096 DOI: 10.2174/1381612826666201124113214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/16/2020] [Accepted: 07/23/2020] [Indexed: 11/22/2022]
Abstract
Chagas disease results from infection with the trypanosomatid parasite Trypanosoma cruzi. Progress in developing new drugs has been hampered by the long term and complex nature of the condition and by our limited understanding of parasite biology. Technical difficulties in assessing the parasite burden during the chronic stage of infection have also proven to be a particular challenge. In this context, the development of noninvasive, highly sensitive bioluminescence imaging procedures based on parasites that express a red-shifted luciferase has greatly enhanced our ability to monitor infections in experimental models. Applications of this methodology have led to new insights into tissue tropism and infection dynamics and have been a major driver in drug development. The system has been further modified by the generation of parasite reporter lines that express bioluminescent:fluorescent fusion proteins, an advancement that has allowed chronic infections in mice to be examined at a cellular level. By exploiting bioluminescence, to identify the rare sites of tissue infection, and fluorescence to detect T. cruzi at the level of individual host cells in histological sections, it has been possible to investigate the replication and differentiation status of parasites in vivo and to examine the cellular environment of infection foci. In combination, these data provide a framework for the detailed dissection of disease pathogenesis and drug activity.
Collapse
Affiliation(s)
- Martin C Taylor
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Alexander I Ward
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Francisco Olmo
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Amanda F Francisco
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Shiromani Jayawardhana
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Fernanda C Costa
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Michael D Lewis
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - John M Kelly
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| |
Collapse
|
5
|
Thompson AM, O'Connor PD, Marshall AJ, Francisco AF, Kelly JM, Riley J, Read KD, Perez CJ, Cornwall S, Thompson RCA, Keenan M, White KL, Charman SA, Zulfiqar B, Sykes ML, Avery VM, Chatelain E, Denny WA. Re-evaluating pretomanid analogues for Chagas disease: Hit-to-lead studies reveal both in vitro and in vivo trypanocidal efficacy. Eur J Med Chem 2020; 207:112849. [PMID: 33007723 DOI: 10.1016/j.ejmech.2020.112849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/08/2020] [Accepted: 09/12/2020] [Indexed: 01/08/2023]
Abstract
Phenotypic screening of a 900 compound library of antitubercular nitroimidazole derivatives related to pretomanid against the protozoan parasite Trypanosoma cruzi (the causative agent for Chagas disease) identified several structurally diverse hits with an unknown mode of action. Following initial profiling, a first proof-of-concept in vivo study was undertaken, in which once daily oral dosing of a 7-substituted 2-nitroimidazooxazine analogue suppressed blood parasitemia to low or undetectable levels, although sterile cure was not achieved. Limited hit expansion studies alongside counter-screening of new compounds targeted at visceral leishmaniasis laid the foundation for a more in-depth assessment of the best leads, focusing on both drug-like attributes (solubility, metabolic stability and safety) and maximal killing of the parasite in a shorter timeframe. Comparative appraisal of one preferred lead (58) in a chronic infection mouse model, monitored by highly sensitive bioluminescence imaging, provided the first definitive evidence of (partial) curative efficacy with this promising nitroimidazooxazine class.
Collapse
Affiliation(s)
- Andrew M Thompson
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
| | - Patrick D O'Connor
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Andrew J Marshall
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Amanda F Francisco
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - John M Kelly
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Jennifer Riley
- Drug Discovery Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, United Kingdom
| | - Kevin D Read
- Drug Discovery Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, United Kingdom
| | - Catherine J Perez
- Department of Parasitology & Veterinary Sciences, Murdoch University, South Street, Murdoch, Western Australia, 6150, Australia
| | - Scott Cornwall
- Department of Parasitology & Veterinary Sciences, Murdoch University, South Street, Murdoch, Western Australia, 6150, Australia
| | - R C Andrew Thompson
- Department of Parasitology & Veterinary Sciences, Murdoch University, South Street, Murdoch, Western Australia, 6150, Australia
| | - Martine Keenan
- Epichem Pty Ltd, Suite 5, 3 Brodie-Hall Drive, Technology Park, Bentley, Western Australia, 6102, Australia
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia
| | - Bilal Zulfiqar
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland, 4111, Australia
| | - Melissa L Sykes
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland, 4111, Australia
| | - Vicky M Avery
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland, 4111, Australia
| | - Eric Chatelain
- Drugs for Neglected Diseases initiative, 15 Chemin Louis Dunant, 1202, Geneva, Switzerland
| | - William A Denny
- Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| |
Collapse
|
6
|
Francisco AF, Jayawardhana S, Olmo F, Lewis MD, Wilkinson SR, Taylor MC, Kelly JM. Challenges in Chagas Disease Drug Development. Molecules 2020; 25:E2799. [PMID: 32560454 PMCID: PMC7355550 DOI: 10.3390/molecules25122799] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 02/08/2023] Open
Abstract
The protozoan parasite Trypanosoma cruzi causes Chagas disease, an important public health problem throughout Latin America. Current therapeutic options are characterised by limited efficacy, long treatment regimens and frequent toxic side-effects. Advances in this area have been compromised by gaps in our knowledge of disease pathogenesis, parasite biology and drug activity. Nevertheless, several factors have come together to create a more optimistic scenario. Drug-based research has become more systematic, with increased collaborations between the academic and commercial sectors, often within the framework of not-for-profit consortia. High-throughput screening of compound libraries is being widely applied, and new technical advances are helping to streamline the drug development pipeline. In addition, drug repurposing and optimisation of current treatment regimens, informed by laboratory research, are providing a basis for new clinical trials. Here, we will provide an overview of the current status of Chagas disease drug development, highlight those areas where progress can be expected, and describe how fundamental research is helping to underpin the process.
Collapse
Affiliation(s)
- Amanda F. Francisco
- Department of Infection Biology, London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT, UK; (A.F.F.); (S.J.); (F.O.); (M.D.L.); (M.C.T.)
| | - Shiromani Jayawardhana
- Department of Infection Biology, London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT, UK; (A.F.F.); (S.J.); (F.O.); (M.D.L.); (M.C.T.)
| | - Francisco Olmo
- Department of Infection Biology, London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT, UK; (A.F.F.); (S.J.); (F.O.); (M.D.L.); (M.C.T.)
| | - Michael D. Lewis
- Department of Infection Biology, London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT, UK; (A.F.F.); (S.J.); (F.O.); (M.D.L.); (M.C.T.)
| | - Shane R. Wilkinson
- School of Biological and Chemical Sciences, Queen Mary University of London Mile End Road, London E1 4NS, UK;
| | - Martin C. Taylor
- Department of Infection Biology, London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT, UK; (A.F.F.); (S.J.); (F.O.); (M.D.L.); (M.C.T.)
| | - John M. Kelly
- Department of Infection Biology, London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT, UK; (A.F.F.); (S.J.); (F.O.); (M.D.L.); (M.C.T.)
| |
Collapse
|
7
|
Taylor MC, Ward A, Olmo F, Jayawardhana S, Francisco AF, Lewis MD, Kelly JM. Intracellular DNA replication and differentiation of Trypanosoma cruzi is asynchronous within individual host cells in vivo at all stages of infection. PLoS Negl Trop Dis 2020; 14:e0008007. [PMID: 32196491 PMCID: PMC7112235 DOI: 10.1371/journal.pntd.0008007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [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: 12/13/2019] [Revised: 04/01/2020] [Accepted: 02/29/2020] [Indexed: 12/21/2022] Open
Abstract
Investigations into intracellular replication and differentiation of Trypanosoma cruzi within the mammalian host have been restricted by limitations in our ability to detect parasitized cells throughout the course of infection. We have overcome this problem by generating genetically modified parasites that express a bioluminescent/fluorescent fusion protein. By combining in vivo imaging and confocal microscopy, this has enabled us to routinely visualise murine infections at the level of individual host cells. These studies reveal that intracellular parasite replication is an asynchronous process, irrespective of tissue location or disease stage. Furthermore, using TUNEL assays and EdU labelling, we demonstrate that within individual infected cells, replication of both mitochondrial (kDNA) and nuclear genomes is not co-ordinated within the parasite population, and that replicating amastigotes and non-replicating trypomastigotes can co-exist in the same cell. Finally, we report the presence of distinct non-canonical morphological forms of T. cruzi in the mammalian host. These appear to represent transitional forms in the amastigote to trypomastigote differentiation process. Therefore, the intracellular life-cycle of T. cruzi in vivo is more complex than previously realised, with potential implications for our understanding of disease pathogenesis, immune evasion and drug development. Dissecting the mechanisms involved will be an important experimental challenge. Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is becoming an emerging threat in non-endemic countries and establishing new foci in endemic countries. The treatment available has not changed significantly in over 40 years. Therefore, there is an urgent need for a greater understanding of parasite biology and disease pathogenesis to identify new therapeutic targets and to maximise the efficient use of existing drugs. We have used genetically modified strains of T. cruzi carrying a bioluminescence/fluorescence dual reporter fusion gene to monitor parasite replication in vivo during both acute and chronic infections in a mouse model. Utilising TUNEL assays for mitochondrial DNA replication and EdU incorporation for total DNA replication, we have found that parasite division within infected cells is asynchronous in all phases of infection. Differentiation also appears to be uncoordinated, with replicating amastigotes co-existing with non-dividing trypomastigotes in the same host cell.
Collapse
Affiliation(s)
- Martin C. Taylor
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Alexander Ward
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Francisco Olmo
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Shiromani Jayawardhana
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Amanda F. Francisco
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Michael D. Lewis
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - John M. Kelly
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| |
Collapse
|
8
|
MacGregor P, Gonzalez-Munoz AL, Jobe F, Taylor MC, Rust S, Sandercock AM, Macleod OJS, Van Bocxlaer K, Francisco AF, D’Hooge F, Tiberghien A, Barry CS, Howard P, Higgins MK, Vaughan TJ, Minter R, Carrington M. A single dose of antibody-drug conjugate cures a stage 1 model of African trypanosomiasis. PLoS Negl Trop Dis 2019; 13:e0007373. [PMID: 31120889 PMCID: PMC6532856 DOI: 10.1371/journal.pntd.0007373] [Citation(s) in RCA: 9] [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: 02/14/2019] [Accepted: 04/09/2019] [Indexed: 02/02/2023] Open
Abstract
Infections of humans and livestock with African trypanosomes are treated with drugs introduced decades ago that are not always fully effective and often have severe side effects. Here, the trypanosome haptoglobin-haemoglobin receptor (HpHbR) has been exploited as a route of uptake for an antibody-drug conjugate (ADC) that is completely effective against Trypanosoma brucei in the standard mouse model of infection. Recombinant human anti-HpHbR monoclonal antibodies were isolated and shown to be internalised in a receptor-dependent manner. Antibodies were conjugated to a pyrrolobenzodiazepine (PBD) toxin and killed T. brucei in vitro at picomolar concentrations. A single therapeutic dose (0.25 mg/kg) of a HpHbR antibody-PBD conjugate completely cured a T. brucei mouse infection within 2 days with no re-emergence of infection over a subsequent time course of 77 days. These experiments provide a demonstration of how ADCs can be exploited to treat protozoal diseases that desperately require new therapeutics.
Collapse
Affiliation(s)
- Paula MacGregor
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Fatoumatta Jobe
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Martin C. Taylor
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Steven Rust
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Alan M. Sandercock
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | | | | | | | | | | | | | | | - Matthew K. Higgins
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Tristan J. Vaughan
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Ralph Minter
- Department of Antibody Discovery and Protein Engineering, Medimmune, Cambridge, United Kingdom
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| |
Collapse
|
9
|
Lewis MD, Francisco AF, Jayawardhana S, Langston H, Taylor MC, Kelly JM. Imaging the development of chronic Chagas disease after oral transmission. Sci Rep 2018; 8:11292. [PMID: 30050153 PMCID: PMC6062536 DOI: 10.1038/s41598-018-29564-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [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: 04/05/2018] [Accepted: 07/10/2018] [Indexed: 12/26/2022] Open
Abstract
Chagas disease is a zoonosis caused by the protozoan parasite Trypanosoma cruzi. Transmission cycles are maintained by haematophagous triatomine bug vectors that carry infective T. cruzi in their faeces. Most human infections are acquired by contamination of mucosal membranes with triatomine faeces after being bitten, however, T. cruzi can be transmitted by several other routes. Oral transmission is an increasingly important aspect of Chagas disease epidemiology, typically involving food or drink products contaminated with triatomines. This has recently caused numerous outbreaks and been linked to unusually severe acute infections. The long-term impact of oral transmission on infection dynamics and disease pathogenesis is unclear. We used highly sensitive bioluminescence imaging and quantitative histopathology to study orally transmitted T. cruzi infections in mice. Both metacyclic and bloodform trypomastigotes were infectious via the oral cavity, but only metacyclics led to established infections by intra-gastric gavage. Mice displayed only mild acute symptoms but later developed significantly increased myocardial collagen content (p = 0.017), indicative of fibrosis. Gastrointestinal tissues and skin were the principal chronic infection reservoirs. Chronic phase parasite load profiles, tissue distribution and myocardial fibrosis severity were comparable to needle-injected controls. Thus, the oral route neither exacerbates nor ameliorates experimental Chagas disease.
Collapse
Affiliation(s)
- Michael D Lewis
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom.
| | - Amanda F Francisco
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Shiromani Jayawardhana
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Harry Langston
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Martin C Taylor
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - John M Kelly
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| |
Collapse
|
10
|
Brand S, Ko EJ, Viayna E, Thompson S, Spinks D, Thomas M, Sandberg L, Francisco AF, Jayawardhana S, Smith VC, Jansen C, De Rycker M, Thomas J, MacLean L, Osuna-Cabello M, Riley J, Scullion P, Stojanovski L, Simeons FRC, Epemolu O, Shishikura Y, Crouch SD, Bakshi TS, Nixon CJ, Reid IH, Hill AP, Underwood TZ, Hindley SJ, Robinson SA, Kelly JM, Fiandor JM, Wyatt PG, Marco M, Miles TJ, Read KD, Gilbert IH. Discovery and Optimization of 5-Amino-1,2,3-triazole-4-carboxamide Series against Trypanosoma cruzi. J Med Chem 2017; 60:7284-7299. [PMID: 28844141 PMCID: PMC5601362 DOI: 10.1021/acs.jmedchem.7b00463] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
![]()
Chagas’
disease, caused by the protozoan parasite Trypanosoma
cruzi, is the most common cause of cardiac-related
deaths in endemic regions of Latin America. There is an urgent need
for new safer treatments because current standard therapeutic options,
benznidazole and nifurtimox, have significant side effects and are
only effective in the acute phase of the infection with limited efficacy
in the chronic phase. Phenotypic high content screening against the
intracellular parasite in infected VERO cells was used to identify
a novel hit series of 5-amino-1,2,3-triazole-4-carboxamides (ATC).
Optimization of the ATC series gave improvements in potency, aqueous
solubility, and metabolic stability, which combined to give significant
improvements in oral exposure. Mitigation of a potential Ames and hERG liability ultimately led to two promising compounds, one of which demonstrated significant suppression of parasite burden in a mouse model of Chagas’ disease.
Collapse
Affiliation(s)
- Stephen Brand
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Eun Jung Ko
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Elisabet Viayna
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Stephen Thompson
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Daniel Spinks
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Michael Thomas
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Lars Sandberg
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Amanda F Francisco
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine , Keppel Street, London WC1E 7HT, U.K
| | - Shiromani Jayawardhana
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine , Keppel Street, London WC1E 7HT, U.K
| | - Victoria C Smith
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Chimed Jansen
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Manu De Rycker
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - John Thomas
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Lorna MacLean
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Maria Osuna-Cabello
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Jennifer Riley
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Paul Scullion
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Laste Stojanovski
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Frederick R C Simeons
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Ola Epemolu
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Yoko Shishikura
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Sabrinia D Crouch
- Diseases of the Developing World, GlaxoSmithKline , Calle Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Tania S Bakshi
- GlaxoSmithKline , 1250 South Collegeville Road, PO Box 5089, Collegeville, Pennsylvania 19426-0989, United States
| | - Christopher J Nixon
- GlaxoSmithKline , 1250 South Collegeville Road, PO Box 5089, Collegeville, Pennsylvania 19426-0989, United States
| | - Iain H Reid
- Medicines Research Centre, GlaxoSmithKline , Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Alan P Hill
- Medicines Research Centre, GlaxoSmithKline , Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Tim Z Underwood
- Medicines Research Centre, GlaxoSmithKline , Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Sean J Hindley
- Medicines Research Centre, GlaxoSmithKline , Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Sharon A Robinson
- David Jack Centre for R&D, GlaxoSmithKline , Park Road, Ware, Hertfordshire SG12 0DP, United Kingdom
| | - John M Kelly
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine , Keppel Street, London WC1E 7HT, U.K
| | - Jose M Fiandor
- Diseases of the Developing World, GlaxoSmithKline , Calle Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Paul G Wyatt
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Maria Marco
- Diseases of the Developing World, GlaxoSmithKline , Calle Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Timothy J Miles
- Diseases of the Developing World, GlaxoSmithKline , Calle Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Kevin D Read
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Ian H Gilbert
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| |
Collapse
|