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Henry B, Phillips AJ, Sibley LD, Rosenberg A. A combination of four Toxoplasma gondii nuclear-targeted effectors protects against interferon gamma-driven human host cell death. mBio 2024; 15:e0212424. [PMID: 39292011 PMCID: PMC11481881 DOI: 10.1128/mbio.02124-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Accepted: 08/20/2024] [Indexed: 09/19/2024] Open
Abstract
In both mice and humans, Type II interferon gamma (IFNγ) is crucial for the regulation of Toxoplasma gondii (T. gondii) infection, during acute or chronic phases. To thwart this defense, T. gondii secretes protein effectors hindering the host's 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 parasite premature egress and host cell death in human cells stimulated with IFNγ post-infection, 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.IMPORTANCEToxoplasma gondii, an intracellular parasite, affects nearly one-third of the global human population, posing significant risks for immunocompromised patients and infants infected in utero. In murine models, the core mechanisms of IFNγ-mediated immunity against T. gondii are consistently preserved, showcasing a remarkable conservation of immune defense mechanisms. In humans, the recognized restriction mechanisms vary among cell types, lacking a universally applicable mechanism. This difference underscores a significant variation in the genes employed by T. gondii to shield itself against the IFNγ response in human vs murine cells. Here, we identified a specific combination of four parasite-secreted effectors deployed into the host cell nucleus, disrupting IFNγ signaling. This disruption is crucial in preventing premature egress of the parasite and host cell death. Notably, this phenotype is exclusive to human cells, highlighting the intricate and unique mechanisms T. gondii employs to modulate host responses in the human cellular environment.
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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
| | - Aubrey J. Phillips
- 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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2
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Wu D, Zhang K, Guan K, Khan FA, Pandupuspitasari NS, Negara W, Sun F, Huang C. Future in the past: paternal reprogramming of offspring phenotype and the epigenetic mechanisms. Arch Toxicol 2024; 98:1685-1703. [PMID: 38460001 DOI: 10.1007/s00204-024-03713-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/20/2024] [Indexed: 03/11/2024]
Abstract
That certain preconceptual paternal exposures reprogram the developmental phenotypic plasticity in future generation(s) has conceptualized the "paternal programming of offspring health" hypothesis. This transgenerational effect is transmitted primarily through sperm epigenetic mechanisms-DNA methylation, non-coding RNAs (ncRNAs) and associated RNA modifications, and histone modifications-and potentially through non-sperm-specific mechanisms-seminal plasma and circulating factors-that create 'imprinted' memory of ancestral information. The epigenetic landscape in sperm is highly responsive to environmental cues, due to, in part, the soma-to-germline communication mediated by epididymosomes. While human epidemiological studies and experimental animal studies have provided solid evidences in support of transgenerational epigenetic inheritance, how ancestral information is memorized as epigenetic codes for germline transmission is poorly understood. Particular elusive is what the downstream effector pathways that decode those epigenetic codes into persistent phenotypes. In this review, we discuss the paternal reprogramming of offspring phenotype and the possible underlying epigenetic mechanisms. Cracking these epigenetic mechanisms will lead to a better appreciation of "Paternal Origins of Health and Disease" and guide innovation of intervention algorithms to achieve 'healthier' outcomes in future generations. All this will revolutionize our understanding of human disease etiology.
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Affiliation(s)
- Di Wu
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, 226001, China
| | - Kejia Zhang
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, 226001, China
| | - Kaifeng Guan
- School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
| | - Faheem Ahmed Khan
- Research Center for Animal Husbandry, National Research and Innovation Agency, Jakarta Pusat, 10340, Indonesia
| | | | - Windu Negara
- Research Center for Animal Husbandry, National Research and Innovation Agency, Jakarta Pusat, 10340, Indonesia
| | - Fei Sun
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, 226001, China.
| | - Chunjie Huang
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, 226001, China.
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3
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Bando H, Murata Y, Han Y, Sugi T, Fukuda Y, Bzik DJ, Fox BA, Kato K. Toxoplasma gondii chitinase-like protein TgCLP1 regulates the parasite cyst burden. Front Cell Infect Microbiol 2024; 14:1359888. [PMID: 38828265 PMCID: PMC11140023 DOI: 10.3389/fcimb.2024.1359888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/23/2024] [Indexed: 06/05/2024] Open
Abstract
Toxoplasma, an important intracellular parasite of humans and animals, causes life-threatening toxoplasmosis in immunocompromised individuals. Although Toxoplasma secretory proteins during acute infection (tachyzoite, which divides rapidly and causes inflammation) have been extensively characterized, those involved in chronic infection (bradyzoite, which divides slowly and is surrounded by a cyst wall) remain uncertain. Regulation of the cyst wall is essential to the parasite life cycle, and polysaccharides, such as chitin, in the cyst wall are necessary to sustain latent infection. Toxoplasma secretory proteins during the bradyzoite stage may have important roles in regulating the cyst wall via polysaccharides. Here, we focused on characterizing the hypothetical T. gondii chitinase, chitinase-like protein 1 (TgCLP1). We found that the chitinase-like domain containing TgCLP1 is partially present in the bradyzoite microneme and confirmed, albeit partially, its previous identification in the tachyzoite microneme. Furthermore, although parasites lacking TgCLP1 could convert from tachyzoites to bradyzoites and make an intact cyst wall, they failed to convert from bradyzoites to tachyzoites, indicating that TgCLP1 is necessary for bradyzoite reactivation. Taken together, our findings deepen our understanding of the molecular basis of recrudescence and could contribute to the development of novel strategies for the control of toxoplasmosis.
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Affiliation(s)
- Hironori Bando
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
- Department of Parasitology, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Yuho Murata
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Yongmei Han
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Tatsuki Sugi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
- Division of Collaboration and Education, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Yasuhiro Fukuda
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
| | - David J. Bzik
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Barbara A. Fox
- Department of Microbiology and Immunology, The Geisel School of Medicine at Dartmouth, Lebanon, NH, United States
| | - Kentaro Kato
- Laboratory of Sustainable Animal Environment, Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
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4
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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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5
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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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6
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Pu X, Pan Y, Xiang Q, Lu M, Xu L, Yan R, Li X, Song X. Inhibitory effect of Eimeria maxima IFN-γ inhibitory molecules on the immune function of T cell subsets in chickens. Poult Sci 2023; 102:103098. [PMID: 37797491 PMCID: PMC10622878 DOI: 10.1016/j.psj.2023.103098] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/03/2023] [Accepted: 09/06/2023] [Indexed: 10/07/2023] Open
Abstract
It has been reported that infection of chicken coccidian could inhibit the production of Th1 cytokine IFN-γ, thereby evading clearance by the host immune system. The present study aimed to have a further investigation into the effects of Eimeria maxima IFN-γ inhibitory molecules (EmHPSP-2 and EmHPSP-3) on the immune function of chicken peripheral blood mononuclear cells (PBMC) and various T cell subsets. First, separated PBMC or sorted T cell subsets were used for incubation with recombinant proteins of EmHPSP-2 (rEmHPSP-2) and EmHPSP-3 (rEmHPSP-3). Subsequently, the effects of rEmHPSP-2 and rEmHPSP-3 on proliferative capacity, nitric oxide (NO) release and mRNA levels of cytokines of the above cells were detected. The sorting purity of CD8+, CD4+ CD25-, CD4+, and CD4+ CD25+ T cells was 93.01, 88.88, 87.04, and 81.26%, respectively. The NO release of PBMC was significantly inhibited by rEmHPSP-2 and rEmHPSP-3. The proliferation of PBMC and CD4+ T cells was significantly inhibited by rEmHPSP-2 and rEmHPSP-3, whereas CD8+, CD4+ CD25-, and CD4+ CD25+ T cells was significantly promoted by the 2 proteins. The 2 proteins significantly downregulated interferon-gamma (IFN-γ) mRNA level, upregulated the transcriptional levels of interleukin-10 (IL-10) and transforming growth factor-beta1 (TGF-β1) in PBMC. IFN-γ and IL-2 transcriptional levels were markedly inhibited in CD8+ T cells. IFN-γ transcriptional level was significantly inhibited, but IL-4 was promoted by rEmHPSP-2 and rEmHPSP-3 in CD4+ CD25- T cells. Meanwhile, the inhibitory effects of rEmHPSP-2 and rEmHPSP-3 on the transcriptional levels of IFN-γ and IL-2 were more obvious in CD4+ T cells containing CD25+ cells compared with the CD25+ cells depletion group. It was found that IL-10, TGF-β1, and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) mRNA levels were significantly upregulated upon stimulation of chicken CD4+ CD25+ T cells by proteins. This study is not only of great significance to clarify the immune evasion mechanism of chicken coccidia, but also provides candidate antigen molecules for development of a novel vaccine against chicken coccidiosis.
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Affiliation(s)
- Xianglin Pu
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yangdong Pan
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Quanjia Xiang
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Mingmin Lu
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Lixin Xu
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Ruofeng Yan
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xiangrui Li
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xiaokai Song
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, PR China.
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7
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Ramírez-Flores CJ, Erazo Flores BJ, Tibabuzo Perdomo AM, Barnes KL, Wilson SK, Mendoza Cavazos C, Knoll LJ. A Toxoplasma gondii lipoxygenase-like enzyme is necessary for virulence and changes localization associated with the host immune response. mBio 2023; 14:e0127923. [PMID: 37646522 PMCID: PMC10653942 DOI: 10.1128/mbio.01279-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/12/2023] [Indexed: 09/01/2023] Open
Abstract
IMPORTANCE Lipoxygenases (LOXs) are enzymes that catalyze the deoxygenation of polyunsaturated fatty acids such as linoleic and arachidonic acid. These modifications create signaling molecules that are best characterized for modulating the immune response. Deletion of the first lipoxygenase-like enzyme characterized for Toxoplasma gondii (TgLOXL1) generated a less virulent strain, and infected mice showed a decreased immune response. This virulence defect was dependent on the mouse cytokine interferon gamma IFNγ. TgLOXL1 changes location from inside the parasite in tissue culture conditions to vesicular structures within the host immune cells during mouse infection. These results suggest that TgLOXL1 plays a role in the modification of the host immune response in mice.
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Affiliation(s)
- Carlos J. Ramírez-Flores
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Billy Joel Erazo Flores
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Andrés M. Tibabuzo Perdomo
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Katie L. Barnes
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sarah K. Wilson
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Carolina Mendoza Cavazos
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Laura J. Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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8
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Orchanian SB, Lodoen MB. Monocytes as primary defenders against Toxoplasma gondii infection. Trends Parasitol 2023; 39:837-849. [PMID: 37633758 DOI: 10.1016/j.pt.2023.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/14/2023] [Accepted: 07/21/2023] [Indexed: 08/28/2023]
Abstract
Monocytes are recruited from the bone marrow to sites of infection where they release cytokines and chemokines, function in antimicrobial immunity, and differentiate into macrophages and dendritic cells to control infection. Although many studies have focused on monocyte-derived macrophages and dendritic cells, recent work has examined the unique roles of monocytes during infection to promote immune defense. We focus on the effector functions of monocytes during infection with the parasite Toxoplasma gondii, and discuss the signals that mobilize monocytes to sites of infection, their production of inflammatory cytokines and antimicrobial mediators, their ability to shape the adaptive immune response, and their immunoregulatory functions. Insights from other infections, including Plasmodium and Listeria are also included for comparison and context.
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Affiliation(s)
- Stephanie B Orchanian
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA; Institute for Immunology, University of California Irvine, Irvine, California, USA
| | - Melissa B Lodoen
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA; Institute for Immunology, University of California Irvine, Irvine, California, USA.
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9
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Spens AE, Sutliff NA, Bennett SR, Campbell AE, Tapscott SJ. Human DUX4 and mouse Dux interact with STAT1 and broadly inhibit interferon-stimulated gene induction. eLife 2023; 12:e82057. [PMID: 37092726 PMCID: PMC10195082 DOI: 10.7554/elife.82057] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 04/21/2023] [Indexed: 04/25/2023] Open
Abstract
DUX4 activates the first wave of zygotic gene expression in the early embryo. Mis-expression of DUX4 in skeletal muscle causes facioscapulohumeral dystrophy (FSHD), whereas expression in cancers suppresses IFNγ induction of major histocompatibility complex class I (MHC class I) and contributes to immune evasion. We show that the DUX4 protein interacts with STAT1 and broadly suppresses expression of IFNγ-stimulated genes by decreasing bound STAT1 and Pol-II recruitment. Transcriptional suppression of interferon-stimulated genes (ISGs) requires conserved (L)LxxL(L) motifs in the carboxyterminal region of DUX4 and phosphorylation of STAT1 Y701 enhances interaction with DUX4. Consistent with these findings, expression of endogenous DUX4 in FSHD muscle cells and the CIC-DUX4 fusion containing the DUX4 CTD in a sarcoma cell line inhibit IFNγ induction of ISGs. Mouse Dux similarly interacted with STAT1 and suppressed IFNγ induction of ISGs. These findings identify an evolved role of the DUXC family in modulating immune signaling pathways with implications for development, cancers, and FSHD.
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Affiliation(s)
- Amy E Spens
- Human Biology Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Nicholas A Sutliff
- Human Biology Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Sean R Bennett
- Human Biology Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Amy E Campbell
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical CampusDenverUnited States
| | - Stephen J Tapscott
- Human Biology Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
- Clinical Research Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
- Department of Neurology, University of WashingtonSeattleUnited States
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10
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Deng S, Graham ML, Chen XM. The Complexity of Interferon Signaling in Host Defense against Protozoan Parasite Infection. Pathogens 2023; 12:319. [PMID: 36839591 PMCID: PMC9962834 DOI: 10.3390/pathogens12020319] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/11/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
Protozoan parasites, such as Plasmodium, Leishmania, Toxoplasma, Cryptosporidium, and Trypanosoma, are causative agents of health-threatening diseases in both humans and animals, leading to significant health risks and socioeconomic losses globally. The development of effective therapeutic and prevention strategies for protozoan-caused diseases requires a full understanding of the pathogenesis and protective events occurring in infected hosts. Interferons (IFNs) are a family of cytokines with diverse biological effects in host antimicrobial defense and disease pathogenesis, including protozoan parasite infection. Type II IFN (IFN-γ) has been widely recognized as the essential defense cytokine in intracellular protozoan parasite infection, whereas recent studies also revealed the production and distinct function of type I and III IFNs in host defense against these parasites. Decoding the complex network of the IFN family in host-parasite interaction is critical for exploring potential new therapeutic strategies against intracellular protozoan parasite infection. Here, we review the complex effects of IFNs on the host defense against intracellular protozoan parasites and the crosstalk between distinct types of IFN signaling during infections.
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Affiliation(s)
- Silu Deng
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Marion L. Graham
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
| | - Xian-Ming Chen
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
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11
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Brandão YDO, Molento MB. A Systematic Review of Apicomplexa Looking into Epigenetic Pathways and the Opportunity for Novel Therapies. Pathogens 2023; 12:pathogens12020299. [PMID: 36839571 PMCID: PMC9963874 DOI: 10.3390/pathogens12020299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/03/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Interest in host epigenetic changes during apicomplexan infections increased in the last decade, mainly due to the emergence of new therapies directed to these alterations. This review aims to carry out a bibliometric analysis of the publications related to host epigenetic changes during apicomplexan infections and to summarize the main studied pathways in this context, pointing out those that represent putative drug targets. We used four databases for the article search. After screening, 116 studies were included. The bibliometric analysis revealed that the USA and China had the highest number of relevant publications. The evaluation of the selected studies revealed that Toxoplasma gondii was considered in most of the studies, non-coding RNA was the most frequently reported epigenetic event, and host defense was the most explored pathway. These findings were reinforced by an analysis of the co-occurrence of keywords. Even though we present putative targets for repurposing epidrugs and ncRNA-based drugs in apicomplexan infections, we understand that more detailed knowledge of the hosts' epigenetic pathways is still needed before establishing a definitive drug target.
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12
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Overview of Apoptosis, Autophagy, and Inflammatory Processes in Toxoplasma gondii Infected Cells. Pathogens 2023; 12:pathogens12020253. [PMID: 36839525 PMCID: PMC9966443 DOI: 10.3390/pathogens12020253] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. During the parasitic invasion, T. gondii creates a parasitophorous vacuole, which enables the modulation of cell functions, allowing its replication and host infection. It has effective strategies to escape the immune response and reach privileged immune sites and remain inactive in a controlled environment in tissue cysts. This current review presents the factors that affect host cells and the parasite, as well as changes in the immune system during host cell infection. The secretory organelles of T. gondii (dense granules, micronemes, and rhoptries) are responsible for these processes. They are involved with proteins secreted by micronemes and rhoptries (MIC, AMA, and RONs) that mediate the recognition and entry into host cells. Effector proteins (ROP and GRA) that modify the STAT signal or GTPases in immune cells determine their toxicity. Interference byhost autonomous cells during parasitic infection, gene expression, and production of microbicidal molecules such as reactive oxygen species (ROS) and nitric oxide (NO), result in the regulation of cell death. The high level of complexity in host cell mechanisms prevents cell death in its various pathways. Many of these abilities play an important role in escaping host immune responses, particularly by manipulating the expression of genes involved in apoptosis, necrosis, autophagy, and inflammation. Here we present recent works that define the mechanisms by which T. gondii interacts with these processes in infected host cells.
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Vargas-Villavicencio JA, Cañedo-Solares I, Correa D. Anti-Toxoplasma gondii IgM Long Persistence: What Are the Underlying Mechanisms? Microorganisms 2022; 10:microorganisms10081659. [PMID: 36014077 PMCID: PMC9415799 DOI: 10.3390/microorganisms10081659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Abstract
Diagnosis of Toxoplasma gondii acute infection was first attempted by detection of specific IgM antibodies, as for other infectious diseases. However, it was noted that this immunoglobulin declines slowly and may last for months or even years. Apart from the diagnostic problem imposed on clinical management, this phenomenon called our attention due to the underlying phenomena that may be causing it. We performed a systematic comparison of reports studying IgM antibody kinetics, and the data from the papers were used to construct comparative plots and other graph types. It became clear that this phenomenon is quite generalized, and it may also occur in animals. Moreover, this is not a technical issue, although some tests make more evident the prolonged IgM decay than others. We further investigated biological reasons for its occurrence, i.e., infection dynamics (micro-reactivation–encystment, reinfection and reactivation), parasite strain relevance, as well as host innate, natural B cell responses and Ig class-switch problems inflicted by the parasite. The outcomes of these inquiries are presented and discussed herein.
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Affiliation(s)
| | - Irma Cañedo-Solares
- Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, Mexico City 04530, Mexico
| | - Dolores Correa
- Dirección de Investigación/Centro de Investigación en Ciencias de la Salud, FCS, Universidad Anáhuac México Campus Norte, Av Universidad Anáhuc 46, Lomas Anáhuac, Huixquilucan 52786, Mexico
- Correspondence: ; Tel.: +52-(55)-5627-0210-7637
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Yuan H, Zhang XX, Yang ZP, Wang XH, Mahmmod YS, Zhang P, Yan ZJ, Wang YY, Ren ZW, Guo QY, Yuan ZG. Unveiling of brain transcriptome of masked palm civet (Paguma larvata) with chronic infection of Toxoplasma gondii. Parasit Vectors 2022; 15:263. [PMID: 35871661 PMCID: PMC9308931 DOI: 10.1186/s13071-022-05378-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/15/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study was to gain an understanding of the transcriptomic changes that occur in a wild species when infected with Toxoplasma gondii. The masked palm civet, an artifically domesticated animal, was used as the model of a wild species. Transcriptome analysis was used to study alterations in gene expression in the domesticated masked palm civet after chronic infection with T. gondii. METHODS Masked palm civets were infected with 105 T. gondii cysts and their brain tissue collected after 4 months of infection. RNA sequencing (RNA-Seq) was used to gain insight into the spectrum of genes that were differentially expressed due to infection. Quantitative reverse-transcription PCR (qRT-PCR) was also used to validate the level of expression of a set of differentially expressed genes (DEGs) obtained by sequencing. RESULTS DEGs were screened from the sequencing results and analyzed. A total of 2808 DEGs were detected, of which 860 were upregulated and 1948 were downregulated. RNA-Seq results were confirmed by qRT-PCR. DEGs were mainly enriched in cellular process and metabolic process based on gene ontology enrichment analysis. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that transcriptional changes in the brain of infected masked palm civets evolved over the course of infection and that DEGs were mainly enriched in the signal transduction, immune system processes, transport and catabolic pathways. Finally, 10 essential driving genes were identified from the immune signaling pathway. CONCLUSIONS This study revealed novel host genes which may provide target genes for the development of new therapeutics and detection methods for T. gondii infection in wild animals.
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Affiliation(s)
- Hao Yuan
- grid.413251.00000 0000 9354 9799College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, 830052 Xinjiang People’s Republic of China ,grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China ,grid.20561.300000 0000 9546 5767Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, 510642 People’s Republic of China ,grid.20561.300000 0000 9546 5767Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China
| | - Xiu-Xiang Zhang
- grid.20561.300000 0000 9546 5767College of Agriculture, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China
| | - Zi-Peng Yang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China ,grid.20561.300000 0000 9546 5767Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, 510642 People’s Republic of China
| | - Xiao-Hu Wang
- grid.135769.f0000 0001 0561 6611Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640 Guangdong People’s Republic of China
| | - Yasser S. Mahmmod
- grid.31451.320000 0001 2158 2757Infectious Diseases, Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511 Sharika Egypt ,grid.444463.50000 0004 1796 4519Veterinary Sciences Division, Faculty of Health Sciences, Higher Colleges of Technology, 17155- Al Ain, Abu Dhabi, United Arab Emirates
| | - Pian Zhang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China
| | - Zi-Jing Yan
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China
| | - Yan-Yun Wang
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China
| | - Zhao-Wen Ren
- grid.20561.300000 0000 9546 5767College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642 Guangdong People’s Republic of China
| | - Qing-Yong Guo
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, 830052, Xinjiang, People's Republic of China.
| | - Zi-Guo Yuan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, Guangdong, People's Republic of China. .,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, 510642, People's Republic of China.
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15
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Huang Z, Liu H, Nix J, Xu R, Knoverek CR, Bowman GR, Amarasinghe GK, Sibley LD. The intrinsically disordered protein TgIST from Toxoplasma gondii inhibits STAT1 signaling by blocking cofactor recruitment. Nat Commun 2022; 13:4047. [PMID: 35831295 PMCID: PMC9279507 DOI: 10.1038/s41467-022-31720-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 06/28/2022] [Indexed: 12/31/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) proteins communicate from cell-surface receptors to drive transcription of immune response genes. The parasite Toxoplasma gondii blocks STAT1-mediated gene expression by secreting the intrinsically disordered protein TgIST that traffics to the host nucleus, binds phosphorylated STAT1 dimers, and occupies nascent transcription sites that unexpectedly remain silenced. Here we define a core region within internal repeats of TgIST that is necessary and sufficient to block STAT1-mediated gene expression. Cellular, biochemical, mutational, and structural data demonstrate that the repeat region of TgIST adopts a helical conformation upon binding to STAT1 dimers. The binding interface is defined by a groove formed from two loops in the STAT1 SH2 domains that reorient during dimerization. TgIST binding to this newly exposed site at the STAT1 dimer interface alters its conformation and prevents the recruitment of co-transcriptional activators, thus defining the mechanism of blocked transcription.
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Affiliation(s)
- Zhou Huang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hejun Liu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Jay Nix
- Molecular Biology Consortium, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Rui Xu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Catherine R Knoverek
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gregory R Bowman
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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Hakimi MA. Epigenetic Reprogramming in Host-Parasite Coevolution: The Toxoplasma Paradigm. Annu Rev Microbiol 2022; 76:135-155. [PMID: 35587934 DOI: 10.1146/annurev-micro-041320-011520] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Like many intracellular pathogens, the protozoan parasite Toxoplasma gondii has evolved sophisticated mechanisms to promote its transmission and persistence in a variety of hosts by injecting effector proteins that manipulate many processes in the cells it invades. Specifically, the parasite diverts host epigenetic modulators and modifiers from their native functions to rewire host gene expression to counteract the innate immune response and to limit its strength. The arms race between the parasite and its hosts has led to accelerated adaptive evolution of effector proteins and the unconventional secretion routes they use. This review provides an up-to-date overview of how T. gondii effectors, through the evolution of intrinsically disordered domains, the formation of supramolecular complexes, and the use of molecular mimicry, target host transcription factors that act as coordinating nodes, as well as chromatin-modifying enzymes, to control the fate of infected cells and ultimately the outcome of infection. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Mohamed-Ali Hakimi
- Host-Pathogen Interactions and Immunity to Infection, Institute for Advanced Biosciences (IAB), INSERM U1209, CNRS UMR 5309, Grenoble Alpes University, Grenoble, France;
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17
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Transgenerational epigenetic impacts of parental infection on offspring health and disease susceptibility. Trends Genet 2022; 38:662-675. [PMID: 35410793 PMCID: PMC8992946 DOI: 10.1016/j.tig.2022.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 12/12/2022]
Abstract
Maternal immune activation (MIA) and infection during pregnancy are known to reprogramme offspring phenotypes. However, the epigenetic effects of preconceptual paternal infection and paternal immune activation (PIA) are not currently well understood. Recent reports show that paternal infection and immune activation can affect offspring phenotypes, particularly brain function, behaviour, and immune system functioning, across multiple generations without re-exposure to infection. Evidence from other environmental exposures indicates that epigenetic inheritance also occurs in humans. Given the growing impact of the coronavirus disease 2019 (COVID-19) pandemic, it is imperative that we investigate all of the potential epigenetic mechanisms and multigenerational phenotypes that may arise from both maternal and paternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as well as associated MIA, PIA, and inflammation. This will allow us to understand and, if necessary, mitigate any potential changes in disease susceptibility in the children, and grandchildren, of affected parents.
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18
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Seizova S, Ruparel U, Garnham AL, Bader SM, Uboldi AD, Coffey MJ, Whitehead LW, Rogers KL, Tonkin CJ. Transcriptional modification of host cells harboring Toxoplasma gondii bradyzoites prevents IFN gamma-mediated cell death. Cell Host Microbe 2021; 30:232-247.e6. [PMID: 34921775 DOI: 10.1016/j.chom.2021.11.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/05/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022]
Abstract
Toxoplasma gondii develops a latent infection in the muscle and central nervous system that acts as a reservoir for acute-stage reactivation in vulnerable patients. Little is understood about how parasites manipulate host cells during latent infection and the impact this has on survival. We show that bradyzoites impart a unique transcriptional signature on infected host cells. Many of these transcriptional changes rely on protein export and result in the suppression of type I interferon (IFN) and IFNγ signaling more so than in acute stages. Loss of the protein export component, MYR1, abrogates transcriptional remodeling and prevents suppression of IFN signaling. Among the exported proteins, the inhibitor of STAT1 transcription (IST) plays a key role in limiting IFNγ signaling in bradyzoites. Furthermore, bradyzoite protein export protects host cells from IFNγ-mediated cell death, even when export is restricted to latent stages. These findings highlight the functional importance of host manipulation in Toxoplasma's bradyzoite stages.
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Affiliation(s)
- Simona Seizova
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia; Wellcome Center for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee DD1 5EH, UK
| | - Ushma Ruparel
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Alexandra L Garnham
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Stefanie M Bader
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Alessandro D Uboldi
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael J Coffey
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia; Poseida Therapeutics, San Diego, CA, USA
| | - Lachlan W Whitehead
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Kelly L Rogers
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Christopher J Tonkin
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia.
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19
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Frickel EM, Hunter CA. Lessons from Toxoplasma: Host responses that mediate parasite control and the microbial effectors that subvert them. J Exp Med 2021; 218:212714. [PMID: 34670268 PMCID: PMC8532566 DOI: 10.1084/jem.20201314] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/03/2021] [Accepted: 09/29/2021] [Indexed: 11/15/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii has long provided a tractable experimental system to investigate how the immune system deals with intracellular infections. This review highlights the advances in defining how this organism was first detected and the studies with T. gondii that contribute to our understanding of how the cytokine IFN-γ promotes control of vacuolar pathogens. In addition, the genetic tractability of this eukaryote organism has provided the foundation for studies into the diverse strategies that pathogens use to evade antimicrobial responses and now provides the opportunity to study the basis for latency. Thus, T. gondii remains a clinically relevant organism whose evolving interactions with the host immune system continue to teach lessons broadly relevant to host–pathogen interactions.
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Affiliation(s)
- Eva-Maria Frickel
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, UK
| | - Christopher A Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
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20
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de Faria Junior GM, Murata FHA, Lorenzi HA, Castro BBP, Assoni LCP, Ayo CM, Brandão CC, de Mattos LC. The Role of microRNAs in the Infection by T. gondii in Humans. Front Cell Infect Microbiol 2021; 11:670548. [PMID: 34055667 PMCID: PMC8160463 DOI: 10.3389/fcimb.2021.670548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022] Open
Abstract
MicroRNAs are molecules belonging to an evolutionarily conserved family of small non-coding RNAs, which act on post-transcriptional gene regulation, causing messenger RNA (mRNA) degradation or inhibiting mRNA translation into proteins. These molecules represent potential biomarkers for diagnosis, non-invasive prognosis, and monitoring the development of the disease. Moreover, they may provide additional information on the pathophysiology of parasitic infections and guide strategies for treatment. The Apicomplexan parasite Toxoplasma gondii modifies the levels of microRNAs and mRNAs in infected host cells by modulating the innate and adaptive immune responses, facilitating its survival within the host. Some studies have shown that microRNAs are promising molecular markers for developing diagnostic tools for human toxoplasmosis. MicroRNAs can be detected in human specimens collected using non-invasive procedures. changes in the circulating host microRNAs have been associated with T. gondii infection in mice and ocular toxoplasmosis in humans. Besides, microRNAs can be amplified from samples using sensitive and molecular-specific approaches such as real-time PCR. This review presents recent findings of the role that microRNAs play during T. gondii infection and discuss their potential use of these small nuclei acid molecules to different approaches such as laboratory diagnosis, modulation of cell and tissue infected as other potential applications in human toxoplasmosis.
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Affiliation(s)
- Geraldo Magela de Faria Junior
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Fernando Henrique Antunes Murata
- Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, United States
| | | | - Bruno Bello Pede Castro
- Department of Preventive Veterinary Medicine and Animal Health, Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil
| | - Letícia Carolina Paraboli Assoni
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Christiane Maria Ayo
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Cinara Cássia Brandão
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
| | - Luiz Carlos de Mattos
- Immunogenetics Laboratory, Molecular Biology Department, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, Brazil
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21
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Panas MW, Boothroyd JC. Seizing control: How dense granule effector proteins enable Toxoplasma to take charge. Mol Microbiol 2021; 115:466-477. [PMID: 33400323 PMCID: PMC8344355 DOI: 10.1111/mmi.14679] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/02/2021] [Accepted: 01/03/2021] [Indexed: 12/24/2022]
Abstract
Control of the host cell is crucial to the Apicomplexan parasite, Toxoplasma gondii, while it grows intracellularly. To achieve this goal, these single-celled eukaryotes export a series of effector proteins from organelles known as "dense granules" that interfere with normal cellular processes and responses to invasion. While some effectors are found attached to the outer surface of the parasitophorous vacuole (PV) in which Toxoplasma tachyzoites reside, others are found in the host cell's cytoplasm and yet others make their way into the host nucleus, where they alter host transcription. Among the processes that are severely altered are innate immune responses, host cell cycle, and association with host organelles. The ways in which these crucial processes are altered through the coordinated action of a large collection of effectors is as elegant as it is complex, and is the central focus of the following review; we also discuss the recent advances in our understanding of how dense granule effector proteins are trafficked out of the PV.
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Affiliation(s)
- Michael W. Panas
- Dept. Microbiology and Immunology, Stanford University School of Medicine, Stanford CA 94305
| | - John C. Boothroyd
- Dept. Microbiology and Immunology, Stanford University School of Medicine, Stanford CA 94305
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22
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Hu RS, He JJ, Elsheikha HM, Zou Y, Ehsan M, Ma QN, Zhu XQ, Cong W. Transcriptomic Profiling of Mouse Brain During Acute and Chronic Infections by Toxoplasma gondii Oocysts. Front Microbiol 2020; 11:570903. [PMID: 33193165 PMCID: PMC7604304 DOI: 10.3389/fmicb.2020.570903] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/21/2020] [Indexed: 01/25/2023] Open
Abstract
Infection by the protozoan Toxoplasma gondii can have a devastating impact on the structure and function of the brain of the infected individuals, particularly immunocompromised patients. A systems biology view of the brain transcriptome can identify key molecular targets and pathways that mediate the neuropathogenesis of cerebral toxoplasmosis. Here, we performed transcriptomic analysis of the brain of mice infected by T. gondii Pru strain oocysts at 11 and 33 days post-infection (dpi) compared to uninfected (control) mice using RNA sequencing (RNA-seq). T. gondii altered the expression of 936 and 2,081 transcripts at 11 and 33 dpi, respectively, and most of these were upregulated in the infected brains. Gene Ontology (GO) enrichment and pathway analysis showed that immune response, such as interferon-gamma (IFN-γ) responsive genes were strongly affected at 11dpi. Likewise, differentially expressed transcripts (DETs) related to T cell activation, cytokine production and immune cell proliferation were significantly altered at 33 dpi. Host-parasite interactome analysis showed that some DETs were involved in immune signaling, metabolism, biosynthesis-related processes and interspecies interaction. These findings should increase knowledge of the mouse brain transcriptome and the changes in transcriptional regulation and downstream signaling pathways during acute and chronic T. gondii infections.
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Affiliation(s)
- Rui-Si Hu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Jun-Jun He
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - Yang Zou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Muhammad Ehsan
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qiao-Ni Ma
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - Wei Cong
- Marine College, Shandong University, Weihai, China
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23
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Nast R, Choepak T, Lüder CGK. Epigenetic Control of IFN-γ Host Responses During Infection With Toxoplasma gondii. Front Immunol 2020; 11:581241. [PMID: 33072127 PMCID: PMC7544956 DOI: 10.3389/fimmu.2020.581241] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/26/2020] [Indexed: 01/21/2023] Open
Abstract
Host defense against the human pathogen Toxoplasma gondii depends on secretion of interferon (IFN)-γ and subsequent activation of monocytic cells to combat intracellular parasites. Previous studies have shown that T. gondii evades IFN-γ-mediated immunity by secreting the effector TgIST into the host cell where it binds to STAT1, strengthens its DNA binding activity and recruits the Mi-2/NuRD complex to STAT1-responsive promoters. Here we investigated the impact of the host chromatin environment on parasite interference with IFN-γ-induced gene expression. Luciferase reporters under control of primary and secondary IFN-γ response promoters were only inhibited by T. gondii when they were stably integrated into the host genome but not when expressed from a plasmid vector. Absence of CpG islands upstream and/or downstream of the transcriptional start site allowed more vigorous up-regulation by IFN-γ as compared to CpG-rich promoters. Remarkably, it also favored parasite interference with IFN-γ-induced gene expression indicating that nucleosome occupancy at IFN-γ-responsive promoters is important. Promoter DNA of IFN-γ-responsive genes remained largely non-methylated in T. gondii-infected cells, and inhibition of DNA methylation did not impact parasite interference with host responses. IFN-γ up-regulated histone marks H4ac, H3K9ac, and H3K4me3 but down-regulated H3S10p at primary and secondary response promoters. Infection with T. gondii abolished histone modification, whereas total nuclear activities of histone acetyl transferases and histone deacetylases were not altered. Taken together, our study reveals a critical impact of the host chromatin landscape at IFN-γ-activated promoters on their inhibition by T. gondii with a comprehensive blockade of histone modifications at parasite-inactivated promoters.
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Affiliation(s)
- Roswitha Nast
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August-University, Göttingen, Germany
| | - Tenzin Choepak
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August-University, Göttingen, Germany
| | - Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August-University, Göttingen, Germany
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24
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Sabou M, Doderer-Lang C, Leyer C, Konjic A, Kubina S, Lennon S, Rohr O, Viville S, Cianférani S, Candolfi E, Pfaff AW, Brunet J. Toxoplasma gondii ROP16 kinase silences the cyclin B1 gene promoter by hijacking host cell UHRF1-dependent epigenetic pathways. Cell Mol Life Sci 2020; 77:2141-2156. [PMID: 31492965 PMCID: PMC7256068 DOI: 10.1007/s00018-019-03267-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/12/2019] [Accepted: 08/05/2019] [Indexed: 12/23/2022]
Abstract
Toxoplasmosis, caused by the apicomplexan parasite Toxoplasma gondii, is one of the most common infections in the world due to the lifelong persistence of this parasite in a latent stage. This parasite hijacks host signaling pathways through epigenetic mechanisms which converge on key nuclear proteins. Here, we report a new parasite persistence strategy involving T. gondii rhoptry protein ROP16 secreted early during invasion, which targets the transcription factor UHRF1 (ubiquitin-like containing PHD and RING fingers domain 1), and leads to host cell cycle arrest. This is mediated by DNMT activity and chromatin remodeling at the cyclin B1 gene promoter through recruitment of phosphorylated UHRF1 associated with a repressive multienzymatic protein complex. This leads to deacetylation and methylation of histone H3 surrounding the cyclin B1 promoter to epigenetically silence its transcriptional activity. Moreover, T. gondii infection causes DNA hypermethylation in its host cell, by upregulation of DNMTs. ROP16 is already known to activate and phosphorylate protective immunity transcription factors such as STAT 3/6/5 and modulate host signaling pathways in a strain-dependent manner. Like in the case of STAT6, the strain-dependent effects of ROP16 on UHRF1 are dependent on a single amino-acid polymorphism in ROP16. This study demonstrates that Toxoplasma hijacks a new epigenetic initiator, UHRF1, through an early event initiated by the ROP16 parasite kinase.
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Affiliation(s)
- Marcela Sabou
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
- Service de Parasitologie et Mycologie Médicale, Hôpitaux Universitaires de Strasbourg, Centre National de Référence de la Toxoplasmose, Pôle Sérologie, Strasbourg, France
| | - Cécile Doderer-Lang
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
| | - Caroline Leyer
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
| | - Ana Konjic
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
| | - Sophie Kubina
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
| | - Sarah Lennon
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), Université de Strasbourg, IPHC, CNRS, UMR7178, Strasbourg, France
| | - Olivier Rohr
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
| | - Stéphane Viville
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), Université de Strasbourg, IPHC, CNRS, UMR7178, Strasbourg, France
| | - Ermanno Candolfi
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
- Service de Parasitologie et Mycologie Médicale, Hôpitaux Universitaires de Strasbourg, Centre National de Référence de la Toxoplasmose, Pôle Sérologie, Strasbourg, France
| | - Alexander W Pfaff
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France.
- Service de Parasitologie et Mycologie Médicale, Hôpitaux Universitaires de Strasbourg, Centre National de Référence de la Toxoplasmose, Pôle Sérologie, Strasbourg, France.
| | - Julie Brunet
- Institut de Parasitologie et de Pathologie Tropicale de Strasbourg, « Dynamics of Host-Pathogen Interactions » EA 7292, Fédération de Médecine Translationelle Université de Strasbourg, Strasbourg, France
- Service de Parasitologie et Mycologie Médicale, Hôpitaux Universitaires de Strasbourg, Centre National de Référence de la Toxoplasmose, Pôle Sérologie, Strasbourg, France
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25
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Wong ZS, Borrelli SLS, Coyne CC, Boyle JP. Cell type- and species-specific host responses to Toxoplasma gondii and its near relatives. Int J Parasitol 2020; 50:423-431. [PMID: 32407716 PMCID: PMC8281328 DOI: 10.1016/j.ijpara.2020.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 10/24/2022]
Abstract
Toxoplasma gondii is remarkably unique in its ability to successfully infect vertebrate hosts from multiple phyla and can successfully infect most cells within these organisms. The infection outcome in each of these species is determined by the complex interaction between parasite and host genotype. As techniques to quantify global changes in cell function become more readily available and precise, new data are coming to light about how (i) different host cell types respond to parasitic infection and (ii) different parasite species impact the host. Here we focus on recent studies comparing the response to intracellular parasitism by different cell types and insights into understanding host-parasite interactions from comparative studies on T. gondii and its close extant relatives.
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Affiliation(s)
- Zhee S Wong
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sarah L Sokol Borrelli
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, United States
| | - Carolyn C Coyne
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Jon P Boyle
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, United States.
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26
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Nandakumar R, Paludan SR. T. gondii inveSTING in a latent future. J Biol Chem 2019; 294:16509-16510. [PMID: 31704772 DOI: 10.1074/jbc.h119.011296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii is an obligate protozoan parasite that naturally infects all mammals, where it alters the host environment to establish chronic infection. Wang and colleagues uncover a new role for the T. gondii protein GRA15 in inducing an anti-parasite response via the interferon stimulator STING. This parasite-driven host defense limits Toxoplasma replication while maintaining host survival, creating an ideal niche for the establishment of latency.
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Affiliation(s)
- Ramya Nandakumar
- Department of Biomedicine, Aarhus University, CF Mφllers Alle 6, Building 1115, Aarhus C DK-8000, Denmark
| | - Søren R Paludan
- Department of Biomedicine, Aarhus University, CF Mφllers Alle 6, Building 1115, Aarhus C DK-8000, Denmark
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27
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Toxoplasma gondii effector TgIST blocks type I interferon signaling to promote infection. Proc Natl Acad Sci U S A 2019; 116:17480-17491. [PMID: 31413201 DOI: 10.1073/pnas.1904637116] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In contrast to the importance of type II interferon-γ (IFN-γ) in control of toxoplasmosis, the role of type I IFN is less clear. We demonstrate here that TgIST, a secreted effector previously implicated in blocking type II IFN-γ signaling, also blocked IFN-β responses by inhibiting STAT1/STAT2-mediated transcription in infected cells. Consistent with a role for type I IFN in cell intrinsic control, ∆Tgist mutants were more susceptible to growth inhibition by murine and human macrophages activated with IFN-β. Additionally, type I IFN was important for production of IFN-γ by natural killer (NK) cells and recruitment of inflammatory monocytes at the site of infection. Mice lacking type I IFN receptors (Ifnar1-/-) showed increased mortality following infection with wild-type parasites and decreased virulence of ∆Tgist parasites was restored in Ifnar1-/- mice. The findings highlight the importance of type I IFN in control of toxoplasmosis and illuminate a parasite mechanism to counteract the effects of both type I and II IFN-mediated host defenses.
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28
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Tyebji S, Seizova S, Garnham AL, Hannan AJ, Tonkin CJ. Impaired social behaviour and molecular mediators of associated neural circuits during chronic Toxoplasma gondii infection in female mice. Brain Behav Immun 2019; 80:88-108. [PMID: 30807837 DOI: 10.1016/j.bbi.2019.02.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/15/2019] [Accepted: 02/22/2019] [Indexed: 12/24/2022] Open
Abstract
Toxoplasma gondii (T. gondii) is a neurotropic parasite that is associated with various neuropsychiatric disorders. Rodents infected with T. gondii display a plethora of behavioural alterations, and Toxoplasma infection in humans has been strongly associated with disorders such as schizophrenia, in which impaired social behaviour is an important feature. Elucidating changes at the cellular level relevant to neuropsychiatric conditions can lead to effective therapies. Here, we compare changes in behaviour during an acute and chronic T. gondii infection in female mice. Further, we notice that during chronic phase of infection, mice display impaired sociability when exposed to a novel conspecific. Also, we show that T. gondii infected mice display impaired short-term social recognition memory. However, object recognition memory remains intact. Using c-Fos as a marker of neuronal activity, we show that infection leads to an impairment in neuronal activation in the medial prefrontal cortex, hippocampus as well as the amygdala when mice are exposed to a social environment and a change in functional connectivity between these regions. We found changes in synaptic proteins that play a role in the process of neuronal activation such as synaptophysin, PSD-95 and changes in downstream substrates of cell activity such as cyclic AMP, phospho-CREB and BDNF. Our results point towards an imbalance in neuronal activity that can lead to a wider range of neuropsychiatric problems upon T. gondii infection.
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Affiliation(s)
- Shiraz Tyebji
- The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne 3052, Australia; Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3052, Victoria, Australia.
| | - Simona Seizova
- The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne 3052, Australia.
| | - Alexandra L Garnham
- The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne 3052, Australia.
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3052, Victoria, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville 3052, Victoria, Australia.
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne 3052, Australia.
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29
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Bando H, Lee Y, Sakaguchi N, Pradipta A, Sakamoto R, Tanaka S, Ma JS, Sasai M, Yamamoto M. Toxoplasma Effector GRA15-Dependent Suppression of IFN-γ-Induced Antiparasitic Response in Human Neurons. Front Cell Infect Microbiol 2019; 9:140. [PMID: 31119110 PMCID: PMC6504700 DOI: 10.3389/fcimb.2019.00140] [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: 01/31/2019] [Accepted: 04/16/2019] [Indexed: 01/06/2023] Open
Abstract
Toxoplasma gondii is an important human and animal pathogen that causes life-threatening toxoplasmosis. The host immune system produces interferon-γ (IFN-γ) to inhibit T. gondii proliferation. IFN-γ-inducible indole-2,3-dioxygenase 1 (IDO1), which mediates tryptophan degradation, has a major role in anti-T. gondii immune responses in various human cells. In response to the host's immune system, T. gondii secretes many virulence molecules into the host cells to suppress IFN-γ-dependent antiparasitic immune responses. The GRA15-induced proparasitic mechanism for suppressing IDO1-dependent immune responses has previously been tested only in human hepatocyte and monocyte co-cultures. Thus, whether human cells other than hepatocytes contain this virulence mechanism remains unclear. Here, we show that the GRA15-dependent virulence mechanism for suppressing the IDO1-dependent anti-T. gondii response operates in human neuronal cell lines and primary human neurons. Analysis of various human cell lines revealed that IL-1β-induced iNOS-dependent reduction of IDO1 mRNA expression occurred in brain cell lines (A172; glioblastoma, IMR-32; neuroblastoma, and T98G; glioblastoma) and liver cell lines (Huh7 and HepG2), but not in other cell lines. Moreover, co-culturing type II T. gondii-infected THP-1 human monocytes with the brain cell lines inhibited the IDO1-mediated anti-T. gondii response in a GRA15-dependent manner. These data suggest that a GRA15-dependent virulence mechanism antagonizes the IDO1-dependent host immune response in human brain cells.
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Affiliation(s)
- Hironori Bando
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Youngae Lee
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Naoya Sakaguchi
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan
| | - Ariel Pradipta
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan
| | - Ryoma Sakamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan
| | - Shun Tanaka
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan
| | - Ji Su Ma
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Suita, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
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30
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Lima TS, Lodoen MB. Mechanisms of Human Innate Immune Evasion by Toxoplasma gondii. Front Cell Infect Microbiol 2019; 9:103. [PMID: 31041194 PMCID: PMC6476913 DOI: 10.3389/fcimb.2019.00103] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/25/2019] [Indexed: 12/16/2022] Open
Abstract
Toxoplasma gondii is an intracellular protozoan parasite of global importance that can remarkably infect, survive, and replicate in nearly all mammalian cells. Notably, 110 years after its discovery, Toxoplasmosis is still a neglected parasitic infection. Although most human infections with T. gondii are mild or asymptomatic, T. gondii infection can result in life-threatening disease in immunocompromised individuals and in the developing fetus due to congenital infection, underscoring the role of the host immune system in controlling the parasite. Recent evidence indicates that T. gondii elicits a robust innate immune response during infection. Interestingly, however, T. gondii has evolved strategies to successfully bypass or manipulate the immune system and establish a life-long infection in infected hosts. In particular, T. gondii manipulates host immunity through the control of host gene transcription and dysregulation of signaling pathways that result in modulation of cell adhesion and migration, secretion of immunoregulatory cytokines, production of microbicidal molecules, and apoptosis. Many of these host-pathogen interactions are governed by parasite effector proteins secreted from the apical secretory organelles, including the rhoptries and dense granules. Here, we review recent findings on mechanisms by which T. gondii evades host innate immunity, with a focus on parasite evasion of the human innate immune system.
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Affiliation(s)
- Tatiane S Lima
- Department of Molecular Biology and Biochemistry and the Institute for Immunology, University of California, Irvine, Irvine, CA, United States
| | - Melissa B Lodoen
- Department of Molecular Biology and Biochemistry and the Institute for Immunology, University of California, Irvine, Irvine, CA, United States
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31
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Tyebji S, Seizova S, Hannan AJ, Tonkin CJ. Toxoplasmosis: A pathway to neuropsychiatric disorders. Neurosci Biobehav Rev 2018; 96:72-92. [PMID: 30476506 DOI: 10.1016/j.neubiorev.2018.11.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/23/2018] [Accepted: 11/22/2018] [Indexed: 12/24/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite that resides, in a latent form, in the human central nervous system. Infection with Toxoplasma drastically alters the behaviour of rodents and is associated with the incidence of specific neuropsychiatric conditions in humans. But the question remains: how does this pervasive human pathogen alter behaviour of the mammalian host? This fundamental question is receiving increasing attention as it has far reaching public health implications for a parasite that is very common in human populations. Our current understanding centres on neuronal changes that are elicited directly by this intracellular parasite versus indirect changes that occur due to activation of the immune system within the CNS, or a combination of both. In this review, we explore the interactions between Toxoplasma and its host, the proposed mechanisms and consequences on neuronal function and mental health, and discuss Toxoplasma infection as a public health issue.
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Affiliation(s)
- Shiraz Tyebji
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, 3052, Australia; Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, 3052, Victoria, Australia.
| | - Simona Seizova
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, 3052, Australia.
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, 3052, Victoria, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville, 3052, Victoria, Australia.
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, 3052, Australia.
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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: 30] [Impact Index Per Article: 5.0] [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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De Souza RAG, Kosior N, Thomson SB, Mathelier A, Zhang AW, Bečanović K, Wasserman WW, Leavitt BR. Computational Analysis of Transcriptional Regulation Sites at the HTT Gene Locus. J Huntingtons Dis 2018; 7:223-237. [PMID: 30103339 DOI: 10.3233/jhd-170272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Huntington's disease is a late onset neurological disorder caused by a trinucleotide CAG repeat expansion mutation in the HTT gene encoding for the protein huntingtin. Despite considerable ongoing research, the wild-type function of huntingtin is not yet fully understood. OBJECTIVE To improve knowledge of HTT gene regulation at the transcriptional level and inform future studies aimed at uncovering the HTT gene's normal function. METHODS The HTT gene region was functionally characterized through an in silico analysis using publicly available data sets. ChIP-seq data sets and the online STRING database were used to identify putative transcription factor binding sites (TFBSs) and protein-protein interactions within the HTT promoter region. siRNA-mediated knockdown and ChIP-qPCR of STAT1, a TF identified from the in silico analysis, were used to validate the bioinformatics screen. RESULTS 16 regions containing potential regulatory genomic markers were identified. TFBSs for 59 transcription factors (TFs) were detected in one or more of the 16 candidate regions. Using these TFs, 15 clusters of protein-protein interactions were identified using STRING. siRNA-mediated knockdown of STAT1 resulted in an increase in HTT expression, and ChIP-qPCR detected enrichment of STAT1 binding at one of the predicted regions. These assays confirmed the utility of the bioinformatic analysis. CONCLUSIONS Putative regulatory regions outside of the immediate HTT promoter region have been identified with specific protein-protein interactions. Future work will focus on in vitro and in vivo studies to examine the effect of modulating identified TFBSs and altering the levels of specific TFs of interest in regulating HTT gene expression.
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Affiliation(s)
- Rebecca A G De Souza
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Natalia Kosior
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Sarah B Thomson
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Anthony Mathelier
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Allen W Zhang
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Kristina Bečanović
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Wyeth W Wasserman
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Blair R Leavitt
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
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Nast R, Staab J, Meyer T, Lüder CGK. Toxoplasma gondii stabilises tetrameric complexes of tyrosine-phosphorylated signal transducer and activator of transcription-1 and leads to its sustained and promiscuous DNA binding. Cell Microbiol 2018; 20:e12887. [PMID: 29968354 DOI: 10.1111/cmi.12887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/07/2018] [Accepted: 06/25/2018] [Indexed: 11/29/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite that infects up to 30% of humans worldwide. It can lead to severe diseases particularly in individuals with immature or defective immune responses. Control of T. gondii relies on the IFN-γ-induced signal transducer and activator of transcription-1 (STAT1) pathway. T. gondii, however, largely inactivates STAT1-mediated gene transcription by T. gondii inhibitor of STAT1-dependent transcription (TgIST), a parasite effector protein binding to STAT1. Here, we have analysed requirements of STAT1 to bind TgIST and characterised downstream effects on STAT1 signalling. TgIST bound to STAT1 dimers but more efficiently assembled with STAT1 tetramers, which are essential for effective IFN-γ responsiveness. Such binding was abrogated in N-terminal, but not C-terminal deletion mutants of STAT1. Furthermore, TgIST did not bind to the STAT1F77A substitution mutant that cannot form STAT1 tetramers, resulting in a complete unresponsiveness of parasite-infected STAT1F77A -expressing cells to IFN-γ. Remarkably, binding of TgIST considerably increased the affinity of the aberrant STAT1 tetramers for DNA consensus sequence binding motifs and even enabled binding to nonconsensus sequences. Consistent with the increased DNA binding, STAT1 from parasite-infected cells remained phosphorylated at Tyr701 and Ser727 and was retained within the nucleus in a DNA-bound state. The sustained and promiscuous binding activity particularly of STAT1 tetramers to unspecific DNA sites lacking a consensus STAT1-binding motif is an as yet unrecognised mechanism contributing to the defective IFN-γ-mediated signalling in T. gondii-infected cells.
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Affiliation(s)
- Roswitha Nast
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
| | - Julia Staab
- Psychosomatic Medicine and Psychotherapy, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
| | - Thomas Meyer
- Psychosomatic Medicine and Psychotherapy, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
| | - Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
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Romani R, Manni G, Donati C, Pirisinu I, Bernacchioni C, Gargaro M, Pirro M, Calvitti M, Bagaglia F, Sahebkar A, Clerici G, Matino D, Pomili G, Di Renzo GC, Talesa VN, Puccetti P, Fallarino F. S1P promotes migration, differentiation and immune regulatory activity in amniotic-fluid-derived stem cells. Eur J Pharmacol 2018; 833:173-182. [PMID: 29886240 PMCID: PMC6086338 DOI: 10.1016/j.ejphar.2018.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/01/2018] [Accepted: 06/06/2018] [Indexed: 12/22/2022]
Abstract
Stem cells have high potential for cell therapy in regenerative medicine. We previously isolated stem cell types from human amniotic fluid, derived from prenatal amniocentesis. One type, characterized by a fast doubling time, was designated as fast human amniotic stem cells (fHASCs). These cells exhibited high differentiation potential and immunoregulatory properties. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite that influences stem-cell pluripotency, differentiation, mobility, and regulates immune functions. In this study, we investigated the influence of S1P on fHASC migration, proliferation, differentiation and immune regulatory functions. We found that fHASC stimulation with S1P potentiated their migratory and proliferative activity in vitro. Notably, short fHASC exposure to S1P enhanced their differentiation towards multiple lineages, including adipocytes, osteocytes and endothelial cells, an effect that was associated with downregulation of the main transcription factors involved in the maintenance of a stem-cell undifferentiated state. A specific crosstalk between S1P and tumor growth factor β1 (TGF-β1) has recently been demonstrated. We found that fHASC exposure to S1P in combination with TGF-β1 promoted the expression of the immune regulatory pathway of indoleamine 2,3-dioxygenase 1 (IDO1). In addition, human peripheral blood mononuclear cells, co-cultured with fHASCs treated with S1P and TGF-β1, expanded regulatory T-cells, via a mechanism requiring IDO1. Overall, this study demonstrates that S1P potentiates several properties in fHASCs, an effect that may be critical for exploiting the therapeutic potential of fHASCs and might explain the specific effects of S1P on stem cells during pregnancy.
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Affiliation(s)
- Rita Romani
- Department of Experimental Medicine, University of Perugia, Italy
| | - Giorgia Manni
- Department of Experimental Medicine, University of Perugia, Italy
| | - Chiara Donati
- Department of Experimental Biomedical Sciences and Clinics University of Florence, Italy
| | - Irene Pirisinu
- Department of Experimental Medicine, University of Perugia, Italy
| | - Caterina Bernacchioni
- Department of Experimental Biomedical Sciences and Clinics University of Florence, Italy
| | - Marco Gargaro
- Department of Experimental Medicine, University of Perugia, Italy
| | - Matteo Pirro
- Department of Medicine, University of Perugia, Italy
| | - Mario Calvitti
- Department of Experimental Medicine, University of Perugia, Italy
| | | | - Amirhossein Sahebkar
- Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Graziano Clerici
- Department of Obstetrics and Gynaecology and Centre for Perinatal and Reproductive Medicine, University of Perugia, Perugia, Italy
| | - Davide Matino
- Department of Experimental Medicine, University of Perugia, Italy
| | - Giovanni Pomili
- Department of Obstetrics and Gynaecology and Centre for Perinatal and Reproductive Medicine, University of Perugia, Perugia, Italy
| | - Gian Carlo Di Renzo
- Department of Obstetrics and Gynaecology and Centre for Perinatal and Reproductive Medicine, University of Perugia, Perugia, Italy
| | | | - Paolo Puccetti
- Department of Experimental Medicine, University of Perugia, Italy
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Naor A, Panas MW, Marino N, Coffey MJ, Tonkin CJ, Boothroyd JC. MYR1-Dependent Effectors Are the Major Drivers of a Host Cell's Early Response to Toxoplasma, Including Counteracting MYR1-Independent Effects. mBio 2018; 9:e02401-17. [PMID: 29615509 PMCID: PMC5885026 DOI: 10.1128/mbio.02401-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/07/2018] [Indexed: 01/08/2023] Open
Abstract
The obligate intracellular parasite Toxoplasma gondii controls its host cell from within the parasitophorous vacuole (PV) by using a number of diverse effector proteins, a subset of which require the aspartyl protease 5 enzyme (ASP5) and/or the recently discovered MYR1 protein to cross the PV membrane. To examine the impact these effectors have in the context of the entirety of the host response to Toxoplasma, we used RNA-Seq to analyze the transcriptome expression profiles of human foreskin fibroblasts infected with wild-type RH (RH-WT), RHΔmyr1, and RHΔasp5 tachyzoites. Interestingly, the majority of the differentially regulated genes responding to Toxoplasma infection are MYR1 dependent. A subset of MYR1 responses were ASP5 independent, and MYR1 function did not require ASP5 cleavage, suggesting the export of some effectors requires only MYR1. Gene set enrichment analysis of MYR1-dependent host responses suggests an upregulation of E2F transcription factors and the cell cycle and a downregulation related to interferon signaling, among numerous others. Most surprisingly, "hidden" responses arising in RHΔmyr1- but not RH-WT-infected host cells indicate counterbalancing actions of MYR1-dependent and -independent activities. The host genes and gene sets revealed here to be MYR1 dependent provide new insight into the parasite's ability to co-opt host cell functions.IMPORTANCEToxoplasma gondii is unique in its ability to successfully invade and replicate in a broad range of host species and cells within those hosts. The complex interplay of effector proteins exported by Toxoplasma is key to its success in co-opting the host cell to create a favorable replicative niche. Here we show that a majority of the transcriptomic effects in tachyzoite-infected cells depend on the activity of a novel translocation system involving MYR1 and that the effectors delivered by this system are part of an intricate interplay of activators and suppressors. Removal of all MYR1-dependent effectors reveals previously unknown activities that are masked or hidden by the action of these proteins.
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Affiliation(s)
- Adit Naor
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Michael W Panas
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Nicole Marino
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Michael J Coffey
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Christopher J Tonkin
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
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Kim YH, Bhatt L, Ahn HJ, Yang Z, Lee WK, Nam HW. Suppressors for Human Epidermal Growth Factor Receptor 2/4 (HER2/4): A New Family of Anti-Toxoplasmic Agents in ARPE-19 Cells. THE KOREAN JOURNAL OF PARASITOLOGY 2017; 55:491-503. [PMID: 29103264 PMCID: PMC5678465 DOI: 10.3347/kjp.2017.55.5.491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/17/2017] [Accepted: 09/26/2017] [Indexed: 11/23/2022]
Abstract
The effects of tyrosine kinase inhibitors (TKIs) were evaluated on growth inhibition of intracellular Toxoplasma gondii in host ARPE-19 cells. The number of tachyzoites per parasitophorous vacuolar membrane (PVM) was counted after treatment with TKIs. T. gondii protein expression was assessed by western blot. Immunofluorescence assay was performed using Programmed Cell Death 4 (PDCD4) and T. gondii GRA3 antibodies. The TKIs were divided into 3 groups; non-epidermal growth factor receptor (non-EGFR), anti-human EGFR 2 (anti-HER2), and anti-HER2/4 TKIs, respectively. Group I TKIs (nintedanib, AZD9291, and sunitinib) were unable to inhibit proliferation without destroying host cells. Group II TKIs (lapatinib, gefitinib, erlotinib, and AG1478) inhibited proliferation up to 98% equivalent to control pyrimethamine (5 μM) at 20 μM and higher, without affecting host cells. Group III TKIs (neratinib, dacomitinib, afatinib, and pelitinib) inhibited proliferation up to 98% equivalent to pyrimethamine at 1–5 μM, but host cells were destroyed at 10–20 μM. In Group I, TgHSP90 and SAG1 inhibitions were weak, and GRA3 expression was moderately inhibited. In Group II, TgHSP90 and SAG1 expressions seemed to be slightly enhanced, while GRA3 showed none to mild inhibition; however, AG1478 inhibited all proteins moderately. Protein expression was blocked in Group III, comparable to pyrimethamine. PDCD4 and GRA3 were well localized inside the nuclei in Group I, mildly disrupted in Group II, and were completely disrupted in Group III. This study suggests the possibility of a vital T. gondii TK having potential HER2/4 properties, thus anti-HER2/4 TKIs may inhibit intracellular parasite proliferation with minimal adverse effects on host cells.
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Affiliation(s)
- Yeong Hoon Kim
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Lokraj Bhatt
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Hye-Jin Ahn
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Zhaoshou Yang
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Won-Kyu Lee
- Osong Medical Innovation Foundation, Cheongju 28160, Korea
| | - Ho-Woo Nam
- Department of Parasitology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
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39
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Sumpf K, Nast R, Downie B, Salinas G, Lüder CG. Histone deacetylase inhibitor MS-275 augments expression of a subset of IFN-γ-regulated genes in Toxoplasma gondii-infected macrophages but does not improve parasite control. Exp Parasitol 2017; 180:45-54. [DOI: 10.1016/j.exppara.2017.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 01/10/2017] [Accepted: 02/07/2017] [Indexed: 01/17/2023]
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40
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Olias P, Etheridge RD, Zhang Y, Holtzman MJ, Sibley LD. Toxoplasma Effector Recruits the Mi-2/NuRD Complex to Repress STAT1 Transcription and Block IFN-γ-Dependent Gene Expression. Cell Host Microbe 2017; 20:72-82. [PMID: 27414498 DOI: 10.1016/j.chom.2016.06.006] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/09/2016] [Accepted: 06/09/2016] [Indexed: 12/12/2022]
Abstract
Interferon gamma (IFN-γ) is an essential mediator of host defense against intracellular pathogens, including the protozoan parasite Toxoplasma gondii. However, prior T. gondii infection blocks IFN-γ-dependent gene transcription, despite the downstream transcriptional activator STAT1 being activated and bound to cognate nuclear promoters. We identify the parasite effector that blocks STAT1-dependent transcription and show it is associated with recruitment of the Mi-2 nucleosome remodeling and deacetylase (NuRD) complex, a chromatin-modifying repressor. This secreted effector, toxoplasma inhibitor of STAT1-dependent transcription (TgIST), translocates to the host cell nucleus, where it recruits Mi-2/NuRD to STAT1-dependent promoters, resulting in altered chromatin and blocked transcription. TgIST is conserved across strains, underlying their shared ability to block IFN-γ-dependent transcription. TgIST deletion results in increased parasite clearance in IFN-γ-activated cells and reduced mouse virulence, which is restored in IFN-γ-receptor-deficient mice. These findings demonstrate the importance of both IFN-γ responses and the ability of pathogens to counteract these defenses.
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Affiliation(s)
- Philipp Olias
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ronald D Etheridge
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yong Zhang
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael J Holtzman
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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41
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Abstract
Early electron microscopy studies revealed the elaborate cellular features that define the unique adaptations of apicomplexan parasites. Among these were bulbous rhoptry (ROP) organelles and small, dense granules (GRAs), both of which are secreted during invasion of host cells. These early morphological studies were followed by the exploration of the cellular contents of these secretory organelles, revealing them to be comprised of highly divergent protein families with few conserved domains or predicted functions. In parallel, studies on host-pathogen interactions identified many host signaling pathways that were mysteriously altered by infection. It was only with the advent of forward and reverse genetic strategies that the connections between individual parasite effectors and the specific host pathways that they targeted finally became clear. The current repertoire of parasite effectors includes ROP kinases and pseudokinases that are secreted during invasion and that block host immune pathways. Similarly, many secretory GRA proteins alter host gene expression by activating host transcription factors, through modification of chromatin, or by inducing small noncoding RNAs. These effectors highlight novel mechanisms by which T. gondii has learned to harness host signaling to favor intracellular survival and will guide future studies designed to uncover the additional complexity of this intricate host-pathogen interaction.
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42
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Silva-Barrios S, Stäger S. Protozoan Parasites and Type I IFNs. Front Immunol 2017; 8:14. [PMID: 28154565 PMCID: PMC5243830 DOI: 10.3389/fimmu.2017.00014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 01/05/2017] [Indexed: 12/16/2022] Open
Abstract
For many years, the role of interferon (IFN)-I has been characterized primarily in the context of viral infections. However, regulatory functions mediated by IFN-I have also been described against bacterial infections and in tumor immunology. Only recently, the interest in understanding the immune functions mediated by IFN-I has dramatically increased in the field of protozoan infections. In this review, we discuss the discrete role of IFN-I in the immune response against major protozoan infections: Plasmodium, Leishmania, Trypanosoma, and Toxoplasma.
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Affiliation(s)
- Sasha Silva-Barrios
- INRS-Institut Armand Frappier, Center for Host-Parasite Interactions , Laval, QC , Canada
| | - Simona Stäger
- INRS-Institut Armand Frappier, Center for Host-Parasite Interactions , Laval, QC , Canada
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43
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Li D, Wei J, Yang F, Liu HN, Zhu ZX, Cao WJ, Li S, Liu XT, Zheng HX, Shu HB. Foot-and-mouth disease virus structural protein VP3 degrades Janus kinase 1 to inhibit IFN-γ signal transduction pathways. Cell Cycle 2016; 15:850-60. [PMID: 26901336 DOI: 10.1080/15384101.2016.1151584] [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] [Indexed: 12/24/2022] Open
Abstract
Foot-and-mouth disease is a highly contagious viral disease of cloven-hoofed animals that is caused by foot-and-mouth disease virus (FMDV). To replicate efficiently in vivo, FMDV has evolved methods to circumvent host antiviral defense mechanisms, including those induced by interferons (IFNs). Previous research has focused on the effect of FMDV L(pro) and 3C(pro) on type I IFNs. In this study, FMDV VP3 was found to inhibit type II IFN signaling pathways. The overexpression of FMDV VP3 inhibited the IFN-γ-triggered phosphorylation of STAT1 at Tyr701 and the subsequent expression of downstream genes. Mechanistically, FMDV VP3 interacted with JAK1/2 and inhibited the tyrosine phosphorylation, dimerization and nuclear accumulation of STAT1. FMDV VP3 also disrupted the assembly of the JAK1 complex and degraded JAK1 but not JAK2 via a lysosomal pathway. Taken together, the results reveal a novel mechanism used by which FMDV VP3 counteracts the type II IFN signaling pathways.
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Affiliation(s)
- Dan Li
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Jin Wei
- b Collaborative Innovation Center for Viral Immunology, Medical Research Institute, Wuhan University , Wuhan , China
| | - Fan Yang
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Hua-Nan Liu
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Zi-Xiang Zhu
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Wei-Jun Cao
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Shu Li
- b Collaborative Innovation Center for Viral Immunology, Medical Research Institute, Wuhan University , Wuhan , China
| | - Xiang-Tao Liu
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Hai-Xue Zheng
- a State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Diseases Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences , Lanzhou , China
| | - Hong-Bing Shu
- b Collaborative Innovation Center for Viral Immunology, Medical Research Institute, Wuhan University , Wuhan , China
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Gay G, Braun L, Brenier-Pinchart MP, Vollaire J, Josserand V, Bertini RL, Varesano A, Touquet B, De Bock PJ, Coute Y, Tardieux I, Bougdour A, Hakimi MA. Toxoplasma gondii TgIST co-opts host chromatin repressors dampening STAT1-dependent gene regulation and IFN-γ-mediated host defenses. J Exp Med 2016; 213:1779-98. [PMID: 27503074 PMCID: PMC4995087 DOI: 10.1084/jem.20160340] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/22/2016] [Indexed: 11/04/2022] Open
Abstract
An early hallmark of Toxoplasma gondii infection is the rapid control of the parasite population by a potent multifaceted innate immune response that engages resident and homing immune cells along with pro- and counter-inflammatory cytokines. In this context, IFN-γ activates a variety of T. gondii-targeting activities in immune and nonimmune cells but can also contribute to host immune pathology. T. gondii has evolved mechanisms to timely counteract the host IFN-γ defenses by interfering with the transcription of IFN-γ-stimulated genes. We now have identified TgIST (T. gondii inhibitor of STAT1 transcriptional activity) as a critical molecular switch that is secreted by intracellular parasites and traffics to the host cell nucleus where it inhibits STAT1-dependent proinflammatory gene expression. We show that TgIST not only sequesters STAT1 on dedicated loci but also promotes shaping of a nonpermissive chromatin through its capacity to recruit the nucleosome remodeling deacetylase (NuRD) transcriptional repressor. We found that during mice acute infection, TgIST-deficient parasites are rapidly eliminated by the homing Gr1(+) inflammatory monocytes, thus highlighting the protective role of TgIST against IFN-γ-mediated killing. By uncovering TgIST functions, this study brings novel evidence on how T. gondii has devised a molecular weapon of choice to take control over a ubiquitous immune gene expression mechanism in metazoans, as a way to promote long-term parasitism.
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Affiliation(s)
- Gabrielle Gay
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Laurence Braun
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Marie-Pierre Brenier-Pinchart
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Julien Vollaire
- IAB, OPTIMAL Small Animal Imaging Facility, 38000 Grenoble, France
| | | | - Rose-Laurence Bertini
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Aurélie Varesano
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Bastien Touquet
- IAB, Team Membrane and Cell Dynamics of Host-Parasite Interactions, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Pieter-Jan De Bock
- Institut de Biosciences et Biotechnologies de Grenoble-Laboratoire Biologie à Grande Échelle (BIG-BGE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INSERM, 38000 Grenoble, France
| | - Yohann Coute
- Institut de Biosciences et Biotechnologies de Grenoble-Laboratoire Biologie à Grande Échelle (BIG-BGE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INSERM, 38000 Grenoble, France
| | - Isabelle Tardieux
- IAB, Team Membrane and Cell Dynamics of Host-Parasite Interactions, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Alexandre Bougdour
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Mohamed-Ali Hakimi
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
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45
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Fox BA, Sanders KL, Rommereim LM, Guevara RB, Bzik DJ. Secretion of Rhoptry and Dense Granule Effector Proteins by Nonreplicating Toxoplasma gondii Uracil Auxotrophs Controls the Development of Antitumor Immunity. PLoS Genet 2016; 12:e1006189. [PMID: 27447180 PMCID: PMC4957766 DOI: 10.1371/journal.pgen.1006189] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/22/2016] [Indexed: 12/19/2022] Open
Abstract
Nonreplicating type I uracil auxotrophic mutants of Toxoplasma gondii possess a potent ability to activate therapeutic immunity to established solid tumors by reversing immune suppression in the tumor microenvironment. Here we engineered targeted deletions of parasite secreted effector proteins using a genetically tractable Δku80 vaccine strain to show that the secretion of specific rhoptry (ROP) and dense granule (GRA) proteins by uracil auxotrophic mutants of T. gondii in conjunction with host cell invasion activates antitumor immunity through host responses involving CD8α+ dendritic cells, the IL-12/interferon-gamma (IFN-γ) TH1 axis, as well as CD4+ and CD8+ T cells. Deletion of parasitophorous vacuole membrane (PVM) associated proteins ROP5, ROP17, ROP18, ROP35 or ROP38, intravacuolar network associated dense granule proteins GRA2 or GRA12, and GRA24 which traffics past the PVM to the host cell nucleus severely abrogated the antitumor response. In contrast, deletion of other secreted effector molecules such as GRA15, GRA16, or ROP16 that manipulate host cell signaling and transcriptional pathways, or deletion of PVM associated ROP21 or GRA3 molecules did not affect the antitumor activity. Association of ROP18 with the PVM was found to be essential for the development of the antitumor responses. Surprisingly, the ROP18 kinase activity required for resistance to IFN-γ activated host innate immunity related GTPases and virulence was not essential for the antitumor response. These data show that PVM functions of parasite secreted effector molecules, including ROP18, manipulate host cell responses through ROP18 kinase virulence independent mechanisms to activate potent antitumor responses. Our results demonstrate that PVM associated rhoptry effector proteins secreted prior to host cell invasion and dense granule effector proteins localized to the intravacuolar network and host nucleus that are secreted after host cell invasion coordinately control the development of host immune responses that provide effective antitumor immunity against established ovarian cancer.
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Affiliation(s)
- Barbara A. Fox
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Kiah L. Sanders
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Leah M. Rommereim
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Rebekah B. Guevara
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - David J. Bzik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
- * E-mail:
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Heaslip AT, Nelson SR, Warshaw DM. Dense granule trafficking in Toxoplasma gondii requires a unique class 27 myosin and actin filaments. Mol Biol Cell 2016; 27:2080-9. [PMID: 27146112 PMCID: PMC4927281 DOI: 10.1091/mbc.e15-12-0824] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 04/26/2016] [Indexed: 11/18/2022] Open
Abstract
The survival of Toxoplasma gondii within its host cell requires protein release from vesicles, called dense granules (DGs). Through imaging of the motions of DGs in live intracellular parasites, it is shown that DG transport is dependent on F-actin and a class 27 myosin, TgMyoF, thus uncovering new critical roles for these essential proteins in the parasite’s lytic cycle. The survival of Toxoplasma gondii within its host cell requires protein release from secretory vesicles, called dense granules, to maintain the parasite’s intracellular replicative niche. Despite the importance of DGs, nothing is known about the mechanisms underlying their transport. In higher eukaryotes, secretory vesicles are transported to the plasma membrane by molecular motors moving on their respective cytoskeletal tracks (i.e., microtubules and actin). Because the organization of these cytoskeletal structures differs substantially in T. gondii, the molecular motor dependence of DG trafficking is far from certain. By imaging the motions of green fluorescent protein–tagged DGs in intracellular parasites with high temporal and spatial resolution, we show through a combination of molecular genetics and chemical perturbations that directed DG transport is independent of microtubules and presumably their kinesin/dynein motors. However, directed DG transport is dependent on filamentous actin and a unique class 27 myosin, TgMyoF, which has structural similarity to myosin V, the prototypical cargo transporter. Actomyosin DG transport was unexpected, since filamentous parasite actin has yet to be visualized in vivo due in part to the prevailing model that parasite actin forms short, unstable filaments. Thus our data uncover new critical roles for these essential proteins in the lytic cycle of this devastating pathogen.
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Affiliation(s)
- Aoife T Heaslip
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | - Shane R Nelson
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | - David M Warshaw
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
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Lüder CGK, Sumpf K, Nast R. Releasing the Brake on IFN-γ Signaling on Infection. Trends Parasitol 2015; 31:456-459. [PMID: 26422772 DOI: 10.1016/j.pt.2015.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 08/13/2015] [Indexed: 10/23/2022]
Abstract
Toxoplasma gondii effectively inhibits the responsiveness of its host cell to interferon gamma (IFN-γ). Using a genome-wide genetic screen, Beiting and colleagues have recently identified coactivators of the transcription factor STAT1 that can diminish this inhibitory effect. One of these coactivators, TLX, enhances type 1 helper (Th1) immune responses and restricts parasite replication during chronic toxoplasmosis.
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Affiliation(s)
- Carsten G K Lüder
- Institute for Medical Microbiology, Georg August University, Göttingen, Germany.
| | - Kristina Sumpf
- Institute for Medical Microbiology, Georg August University, Göttingen, Germany
| | - Roswitha Nast
- Institute for Medical Microbiology, Georg August University, Göttingen, Germany
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Abstract
Toxoplasmosis is the clinical and pathological consequence of acute infection with the obligate intracellular apicomplexan parasite Toxoplasma gondii. Symptoms result from tissue destruction that accompanies lytic parasite growth. This review updates current understanding of the host cell invasion, parasite replication, and eventual egress that constitute the lytic cycle, as well as the ways T. gondii manipulates host cells to ensure its survival. Since the publication of a previous iteration of this review 15 years ago, important advances have been made in our molecular understanding of parasite growth and mechanisms of host cell egress, and knowledge of the parasite's manipulation of the host has rapidly progressed. Here we cover molecular advances and current conceptual frameworks that include each of these topics, with an eye to what may be known 15 years from now.
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Affiliation(s)
- Ira J Blader
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York 14127;
| | - Bradley I Coleman
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| | - Chun-Ti Chen
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| | - Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
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Possible role of TLR4 and TLR9 SNPs in protection against congenital toxoplasmosis. Eur J Clin Microbiol Infect Dis 2015; 34:2121-9. [PMID: 26254559 PMCID: PMC4565873 DOI: 10.1007/s10096-015-2461-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 07/20/2015] [Indexed: 12/22/2022]
Abstract
The purpose of this investigation was the determination of the distribution of genotypes at single nucleotide polymorphisms (SNPs) of the toll-like receptor 4 (TLR4) and the toll-like receptor 9 (TLR9) in fetuses and newborns congenitally infected with Toxoplasma gondii and the identification of genetic changes predisposing to infection development. The study involved 20 fetuses and newborns with congenital toxoplasmosis and 50 uninfected controls. The levels of IgG and IgM antibodies against T. gondii, as well as IgG avidity, were estimated by enzyme-linked fluorescent assay (ELFA) tests. T. gondii DNA loads in amniotic fluids were assayed by the real-time (RT) quantitative polymerase chain reaction (Q PCR) technique for parasitic B1 gene. TLR4 and TLR9 SNPs were identified using a self-designed multiplex nested PCR-restriction fragment length polymorphism (RFLP) assay. Randomly selected genotypes at SNPs were confirmed by sequencing. All the genotypes were tested for Hardy–Weinberg equilibrium and TLR4 genotypes were analyzed for linkage disequilibrium. A correlation was studied between the genotypes or haplotypes and the development of congenital toxoplasmosis using a logistic regression model. Single SNP analysis showed no statistically significant differences in the distribution of distinct genotypes at the analyzed TLR4 and TLR9 SNPs between T. gondii-infected fetuses and newborns and the controls. Taking into account the prevalence of alleles residing within polymorphic sites, similar prevalence rates were observed in both of the studied groups. The multiple SNP analysis indicated GTG variants at the TLR4 and TLR9 SNPs to be significantly less frequent in offspring with congenital toxoplasmosis than in uninfected offspring (p ≤ 0.0001). TLR4 and TLR9 SNPs seem to be involved in protection against congenital toxoplasmosis.
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Promoter occupancy of STAT1 in interferon responses is regulated by processive transcription. Mol Cell Biol 2014; 35:716-27. [PMID: 25512607 DOI: 10.1128/mcb.01097-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interferons regulate immunity by inducing DNA binding of the transcription factor STAT1 through Y701 phosphorylation. Transcription by STAT1 needs to be restricted to minimize the adverse effects of prolonged immune responses. It remains unclear how STAT1 inactivation is regulated such that the transcription output is adequate. Here we show that efficient STAT1 inactivation in macrophages is coupled with processive transcription. Ongoing transcription feeds back to reduce the promoter occupancy of STAT1 and, consequently, the transcriptional output. Once released from the promoter, STAT1 is ultimately inactivated by Y701 dephosphorylation. We observe similar regulation for STAT2 and STAT3, suggesting a conserved inactivation mechanism among STATs. These findings reveal that STAT1 promoter occupancy in macrophages is regulated such that it decreases only after initiation of the transcription cycle. This feedback control ensures the fidelity of cytokine responses and provides options for pharmacological intervention.
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