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Nayeri T, Sarvi S, Daryani A. Effective factors in the pathogenesis of Toxoplasmagondii. Heliyon 2024; 10:e31558. [PMID: 38818168 PMCID: PMC11137575 DOI: 10.1016/j.heliyon.2024.e31558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 05/11/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.
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Affiliation(s)
- Tooran Nayeri
- Infectious and Tropical Diseases Research Center, Dezful University of Medical Sciences, Dezful, Iran
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ahmad Daryani
- Department of Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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2
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Lüder CGK. IFNs in host defence and parasite immune evasion during Toxoplasma gondii infections. Front Immunol 2024; 15:1356216. [PMID: 38384452 PMCID: PMC10879624 DOI: 10.3389/fimmu.2024.1356216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 01/23/2024] [Indexed: 02/23/2024] Open
Abstract
Interferons (IFNs) are a family of cytokines with diverse functions in host resistance to pathogens and in immune regulation. Type II IFN, i.e. IFN-γ, is widely recognized as a major mediator of resistance to intracellular pathogens, including the protozoan Toxoplasma gondii. More recently, IFN-α/β, i.e. type I IFNs, and IFN-λ (type III IFN) have been identified to also play important roles during T. gondii infections. This parasite is a widespread pathogen of humans and animals, and it is a model organism to study cell-mediated immune responses to intracellular infection. Its success depends, among other factors, on the ability to counteract the IFN system, both at the level of IFN-mediated gene expression and at the level of IFN-regulated effector molecules. Here, I review recent advances in our understanding of the molecular mechanisms underlying IFN-mediated host resistance and immune regulation during T. gondii infections. I also discuss those mechanisms that T. gondii has evolved to efficiently evade IFN-mediated immunity. Knowledge of these fascinating host-parasite interactions and their underlying signalling machineries is crucial for a deeper understanding of the pathogenesis of toxoplasmosis, and it might also identify potential targets of parasite-directed or host-directed supportive therapies to combat the parasite more effectively.
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Affiliation(s)
- Carsten G. K. Lüder
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
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3
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Bass AR, Egan MS, Alexander-Floyd J, Lopes Fischer N, Doerner J, Shin S. Human GBP1 facilitates the rupture of the Legionella-containing vacuole and inflammasome activation. mBio 2023; 14:e0170723. [PMID: 37737612 PMCID: PMC10653807 DOI: 10.1128/mbio.01707-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 07/27/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE Inflammasomes are essential for host defense against intracellular bacterial pathogens like Legionella, as they activate caspases, which promote cytokine release and cell death to control infection. In mice, interferon (IFN) signaling promotes inflammasome responses against bacteria by inducing a family of IFN-inducible GTPases known as guanylate-binding proteins (GBPs). Within murine macrophages, IFN promotes the rupture of the Legionella-containing vacuole (LCV), while GBPs are dispensable for this process. Instead, GBPs facilitate the lysis of cytosol-exposed Legionella. In contrast, the functions of IFN and GBPs in human inflammasome responses to Legionella are poorly understood. We show that IFN-γ enhances inflammasome responses to Legionella in human macrophages. Human GBP1 is required for these IFN-γ-driven inflammasome responses. Furthermore, GBP1 co-localizes with Legionella and/or LCVs in a type IV secretion system (T4SS)-dependent manner and promotes damage to the LCV, which leads to increased exposure of the bacteria to the host cell cytosol. Thus, our findings reveal species- and pathogen-specific differences in how GBPs function to promote inflammasome responses.
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Affiliation(s)
- Antonia R. Bass
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Marisa S. Egan
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jasmine Alexander-Floyd
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Natasha Lopes Fischer
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jessica Doerner
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sunny Shin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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4
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Abstract
The immune system of multicellular organisms protects them from harmful microbes. To establish an infection in the face of host immune responses, pathogens must evolve specific strategies to target immune defense mechanisms. One such defense is the formation of intracellular protein complexes, termed inflammasomes, that are triggered by the detection of microbial components and the disruption of homeostatic processes that occur during bacterial infection. Formation of active inflammasomes initiates programmed cell death pathways via activation of inflammatory caspases and cleavage of target proteins. Inflammasome-activated cell death pathways such as pyroptosis lead to proinflammatory responses that protect the host. Bacterial infection has the capacity to influence inflammasomes in two distinct ways: activation and perturbation. In this review, we discuss how bacterial activities influence inflammasomes, and we discuss the consequences of inflammasome activation or evasion for both the host and pathogen.
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Affiliation(s)
- Beatrice I Herrmann
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; ,
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - James P Grayczyk
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; ,
- Current affiliation: Oncology Discovery, Abbvie, Inc., Chicago, Illinois, USA;
| | - Igor E Brodsky
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; ,
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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5
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Ha HJ, Kim JH, Lee GH, Kim S, Park HH. Structural basis of IRGB10 oligomerization by GTP hydrolysis. Front Immunol 2023; 14:1254415. [PMID: 37705969 PMCID: PMC10495984 DOI: 10.3389/fimmu.2023.1254415] [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: 07/07/2023] [Accepted: 08/11/2023] [Indexed: 09/15/2023] Open
Abstract
Immunity-related GTPase B10 (IRGB10) is a crucial member of the interferon (IFN)-inducible GTPases and plays a vital role in host defense mechanisms. Following infection, IRGB10 is induced by IFNs and functions by liberating pathogenic ligands to activate the inflammasome through direct disruption of the pathogen membrane. Despite extensive investigation into the significance of the cell-autonomous immune response, the precise molecular mechanism underlying IRGB10-mediated microbial membrane disruption remains elusive. Herein, we present two structures of different forms of IRGB10, the nucleotide-free and GppNHp-bound forms. Based on these structures, we identified that IRGB10 exists as a monomer in nucleotide-free and GTP binding states. Additionally, we identified that GTP hydrolysis is critical for dimer formation and further oligomerization of IRGB10. Building upon these observations, we propose a mechanistic model to elucidate the working mechanism of IRGB10 during pathogen membrane disruption.
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Affiliation(s)
- Hyun Ji Ha
- College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea
| | - Ju Hyeong Kim
- College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
| | - Gwan Hee Lee
- College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
| | - Subin Kim
- College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
| | - Hyun Ho Park
- College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, Republic of Korea
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6
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Kurhade C, Kang S, Biering SB, Hwang S, Randall G. CAPRIN1 Is Required for Control of Viral Replication Complexes by Interferon Gamma. mBio 2023:e0017223. [PMID: 37052473 DOI: 10.1128/mbio.00172-23] [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: 04/14/2023] Open
Abstract
Replication complexes (RCs), formed by positive-strand (+) RNA viruses through rearrangements of host endomembranes, protect their replicating RNA from host innate immune defenses. We have shown that two evolutionarily conserved defense systems, autophagy and interferon (IFN), target viral RCs and inhibit viral replication collaboratively. However, the mechanism by which autophagy proteins target viral RCs and the role of IFN-inducible GTPases in the disruption of RCs remains poorly understood. Here, using murine norovirus (MNV) as a model (+) RNA virus, we show that the guanylate binding protein 1 (GBP1) is the human GTPase responsible for inhibiting RCs. Furthermore, we found that ATG16L1 mediates the LC3 targeting of MNV RC by binding to WIPI2B and CAPRIN1, and that IFN gamma-mediated control of MNV replication was dependent on CAPRIN1. Collectively, this study identifies a novel mechanism for the autophagy machinery-mediated recognition and inhibition of viral RCs, a hallmark of (+) RNA virus replication. IMPORTANCE Replication complexes provide a microenvironment important for (+) RNA virus replication and shield it from host immune response. Previously we have shown that interferon gamma (IFNG) disrupts the RC of MNV via evolutionarily conserved autophagy proteins and IFN-inducible GTPases. Elucidating the mechanism of targeting of viral RC by ATG16L1 and IFN-induced GTPase will pave the way for development of therapeutics targeting the viral replication complexes. Here, we have identified GBP1 as the sole GBP targeting viral RC and uncovered the novel role of CAPRIN1 in recruiting ATG16L1 to the viral RC.
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Affiliation(s)
- Chaitanya Kurhade
- Department of Microbiology, The University of Chicago, Chicago, Illinois, USA
| | - Soowon Kang
- Department of Microbiology, The University of Chicago, Chicago, Illinois, USA
| | - Scott B Biering
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, California, USA
| | - Seungmin Hwang
- Department of Pathology, The University of Chicago, Chicago, Illinois, USA
| | - Glenn Randall
- Department of Microbiology, The University of Chicago, Chicago, Illinois, USA
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Wilburn KM, Meade RK, Heckenberg EM, Dockterman J, Coers J, Sassetti CM, Olive AJ, Smith CM. Differential Requirement for IRGM Proteins during Tuberculosis Infection in Mice. Infect Immun 2023; 91:e0051022. [PMID: 36629440 PMCID: PMC9933630 DOI: 10.1128/iai.00510-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/16/2022] [Indexed: 01/12/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a bacterium that exclusively resides in human hosts and remains a dominant cause of morbidity and mortality among infectious diseases worldwide. Host protection against Mtb infection is dependent on the function of immunity-related GTPase clade M (IRGM) proteins. Polymorphisms in human IRGM associate with altered susceptibility to mycobacterial disease, and human IRGM promotes the delivery of Mtb into degradative autolysosomes. Among the three murine IRGM orthologs, Irgm1 has been singled out as essential for host protection during Mtb infections in cultured macrophages and in vivo. However, whether the paralogous murine Irgm genes, Irgm2 and Irgm3, play roles in host defense against Mtb or exhibit functional relationships with Irgm1 during Mtb infection remains undetermined. Here, we report that Irgm1-/- mice are indeed acutely susceptible to aerosol infection with Mtb, yet the additional deletion of the paralogous Irgm3 gene restores protective immunity to Mtb infections in Irgm1-deficient animals. Mice lacking all three Irgm genes (panIrgm-/-) are characterized by shifted lung cytokine profiles at 5 and 24 weeks postinfection, but control disease until the very late stages of the infection, when panIrgm-/- mice display increased mortality compared to wild-type mice. Collectively, our data demonstrate that disruptions in the balance between Irgm isoforms is more detrimental to the Mtb-infected host than total loss of Irgm-mediated host defense, a concept that also needs to be considered in the context of human Mtb susceptibility linked to IRGM polymorphisms.
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Affiliation(s)
- Kaley M. Wilburn
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Rachel K. Meade
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, USA
| | - Emma M. Heckenberg
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jacob Dockterman
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jörn Coers
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, USA
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Christopher M. Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Andrew J. Olive
- Department of Microbiology and Molecular Genetics, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Clare M. Smith
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- University Program in Genetics and Genomics, Duke University, Durham, North Carolina, USA
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, North Carolina, USA
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8
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Singh S, Murillo-León M, Endres NS, Arenas Soto AF, Gómez-Marín JE, Melbert F, Kanneganti TD, Yamamoto M, Campos C, Howard JC, Taylor GA, Steinfeldt T. ROP39 is an Irgb10-specific parasite effector that modulates acute Toxoplasma gondii virulence. PLoS Pathog 2023; 19:e1011003. [PMID: 36603017 PMCID: PMC9848475 DOI: 10.1371/journal.ppat.1011003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 01/18/2023] [Accepted: 11/14/2022] [Indexed: 01/06/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is a zoonotic apicomplexan parasite that is an important cause of clinical disability in humans. On a global scale, one third of the human population is infected with T. gondii. Mice and other small rodents are believed to be responsible for transmission of T. gondii to the domestic cat, its definitive host. Interferon-inducible Immunity-Related GTPases (IRG proteins) are important for control of murine T. gondii infections. Virulence differences between T. gondii strains are linked to polymorphic rhoptry proteins (ROPs) that cooperate to inactivate individual IRG family members. In particular, the pseudokinase ROP5 isoform B is critically important in laboratory strains of mice. We identified T. gondii ROP39 in complex with ROP5B and demonstrate its contribution to acute T. gondii virulence. ROP39 directly targets Irgb10 and inhibits homodimer formation of the GTPase leading to an overall reduction of IRG protein loading onto the parasitophorous vacuolar membrane (PVM). Maintenance of PVM integrity rescues the parasite from IRG protein-mediated clearance in vitro and in vivo. This study identifies a novel T. gondii effector that is important for specific inactivation of the IRG resistance system. Our data reveal that yet unknown T. gondii effectors can emerge from identification of direct interaction partners of ROP5B.
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Affiliation(s)
- Shishir Singh
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Mateo Murillo-León
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Niklas Sebastian Endres
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ailan Farid Arenas Soto
- Grupo GEPAMOL, Centro de Investigaciones Biomedicas, Universidad del Quindio, Armenia, Quindio, Colombia
| | - Jorge Enrique Gómez-Marín
- Grupo GEPAMOL, Centro de Investigaciones Biomedicas, Universidad del Quindio, Armenia, Quindio, Colombia
| | - Florence Melbert
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Thirumala-Devi Kanneganti
- Department of Immunology, St. Jude Children´s Research Hospital, Memphis, Tenessee, United States of America
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- Laboratory of Immunoparasitology, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Claudia Campos
- Fundacao Calouste Gulbekian, Instituto Gulbekian de Ciencia, Oeiras, Portugal
| | | | - Gregory Alan Taylor
- Departments of Medicine; Molecular Genetics and Microbiology; and Immunology; and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, United States of America
- Geriatric Research, Education, and Clinical Center, Durham VA Health Care System, Durham, North Carolina, United States of America
| | - Tobias Steinfeldt
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail:
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9
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Walsh SC, Reitano JR, Dickinson MS, Kutsch M, Hernandez D, Barnes AB, Schott BH, Wang L, Ko DC, Kim SY, Valdivia RH, Bastidas RJ, Coers J. The bacterial effector GarD shields Chlamydia trachomatis inclusions from RNF213-mediated ubiquitylation and destruction. Cell Host Microbe 2022; 30:1671-1684.e9. [PMID: 36084633 PMCID: PMC9772000 DOI: 10.1016/j.chom.2022.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/13/2022] [Accepted: 08/12/2022] [Indexed: 01/26/2023]
Abstract
Chlamydia trachomatis is the leading cause of sexually transmitted bacterial infections and a major threat to women's reproductive health in particular. This obligate intracellular pathogen resides and replicates within a cellular compartment termed an inclusion, where it is sheltered by unknown mechanisms from gamma-interferon (IFNγ)-induced cell-autonomous host immunity. Through a genetic screen, we uncovered the Chlamydia inclusion membrane protein gamma resistance determinant (GarD) as a bacterial factor protecting inclusions from cell-autonomous immunity. In IFNγ-primed human cells, inclusions formed by garD loss-of-function mutants become decorated with linear ubiquitin and are eliminated. Leveraging cellular genome-wide association data, we identified the ubiquitin E3 ligase RNF213 as a candidate anti-Chlamydia protein. We demonstrate that IFNγ-inducible RNF213 facilitates the ubiquitylation and destruction of GarD-deficient inclusions. Furthermore, we show that GarD operates as a cis-acting stealth factor barring RNF213 from targeting inclusions, thus functionally defining GarD as an RNF213 antagonist essential for chlamydial growth during IFNγ-stimulated immunity.
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Affiliation(s)
- Stephen C. Walsh
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jeffrey R. Reitano
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America.,Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Mary S. Dickinson
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Miriam Kutsch
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Dulcemaria Hernandez
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Alyson B. Barnes
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Benjamin H. Schott
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Dennis C. Ko
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - So Young Kim
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Raphael H. Valdivia
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Robert J. Bastidas
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jörn Coers
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America.,Department of Immunology, Duke University Medical Center, Durham, North Carolina, United States of America.,corresponding author and lead contact:
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10
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Lantz AM, Nicol MR. Translational Models to Predict Target Concentrations for Pre-Exposure Prophylaxis in Women. AIDS Res Hum Retroviruses 2022; 38:909-923. [PMID: 36097755 PMCID: PMC9805887 DOI: 10.1089/aid.2022.0057] [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: 01/25/2023] Open
Abstract
The HIV epidemic remains a significant public health burden. Women represent half of the global HIV epidemic, yet there is an urgent need for a variety of prevention options to meet the needs of more women. Pre-exposure prophylaxis (PrEP) is a valuable prevention tool that uses antiretrovirals before a potential HIV exposure to prevent virus transmission. Development of effective preventive drug regimens for women is dependent on convenient dosing schedules and routes of administration, and on identifying defined target concentrations in mucosal tissues that provide complete protection against HIV transmission. There is a critical need for a translational model that can accurately predict in vivo target concentrations that are completely protective against HIV infection. There is no gold-standard preclinical model to predict PrEP efficacy. In this study, we review the strengths and limitations of three different preclinical models and their utility in predicting target concentrations in the female genital tract: humanized mice, non-human primates, and the ex vivo tissue model.
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Affiliation(s)
- Alyssa M. Lantz
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota, USA
| | - Melanie R. Nicol
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota, USA
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11
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Pant A, Yao X, Lavedrine A, Viret C, Dockterman J, Chauhan S, Chong-Shan Shi, Manjithaya R, Cadwell K, Kufer TA, Kehrl JH, Coers J, Sibley LD, Faure M, Taylor GA, Chauhan S. Interactions of Autophagy and the Immune System in Health and Diseases. AUTOPHAGY REPORTS 2022; 1:438-515. [PMID: 37425656 PMCID: PMC10327624 DOI: 10.1080/27694127.2022.2119743] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Autophagy is a highly conserved process that utilizes lysosomes to selectively degrade a variety of intracellular cargo, thus providing quality control over cellular components and maintaining cellular regulatory functions. Autophagy is triggered by multiple stimuli ranging from nutrient starvation to microbial infection. Autophagy extensively shapes and modulates the inflammatory response, the concerted action of immune cells, and secreted mediators aimed to eradicate a microbial infection or to heal sterile tissue damage. Here, we first review how autophagy affects innate immune signaling, cell-autonomous immune defense, and adaptive immunity. Then, we discuss the role of non-canonical autophagy in microbial infections and inflammation. Finally, we review how crosstalk between autophagy and inflammation influences infectious, metabolic, and autoimmune disorders.
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Affiliation(s)
- Aarti Pant
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Xiaomin Yao
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Aude Lavedrine
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France
- Equipe Labellisée par la Fondation pour la Recherche Médicale, FRM
| | - Christophe Viret
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France
- Equipe Labellisée par la Fondation pour la Recherche Médicale, FRM
| | - Jake Dockterman
- Department of Immunology, Duke University, Medical Center, Durham, North Carolina, USA
| | - Swati Chauhan
- Cell biology and Infectious diseases, Institute of Life Sciences, Bhubaneswar, India
| | - Chong-Shan Shi
- Laboratory of Immunoregulation, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Ravi Manjithaya
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Ken Cadwell
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University Grossman School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, United States of America
- Division of Gastroenterology and Hepatology, Department of Medicine, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Thomas A. Kufer
- Department of Immunology, Institute of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - John H. Kehrl
- Laboratory of Immunoregulation, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Jörn Coers
- Department of Immunology, Duke University, Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University, Medical Center, Durham, North Carolina, USA
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University Sch. Med., St Louis, MO, 63110, USA
| | - Mathias Faure
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007, Lyon, France
- Equipe Labellisée par la Fondation pour la Recherche Médicale, FRM
| | - Gregory A Taylor
- Department of Immunology, Duke University, Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University, Medical Center, Durham, North Carolina, USA
- Department of Molecular Microbiology, Washington University Sch. Med., St Louis, MO, 63110, USA
- Geriatric Research, Education, and Clinical Center, VA Health Care Center, Durham, North Carolina, USA
- Departments of Medicine, Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University, Medical Center, Durham, North Carolina, USA
| | - Santosh Chauhan
- Cell biology and Infectious diseases, Institute of Life Sciences, Bhubaneswar, India
- CSIR–Centre For Cellular And Molecular Biology (CCMB), Hyderabad, Telangana
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12
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Dockterman J, Coers J. How did we get here? Insights into mechanisms of immunity-related GTPase targeting to intracellular pathogens. Curr Opin Microbiol 2022; 69:102189. [PMID: 35963099 PMCID: PMC9745802 DOI: 10.1016/j.mib.2022.102189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/28/2022] [Accepted: 07/11/2022] [Indexed: 12/15/2022]
Abstract
The cytokine gamma-interferon activates cell-autonomous immunity against intracellular bacterial and protozoan pathogens by inducing a slew of antimicrobial proteins, some of which hinge upon immunity-related GTPases (IRGs) for their function. Three regulatory IRG clade M (Irgm) proteins chaperone about approximately 20 effector IRGs (GKS IRGs) to localize to pathogen-containing vacuoles (PVs) within mouse cells, initiating a cascade that results in PV elimination and killing of PV-resident pathogens. However, the mechanisms that allow IRGs to identify and traffic specifically to 'non-self' PVs have remained elusive. Integrating recent findings demonstrating direct interactions between GKS IRGs and lipids with previous work, we propose that three attributes mark PVs as GKS IRG targets: the absence of membrane-bound Irgm proteins, Atg8 lipidation, and the presence of specific lipid species. Combinatorial recognition of these three distinct signals may have evolved as a mechanism to ensure safe delivery of potent host antimicrobial effectors exclusively to PVs.
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Affiliation(s)
- Jacob Dockterman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Jörn Coers
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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13
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Interferon-Inducible E3 Ligase RNF213 Facilitates Host-Protective Linear and K63-Linked Ubiquitylation of Toxoplasma gondii Parasitophorous Vacuoles. mBio 2022; 13:e0188822. [PMID: 36154443 PMCID: PMC9601232 DOI: 10.1128/mbio.01888-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The obligate intracellular protozoan pathogen Toxoplasma gondii infects a wide range of vertebrate hosts and frequently causes zoonotic infections in humans. Whereas infected immunocompetent individuals typically remain asymptomatic, toxoplasmosis in immunocompromised individuals can manifest as a severe, potentially lethal disease, and congenital Toxoplasma infections are associated with adverse pregnancy outcomes. The protective immune response of healthy individuals involves the production of lymphocyte-derived cytokines such as interferon gamma (IFN-γ), which elicits cell-autonomous immunity in host cells. IFN-γ-inducible antiparasitic defense programs comprise nutritional immunity, the production of noxious gases, and the ubiquitylation of the Toxoplasma-containing parasitophorous vacuole (PV). PV ubiquitylation prompts the recruitment of host defense proteins to the PV and the consequential execution of antimicrobial effector programs, which reduce parasitic burden. However, the ubiquitin E3 ligase orchestrating these events has remained unknown. Here, we demonstrate that the IFN-γ-inducible E3 ligase RNF213 translocates to Toxoplasma PVs and facilitates PV ubiquitylation in human cells. Toxoplasma PVs become decorated with linear and K63-linked ubiquitin and recruit ubiquitin adaptor proteins in a process that is RNF213 dependent but independent of the linear ubiquitin chain assembly complex (LUBAC). IFN-γ priming fails to restrict Toxoplasma growth in cells lacking RNF213 expression, thus identifying RNF213 as a potent executioner of ubiquitylation-driven antiparasitic host defense.
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14
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Yamada H, Abe T, Nagaoka H, Takashima E, Nitta R, Yamamoto M, Takei K. Recruitment of Irgb6 to the membrane is a direct trigger for membrane deformation. Front Cell Infect Microbiol 2022; 12:992198. [PMID: 36159643 PMCID: PMC9504060 DOI: 10.3389/fcimb.2022.992198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/12/2022] [Indexed: 11/13/2022] Open
Abstract
Irgb6 is a member of interferon γ-induced immunity related GTPase (IRG), and one of twenty “effector” IRGs, which coordinately attack parasitophorous vacuole membrane (PVM), causing death of intracellular pathogen. Although Irgb6 plays a pivotal role as a pioneer in the process of PVM disruption, the direct effect of Irgb6 on membrane remained to be elucidated. Here, we utilized artificial lipid membranes to reconstitute Irgb6-membrane interaction in vitro, and revealed that Irgb6 directly deformed the membranes. Liposomes incubated with recombinant Irgb6 were drastically deformed generating massive tubular protrusions in the absence of guanine nucleotide, or with GMP-PNP. Liposome deformation was abolished by incubating with Irgb6-K275A/R371A, point mutations at membrane targeting residues. The membrane tubules generated by Irgb6 were mostly disappeared by the addition of GTP or GDP, which are caused by detachment of Irgb6 from membrane. Binding of Irgb6 to the membrane, which was reconstituted in vitro using lipid monolayer, was stimulated at GTP-bound state. Irgb6 GTPase activity was stimulated by the presence of liposomes more than eightfold. Irgb6 GTPase activity in the absence of membrane was also slightly stimulated, by lowering ionic strength, or by increasing protein concentration, indicating synergistic stimulation of the GTPase activity. These results suggest that membrane targeting of Irgb6 and resulting membrane deformation does not require GTP, but converting into GTP-bound state is crucial for detaching Irgb6 from the membrane, which might coincident with local membrane disruption.
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Affiliation(s)
- Hiroshi Yamada
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
- *Correspondence: Hiroshi Yamada, ; Kohji Takei,
| | - Tadashi Abe
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Ryo Nitta
- Division of Structural Medicine and Anatomy, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Kohji Takei
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
- *Correspondence: Hiroshi Yamada, ; Kohji Takei,
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15
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Kaneda Y, Miyata H, Shimada K, Oyama Y, Iida-Norita R, Ikawa M. IRGC1, a testis-enriched immunity related GTPase, is important for fibrous sheath integrity and sperm motility in mice. Dev Biol 2022; 488:104-113. [PMID: 35618043 PMCID: PMC9232189 DOI: 10.1016/j.ydbio.2022.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/02/2022] [Accepted: 05/18/2022] [Indexed: 11/22/2022]
Abstract
Immunity-related GTPases (IRGs), also known as p47 GTPases, are a family of interferon-inducible proteins that play roles in immunity defense against intracellular pathogens. Although the molecular functions of IRGs have been well studied, the function of the family member, IRGC1, remains unclear. IRGC1 is unique among IRGs because its expression is not induced by interferon and it is expressed predominantly in the testis. Further, IRGC1 is well conserved in mammals unlike other IRGs. Here, we knocked out (KO) Irgc1 in mice using the CRISPR/Cas9 system and found that the fertility of Irgc1 KO males was severely impaired because of abnormal sperm motility. Further analyses with a transmission electron microscope revealed that the fibrous sheath (FS), an accessory structure of the sperm tail, was disorganized in Irgc1 KO mice. In addition, IRGC1 was detected in the sperm tail and fractionated with FS proteins. These results suggest that IRGC1 is a component of the FS and is involved in the correct formation of the FS.
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Affiliation(s)
- Yuki Kaneda
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 5650871, Japan; Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 5650871, Japan.
| | - Haruhiko Miyata
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 5650871, Japan.
| | - Keisuke Shimada
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 5650871, Japan.
| | - Yuki Oyama
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 5650871, Japan; Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 5650871, Japan.
| | - Rie Iida-Norita
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 5650871, Japan.
| | - Masahito Ikawa
- Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 5650871, Japan; Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 5650871, Japan; The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 1088639, Japan; Center for Infectious Disease Education and Research, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 5650871, Japan.
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16
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Immunity-related GTPase IRGM at the intersection of autophagy, inflammation, and tumorigenesis. Inflamm Res 2022; 71:785-795. [PMID: 35699756 PMCID: PMC9192921 DOI: 10.1007/s00011-022-01595-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/25/2022] [Indexed: 12/26/2022] Open
Abstract
The human immunity-related GTPase M (IRGM) is a GTP-binding protein that regulates selective autophagy including xenophagy and mitophagy. IRGM impacts autophagy by (1) affecting mitochondrial fusion and fission, (2) promoting the co-assembly of ULK1 and Beclin 1, (3) enhancing Beclin 1 interacting partners (AMBRA1, ATG14L1, and UVRAG), (4) interacting with other key proteins (ATG16L1, p62, NOD2, cGAS, TLR3, and RIG-I), and (5) regulating lysosomal biogenesis. IRGM also negatively regulates NLRP3 inflammasome formation and therefore, maturation of the important pro-inflammatory cytokine IL-1β, impacting inflammation and pyroptosis. Ultimately, this affords protection against chronic inflammatory diseases. Importantly, ten IRGM polymorphisms (rs4859843, rs4859846, rs4958842, rs4958847, rs1000113, rs10051924, rs10065172, rs11747270, rs13361189, and rs72553867) have been associated with human inflammatory disorders including cancer, which suggests that these genetic variants are functionally relevant to the autophagic and inflammatory responses. The current review contextualizes IRGM, its modulation of autophagy, and inflammation, and emphasizes the role of IRGM as a cross point of immunity and tumorigenesis.
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17
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Sasai M, Yamamoto M. Anti-toxoplasma host defense systems and the parasitic counterdefense mechanisms. Parasitol Int 2022; 89:102593. [DOI: 10.1016/j.parint.2022.102593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 04/12/2022] [Accepted: 04/26/2022] [Indexed: 10/18/2022]
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18
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Abstract
The gene RARRES3 uses an unexpected strategy to eliminate the parasite Toxoplasma gondii from human cells.
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Affiliation(s)
- Juan C Sánchez-Arcila
- Department of Molecular and Cell Biology, University of California Merced, Merced, United States
| | - Kirk Dc Jensen
- Department of Molecular and Cell Biology, University of California Merced, Merced, United States.,Health Science Research Institute, University of California, Merced, Merced, United States
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19
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Rinkenberger N, Abrams ME, Matta SK, Schoggins JW, Alto NM, Sibley LD. Over-expression screen of interferon-stimulated genes identifies RARRES3 as a restrictor of Toxoplasma gondii infection. eLife 2021; 10:73137. [PMID: 34871166 PMCID: PMC8789288 DOI: 10.7554/elife.73137] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/05/2021] [Indexed: 12/26/2022] Open
Abstract
Toxoplasma gondii is an important human pathogen infecting an estimated one in three people worldwide. The cytokine interferon gamma (IFNγ) is induced during infection and is critical for restricting T. gondii growth in human cells. Growth restriction is presumed to be due to the induction of interferon-stimulated genes (ISGs) that are upregulated to protect the host from infection. Although there are hundreds of ISGs induced by IFNγ, their individual roles in restricting parasite growth in human cells remain somewhat elusive. To address this deficiency, we screened a library of 414 IFNγ induced ISGs to identify factors that impact T. gondii infection in human cells. In addition to IRF1, which likely acts through the induction of numerous downstream genes, we identified RARRES3 as a single factor that restricts T. gondii infection by inducing premature egress of the parasite in multiple human cell lines. Overall, while we successfully identified a novel IFNγ induced factor restricting T. gondii infection, the limited number of ISGs capable of restricting T. gondii infection when individually expressed suggests that IFNγ-mediated immunity to T. gondii infection is a complex, multifactorial process.
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Affiliation(s)
- Nicholas Rinkenberger
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
| | - Michael E Abrams
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Sumit K Matta
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
| | - John W Schoggins
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Neal M Alto
- Microbiology, University of Texas Southwestern Medical Center, Dallas, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, United States
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20
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Dockterman J, Fee BE, Taylor GA, Coers J. Murine Irgm Paralogs Regulate Nonredundant Functions To Execute Host Defense to Toxoplasma gondii. Infect Immun 2021; 89:e0020221. [PMID: 34338548 PMCID: PMC8519265 DOI: 10.1128/iai.00202-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/16/2021] [Indexed: 12/22/2022] Open
Abstract
Gamma interferon (IFN-γ)-induced immunity-related GTPases (IRGs) confer cell-autonomous immunity to the intracellular protozoan pathogen Toxoplasma gondii. Effector IRGs are loaded onto the Toxoplasma-containing parasitophorous vacuole (PV), where they recruit ubiquitin ligases, ubiquitin-binding proteins, and IFN-γ-inducible guanylate-binding proteins (Gbps), prompting PV lysis and parasite destruction. Host cells lacking the regulatory IRGs Irgm1 and Irgm3 fail to load effector IRGs, ubiquitin, and Gbps onto the PV and are consequently defective for cell-autonomous immunity to Toxoplasma. However, the role of the third regulatory IRG, Irgm2, in cell-autonomous immunity to Toxoplasma has remained unexplored. Here, we report that Irgm2 unexpectedly plays a limited role in the targeting of effector IRGs, ubiquitin, and Gbps to the Toxoplasma PV. Instead, Irgm2 is instrumental in the decoration of PVs with γ-aminobutyric acid receptor-associated protein-like 2 (GabarapL2). Cells lacking Irgm2 are as defective for cell-autonomous host defense to Toxoplasma as pan-Irgm-/- cells lacking all three Irgm proteins, and Irgm2-/- mice succumb to Toxoplasma infections as readily as pan-Irgm-/- mice. These findings demonstrate that, relative to Irgm1 and Irgm3, Irgm2 plays a distinct but critically important role in host resistance to Toxoplasma.
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Affiliation(s)
- Jacob Dockterman
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Brian E. Fee
- Geriatric Research, Education, and Clinical Center, VA Health Care Center, Durham, North Carolina, USA
- Departments of Medicine, Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, USA
| | - Gregory A. Taylor
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
- Geriatric Research, Education, and Clinical Center, VA Health Care Center, Durham, North Carolina, USA
- Departments of Medicine, Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jörn Coers
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
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21
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Tomita T, Guevara RB, Shah LM, Afrifa AY, Weiss LM. Secreted Effectors Modulating Immune Responses to Toxoplasma gondii. Life (Basel) 2021; 11:988. [PMID: 34575137 PMCID: PMC8467511 DOI: 10.3390/life11090988] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 12/18/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite that chronically infects a third of humans. It can cause life-threatening encephalitis in immune-compromised individuals. Congenital infection also results in blindness and intellectual disabilities. In the intracellular milieu, parasites encounter various immunological effectors that have been shaped to limit parasite infection. Parasites not only have to suppress these anti-parasitic inflammatory responses but also ensure the host organism's survival until their subsequent transmission. Recent advancements in T. gondii research have revealed a plethora of parasite-secreted proteins that suppress as well as activate immune responses. This mini-review will comprehensively examine each secreted immunomodulatory effector based on the location of their actions. The first section is focused on secreted effectors that localize to the parasitophorous vacuole membrane, the interface between the parasites and the host cytoplasm. Murine hosts are equipped with potent IFNγ-induced immune-related GTPases, and various parasite effectors subvert these to prevent parasite elimination. The second section examines several cytoplasmic and ER effectors, including a recently described function for matrix antigen 1 (MAG1) as a secreted effector. The third section covers the repertoire of nuclear effectors that hijack transcription factors and epigenetic repressors that alter gene expression. The last section focuses on the translocation of dense-granule effectors and effectors in the setting of T. gondii tissue cysts (the bradyzoite parasitophorous vacuole).
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Affiliation(s)
- Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (T.T.); (R.B.G.)
| | - Rebekah B. Guevara
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (T.T.); (R.B.G.)
| | - Lamisha M. Shah
- Department of Biological Science, Lehman College of the City University of New York, Bronx, NY 10468, USA; (L.M.S.); (A.Y.A.)
| | - Andrews Y. Afrifa
- Department of Biological Science, Lehman College of the City University of New York, Bronx, NY 10468, USA; (L.M.S.); (A.Y.A.)
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (T.T.); (R.B.G.)
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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22
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Guanylate-Binding Protein-Dependent Noncanonical Inflammasome Activation Prevents Burkholderia thailandensis-Induced Multinucleated Giant Cell Formation. mBio 2021; 12:e0205421. [PMID: 34399626 PMCID: PMC8406320 DOI: 10.1128/mbio.02054-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Inflammasomes are cytosolic multiprotein signaling complexes that are activated upon pattern recognition receptor-mediated recognition of pathogen-derived ligands or endogenous danger signals. Their assembly activates the downstream inflammatory caspase-1 and caspase-4/5 (human) or caspase-11 (mouse), which induces cytokine release and pyroptotic cell death through the cleavage of the pore-forming effector gasdermin D. Pathogen detection by host cells also results in the production and release of interferons (IFNs), which fine-tune inflammasome-mediated responses. IFN-induced guanylate-binding proteins (GBPs) have been shown to control the activation of the noncanonical inflammasome by recruiting caspase-4 on the surface of cytosolic Gram-negative bacteria and promoting its interaction with lipopolysaccharide (LPS). The Gram-negative opportunistic bacterial pathogen Burkholderia thailandensis infects epithelial cells and macrophages and hijacks the host actin polymerization machinery to spread into neighboring cells. This process causes host cell fusion and the formation of so-called multinucleated giant cells (MNGCs). Caspase-1- and IFN-regulated caspase-11-mediated inflammasome pathways play an important protective role against B. thailandensis in mice, but little is known about the role of IFNs and inflammasomes during B. thailandensis infection of human cells, particularly epithelial cells. Here, we report that IFN-γ priming of human epithelial cells restricts B. thailandensis-induced MNGC formation in a GBP1-dependent manner. Mechanistically, GBP1 does not promote bacteriolysis or impair actin-based bacterial motility but acts by inducing caspase-4-dependent pyroptosis of the infected cell. In addition, we show that IFN-γ priming of human primary macrophages confers a more efficient antimicrobial effect through inflammasome activation, further confirming the important role that interferon signaling plays in restricting Burkholderia replication and spread.
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23
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Dowdell AS, Colgan SP. Metabolic Host-Microbiota Interactions in Autophagy and the Pathogenesis of Inflammatory Bowel Disease (IBD). Pharmaceuticals (Basel) 2021; 14:ph14080708. [PMID: 34451805 PMCID: PMC8399382 DOI: 10.3390/ph14080708] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 12/17/2022] Open
Abstract
Inflammatory bowel disease (IBD) is a family of conditions characterized by chronic, relapsing inflammation of the gastrointestinal tract. IBD afflicts over 3 million adults in the United States and shows increasing prevalence in the Westernized world. Current IBD treatments center on modulation of the damaging inflammatory response and carry risks such as immunosuppression, while the development of more effective treatments is hampered by our poor understanding of the molecular mechanisms of IBD pathogenesis. Previous genome-wide association studies (GWAS) have demonstrated that gene variants linked to the cellular response to microorganisms are most strongly associated with an increased risk of IBD. These studies are supported by mechanistic work demonstrating that IBD-associated polymorphisms compromise the intestine's anti-microbial defense. In this review, we summarize the current knowledge regarding IBD as a disease of defects in host-microbe interactions and discuss potential avenues for targeting this mechanism for future therapeutic development.
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Affiliation(s)
| | - Sean P. Colgan
- Correspondence: ; Tel.: +303-724-7235; Fax: +303-724-7243
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24
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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: 85] [Impact Index Per Article: 28.3] [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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25
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The role of IL-12 in stimulating NK cells against Toxoplasma gondii infection: a mini-review. Parasitol Res 2021; 120:2303-2309. [PMID: 34110502 DOI: 10.1007/s00436-021-07204-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
Toxoplasma gondii is an intracellular protozoan parasite that can remarkably infect, survive, and replicate in almost all mammalian cells and can cause severe neurological and ocular damage in immunocompromised individuals. It is known that Natural Killer cells (NK cells), as a type of cytotoxic lymphocyte, have critical protective roles in innate immunity during the T. gondii infection through releasing interferon gamma (IFN-γ). Interleukin 12 (IL-12) is a pivotal critical cytokine for the generation of IFN-γ-producing NK cells. Several studies have shown cytokines' impact on NK cell activation; and IL-2 has an important role with a potent stimulatory factor for NK cells. In this review, we summarized the mechanism of interleukin-12 production stimulation by T. gondii tachyzoites and discussed several factors affecting this mechanism.
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26
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Subauste CS. Recent Advances in the Roles of Autophagy and Autophagy Proteins in Host Cells During Toxoplasma gondii Infection and Potential Therapeutic Implications. Front Cell Dev Biol 2021; 9:673813. [PMID: 34179003 PMCID: PMC8220159 DOI: 10.3389/fcell.2021.673813] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/30/2021] [Indexed: 11/29/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan that can cause encephalitis and retinitis in humans. The success of T. gondii as a pathogen depends in part on its ability to form an intracellular niche (parasitophorous vacuole) that allows protection from lysosomal degradation and parasite replication. The parasitophorous vacuole can be targeted by autophagy or by autophagosome-independent processes triggered by autophagy proteins. However, T. gondii has developed many strategies to preserve the integrity of the parasitophorous vacuole. Here, we review the interaction between T. gondii, autophagy, and autophagy proteins and expand on recent advances in the field, including the importance of autophagy in the regulation of invasion of the brain and retina by the parasite. We discuss studies that have begun to explore the potential therapeutic applications of the knowledge gained thus far.
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Affiliation(s)
- Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, United States.,Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
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Pradipta A, Sasai M, Motani K, Ma JS, Lee Y, Kosako H, Yamamoto M. Cell-autonomous Toxoplasma killing program requires Irgm2 but not its microbe vacuolar localization. Life Sci Alliance 2021; 4:4/7/e202000960. [PMID: 34078740 PMCID: PMC8200298 DOI: 10.26508/lsa.202000960] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 05/17/2021] [Accepted: 05/20/2021] [Indexed: 01/16/2023] Open
Abstract
Interferon-inducible GTPases, such as immunity-related GTPases (IRGs) and guanylate-binding proteins (GBPs), are essential for cell-autonomous immunity against a wide variety of intracellular pathogens including Toxoplasma IRGs comprise regulatory and effector subfamily proteins. Regulatory IRGs Irgm1 and Irgm3 play important roles in anti-Toxoplasma immunity by globally controlling effector IRGs and GBPs. There is a remaining regulatory IRG, called Irgm2, which highly accumulates on parasitophorous vacuole membranes (PVMs). Very little is known about the mechanism of the unique localization on Toxoplasma PVMs. Here, we show that Irgm2 is important to control parasite killing through recruitment of Gbp1 and Irgb6, which does not require Irgm2 localization at Toxoplasma PVMs. Ubiquitination of Irgm2 in the cytosol, but not at the PVM, is also important for parasite killing through recruitment of Gbp1 to the PVM. Conversely, PVM ubiquitination and p62/Sqstm1 loading at later time points post-Toxoplasma infection require Irgm2 localization at the PVM. Irgm2-deficient mice are highly susceptible to Toxoplasma infection. Taken together, these data indicate that Irgm2 selectively controls accumulation of anti-Toxoplasma effectors to the vacuole in a manner dependent or independent on Irgm2 localization at the Toxoplasma PVM, which mediates parasite killing.
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Affiliation(s)
- Ariel Pradipta
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Kou Motani
- Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan
| | - Ji Su Ma
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Youngae Lee
- Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Hidetaka Kosako
- Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Tokushima University, Tokushima, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan .,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.,Division of Microbiology and Immunology, Center for Infectious Disease Education and Research, Osaka University, Osaka, Japan
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28
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Fisch D, Clough B, Domart MC, Encheva V, Bando H, Snijders AP, Collinson LM, Yamamoto M, Shenoy AR, Frickel EM. Human GBP1 Differentially Targets Salmonella and Toxoplasma to License Recognition of Microbial Ligands and Caspase-Mediated Death. Cell Rep 2021; 32:108008. [PMID: 32783936 PMCID: PMC7435695 DOI: 10.1016/j.celrep.2020.108008] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/19/2020] [Accepted: 07/15/2020] [Indexed: 12/12/2022] Open
Abstract
Interferon-inducible guanylate-binding proteins (GBPs) promote cell-intrinsic defense through host cell death. GBPs target pathogens and pathogen-containing vacuoles and promote membrane disruption for release of microbial molecules that activate inflammasomes. GBP1 mediates pyroptosis or atypical apoptosis of Salmonella Typhimurium (STm)- or Toxoplasma gondii (Tg)- infected human macrophages, respectively. The pathogen-proximal detection-mechanisms of GBP1 remain poorly understood, as humans lack functional immunity-related GTPases (IRGs) that assist murine Gbps. Here, we establish that GBP1 promotes the lysis of Tg-containing vacuoles and parasite plasma membranes, releasing Tg-DNA. In contrast, we show GBP1 targets cytosolic STm and recruits caspase-4 to the bacterial surface for its activation by lipopolysaccharide (LPS), but does not contribute to bacterial vacuole escape. Caspase-1 cleaves and inactivates GBP1, and a cleavage-deficient GBP1D192E mutant increases caspase-4-driven pyroptosis due to the absence of feedback inhibition. Our studies elucidate microbe-specific roles of GBP1 in infection detection and its triggering of the assembly of divergent caspase signaling platforms. Development of two microscopy assays for microbe/microbe-containing vacuole lysis Human GBP1 is essential for the lysis of Toxoplasma gondii vacuoles and parasites Caspase-4 recruitment, but not cytosolic escape of Salmonella, is GBP1 dependent Caspase-1 cleaves and inactivates GBP1 and suppresses caspase-4-driven pyroptosis
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Affiliation(s)
- Daniel Fisch
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London NW1 1AT, UK; MRC Centre for Molecular Bacteriology & Infection, Department of Infectious Disease, Imperial College London, London SW7 2AZ, UK
| | - Barbara Clough
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Marie-Charlotte Domart
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Vesela Encheva
- Mass Spectrometry and Proteomics Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Hironori Bando
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Ambrosius P Snijders
- Mass Spectrometry and Proteomics Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Lucy M Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Avinash R Shenoy
- MRC Centre for Molecular Bacteriology & Infection, Department of Infectious Disease, Imperial College London, London SW7 2AZ, UK; The Francis Crick Institute, London NW1 1AT, UK.
| | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK.
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Interferon-induced GTPases orchestrate host cell-autonomous defence against bacterial pathogens. Biochem Soc Trans 2021; 49:1287-1297. [PMID: 34003245 PMCID: PMC8286824 DOI: 10.1042/bst20200900] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 01/08/2023]
Abstract
Interferon (IFN)-induced guanosine triphosphate hydrolysing enzymes (GTPases) have been identified as cornerstones of IFN-mediated cell-autonomous defence. Upon IFN stimulation, these GTPases are highly expressed in various host cells, where they orchestrate anti-microbial activities against a diverse range of pathogens such as bacteria, protozoan and viruses. IFN-induced GTPases have been shown to interact with various host pathways and proteins mediating pathogen control via inflammasome activation, destabilising pathogen compartments and membranes, orchestrating destruction via autophagy and the production of reactive oxygen species as well as inhibiting pathogen mobility. In this mini-review, we provide an update on how the IFN-induced GTPases target pathogens and mediate host defence, emphasising findings on protection against bacterial pathogens.
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Ihara F, Nishikawa Y. Toxoplasma gondii manipulates host cell signaling pathways via its secreted effector molecules. Parasitol Int 2021; 83:102368. [PMID: 33905814 DOI: 10.1016/j.parint.2021.102368] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 03/13/2021] [Accepted: 04/07/2021] [Indexed: 01/07/2023]
Abstract
The obligate intracellular parasite Toxoplasma gondii secretes a vast variety of effector molecules from organelles known as rhoptries (ROPs) and dense granules (GRAs). ROP proteins are released into the cytosol of the host cell where they are directed to the cell nucleus or to the parasitophorous vacuole (PV) membrane. ROPs secrete proteins that enable host cell penetration and vacuole formation by the parasites, as well as hijacking host-immune responses. After invading host cells, T. gondii multiplies within a PV that is maintained by the parasite proteins secreted from GRAs. Most GRA proteins remain within the PV, but some are known to access the host cytosol across the PV membrane, and a few are able to traffic into the host-cell nucleus. These effectors bind to host cell proteins and affect host cell signaling pathways to favor the parasite. Studies on host-pathogen interactions have identified many infection-altered host signal transductions. Notably, the relationship between individual parasite effector molecules and the specific targeting of host-signaling pathways is being elucidated through the advent of forward and reverse genetic strategies. Understanding the complex nature of the host-pathogen interactions underlying how the host-signaling pathway is manipulated by parasite effectors may lead to new molecular biological knowledge and novel therapeutic methods for toxoplasmosis. In this review, we discuss how T. gondii modulates cell signaling pathways in the host to favor its survival.
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Affiliation(s)
- Fumiaki Ihara
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
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31
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Tan YQ, Wang F, Ma RJ, Zhang J, Zhou G. Interferon-γ activated T-cell IRGM-autophagy axis in oral lichen planus. Int Immunopharmacol 2021; 94:107478. [PMID: 33639564 DOI: 10.1016/j.intimp.2021.107478] [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: 10/21/2020] [Revised: 12/30/2020] [Accepted: 02/04/2021] [Indexed: 10/22/2022]
Abstract
Oral lichen planus (OLP) is an inflammatory immune disease featured by dense T-cell infiltrate and basal keratinocytes degeneration. Immunity related GTPase M (IRGM) is vital for the induction of autophagy. Our previous studies have demonstrated aberrant autophagy in OLP, however, the involvement of IRGM-autophagy axis in OLP has not yet been revealed. The expression of IRGM and autophagy activity were evaluated in oral mucosal tissues and peripheral T cells of OLP patients and healthy controls, respectively. We found significant upregulation of IRGM and LC3B in lesions of patients with OLP as compared with healthy donors. IRGM, LC3B and NOD2 levels were also elevated in the peripheral T cells of OLP. Then, knockdown of IRGM after electrotransfection with siRNA resulted in attenuated autophagy, growth inhibition, and apoptosis of T cells. In addition, preincubation with IFN-γ promoted the expression of IRGM mRNA and induced autophagy in T cells. Furthermore, IFN-γ decreased the proliferation and apoptosis of T cells, whereas facilitated the viability of keratinocytes in a co-culture system of activated T cells and keratinocytes. Taken together, activated IRGM-autophagy axis under IFN-γ regulation in T cells might participate in the immunoregulatory mechanism of OLP.
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Affiliation(s)
- Ya-Qin Tan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, China; Department of Oral Medicine, School and Hospital of Stomatology, Wuhan University, China
| | - Fang Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, China
| | - Rui-Jie Ma
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, China
| | - Jing Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, China; Department of Oral Medicine, School and Hospital of Stomatology, Wuhan University, China
| | - Gang Zhou
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, China; Department of Oral Medicine, School and Hospital of Stomatology, Wuhan University, China.
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32
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Molecular basis of IRGB10 oligomerization and membrane association for pathogen membrane disruption. Commun Biol 2021; 4:92. [PMID: 33469160 PMCID: PMC7815755 DOI: 10.1038/s42003-020-01640-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 12/24/2020] [Indexed: 12/14/2022] Open
Abstract
Immunity-related GTPase B10 (IRGB10) belongs to the interferon (IFN)-inducible GTPases, a family of proteins critical to host defense. It is induced by IFNs after pathogen infection, and plays a role in liberating pathogenic ligands for the activation of the inflammasome by directly disrupting the pathogen membrane. Although IRGB10 has been intensively studied owing to its functional importance in the cell-autonomous immune response, the molecular mechanism of IRGB10-mediated microbial membrane disruption is still unclear. In this study, we report the structure of mouse IRGB10. Our structural study showed that IRGB10 bound to GDP forms an inactive head-to-head dimer. Further structural analysis and comparisons indicated that IRGB10 might change its conformation to activate its membrane-binding and disruptive functions. Based on this observation, we propose a model of the working mechanism of IRGB10 during pathogen membrane disruption. Ha et al. present a crystal structure of mouse IRGB10, a mouse interferon-inducible GTPase that mediates bacteriolysis in cell autonomous immunity. With further mutagenesis studies, they show that IRGB10 bound to GDP forms an inactive head-to-head dimer, which changes its conformation to activate its membrane-binding and disruptive functions.
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Finethy R, Dockterman J, Kutsch M, Orench‐Rivera N, Wallace GD, Piro AS, Luoma S, Haldar AK, Hwang S, Martinez J, Kuehn MJ, Taylor GA, Coers J. Dynamin-related Irgm proteins modulate LPS-induced caspase-11 activation and septic shock. EMBO Rep 2020; 21:e50830. [PMID: 33124745 PMCID: PMC7645254 DOI: 10.15252/embr.202050830] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/08/2020] [Accepted: 09/25/2020] [Indexed: 12/15/2022] Open
Abstract
Inflammation associated with gram-negative bacterial infections is often instigated by the bacterial cell wall component lipopolysaccharide (LPS). LPS-induced inflammation and resulting life-threatening sepsis are mediated by the two distinct LPS receptors TLR4 and caspase-11 (caspase-4/-5 in humans). Whereas the regulation of TLR4 activation by extracellular and phago-endosomal LPS has been studied in great detail, auxiliary host factors that specifically modulate recognition of cytosolic LPS by caspase-11 are largely unknown. This study identifies autophagy-related and dynamin-related membrane remodeling proteins belonging to the family of Immunity-related GTPases M clade (IRGM) as negative regulators of caspase-11 activation in macrophages. Phagocytes lacking expression of mouse isoform Irgm2 aberrantly activate caspase-11-dependent inflammatory responses when exposed to extracellular LPS, bacterial outer membrane vesicles, or gram-negative bacteria. Consequently, Irgm2-deficient mice display increased susceptibility to caspase-11-mediated septic shock in vivo. This Irgm2 phenotype is partly reversed by the simultaneous genetic deletion of the two additional Irgm paralogs Irgm1 and Irgm3, indicating that dysregulated Irgm isoform expression disrupts intracellular LPS processing pathways that limit LPS availability for caspase-11 activation.
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Affiliation(s)
- Ryan Finethy
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
| | - Jacob Dockterman
- Department of ImmunologyDuke University Medical CenterDurhamNCUSA
| | - Miriam Kutsch
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
| | | | - Graham D Wallace
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
| | - Anthony S Piro
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
| | - Sarah Luoma
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
| | - Arun K Haldar
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
- Present address:
Division of BiochemistryCentral Drug Research Institute (CDRI)Council of Scientific and Industrial Research (CSIR)LucknowIndia
| | - Seungmin Hwang
- Department of PathologyThe University of ChicagoChicagoILUSA
- Present address:
VIR BiotechnologySan FranciscoCAUSA
| | - Jennifer Martinez
- Immunity, Inflammation, and Disease LaboratoryNational Institute of Environmental Health SciencesNational Institutes of HealthResearch Triangle ParkNCUSA
| | - Meta J Kuehn
- Department of BiochemistryDuke University Medical CenterDurhamNCUSA
| | - Gregory A Taylor
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
- Department of ImmunologyDuke University Medical CenterDurhamNCUSA
- Division of GeriatricsDepartment of MedicineCenter for the Study of Aging and Human DevelopmentDuke University Medical CenterDurhamNCUSA
- Geriatric Research, Education, and Clinical Center, VA Medical CenterDurhamNCUSA
| | - Jörn Coers
- Department of Molecular Genetics and MicrobiologyDuke University Medical CenterDurhamNCUSA
- Department of ImmunologyDuke University Medical CenterDurhamNCUSA
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Nyonda MA, Hammoudi PM, Ye S, Maire J, Marq JB, Yamamoto M, Soldati-Favre D. Toxoplasma gondii GRA60 is an effector protein that modulates host cell autonomous immunity and contributes to virulence. Cell Microbiol 2020; 23:e13278. [PMID: 33040458 DOI: 10.1111/cmi.13278] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 10/04/2020] [Accepted: 10/08/2020] [Indexed: 02/06/2023]
Abstract
Toxoplasma gondii infects virtually any nucleated cell and resides inside a non-phagocytic vacuole surrounded by a parasitophorous vacuolar membrane (PVM). Pivotal to the restriction of T. gondii dissemination upon infection in murine cells is the recruitment of immunity regulated GTPases (IRGs) and guanylate binding proteins (GBPs) to the PVM that leads to pathogen elimination. The virulent T. gondii type I RH strain secretes a handful of effectors including the dense granule protein GRA7, the serine-threonine kinases ROP17 and ROP18, and a pseudo-kinase ROP5, that synergistically inhibit the recruitment of IRGs to the PVM. Here, we characterise GRA60, a novel dense granule effector, which localises to the vacuolar space and PVM and contributes to virulence of RH in mice, suggesting a role in the subversion of host cell defence mechanisms. Members of the host cell IRG defence system Irgb10 and Irga6 are recruited to the PVM of RH parasites lacking GRA60 as observed previously for the avirulent RHΔrop5 mutant, with RH preventing such recruitment. Deletion of GRA60 in RHΔrop5 leads to a recruitment of IRGs comparable to the single knockouts. GRA60 therefore represents a novel parasite effector conferring resistance to IRGs in type I parasites, and found associated to ROP18, a member of the virulence complex.
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Affiliation(s)
- Mary Akinyi Nyonda
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Pierre-Mehdi Hammoudi
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Shu Ye
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Jessica Maire
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Jean-Baptiste Marq
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Division of Infectious Diseases, Osaka University, Suita, Japan
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
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35
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Schwerbel K, Kamitz A, Krahmer N, Hallahan N, Jähnert M, Gottmann P, Lebek S, Schallschmidt T, Arends D, Schumacher F, Kleuser B, Haltenhof T, Heyd F, Gancheva S, Broman KW, Roden M, Joost HG, Chadt A, Al-Hasani H, Vogel H, Jonas W, Schürmann A. Immunity-related GTPase induces lipophagy to prevent excess hepatic lipid accumulation. J Hepatol 2020; 73:771-782. [PMID: 32376415 PMCID: PMC7957830 DOI: 10.1016/j.jhep.2020.04.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/08/2020] [Accepted: 04/16/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Currently, only a few genetic variants explain the heritability of fatty liver disease. Quantitative trait loci (QTL) analysis of mouse strains has identified the susceptibility locus Ltg/NZO (liver triglycerides from New Zealand obese [NZO] alleles) on chromosome 18 as associating with increased hepatic triglycerides. Herein, we aimed to identify genomic variants responsible for this association. METHODS Recombinant congenic mice carrying 5.3 Mbp of Ltg/NZO were fed a high-fat diet and characterized for liver fat. Bioinformatic analysis, mRNA profiles and electrophoretic mobility shift assays were performed to identify genes responsible for the Ltg/NZO phenotype. Candidate genes were manipulated in vivo by injecting specific microRNAs into C57BL/6 mice. Pulldown coupled with mass spectrometry-based proteomics and immunoprecipitation were performed to identify interaction partners of IFGGA2. RESULTS Through positional cloning, we identified 2 immunity-related GTPases (Ifgga2, Ifgga4) that prevent hepatic lipid storage. Expression of both murine genes and the human orthologue IRGM was significantly lower in fatty livers. Accordingly, liver-specific suppression of either Ifgga2 or Ifgga4 led to a 3-4-fold greater increase in hepatic fat content. In the liver of low-fat diet-fed mice, IFGGA2 localized to endosomes/lysosomes, while on a high-fat diet it associated with lipid droplets. Pulldown experiments and proteomics identified the lipase ATGL as a binding partner of IFGGA2 which was confirmed by co-immunoprecipitation. Both proteins partially co-localized with the autophagic marker LC3B. Ifgga2 suppression in hepatocytes reduced the amount of LC3B-II, whereas overexpression of Ifgga2 increased the association of LC3B with lipid droplets and decreased triglyceride storage. CONCLUSION IFGGA2 interacts with ATGL and protects against hepatic steatosis, most likely by enhancing the binding of LC3B to lipid droplets. LAY SUMMARY The genetic basis of non-alcoholic fatty liver disease remains incompletely defined. Herein, we identified members of the immunity-related GTPase family in mice and humans that act as regulators of hepatic fat accumulation, with links to autophagy. Overexpression of the gene Ifgga2 was shown to reduce hepatic lipid storage and could be a therapeutic target for the treatment of fatty liver disease.
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Affiliation(s)
- Kristin Schwerbel
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Anne Kamitz
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Natalie Krahmer
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Department of Proteomics and Signal Transduction, Max-Planck Institute of Biochemistry, D-82152 Martinsried, Germany; Institute for Diabetes and Obesity, Helmholtz Zentrum München, D-85764 München-Neuherberg, Germany
| | - Nicole Hallahan
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Markus Jähnert
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Pascal Gottmann
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Sandra Lebek
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Medical Faculty, Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Tanja Schallschmidt
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Medical Faculty, Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Danny Arends
- Animal Breeding Biology and Molecular Genetics, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Fabian Schumacher
- Institute of Nutritional Science, Department of Toxicology, University of Potsdam, D-14558 Nuthetal, Germany
| | - Burkhard Kleuser
- Institute of Nutritional Science, Department of Toxicology, University of Potsdam, D-14558 Nuthetal, Germany
| | - Tom Haltenhof
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, D-14195 Berlin, Germany
| | - Florian Heyd
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, D-14195 Berlin, Germany
| | - Sofiya Gancheva
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Institute for Diabetes Research, Heinrich-Heine University Düsseldorf, D-40225 Düsseldorf, Germany; Department of Endocrinology and Diabetology, Medical Faculty, Heinrich-Heine University, D-40225 Düsseldorf, Germany
| | - Karl W Broman
- Department of Biostatistics and Medical Informatics, University of Wisconsin, WI 53706 Madison, Wisconsin, United States
| | - Michael Roden
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Institute for Diabetes Research, Heinrich-Heine University Düsseldorf, D-40225 Düsseldorf, Germany; Department of Endocrinology and Diabetology, Medical Faculty, Heinrich-Heine University, D-40225 Düsseldorf, Germany
| | - Hans-Georg Joost
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Alexandra Chadt
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Medical Faculty, Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Hadi Al-Hasani
- German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; Medical Faculty, Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Heike Vogel
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany
| | - Wenke Jonas
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany.
| | - Annette Schürmann
- Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbruecke, D-14558 Nuthetal, Germany; German Center for Diabetes Research, D-85764 München-Neuherberg, Germany; University of Potsdam, Institute of Nutritional Sciences, D-14558 Nuthetal, Germany.
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36
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Buechner M, Yang Z, Al-Hashimi H. A Series of Tubes: The C. elegans Excretory Canal Cell as a Model for Tubule Development. J Dev Biol 2020; 8:jdb8030017. [PMID: 32906663 PMCID: PMC7557474 DOI: 10.3390/jdb8030017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 12/25/2022] Open
Abstract
Formation and regulation of properly sized epithelial tubes is essential for multicellular life. The excretory canal cell of C. elegans provides a powerful model for investigating the integration of the cytoskeleton, intracellular transport, and organismal physiology to regulate the developmental processes of tube extension, lumen formation, and lumen diameter regulation in a narrow single cell. Multiple studies have provided new understanding of actin and intermediate filament cytoskeletal elements, vesicle transport, and the role of vacuolar ATPase in determining tube size. Most of the genes discovered have clear homologues in humans, with implications for understanding these processes in mammalian tissues such as Schwann cells, renal tubules, and brain vasculature. The results of several new genetic screens are described that provide a host of new targets for future studies in this informative structure.
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Affiliation(s)
- Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA;
- Correspondence:
| | - Zhe Yang
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA;
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Kongsomboonvech AK, Rodriguez F, Diep AL, Justice BM, Castallanos BE, Camejo A, Mukhopadhyay D, Taylor GA, Yamamoto M, Saeij JPJ, Reese ML, Jensen KDC. Naïve CD8 T cell IFNγ responses to a vacuolar antigen are regulated by an inflammasome-independent NLRP3 pathway and Toxoplasma gondii ROP5. PLoS Pathog 2020; 16:e1008327. [PMID: 32853276 PMCID: PMC7480859 DOI: 10.1371/journal.ppat.1008327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 09/09/2020] [Accepted: 07/05/2020] [Indexed: 12/31/2022] Open
Abstract
Host resistance to Toxoplasma gondii relies on CD8 T cell IFNγ responses, which if modulated by the host or parasite could influence chronic infection and parasite transmission between hosts. Since host-parasite interactions that govern this response are not fully elucidated, we investigated requirements for eliciting naïve CD8 T cell IFNγ responses to a vacuolar resident antigen of T. gondii, TGD057. Naïve TGD057 antigen-specific CD8 T cells (T57) were isolated from transnuclear mice and responded to parasite-infected bone marrow-derived macrophages (BMDMs) in an antigen-dependent manner, first by producing IL-2 and then IFNγ. T57 IFNγ responses to TGD057 were independent of the parasite’s protein export machinery ASP5 and MYR1. Instead, host immunity pathways downstream of the regulatory Immunity-Related GTPases (IRG), including partial dependence on Guanylate-Binding Proteins, are required. Multiple T. gondii ROP5 isoforms and allele types, including ‘avirulent’ ROP5A from clade A and D parasite strains, were able to suppress CD8 T cell IFNγ responses to parasite-infected BMDMs. Phenotypic variance between clades B, C, D, F, and A strains suggest T57 IFNγ differentiation occurs independently of parasite virulence or any known IRG-ROP5 interaction. Consistent with this, removal of ROP5 is not enough to elicit maximal CD8 T cell IFNγ production to parasite-infected cells. Instead, macrophage expression of the pathogen sensors, NLRP3 and to a large extent NLRP1, were absolute requirements. Other members of the conventional inflammasome cascade are only partially required, as revealed by decreased but not abrogated T57 IFNγ responses to parasite-infected ASC, caspase-1/11, and gasdermin D deficient cells. Moreover, IFNγ production was only partially reduced in the absence of IL-12, IL-18 or IL-1R signaling. In summary, T. gondii effectors and host machinery that modulate parasitophorous vacuolar membranes, as well as NLR-dependent but inflammasome-independent pathways, determine the full commitment of CD8 T cells IFNγ responses to a vacuolar antigen. Parasites are excellent “students” of our immune system as they can deflect, antagonize and confuse the immune response making it difficult to vaccinate against these pathogens. In this report, we analyzed how a widespread parasite of mammals, Toxoplasma gondii, manipulates an immune cell needed for immunity to many intracellular pathogens, the CD8 T cell. Host pathways that govern CD8 T cell production of the immune protective cytokine, IFNγ, were also explored. We hypothesized the secreted T. gondii virulence factor, ROP5, work to inhibit the MHC 1 antigen presentation pathway therefore making it difficult for CD8 T cells to see T. gondii antigens sequestered inside a parasitophorous vacuole. However, manipulation through T. gondii ROP5 does not fully explain how CD8 T cells commit to making IFNγ in response to infection. Importantly, CD8 T cell IFNγ responses to T. gondii require the pathogen sensor NLRP3 to be expressed in the infected cell. Other proteins associated with NLRP3 activation, including members of the conventional inflammasome activation cascade pathway, are only partially involved. Our results identify a novel pathway by which NLRP3 regulates T cell function and underscore the need for NLRP3-activating adjuvants in vaccines aimed at inducing CD8 T cell IFNγ responses to parasites.
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Affiliation(s)
- Angel K. Kongsomboonvech
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Felipe Rodriguez
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Anh L. Diep
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Brandon M. Justice
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Brayan E. Castallanos
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
| | - Ana Camejo
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Debanjan Mukhopadhyay
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Gregory A. Taylor
- Departments of Medicine; Molecular Genetics and Microbiology; and Immunology; and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, United States of America
- Geriatric Research, Education, and Clinical Center, Durham VA Health Care System, Durham, North Carolina, United States of America
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Jeroen P. J. Saeij
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Michael L. Reese
- Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas, Texas, United States of America
| | - Kirk D. C. Jensen
- Department of Molecular and Cell Biology, University of California, Merced, Merced, California, United States of America
- Health Sciences Research Institute, University of California, Merced, Merced, California, United States of America
- * E-mail:
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Mammalian Atg8 proteins and the autophagy factor IRGM control mTOR and TFEB at a regulatory node critical for responses to pathogens. Nat Cell Biol 2020; 22:973-985. [PMID: 32753672 PMCID: PMC7482486 DOI: 10.1038/s41556-020-0549-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 06/24/2020] [Indexed: 12/26/2022]
Abstract
Autophagy is a homeostatic process with multiple functions in mammalian cells. Here, we show that mammalian Atg8 proteins (mAtg8s) and the autophagy regulator IRGM control TFEB, a transcriptional activator of the lysosomal system. IRGM directly interacted with TFEB and promoted the nuclear translocation of TFEB. An mAtg8 partner of IRGM, GABARAP, interacted with TFEB. Deletion of all mAtg8s or GABARAPs affected the global transcriptional response to starvation and downregulated subsets of TFEB targets. IRGM and GABARAPs countered the action of mTOR as a negative regulator of TFEB. This was suppressed by constitutively active RagB, an activator of mTOR. Infection of macrophages with the membrane-permeabilizing microbe Mycobacterium tuberculosis or infection of target cells by HIV elicited TFEB activation in an IRGM-dependent manner. Thus, IRGM and its interactors mAtg8s close a loop between the autophagosomal pathway and the control of lysosomal biogenesis by TFEB, thus ensuring coordinated activation of the two systems that eventually merge during autophagy.
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Hu S, Shi Y, Ding T, Duan W, Qiu Z, Zhao Z. Functional characterization of an immunity-related GTPase gene in immune defense from obscure puffer (Takifugu obscurus). FISH & SHELLFISH IMMUNOLOGY 2020; 103:248-255. [PMID: 32408018 DOI: 10.1016/j.fsi.2020.05.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/18/2020] [Accepted: 05/09/2020] [Indexed: 06/11/2023]
Abstract
Immunity-related GTPases (IRGs) are a family of large interferon-inducible GTPases that function in effective host defense against invading pathogens. IRGs have been extensively studied in mammals for their roles in the elimination of intracellular pathogens; however, their homologs in lower vertebrates are not well known. In this study, an IRG from obscure puffer (Takifugu obscurus), ToIRG, was identified and further characterized for its functional activity. The ToIRG gene encodes a protein of 396 amino acids containing a typical N-terminal GTPase domain with three conserved motifs. Phylogenetic analysis revealed that it has a closer evolutionary relationship with mammalian GKS IRGs. Gene expression profile analysis revealed that ToIRG was ubiquitously expressed in all tested healthy tissues of obscure puffer and upregulated in response to Aeromonas hydrophila or Edwardsiella tarda challenge. The subcellular localization of ToIRG is characterized as condensed forms around the nucleus. Importantly, an antimicrobial assay in vitro suggested that ToIRG enhanced the ability of host cells to resist both intracellular (E. tarda) and extracellular pathogens (A. hydrophila). Taken together, these results provide the functional characterization of obscure puffer IRGs in immune defense, which is the first study to reveal the function of IRGs in bony fish and will provide important insights into the evolutionary divergence of IRGs.
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Affiliation(s)
- Sufei Hu
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, 210098, China
| | - Yan Shi
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, 210098, China.
| | - Tie Ding
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, 210098, China
| | - Wen Duan
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, 210098, China
| | - Ziyue Qiu
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, 210098, China
| | - Zhe Zhao
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, 210098, China.
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Wandel MP, Kim BH, Park ES, Boyle KB, Nayak K, Lagrange B, Herod A, Henry T, Zilbauer M, Rohde J, MacMicking JD, Randow F. Guanylate-binding proteins convert cytosolic bacteria into caspase-4 signaling platforms. Nat Immunol 2020; 21:880-891. [PMID: 32541830 PMCID: PMC7381384 DOI: 10.1038/s41590-020-0697-2] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 04/29/2020] [Indexed: 02/01/2023]
Abstract
Bacterial lipopolysaccharide triggers human caspase-4 (murine caspase-11) to cleave gasdermin-D and induce pyroptotic cell death. How lipopolysaccharide sequestered in the membranes of cytosol-invading bacteria activates caspases remains unknown. Here we show that in interferon-γ-stimulated cells guanylate-binding proteins (GBPs) assemble on the surface of Gram-negative bacteria into polyvalent signaling platforms required for activation of caspase-4. Caspase-4 activation is hierarchically controlled by GBPs; GBP1 initiates platform assembly, GBP2 and GBP4 control caspase-4 recruitment, and GBP3 governs caspase-4 activation. In response to cytosol-invading bacteria, activation of caspase-4 through the GBP platform is essential to induce gasdermin-D-dependent pyroptosis and processing of interleukin-18, thereby destroying the replicative niche for intracellular bacteria and alerting neighboring cells, respectively. Caspase-11 and GBPs epistatically protect mice against lethal bacterial challenge. Multiple antagonists of the pathway encoded by Shigella flexneri, a cytosol-adapted bacterium, provide compelling evolutionary evidence for the importance of the GBP-caspase-4 pathway in antibacterial defense.
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Affiliation(s)
- Michal P Wandel
- Division of Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK.
| | - Bae-Hoon Kim
- Howard Hughes Medical Institute and Systems Biology Institute, Yale University, West Haven, CT, USA
- Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Eui-Soon Park
- Howard Hughes Medical Institute and Systems Biology Institute, Yale University, West Haven, CT, USA
- Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Keith B Boyle
- Division of Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Komal Nayak
- Department of Paediatrics, University of Cambridge, Cambridge, UK
- Department of Paediatric Gastroenterology, Hepatology and Nutrition, Cambridge University Hospitals, Addenbrooke's Hospital, Cambridge, UK
| | - Brice Lagrange
- CIRI, Centre International de Recherche en Infectiologie, University of Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, University of Lyon, Lyon, France
| | - Adrian Herod
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Thomas Henry
- CIRI, Centre International de Recherche en Infectiologie, University of Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, University of Lyon, Lyon, France
| | - Matthias Zilbauer
- Department of Paediatrics, University of Cambridge, Cambridge, UK
- Department of Paediatric Gastroenterology, Hepatology and Nutrition, Cambridge University Hospitals, Addenbrooke's Hospital, Cambridge, UK
| | - John Rohde
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - John D MacMicking
- Howard Hughes Medical Institute and Systems Biology Institute, Yale University, West Haven, CT, USA
- Departments of Immunobiology and Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Felix Randow
- Division of Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK.
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
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Strain-specific disruption of interferon-stimulated N-myc and STAT interactor (NMI) function by Toxoplasma gondii type I ROP18 in human cells. Parasitology 2020; 147:1433-1442. [PMID: 32729455 DOI: 10.1017/s0031182020001249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Toxoplasma gondii rhoptry protein TgROP18 is a polymorphic virulence effector that targets immunity-related GTPases (IRGs) in rodents. Given that IRGs are uniquely diversified in rodents and not in other T. gondii intermediate hosts, the role of TgROP18 in manipulating non-rodent cells is unclear. Here we show that in human cells TgROP18I interacts with the interferon-gamma-inducible protein N-myc and STAT interactor (NMI) and that this is a property that is unique to the type I TgROP18 allele. Specifically, when expressed ectopically in mammalian cells only TgROP18I co-immunoprecipitates with NMI in IFN-γ-treated cells, while TgROP18II does not. In parasites expressing TgROP18I or TgROP18II, NMI only co-immunoprecipitates with TgROP18I and this is associated with allele-specific immunolocalization of NMI on the parasitophorous vacuolar membrane (PVM). We also found that TgROP18I reduces NMI association with IFN-γ-activated sequences (GAS) in the IRF1 gene promoter. Finally, we determined that polymorphisms in the C-terminal kinase domain of TgROP18I are required for allele-specific effects on NMI. Together, these data further define new host pathway targeted by TgROP18I and provide the first function driven by allelic differences in the highly polymorphic ROP18 locus.
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42
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Toxoplasma gondii Recombinant Antigens in the Serodiagnosis of Toxoplasmosis in Domestic and Farm Animals. Animals (Basel) 2020; 10:ani10081245. [PMID: 32707821 PMCID: PMC7459674 DOI: 10.3390/ani10081245] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 12/22/2022] Open
Abstract
Simple Summary The very common parasite infections in animals are caused by members of Apicomplexa, including Toxoplasma gondii, Neospora sp., and Sarcocystis sp. These parasites pose serious veterinary problems. For example, the development of unambiguous diagnostic algorithms and determining the correct diagnosis are hindered by the similar antigenic structure of these parasites, as well as the multitude of similar disease symptoms presented in an infected animal. The intracellular parasite, T. gondii, infects a wide range of warm-blooded animals, including humans. This parasite is widespread among different animal populations, contributes to the loss of reproductive and malformations in young individuals, and can become a serious economic concern for farmers. Additionally, the consumption of undercooked or raw meat and the consumption of improperly processed milk product derived from farm animals are the main parasite transmission routes in humans. This work reviews potential improvements to diagnostic techniques that use recombinant antigens for serodiagnosis of toxoplasmosis in various species of animals. Abstract Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, and is a parasitic disease that occurs in all warm-blooded animals, including humans. Toxoplasmosis is one of the most common parasitic diseases of animals and results in reproductive losses. Toxoplasmosis in humans is usually caused by eating raw or undercooked meat or consuming dairy products containing the parasite. Diagnosis of toxoplasmosis is currently based on serological assays using native antigens to detect specific anti-T. gondii antibodies. Due to the high price, the available commercial agglutination assays are not suited to test a large number of animal serum samples. The recent development of proteomics elucidated the antigenic structure of T. gondii and enabled the development of various recombinant antigens that can be used in new, cheaper, and more effective diagnostic tools. Continuous development of scientific disciplines, such as molecular biology and genetic engineering, allows for the production of new recombinant antigens and provides the basis for new diagnostic tests for the detection of anti-T. gondii antibodies in animal serum samples.
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Santos JC, Boucher D, Schneider LK, Demarco B, Dilucca M, Shkarina K, Heilig R, Chen KW, Lim RYH, Broz P. Human GBP1 binds LPS to initiate assembly of a caspase-4 activating platform on cytosolic bacteria. Nat Commun 2020; 11:3276. [PMID: 32581219 PMCID: PMC7314798 DOI: 10.1038/s41467-020-16889-z] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/01/2020] [Indexed: 01/16/2023] Open
Abstract
The human non-canonical inflammasome controls caspase-4 activation and gasdermin-D-dependent pyroptosis in response to cytosolic bacterial lipopolysaccharide (LPS). Since LPS binds and oligomerizes caspase-4, the pathway is thought to proceed without dedicated LPS sensors or an activation platform. Here we report that interferon-induced guanylate-binding proteins (GBPs) are required for non-canonical inflammasome activation by cytosolic Salmonella or upon cytosolic delivery of LPS. GBP1 associates with the surface of cytosolic Salmonella seconds after bacterial escape from their vacuole, initiating the recruitment of GBP2-4 to assemble a GBP coat. The GBP coat then promotes the recruitment of caspase-4 to the bacterial surface and caspase activation, in absence of bacteriolysis. Mechanistically, GBP1 binds LPS with high affinity through electrostatic interactions. Our findings indicate that in human epithelial cells GBP1 acts as a cytosolic LPS sensor and assembles a platform for caspase-4 recruitment and activation at LPS-containing membranes as the first step of non-canonical inflammasome signaling. Detection of LPS derived from Gram-negative bacteria by innate immune receptors is a critical step in the host response. Here Santos and colleagues show human GBP1 binds to LPS resulting in non-canonical inflammasome activation.
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Affiliation(s)
- José Carlos Santos
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Dave Boucher
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | | | - Benjamin Demarco
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Marisa Dilucca
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Kateryna Shkarina
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Rosalie Heilig
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Kaiwen W Chen
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Roderick Y H Lim
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056, Basel, Switzerland
| | - Petr Broz
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland.
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Bekpen C, Tautz D. Human core duplicon gene families: game changers or game players? Brief Funct Genomics 2020; 18:402-411. [PMID: 31529038 PMCID: PMC6920530 DOI: 10.1093/bfgp/elz016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/01/2019] [Accepted: 06/24/2019] [Indexed: 01/09/2023] Open
Abstract
Illuminating the role of specific gene duplications within the human lineage can provide insights into human-specific adaptations. The so-called human core duplicon gene families have received particular attention in this respect, due to special features, such as expansion along single chromosomes, newly acquired protein domains and signatures of positive selection. Here, we summarize the data available for 10 such families and include some new analyses. A picture emerges that suggests broad functions for these protein families, possibly through modification of core cellular pathways. Still, more dedicated studies are required to elucidate the function of core-duplicons gene families and how they have shaped adaptations and evolution of humans.
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Affiliation(s)
| | - Diethard Tautz
- Max-Planck Institute for Evolutionary Biology, 24306 Plön, Germany
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45
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Cui J, Shen B. Transcriptomic analyses reveal distinct response of porcine macrophages to Toxoplasma gondii infection. Parasitol Res 2020; 119:1819-1828. [PMID: 32399721 DOI: 10.1007/s00436-020-06677-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/24/2020] [Indexed: 02/08/2023]
Abstract
Toxoplasma gondii is an obligate protozoan parasite infecting diverse hosts. Studies have demonstrated that different hosts respond differently to Toxoplasma infection. Pigs are among the most susceptible hosts of T. gondii, but the host-pathogen interactions that shape the outcome of infection in pigs are completely unknown. Here, we used dual RNA-seq to profile the transcriptomic changes of porcine alveolar macrophages (PAMs) upon Toxoplasma infection. Our results indicated that PAMs initiated different responses to Toxoplasma infection compared with mouse macrophages. First, although infected PAMs upregulated numerous pro-inflammatory factors, IL-12, which plays critical roles in IL-12~IFN-γ-mediated immunity against Toxoplasma infection in mice, was found unchanged during PAM infection. Second, the gene encoding iNOS that is responsible for nitric oxide (NO) production was also not induced in infected PAMs. Consistently, there was no NO level change in PAMs after infection. Third, it seems like Toxoplasma infection inhibited apoptosis in PAMs. On the parasite side, the most obvious change is the upregulation of genes involved in metabolism and macromolecule synthesis, such as the type II fatty acid synthesis in the apicoplast. Together, these results revealed distinct responses of PAMs to Toxoplasma infection and provide novel insights into Toxoplasma-pig interactions.
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Affiliation(s)
- Jianmin Cui
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China. .,Key Laboratory of Preventive Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China.
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Irgm1 knockout indirectly inhibits regeneration after skeletal muscle injury in mice. Int Immunopharmacol 2020; 84:106515. [PMID: 32311672 DOI: 10.1016/j.intimp.2020.106515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/13/2020] [Accepted: 04/13/2020] [Indexed: 11/24/2022]
Abstract
Immunity-related GTPase family M1 protein (lRGM1) plays an important role in host resistance to infection, immune inflammation, and tumors, and it is expressed in various tissues and cells, including the central nervous system, cardiovascular system, bone marrow-derived cells, glioma, and melanoma. However, the effect of IRGM1 in the muscles has not been reported to date. In this study, Irgm1-/- mice were used to evaluate the effect of lrgm1 on regeneration after skeletal muscle injury. The tibialis anterior muscle in Irgm1-/- mice was poorly repaired after BaCl2-induced injury, whereas lrgm1 knockout itself had no significant effect on the differentiation of myoblasts. However, the microenvironment of Irgm1-/- mice with a high interferon-gamma level inhibited the differentiation of myoblasts in vivo. These results suggest that lrgm1 knockout indirectly inhibits skeletal muscle regeneration after injury, providing new insights into the biological function of IRGM1.
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Autophagy-Independent Functions of the Autophagy Machinery. Cell 2020; 177:1682-1699. [PMID: 31199916 PMCID: PMC7173070 DOI: 10.1016/j.cell.2019.05.026] [Citation(s) in RCA: 531] [Impact Index Per Article: 132.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/11/2019] [Accepted: 05/13/2019] [Indexed: 02/07/2023]
Abstract
Macroautophagy (herein referred to as autophagy) is an evolutionary ancient mechanism that culminates with the lysosomal degradation of superfluous or potentially dangerous cytosolic entities. Over the past 2 decades, the molecular mechanisms underlying several variants of autophagy have been characterized in detail. Accumulating evidence suggests that most, if not all, components of the molecular machinery for autophagy also mediate autophagy-independent functions. Here, we discuss emerging data on the non-autophagic functions of autophagy-relevant proteins.
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Kee BP, Ng JG, Ng CC, Hilmi I, Goh KL, Chua KH. Genetic polymorphisms of ATG16L1 and IRGM genes in Malaysian patients with Crohn's disease. J Dig Dis 2020; 21:29-37. [PMID: 31654602 DOI: 10.1111/1751-2980.12829] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 10/15/2019] [Accepted: 10/22/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To investigate the association between genetic polymorphisms in ATG16L1 and IRGM genes and the development of Crohn's disease (CD) in Malaysian patients. METHODS Altogether 335 participants were recruited, including 85 patients with CD and 250 unrelated healthy controls, and their informed consent was obtained. Genomic DNA was extracted via a conventional phenol-chloroform extraction method. Six single nucleotide polymorphisms (SNPs) in ATG16L1 and IRGM genes were genotyped using TaqMan SNP genotyping assays. Associations between SNP and CD were determined using Fisher's exact test, odds ratio, and 95% confidence interval. Statistical power and the Hardy-Weinberg equilibrium were also calculated. RESULTS Two SNPs (rs2241880 and rs6754677) in the ATG16L1 gene were significantly associated with the onset of CD in the Malaysian population. The A allele and homozygous A/A genotype of the rs2241880 A/G polymorphism were protective against CD in the overall Malaysian and Malay population. The G allele and homozygous G/G genotype of the rs6754677 G/A polymorphism were protective in the Indian population, whereas the homozygous A/A genotype showed a risk of developing CD. The homozygous G/G genotype of IRGM rs11747270 was significantly present in the controls. However, this significance was not observed in a race-stratified analysis. All three ATG16L1 SNPs were associated with inflamed terminal ileum. IRGM rs4958847 and rs11747270 increased the risk of developing arthritis in patients with CD. CONCLUSION We found a significant association between SNP, which are located in autophagy-related genes, and CD in a Malaysian population.
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Affiliation(s)
- Boon Pin Kee
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Jin Guan Ng
- Division of Genetics and Molecular Biology, Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Ching Ching Ng
- Division of Genetics and Molecular Biology, Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Ida Hilmi
- Division of Gastroenterology and Hepatology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Khean Lee Goh
- Division of Gastroenterology and Hepatology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Lee Y, Yamada H, Pradipta A, Ma JS, Okamoto M, Nagaoka H, Takashima E, Standley DM, Sasai M, Takei K, Yamamoto M. Initial phospholipid-dependent Irgb6 targeting to Toxoplasma gondii vacuoles mediates host defense. Life Sci Alliance 2019; 3:3/1/e201900549. [PMID: 31852733 PMCID: PMC6925386 DOI: 10.26508/lsa.201900549] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/02/2019] [Accepted: 12/02/2019] [Indexed: 12/19/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite capable of infecting warm-blooded animals by ingestion. The organism enters host cells and resides in the cytoplasm in a membrane-bound parasitophorous vacuole (PV). Inducing an interferon response enables IFN-γ-inducible immunity-related GTPase (IRG protein) to accumulate on the PV and to restrict parasite growth. However, little is known about the mechanisms by which IRG proteins recognize and destroy T. gondii PV. We characterized the role of IRG protein Irgb6 in the cell-autonomous response against T. gondii, which involves vacuole ubiquitination and breakdown. We show that Irgb6 is capable of binding a specific phospholipid on the PV membrane. Furthermore, the absence of Irgb6 causes reduced targeting of other effector IRG proteins to the PV. This suggests that Irgb6 has a role as a pioneer in the process by which multiple IRG proteins access the PV. Irgb6-deficient mice are highly susceptible to infection by a strain of T. gondii avirulent in wild-type mice.
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Affiliation(s)
- Youngae Lee
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Hiroshi Yamada
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Ariel Pradipta
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Ji Su Ma
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Masaaki Okamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Ehime, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Ehime, Japan
| | - Daron M Standley
- Department of Genome Informatics, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Systems Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Kohji Takei
- Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan .,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
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50
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Sasai M, Yamamoto M. Innate, adaptive, and cell-autonomous immunity against Toxoplasma gondii infection. Exp Mol Med 2019; 51:1-10. [PMID: 31827072 PMCID: PMC6906438 DOI: 10.1038/s12276-019-0353-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 12/15/2022] Open
Abstract
Hosts have been fighting pathogens throughout the evolution of all infectious diseases. Toxoplasma gondii is one of the most common infectious agents in humans but causes only opportunistic infection in healthy individuals. Similar to antimicrobial immunity against other organisms, the immune response against T. gondii activates innate immunity and in turn induces acquired immune responses. After activation of acquired immunity, host immune cells robustly produce the proinflammatory cytokine interferon-γ (IFN-γ), which activates a set of IFN-γ-inducible proteins, including GTPases. IFN-inducible GTPases are essential for cell-autonomous immunity and are specialized for effective clearance and growth inhibition of T. gondii by accumulating in parasitophorous vacuole membranes. Recent studies suggest that the cell-autonomous immune response plays a protective role in host defense against not only T. gondii but also various intracellular bacteria. Moreover, the negative regulatory mechanisms of such strong immune responses are also important for host survival after infection. In this review, we will discuss in detail recent advances in the understanding of host defenses against T. gondii and the roles played by cell-autonomous immune responses. Researchers are extensively studying immune responses to the single-celled parasite Toxoplasma gondii, which infects around one-third of humans, often harmlessly, but can cause life-threatening toxoplasmosis infections in patients with weakened immune systems. Masahiro Yamamoto and Miwa Sasai at Osaka University in Japan review recent advances in understanding the interactions between the immune system and the parasite. They consider non-specific ‘innate’ immune responses and also the ‘acquired’ responses that target specific parts of the parasite, referred to as antigens. Methods that selectively switch off genes in mice are revealing details presumed to also be relevant for humans. Significant molecules, molecular signaling pathways and immune-regulating processes are being identified. Recent studies suggest cell-autonomous immunity, the ability of host cells to defend themselves against attack, plays a significant role in fighting Toxoplasma gondii infection.
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Affiliation(s)
- Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan. .,Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
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