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Overview of Apoptosis, Autophagy, and Inflammatory Processes in Toxoplasma gondii Infected Cells. Pathogens 2023; 12:pathogens12020253. [PMID: 36839525 PMCID: PMC9966443 DOI: 10.3390/pathogens12020253] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. During the parasitic invasion, T. gondii creates a parasitophorous vacuole, which enables the modulation of cell functions, allowing its replication and host infection. It has effective strategies to escape the immune response and reach privileged immune sites and remain inactive in a controlled environment in tissue cysts. This current review presents the factors that affect host cells and the parasite, as well as changes in the immune system during host cell infection. The secretory organelles of T. gondii (dense granules, micronemes, and rhoptries) are responsible for these processes. They are involved with proteins secreted by micronemes and rhoptries (MIC, AMA, and RONs) that mediate the recognition and entry into host cells. Effector proteins (ROP and GRA) that modify the STAT signal or GTPases in immune cells determine their toxicity. Interference byhost autonomous cells during parasitic infection, gene expression, and production of microbicidal molecules such as reactive oxygen species (ROS) and nitric oxide (NO), result in the regulation of cell death. The high level of complexity in host cell mechanisms prevents cell death in its various pathways. Many of these abilities play an important role in escaping host immune responses, particularly by manipulating the expression of genes involved in apoptosis, necrosis, autophagy, and inflammation. Here we present recent works that define the mechanisms by which T. gondii interacts with these processes in infected host cells.
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Daher D, Shaghlil A, Sobh E, Hamie M, Hassan ME, Moumneh MB, Itani S, El Hajj R, Tawk L, El Sabban M, El Hajj H. Comprehensive Overview of Toxoplasma gondii-Induced and Associated Diseases. Pathogens 2021; 10:pathogens10111351. [PMID: 34832507 PMCID: PMC8625914 DOI: 10.3390/pathogens10111351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/07/2021] [Accepted: 10/14/2021] [Indexed: 12/03/2022] Open
Abstract
Toxoplasma gondii (T. gondii) is a prevalent protozoan parasite of medical and veterinary significance. It is the etiologic agent of toxoplasmosis, a neglected disease in which incidence and symptoms differ between patients and regions. In immunocompetent patients, toxoplasmosis manifests as acute and chronic forms. Acute toxoplasmosis presents as mild or asymptomatic disease that evolves, under the host immune response, into a persistent chronic disease in healthy individuals. Chronic toxoplasmosis establishes as latent tissue cysts in the brain and skeletal muscles. In immunocompromised patients, chronic toxoplasmosis may reactivate, leading to a potentially life-threatening condition. Recently, the association between toxoplasmosis and various diseases has been shown. These span primary neuropathies, behavioral and psychiatric disorders, and different types of cancer. Currently, a direct pre-clinical or clinical molecular connotation between toxoplasmosis and most of its associated diseases remains poorly understood. In this review, we provide a comprehensive overview on Toxoplasma-induced and associated diseases with a focus on available knowledge of the molecular players dictating these associations. We will also abridge the existing therapeutic options of toxoplasmosis and highlight the current gaps to explore the implications of toxoplasmosis on its associated diseases to advance treatment modalities.
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Affiliation(s)
- Darine Daher
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; (D.D.); (M.H.); (M.E.H.); (M.B.M.); (S.I.)
| | - Ahmad Shaghlil
- Department of Biology, Faculty of Sciences, R. Hariri Campus, Lebanese University, Beirut 1107 2020, Lebanon; (A.S.); (E.S.)
| | - Eyad Sobh
- Department of Biology, Faculty of Sciences, R. Hariri Campus, Lebanese University, Beirut 1107 2020, Lebanon; (A.S.); (E.S.)
| | - Maguy Hamie
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; (D.D.); (M.H.); (M.E.H.); (M.B.M.); (S.I.)
| | - Malika Elhage Hassan
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; (D.D.); (M.H.); (M.E.H.); (M.B.M.); (S.I.)
| | - Mohamad Bahij Moumneh
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; (D.D.); (M.H.); (M.E.H.); (M.B.M.); (S.I.)
| | - Shaymaa Itani
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; (D.D.); (M.H.); (M.E.H.); (M.B.M.); (S.I.)
| | - Rana El Hajj
- Department of Biological Sciences, Beirut Arab University, Beirut 1107 2809, Lebanon;
| | - Lina Tawk
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100 2807, Lebanon;
| | - Marwan El Sabban
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon;
| | - Hiba El Hajj
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon; (D.D.); (M.H.); (M.E.H.); (M.B.M.); (S.I.)
- Correspondence: ; Tel.: +961–1-350000 (ext. 4897)
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Alves E, Benns HJ, Magnus L, Dominicus C, Dobai T, Blight J, Wincott CJ, Child MA. An Extracellular Redox Signal Triggers Calcium Release and Impacts the Asexual Development of Toxoplasma gondii. Front Cell Infect Microbiol 2021; 11:728425. [PMID: 34447699 PMCID: PMC8382974 DOI: 10.3389/fcimb.2021.728425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
The ability of an organism to sense and respond to environmental redox fluctuations relies on a signaling network that is incompletely understood in apicomplexan parasites such as Toxoplasma gondii. The impact of changes in redox upon the development of this intracellular parasite is not known. Here, we provide a revised collection of 58 genes containing domains related to canonical antioxidant function, with their encoded proteins widely dispersed throughout different cellular compartments. We demonstrate that addition of exogenous H2O2 to human fibroblasts infected with T. gondii triggers a Ca2+ flux in the cytosol of intracellular parasites that can induce egress. In line with existing models, egress triggered by exogenous H2O2 is reliant upon both Calcium-Dependent Protein Kinase 3 and diacylglycerol kinases. Finally, we show that the overexpression a glutaredoxin-roGFP2 redox sensor fusion protein in the parasitophorous vacuole severely impacts parasite replication. These data highlight the rich redox network that exists in T. gondii, evidencing a link between extracellular redox and intracellular Ca2+ signaling that can culminate in parasite egress. Our findings also indicate that the redox potential of the intracellular environment contributes to normal parasite growth. Combined, our findings highlight the important role of redox as an unexplored regulator of parasite biology.
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Affiliation(s)
- Eduardo Alves
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Henry J Benns
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Department of Chemistry, Imperial College London, London, United Kingdom
| | - Lilian Magnus
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Caia Dominicus
- Signaling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Tamás Dobai
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Joshua Blight
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ceire J Wincott
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Matthew A Child
- Department of Life Sciences, Imperial College London, London, United Kingdom
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de Faria Junior GM, Murata FHA, Lorenzi HA, Castro BBP, Assoni LCP, Ayo CM, Brandão CC, de Mattos LC. The Role of microRNAs in the Infection by T. gondii in Humans. Front Cell Infect Microbiol 2021; 11:670548. [PMID: 34055667 PMCID: PMC8160463 DOI: 10.3389/fcimb.2021.670548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022] Open
Abstract
MicroRNAs are molecules belonging to an evolutionarily conserved family of small non-coding RNAs, which act on post-transcriptional gene regulation, causing messenger RNA (mRNA) degradation or inhibiting mRNA translation into proteins. These molecules represent potential biomarkers for diagnosis, non-invasive prognosis, and monitoring the development of the disease. Moreover, they may provide additional information on the pathophysiology of parasitic infections and guide strategies for treatment. The Apicomplexan parasite Toxoplasma gondii modifies the levels of microRNAs and mRNAs in infected host cells by modulating the innate and adaptive immune responses, facilitating its survival within the host. Some studies have shown that microRNAs are promising molecular markers for developing diagnostic tools for human toxoplasmosis. MicroRNAs can be detected in human specimens collected using non-invasive procedures. changes in the circulating host microRNAs have been associated with T. gondii infection in mice and ocular toxoplasmosis in humans. Besides, microRNAs can be amplified from samples using sensitive and molecular-specific approaches such as real-time PCR. This review presents recent findings of the role that microRNAs play during T. gondii infection and discuss their potential use of these small nuclei acid molecules to different approaches such as laboratory diagnosis, modulation of cell and tissue infected as other potential applications in human toxoplasmosis.
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Affiliation(s)
- Geraldo Magela de Faria Junior
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Fernando Henrique Antunes Murata
- Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, United States
| | | | - Bruno Bello Pede Castro
- Department of Preventive Veterinary Medicine and Animal Health, Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
| | - Letícia Carolina Paraboli Assoni
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Christiane Maria Ayo
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Cinara Cássia Brandão
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Luiz Carlos de Mattos
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
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Acetylome analysis of the feline small intestine following Toxoplasma gondii infection. Parasitol Res 2020; 119:3649-3657. [PMID: 32951143 PMCID: PMC7502155 DOI: 10.1007/s00436-020-06880-4] [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: 05/28/2020] [Accepted: 09/07/2020] [Indexed: 10/26/2022]
Abstract
Toxoplasma gondii is a protozoan parasite capable of infecting a large number of warm-blooded animals and causes serious health complications in immunocompromised patients. T. gondii infection of the feline small intestine is critical for the completion of the life cycle and transmission of T. gondii. Protein acetylation is an important posttranslational modification, which plays roles in the regulation of various cellular processes. Therefore, understanding of how T. gondii reprograms the protein acetylation status of feline definitive host can help to thwart the production and spread of T. gondii. Here, we used affinity enrichment and high-resolution liquid chromatography with tandem mass spectrometry to profile the alterations of the acetylome in cat small intestine 10 days after infection by T. gondii Prugniuad (Pru) strain. Our analysis showed that T. gondii induced significant changes in the acetylation of proteins in the cat intestine. We identified 2606 unique lysine acetylation sites in 1357 acetylated proteins. The levels of 334 acetylated peptides were downregulated, while the levels of 82 acetylated peptides were increased in the infected small intestine. The proteins with differentially acetylated peptides were particularly enriched in the bioenergetics-related processes, such as tricarboxylic acid cycle, oxidative phosphorylation, and oxidation-reduction. These results provide the first baseline of the global acetylome of feline small intestine following T. gondii infection and should facilitate further analysis of the role of acetylated protein in the pathogenesis of T. gondii infection in its definitive host.
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Comparative Pathobiology of the Intestinal Protozoan Parasites Giardia lamblia, Entamoeba histolytica, and Cryptosporidium parvum. Pathogens 2019; 8:pathogens8030116. [PMID: 31362451 PMCID: PMC6789772 DOI: 10.3390/pathogens8030116] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 02/07/2023] Open
Abstract
Protozoan parasites can infect the human intestinal tract causing serious diseases. In the following article, we focused on the three most prominent intestinal protozoan pathogens, namely, Giardia lamblia, Entamoeba histolytica, and Cryptosporidium parvum. Both C. parvum and G. lamblia colonize the duodenum, jejunum, and ileum and are the most common causative agents of persistent diarrhea (i.e., cryptosporidiosis and giardiasis). Entamoeba histolytica colonizes the colon and, unlike the two former pathogens, may invade the colon wall and disseminate to other organs, mainly the liver, thereby causing life-threatening amebiasis. Here, we present condensed information concerning the pathobiology of these three diseases.
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Zhou LJ, Chen M, Puthiyakunnon S, He C, Xia J, He CY, Deng SQ, Peng HJ. Toxoplasma gondii ROP18 inhibits human glioblastoma cell apoptosis through a mitochondrial pathway by targeting host cell P2X1. Parasit Vectors 2019; 12:284. [PMID: 31164145 PMCID: PMC6547611 DOI: 10.1186/s13071-019-3529-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 05/23/2019] [Indexed: 12/14/2022] Open
Abstract
Background Apoptosis plays a critical role in the embryonic development, homeostasis of immune system and host defense against intracellular microbial pathogens. Infection by the obligate intracellular pathogen Toxoplasma gondii can both inhibit and induce host cell apoptosis; however, the parasitic factors involved remain unclear. The T. gondii virulence factor ROP18 (TgROP18) has been reported to regulate host cell apoptosis; nevertheless, results for this regulation have been rarely reported or have provided contradictory findings. Human purinergic receptor 1 (P2X1) is an ATP-gated ion channel that responds to ATP stimulation and functions in cell apoptosis mediation. The precise roles of TgROP18 in T. gondii pathogenesis, and the relationship between TgROP18 and host P2X1 in host cell apoptosis are yet to be revealed. Methods Apoptosis rates were determined by flow cytometry (FCM) and TUNEL assay. The interaction between TgROP18 and the host P2X1 was measured by fluorescence resonance energy transfer (FRET) and co-immunoprecipitation (co-IP) assay. Calcium influx and mitochondrial membrane depolarization were determined by FCM after JC-1 staining. The translocation of cytochrome C (Cyt C), Bax and Bcl2 proteins, expression of the apoptotic proteins PARP and caspase activation were detected by western blotting. Results The apoptosis rates of glial or immune cells (human SF268, mouse RAW264.7 and human THP-1 cells) infected by any T. gondii strain (RH-type I, ME49-type II and VEG-type III) were significantly inhibited compared with their uninfected controls. TgROP18 inhibited ATP-induced apoptosis of SF268 with P2X1 expression, but had no effect on RAW264.7 or THP-1 cells without detectable P2X1 expression. It was further identified that TgROP18 interacted with P2X1, and overexpression of ROP18 in COS7 cells significantly inhibited cell apoptosis mediated by P2X1. Moreover, TgROP18 also inhibited P2X1-mediated Ca2+ influx, translocation of cytochrome C from the mitochondria to the cytosol, and ATP-triggered caspase activation. Conclusions Toxoplasma gondii infection inhibits ATP-induced host cell apoptosis, regardless of strain virulence and host cell lines. TgROP18 targets the purinergic receptor P2X1 of the SF268 human neural cells and inhibits ATP-induced apoptosis through the mitochondrial pathway, suggesting a sensor role for the host proapoptotic protein P2X1 in this process. Electronic supplementary material The online version of this article (10.1186/s13071-019-3529-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Li-Juan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Min Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Santhosh Puthiyakunnon
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Cheng He
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Jing Xia
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Sheng-Qun Deng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China
| | - Hong-Juan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong, People's Republic of China.
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Menard KL, Haskins BE, Denkers EY. Impact of Toxoplasma gondii Infection on Host Non-coding RNA Responses. Front Cell Infect Microbiol 2019; 9:132. [PMID: 31157172 PMCID: PMC6530353 DOI: 10.3389/fcimb.2019.00132] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/12/2019] [Indexed: 12/12/2022] Open
Abstract
As an intracellular microbe, Toxoplasma gondii must establish a highly intimate relationship with its host to ensure success as a parasite. Many studies over the last decade-and-a-half have highlighted how the host reshapes its immunoproteome to survive infection, and conversely how the parasite regulates host responses to ensure persistence. The role of host non-protein-coding RNA during infection is a vast and largely unexplored area of emerging interest. The potential importance of this facet of the host-parasite interaction is underscored by current estimates that as much as 80% of the host genome is transcribed into non-translated RNA. Here, we review the current state of knowledge with respect to two major classes of non-coding RNA, microRNA (miRNA) and long non-coding RNA (lncRNA), in the host response to T. gondii infection. These two classes of regulatory RNA are known to have profound and widespread effects on cell function. However, their impact on infection and immunity is not well-understood, particularly for the response to T. gondii. Nevertheless, numerous miRNAs have been identified that are upregulated by Toxoplasma, and emerging evidence suggests a functional role during infection. While the field of lncRNA is in its infancy, it is already clear that Toxoplasma is also a strong trigger for this class of regulatory RNA. Non-coding RNA responses induced by T. gondii are likely to be major determinants of the host's ability to resist infection and the parasite's ability to establish long-term latency.
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Affiliation(s)
- Kayla L Menard
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM, United States
| | - Breanne E Haskins
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM, United States
| | - Eric Y Denkers
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM, United States
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Hiob L, Berndt A, Daugschies A, Bangoura B. Host-pathogen interaction in Toxoplasma gondii-infected mixed chicken blood cell cultures. Parasitol Res 2019; 118:1479-1491. [PMID: 30798368 DOI: 10.1007/s00436-019-06265-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/11/2019] [Indexed: 11/26/2022]
Abstract
Toxoplasma gondii has the ability to infect various nucleated cell types in different hosts. The aim of the present study was to investigate which chicken blood cells were targeted by T. gondii in a mixed blood cell culture similar to in vivo conditions and to evaluate parasite-host cell interactions. The study consisted of two subsequent experiments. In experiment 1, we applied T. gondii tachyzoites (ME49) at a multiplicity of infection of 1 tachyzoite per blood cell and examined parasite replication, cytokine, and inducible nitric oxide synthase (iNOS) mRNA expression between 1 h and 48 h post-infection (p.i.) by quantitative PCR. By using T. gondii RH-GFP tachyzoites expressing the green fluorescent protein (GFP) in experiment 2, we aimed for visualizing infected cells by confocal laser scanning microscopy (CLSM) and flow cytometric analysis at 24 h p.i. The parasite replication curve showed a massive decrease of parasite stages until 24 h p.i. followed by an approximately plateau phase. We observed mainly significantly increased iNOS mRNA expression levels in T. gondii-infected culture compared to uninfected cells. Flow cytometry and CLSM data confirmed monocytes/macrophages as main target cells for T. gondii. Moreover, different lymphocytes like B cells and cytotoxic T cells seem to be targeted to a low extent. Our findings indicate that monocytes/macrophages play a key role during T. gondii infection in chicken as host cells and triggering of immune response. To the best of our knowledge, this is the first report of a mixed chicken blood cell culture experimentally infected with T. gondii.
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Affiliation(s)
- Lysanne Hiob
- Institute of Parasitology, Centre for Infectious Diseases, University Leipzig, An den Tierkliniken 35, D-04103, Leipzig, Germany.
- Albrecht-Daniel-Thaer Institute, An den Tierkliniken 29, D-04103, Leipzig, Germany.
| | - A Berndt
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Str. 96a, D-07743, Jena, Germany
| | - A Daugschies
- Institute of Parasitology, Centre for Infectious Diseases, University Leipzig, An den Tierkliniken 35, D-04103, Leipzig, Germany
- Albrecht-Daniel-Thaer Institute, An den Tierkliniken 29, D-04103, Leipzig, Germany
| | - B Bangoura
- Institute of Parasitology, Centre for Infectious Diseases, University Leipzig, An den Tierkliniken 35, D-04103, Leipzig, Germany
- Department of Veterinary Medicine, University of Wyoming, 1174 Snowy Range Road, Laramie, WY, 82070, USA
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Zhao Z, Zhao Q, Zhu S, Huang B, Lv L, Chen T, Yan M, Han H, Dong H. iTRAQ-based comparative proteomic analysis of cells infected with Eimeria tenella sporozoites. ACTA ACUST UNITED AC 2019; 26:7. [PMID: 30789155 PMCID: PMC6383524 DOI: 10.1051/parasite/2019009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/11/2019] [Indexed: 12/03/2022]
Abstract
Eimeria tenella is an obligate intracellular parasite that actively invades cecal epithelial cells of chickens. When E. tenella infects a host cell, the host produces a corresponding change to deal with damage caused by this infection. To date, our knowledge on the mechanism of how the host cell responds to E. tenella infection is highly limited at both the molecular and cellular levels. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) coupled with LC-MS/MS was used to screen the differentially expressed proteins (DEPs) in BHK-21 cells infected with E. tenella sporozoites for 24 h post infection. In total, 6139 non-redundant distinct proteins were identified and 195 of these were found to have a fold change ratio ≥1.3 or ≤0.7 and p < 0.05, including 151 up-regulated proteins and 44 down-regulated proteins. The reliability of the proteomic data was further validated with qPCR and western blot. Gene Ontology enrichment indicated that the up-regulated DEPs were mainly involved in binding and catalytic activity, whereas the down-regulated DEPs were catalytic activity and molecular function regulators. Furthermore, KEGG pathway analysis showed that the DEPs participated in the PI3K-Akt, chemokine, Ras, Wnt, and p53 signaling pathways and so on, and the up-regulated and down-regulated DEPs mainly related to the ribosome and mRNA surveillance pathway, respectively. The data in this study provide an important basis to further analyze E. tenella host cell interactions.
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Affiliation(s)
- Zongping Zhao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Qiping Zhao
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Shunhai Zhu
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Bing Huang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Ling Lv
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Ting Chen
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Ming Yan
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Hongyu Han
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
| | - Hui Dong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Shanghai 200241, PR China
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Affiliation(s)
- Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail: (IC); (JDR)
| | - Julia D. Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail: (IC); (JDR)
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12
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Xia J, Kong L, Zhou LJ, Wu SZ, Yao LJ, He C, He CY, Peng HJ. Genome-Wide Bimolecular Fluorescence Complementation-Based Proteomic Analysis of Toxoplasma gondii ROP18's Human Interactome Shows Its Key Role in Regulation of Cell Immunity and Apoptosis. Front Immunol 2018; 9:61. [PMID: 29459857 PMCID: PMC5807661 DOI: 10.3389/fimmu.2018.00061] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 01/10/2018] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii rhoptry protein ROP18 (TgROP18) is a key virulence factor secreted into the host cell during invasion, where it modulates the host cell response by interacting with its host targets. However, only a few TgROP18 targets have been identified. In this study, we applied a high-throughput protein-protein interaction (PPI) screening in human cells using bimolecular fluorescence complementation (BiFC) to identify the targets of Type I strain ROP18 (ROP18I) and Type II strain ROP18 (ROP18II). From a pool of more than 18,000 human proteins, 492 and 141 proteins were identified as the targets of ROP18I and ROP18II, respectively. Gene ontology, search tool for the retrieval of interacting genes/proteins PPI network, and Ingenuity pathway analyses revealed that the majority of these proteins were associated with immune response and apoptosis. This indicates a key role of TgROP18 in manipulating host's immunity and cell apoptosis, which might contribute to the immune escape and successful parasitism of the parasite. Among the proteins identified, the immunity-related proteins N-myc and STAT interactor, IL20RB, IL21, ubiquitin C, and vimentin and the apoptosis-related protein P2RX1 were further verified as ROP18I targets by sensitized emission-fluorescence resonance energy transfer (SE-FRET) and co-immunoprecipitation. Our study substantially contributes to the current limited knowledge on human targets of TgROP18 and provides a novel tool to investigate the function of parasite effectors in human cells.
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Affiliation(s)
- Jing Xia
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Ling Kong
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Li-Juan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Shui-Zhen Wu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Li-Jie Yao
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Cheng He
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Hong-Juan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
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Syn G, Anderson D, Blackwell JM, Jamieson SE. Toxoplasma gondii Infection Is Associated with Mitochondrial Dysfunction in-Vitro. Front Cell Infect Microbiol 2017; 7:512. [PMID: 29312892 PMCID: PMC5733060 DOI: 10.3389/fcimb.2017.00512] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/28/2017] [Indexed: 12/31/2022] Open
Abstract
Upon invasion of host cells, the ubiquitous pathogen Toxoplasma gondii manipulates several host processes, including re-organization of host organelles, to create a replicative niche. Host mitochondrial association to T. gondii parasitophorous vacuoles is rapid and has roles in modulating host immune responses. Here gene expression profiling of T. gondii infected cells reveals enrichment of genes involved in oxidative phosphorylation (OXPHOS) and mitochondrial dysfunction 6 h post-infection. We identified 11 hub genes (HIF-1α, CASP8, FN1, POU5F1, CD44, ISG15, HNRNPA1, MDM2, RPL35, VHL, and NUPR1) and 10 predicted upstream regulators, including 4 endogenous regulators RICTOR, KDM5A, RB1, and D-glucose. We characterized a number of mitochondrial parameters in T. gondii infected human foreskin fibroblast cells over a 36 h time-course. In addition to the usual rapid recruitment and apparent enlargement of mitochondria around the parasitophorous vacuole we observed fragmented host mitochondria in infected cells, not linked to cellular apoptosis, from 24 h post-infection. An increase in mitochondrial superoxide levels in T. gondii infected cells was observed that required active parasite invasion and peaked at 30 h post-infection. Measurement of OXPHOS proteins showed decreased expression of Complex IV in infected cells at 24 h post-infection, followed by decreased expression of Complexes I and II at 36 h post-infection. No change occurred in Complex V. No difference in host mitochondrial membrane potential between infected and mock-infected cells was observed at any time. Our results show perturbation of host mitochondrial function following T. gondii infection that likely impacts on pathogenesis of disease.
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Affiliation(s)
- Genevieve Syn
- Genetics and Health, Telethon Kids Institute, University of Western Australia, Subiaco, WA, Australia
| | - Denise Anderson
- Genetics and Health, Telethon Kids Institute, University of Western Australia, Subiaco, WA, Australia
| | - Jenefer M Blackwell
- Genetics and Health, Telethon Kids Institute, University of Western Australia, Subiaco, WA, Australia
| | - Sarra E Jamieson
- Genetics and Health, Telethon Kids Institute, University of Western Australia, Subiaco, WA, Australia
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14
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He C, Kong L, Zhou L, Xia J, Wei H, Liu M, Peng H. Host Cell Vimentin Restrains Toxoplasma gondii Invasion and Phosphorylation of Vimentin is Partially Regulated by Interaction with TgROP18. Int J Biol Sci 2017; 13:1126-1137. [PMID: 29104504 PMCID: PMC5666328 DOI: 10.7150/ijbs.21247] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 06/23/2017] [Indexed: 12/14/2022] Open
Abstract
The obligate intracellular parasite, Toxoplasma gondii, manipulates the cytoskeleton of its host cells to facilitate infection. A significant rearrangement of host cell vimentin around Toxoplasma parasitophorous vacuoles is observed during the course of infection. ROP18 (TgROP18) is a serine-threonine kinase secreted by T. gondii rhoptry and a major virulence factor; however, the mechanisms by which this kinase modulates host factors remain poorly understood. Different and dynamic patterns of vimentin solubility, phosphorylation, and expression levels were observed in host cells infected with T. gondii strain RH and RH Δrop18 strains, suggesting that TgROP18 contributes to the regulation of these dynamic patterns. Additionally, host cell vimentin was demonstrated to interact with and be phosphorylated by TgROP18. A significant increase in T. gondii infection rate was observed in vimentin knockout human brain microvessel endothelial cells (HBMEC), while vimentin knockout or knock down in host cells had no impact on parasite proliferation and egress. These results indicate that host cell vimentin can inhibit T. gondii invasion. Interestingly, western blotting of different mouse tissues indicated that the lowest vimentin expression level was present in the brain, which may explain the mechanism underlying the nervous system tropism of T. gondii, and the phenomenon of huge cyst burdens developing in the mouse brain during chronic infection.
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Affiliation(s)
- Cheng He
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
| | - Ling Kong
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
| | - Lijuan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
| | - Jing Xia
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
| | - Haixia Wei
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
| | - Min Liu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
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15
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Abstract
Early electron microscopy studies revealed the elaborate cellular features that define the unique adaptations of apicomplexan parasites. Among these were bulbous rhoptry (ROP) organelles and small, dense granules (GRAs), both of which are secreted during invasion of host cells. These early morphological studies were followed by the exploration of the cellular contents of these secretory organelles, revealing them to be comprised of highly divergent protein families with few conserved domains or predicted functions. In parallel, studies on host-pathogen interactions identified many host signaling pathways that were mysteriously altered by infection. It was only with the advent of forward and reverse genetic strategies that the connections between individual parasite effectors and the specific host pathways that they targeted finally became clear. The current repertoire of parasite effectors includes ROP kinases and pseudokinases that are secreted during invasion and that block host immune pathways. Similarly, many secretory GRA proteins alter host gene expression by activating host transcription factors, through modification of chromatin, or by inducing small noncoding RNAs. These effectors highlight novel mechanisms by which T. gondii has learned to harness host signaling to favor intracellular survival and will guide future studies designed to uncover the additional complexity of this intricate host-pathogen interaction.
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16
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Neurophysiological Changes Induced by Chronic Toxoplasma gondii Infection. Pathogens 2017; 6:pathogens6020019. [PMID: 28513566 PMCID: PMC5488653 DOI: 10.3390/pathogens6020019] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/08/2017] [Accepted: 05/12/2017] [Indexed: 01/13/2023] Open
Abstract
Although the parasite Toxoplasma gondii is one of the most pervasive neurotropic pathogens in the world, the host-parasite interactions during CNS infection and the consequences of neurological infection are just beginning to be unraveled. The chronic stages of infection have been considered dormant, although several studies have found correlations of infection with an array of host behavioral changes. These may facilitate parasite transmission and impact neurological diseases. During infection, in addition to the presence of the parasites within neurons, host-mediated neuroimmune and hormonal responses to infection are also present. T. gondii induces numerous changes to host neurons during infection and globally alters host neurological signaling pathways, as discussed in this review. Understanding the neurophysiological changes in the host brain is imperative to understanding the parasitic mechanisms and to delineate the effects of this single-celled parasite on health and its contribution to neurological disease.
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Proteomic Profiling of Mouse Liver following Acute Toxoplasma gondii Infection. PLoS One 2016; 11:e0152022. [PMID: 27003162 PMCID: PMC4803215 DOI: 10.1371/journal.pone.0152022] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 03/08/2016] [Indexed: 02/05/2023] Open
Abstract
Toxoplasma gondii remains a global public health problem. However, its pathophysiology is still not-completely understood particularly the impact of infection on host liver metabolism. We performed iTRAQ-based proteomic analysis to evaluate early liver protein responses in BALB/c mice following infection with T. gondii PYS strain (genotype ToxoDB#9) infection. Our data revealed modification of protein expression in key metabolic pathways, as indicated by the upregulation of immune response and downregulation of mitochondrial respiratory chain, and the metabolism of fatty acids, lipids and xenobiotics. T. gondii seems to hijack host PPAR signaling pathway to downregulate the metabolism of fatty acids, lipids and energy in the liver. The metabolism of over 400 substances was affected by the downregulation of genes involved in xenobiotic metabolism. The top 10 transcription factors used by upregulated genes were Stat2, Stat1, Irf2, Irf1, Sp2, Egr1, Stat3, Klf4, Elf1 and Gabpa, while the top 10 transcription factors of downregulated genes were Hnf4A, Ewsr1, Fli1, Hnf4g, Nr2f1, Pparg, Rxra, Hnf1A, Foxa1 and Foxo1. These findings indicate global reprogramming of the metabolism of the mouse liver after acute T. gondii infection. Functional characterization of the altered proteins may enhance understanding of the host responses to T. gondii infection and lead to the identification of new therapeutic targets.
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Judice CC, Bourgard C, Kayano ACAV, Albrecht L, Costa FTM. MicroRNAs in the Host-Apicomplexan Parasites Interactions: A Review of Immunopathological Aspects. Front Cell Infect Microbiol 2016; 6:5. [PMID: 26870701 PMCID: PMC4735398 DOI: 10.3389/fcimb.2016.00005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 01/13/2016] [Indexed: 01/08/2023] Open
Abstract
MicroRNAs (miRNAs), a class of small non-coding regulatory RNAs, have been detected in a variety of organisms ranging from ancient unicellular eukaryotes to mammals. They have been associated with numerous molecular mechanisms involving developmental, physiological and pathological changes of cells and tissues. Despite the fact that miRNA-silencing mechanisms appear to be absent in some Apicomplexan species, an increasing number of studies have reported a role for miRNAs in host-parasite interactions. Host miRNA expression can change following parasite infection and the consequences can lead, for instance, to parasite clearance. In this context, the immune system signaling appears to have a crucial role.
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Affiliation(s)
- Carla C Judice
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
| | - Catarina Bourgard
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
| | - Ana C A V Kayano
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
| | | | - Fabio T M Costa
- Laboratory of Tropical Diseases, Department of Genetics, Evolution and Bioagents, University of Campinas UNICAMP, Campinas, Brazil
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19
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Cohen SB, Denkers EY. Impact of Toxoplasma gondii on Dendritic Cell Subset Function in the Intestinal Mucosa. THE JOURNAL OF IMMUNOLOGY 2015; 195:2754-62. [PMID: 26283477 DOI: 10.4049/jimmunol.1501137] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/20/2015] [Indexed: 01/10/2023]
Abstract
The function of mucosal dendritic cell (DC) subsets in immunity and inflammation is not well understood. In this study, we define four DC subsets present within the lamina propria and mesenteric lymph node compartments based on expression of CD103 and CD11b. Using IL-12p40 YFP (Yet40) reporter mice, we show that CD103(+)CD11b(-) mucosal DCs are primary in vivo sources of IL-12p40; we also identified CD103(-)CD11b(-) mucosal DCs as a novel population producing this cytokine. Infection was preferentially found in CD11b(+) DCs that were negative for CD103. Lamina propria DCs containing parasites were negative for IL-12p40. Instead, production of the cytokine was strictly a property of noninfected cells. We also show that vitamin A metabolism, as measured by ALDH activity, was preferentially found in CD103(+)CD11b(+) DC and was strongly downregulated in all mucosal DC subsets during infection. Finally, overall apoptosis of lamina propria DC subsets was increased during infection. Combined, these results highlight the ability of intestinal Toxoplasma infection to alter mucosal DC activity at both the whole population level and at the level of individual subsets.
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Affiliation(s)
- Sara B Cohen
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
| | - Eric Y Denkers
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
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20
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Moreira-Souza ACA, Marinho Y, Correa G, Santoro GF, Coutinho CMLM, Vommaro RC, Coutinho-Silva R. Pyrimidinergic Receptor Activation Controls Toxoplasma gondii Infection in Macrophages. PLoS One 2015; 10:e0133502. [PMID: 26192447 PMCID: PMC4507979 DOI: 10.1371/journal.pone.0133502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 06/29/2015] [Indexed: 12/20/2022] Open
Abstract
Infection by the protozoan parasite Toxoplasma gondii is highly prevalent worldwide and may have serious clinical manifestations in immunocompromised patients. T. gondii is an obligate intracellular parasite that infects almost any cell type in mammalian hosts, including immune cells. The immune cells express purinergic P2 receptors in their membrane--subdivided into P2Y and P2X subfamilies--whose activation is important for infection control. Here, we examined the effect of treatment with UTP and UDP in mouse peritoneal macrophages infected with T. gondii tachyzoites. Treatment with these nucleotides reduced parasitic load by 90%, but did not increase the levels of the inflammatory mediators NO and ROS, nor did it modulate host cell death by apoptosis or necrosis. On the other hand, UTP and UDP treatments induced early egress of tachyzoites from infected macrophages, in a Ca2+-dependent manner, as shown by scanning electron microscopy analysis, and videomicroscopy. In subsequent infections, prematurely egressed parasites had reduced infectivity, and could neither replicate nor inhibit the fusion of lysosomes to the parasitophorous vacuole. The use of selective agonists and antagonists of the receptor subtypes P2Y2 and P2Y4 and P2Y6 showed that premature parasite egress may be mediated by the activation of these receptor subtypes. Our results suggest that the activity of P2Y host cell receptors controls T. gondii infection in macrophages, highlighting the importance of pyrimidinergic signaling for innate immune system response against infection. Finally the P2Y receptors should be considered as new target for the development of drugs against T. gondii infection.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Cells, Cultured
- Female
- Host-Parasite Interactions/drug effects
- Macrophages/metabolism
- Macrophages/parasitology
- Macrophages/ultrastructure
- Macrophages, Peritoneal/metabolism
- Macrophages, Peritoneal/parasitology
- Macrophages, Peritoneal/ultrastructure
- Male
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Microscopy, Electron, Scanning
- Microscopy, Electron, Transmission
- Microscopy, Fluorescence
- Nitric Oxide/metabolism
- Purinergic P2Y Receptor Agonists/pharmacology
- Purinergic P2Y Receptor Antagonists/pharmacology
- Reactive Oxygen Species/metabolism
- Receptors, Purinergic P2Y/metabolism
- Suramin/pharmacology
- Toxoplasma/physiology
- Uridine Diphosphate/pharmacology
- Uridine Triphosphate/pharmacology
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Affiliation(s)
- Aline Cristina Abreu Moreira-Souza
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941–902, Brazil
| | - Ygor Marinho
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941–902, Brazil
| | - Gladys Correa
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941–902, Brazil
| | - Giani França Santoro
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Laboratório de Inovações, Terapias, Ensino e Bioprodutos (LITEB), Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, 21.040–900, Brazil
- Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941–902, Brazil
| | - Claudia Mara Lara Melo Coutinho
- Laboratório de Inovações, Terapias, Ensino e Bioprodutos (LITEB), Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, 21.040–900, Brazil
- Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ, 24020–140, Brazil
| | - Rossiane Claudia Vommaro
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
| | - Robson Coutinho-Silva
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941–902, Brazil
- Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941–902, Brazil
- * E-mail:
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Graumann K, Schaumburg F, Reubold TF, Hippe D, Eschenburg S, Lüder CGK. Toxoplasma gondii inhibits cytochrome c-induced caspase activation in its host cell by interference with holo-apoptosome assembly. MICROBIAL CELL 2015; 2:150-162. [PMID: 28357287 PMCID: PMC5349237 DOI: 10.15698/mic2015.05.201] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Inhibition of programmed cell death pathways of mammalian cells often facilitates the sustained survival of intracellular microorganisms. The apicomplexan parasite Toxoplasma gondii is a master regulator of host cell apoptotic pathways. Here, we have characterized a novel anti-apoptotic activity of T. gondii. Using a cell-free cytosolic extract model, we show that T. gondii interferes with the activities of caspase 9 and caspase 3/7 which have been induced by exogenous cytochrome c and dATP. Proteolytic cleavage of caspases 9 and 3 is also diminished suggesting inhibition of holo-apoptosome function. Parasite infection of Jurkat T cells and subsequent triggering of apoptosome formation by exogenous cytochrome cin vitro and in vivo indicated that T. gondii also interferes with caspase activation in infected cells. Importantly, parasite inhibition of cytochrome c-induced caspase activation considerably contributes to the overall anti-apoptotic activity of T. gondii as observed in staurosporine-treated cells. Co-immunoprecipitation showed that T. gondii abolishes binding of caspase 9 to Apaf-1 whereas the interaction of cytochrome c with Apaf-1 remains unchanged. Finally, T. gondii lysate mimics the effect of viable parasites and prevents holo-apoptosome functionality in a reconstituted in vitro system comprising recombinant Apaf-1 and caspase 9. Beside inhibition of cytochrome c release from host cell mitochondria, T. gondii thus also targets the holo-apoptosome assembly as a second mean to efficiently inhibit the caspase-dependent intrinsic cell death pathway.
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Affiliation(s)
- Kristin Graumann
- Institute for Medical Microbiology, Georg-August-University, Göttingen, Germany. ; Present address: In den Brühlwiesen 12, 61352 Bad Homburg, Germany
| | - Frieder Schaumburg
- Institute for Medical Microbiology, Georg-August-University, Göttingen, Germany. ; Present address: Institute for Medical Microbiology, University Hospital Münster, Domagkstraße 10, 48149 Münster, Germany
| | - Thomas F Reubold
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Diana Hippe
- Institute for Medical Microbiology, Georg-August-University, Göttingen, Germany
| | - Susanne Eschenburg
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Carsten G K Lüder
- Institute for Medical Microbiology, Georg-August-University, Göttingen, Germany
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22
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Infection by Toxoplasma gondii specifically induces host c-Myc and the genes this pivotal transcription factor regulates. EUKARYOTIC CELL 2014; 13:483-93. [PMID: 24532536 DOI: 10.1128/ec.00316-13] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Toxoplasma gondii infection has previously been described to cause dramatic changes in the host transcriptome by manipulating key regulators, including STATs, NF-κB, and microRNAs. Here, we report that Toxoplasma tachyzoites also mediate rapid and sustained induction of another pivotal regulator of host cell transcription, c-Myc. This induction is seen in cells infected with all three canonical types of Toxoplasma but not the closely related apicomplexan parasite Neospora caninum. Coinfection of cells with both Toxoplasma and Neospora still results in an increase in the level of host c-Myc, showing that c-Myc is actively upregulated by Toxoplasma infection (rather than repressed by Neospora). We further demonstrate that this upregulation may be mediated through c-Jun N-terminal protein kinase (JNK) and is unlikely to be a nonspecific host response, as heat-killed Toxoplasma parasites do not induce this increase and neither do nonviable parasites inside the host cell. Finally, we show that the induced c-Myc is active and that transcripts dependent on its function are upregulated, as predicted. Hence, c-Myc represents an additional way in which Toxoplasma tachyzoites have evolved to specifically alter host cell functions during intracellular growth.
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23
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Cai Y, Chen H, Jin L, You Y, Shen J. STAT3-dependent transactivation of miRNA genes following Toxoplasma gondii infection in macrophage. Parasit Vectors 2013; 6:356. [PMID: 24341525 PMCID: PMC3878672 DOI: 10.1186/1756-3305-6-356] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/08/2013] [Indexed: 12/21/2022] Open
Abstract
Background The apicomplexan parasite Toxoplasma gondii can infect and replicate in virtually any nucleated cell in many species of warm-blooded animals; T. gondii has elaborate mechanisms to counteract host-cell apoptosis in order to maintain survival and breed in the host cells. Methods Using microarray profiling and a combination of conventional molecular approaches, we investigated the levels of microRNAs (miRNAs ) in human macrophage during T. gondii infection. We used molecular tools to examine Toxoplasma-upregualted miRNAs to revealed potential signal transducers and activators of transcription 3(STAT3) binding sites in the promoter elements of a subset of miRNA genes. We analysed the apoptosis of human macrophage with the functional inhibition of the STAT3-binding miRNAs by flow cytometry. Results Our results demonstrated differential alterations in the mature miRNA expression profile in human macrophage following T. gondii infection. Database analysis of Toxoplasma-upregulated miRNAs revealed potential STAT3 binding sites in the promoter elements of a subset of miRNA genes. We demonstrated that miR-30c-1, miR-125b-2, miR-23b-27b-24-1 and miR-17 ~ 92 cluster genes were transactivated through promoter binding of the STAT3 following T. gondii infection. Importantly, functional inhibition of selected STAT3-binding miRNAs in human macropahges increased apoptosis of host cells. Conclusions A panel of miRNAs is regulated through promoter binding of the STAT3 in human macrophage and these miRNAs are involved in anti-apoptosis in response to T. gondii infection.
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Affiliation(s)
| | | | | | | | - Jilong Shen
- Anhui Provincial Laboratories of Pathogen Biology and Zoonoses, Department of Microbiology and Parasitology, Anhui Medical University, Hefei, China.
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Malkwitz I, Berndt A, Daugschies A, Bangoura B. Long-term investigations on Toxoplasma gondii-infected primary chicken macrophages. Parasitol Res 2013; 112:3115-22. [PMID: 23749093 DOI: 10.1007/s00436-013-3486-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 05/29/2013] [Indexed: 12/14/2022]
Abstract
Toxoplasma (T.) gondii is known to infect various cell types including macrophages. In the present study, we generated monocyte-derived macrophage cultures from chicken blood. By flow cytometrical analysis, 84.5% of the cultivated cells showed typical macrophage properties. Macrophage cultures were cultivated at either 37 °C or 40 °C, respectively, and were infected 72 to 96 h post isolationem with tachyzoites of the T. gondii type II strain ME49 at a rate of 7.5 tachyzoites per host cell. Light microscopical investigations revealed incorporation of tachyzoites into the macrophages and gradual destruction of the infected macrophage culture. Parasite multiplication was observed by a quantitative real time PCR (qPCR) based on the 529-bp fragment specific for T. gondii. Samples were drawn 1 h post infectionem (p.i.), as well as 12, 24, 36, 48, and 72 h p.i. The parasite replication curve showed a transient decrease of parasite stages 12 h p.i. followed by a tachyzoite multiplication. The comparison of different culture conditions showed a significantly higher replication rate of T. gondii at 37 °C (median value 48 h p.i., 289.2% of the initial tachyzoite number) compared to cultures incubated at 40 °C (median value 48 h p.i., 73.1% of the initial tachyzoite number) throughout the observation period (P < 0.05). In general, replication rates were significantly lower than in a standard VERO cell cultures at 37 °C (P < 0.05). The observed differences were attributed to the physiological chicken macrophage reaction at 40 °C probably approximating the situation in vivo.
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Affiliation(s)
- Irene Malkwitz
- Institute of Parasitology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, University Leipzig, An den Tierkliniken 35, 04103, Leipzig, Germany
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Best A, Long G, White A, Boots M. The implications of immunopathology for parasite evolution. Proc Biol Sci 2012; 279:3234-40. [PMID: 22553095 PMCID: PMC3385737 DOI: 10.1098/rspb.2012.0647] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 04/13/2012] [Indexed: 11/12/2022] Open
Abstract
By definition, parasites harm their hosts, but in many infections much of the pathology is driven by the host immune response rather than through direct damage inflicted by parasites. While these immunopathological effects are often well studied and understood mechanistically in individual disease interactions, there remains relatively little understanding of their broader impact on the evolution of parasites and their hosts. Here, we theoretically investigate the implications of immunopathology, broadly defined as additional mortality associated with the host's immune response, on parasite evolution. In particular, we examine how immunopathology acting on different epidemiological traits (namely transmission, virulence and recovery) affects the evolution of disease severity. When immunopathology is costly to parasites, such that it reduces their fitness, for example by decreasing transmission, there is always selection for increased disease severity. However, we highlight a number of host-parasite interactions where the parasite may benefit from immunopathology, and highlight scenarios that may lead to the evolution of slower growing parasites and potentially reduced disease severity. Importantly, we find that conclusions on disease severity are highly dependent on how severity is measured. Finally, we discuss the effect of treatments used to combat disease symptoms caused by immunopathology.
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Affiliation(s)
- Alex Best
- School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH, UK.
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Haroon F, Händel U, Angenstein F, Goldschmidt J, Kreutzmann P, Lison H, Fischer KD, Scheich H, Wetzel W, Schlüter D, Budinger E. Toxoplasma gondii actively inhibits neuronal function in chronically infected mice. PLoS One 2012; 7:e35516. [PMID: 22530040 PMCID: PMC3329480 DOI: 10.1371/journal.pone.0035516] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 03/18/2012] [Indexed: 12/11/2022] Open
Abstract
Upon infection with the obligate intracellular parasite Toxoplasma gondii, fast replicating tachyzoites infect a broad spectrum of host cells including neurons. Under the pressure of the immune response, tachyzoites convert into slow-replicating bradyzoites, which persist as cysts in neurons. Currently, it is unclear whether T. gondii alters the functional activity of neurons, which may contribute to altered behaviour of T. gondii-infected mice and men. In the present study we demonstrate that upon oral infection with T. gondii cysts, chronically infected BALB/c mice lost over time their natural fear against cat urine which was paralleled by the persistence of the parasite in brain regions affecting behaviour and odor perception. Detailed immunohistochemistry showed that in infected neurons not only parasitic cysts but also the host cell cytoplasm and some axons stained positive for Toxoplasma antigen suggesting that parasitic proteins might directly interfere with neuronal function. In fact, in vitro live cell calcium (Ca(2+)) imaging studies revealed that tachyzoites actively manipulated Ca(2+) signalling upon glutamate stimulation leading either to hyper- or hypo-responsive neurons. Experiments with the endoplasmatic reticulum Ca(2+) uptake inhibitor thapsigargin indicate that tachyzoites deplete Ca(2+) stores in the endoplasmatic reticulum. Furthermore in vivo studies revealed that the activity-dependent uptake of the potassium analogue thallium was reduced in cyst harbouring neurons indicating their functional impairment. The percentage of non-functional neurons increased over time In conclusion, both bradyzoites and tachyzoites functionally silence infected neurons, which may significantly contribute to the altered behaviour of the host.
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Affiliation(s)
- Fahad Haroon
- Institut für Medizinische Mikrobiologie, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Ulrike Händel
- Institut für Medizinische Mikrobiologie, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Frank Angenstein
- Leibniz-Institut für Neurobiologie, Speziallabor Nicht-Invasive Bildgebung, Magdeburg, Germany
| | - Jürgen Goldschmidt
- Leibniz-Institut für Neurobiologie, Abteilung Akustik, Lernen und Sprache, Magdeburg, Germany
| | - Peter Kreutzmann
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Holger Lison
- Leibniz-Institut für Neurobiologie, Abteilung Akustik, Lernen und Sprache, Magdeburg, Germany
| | - Klaus-Dieter Fischer
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Henning Scheich
- Leibniz-Institut für Neurobiologie, Abteilung Akustik, Lernen und Sprache, Magdeburg, Germany
| | - Wolfram Wetzel
- Leibniz-Institut für Neurobiologie, Speziallabor Verhaltenspharmakologie, Magdeburg, Germany
| | - Dirk Schlüter
- Institut für Medizinische Mikrobiologie, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
- * E-mail:
| | - Eike Budinger
- Leibniz-Institut für Neurobiologie, Abteilung Akustik, Lernen und Sprache, Magdeburg, Germany
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Miller CM, Boulter NR, Fuller SJ, Zakrzewski AM, Lees MP, Saunders BM, Wiley JS, Smith NC. The role of the P2X₇ receptor in infectious diseases. PLoS Pathog 2011; 7:e1002212. [PMID: 22102807 PMCID: PMC3213081 DOI: 10.1371/journal.ppat.1002212] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
ATP is an extracellular signal for the immune system, particularly during an inflammatory response. It is sensed by the P2X7 receptor, the expression of which is upregulated by pro-inflammatory cytokines. Activation of the P2X7 receptor opens a cation-specific channel that alters the ionic environment of the cell, activating several pathways, including (i) the inflammasome, leading to production of IL-1β and IL-18; (ii) the stress-activated protein kinase pathway, resulting in apoptosis; (iii) the mitogen-activated protein kinase pathway, leading to generation of reactive oxygen and nitrogen intermediates; and (iv) phospholipase D, stimulating phagosome-lysosome fusion. The P2X7 receptor can initiate host mechanisms to remove pathogens, most particularly those that parasitise macrophages. At the same time, the P2X7 receptor may be subverted by pathogens to modulate host responses. Moreover, recent genetic studies have demonstrated significant associations between susceptibility or resistance to parasites and bacteria, and loss-of-function or gain-of-function polymorphisms in the P2X7 receptor, underscoring its importance in infectious disease.
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Affiliation(s)
- Catherine M. Miller
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway, New South Wales, Australia
| | - Nicola R. Boulter
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway, New South Wales, Australia
| | - Stephen J. Fuller
- Nepean Clinical School, Nepean Hospital, The University of Sydney, Penrith, New South Wales, Australia
| | - Alana M. Zakrzewski
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway, New South Wales, Australia
| | - Michael P. Lees
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway, New South Wales, Australia
| | - Bernadette M. Saunders
- Centenary Institute of Cancer Medicine & Cell Biology, The University of Sydney, Camperdown, New South Wales, Australia
| | - James S. Wiley
- Florey Neuroscience Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Nicholas C. Smith
- Queensland Tropical Health Alliance, Faculty of Medicine, Health and Molecular Sciences, James Cook University, Smithfield, Cairns, Queensland, Australia
- * E-mail:
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Hakimi MA, Cannella D. Apicomplexan parasites and subversion of the host cell microRNA pathway. Trends Parasitol 2011; 27:481-6. [PMID: 21840260 DOI: 10.1016/j.pt.2011.07.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 07/05/2011] [Accepted: 07/06/2011] [Indexed: 12/21/2022]
Abstract
RNA silencing plays a major role in innate antiviral and antibacterial defenses in plants, insects, and animals through the action of microRNAs (miRNAs). miRNAs can act in favor of the microorganism, either when it is pathogen-encoded or when the microorganism subverts host miRNAs to its benefit. Recent data point to the possibility that apicomplexan parasites have developed tactics to interfere with host miRNA populations in a parasite-specific manner, thereby identifying the RNA-silencing pathway as a new means to reshape their cellular environment. This review highlights the current understanding and new insights concerning the mechanisms that could be involved and the potential roles of the host microRNome (miRNome) in apicomplexan infection.
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Affiliation(s)
- Mohamed-ali Hakimi
- Unité Mixte de Recherche 5163, Laboratoire Adaptation et Pathogénie des Micro-organismes, Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier Grenoble 1, BP 170, F-38042 Grenoble CEDEX 9, France. (
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Abstract
Toxoplasma gondii is an obligate intracellular parasite. Following oral infection the parasite crosses the intestinal epithelial barrier to disseminate throughout the body and establish latent infection in central nervous tissues. The clinical presentation ranges from asymptomatic to severe neurological disorders in immunocompromised individuals. Since the clinical presentation is diverse and depends, among other factors, on the immune status of the host, in the present review, we introduce parasitological, epidemiological, clinical, and molecular biological aspects of infection with T. gondii to set the stage for an in-depth discussion of host immune responses. Since immune responses in humans have not been investigated in detail the present review is exclusively referring to immune responses in experimental models of infection. Systemic and local immune responses in different models of infection are discussed, and a separate chapter introduces commonly used animal models of infection.
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Affiliation(s)
- Melba Munoz
- Charite Medical School Berlin - Microbiology and Hygiene, Berlin, Germany
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Choi SH, Park SJ, Cha GH, Quan JH, Chang NS, Ahn MH, Shin DW, Lee YH. Toxoplasma gondii protects against H(2)O(2) -induced apoptosis in ARPE-19 cells through the transcriptional regulation of apoptotic elements and downregulation of the p38 MAPK pathway. Acta Ophthalmol 2011; 89:e350-6. [PMID: 21385331 DOI: 10.1111/j.1755-3768.2011.02113.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Toxoplasmosis, which is caused by the protozoan parasite Toxoplasma gondii, can lead to severe visual impairment. T. gondii inhibits or delays programmed cell death caused by various apoptotic triggers; however, the mechanisms involved in the T. gondii-induced suppression of apoptosis in retinal cells have not been analysed in detail. METHODS We investigated the role of T. gondii infection in H(2)O(2) -induced apoptosis in human retinal pigment epithelial cells (ARPE-19) by monitoring the activities of apoptosis-regulating molecules and mitogen-activated protein kinases (MAPKs), including p38 MAPK. We also examined the gene downstream from p38 MAPK. RESULTS T. gondii infection significantly inhibited the cellular toxicity of H(2)O(2) (500 μm) and increased cell viability in a multiplicity of infection (MOI)-dependent manner by reducing DNA fragmentation and reactive oxygen species (ROS) generation in ARPE-19 cells. Western blot analysis also showed that T. gondii infection prevented the host cell expression of pro-apoptotic factors, such as Bad and Bax, and the activation of caspase-3. Infection with T. gondii increased the expression of the anti-apoptotic factor Bcl-2 in ARPE-19 cells under oxidative stress. In accordance with these findings, Toxoplasma infection was protective enough to suppress the phosphorylation of p38 MAPK following H(2)O(2) treatment. Exposure to H(2)O(2) increased the expression of heme oxygenase-1 (HO-1) in ARPE-19 cells, and its expression was significantly inhibited in H(2)O(2) -treated infected cells. CONCLUSION The protective function of T. gondii infection against ROS-induced apoptosis results from changes in the expression of apoptotic molecules and the downregulation of stress-induced intracellular signalling.
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Affiliation(s)
- Si-Hwan Choi
- Department of Ophthalmology, Chungnam National University School of Medicine, Daejeon, Korea
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31
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Long GH, Boots M. How can immunopathology shape the evolution of parasite virulence? Trends Parasitol 2011; 27:300-5. [PMID: 21531628 DOI: 10.1016/j.pt.2011.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 03/31/2011] [Accepted: 03/31/2011] [Indexed: 01/05/2023]
Abstract
Immunopathology (immune-mediated pathology) is a ubiquitous cause of disease during infection, but how will parasite exploitation strategies evolve in its presence? Immunopathology can act to increase parasite fitness if it increases transmission rate, but can equally act to decrease parasite fitness if it increases host mortality. The focus here is on understanding how immunopathology, mediated through different immune mechanisms, can influence parasite fitness and how experimental manipulations of the immune system can be carried out to examine this. A better understanding of how parasite fitness scales with, or responds to, immunopathology is crucial to understanding the nature of selection acting on parasite virulence traits and will allow more informed predictions to be made regarding the trajectory of parasite virulence evolution.
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Affiliation(s)
- Gráinne H Long
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
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Qu DF, Yu HJ, Liu Z, Zhang DF, Zhou QJ, Zhang HL, Du AF. Ginsenoside Rg1 enhances immune response induced by recombinant Toxoplasma gondii SAG1 antigen. Vet Parasitol 2011; 179:28-34. [PMID: 21439733 DOI: 10.1016/j.vetpar.2011.02.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 02/10/2011] [Accepted: 02/14/2011] [Indexed: 01/10/2023]
Abstract
Ginsenoside, the most important component isolated from Panax ginseng, exhibits a variety of biological activities. Particularly, ginsenoside Rg1 is known to have immune-modulating activities such as increase of immune activity of T helper (Th) cells. In the present study, we evaluated the immunomodulatory potentials of the Rg1 at three dose levels on the cellular and humoral immune responses of ICR mice against T. gondii recombinant surface antigen 1 (rSAG1). ICR mice were immunized subcutaneously with 50 μg Rg1 alone, 100 μg rSAG1 alone or with 100 μg rSAG1 dissolved in saline containing ginsenoside Rg1 (10 μg, 50 μg or 100 μg). After immunization, we evaluated the immune response using lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged lethally. The results showed that the groups immunized with rSAG1 and Rg1 (50 μg, 100 μg) developed a high level of specific antibody responses against T. gondii rSAG1, a strong lymphoproliferative response, and significant levels of cytokine production, compared with the other groups. After lethal challenge, the mice immunized with the rSAG1 and Rg1 (50 μg, 100 μg) showed a significantly increased survival time compared with control mice which died within 6 days of challenge. Our data demonstrate that by addition of ginsenoside Rg1, the rSAG1 triggered a stronger humoral and cellular response against T. gondii, and that Rg1 is a promising vaccine adjuvant against toxoplasmosis, worth further development.
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Affiliation(s)
- Dao-Feng Qu
- Key Laboratory of Animal Epidemic Etiology and Immunological Prevention of Ministry of Agriculture, Zhejiang University, Hangzhou 310029, China
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Peng HJ, Chen XG, Lindsay DS. A review: Competence, compromise, and concomitance-reaction of the host cell to Toxoplasma gondii infection and development. J Parasitol 2011; 97:620-8. [PMID: 21506833 DOI: 10.1645/ge-2712.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Toxoplasma gondii is an important zoonotic parasite with a worldwide distribution. It infects about one-third of the world's population, causing serious illness in immunosuppressed individuals, fetuses, and infants. Toxoplasma gondii biology within the host cell includes several important phases: (1) active invasion and establishment of a nonfusogenic parasitophorous vacuole in the host cell, (2) extensive modification of the parasitophorous vacuolar membrane for nutrient acquisition, (3) intracellular proliferation by endodyogeny, (4) egress and invasion of new host cells, and (5) stage conversion from tachyzoite to bradyzoite and establishment of chronic infection. During these processes, T. gondii regulates the host cell by modulating morphological, physiological, immunological, genetic, and cellular biological aspects of the host cell. Overall, the infection/development predispositions of T. gondii -host cell interactions overtakes the infection resistance aspects. Upon invasion and development, host cells are modulated to keep a delicate balance between facilitating and eliminating the infection.
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Affiliation(s)
- Hong-Juan Peng
- Department of Etio-biology, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Rd, Guangzhou, Guangdong Province 510515, People's Republic of China
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Morgado FN, Schubach AO, Barros MBL, Conceição-Silva F. The in situ inflammatory profile of lymphocutaneous and fixed forms of human sporotrichosis. Med Mycol 2011; 49:612-20. [PMID: 21254963 DOI: 10.3109/13693786.2011.552532] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The most common clinical presentations of sporotrichosis are the lymphocutaneous (LC) and fixed cutaneous (F) forms, but little is known about the immunopathologic differences between them. The aim of this study was to evaluate through immunohistochemistry the composition of the in situ inflammatory reaction so as to correlate the results with the clinical presentation of the disease. The following two groups of patients were involved in the studies, i.e., LC (n=19) and F (n=11) patients. Those with the LC form, in contrast to F patients, were found to have a larger number of lesions (P=0.001), of longer duration (P=0.026) and require a more extended course of treatment (P=0.049). LC patients also presented a greater fungal burden (LC:0-6.5; F:0-1.5; P=0.021), a higher percentage of neutrophils (median LC:24.7%; F:6.7%, P=0.002), CD4(+) cells (median LC:40.9%; F:30.0%, P=0.0024), CD22(+) cells (median LC:15.3%; F:2.9%, P=0.048), and higher intensity of NOS2 expression (P=0.009). Thus, our data identified differences in cell profile and inflammatory activity in lesions of LC and F forms of human sporotrichosis.
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Affiliation(s)
- Fernanda N Morgado
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
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35
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Lutz K, Schmitt S, Linder M, Hermosilla C, Zahner H, Taubert A. Eimeria bovis-induced modulation of the host cell proteome at the meront I stage. Mol Biochem Parasitol 2010; 175:1-9. [PMID: 20801164 DOI: 10.1016/j.molbiopara.2010.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Revised: 07/25/2010] [Accepted: 08/20/2010] [Indexed: 01/15/2023]
Abstract
The proteome of Eimeria bovis meront I-carrying host cells was analyzed by two-dimensional gel electrophoresis (2DE) at 14 days p.i. and compared to non-infected control cells. A total of 221 protein spots were modulated in their abundance in E. bovis-infected host cells and were subsequently analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectometry (MALDI-TOF-MS). These analyses identified 104 proteins in total with 25 host cell proteins being up-regulated and 79 proteins being down-regulated in E. bovis-infected host cells. Moreover, 20 newly expressed proteins were identified exclusively in E. bovis-infected host cells and were most likely of parasite origin. Parasite-induced differences in protein abundance concerned distinct functional categories, with most proteins being involved in host cell metabolism, cell structure, protein fate and gene transcription. Some of the modulated molecules also indicated regulatory processes on the level of host cell stress response (HSP70, HSP90), host cell apoptosis (caspase 8) and actin elongation/depolymerization (α-actinin-1, gelsonin, tropomodulin-3, transgelin). Since merozoites I were already released shortly after cell sampling, the current data reflect the situation at the end of first merogony. This is the first proteomic approach on E. bovis-infected host cells that was undertaken to gain a rather broad insight into Eimeria-induced host cell modulation. The data processed in this investigation should provide a useful basis for more detailed analyses concerning Eimeria-host cell interactions.
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Affiliation(s)
- Kathleen Lutz
- Institute of Parasitology, Justus Liebig University Giessen, 35392 Giessen, Germany
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36
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Elsheikha HM, Khan NA. Protozoa traversal of the blood–brain barrier to invade the central nervous system. FEMS Microbiol Rev 2010; 34:532-53. [DOI: 10.1111/j.1574-6976.2010.00215.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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CD69 limits early inflammatory diseases associated with immune response to
Listeria monocytogenes
infection. Immunol Cell Biol 2010; 88:707-15. [DOI: 10.1038/icb.2010.62] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Debierre-Grockiego F, Schwarz RT. Immunological reactions in response to apicomplexan glycosylphosphatidylinositols. Glycobiology 2010; 20:801-11. [PMID: 20378610 DOI: 10.1093/glycob/cwq038] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Apicomplexan protozoa are a phylum of parasites that includes pathogens such as Plasmodium, the causative agent of the most severe form of malaria responsible for almost 1 million deaths per year and Toxoplasma gondii causing toxoplasmosis, a disease leading to cerebral meningitis in immunocompromised individuals or to abortion in farm animals or in women that are infected for the first time during pregnancy. The initial immune reactions developed by the host are similar in response to an infection with Plasmodium and Toxoplasma in the sense that the same cells of the innate immune system are stimulated to produce inflammatory cytokines. The glycosylphosphatidylinositol (GPI) anchor is the major carbohydrate modification in parasite proteins and the GPIs are essential for parasite survival. Two immediate GPI precursors with the structures ethanolamine phosphate-6(Manalpha1-2)Manalpha1-2Manalpha1-6Manalpha1-4GlcN-PI and ethanolamine phosphate-6Manalpha1-2Manalpha1-6Man-alpha1-4-GlcN-PI are synthesized by P. falciparum. Two main structures are synthesized by T. gondii: ethanolamine phosphate-6Manalpha1-2Manalpha1-6(GalNAcbeta1-4)Manalpha1-4GlcN-PI and ethanolamine phosphate-6Manalpha1-2Manalpha1-6(Glcalpha1-4GalNAcbeta1-4)Manalpha1-4GlcN-PI. This review describes the biosynthesis of the apicomplexan GPIs and their role in the activation of the host immune system.
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Affiliation(s)
- Françoise Debierre-Grockiego
- UMR Université-INRA 0483, Immunologie Parasitaire Vaccinologie et Biothérapies anti-infectieuses, UFR Sciences Pharmaceutiques, 31 avenue Monge, 37200 Tours, France
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Leng J, Butcher BA, Denkers EY. Dysregulation of macrophage signal transduction by Toxoplasma gondii: past progress and recent advances. Parasite Immunol 2010; 31:717-28. [PMID: 19891610 DOI: 10.1111/j.1365-3024.2009.01122.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The opportunistic protozoan parasite Toxoplasma gondii is well known as a strong inducer of cell-mediated immunity, largely as a result of proinflammatory cytokine induction during in vivo infection. Yet, during intracellular infection the parasite suppresses signal transduction pathways leading to these proinflammatory responses. The opposing responses are likely to reflect the parasite's need to stimulate immunity allowing host survival and parasite persistence, and at the same time avoiding excessive responses that could result in parasite elimination and host immunopathology. This Review summarizes past and present investigations into the effects of Toxoplasma on host cell signal transduction. These studies reveal insight into the profound suppression of proinflammatory cytokine responses that occurs when the parasite infects macrophages and other cells of innate immunity.
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Affiliation(s)
- J Leng
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA
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40
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Zeiner GM, Norman KL, Thomson JM, Hammond SM, Boothroyd JC. Toxoplasma gondii infection specifically increases the levels of key host microRNAs. PLoS One 2010; 5:e8742. [PMID: 20090903 PMCID: PMC2806928 DOI: 10.1371/journal.pone.0008742] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 12/22/2009] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The apicomplexan parasite Toxoplasma gondii can infect and replicate in virtually any nucleated cell in many species of warm-blooded animals; thus, it has evolved the ability to exploit well-conserved biological processes common to its diverse hosts. Here we have investigated whether Toxoplasma modulates the levels of host microRNAs (miRNAs) during infection. METHODOLOGY/PRINCIPAL FINDINGS Using microarray profiling and a combination of conventional molecular approaches we report that Toxoplasma specifically modulates the expression of important host microRNAs during infection. We show that both the primary transcripts for miR-17 approximately 92 and miR-106b approximately 25 and the pivotal miRNAs that are derived from miR-17 approximately 92 display increased abundance in Toxoplasma-infected primary human cells; a Toxoplasma-dependent up-regulation of the miR-17 approximately 92 promoter is at least partly responsible for this increase. The abundance of mature miR-17 family members, which are derived from these two miRNA clusters, remains unchanged in host cells infected with the closely related apicomplexan Neospora caninum; thus, the Toxoplasma-induced increase in their abundance is a highly directed process rather than a general host response to infection. CONCLUSIONS/SIGNIFICANCE Altered levels of miR-17 approximately 92 and miR-106b approximately 25 are known to play crucial roles in mammalian cell regulation and have been implicated in numerous hyperproliferative diseases although the mechanisms driving their altered expression are unknown. Hence, in addition to the implications of these findings on the host-pathogen interaction, Toxoplasma may represent a powerful probe for understanding the normal mechanisms that regulate the levels of key host miRNAs.
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Affiliation(s)
- Gusti M. Zeiner
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Kara L. Norman
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - J. Michael Thomson
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Scott M. Hammond
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - John C. Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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41
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Begum-Haque S, Haque A, Kasper LH. Apoptosis in Toxoplasma gondii activated T cells: the role of IFNgamma in enhanced alteration of Bcl-2 expression and mitochondrial membrane potential. Microb Pathog 2009; 47:281-8. [PMID: 19748565 DOI: 10.1016/j.micpath.2009.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Revised: 08/21/2009] [Accepted: 09/01/2009] [Indexed: 12/27/2022]
Abstract
In the present study we addressed the question whether Toxoplasma gondii could promote apoptosis in T lymphocytes in the acute stage of infection. Using in vivo activated T cells and then culturing them for a short time, we observed activation-induced cell death in T. gondii infected mice. A higher level of activation-induced cell death (AICD) was seen in susceptible C57BL/6 mice than in resistant CBA/J mice following infection with the same P strain of parasite. Apoptosis in T cells of susceptible mice was associated with altered induction of Bcl-2/Bax, loss of Mitochondrial Transmembrane Potential. Both CD4+ and CD8+ T cells were found to be susceptible to apoptosis; CD4+ T cells were sensitive to Fas-mediated death whereas CD8+ T cells were insensitive to this signal. Caspase inhibitors had less effect on DNA fragmentation in CD4+ compared to CD8+ T cells. Exposure of CD4+ T cells to anti-IFNgamma mAb resulted in an increase in the number of T cells that were positive for anti-apoptotic molecule Bcl-2 and DiOC6, a cationic dye that accumulates in intact mitochondria. These changes were less noticeable in CD8+ T cells following treatment with anti-IFNgamma mAb. These findings provide further insight into the mechanisms of T cell apoptosis in T. gondii infection.
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Affiliation(s)
- Sakhina Begum-Haque
- Department of Medicine and Microbiology, Dartmouth Medical School Hanover, Lebanon, NH 03755, USA
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42
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Hippe D, Weber A, Zhou L, Chang DC, Häcker G, Lüder CGK. Toxoplasma gondii infection confers resistance against BimS-induced apoptosis by preventing the activation and mitochondrial targeting of pro-apoptotic Bax. J Cell Sci 2009; 122:3511-21. [PMID: 19737817 DOI: 10.1242/jcs.050963] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In order to accomplish their life style, intracellular pathogens, including the apicomplexan Toxoplasma gondii, subvert the innate apoptotic response of infected host cells. However, the precise mechanisms of parasite interference with the mitochondrial apoptotic pathway remain unknown. Here, we used the conditional expression of the BH3-only protein Bim(S) to pinpoint the interaction of T. gondii with the intrinsic pathway of apoptosis. Infection of epithelial cells with T. gondii dose-dependently abrogated Bim(S)-triggered release of cytochrome c from host-cell mitochondria into the cytosol, induction of activity of caspases 3, 7 and 9, and chromatin condensation. Furthermore, inhibition of apoptosis in parasite-infected lymphocytes counteracted death of Toxoplasma-infected host cells. Although total cellular levels and mitochondrial targeting of Bim(S) was not altered by the infection, the activation of pro-apoptotic effector proteins Bax and Bak was strongly impaired. Inhibition of Bax and Bak activation by T. gondii was seen with regard to their conformational changes, the cytosol-to-mitochondria targeting and the oligomerization of Bax but not their cellular protein levels. Blockade of Bax and Bak activation was not mediated by the upregulation of anti-apoptotic Bcl-2-like proteins following infection. Further, the BH3-mimetic ABT-737 failed to overcome the Toxoplasma-imposed inhibition of Bim(S)-triggered apoptosis. These results indicate that T. gondii targets activation of pro-apoptotic Bax and Bak to inhibit the apoptogenic function of mitochondria and to increase host-cell viability.
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Affiliation(s)
- Diana Hippe
- Institute for Medical Microbiology, Georg-August-University, Kreuzbergring 57, D-37075 Göttingen, Germany
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43
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Lang M, Kann M, Zahner H, Taubert A, Hermosilla C. Inhibition of host cell apoptosis by Eimeria bovis sporozoites. Vet Parasitol 2009; 160:25-33. [DOI: 10.1016/j.vetpar.2008.10.100] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 10/17/2008] [Accepted: 10/20/2008] [Indexed: 10/21/2022]
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44
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Egan CE, Sukhumavasi W, Butcher BA, Denkers EY. Functional aspects of Toll-like receptor/MyD88 signalling during protozoan infection: focus on Toxoplasma gondii. Clin Exp Immunol 2009; 156:17-24. [PMID: 19161444 DOI: 10.1111/j.1365-2249.2009.03876.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Toll-like receptor (TLR)/MyD88 signalling has emerged as a major pathway of pathogen recognition in the innate immune system. Here, we review recent data that begin to show how this pathway controls the immune response to protozoan infection, with particular emphasis on the opportunistic pathogen Toxoplasma gondii. The various ways that the parasite activates and suppresses TLR/MyD88 signalling defines several key principals that illuminate the complexities of the host-pathogen interaction. We also speculate how TLR/MyD88 signalling might be exploited to provide protection against Toxoplasma, as well as other protozoa and infection in general.
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Affiliation(s)
- C E Egan
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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45
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Chapter 9 GPIs of Apicomplexan Protozoa. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s1874-6047(09)26009-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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46
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BANNAI H, NISHIKAWA Y, IBRAHIM HM, YAMADA K, KAWASE O, WATANABE JI, SUGIMOTO C, XUAN X. Overproduction of the Pro-Apoptotic Molecule, Programmed Cell Death 5, in Toxoplasma gondii Leads to Increased Apoptosis of Host Macrophages. J Vet Med Sci 2009; 71:1183-9. [DOI: 10.1292/jvms.71.1183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Hiroshi BANNAI
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine
| | - Yoshifumi NISHIKAWA
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine
| | - Hany Mohamed IBRAHIM
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine
| | - Kyoko YAMADA
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine
| | - Osamu KAWASE
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine
| | | | | | - Xuenan XUAN
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine
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47
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Abstract
Defending self against nonself is a major problem in a world in which individuals are under constant pressure from parasites that gain fitness benefits at a cost to their host. Defences that have evolved are diverse, and range from behavioural adaptations to physiochemical barriers. The immune defence is a final line of protection and is therefore of great importance. Given this importance, variability in immune defence would seem counterintuitive, yet that is what is observed. Ecological immunology attempts to explain this variation by invoking costs and trade-offs, and in turn proposing that the optimal immune defence will vary over environments. Studies in this field have been highly successful in establishing an evolutionary ecology framework around immunology. However, in order enrich our understanding of this area, it is perhaps time to broaden the focus to include parasites as more than simply elicitors of immune responses. In essence, to view immunity as produced by the host, the environment, and the active involvement of parasites.
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Affiliation(s)
- Ben M Sadd
- Institute for Integrative Biology (IBZ), Experimental Ecology ETH Zentrum, CHN, Zurich, Switzerland
| | - Paul Schmid-Hempel
- Institute for Integrative Biology (IBZ), Experimental Ecology ETH Zentrum, CHN, Zurich, Switzerland
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48
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Maubon D, Ajzenberg D, Brenier-Pinchart MP, Dardé ML, Pelloux H. What are the respective host and parasite contributions to toxoplasmosis? Trends Parasitol 2008; 24:299-303. [PMID: 18514029 DOI: 10.1016/j.pt.2008.03.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 03/04/2008] [Accepted: 03/15/2008] [Indexed: 12/31/2022]
Abstract
The toxoplasmosis pathogenesis mechanism is complex because parasite and host specificities are interrelated. Advances in fundamental research (including strain genotyping, analyzing the progeny from crosses of different strains and exploring the implication of epigenetic effects on the parasite) have contributed greatly to our current knowledge of this mechanism. At the same time new data on the clinical characteristics of the disease have come to light. For example, highly virulent strains have been isolated recently in immunocompetent patients, and some studies suggest that toxoplasmosis also might be implicated in brain disorders. These recent tools and discoveries are likely to cast new light on the pathogenicity of Toxoplasma parasites and provide the key to understanding this unique form of parasitism.
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Affiliation(s)
- Danièle Maubon
- Laboratoire Adaptation et Pathogénie des Microorganismes, UMR 5163 CNRS-Université Joseph Fourier, Institut J. Roget, BP 170, 38042 Grenoble Cedex 9, France.
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49
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Sheets SM, Robles-Price AG, McKenzie RME, Casiano CA, Fletcher HM. Gingipain-dependent interactions with the host are important for survival of Porphyromonas gingivalis. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2008; 13:3215-38. [PMID: 18508429 PMCID: PMC3403687 DOI: 10.2741/2922] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Porphyromonas gingivalis, a major periodontal pathogen, must acquire nutrients from host derived substrates, overcome oxidative stress and subvert the immune system. These activities can be coordinated via the gingipains which represent the most significant virulence factor produced by this organism. In the context of our contribution to this field, we will review the current understanding of gingipain biogenesis, glycosylation, and regulation, as well as discuss their role in oxidative stress resistance and apoptosis. We can postulate a model, in which gingipains may be part of the mechanism for P. gingivalis virulence.
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Affiliation(s)
- Shaun M. Sheets
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Antonette G. Robles-Price
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Rachelle M. E. McKenzie
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Carlos A. Casiano
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
- The Center for Health Disparities and Molecular Medicine, Loma Linda University, Loma Linda, California
| | - Hansel M. Fletcher
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
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50
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Kelly DM, ten Bokum AMC, O'Leary SM, O'Sullivan MP, Keane J. Bystander macrophage apoptosis after Mycobacterium tuberculosis H37Ra infection. Infect Immun 2008; 76:351-60. [PMID: 17954721 PMCID: PMC2223650 DOI: 10.1128/iai.00614-07] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 06/19/2007] [Accepted: 10/10/2007] [Indexed: 01/22/2023] Open
Abstract
Human macrophages infected with Mycobacterium tuberculosis may undergo apoptosis. Macrophage apoptosis contributes to the innate immune response against M. tuberculosis by containing and limiting the growth of mycobacteria and also by depriving the bacillus of its niche cell. Apoptosis of infected macrophages is well documented; however, bystander apoptosis of uninfected macrophages has not been described in the setting of M. tuberculosis. We observed that uninfected human macrophages underwent significant bystander apoptosis 48 and 96 h after they came into contact with macrophages infected with avirulent M. tuberculosis. The bystander apoptosis was significantly greater than the background apoptosis observed in uninfected control cells cultured for the same length of time. There was no evidence of the involvement of tumor necrosis factor alpha, Fas, tumor necrosis factor-related apoptosis-inducing ligand, transforming growth factor beta, Toll-like receptor 2, or MyD88 in contact-mediated bystander apoptosis. This newly described phenomenon may further limit the spread of M. tuberculosis by eliminating the niche cells on which the bacillus relies.
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Affiliation(s)
- Deirdre M Kelly
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College Dublin, and St. James's Hospital, Dublin, Ireland
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