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Ju K, Zhang Y, Xu Z, Li L, Zhao X, Zhou H. Protective Efficacy of a Novel DNA Vaccine with a CL264 Molecular Adjuvant against Toxoplasma gondii in a Murine Model. Vaccines (Basel) 2024; 12:577. [PMID: 38932306 PMCID: PMC11209281 DOI: 10.3390/vaccines12060577] [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: 04/22/2024] [Revised: 05/15/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
Toxoplasmosis is a significant global zoonosis with devastating impacts, and an effective vaccine against toxoplasmosis for humans has not yet been developed. In this study, we designed and formulated a novel DNA vaccine encoding the inhibitor of STAT1 transcriptional activity (IST) of T. gondii utilizing the eukaryotic expression vector pEGFP-N1 for the first time, with CL264 being a molecular adjuvant. Following intramuscular injection of the vaccine into mice, the levels of antibodies and cytokines were assessed to evaluate the immune response. Additionally, mice were challenged with highly virulent RH-strain tachyzoites of T. gondii, and their survival time was observed. The results show that the levels of IgG in serum, the ratio of IgG2a/IgG1 and the levels of IFN-γ in splenocytes of mice were significantly higher in the pEGFP-TgIST group and the pEGFP-TgIST + CL264 group than in the control group. In addition, the proportion of CD4+/CD8+ T cells was higher in mice immunized with either the pEGFP-TgIST group (p < 0.001) or the pEGFP-TgIST + CL264 group (p < 0.05) compared to the three control groups. Notably, TgIST-immunized mice exhibited prolonged survival times after T. gondii RH strain infection (p < 0.05). Our findings collectively demonstrate that the TgIST DNA vaccine elicits a significant humoral and cellular immune response and offers partial protection against acute T. gondii infection in the immunized mice, which suggests that TgIST holds potential as a candidate for further development as a DNA vaccine.
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Affiliation(s)
| | | | | | | | | | - Huaiyu Zhou
- Department of Pathogen Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China; (K.J.); (Y.Z.); (Z.X.); (L.L.); (X.Z.)
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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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Scimeca RC, Reichard MV. Differential gene expression response to acute and chronic Cytauzxoon felis infection in domestic cats (Felis catus). Ticks Tick Borne Dis 2023; 14:102242. [PMID: 37651848 DOI: 10.1016/j.ttbdis.2023.102242] [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: 04/03/2023] [Revised: 07/25/2023] [Accepted: 08/13/2023] [Indexed: 09/02/2023]
Abstract
Cytauxzoonosis is a severe tick transmitted protozoan disease of domestic cats, caused by Cytauxzoon felis. The disease is characterized by acute onset of high fever, depression, lethargy, inappentence, anorexia, icterus, dehydration, hemolytic anemia, and alteration of immune response. The aim of our study was to further detail the immune response of domestic cats to C. felis infection by comparing the differential expression of feline immune transcriptional elements during acute and chronic cytauxzoonosis. True single molecule sequencing (tSMS) was used to analyze the whole genome of acutely and chronically infected C. felis cats, focusing on the analysis of genes involved on the immune response. Two C. felis donor cats were infested with Amblyomma americanum nymphs, which after repletion were collected and kept in humidity chambers until they molted. The resulting A. americanum were randomly selected to infest three C. felis naïve principal cats. Infection of these cats was confirmed by nested PCR of the 18S rRNA C. felis gene and clinical signs. RNA was extracted from whole blood at different time points and used for tSMS analyses, the results revealed overexpression in transcripts involved in type I interferon signaling, cellular and cytokine responses during the acute stage of infection, while cell cycle, and metabolic processes were downregulated. Genes involved in cell adhesion increased their expression in the chronic infected cats, whereas inflammatory and apoptotic related genes were downregulated. This study provided information on the host immune response to C. felis in domestic cats, demonstrating that inflammatory, apoptotic, and cell adhesion are some of the pathways altered during acute and chronic infection.
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Affiliation(s)
- Ruth C Scimeca
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK 74078.
| | - Mason V Reichard
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK 74078
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Olajide JS, Qu Z, Yang S, Yang B, Xu X, Wang J, Cai J. Quantitative proteomic analysis of local and systemic extracellular vesicles during Eimeria falciformis infectious cycle in the host. Parasit Vectors 2023; 16:339. [PMID: 37759313 PMCID: PMC10523797 DOI: 10.1186/s13071-023-05906-x] [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: 04/11/2023] [Accepted: 07/27/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Extracellular vesicles (EVs) are membranous structures that are formed during pathophysiology, host-parasite interactions and parasite motility. Typically, apicomplexan-infected host cells secrete EVs which traverse local and systemic strata of the host as the parasites develop. METHODS Extracellular vesicles were isolated from the caecum and serum of Eimeria falciformis-infected mice during oocyst ingestion (0 h post-infection [0 hpi]), merozont stages 1 and 2 (68 and 116 hpi), oocyst shedding (7 days post-infection [7 dpi]) and host recovery (10 dpi) and subsequently characterized and profiled by tandem mass tag (TMT). RESULTS With the progression of E. falciformis life stages, subpopulation of EVs bearing EV biomarkers, including CD9, CD82, heat shock protein 70 (HSP70) and major histocompatibility complex (MHC) molecules, increased. A total of 860 and 1024 differentially expressed proteins were identified in serum EVs (sEVs) and caecum EVs (cEVs), respectively. Identified immune-related molecules (such as cytokines, receptors, immunoglobins, complements, hormones, inflammasomes), ion exchange and cell death-associated proteins were significantly expressed, at least during the E. falciformis first and second merozont stages. Bioinformatics assessment indicated that sEV proteins were at all time points implicated in antigen processing and presentation as well as natural killer cell-mediated cytotoxicity (68 hpi), complement activation/blood coagulation (116 hpi/10 dpi) and catabolic activities (7 dpi). In contrast, cEV proteins were involved in catabolic process, ion transport and antigen presentation (68 and 116 hpi). Host response to E. falciformis infection was similar to intestinal bacterium at 7 dpi and cell adhesion and intercellular protein transport at 10 dpi. In both systems, ferroptosis and necroptosis were common across the parasite's infectious cycle while apoptosis occurred at 68 hpi. CONCLUSION The proteomic data indicate that E. falciformis infection co-opts cellular and humoral responses through EV secretions, and that, host cell death and ionic imbalance are associated with E. falciformis infection. This study offers additional insight into host-parasite interactions and host regulatory EV proteins as potential disease indicators or diagnostic molecules.
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Affiliation(s)
- Joshua Seun Olajide
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
- Centre for Distance Learning, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Zigang Qu
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Shunli Yang
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, China
| | - Bin Yang
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Xiao Xu
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Jing Wang
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Jianping Cai
- State Key Laboratory of Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China.
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5
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Romano PS, Akematsu T, Besteiro S, Bindschedler A, Carruthers VB, Chahine Z, Coppens I, Descoteaux A, Alberto Duque TL, He CY, Heussler V, Le Roch KG, Li FJ, de Menezes JPB, Menna-Barreto RFS, Mottram JC, Schmuckli-Maurer J, Turk B, Tavares Veras PS, Salassa BN, Vanrell MC. Autophagy in protists and their hosts: When, how and why? AUTOPHAGY REPORTS 2023; 2:2149211. [PMID: 37064813 PMCID: PMC10104450 DOI: 10.1080/27694127.2022.2149211] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/15/2022] [Indexed: 03/12/2023]
Abstract
Pathogenic protists are a group of organisms responsible for causing a variety of human diseases including malaria, sleeping sickness, Chagas disease, leishmaniasis, and toxoplasmosis, among others. These diseases, which affect more than one billion people globally, mainly the poorest populations, are characterized by severe chronic stages and the lack of effective antiparasitic treatment. Parasitic protists display complex life-cycles and go through different cellular transformations in order to adapt to the different hosts they live in. Autophagy, a highly conserved cellular degradation process, has emerged as a key mechanism required for these differentiation processes, as well as other functions that are crucial to parasite fitness. In contrast to yeasts and mammals, protist autophagy is characterized by a modest number of conserved autophagy-related proteins (ATGs) that, even though, can drive the autophagosome formation and degradation. In addition, during their intracellular cycle, the interaction of these pathogens with the host autophagy system plays a crucial role resulting in a beneficial or harmful effect that is important for the outcome of the infection. In this review, we summarize the current state of knowledge on autophagy and other related mechanisms in pathogenic protists and their hosts. We sought to emphasize when, how, and why this process takes place, and the effects it may have on the parasitic cycle. A better understanding of the significance of autophagy for the protist life-cycle will potentially be helpful to design novel anti-parasitic strategies.
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Affiliation(s)
- Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - Takahiko Akematsu
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | | | | | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Zeinab Chahine
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology. Department of Molecular Microbiology and Immunology. Johns Hopkins Malaria Research Institute. Johns Hopkins University Bloomberg School of Public Health. Baltimore 21205, MD, USA
| | - Albert Descoteaux
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique, Laval, QC
| | - Thabata Lopes Alberto Duque
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Volker Heussler
- Institute of Cell Biology.University of Bern. Baltzerstr. 4 3012 Bern
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Feng-Jun Li
- Department of Biological Sciences, National University of Singapore, Singapore
| | | | | | - Jeremy C Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York, UK
| | | | - Boris Turk
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia
- National Institute of Science and Technology of Tropical Diseases - National Council for Scientific Research and Development (CNPq)
| | - Betiana Nebai Salassa
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
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6
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Moretto MM, Chen J, Meador M, Phan J, Khan IA. A Lower Dose of Infection Generates a Better Long-Term Immune Response against Toxoplasma gondii. Immunohorizons 2023; 7:177-190. [PMID: 36883950 PMCID: PMC10563383 DOI: 10.4049/immunohorizons.2300006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 03/09/2023] Open
Abstract
Toxoplasma gondii, an obligate intracellular pathogen, induces a strong immune response in the infected host. In the encephalitis model of infection, long-term protective immunity is mediated by CD8 T cells, with the CD4 T cell population providing important help. Most of the immune studies have used a 10- to 20-cyst dose of T. gondii, which leads to T cell dysfunctionality during the late phase of chronic infection and increases the chances of reactivation. In the current study, we compared the immune response of mice orally infected with either 2 or 10 cysts of T. gondii. During the acute phase, we demonstrate that the lower dose of infection generates a reduced number of CD4 and CD8 T cells, but the frequency of functional CD4 or CD8 T cells is similar in animals infected with two different doses. However, Ag-experienced T cells (both CD4 and CD8) are better maintained in lower dose-infected mice at 8 wk postinfection, with an increase number functional cells that exhibit lower multiple inhibitory receptor expression. In addition to better long-term T cell immunity, animals infected with a lower dose display reduced inflammation manifested by lesser Ag-specific T cell and cytokine responses during the very early stage of the acute infection. Our studies suggest a previously unappreciated role of dose-dependent early programming/imprinting of the long-term CD4/CD8 T cell response during T. gondii infection. These observations point to the need for an in-depth analysis of how early events shape long-term immunity against this pathogen.
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Affiliation(s)
- Magali M. Moretto
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC
| | - Jie Chen
- Department of Medicine, The George Washington University, Washington, DC
| | - Morgan Meador
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC
| | - Jasmine Phan
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC
| | - Imtiaz A. Khan
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC
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7
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Guo XD, Zhou CX, Li LY, Ai K, Wang YL, Zhou DH. Comprehensive analysis of mRNA-lncRNA co-expression profiles in mouse brain during infection with Toxoplasma gondii. Acta Trop 2023; 237:106722. [DOI: 10.1016/j.actatropica.2022.106722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/21/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
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8
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Frickel EM, Hunter CA. Lessons from Toxoplasma: Host responses that mediate parasite control and the microbial effectors that subvert them. J Exp Med 2021; 218:212714. [PMID: 34670268 PMCID: PMC8532566 DOI: 10.1084/jem.20201314] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/03/2021] [Accepted: 09/29/2021] [Indexed: 11/15/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii has long provided a tractable experimental system to investigate how the immune system deals with intracellular infections. This review highlights the advances in defining how this organism was first detected and the studies with T. gondii that contribute to our understanding of how the cytokine IFN-γ promotes control of vacuolar pathogens. In addition, the genetic tractability of this eukaryote organism has provided the foundation for studies into the diverse strategies that pathogens use to evade antimicrobial responses and now provides the opportunity to study the basis for latency. Thus, T. gondii remains a clinically relevant organism whose evolving interactions with the host immune system continue to teach lessons broadly relevant to host–pathogen interactions.
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Affiliation(s)
- Eva-Maria Frickel
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, UK
| | - Christopher A Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
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9
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STAT1-Dependent Recruitment of Ly6C hiCCR2 + Inflammatory Monocytes and M2 Macrophages in a Helminth Infection. Pathogens 2021; 10:pathogens10101287. [PMID: 34684235 PMCID: PMC8540143 DOI: 10.3390/pathogens10101287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/28/2021] [Accepted: 10/01/2021] [Indexed: 12/11/2022] Open
Abstract
Signal Transducer and Activator of Transcription (STAT) 1 signaling is critical for IFN-γ-mediated immune responses and resistance to protozoan and viral infections. However, its role in immunoregulation during helminth parasitic infections is not fully understood. Here, we used STAT1-/- mice to investigate the role of this transcription factor during a helminth infection caused by the cestode Taenia crassiceps and show that STAT1 is a central molecule favoring susceptibility to this infection. STAT1-/- mice displayed lower parasite burdens at 8 weeks post-infection compared to STAT1+/+ mice. STAT1 mediated the recruitment of inflammatory monocytes and the development of alternatively activated macrophages (M2) at the site of infection. The absence of STAT1 prevented the recruitment of CD11b+Ly6ChiLy6G- monocytic cells and therefore their suppressive activity. This failure was associated with the defective expression of CCR2 on CD11b+Ly6ChiLy6G- cells. Importantly, CD11b+Ly6ChiLy6G- cells highly expressed PDL-1 and suppressed T-cell proliferation elicited by anti-CD3 stimulation. PDL-1+ cells were mostly absent in STAT1-/- mice. Furthermore, only STAT1+/+ mice developed M2 macrophages at 8 weeks post-infection, although macrophages from both T. crassiceps-infected STAT1+/+ and STAT1-/- mice responded to IL-4 in vitro, and both groups of mice were able to produce the Th2 cytokine IL-13. This suggests that CD11b+CCR2+Ly6ChiLy6G- cells give rise to M2 macrophages in this infection. In summary, a lack of STAT1 resulted in impaired recruitment of CD11b+CCR2+Ly6ChiLy6G- cells, failure to develop M2 macrophages, and increased resistance against T. crassiceps infection.
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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: 98] [Impact Index Per Article: 32.7] [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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11
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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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12
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French T, Israel N, Düsedau HP, Tersteegen A, Steffen J, Cammann C, Topfstedt E, Dieterich D, Schüler T, Seifert U, Dunay IR. The Immunoproteasome Subunits LMP2, LMP7 and MECL-1 Are Crucial Along the Induction of Cerebral Toxoplasmosis. Front Immunol 2021; 12:619465. [PMID: 33968021 PMCID: PMC8099150 DOI: 10.3389/fimmu.2021.619465] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 03/16/2021] [Indexed: 11/28/2022] Open
Abstract
Cell survival and function critically relies on the fine-tuned balance of protein synthesis and degradation. In the steady state, the standard proteasome is sufficient to maintain this proteostasis. However, upon inflammation, the sharp increase in protein production requires additional mechanisms to limit protein-associated cellular stress. Under inflammatory conditions and the release of interferons, the immunoproteasome (IP) is induced to support protein processing and recycling. In antigen-presenting cells constitutively expressing IPs, inflammation-related mechanisms contribute to the formation of MHC class I/II-peptide complexes, which are required for the induction of T cell responses. The control of Toxoplasma gondii infection relies on Interferon-γ (IFNγ)-related T cell responses. Whether and how the IP affects the course of anti-parasitic T cell responses along the infection as well as inflammation of the central nervous system is still unknown. To answer this question we used triple knockout (TKO) mice lacking the 3 catalytic subunits of the immunoproteasome (β1i/LMP2, β2i/MECL-1 and β5i/LMP7). Here we show that the numbers of dendritic cells, monocytes and CD8+ T cells were reduced in Toxoplasma gondii-infected TKO mice. Furthermore, impaired IFNγ, TNF and iNOS production was accompanied by dysregulated chemokine expression and altered immune cell recruitment to the brain. T cell differentiation was altered, apoptosis rates of microglia and monocytes were elevated and STAT3 downstream signaling was diminished. Consequently, anti-parasitic immune responses were impaired in TKO mice leading to elevated T. gondii burden and prolonged neuroinflammation. In summary we provide evidence for a critical role of the IP subunits β1i/LMP2, β2i/MECL-1 and β5i/LMP7 for the control of cerebral Toxoplasma gondii infection and subsequent neuroinflammation.
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Affiliation(s)
- Timothy French
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Nicole Israel
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Henning Peter Düsedau
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Anne Tersteegen
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Johannes Steffen
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Clemens Cammann
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Eylin Topfstedt
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany
| | - Daniela Dieterich
- Institute of Pharmacology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Thomas Schüler
- Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Ulrike Seifert
- Friedrich Loeffler-Institute of Medical Microbiology-Virology, University Medicine Greifswald, Greifswald, Germany.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Ildiko Rita Dunay
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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13
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Yue R, Wei X, Zhao J, Zhou Z, Zhong W. Essential Role of IFN-γ in Regulating Gut Antimicrobial Peptides and Microbiota to Protect Against Alcohol-Induced Bacterial Translocation and Hepatic Inflammation in Mice. Front Physiol 2021; 11:629141. [PMID: 33536944 PMCID: PMC7848155 DOI: 10.3389/fphys.2020.629141] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022] Open
Abstract
The mechanisms by which alcohol provokes bacterial translocation in the development of alcoholic liver disease (ALD) remain incompletely defined. Our previous study demonstrates that impaired gut epithelial antimicrobial defense is critically involved in the pathogenesis of ALD. The study was set to determine the mechanisms of how alcohol inhibits the antimicrobial ability of intestinal epithelial cells (IECs) and to explore possible solutions to this issue. C57BL/6J mice were fed either alcohol or isocaloric dextrin liquid diet for 8 weeks, and intestinal IFN-γ-signal transducer and activator of transcription (STAT) signaling was analyzed. We found that chronic alcohol exposure led to a significant reduction in intestinal IFN-γ levels compared to a control; the protein levels of phosphorylated STAT1 (p-STAT1) and p-STAT3 were both declined by alcohol. We then tested the effects of IFN-γ-STAT signaling on regulating antimicrobial peptides (AMPs), gut microbiota, and disease progression of ALD in a mouse model of chronic alcohol feeding, time-course acute IFN-γ treatment, and in vivo and in vitro IEC-specific STAT1 or STAT3 knockout mouse models, respectively. Administration of IFN-γ activated intestinal STAT1 and STAT3, upregulated the expression of Reg3 and α-defensins, orchestrated gut microbiota, and reversed alcohol-induced intestinal ZO-1 disruption and systemic endotoxin elevation as well as hepatic inflammation. Meanwhile, acute IFN-γ treatment time-dependently induced AMP expression and α-defensin activation. We then dissected the roles of STAT1 and STAT3 in this progress. Lack of IEC-specific STAT3 inhibited IFN-γ-induced expression of Reg3 and α-defensins and hindered activation of α-defensins via inactivating matrix metallopeptidase 7 (MMP7), whereas lack of IEC-specific STAT1 impaired IFN-γ-stimulated expression of α-defensins and the IEC marker, sodium-hydrogen exchanger 3. Lastly, we found that interleukin (IL)-18, a known IFN-γ inducer, was also reduced by alcohol in mice. IL-18 treatment to alcohol-fed mice normalized gut IFN-γ levels and ameliorated organ damages in both the intestine and liver. Taken together, the study reveals that IFN-γ is critically involved in the regulation of AMPs through regulation of STAT1 and STAT3; impaired IFN-γ-STAT signaling provides an explanation for alcohol-induced gut antimicrobial dysfunction and microbial dysbiosis. Therefore, IFN-γ remains a promising host defense-enhancing cytokine with unexplored clinical potential in ALD therapy.
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Affiliation(s)
- Ruichao Yue
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC, United States
| | - Xiaoyuan Wei
- Division of Agriculture, Department of Animal Science, University of Arkansas, Fayetteville, AR, United States
| | - Jiangchao Zhao
- Division of Agriculture, Department of Animal Science, University of Arkansas, Fayetteville, AR, United States
| | - Zhanxiang Zhou
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC, United States.,Department of Nutrition, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC, United States
| | - Wei Zhong
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC, United States.,Department of Nutrition, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC, United States
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14
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Hu RS, He JJ, Elsheikha HM, Zou Y, Ehsan M, Ma QN, Zhu XQ, Cong W. Transcriptomic Profiling of Mouse Brain During Acute and Chronic Infections by Toxoplasma gondii Oocysts. Front Microbiol 2020; 11:570903. [PMID: 33193165 PMCID: PMC7604304 DOI: 10.3389/fmicb.2020.570903] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/21/2020] [Indexed: 01/25/2023] Open
Abstract
Infection by the protozoan Toxoplasma gondii can have a devastating impact on the structure and function of the brain of the infected individuals, particularly immunocompromised patients. A systems biology view of the brain transcriptome can identify key molecular targets and pathways that mediate the neuropathogenesis of cerebral toxoplasmosis. Here, we performed transcriptomic analysis of the brain of mice infected by T. gondii Pru strain oocysts at 11 and 33 days post-infection (dpi) compared to uninfected (control) mice using RNA sequencing (RNA-seq). T. gondii altered the expression of 936 and 2,081 transcripts at 11 and 33 dpi, respectively, and most of these were upregulated in the infected brains. Gene Ontology (GO) enrichment and pathway analysis showed that immune response, such as interferon-gamma (IFN-γ) responsive genes were strongly affected at 11dpi. Likewise, differentially expressed transcripts (DETs) related to T cell activation, cytokine production and immune cell proliferation were significantly altered at 33 dpi. Host-parasite interactome analysis showed that some DETs were involved in immune signaling, metabolism, biosynthesis-related processes and interspecies interaction. These findings should increase knowledge of the mouse brain transcriptome and the changes in transcriptional regulation and downstream signaling pathways during acute and chronic T. gondii infections.
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Affiliation(s)
- Rui-Si Hu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Jun-Jun He
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - Yang Zou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Muhammad Ehsan
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qiao-Ni Ma
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - Wei Cong
- Marine College, Shandong University, Weihai, China
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15
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Nast R, Choepak T, Lüder CGK. Epigenetic Control of IFN-γ Host Responses During Infection With Toxoplasma gondii. Front Immunol 2020; 11:581241. [PMID: 33072127 PMCID: PMC7544956 DOI: 10.3389/fimmu.2020.581241] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/26/2020] [Indexed: 01/21/2023] Open
Abstract
Host defense against the human pathogen Toxoplasma gondii depends on secretion of interferon (IFN)-γ and subsequent activation of monocytic cells to combat intracellular parasites. Previous studies have shown that T. gondii evades IFN-γ-mediated immunity by secreting the effector TgIST into the host cell where it binds to STAT1, strengthens its DNA binding activity and recruits the Mi-2/NuRD complex to STAT1-responsive promoters. Here we investigated the impact of the host chromatin environment on parasite interference with IFN-γ-induced gene expression. Luciferase reporters under control of primary and secondary IFN-γ response promoters were only inhibited by T. gondii when they were stably integrated into the host genome but not when expressed from a plasmid vector. Absence of CpG islands upstream and/or downstream of the transcriptional start site allowed more vigorous up-regulation by IFN-γ as compared to CpG-rich promoters. Remarkably, it also favored parasite interference with IFN-γ-induced gene expression indicating that nucleosome occupancy at IFN-γ-responsive promoters is important. Promoter DNA of IFN-γ-responsive genes remained largely non-methylated in T. gondii-infected cells, and inhibition of DNA methylation did not impact parasite interference with host responses. IFN-γ up-regulated histone marks H4ac, H3K9ac, and H3K4me3 but down-regulated H3S10p at primary and secondary response promoters. Infection with T. gondii abolished histone modification, whereas total nuclear activities of histone acetyl transferases and histone deacetylases were not altered. Taken together, our study reveals a critical impact of the host chromatin landscape at IFN-γ-activated promoters on their inhibition by T. gondii with a comprehensive blockade of histone modifications at parasite-inactivated promoters.
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Affiliation(s)
- Roswitha Nast
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August-University, Göttingen, Germany
| | - Tenzin Choepak
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August-University, Göttingen, Germany
| | - Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August-University, Göttingen, Germany
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16
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López-Osorio S, Chaparro-Gutiérrez JJ, Gómez-Osorio LM. Overview of Poultry Eimeria Life Cycle and Host-Parasite Interactions. Front Vet Sci 2020; 7:384. [PMID: 32714951 PMCID: PMC7351014 DOI: 10.3389/fvets.2020.00384] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 05/29/2020] [Indexed: 11/13/2022] Open
Abstract
Apicomplexan parasites of the genus Eimeria are organisms which invade the intestinal tract, causing coccidiosis, an enteric disease of major economic importance worldwide. The disease causes high morbidity ranging from an acute, bloody enteritis with high mortality, to subclinical disease. However, the presence of intestinal lesions depends on the Eimeria species. The most important poultry Eimeria species are: E. tenella, E. necatrix, E. acervulina, E. maxima, E. brunetti, E. mitis, and E. praecox. Key points to better understanding the behavior of this species are the host-parasite interactions and its life cycle. The present paper reviews the literature available regarding the life cycle and the initial host-parasite interaction. More studies are needed to better understand these interactions in poultry Eimerias, taking into account that almost all the information available was generated from other apicomplexan parasites that generate human disease.
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Affiliation(s)
- Sara López-Osorio
- CIBAV Research Group, Facultad de Ciencias Agrarias, Universidad de Antioquia, Medellín, Colombia
| | | | - Luis M. Gómez-Osorio
- CIBAV Research Group, Facultad de Ciencias Agrarias, Universidad de Antioquia, Medellín, Colombia
- Alura Animal Health and Nutrition, Medellin, Colombia
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17
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Park J, Hunter CA. The role of macrophages in protective and pathological responses to Toxoplasma gondii. Parasite Immunol 2020; 42:e12712. [PMID: 32187690 DOI: 10.1111/pim.12712] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/12/2020] [Accepted: 02/24/2020] [Indexed: 02/06/2023]
Abstract
The ability of Toxoplasma gondii to cause clinical disease in immune-competent and immune-deficient hosts coupled with its ease of use in vitro and availability of murine models has led to its use as a model organism to study how the immune system controls an intracellular infection. This article reviews the studies that established the role of the cytokine IFN-γ in the activation of macrophages to control T gondii and the events that lead to the mobilization and expansion of macrophage populations and their ability to limit parasite replication. Macrophages also have pro-inflammatory functions that promote protective NK and T-cell activities as well as regulatory properties that facilitate the resolution of inflammation. Nevertheless, while macrophages are important in determining the outcome of infection, T gondii has evolved mechanisms to subvert macrophage activation and can utilize their migratory activities to promote dissemination and these two properties underlie the ability of this parasite to persist and cause disease.
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Affiliation(s)
- Jeongho Park
- University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, USA.,Kangwon National University College of Veterinary Medicine and Institute of Veterinary Science, Chuncheon, Korea
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18
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Huang SY, Chen K, Wang JL, Yang B, Zhu XQ. Evaluation of protective immunity induced by recombinant calcium-dependent protein kinase 1 (TgCDPK1) protein against acute toxoplasmosis in mice. Microb Pathog 2019; 133:103560. [PMID: 31145981 DOI: 10.1016/j.micpath.2019.103560] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/23/2019] [Accepted: 05/25/2019] [Indexed: 12/23/2022]
Abstract
Toxoplasma gondii is an intracellular zoonotic parasite that causes toxoplasmosis, which can cause economic losses and serious public health problems worldwide. A member of the T. gondii calcium-dependent protein kinases family, TgCDPK1 was recently identified as an essential regulator of exocytosis in T. gondii, and participated in direct parasite motility, host-cell invasion and egress. In the present study, the protective immunity of recombinant TgCDPK1 protein (rTgCDPK1) was evaluated against acute toxoplasmosis in mice. rTgCDPK1 were expressed and purified, BABL/c mice were intraperitoneally immunized with rTgCDPK1 and challenged with the highly virulent RH strain of T. gondii. The specific immune responses were analyzed by measuring the cytokine and serum antibody, and lymphocyte proliferation assays, flow cytometry of lymphocytes and the survival curve were employed to evaluate the protective efficacy. From the results we found that special humoral and cellular responses could be elicited in vaccine mice, and higher level of IgG antibody, and the significant increased levels of Th1-type cytokines IFN-γ, IL-12 (p70), IL10 and CD3+CD4+CD8- and CD3+CD8+CD4- T cells could also be detected comparing to control mice (P < 0.05). All vaccinated mice prolonged survival time (14.90 ± 2.89 days) challenge with 1000 tachyzoites of RH, while the control mice died within 8 days. These results indicated that TgCDPK1 protein was a potential vaccine candidate against acute toxoplasmosis.
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MESH Headings
- Animals
- Antibodies, Protozoan/blood
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Cloning, Molecular
- Cytokines/metabolism
- Female
- Genes, Protozoan/genetics
- Immunity, Cellular
- Immunity, Humoral
- Immunization
- Immunoglobulin G/blood
- Lymphocytes/immunology
- Mice
- Protein Kinases/genetics
- Protein Kinases/immunology
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Spleen/immunology
- Survival Analysis
- Toxoplasma/genetics
- Toxoplasma/immunology
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/prevention & control
- Vaccines, DNA/immunology
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Affiliation(s)
- Si-Yang Huang
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province, 225009, PR China.
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| | - Bin Yang
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province, 225009, PR China
| | - Xing-Quan Zhu
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province, 225009, PR China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
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19
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Olbrich P, Freeman AF. STAT1 and STAT3 mutations: important lessons for clinical immunologists. Expert Rev Clin Immunol 2018; 14:1029-1041. [PMID: 30280610 DOI: 10.1080/1744666x.2018.1531704] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION The transcription factors signal transducer and activator of transcription (STAT) 1 and STAT3 fulfill fundamental functions in nonimmune and immune cells. The description and follow-up of patients with germline mutations that result in either loss-of-function or gain-of-function have contributed to our understanding of the pathophysiology of these regulators. Depending on the type of mutations, clinical symptoms are complex and can include infection susceptibility, immune dysregulation as well as characteristic nonimmune features. Areas covered: In this review, we provide an overview about mechanistic concepts, clinical manifestations, diagnostic process, and traditional as well as innovative treatment options aiming to help the clinical immunologist to better understand and manage these complex and rare diseases. Clinical and research papers were identified and summarized through PubMed Internet searches, and expert opinions are provided. Expert commentary: The last several years have seen an explosion in the clinical descriptions and pathogenesis knowledge of the diseases caused by GOF and LOF mutations in STAT1 and STAT3. However, harmonization of laboratory testing and follow-up in international cohorts is needed to increase our knowledge about the natural history of these disorders as well as the development of curative or supportive targeted therapies.
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Affiliation(s)
- Peter Olbrich
- a Sección de Infectología, Reumatologíe e Inmunología Pediátrica (SIRIP) , Hospital Infantil Universitario Virgen del Rocío , Seville , Spain.,b Grupo de Enfermedades Infecciosas e Inmunodeficiencias , Instituto de Biomedicina de Sevilla (IBiS) , Seville , Spain
| | - Alexandra F Freeman
- c National Institute of Allergy and Infectious Diseases, NIH , Bethesda , MD , USA
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20
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Nast R, Staab J, Meyer T, Lüder CGK. Toxoplasma gondii stabilises tetrameric complexes of tyrosine-phosphorylated signal transducer and activator of transcription-1 and leads to its sustained and promiscuous DNA binding. Cell Microbiol 2018; 20:e12887. [PMID: 29968354 DOI: 10.1111/cmi.12887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/07/2018] [Accepted: 06/25/2018] [Indexed: 11/29/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite that infects up to 30% of humans worldwide. It can lead to severe diseases particularly in individuals with immature or defective immune responses. Control of T. gondii relies on the IFN-γ-induced signal transducer and activator of transcription-1 (STAT1) pathway. T. gondii, however, largely inactivates STAT1-mediated gene transcription by T. gondii inhibitor of STAT1-dependent transcription (TgIST), a parasite effector protein binding to STAT1. Here, we have analysed requirements of STAT1 to bind TgIST and characterised downstream effects on STAT1 signalling. TgIST bound to STAT1 dimers but more efficiently assembled with STAT1 tetramers, which are essential for effective IFN-γ responsiveness. Such binding was abrogated in N-terminal, but not C-terminal deletion mutants of STAT1. Furthermore, TgIST did not bind to the STAT1F77A substitution mutant that cannot form STAT1 tetramers, resulting in a complete unresponsiveness of parasite-infected STAT1F77A -expressing cells to IFN-γ. Remarkably, binding of TgIST considerably increased the affinity of the aberrant STAT1 tetramers for DNA consensus sequence binding motifs and even enabled binding to nonconsensus sequences. Consistent with the increased DNA binding, STAT1 from parasite-infected cells remained phosphorylated at Tyr701 and Ser727 and was retained within the nucleus in a DNA-bound state. The sustained and promiscuous binding activity particularly of STAT1 tetramers to unspecific DNA sites lacking a consensus STAT1-binding motif is an as yet unrecognised mechanism contributing to the defective IFN-γ-mediated signalling in T. gondii-infected cells.
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Affiliation(s)
- Roswitha Nast
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
| | - Julia Staab
- Psychosomatic Medicine and Psychotherapy, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
| | - Thomas Meyer
- Psychosomatic Medicine and Psychotherapy, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
| | - Carsten G K Lüder
- Institute for Medical Microbiology, University Medical Center Goettingen, Georg-August University, Göttingen, Germany
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21
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Shi Y, Shen S, Hu S, Ding T, Hong X, Chen C, Zhu X, Zhao Z. Comparative study of two immunity-related GTPase genes in Chinese soft-shell turtle reveals their molecular characteristics and functional activity in immune defense. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 81:63-73. [PMID: 29154856 DOI: 10.1016/j.dci.2017.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/13/2017] [Accepted: 11/13/2017] [Indexed: 06/07/2023]
Abstract
The immunity-related GTPases (IRGs) are a family of proteins that play critical roles in innate resistance to intracellular pathogens. The number and diversity of IRG genes differ greatly in different species. Although IRG proteins have been well studies in mammals, they remain poorly characterized in lower vertebrates. In this study, we cloned two IRG genes, PsIRG5 and PsIRG8, from the Chinese soft-shelled turtle and compared their characterization and functional activity with mammalian IRGs. The PsIRG5 is a gene of 1896 bp that encodes a protein of 413 amino acid and PsIRG8 is 1543 bp in length encoding another 413 aa protein. Sequence alignment between all turtle IRG-like genes and mammalian IRGs showed that both PsIRG5 and PsIRG8 were conserved with mammalian GKS IRGs, while PsIRG5 appeared a closer evolutionary relationship with mammalian GMS IRGs. The expression and subcellular characterization revealed that PsIRG5 was dramatically upregulated under Aeromonas hydrophila challenge and exhibited co-localization with lysosomes in cells; whereas PsIRG8 was downregulated and has no distinct localization. Functional activity assay demonstrated that PsIRG5 plays a role in autophagy induction and IFN-γ contributes to enhance the induction, since it has IFN-inducible elements in its promoter region. These data above unravel the molecular characterization and functional activity of IRGs in lower vertebrate for the first time and will provide insights into the comparative immunity and evolutionary relationships of IRGs between mammals and reptiles.
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Affiliation(s)
- Yan Shi
- College of Oceanography, Hohai University, Nanjing 210098, China; Pear River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
| | - Sixian Shen
- Pear River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
| | - Sufei Hu
- College of Oceanography, Hohai University, Nanjing 210098, China
| | - Tie Ding
- College of Oceanography, Hohai University, Nanjing 210098, China
| | - Xiaoyou Hong
- Pear River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
| | - Chen Chen
- Pear River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
| | - Xinping Zhu
- Pear River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
| | - Zhe Zhao
- College of Oceanography, Hohai University, Nanjing 210098, China.
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22
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Liu W, Huang L, Wei Q, Zhang Y, Zhang S, Zhang W, Cai L, Liang S. Microarray analysis of long non-coding RNA expression profiles uncovers a Toxoplasma-induced negative regulation of host immune signaling. Parasit Vectors 2018. [PMID: 29530077 PMCID: PMC5848448 DOI: 10.1186/s13071-018-2697-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Toxoplasma gondii is an obligate intracellular protozoan parasite that can infect mammalian cells and thereby regulate host gene expression. The long non-coding RNAs (lncRNAs) have been demonstrated to be an important class of RNA molecules that regulate many biological processes, including host-pathogen interactions. However, the role of host lncRNAs in the response to T. gondii infection remains largely unknown. METHODS We applied a microarray approach to determine the differential expression profiles of both lncRNAs and mRNAs in the human foreskin fibroblast (HFF) cells after T. gondii infection. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to reveal the potential functions of T. gondii-induced genes. Based on the co-expression networks of lncRNAs and immune-related genes, the role of NONSHAT022487 on the regulation of UNC93B1 related immune signaling was investigated by the knockdown and over-expression of lncRNA in human macrophage derived from the PMA-induced promonocytic cell line THP-1. RESULTS Our data showed that 996 lncRNAs and 109 mRNAs in HFF cells were significantly and differentially expressed following T. gondii infection (fold change ≥ 5, P < 0.05). The results from the GO and KEGG pathway analyses indicated that the mRNAs with differential expression were mainly involved in the host immune response. Remarkably, we identified a novel lncRNA, NONSHAT022487, which suppresses the expression of the immune-related molecule UNC93B1. After T. gondii infection, NONSHAT022487 impaired the secretion of the cytokines IL-12, TNF-α, IL-1β and IFN-γ by downregulating UNC93B1 expression in human macrophage cells. CONCLUSIONS Our study identified infection-induced lncRNA expression as a novel mechanism by which the Toxoplasma parasite regulates host immune signaling, which advances our understanding of the interaction of T. gondii parasites and host cells.
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Affiliation(s)
- Wenquan Liu
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Liyang Huang
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Qimei Wei
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Yu Zhang
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Shengnan Zhang
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Wenting Zhang
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Liya Cai
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Shaohui Liang
- Department of Parasitology, Wenzhou Medical University, Wenzhou, Zhejiang Province, China.
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Hwang YS, Shin JH, Yang JP, Jung BK, Lee SH, Shin EH. Characteristics of Infection Immunity Regulated by Toxoplasma gondii to Maintain Chronic Infection in the Brain. Front Immunol 2018; 9:158. [PMID: 29459868 PMCID: PMC5807351 DOI: 10.3389/fimmu.2018.00158] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 01/18/2018] [Indexed: 01/28/2023] Open
Abstract
To examine the immune environment of chronic Toxoplasma gondii infection in the brain, the characteristics of infection-immunity (premunition) in infection with T. gondii strain ME49 were investigated for 12 weeks postinfection (PI). The results showed that neuronal cell death, microglia infiltration and activation, inflammatory and anti-inflammatory cytokine expression, Stat1 phosphorylation, and microglia activation and inflammatory gene transcripts related to M1 polarization in the brain were increased during the acute infection (AI) stage (within 6 weeks PI), suggesting that innate and cellular inflammatory response activation and neurodegeneration contributed to excessive inflammatory responses. However, these immune responses decreased during the chronic infection (CI) stage (over 6 weeks PI) with reductions in phosphorylated STAT1 (pSTAT1) and eosinophilic neurons. Notably, increases were observed in transcripts of T-cell exhaustion markers (TIM3, LAG3, KLRG1, etc.), suppressor of cytokines signaling 1 protein (SOCS1), inhibitory checkpoint molecules (PD-1 and PD-L1), and Arg1 from the AI stage (3 weeks PI), implying active immune intervention under the immune environment of M1 polarization of microglia and increases in inflammatory cytokine levels. However, when BV-2 microglia were stimulated with T. gondii lysate antigens (strain RH or ME49) in vitro, nitrite production increased and urea production decreased. Furthermore, when BV-2 cells were infected by T. gondii tachyzoites (strain RH or ME49) in vitro, nitric oxide synthase and COX-2 levels decreased, whereas Arg1 levels significantly increased. Moreover, Arg1 expression was higher in ME49 infection than in RH infection, whereas nitrite production was lower in ME49 infection than in RH infection. Accordingly, these results strongly suggest that immune triggering of T. gondii antigens induces M1 polarization and activation of microglia as well as increase NO production, whereas T. gondii infection induces the inhibition of harmful inflammatory responses, even with M1 polarization and activation of microglia and Th1 inflammatory responses, suggesting a host–parasite relationship through immune regulation during CI. This is a characteristic of infection immunity in infection with T. gondii in the central nervous system, and SOCS1, a negative regulator of toxoplasmic encephalitis, may play a role in the increase in Arg1 levels to suppress NO production.
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Affiliation(s)
- Young Sang Hwang
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University, Seoul, South Korea
| | - Ji-Hun Shin
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University, Seoul, South Korea
| | - Jung-Pyo Yang
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University, Seoul, South Korea
| | - Bong-Kwang Jung
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University, Seoul, South Korea.,Institute of Parasitic Diseases, Korea Association of Health Promotion, Seoul, South Korea
| | - Sang Hyung Lee
- Department of Neurosurgery, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Seoul, South Korea
| | - Eun-Hee Shin
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University, Seoul, South Korea.,Seoul National University Bundang Hospital, Seongnam, South Korea
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Chen K, Wang JL, Huang SY, Yang WB, Zhu WN, Zhu XQ. Immune responses and protection after DNA vaccination against Toxoplasma gondii calcium-dependent protein kinase 2 (TgCDPK2). ACTA ACUST UNITED AC 2017; 24:41. [PMID: 29119944 PMCID: PMC5678354 DOI: 10.1051/parasite/2017045] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/04/2017] [Indexed: 12/21/2022]
Abstract
Toxoplasma gondii, an intracellular zoonotic protozoan parasite, is possibly the most widespread parasite of warm-blooded animals and can cause serious public health problems and economic losses worldwide. TgCDPK2, a member of the T. gondii calcium-dependent protein kinase family, was recently identified as an essential regulator for viable cyst development in T. gondii. In the present study, we evaluated the protective immunity induced by DNA vaccination based on a recombinant eukaryotic plasmid, pVAX-TgCDPK2, against acute toxoplasmosis in mice. BALB/c mice were intramuscularly immunized with pVAX-TgCDPK2 plasmid and then challenged by infection with the highly virulent RH strain of T. gondii. The specific immune responses and protective efficacy against T. gondii were analyzed by cytokine and serum antibody measurements, lymphocyte proliferation assays, flow cytometric on lymphocytes and the survival time of mice after challenge. Our results showed that mice immunized with pVAX-TgCDPK2 could elicit special humoral and cellular responses, with higher levels of IgG antibody, and increased levels of Th1-type cytokines IFN-γ, IL-12(p70), and CD3 + CD4 + CD8 − and CD3 + CD8 + CD4 − T cells, and had a prolonged survival time (14.0 ± 2.32 days) compared to control mice. These results demonstrate that pVAX-TgCDPK2 is a potential vaccine candidate against acute toxoplasmosis.
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Affiliation(s)
- Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China - Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province 225009, PR China
| | - Wen-Bin Yang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China - College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China
| | - Wei-Ning Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China - College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin, Heilongjiang Province 150030, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China - Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu Province 225009, PR China
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25
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Downmodulation of Effector Functions in NK Cells upon Toxoplasma gondii Infection. Infect Immun 2017; 85:IAI.00069-17. [PMID: 28760930 DOI: 10.1128/iai.00069-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 07/15/2017] [Indexed: 12/29/2022] Open
Abstract
The obligate intracellular parasite Toxoplasma gondii can actively infect any nucleated cell type, including cells from the immune system. The rapid transfer of T. gondii from infected dendritic cells to effector natural killer (NK) cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection. However, subversion of NK cell functions, such as cytotoxicity or production of proinflammatory cytokines, such as gamma interferon (IFN-γ), upon parasite infection might also be beneficial to the parasite. In the present study, we investigated the effects of T. gondii infection on NK cells. In vitro, infected NK cells were found to be poor at killing target cells and had reduced levels of IFN-γ production. This could be attributed in part to the inability of infected cells to form conjugates with their target cells. However, even upon NK1.1 cross-linking of NK cells, the infected NK cells also exhibited poor degranulation and IFN-γ production. Similarly, NK cells infected in vivo were also poor at killing target cells and producing IFN-γ. Increased levels of transforming growth factor β production, as well as increased levels of expression of SHP-1 in the cytosol of infected NK cells upon infection, were observed in infected NK cells. However, the phosphorylation of STAT4 was not altered in infected NK cells, suggesting that transcriptional regulation mediates the reduced IFN-γ production, which was confirmed by quantitative PCR. These data suggest that infection of NK cells by T. gondii impairs NK cell recognition of target cells and cytokine release, two mechanisms that independently could enhance T. gondii survival.
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Olias P, Etheridge RD, Zhang Y, Holtzman MJ, Sibley LD. Toxoplasma Effector Recruits the Mi-2/NuRD Complex to Repress STAT1 Transcription and Block IFN-γ-Dependent Gene Expression. Cell Host Microbe 2017; 20:72-82. [PMID: 27414498 DOI: 10.1016/j.chom.2016.06.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/09/2016] [Accepted: 06/09/2016] [Indexed: 12/12/2022]
Abstract
Interferon gamma (IFN-γ) is an essential mediator of host defense against intracellular pathogens, including the protozoan parasite Toxoplasma gondii. However, prior T. gondii infection blocks IFN-γ-dependent gene transcription, despite the downstream transcriptional activator STAT1 being activated and bound to cognate nuclear promoters. We identify the parasite effector that blocks STAT1-dependent transcription and show it is associated with recruitment of the Mi-2 nucleosome remodeling and deacetylase (NuRD) complex, a chromatin-modifying repressor. This secreted effector, toxoplasma inhibitor of STAT1-dependent transcription (TgIST), translocates to the host cell nucleus, where it recruits Mi-2/NuRD to STAT1-dependent promoters, resulting in altered chromatin and blocked transcription. TgIST is conserved across strains, underlying their shared ability to block IFN-γ-dependent transcription. TgIST deletion results in increased parasite clearance in IFN-γ-activated cells and reduced mouse virulence, which is restored in IFN-γ-receptor-deficient mice. These findings demonstrate the importance of both IFN-γ responses and the ability of pathogens to counteract these defenses.
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Affiliation(s)
- Philipp Olias
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ronald D Etheridge
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yong Zhang
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael J Holtzman
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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27
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Biswas A, French T, Düsedau HP, Mueller N, Riek-Burchardt M, Dudeck A, Bank U, Schüler T, Dunay IR. Behavior of Neutrophil Granulocytes during Toxoplasma gondii Infection in the Central Nervous System. Front Cell Infect Microbiol 2017; 7:259. [PMID: 28680853 PMCID: PMC5478696 DOI: 10.3389/fcimb.2017.00259] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/02/2017] [Indexed: 01/12/2023] Open
Abstract
Cerebral toxoplasmosis is characterized by activation of brain resident cells and recruitment of specific immune cell subsets from the periphery to the central nervous system (CNS). Our studies revealed that the rapidly invaded Ly6G+ neutrophil granulocytes are an early non-lymphoid source of interferon-gamma (IFN-γ), the cytokine known to be the major mediator of host resistance to Toxoplasma gondii (T. gondii). Upon selective depletion of Ly6G+ neutrophils, we detected reduced IFN-γ production and increased parasite burden in the CNS. Ablation of Ly6G+ cells resulted in diminished recruitment of Ly6Chi monocytes into the CNS, indicating a pronounced interplay. Additionally, we identified infiltrated Ly6G+ neutrophils to be a heterogeneous population. The Ly6G+CD62-LhiCXCR4+ subset released cathelicidin-related antimicrobial peptide (CRAMP), which can promote monocyte dynamics. On the other hand, the Ly6G+CD62-LloCXCR4+ subset produced IFN-γ to establish early inflammatory response. Collectively, our findings revealed that the recruited Ly6G+CXCR4+ neutrophil granulocytes display a heterogeneity in the CNS with a repertoire of effector functions crucial in parasite control and immune regulation upon experimental cerebral toxoplasmosis.
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Affiliation(s)
- Aindrila Biswas
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Timothy French
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Henning P Düsedau
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Nancy Mueller
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Monika Riek-Burchardt
- Institute for Molecular and Clinical Immunology, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Anne Dudeck
- Institute for Molecular and Clinical Immunology, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Ute Bank
- Institute for Molecular and Clinical Immunology, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Thomas Schüler
- Institute for Molecular and Clinical Immunology, Otto-von-Guericke University MagdeburgMagdeburg, Germany
| | - Ildiko Rita Dunay
- Institute of Inflammation and Neurodegeneration, Otto-von-Guericke University MagdeburgMagdeburg, Germany
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28
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Abstract
Early electron microscopy studies revealed the elaborate cellular features that define the unique adaptations of apicomplexan parasites. Among these were bulbous rhoptry (ROP) organelles and small, dense granules (GRAs), both of which are secreted during invasion of host cells. These early morphological studies were followed by the exploration of the cellular contents of these secretory organelles, revealing them to be comprised of highly divergent protein families with few conserved domains or predicted functions. In parallel, studies on host-pathogen interactions identified many host signaling pathways that were mysteriously altered by infection. It was only with the advent of forward and reverse genetic strategies that the connections between individual parasite effectors and the specific host pathways that they targeted finally became clear. The current repertoire of parasite effectors includes ROP kinases and pseudokinases that are secreted during invasion and that block host immune pathways. Similarly, many secretory GRA proteins alter host gene expression by activating host transcription factors, through modification of chromatin, or by inducing small noncoding RNAs. These effectors highlight novel mechanisms by which T. gondii has learned to harness host signaling to favor intracellular survival and will guide future studies designed to uncover the additional complexity of this intricate host-pathogen interaction.
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29
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Zhang J, Zhang Y, Xu T, Pan SJ, Nie G, Miao XY, Qiu JY, Yu WQ, Zhang SY, Liang TB. Severe traumatic hemorrhagic shock induces compromised immune barrier function of the mesenteric lymph node leading to an increase in intestinal bacterial translocation. Am J Transl Res 2017; 9:2363-2373. [PMID: 28559986 PMCID: PMC5446518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/26/2017] [Indexed: 06/07/2023]
Abstract
Critically ill patients have increased susceptibility to translocation of gut bacteria. However, the mechanisms are complicated and remain unclear, and the aim of this study was to explore these mechanisms. Rats exposed to different levels of shock were orally administrated with bioluminescent Citrobacter. We found that severe shock caused an increase in bacterial translocation to the visceral organs, such as liver, spleen and blood, compared with mild shock. Surprisingly, bacterial translocation to mesenteric lymph node (MLN) was unchanged between the two shock groups. Various methods, including flow cytometry, a co-culture model and western blots, were used to evaluate MLN-associated immune function. Specifically, we focused on mesenteric lymph node dendritic cells (MLN-DCs), the critical antigen presenting cells involved in the construction of the immune barrier in MLN. We also found that severe shock impaired the phenotypic maturation of MLN-DCs and induced a tolerogenic phenotype. Furthermore, co-culture assays of DCs with naive CD4+ T cells showed that DCs subject to severe shock were more inclined to polarize native CD4+ T cells into Th2 and Treg cells. This study successfully reproduced the clinical phenomenon of severe shock resulting in increased bacterial translocation to extraintestinal tissues, and this may be related to the compromised immune barrier function of MLN, as maturation and function of MLN-DC's were badly impaired.
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Affiliation(s)
- Jian Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Yun Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Tao Xu
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Sheng-Jing Pan
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Gang Nie
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Xiao-Yan Miao
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
| | - Jun-Yu Qiu
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Wen-Qiao Yu
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Shao-Yang Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
| | - Ting-Bo Liang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang UniversityHangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Pancreatic DiseaseChina
- Zhejiang University, Collaborative Innovation Center for Cancer MedicineGuangzhou, China
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30
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STAT1 Signaling in Astrocytes Is Essential for Control of Infection in the Central Nervous System. mBio 2016; 7:mBio.01881-16. [PMID: 27834206 PMCID: PMC5101356 DOI: 10.1128/mbio.01881-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The local production of gamma interferon (IFN-γ) is important to control Toxoplasma gondii in the brain, but the basis for these protective effects is not fully understood. The studies presented here reveal that the ability of IFN-γ to inhibit parasite replication in astrocytes in vitro is dependent on signal transducer and activator of transcription 1 (STAT1) and that mice that specifically lack STAT1 in astrocytes are unable to limit parasite replication in the central nervous system (CNS). This susceptibility is associated with a loss of antimicrobial pathways and increased cyst formation in astrocytes. These results identify a critical role for astrocytes in limiting the replication of an important opportunistic pathogen. Astrocytes are the most numerous cell type in the brain, and they are activated in response to many types of neuroinflammation, but their function in the control of CNS-specific infection is unclear. The parasite Toxoplasma gondii is one of the few clinically relevant microorganisms that naturally infects astrocytes, and the studies presented here establish that the ability of astrocytes to inhibit parasite replication is essential for the local control of this opportunistic pathogen. Together, these studies establish a key role for astrocytes as effector cells and in the coordination of many aspects of the protective immune response that operates in the brain.
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31
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Gay G, Braun L, Brenier-Pinchart MP, Vollaire J, Josserand V, Bertini RL, Varesano A, Touquet B, De Bock PJ, Coute Y, Tardieux I, Bougdour A, Hakimi MA. Toxoplasma gondii TgIST co-opts host chromatin repressors dampening STAT1-dependent gene regulation and IFN-γ-mediated host defenses. J Exp Med 2016; 213:1779-98. [PMID: 27503074 PMCID: PMC4995087 DOI: 10.1084/jem.20160340] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/22/2016] [Indexed: 11/04/2022] Open
Abstract
An early hallmark of Toxoplasma gondii infection is the rapid control of the parasite population by a potent multifaceted innate immune response that engages resident and homing immune cells along with pro- and counter-inflammatory cytokines. In this context, IFN-γ activates a variety of T. gondii-targeting activities in immune and nonimmune cells but can also contribute to host immune pathology. T. gondii has evolved mechanisms to timely counteract the host IFN-γ defenses by interfering with the transcription of IFN-γ-stimulated genes. We now have identified TgIST (T. gondii inhibitor of STAT1 transcriptional activity) as a critical molecular switch that is secreted by intracellular parasites and traffics to the host cell nucleus where it inhibits STAT1-dependent proinflammatory gene expression. We show that TgIST not only sequesters STAT1 on dedicated loci but also promotes shaping of a nonpermissive chromatin through its capacity to recruit the nucleosome remodeling deacetylase (NuRD) transcriptional repressor. We found that during mice acute infection, TgIST-deficient parasites are rapidly eliminated by the homing Gr1(+) inflammatory monocytes, thus highlighting the protective role of TgIST against IFN-γ-mediated killing. By uncovering TgIST functions, this study brings novel evidence on how T. gondii has devised a molecular weapon of choice to take control over a ubiquitous immune gene expression mechanism in metazoans, as a way to promote long-term parasitism.
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Affiliation(s)
- Gabrielle Gay
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Laurence Braun
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Marie-Pierre Brenier-Pinchart
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Julien Vollaire
- IAB, OPTIMAL Small Animal Imaging Facility, 38000 Grenoble, France
| | | | - Rose-Laurence Bertini
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Aurélie Varesano
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Bastien Touquet
- IAB, Team Membrane and Cell Dynamics of Host-Parasite Interactions, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Pieter-Jan De Bock
- Institut de Biosciences et Biotechnologies de Grenoble-Laboratoire Biologie à Grande Échelle (BIG-BGE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INSERM, 38000 Grenoble, France
| | - Yohann Coute
- Institut de Biosciences et Biotechnologies de Grenoble-Laboratoire Biologie à Grande Échelle (BIG-BGE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INSERM, 38000 Grenoble, France
| | - Isabelle Tardieux
- IAB, Team Membrane and Cell Dynamics of Host-Parasite Interactions, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Alexandre Bougdour
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
| | - Mohamed-Ali Hakimi
- Institute for Advanced Biosciences (IAB), Team Host-Pathogen Interactions and Immunity to Infection, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, F-38700 Grenoble, France
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32
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Targeted disruption of CK1α in Toxoplasma gondii increases acute virulence in mice. Eur J Protistol 2016; 56:90-101. [PMID: 27567091 DOI: 10.1016/j.ejop.2016.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 07/18/2016] [Accepted: 07/18/2016] [Indexed: 01/02/2023]
Abstract
Toxoplasma gondii, the causative agent of toxoplasmosis, encodes two casein kinase 1 (CK1) isoforms, CK1α and CK1β, with only CK1α having enzyme activity. Here we investigated the biological role of CK1α by construction of a CK1α deletion mutant (Δck1α) based on the type I parasite, and complement the mutant with restored expression of CK1α. Deletion of CK1α resulted in markedly defective parasite replication in vitro. Infected mice with Δck1α parasite caused suppression of IL-12 production, severe liver damage, higher tissue burdens, and short survival time relative to the CK1α-positive parental strain. Western blot analysis revealed that deletion of CK1α led to increased activation of the signal transducer and activator of transcription (STAT)-3 in infected mice and bone marrow-derived microphages. The transcriptome analysis showed that deletion of CK1α may increase expression of rhoptry proteins (ROPs). Western blot showed enhanced expression of ROP16 in the Δck1α parasite as compared with the wild-type and complemented parasites. These findings demonstrated that deletion of CK1α may increase acute virulence of T. gondii in mice by increased expression of ROPs, activation of STAT3, and suppression of IL-12 production, which have important implications for elucidating regulation mechanism of virulence factors for T. gondii.
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33
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Altered signaling in systemic juvenile idiopathic arthritis monocytes. Clin Immunol 2015; 163:66-74. [PMID: 26747737 DOI: 10.1016/j.clim.2015.12.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 12/23/2015] [Indexed: 11/20/2022]
Abstract
Systemic juvenile idiopathic arthritis (sJIA) is characterized by systemic inflammation and arthritis. Monocytes are implicated in sJIA pathogenesis, but their role in disease is unclear. The response of sJIA monocytes to IFN may be dysregulated. We examined intracellular signaling in response to IFN type I (IFNα) and type II (IFNγ) in monocytes during sJIA activity and quiescence, in 2 patient groups. Independent of disease activity, monocytes from Group 1 (collected between 2002 and 2009) showed defective STAT1 phosphorylation downstream of IFNs, and expressed higher transcript levels of SOCS1, an inhibitor of IFN signaling. In the Group 2 (collected between 2011 and 2014), monocytes of patients with recent disease onset were IFNγ hyporesponsive, but in treated, quiescent subjects, monocytes were hyperresponsive to IFNγ. Recent changes in medication in sJIA may alter the IFN hyporesponsiveness. Impaired IFN/pSTAT1 signaling is consistent with skewing of sJIA monocytes away from an M1 phenotype and may contribute to disease pathology.
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34
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Gao Y, Wu J, Zhang M, Hou M, Ji M. Mice lack of LRG-47 display the attenuated outcome of infection with Schistosoma japonicum. Parasitol Res 2015; 115:1185-93. [PMID: 26660918 DOI: 10.1007/s00436-015-4853-9] [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: 09/14/2015] [Accepted: 11/27/2015] [Indexed: 10/22/2022]
Abstract
Interferon-inducible GTPase LRG-47 (also named immune-related GTPase M, Irgm1) is a member of the p47 GTPase family that has been shown to regulate host resistance to intracellular pathogens. Little knowledge has been known about the role of LRG-47 in host's responses to extracellular pathogens. To investigate possible roles of LRG-47 in the course of Schistosoma japonicum infection, LRG-47-deficient (LRG-47(-/-)) and wild-type (WT) mice were challenged with cercariae of S. japonicum, and the cellular and humoral responses in mice were analyzed. At the acute stage of S. japonicum infection, in contrast to WT mice, LRG-47(-/-) mice showed the significantly decreased egg burden, low schistosome-specific antibody response, and the decreased Th1 and increased Tc1 responses. Additionally, Schistosoma japonicum-specific egg antigen immunization also produced the similar humoral and cellular immune responses as S. japonicum infection. Taken together, these data suggested that the deficiency of LRG-47 might affect host's CD4(+) T cell immune response via the weakening of IFN-γ downstream signaling; however, the specific function of LRG-47 on dealing with extracellular worm needs to be further studied.
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Affiliation(s)
- Yanan Gao
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, 210029, China.,College of Basic Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Jingjiao Wu
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, 210029, China.,Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing, China
| | - Meijuan Zhang
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, 210029, China
| | - Min Hou
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, 210029, China
| | - Minjun Ji
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, 210029, China. .,Jiangsu Province Key Laboratory of Modern Pathogen Biology, Nanjing, Jiangsu, China.
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STAT1 signaling within macrophages is required for antifungal activity against Cryptococcus neoformans. Infect Immun 2015; 83:4513-27. [PMID: 26351277 DOI: 10.1128/iai.00935-15] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/03/2015] [Indexed: 02/07/2023] Open
Abstract
Cryptococcus neoformans, the predominant etiological agent of cryptococcosis, is an opportunistic fungal pathogen that primarily affects AIDS patients and patients undergoing immunosuppressive therapy. In immunocompromised individuals, C. neoformans can lead to life-threatening meningoencephalitis. Studies using a virulent strain of C. neoformans engineered to produce gamma interferon (IFN-γ), denoted H99γ, demonstrated that protection against pulmonary C. neoformans infection is associated with the generation of a T helper 1 (Th1)-type immune response and signal transducer and activator of transcription 1 (STAT1)-mediated classical (M1) macrophage activation. However, the critical mechanism by which M1 macrophages mediate their anti-C. neoformans activity remains unknown. The current studies demonstrate that infection with C. neoformans strain H99γ in mice with macrophage-specific STAT1 ablation resulted in severely increased inflammation of the pulmonary tissue, a dysregulated Th1/Th2-type immune response, increased fungal burden, deficient M1 macrophage activation, and loss of protection. STAT1-deficient macrophages produced significantly less nitric oxide (NO) than STAT1-sufficient macrophages, correlating with an inability to control intracellular cryptococcal proliferation, even in the presence of reactive oxygen species (ROS). Furthermore, macrophages from inducible nitric oxide synthase knockout mice, which had intact ROS production, were deficient in anticryptococcal activity. These data indicate that STAT1 activation within macrophages is required for M1 macrophage activation and anti-C. neoformans activity via the production of NO.
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Beiting DP, Hidano S, Baggs JE, Geskes JM, Fang Q, Wherry EJ, Hunter CA, Roos DS, Cherry S. The Orphan Nuclear Receptor TLX Is an Enhancer of STAT1-Mediated Transcription and Immunity to Toxoplasma gondii. PLoS Biol 2015. [PMID: 26196739 PMCID: PMC4509904 DOI: 10.1371/journal.pbio.1002200] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The protozoan parasite, Toxoplasma, like many intracellular pathogens, suppresses interferon gamma (IFN-γ)-induced signal transducer and activator of transcription 1 (STAT1) activity. We exploited this well-defined host–pathogen interaction as the basis for a high-throughput screen, identifying nine transcription factors that enhance STAT1 function in the nucleus, including the orphan nuclear hormone receptor TLX. Expression profiling revealed that upon IFN-γ treatment TLX enhances the output of a subset of IFN-γ target genes, which we found is dependent on TLX binding at those loci. Moreover, infection of TLX deficient mice with the intracellular parasite Toxoplasma results in impaired production of the STAT1-dependent cytokine interleukin-12 by dendritic cells and increased parasite burden in the brain during chronic infection. These results demonstrate a previously unrecognized role for this orphan nuclear hormone receptor in regulating STAT1 signaling and host defense and reveal that STAT1 activity can be modulated in a context-specific manner by such “modifiers.” Exploitation of the parasite Toxoplasma gondii identifies the host orphan nuclear hormone receptor TLX as a key enhancer of STAT1-dependent immune signaling and host defense. Immune responses are orchestrated by a diverse array of secreted ligands, yet the downstream transcriptional responses are coordinated by a relatively small set of key transcription factors, including nuclear factor kappa B (NF-κB) and signal transducers and activators of transcription (STATs). The molecular mechanisms that tailor the output of these immune signaling pathways to generate cell-, tissue-, or context-specific responses are poorly understood. In this study, we exploit a host–pathogen interaction, Toxoplasma gondii infection in mice, using a genetic screen to identify host factors that overcome parasite suppression of STAT1 signaling. We show that the orphan nuclear receptor TLX, a key regulator of brain development, enhances expression of a subset of STAT1-dependent genes in response to IFN-γ stimulation. Through genetic and pharmacological studies, we show that endogenous TLX function is required for triggering appropriate responses to IFN-γ in astrocytes. Moreover, we found that genetic disruption of TLX in mice impairs their ability to mount an effective immune response and control T. gondii infection in the brain. These data suggest that natural or synthetic ligands for TLX might be effective tools for modulating immune responses, particularly in the brain where TLX expression is highest.
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Affiliation(s)
- Daniel P. Beiting
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania, Philadelphia, United States of America
| | - Shinya Hidano
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania, Philadelphia, United States of America
| | - Julie E. Baggs
- Department of Pharmacology and the Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jeanne M. Geskes
- Department of Pharmacology and the Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Qun Fang
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania, Philadelphia, United States of America
| | - E. John Wherry
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Christopher A. Hunter
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania, Philadelphia, United States of America
| | - David S. Roos
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (DSR); (SC)
| | - Sara Cherry
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail: (DSR); (SC)
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Franceschi V, Parker S, Jacca S, Crump RW, Doronin K, Hembrador E, Pompilio D, Tebaldi G, Estep RD, Wong SW, Buller MR, Donofrio G. BoHV-4-Based Vector Single Heterologous Antigen Delivery Protects STAT1(-/-) Mice from Monkeypoxvirus Lethal Challenge. PLoS Negl Trop Dis 2015; 9:e0003850. [PMID: 26086739 PMCID: PMC4473039 DOI: 10.1371/journal.pntd.0003850] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 05/27/2015] [Indexed: 01/13/2023] Open
Abstract
Monkeypox virus (MPXV) is the etiological agent of human (MPX). It is an emerging orthopoxvirus zoonosis in the tropical rain forest of Africa and is endemic in the Congo-basin and sporadic in West Africa; it remains a tropical neglected disease of persons in impoverished rural areas. Interaction of the human population with wildlife increases human infection with MPX virus (MPXV), and infection from human to human is possible. Smallpox vaccination provides good cross-protection against MPX; however, the vaccination campaign ended in Africa in 1980, meaning that a large proportion of the population is currently unprotected against MPXV infection. Disease control hinges on deterring zoonotic exposure to the virus and, barring that, interrupting person-to-person spread. However, there are no FDA-approved therapies against MPX, and current vaccines are limited due to safety concerns. For this reason, new studies on pathogenesis, prophylaxis and therapeutics are still of great interest, not only for the scientific community but also for the governments concerned that MPXV could be used as a bioterror agent. In the present study, a new vaccination strategy approach based on three recombinant bovine herpesvirus 4 (BoHV-4) vectors, each expressing different MPXV glycoproteins, A29L, M1R and B6R were investigated in terms of protection from a lethal MPXV challenge in STAT1 knockout mice. BoHV-4-A-CMV-A29LgD106ΔTK, BoHV-4-A-EF1α-M1RgD106ΔTK and BoHV-4-A-EF1α-B6RgD106ΔTK were successfully constructed by recombineering, and their capacity to express their transgene was demonstrated. A small challenge study was performed, and all three recombinant BoHV-4 appeared safe (no weight-loss or obvious adverse events) following intraperitoneal administration. Further, BoHV-4-A-EF1α-M1RgD106ΔTK alone or in combination with BoHV-4-A-CMV-A29LgD106ΔTK and BoHV-4-A-EF1α-B6RgD106ΔTK, was shown to be able to protect, 100% alone and 80% in combination, STAT1(-/-) mice against mortality and morbidity. This work demonstrated the efficacy of BoHV-4 based vectors and the use of BoHV-4 as a vaccine-vector platform.
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Affiliation(s)
| | - Scott Parker
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Sarah Jacca
- Department of Medical-Veterinary Science, University of Parma, Parma, Italy
| | - Ryan W. Crump
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Konstantin Doronin
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Edguardo Hembrador
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Daniela Pompilio
- Department of Medical-Veterinary Science, University of Parma, Parma, Italy
| | - Giulia Tebaldi
- Department of Medical-Veterinary Science, University of Parma, Parma, Italy
| | - Ryan D. Estep
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Scott W. Wong
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Mark R. Buller
- Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Gaetano Donofrio
- Department of Medical-Veterinary Science, University of Parma, Parma, Italy
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Wang Z, Zhang DX, Zhao Q. Infection-stimulated anemia results primarily from interferon gamma-dependent, signal transducer and activator of transcription 1-independent red cell loss. Chin Med J (Engl) 2015; 128:948-55. [PMID: 25836617 PMCID: PMC4834013 DOI: 10.4103/0366-6999.154303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Although the onset of anemia during infectious disease is commonly correlated with production of inflammatory cytokines, the mechanisms by which cytokines induce anemia are poorly defined. This study focused on the mechanism research. METHODS Different types of mice were infected perorally with Toxoplasma gondii strain ME49. At the indicated times, samples from each mouse were harvested, processed, and analyzed individually. Blood samples were analyzed using a Coulter Counter and red blood cell (RBC) survival was measured by biotinylation. Levels of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), and inducible protein 10 (IP-10) mRNA in liver tissue were measured by real-time polymerase chain reaction. RESULTS T. gondii-infected mice exhibited anemia due to a decrease in both erythropoiesis and survival time of RBC in the circulation (P < 0.02). In addition, infection-stimulated anemia was associated with fecal occult, supporting previous literature that hemorrhage is a consequence of T. gondii infection in mice. Infection-induced anemia was abolished in interferon gamma (IFNγ) and IFNγ receptor deficient mice (P < 0.05) but was still evident in mice lacking TNF-α, iNOS, phagocyte NADPH oxidase or IP-10 (P < 0.02). Neither signal transducer and activator of transcription 1 (STAT1) deficient mice nor 129S6 controls exhibited decreased erythropoiesis, but rather suffered from an anemia resulting solely from increased loss of circulating RBC. CONCLUSIONS Infection-stimulated decrease in erythropoiesis and losses of RBC have distinct mechanistic bases. These results show that during T. gondii infection, IFNγ is responsible for an anemia that results from both a decrease in erythropoiesis and a STAT1 independent loss of circulating RBC.
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Affiliation(s)
- Zheng Wang
- Department of Pediatric Surgery, General Hospital of Chinese People's Liberation Army, Beijing 100037, China
| | - Dong-Xia Zhang
- Department of Immunology, Yuhuangding Hospital, Yantai, Shandong 264000, China
| | - Qi Zhao
- Department of Immunology, Yuhuangding Hospital, Yantai, Shandong 264000, China
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Leopold Wager CM, Hole CR, Wozniak KL, Olszewski MA, Wormley FL. STAT1 signaling is essential for protection against Cryptococcus neoformans infection in mice. THE JOURNAL OF IMMUNOLOGY 2014; 193:4060-71. [PMID: 25200956 DOI: 10.4049/jimmunol.1400318] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Nonprotective immune responses to highly virulent Cryptococcus neoformans strains, such as H99, are associated with Th2-type cytokine production, alternatively activated macrophages, and inability of the host to clear the fungus. In contrast, experimental studies show that protective immune responses against cryptococcosis are associated with Th1-type cytokine production and classical macrophage activation. The protective response induced during C. neoformans strain H99γ (C. neoformans strain H99 engineered to produce murine IFN-γ) infection correlates with enhanced phosphorylation of the transcription factor STAT1 in macrophages; however, the role of STAT1 in protective immunity to C. neoformans is unknown. The current studies examined the effect of STAT1 deletion in murine models of protective immunity to C. neoformans. Survival and fungal burden were evaluated in wild-type and STAT1 knockout (KO) mice infected with either strain H99γ or C. neoformans strain 52D (unmodified clinical isolate). Both strains H99γ and 52D were rapidly cleared from the lungs, did not disseminate to the CNS, or cause mortality in the wild-type mice. Conversely, STAT1 KO mice infected with H99γ or 52D had significantly increased pulmonary fungal burden, CNS dissemination, and 90-100% mortality. STAT1 deletion resulted in a shift from Th1 to Th2 cytokine bias, pronounced lung inflammation, and defective classical macrophage activation. Pulmonary macrophages from STAT1 KO mice exhibited defects in NO production correlating with inefficient inhibition of fungal proliferation. These studies demonstrate that STAT1 signaling is essential not only for regulation of immune polarization but also for the classical activation of macrophages that occurs during protective anticryptococcal immune responses.
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Affiliation(s)
- Chrissy M Leopold Wager
- Department of Biology, University of Texas, San Antonio, TX 78249; South Texas Center for Emerging Infectious Diseases, University of Texas, San Antonio, TX 78249
| | - Camaron R Hole
- Department of Biology, University of Texas, San Antonio, TX 78249; South Texas Center for Emerging Infectious Diseases, University of Texas, San Antonio, TX 78249
| | - Karen L Wozniak
- Department of Biology, University of Texas, San Antonio, TX 78249; South Texas Center for Emerging Infectious Diseases, University of Texas, San Antonio, TX 78249
| | - Michal A Olszewski
- Veterans Affairs Ann Arbor Health System, University of Michigan Health System, Ann Arbor, MI 48109; and Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Floyd L Wormley
- Department of Biology, University of Texas, San Antonio, TX 78249; South Texas Center for Emerging Infectious Diseases, University of Texas, San Antonio, TX 78249;
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The local immune response to intraocular Toxoplasma re-challenge: less pathology and better parasite control through Treg/Th1/Th2 induction. Int J Parasitol 2013; 43:721-8. [PMID: 23702129 DOI: 10.1016/j.ijpara.2013.04.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/09/2013] [Accepted: 04/10/2013] [Indexed: 01/10/2023]
Abstract
Ocular toxoplasmosis is a major cause of blindness world-wide. Ocular involvement is frequently seen following congenital infection. Many of these infections are quiescent but pose a life-time risk of reactivation. However, the physiopathology of ocular toxoplasmosis reactivation is largely unexplored. We previously developed a Swiss-Webster outbred mouse model for congenital toxoplasmosis by neonatal injection of Toxoplasma gondii cysts. We also used a mouse model of direct intraocular infection to show a deleterious local T helper 17 type response upon primary infection. In the present study, our two models were combined to study intravitreal re-challenge of neonatally infected mice, as an approximate model of reactivation, in comparison with a primary ocular infection. Using BioPlex proteomic assays in aqueous humour and reverse transcription-PCR for T helper cell transcription factors, we observed diminished T helper 17 type reaction in reinfection, compared with primary infection. In contrast, T helper 2 and T regulatory responses were enhanced. Interestingly, this was also true for T helper 1 markers such as IFN-γ, which was paralleled by better parasite control. Secretion of IL-27, a central cytokine for shifting the immune response from T helper 17 to T helper 1, was also greatly enhanced. We observed a similar protective immune reaction pattern in the eye upon reinfection with the virulent RH strain, with the notable exception of IFN-γ. In summary, our results show that the balance is shifted from T helper 17 to a less pathogenic but more effective anti-parasite Treg/T helper 1/T helper 2 pattern in a reactivation setting.
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Schneider AG, Abi Abdallah DS, Butcher BA, Denkers EY. Toxoplasma gondii triggers phosphorylation and nuclear translocation of dendritic cell STAT1 while simultaneously blocking IFNγ-induced STAT1 transcriptional activity. PLoS One 2013; 8:e60215. [PMID: 23527309 PMCID: PMC3603897 DOI: 10.1371/journal.pone.0060215] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 02/23/2013] [Indexed: 12/29/2022] Open
Abstract
The protozoan Toxoplasma gondii actively modulates cytokine-induced JAK/STAT signaling pathways to facilitate survival within the host, including blocking IFNγ-mediated STAT1-dependent proinflammatory gene expression. We sought to further characterize inhibition of STAT1 signaling in infected murine dendritic cells (DC) because this cell type has not previously been examined, yet is known to serve as an early target of in vivo infection. Unexpectedly, we discovered that T. gondii infection alone induced sustained STAT1 phosphorylation and nuclear translocation in DC in a parasite strain-independent manner. Maintenance of STAT1 phosphorylation required active invasion but intracellular parasite replication was dispensable. The parasite rhoptry protein ROP16, recently shown to mediate STAT3 and STAT6 phosphorylation, was not required for STAT1 phosphorylation. In combination with IFNγ, T. gondii induced synergistic STAT1 phosphorylation and binding of aberrant STAT1-containing complexes to IFNγ consensus sequence oligonucleotides. Despite these findings, parasite infection blocked STAT1 binding to the native promoters of the IFNγ-inducible genes Irf-1 and Lrg47, along with subsequent gene expression. These results reinforce the importance of parasite-mediated blockade of IFNγ responses in dendritic cells, while simultaneously showing that T. gondii alone induces STAT1 phosphorylation.
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Affiliation(s)
- Anne G. Schneider
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Delbert S. Abi Abdallah
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Barbara A. Butcher
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Eric Y. Denkers
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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Kemp LE, Yamamoto M, Soldati-Favre D. Subversion of host cellular functions by the apicomplexan parasites. FEMS Microbiol Rev 2012. [PMID: 23186105 DOI: 10.1111/1574-6976.12013] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Rhoptries are club-shaped secretory organelles located at the anterior pole of species belonging to the phylum of Apicomplexa. Parasites of this phylum are responsible for a huge burden of disease in humans and animals and a loss of economic productivity. Members of this elite group of obligate intracellular parasites include Plasmodium spp. that cause malaria and Cryptosporidium spp. that cause diarrhoeal disease. Although rhoptries are almost ubiquitous throughout the phylum, the relevance and role of the proteins contained within the rhoptries varies. Rhoptry contents separate into two intra-organellar compartments, the neck and the bulb. A number of rhoptry neck proteins are conserved between species and are involved in functions such as host cell invasion. The bulb proteins are less well-conserved and probably evolved for a particular lifestyle. In the majority of species studied to date, rhoptry content is involved in formation and maintenance of the parasitophorous vacuole; however some species live free within the host cytoplasm. In this review, we will summarise the knowledge available regarding rhoptry proteins. Specifically, we will discuss the role of the rhoptry kinases that are used by Toxoplasma gondii and other coccidian parasites to subvert the host cellular functions and prevent parasite death.
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Affiliation(s)
- Louise E Kemp
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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Boisson-Dupuis S, Kong XF, Okada S, Cypowyj S, Puel A, Abel L, Casanova JL. Inborn errors of human STAT1: allelic heterogeneity governs the diversity of immunological and infectious phenotypes. Curr Opin Immunol 2012; 24:364-78. [PMID: 22651901 PMCID: PMC3477860 DOI: 10.1016/j.coi.2012.04.011] [Citation(s) in RCA: 204] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 04/30/2012] [Indexed: 01/04/2023]
Abstract
The genetic dissection of various human infectious diseases has led to the definition of inborn errors of human STAT1 immunity of four types, including (i) autosomal recessive (AR) complete STAT1 deficiency, (ii) AR partial STAT1 deficiency, (iii) autosomal dominant (AD) STAT1 deficiency, and (iv) AD gain of STAT1 activity. The two types of AR STAT1 defect give rise to a broad infectious phenotype with susceptibility to intramacrophagic bacteria (mostly mycobacteria) and viruses (herpes viruses at least), due principally to the impairment of IFN-γ-mediated and IFN-α/β-mediated immunity, respectively. Clinical outcome depends on the extent to which the STAT1 defect decreases responsiveness to these cytokines. AD STAT1 deficiency selectively predisposes individuals to mycobacterial disease, owing to the impairment of IFN-γ-mediated immunity, as IFN-α/β-mediated immunity is maintained. Finally, AD gain of STAT1 activity is associated with autoimmunity, probably owing to an enhancement of IFN-α/β-mediated immunity. More surprisingly, it is also associated with chronic mucocutaneous candidiasis, through as yet undetermined mechanisms involving an inhibition of the development of IL-17-producing T cells. Thus, germline mutations in human STAT1 define four distinct clinical disorders. Various combinations of viral, mycobacterial and fungal infections are therefore allelic at the human STAT1 locus. These experiments of Nature neatly highlight the clinical and immunological impact of the human genetic dissection of infectious phenotypes.
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Affiliation(s)
- Stephanie Boisson-Dupuis
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA.
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Involvement of Stat1 in the phagocytosis of M. avium. Clin Dev Immunol 2012; 2012:652683. [PMID: 22811740 PMCID: PMC3395244 DOI: 10.1155/2012/652683] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/24/2012] [Accepted: 04/09/2012] [Indexed: 01/14/2023]
Abstract
Mycobacterium avium is an intracellular pathogen preferentially infecting human macrophages where they activate the JAK/STAT1 pathway. This activation enhances the survival of infected cells, but, at the same time, makes macrophages optimal targets for drugs development against p-tyr701stat1. In this study, we demonstrate that the fast and transient activity of the JAK/STAT1 pathway occurs immediately after macrophages internalization of heat-killed M. avium or inert particles. Furthermore, we show that a persistent Stat1 pathway activation occurs only when an intracellular M. avium infection is established in macrophages. These results strongly indicate different mechanisms of p-tyr701Stat1 activation. In particular, here we report findings aiming at explaining the short-time enhancement of p-tyr701Stat1 and shows its predominant relationship with FcγRs engagement during the internalization process. Furthermore, we demonstrate that opsonized live M. avium is phagocytosed by macrophages involving membrane receptors not related with JAK/STAT1 signalling pathway. On the contrary, heat-inactivated bacilli or latex particles seem to be internalized only after involvement of FcγRs and subsequent Stat1 phosphorylation.
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Jardin C, Sticht H. Identification of the Structural Features that Mediate Binding Specificity in the Recognition of STAT Proteins by Dual-Specificity Phosphatases. J Biomol Struct Dyn 2012; 29:777-92. [DOI: 10.1080/07391102.2012.10507413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Egan CE, Cohen SB, Denkers EY. Insights into inflammatory bowel disease using Toxoplasma gondii as an infectious trigger. Immunol Cell Biol 2011; 90:668-75. [PMID: 22064707 DOI: 10.1038/icb.2011.93] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Oral infection of certain inbred mouse strains with the protozoan Toxoplasma gondii triggers inflammatory pathology resembling lesions seen during human inflammatory bowel disease, in particular Crohn's disease (CD). Damage triggered by the parasite is largely localized to the distal portion of the small intestine, and as such is one of only a few models for ileal inflammation. This is important because ileal involvement is a characteristic of CD in over two-thirds of patients. The disease induced by Toxoplasma is mediated by Th1 cells and the cytokines tumor necrosis factor-α and interferon-γ. Inflammation is dependent upon IL-23, also identified by genome-wide association studies as a risk factor in CD. Development of lesions is concomitant with emergence of E. coli that display enhanced adhesion to the intestinal epithelium and subepithelial translocation. Furthermore, depletion of gut flora renders mice resistant to Toxoplasma-triggered ileitis. Recent findings suggest complex CCR2-dependent interactions between lamina propria T cells and intraepithelial lymphocytes in fueling proinflammatory pathology in the intestine. The advantage of the Toxoplasma model is that disease develops rapidly (within 7-10 days of infection) and can be induced in immunodeficient mice by adoptive transfer of mucosal T cells from infected donors. We propose that Toxoplasma acts as a trigger setting into motion a series of events culminating in loss of tolerance in the intestine and emergence of pathogenic T cell effectors. The Toxoplasma trigger model is providing new leaps in our understanding of immunity in the intestine.
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Affiliation(s)
- Charlotte E Egan
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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Li J, Bessho K, Shivakumar P, Mourya R, Mohanty SK, Dos Santos JL, Miura IK, Porta G, Bezerra JA. Th2 signals induce epithelial injury in mice and are compatible with the biliary atresia phenotype. J Clin Invest 2011; 121:4244-56. [PMID: 22005305 DOI: 10.1172/jci57728] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 09/07/2011] [Indexed: 12/13/2022] Open
Abstract
Biliary atresia (BA) is a destructive cholangiopathy of childhood in which Th1 immunity has been mechanistically linked to the bile duct inflammation and obstruction that culminate in liver injury. Based on reports of decreased Th1 cytokines in some patients and the development of BA in mice lacking CD4+ T cells, we hypothesized that Th1-independent mechanisms can also activate effector cells and induce BA. Here, we tested this hypothesis using Stat1-/- mice, which lack the ability to mount Th1 immune responses. Infection of Stat1-/- mice with rhesus rotavirus type A (RRV) on postnatal day 1 induced a prominent Th2 response, duct epithelial injury and obstruction within 7 days, and atresia shortly thereafter. A high degree of phosphorylation of the Th2 transcription factor Stat6 was observed; however, concurrent inactivation of Stat1 and Stat6 in mice did not prevent BA after RRV infection. In contrast, depletion of macrophages or combined loss of Il13 and Stat1 reduced tissue infiltration by lymphocytes and myeloid cells, maintained epithelial integrity, and prevented duct obstruction. In concordance with our mouse model, humans at the time of BA diagnosis exhibited differential hepatic expression of Th2 genes and serum Th2 cytokines. These findings demonstrate compatibility between Th2 commitment and the pathogenesis of BA, and suggest that patient subgrouping in future clinical trials should account for differences in Th2 status.
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Affiliation(s)
- Jun Li
- Cincinnati Children’s Hospital Medical Center and the Department of Pediatrics of the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Portillo JAC, Okenka G, Reed E, Subauste A, Van Grol J, Gentil K, Komatsu M, Tanaka K, Landreth G, Levine B, Subauste CS. The CD40-autophagy pathway is needed for host protection despite IFN-Γ-dependent immunity and CD40 induces autophagy via control of P21 levels. PLoS One 2010; 5:e14472. [PMID: 21217818 PMCID: PMC3013095 DOI: 10.1371/journal.pone.0014472] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 12/03/2010] [Indexed: 02/02/2023] Open
Abstract
Autophagy degrades pathogens in vitro. The autophagy gene Atg5 has been reported to be required for IFN-γ-dependent host protection in vivo. However, these protective effects occur independently of autophagosome formation. Thus, the in vivo role of classic autophagy in protection conferred by adaptive immunity and how adaptive immunity triggers autophagy are incompletely understood. Employing biochemical, genetic and morphological studies, we found that CD40 upregulates the autophagy molecule Beclin 1 in microglia and triggers killing of Toxoplasma gondii dependent on the autophagy machinery. Infected CD40(-/-) mice failed to upregulate Beclin 1 in microglia/macrophages in vivo. Autophagy-deficient Beclin 1(+/-) mice, mice with deficiency of the autophagy protein Atg7 targeted to microglia/macrophages as well as CD40(-/-) mice exhibited impaired killing of T. gondii and were susceptible to cerebral and ocular toxoplasmosis. Susceptibility to toxoplasmosis occurred despite upregulation of IFN-γ, TNF-α and NOS2, preservation of IFN-γ-induced microglia/macrophage anti-T. gondii activity and the generation of anti-T. gondii T cell immunity. CD40 upregulated Beclin 1 and triggered killing of T. gondii by decreasing protein levels of p21, a molecule that degrades Beclin 1. These studies identified CD40-p21-Beclin 1 as a pathway by which adaptive immunity stimulates autophagy. In addition, they support that autophagy is a mechanism through which CD40-dependent immunity mediates in vivo protection and that the CD40-autophagic machinery is needed for host resistance despite IFN-γ.
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Affiliation(s)
- Jose-Andres C. Portillo
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Genevieve Okenka
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Erin Reed
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Angela Subauste
- Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Jennifer Van Grol
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Katrin Gentil
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Masaaki Komatsu
- Laboratory for Frontier Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Keiji Tanaka
- Laboratory for Frontier Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Gary Landreth
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Beth Levine
- Department of Internal Medicine, Department of Microbiology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Carlos S. Subauste
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * E-mail:
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Tait ED, Jordan KA, Dupont CD, Harris TH, Gregg B, Wilson EH, Pepper M, Dzierszinski F, Roos DS, Hunter CA. Virulence of Toxoplasma gondii is associated with distinct dendritic cell responses and reduced numbers of activated CD8+ T cells. THE JOURNAL OF IMMUNOLOGY 2010; 185:1502-12. [PMID: 20592284 DOI: 10.4049/jimmunol.0903450] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Toxoplasma gondii population consists of multiple strains, defined by genotype and virulence. Previous studies have established that protective immunity to this organism is mediated by IL-12, which drives T cells to produce IFN-gamma. Paradoxically, although type I and type II strains of T. gondii both induce IL-12 and IFN-gamma in the mouse, type I parasites are lethal, whereas type II strains establish chronic infection. The cellular basis for these strain-dependent differences remains unclear. To better understand these events, the CD8(+) T cell and dendritic cell (DC) responses to transgenic, OVA-expressing type I RH (RH OVA) and type II Prugniuad (Pru OVA) parasites were examined. Pru OVA-infected mice developed a robust DC response at the site of infection and the draining lymph node and generated a population of endogenous OVA-specific CD8(+) T cells. In contrast, RH OVA-infected mice had fewer DCs and OVA-specific CD8(+) T cells. RH OVA-infected mice given preactivated OVA-specific CD8(+) T cells were protected, suggesting that reduced DC-derived signals contributed to the low OVA-specific CD8(+) T cell numbers observed during type I infection. Indeed, DC depletion prior to Pru OVA infection resulted in a failure to generate activated OVA-specific CD8(+) T cells, and IL-12p70 treatment during RH OVA infection modestly increased the number of Ag-specific cells. Together, these data are consistent with a model of immunity to T. gondii in which strain-dependent DC responses shape the generation of Ag-specific CD8(+) T cells and determine the outcome of infection.
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Affiliation(s)
- Elia D Tait
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Room H310F Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104, USA
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