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Johnson HJ, Kochanowsky JA, Chandrasekaran S, Hunter CA, Beiting DP, Koshy AA. Defining neuronal responses to the neurotropic parasite Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.31.645603. [PMID: 40236177 PMCID: PMC11996365 DOI: 10.1101/2025.03.31.645603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/17/2025]
Abstract
A select group of pathogens infect neurons in the brain. Prior dogma held that neurons were "defenseless" against infecting microbes, but many studies suggest that neurons can mount anti-microbial defenses. However, a knowledge gap in understanding how neurons respond in vitro and in vivo to different classes of micro-organisms remains. To address this gap, we compared a transcriptional dataset derived from primary neuron cultures (PNCs) infected with the neurotropic intracellular parasite Toxoplasma gondii with a dataset derived from neurons injected with T. gondii protein in vivo . These curated responses were then compared to the transcriptional responses of PNCs infected with the single stranded RNA viruses West Nile Virus (WNV) or Zika Virus (ZKV). These analyses highlighted a conserved response to infection associated with chemokines ( Cxcl10, Ccl2 ) and cytokines (interferon signaling). However, T. gondii had diminished IFN-α signaling in vitro compared to the viral datasets and was uniquely associated with a decrease in neuron-specific genes ( Snap25 , Slc17a7 , Prkcg ). These data underscore that neurons participate in infection-induced neuroinflammation and illustrate that neurons possess both pathogen-specific and pathogen-conserved responses. Importance Though neurons are commonly the target of pathogens that infect the CNS, few datasets assess the neuronal response to infection. This paucity of data is likely because neurons are perceived to have diminished immune capabilities. However, to understand the role of neurons in neuroinflammation and their immune capabilities, their responses must be investigated. Here we analyzed publicly accessible, neuron-specific datasets to compare neuron responses to a eukaryotic pathogen versus two Orthoflaviviruses. A better understanding of neuron responses to different infections will allow us to develop methods for inhibiting pathways that lead to neuron dysfunction, enhancing those that limit pathogen survival, and mitigating infection-induced damage to the CNS.
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Torelli F, da Fonseca DM, Butterworth SW, Young JC, Treeck M. Paracrine rescue of MYR1-deficient Toxoplasma gondii mutants reveals limitations of pooled in vivo CRISPR screens. eLife 2024; 13:RP102592. [PMID: 39654402 PMCID: PMC11630813 DOI: 10.7554/elife.102592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2024] Open
Abstract
Toxoplasma gondii is an intracellular parasite that subverts host cell functions via secreted virulence factors. Up to 70% of parasite-controlled changes in the host transcriptome rely on the MYR1 protein, which is required for the translocation of secreted proteins into the host cell. Mice infected with MYR1 knock-out (KO) strains survive infection, supporting a paramount function of MYR1-dependent secreted proteins in Toxoplasma virulence and proliferation. However, we have previously shown that MYR1 mutants have no growth defect in pooled in vivo CRISPR-Cas9 screens in mice, suggesting that the presence of parasites that are wild-type at the myr1 locus in pooled screens can rescue the phenotype. Here, we demonstrate that MYR1 is not required for the survival in IFN-γ-activated murine macrophages, and that parasites lacking MYR1 are able to expand during the onset of infection. While ΔMYR1 parasites have restricted growth in single-strain murine infections, we show that the phenotype is rescued by co-infection with wild-type (WT) parasites in vivo, independent of host functional adaptive immunity or key pro-inflammatory cytokines. These data show that the major function of MYR1-dependent secreted proteins is not to protect the parasite from clearance within infected cells. Instead, MYR-dependent proteins generate a permissive niche in a paracrine manner, which rescues ΔMYR1 parasites within a pool of CRISPR mutants in mice. Our results highlight an important limitation of otherwise powerful in vivo CRISPR screens and point towards key functions for MYR1-dependent Toxoplasma-host interactions beyond the infected cell.
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Affiliation(s)
- Francesca Torelli
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Host-Pathogen Interactions Laboratory, Gulbenkian Institute for Molecular MedicineOeirasPortugal
| | - Diogo M da Fonseca
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Host-Pathogen Interactions Laboratory, Gulbenkian Institute for Molecular MedicineOeirasPortugal
| | - Simon W Butterworth
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Whitehead Institute, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Joanna C Young
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Institute of Immunology and Infection Research, University of EdinburghEdinburghUnited Kingdom
| | - Moritz Treeck
- Signalling in Apicomplexan Parasites Laboratory, The Francis Crick InstituteLondonUnited Kingdom
- Host-Pathogen Interactions Laboratory, Gulbenkian Institute for Molecular MedicineOeirasPortugal
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3
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Kegawa Y, Male F, Jiménez-Munguía I, Blank PS, Mekhedov E, Ward G, Zimmerberg J. The invasion pore induced by Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.11.617945. [PMID: 39416144 PMCID: PMC11482919 DOI: 10.1101/2024.10.11.617945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2024]
Abstract
Obligate intracellular parasites invade host cells to survive. Following host cell contact, the apicomplexan Toxoplasma gondii injects proteins required for invasion into the host cell. Here, electrophysiological recordings of host cells acquired at sub-200 ms resolution allowed detection and analysis of a transient increase in host membrane conductance following exposure to Toxoplasma gondii. Transients always preceded invasion but parasites depleted of the moving junction protein RON2 generated transients without invading, ruling out a direct structural role for RON2 in generating the conductance pathway or restricting the diffusion of its components. Time-series analysis developed for transients and applied to the entire transient dataset (910,000 data points) revealed multiple quantal conductance changes in the parasite-induced transient, consistent with a rapid insertion, then slower removal, blocking, or inactivation of pore-like conductance steps. Quantal steps for RH had a principal mode with Gaussian mean of 0.26 nS, similar in step size to the apicomplexan protein translocon EXP2. Without RON2 the quantal mean was significantly different (0.19 nS). Because no invasion occurs without poration, the term 'invasion pore' is proposed.
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Affiliation(s)
- Y Kegawa
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - F Male
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, United States
| | - I Jiménez-Munguía
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - P S Blank
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - E Mekhedov
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
| | - G Ward
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, United States
| | - J Zimmerberg
- Section on Integrative Biophysics; Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH)
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4
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Carrillo GL, Su J, Cawley ML, Wei D, Gill SK, Blader IJ, Fox MA. Complement-dependent loss of inhibitory synapses on pyramidal neurons following Toxoplasma gondii infection. J Neurochem 2024; 168:3365-3385. [PMID: 36683435 PMCID: PMC10363253 DOI: 10.1111/jnc.15770] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 01/06/2023] [Accepted: 01/15/2023] [Indexed: 01/24/2023]
Abstract
The apicomplexan parasite Toxoplasma gondii has developed mechanisms to establish a central nervous system infection in virtually all warm-blooded animals. Acute T. gondii infection can cause neuroinflammation, encephalitis, and seizures. Meanwhile, studies in humans, nonhuman primates, and rodents have linked chronic T. gondii infection with altered behavior and increased risk for neuropsychiatric disorders, including schizophrenia. These observations and associations raise questions about how this parasitic infection may alter neural circuits. We previously demonstrated that T. gondii infection triggers the loss of inhibitory perisomatic synapses, a type of synapse whose dysfunction or loss has been linked to neurological and neuropsychiatric disorders. We showed that phagocytic cells (including microglia and infiltrating monocytes) contribute to the loss of these inhibitory synapses. Here, we show that these phagocytic cells specifically ensheath excitatory pyramidal neurons, leading to the preferential loss of perisomatic synapses on these neurons and not those on cortical interneurons. Moreover, we show that infection induces an increased expression of the complement C3 gene, including by populations of these excitatory neurons. Infecting C3-deficient mice with T. gondii revealed that C3 is required for the loss of perisomatic inhibitory synapses. Interestingly, loss of C1q did not prevent the loss of perisomatic synapses following infection. Together, these findings provide evidence that T. gondii induces changes in excitatory pyramidal neurons that trigger the selective removal of inhibitory perisomatic synapses and provide a role for a nonclassical complement pathway in the remodeling of inhibitory circuits in the infected brain.
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Affiliation(s)
- Gabriela L. Carrillo
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Jianmin Su
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- School of Neuroscience, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Mikel L. Cawley
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Derek Wei
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- School of Neuroscience, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Simran K. Gill
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- Department of Psychology, Roanoke College, Salem, Virginia, 24153, USA
- NeuroSURF Program, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
| | - Ira J. Blader
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York, 14203, USA
| | - Michael A. Fox
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- School of Neuroscience, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
- Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
- Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, 24016, USA
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5
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Giuliano CJ, Wei KJ, Harling FM, Waldman BS, Farringer MA, Boydston EA, Lan TCT, Thomas RW, Herneisen AL, Sanderlin AG, Coppens I, Dvorin JD, Lourido S. CRISPR-based functional profiling of the Toxoplasma gondii genome during acute murine infection. Nat Microbiol 2024; 9:2323-2343. [PMID: 38977907 PMCID: PMC11811839 DOI: 10.1038/s41564-024-01754-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/07/2024] [Indexed: 07/10/2024]
Abstract
Examining host-pathogen interactions in animals can capture aspects of infection that are obscured in cell culture. Using CRISPR-based screens, we functionally profile the entire genome of the apicomplexan parasite Toxoplasma gondii during murine infection. Barcoded gRNAs enabled bottleneck detection and mapping of population structures within parasite lineages. Over 300 genes with previously unknown roles in infection were found to modulate parasite fitness in mice. Candidates span multiple axes of host-parasite interaction. Rhoptry Apical Surface Protein 1 was characterized as a mediator of host-cell tropism that facilitates repeated invasion attempts. GTP cyclohydrolase I was also required for fitness in mice and druggable through a repurposed compound, 2,4-diamino-6-hydroxypyrimidine. This compound synergized with pyrimethamine against T. gondii and malaria-causing Plasmodium falciparum parasites. This work represents a complete survey of an apicomplexan genome during infection of an animal host and points to novel interfaces of host-parasite interaction.
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Affiliation(s)
| | - Kenneth J Wei
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | | | - Benjamin S Waldman
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | - Madeline A Farringer
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
- Biological Sciences in Public Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | | | - Raina W Thomas
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | - Alice L Herneisen
- Whitehead Institute, Cambridge, MA, USA
- Biology Department, MIT, Cambridge, MA, USA
| | | | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Sebastian Lourido
- Whitehead Institute, Cambridge, MA, USA.
- Biology Department, MIT, Cambridge, MA, USA.
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6
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Nguyen YTM, Sibley L, Przanowski P, Zhao XY, Kovacs M, Wang S, Jones MK, Cowan M, Liu W, Merchak AR, Gaultier A, Janes K, Zang C, Harris T, Ewald SE, Zong H. Toxoplasma gondii infection supports the infiltration of T cells into brain tumors. J Neuroimmunol 2024; 393:578402. [PMID: 38996717 PMCID: PMC11318612 DOI: 10.1016/j.jneuroim.2024.578402] [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: 04/30/2024] [Revised: 07/03/2024] [Accepted: 07/07/2024] [Indexed: 07/14/2024]
Abstract
Few T cells infiltrate into primary brain tumors, fundamentally hampering the effectiveness of immunotherapy. We hypothesized that Toxoplasma gondii, a microorganism that naturally elicits a Th1 response in the brain, can promote T cell infiltration into brain tumors despite their immune suppressive microenvironment. Using a mouse genetic model for medulloblastoma, we found that T. gondii infection induced the infiltration of activatable T cells into the tumor mass and led to myeloid cell reprogramming toward a T cell-supportive state, without causing severe health issues in mice. The study provides a concrete foundation for future studies to take advantage of the immune modulatory capacity of T. gondii to facilitate brain tumor immunotherapy.
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Affiliation(s)
- Yen T M Nguyen
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Lydia Sibley
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Piotr Przanowski
- Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Xiao-Yu Zhao
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Michael Kovacs
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Shengyuan Wang
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Marieke K Jones
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Maureen Cowan
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Wenjie Liu
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Andrea R Merchak
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Alban Gaultier
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Kevin Janes
- Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Chongzhi Zang
- Department of Biomedical Engineering, University of Virginia School of Medicine, Charlottesville, VA, USA; Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA; Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Tajie Harris
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Sarah E Ewald
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, USA.
| | - Hui Zong
- Department of Microbiology, Immunology, and Cancer Biology at the Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, USA.
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7
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Gallego-López GM, Contreras Guzman E, Desa DE, Knoll LJ, Skala MC. Metabolic changes in Toxoplasma gondii-infected host cells measured by autofluorescence imaging. mBio 2024; 15:e0072724. [PMID: 38975793 PMCID: PMC11323734 DOI: 10.1128/mbio.00727-24] [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: 04/05/2024] [Accepted: 05/06/2024] [Indexed: 07/09/2024] Open
Abstract
Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular parasite that infects warm-blooded vertebrates across the world. In humans, seropositivity rates of T. gondii range from 10% to 90% across communities. Despite its prevalence, few studies address how T. gondii infection changes the metabolism of host cells. In this study, we investigate how T. gondii manipulates the host cell metabolic environment by monitoring the metabolic response over time using noninvasive autofluorescence lifetime imaging of single cells, metabolite analysis, extracellular flux analysis, and reactive oxygen species (ROS) production. Autofluorescence lifetime imaging indicates that infected host cells become more oxidized and have an increased proportion of bound NAD(P)H compared to uninfected controls. Over time, infected cells also show decreases in levels of intracellular glucose and lactate, increases in oxygen consumption, and variability in ROS production. We further examined changes associated with the pre-invasion "kiss and spit" process using autofluorescence lifetime imaging, which also showed a more oxidized host cell with an increased proportion of bound NAD(P)H over 48 hours compared to uninfected controls, suggesting that metabolic changes in host cells are induced by T. gondii kiss and spit even without invasion.IMPORTANCEThis study sheds light on previously unexplored changes in host cell metabolism induced by T. gondii infection using noninvasive, label-free autofluorescence imaging. In this study, we use optical metabolic imaging (OMI) to measure the optical redox ratio (ORR) in conjunction with fluorescence lifetime imaging microscopy (FLIM) to noninvasively monitor single host cell response to T. gondii infection over 48 hours. Collectively, our results affirm the value of using autofluorescence lifetime imaging to noninvasively monitor metabolic changes in host cells over the time course of a microbial infection. Understanding this metabolic relationship between the host cell and the parasite could uncover new treatment and prevention options for T. gondii infections worldwide.
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Affiliation(s)
- Gina M. Gallego-López
- Morgridge Institute for Research, Madison, Wisconsin, USA
- Department of Medical Microbiology & Immunology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | | | | | - Laura J. Knoll
- Department of Medical Microbiology & Immunology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, Wisconsin, USA
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, Wisconsin, USA
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8
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Bracha S, Johnson HJ, Pranckevicius NA, Catto F, Economides AE, Litvinov S, Hassi K, Rigoli MT, Cheroni C, Bonfanti M, Valenti A, Stucchi S, Attreya S, Ross PD, Walsh D, Malachi N, Livne H, Eshel R, Krupalnik V, Levin D, Cobb S, Koumoutsakos P, Caporale N, Testa G, Aguzzi A, Koshy AA, Sheiner L, Rechavi O. Engineering Toxoplasma gondii secretion systems for intracellular delivery of multiple large therapeutic proteins to neurons. Nat Microbiol 2024; 9:2051-2072. [PMID: 39075233 PMCID: PMC11306108 DOI: 10.1038/s41564-024-01750-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 06/05/2024] [Indexed: 07/31/2024]
Abstract
Delivering macromolecules across biological barriers such as the blood-brain barrier limits their application in vivo. Previous work has demonstrated that Toxoplasma gondii, a parasite that naturally travels from the human gut to the central nervous system (CNS), can deliver proteins to host cells. Here we engineered T. gondii's endogenous secretion systems, the rhoptries and dense granules, to deliver multiple large (>100 kDa) therapeutic proteins into neurons via translational fusions to toxofilin and GRA16. We demonstrate delivery in cultured cells, brain organoids and in vivo, and probe protein activity using imaging, pull-down assays, scRNA-seq and fluorescent reporters. We demonstrate robust delivery after intraperitoneal administration in mice and characterize 3D distribution throughout the brain. As proof of concept, we demonstrate GRA16-mediated brain delivery of the MeCP2 protein, a putative therapeutic target for Rett syndrome. By characterizing the potential and current limitations of the system, we aim to guide future improvements that will be required for broader application.
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Affiliation(s)
- Shahar Bracha
- Department of Neurobiology, Biochemistry and Biophysics, Wise Faculty of Life Sciences and Sagol School for Neuroscience, Tel Aviv University, Tel Aviv, Israel.
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA.
| | - Hannah J Johnson
- Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA
- Departments of Neurology and Immunobiology, College of Medicine, and BIO5 Institute, University of Arizona, Tucson, AZ, USA
| | - Nicole A Pranckevicius
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Francesca Catto
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Athena E Economides
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Sergey Litvinov
- Computational Science and Engineering Laboratory, School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Karoliina Hassi
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Marco Tullio Rigoli
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Cristina Cheroni
- Human Technopole, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | | | - Alessia Valenti
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Sarah Stucchi
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Shruti Attreya
- Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, USA
| | - Paul D Ross
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Daniel Walsh
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | | | | | | | | | | | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Petros Koumoutsakos
- Computational Science and Engineering Laboratory, School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Nicolò Caporale
- Human Technopole, Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy
| | - Giuseppe Testa
- Human Technopole, Milan, Italy.
- Department of Experimental Oncology, European Institute of Oncology IRCCS, Milan, Italy.
- Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy.
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Anita A Koshy
- Departments of Neurology and Immunobiology, College of Medicine, and BIO5 Institute, University of Arizona, Tucson, AZ, USA.
| | - Lilach Sheiner
- Centre for Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Oded Rechavi
- Department of Neurobiology, Biochemistry and Biophysics, Wise Faculty of Life Sciences and Sagol School for Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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9
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Ben Chaabene R, Martinez M, Bonavoglia A, Maco B, Chang YW, Lentini G, Soldati-Favre D. Toxoplasma gondii rhoptry discharge factor 3 is essential for invasion and microtubule-associated vesicle biogenesis. PLoS Biol 2024; 22:e3002745. [PMID: 39137211 PMCID: PMC11343613 DOI: 10.1371/journal.pbio.3002745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 08/23/2024] [Accepted: 07/10/2024] [Indexed: 08/15/2024] Open
Abstract
Rhoptries are specialized secretory organelles conserved across the Apicomplexa phylum, essential for host cell invasion and critical for subverting of host cellular and immune functions. They contain proteins and membranous materials injected directly into the host cells, participating in parasitophorous vacuole formation. Toxoplasma gondii tachyzoites harbor 8 to 12 rhoptries, 2 of which are docked to an apical vesicle (AV), a central element associated with a rhoptry secretory apparatus prior to injection into the host cell. This parasite is also equipped with 5 to 6 microtubule-associated vesicles, presumably serving as AV replenishment for iterative rhoptry discharge. Here, we characterized a rhoptry protein, rhoptry discharge factor 3 (RDF3), crucial for rhoptry discharge and invasion. RDF3 enters the secretory pathway, localizing near the AV and associated with the rhoptry bulb. Upon invasion, RDF3 dynamically delocalizes, suggesting a critical role at the time of rhoptry discharge. Cryo-electron tomography analysis of RDF3-depleted parasites reveals irregularity in microtubule-associated vesicles morphology, presumably impacting on their preparedness to function as an AV. Our findings suggest that RDF3 is priming the microtubule-associated vesicles for rhoptry discharge by a mechanism distinct from the rhoptry secretory apparatus contribution.
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Affiliation(s)
- Rouaa Ben Chaabene
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Matthew Martinez
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alessandro Bonavoglia
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gaëlle Lentini
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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10
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Nayeri T, Sarvi S, Daryani A. Effective factors in the pathogenesis of Toxoplasmagondii. Heliyon 2024; 10:e31558. [PMID: 38818168 PMCID: PMC11137575 DOI: 10.1016/j.heliyon.2024.e31558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 05/11/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.
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Affiliation(s)
- Tooran Nayeri
- Infectious and Tropical Diseases Research Center, Dezful University of Medical Sciences, Dezful, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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11
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Lin GH, Yu TA, Chang CF, Hsu CH. Proline Isomerization and Molten Globular Property of TgPDCD5 Secreted from Toxoplasma gondii Confers Its Regulation of Heparin Sulfate Binding. JACS AU 2024; 4:1763-1774. [PMID: 38818051 PMCID: PMC11134355 DOI: 10.1021/jacsau.3c00577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 06/01/2024]
Abstract
Toxoplasmosis, caused by Toxoplasma gondii, poses risks to vulnerable populations. TgPDCD5, a secreted protein of T. gondii, induces apoptosis through heparan sulfate-mediated endocytosis. The entry mechanism of TgPDCD5 has remained elusive. Here, we present the solution structure of TgPDCD5 as a helical bundle with an extended N-terminal helix, exhibiting molten globule characteristics. NMR perturbation studies reveal heparin/heparan sulfate binding involving the heparan sulfate/heparin proteoglycans-binding motif and the core region, influenced by proline isomerization of P107 residue. The heterogeneous proline recruits a cyclophilin TgCyp18, accelerating interconversion between conformers and regulating heparan/heparin binding. These atomic-level insights elucidate the binary switch's functionality, expose novel heparan sulfate-binding surfaces, and illuminate the unconventional cellular entry of pathogenic TgPDCD5.
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Affiliation(s)
- Gloria
Meng-Hsuan Lin
- Department
of Agricultural Chemistry, National Taiwan
University, Taipei 10617, Taiwan
- Genome
and Systems Biology Degree Program, National
Taiwan University and Academia Sinica, Taipei 10617, Taiwan
| | - Tsun-Ai Yu
- Genomic
Research Center, Academia Sinica, Taipei 115201, Taiwan
| | - Chi-Fon Chang
- Genomic
Research Center, Academia Sinica, Taipei 115201, Taiwan
| | - Chun-Hua Hsu
- Department
of Agricultural Chemistry, National Taiwan
University, Taipei 10617, Taiwan
- Genome
and Systems Biology Degree Program, National
Taiwan University and Academia Sinica, Taipei 10617, Taiwan
- Institute
of Biochemical Sciences, National Taiwan
University, Taipei 115201, Taiwan
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12
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Tell I Puig A, Soldati-Favre D. Roles of the tubulin-based cytoskeleton in the Toxoplasma gondii apical complex. Trends Parasitol 2024; 40:401-415. [PMID: 38531711 DOI: 10.1016/j.pt.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/26/2024] [Accepted: 02/28/2024] [Indexed: 03/28/2024]
Abstract
Microtubules (MTs) play a vital role as key components of the eukaryotic cytoskeleton. The phylum Apicomplexa comprises eukaryotic unicellular parasitic organisms defined by the presence of an apical complex which consists of specialized secretory organelles and tubulin-based cytoskeletal elements. One apicomplexan parasite, Toxoplasma gondii, is an omnipresent opportunistic pathogen with significant medical and veterinary implications. To ensure successful infection and widespread dissemination, T. gondii heavily relies on the tubulin structures present in the apical complex. Recent advances in high-resolution imaging, coupled with reverse genetics, have offered deeper insights into the composition, functionality, and dynamics of these tubulin-based structures. The apicomplexan tubulins differ from those of their mammalian hosts, endowing them with unique attributes and susceptibility to specific classes of inhibitory compounds.
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Affiliation(s)
- Albert Tell I Puig
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
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13
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Shapira T, Christofferson M, Av-Gay Y. The antimicrobial activity of innate host-directed therapies: A systematic review. Int J Antimicrob Agents 2024; 63:107138. [PMID: 38490573 DOI: 10.1016/j.ijantimicag.2024.107138] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 02/23/2024] [Accepted: 03/07/2024] [Indexed: 03/17/2024]
Abstract
Intracellular human pathogens are the deadliest infectious diseases and are difficult to treat effectively due to their protection inside the host cell and the development of antimicrobial resistance (AMR). An emerging approach to combat these intracellular pathogens is host-directed therapies (HDT), which harness the innate immunity of host cells. HDT rely on small molecules to promote host protection mechanisms that ultimately lead to pathogen clearance. These therapies are hypothesized to: (1) possess indirect yet broad, cross-species antimicrobial activity, (2) effectively target drug-resistant pathogens, (3) carry a reduced susceptibility to the development of AMR and (4) have synergistic action with conventional antimicrobials. As the field of HDT expands, this systematic review was conducted to collect a compendium of HDT and their characteristics, such as the host mechanisms affected, the pathogen inhibited, the concentrations investigated and the magnitude of pathogen inhibition. The evidential support for the main four HDT hypotheses was assessed and concluded that HDT demonstrate robust cross-species activity, are active against AMR pathogens, clinical isolates and laboratory-adapted pathogens. However, limited information exists to support the notion that HDT are synergistic with canonical antimicrobials and are less predisposed to AMR development.
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Affiliation(s)
- Tirosh Shapira
- Department of Medicine, Division of Infectious Disease, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Matthew Christofferson
- Department of Microbiology and Immunology, Division of Infectious Disease, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Yossef Av-Gay
- Department of Medicine, Division of Infectious Disease, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada; Department of Microbiology and Immunology, Division of Infectious Disease, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
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14
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Merritt EF, Kochanowsky JA, Hervé P, Watson AA, Koshy AA. Toxoplasma type II effector GRA15 has limited influence in vivo. PLoS One 2024; 19:e0300764. [PMID: 38551902 PMCID: PMC10980211 DOI: 10.1371/journal.pone.0300764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 03/03/2024] [Indexed: 04/01/2024] Open
Abstract
Toxoplasma gondii is an intracellular parasite that establishes a long-term infection in the brain of many warm-blooded hosts, including humans and rodents. Like all obligate intracellular microbes, Toxoplasma uses many effector proteins to manipulate the host cell to ensure parasite survival. While some of these effector proteins are universal to all Toxoplasma strains, some are polymorphic between Toxoplasma strains. One such polymorphic effector is GRA15. The gra15 allele carried by type II strains activates host NF-κB signaling, leading to the release of cytokines such as IL-12, TNF, and IL-1β from immune cells infected with type II parasites. Prior work also suggested that GRA15 promotes early host control of parasites in vivo, but the effect of GRA15 on parasite persistence in the brain and the peripheral immune response has not been well defined. For this reason, we sought to address this gap by generating a new IIΔgra15 strain and comparing outcomes at 3 weeks post infection between WT and IIΔgra15 infected mice. We found that the brain parasite burden and the number of macrophages/microglia and T cells in the brain did not differ between WT and IIΔgra15 infected mice. In addition, while IIΔgra15 infected mice had a lower number and frequency of splenic M1-like macrophages and frequency of PD-1+ CTLA-4+ CD4+ T cells and NK cells compared to WT infected mice, the IFN-γ+ CD4 and CD8 T cell populations were equivalent. In summary, our results suggest that in vivo GRA15 may have a subtle effect on the peripheral immune response, but this effect is not strong enough to alter brain parasite burden or parenchymal immune cell number at 3 weeks post infection.
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Affiliation(s)
- Emily F. Merritt
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Joshua A. Kochanowsky
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Perrine Hervé
- Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Université de Bordeaux, Bordeaux, France
| | - Alison A. Watson
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
| | - Anita A. Koshy
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
- Department of Neurology, University of Arizona, Tucson, Arizona, United States of America
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15
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Dos Santos Pacheco N, Tell I Puig A, Guérin A, Martinez M, Maco B, Tosetti N, Delgado-Betancourt E, Lunghi M, Striepen B, Chang YW, Soldati-Favre D. Sustained rhoptry docking and discharge requires Toxoplasma gondii intraconoidal microtubule-associated proteins. Nat Commun 2024; 15:379. [PMID: 38191574 PMCID: PMC10774369 DOI: 10.1038/s41467-023-44631-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/21/2023] [Indexed: 01/10/2024] Open
Abstract
In Apicomplexa, rhoptry discharge is essential for invasion and involves an apical vesicle (AV) docking one or two rhoptries to a macromolecular secretory apparatus. Toxoplasma gondii is armed with 10-12 rhoptries and 5-6 microtubule-associated vesicles (MVs) presumably for iterative rhoptry discharge. Here, we have addressed the localization and functional significance of two intraconoidal microtubule (ICMT)-associated proteins instrumental for invasion. Mechanistically, depletion of ICMAP2 leads to a dissociation of the ICMTs, their detachment from the conoid and dispersion of MVs and rhoptries. ICMAP3 exists in two isoforms that contribute to the control of the ICMTs length and the docking of the two rhoptries at the AV, respectively. This study illuminates the central role ICMTs play in scaffolding the discharge of multiple rhoptries. This process is instrumental for virulence in the mouse model of infection and in addition promotes sterile protection against T. gondii via the release of key effectors inducing immunity.
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Affiliation(s)
- Nicolas Dos Santos Pacheco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Albert Tell I Puig
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Amandine Guérin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew Martinez
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bohumil Maco
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Nicolò Tosetti
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Estefanía Delgado-Betancourt
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Matteo Lunghi
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Institute of Structural Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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16
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Seizova S, Ferrel A, Boothroyd J, Tonkin CJ. Toxoplasma protein export and effector function. Nat Microbiol 2024; 9:17-28. [PMID: 38172621 DOI: 10.1038/s41564-023-01563-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 11/16/2023] [Indexed: 01/05/2024]
Abstract
Toxoplasma gondii is a single-celled eukaryotic parasite with a considerable host range that must invade the cells of warm-blooded hosts to survive and replicate. The challenges and opportunities that such a strategy represent have been met by the evolution of effectors that are delivered into host cells, counter host defences and co-opt host cell functions for their own purposes. These effectors are delivered in two waves using distinct machinery for each. In this Review, we focus on understanding the architecture of these protein-export systems and how their protein cargo is recognized and selected. We discuss the recent findings on the role that host manipulation has in latent Toxoplasma infections. We also discuss how these recent findings compare to protein export in the related Plasmodium spp. (the causative agent of malaria) and how this can inform our understanding of host manipulation in the larger Apicomplexa phylum and its evolution.
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Affiliation(s)
- Simona Seizova
- School of Life Sciences, The University of Dundee, Dundee, UK
| | - Abel Ferrel
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | - John Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA.
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
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17
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Grochow T, Beck B, Rentería-Solís Z, Schares G, Maksimov P, Strube C, Raqué L, Kacza J, Daugschies A, Fietz SA. Reduced neural progenitor cell count and cortical neurogenesis in guinea pigs congenitally infected with Toxoplasma gondii. Commun Biol 2023; 6:1209. [PMID: 38012384 PMCID: PMC10682419 DOI: 10.1038/s42003-023-05576-6] [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: 04/17/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023] Open
Abstract
Toxoplasma (T.) gondii is an obligate intracellular parasite with a worldwide distribution. Congenital infection can lead to severe pathological alterations in the brain. To examine the effects of toxoplasmosis in the fetal brain, pregnant guinea pigs are infected with T. gondii oocysts on gestation day 23 and dissected 10, 17 and 25 days afterwards. We show the neocortex to represent a target region of T. gondii and the parasite to infect neural progenitor cells (NPCs), neurons and astrocytes in the fetal brain. Importantly, we observe a significant reduction in neuron number at end-neurogenesis and find a marked reduction in NPC count, indicating that impaired neurogenesis underlies the neuronal decrease in infected fetuses. Moreover, we observe focal microglioses to be associated with T. gondii in the fetal brain. Our findings expand the understanding of the pathophysiology of congenital toxoplasmosis, especially contributing to the development of cortical malformations.
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Affiliation(s)
- Thomas Grochow
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
- Institute of Parasitology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Britta Beck
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
- Institute of Parasitology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Zaida Rentería-Solís
- Institute of Parasitology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Gereon Schares
- National Reference Laboratory for Toxoplasmosis, Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Pavlo Maksimov
- National Reference Laboratory for Toxoplasmosis, Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Lisa Raqué
- Veterinary practice Raqué, Leipzig, Germany
| | - Johannes Kacza
- BioImaging Core Facility, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Arwid Daugschies
- Institute of Parasitology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany
| | - Simone A Fietz
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany.
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18
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Dupont D, Robert M, Brenier-Pinchart M, Lefevre A, Wallon M, Pelloux H. Toxoplasma gondii, a plea for a thorough investigation of its oncogenic potential. Heliyon 2023; 9:e22147. [PMID: 38034818 PMCID: PMC10685377 DOI: 10.1016/j.heliyon.2023.e22147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/20/2023] [Accepted: 11/05/2023] [Indexed: 12/02/2023] Open
Abstract
It is estimated that 30 % of the world's population harbours the parasite Toxoplasma gondii, particularly in the brain. Beyond its implication in potentially severe opportunistic or congenital infections, this persistence has long been considered as without consequence. However, certain data in animals and humans suggest that this carriage may be linked to various neuropsychiatric or neurodegenerative disorders. The hypothesis of a potential cerebral oncogenicity of the parasite is also emerging. In this personal view, we will present the epidemiological arguments in favour of an association between toxoplasmosis and cerebral malignancy, before considering the points that could underlie a potential causal link. More specifically, we will focus on the brain as the preferred location for T. gondii persistence and the propensity of this parasite to interfere with the apoptosis and cell cycle signalling pathways of their host cell.
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Affiliation(s)
- D. Dupont
- Institut des Agents Infectieux, Parasitologie Mycologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, Lyon, 69004, France
- Physiologie intégrée du système d’éveil, Centre de Recherche en Neurosciences de Lyon, INSERM U1028-CNRS UMR 5292, Faculté de Médecine, Université Claude Bernard Lyon 1, Bron, 69500, France
| | - M.G. Robert
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, 38000, France
- Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), INSERM U1209-CNRS UMR 5309, Grenoble, 38000, France
| | - M.P. Brenier-Pinchart
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, 38000, France
- Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), INSERM U1209-CNRS UMR 5309, Grenoble, 38000, France
| | - A. Lefevre
- Institut des Agents Infectieux, Parasitologie Mycologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, Lyon, 69004, France
| | - M. Wallon
- Institut des Agents Infectieux, Parasitologie Mycologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, Lyon, 69004, France
- Physiologie intégrée du système d’éveil, Centre de Recherche en Neurosciences de Lyon, INSERM U1028-CNRS UMR 5292, Faculté de Médecine, Université Claude Bernard Lyon 1, Bron, 69500, France
| | - H. Pelloux
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, 38000, France
- Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), INSERM U1209-CNRS UMR 5309, Grenoble, 38000, France
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19
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Gallego-López GM, Guzman EC, Knoll LJ, Skala M. Metabolic changes to host cells with Toxoplasma gondii infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552811. [PMID: 37609172 PMCID: PMC10441426 DOI: 10.1101/2023.08.10.552811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular parasite that infects warm-blooded vertebrates across the world. In humans, seropositivity rates of T. gondii range from 10% to 90%. Despite its prevalence, few studies address how T. gondii infection changes the metabolism of host cells. Here, we investigate how T. gondii manipulates the host cell metabolic environment by monitoring metabolic response over time using non-invasive autofluorescence lifetime imaging of single cells, seahorse metabolic flux analysis, reactive oxygen species (ROS) production, and metabolomics. Autofluorescence lifetime imaging indicates that infected host cells become more oxidized and have an increased proportion of bound NAD(P)H with infection. These findings are consistent with changes in mitochondrial and glycolytic function, decrease of intracellular glucose, fluctuations in lactate and ROS production in infected cells over time. We also examined changes associated with the pre-invasion "kiss and spit" process using autofluorescence lifetime imaging, which similarly showed a more oxidized host cell with an increased proportion of bound NAD(P)H over 48 hours. Glucose metabolic flux analysis indicated that these changes are driven by NADH and NADP+ in T. gondii infection. In sum, metabolic changes in host cells with T. gondii infection were similar during full infection, and kiss and spit. Autofluorescence lifetime imaging can non-invasively monitor metabolic changes in host cells over a microbial infection time-course.
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Affiliation(s)
- Gina M. Gallego-López
- Morgridge Institute for Research, Madison, WI, 53706
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706
| | | | - Laura J. Knoll
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706
| | - Melissa Skala
- Morgridge Institute for Research, Madison, WI, 53706
- Department of Biomedical Engineering, University of Wisconsin- Madison, WI 53706, USA
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20
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Rahdar M, Farbod Y, Seydinejad S, Zarrin M. The effect of chronic experimental toxoplasmosis on some brain neurotransmitters level and behavior changes. Exp Parasitol 2023:108575. [PMID: 37394088 DOI: 10.1016/j.exppara.2023.108575] [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: 01/07/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 07/04/2023]
Abstract
Toxoplasma is capable of causing long-lasting brain cysts in its hosts, which can lead to physiological disturbances in brain neurotransmitters and result in changes in the host's behavior. This study aimed to investigate these changes using an experimental model. Twenty-five female Wistar rats, weighing 220-220 g and six weeks old, were selected for the study. The rats were divided into two control and experimental groups. The experimental group was injected with 5 × 105 tachyzoites of Toxoplasma gondii (virulent RH strain) intra-peritoneally. Four months after the injection, the rats were subjected to behavioral tests, including learning, memory, depression, and locomotor activity tests. The rats were then euthanized, and their brain and serum samples were analyzed for dopamine and serotonin levels. To ensure the presence of cysts in the brain tissue, a PCR test and preparation of pathological slides from the brain tissue were performed. The results showed that the amount of dopamine in the brain of the infected group was significantly higher than that of the control group, while the level of serotonin in brain of the infected group was significantly lower than that of the control group (P < 0.05). However, no significant difference was observed in the amount of these neurotransmitters in the blood of the two groups (P > 0.05). Behavioral changes were evaluated, and it was found that the learning and memory levels of the infected rats were significantly lower than those of the control group (P < 0.05), but no difference was observed in locomotor activity between the two groups (P > 0.05). This experimental infection model indicated that changes in neurotransmitter levels lead to behavior changes. CONCLUSION: The presence of parasite cysts in the brain can affect some of the host's behaviors through changes in neurotransmitter levels. Therefore, there is a possibility that there is a relationship between the presence of Toxoplasma cysts in the brain and neurological disorders. The results of this study suggest that chronic toxoplasmosis may play a role in behavior changes in psychotic diseases.
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Affiliation(s)
- Mahmoud Rahdar
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - Yaghoub Farbod
- Department of Medical Physiology Department, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Samira Seydinejad
- Department of Medical Parasitology, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Zarrin
- Department of Medical Mycology, Medical School, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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21
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Tedford E, Badya NB, Laing C, Asaoka N, Kaneko S, Filippi BM, McConkey GA. Infection-induced extracellular vesicles evoke neuronal transcriptional and epigenetic changes. Sci Rep 2023; 13:6913. [PMID: 37106020 PMCID: PMC10140046 DOI: 10.1038/s41598-023-34074-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 04/24/2023] [Indexed: 04/29/2023] Open
Abstract
Infection with the protozoan Toxoplasma gondii induces changes in neurotransmission, neuroinflammation, and behavior, yet it remains elusive how these changes come about. In this study we investigated how norepinephrine levels are altered by infection. TINEV (Toxoplasma-induced neuronal extracellular vesicles) isolated from infected noradrenergic cells down-regulated dopamine ß-hydroxylase (DBH) gene expression in human and rodent cells. Here we report that intracerebral injection of TINEVs into the brain is sufficient to induce DBH down-regulation and distrupt catecholaminergic signalling. Further, TINEV treatment induced hypermethylation upstream of the DBH gene. An antisense lncRNA to DBH was found in purified TINEV preparations. Paracrine signalling to induce transcriptional gene silencing and DNA methylation may be a common mode to regulate neurologic function.
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Affiliation(s)
- Ellen Tedford
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Norhidayah Binti Badya
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Conor Laing
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Nozomi Asaoka
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-Cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shuji Kaneko
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-Cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Beatrice Maria Filippi
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Glenn Alan McConkey
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
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22
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Kochanowsky JA, Chandrasekaran S, Sanchez JR, Thomas KK, Koshy AA. ROP16-mediated activation of STAT6 enhances cyst development of type III Toxoplasma gondii in neurons. PLoS Pathog 2023; 19:e1011347. [PMID: 37068104 PMCID: PMC10138205 DOI: 10.1371/journal.ppat.1011347] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 04/27/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023] Open
Abstract
Toxoplasma gondii establishes a long-lived latent infection in the central nervous system (CNS) of its hosts. Reactivation in immunocompromised individuals can lead to life threatening disease. Latent infection is driven by the ability of the parasite to convert from the acute-stage tachyzoite to the latent-stage bradyzoite which resides in long-lived intracellular cysts. While much work has focused on the parasitic factors that drive cyst development, the host factors that influence encystment are not well defined. Here we show that a polymorphic secreted parasite kinase (ROP16), that phosphorylates host cell proteins, mediates efficient encystment of T. gondii in a stress-induced model of encystment and primary neuronal cell cultures (PNCs) in a strain-specific manner. Using short-hairpin RNA (shRNA) knockdowns in human foreskin fibroblasts (HFFs) and PNCs from transgenic mice, we determined that ROP16's cyst enhancing abilities are mediated, in part, by phosphorylation-and therefore activation-of the host cell transcription factor STAT6. To test the role of STAT6 in vivo, we infected wild-type (WT) and STAT6KO mice, finding that, compared to WT mice, STAT6KO mice have a decrease in CNS cyst burden but not overall parasite burden or dissemination to the CNS. Finally, we found a similar ROP16-dependent encystment defect in human pluripotent stem cell-derived neurons. Together, these findings identify a host cell factor (STAT6) that T. gondii manipulates in a strain-specific manner to generate a favorable encystment environment.
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Affiliation(s)
- Joshua A. Kochanowsky
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | | | - Jacqueline R. Sanchez
- Postbaccalaureate Research Education Program, University of Arizona, Tucson, Arizona, United States of America
| | - Kaitlin K. Thomas
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Anita A. Koshy
- Department of Immunobiology, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
- Department of Neurology, University of Arizona, Tucson, Arizona, United States of America
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23
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Giuliano CJ, Wei KJ, Harling FM, Waldman BS, Farringer MA, Boydston EA, Lan TCT, Thomas RW, Herneisen AL, Sanderlin AG, Coppens I, Dvorin JD, Lourido S. Functional profiling of the Toxoplasma genome during acute mouse infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.05.531216. [PMID: 36945434 PMCID: PMC10028831 DOI: 10.1101/2023.03.05.531216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Within a host, pathogens encounter a diverse and changing landscape of cell types, nutrients, and immune responses. Examining host-pathogen interactions in animal models can therefore reveal aspects of infection absent from cell culture. We use CRISPR-based screens to functionally profile the entire genome of the model apicomplexan parasite Toxoplasma gondii during mouse infection. Barcoded gRNAs were used to track mutant parasite lineages, enabling detection of bottlenecks and mapping of population structures. We uncovered over 300 genes that modulate parasite fitness in mice with previously unknown roles in infection. These candidates span multiple axes of host-parasite interaction, including determinants of tropism, host organelle remodeling, and metabolic rewiring. We mechanistically characterized three novel candidates, including GTP cyclohydrolase I, against which a small-molecule inhibitor could be repurposed as an antiparasitic compound. This compound exhibited antiparasitic activity against T. gondii and Plasmodium falciparum, the most lethal agent of malaria. Taken together, we present the first complete survey of an apicomplexan genome during infection of an animal host, and point to novel interfaces of host-parasite interaction that may offer new avenues for treatment.
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Affiliation(s)
| | - Kenneth J. Wei
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | - Faye M. Harling
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | | | - Madeline A. Farringer
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, USA
- Biological Sciences in Public Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | | | | | - Raina W. Thomas
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | - Alice L. Herneisen
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
| | | | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Jeffrey D. Dvorin
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Sebastian Lourido
- Whitehead Institute, Cambridge, MA
- Biology Department, MIT, Cambridge, MA
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24
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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: 3.0] [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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25
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Christian DA, Adams TA, Shallberg LA, Phan AT, Smith TE, Abraha M, Perry J, Ruthel G, Clark JT, Pritchard GH, Aronson LR, Gossa S, McGavern DB, Kedl RM, Hunter CA. cDC1 coordinate innate and adaptive responses in the omentum required for T cell priming and memory. Sci Immunol 2022; 7:eabq7432. [PMID: 36179012 PMCID: PMC9835709 DOI: 10.1126/sciimmunol.abq7432] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In the peritoneal cavity, the omentum contains fat-associated lymphoid clusters (FALCs) whose role in response to infection is poorly understood. After intraperitoneal immunization with Toxoplasma gondii, conventional type 1 dendritic cells (cDC1s) were critical to induce innate sources of IFN-γ and cellular changes in the FALCs. Unexpectedly, infected peritoneal macrophages that migrated into the FALCs primed CD8+ T cells. Although T cell priming was cDC1 independent, these DCs were required for maximal CD8+ T cell expansion. An agent-based computational model and experimental data highlighted that cDC1s affected the magnitude of the proliferative burst and promoted CD8+ T cell expression of nutrient uptake receptors and cell survival. Thus, although FALCs lack the organization of secondary lymphoid organs, cDC1s resident in this tissue coordinate innate responses to microbial challenge and provide secondary signals required for T cell expansion and memory formation.
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Affiliation(s)
- David A. Christian
- Department of Pathobiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Thomas A. Adams
- Department of Chemical Engineering, McMaster University, Hamilton, Ontario
| | | | - Anthony T. Phan
- Department of Pathobiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Tony E. Smith
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Mosana Abraha
- Department of Chemical Engineering, McMaster University, Hamilton, Ontario
| | - Joseph Perry
- Department of Pathobiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Gordon Ruthel
- Department of Pathobiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Joseph T. Clark
- Department of Pathobiology, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Lillian R. Aronson
- Department of Pathobiology, University of Pennsylvania, Philadelphia, PA 19104
- Section of Surgery, Department of Clinical Studies, University of Pennsylvania, Philadelphia, PA 19104
| | - Selamawit Gossa
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20814
| | - Dorian B. McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20814
| | - Ross M. Kedl
- Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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26
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Sardinha-Silva A, Alves-Ferreira EVC, Grigg ME. Intestinal immune responses to commensal and pathogenic protozoa. Front Immunol 2022; 13:963723. [PMID: 36211380 PMCID: PMC9533738 DOI: 10.3389/fimmu.2022.963723] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
The physical barrier of the intestine and associated mucosal immunity maintains a delicate homeostatic balance between the host and the external environment by regulating immune responses to commensals, as well as functioning as the first line of defense against pathogenic microorganisms. Understanding the orchestration and characteristics of the intestinal mucosal immune response during commensal or pathological conditions may provide novel insights into the mechanisms underlying microbe-induced immunological tolerance, protection, and/or pathogenesis. Over the last decade, our knowledge about the interface between the host intestinal mucosa and the gut microbiome has been dominated by studies focused on bacterial communities, helminth parasites, and intestinal viruses. In contrast, specifically how commensal and pathogenic protozoa regulate intestinal immunity is less well studied. In this review, we provide an overview of mucosal immune responses induced by intestinal protozoa, with a major focus on the role of different cell types and immune mediators triggered by commensal (Blastocystis spp. and Tritrichomonas spp.) and pathogenic (Toxoplasma gondii, Giardia intestinalis, Cryptosporidium parvum) protozoa. We will discuss how these various protozoa modulate innate and adaptive immune responses induced in experimental models of infection that benefit or harm the host.
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27
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Segev-Zarko LA, Dahlberg PD, Sun SY, Pelt DM, Kim CY, Egan ES, Sethian JA, Chiu W, Boothroyd JC. Cryo-electron tomography with mixed-scale dense neural networks reveals key steps in deployment of Toxoplasma invasion machinery. PNAS NEXUS 2022; 1:pgac183. [PMID: 36329726 PMCID: PMC9615128 DOI: 10.1093/pnasnexus/pgac183] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/30/2022] [Indexed: 01/29/2023]
Abstract
Host cell invasion by intracellular, eukaryotic parasites within the phylum Apicomplexa is a remarkable and active process involving the coordinated action of apical organelles and other structures. To date, capturing how these structures interact during invasion has been difficult to observe in detail. Here, we used cryogenic electron tomography to image the apical complex of Toxoplasma gondii tachyzoites under conditions that mimic resting parasites and those primed to invade through stimulation with calcium ionophore. Through the application of mixed-scale dense networks for image processing, we developed a highly efficient pipeline for annotation of tomograms, enabling us to identify and extract densities of relevant subcellular organelles and accurately analyze features in 3-D. The results reveal a dramatic change in the shape of the anteriorly located apical vesicle upon its apparent fusion with a rhoptry that occurs only in the stimulated parasites. We also present information indicating that this vesicle originates from the vesicles that parallel the intraconoidal microtubules and that the latter two structures are linked by a novel tether. We show that a rosette structure previously proposed to be involved in rhoptry secretion is associated with apical vesicles beyond just the most anterior one. This result, suggesting multiple vesicles are primed to enable rhoptry secretion, may shed light on the mechanisms Toxoplasma employs to enable repeated invasion attempts. Using the same approach, we examine Plasmodium falciparum merozoites and show that they too possess an apical vesicle just beneath a rosette, demonstrating evolutionary conservation of this overall subcellular organization.
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Affiliation(s)
- Li-av Segev-Zarko
- Department of Microbiology and Immunology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - Peter D Dahlberg
- Department of Chemistry, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA
| | - Stella Y Sun
- Department of Bioengineering, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA,Department of Structural Biology, University of Pittsburgh, 4200 Fifth Ave, Pittsburgh, PA 15260, USA
| | - Daniël M Pelt
- Leiden Institute of Advanced Computer Science, Leiden University, Rapenburg 70, 2311 EZ Leiden, The Netherlands
| | - Chi Yong Kim
- Department of Microbiology and Immunology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA,Department of Pediatrics––Infectious Diseases, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - Elizabeth S Egan
- Department of Microbiology and Immunology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA,Department of Pediatrics––Infectious Diseases, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - James A Sethian
- Department of Mathematics, University of California, Berkeley, CA 94720, USA,Center for Advanced Mathematics for Energy Research Application (CAMERA), Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA
| | - Wah Chiu
- To whom correspondence should be addressed:
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28
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Chandrasekaran S, Kochanowsky JA, Merritt EF, Lagas JS, Swannigan A, Koshy AA. IFN-γ stimulated murine and human neurons mount anti-parasitic defenses against the intracellular parasite Toxoplasma gondii. Nat Commun 2022; 13:4605. [PMID: 35941154 PMCID: PMC9360015 DOI: 10.1038/s41467-022-32225-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 07/19/2022] [Indexed: 01/13/2023] Open
Abstract
Dogma holds that Toxoplasma gondii persists in neurons because neurons cannot clear intracellular parasites, even with IFN-γ stimulation. As several recent studies questioned this idea, here we use primary murine neuronal cultures from wild type and transgenic mice in combination with IFN-γ stimulation and parental and transgenic parasites to reassess IFN-γ dependent neuronal clearance of intracellular parasites. We find that neurons respond to IFN-γ and that a subset of neurons clear intracellular parasites via immunity regulated GTPases. Whole neuron reconstructions from mice infected with parasites that trigger neuron GFP expression only after full invasion reveal that ~50% of these T. gondii-invaded neurons no longer harbor parasites. Finally, IFN-γ stimulated human pluripotent stem cell derived neurons show an ~50% decrease in parasite infection rate when compared to unstimulated cultures. This work highlights the capability of human and murine neurons to mount cytokine-dependent anti-T. gondii defense mechanisms in vitro and in vivo.
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Affiliation(s)
| | - Joshua A Kochanowsky
- Department of Immunobiology, University of Arizona, Tucson, AZ, USA
- University of California, Los Angeles, CA, USA
| | - Emily F Merritt
- Department of Immunobiology, University of Arizona, Tucson, AZ, USA
| | - Joseph S Lagas
- Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, USA
| | - Ayesha Swannigan
- Undergraduate Research Opportunities Consortium, University of Arizona, Tucson, AZ, USA
| | - Anita A Koshy
- BIO5 Institute, University of Arizona, Tucson, AZ, USA.
- Department of Immunobiology, University of Arizona, Tucson, AZ, USA.
- Department of Neurology, University of Arizona, Tucson, AZ, USA.
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29
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Li S, Qian J, Xu M, Yang J, He Z, Zhao T, Zhao J, Fang R. A new adenine nucleotide transporter located in the ER is essential for maintaining the growth of Toxoplasma gondii. PLoS Pathog 2022; 18:e1010665. [PMID: 35788770 PMCID: PMC9286291 DOI: 10.1371/journal.ppat.1010665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 07/15/2022] [Accepted: 06/12/2022] [Indexed: 11/30/2022] Open
Abstract
The lumen of the endoplasmic reticulum (ER) is the subcellular site where secretory protein folding, glycosylation and sulfation of membrane-bound proteins, proteoglycans, and lipids occur. The protein folding and degradation in the lumen of the ER require high levels of energy in the form of ATP. Biochemical and genetic approaches show that ATP must first be translocated across ER membrane by particular transporters before serving as substrates and energy sources in the lumenal reactions. Here we describe an ATP/ADP transporter residing in the ER membranes of T.gondii. Immunofluorescence (IFA) assay in transgenic TgANT1-HA tag revealed that TgANT1 is a protein specifically expressed in the ER. In vitro assays, functional integration of TgANT in the cytoplasmic membrane of intact E. coli cells reveals high specificity for an ATP/ADP antiport. The depletion of TgANT leads to fatal growth defects in T.gondii, including a significant slowdown in replication, no visible plaque formation, and reduced ability to invade. We also found that the amino acid mutations in two domains of TgANT lead to the complete loss of its function. Since these two domains are conserved in multiple species, they may share the same transport mechanism. Our results indicate that TgANT is the only ATP/ADP transporter in the ER of T. gondii, and the lack of ATP in the ER is the cause of the death of T. gondii. The secretory protein of T. gondii is essential for its invasion and normal growth in host cells, all the secretory proteins are synthesized in the ER before being destined for these distinct organelles, such as apicoplast, microneme, dense granule and rhoptry. ER ATP is demanded to support secretory protein folding and trafficking, and the level of ER ATP determines which proteins are able to be directed to the distinct organelles. In theory, the supply of ATP in the ER is necessary for T. gondii. However, the transport mechanism and importance of the ER ATP in T. gondii are still unclear. In our study, we identified an ATP/ADP transporter (TgANT) located in the ER and verified its function through various methods. Unlike the ER ATP/ADP transporter in mammals, we proved that TgANT is functionally specific; the deletion of TgANT caused the interruption of the supply of ATP in the ER, which leads to fatal phenotypic defects of T. gondii. Our research further expands the understanding of the growth regulation in T. gondii.
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Affiliation(s)
- Senyang Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Jiahui Qian
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Ming Xu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Jing Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Zhengming He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Tongjie Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Rui Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province, China
- * E-mail:
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30
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Cova MM, Lamarque MH, Lebrun M. How Apicomplexa Parasites Secrete and Build Their Invasion Machinery. Annu Rev Microbiol 2022; 76:619-640. [PMID: 35671531 DOI: 10.1146/annurev-micro-041320-021425] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Apicomplexa are obligatory intracellular parasites that sense and actively invade host cells. Invasion is a conserved process that relies on the timely and spatially controlled exocytosis of unique specialized secretory organelles termed micronemes and rhoptries. Microneme exocytosis starts first and likely controls the intricate mechanism of rhoptry secretion. To assemble the invasion machinery, micronemal proteins-associated with the surface of the parasite-interact and form complexes with rhoptry proteins, which in turn are targeted into the host cell. This review covers the molecular advances regarding microneme and rhoptry exocytosis and focuses on how the proteins discharged from these two compartments work in synergy to drive a successful invasion event. Particular emphasis is given to the structure and molecular components of the rhoptry secretion apparatus, and to the current conceptual framework of rhoptry exocytosis that may constitute an unconventional eukaryotic secretory machinery closely related to the one described in ciliates. 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)
- Marta Mendonça Cova
- Laboratory of Pathogen Host Interactions (LPHI), CNRS, University of Montpellier, Montpellier, France;
| | - Mauld H Lamarque
- Laboratory of Pathogen Host Interactions (LPHI), CNRS, University of Montpellier, Montpellier, France;
| | - Maryse Lebrun
- Laboratory of Pathogen Host Interactions (LPHI), CNRS, University of Montpellier, Montpellier, France;
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31
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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: 45] [Impact Index Per Article: 11.3] [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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32
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Rostami-Mansoor S, Kalantari N, Gorgani-Firouzjaee T, Ghaffari S, Ghasemi-Kasman M. Modulation of mRNA Expression of Monoacylglycerol Lipase, Diacylglycerol Lipase and Cannabinoid Receptor-1 in Mice Experimentally Infected with T. gondii. INTERNATIONAL JOURNAL OF MOLECULAR AND CELLULAR MEDICINE 2021; 10:149-155. [PMID: 34703798 PMCID: PMC8496245 DOI: 10.22088/ijmcm.bums.10.2.149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/15/2021] [Indexed: 11/01/2022]
Abstract
Toxoplasma gondii, an obligate intracellular parasite, infects more than 30% of world's population. This parasite is considered to be neurotropic, and has high tropism for the central nervous system, and potentially induces cryptogenic epilepsy by no clear mechanism. The current study aimed to investigate the alteration of the main components of the endocannabinoid signaling systems in T. gondii-infected mice. For this purpose, the levels of mRNA expression of monoacylglycerol lipase (MAGL), diacylglycerol lipase (DAGL) and cannabinoid receptor-1 (CB1), were measured by quantitative real time PCR.The mRNA expression level of MAGL was increased by ~ 8-fold in the brains of the Toxoplasma-infected group in comparison with non-infected mice (P<0.0001). The mRNA expression of CB1 gene in the brain of the infected mice was ~ 2 times higher than that measured in control group (P<0.01). The mRNA expression level of DAGL remained unchanged in the infected mice. Overall a substantial increase in MAGL and CB1 expression without any changes in DAGL, in the brain of infected mice suggests that T. gondii disturbs the endocannabinoid signaling pathways, which are known as neurotransmitter modulators involved in epilepsy.
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Affiliation(s)
- Sahar Rostami-Mansoor
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Narges Kalantari
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Tahmineh Gorgani-Firouzjaee
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Salman Ghaffari
- Department of Mycology and Parasitology, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Maryam Ghasemi-Kasman
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
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Bhandage AK, Friedrich LM, Kanatani S, Jakobsson-Björkén S, Escrig-Larena JI, Wagner AK, Chambers BJ, Barragan A. GABAergic signaling in human and murine NK cells upon challenge with Toxoplasma gondii. J Leukoc Biol 2021; 110:617-628. [PMID: 34028876 DOI: 10.1002/jlb.3hi0720-431r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Protective cytotoxic and proinflammatory cytokine responses by NK cells impact the outcome of infections by Toxoplasma gondii, a common parasite in humans and other vertebrates. However, T. gondii can also sequester within NK cells and downmodulate their effector functions. Recently, the implication of GABA signaling in infection and inflammation-related responses of mononuclear phagocytes and T cells has become evident. Yet, the role of GABAergic signaling in NK cells has remained unknown. Here, we report that human and murine NK cells synthesize and secrete GABA in response to infection challenge. Parasitized NK cells secreted GABA, whereas activation stimuli, such as IL-12/IL-18 or parasite lysates, failed to induce GABA secretion. GABA secretion by NK cells was associated to a transcriptional up-regulation of GABA synthesis enzymes (glutamate decarboxylases [GAD65/67]) and was abrogated by GAD inhibition. Further, NK cells expressed GABA-A receptor subunits and GABA signaling regulators, with transcriptional modulations taking place upon challenge with T. gondii. Exogenous GABA and GABA-containing supernatants from parasitized dendritic cells (DCs) impacted NK cell function by reducing the degranulation and cytotoxicity of NK cells. Conversely, GABA-containing supernatants from NK cells enhanced the migratory responses of parasitized DCs. This enhanced DC migration was abolished by GABA-A receptor antagonism or GAD inhibition and was reconstituted by exogenous GABA. Jointly, the data show that NK cells are GABAergic cells and that GABA hampers NK cell cytotoxicity in vitro. We hypothesize that GABA secreted by parasitized immune cells modulates the immune responses to T. gondii infection.
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Affiliation(s)
- Amol K Bhandage
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Laura M Friedrich
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Huddinge, Sweden
| | - Sachie Kanatani
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Simon Jakobsson-Björkén
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Huddinge, Sweden
| | - J Ignacio Escrig-Larena
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Huddinge, Sweden
| | - Arnika K Wagner
- Center for Hematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Benedict J Chambers
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Huddinge, Sweden
| | - Antonio Barragan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Mageswaran SK, Guérin A, Theveny LM, Chen WD, Martinez M, Lebrun M, Striepen B, Chang YW. In situ ultrastructures of two evolutionarily distant apicomplexan rhoptry secretion systems. Nat Commun 2021; 12:4983. [PMID: 34404783 PMCID: PMC8371170 DOI: 10.1038/s41467-021-25309-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 08/03/2021] [Indexed: 12/03/2022] Open
Abstract
Parasites of the phylum Apicomplexa cause important diseases including malaria, cryptosporidiosis and toxoplasmosis. These intracellular pathogens inject the contents of an essential organelle, the rhoptry, into host cells to facilitate invasion and infection. However, the structure and mechanism of this eukaryotic secretion system remain elusive. Here, using cryo-electron tomography and subtomogram averaging, we report the conserved architecture of the rhoptry secretion system in the invasive stages of two evolutionarily distant apicomplexans, Cryptosporidium parvum and Toxoplasma gondii. In both species, we identify helical filaments, which appear to shape and compartmentalize the rhoptries, and an apical vesicle (AV), which facilitates docking of the rhoptry tip at the parasite's apical region with the help of an elaborate ultrastructure named the rhoptry secretory apparatus (RSA); the RSA anchors the AV at the parasite plasma membrane. Depletion of T. gondii Nd9, a protein required for rhoptry secretion, disrupts the RSA ultrastructure and AV-anchoring. Moreover, T. gondii contains a line of AV-like vesicles, which interact with a pair of microtubules and accumulate towards the AV, leading to a working model for AV-reloading and discharging of multiple rhoptries. Together, our analyses provide an ultrastructural framework to understand how these important parasites deliver effectors into host cells.
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Affiliation(s)
- Shrawan Kumar Mageswaran
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Amandine Guérin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Liam M Theveny
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - William David Chen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew Martinez
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maryse Lebrun
- LPHI, UMR 5235 CNRS, Université de Montpellier, Montpellier, France
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yi-Wei Chang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Matta SK, Rinkenberger N, Dunay IR, Sibley LD. Toxoplasma gondii infection and its implications within the central nervous system. Nat Rev Microbiol 2021; 19:467-480. [PMID: 33627834 DOI: 10.1038/s41579-021-00518-7] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2021] [Indexed: 01/31/2023]
Abstract
Toxoplasma gondii is a parasite that infects a wide range of animals and causes zoonotic infections in humans. Although it normally only results in mild illness in healthy individuals, toxoplasmosis is a common opportunistic infection with high mortality in individuals who are immunocompromised, most commonly due to reactivation of infection in the central nervous system. In the acute phase of infection, interferon-dependent immune responses control rapid parasite expansion and mitigate acute disease symptoms. However, after dissemination the parasite differentiates into semi-dormant cysts that form within muscle cells and neurons, where they persist for life in the infected host. Control of infection in the central nervous system, a compartment of immune privilege, relies on modified immune responses that aim to balance infection control while limiting potential damage due to inflammation. In response to the activation of interferon-mediated pathways, the parasite deploys an array of effector proteins to escape immune clearance and ensure latent survival. Although these pathways are best studied in the laboratory mouse, emerging evidence points to unique mechanisms of control in human toxoplasmosis. In this Review, we explore some of these recent findings that extend our understanding for proliferation, establishment and control of toxoplasmosis in humans.
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Affiliation(s)
- Sumit K Matta
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Nicholas Rinkenberger
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Ildiko R Dunay
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - L David Sibley
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, USA.
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36
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Mendez OA, Flores Machado E, Lu J, Koshy AA. Injection with Toxoplasma gondii protein affects neuron health and survival. eLife 2021; 10:e67681. [PMID: 34106047 PMCID: PMC8270641 DOI: 10.7554/elife.67681] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/09/2021] [Indexed: 01/22/2023] Open
Abstract
Toxoplasma gondii is an intracellular parasite that causes a long-term latent infection of neurons. Using a custom MATLAB-based mapping program in combination with a mouse model that allows us to permanently mark neurons injected with parasite proteins, we found that Toxoplasma-injected neurons (TINs) are heterogeneously distributed in the brain, primarily localizing to the cortex followed by the striatum. In addition, we determined that cortical TINs are commonly (>50%) excitatory neurons (FoxP2+) and that striatal TINs are often (>65%) medium spiny neurons (MSNs) (FoxP2+). By performing single neuron patch clamping on striatal TINs and neighboring uninfected MSNs, we discovered that TINs have highly aberrant electrophysiology. As approximately 90% of TINs will die by 8 weeks post-infection, this abnormal physiology suggests that injection with Toxoplasma protein-either directly or indirectly-affects neuronal health and survival. Collectively, these data offer the first insights into which neurons interact with Toxoplasma and how these interactions alter neuron physiology in vivo.
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Affiliation(s)
- Oscar A Mendez
- Graduate Interdisciplinary Program in Neuroscience, University of ArizonaTucsonUnited States
| | | | - Jing Lu
- College of Nursing, University of ArizonaTucsonUnited States
| | - Anita A Koshy
- BIO5 Institute, University of ArizonaTucsonUnited States
- Department of Immunobiology, University of ArizonaTucsonUnited States
- Department of Neurology, University of ArizonaTucsonUnited States
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Sparvoli D, Lebrun M. Unraveling the Elusive Rhoptry Exocytic Mechanism of Apicomplexa. Trends Parasitol 2021; 37:622-637. [PMID: 34045149 DOI: 10.1016/j.pt.2021.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022]
Abstract
Apicomplexan parasites are unicellular eukaryotes that invade the cells in which they proliferate. The development of genetic tools in Toxoplasma, and then in Plasmodium, in the 1990s allowed the first description of the molecular machinery used for motility and invasion, revealing a crucial role for two different secretory organelles, micronemes and rhoptries. Rhoptry proteins are injected directly into the host cytoplasm not only to promote invasion but also to manipulate host functions. Nonetheless, the injection machinery has remained mysterious, a major conundrum in the field. Here we review recent progress in uncovering structural components and proteins implicated in rhoptry exocytosis and explain how revisiting early findings and considering the evolutionary origins of Apicomplexa contributed to some of these discoveries.
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Affiliation(s)
- Daniela Sparvoli
- LPHI UMR5235, Univ Montpellier, CNRS, F-34095 Montpellier, France
| | - Maryse Lebrun
- LPHI UMR5235, Univ Montpellier, CNRS, F-34095 Montpellier, France.
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38
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Augusto L, Wek RC, Sullivan WJ. Host sensing and signal transduction during Toxoplasma stage conversion. Mol Microbiol 2021; 115:839-848. [PMID: 33118234 PMCID: PMC9364677 DOI: 10.1111/mmi.14634] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/20/2020] [Accepted: 10/24/2020] [Indexed: 12/14/2022]
Abstract
The intracellular parasite Toxoplasma gondii infects nucleated cells in virtually all warm-blooded vertebrates, including one-third of the human population. While immunocompetent hosts do not typically show symptoms of acute infection, parasites are retained in latent tissue cysts that can be reactivated upon immune suppression, potentially damaging key organ systems. Toxoplasma has a multistage life cycle that is intimately linked to environmental stresses and host signals. As this protozoan pathogen is transmitted between multiple hosts and tissues, it evaluates these external signals to appropriately differentiate into distinct life cycle stages, such as the transition from its replicative stage (tachyzoite) to the latent stage (bradyzoite) that persists as tissue cysts. Additionally, in the gut of its definitive host, felines, Toxoplasma converts into gametocytes that produce infectious oocysts (sporozoites) that are expelled into the environment. In this review, we highlight recent advances that have illuminated the interfaces between Toxoplasma and host and how these interactions control parasite stage conversion. Mechanisms underlying these stage transitions are important targets for therapeutic intervention aimed at thwarting parasite transmission and pathogenesis.
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Affiliation(s)
- Leonardo Augusto
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
| | - Ronald C. Wek
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
| | - William J. Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
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39
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Ben Chaabene R, Lentini G, Soldati-Favre D. Biogenesis and discharge of the rhoptries: Key organelles for entry and hijack of host cells by the Apicomplexa. Mol Microbiol 2021; 115:453-465. [PMID: 33368727 DOI: 10.1111/mmi.14674] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/17/2020] [Accepted: 12/19/2020] [Indexed: 12/14/2022]
Abstract
Rhoptries are specialized secretory organelles found in the Apicomplexa phylum, playing a central role in the establishment of parasitism. The rhoptry content includes membranous as well as proteinaceous materials that are discharged into the host cell in a regulated fashion during parasite entry. A set of rhoptry neck proteins form a RON complex that critically participates in the moving junction formation during invasion. Some of the rhoptry bulb proteins are associated with the membranous materials and contribute to the formation of the parasitophorous vacuole membrane while others are targeted into the host cell including the nucleus to subvert cellular functions. Here, we review the recent studies on Toxoplasma and Plasmodium parasites that shed light on the key steps leading to rhoptry biogenesis, trafficking, and discharge.
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Affiliation(s)
- Rouaa Ben Chaabene
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Gaëlle Lentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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40
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Tagoe DNA, Drozda AA, Falco JA, Bechtel TJ, Weerapana E, Gubbels MJ. Ferlins and TgDOC2 in Toxoplasma Microneme, Rhoptry and Dense Granule Secretion. Life (Basel) 2021; 11:217. [PMID: 33803212 PMCID: PMC7999867 DOI: 10.3390/life11030217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/02/2021] [Accepted: 03/05/2021] [Indexed: 12/25/2022] Open
Abstract
The host cell invasion process of apicomplexan parasites like Toxoplasma gondii is facilitated by sequential exocytosis of the microneme, rhoptry and dense granule organelles. Exocytosis is facilitated by a double C2 domain (DOC2) protein family. This class of C2 domains is derived from an ancestral calcium (Ca2+) binding archetype, although this feature is optional in extant C2 domains. DOC2 domains provide combinatorial power to the C2 domain, which is further enhanced in ferlins that harbor 5-7 C2 domains. Ca2+ conditionally engages the C2 domain with lipids, membranes, and/or proteins to facilitating vesicular trafficking and membrane fusion. The widely conserved T. gondii ferlins 1 (FER1) and 2 (FER2) are responsible for microneme and rhoptry exocytosis, respectively, whereas an unconventional TgDOC2 is essential for microneme exocytosis. The general role of ferlins in endolysosmal pathways is consistent with the repurposed apicomplexan endosomal pathways in lineage specific secretory organelles. Ferlins can facilitate membrane fusion without SNAREs, again pertinent to the Apicomplexa. How temporal raises in Ca2+ combined with spatiotemporally available membrane lipids and post-translational modifications mesh to facilitate sequential exocytosis events is discussed. In addition, new data on cross-talk between secretion events together with the identification of a new microneme protein, MIC21, is presented.
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Affiliation(s)
- Daniel N A Tagoe
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | - Allison A Drozda
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | - Julia A Falco
- Department of Chemistry, Boston College, Chestnut Hill, MA 02467, USA
| | - Tyler J Bechtel
- Department of Chemistry, Boston College, Chestnut Hill, MA 02467, USA
| | | | - Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
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41
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Li T, Cui L, Xu X, Zhang H, Jiang Y, Ren L, Yang C, Liu X, Hu X. The Role of Tim-3 on dNK Cells Dysfunction During Abnormal Pregnancy With Toxoplasma gondii Infection. Front Cell Infect Microbiol 2021; 11:587150. [PMID: 33718261 PMCID: PMC7953497 DOI: 10.3389/fcimb.2021.587150] [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: 07/25/2020] [Accepted: 01/15/2021] [Indexed: 11/18/2022] Open
Abstract
Vertical transmission of Toxoplasma gondii (T. gondii) infection during gestation can result in severe complications such as abortion, congenital malformation, fetal teratogenesis, etc. Immune inhibitory molecule Tim-3 was discovered to be expressed on some decidual immune cells and participates in the maintenance of maternal-fetal tolerance. Dysregulation of Tim-3 expression on decidual NK (dNK) cells was observed in several cases of pregnancy complications, whereas the role of Tim-3 on dNK cells during T. gondii infection remains unclear. In the present study, T. gondii infected Tim-3-/- pregnant mice, and anti-Tim-3 neutralizing antibody treated and infected human dNK cells were successfully established to explore the role of Tim-3 in dysfunction of dNK cells during abnormal pregnancy. Our results illustrated that Tim-3-/- pregnant mice displayed more worse pregnancy outcomes with T. gondii infection compared to infected WT pregnant mice. Also, it demonstrated that Tim-3 expression on dNK cells was significantly down-regulated following T. gondii infection. Data suggested a remarkable activation of dNK cells in Tim-3-/- mice and anti-Tim-3 neutralizing antibody treated and infected groups, with higher ratios of activating receptor NKG2D to inhibitory receptor NKG2A or KIR2DL4, IFN-γ/IL-10, and increased granule production compared with that of the infected group. Mechanism analysis proved that T. gondii-induced Tim-3 down-regulation significantly activated the phosphatidylinositol-3-kinase (PI3K)-AKT and JAK-STAT signaling pathway, by which the GranzymeB, Perforin, IFN-γ, and IL-10 production were further up-regulated. Our research demonstrated that the decrease of Tim-3 on dNK cells caused by T. gondii infection further led to dNK cells function disorder, which finally contributed to the development of abnormal pregnancy outcomes.
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Affiliation(s)
- Teng Li
- Department of Immunology, Binzhou Medical University, Yantai, China
| | - Lijun Cui
- Department of Immunology, Binzhou Medical University, Yantai, China
| | - Xiaoyan Xu
- Department of Immunology, Binzhou Medical University, Yantai, China
| | - Haixia Zhang
- Department of Immunology, Binzhou Medical University, Yantai, China
| | - Yuzhu Jiang
- Department of Immunology, Binzhou Medical University, Yantai, China
| | - Liqin Ren
- Medicine & Pharmacy Research Center, Binzhou Medical University, Yantai, China
| | - Chunyan Yang
- School of Stomatology, Binzhou Medical University, Yantai, China
| | - Xianbing Liu
- Department of Immunology, Binzhou Medical University, Yantai, China
| | - Xuemei Hu
- Department of Immunology, Binzhou Medical University, Yantai, China
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42
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Jin Y, El-Ashram S, Yao Y, Shen J, Suo X, Liu X, Ji Y. Video Microscopic Analysis of Invasion of Toxoplasma gondii into Peritoneal Macrophages. J Parasitol 2021; 106:715-720. [PMID: 33184636 DOI: 10.1645/19-152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite that can infect all nucleated cells through active invasion. Some non-canonical pathways for T. gondii infection of macrophages have recently been reported. We report a new mode of T. gondii invasion using a time-lapse imaging system, in which T. gondii tachyzoites are engulfed by a tube-like structure on peritoneal macrophage phagosomes and then escape from the phagosomes. Escaped parasites re-invade macrophages through intercellular junctions between their apical end and host cell membranes. We call this invasion pathway of T. gondii "pseudopod-assisted invasion" (PAI). The completion of this invasion process depends on parasitic motility and secretion of adhesins from parasitic micronemes. Our results provide new information about T. gondii infection and establish another platform for studying interactions between T. gondii and macrophages.
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Affiliation(s)
- Yu Jin
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology, Laboratory of Tropical and Parasitic Diseases Control, Anhui Medical University, Hefei, Anhui 230032, China
| | - Saeed El-Ashram
- College of Life Science and Engineering, Foshan University, 18 Jiangwan Street, Foshan, 528231 Guangdong Province, China.,Faculty of Science, Kafrelsheikh University, Kafrelsheikh, Kafrelsheikh 33516, Egypt
| | - Yong Yao
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology, Laboratory of Tropical and Parasitic Diseases Control, Anhui Medical University, Hefei, Anhui 230032, China
| | - Jijia Shen
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Microbiology and Parasitology, Laboratory of Tropical and Parasitic Diseases Control, Anhui Medical University, Hefei, Anhui 230032, China
| | - Xun Suo
- State Key Laboratory of Agrobiotechnology & National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Xianyong Liu
- State Key Laboratory of Agrobiotechnology & National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yongsheng Ji
- School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
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43
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Snyder LM, Denkers EY. From Initiators to Effectors: Roadmap Through the Intestine During Encounter of Toxoplasma gondii With the Mucosal Immune System. Front Cell Infect Microbiol 2021; 10:614701. [PMID: 33505924 PMCID: PMC7829212 DOI: 10.3389/fcimb.2020.614701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/24/2020] [Indexed: 12/26/2022] Open
Abstract
The gastrointestinal tract is a major portal of entry for many pathogens, including the protozoan parasite Toxoplasma gondii. Billions of people worldwide have acquired T. gondii at some point in their life, and for the vast majority this has led to latent infection in the central nervous system. The first line of host defense against Toxoplasma is located within the intestinal mucosa. Appropriate coordination of responses by the intestinal epithelium, intraepithelial lymphocytes, and lamina propria cells results in an inflammatory response that controls acute infection. Under some conditions, infection elicits bacterial dysbiosis and immune-mediated tissue damage in the intestine. Here, we discuss the complex interactions between the microbiota, the epithelium, as well as innate and adaptive immune cells in the intestinal mucosa that induce protective immunity, and that sometimes switch to inflammatory pathology as T. gondii encounters tissues of the gut.
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Affiliation(s)
- Lindsay M Snyder
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, NM, United States
| | - Eric Y Denkers
- Center for Evolutionary and Theoretical Immunology and Department of Biology, University of New Mexico, Albuquerque, NM, United States
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44
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Single-cell RNA-seq reveals CD16 - monocytes as key regulators of human monocyte transcriptional response to Toxoplasma. Sci Rep 2020; 10:21047. [PMID: 33273621 PMCID: PMC7713135 DOI: 10.1038/s41598-020-78250-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 11/18/2020] [Indexed: 12/14/2022] Open
Abstract
Monocytes are among the major myeloid cells that respond to Toxoplasma, a ubiquitous foodborne that infects ≥ 1 billion people worldwide, in human peripheral blood. As such, a molecular understanding of human monocyte-Toxoplasma interactions can expedite the development of novel human toxoplasmosis control strategies. Current molecular studies on monocyte-Toxoplasma interactions are based on average cell or parasite responses across bulk cell populations. Although informative, population-level averages of monocyte responses to Toxoplasma have sometimes produced contradictory results, such as whether CCL2 or IL12 define effective monocyte responses to the parasite. Here, we used single-cell dual RNA sequencing (scDual-Seq) to comprehensively define, for the first time, the monocyte and parasite transcriptional responses that underpin human monocyte-Toxoplasma encounters at the single cell level. We report extreme transcriptional variability between individual monocytes. Furthermore, we report that Toxoplasma-exposed and unexposed monocytes are transcriptionally distinguished by a reactive subset of CD14+CD16- monocytes. Functional cytokine assays on sorted monocyte populations show that the infection-distinguishing monocytes secrete high levels of chemokines, such as CCL2 and CXCL5. These findings uncover the Toxoplasma-induced monocyte transcriptional heterogeneity and shed new light on the cell populations that largely define cytokine and chemokine secretion in human monocytes exposed to Toxoplasma.
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45
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Chen L, Christian DA, Kochanowsky JA, Phan AT, Clark JT, Wang S, Berry C, Oh J, Chen X, Roos DS, Beiting DP, Koshy AA, Hunter CA. The Toxoplasma gondii virulence factor ROP16 acts in cis and trans, and suppresses T cell responses. J Exp Med 2020; 217:133618. [PMID: 31961916 PMCID: PMC7062521 DOI: 10.1084/jem.20181757] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/10/2019] [Accepted: 11/25/2019] [Indexed: 01/19/2023] Open
Abstract
The ability of Toxoplasma gondii to inject the rhoptry kinase ROP16 into host cells results in the activation of the transcription factors STAT3 and STAT6, but it is unclear how these events impact infection. Here, parasites that inject Cre-recombinase with rhoptry proteins were used to distinguish infected macrophages from those only injected with parasite proteins. Transcriptional profiling revealed that injection of rhoptry proteins alone was sufficient to induce an M2 phenotype that is dependent on STAT3 and STAT6, but only infected cells displayed reduced expression of genes associated with antimicrobial activity and protective immunity. In vivo, the absence of STAT3 or STAT6 improved parasite control, while the loss of ROP16 resulted in a marked reduction in parasite numbers and heightened parasite-specific T cell responses. Thus, ROP16 is a virulence factor that can act in cis and trans to promote M2 programs and which limits the magnitude of parasite-specific T cell responses.
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Affiliation(s)
- Longfei Chen
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.,Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - David A Christian
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Joshua A Kochanowsky
- Department of Neurology and Department of Immunobiology, BIO5 Institute, University of Arizona, Tucson, AZ
| | - Anthony T Phan
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Joseph T Clark
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Shuai Wang
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Corbett Berry
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jung Oh
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Xiaoguang Chen
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - David S Roos
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Daniel P Beiting
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Anita A Koshy
- Department of Neurology and Department of Immunobiology, BIO5 Institute, University of Arizona, Tucson, AZ
| | - Christopher A Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
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Gossner A, Hassan MA. Transcriptional Analyses Identify Genes That Modulate Bovine Macrophage Response to Toxoplasma Infection and Immune Stimulation. Front Cell Infect Microbiol 2020; 10:437. [PMID: 33014886 PMCID: PMC7508302 DOI: 10.3389/fcimb.2020.00437] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/16/2020] [Indexed: 11/26/2022] Open
Abstract
The obligate intracellular parasite, Toxoplasma gondii, is highly prevalent among livestock species. Although cattle are generally resistant to Toxoplasma strains circulating in Europe and North America, the underlying mechanisms are largely unknown. Here, we report that bovine bone marrow-derived macrophage (BMDM) pre-stimulated with interferon gamma (IFNγ) restricts intracellular Toxoplasma growth independently of nitric oxide. While Toxoplasma promoted the expression of genes associated with alternative macrophage activation and lipid metabolism, IFNγ abrogated parasite-induced transcriptional responses and promoted the expression of genes linked to the classical macrophage activation phenotype. Additionally, several chemokines, including CCL22, that are linked to parasite-induced activation of the Wnt/β-catenin signaling were highly expressed in Toxoplasma-exposed naïve BMDMs. A chemical Wnt/β-catenin signaling pathway antagonist (IWR-1-endo) significantly reduced intracellular parasite burden in naïve BMDMs, suggesting that Toxoplasma activates this pathway to evade bovine macrophage anti-parasitic responses. Congruently, intracellular burden of a mutant Toxoplasma strain (RHΔASP5) that does not secrete dense granule proteins into the host cell, which is an essential requirement for parasite-induced activation of the Wnt/β-catenin pathway, was significantly reduced in naïve BMDMs. However, both the Wnt/β-catenin antagonist and RHASPΔ5 did not abolish parasite burden differences in naïve and IFNγ-stimulated BMDMs. Finally, we observed that parasites infecting IFNγ-stimulated BMDMs largely express genes associated with the slow dividing bradyzoite stage. Overall, this study provides novel insights into bovine macrophage transcriptional response to Toxoplasma. It establishes a foundation for a mechanistic analysis IFNγ-induced bovine anti-Toxoplasma responses and the counteracting Toxoplasma survival strategies.
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Affiliation(s)
- Anton Gossner
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Musa A Hassan
- Division of Infection and Immunity, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom.,Centre for Tropical Livestock Genetics and Health, The University of Edinburgh, Edinburgh, United Kingdom
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Transcriptional Profiling Suggests T Cells Cluster around Neurons Injected with Toxoplasma gondii Proteins. mSphere 2020; 5:5/5/e00538-20. [PMID: 32878927 PMCID: PMC7471001 DOI: 10.1128/msphere.00538-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Like other persistent intracellular pathogens, Toxoplasma gondii, a protozoan parasite, has evolved to evade the immune system and establish a chronic infection in specific cells and organs, including neurons in the CNS. Understanding T. gondii’s persistence in neurons holds the potential to identify novel, curative drug targets. The work presented here offers new insights into the neuron-T. gondii interaction in vivo. By transcriptionally profiling neurons manipulated by T. gondii, we unexpectedly revealed that immune cells, and specifically CD8+ T cells, appear to cluster around these neurons, suggesting that CD8+ T cells specifically recognize parasite-manipulated neurons. Such a possibility supports evidence from other labs that questions the long-standing dogma that neurons are often persistently infected because they are not directly recognized by immune cells such as CD8+ T cells. Collectively, these data suggest we reconsider the broader role of neurons in the context of infection and neuroinflammation. Toxoplasma gondii’s tropism for and persistence in the central nervous system (CNS) underlies the symptomatic disease that T. gondii causes in humans. Our recent work has shown that neurons are the primary CNS cell with which Toxoplasma interacts and which it infects in vivo. This predilection for neurons suggests that T. gondii’s persistence in the CNS depends specifically upon parasite manipulation of the host neurons. Yet, most work on T. gondii-host cell interactions has been done in vitro and in nonneuronal cells. We address this gap by utilizing our T. gondii-Cre system that allows permanent marking and tracking of neurons injected with parasite effector proteins in vivo. Using laser capture microdissection (LCM) and RNA sequencing using RNA-seq, we isolated and transcriptionally profiled T. gondii-injected neurons (TINs), Bystander neurons (nearby non-T. gondii-injected neurons), and neurons from uninfected mice (controls). These profiles show that TIN transcriptomes significantly differ from the transcriptomes of Bystander and control neurons and that much of this difference is driven by increased levels of transcripts from immune cells, especially CD8+ T cells and monocytes. These data suggest that when we used LCM to isolate neurons from infected mice, we also picked up fragments of CD8+ T cells and monocytes clustering in extreme proximity around TINs and, to a lesser extent, Bystander neurons. In addition, we found that T. gondii transcripts were primarily found in the TIN transcriptome, not in the Bystander transcriptome. Collectively, these data suggest that, contrary to common perception, neurons that directly interact with or harbor parasites can be recognized by CD8+ T cells. IMPORTANCE Like other persistent intracellular pathogens, Toxoplasma gondii, a protozoan parasite, has evolved to evade the immune system and establish a chronic infection in specific cells and organs, including neurons in the CNS. Understanding T. gondii’s persistence in neurons holds the potential to identify novel, curative drug targets. The work presented here offers new insights into the neuron-T. gondii interaction in vivo. By transcriptionally profiling neurons manipulated by T. gondii, we unexpectedly revealed that immune cells, and specifically CD8+ T cells, appear to cluster around these neurons, suggesting that CD8+ T cells specifically recognize parasite-manipulated neurons. Such a possibility supports evidence from other labs that questions the long-standing dogma that neurons are often persistently infected because they are not directly recognized by immune cells such as CD8+ T cells. Collectively, these data suggest we reconsider the broader role of neurons in the context of infection and neuroinflammation.
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48
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Kong L, Jiang D, He C, Xia J, Wei H, Zhou L, Peng H. TgROP18 targets IL20RB for host-defense-related-STAT3 activation during Toxoplasma gondii infection. Parasit Vectors 2020; 13:400. [PMID: 32767999 PMCID: PMC7412674 DOI: 10.1186/s13071-020-04251-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/20/2020] [Indexed: 11/17/2022] Open
Abstract
Background Toxoplasma gondii is an opportunistic protozoan infecting almost one-third of the world’s population. Toxoplasma gondii rhoptry protein 18 (TgROP18) is a key virulence factor determining the parasite’s acute virulence and is secreted into host cells during infection. We previously identified the interaction of TgROP18 and host cell immune-related receptor protein IL20RB, and observed the activation of STAT3 in human keratinocytes (HaCaT) cells infected by the rop16 knockout RH strain, though TgROP16 is regarded as being responsible for host STAT3 activation during T. gondii invasion. Therefore, we hypothesize TgROP18 can activate host STAT3 through binding to IL20RB. Methods CRISPR-CAS9 technology was used to generate the ROP16 and ROP18 double knockout RH strain, RH-∆rop16∆rop18. SDS-PAGE and western blot were used to detect STAT3 activation in different HaCaT cells with high endogenous IL20RB expression treated with T. gondii tachyzoites infection, recombinant ROP18, or IL-20. FRET and co-immunoprecipitation (Co-IP) was used to detect the protein-protein interaction. Results We observed that TgROP18 was involved in a synergic activation of the host JAK/STAT3 pathway together with TgROP16 in human HaCaT cells infected with T. gondii or treated with recombinant TgROP18 protein, stimulating host proinflammatory immune responses such as expression of TNF-α. The effect of recombinant ROP18 on STAT3 phosphorylation was presented in a dose-dependent manner. Additionally, TgROP18 was identified to target IL20RB on its extracellular domain. When we treated different cell lines with the recombinant ROP18, STAT3 phosphorylation could only be observed in the cells with endogenous IL20RB expression, such as HaCaT cells. Conclusions These findings indicate that TgROP18-IL20RB interaction upon T. gondii invasion was involved in STAT3 activation, which is associated with host cell defense.![]()
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Affiliation(s)
- Ling Kong
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Dan Jiang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Cheng He
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Jing Xia
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Haixia Wei
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Lijuan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.
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49
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Baker TL, Sun M, Semple BD, Tyebji S, Tonkin CJ, Mychasiuk R, Shultz SR. Catastrophic consequences: can the feline parasite Toxoplasma gondii prompt the purrfect neuroinflammatory storm following traumatic brain injury? J Neuroinflammation 2020; 17:222. [PMID: 32711529 PMCID: PMC7382044 DOI: 10.1186/s12974-020-01885-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/02/2020] [Indexed: 12/02/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality worldwide; however, treatment development is hindered by the heterogenous nature of TBI presentation and pathophysiology. In particular, the degree of neuroinflammation after TBI varies between individuals and may be modified by other factors such as infection. Toxoplasma gondii, a parasite that infects approximately one-third of the world’s population, has a tropism for brain tissue and can persist as a life-long infection. Importantly, there is notable overlap in the pathophysiology between TBI and T. gondii infection, including neuroinflammation. This paper will review current understandings of the clinical problems, pathophysiological mechanisms, and functional outcomes of TBI and T. gondii, before considering the potential synergy between the two conditions. In particular, the discussion will focus on neuroinflammatory processes such as microglial activation, inflammatory cytokines, and peripheral immune cell recruitment that occur during T. gondii infection and after TBI. We will present the notion that these overlapping pathologies in TBI individuals with a chronic T. gondii infection have the strong potential to exacerbate neuroinflammation and related brain damage, leading to amplified functional deficits. The impact of chronic T. gondii infection on TBI should therefore be investigated in both preclinical and clinical studies as the possible interplay could influence treatment strategies.
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Affiliation(s)
- Tamara L Baker
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Mujun Sun
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Bridgette D Semple
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia.,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
| | - Shiraz Tyebji
- Division of Infectious Diseases and Defence, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Christopher J Tonkin
- Division of Infectious Diseases and Defence, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Monash University, 6th Floor, The Alfred Centre, 99 Commercial Road, Melbourne, VIC, 3004, Australia. .,Department of Medicine, The University of Melbourne, Parkville, VIC, Australia.
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50
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Rastogi S, Xue Y, Quake SR, Boothroyd JC. Differential Impacts on Host Transcription by ROP and GRA Effectors from the Intracellular Parasite Toxoplasma gondii. mBio 2020; 11:e00182-20. [PMID: 32518180 PMCID: PMC7373195 DOI: 10.1128/mbio.00182-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/06/2020] [Indexed: 12/21/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii employs a vast array of effector proteins from the rhoptry and dense granule organelles to modulate host cell biology; these effectors are known as ROPs and GRAs, respectively. To examine the individual impacts of ROPs and GRAs on host gene expression, we developed a robust, novel protocol to enrich for ultrapure populations of a naturally occurring and reproducible population of host cells called uninfected-injected (U-I) cells, which Toxoplasma injects with ROPs but subsequently fails to invade. We then performed single-cell transcriptomic analysis at 1 to 3 h postinfection on U-I cells (as well as on uninfected and infected controls) arising from infection with either wild-type parasites or parasites lacking the MYR1 protein, which is required for soluble GRAs to cross the parasitophorous vacuole membrane (PVM) and reach the host cell cytosol. Based on comparisons of infected and U-I cells, the host's earliest response to infection appears to be driven primarily by the injected ROPs, which appear to induce immune and cellular stress pathways. These ROP-dependent proinflammatory signatures appear to be counteracted by at least some of the MYR1-dependent GRAs and may be enhanced by the MYR-independent GRAs (which are found embedded within the PVM). Finally, signatures detected in uninfected bystander cells from the infected monolayers suggest that MYR1-dependent paracrine effects also counteract inflammatory ROP-dependent processes.IMPORTANCE This work performs transcriptomic analysis of U-I cells, captures the earliest stage of a host cell's interaction with Toxoplasma gondii, and dissects the effects of individual classes of parasite effectors on host cell biology.
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Affiliation(s)
- Suchita Rastogi
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Department of Applied Physics, Stanford University, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - John C Boothroyd
- Department of Bioengineering, Stanford University, Stanford, California, USA
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