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Ribeiro E. Silva A, Diallo MA, Sausset A, Robert T, Bach S, Bussière FI, Laurent F, Lacroix-Lamandé S, Silvestre A. Overexpression of Eimeria tenella Rhoptry Kinase 2 Induces Early Production of Schizonts. Microbiol Spectr 2023; 11:e0013723. [PMID: 37260371 PMCID: PMC10434272 DOI: 10.1128/spectrum.00137-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/04/2023] [Indexed: 06/02/2023] Open
Abstract
Eimeria tenella is an obligate intracellular parasite responsible for avian coccidiosis. Like other apicomplexan parasites, such as Toxoplasma gondii, cell invasion and intracellular development rely on apical organelle content discharge, named micronemes and rhoptries. Some rhoptry (ROP) kinases (ROPK) are key virulence factors in T. gondii. To date, among the 28 ropk genes carried by E. tenella, only two to four were confirmed by proteomic analysis or immunostaining to be expressed at the sporozoite stage. We have previously shown that EtROP1 is implicated in the inhibition of host cell apoptosis by interacting with the cellular p53. This work functionally described the second ROP kinase expressed at the sporozoite stage in E. tenella. EtROP2 is an active kinase that phosphorylates cell substrates of approximately 50 kDa. Its overexpression leads to the shortening of the prepatent period and to the early development of first-generation schizonts. Conduction of RNA sequencing analysis and reverse transcriptase quantitative PCR (RT-qPCR) on the host cell allowed us to identify the mitogen-activated protein kinase (MAPK) pathway and the transcription factor cFos to be upregulated by EtROP2. We also showed by immunofluorescence assay that the active kinase EtROP2 is implicated in the p38 MAPK pathway activation. We established here that EtROP2 activates the p38 MAPK pathway through a direct or indirect phosphorylation, leading to the overexpression of the master transcription factor cFos known to be implicated in E. tenella development. IMPORTANCE Rhoptries are specialized secretory organelles found in zoite stages of apicomplexan parasites. In addition to well-conserved rhoptry neck proteins, their protein consists mostly of kinase proteins, highly divergent from eukaryotic kinases. Some of those kinases are described as major virulence factors in Toxoplasma gondii, secreted into the host cell to hijack signaling pathways. Most of those kinases remain to be characterized in Eimeria tenella. Deciphering their cellular function is a prerequisite to supporting their relevance as a druggable target in development of new means of Eimeria tenella control. Secreted divergent kinases that interact with host cell partners to modulate pathways are good candidates, as they coevolve with their host targets to ensure their function within the host and are less prone to mutations that would lead to drug resistance. The absence of any orthologous kinase in host cells makes these parasite kinases a promising drug target candidate.
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Affiliation(s)
| | | | - Alix Sausset
- ISP, INRAE, Université de Tours, Nouzilly, France
| | - Thomas Robert
- Sorbonne Université, CNRS, UMR 8227, Integrative Biology of Marine Models Laboratory (LBI2M), Station Biologique de Roscoff, Roscoff, France
- Sorbonne Université, CNRS, FR 2424, Plateforme de Criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, Roscoff, France
| | - Stéphane Bach
- Sorbonne Université, CNRS, UMR 8227, Integrative Biology of Marine Models Laboratory (LBI2M), Station Biologique de Roscoff, Roscoff, France
- Sorbonne Université, CNRS, FR 2424, Plateforme de Criblage KISSf (Kinase Inhibitor Specialized Screening Facility), Station Biologique de Roscoff, Roscoff, France
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
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Neubert P, Homann A, Wendelborn D, Bär AL, Krampert L, Trum M, Schröder A, Ebner S, Weichselbaum A, Schatz V, Linz P, Veelken R, Schulte-Schrepping J, Aschenbrenner AC, Quast T, Kurts C, Geisberger S, Kunzelmann K, Hammer K, Binger KJ, Titze J, Müller DN, Kolanus W, Schultze JL, Wagner S, Jantsch J. NCX1 represents an ionic Na+ sensing mechanism in macrophages. PLoS Biol 2020; 18:e3000722. [PMID: 32569301 PMCID: PMC7307728 DOI: 10.1371/journal.pbio.3000722] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/22/2020] [Indexed: 01/20/2023] Open
Abstract
Inflammation and infection can trigger local tissue Na+ accumulation. This Na+-rich environment boosts proinflammatory activation of monocyte/macrophage-like cells (MΦs) and their antimicrobial activity. Enhanced Na+-driven MΦ function requires the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5), which augments nitric oxide (NO) production and contributes to increased autophagy. However, the mechanism of Na+ sensing in MΦs remained unclear. High extracellular Na+ levels (high salt [HS]) trigger a substantial Na+ influx and Ca2+ loss. Here, we show that the Na+/Ca2+ exchanger 1 (NCX1, also known as solute carrier family 8 member A1 [SLC8A1]) plays a critical role in HS-triggered Na+ influx, concomitant Ca2+ efflux, and subsequent augmented NFAT5 accumulation. Moreover, interfering with NCX1 activity impairs HS-boosted inflammatory signaling, infection-triggered autolysosome formation, and subsequent antibacterial activity. Taken together, this demonstrates that NCX1 is able to sense Na+ and is required for amplifying inflammatory and antimicrobial MΦ responses upon HS exposure. Manipulating NCX1 offers a new strategy to regulate MΦ function.
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Affiliation(s)
- Patrick Neubert
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Arne Homann
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - David Wendelborn
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Anna-Lorena Bär
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Luka Krampert
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Maximilian Trum
- Department of Internal Medicine II, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Agnes Schröder
- Institute of Orthodontics, University Hospital of Regensburg, Regensburg, Germany
| | - Stefan Ebner
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Andrea Weichselbaum
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Valentin Schatz
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Peter Linz
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Roland Veelken
- Department of Internal Medicine 4, University Hospital Erlangen, Erlangen, Germany
| | - Jonas Schulte-Schrepping
- Department for Genomics and Immunoregulation, Life and Medical Sciences (LIMES) Institute, University of Bonn, Bonn, Germany
| | - Anna C. Aschenbrenner
- Department for Genomics and Immunoregulation, Life and Medical Sciences (LIMES) Institute, University of Bonn, Bonn, Germany
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Thomas Quast
- Molecular Immunology and Cell Biology LIMES Institute, University of Bonn, Bonn, Germany
| | - Christian Kurts
- Institute of Experimental Immunology, University of Bonn, Bonn, Germany
| | - Sabrina Geisberger
- Experimental and Clinical Research Center (ECRC), a cooperation of Charité-Universitätsmedizin Berlin and Max Delbruck Center for Molecular Medicine, Berlin, Germany
- Max Delbruck Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Karl Kunzelmann
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Karin Hammer
- Department of Internal Medicine II, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Katrina J. Binger
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Jens Titze
- Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore
| | - Dominik N. Müller
- Experimental and Clinical Research Center (ECRC), a cooperation of Charité-Universitätsmedizin Berlin and Max Delbruck Center for Molecular Medicine, Berlin, Germany
- Max Delbruck Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Waldemar Kolanus
- Molecular Immunology and Cell Biology LIMES Institute, University of Bonn, Bonn, Germany
| | - Joachim L. Schultze
- Department for Genomics and Immunoregulation, Life and Medical Sciences (LIMES) Institute, University of Bonn, Bonn, Germany
- Platform for Single Cell Genomics & Epigenomics at the German Center for Neurodegenerative Diseases (DZNE) and the University of Bonn, Bonn, Germany
| | - Stefan Wagner
- Department of Internal Medicine II, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, University Hospital of Regensburg and University of Regensburg, Regensburg, Germany
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Lopez Corcino Y, Gonzalez Ferrer S, Mantilla LE, Trikeriotis S, Yu JS, Kim S, Hansen S, Portillo JAC, Subauste CS. Toxoplasma gondii induces prolonged host epidermal growth factor receptor signalling to prevent parasite elimination by autophagy: Perspectives for in vivo control of the parasite. Cell Microbiol 2019; 21:e13084. [PMID: 31290228 PMCID: PMC6771541 DOI: 10.1111/cmi.13084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/03/2019] [Accepted: 07/07/2019] [Indexed: 12/23/2022]
Abstract
Toxoplasma gondii causes retinitis and encephalitis. Avoiding targeting by autophagosomes is key for its survival because T. gondii cannot withstand lysosomal degradation. During invasion of host cells, T. gondii triggers epidermal growth factor receptor (EGFR) signalling enabling the parasite to avoid initial autophagic targeting. However, autophagy is a constitutive process indicating that the parasite may also use a strategy operative beyond invasion to maintain blockade of autophagic targeting. Finding that such a strategy exists would be important because it could lead to inhibition of host cell signalling as a novel approach to kill the parasite in previously infected cells and treat toxoplasmosis. We report that T. gondii induced prolonged EGFR autophosphorylation. This effect was mediated by PKCα/PKCβ ➔ Src because T. gondii caused prolonged activation of these molecules and their knockdown or incubation with inhibitors of PKCα/PKCβ or Src after host cell invasion impaired sustained EGFR autophosphorylation. Addition of EGFR tyrosine kinase inhibitor (TKI) to previously infected cells led to parasite entrapment by LC3 and LAMP-1 and pathogen killing dependent on the autophagy proteins ULK1 and Beclin 1 as well as lysosomal enzymes. Administration of gefitinib (EGFR TKI) to mice with ocular and cerebral toxoplasmosis resulted in disease control that was dependent on Beclin 1. Thus, T. gondii promotes its survival through sustained EGFR signalling driven by PKCα/β ➔ Src, and inhibition of EGFR controls pre-established toxoplasmosis.
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Affiliation(s)
| | - Shekina Gonzalez Ferrer
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | | | - Sophia Trikeriotis
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jin-Sang Yu
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Steven Kim
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Samuel Hansen
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jose-Andres C Portillo
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Carlos S Subauste
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA.,Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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He C, Kong L, Puthiyakunnon S, Wei HX, Zhou LJ, Peng HJ. iTRAQ-based phosphoproteomic analysis reveals host cell's specific responses to Toxoplasma gondii at the phases of invasion and prior to egress. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1867:202-212. [PMID: 30576742 DOI: 10.1016/j.bbapap.2018.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 10/27/2022]
Abstract
Protein phosphorylation plays a key role in host cell-T. gondii interaction. However, the phosphoproteome data of host cell at various phases of T. gondii infection has not been thoroughly described. In this study, we assessed the host phosphoproteome data with isobaric tags for relative and absolute quantification (iTRAQ) method during the phases of T. gondii invasion (30 min post infection, PI) and prior to egress (28 h PI). Our iTRAQ analysis revealed a total of 665 phosphoproteins, among which the significantly regulated phosphoproteins in different between-group comparisons were further analyzed. Functional analysis of these significantly regulated phosphoproteins suggested that T. gondii modulated host cell processes through phosphorylation including cell cycle regulation, inducing apoptosis, blocking the synthesis of some inflammatory factors, mediating metabolism to support its proliferation at the infection phase prior to egress, and utilizing membrane and energy from host cell, reorganizing cytoskeleton to favor its invasion and PV formation at the phase of invasion. The phosphorylation level of Smad2, CTNNA1, and HSPB1 identified with western blot revealed a consistent trend of change with iTRAQ result. These newly identified and significantly regulated phosphoproteins from our phosphoproteome data may provide new clues to unravel the host cell's complex reaction against T. gondii infection and the interaction between the host cell and T. gondii.
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Affiliation(s)
- Cheng He
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China; Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou 221004, Jiangsu Province, China
| | - Ling Kong
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Santhosh Puthiyakunnon
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Hai-Xia Wei
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Li-Juan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Hong-Juan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China.
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Yang J, Du F, Zhou X, Wang L, Li S, Fang R, Zhao J. Brain proteomic differences between wild-type and CD44- mice induced by chronic Toxoplasma gondii infection. Parasitol Res 2018; 117:2623-2633. [PMID: 29948204 DOI: 10.1007/s00436-018-5954-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 05/31/2018] [Indexed: 11/29/2022]
Abstract
Chronic clinical Toxoplasma gondii (T. gondii) infection is the primary disease state that causes severe encephalitis. CD44 is a member of the cell adhesion molecule family and plays an important role in T. gondii infection. However, proteomic changes in CD44 during chronic T. gondii infection have rarely been reported. Thus, an iTRAQ-based proteomic study coupled with 2D-LC-MS/MS analysis was performed to screen CD44-related proteins during chronic T. gondii infection. As a result, a total of 2612 proteins were reliably identified and quantified. Subsequently, 259, 106, and 249 differentially expressed proteins (DEPs) were compared between CD44- mice (A) vs wild-type mice (B), B vs wild-type mice infected with T. gondii (C), and C vs CD44- mice infected with T. gondii (D). Gene ontology, KEGG pathway, and protein-protein interaction analyses were performed on the DEPs. According to the results, immune-related proteins were altered significantly among the A vs B, B vs C, and C vs D comparisons, which might indicate that chronic T. gondii infection caused changes in the host immune response. Additionally, Ca2+- and metabolism-related proteins were upregulated in C vs D, which supported the hypothesis that CD44 mediated the production of host Ca2+ and IFN-γ and that the parasite preferentially invaded cells expressing high levels of CD44. The present findings validate and enable a more comprehensive knowledge of the role of CD44 in hosts chronically infected with T. gondii, thus providing new ideas for future studies on the specific functions of CD44 in latent toxoplasmosis.
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Affiliation(s)
- Jing Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Fen Du
- Hubei Centre for Animal Diseases Control and Prevention, Wuhan, 430070, Hubei, People's Republic of China
| | - Xiaoliu Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Lixia Wang
- Hubei Provincial Centre for Diseases Control and Prevention, Wuhan, 430079, Hubei, People's Republic of China
| | - Senyang Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Rui Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
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Koh HJ, Kim YR, Kim JS, Yun JS, Jang K, Yang CS. Toxoplasma gondii GRA7-Targeted ASC and PLD1 Promote Antibacterial Host Defense via PKCα. PLoS Pathog 2017; 13:e1006126. [PMID: 28125719 PMCID: PMC5268361 DOI: 10.1371/journal.ppat.1006126] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 12/14/2016] [Indexed: 11/19/2022] Open
Abstract
Tuberculosis is a global health problem and at least one-third of the world’s population is infected with Mycobacterium tuberculosis (MTB). MTB is a successful pathogen that enhances its own intracellular survival by inhibiting inflammation and arresting phago-lysosomal fusion. We previously demonstrated that Toxoplasma gondii (T. gondii) dense granule antigen (GRA) 7 interacts with TNF receptor-associated factor 6 via Myeloid differentiation primary response gene 88, enabling innate immune responses in macrophages. To extend these studies, we found that GRA7 interacts with host proteins involved in antimicrobial host defense mechanisms as a therapeutic strategy for tuberculosis. Here, we show that protein kinase C (PKC)α-mediated phosphorylation of T. gondii GRA7-I (Ser52) regulates the interaction of GRA7 with PYD domain of apoptosis-associated speck-like protein containing a carboxy-terminal CARD, which is capable of oligomerization and inflammasome activation can lead to antimicrobial defense against MTB. Furthermore, GRA7-III interacted with the PX domain of phospholipase D1, facilitating its enzyme activity, phago-lysosomal maturation, and subsequent antimicrobial activity in a GRA7-III (Ser135) phosphorylation-dependent manner via PKCα. Taken together, these results underscore a previously unrecognized role of GRA7 in modulating antimicrobial host defense mechanism during mycobacterial infection. We previously demonstrated that Toxoplasma gondii (T. gondii) dense granule antigen (GRA) 7 interacts with TRAF6 via MyD88, enabling innate immune responses in macrophages and effective protection against T. gondii infection in vivo. However, its exact role and how it regulates host innate immune responses have not been fully explained. Herein, we show that PKCα-mediated phosphorylation of GRA7 is essential for the interaction between GRA7 and ASC or PLD1, which can promote antimicrobial defense against Mycobacterium tuberculosis (MTB). Notably, PKCα specifically phosphorylated Ser52 and Ser135 of GRA7 in vitro and in vivo, indicating that GRA7 is a substrate of PKCα. The N-terminal of GRA7 (GRA7-I) was sufficient for interaction with the PYD domain of ASC, which is capable of ASC oligomerization and inflammasome activation. Furthermore, GRA7-III interacted with the PX domain of PLD1, facilitating its enzyme activity, phago-lysosomal maturation, and subsequent antimicrobial activity in a GRA7 phosphorylation-dependent manner. Interestingly, phosphomimetic mutation in GRA7 overcame the need for PKCα. Collectively, these results provide novel insight into how GRA7 can promote ASC and PLD1 activation in a PKCα-dependent manner as an antimicrobial host defense mechanism.
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Affiliation(s)
- Hyun-Jung Koh
- Department of Molecular and Life Science, College of Science and Technology, Hanyang University, Ansan, S. Korea
| | - Ye-Ram Kim
- Department of Molecular and Life Science, College of Science and Technology, Hanyang University, Ansan, S. Korea
| | - Jae-Sung Kim
- Department of Molecular and Life Science, College of Science and Technology, Hanyang University, Ansan, S. Korea
| | - Jin-Seung Yun
- Department of Molecular and Life Science, College of Science and Technology, Hanyang University, Ansan, S. Korea
| | - Kiseok Jang
- Department of Pathology, College of Medicine, Hanyang University, Seoul, S. Korea
| | - Chul-Su Yang
- Department of Molecular and Life Science, College of Science and Technology, Hanyang University, Ansan, S. Korea
- * E-mail:
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Mota CM, Oliveira ACM, Davoli-Ferreira M, Silva MV, Santiago FM, Nadipuram SM, Vashisht AA, Wohlschlegel JA, Bradley PJ, Silva JS, Mineo JR, Mineo TWP. Neospora caninum Activates p38 MAPK as an Evasion Mechanism against Innate Immunity. Front Microbiol 2016; 7:1456. [PMID: 27679624 PMCID: PMC5020094 DOI: 10.3389/fmicb.2016.01456] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/31/2016] [Indexed: 01/08/2023] Open
Abstract
Due to the high prevalence and economic impact of neosporosis, the development of safe and effective vaccines and therapies against this parasite has been a priority in the field and is crucial to limit horizontal and vertical transmission in natural hosts. Limited data is available regarding factors that regulate the immune response against this parasite and such knowledge is essential in order to understand Neospora caninum induced pathogenesis. Mitogen-activated protein kinases (MAPKs) govern diverse cellular processes, including growth, differentiation, apoptosis, and immune-mediated responses. In that sense, our goal was to understand the role of MAPKs during the infection by N. caninum. We found that p38 phosphorylation was quickly triggered in macrophages stimulated by live tachyzoites and antigen extracts, while its chemical inhibition resulted in upregulation of IL-12p40 production and augmented B7/MHC expression. In vivo blockade of p38 resulted in an amplified production of cytokines, which preceded a reduction in latent parasite burden and enhanced survival against the infection. Additionally, the experiments indicate that the p38 activation is induced by a mechanism that depends on GPCR, PI3K and AKT signaling pathways, and that the phenomena here observed is distinct that those induced by Toxoplasma gondii’s GRA24 protein. Altogether, these results showed that N. caninum manipulates p38 phosphorylation in its favor, in order to downregulate the host’s innate immune responses. Additionally, those results infer that active interference in this signaling pathway may be useful for the development of a new therapeutic strategy against neosporosis.
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Affiliation(s)
- Caroline M Mota
- Laboratory of Immunoparasitology "Dr. Mário Endsfeldz Camargo," Department of Immunology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Ana C M Oliveira
- Laboratory of Immunoparasitology "Dr. Mário Endsfeldz Camargo," Department of Immunology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Marcela Davoli-Ferreira
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo Ribeirão Preto, Brazil
| | - Murilo V Silva
- Laboratory of Immunoparasitology "Dr. Mário Endsfeldz Camargo," Department of Immunology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Fernanda M Santiago
- Laboratory of Immunoparasitology "Dr. Mário Endsfeldz Camargo," Department of Immunology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Santhosh M Nadipuram
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles CA, USA
| | - Ajay A Vashisht
- Department of Biological Chemistry and Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles CA, USA
| | - James A Wohlschlegel
- Department of Biological Chemistry and Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles CA, USA
| | - Peter J Bradley
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los AngelesCA, USA; Molecular Biology Institute, University of California, Los Angeles, Los AngelesCA, USA
| | - João S Silva
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo Ribeirão Preto, Brazil
| | - José R Mineo
- Laboratory of Immunoparasitology "Dr. Mário Endsfeldz Camargo," Department of Immunology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Tiago W P Mineo
- Laboratory of Immunoparasitology "Dr. Mário Endsfeldz Camargo," Department of Immunology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
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Xiao B, Kuang Z, Zhan Y, Chen D, Gao Y, Li M, Luo S, Hao W. A Novel Polyclonal Antiserum against Toxoplasma gondii Sodium Hydrogen Exchanger 1. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:21-9. [PMID: 26951975 PMCID: PMC4792324 DOI: 10.3347/kjp.2016.54.1.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022]
Abstract
The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
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Affiliation(s)
- Bin Xiao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Zhenzhan Kuang
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yanli Zhan
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Daxiang Chen
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Yang Gao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Ming Li
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Shuhong Luo
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
| | - Wenbo Hao
- State Key Laboratory of Organ Failure, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Biotechnology, Southern Medical University, Guangzhou 510515, People's Republic of China
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de Carvalho TMU, Barrias ES, de Souza W. Macropinocytosis: a pathway to protozoan infection. Front Physiol 2015; 6:106. [PMID: 25914647 PMCID: PMC4391238 DOI: 10.3389/fphys.2015.00106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/17/2015] [Indexed: 11/13/2022] Open
Abstract
Among the various endocytic mechanisms in mammalian cells, macropinocytosis involves internalization of large amounts of plasma membrane together with extracellular medium, leading to macropinosome formation. These structures are formed when plasma membrane ruffles are assembled after actin filament rearrangement. In dendritic cells, macropinocytosis has been reported to play a role in antigen presentation. Several intracellular pathogens are internalized by host cells via multiple endocytic pathways and macropinocytosis has been described as an important entry site for various organisms. Some bacteria, such as Legionella pneumophila, as well as various viruses, use this pathway to penetrate and subvert host cells. Some protozoa, which are larger than bacteria and virus, can also use this pathway to invade host cells. As macropinocytosis is characterized by the formation of large uncoated vacuoles and is triggered by various signaling pathways, which is similar to what occurs during the formation of the majority of parasitophorous vacuoles, it is believed that this phenomenon may be more widely used by parasites than is currently appreciated. Here we review protozoa host cell invasion via macropinocytosis.
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Affiliation(s)
- Tecia M U de Carvalho
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciência da Saúde, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil ; Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens e Centro Nacional de Bioimagens-CENABIO, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Emile S Barrias
- Instituto Nacional de Metrologia, Qualidade e Tecnologia-Inmetro Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciência da Saúde, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil ; Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens e Centro Nacional de Bioimagens-CENABIO, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
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Li Z, Hao Y, Wang L, Xiang H, Zhou Z. Genome-wide identification and comprehensive analyses of the kinomes in four pathogenic microsporidia species. PLoS One 2014; 9:e115890. [PMID: 25549259 PMCID: PMC4280135 DOI: 10.1371/journal.pone.0115890] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/02/2014] [Indexed: 11/18/2022] Open
Abstract
Microsporidia have attracted considerable attention because they infect a wide range of hosts, from invertebrates to vertebrates, and cause serious human diseases and major economic losses in the livestock industry. There are no prospective drugs to counteract this pathogen. Eukaryotic protein kinases (ePKs) play a central role in regulating many essential cellular processes and are therefore potential drug targets. In this study, a comprehensive summary and comparative analysis of the protein kinases in four microsporidia–Enterocytozoon bieneusi, Encephalitozoon cuniculi, Nosema bombycis and Nosema ceranae–was performed. The results show that there are 34 ePKs and 4 atypical protein kinases (aPKs) in E. bieneusi, 29 ePKs and 6 aPKs in E. cuniculi, 41 ePKs and 5 aPKs in N. bombycis, and 27 ePKs and 4 aPKs in N. ceranae. These data support the previous conclusion that the microsporidian kinome is the smallest eukaryotic kinome. Microsporidian kinomes contain only serine-threonine kinases and do not contain receptor-like and tyrosine kinases. Many of the kinases related to nutrient and energy signaling and the stress response have been lost in microsporidian kinomes. However, cell cycle-, development- and growth-related kinases, which are important to parasites, are well conserved. This reduction of the microsporidian kinome is in good agreement with genome compaction, but kinome density is negatively correlated with proteome size. Furthermore, the protein kinases in each microsporidian genome are under strong purifying selection pressure. No remarkable differences in kinase family classification, domain features, gain and/or loss, and selective pressure were observed in these four species. Although microsporidia adapt to different host types, the coevolution of microsporidia and their hosts was not clearly reflected in the protein kinases. Overall, this study enriches and updates the microsporidian protein kinase database and may provide valuable information and candidate targets for the design of treatments for pathogenic diseases.
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Affiliation(s)
- Zhi Li
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Youjin Hao
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Linling Wang
- College of Life Sciences, Chongqing Normal University, Chongqing, China
| | - Heng Xiang
- College of Animal Science and Technology, Southwest University, Chongqing, China
| | - Zeyang Zhou
- College of Life Sciences, Chongqing Normal University, Chongqing, China
- The State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- * E-mail:
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11
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Bougdour A, Tardieux I, Hakimi MA. Toxoplasmaexports dense granule proteins beyond the vacuole to the host cell nucleus and rewires the host genome expression. Cell Microbiol 2014; 16:334-43. [DOI: 10.1111/cmi.12255] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Alexandre Bougdour
- CNRS; UMR5163; LAPM; Grenoble 38041 France
- Université Joseph Fourier; Grenoble 38000 France
| | - Isabelle Tardieux
- Institut Cochin; INSERM U1016; CNRS UMR 8104; Université Paris Descartes; Paris 75014 France
| | - Mohamed-Ali Hakimi
- CNRS; UMR5163; LAPM; Grenoble 38041 France
- Université Joseph Fourier; Grenoble 38000 France
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12
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Braun L, Brenier-Pinchart MP, Yogavel M, Curt-Varesano A, Curt-Bertini RL, Hussain T, Kieffer-Jaquinod S, Coute Y, Pelloux H, Tardieux I, Sharma A, Belrhali H, Bougdour A, Hakimi MA. A Toxoplasma dense granule protein, GRA24, modulates the early immune response to infection by promoting a direct and sustained host p38 MAPK activation. ACTA ACUST UNITED AC 2013; 210:2071-86. [PMID: 24043761 PMCID: PMC3782045 DOI: 10.1084/jem.20130103] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Toxoplasma gondii secretes a novel dense granule protein, GRA24, that traffics from the vacuole to the host cell nucleus where it prolongs p38a activation and correlates with proinflammatory cytokine production. Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan parasite that resides inside a parasitophorous vacuole. During infection, Toxoplasma actively remodels the transcriptome of its hosting cells with profound and coupled impact on the host immune response. We report that Toxoplasma secretes GRA24, a novel dense granule protein which traffics from the vacuole to the host cell nucleus. Once released into the host cell, GRA24 has the unique ability to trigger prolonged autophosphorylation and nuclear translocation of the host cell p38α MAP kinase. This noncanonical kinetics of p38α activation correlates with the up-regulation of the transcription factors Egr-1 and c-Fos and the correlated synthesis of key proinflammatory cytokines, including interleukin-12 and the chemokine MCP-1, both known to control early parasite replication in vivo. Remarkably, the GRA24–p38α complex is defined by peculiar structural features and uncovers a new regulatory signaling path distinct from the MAPK signaling cascade and otherwise commonly activated by stress-related stimuli or various intracellular microbes.
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Affiliation(s)
- Laurence Braun
- Centre National de la Recherche Scientifique (CNRS), UMR5163, Laboratoire Adaptation et Pathogénie des Microorganismes, F-38041 Grenoble, France
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13
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Smith NL, Abi Abdallah DS, Butcher BA, Denkers EY, Baird B, Holowka D. Toxoplasma gondii inhibits mast cell degranulation by suppressing phospholipase Cγ-mediated Ca(2+) mobilization. Front Microbiol 2013; 4:179. [PMID: 23847603 PMCID: PMC3701878 DOI: 10.3389/fmicb.2013.00179] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/14/2013] [Indexed: 12/21/2022] Open
Abstract
Toxoplasma gondii is well-known to subvert normal immune responses, however, mechanisms are incompletely understood. In particular, its capacity to alter receptor-activated Ca2+-mediated signaling processes has not been well-characterized. In initial experiments, we found evidence that T. gondii infection inhibits Ca2+ responses to fMetLeuPhe in murine macrophages. To further characterize the mechanism of inhibition of Ca2+ mobilization by T. gondii, we used the well-studied RBL mast cell model to probe the capacity of T. gondii to modulate IgE receptor-activated signaling within the first hour of infection. Ca2+ mobilization that occurs via IgE/FcεRI signaling leads to granule exocytosis in mast cells. We found that T. gondii inhibits antigen-stimulated degranulation in infected cells in a strain-independent manner. Under these conditions, we found that cytoplasmic Ca2+ mobilization, particularly antigen-mediated Ca2+ release from intracellular stores, is significantly reduced. Furthermore, stimulation-dependent activation of Syk kinase leading to tyrosine phosphorylation and activation of phospholipase Cγ is inhibited by infection. Therefore, we conclude that inhibitory effects of infection are likely due to parasite-mediated inhibition of the tyrosine kinase signaling cascade that results in reduced hydrolysis of phosphatidylinositol 4,5-bisphosphate. Interestingly, inhibition of IgE/FcεRI signaling persists when tachyzoite invasion is arrested via cytochalasin D treatment, suggesting inhibition is mediated by a parasite-derived factor secreted into the cells during the invasion process. Our study provides direct evidence that immune subversion by T. gondii is initiated concurrently with invasion.
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Affiliation(s)
- Norah L Smith
- Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University Ithaca, NY, USA
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14
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Li RW, Schroeder SG. Cytoskeleton remodeling and alterations in smooth muscle contractility in the bovine jejunum during nematode infection. Funct Integr Genomics 2011; 12:35-44. [PMID: 22203460 DOI: 10.1007/s10142-011-0259-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/28/2011] [Accepted: 12/05/2011] [Indexed: 11/27/2022]
Abstract
Gastrointestinal nematodes of the genus Cooperia are arguably the most important parasites of cattle. The bovine jejunal transcriptome was characterized in response to Cooperia oncophora infection using RNA-seq technology. Approximately 71% of the 25,670 bovine genes were detected in the jejunal transcriptome. However, 16,552 genes were expressed in all samples tested, probably representing the core component of the transcriptome. Twenty of the most abundant genes accounted for 12.7% of the sequences from the transcriptome. A 164-h infection seemingly induced a minor change in the transcriptome (162 genes). Additionally, a total of 162,412 splice junctions were identified. Among them, 1,164 appeared unique to 1 of the 2 groups: 868 splice junctions were observed only in infected animals, while 278 were only present in all 4 control animals. Biological functions associated with muscle contraction were predominant Gene Ontology terms enriched in the genes differentially expressed by infection. The primary function of two of the four regulatory networks impacted was related to skeletal and muscular systems. A total of 34 pathways were significantly impacted by infection. Several pathways were directly related to host immune responses, such as acute phase response, leukocyte extravasation, and antigen presentation, consistent with previous findings. Calcium signaling and actin cytoskeleton signaling were among the pathways most significantly impacted by infection in the bovine jejunum. Together, these data suggest that smooth muscle hypercontractility may be initiated as a result of a primary C. oncophora infection, which may represent a mechanism for host responses in the jejunum during nematode infection.
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Affiliation(s)
- Robert W Li
- Bovine Functional Genomics Laboratory, Animal and Natural Resources Institute, USDA-ARS, Beltsville, MD 20705, USA.
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15
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Effect of macrophage migration inhibitory factor (MIF) in human placental explants infected with Toxoplasma gondii depends on gestational age. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:2792-801. [PMID: 21641401 DOI: 10.1016/j.ajpath.2011.02.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 02/22/2011] [Accepted: 02/28/2011] [Indexed: 12/13/2022]
Abstract
Because macrophage migration inhibitory factor (MIF) is a key cytokine in pregnancy and has a role in inflammatory response and pathogen defense, the objective of the present study was to investigate the effects of MIF in first- and third-trimester human placental explants infected with Toxoplasma gondii. Explants were treated with recombinant MIF, IL-12, interferon-γ, transforming growth factor-β1, or IL-10, followed by infection with T. gondii RH strain tachyzoites. Supernatants of cultured explants were assessed for MIF production. Explants were processed for morphologic analysis, immunohistochemistry, and real-time PCR analysis. Comparison of infected and stimulated explants versus noninfected control explants demonstrated a significant increase in MIF release in first-trimester but not third-trimester explants. Tissue parasitism was higher in third- than in first-trimester explants. Moreover, T. gondii DNA content was lower in first-trimester explants treated with MIF compared with untreated explants. However, in third-trimester explants, MIF stimulus decreased T. gondii DNA content only at the highest concentration of the cytokine. In addition, high expression of MIF receptor was observed in first-trimester placental explants, whereas MIF receptor expression was low in third-trimester explants. In conclusion, MIF was up-regulated and demonstrated to be important for control of T. gondii infection in first-trimester explants, whereas lack of MIF up-regulation in third-trimester placentas may be involved in higher susceptibility to infection at this gestational age.
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16
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Wiley M, Teygong C, Phelps E, Radke J, Blader IJ. Serum response factor regulates immediate early host gene expression in Toxoplasma gondii-infected host cells. PLoS One 2011; 6:e18335. [PMID: 21479245 PMCID: PMC3066233 DOI: 10.1371/journal.pone.0018335] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 02/25/2011] [Indexed: 11/02/2022] Open
Abstract
Toxoplasma gondii is a wide spread pathogen that can cause severe and even fatal disease in fetuses and immune-compromised hosts. As an obligate intracellular parasite, Toxoplasma must alter the environment of its host cell in order to establish its replicative niche. This is accomplished, in part, by secretion of factors into the host cell that act to modulate processes such as transcription. Previous studies demonstrated that genes encoding transcription factors such as c-jun, junB, EGR1, and EGR2 were amongst the host genes that were the most rapidly upregulated following infection. In cells stimulated with growth factors, these genes are regulated by a transcription factor named Serum Response Factor. Serum Response Factor is a ubiquitously expressed DNA binding protein that regulates growth and actin cytoskeleton genes via MAP kinase or actin cytoskeletal signaling, respectively. Here, we report that Toxoplasma infection leads to the rapid activation of Serum Response Factor. Serum Response Factor activation is a Toxoplasma-specific event since the transcription factor is not activated by the closely related protozoan parasite, Neospora caninum. We further demonstrate that Serum Response Factor activation requires a parasite-derived secreted factor that signals via host MAP kinases but independently of the host actin cytoskeleton. Together, these data define Serum Response Factor as a host cell transcription factor that regulates immediate early gene expression in Toxoplasma-infected cells.
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Affiliation(s)
- Mandi Wiley
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Crystal Teygong
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Eric Phelps
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Jay Radke
- Department of Veterinary Molecular Biology & the Center for Immunotherapies to Zoonotic Diseases, Montana State University, Bozeman, Montana, United States of America
| | - Ira J. Blader
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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17
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Bansal K, Balaji KN. Intracellular pathogen sensor NOD2 programs macrophages to trigger Notch1 activation. J Biol Chem 2010; 286:5823-35. [PMID: 21156799 DOI: 10.1074/jbc.m110.192393] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Intracellular pathogen sensor, NOD2, has been implicated in regulation of wide range of anti-inflammatory responses critical during development of a diverse array of inflammatory diseases; however, underlying molecular details are still imprecisely understood. In this study, we demonstrate that NOD2 programs macrophages to trigger Notch1 signaling. Signaling perturbations or genetic approaches suggest signaling integration through cross-talk between Notch1-PI3K during the NOD2-triggered expression of a multitude of immunological parameters including COX-2/PGE(2) and IL-10. NOD2 stimulation enhanced active recruitment of CSL/RBP-Jk on the COX-2 promoter in vivo. Intriguingly, nitric oxide assumes critical importance in NOD2-mediated activation of Notch1 signaling as iNOS(-/-) macrophages exhibited compromised ability to execute NOD2-triggered Notch1 signaling responses. Correlative evidence demonstrates that this mechanism operates in vivo in brain and splenocytes derived from wild type, but not from iNOS(-/-) mice. Importantly, NOD2-driven activation of the Notch1-PI3K signaling axis contributes to its capacity to impart survival of macrophages against TNF-α or IFN-γ-mediated apoptosis and resolution of inflammation. Current investigation identifies Notch1-PI3K as signaling cohorts involved in the NOD2-triggered expression of a battery of genes associated with anti-inflammatory functions. These findings serve as a paradigm to understand the pathogenesis of NOD2-associated inflammatory diseases and clearly pave a way toward development of novel therapeutics.
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Affiliation(s)
- Kushagra Bansal
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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18
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Tomita T, Yamada T, Weiss LM, Orlofsky A. Externally triggered egress is the major fate of Toxoplasma gondii during acute infection. THE JOURNAL OF IMMUNOLOGY 2009; 183:6667-80. [PMID: 19846885 DOI: 10.4049/jimmunol.0900516] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The apicomplexan parasite Toxoplasma gondii expands during acute infection via a cycle of invasion, intracellular replication, and lytic egress. Physiological regulation has not yet been demonstrated for either invasion or egress. We now report that, in contrast to cell culture systems, in which egress occurs only after five or more parasite divisions (2-3 days), intracellular residence is strikingly abbreviated in inflammatory cells in vivo, and early egress (after zero to two divisions) is the dominant parasite fate in acutely infected mice. Adoptive transfer experiments demonstrate rapid, reciprocal, kinetically uniform parasite transfer between donor and recipient compartments, with a t(1/2) of approximately 3 h. Inflammatory macrophages are major participants in this cycle of lytic egress and reinfection, which drives rapid macrophage turnover. Inflammatory triggering cells, principally macrophages, elicit egress in infected target macrophages, a process we term externally triggered egress (ETE). The mechanism of ETE does not require reactive oxygen or nitrogen species, the mitochondrial permeability transition pore, or a variety of signal transduction mediators, but is dependent on intracellular calcium and is highly sensitive to SB203580, an inhibitor of p38 MAPK as well as a related parasite-encoded kinase. SB203580 both inhibited the initiation of ETE and altered the progression of egress. Parasites recently completing a cycle of egress and reinfection were preferentially restricted in vivo, supporting a model in which ETE may favor host defense by a process of haven disruption. ETE represents a novel example of interaction between a parasite infectious cycle and host microenvironment.
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Affiliation(s)
- Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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19
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Toxoplasma gondii rhoptry discharge correlates with activation of the early growth response 2 host cell transcription factor. Infect Immun 2008; 76:4703-12. [PMID: 18678671 DOI: 10.1128/iai.01447-07] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous apicomplexan parasite that can cause severe disease in fetuses and immune-compromised patients. Rhoptries, micronemes, and dense granules, which are secretory organelles unique to Toxoplasma and other apicomplexan parasites, play critical roles in parasite growth and virulence. To understand how these organelles modulate infected host cells, we sought to identify host cell transcription factors triggered by their release. Early growth response 2 (EGR2) is a host cell transcription factor that is rapidly upregulated and activated in Toxoplasma-infected cells but not in cells infected with the closely related apicomplexan parasite Neospora caninum. EGR2 upregulation occurred only when live parasites were in direct contact with the host cell and not from exposure to cell extracts that contain dense granule or micronemal proteins. When microneme-mediated attachment was blocked by pretreating parasites with a calcium chelator, EGR2 expression was significantly reduced. In contrast, when host cells were infected with parasites in the presence of cytochalasin D, which allows rhoptry secretion but prevents parasite invasion, EGR2 was activated. Finally, we demonstrate that Toxoplasma activation of host p38 mitogen-activated protein kinase is necessary but not sufficient for EGR2 activation. Collectively, these data indicate that EGR2 is specifically upregulated by a parasite-derived secreted factor that is most likely a resident rhoptry protein.
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Lee CW, Sukhumavasi W, Denkers EY. Phosphoinositide-3-kinase-dependent, MyD88-independent induction of CC-type chemokines characterizes the macrophage response to Toxoplasma gondii strains with high virulence. Infect Immun 2007; 75:5788-97. [PMID: 17908814 PMCID: PMC2168350 DOI: 10.1128/iai.00821-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chemokines play an important role in inflammation and infection due to their ability to recruit cells of innate and adaptive immunity. Here we examined mouse macrophage chemokine responses during intracellular infections with high- and low-virulence Toxoplasma gondii strains. The high-virulence type I strain RH induced a large panel of CC-type chemokines, whereas responses elicited by strains PTG (type II) and M7741 (type III) were much weaker. Strikingly, the T. gondii-induced chemokine response occurred independently of signaling through the Toll-like receptor adaptor MyD88. Instead, production of chemokines during infection was heavily dependent upon phosphoinositide-3-kinase signaling pathways. Because infection with type I strains such as RH results in an uncontrolled proinflammatory cytokine response, we hypothesize that this virulence phenotype is a consequence of early strong induction of chemokines by type I, but not type II or III, Toxoplasma strains.
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Affiliation(s)
- Chiang W Lee
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA
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21
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Masek KS, Zhu P, Freedman BD, Hunter CA. Toxoplasma gondiiinduces changes in intracellular calcium in macrophages. Parasitology 2007; 134:1973-9. [PMID: 17767794 DOI: 10.1017/s0031182007003447] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYToxoplasma gondiiis an obligate intracellular parasite that interacts with calcium storage organelles and induces calcium-dependent signalling in macrophages. This study was performed to determine whetherToxoplasmainduces changes in intracellular calcium in these cells. Ratiometric imaging of live, Fura-2 loaded macrophages challenged withT. gondiirevealed robust elevations in intracellular calcium. These elevations were late in onset, beginning 15–20 min after addition of parasites and occurred in up to 20% of macrophages in an imaging field. Further characterization of these events revealed that they follow from challenge with liveT. gondii, but not heat-killed parasites or solubleToxoplasmaantigen (STAg). Parasite-induced calcium elevations derived from extracellular sources, and were independent of host recognition factors MyD88 and CCR5. These findings indicate thatToxoplasma gondiialters calcium homeostasis in macrophages and this activity is independent of known pathways involved in the innate recognition of this organism.
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Affiliation(s)
- K S Masek
- Department of Pathobiology, School of Veterinary Medicine, Room 313, Hill Pavilion, 380 South University Avenue, University of Pennsylvania, Philadelphia, PA 19104, USA
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22
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Liu CH, Machado FS, Guo R, Nichols KE, Burks AW, Aliberti JC, Zhong XP. Diacylglycerol kinase zeta regulates microbial recognition and host resistance to Toxoplasma gondii. ACTA ACUST UNITED AC 2007; 204:781-92. [PMID: 17371930 PMCID: PMC2118554 DOI: 10.1084/jem.20061856] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mammalian Toll-like receptors (TLRs) recognize microbial pathogen-associated molecular patterns and are critical for innate immunity against microbial infection. Diacylglycerol (DAG) kinases (DGKs) regulate the intracellular levels of two important second messengers involved in signaling from many surface receptors by converting DAG to phosphatidic acid (PA). We demonstrate that the ζ isoform of the DGK family (DGKζ) is expressed in macrophages (Mφ) and dendritic cells. DGKζ deficiency results in impaired interleukin (IL) 12 and tumor necrosis factor α production following TLR stimulation in vitro and in vivo, increased resistance to endotoxin shock, and enhanced susceptibility to Toxoplasma gondii infection. We further show that DGKζ negatively controls the phosphatidylinositol 3–kinase (PI3K)–Akt pathway and that inhibition of PI3K activity or treatment with PA can restore lipopolysaccharide-induced IL-12 production by DGKζ-deficient Mφ. Collectively, our data provide the first genetic evidence that an enzyme involved in DAG/PA metabolism plays an important role in innate immunity and indicate that DGKζ promotes TLR responses via a pathway involving inhibition of PI3K.
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Affiliation(s)
- Cheng-Hu Liu
- Department of Pediatrics-Allergy and Immunology, Duke University Medical Center, Durham, NC 27710, USA
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