1
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Cordonnier C, Mandalasi M, Gigley J, Wohlfert EA, West CM, Blader IJ. The Toxoplasma oxygen-sensing protein, TgPhyA, is required for resistance to interferon gamma-mediated nutritional immunity in mice. PLoS Biol 2024; 22:e3002690. [PMID: 38857298 PMCID: PMC11192375 DOI: 10.1371/journal.pbio.3002690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/21/2024] [Accepted: 05/23/2024] [Indexed: 06/12/2024] Open
Abstract
As Toxoplasma gondii disseminates through its host, the parasite must sense and adapt to its environment and scavenge nutrients. Oxygen (O2) is one such environmental factor and cytoplasmic prolyl 4-hydroxylases (PHDs) are evolutionarily conserved O2 cellular sensing proteins that regulate responses to changes in O2 availability. Toxoplasma expresses 2 PHDs. One of them, TgPHYa hydroxylates SKP1, a subunit of the SCF-E3 ubiquitin ligase complex. In vitro, TgPHYa is important for growth at low O2 levels. However, studies have yet to examine the role that TgPHYa or any other pathogen-encoded PHD plays in virulence and disease. Using a type II ME49 Toxoplasma TgPHYa knockout, we report that TgPHYa is important for Toxoplasma virulence and brain cyst formation in mice. We further find that while TgPHYa mutant parasites can establish an infection in the gut, they are unable to efficiently disseminate to peripheral tissues because the mutant parasites are unable to survive within recruited immune cells. Since this phenotype was abrogated in IFNγ knockout mice, we studied how TgPHYa mediates survival in IFNγ-treated cells. We find that TgPHYa is not required for release of parasite-encoded effectors into host cells that neutralize anti-parasitic processes induced by IFNγ. In contrast, we find that TgPHYa is required for the parasite to scavenge tryptophan, which is an amino acid whose levels are decreased after IFNγ up-regulates the tryptophan-catabolizing enzyme, indoleamine dioxygenase (IDO). We further find, relative to wild-type mice, that IDO knockout mice display increased morbidity when infected with TgPHYa knockout parasites. Together, these data identify the first parasite mechanism for evading IFNγ-induced nutritional immunity and highlight a novel role that oxygen-sensing proteins play in pathogen growth and virulence.
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Affiliation(s)
- Charlotte Cordonnier
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Msano Mandalasi
- Department of Biochemistry & Molecular Biology, Center for Tropical & Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Jason Gigley
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, United States of America
| | - Elizabeth A. Wohlfert
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Christopher M. West
- Department of Biochemistry & Molecular Biology, Center for Tropical & Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Ira J. Blader
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
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2
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Lüder CGK. IFNs in host defence and parasite immune evasion during Toxoplasma gondii infections. Front Immunol 2024; 15:1356216. [PMID: 38384452 PMCID: PMC10879624 DOI: 10.3389/fimmu.2024.1356216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 01/23/2024] [Indexed: 02/23/2024] Open
Abstract
Interferons (IFNs) are a family of cytokines with diverse functions in host resistance to pathogens and in immune regulation. Type II IFN, i.e. IFN-γ, is widely recognized as a major mediator of resistance to intracellular pathogens, including the protozoan Toxoplasma gondii. More recently, IFN-α/β, i.e. type I IFNs, and IFN-λ (type III IFN) have been identified to also play important roles during T. gondii infections. This parasite is a widespread pathogen of humans and animals, and it is a model organism to study cell-mediated immune responses to intracellular infection. Its success depends, among other factors, on the ability to counteract the IFN system, both at the level of IFN-mediated gene expression and at the level of IFN-regulated effector molecules. Here, I review recent advances in our understanding of the molecular mechanisms underlying IFN-mediated host resistance and immune regulation during T. gondii infections. I also discuss those mechanisms that T. gondii has evolved to efficiently evade IFN-mediated immunity. Knowledge of these fascinating host-parasite interactions and their underlying signalling machineries is crucial for a deeper understanding of the pathogenesis of toxoplasmosis, and it might also identify potential targets of parasite-directed or host-directed supportive therapies to combat the parasite more effectively.
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Affiliation(s)
- Carsten G. K. Lüder
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
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3
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Henry B, Sibley LD, Rosenberg A. A Combination of Four Nuclear Targeted Effectors Protects Toxoplasma Against Interferon Gamma Driven Human Host Cell Death During Acute Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.24.573224. [PMID: 38234811 PMCID: PMC10793417 DOI: 10.1101/2023.12.24.573224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
In both mice and humans, Type II interferon-gamma (IFNγ) is crucial for regulation of Toxoplasma gondii (T. gondii) infection, during acute or chronic phases. To thwart this defense, T. gondii secretes protein effectors hindering the hosťs immune response. For example, T. gondii relies on the MYR translocon complex to deploy soluble dense granule effectors (GRAs) into the host cell cytosol or nucleus. Recent genome-wide loss-of-function screens in IFNγ-primed primary human fibroblasts identified MYR translocon components as crucial for parasite resistance against IFNγ driven vacuole clearance. However, these screens did not pinpoint specific MYR-dependent GRA proteins responsible for IFNγ signaling blockade, suggesting potential functional redundancy. Our study reveals that T. gondii depends on the MYR translocon complex to prevent host cell death and parasite premature egress in human cells stimulated with IFNγ postinfection, a unique phenotype observed in various human cell lines but not in murine cells. Intriguingly, inhibiting parasite egress did not prevent host cell death, indicating this mechanism is distinct from those described previously. Genome-wide loss-of-function screens uncovered TgIST, GRA16, GRA24, and GRA28 as effectors necessary for a complete block of IFNγ response. GRA24 and GRA28 directly influenced IFNγ driven transcription, GRA24's action depended on its interaction with p38 MAPK, while GRA28 disrupted histone acetyltransferase activity of CBP/p300. Given the intricate nature of the immune response to T. gondii, it appears that the parasite has evolved equally elaborate mechanisms to subvert IFNγ signaling, extending beyond direct interference with the JAK/STAT1 pathway, to encompass other signaling pathways as well.
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Affiliation(s)
- Brittany Henry
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA
| | - Alex Rosenberg
- Department of Infectious Diseases, Center for Tropical and Emerging Infectious Diseases, University of Georgia, Athens, Georgia, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, USA
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4
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Lockyer EJ, Torelli F, Butterworth S, Song OR, Howell S, Weston A, East P, Treeck M. A heterotrimeric complex of Toxoplasma proteins promotes parasite survival in interferon gamma-stimulated human cells. PLoS Biol 2023; 21:e3002202. [PMID: 37459303 PMCID: PMC10373997 DOI: 10.1371/journal.pbio.3002202] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/27/2023] [Accepted: 06/16/2023] [Indexed: 07/28/2023] Open
Abstract
Toxoplasma gondii secretes protein effectors to subvert the human immune system sufficiently to establish a chronic infection. Relative to murine infections, little is known about which parasite effectors disarm human immune responses. Here, we used targeted CRISPR screening to identify secreted protein effectors required for parasite survival in IFNγ-activated human cells. Independent screens were carried out using 2 Toxoplasma strains that differ in virulence in mice, leading to the identification of effectors required for survival in IFNγ-activated human cells. We identify the secreted protein GRA57 and 2 other proteins, GRA70 and GRA71, that together form a complex which enhances the ability of parasites to persist in IFNγ-activated human foreskin fibroblasts (HFFs). Components of the protein machinery required for export of Toxoplasma proteins into the host cell were also found to be important for parasite resistance to IFNγ in human cells, but these export components function independently of the identified protein complex. Host-mediated ubiquitination of the parasite vacuole has previously been associated with increased parasite clearance from human cells, but we find that vacuoles from GRA57, GRA70, and GRA71 knockout strains are surprisingly less ubiquitinated by the host cell. We hypothesise that this is likely a secondary consequence of deletion of the complex, unlinked to the IFNγ resistance mediated by these effectors.
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Affiliation(s)
- Eloise J Lockyer
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Francesca Torelli
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Simon Butterworth
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ok-Ryul Song
- High-Throughput Screening Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Steven Howell
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Anne Weston
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Philip East
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick Institute, London, United Kingdom
- Cell Biology of Host-Pathogen Interaction Laboratory, Instituto Gulbenkian Ciência, Oeiras, Portugal
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5
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Diao Y, Yao Y, El-Ashram S, Bian M. Egress Regulatory Factors: How Toxoplasma Exits from Infected Cells? Pathogens 2023; 12:pathogens12050679. [PMID: 37242349 DOI: 10.3390/pathogens12050679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Toxoplasma gondii is an obligatory intracellular protozoan in the family Apicomplexa. It infects almost one-third of the world's population and causes toxoplasmosis, a prevalent disease. The parasite's egress from infected cells is a key step in the pathology caused by T. gondii. Moreover, T. gondii's continuous infection relies heavily on its capacity to migrate from one cell to another. Many pathways are involved in T. gondii egress. Individual routes may be modified to respond to various environmental stimuli, and many paths can converge. Regardless of the stimuli, the relevance of Ca2+ as a second messenger in transducing these signals, and the convergence of various signaling pathways in the control of motility and, ultimately, egress, is well recognized. This review attempts to outline intra- and extra-parasitic regulators that mediate T. gondii egress, and provides insight into potential clinical interventions and research.
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Affiliation(s)
- Yujie Diao
- Department of Blood Transfusion, The First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
| | - Yong Yao
- College of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Saeed El-Ashram
- College of Life Science and Engineering, Foshan University, 18 Jiangwan Street, Foshan 528231, China
- Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
| | - Maohong Bian
- Department of Blood Transfusion, The First Affiliated Hospital of Anhui Medical University, Hefei 230032, China
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6
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CRISPR Screens Identify Toxoplasma Genes That Determine Parasite Fitness in Interferon Gamma-Stimulated Human Cells. mBio 2023; 14:e0006023. [PMID: 36916910 PMCID: PMC10128063 DOI: 10.1128/mbio.00060-23] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Toxoplasma virulence depends on its ability to evade or survive the toxoplasmacidal mechanisms induced by interferon gamma (IFNγ). While many Toxoplasma genes involved in the evasion of the murine IFNγ response have been identified, genes required to survive the human IFNγ response are largely unknown. In this study, we used a genome-wide loss-of-function screen to identify Toxoplasma genes important for parasite fitness in IFNγ-stimulated primary human fibroblasts. We generated gene knockouts for the top six hits from the screen and confirmed their importance for parasite growth in IFNγ-stimulated human fibroblasts. Of these six genes, three have homology to GRA32, localize to dense granules, and coimmunoprecipitate with each other and GRA32, suggesting they might form a complex. Deletion of individual members of this complex leads to early parasite egress in IFNγ-stimulated cells. Thus, prevention of early egress is an important Toxoplasma fitness determinant in IFNγ-stimulated human cells. IMPORTANCE Toxoplasma infection causes serious complications in immunocompromised individuals and in the developing fetus. During infection, certain immune cells release a protein called interferon gamma that activates cells to destroy the parasite or inhibit its growth. While most Toxoplasma parasites are cleared by this immune response, some can survive by blocking or evading the IFNγ-induced restrictive environment. Many Toxoplasma genes that determine parasite survival in IFNγ-activated murine cells are known but parasite genes conferring fitness in IFNγ-activated human cells are largely unknown. Using a Toxoplasma adapted genome-wide loss-of-function screen, we identified many Toxoplasma genes that determine parasite fitness in IFNγ-activated human cells. The gene products of four top hits play a role in preventing early parasite egress in IFNγ-stimulated human cells. Understanding how IFNγ-stimulated human cells inhibit Toxoplasma growth and how Toxoplasma counteracts this, could lead to the development of novel therapeutics.
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7
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He J, Hou Y, Lu F. Blockage of Galectin-Receptor Interactions Attenuates Mouse Hepatic Pathology Induced by Toxoplasma gondii Infection. Front Immunol 2022; 13:896744. [PMID: 35911679 PMCID: PMC9327616 DOI: 10.3389/fimmu.2022.896744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022] Open
Abstract
Toxoplasma gondii (T. gondii), one of the most important Apicomplexan protozoa, causes toxoplasmosis in human throughout the world. Galectin (Gal)-9 triggers a series of immune events via binding to its receptors, including T cell immunoglobulin and mucin-containing molecule 3, CD137, CD44, and protein disulfide isomerase. To examine the regulatory role of galectin-receptor interactions in anti-toxoplasmic activities, C57BL/6 mice were infected with T. gondii RH strain and intraperitoneally injected with alpha (α)-lactose to block the interactions of galectins and their receptors. Heatmaps showed upregulated values for Gal-9 and CD137 in the livers of T. gondii-infected mice and T. gondii-infected mice treated with α-lactose. Compared with T. gondii-infected mice, T. gondii-infected mice treated with α-lactose showed significantly increased survival rate, decreased tissue parasite burden, attenuated liver histopathology, increased mRNA expression levels of CD137, IFNγ, IL-4, and IL-10 in the liver, and increased Gal-9 mRNA expression level in the spleen. Correlation analysis showed that significant positive correlations existed between the mRNA expression levels of Gal-9 and CD137, Gal-9 and IFNγ, as well as between CD137 and IFNγ in the liver and spleen of T. gondii-infected mice; between CD137 and IFNγ in the liver of T. gondii-infected mice treated with α-lactose. In addition, blockage of galectin-receptor interactions showed enhanced M2 macrophage polarization in the liver of T. gondii-infected mice. Our data indicate that Gal-9-CD137 interaction may play an important role in T. gondii proliferation and liver inflammation in mice during acute T. gondii infection, through regulating T cell and macrophage immune responses.
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Affiliation(s)
- Jian He
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yongheng Hou
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Fangli Lu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Clinical Laboratory, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
- Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Fangli Lu,
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8
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Skariah S, Sultan AA, Mordue DG. IFN-induced cell-autonomous immune mechanisms in the control of intracellular protozoa. Parasitol Res 2022; 121:1559-1571. [DOI: 10.1007/s00436-022-07514-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 04/04/2022] [Indexed: 10/18/2022]
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9
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Simpson DS, Pang J, Weir A, Kong IY, Fritsch M, Rashidi M, Cooney JP, Davidson KC, Speir M, Djajawi TM, Hughes S, Mackiewicz L, Dayton M, Anderton H, Doerflinger M, Deng Y, Huang AS, Conos SA, Tye H, Chow SH, Rahman A, Norton RS, Naderer T, Nicholson SE, Burgio G, Man SM, Groom JR, Herold MJ, Hawkins ED, Lawlor KE, Strasser A, Silke J, Pellegrini M, Kashkar H, Feltham R, Vince JE. Interferon-γ primes macrophages for pathogen ligand-induced killing via a caspase-8 and mitochondrial cell death pathway. Immunity 2022; 55:423-441.e9. [PMID: 35139355 PMCID: PMC8822620 DOI: 10.1016/j.immuni.2022.01.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/19/2021] [Accepted: 01/05/2022] [Indexed: 12/12/2022]
Abstract
Cell death plays an important role during pathogen infections. Here, we report that interferon-γ (IFNγ) sensitizes macrophages to Toll-like receptor (TLR)-induced death that requires macrophage-intrinsic death ligands and caspase-8 enzymatic activity, which trigger the mitochondrial apoptotic effectors, BAX and BAK. The pro-apoptotic caspase-8 substrate BID was dispensable for BAX and BAK activation. Instead, caspase-8 reduced pro-survival BCL-2 transcription and increased inducible nitric oxide synthase (iNOS), thus facilitating BAX and BAK signaling. IFNγ-primed, TLR-induced macrophage killing required iNOS, which licensed apoptotic caspase-8 activity and reduced the BAX and BAK inhibitors, A1 and MCL-1. The deletion of iNOS or caspase-8 limited SARS-CoV-2-induced disease in mice, while caspase-8 caused lethality independent of iNOS in a model of hemophagocytic lymphohistiocytosis. These findings reveal that iNOS selectively licenses programmed cell death, which may explain how nitric oxide impacts disease severity in SARS-CoV-2 infection and other iNOS-associated inflammatory conditions.
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Affiliation(s)
- Daniel S. Simpson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jiyi Pang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia,College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Ashley Weir
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Isabella Y. Kong
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Melanie Fritsch
- Institute for Molecular Immunology, Centre for Molecular Medicine Cologne and Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases, University of Cologne, Cologne, 50931, Germany
| | - Maryam Rashidi
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - James P. Cooney
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kathryn C. Davidson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Mary Speir
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia
| | - Tirta M. Djajawi
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia
| | - Sebastian Hughes
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Liana Mackiewicz
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Merle Dayton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Holly Anderton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Marcel Doerflinger
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Yexuan Deng
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Allan Shuai Huang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Stephanie A. Conos
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia
| | - Hazel Tye
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia
| | - Seong H. Chow
- The Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Arfatur Rahman
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia,ARC Centre for Fragment-Based Design, Monash University, Parkville, VIC, 3052, Australia
| | - Thomas Naderer
- The Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Sandra E. Nicholson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Gaetan Burgio
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, 2601, Australia
| | - Si Ming Man
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, 2601, Australia
| | - Joanna R. Groom
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Marco J. Herold
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Edwin D. Hawkins
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kate E. Lawlor
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - John Silke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Marc Pellegrini
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Hamid Kashkar
- Institute for Molecular Immunology, Centre for Molecular Medicine Cologne and Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases, University of Cologne, Cologne, 50931, Germany
| | - Rebecca Feltham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia; The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia.
| | - James E. Vince
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia,The Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia,Corresponding author
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10
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Chen M, Yao L, Zhou L, Yang P, Zou W, Xu L, Li S, Peng H. Toxoplasma gondii
ROP18
I
inhibits host innate immunity through cGAS‐STING signaling. FASEB J 2022; 36:e22171. [DOI: 10.1096/fj.202101347r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/19/2021] [Accepted: 01/10/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Min Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Lijie Yao
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Lijuan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Pei Yang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Weihao Zou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Liqing Xu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Shengmin Li
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health Southern Medical University Guangzhou P. R. China
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11
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Rinkenberger N, Abrams ME, Matta SK, Schoggins JW, Alto NM, Sibley LD. Over-expression screen of interferon-stimulated genes identifies RARRES3 as a restrictor of Toxoplasma gondii infection. eLife 2021; 10:73137. [PMID: 34871166 PMCID: PMC8789288 DOI: 10.7554/elife.73137] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/05/2021] [Indexed: 12/26/2022] Open
Abstract
Toxoplasma gondii is an important human pathogen infecting an estimated one in three people worldwide. The cytokine interferon gamma (IFNγ) is induced during infection and is critical for restricting T. gondii growth in human cells. Growth restriction is presumed to be due to the induction of interferon-stimulated genes (ISGs) that are upregulated to protect the host from infection. Although there are hundreds of ISGs induced by IFNγ, their individual roles in restricting parasite growth in human cells remain somewhat elusive. To address this deficiency, we screened a library of 414 IFNγ induced ISGs to identify factors that impact T. gondii infection in human cells. In addition to IRF1, which likely acts through the induction of numerous downstream genes, we identified RARRES3 as a single factor that restricts T. gondii infection by inducing premature egress of the parasite in multiple human cell lines. Overall, while we successfully identified a novel IFNγ induced factor restricting T. gondii infection, the limited number of ISGs capable of restricting T. gondii infection when individually expressed suggests that IFNγ-mediated immunity to T. gondii infection is a complex, multifactorial process.
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Affiliation(s)
- Nicholas Rinkenberger
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
| | - Michael E Abrams
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Sumit K Matta
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
| | - John W Schoggins
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Neal M Alto
- Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
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12
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Nemati S, Pazoki H, Mohammad Rahimi H, Asadzadeh Aghdaei H, Shahrokh S, Baghaei K, Mirjalali H, Zali MR. Toxoplasma gondii profilin and tachyzoites RH strain may manipulate autophagy via downregulating Atg5 and Atg12 and upregulating Atg7. Mol Biol Rep 2021; 48:7041-7047. [PMID: 34453672 DOI: 10.1007/s11033-021-06667-5] [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: 05/29/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Autophagy process is an important defense mechanism against intracellular infection. This process plays a critical role in limiting the development of Toxoplasma gondii. This study aimed to investigate the effects of T. gondii profilin and tachyzoites on the expression of autophagy genes. METHODS AND RESULTS PMA-activated THP-1 cell line was incubated with T. gondii profilin and tachyzoites for 6 h. After RNA extraction and cDNA synthesis, the expression of Atg5, Atg7, Atg12, and LC3b was evaluated using real-time PCR. The results revealed statistically significant downregulation of Atg5 for 1.43 (P-value = 0.0062) and 4.15 (P-value = 0.0178) folds after treatment with T. gondii profilin and tachyzoites, respectively. Similar to Atg 5, Atg 12 revealed a statistically significant downregulation for profilin (1.41 fold; P-value = 0.0047) and T. gondii tachyzoites (3.25 fold; P-value = 0.011). The expression of Atg7 elevated in both T. gondii profilin (2.083 fold; P-value = 0.0087) and tachyzoites (1.64 fold; P-value = 0.206). T. gondii profilin and tachyzoites downregulated (1.04 fold; P-value = 0.0028) and upregulated (twofold; P-value = 0.091) the expression of LC3b, respectively. CONCLUSIONS Our findings suggest that T. gondii and profilin may manipulate autophagy via preventing from the formation of Atg5-12-16L complex to facilitate replication of T. gondii and development of toxoplasmosis.
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Affiliation(s)
- Sara Nemati
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Pazoki
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hanieh Mohammad Rahimi
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Asadzadeh Aghdaei
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shabnam Shahrokh
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kaveh Baghaei
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Mirjalali
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad Reza Zali
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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13
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3D holotomographic monitoring of Ca ++ dynamics during ionophore-induced Neospora caninum tachyzoite egress from primary bovine host endothelial cells. Parasitol Res 2021; 121:1169-1177. [PMID: 34386856 PMCID: PMC8986705 DOI: 10.1007/s00436-021-07260-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/18/2021] [Indexed: 12/04/2022]
Abstract
Neospora caninum represents an obligate intracellular parasite that belongs to the phylum Apicomplexa and is a major abortive agent in bovines. During merogony, N. caninum tachyzoites invade and proliferate in host cells in vivo, including endothelial cells of lymphatic and blood vessels. The egress at the end of the lytic cycle is tightly regulated in apicomplexans. Evidence in Toxoplasma gondii shows that Ca++ signalling governs tachyzoite egress. Much less is known on egress mechanisms of N. caninum. Here, we show, using 3D live cell holotomographic microscopy in fluo-4 AM-loaded N. caninum-infected BUVEC, that treatments with the calcium ionophore A23187 at 24- and 42-h post-infection (h p. i.) induced a fast and sustained increase in Ca++ signals in parallel to tachyzoite egress. A23187 treatments exclusively triggered tachyzoite release at 42-h p. i. but failed to do so at 24-h p. i. indicating a role for meront maturation in calcium-induced tachyzoite egress. Overall, we show that live cell 3D holotomographic analysis in combination with epifluorescence is a suitable tool to study calcium dynamics related to coccidian egress or other important cell functions.
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14
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Rosenberg A, Sibley LD. Toxoplasma gondii secreted effectors co-opt host repressor complexes to inhibit necroptosis. Cell Host Microbe 2021; 29:1186-1198.e8. [PMID: 34043960 PMCID: PMC8711274 DOI: 10.1016/j.chom.2021.04.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 02/22/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023]
Abstract
Toxoplasma gondii translocates effector proteins into its host cell to subvert various host pathways. T. gondii effector TgIST blocks the transcription of interferon-stimulated genes to reduce immune defense. Interferons upregulate numerous genes, including protein kinase R (PKR), which induce necrosome formation to activate mixed-lineage-kinase-domain-like (MLKL) pseudokinase and induce necroptosis. Whether these interferon functions are targeted by Toxoplasma is unknown. Here, we examine secreted effectors that localize to the host cell nucleus and find that the chronic bradyzoite stage secretes effector TgNSM that targets the NCoR/SMRT complex, a repressor for various transcription factors, to inhibit interferon-regulated genes involved in cell death. TgNSM acts with TgIST to block IFN-driven expression of PKR and MLKL, thus preventing host cell necroptotic death and protecting the parasite's intracellular niche. The mechanism of action of TgNSM uncovers a role of NCoR/SMRT in necroptosis, assuring survival of intracellular cysts and chronic infection.
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Affiliation(s)
- Alex Rosenberg
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63130, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63130, USA.
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15
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Subauste CS. Recent Advances in the Roles of Autophagy and Autophagy Proteins in Host Cells During Toxoplasma gondii Infection and Potential Therapeutic Implications. Front Cell Dev Biol 2021; 9:673813. [PMID: 34179003 PMCID: PMC8220159 DOI: 10.3389/fcell.2021.673813] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/30/2021] [Indexed: 11/29/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan that can cause encephalitis and retinitis in humans. The success of T. gondii as a pathogen depends in part on its ability to form an intracellular niche (parasitophorous vacuole) that allows protection from lysosomal degradation and parasite replication. The parasitophorous vacuole can be targeted by autophagy or by autophagosome-independent processes triggered by autophagy proteins. However, T. gondii has developed many strategies to preserve the integrity of the parasitophorous vacuole. Here, we review the interaction between T. gondii, autophagy, and autophagy proteins and expand on recent advances in the field, including the importance of autophagy in the regulation of invasion of the brain and retina by the parasite. We discuss studies that have begun to explore the potential therapeutic applications of the knowledge gained thus far.
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Affiliation(s)
- Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, United States.,Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
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16
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Ihara F, Nishikawa Y. Toxoplasma gondii manipulates host cell signaling pathways via its secreted effector molecules. Parasitol Int 2021; 83:102368. [PMID: 33905814 DOI: 10.1016/j.parint.2021.102368] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 03/13/2021] [Accepted: 04/07/2021] [Indexed: 01/07/2023]
Abstract
The obligate intracellular parasite Toxoplasma gondii secretes a vast variety of effector molecules from organelles known as rhoptries (ROPs) and dense granules (GRAs). ROP proteins are released into the cytosol of the host cell where they are directed to the cell nucleus or to the parasitophorous vacuole (PV) membrane. ROPs secrete proteins that enable host cell penetration and vacuole formation by the parasites, as well as hijacking host-immune responses. After invading host cells, T. gondii multiplies within a PV that is maintained by the parasite proteins secreted from GRAs. Most GRA proteins remain within the PV, but some are known to access the host cytosol across the PV membrane, and a few are able to traffic into the host-cell nucleus. These effectors bind to host cell proteins and affect host cell signaling pathways to favor the parasite. Studies on host-pathogen interactions have identified many infection-altered host signal transductions. Notably, the relationship between individual parasite effector molecules and the specific targeting of host-signaling pathways is being elucidated through the advent of forward and reverse genetic strategies. Understanding the complex nature of the host-pathogen interactions underlying how the host-signaling pathway is manipulated by parasite effectors may lead to new molecular biological knowledge and novel therapeutic methods for toxoplasmosis. In this review, we discuss how T. gondii modulates cell signaling pathways in the host to favor its survival.
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Affiliation(s)
- Fumiaki Ihara
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
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17
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Yan X, Han W, Liu X, Suo X. Exogenous nitric oxide stimulates early egress of Eimeria tenella sporozoites from primary chicken kidney cells in vitro. Parasite 2021; 28:11. [PMID: 33576739 PMCID: PMC7880050 DOI: 10.1051/parasite/2021007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/24/2021] [Indexed: 11/21/2022] Open
Abstract
Egress plays a vital role in the life cycle of apicomplexan parasites including Eimeria tenella, which has been attracting attention from various research groups. Many recent studies have focused on early egress induced by immune molecules to develop a new method of apicomplexan parasite elimination. In this study, we investigated whether nitric oxide (NO), an immune molecule produced by different types of cells in response to cytokine stimulation, could induce early egress of eimerian sporozoites in vitro. Eimeria tenella sporozoites were extracted and cultured in primary chicken kidney cells. The number of sporozoites egressed from infected cells was analyzed by flow cytometry after treatment with NO released by sodium nitroferricyanide (II) dihydrate. The results showed that exogenous NO stimulated the rapid egress of E. tenella sporozoites from primary chicken kidney cells before replication of the parasite. We also found that egress was dependent on intra-parasitic calcium ion (Ca2+) levels and no damage occurred to host cells after egress. The virulence of egressed sporozoites was significantly lower than that of fresh sporozoites. The results of this study contribute to a novel field examining the interactions between apicomplexan parasites and their host cells, as well as that of the clearance of intracellular pathogens by the host immune system.
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Affiliation(s)
- Xinlei Yan
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Food Science and Engineering College of Inner Mongolia Agricultural University Hohhot 010018 China
| | - Wenying Han
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Food Science and Engineering College of Inner Mongolia Agricultural University Hohhot 010018 China
| | - Xianyong Liu
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State Key Laboratory of Agrobiotechnology, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University Beijing 100193 China
| | - Xun Suo
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State Key Laboratory of Agrobiotechnology, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University Beijing 100193 China
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18
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Sistemich L, Dimitrov Stanchev L, Kutsch M, Roux A, Günther Pomorski T, Herrmann C. Structural requirements for membrane binding of human guanylate-binding protein 1. FEBS J 2021; 288:4098-4114. [PMID: 33405388 DOI: 10.1111/febs.15703] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/25/2020] [Accepted: 12/29/2020] [Indexed: 12/14/2022]
Abstract
Human guanylate-binding protein 1 (hGBP1) is a key player in innate immunity and fights diverse intracellular microbial pathogens. Its antimicrobial functions depend on hGBP1's GTP binding- and hydrolysis-induced abilities to form large, structured polymers and to attach to lipid membranes. Crucial for both of these biochemical features is the nucleotide-controlled release of the C terminally located farnesyl moiety. Here, we address molecular details of the hGBP1 membrane binding mechanism by employing recombinant, fluorescently labeled hGBP1, and artificial membranes. We demonstrate the importance of the GTPase activity and the resulting structural rearrangement of the hGBP1 molecule, which we term the open state. This open state is supported and stabilized by homodimer contacts involving the middle domain of the protein and is further stabilized by binding to the lipid bilayer surface. We show that on the surface of the lipid bilayer a hGBP1 monolayer is built in a pins in a pincushion-like arrangement with the farnesyl tail integrated in the membrane and the N-terminal GTPase domain facing outwards. We suggest that similar intramolecular contacts between neighboring hGBP1 molecules are responsible for both polymer formation and monolayer formation on lipid membranes. Finally, we show that tethering of large unilamellar vesicles occurs after the vesicle surface is fully covered by the monolayer. Both hGBP1 polymer formation and hGBP1-induced vesicle tethering have implications for understanding the molecular mechanism of combating bacterial pathogens. DATABASES: Structural data are available in RCSB Protein Data Bank under the accession numbers: 6K1Z, 2D4H.
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Affiliation(s)
- Linda Sistemich
- Faculty of Chemistry and Biochemistry, Physical Chemistry I, Ruhr-University Bochum, Bochum, Germany
| | - Lyubomir Dimitrov Stanchev
- Faculty of Chemistry and Biochemistry, Molecular Biochemistry, Ruhr University Bochum, Bochum, Germany.,Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Miriam Kutsch
- Faculty of Chemistry and Biochemistry, Physical Chemistry I, Ruhr-University Bochum, Bochum, Germany.,Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Aurélien Roux
- Biochemistry Department, University of Geneva, Geneva, Switzerland
| | - Thomas Günther Pomorski
- Faculty of Chemistry and Biochemistry, Molecular Biochemistry, Ruhr University Bochum, Bochum, Germany.,Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Christian Herrmann
- Faculty of Chemistry and Biochemistry, Physical Chemistry I, Ruhr-University Bochum, Bochum, Germany
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19
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Uboldi AD, Wilde ML, Bader SM, Tonkin CJ. Environmental sensing and regulation of motility in Toxoplasma. Mol Microbiol 2020; 115:916-929. [PMID: 33278047 DOI: 10.1111/mmi.14661] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 12/28/2022]
Abstract
Toxoplasma and other apicomplexan parasites undergo a unique form of cellular locomotion referred to as "gliding motility." Gliding motility is crucial for parasite survival as it powers tissue dissemination, host cell invasion and egress. Distinct environmental cues lead to activation of gliding motility and have become a prominent focus of recent investigation. Progress has been made toward understanding what environmental cues are sensed and how these signals are transduced in order to regulate the machinery and cellular events powering gliding motility. In this review, we will discuss new findings and integrate these into our current understanding to propose a model of how environmental sensing is achieved to regulate gliding motility in Toxoplasma. Collectively, these findings also have implications for the understanding of gliding motility across Apicomplexa more broadly.
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Affiliation(s)
- Alessandro D Uboldi
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Mary-Louise Wilde
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Stefanie M Bader
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Christopher J Tonkin
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
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20
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Wu M, Cudjoe O, Shen J, Chen Y, Du J. The Host Autophagy During Toxoplasma Infection. Front Microbiol 2020; 11:589604. [PMID: 33193253 PMCID: PMC7642512 DOI: 10.3389/fmicb.2020.589604] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an important homeostatic mechanism, in which lysosomes degrade and recycle cytosolic components. As a key defense mechanism against infections, autophagy is involved in the capture and elimination of intracellular parasites. However, intracellular parasites, such as Toxoplasma gondii, have developed several evasion mechanisms to manipulate the host cell autophagy for their growth and establish a chronic infection. This review provides an insight into the autophagy mechanism used by the host cells in the control of T. gondii and the host exploitation by the parasite. First, we summarize the mechanism of autophagy, xenophagy, and LC3-associated phagocytosis. Then, we illustrate the process of autophagy proteins-mediated T. gondii clearance. Furthermore, we discuss how the parasite blocks and exploits this process for its survival.
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Affiliation(s)
- Minmin Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,The Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China.,The Key Laboratory of Pathogen Biology of Anhui Province, Anhui Medical University, Hefei, China
| | - Obed Cudjoe
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,The Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China.,The Key Laboratory of Pathogen Biology of Anhui Province, Anhui Medical University, Hefei, China
| | - Jilong Shen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,The Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China.,The Key Laboratory of Pathogen Biology of Anhui Province, Anhui Medical University, Hefei, China
| | - Ying Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,The Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China.,The Key Laboratory of Pathogen Biology of Anhui Province, Anhui Medical University, Hefei, China.,School of Nursing, Anhui Medical University, Hefei, China
| | - Jian Du
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,The Key Laboratory of Zoonoses of Anhui, Anhui Medical University, Hefei, China.,The Key Laboratory of Pathogen Biology of Anhui Province, Anhui Medical University, Hefei, China
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21
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Acosta-Dávila A, Acosta-Espinel A, Hernández-de-Los-Ríos A, Gómez-Marín JE. Human peripheral blood mononuclear cells as an ex vivo model to study the host parasite interaction in Toxoplasma gondii. Exp Parasitol 2020; 219:108020. [PMID: 33058858 DOI: 10.1016/j.exppara.2020.108020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii is a parasite that can invade any cell in the human body. Here, we implemented and described an ex vivo model with human peripheral blood mononuclear cells (PBMCs) without using culture supplements/antibiotics and without cryopreserved cells (EXMOWS) to study the interactions between T. gondii and human cells. To establish the EXMOWS, three independent tests were carried out. Firstly, blood samples from 5 individuals were included to assess the viability and adherence of PBMCs in plate culture. In a second trial, blood samples from three seropositive and two seronegative individuals for T. gondii were used to evaluate human PBMCs cells: parasites, multiplicity of infection (MOI) 1:1, 1:3 and 1:5 at different times post infection (1 h, 6 h and 24 h). The possible immunomodulatory effect of the infection for this EXMOWS were evaluated in a third trial where HFF cells were infected with T. gondii and co-cultured with PBMCs obtained from anti-Toxoplasma IgG positive and IgG negative individuals. One hour was enough time for T. gondii infection of human PBMCs and 2 h was the minimum incubation time to guarantee adherence before carrying out any infection assay. A minimum of 1:3 MOI was necessary to guarantee efficient infection in human PBMCs with T. gondii RH-GFP. All protocols, including PBMCs isolation and stimulation, should be conducted the same day. This EXMOWS can be adapted to study the early stages of interaction with other microorganisms of human interest, without need of using cryopreservation and supplements/antibiotics.
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Affiliation(s)
- Alejandro Acosta-Dávila
- Grupo GEPAMOL, Centro de Investigaciones Biomédicas, Facultad de Ciencias de La Salud, Universidad Del Quindio, Colombia
| | - Alejandra Acosta-Espinel
- Grupo GEPAMOL, Centro de Investigaciones Biomédicas, Facultad de Ciencias de La Salud, Universidad Del Quindio, Colombia
| | | | - Jorge Enrique Gómez-Marín
- Grupo GEPAMOL, Centro de Investigaciones Biomédicas, Facultad de Ciencias de La Salud, Universidad Del Quindio, Colombia.
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22
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Mukhopadhyay D, Arranz-Solís D, Saeij JPJ. Influence of the Host and Parasite Strain on the Immune Response During Toxoplasma Infection. Front Cell Infect Microbiol 2020; 10:580425. [PMID: 33178630 PMCID: PMC7593385 DOI: 10.3389/fcimb.2020.580425] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/11/2020] [Indexed: 01/02/2023] Open
Abstract
Toxoplasma gondii is an exceptionally successful parasite that infects a very broad host range, including humans, across the globe. The outcome of infection differs remarkably between hosts, ranging from acute death to sterile infection. These differential disease patterns are strongly influenced by both host- and parasite-specific genetic factors. In this review, we discuss how the clinical outcome of toxoplasmosis varies between hosts and the role of different immune genes and parasite virulence factors, with a special emphasis on Toxoplasma-induced ileitis and encephalitis.
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Affiliation(s)
- Debanjan Mukhopadhyay
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - David Arranz-Solís
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Jeroen P J Saeij
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
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23
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Gossner A, Hassan MA. Transcriptional Analyses Identify Genes That Modulate Bovine Macrophage Response to Toxoplasma Infection and Immune Stimulation. Front Cell Infect Microbiol 2020; 10:437. [PMID: 33014886 PMCID: PMC7508302 DOI: 10.3389/fcimb.2020.00437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/16/2020] [Indexed: 11/26/2022] Open
Abstract
The obligate intracellular parasite, Toxoplasma gondii, is highly prevalent among livestock species. Although cattle are generally resistant to Toxoplasma strains circulating in Europe and North America, the underlying mechanisms are largely unknown. Here, we report that bovine bone marrow-derived macrophage (BMDM) pre-stimulated with interferon gamma (IFNγ) restricts intracellular Toxoplasma growth independently of nitric oxide. While Toxoplasma promoted the expression of genes associated with alternative macrophage activation and lipid metabolism, IFNγ abrogated parasite-induced transcriptional responses and promoted the expression of genes linked to the classical macrophage activation phenotype. Additionally, several chemokines, including CCL22, that are linked to parasite-induced activation of the Wnt/β-catenin signaling were highly expressed in Toxoplasma-exposed naïve BMDMs. A chemical Wnt/β-catenin signaling pathway antagonist (IWR-1-endo) significantly reduced intracellular parasite burden in naïve BMDMs, suggesting that Toxoplasma activates this pathway to evade bovine macrophage anti-parasitic responses. Congruently, intracellular burden of a mutant Toxoplasma strain (RHΔASP5) that does not secrete dense granule proteins into the host cell, which is an essential requirement for parasite-induced activation of the Wnt/β-catenin pathway, was significantly reduced in naïve BMDMs. However, both the Wnt/β-catenin antagonist and RHASPΔ5 did not abolish parasite burden differences in naïve and IFNγ-stimulated BMDMs. Finally, we observed that parasites infecting IFNγ-stimulated BMDMs largely express genes associated with the slow dividing bradyzoite stage. Overall, this study provides novel insights into bovine macrophage transcriptional response to Toxoplasma. It establishes a foundation for a mechanistic analysis IFNγ-induced bovine anti-Toxoplasma responses and the counteracting Toxoplasma survival strategies.
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Affiliation(s)
- Anton Gossner
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Musa A Hassan
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom.,Centre for Tropical Livestock Genetics and Health, The University of Edinburgh, Edinburgh, United Kingdom
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24
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Mukhopadhyay D, Sangaré LO, Braun L, Hakimi MA, Saeij JP. Toxoplasma GRA15 limits parasite growth in IFNγ-activated fibroblasts through TRAF ubiquitin ligases. EMBO J 2020; 39:e103758. [PMID: 32293748 DOI: 10.15252/embj.2019103758] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 01/01/2023] Open
Abstract
The protozoan parasite Toxoplasma gondii lives inside a vacuole in the host cytosol where it is protected from host cytoplasmic innate immune responses. However, IFNγ-dependent cell-autonomous immunity can destroy the vacuole and the parasite inside. Toxoplasma strain differences in susceptibility to human IFNγ exist, but the Toxoplasma effector(s) that determine these differences are unknown. We show that in human primary fibroblasts, the polymorphic Toxoplasma-secreted effector GRA15 mediates the recruitment of ubiquitin ligases, including TRAF2 and TRAF6, to the vacuole membrane, which enhances recruitment of ubiquitin receptors (p62/NDP52) and ubiquitin-like molecules (LC3B, GABARAP). This ultimately leads to lysosomal degradation of the vacuole. In murine fibroblasts, GRA15-mediated TRAF6 recruitment mediates the recruitment of immunity-related GTPases and destruction of the vacuole. Thus, we have identified how the Toxoplasma effector GRA15 affects cell-autonomous immunity in human and murine cells.
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Affiliation(s)
- Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Lamba Omar Sangaré
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Laurence Braun
- Institute for Advanced Biosciences, Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS, UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Mohamed-Ali Hakimi
- Institute for Advanced Biosciences, Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS, UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Jeroen Pj Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
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25
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Sistemich L, Kutsch M, Hämisch B, Zhang P, Shydlovskyi S, Britzen-Laurent N, Stürzl M, Huber K, Herrmann C. The Molecular Mechanism of Polymer Formation of Farnesylated Human Guanylate-binding Protein 1. J Mol Biol 2020; 432:2164-2185. [PMID: 32087202 DOI: 10.1016/j.jmb.2020.02.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/30/2020] [Accepted: 02/09/2020] [Indexed: 02/07/2023]
Abstract
The human guanylate-binding protein 1 (hGBP1) belongs to the dynamin superfamily proteins and represents a key player in the innate immune response. Farnesylation at the C-terminus is required for hGBP1's activity against microbial pathogens, as well as for its antiproliferative and antitumor activity. The farnesylated hGBP1 (hGBP1fn) retains many characteristics of the extensively studied nonfarnesylated protein and gains additional abilities like binding to lipid membranes and formation of hGBP1fn polymers. These polymers are believed to serve as a protein depot, making the enzyme immediately available to fight the invasion of intracellular pathogens. Here we study the molecular mechanism of hGBP1 polymer formation as it is a crucial state of this enzyme, allowing for a rapid response demanded by the biological function. We employ Förster resonance energy transfer in order to trace intra and intermolecular distance changes of protein domains. Light scattering techniques yield deep insights into the changes in size and shape. The GTP hydrolysis driven cycling between a closed, farnesyl moiety hidden state and an opened, farnesyl moiety exposed state represents the first phase, preparing the molecule for polymerization. Within the second phase of polymer growth, opened hGBP1 molecules can be incorporated in the growing polymer where the opened structure is stabilized, similar to a surfactant molecule in a micelle, pointing the farnesyl moieties into the hydrophobic center and positioning the head groups at the periphery of the polymer. We contribute the molecular mechanism of polymer formation, paving the ground for a detailed understanding of hGBP1 function.
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Affiliation(s)
- Linda Sistemich
- Physical Chemistry I, Ruhr-University Bochum, 44780, Bochum, Germany
| | - Miriam Kutsch
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC27710, USA
| | - Benjamin Hämisch
- Chemistry Department, University of Paderborn, 33098, Paderborn, Germany
| | - Ping Zhang
- Physical Chemistry I, Ruhr-University Bochum, 44780, Bochum, Germany
| | | | - Nathalie Britzen-Laurent
- Division of Molecular and Experimental Surgery, Translational Research Center, Department of Surgery, University Medical Center Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Michael Stürzl
- Division of Molecular and Experimental Surgery, Translational Research Center, Department of Surgery, University Medical Center Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Klaus Huber
- Chemistry Department, University of Paderborn, 33098, Paderborn, Germany
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26
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Abstract
The obligate intracellular protozoan parasite Toxoplasma gondii can infect any nucleated cell from a warm-blooded host. However, its interaction with host macrophages plays a critical role in shaping the immune response during infection. Therefore, assessing Toxoplasma-macrophage interactions at a cellular level is important. In this chapter, we describe assays that can be used to characterize Toxoplasma-macrophage interactions. These assays can also be used to evaluate other host-pathogen interactions. We describe multiplex approaches for measuring arginase activity, indoleamine 2,3 dioxygenase activity, cell death, and parasite growth during Toxoplasma-macrophage interactions. These assays can be used to compare how different Toxoplasma strains differ in their interaction with macrophages, and we describe how to properly assess Toxoplasma strain differences in Toxoplasma-macrophage interactions.
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Affiliation(s)
- Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Jeroen P J Saeij
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA.
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27
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Affiliation(s)
- Daniel Fisch
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Barbara Clough
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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28
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Fisch D, Bando H, Clough B, Hornung V, Yamamoto M, Shenoy AR, Frickel E. Human GBP1 is a microbe-specific gatekeeper of macrophage apoptosis and pyroptosis. EMBO J 2019; 38:e100926. [PMID: 31268602 PMCID: PMC6600649 DOI: 10.15252/embj.2018100926] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 12/31/2022] Open
Abstract
The guanylate binding protein (GBP) family of interferon-inducible GTPases promotes antimicrobial immunity and cell death. During bacterial infection, multiple mouse Gbps, human GBP2, and GBP5 support the activation of caspase-1-containing inflammasome complexes or caspase-4 which trigger pyroptosis. Whether GBPs regulate other forms of cell death is not known. The apicomplexan parasite Toxoplasma gondii causes macrophage death through unidentified mechanisms. Here we report that Toxoplasma-induced death of human macrophages requires GBP1 and its ability to target Toxoplasma parasitophorous vacuoles through its GTPase activity and prenylation. Mechanistically, GBP1 promoted Toxoplasma detection by AIM2, which induced GSDMD-independent, ASC-, and caspase-8-dependent apoptosis. Identical molecular determinants targeted GBP1 to Salmonella-containing vacuoles. GBP1 facilitated caspase-4 recruitment to Salmonella leading to its enhanced activation and pyroptosis. Notably, GBP1 could be bypassed by the delivery of Toxoplasma DNA or bacterial LPS into the cytosol, pointing to its role in liberating microbial molecules. GBP1 thus acts as a gatekeeper of cell death pathways, which respond specifically to infecting microbes. Our findings expand the immune roles of human GBPs in regulating not only pyroptosis, but also apoptosis.
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Affiliation(s)
- Daniel Fisch
- Host‐Toxoplasma Interaction LaboratoryThe Francis Crick InstituteLondonUK
- MRC Centre for Molecular Bacteriology & InfectionImperial CollegeLondonUK
| | - Hironori Bando
- Department of ImmunoparasitologyResearch Institute for Microbial DiseasesOsaka UniversityOsakaJapan
- Laboratory of ImmunoparasitologyWPI Immunology Frontier Research CenterOsaka UniversityOsakaJapan
| | - Barbara Clough
- Host‐Toxoplasma Interaction LaboratoryThe Francis Crick InstituteLondonUK
| | - Veit Hornung
- Gene Center and Department of Biochemistry & Center for Integrated Protein Science (CIPSM)Ludwig‐Maximilians‐Universität MünchenMunichGermany
| | - Masahiro Yamamoto
- Department of ImmunoparasitologyResearch Institute for Microbial DiseasesOsaka UniversityOsakaJapan
- Laboratory of ImmunoparasitologyWPI Immunology Frontier Research CenterOsaka UniversityOsakaJapan
| | - Avinash R Shenoy
- MRC Centre for Molecular Bacteriology & InfectionImperial CollegeLondonUK
- The Francis Crick InstituteLondonUK
| | - Eva‐Maria Frickel
- Host‐Toxoplasma Interaction LaboratoryThe Francis Crick InstituteLondonUK
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29
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Subauste CS. Interplay Between Toxoplasma gondii, Autophagy, and Autophagy Proteins. Front Cell Infect Microbiol 2019; 9:139. [PMID: 31119109 PMCID: PMC6506789 DOI: 10.3389/fcimb.2019.00139] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/16/2019] [Indexed: 12/31/2022] Open
Abstract
Survival of Toxoplasma gondii within host cells depends on its ability of reside in a vacuole that avoids lysosomal degradation and enables parasite replication. The interplay between immune-mediated responses that lead to either autophagy-driven lysosomal degradation or disruption of the vacuole and the strategies used by the parasite to avoid these responses are major determinants of the outcome of infection. This article provides an overview of this interplay with an emphasis on autophagy.
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Affiliation(s)
- Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, United States.,Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
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30
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Tretina K, Park ES, Maminska A, MacMicking JD. Interferon-induced guanylate-binding proteins: Guardians of host defense in health and disease. J Exp Med 2019; 216:482-500. [PMID: 30755454 PMCID: PMC6400534 DOI: 10.1084/jem.20182031] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/31/2018] [Accepted: 01/24/2019] [Indexed: 12/15/2022] Open
Abstract
The role of guanylate-binding proteins in host defense. Guanylate-binding proteins (GBPs) have recently emerged as central orchestrators of immunity to infection, inflammation, and neoplastic diseases. Within numerous host cell types, these IFN-induced GTPases assemble into large nanomachines that execute distinct host defense activities against a wide variety of microbial pathogens. In addition, GBPs customize inflammasome responses to bacterial infection and sepsis, where they act as critical rheostats to amplify innate immunity and regulate tissue damage. Similar functions are becoming evident for metabolic inflammatory syndromes and cancer, further underscoring the importance of GBPs within infectious as well as altered homeostatic settings. A better understanding of the basic biology of these IFN-induced GTPases could thus benefit clinical approaches to a wide spectrum of important human diseases.
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Affiliation(s)
- Kyle Tretina
- Howard Hughes Medical Institute, Chevy Chase, MD.,Yale Systems Biology Institute, West Haven, CT.,Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT
| | - Eui-Soon Park
- Howard Hughes Medical Institute, Chevy Chase, MD.,Yale Systems Biology Institute, West Haven, CT.,Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT
| | - Agnieszka Maminska
- Howard Hughes Medical Institute, Chevy Chase, MD.,Yale Systems Biology Institute, West Haven, CT.,Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT
| | - John D MacMicking
- Howard Hughes Medical Institute, Chevy Chase, MD .,Yale Systems Biology Institute, West Haven, CT.,Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT
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31
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Radke JB, Carey KL, Shaw S, Metkar SR, Mulrooney C, Gale JP, Bittker JA, Hilgraf R, Comer E, Schreiber SL, Virgin HW, Perez JR, Sibley LD. High Throughput Screen Identifies Interferon γ-Dependent Inhibitors of Toxoplasma gondii Growth. ACS Infect Dis 2018; 4:1499-1507. [PMID: 30058798 DOI: 10.1021/acsinfecdis.8b00135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite capable of causing severe disease due to congenital infection and in patients with compromised immune systems. Control of infection is dependent on a robust Th1 type immune response including production of interferon gamma (IFN-γ), which is essential for control. IFN-γ activates a variety of antimicrobial mechanisms in host cells, which are then able to control intracellular parasites such as T. gondii. Despite the effectiveness of these pathways in controlling acute infection, the immune system is unable to eradicate chronic infections that can persist for life. Similarly, while antibiotic treatment can control acute infection, it is unable to eliminate chronic infection. To identify compounds that would act synergistically with IFN-γ, we performed a high-throughput screen of diverse small molecule libraries to identify inhibitors of T. gondii. We identified a number of compounds that inhibited parasite growth in vitro at low μM concentrations and that demonstrated enhanced potency in the presence of a low level of IFN-γ. A subset of these compounds act by enhancing the recruitment of light chain 3 (LC3) to the parasite-containing vacuole, suggesting they work by an autophagy-related process, while others were independent of this pathway. The pattern of IFN-γ dependence was shared among the majority of analogs from 6 priority scaffolds, and analysis of structure activity relationships for one such class revealed specific stereochemistry associated with this feature. Identification of these IFN-γ-dependent leads may lead to development of improved therapeutics due to their synergistic interactions with immune responses.
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Affiliation(s)
- Joshua B. Radke
- Department of Molecular Microbiology, Washington University in Saint Louis School of Medicine, 660 S. Euclid Avenue, St. Louis, Missouri 63110, United States
| | - Kimberly L. Carey
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts 02142, United States
| | - Subrata Shaw
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - Shailesh R. Metkar
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - Carol Mulrooney
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - Jennifer P. Gale
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - Joshua A. Bittker
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - Robert Hilgraf
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - Eamon Comer
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, Massachusetts 02142, United States
| | - Stuart L. Schreiber
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, Massachusetts 02142, United States
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Herbert W. Virgin
- Department of Pathology and Immunology, Washington University in Saint Louis School of Medicine, 660 S. Euclid Avenue, St. Louis, Missouri 63110, United States
| | - Jose R. Perez
- Center for the Development of Therapeutics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02142, United States
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University in Saint Louis School of Medicine, 660 S. Euclid Avenue, St. Louis, Missouri 63110, United States
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32
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Inducible Nitric Oxide Synthase Is a Key Host Factor for Toxoplasma GRA15-Dependent Disruption of the Gamma Interferon-Induced Antiparasitic Human Response. mBio 2018; 9:mBio.01738-18. [PMID: 30301855 PMCID: PMC6178625 DOI: 10.1128/mbio.01738-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Although Toxoplasma virulence mechanisms targeting gamma interferon (IFN-γ)-induced cell-autonomous antiparasitic immunity have been extensively characterized in mice, the virulence mechanisms in humans remain uncertain, partly because cell-autonomous immune responses against Toxoplasma differ markedly between mice and humans. Despite the identification of inducible nitric oxide synthase (iNOS) as an anti-Toxoplasma host factor in mice, here we show that iNOS in humans is a pro-Toxoplasma host factor that promotes the growth of the parasite. The GRA15 Toxoplasma effector-dependent disarmament of IFN-γ-induced parasite growth inhibition was evident when parasite-infected monocytes were cocultured with hepatocytes. Interleukin-1β (IL-1β), produced from monocytes in a manner dependent on GRA15 and the host's NLRP3 inflammasome, combined with IFN-γ to strongly stimulate iNOS expression in hepatocytes; this dramatically reduced the levels of indole 2,3-dioxygenase 1 (IDO1), a critically important IFN-γ-inducible anti-Toxoplasma protein in humans, thus allowing parasite growth. Taking the data together, Toxoplasma utilizes human iNOS to antagonize IFN-γ-induced IDO1-mediated cell-autonomous immunity via its GRA15 virulence factor.IMPORTANCE Toxoplasma, an important intracellular parasite of humans and animals, causes life-threatening toxoplasmosis in immunocompromised individuals. Gamma interferon (IFN-γ) is produced in the host to inhibit the proliferation of this parasite and eventually cause its death. Unlike mouse disease models, which involve well-characterized virulence strategies that are used by Toxoplasma to suppress IFN-γ-dependent immunity, the strategies used by Toxoplasma in humans remain unclear. Here, we show that GRA15, a Toxoplasma effector protein, suppresses the IFN-γ-induced indole-2,3-dioxygenase 1-dependent antiparasite immune response in human cells. Because NLRP3-dependent production of IL-1β and nitric oxide (NO) in Toxoplasma-infected human cells is involved in the GRA15-dependent virulence mechanism, blocking NO or IL-1β production in the host could represent a novel therapeutic approach for treating human toxoplasmosis.
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33
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Bando H, Sakaguchi N, Lee Y, Pradipta A, Ma JS, Tanaka S, Lai DH, Liu J, Lun ZR, Nishikawa Y, Sasai M, Yamamoto M. Toxoplasma Effector TgIST Targets Host IDO1 to Antagonize the IFN-γ-Induced Anti-parasitic Response in Human Cells. Front Immunol 2018; 9:2073. [PMID: 30283439 PMCID: PMC6156249 DOI: 10.3389/fimmu.2018.02073] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/21/2018] [Indexed: 12/24/2022] Open
Abstract
Toxoplasma gondii is an important human and animal pathogen that causes life-threatening toxoplasmosis. Interferon-γ (IFN-γ) is critical for anti-T. gondii cell-autonomous immunity in both humans and mice. To proliferate efficiently within the hosts, virulent strains of T. gondii can suppress IFN-γ-dependent immunity. During parasite infection, it is well-characterized that various virulence effectors are secreted to transcriptionally or post-translationally target IFN-γ-inducible GTPases, which are essential for anti-parasite responses in mice. However, the role of IFN-γ-inducible GTPases in anti-T. gondii responses in human cells is controversial since they are non-functional or absent in humans. Instead, IFN-γ-induced tryptophan degradation by indole-2,3-dioxygenase (IDO) is important for the anti-T. gondii human response. To date, the T. gondii virulent mechanism targeting IDO in human cells remains elusive. Here we show that although humans possess two IDO isozymes, IDO1 and IDO2, human cells of various origins require IDO1 but not IDO2 for IFN-γ-induced cell-autonomous immunity to T. gondii. T. gondii secretes an effector TgIST to inhibit IDO1 mRNA expression. Taken together, the data suggests that T. gondii possesses virulence programs operated by TgIST to antagonize IFN-γ-induced IDO1-mediated anti-parasite cell-autonomous immunity in human cells.
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Affiliation(s)
- Hironori Bando
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Naoya Sakaguchi
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Youngae Lee
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Ariel Pradipta
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Ji Su Ma
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Shun Tanaka
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - De-Hua Lai
- State Key Laboratory of Biocontrol, Center for Parasitic Organisms, School of Life Sciences, Guangzhou, China
| | - Jianfa Liu
- Department of Pathology and Pathogenic Biology, Medical College of Ningbo University, Ningbo, China
| | - Zhao-Rong Lun
- State Key Laboratory of Biocontrol, Center for Parasitic Organisms, School of Life Sciences, Guangzhou, China
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
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34
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Evans RJ, Sundaramurthy V, Frickel EM. The Interplay of Host Autophagy and Eukaryotic Pathogens. Front Cell Dev Biol 2018; 6:118. [PMID: 30271774 PMCID: PMC6146372 DOI: 10.3389/fcell.2018.00118] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/29/2018] [Indexed: 12/11/2022] Open
Abstract
For intracellular pathogens, host cells provide a replicative niche, but are also armed with innate defense mechanisms to combat the intruder. Co-evolution of host and pathogens has produced a complex interplay of host-pathogen interactions during infection, with autophagy emerging as a key player in the recent years. Host autophagy as a degradative process is a significant hindrance to intracellular growth of the pathogens, but also can be subverted by the pathogens to provide support such as nutrients. While the role of host cell autophagy in the pathogenesis mechanisms of several bacterial and viral pathogens have been extensively studied, less is known for eukaryotic pathogens. In this review, we focus on the interplay of host autophagy with the eukaryotic pathogens Plasmodium spp, Toxoplasma, Leishmania spp and the fungal pathogens Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans. The differences between these eukaryotic pathogens in terms of the host cell types they infect, infective strategies and the host responses required to defend against them provide an interesting insight into how they respond to and interact with host cell autophagy. Due to the ability to infect multiple host species and cell types during the course of their usually complex lifestyles, autophagy plays divergent roles even for the same pathogen. The scenario is further compounded since many of the eukaryotic pathogens have their own sets of either complete or partial autophagy machinery. Eukaryotic pathogen-autophagy interplay is thus a complex relationship with many novel insights for the basic understanding of autophagy, and potential for clinical relevance.
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Affiliation(s)
- Robert J. Evans
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
| | | | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, United Kingdom
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35
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Caldas LA, de Souza W. A Window to Toxoplasma gondii Egress. Pathogens 2018; 7:pathogens7030069. [PMID: 30110938 PMCID: PMC6161258 DOI: 10.3390/pathogens7030069] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 11/23/2022] Open
Abstract
The Toxoplasma gondii cellular cycle has been widely studied in many lifecycle stages; however, the egress event still is poorly understood even though different types of molecules were shown to be involved. Assuming that there is no purpose or intentionality in biological phenomena, there is no such question as “Why does the parasite leaves the host cell”, but “Under what conditions and how?”. In this review we aimed to summarize current knowledge concerning T. gondii egress physiology (signalling pathways), structures, and route.
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Affiliation(s)
- Lucio Ayres Caldas
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Cidade Universitária, Rio de Janeiro, RJ 21941-902, Brazil.
| | - Wanderley de Souza
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Cidade Universitária, Rio de Janeiro, RJ 21941-902, Brazil.
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Santos JC, Broz P. Sensing of invading pathogens by GBPs: At the crossroads between cell-autonomous and innate immunity. J Leukoc Biol 2018; 104:729-735. [PMID: 30020539 DOI: 10.1002/jlb.4mr0118-038r] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/24/2018] [Accepted: 06/18/2018] [Indexed: 12/19/2022] Open
Abstract
Guanylate-binding proteins (GBPs) are conserved family of IFN-inducible GTPases that play an important role in the host immunity against bacterial, viral, and protozoan pathogens. GBPs protect the host by associating with intracellular microbes, their vacuolar niche or, in the case of viruses, with their replication complex. This association results in a restriction of the respective pathogen, yet the exact molecular mechanisms of the antimicrobial functions of GBPs are still unclear. Recent work has linked the GBPs with the activation of inflammasomes, multi-protein complexes that assemble upon recognition of pathogen- or host-derived signals and that drive the release of cytokines and host cell death. Here, we will focus on the most recent findings that have started to unravel the manifold restriction mechanism controlled by GBPs in mouse and human cells, and that shed light on the molecular cues that control GBP recruitment to bacterial membranes.
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Affiliation(s)
- José Carlos Santos
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Petr Broz
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
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37
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Oliveira T, Costa I, Marinho V, Carvalho V, Uchôa K, Ayres C, Teixeira S, Vasconcelos DFP. Human foreskin fibroblasts: from waste bag to important biomedical applications. JOURNAL OF CLINICAL UROLOGY 2018. [DOI: 10.1177/2051415818761526] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Circumcision is one of the most performed surgical procedures worldwide, and it is estimated that one in three men worldwide is circumcised, which makes the preputial skin removed after surgery an abundant material for possible applications. In particular, it is possible efficiently to isolate the cells of the foreskin, with fibroblasts being the most abundant cells of the dermis and the most used in biomedical research. This work aimed to review the knowledge and obtain a broad view of the main applications of human foreskin fibroblast cell culture. A literature search was conducted, including clinical trials, preclinical basic research studies, reviews and experimental studies. Several medical and laboratory applications of human foreskin fibroblast cell culture have been described, especially when it comes to the use of human foreskin fibroblasts as feeder cells for the cultivation of human embryonic stem cells, in addition to co-culture with other cell types. The culture of foreskin fibroblasts has also been used to: obtain induced pluripotent stem cells; the diagnosis of Clostridium difficile; to test the toxicity and effect of substances on normal cells, especially the toxicity of possible antineoplastic drugs; in viral culture, mainly of the human cytomegalovirus, study of the pathogenesis of other microorganisms; varied studies of cellular physiology and cellular interactions. Fibroblasts are important for cell models for varied application cultures, demonstrating how the preputial material can be reused, making possible new applications. Level of evidence: Not applicable for this multicentre audit.
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Affiliation(s)
- Thomaz Oliveira
- Genetics and Molecular Biology Laboratory, Federal University of Piauí (UFPI), Brazil
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Ilana Costa
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Victor Marinho
- Genetics and Molecular Biology Laboratory, Federal University of Piauí (UFPI), Brazil
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Valécia Carvalho
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Karla Uchôa
- Genetics and Molecular Biology Laboratory, Federal University of Piauí (UFPI), Brazil
- Biomedical Sciences, Federal University of Piauí (UFPI), Brazil
| | - Carla Ayres
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
| | - Silmar Teixeira
- Brain Mapping and Plasticity Laboratory, Federal University of Piauí (UFPI), Brazil
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38
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Yao Y, Liu M, Ren C, Shen J, Ji Y. Exogenous tumor necrosis factor-alpha could induce egress of Toxoplasma gondii from human foreskin fibroblast cells. ACTA ACUST UNITED AC 2017; 24:45. [PMID: 29173277 PMCID: PMC5703069 DOI: 10.1051/parasite/2017051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 11/11/2017] [Indexed: 01/06/2023]
Abstract
Toxoplasma gondii is an intra-cellular protozoan parasite that can infect almost all nucleated cells, eliciting host immune responses against infection. Host tissue damage is mainly caused by cellular lysis when T. gondii egresses from infected cells. However, the effects of cytokines released by host immune cells on egression of T. gondii remain elusive. This study aimed to investigate the role of tumor necrosis factor-alpha (TNF-α) on the egress of T. gondii from infected human foreskin fibroblast (HFF) cells and to elucidate the underlying mechanisms that regulate TNF-α-induced egress. Using flow cytometry to count tachyzoites of T. gondii released into cell culture medium, we found that egress of T. gondii from infected HFF cells could be induced by 10 ng/mL TNF-α in a time-dependent manner. Pre-treatment of infected HFF cells with BAPTA-AM to chelate intra-parasitic calcium could greatly inhibit TNF-α-induced egress. Similar results were obtained when using cytochalasin D to block parasite motility before the TNF-α-induced egress assay. In addition, blocking host apoptosis by Z-VAD-FMK could decrease TNF-α induced egress, while blocking necroptosis by necrostatin-1 has little impact on TNF-α-induced egress. The egressed tachyzoites displayed a normal growth rate and lost no virulence. Our results suggest that host cytokines could influence the cellular lytic processes of T. gondii, providing new insights into the relationship between host TNF-α and T. gondii pathogenesis.
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Affiliation(s)
- Yong Yao
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Laboratory of Tropical and Parasitic Diseases Control; Anhui Medical University, Hefei, Anhui 230032, China
| | - Miao Liu
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Laboratory of Tropical and Parasitic Diseases Control; Anhui Medical University, Hefei, Anhui 230032, China
| | - Cuiping Ren
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Laboratory of Tropical and Parasitic Diseases Control; Anhui Medical University, Hefei, Anhui 230032, China
| | - Jijia Shen
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Laboratory of Tropical and Parasitic Diseases Control; Anhui Medical University, Hefei, Anhui 230032, China
| | - Yongsheng Ji
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology; Laboratory of Tropical and Parasitic Diseases Control; Anhui Medical University, Hefei, Anhui 230032, China
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39
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Saeij JP, Frickel EM. Exposing Toxoplasma gondii hiding inside the vacuole: a role for GBPs, autophagy and host cell death. Curr Opin Microbiol 2017; 40:72-80. [PMID: 29141239 PMCID: PMC7004510 DOI: 10.1016/j.mib.2017.10.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 10/24/2017] [Indexed: 11/28/2022]
Abstract
The intracellular parasite Toxoplasma gondii resides inside a vacuole, which shields it from the host’s intracellular defense mechanisms. The cytokine interferon gamma (IFNγ) upregulates host cell effector pathways that are able to destroy the vacuole, restrict parasite growth and induce host cell death. Interferon-inducible GTPases such as the Guanylate Binding Proteins (GBPs), autophagy proteins and ubiquitin-driven mechanisms play important roles in Toxoplasma control in mice and partly also in humans. The host inflammasome is regulated by GBPs in response to bacterial infection in murine cells and may also respond to Toxoplasma infection. Elucidation of murine Toxoplasma defense mechanisms are guiding studies on human cells, while inevitably leading to the discovery of human-specific pathways that often function in a cell type-dependent manner.
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Affiliation(s)
- Jeroen P Saeij
- School of Veterinary Medicine, Department of Pathology, Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA.
| | - Eva-Maria Frickel
- The Francis Crick Institute, Host-Toxoplasma Interaction Laboratory, 1 Midland Road, London NW1 1AT, UK.
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40
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Praefcke GJK. Regulation of innate immune functions by guanylate-binding proteins. Int J Med Microbiol 2017; 308:237-245. [PMID: 29174633 DOI: 10.1016/j.ijmm.2017.10.013] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 01/02/2023] Open
Abstract
Guanylate-binding proteins (GBP) are a family of dynamin-related large GTPases which are expressed in response to interferons and other pro-inflammatory cytokines. GBPs mediate a broad spectrum of innate immune functions against intracellular pathogens ranging from viruses to bacteria and protozoa. Several binding partners for individual GBPs have been identified and several different mechanisms of action have been proposed depending on the organisms, the cell type and the pathogen used. Many of these anti-pathogenic functions of GBPs involve the recruitment to and the subsequent destruction of pathogen containing vacuolar compartments, the assembly of large oligomeric innate immune complexes such as the inflammasome, or the induction of autophagy. Furthermore, GBPs often cooperate with immunity-related GTPases (IRGs), another family of dynamin-related GTPases, to exert their anti-pathogenic function, but since most IRGs have been lost in the evolution of higher primates, the anti-pathogenic function of human GBPs seems to be IRG-independent. GBPs and IRGs share biochemical and structural properties with the other members of the dynamin superfamily such as low nucleotide affinity and a high intrinsic GTPase activity which can be further enhanced by oligomerisation. Furthermore, GBPs and IRGs can interact with lipid membranes. In the case of three human and murine GBP isoforms this interaction is mediated by C-terminal isoprenylation. Based on cell biological studies, and in analogy to the function of other dynamins in membrane scission events, it has been postulated that both GBPs and IRGs might actively disrupt the outer membrane of pathogen-containing vacuole leading to the detection and destruction of the pathogen by the cytosolic innate immune system of the host. Recent evidence, however, indicates that GBPs might rather function by mediating membrane tethering events similar to the dynamin-related atlastin and mitofusin proteins, which mediate fusion of the ER and mitochondria, respectively. The aim of this review is to highlight the current knowledge on the function of GBPs in innate immunity and to combine it with the recent progress in the biochemical characterisation of this protein family.
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Affiliation(s)
- Gerrit J K Praefcke
- Division of Haematology / Transfusion Medicine, Paul-Ehrlich-Institut, Langen, Germany; Institute for Genetics, University of Cologne, Cologne, Germany.
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41
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Klein RS, Hunter CA. Protective and Pathological Immunity during Central Nervous System Infections. Immunity 2017; 46:891-909. [PMID: 28636958 PMCID: PMC5662000 DOI: 10.1016/j.immuni.2017.06.012] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/05/2017] [Accepted: 06/05/2017] [Indexed: 02/08/2023]
Abstract
The concept of immune privilege of the central nervous system (CNS) has dominated the study of inflammatory processes in the brain. However, clinically relevant models have highlighted that innate pathways limit pathogen invasion of the CNS and adaptive immunity mediates control of many neural infections. As protective responses can result in bystander damage, there are regulatory mechanisms that balance protective and pathological inflammation, but these mechanisms might also allow microbial persistence. The focus of this review is to consider the host-pathogen interactions that influence neurotropic infections and to highlight advances in our understanding of innate and adaptive mechanisms of resistance as key determinants of the outcome of CNS infection. Advances in these areas have broadened our comprehension of how the immune system functions in the brain and can readily overcome immune privilege.
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Affiliation(s)
- Robyn S Klein
- Departments of Medicine, Pathology and Immunology, Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Christopher A Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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42
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The Toxoplasma Parasitophorous Vacuole: An Evolving Host-Parasite Frontier. Trends Parasitol 2017; 33:473-488. [PMID: 28330745 DOI: 10.1016/j.pt.2017.02.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/20/2017] [Accepted: 02/24/2017] [Indexed: 01/17/2023]
Abstract
The parasitophorous vacuole is a unique replicative niche for apicomplexan parasites, including Toxoplasma gondii. Derived from host plasma membrane, the vacuole is rendered nonfusogenic with the host endolysosomal system. Toxoplasma secretes numerous proteins to modify the forming vacuole, enable nutrient uptake, and set up mechanisms of host subversion. Here we describe the pathways of host-parasite interaction at the parasitophorous vacuole employed by Toxoplasma and host, leading to the intricate balance of host defence versus parasite survival.
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43
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Krishnamurthy S, Konstantinou EK, Young LH, Gold DA, Saeij JPJ. The human immune response to Toxoplasma: Autophagy versus cell death. PLoS Pathog 2017; 13:e1006176. [PMID: 28278184 PMCID: PMC5344534 DOI: 10.1371/journal.ppat.1006176] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Shruthi Krishnamurthy
- Department of Pathology, Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Eleni K. Konstantinou
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lucy H. Young
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniel A. Gold
- Department of Pathology, Microbiology and Immunology, University of California Davis, Davis, California, United States of America
| | - Jeroen P. J. Saeij
- Department of Pathology, Microbiology and Immunology, University of California Davis, Davis, California, United States of America
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44
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Guanylate-binding protein 1 (GBP1) contributes to the immunity of human mesenchymal stromal cells against Toxoplasma gondii. Proc Natl Acad Sci U S A 2017; 114:1365-1370. [PMID: 28123064 DOI: 10.1073/pnas.1619665114] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mesenchymal stromal cells (MSCs) have recently been shown to play important roles in mammalian host defenses against intracellular pathogens, but the molecular mechanism still needs to be clarified. We confirmed that human MSCs (hMSCs) prestimulated with IFN-γ showed a significant and dose-dependent ability to inhibit the growth of two types of Toxoplasma gondii [type I RH strain with green fluorescent proteins (RH/GFP) or type II PLK strain with red fluorescent proteins (PLK/RED)]. However, in contrast to previous reports, the anti-T. gondii activity of hMSCs was not mediated by indoleamine 2,3-dioxygenase (IDO). Genome-wide RNA sequencing (RNA-seq) analysis revealed that IFN-γ increased the expression of the p65 family of human guanylate-binding proteins (hGBPs) in hMSCs, especially hGBP1. To analyze the functional role of hGBPs, stable knockdowns of hGBP1, -2, and -5 in hMSCs were established using a lentiviral transfection system. hGBP1 knockdown in hMSCs resulted in a significant loss of the anti-T. gondii host defense property, compared with hMSCs infected with nontargeted control sequences. hGBP2 and -5 knockdowns had no effect. Moreover, the hGBP1 accumulation on the parasitophorous vacuole (PV) membranes of IFN-γ-stimulated hMSCs might protect against T. gondii infection. Taken together, our results suggest that hGBP1 plays a pivotal role in anti-T. gondii protection of hMSCs and may shed new light on clarifying the mechanism of host defense properties of hMSCs.
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45
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Stewart RJ, Whitehead L, Nijagal B, Sleebs BE, Lessene G, McConville MJ, Rogers KL, Tonkin CJ. Analysis of Ca 2+ mediated signaling regulating Toxoplasma infectivity reveals complex relationships between key molecules. Cell Microbiol 2017; 19. [PMID: 27781359 DOI: 10.1111/cmi.12685] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/14/2016] [Indexed: 12/28/2022]
Abstract
Host cell invasion, exit and parasite dissemination is critical to the pathogenesis of apicomplexan parasites such as Toxoplasma gondii and Plasmodium spp. These processes are regulated by intracellular Ca2+ signaling although the temporal dynamics of Ca2+ fluxes and down-stream second messenger pathways are poorly understood. Here, we use a genetically encoded biosensor, GFP-Calmodulin-M13-6 (GCaMP6), to capture Ca2+ flux in live Toxoplasma and investigate the role of Ca2+ signaling in egress and motility. Our analysis determines how environmental cues and signal activation influence intracellular Ca2+ flux, allowing placement of effector molecules within this pathway. Importantly, we have identified key interrelationships between cGMP and Ca2+ signaling that are required for activation of egress and motility. Furthermore, we extend this analysis to show that the Ca2+ Dependent Protein Kinases-TgCDPK1 and TgCDPK3-play a role in signal quenching before egress. This work highlights the interrelationships of second messenger pathways of Toxoplasma in space and time, which is likely required for pathogenesis of all apicomplexan species.
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Affiliation(s)
- Rebecca J Stewart
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Brunda Nijagal
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Guillaume Lessene
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia.,Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Australia
| | - Kelly L Rogers
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
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46
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The kynurenine pathway and parasitic infections that affect CNS function. Neuropharmacology 2017; 112:389-398. [DOI: 10.1016/j.neuropharm.2016.02.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 02/19/2016] [Accepted: 02/23/2016] [Indexed: 12/14/2022]
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47
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Toxoplasma gondii: One Organism, Multiple Models. Trends Parasitol 2016; 33:113-127. [PMID: 27988095 DOI: 10.1016/j.pt.2016.11.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 12/13/2022]
Abstract
Toxoplasma gondii is an intensely studied protozoan parasite. It is also used as a model organism to research additional clinically relevant human and veterinary parasites due to ease of in vitro culture and genetic manipulation. Recently, it has been developed as a model of inflammatory bowel disease, due to their similar pathologies. However, researchers vary widely in how they use T. gondii, which makes study comparisons and interpretation difficult. The aim of this review is to provide researchers with a tool to: (i) determine the appropriateness of the different T. gondii models to their research, (ii) interpret results from the wide range of study conditions, and (iii) consider new advances in technology which could improve or refine their experimental setup.
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48
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Clough B, Wright JD, Pereira PM, Hirst EM, Johnston AC, Henriques R, Frickel EM. K63-Linked Ubiquitination Targets Toxoplasma gondii for Endo-lysosomal Destruction in IFNγ-Stimulated Human Cells. PLoS Pathog 2016; 12:e1006027. [PMID: 27875583 PMCID: PMC5119857 DOI: 10.1371/journal.ppat.1006027] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/26/2016] [Indexed: 12/03/2022] Open
Abstract
Toxoplasma gondii is the most common protozoan parasitic infection in man. Gamma interferon (IFNγ) activates haematopoietic and non-haematopoietic cells to kill the parasite and mediate host resistance. IFNγ-driven host resistance pathways and parasitic virulence factors are well described in mice, but a detailed understanding of pathways that kill Toxoplasma in human cells is lacking. Here we show, that contrary to the widely held belief that the Toxoplasma vacuole is non-fusogenic, in an immune-stimulated environment, the vacuole of type II Toxoplasma in human cells is able to fuse with the host endo-lysosomal machinery leading to parasite death by acidification. Similar to murine cells, we find that type II, but not type I Toxoplasma vacuoles are targeted by K63-linked ubiquitin in an IFNγ-dependent manner in non-haematopoetic primary-like human endothelial cells. Host defence proteins p62 and NDP52 are subsequently recruited to the type II vacuole in distinct, overlapping microdomains with a loss of IFNγ-dependent restriction in p62 knocked down cells. Autophagy proteins Atg16L1, GABARAP and LC3B are recruited to <10% of parasite vacuoles and show no parasite strain preference, which is consistent with inhibition and enhancement of autophagy showing no effect on parasite replication. We demonstrate that this differs from HeLa human epithelial cells, where type II Toxoplasma are restricted by non-canonical autophagy leading to growth stunting that is independent of lysosomal acidification. In contrast to mouse cells, human vacuoles do not break. In HUVEC, the ubiquitinated vacuoles are targeted for destruction in acidified LAMP1-positive endo-lysosomal compartments. Consequently, parasite death can be prevented by inhibiting host ubiquitination and endosomal acidification. Thus, K63-linked ubiquitin recognition leading to vacuolar endo-lysosomal fusion and acidification is an important, novel virulence-driven Toxoplasma human host defence pathway. Toxoplasma gondii is an intracellular parasite that can invade nucleated cells of any warm-blooded animal into a compartment known as a parasitophorous vacuole (PV). The production of gamma interferon (IFNγ) drives the restriction and killing of Toxoplasma. It is not fully known how the parasite inside the PV is eliminated in human cells, although its fate depends on the cell type into which it invades. In IFNγ-stimulated epithelial HeLa cells for instance growth of type II parasites is restricted 24h post-infection by employing the cellular autophagy pathway. Distinctly, we show here that in human endothelial cells the parasite is destroyed by fusion of the PV with the cell’s endo-lysosomal pathway as early as 6h post-infection. This process, which is at odds with the normally non-fusogenic nature of the PV, is dependent on IFNγ. Parasite death follows Lysine63-linked ubiquitination of the PV and is specific to type II Toxoplasma. Our results demonstrate for the first time that vacuolar acidification leading to parasite death is central to controlling infection by Toxoplasma in human endothelial cells.
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Affiliation(s)
- Barbara Clough
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, United Kingdom
| | - Joseph D. Wright
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, United Kingdom
| | - Pedro M. Pereira
- MRC Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, United Kingdom
| | - Elizabeth M. Hirst
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, United Kingdom
| | - Ashleigh C. Johnston
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, United Kingdom
| | - Ricardo Henriques
- MRC Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, United Kingdom
| | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, United Kingdom
- * E-mail:
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49
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Kim BH, Chee JD, Bradfield CJ, Park ES, Kumar P, MacMicking JD. Interferon-induced guanylate-binding proteins in inflammasome activation and host defense. Nat Immunol 2016; 17:481-9. [PMID: 27092805 DOI: 10.1038/ni.3440] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/16/2016] [Indexed: 02/06/2023]
Abstract
Traditional views of the inflammasome highlight the assembly of pre-existing core components shortly after infection or tissue damage. Emerging work, however, suggests that the inflammasome machinery is also subject to 'tunable' or inducible signals that might accelerate its autocatalytic properties and dictate where inflammasome assembly takes place in the cell. Many of these signals operate downstream of interferon receptors to elicit inflammasome regulators, including a new family of interferon-induced GTPases called 'guanylate-binding proteins' (GBPs). Here we investigate the critical roles of interferon-induced GBPs in directing inflammasome subtype-specific responses and their consequences for cell-autonomous immunity to a wide variety of microbial pathogens. We discuss emerging mechanisms of action and the potential effect of these GBPs on predisposition to sepsis and other infectious or inflammatory diseases.
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Affiliation(s)
- Bae-Hoon Kim
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jonathan D Chee
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Clinton J Bradfield
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Eui-Soon Park
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Pradeep Kumar
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - John D MacMicking
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
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50
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Pentoxifylline triggers autophagy via ER stress response that interferes with Pentoxifylline induced apoptosis in human melanoma cells. Biochem Pharmacol 2016; 103:17-28. [PMID: 26793997 DOI: 10.1016/j.bcp.2015.12.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 12/22/2015] [Indexed: 12/17/2022]
Abstract
Pentoxifylline (PTX), a non-specific phosphodiesterase inhibitor is known to inhibit the growth of various cancer cells including melanoma. Here in this study, we have found that PTX induces autophagy in human melanoma cell lines (A375 and MeWo). Induction of autophagy is associated with the increase in Atg5 expression as knockdown of Atg5 effectively inhibited PTX mediated autophagy. A decrease in mTOR activation was also observed after PTX treatment. We observed that autophagy was activated as a downstream effector mechanism of ER stress induced by PTX. ER stress response was confirmed by upregulation of IRE-1α, GRP78 and CHOP expression. PTX treatment also resulted in an increase in intracellular calcium (Ca(2+)) level. Ca(2+) is the central player as blocking Ca(2+) by intracellular calcium chelator (BAPTA-AM) effectively inhibited the PTX induced ER stress response as well as autophagy. Moreover, silencing of CHOP also resulted in autophagy inhibition with a decrease in Atg5 expression. Collectively, PTX triggers ER stress response followed by induction of autophagy via involvement of Ca(2+)→CHOP→Atg5 signalling cascade. Interestingly, inhibition of intracellular calcium level by BAPTA-AM significantly increased PTX mediated cell death by augmenting intrinsic apoptotic pathway. Inhibition of autophagy by the ATG5 siRNA and pharmacological inhibitor, chloroquine also enhances PTX induced cell death. Taken together, our results clearly indicate that activation of ER stress response and autophagy provides resistance to PTX mediated apoptosis, and thus, interferes with the anticancer activity of PTX in human melanoma cells.
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