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MacLean LM, Thomas J, Lewis MD, Cotillo I, Gray DW, De Rycker M. Development of Trypanosoma cruzi in vitro assays to identify compounds suitable for progression in Chagas' disease drug discovery. PLoS Negl Trop Dis 2018; 12:e0006612. [PMID: 30001347 PMCID: PMC6057682 DOI: 10.1371/journal.pntd.0006612] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/24/2018] [Accepted: 06/14/2018] [Indexed: 01/08/2023] Open
Abstract
Chagas' disease is responsible for significant mortality and morbidity in Latin America. Current treatments display variable efficacy and have adverse side effects, hence more effective, better tolerated drugs are needed. However, recent efforts have proved unsuccessful with failure of the ergosterol biosynthesis inhibitor posaconazole in phase II clinical trials despite promising in vitro and in vivo studies. The lack of translation between laboratory experiments and clinical outcome is a major issue for further drug discovery efforts. Our goal was to identify cell-based assays that could differentiate current nitro-aromatic drugs nifurtimox and benznidazole from posaconazole. Using a panel of T. cruzi strains including the six major lineages (TcI-VI), we found that strain PAH179 (TcV) was markedly less susceptible to posaconazole in vitro. Determination of parasite doubling and cycling times as well as EdU labelling experiments all indicate that this lack of sensitivity is due to the slow doubling and cycling time of strain PAH179. This is in accordance with ergosterol biosynthesis inhibition by posaconazole leading to critically low ergosterol levels only after multiple rounds of division, and is further supported by the lack of effect of posaconazole on the non-replicative trypomastigote form. A washout experiment with prolonged posaconazole treatment showed that, even for more rapidly replicating strains, this compound cannot clear all parasites, indicative of a heterogeneous parasite population in vitro and potentially the presence of quiescent parasites. Benznidazole in contrast was able to kill all parasites. The work presented here shows clear differentiation between the nitro-aromatic drugs and posaconazole in several assays, and suggests that in vitro there may be clinically relevant heterogeneity in the parasite population that can be revealed in long-term washout experiments. Based on these findings we have adjusted our in vitro screening cascade so that only the most promising compounds are progressed to in vivo experiments.
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Affiliation(s)
- Lorna M. MacLean
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (LML); (DWG)
| | - John Thomas
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michael D. Lewis
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Ignacio Cotillo
- GlaxoSmithKline, Diseases of the Developing World, Tres Cantos, Madrid, Spain
| | - David W. Gray
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (LML); (DWG)
| | - Manu De Rycker
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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Liu Q, Zhou XN. Preventing the transmission of American trypanosomiasis and its spread into non-endemic countries. Infect Dis Poverty 2015; 4:60. [PMID: 26715535 PMCID: PMC4693433 DOI: 10.1186/s40249-015-0092-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 12/11/2015] [Indexed: 11/10/2022] Open
Abstract
American trypanosomiasis, commonly known as Chagas disease, is caused by the flagellate protozoan parasite Trypanosoma cruzi. An estimated eight million people infected with T. cruzi currently reside in the endemic regions of Latin America. However, as the disease has now been imported into many non-endemic countries outside of Latin America, it has become a global health issue. We reviewed the transmission patterns and current status of disease spread pertaining to American trypanosomiasis at the global level, as well as recent advances in research. Based on an analysis of the gaps in American trypanosomiasis control, we put forward future research priorities that must be implemented to stop the global spread of the disease.
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Affiliation(s)
- Qin Liu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Health;, WHO Collaborating Center for Tropical Diseases, Shanghai, 200025, P. R. China
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Health;, WHO Collaborating Center for Tropical Diseases, Shanghai, 200025, P. R. China.
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Abstract
PURPOSE OF REVIEW The diagnosis and management of acute and chronic infections with the microorganism Trypanosoma cruzi, which causes Chagas disease, is important in solid organ transplantation in both endemic and nonendemic countries. In this review, we examine recently published data on the topic of Chagas disease in solid organ transplantation, with an emphasis on data relevant to heart transplantation. RECENT FINDINGS Most people with chronic T. cruzi infection have the intermediate form of disease, but approximately 2% of infected persons will progress to Chagas cardiomyopathy per year. The risk of T. cruzi transmission with liver or kidney transplantation appears to be substantially less than that with heart transplantation. For patients with Chagas cardiomyopathy undergoing heart transplant, a structured clinical and laboratory monitoring protocol is necessary to monitor for T. cruzi reactivation. Recent data indicate that laboratory monitoring of peripheral blood with polymerase chain reaction testing can identify reactivation prior to the occurrence of symptoms and allograft injury. SUMMARY Transplant clinicians should exercise vigilance in surveillance for Chagas disease in both organ donors and recipients. Although Chagas disease may seem uncommon, it is pervasive in endemic and several nonendemic countries, including the United States and Spain.
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de Souza SM, Vieira PMDA, Roatt BM, Reis LES, da Silva Fonseca K, Nogueira NC, Reis AB, Tafuri WL, Carneiro CM. Dogs infected with the blood trypomastigote form of Trypanosoma cruzi display an increase expression of cytokines and chemokines plus an intense cardiac parasitism during acute infection. Mol Immunol 2013; 58:92-7. [PMID: 24317279 DOI: 10.1016/j.molimm.2013.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/05/2013] [Accepted: 11/09/2013] [Indexed: 02/06/2023]
Abstract
The recent increase in immigration of people from areas endemic for Chagas disease (Trypanosoma cruzi) to the United States and Europe has raised concerns about the transmission via blood transfusion and organ transplants in these countries. Infection by these pathways occurs through blood trypomastigotes (BT), and these forms of T. cruzi are completely distinct of metacyclic trypomastigotes (MT), released by triatomine vector, in relation to parasite-host interaction. Thus, research comparing infection with these different infective forms is important for explaining the potential impacts on the disease course. Here, we investigated tissue parasitism and relative mRNA expression of cytokines, chemokines, and chemokine receptors in the heart during acute infection by MT or BT forms in dogs. BT-infected dogs presented a higher cardiac parasitism, increased relative mRNA expression of pro-inflammatory and immunomodulatory cytokines and of the chemokines CCL3/MIP-1α, CCL5/RANTES, and the chemokine receptor CCR5 during the acute phase of infection, as compared to MT-infected dogs. These results suggest that infection with BT forms may lead to an increased immune response, as revealed by the cytokines ratio, but this kind of immune response was not able to control the cardiac parasitism. Infection with the MT form presented an increase in the relative mRNA expression of IL-12p40 as compared to that of IL-10 or TGF-β1. Correlation analysis showed increased relative mRNA expression of IFN-γ as well as IL-10, which may be an immunomodulatory response, as well as an increase in the correlation of CCL5/RANTES and its CCR5 receptor. Our findings revealed a difference between inoculum sources of T. cruzi, as vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase, which may influence immunopathological aspects of Chagas disease.
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Affiliation(s)
- Sheler Martins de Souza
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Paula Melo de Abreu Vieira
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Bruno Mendes Roatt
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Levi Eduardo Soares Reis
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Laboratório de Pesquisas Clínicas, Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Kátia da Silva Fonseca
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Nívia Carolina Nogueira
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Alexandre Barbosa Reis
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Laboratório de Pesquisas Clínicas, Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Washington Luiz Tafuri
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Cláudia Martins Carneiro
- Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil; Laboratório de Pesquisas Clínicas, Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
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