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Nayeri T, Sarvi S, Daryani A. Effective factors in the pathogenesis of Toxoplasmagondii. Heliyon 2024; 10:e31558. [PMID: 38818168 PMCID: PMC11137575 DOI: 10.1016/j.heliyon.2024.e31558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 05/11/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.
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Affiliation(s)
- Tooran Nayeri
- Infectious and Tropical Diseases Research Center, Dezful University of Medical Sciences, Dezful, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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2
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Moss WJ, Brusini L, Kuehnel R, Brochet M, Brown KM. Apicomplexan phosphodiesterases in cyclic nucleotide turnover: conservation, function, and therapeutic potential. mBio 2024; 15:e0305623. [PMID: 38132724 PMCID: PMC10865986 DOI: 10.1128/mbio.03056-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023] Open
Abstract
Apicomplexa encompasses a large number of intracellular parasites infecting a wide range of animals. Cyclic nucleotide signaling is crucial for a variety of apicomplexan life stages and cellular processes. The cyclases and kinases that synthesize and respond to cyclic nucleotides (i.e., 3',5'-cyclic guanosine monophosphate and 3',5'-cyclic adenosine monophosphate) are highly conserved and essential throughout the parasite phylum. Growing evidence indicates that phosphodiesterases (PDEs) are also critical for regulating cyclic nucleotide signaling via cyclic nucleotide hydrolysis. Here, we discuss recent advances in apicomplexan PDE biology and opportunities for therapeutic interventions, with special emphasis on the major human apicomplexan parasite genera Plasmodium, Toxoplasma, Cryptosporidium, and Babesia. In particular, we show a highly flexible repertoire of apicomplexan PDEs associated with a wide range of cellular requirements across parasites and lifecycle stages. Despite this phylogenetic diversity, cellular requirements of apicomplexan PDEs for motility, host cell egress, or invasion are conserved. However, the molecular wiring of associated PDEs is extremely malleable suggesting that PDE diversity and redundancy are key for the optimization of cyclic nucleotide turnover to respond to the various environments encountered by each parasite and life stage. Understanding how apicomplexan PDEs are regulated and integrating multiple signaling systems into a unified response represent an untapped avenue for future exploration.
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Affiliation(s)
- William J. Moss
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Lorenzo Brusini
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Ronja Kuehnel
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Mathieu Brochet
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Kevin M. Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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3
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Vizcarra EA, Goerner AL, Ulu A, Hong DD, Bergersen KV, Talavera MA, Le Roch K, Wilson EH, White MW. An ex vivo model of Toxoplasma recrudescence reveals developmental plasticity of the bradyzoite stage. mBio 2023; 14:e0183623. [PMID: 37675999 PMCID: PMC10653814 DOI: 10.1128/mbio.01836-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 09/08/2023] Open
Abstract
IMPORTANCE The classical depiction of the Toxoplasma lifecycle is bradyzoite excystation conversion to tachyzoites, cell lysis, and immune control, followed by the reestablishment of bradyzoites and cysts. In contrast, we show that tachyzoite growth slows independent of the host immune response at a predictable time point following excystation. Furthermore, we demonstrate a host cell-dependent pathway of continuous amplification of the cyst-forming bradyzoite population. The developmental plasticity of the excysted bradyzoites further underlines the critical role the cyst plays in the flexibility of the lifecycle of this ubiquitous parasite. This revised model of Toxoplasma recrudescence uncovers previously unknown complexity in the clinically important bradyzoite stage of the parasite, which opens the door to further study these novel developmental features of the Toxoplasma intermediate life cycle.
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Affiliation(s)
- Edward A. Vizcarra
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Amber L. Goerner
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Arzu Ulu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - David D. Hong
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Kristina V. Bergersen
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Michael A. Talavera
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Karine Le Roch
- Department of Molecular, Cell, and Systems Biology, University of California, Riverside, California, USA
| | - Emma H. Wilson
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Michael W. White
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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4
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Tarannum A, Rodríguez-Almonacid CC, Salazar-Bravo J, Karamysheva ZN. Molecular Mechanisms of Persistence in Protozoan Parasites. Microorganisms 2023; 11:2248. [PMID: 37764092 PMCID: PMC10534552 DOI: 10.3390/microorganisms11092248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Protozoan parasites are known for their remarkable capacity to persist within the bodies of vertebrate hosts, which frequently results in prolonged infections and the recurrence of diseases. Understanding the molecular mechanisms that underlie the event of persistence is of paramount significance to develop innovative therapeutic approaches, given that these pathways still need to be thoroughly elucidated. The present article provides a comprehensive overview of the latest developments in the investigation of protozoan persistence in vertebrate hosts. The focus is primarily on the function of persisters, their formation within the host, and the specific molecular interactions between host and parasite while they persist. Additionally, we examine the metabolomic, transcriptional, and translational changes that protozoan parasites undergo during persistence within vertebrate hosts, focusing on major parasites such as Plasmodium spp., Trypanosoma spp., Leishmania spp., and Toxoplasma spp. Key findings of our study suggest that protozoan parasites deploy several molecular and physiological strategies to evade the host immune surveillance and sustain their persistence. Furthermore, some parasites undergo stage differentiation, enabling them to acclimate to varying host environments and immune challenges. More often, stressors such as drug exposure were demonstrated to impact the formation of protozoan persisters significantly. Understanding the molecular mechanisms regulating the persistence of protozoan parasites in vertebrate hosts can reinvigorate our current insights into host-parasite interactions and facilitate the development of more efficacious disease therapeutics.
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Affiliation(s)
| | | | | | - Zemfira N. Karamysheva
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA; (A.T.); (C.C.R.-A.); (J.S.-B.)
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5
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Sanchez SG, Bassot E, Cerutti A, Mai Nguyen H, Aïda A, Blanchard N, Besteiro S. The apicoplast is important for the viability and persistence of Toxoplasma gondii bradyzoites. Proc Natl Acad Sci U S A 2023; 120:e2309043120. [PMID: 37590416 PMCID: PMC10450435 DOI: 10.1073/pnas.2309043120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 06/27/2023] [Indexed: 08/19/2023] Open
Abstract
Toxoplasma gondii is responsible for toxoplasmosis, a disease that can be serious when contracted during pregnancy, but can also be a threat for immunocompromised individuals. Acute infection is associated with the tachyzoite form that spreads rapidly within the host. However, under stress conditions, some parasites can differentiate into cyst-forming bradyzoites, residing mainly in the central nervous system, retina and muscle. Because this latent form of the parasite is resistant to all currently available treatments, and is central to persistence and transmission of the parasite, specific therapeutic strategies targeting this developmental stage need to be found. T. gondii contains a plastid of endosymbiotic origin called the apicoplast, which is an appealing drug target because it is essential for tachyzoite viability and contains several key metabolic pathways that are largely absent from the mammalian host. Its function in bradyzoites, however, is unknown. Our objective was thus to study the contribution of the apicoplast to the viability and persistence of bradyzoites during chronic toxoplasmosis. We have used complementary strategies based on stage-specific promoters to generate conditional bradyzoite mutants of essential apicoplast genes. Our results show that specifically targeting the apicoplast in both in vitro or in vivo-differentiated bradyzoites leads to a loss of long-term bradyzoite viability, highlighting the importance of this organelle for this developmental stage. This validates the apicoplast as a potential area to look for therapeutic targets in bradyzoites, with the aim to interfere with this currently incurable parasite stage.
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Affiliation(s)
- Syrian G. Sanchez
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| | - Emilie Bassot
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, University of Toulouse, CNRS, Inserm, Université Paul Sabatier, 31059Toulouse, France
| | - Aude Cerutti
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| | - Hoa Mai Nguyen
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
| | - Amel Aïda
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, University of Toulouse, CNRS, Inserm, Université Paul Sabatier, 31059Toulouse, France
| | - Nicolas Blanchard
- Toulouse Institute for Infectious and Inflammatory Diseases, Infinity, University of Toulouse, CNRS, Inserm, Université Paul Sabatier, 31059Toulouse, France
| | - Sébastien Besteiro
- Laboratory of Pathogens and Host Immunity, CNRS, University of Montpellier, 34095Montpellier, France
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Invasion of Toxoplasma gondii bradyzoites: Molecular dissection of the moving junction proteins and effective vaccination targets. Proc Natl Acad Sci U S A 2023; 120:e2219533120. [PMID: 36693095 PMCID: PMC9945962 DOI: 10.1073/pnas.2219533120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Toxoplasmosis is a neglected parasitic disease necessitating public health control. Host cell invasion by Toxoplasma occurs at different stages of the parasite's life cycle and is crucial for survival and establishment of infection. In tachyzoites, which are responsible for acute toxoplasmosis, invasion involves the formation of a molecular bridge between the parasite and host cell membranes, referred to as the moving junction (MJ). The MJ is shaped by the assembly of AMA1 and RON2, as part of a complex involving additional RONs. While this essential process is well characterized in tachyzoites, the invasion process remains unexplored in bradyzoites, which form cysts and are responsible for chronic toxoplasmosis and contribute to the dissemination of the parasite between hosts. Here, we show that bradyzoites invade host cells in an MJ-dependent fashion but differ in protein composition from the tachyzoite MJ, relying instead on the paralogs AMA2 and AMA4. Functional characterization of AMA4 reveals its key role for cysts burden during the onset of chronic infection, while being dispensable for the acute phase. Immunizations with AMA1 and AMA4, alone or in complex with their rhoptry neck respective partners RON2 and RON2L1, showed that the AMA1-RON2 pair induces strong protection against acute and chronic infection, while the AMA4-RON2L1 complex targets more selectively the chronic form. Our study provides important insights into the molecular players of bradyzoite invasion and indicates that invasion of cyst-forming bradyzoites contributes to cyst burden. Furthermore, we validate AMA-RON complexes as potential vaccine candidates to protect against toxoplasmosis.
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Pan M, Ge CC, Fan YM, Jin QW, Shen B, Huang SY. The determinants regulating Toxoplasma gondii bradyzoite development. Front Microbiol 2022; 13:1027073. [PMID: 36439853 PMCID: PMC9691885 DOI: 10.3389/fmicb.2022.1027073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/24/2022] [Indexed: 11/04/2023] Open
Abstract
Toxoplasma gondii is an obligate intracellular zoonotic pathogen capable of infecting almost all cells of warm-blooded vertebrates. In intermediate hosts, this parasite reproduces asexually in two forms, the tachyzoite form during acute infection that proliferates rapidly and the bradyzoite form during chronic infection that grows slowly. Depending on the growth condition, the two forms can interconvert. The conversion of tachyzoites to bradyzoites is critical for T. gondii transmission, and the reactivation of persistent bradyzoites in intermediate hosts may lead to symptomatic toxoplasmosis. However, the mechanisms that control bradyzoite differentiation have not been well studied. Here, we review recent advances in the study of bradyzoite biology and stage conversion, aiming to highlight the determinants associated with bradyzoite development and provide insights to design better strategies for controlling toxoplasmosis.
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Affiliation(s)
- Ming Pan
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Ceng-Ceng Ge
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yi-Min Fan
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Qi-Wang Jin
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Si-Yang Huang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
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8
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A Signaling Factor Linked to Toxoplasma gondii Guanylate Cyclase Complex Controls Invasion and Egress during Acute and Chronic Infection. mBio 2022; 13:e0196522. [PMID: 36200777 PMCID: PMC9600588 DOI: 10.1128/mbio.01965-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is an intracellular apicomplexan parasite that relies on cyclic GMP (cGMP)-dependent signaling to trigger timely egress from host cells in response to extrinsic and intrinsic signals. A guanylate cyclase (GC) complex, conserved across the Apicomplexa, plays a pivotal role in integrating these signals, such as the key lipid mediator phosphatidic acid and changes in pH and ionic composition. This complex is composed of an atypical GC fused to a flippase-like P4-ATPase domain and assembled with the cell division control protein CDC50.1 and a unique GC organizer (UGO). While the dissemination of the fast-replicating tachyzoites responsible for acute infection is well understood, it is less clear if the cyst-forming bradyzoites can disseminate and contribute to cyst burden. Here, we characterized a novel component of the GC complex recently termed signaling linking factor (SLF). Tachyzoites conditionally depleted in SLF are impaired in microneme exocytosis, conoid extrusion, and motility and hence unable to invade and egress. A stage-specific promoter swap strategy allowed the generation of SLF- and GC-deficient bradyzoites that are viable as tachyzoites but show a reduction in cyst burden during the onset of chronic infection. Upon oral infection, SLF-deficient cysts failed to establish infection in mice, suggesting SLF's importance for the natural route of T. gondii infection. IMPORTANCE Toxoplasma gondii is an obligate intracellular parasite of the phylum Apicomplexa. This life-threatening opportunistic pathogen establishes a chronic infection in human and animals that is resistant to immune attacks and chemotherapeutic intervention. The slow-growing parasites persist in tissue cysts that constitute a predominant source of transmission. Host cell invasion and egress are two critical steps of the parasite lytic cycle that are governed by a guanylate cyclase complex conserved across the Apicomplexa. A signaling linked factor is characterized here as an additional component of the complex that not only is essential during acute infection but also plays a pivotal role during natural oral infection with tissue cysts' dissemination and persistence.
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Zhao W, Yu H, Liu X, Wang T, Yao Y, Zhou Q, Zheng X, Tan F. Systematic identification of the lysine lactylation in the protozoan parasite Toxoplasma gondii. Parasit Vectors 2022; 15:180. [PMID: 35610722 PMCID: PMC9131557 DOI: 10.1186/s13071-022-05315-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/06/2022] [Indexed: 11/10/2022] Open
Abstract
Background Lysine lactylation (Kla) is a novelposttranslational modification (PTM) identified in histone and nonhistone proteins of several eukaryotic cells that directly activates gene expression and DNA replication. However, very little is known about the scope and cellular distribution of Kla in apicomplexan parasites despite its significance in public and animal health care. Methods Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular apicomplexan parasite that can infect different nucleated cell types of animals and humans. We used this parasite as a model organism and extracted the total protein of tachyzoites to produce the first global lysine lactylome profile of T. gondii through liquid chromatography–tandem mass spectrometry. We also investigated the level and localization of the Kla protein in T. gondii using western blotting and the indirect fluorescent antibody test (IFA), respectively. Results A total of 983 Kla sites occurring on 523 lactylated proteins were identified in the total protein extracted from Toxoplasma tachyzoites, the acute toxoplasmosis-causing stage. Bioinformatics analysis revealed that the lactylated proteins were evolutionarily conserved and involved in a wide variety of cellular functions, such as energy metabolism, gene regulation and protein biosynthesis. Subcellular localization analysis and IFA results further revealed that most of the lactylated T. gondii proteins were localized in the nucleus, indicating the potential impact of Kla on gene regulation in the T. gondii model. Notably, an extensive batch of parasite-specific proteins unique to phylum Apicomplexa is lactylated in T. gondii. Conclusions This study revealed that Kla is widespread in early dividing eukaryotic cells. Lactylated proteins, including a batch of unique parasite proteins, are involved in a remarkably diverse array of cellular functions. These valuable data will improve our understanding of the evolution of Kla and potentially provide the basis for developing novel therapeutic avenues. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05315-6.
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Affiliation(s)
- Wei Zhao
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Helin Yu
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Xiaona Liu
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Tingting Wang
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Yinning Yao
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Qixin Zhou
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Xiaozi Zheng
- Teaching Center of Morphological Experiment, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China
| | - Feng Tan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, People's Republic of China.
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Castaño BL, Silva AA, Hernandez-Velasco LL, Pinheiro APDS, Gibaldi D, Mineo JR, Silva NM, Lannes-Vieira J. Sulfadiazine Plus Pyrimethamine Therapy Reversed Multiple Behavioral and Neurocognitive Changes in Long-Term Chronic Toxoplasmosis by Reducing Brain Cyst Load and Inflammation-Related Alterations. Front Immunol 2022; 13:822567. [PMID: 35572567 PMCID: PMC9091718 DOI: 10.3389/fimmu.2022.822567] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii infects one-third of the world population. For decades, it has been considered a silent lifelong infection. However, chronically T. gondii-infected persons may present psychiatric and neurocognitive changes as anxiety, depression, and memory loss. In a model of long-term chronic infection, behavioral alterations parallel neuroinflammation and systemic high cytokine levels, and may reflect brain cyst load. Recent findings support that in chronic infection an active parasite-host interplay involves an immune-mediated control of tissue cysts. Here, we tested the idea that etiological treatment in chronic phase may add advantage to intrinsic immune-mediated cyst control and impact behavioral changes. Thus, we combined sulfadiazine-plus-pyrimethamine (S+P), the first-choice therapy for toxoplasmosis, to study the association of brain cyst load and biological processes related to the immune response (neuroinflammation, blood-brain barrier -BBB- disruption and serum cytokine levels), with behavioral and neurocognitive changes of long-term chronic infection. Female C57BL/6 mice (H-2b) were infected (5 cysts, ME-49 strain) and treated with S+P from 30 to 60 days postinfection (dpi), compared with vehicle (Veh)-treated and noninfected controls. At endpoints (pre-therapy, 30 dpi; S+P therapy, 60 dpi; after ceased therapy, 90 dpi), independent groups were subjected to behavioral tests, and brain tissues and sera were collected. Multiple behavioral and neurocognitive changes were detected in the early (30 dpi) and long-term (60 and 90 dpi) chronic infection. S+P therapy resolved locomotor alterations, anxiety, and depressive-like behavior, partially or transiently ameliorated hyperactivity and habituation memory loss. Analysis after therapy cessation showed that S+P therapy reduced the number of stimuli required for aversive memory consolidation. S+P therapy resulted in reduced brain cyst load, neuroinflammation and BBB disruption, and lowered systemic Th1-cytokine levels. Correlation analysis revealed association between IFNγ, TNF and MCP-1/CCL2 serum levels, brain cyst load and behavioral and neurocognitive alterations. Moreover, principal-component analysis (PCA-2D and 3D projections) highlighted distinction between clusters (noninfected; Veh-treated and S+P-treated infected). Thus, our data suggest that S+P therapy added gain to intrinsic brain cyst control and, direct or indirectly, ameliorated inflammation-related alterations, traits associated with behavioral and neurocognitive alterations.
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Affiliation(s)
- Barrios Leda Castaño
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Andrea Alice Silva
- Multiuser Laboratory for Research Support in Nephrology and Medical Sciences, Federal University Fluminense, Niterói, Brazil
| | | | | | - Daniel Gibaldi
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - José Roberto Mineo
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Neide Maria Silva
- Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Joseli Lannes-Vieira
- Laboratory of Biology of the Interactions, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
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11
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J. Steptoe P, Guly CM, Dick AD. Ocular Toxoplasmosis Associated Dark Without Pressure. Ocul Immunol Inflamm 2022; 31:624-626. [PMID: 35499545 DOI: 10.1080/09273948.2022.2037658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Paul J. Steptoe
- Bristol Eye Hospital, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Catherine M. Guly
- Bristol Eye Hospital, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Andrew D. Dick
- Bristol Eye Hospital, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
- Bristol Medical School, University of Bristol, Bristol, UK
- Institute of Ophthalmology, University College London, London, UK
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12
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Hartman EJ, Asady B, Romano JD, Coppens I. The Rab11-Family Interacting Proteins reveal selective interaction of mammalian recycling endosomes with the Toxoplasma parasitophorous vacuole in a Rab11- and Arf6-dependent manner. Mol Biol Cell 2022; 33:ar34. [PMID: 35274991 PMCID: PMC9282008 DOI: 10.1091/mbc.e21-06-0284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
After mammalian cell invasion, the parasite Toxoplasma multiplies in a self-made membrane-bound compartment, the parasitophorous vacuole (PV). We previously showed that Toxoplasma interacts with many host cell organelles, especially from recycling pathways, and sequestrates Rab11A and Rab11B vesicles into the PV. Here, we examine the specificity of host Rab11 vesicle interaction with the PV by focusing on the recruitment of subpopulations of Rab11 vesicles characterized by different effectors, for example, Rab11-family interacting roteins (FIPs) or Arf6. Our quantitative microscopic analysis illustrates the presence of intra-PV vesicles with FIPs from class I (FIP1C, FIP2, FIP5) and class II (FIP3, FIP4) but to various degrees. The intra-PV delivery of vesicles with class I, but not class II, FIPs is dependent on Rab11 binding. Cell depletion of Rab11A results in a significant decrease in intra-PV FIP5, but not FIP3 vesicles. Class II FIPs also bind to Arf6, and we observe vesicles associated with FIP3-Rab11A or FIP3-Arf6 complexes concomitantly within the PV. Abolishing FIP3 binding to both Rab11 and Arf6 reduces the number of intra-PV FIP3 vesicles. These data point to a selective process of mammalian Rab11 vesicle recognition and scavenging mediated by Toxoplasma, suggesting that specific parasite PV proteins may be involved in these processes.
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Affiliation(s)
- Eric J Hartman
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, 615N Wolfe Street, Baltimore, MD 21205, USA
| | - Beejan Asady
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, 615N Wolfe Street, Baltimore, MD 21205, USA
| | - Julia D Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, 615N Wolfe Street, Baltimore, MD 21205, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, 615N Wolfe Street, Baltimore, MD 21205, USA
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Abstract
Toxoplasma gondii is a parasitic protist infecting a wide group of warm-blooded animals, ranging from birds to humans. While this infection is usually asymptomatic in healthy individuals, it can also lead to severe ocular or neurological outcomes in immunocompromised individuals or in developing fetuses. This obligate intracellular parasite has the ability to infect a considerable range of nucleated cells and can propagate in the intermediate host. Yet, under the pressure of the immune system it transforms into an encysted persistent form residing primarily in the brain and muscle tissues. Encysted parasites, which are resistant to current medication, may reactivate and give rise to an acute infection. The clinical outcome of toxoplasmosis depends on a complex balance between the host immune response and parasite virulence factors. Susceptibility to the disease is thus determined by both parasite strains and host species. Recent advances on our understanding of host cell-parasite interactions and parasite virulence have brought new insights into the pathophysiology of T. gondii infection and are summarized here.
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14
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Fu Y, Brown KM, Jones NG, Moreno SNJ, Sibley LD. Toxoplasma bradyzoites exhibit physiological plasticity of calcium and energy stores controlling motility and egress. eLife 2021; 10:e73011. [PMID: 34860156 PMCID: PMC8683080 DOI: 10.7554/elife.73011] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/03/2021] [Indexed: 01/01/2023] Open
Abstract
Toxoplasma gondii has evolved different developmental stages for disseminating during acute infection (i.e., tachyzoites) and establishing chronic infection (i.e., bradyzoites). Calcium ion (Ca2+) signaling tightly regulates the lytic cycle of tachyzoites by controlling microneme secretion and motility to drive egress and cell invasion. However, the roles of Ca2+ signaling pathways in bradyzoites remain largely unexplored. Here, we show that Ca2+ responses are highly restricted in bradyzoites and that they fail to egress in response to agonists. Development of dual-reporter parasites revealed dampened Ca2+ responses and minimal microneme secretion by bradyzoites induced in vitro or harvested from infected mice and tested ex vivo. Ratiometric Ca2+ imaging demonstrated lower Ca2+ basal levels, reduced magnitude, and slower Ca2+ kinetics in bradyzoites compared with tachyzoites stimulated with agonists. Diminished responses in bradyzoites were associated with downregulation of Ca2+-ATPases involved in intracellular Ca2+ storage in the endoplasmic reticulum (ER) and acidocalcisomes. Once liberated from cysts by trypsin digestion, bradyzoites incubated in glucose plus Ca2+ rapidly restored their intracellular Ca2+ and ATP stores, leading to enhanced gliding. Collectively, our findings indicate that intracellular bradyzoites exhibit dampened Ca2+ signaling and lower energy levels that restrict egress, and yet upon release they rapidly respond to changes in the environment to regain motility.
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Affiliation(s)
- Yong Fu
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Kevin M Brown
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
| | - Silvia NJ Moreno
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of GeorgiaAthensUnited States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University in St. Louis, School of MedicineSt LouisUnited States
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15
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In vitro activity of N-phenyl-1,10-phenanthroline-2-amines against tachyzoites and bradyzoites of Toxoplasma gondii. Bioorg Med Chem 2021; 50:116467. [PMID: 34666274 DOI: 10.1016/j.bmc.2021.116467] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 01/19/2023]
Abstract
Toxoplasma gondiiis an apicomplexan parasite, the causative agent of toxoplasmosis, a common disease in the world. Toxoplasmosis could be severe, especially in immunocompromised patients. The current therapy is limited, where pyrimethamine and sulfadiazine are the best choices despite being associated with side effects and ineffective against the bradyzoites, the parasitic form present during the chronic phase of the infection. Thus, new therapies against both tachyzoites and bradyzoites from T. gondii are urgent. Herein, we present the anti-T. gondii effect of 1,10-phenanthroline and its N-phenyl-1,10-phenanthroline-2-amine derivatives. The chemical modification of 1,10-phenanthroline tonew derivatives improved the anti-T. gondiiactivity 3.4 fold. The most active derivative presented ED50in the nanomolar range, the smallest value found was for Ph8, 0.1 µM for 96 h of treatment. The host cell viability was maintained after the treatment with the compounds, which were found to be highly selective presenting large selectivity indexes. Treatment with derivatives for 96 h was able to eliminate the T. gondii infection irreversibly. The ultrastructural alterations caused after the treatment with the most effective derivative (Ph8) included signs of cell death, specifically revealed by the Tunel assay for detection of DNA fragmentation. The Phen derivatives were also able to control the growth of the in vitro-derived bradyzoite forms of T. gondii EGS strain, causing its lysis and death. These findings promote the 1,10-phenanthroline derivatives as potential lead compounds for the development of a treatment for acute and chronic phases of toxoplasmosis.
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16
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Pamukcu S, Cerutti A, Bordat Y, Hem S, Rofidal V, Besteiro S. Differential contribution of two organelles of endosymbiotic origin to iron-sulfur cluster synthesis and overall fitness in Toxoplasma. PLoS Pathog 2021; 17:e1010096. [PMID: 34793583 PMCID: PMC8639094 DOI: 10.1371/journal.ppat.1010096] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/02/2021] [Accepted: 11/05/2021] [Indexed: 11/21/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are one of the most ancient and ubiquitous prosthetic groups, and they are required by a variety of proteins involved in important metabolic processes. Apicomplexan parasites have inherited different plastidic and mitochondrial Fe-S clusters biosynthesis pathways through endosymbiosis. We have investigated the relative contributions of these pathways to the fitness of Toxoplasma gondii, an apicomplexan parasite causing disease in humans, by generating specific mutants. Phenotypic analysis and quantitative proteomics allowed us to highlight notable differences in these mutants. Both Fe-S cluster synthesis pathways are necessary for optimal parasite growth in vitro, but their disruption leads to markedly different fates: impairment of the plastidic pathway leads to a loss of the organelle and to parasite death, while disruption of the mitochondrial pathway trigger differentiation into a stress resistance stage. This highlights that otherwise similar biochemical pathways hosted by different sub-cellular compartments can have very different contributions to the biology of the parasites, which is something to consider when exploring novel strategies for therapeutic intervention.
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Affiliation(s)
| | - Aude Cerutti
- LPHI, Univ Montpellier, CNRS, Montpellier, France
| | - Yann Bordat
- LPHI, Univ Montpellier, CNRS, Montpellier, France
| | - Sonia Hem
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
| | - Valérie Rofidal
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France
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17
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Valproic acid inhibits chronic Toxoplasma infection and associated brain inflammation in mice. Antimicrob Agents Chemother 2021; 65:e0100321. [PMID: 34339265 DOI: 10.1128/aac.01003-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Individuals infected with Toxoplasma gondii (T. gondii) are prone to psycho-behavioral disorders, most notably schizophrenia and bipolar. Valproic acid reportedly inhibited the proliferation of T. gondii tachyzoites in vitro. However, animals treated with the drug neither lived longer during acute infection nor had fewer brain cysts upon chronic infection. In this study, a quantitative real-time PCR (qPCR) method was applied to quantify copy numbers of BAG1 (a bradyzoite-specific protein), REP529 DNA (a repetitive DNA fragment of the parasite), and SAG1 (a highly expressed tachyzoite-specific surface protein) in brains of chronically infected mice treated by valproic acid. The treatment inhibited the infection and decreased BAG1, SAG1, and REP529 copy numbers in mice brains (P < 0.0001), comparable to Trimethoprim/Sulfamethoxazole (TMP/SMZ), the common medication for Toxoplasmosis treatment. Moreover, valproic acid decreased brain TNF-α expression (P < 0.0001), comparable to TMP/SMZ. Histological examination of mice brains showed a marked reduction in cyst establishment, perivascular infiltration of lymphocytes, and glial nodules to the same level as the TMP/SMZ group. Our results provide direct evidence for the efficacy of valproic acid, a mood-stabilizing and antipsychotic drug against chronic Toxoplasma infection. These results might help modulate therapeutic regimens for neuropsychiatric patients and design more effective anti-Toxoplasma drugs.
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18
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Smith D, Kannan G, Coppens I, Wang F, Nguyen HM, Cerutti A, Olafsson EB, Rimple PA, Schultz TL, Mercado Soto NM, Di Cristina M, Besteiro S, Carruthers VB. Toxoplasma TgATG9 is critical for autophagy and long-term persistence in tissue cysts. eLife 2021; 10:e59384. [PMID: 33904393 PMCID: PMC8128441 DOI: 10.7554/elife.59384] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 04/27/2021] [Indexed: 12/29/2022] Open
Abstract
Many of the world's warm-blooded species are chronically infected with Toxoplasma gondii tissue cysts, including an estimated one-third of the global human population. The cellular processes that permit long-term persistence within the cyst are largely unknown for T. gondii and related coccidian parasites that impact human and animal health. Herein, we show that genetic ablation of TgATG9 substantially reduces canonical autophagy and compromises bradyzoite viability. Transmission electron microscopy revealed numerous structural abnormalities occurring in ∆atg9 bradyzoites. Intriguingly, abnormal mitochondrial networks were observed in TgATG9-deficient bradyzoites, some of which contained numerous different cytoplasmic components and organelles. ∆atg9 bradyzoite fitness was drastically compromised in vitro and in mice, with very few brain cysts identified in mice 5 weeks post-infection. Taken together, our data suggests that TgATG9, and by extension autophagy, is critical for cellular homeostasis in bradyzoites and is necessary for long-term persistence within the cyst of this coccidian parasite.
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Affiliation(s)
- David Smith
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Geetha Kannan
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public HealthBaltimoreUnited States
| | - Fengrong Wang
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Hoa Mai Nguyen
- Laboratory of PathogenHost Interactions, UMR 5235, CNRS, Université de MontpellierMontpellierFrance
| | - Aude Cerutti
- Laboratory of PathogenHost Interactions, UMR 5235, CNRS, Université de MontpellierMontpellierFrance
| | - Einar B Olafsson
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Patrick A Rimple
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Tracey L Schultz
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Nayanna M Mercado Soto
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Manlio Di Cristina
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
- Department of Chemistry, Biology and Biotechnology, Università degli Studi di PerugiaPerugiaItaly
| | - Sébastien Besteiro
- Laboratory of PathogenHost Interactions, UMR 5235, CNRS, Université de MontpellierMontpellierFrance
| | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical SchoolAnn ArborUnited States
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19
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Dard C, Swale C, Brenier-Pinchart MP, Farhat DC, Bellini V, Robert MG, Cannella D, Pelloux H, Tardieux I, Hakimi MA. A brain cyst load-associated antigen is a Toxoplasma gondii biomarker for serodetection of persistent parasites and chronic infection. BMC Biol 2021; 19:25. [PMID: 33557824 PMCID: PMC7871634 DOI: 10.1186/s12915-021-00959-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 01/12/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Biomarker discovery remains a major challenge for predictive medicine, in particular, in the context of chronic diseases. This is true for the widespread protozoan Toxoplasma gondii which establishes long-lasting parasitism in metazoans, humans included. This microbe successively unfolds distinct genetic programs that direct the transition from high to low replicative potential inside host cells. As a slow-replicating cell, the T. gondii bradyzoite developmental stage persists enclosed in a cyst compartment within tissues including the nervous system, being held by a sustained immune equilibrium which accounts for the prolonged clinically silent phase of parasitism. Serological surveys indicate that nearly one third of the human population has been exposed to T. gondii and possibly host bradyzoites. Because any disruption of the immune balance drives the reverse transition from bradyzoite to fast replicating tachyzoite and uncontrolled growth of the latter, these people are at risk for life-threatening disease. While serological tests for discriminating recent from past infection are available, there is yet no immunogenic biomarker used in the serological test to allow ascertaining the presence of persistent bradyzoites. RESULTS Capitalizing on genetically engineered parasites induced to produce mature bradyzoites in vitro, we have identified the BCLA/MAG2 protein being restricted to the bradyzoite and the cyst envelope. Using laboratory mice as relevant T. gondii host models, we demonstrated that BCLA/MAG2 drives the generation of antibodies that recognize bradyzoite and the enveloping cyst structure. We have designed an ELISA assay based on a bacterially produced BCLA recombinant polypeptide, which was validated using a large collection of sera from mice of different genetic backgrounds and infected with bcla+ or bcla-null cystogenic and non-cystogenic T. gondii strains. To refine the design of the ELISA assay, we applied high-resolution BCLA epitope mapping and identified a specific combination of peptides and accordingly set up a selective and sensitive ELISA assay which allowed the detection of anti-BCLA/MAG2 antibodies in the sera of human patients with various forms of toxoplasmosis. CONCLUSIONS We brought proof of principle that anti-BCLA/MAG2 antibodies serve as specific and sensitive serological markers in the perspective of a combinatorial strategy for detection of persistent T. gondii parasitism.
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Affiliation(s)
- Céline Dard
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
- Laboratory of Parasitology and Mycology, Grenoble Alpes University Hospital, CS10217, 38043, Grenoble, France
| | - Christopher Swale
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Marie-Pierre Brenier-Pinchart
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
- Laboratory of Parasitology and Mycology, Grenoble Alpes University Hospital, CS10217, 38043, Grenoble, France
| | - Dayana C Farhat
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Valeria Bellini
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Marie Gladys Robert
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
- Laboratory of Parasitology and Mycology, Grenoble Alpes University Hospital, CS10217, 38043, Grenoble, France
| | - Dominique Cannella
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Hervé Pelloux
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
- Laboratory of Parasitology and Mycology, Grenoble Alpes University Hospital, CS10217, 38043, Grenoble, France
| | - Isabelle Tardieux
- Team Membrane and Cell Dynamics of Host Parasite Interactions, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Mohamed-Ali Hakimi
- Team Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France.
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20
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Wang C, Hu D, Tang X, Song X, Wang S, Zhang S, Duan C, Sun P, Suo J, Ma H, Suo X, Liu X. Internal daughter formation of Toxoplasma gondii tachyzoites is coordinated by transcription factor TgAP2IX-5. Cell Microbiol 2020; 23:e13291. [PMID: 33217129 DOI: 10.1111/cmi.13291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023]
Abstract
Toxoplasma gondii rapidly propagates through endodyogeny of tachyzoites, a process in which daughter parasites divide within the cell of the mother parasite. Recent studies have revealed that transcription factors with AP2-domain participate in the process of cell division in T. gondii. However, the concise regulation of the division cycles by AP2 proteins is poorly understood. In this study, we evaluated the effect of the transcription factor TgAP2IX-5 on the daughter cell formation in T. gondii. TgAP2IX-5 is a nuclear protein and is highly expressed during the S phase of the cell cycle of tachyzoites. TgAP2IX-5-disrupted strain showed a severe defect in replication and completely blocked lytic parasite growth. Following 3-indoleacetic acid treatment or without treatment of AP2IX-5-AID-3HA tagged strain for 30 min, 1 and 2 hr, the differentially expressed genes were 8, 54 and 202, respectively. Among these genes, the significantly downregulated ones were AP2 proteins, inner membrane complex (IMC) proteins and SAG-related proteins. Interestingly, loss of TgAP2IX-5 leads to a defect in internal daughter IMC formation and abnormalities in the morphology of organelles during cell division. Together, our study suggests that TgAP2IX-5 is crucial in regulating IMC formation of daughter cells in T. gondii.
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Affiliation(s)
- Chaoyue Wang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Dandan Hu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xinming Tang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xingju Song
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Si Wang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Sixin Zhang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Chunhui Duan
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Pei Sun
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jingxia Suo
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Huiming Ma
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xun Suo
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xianyong Liu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
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21
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Tomasina R, Francia ME. The Structural and Molecular Underpinnings of Gametogenesis in Toxoplasma gondii. Front Cell Infect Microbiol 2020; 10:608291. [PMID: 33365279 PMCID: PMC7750520 DOI: 10.3389/fcimb.2020.608291] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/04/2020] [Indexed: 01/18/2023] Open
Abstract
Toxoplasma gondii is a widely prevalent protozoan parasite member of the phylum Apicomplexa. It causes disease in humans with clinical outcomes ranging from an asymptomatic manifestation to eye disease to reproductive failure and neurological symptoms. In farm animals, and particularly in sheep, toxoplasmosis costs the industry millions by profoundly affecting their reproductive potential. As do all the parasites in the phylum, T. gondii parasites go through sexual and asexual replication in the context of an heteroxenic life cycle involving members of the Felidae family and any warm-blooded vertebrate as definitive and intermediate hosts, respectively. During sexual replication, merozoites differentiate into female and male gametes; their combination gives rise to a zygotes which evolve into sporozoites that encyst and are shed in cat's feces as environmentally resistant oocysts. During zygote formation T. gondii parasites are diploid providing the parasite with a window of opportunity for genetic admixture making this a key step in the generation of genetic diversity. In addition, oocyst formation and shedding are central to dissemination and environmental contamination with infectious parasite forms. In this minireview we summarize the current state of the art on the process of gametogenesis. We discuss the unique structures of macro and microgametes, an insight acquired through classical techniques, as well as the more recently attained molecular understanding of the routes leading up to these life forms by in vitro and in vivo systems. We pose a number of unanswered questions and discuss these in the context of the latest findings on molecular cues mediating stage switching, and the implication for the field of newly available in vitro tools.
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Affiliation(s)
- Ramiro Tomasina
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - María E Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Department of Parasitology and Mycology, School of Medicine, Universidad de la Republica, Montevideo, Uruguay
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22
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Computational image analysis reveals the structural complexity of Toxoplasma gondii tissue cysts. PLoS One 2020; 15:e0234169. [PMID: 32810131 PMCID: PMC7444489 DOI: 10.1371/journal.pone.0234169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/25/2020] [Indexed: 11/19/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite infecting up to one third of the human population. The central event in the pathogenesis of toxoplasmosis is the conversion of tachyzoites into encysted bradyzoites. A novel approach to analyze the structure of in vivo-derived tissue cysts may be the increasingly used computational image analysis. The objective of this study was to quantify the geometrical complexity of T. gondii cysts by morphological, particle, and fractal analysis, as well as to determine if it is impacted by parasite strain, cyst age, and host type. A total of 31 images of T. gondii brain cysts of four type-2 strains (Me49, and local isolates BGD1, BGD14, and BGD26) was analyzed using ImageJ software. The parameters of interest included diameter, circularity, packing density (PD), fractal dimension (FD), and lacunarity. Although cyst diameter varied widely, its negative correlation with PD was observed. Circularity was remarkably close to 1, indicating a perfectly round shape of the cysts. PD and FD did not vary among cysts of different strains, age, and derived from mice of different genetic background. Conversely, lacunarity, which is a measure of heterogeneity, was significantly lower for BGD1 strain vs. all other strains, and higher for Me49 vs. BGD14 and BGD26, but did not differ among Me49 cysts of different age, or those derived from genetically different mice. The results indicate a highly uniform structure and occupancy of the different T. gondii tissue cysts. This study furthers the use of image analysis in describing the structural complexity of T. gondii cyst morphology, and presents the first application of fractal analysis for this purpose. The presented results show that use of a freely available software is a cost-effective approach to advance automated image scoring for T. gondii cysts.
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23
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Smith JR, Ashander LM, Arruda SL, Cordeiro CA, Lie S, Rochet E, Belfort R, Furtado JM. Pathogenesis of ocular toxoplasmosis. Prog Retin Eye Res 2020; 81:100882. [PMID: 32717377 DOI: 10.1016/j.preteyeres.2020.100882] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022]
Abstract
Ocular toxoplasmosis is a retinitis -almost always accompanied by vitritis and choroiditis- caused by intraocular infection with Toxoplasma gondii. Depending on retinal location, this condition may cause substantial vision impairment. T. gondii is an obligate intracellular protozoan parasite, with both sexual and asexual life cycles, and infection is typically contracted orally by consuming encysted bradyzoites in undercooked meat, or oocysts on unwashed garden produce or in contaminated water. Presently available anti-parasitic drugs cannot eliminate T. gondii from the body. In vitro studies using T. gondii tachyzoites, and human retinal cells and tissue have provided important insights into the pathogenesis of ocular toxoplasmosis. T. gondii may cross the vascular endothelium to access human retina by at least three routes: in leukocyte taxis; as a transmigrating tachyzoite; and after infecting endothelial cells. The parasite is capable of navigating the human neuroretina, gaining access to a range of cell populations. Retinal Müller glial cells are preferred initial host cells. T. gondii infection of the retinal pigment epithelial cells alters the secretion of growth factors and induces proliferation of adjacent uninfected epithelial cells. This increases susceptibility of the cells to parasite infection, and may be the basis of the characteristic hyperpigmented toxoplasmic retinal lesion. Infected epithelial cells also generate a vigorous immunologic response, and influence the activity of leukocytes that infiltrate the retina. A range of T. gondii genotypes are associated with human ocular toxoplasmosis, and individual immunogenetics -including polymorphisms in genes encoding innate immune receptors, human leukocyte antigens and cytokines- impacts the clinical manifestations. Research into basic pathogenic mechanisms of ocular toxoplasmosis highlights the importance of prevention and suggests new biological drug targets for established disease.
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Affiliation(s)
- Justine R Smith
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia; Formerly of Casey Eye Institute, Oregon Health & Science University, USA.
| | - Liam M Ashander
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia; Formerly of Casey Eye Institute, Oregon Health & Science University, USA
| | - Sigrid L Arruda
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Cynthia A Cordeiro
- Cordeiro et Costa Ophtalmologie, Campos dos Goytacazes, Brazil; Formerly of Department of Ophthalmology, Federal University of Minas Gerais School of Medicine, Belo Horizonte, Brazil
| | - Shervi Lie
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia
| | - Elise Rochet
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia
| | - Rubens Belfort
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | - João M Furtado
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil; Formerly of Casey Eye Institute, Oregon Health & Science University, USA
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Azadi Y, Ahmadpour E, Ahmadi A. Targeting Strategies in Therapeutic Applications of Toxoplasmosis: Recent Advances in Liposomal Vaccine Delivery Systems. Curr Drug Targets 2020; 21:541-558. [DOI: 10.2174/1389450120666191023151423] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/10/2019] [Accepted: 10/15/2019] [Indexed: 11/22/2022]
Abstract
Toxoplasma gondii is a prevalent parasitic pathogen that infected over one-third of the global population. Toxoplasmosis is diagnosed by isolating the parasite and detecting host antibodies. In contrast, the main problem with diagnosis relates to the sensitivity and specificity of the tests. Currently, treatment with pyrimethamine and sulfadiazine is recommended, despite their side effects and toxicity to humans. Moreover, the absence of a vaccine to completely protect against this infection is the main obstacle to the effective treatment and prevention of toxoplasmosis. Recently, nanoparticles and nanomaterials have been studied as delivery systems for the immunization and treatment of T. gondii infections. One of the most important applications of liposomes is drug and vaccine delivery, due to their biodegradability, low inherent toxicity, and immunogenicity. Liposomes are flexible delivery systems and immunological adjuvants able not only to load diverse antigens, such as proteins, peptides, nucleic acids, and carbohydrates but also to combine them with immunostimulators. Liposomes have the incredible potential within the development of modern types of vaccines and numerous endeavors have been made to improve the effectiveness of vaccines in recent years. In this review, we concentrate on the viable targeting strategies of liposome-based vaccine delivery systems to prevent, control and treat toxoplasmosis.
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Affiliation(s)
- Yaghob Azadi
- Infectious and Tropical Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ehsan Ahmadpour
- Infectious and Tropical Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amirhossein Ahmadi
- Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
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The Bradyzoite: A Key Developmental Stage for the Persistence and Pathogenesis of Toxoplasmosis. Pathogens 2020; 9:pathogens9030234. [PMID: 32245165 PMCID: PMC7157559 DOI: 10.3390/pathogens9030234] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/19/2022] Open
Abstract
Toxoplasma gondii is a ubiquitous parasitic protist found in a wide variety of hosts, including a large proportion of the human population. Beyond an acute phase which is generally self-limited in immunocompetent individuals, the ability of the parasite to persist as a dormant stage, called bradyzoite, is an important aspect of toxoplasmosis. Not only is this stage not eliminated by current treatments, but it can also reactivate in immunocompromised hosts, leading to a potentially fatal outcome. Yet, despite its critical role in the pathology, the bradyzoite stage is relatively understudied. One main explanation is that it is a considerably challenging model, which essentially has to be derived from in vivo sources. However, recent progress on genetic manipulation and in vitro differentiation models now offers interesting perspectives for tackling key biological questions related to this particularly important developmental stage.
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26
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Waldman BS, Schwarz D, Wadsworth MH, Saeij JP, Shalek AK, Lourido S. Identification of a Master Regulator of Differentiation in Toxoplasma. Cell 2020; 180:359-372.e16. [PMID: 31955846 PMCID: PMC6978799 DOI: 10.1016/j.cell.2019.12.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/28/2019] [Accepted: 12/10/2019] [Indexed: 01/06/2023]
Abstract
Toxoplasma gondii chronically infects a quarter of the world's population, and its recrudescence can cause life-threatening disease in immunocompromised individuals and recurrent ocular lesions in the immunocompetent. Acute-stage tachyzoites differentiate into chronic-stage bradyzoites, which form intracellular cysts resistant to immune clearance and existing therapies. The molecular basis of this differentiation is unknown, despite being efficiently triggered by stresses in culture. Through Cas9-mediated screening and single-cell profiling, we identify a Myb-like transcription factor (BFD1) necessary for differentiation in cell culture and in mice. BFD1 accumulates during stress and its synthetic expression is sufficient to drive differentiation. Consistent with its function as a transcription factor, BFD1 binds the promoters of many stage-specific genes and represents a counterpoint to the ApiAP2 factors that dominate our current view of parasite gene regulation. BFD1 provides a genetic switch to study and control Toxoplasma differentiation and will inform prevention and treatment of chronic infections.
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Affiliation(s)
- Benjamin S Waldman
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Dominic Schwarz
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
| | - Marc H Wadsworth
- Institute for Medical Engineering & Science, Department of Chemistry, and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02319, USA
| | - Jeroen P Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Alex K Shalek
- Institute for Medical Engineering & Science, Department of Chemistry, and Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02319, USA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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27
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Boillat M, Hammoudi PM, Dogga SK, Pagès S, Goubran M, Rodriguez I, Soldati-Favre D. Neuroinflammation-Associated Aspecific Manipulation of Mouse Predator Fear by Toxoplasma gondii. Cell Rep 2020; 30:320-334.e6. [PMID: 31940479 PMCID: PMC6963786 DOI: 10.1016/j.celrep.2019.12.019] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/27/2019] [Accepted: 12/06/2019] [Indexed: 12/13/2022] Open
Abstract
In rodents, the decrease of felid aversion induced by Toxoplasma gondii, a phenomenon termed fatal attraction, is interpreted as an adaptive manipulation by the neurotropic protozoan parasite. With the aim of understanding how the parasite induces such specific behavioral modifications, we performed a multiparametric analysis of T. gondii-induced changes on host behavior, physiology, and brain transcriptome as well as parasite cyst load and distribution. Using a set of complementary behavioral tests, we provide strong evidence that T. gondii lowers general anxiety in infected mice, increases explorative behaviors, and surprisingly alters predator aversion without selectivity toward felids. Furthermore, we show a positive correlation between the severity of the behavioral alterations and the cyst load, which indirectly reflects the level of inflammation during brain colonization. Taken together, these findings refute the myth of a selective loss of cat fear in T. gondii-infected mice and point toward widespread immune-related alterations of behaviors.
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Affiliation(s)
- Madlaina Boillat
- Department of Genetics and Evolution, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Pierre-Mehdi Hammoudi
- Department of Microbiology and Molecular Medicine, Faculty of Medicine-University of Geneva CMU, 1 rue Michel-Servet 1211 Geneva 4, Switzerland
| | - Sunil Kumar Dogga
- Department of Microbiology and Molecular Medicine, Faculty of Medicine-University of Geneva CMU, 1 rue Michel-Servet 1211 Geneva 4, Switzerland
| | - Stéphane Pagès
- Wyss Center for Bio- and Neuroengineering, Geneva, Switzerland; Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | - Maged Goubran
- Hurvitz Brain Sciences Program, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Ivan Rodriguez
- Department of Genetics and Evolution, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland.
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine-University of Geneva CMU, 1 rue Michel-Servet 1211 Geneva 4, Switzerland.
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28
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Affiliation(s)
- Daniel Fisch
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Barbara Clough
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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29
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Alonso AM, Corvi MM, Diambra L. Gene target discovery with network analysis in Toxoplasma gondii. Sci Rep 2019; 9:646. [PMID: 30679502 PMCID: PMC6345969 DOI: 10.1038/s41598-018-36671-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 11/26/2018] [Indexed: 12/30/2022] Open
Abstract
Infectious diseases are of great relevance for global health, but needed drugs and vaccines have not been developed yet or are not effective in many cases. In fact, traditional scientific approaches with intense focus on individual genes or proteins have not been successful in providing new treatments. Hence, innovations in technology and computational methods provide new tools to further understand complex biological systems such as pathogen biology. In this paper, we apply a gene regulatory network approach to analyze transcriptomic data of the parasite Toxoplasma gondii. By means of an optimization procedure, the phenotypic transitions between the stages associated with the life cycle of T. gondii were embedded into the dynamics of a gene regulatory network. Thus, through this methodology we were able to reconstruct a gene regulatory network able to emulate the life cycle of the pathogen. The community network analysis has revealed that nodes of the network can be organized in seven communities which allow us to assign putative functions to 338 previously uncharacterized genes, 25 of which are predicted as new pathogenic factors. Furthermore, we identified a small gene circuit that drives a series of phenotypic transitions that characterize the life cycle of this pathogen. These new findings can contribute to the understanding of parasite pathogenesis.
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Affiliation(s)
- Andres M Alonso
- Instituto de Investigaciones Biotecnológicas "Dr. Raul Alfonsin", CONICET-Universidad Nacional de General San Martín, Chascomús, B7130IWA, Argentina
- CREG, CONICET-Universidad Nacional de La Plata, La Plata, CP 1900, Argentina
| | - Maria M Corvi
- Instituto de Investigaciones Biotecnológicas "Dr. Raul Alfonsin", CONICET-Universidad Nacional de General San Martín, Chascomús, B7130IWA, Argentina
| | - Luis Diambra
- CREG, CONICET-Universidad Nacional de La Plata, La Plata, CP 1900, Argentina.
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30
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Tu V, Yakubu R, Weiss LM. Observations on bradyzoite biology. Microbes Infect 2018; 20:466-476. [PMID: 29287987 PMCID: PMC6019562 DOI: 10.1016/j.micinf.2017.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 02/06/2023]
Abstract
Tachyzoites of the Apicomplexan Toxoplasma gondii cause acute infection, disseminate widely in their host, and eventually differentiate into a latent encysted form called bradyzoites that are found within tissue cysts. During latent infection, whenever transformation to tachyzoites occurs, any tachyzoites that develop are removed by the immune system. In contrast, cysts containing bradyzoites are sequestered from the immune system. In the absence of an effective immune response released organisms that differentiate into tachyzoites cause acute infection. Tissue cysts, therefore, serve as a reservoir for the reactivation of toxoplasmosis when the host becomes immunocompromised by conditions such as HIV infection, organ transplantation, or due to the impaired immune response that occurs when pathogens are acquired in utero. While tachyzoites and bradyzoites are well defined morphologically, there is no clear consensus on how interconversion occurs or what exact signal(s) mediate this transformation. Advances in research methods have facilitated studies on T. gondii bradyzoites providing important new insights into the biology of latent infection.
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Affiliation(s)
- Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rama Yakubu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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31
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Novel Approaches To Kill Toxoplasma gondii by Exploiting the Uncontrolled Uptake of Unsaturated Fatty Acids and Vulnerability to Lipid Storage Inhibition of the Parasite. Antimicrob Agents Chemother 2018; 62:AAC.00347-18. [PMID: 30061287 DOI: 10.1128/aac.00347-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/21/2018] [Indexed: 12/17/2022] Open
Abstract
Toxoplasma gondii, an obligate intracellular parasite replicating in mammalian cells within a parasitophorous vacuole (PV), is an avid scavenger of lipids retrieved from the host cell. Following lipid uptake, this parasite stores excess lipids in lipid droplets (LD). Here, we examined the lipid storage capacities of Toxoplasma upon supplementation of the culture medium with various fatty acids at physiological concentrations. Supplemental unsaturated fatty acids (oleate [OA], palmitoleate, linoleate) accumulate in large LD and impair parasite replication, whereas saturated fatty acids (palmitate, stearate) neither stimulate LD formation nor impact growth. Examination of parasite growth defects with 0.4 mM OA revealed massive lipid deposits outside LD, indicating enzymatic inadequacies for storing neutral lipids in LD in response to the copious salvage of OA. Toxoplasma exposure to 0.5 mM OA led to irreversible growth arrest and lipid-induced damage, confirming a major disconnect between fatty acid uptake and the parasite's cellular lipid requirements. The importance of neutral lipid synthesis and storage to avoid lipotoxicity was further highlighted by the selective vulnerability of Toxoplasma, both the proliferative and the encysted forms, to subtoxic concentrations of the acyl coenzyme A:diacylglycerol acyltransferase 1 (DGAT1) pharmacological inhibitor T863. T863-treated parasites did not form LD but instead built up large membranous structures within the cytoplasm, which suggests improper channeling and management of the excess lipid. Dual addition of OA and T863 to infected cells intensified the deterioration of the parasite. Overall, our data pinpoint Toxoplasma DGAT as a promising drug target for the treatment of toxoplasmosis that would not incur the risk of toxicity for mammalian cells.
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Dard C, Marty P, Brenier-Pinchart MP, Garnaud C, Fricker-Hidalgo H, Pelloux H, Pomares C. Management of toxoplasmosis in transplant recipients: an update. Expert Rev Anti Infect Ther 2018; 16:447-460. [DOI: 10.1080/14787210.2018.1483721] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Céline Dard
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Cedex France
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209 - CNRS UMR5309, Université Grenoble Alpes, Grenoble France
| | - Pierre Marty
- Faculté de Médecine, Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Nice, 06202 Nice, France Université de la Côte d’Azur, Nice, France
- 38043, INSERM U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Nice, France
| | - Marie-Pierre Brenier-Pinchart
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Cedex France
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209 - CNRS UMR5309, Université Grenoble Alpes, Grenoble France
| | - Cécile Garnaud
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Cedex France
| | - Hélène Fricker-Hidalgo
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Cedex France
| | - Hervé Pelloux
- Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble Cedex France
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209 - CNRS UMR5309, Université Grenoble Alpes, Grenoble France
| | - Christelle Pomares
- Faculté de Médecine, Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Nice, 06202 Nice, France Université de la Côte d’Azur, Nice, France
- 38043, INSERM U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Nice, France
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33
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Jeffers V, Tampaki Z, Kim K, Sullivan WJ. A latent ability to persist: differentiation in Toxoplasma gondii. Cell Mol Life Sci 2018; 75:2355-2373. [PMID: 29602951 PMCID: PMC5988958 DOI: 10.1007/s00018-018-2808-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/01/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023]
Abstract
A critical factor in the transmission and pathogenesis of Toxoplasma gondii is the ability to convert from an acute disease-causing, proliferative stage (tachyzoite), to a chronic, dormant stage (bradyzoite). The conversion of the tachyzoite-containing parasitophorous vacuole membrane into the less permeable bradyzoite cyst wall allows the parasite to persist for years within the host to maximize transmissibility to both primary (felids) and secondary (virtually all other warm-blooded vertebrates) hosts. This review presents our current understanding of the latent stage, including the factors that are important in bradyzoite induction and maintenance. Also discussed are the recent studies that have begun to unravel the mechanisms behind stage switching.
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Affiliation(s)
- Victoria Jeffers
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| | - Zoi Tampaki
- Departments of Medicine, Microbiology and Immunology, and Pathology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Kami Kim
- Departments of Medicine, Microbiology and Immunology, and Pathology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - William J Sullivan
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
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34
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Mycophenolic acid induces differentiation of Toxoplasma gondii RH strain tachyzoites into bradyzoites and formation of cyst-like structure in vitro. Parasitol Res 2018; 117:547-563. [DOI: 10.1007/s00436-017-5738-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/27/2017] [Indexed: 10/18/2022]
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35
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Romano JD, Nolan SJ, Porter C, Ehrenman K, Hartman EJ, Hsia RC, Coppens I. The parasite Toxoplasma sequesters diverse Rab host vesicles within an intravacuolar network. J Cell Biol 2017; 216:4235-4254. [PMID: 29070609 PMCID: PMC5716271 DOI: 10.1083/jcb.201701108] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 07/28/2017] [Accepted: 09/08/2017] [Indexed: 02/01/2023] Open
Abstract
Many intracellular pathogens subvert host membrane trafficking pathways to promote their replication. Toxoplasma multiplies in a membrane-bound parasitophorous vacuole (PV) that interacts with mammalian host organelles and intercepts Golgi Rab vesicles to acquire sphingolipids. The mechanisms of host vesicle internalization and processing within the PV remain undefined. We demonstrate that Toxoplasma sequesters a broad range of Rab vesicles into the PV. Correlative light and electron microscopy analysis of infected cells illustrates that intravacuolar Rab1A vesicles are surrounded by the PV membrane, suggesting a phagocytic-like process for vesicle engulfment. Rab11A vesicles concentrate to an intravacuolar network (IVN), but this is reduced in Δgra2 and Δgra2Δgra6 parasites, suggesting that tubules stabilized by the TgGRA2 and TgGRA6 proteins secreted by the parasite within the PV contribute to host vesicle sequestration. Overexpression of a phospholipase TgLCAT, which is localized to the IVN, results in a decrease in the number of intravacuolar GFP-Rab11A vesicles, suggesting that TgLCAT controls lipolytic degradation of Rab vesicles for cargo release.
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Affiliation(s)
- Julia D Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Sabrina J Nolan
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Corey Porter
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Karen Ehrenman
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Eric J Hartman
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Ru-Ching Hsia
- Electron Microscopy Core Imaging Facility, University of Maryland Baltimore, Baltimore, MD
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
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36
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Toxoplasma gondii reorganizes the host cell architecture during spontaneous cyst formation in vitro. Parasitology 2017; 145:1027-1038. [PMID: 29179785 DOI: 10.1017/s0031182017002050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Toxoplasma gondii is an intracellular protozoan parasite that causes toxoplasmosis, a prevalent infection related to abortion, ocular diseases and encephalitis in immuno-compromised individuals. In the untreatable (and life-long) chronic stage of toxoplasmosis, parasitophorous vacuoles (PVs, containing T. gondii tachyzoites) transform into tissue cysts, containing slow-dividing bradyzoite forms. While acute-stage infection with tachyzoites involves global rearrangement of the host cell cytoplasm, focused on favouring tachyzoite replication, the cytoplasmic architecture of cells infected with cysts had not been described. Here, we characterized (by fluorescence and electron microscopy) the redistribution of host cell structures around T. gondii cysts, using a T. gondii strain (EGS) with high rates of spontaneous cystogenesis in vitro. Microtubules and intermediate filaments (but not actin microfilaments) formed a 'cage' around the cyst, and treatment with taxol (to inhibit microtubule dynamics) favoured cystogenesis. Mitochondria, which appeared adhered to the PV membrane, were less closely associated with the cyst wall. Endoplasmic reticulum (ER) profiles were intimately associated with folds in the cyst wall membrane. However, the Golgi complex was not preferentially localized relative to the cyst, and treatment with tunicamycin or brefeldin A (to disrupt Golgi or ER function, respectively) had no significant effect on cystogenesis. Lysosomes accumulated around cysts, while early and late endosomes were more evenly distributed in the cytoplasm. The endocytosis tracer HRP (but not BSA or transferrin) reached bradyzoites after uptake by infected host cells. These results suggest that T. gondii cysts reorganize the host cell cytoplasm, which may fulfil specific requirements of the chronic stage of infection.
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37
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Caldas LA, Attias M, de Souza W. A structural analysis of the natural egress of Toxoplasma gondii. Microbes Infect 2017; 20:57-62. [PMID: 28951315 DOI: 10.1016/j.micinf.2017.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/29/2017] [Accepted: 09/11/2017] [Indexed: 01/18/2023]
Abstract
Previous studies have analysed the process of Toxoplasma gondii egress with the aid of inducers, such as calcium ionophores. Although calcium transients have been successful in triggering T. gondii egress, the structural panorama of "natural" and artificial events should match. The present study approaches the natural egress of this parasite using super-resolution and electron microscopy and reveals lytic and non-lytic events of individual egress; this corroborates the use of calcium ionophore as a reliable tool to trigger parasite egress. Altogether, our data suggest that different signalling routes can converge to similar structural aspects in natural and induced egress.
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Affiliation(s)
- Lúcio Ayres Caldas
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
| | - Marcia Attias
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil; Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Rio de Janeiro, Brazil
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Resistance towards monensin is proposed to be acquired in a Toxoplasma gondii model by reduced invasion and egress activities, in addition to increased intracellular replication. Parasitology 2017; 145:313-325. [PMID: 28870270 DOI: 10.1017/s0031182017001512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Monensin (Mon) is an anticoccidial polyether ionophore widely used to control coccidiosis. The extensive use of polyether ionophores on poultry farms resulted in widespread resistance, but the underlying resistance mechanisms are unknown in detail. For analysing the mode of action by which resistance against polyether ionophores is obtained, we induced in vitro Mon resistance in Toxoplasma gondii-RH strain (MonR-RH) and compared it with the sensitive parental strain (Sen-RH). The proteome assessment of MonR-RH and Sen-RH strains was obtained after isotopic labelling using stable isotope labelling by amino acid in cell culture. Relative proteomic quantification between resistant and sensitive strains was performed using liquid chromatography-mass spectrometry/mass spectrometry. Overall, 1024 proteins were quantified and 52 proteins of them were regulated. The bioinformatic analysis revealed regulation of cytoskeletal and transmembrane proteins being involved in transport mechanisms, metal ion-binding and invasion. During invasion, actin and microneme protein 8 (MIC8) are seem to be important for conoid extrusion and forming moving junction with host cells, respectively. Actin was significantly upregulated, while MIC8 was downregulated, which indicate an invasion reduction in the resistant strain. Resistance against Mon is not a simple process but it involves reduced invasion and egress activity of T. gondii tachyzoites while intracellular replication is enhanced.
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Toxoplasma gondii Requires Glycogen Phosphorylase for Balancing Amylopectin Storage and for Efficient Production of Brain Cysts. mBio 2017; 8:mBio.01289-17. [PMID: 28851850 PMCID: PMC5574715 DOI: 10.1128/mbio.01289-17] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In immunocompromised hosts, latent infection with Toxoplasma gondii can reactivate from tissue cysts, leading to encephalitis. A characteristic of T. gondii bradyzoites in tissue cysts is the presence of amylopectin granules. The regulatory mechanisms and role of amylopectin accumulation in this organism are not fully understood. The T. gondii genome encodes a putative glycogen phosphorylase (TgGP), and mutants were constructed to manipulate the activity of TgGP and to evaluate the function of TgGP in amylopectin storage. Both a stop codon mutant (Pru/TgGPS25stop [expressing a Ser-to-stop codon change at position 25 in TgGP]) and a phosphorylation null mutant (Pru/TgGPS25A [expressing a Ser-to-Ala change at position 25 in TgGp]) mutated at Ser25 displayed amylopectin accumulation, while the phosphorylation-mimetic mutant (Pru/TgGPS25E [expressing a Ser-to-Glu change at position 25 in TgGp]) had minimal amylopectin accumulation under both tachyzoite and bradyzoite growth conditions. The expression of active TgGPS25S or TgGPS25E restored amylopectin catabolism in Pru/TgGPS25A To understand the relation between GP and calcium-dependent protein kinase 2 (CDPK2), which was recently reported to regulate amylopectin consumption, we knocked out CDPK2 in these mutants. PruΔcdpk2/TgGPS25E had minimal amylopectin accumulation, whereas the Δcdpk2 phenotype in the other GP mutants and parental lines displayed amylopectin accumulation. Both the inactive S25A and hyperactive S25E mutant produced brain cysts in infected mice, but the numbers of cysts produced were significantly less than the number produced by the S25S wild-type GP parasite. Complementation that restored amylopectin regulation restored brain cyst production to the control levels seen in infected mice. These data suggest that T. gondii requires tight regulation of amylopectin expression for efficient production of cysts and persistent infections and that GP phosphorylation is a regulatory mechanism involved in amylopectin storage and utilization.IMPORTANCEToxoplasma gondii is an obligate intracellular parasite that causes disease in immune-suppressed individuals, as well as a fetopathy in pregnant women who acquire infection for the first time during pregnancy. This parasite can differentiate between tachyzoites (seen in acute infection) and bradyzoites (seen in latent infection), and this differentiation is associated with disease relapse. A characteristic of bradyzoites is that they contain cytoplasmic amylopectin granules. The regulatory mechanisms and the roles of amylopectin granules during latent infection remain to be elucidated. We have identified a role of T. gondii glycogen phosphorylase (TgGP) in the regulation of starch digestion and a role of posttranslational modification of TgGP, i.e., phosphorylation of Ser25, in the regulation of amylopectin digestion. By manipulating TgGP activity in the parasite with genome editing, we found that the digestion and storage of amylopectin due to TgGP activity are both important for latency in the brain.
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Swierzy IJ, Händel U, Kaever A, Jarek M, Scharfe M, Schlüter D, Lüder CGK. Divergent co-transcriptomes of different host cells infected with Toxoplasma gondii reveal cell type-specific host-parasite interactions. Sci Rep 2017; 7:7229. [PMID: 28775382 PMCID: PMC5543063 DOI: 10.1038/s41598-017-07838-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/30/2017] [Indexed: 02/06/2023] Open
Abstract
The apicomplexan parasite Toxoplasma gondii infects various cell types in avian and mammalian hosts including humans. Infection of immunocompetent hosts is mostly asymptomatic or benign, but leads to development of largely dormant bradyzoites that persist predominantly within neurons and muscle cells. Here we have analyzed the impact of the host cell type on the co-transcriptomes of host and parasite using high-throughput RNA sequencing. Murine cortical neurons and astrocytes, skeletal muscle cells (SkMCs) and fibroblasts differed by more than 16,200 differentially expressed genes (DEGs) before and after infection with T. gondii. However, only a few hundred of them were regulated by infection and these largely diverged in neurons, SkMCs, astrocytes and fibroblasts indicating host cell type-specific transcriptional responses after infection. The heterogeneous transcriptomes of host cells before and during infection coincided with ~5,400 DEGs in T. gondii residing in different cell types. Finally, we identified gene clusters in both T. gondii and its host, which correlated with the predominant parasite persistence in neurons or SkMCs as compared to astrocytes or fibroblasts. Thus, heterogeneous expression profiles of different host cell types and the parasites’ ability to adapting to them may govern the parasite-host cell interaction during toxoplasmosis.
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Affiliation(s)
- Izabela J Swierzy
- Institute for Medical Microbiology, University Medical Center, Georg-August-University, 37075, Göttingen, Germany
| | - Ulrike Händel
- Institute of Medical Microbiology, Infection Control and Prevention, Otto-von-Guericke-University, 39120, Magdeburg, Germany
| | - Alexander Kaever
- Institute of Microbiology and Genetics, Department of Bioinformatics, Georg-August-University, 37077, Göttingen, Germany
| | - Michael Jarek
- Genome Analytics, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Maren Scharfe
- Genome Analytics, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Dirk Schlüter
- Institute of Medical Microbiology, Infection Control and Prevention, Otto-von-Guericke-University, 39120, Magdeburg, Germany.,Organ-Specific Immune Regulation, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center, Georg-August-University, 37075, Göttingen, Germany.
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41
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Abstract
The unicellular parasite Toxoplasma gondii infects warm-blooded animals and humans, and it is highly prevalent throughout the world. Infection of immunocompetent hosts is usually asymptomatic or benign but leads to long-term parasite persistence mainly within neural and muscular tissues. The transition from acute primary infection towards chronic toxoplasmosis is accompanied by a developmental switch from fast replicating and metabolically highly active tachyzoites to slow replicating and largely dormant bradyzoites within tissue cysts. Such developmental differentiation is critical for T. gondii in order to complete its life cycle and for pathogenesis. Herein, we summarize accumulating evidence indicating a major impact of the host cell physiology on stage conversion between the tachyzoite and the bradyzoite stage of the parasite. Withdrawal from cell cycle progression, proinflammatory responses, reduced availability of nutrients and extracellular adenosine can indeed induce tachyzoite-to-bradyzoite differentiation and tissue cyst formation. In contrast, high glycolytic activity as indicated by increased lactate secretion can inhibit bradyzoite formation. These examples argue for the intriguing possibility that after dissemination within its host, T. gondii can sense its cellular microenvironment to initiate the developmental program towards the bradyzoite stage in distinct cells. This may also explain the predominant localization of T. gondii in neural and muscular tissues during chronic toxoplasmosis.
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Affiliation(s)
- Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center Goettingen, Goettingen, Germany
| | - Taibur Rahman
- Institute for Medical Microbiology, University Medical Center Goettingen, Goettingen, Germany
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Sun H, Zhuo X, Zhao X, Yang Y, Chen X, Yao C, Du A. The heat shock protein 90 of Toxoplasma gondii is essential for invasion of host cells and tachyzoite growth. ACTA ACUST UNITED AC 2017. [PMID: 28627357 PMCID: PMC5479401 DOI: 10.1051/parasite/2017023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Toxoplasma gondii is an obligate intracellular apicomplexan parasite that infects almost all warm-blooded vertebrates. Heat shock proteins (HSP) regulate key signal transduction events in many organisms, and heat shock protein 90 (Hsp90) plays an important role in growth, development, and virulence in several parasitic protozoa. Here, we discovered increased transcription of the Hsp90 gene under conditions for bradyzoite differentiation, i.e. alkaline and heat shock conditions in vitro, suggesting that Hsp90 may be connected with bradyzoite development in T. gondii. A knockout of the TgHsp90 strain (ΔHsp90) and a complementation strain were constructed. The TgHsp90 knockout cells were found to be defective in host-cell invasion, were not able to proliferate in vitro in Vero cells, and did not show long-time survival in mice in vivo. These inabilities of the knockout parasites were restored upon complementation of TgHsp90. These data unequivocally show that TgHsp90 contributes to bradyzoite development, and to invasion and replication of T. gondii in host cells.
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Affiliation(s)
- Hongchao Sun
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xunhui Zhuo
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xianfeng Zhao
- Shenzhen Entry-exit Inspection and Quarantine Bureau, Shenzhen 518045, PR China
| | - Yi Yang
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xueqiu Chen
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Chaoqun Yao
- Department of Biomedical Sciences and One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies
| | - Aifang Du
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
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43
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Identification of compounds that suppress Toxoplasma gondii tachyzoites and bradyzoites. PLoS One 2017; 12:e0178203. [PMID: 28609444 PMCID: PMC5469451 DOI: 10.1371/journal.pone.0178203] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 05/08/2017] [Indexed: 11/25/2022] Open
Abstract
Drug treatment for toxoplasmosis is problematic, because current drugs cannot eradicate latent infection with Toxoplasma gondii and can cause bone marrow toxicity. Because latent infection remains after treatment, relapse of infection is a problem in both infections in immunocompromised patients and in congenitally infected patients. To identify lead compounds for novel drugs against Toxoplasma gondii, we screened a chemical compound library for anti-Toxoplasma activity, host cell cytotoxicity, and effect on bradyzoites. Of 878 compounds screened, 83 demonstrated >90% parasite growth inhibition. After excluding compounds that affected host cell viability, we further characterized two compounds, tanshinone IIA and hydroxyzine, which had IC50 values for parasite growth of 2.5 μM and 1.0 μM, respectively, and had no effect on host cell viability at 25 μM. Both tanshinone IIA and hydroxyzine inhibited parasite replication after invasion and both reduced the number of in vitro-induced bradyzoites, whereas, pyrimethamine, the current therapy, had no effect on bradyzoites. Both tanshinone IIA and hydroxyzine are potent lead compounds for further medicinal chemistry. The method presented for evaluating compounds for bradyzoite efficacy represents a new approach to the development of anti-Toxoplasma drugs to eliminate latency and treat acute infection.
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44
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Frénal K, Jacot D, Hammoudi PM, Graindorge A, Maco B, Soldati-Favre D. Myosin-dependent cell-cell communication controls synchronicity of division in acute and chronic stages of Toxoplasma gondii. Nat Commun 2017; 8:15710. [PMID: 28593938 PMCID: PMC5477499 DOI: 10.1038/ncomms15710] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 04/17/2017] [Indexed: 01/20/2023] Open
Abstract
The obligate intracellular parasite Toxoplasma gondii possesses a repertoire of 11 myosins. Three class XIV motors participate in motility, invasion and egress, whereas the class XXII myosin F is implicated in organelle positioning and inheritance of the apicoplast. Here we provide evidence that TgUNC acts as a chaperone dedicated to the folding, assembly and function of all Toxoplasma myosins. The conditional ablation of TgUNC recapitulates the phenome of the known myosins and uncovers two functions in parasite basal complex constriction and synchronized division within the parasitophorous vacuole. We identify myosin J and centrin 2 as essential for the constriction. We demonstrate the existence of an intravacuolar cell–cell communication ensuring synchronized division, a process dependent on myosin I. This connectivity contributes to the delayed death phenotype resulting from loss of the apicoplast. Cell–cell communication is lost in activated macrophages and during bradyzoite differentiation resulting in asynchronized, slow division in the cysts. The mechanism by which Toxoplasma gondii achieves synchronized cell division is incompletely understood. Here, the authors identify an intravacuolar cell-cell communication that ensures synchronized division and depends on myosin I.
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Affiliation(s)
- Karine Frénal
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, 1206 Geneva, Switzerland
| | - Damien Jacot
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, 1206 Geneva, Switzerland
| | - Pierre-Mehdi Hammoudi
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, 1206 Geneva, Switzerland
| | - Arnault Graindorge
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, 1206 Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, 1206 Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, 1206 Geneva, Switzerland
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45
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Watts EA, Dhara A, Sinai AP. Purification Toxoplasma gondii Tissue Cysts Using Percoll Gradients. CURRENT PROTOCOLS IN MICROBIOLOGY 2017; 45:20C.2.1-20C.2.19. [PMID: 28510363 PMCID: PMC5568674 DOI: 10.1002/cpmc.30] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The protozoan parasite Toxoplasma gondii is capable of infecting all warm-blooded animals and humans. Infectious, transmissible forms of the parasite include oocysts produced by the sexual cycle within the definitive feline host and tissue cysts that form Toxoplasma in the central nervous system and muscle during the asexual cycle within all chronically infected warm-blooded hosts. These tissue cysts are populated with slow-growing bradyzoites, which until recently have been thought to be dormant entities in the context of immune sufficiency. Reactivation to active growth during immune suppression is of critical clinical importance. However, little is known about tissue cysts or the bradyzoites they house, as the diversity of tissue cysts cannot be replicated in cell culture systems. This protocol for optimization of tissue cyst purification from the brains of infected mice using Percoll gradients provides an efficient means to recover in vivo-derived tissue cysts that can be applied to imaging, cell biological, biochemical, transcriptomic, and proteomic analyses. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Elizabeth A Watts
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky
- Current Address: Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia
| | - Animesh Dhara
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky
| | - Anthony P Sinai
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky
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Chen AL, Moon AS, Bell HN, Huang AS, Vashisht AA, Toh JY, Lin AH, Nadipuram SM, Kim EW, Choi CP, Wohlschlegel JA, Bradley PJ. Novel insights into the composition and function of the Toxoplasma IMC sutures. Cell Microbiol 2017; 19:10.1111/cmi.12678. [PMID: 27696623 PMCID: PMC5909696 DOI: 10.1111/cmi.12678] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/19/2016] [Accepted: 09/28/2016] [Indexed: 12/29/2022]
Abstract
The Toxoplasma inner membrane complex (IMC) is a specialized organelle underlying the parasite's plasma membrane that consists of flattened rectangular membrane sacs that are sutured together and positioned atop a supportive cytoskeleton. We have previously identified a novel class of proteins localizing to the transverse and longitudinal sutures of the IMC, which we named IMC sutures components (ISCs). Here, we have used proximity-dependent biotin identification at the sutures to better define the composition of this IMC subcompartment. Using ISC4 as bait, we demonstrate biotin-dependent labeling of the sutures and have uncovered two new ISCs. We also identified five new proteins that exclusively localize to the transverse sutures that we named transverse sutures components (TSCs), demonstrating that components of the IMC sutures consist of two groups: those that localize to the transverse and longitudinal sutures (ISCs) and those residing only in the transverse sutures (TSCs). In addition, we functionally analyze the ISC protein ISC3 and demonstrate that ISC3-null parasites have morphological defects and reduced fitness in vitro. Most importantly, Δisc3 parasites exhibit a complete loss of virulence in vivo. These studies expand the known composition of the IMC sutures and highlight the contribution of ISCs to the ability of the parasite to proliferate and cause disease.
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Affiliation(s)
- Allan L. Chen
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Andy S. Moon
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Hannah N. Bell
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Amy S. Huang
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Ajay A. Vashisht
- Department of Biological Chemistry and Institute of Genomics and Proteomics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Justin Y. Toh
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Andrew H. Lin
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Santhosh M. Nadipuram
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Elliot W. Kim
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Charles P. Choi
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - James A. Wohlschlegel
- Department of Biological Chemistry and Institute of Genomics and Proteomics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA 90095
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA 90095
| | - Peter J. Bradley
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA 90095
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA 90095
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Toxoplasma gondii AP2IX-4 Regulates Gene Expression during Bradyzoite Development. mSphere 2017; 2:mSphere00054-17. [PMID: 28317026 PMCID: PMC5352832 DOI: 10.1128/msphere.00054-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 02/24/2017] [Indexed: 11/21/2022] Open
Abstract
Toxoplasma gondii is a single-celled parasite that persists in its host as a transmissible tissue cyst. How the parasite converts from its replicative form to the bradyzoites housed in tissue cysts is not well understood, but the process clearly involves changes in gene expression. Here we report that parasites lacking a cell cycle-regulated transcription factor called AP2IX-4 display reduced frequencies of tissue cyst formation in culture and in a mouse model of infection. Parasites missing AP2IX-4 lose the ability to regulate bradyzoite genes during tissue cyst development. Expressed in developing bradyzoites still undergoing division, AP2IX-4 may serve as a useful marker in the study of transitional forms of the parasite. Toxoplasma gondii is a protozoan parasite of great importance to human and animal health. In the host, this obligate intracellular parasite persists as a tissue cyst that is imperceptible to the immune response and unaffected by current therapies. The tissue cysts facilitate transmission through predation and give rise to chronic cycles of toxoplasmosis in immunocompromised patients. Transcriptional changes accompany conversion of the rapidly replicating tachyzoites into the encysted bradyzoites, and yet the mechanisms underlying these alterations in gene expression are not well defined. Here we show that AP2IX-4 is a nuclear protein exclusively expressed in tachyzoites and bradyzoites undergoing division. Knockout of AP2IX-4 had no discernible effect on tachyzoite replication but resulted in a reduced frequency of tissue cyst formation following alkaline stress induction—a defect that is reversible by complementation. AP2IX-4 has a complex role in regulating bradyzoite gene expression, as the levels of many bradyzoite mRNAs dramatically increased beyond those seen under conditions of normal stress induction in AP2IX-4 knockout parasites exposed to alkaline media. The loss of AP2IX-4 also resulted in a modest virulence defect and reduced cyst burden in chronically infected mice, which was reversed by complementation. These findings illustrate that the transcriptional mechanisms responsible for tissue cyst development operate across the intermediate life cycle from the dividing tachyzoite to the dormant bradyzoite. IMPORTANCEToxoplasma gondii is a single-celled parasite that persists in its host as a transmissible tissue cyst. How the parasite converts from its replicative form to the bradyzoites housed in tissue cysts is not well understood, but the process clearly involves changes in gene expression. Here we report that parasites lacking a cell cycle-regulated transcription factor called AP2IX-4 display reduced frequencies of tissue cyst formation in culture and in a mouse model of infection. Parasites missing AP2IX-4 lose the ability to regulate bradyzoite genes during tissue cyst development. Expressed in developing bradyzoites still undergoing division, AP2IX-4 may serve as a useful marker in the study of transitional forms of the parasite.
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Sinai AP, Watts EA, Dhara A, Murphy RD, Gentry MS, Patwardhan A. Reexamining Chronic Toxoplasma gondii Infection: Surprising Activity for a "Dormant" Parasite. CURRENT CLINICAL MICROBIOLOGY REPORTS 2016; 3:175-185. [PMID: 28191447 PMCID: PMC5295825 DOI: 10.1007/s40588-016-0045-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW Despite over a third of the world's population being chronically infected with Toxoplasma gondii, little is known about this largely asymptomatic phase of infection. This stage is mediated in vivo by bradyzoites within tissue cysts. The absence of overt symptoms has been attributed to the dormancy of bradyzoites. In this review, we reexamine the conventional view of chronic toxoplasmosis in light of emerging evidence challenging both the nature of dormancy and the consequences of infection in the CNS. RECENT FINDINGS New and emerging data reveal a previously unrecognized level of physiological and replicative capacity of bradyzoites within tissue cysts. These findings have emerged in the context of a reexamination of the chronic infection in the brain that correlates with changes in neuronal architecture, neurochemistry, and behavior that suggest that the chronic infection is not without consequence. SUMMARY The emerging data driven by the development of new approaches to study the progression of chronic toxoplasma infection reveals significant physiological and replicative capacity for what has been viewed as a dormant state. The emergence of bradyzoite and tissue cyst biology from what was viewed as a physiological "black box" offers exciting new areas for investigation with direct implications on the approaches to drug development targeting this drug-refractory state. In addition, new insights from studies on the neurobiology on chronic infection reveal a complex and dynamic interplay between the parasite, brain microenvironment, and the immune response that results in the detente that promotes the life-long persistence of the parasite in the host.
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Affiliation(s)
- Anthony P Sinai
- Department of Microbiology Immunology and Molecular Genetics, Lexington, KY, USA
| | - Elizabeth A Watts
- Department of Microbiology Immunology and Molecular Genetics, Lexington, KY, USA
| | - Animesh Dhara
- Department of Microbiology Immunology and Molecular Genetics, Lexington, KY, USA
| | - Robert D Murphy
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - Abhijit Patwardhan
- Department of Biomedical Engineering, College of Engineering, University of Kentucky, Lexington, KY 40506, USA
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Peng J, Lin X, Lin H, Chen S, Liu J, Guo Z, Liang Y, Huang S, Lu F. Up-regulated TLR2 and TLR4 expressions in liver and spleen during acute murine T. gondii infection. Parasitol Res 2016; 115:4681-4686. [DOI: 10.1007/s00436-016-5226-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/29/2016] [Indexed: 12/15/2022]
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50
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Martins-Duarte ÉS, Carias M, Vommaro R, Surolia N, de Souza W. Apicoplast fatty acid synthesis is essential for pellicle formation at the end of cytokinesis in Toxoplasma gondii. J Cell Sci 2016; 129:3320-31. [PMID: 27457282 DOI: 10.1242/jcs.185223] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 07/19/2016] [Indexed: 01/19/2023] Open
Abstract
The apicomplexan protozoan Toxoplasma gondii, the causative agent of toxoplasmosis, harbors an apicoplast, a plastid-like organelle with essential metabolic functions. Although the FASII fatty acid biosynthesis pathway located in the apicoplast is essential for parasite survival, the cellular effects of FASII disruption in T. gondii had not been examined in detail. Here, we combined light and electron microscopy techniques - including focused ion beam scanning electron microscopy (FIB-SEM) - to characterize the effect of FASII disruption in T. gondii, by treatment with the FASII inhibitor triclosan or by inducible knockdown of the FASII component acyl carrier protein. Morphological analyses showed that FASII disruption prevented cytokinesis completion in T. gondii tachyzoites, leading to the formation of large masses of 'tethered' daughter cells. FIB-SEM showed that tethered daughters had a mature basal complex, but a defect in new membrane addition between daughters resulted in incomplete pellicle formation. Addition of exogenous fatty acids to medium suppressed the formation of tethered daughter cells and supports the notion that FASII is essential to generate lipid substrates required for the final step of parasite division.
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Affiliation(s)
- Érica S Martins-Duarte
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
| | - Maira Carias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
| | - Rossiane Vommaro
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
| | - Namita Surolia
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India, 560064
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
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