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Son S, Park SR. Plant translational reprogramming for stress resilience. FRONTIERS IN PLANT SCIENCE 2023; 14:1151587. [PMID: 36909402 PMCID: PMC9998923 DOI: 10.3389/fpls.2023.1151587] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Organisms regulate gene expression to produce essential proteins for numerous biological processes, from growth and development to stress responses. Transcription and translation are the major processes of gene expression. Plants evolved various transcription factors and transcriptome reprogramming mechanisms to dramatically modulate transcription in response to environmental cues. However, even the genome-wide modulation of a gene's transcripts will not have a meaningful effect if the transcripts are not properly biosynthesized into proteins. Therefore, protein translation must also be carefully controlled. Biotic and abiotic stresses threaten global crop production, and these stresses are seriously deteriorating due to climate change. Several studies have demonstrated improved plant resistance to various stresses through modulation of protein translation regulation, which requires a deep understanding of translational control in response to environmental stresses. Here, we highlight the translation mechanisms modulated by biotic, hypoxia, heat, and drought stresses, which are becoming more serious due to climate change. This review provides a strategy to improve stress tolerance in crops by modulating translational regulation.
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Guo X, Qi H, Lin G, Yu J, Zhang M, Gao X. ARID3A plays a key regulatory role in palmitic acid-stimulated milk fat synthesis in mouse mammary epithelial cells. Cell Biol Int 2023; 47:1106-1117. [PMID: 36786478 DOI: 10.1002/cbin.12003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/18/2023] [Accepted: 02/05/2023] [Indexed: 02/15/2023]
Abstract
Palmitic acid (PA) can stimulate milk fat synthesis in mammary gland, but the specific mechanism is still unclear. In our research, we aim to explore the role and corresponding mechanism of AT-rich interaction domain 3A (ARID3A) in milk fat synthesis stimulated by PA. We found that ARID3A protein level in mouse mammary gland tissues during lactation was much higher than that during puberty and involution. ARID3A knockdown and gene activation showed that ARID3A stimulated the synthesis of triglycerides and cholesterol in HC11 cells, secretion of free fatty acids from cells and lipid droplet formation in cells. ARID3A also promoted the expression and maturation of SREBP1 in HC11 cells. PA stimulated ARID3A protein expression and SREBP1 expression and maturation in a dose-dependent manner, and the PI3K specific inhibitor LY294002 blocked the stimulation of PA on ARID3A expression. ARID3A knockdown blocked the stimulation of PA on SREBP1 protein expression and maturation. We further showed that ARID3A was localized in the nucleus and PA stimulated this localization, and ARID3A knockdown blocked the stimulation of PA on the mRNA expression of SREBP1. To sum up, our data reveal that ARID3A is a key mediator for PA to promote SREBP1 mRNA expression and stimulate milk fat synthesis in mammary epithelial cells.
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Affiliation(s)
- Xudong Guo
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Hao Qi
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Gang Lin
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Jiaxiao Yu
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Minghui Zhang
- College of Animal Science, Yangtze University, Jingzhou, China
| | - Xuejun Gao
- College of Animal Science, Yangtze University, Jingzhou, China
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Fraschilla I, Evavold CL. Biting the hand that feeds: Metabolic determinants of cell fate during infection. Front Immunol 2022; 13:923024. [DOI: 10.3389/fimmu.2022.923024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Metabolic shifts can occur in cells of the innate immune system in response to microbial infection. Whether these metabolic shifts benefit host defense and propagation of an immune response appears to be context dependent. In an arms race, host-adapted microbes and mammalian cells vie for control of biosynthetic machinery, organelles, and metabolites. Herein, we discuss the intersection of host metabolism and cell-intrinsic immunity with implications for cell fate during infection. Sensation of microbial ligands in isolation results in host metabolic shifts that imbues normal innate immune function, such as cytokine secretion. However, living microbes have an arsenal of effectors and strategies to subvert cell-intrinsic immune responses by manipulating host metabolism. Consequently, host metabolism is monitored as an indicator of invasion or manipulation by a pathogen, primarily through the actions of guard proteins and inflammasome pathways. In this review, we frame initiation of cell-intrinsic immunity in the context of host metabolism to include a physiologic “Goldilocks zone” of allowable shifts with guard circuits monitoring wide perturbations away from this zone for the initiation of innate immune responses. Through comparison of studies with purified microbial ligands, dead microbes, and live pathogens we may begin to understand how shifts in metabolism determine the outcome of host-pathogen interactions.
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Liu J, Gao M, Yang Z, Zhao Y, Guo K, Sun B, Gao Z, Wang L. Macrophages and Metabolic Reprograming in the Tumor Microenvironment. Front Oncol 2022; 12:795159. [PMID: 35242705 PMCID: PMC8885627 DOI: 10.3389/fonc.2022.795159] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/21/2022] [Indexed: 12/12/2022] Open
Abstract
Due to the emergence of traditional drug resistance in tumor treatment, the anti-cancer therapies are facing multiple challenges. Immunotherapy, as a new and universal treatment, has been gradually concerned. The macrophages, as an important part of the immune system, play an important role in it. Many studies have shown that immune state is essential in cancer progression and prognosis, rebuilding the architecture and functional orientation of the tumor region. Most tumors are complex ecosystems that change temporally and spatially under the pressure of proliferation, apoptosis, and extension of every cell in the microenvironment. Here, we review how macrophages states can be dynamically altered in different metabolic states and we also focus on the formation of immune exhaustion. Finally, we look forward to the explorations of clinical treatment for immune metabolism process.
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Affiliation(s)
- Jin Liu
- Engineering Research Center for New Materials and Precision Treatment Technology of Malignant Tumors Therapy, Dalian Medical University, Dalian, China
- Engineering Technology Research Center for Translational Medicine, Dalian Medical University, Dalian, China
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Mingwei Gao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Zhou Yang
- Engineering Research Center for New Materials and Precision Treatment Technology of Malignant Tumors Therapy, Dalian Medical University, Dalian, China
| | - Yidan Zhao
- Engineering Technology Research Center for Translational Medicine, Dalian Medical University, Dalian, China
| | - Kun Guo
- Engineering Research Center for New Materials and Precision Treatment Technology of Malignant Tumors Therapy, Dalian Medical University, Dalian, China
- Engineering Technology Research Center for Translational Medicine, Dalian Medical University, Dalian, China
| | - Binwen Sun
- Engineering Research Center for New Materials and Precision Treatment Technology of Malignant Tumors Therapy, Dalian Medical University, Dalian, China
- Engineering Technology Research Center for Translational Medicine, Dalian Medical University, Dalian, China
| | - Zhenming Gao
- Engineering Research Center for New Materials and Precision Treatment Technology of Malignant Tumors Therapy, Dalian Medical University, Dalian, China
- Engineering Technology Research Center for Translational Medicine, Dalian Medical University, Dalian, China
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Liming Wang
- Engineering Research Center for New Materials and Precision Treatment Technology of Malignant Tumors Therapy, Dalian Medical University, Dalian, China
- Engineering Technology Research Center for Translational Medicine, Dalian Medical University, Dalian, China
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
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Hu J, Gao Q, Yang Y, Xia J, Zhang W, Chen Y, Zhou Z, Chang L, Hu Y, Zhou H, Liang L, Li X, Long Q, Wang K, Huang A, Tang N. Hexosamine biosynthetic pathway promotes the antiviral activity of SAMHD1 by enhancing O-GlcNAc transferase-mediated protein O-GlcNAcylation. Am J Cancer Res 2021; 11:805-823. [PMID: 33391506 PMCID: PMC7738853 DOI: 10.7150/thno.50230] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
Rationale: Viruses hijack the host cell machinery to promote viral replication; however, the mechanism by which metabolic reprogramming regulates innate antiviral immunity in the host remains elusive. Herein, we explore how the hexosamine biosynthesis pathway (HBP) and O-linked-N-acetylglucosaminylation (O-GlcNAcylation) regulate host antiviral response against hepatitis B virus (HBV) in vitro and in vivo. Methods: We conducted a metabolomics assay to evaluate metabolic responses of host cells to HBV infection. We systematically explored the role of HBP and protein O-GlcNAcylation in regulating HBV infection in cell and mouse models. O-linked N-acetylglucosamine (O-GlcNAc) target proteins were identified via liquid chromatography-tandem mass spectrometry (LC-MS) and co-immunoprecipitation assays. Additionally, we also examined uridine diphosphate (UDP)-GlcNAc biosynthesis and O-GlcNAcylation levels in patients with chronic hepatitis B (CHB). Results: HBV infection upregulated GLUT1 expression on the hepatocyte surface and facilitated glucose uptake, which provides substrates to HBP to synthesize UDP-GlcNAc, leading to an increase in protein O-GlcNAcylation. Pharmacological or transcriptional inhibition of HBP and O-GlcNAcylation promoted HBV replication. Mechanistically, O-GlcNAc transferase (OGT)-mediated O-GlcNAcylation of sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1) on Ser93 stabilizes SAMHD1 and enhances its antiviral activity. Analysis of clinical samples revealed that UDP-GlcNAc level was increased, and SAMHD1 was O-GlcNAcylated in patients with CHB. Conclusions: HBP-mediated O-GlcNAcylation positively regulates host antiviral response against HBV in vitro and in vivo. The findings reveal a link between HBP, O-GlcNAc modification, and innate antiviral immunity by targeting SAMHD1.
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Kumar M, Skillman K, Duraisingh MT. Linking nutrient sensing and gene expression in Plasmodium falciparum blood-stage parasites. Mol Microbiol 2020; 115:891-900. [PMID: 33236377 DOI: 10.1111/mmi.14652] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/17/2020] [Accepted: 11/20/2020] [Indexed: 12/21/2022]
Abstract
Malaria is one of the most life-threatening infectious diseases worldwide, caused by infection of humans with parasites of the genus Plasmodium. The complex life cycle of Plasmodium parasites is shared between two hosts, with infection of multiple cell types, and the parasite needs to adapt for survival and transmission through significantly different metabolic environments. Within the blood-stage alone, parasites encounter changing levels of key nutrients, including sugars, amino acids, and lipids, due to differences in host dietary nutrition, cellular tropism, and pathogenesis. In this review, we consider the mechanisms that the most lethal of malaria parasites, Plasmodium falciparum, uses to sense nutrient levels and elicit changes in gene expression during blood-stage infections. These changes are brought about by several metabolic intermediates and their corresponding sensor proteins. Sensing of distinct nutritional signals can drive P. falciparum to alter the key blood-stage processes of proliferation, antigenic variation, and transmission.
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Affiliation(s)
- Manish Kumar
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Kristen Skillman
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
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Aminoacyl-tRNA synthetase inhibition activates a pathway that branches from the canonical amino acid response in mammalian cells. Proc Natl Acad Sci U S A 2020; 117:8900-8911. [PMID: 32253314 DOI: 10.1073/pnas.1913788117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Signaling pathways that sense amino acid abundance are integral to tissue homeostasis and cellular defense. Our laboratory has previously shown that halofuginone (HF) inhibits the prolyl-tRNA synthetase catalytic activity of glutamyl-prolyl-tRNA synthetase (EPRS), thereby activating the amino acid response (AAR). We now show that HF treatment selectively inhibits inflammatory responses in diverse cell types and that these therapeutic benefits occur in cells that lack GCN2, the signature effector of the AAR. Depletion of arginine, histidine, or lysine from cultured fibroblast-like synoviocytes recapitulates key aspects of HF treatment, without utilizing GCN2 or mammalian target of rapamycin complex 1 pathway signaling. Like HF, the threonyl-tRNA synthetase inhibitor borrelidin suppresses the induction of tissue remodeling and inflammatory mediators in cytokine-stimulated fibroblast-like synoviocytes without GCN2, but both aminoacyl-tRNA synthetase (aaRS) inhibitors are sensitive to the removal of GCN1. GCN1, an upstream component of the AAR pathway, binds to ribosomes and is required for GCN2 activation. These observations indicate that aaRS inhibitors, like HF, can modulate inflammatory response without the AAR/GCN2 signaling cassette, and that GCN1 has a role that is distinct from its activation of GCN2. We propose that GCN1 participates in a previously unrecognized amino acid sensor pathway that branches from the canonical AAR.
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8
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Nouwen LV, Everts B. Pathogens MenTORing Macrophages and Dendritic Cells: Manipulation of mTOR and Cellular Metabolism to Promote Immune Escape. Cells 2020; 9:cells9010161. [PMID: 31936570 PMCID: PMC7017145 DOI: 10.3390/cells9010161] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/01/2020] [Accepted: 01/07/2020] [Indexed: 02/06/2023] Open
Abstract
Myeloid cells, including macrophages and dendritic cells, represent an important first line of defense against infections. Upon recognition of pathogens, these cells undergo a metabolic reprogramming that supports their activation and ability to respond to the invading pathogens. An important metabolic regulator of these cells is mammalian target of rapamycin (mTOR). During infection, pathogens use host metabolic pathways to scavenge host nutrients, as well as target metabolic pathways for subversion of the host immune response that together facilitate pathogen survival. Given the pivotal role of mTOR in controlling metabolism and DC and macrophage function, pathogens have evolved strategies to target this pathway to manipulate these cells. This review seeks to discuss the most recent insights into how pathogens target DC and macrophage metabolism to subvert potential deleterious immune responses against them, by focusing on the metabolic pathways that are known to regulate and to be regulated by mTOR signaling including amino acid, lipid and carbohydrate metabolism, and autophagy.
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Liu X, Afrin T, Pajerowska-Mukhtar KM. Arabidopsis GCN2 kinase contributes to ABA homeostasis and stomatal immunity. Commun Biol 2019; 2:302. [PMID: 31428690 PMCID: PMC6687712 DOI: 10.1038/s42003-019-0544-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/28/2019] [Indexed: 12/28/2022] Open
Abstract
General Control Non-derepressible 2 (GCN2) is an evolutionarily conserved serine/threonine kinase that modulates amino acid homeostasis in response to nutrient deprivation in yeast, human and other eukaryotes. However, the GCN2 signaling pathway in plants remains largely unknown. Here, we demonstrate that in Arabidopsis, bacterial infection activates AtGCN2-mediated phosphorylation of eIF2α and promotes TBF1 translational derepression. Consequently, TBF1 regulates a subset of abscisic acid signaling components to modulate pre-invasive immunity. We show that GCN2 fine-tunes abscisic acid accumulation and signaling during both pre-invasive and post-invasive stages of an infection event. Finally, we also demonstrate that AtGCN2 participates in signaling triggered by phytotoxin coronatine secreted by P. syringae. During the preinvasive phase, AtGCN2 regulates stomatal immunity by affecting pathogen-triggered stomatal closure and coronatine-mediated stomatal reopening. Our conclusions support a conserved role of GCN2 in various forms of immune responses across kingdoms, highlighting GCN2's importance in studies on both plant and mammalian immunology.
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Affiliation(s)
- Xiaoyu Liu
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., Birmingham, AL 35294 USA
- Present Address: Bayer Crop Science, 800 N Lindbergh Blvd., Creve Coeur, MO 63144 USA
| | - Taiaba Afrin
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., Birmingham, AL 35294 USA
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Remodeling mTORC1 Responsiveness to Amino Acids by the Herpes Simplex Virus UL46 and Us3 Gene Products Supports Replication during Nutrient Insufficiency. J Virol 2018; 92:JVI.01377-18. [PMID: 30282708 DOI: 10.1128/jvi.01377-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 09/26/2018] [Indexed: 12/20/2022] Open
Abstract
By sensing fundamental parameters, including nutrient availability, activated mechanistic target of rapamycin complex 1 (mTORC1) suppresses catabolic outcomes and promotes anabolic processes needed for herpes simplex virus 1 (HSV-1) productive growth. While the virus-encoded Us3 Ser/Thr kinase is required to activate mTORC1, whether stress associated with amino acid insufficiency impacts mTORC1 activation in infected cells and virus reproduction was unknown. In contrast to uninfected cells, where amino acid withdrawal inhibits mTORC1 activation, we demonstrate that mTORC1 activity is sustained in HSV-1-infected cells during amino acid insufficiency. We show that in the absence of Us3, the insensitivity of mTORC1 to amino acid withdrawal in infected cells was dependent on the host kinase Akt and establish a role for the HSV-1 UL46 gene product, which stimulates phosphatidylinositol (PI) 3-kinase signaling. Significantly, virus reproduction during amino acid insufficiency was stimulated by the viral UL46 gene product. By synergizing with Us3, UL46 reprograms mTORC1 such that it is insensitive to amino acid withdrawal and supports sustained mTORC1 activation and virus reproduction during amino acid insufficiency. This identifies an unexpected function for UL46 in supporting virus reproduction during physiological stress and identifies a new class of virus-encoded mTORC1 regulators that selectively uncouple mTORC1 activation from amino acid sufficiency.IMPORTANCE Mechanistic target of rapamycin complex 1 (mTORC1) is a multisubunit cellular kinase that coordinates protein synthesis with changing amino acid levels. During amino acid insufficiency, mTORC1 is repressed in uninfected cells, dampening protein synthesis and potentially restricting virus reproduction. Here, we establish that HSV-1 alters the responsiveness of mTORC1 to metabolic stress resulting from amino acid insufficiency. Unlike in uninfected cells, mTORC1 remains activated in HSV-1-infected cells deprived of amino acids. Synergistic action of the HSV-1 UL46 gene product, which stimulates PI 3-kinase, and the Us3 kinase supports virus reproduction during amino acid withdrawal. These results define how HSV-1, a medically important human pathogen associated with a range of diseases, uncouples mTORC1 activation from amino acid availability. Furthermore, they help explain how the virus reproduces during physiological stress. Reproduction triggered by physiological stress is characteristic of herpesvirus infections, where lifelong latency is punctuated by episodic reactivation events.
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11
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Bretin A, Lucas C, Larabi A, Dalmasso G, Billard E, Barnich N, Bonnet R, Nguyen HTT. AIEC infection triggers modification of gut microbiota composition in genetically predisposed mice, contributing to intestinal inflammation. Sci Rep 2018; 8:12301. [PMID: 30120269 PMCID: PMC6098085 DOI: 10.1038/s41598-018-30055-y] [Citation(s) in RCA: 38] [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: 04/04/2018] [Accepted: 07/21/2018] [Indexed: 12/12/2022] Open
Abstract
A high prevalence of adherent-invasive E. coli (AIEC) in the intestinal mucosa of Crohn's disease patients has been shown. AIEC colonize the intestine and induce inflammation in genetically predisposed mouse models including CEABAC10 transgenic (Tg) mice expressing human CEACAM6-receptor for AIEC and eif2ak4-/- mice exhibiting autophagy defect in response to AIEC infection. Here, we aimed at investigating whether gut microbiota modification contributes to AIEC-induced intestinal inflammation in these mouse models. For this, eif2ak4+/+ and eif2ak4-/- mice or CEABAC10 Tg mice invalidated for Eif2ak4 gene (Tg/eif2ak4-/-) or not (Tg/eif2ak4+/+) were infected with the AIEC reference strain LF82 or the non-pathogenic E. coli K12 MG1655 strain. In all mouse groups, LF82 colonized the gut better and longer than MG1655. No difference in fecal microbiota composition was observed in eif2ak4+/+ and eif2ak4-/- mice before infection and at day 1 and 4 post-infection. LF82-infected eif2ak4-/- mice exhibited altered fecal microbiota composition at day 14 and 21 post-infection and increased fecal lipocalin-2 level at day 21 post-infection compared to other groups, indicating that intestinal inflammation developed after microbiota modification. Similar results were obtained for LF82-infected Tg/eif2ak4-/- mice. These results suggest that in genetically predisposed hosts, AIEC colonization might induce chronic intestinal inflammation by altering the gut microbiota composition.
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Affiliation(s)
- Alexis Bretin
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
| | - Cécily Lucas
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
| | - Anaïs Larabi
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
| | - Guillaume Dalmasso
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
| | - Elisabeth Billard
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
| | - Nicolas Barnich
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
| | - Richard Bonnet
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France
- Centre Hospitalier Universitaire (CHU), Clermont-Ferrand, 63001, France
| | - Hang Thi Thu Nguyen
- M2iSH (Microbes, intestine, inflammation and Susceptibility of the Host), UMR 1071 Inserm, Université Clermont Auvergne, INRA USC 2018, Clermont-Ferrand, 63001, France.
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12
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MicroRNA Expression Profiling in Behçet's Disease. J Immunol Res 2018; 2018:2405150. [PMID: 29854829 PMCID: PMC5964440 DOI: 10.1155/2018/2405150] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/07/2018] [Indexed: 01/17/2023] Open
Abstract
Background Behçet's disease (BD) is a chronic inflammatory multisystem disease characterized by oral and genital ulcers, uveitis, and skin lesions. MicroRNAs (miRNAs) are key regulators of immune responses. Differential expression of miRNAs has been reported in several inflammatory autoimmune diseases; however, their role in BD is not fully elucidated. We aimed to identify miRNA expression signatures associated with BD and to investigate their potential implication in the disease pathogenesis. Methods miRNA microarray analysis was performed in blood cells of BD patients and healthy controls. miRNA expression profiles were analyzed using Affymetrix arrays with a comprehensive coverage of miRNA sequences. Pathway analyses were performed, and the global miRNA profiling was combined with transcriptoma data in BD. Deregulation of selected miRNAs was validated by real-time PCR. Results We identified specific miRNA signatures associated with BD patients with active disease. These miRNAs target pathways relevant in BD, such as TNF, IFN gamma, and VEGF-VEGFR signaling cascades. Network analysis revealed several miRNAs regulating highly connected genes within the BD transcriptoma. Conclusions The combined analysis of deregulated miRNAs and BD transcriptome sheds light on some epigenetic aspects of BD identifying specific miRNAs, which may represent promising candidates as biomarkers and/or for the design of novel therapeutic strategies in BD.
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13
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Dunn JLM, Kartchner LB, Gast K, Sessions M, Hunter RA, Thurlow L, Richardson A, Schoenfisch M, Cairns BA, Maile R. Mammalian target of rapamycin regulates a hyperresponsive state in pulmonary neutrophils late after burn injury. J Leukoc Biol 2018; 103:909-918. [PMID: 29393976 DOI: 10.1002/jlb.3ab0616-251rrr] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 12/28/2017] [Accepted: 01/04/2018] [Indexed: 12/11/2022] Open
Abstract
Bacterial pneumonia is a leading cause of death late after burn injury due to the severe immune dysfunction that follows this traumatic injury. The Mechanistic/Mammalian Target of Rapamycin (mTOR) pathway drives many effector functions of innate immune cells required for bacterial clearance. Studies have demonstrated alterations in multiple cellular processes in patients and animal models following burn injury in which mTOR is a central component. Goals of this study were to (1) investigate the importance of mTOR signaling in antimicrobial activity by neutrophils and (2) therapeutically target mTOR to promote normalization of the immune response. We utilized a murine model of 20% total body surface area burn and the mTOR-specific inhibitor rapamycin. Burn injury led to innate immune hyperresponsiveness in the lung including recruitment of neutrophils with greater ex vivo oxidative activity compared with neutrophils from sham-injured mice. Elevated oxidative function correlated with improved clearance of Pseudomonas aeruginosa, despite down-regulated expression of the bacterial-sensing TLR molecules. Rapamycin administration reversed the burn injury-induced lung innate immune hyperresponsiveness and inhibited enhanced bacterial clearance in burn mice compared with untreated burn mice, resulting in significantly higher mortality. Neutrophil ex vivo oxidative burst was decreased by rapamycin treatment. These data indicate that (1) neutrophil function within the lung is more important than recruitment for bacterial clearance following burn injury and (2) mTOR inhibition significantly impacts innate immune hyperresponsiveness, including neutrophil effector function, allowing normalization of the immune response late after burn injury.
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Affiliation(s)
- Julia L M Dunn
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Laurel B Kartchner
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Karli Gast
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Marci Sessions
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rebecca A Hunter
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Lance Thurlow
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Anthony Richardson
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Mark Schoenfisch
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Bruce A Cairns
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Surgery, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Robert Maile
- Department of Microbiology & Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Surgery, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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14
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Moreira D, Silvestre R, Cordeiro-da-Silva A, Estaquier J, Foretz M, Viollet B. AMP-activated Protein Kinase As a Target For Pathogens: Friends Or Foes? Curr Drug Targets 2017; 17:942-53. [PMID: 25882224 DOI: 10.2174/1389450116666150416120559] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 03/24/2015] [Accepted: 04/10/2015] [Indexed: 12/21/2022]
Abstract
Intracellular pathogens are known to manipulate host cell regulatory pathways to establish an optimal environment for their growth and survival. Pathogens employ active mechanisms to hijack host cell metabolism and acquire existing nutrient and energy store. The role of the cellular energy sensor AMP-activated protein kinase (AMPK) in the regulation of cellular energy homeostasis is well documented. Here, we highlight recent advances showing the importance of AMPK signaling in pathogen-host interactions. Pathogens interact with AMPK by a variety of mechanisms aimed at reprogramming host cell metabolism to their own benefit. Stimulation of AMPK activity provides an efficient process to rapidly adapt pathogen metabolism to the major nutritional changes often encountered during the different phases of infection. However, inhibition of AMPK is also used by pathogens to manipulate innate host response, indicating that AMPK appears relevant to restriction of pathogen infection. We also document the effects of pharmacological AMPK modulators on pathogen proliferation and survival. This review illustrates intricate pathogen-AMPK interactions that may be exploited to the development of novel anti-pathogen therapies.
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Affiliation(s)
| | | | | | | | | | - Benoit Viollet
- Institut Cochin, Inserm U1016, CNRS UMR8104, Université Paris Descartes, 24 rue du faubourg Saint Jacques 75014 Paris, France.
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15
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Toxoplasma gondii and Neospora caninum induce different host cell responses at proteome-wide phosphorylation events; a step forward for uncovering the biological differences between these closely related parasites. Parasitol Res 2017; 116:2707-2719. [DOI: 10.1007/s00436-017-5579-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 07/31/2017] [Indexed: 10/19/2022]
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16
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Eisenreich W, Rudel T, Heesemann J, Goebel W. To Eat and to Be Eaten: Mutual Metabolic Adaptations of Immune Cells and Intracellular Bacterial Pathogens upon Infection. Front Cell Infect Microbiol 2017; 7:316. [PMID: 28752080 PMCID: PMC5508010 DOI: 10.3389/fcimb.2017.00316] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/26/2017] [Indexed: 12/11/2022] Open
Abstract
Intracellular bacterial pathogens (IBPs) invade and replicate in different cell types including immune cells, in particular of the innate immune system (IIS) during infection in the acute phase. However, immune cells primarily function as essential players in the highly effective and integrated host defense systems comprising the IIS and the adaptive immune system (AIS), which cooperatively protect the host against invading microbes including IBPs. As countermeasures, the bacterial pathogens (and in particular the IBPs) have developed strategies to evade or reprogram the IIS at various steps. The intracellular replication capacity and the anti-immune defense responses of the IBP's as well as the specific antimicrobial responses of the immune cells of the innate and the AIS depend on specific metabolic programs of the IBPs and their host cells. The metabolic programs of the immune cells supporting or counteracting replication of the IBPs appear to be mutually exclusive. Indeed, recent studies show that upon interaction of naïve, metabolically quiescent immune cells with IBPs, different metabolic activation processes occur which may result in the provision of a survival and replication niche for the pathogen or its eradication. It is therefore likely that within a possible host cell population subsets exist that are metabolically programmed for pro- or anti-microbial conditions. These metabolic programs may be triggered by the interactions between different bacterial agonistic components and host cell receptors. In this review, we summarize the current status in the field and discuss metabolic adaptation processes within immune cells of the IIS and the IBPs that support or restrict the intracellular replication of the pathogens.
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Affiliation(s)
- Wolfgang Eisenreich
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Thomas Rudel
- Department of Microbiology, Biocenter, University of WürzburgWürzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Chair of Medical Microbiology and Hospital Epidemiology, Ludwig Maximilian University of MunichMünchen, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Chair of Medical Microbiology and Hospital Epidemiology, Ludwig Maximilian University of MunichMünchen, Germany
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17
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Ren W, Yin J, Xiao H, Chen S, Liu G, Tan B, Li N, Peng Y, Li T, Zeng B, Li W, Wei H, Yin Z, Wu G, Hardwidge PR, Yin Y. Intestinal Microbiota-Derived GABA Mediates Interleukin-17 Expression during Enterotoxigenic Escherichia coli Infection. Front Immunol 2017; 7:685. [PMID: 28138329 PMCID: PMC5237640 DOI: 10.3389/fimmu.2016.00685] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/22/2016] [Indexed: 12/21/2022] Open
Abstract
Intestinal microbiota has critical importance in pathogenesis of intestinal infection; however, the role of intestinal microbiota in intestinal immunity during enterotoxigenic Escherichia coli (ETEC) infection is poorly understood. The present study tested the hypothesis that the intestinal microbiota is associated with intestinal interleukin-17 (IL-17) expression in response to ETEC infection. Here, we found ETEC infection induced expression of intestinal IL-17 and dysbiosis of intestinal microbiota, increasing abundance of γ-aminobutyric acid (GABA)-producing Lactococcus lactis subsp. lactis. Antibiotics treatment in mice lowered the expression of intestinal IL-17 during ETEC infection, while GABA or L. lactis subsp. lactis administration restored the expression of intestinal IL-17. L. lactis subsp. lactis administration also promoted expression of intestinal IL-17 in germ-free mice during ETEC infection. GABA enhanced intestinal IL-17 expression in the context of ETEC infection through activating mechanistic target of rapamycin complex 1 (mTORC1)-ribosomal protein S6 kinase 1 (S6K1) signaling. GABA-mTORC1 signaling also affected intestinal IL-17 expression in response to Citrobacter rodentium infection and in drug-induced model of intestinal inflammation. These findings highlight the importance of intestinal GABA signaling in intestinal IL-17 expression during intestinal infection and indicate the potential of intestinal microbiota-GABA signaling in IL-17-associated intestinal diseases.
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Affiliation(s)
- Wenkai Ren
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Jie Yin
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
| | - Hao Xiao
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
| | - Shuai Chen
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
| | - Gang Liu
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
| | - Bie Tan
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
| | - Nengzhang Li
- Chongqing Key Laboratory of Forage and Herbivorce, College of Animal Science and Technology, Southwest University, Chongqing, China
| | - Yuanyi Peng
- Chongqing Key Laboratory of Forage and Herbivorce, College of Animal Science and Technology, Southwest University, Chongqing, China
| | - Tiejun Li
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- Key Laboratory of Agro-Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
| | - Benhua Zeng
- Department of Laboratory Animal Science, College of Basic Medicine Science, Third Military Medical University, Chongqing, China
| | - Wenxia Li
- Department of Laboratory Animal Science, College of Basic Medicine Science, Third Military Medical University, Chongqing, China
| | - Hong Wei
- Department of Laboratory Animal Science, College of Basic Medicine Science, Third Military Medical University, Chongqing, China
| | - Zhinan Yin
- Biomedical Translational Research Institute, Jinan University, Guangzhou, China
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Philip R. Hardwidge
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Yulong Yin
- National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, China
- College of Animal Science, South China Agricultural University, Guangzhou, China
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18
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Microfilariae of Brugia malayi Inhibit the mTOR Pathway and Induce Autophagy in Human Dendritic Cells. Infect Immun 2016; 84:2463-72. [PMID: 27297394 DOI: 10.1128/iai.00174-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 09/08/2016] [Indexed: 01/04/2023] Open
Abstract
Immune modulation is a hallmark of patent filarial infection, including suppression of antigen-presenting cell function and downmodulation of filarial antigen-specific T cell responses. The mammalian target of rapamycin (mTOR) signaling pathway has been implicated in immune regulation, not only by suppressing T cell responses but also by regulating autophagy (through mTOR sensing amino acid availability). Global proteomic analysis (liquid chromatography-tandem mass spectrometry) of microfilaria (mf)-exposed monocyte-derived dendritic cells (DC) indicated that multiple components of the mTOR signaling pathway, including mTOR, eIF4A, and eIF4E, are downregulated by mf, suggesting that mf target this pathway for immune modulation in DC. Utilizing Western blot analysis, we demonstrate that similar to rapamycin (a known mTOR inhibitor), mf downregulate the phosphorylation of mTOR and its regulatory proteins, p70S6K1 and 4E-BP1, a process essential for DC protein synthesis. As active mTOR signaling regulates autophagy, we examined whether mf exposure alters autophagy-associated processes. mf-induced autophagy was reflected in marked upregulation of phosphorylated Beclin 1, known to play an important role in both autophagosome formation and autolysosome fusion, in induction of LC3II, a marker of autophagosome formation, and in induced degradation of p62, a ubiquitin-binding protein that aggregates protein in autophagosomes and is degraded upon autophagy that was reduced significantly by mf exposure and by rapamycin. Together, these results suggest that Brugia malayi mf employ mechanisms of metabolic modulation in DC to influence the regulation of the host immune response by downregulating mTOR signaling, resulting in increased autophagy. Whether this is a result of the parasite-secreted rapamycin homolog is currently under study.
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19
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González Plaza JJ, Hulak N, Kausova G, Zhumadilov Z, Akilzhanova A. Role of metabolism during viral infections, and crosstalk with the innate immune system. Intractable Rare Dis Res 2016; 5:90-6. [PMID: 27195191 PMCID: PMC4869588 DOI: 10.5582/irdr.2016.01008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Viruses have been for long polemic biological particles which stand in the twilight of being living entities or not. As their genome is reduced, they rely on the metabolic machinery of their host in order to replicate and be able to continue with their infection process. The understanding of their metabolic requirements is thus of paramount importance in order to develop tailored drugs to control their population, without affecting the normal functioning of their host. New advancements in high throughput technologies, especially metabolomics are allowing researchers to uncover the metabolic mechanisms of viral replication. In this short review, we present the latest discoveries that have been made in the field and an overview of the intrinsic relationship between metabolism and innate immunity as an important part of the immune system.
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Affiliation(s)
- Juan José González Plaza
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Zagreb, Croatia
- Research Department, University Hospital for Infectious Diseases “Dr. Fran Mihaljević”, Zagreb, Croatia
- Address correspondence to: Dr. Juan José González Plaza, Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10002 Zagreb, Croatia. E-mail:
| | - Nataša Hulak
- Department of Microbiology, Faculty of Agriculture, University of Zagreb, Zagreb, Croatia
| | | | - Zhaxybay Zhumadilov
- Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, PI “National Laboratory Astana”, AOE “Nazarbayev University”, Astana, Kazakhstan
| | - Ainur Akilzhanova
- Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, PI “National Laboratory Astana”, AOE “Nazarbayev University”, Astana, Kazakhstan
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20
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Bretin A, Carrière J, Dalmasso G, Bergougnoux A, B'chir W, Maurin AC, Müller S, Seibold F, Barnich N, Bruhat A, Darfeuille-Michaud A, Nguyen HTT. Activation of the EIF2AK4-EIF2A/eIF2α-ATF4 pathway triggers autophagy response to Crohn disease-associated adherent-invasive Escherichia coli infection. Autophagy 2016; 12:770-83. [PMID: 26986695 PMCID: PMC4854551 DOI: 10.1080/15548627.2016.1156823] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The intestinal mucosa of Crohn disease (CD) patients is abnormally colonized by adherent-invasive E. coli (AIEC). Upon AIEC infection, autophagy is induced in host cells to restrain bacterial intracellular replication. The underlying mechanism, however, remains unknown. Here, we investigated the role of the EIF2AK4-EIF2A/eIF2α-ATF4 pathway in the autophagic response to AIEC infection. We showed that infection of human intestinal epithelial T84 cells with the AIEC reference strain LF82 activated the EIF2AK4-EIF2A-ATF4 pathway, as evidenced by increased phospho-EIF2AK4, phospho-EIF2A and ATF4 levels. EIF2AK4 depletion inhibited autophagy activation in response to LF82 infection, leading to increased LF82 intracellular replication and elevated pro-inflammatory cytokine production. Mechanistically, EIF2AK4 depletion suppressed the LF82-induced ATF4 binding to promoters of several autophagy genes including MAP1LC3B, BECN1, SQSTM1, ATG3 and ATG7, and this subsequently inhibited transcription of these genes. LF82 infection of wild-type (WT), but not eif2ak4(-/-), mice activated the EIF2AK4-EIF2A-ATF4 pathway, inducing autophagy gene transcription and autophagy response in enterocytes. Consequently, eif2ak4(-/-) mice exhibited increased intestinal colonization by LF82 bacteria and aggravated inflammation compared to WT mice. Activation of the EIF2AK4-EIF2A-ATF4 pathway was observed in ileal biopsies from patients with noninflamed CD, and this was suppressed in inflamed CD, suggesting that a defect in the activation of this pathway could be one of the mechanisms contributing to active disease. In conclusion, we show that activation of the EIF2AK4-EIF2A-ATF4 pathway upon AIEC infection serves as a host defense mechanism to induce functional autophagy to control AIEC intracellular replication.
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Affiliation(s)
- Alexis Bretin
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
| | - Jessica Carrière
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
| | - Guillaume Dalmasso
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
| | - Agnès Bergougnoux
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
| | - Wafa B'chir
- c University of Clermont Auvergne, UMR 1019 INRA , University of Auvergne , Saint Genès Champanelle, France
| | - Anne-Catherine Maurin
- c University of Clermont Auvergne, UMR 1019 INRA , University of Auvergne , Saint Genès Champanelle, France
| | - Stefan Müller
- d Department of Clinical Research , Division of Gastroenterology and Cytometry Laboratory, University of Bern , Bern , Switzerland
| | - Frank Seibold
- e Department of Gastroenterology , Spital Tiefenau , Bern , Switzerland
| | - Nicolas Barnich
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
| | - Alain Bruhat
- c University of Clermont Auvergne, UMR 1019 INRA , University of Auvergne , Saint Genès Champanelle, France
| | - Arlette Darfeuille-Michaud
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
| | - Hang Thi Thu Nguyen
- a University of Clermont Auvergne, M2iSH, UMR 1071 INSERM/University of Auvergne , Clermont-Ferrand , France.,b INRA USC 2018 , Clermont-Ferrand , France
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21
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Interactions between Autophagy and Bacterial Toxins: Targets for Therapy? Toxins (Basel) 2015; 7:2918-58. [PMID: 26248079 PMCID: PMC4549733 DOI: 10.3390/toxins7082918] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/27/2015] [Accepted: 07/28/2015] [Indexed: 01/07/2023] Open
Abstract
Autophagy is a physiological process involved in defense mechanisms for clearing intracellular bacteria. The autophagic pathway is finely regulated and bacterial toxins interact with this process in a complex manner. Bacterial toxins also interact significantly with many biochemical processes. Evaluations of the effects of bacterial toxins, such as endotoxins, pore-forming toxins and adenylate cyclases, on autophagy could support the development of new strategies for counteracting bacterial pathogenicity. Treatment strategies could focus on drugs that enhance autophagic processes to improve the clearance of intracellular bacteria. However, further in vivo studies are required to decipher the upregulation of autophagy and potential side effects limiting such approaches. The capacity of autophagy activation strategies to improve the outcome of antibiotic treatment should be investigated in the future.
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22
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Tsalikis J, Tattoli I, Ling A, Sorbara MT, Croitoru DO, Philpott DJ, Girardin SE. Intracellular Bacterial Pathogens Trigger the Formation of U Small Nuclear RNA Bodies (U Bodies) through Metabolic Stress Induction. J Biol Chem 2015; 290:20904-20918. [PMID: 26134566 DOI: 10.1074/jbc.m115.659466] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Indexed: 12/30/2022] Open
Abstract
Invasive bacterial pathogens induce an amino acid starvation (AAS) response in infected host cells that controls host defense in part by promoting autophagy. However, whether AAS has additional significant effects on the host response to intracellular bacteria remains poorly characterized. Here we showed that Shigella, Salmonella, and Listeria interfere with spliceosomal U snRNA maturation in the cytosol. Bacterial infection resulted in the rerouting of U snRNAs and their cytoplasmic escort, the survival motor neuron (SMN) complex, to processing bodies, thus forming U snRNA bodies (U bodies). This process likely contributes to the decline in the cytosolic levels of U snRNAs and of the SMN complex proteins SMN and DDX20 that we observed in infected cells. U body formation was triggered by membrane damage in infected cells and was associated with the induction of metabolic stresses, such as AAS or endoplasmic reticulum stress. Mechanistically, targeting of U snRNAs to U bodies was regulated by translation initiation inhibition and the ATF4/ATF3 pathway, and U bodies rapidly disappeared upon removal of the stress, suggesting that their accumulation represented an adaptive response to metabolic stress. Importantly, this process likely contributed to shape the host response to invasive bacteria because down-regulation of DDX20 expression using short hairpin RNA (shRNA) amplified ATF3- and NF-κB-dependent signaling. Together, these results identify a critical role for metabolic stress and invasive bacterial pathogens in U body formation and suggest that this process contributes to host defense.
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Affiliation(s)
- Jessica Tsalikis
- Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M6G 2T6, Canada
| | - Ivan Tattoli
- Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M6G 2T6, Canada; Departments of Immunology, University of Toronto, Toronto M6G 2T6, Canada
| | - Arthur Ling
- Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M6G 2T6, Canada
| | - Matthew T Sorbara
- Departments of Immunology, University of Toronto, Toronto M6G 2T6, Canada
| | - David O Croitoru
- Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M6G 2T6, Canada
| | - Dana J Philpott
- Departments of Immunology, University of Toronto, Toronto M6G 2T6, Canada
| | - Stephen E Girardin
- Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M6G 2T6, Canada.
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Affiliation(s)
- Yousef Abu Kwaik
- Department of Microbiology and Immunology, Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail: (YAK); (DB)
| | - Dirk Bumann
- Focal Area Infection Biology, Biozentrum, Universität Basel, Basel, Switzerland
- * E-mail: (YAK); (DB)
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24
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Virus-induced translational arrest through 4EBP1/2-dependent decay of 5'-TOP mRNAs restricts viral infection. Proc Natl Acad Sci U S A 2015; 112:E2920-9. [PMID: 26038567 DOI: 10.1073/pnas.1418805112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The mosquito-transmitted bunyavirus, Rift Valley fever virus (RVFV), is a highly successful pathogen for which there are no vaccines or therapeutics. Translational arrest is a common antiviral strategy used by hosts. In response, RVFV inhibits two well-known antiviral pathways that attenuate translation during infection, PKR and type I IFN signaling. Despite this, translational arrest occurs during RVFV infection by unknown mechanisms. Here, we find that RVFV infection triggers the decay of core translation machinery mRNAs that possess a 5'-terminal oligopyrimidine (5'-TOP) motif in their 5'-UTR, including mRNAs encoding ribosomal proteins, which leads to a decrease in overall ribosomal protein levels. We find that the RNA decapping enzyme NUDT16 selectively degrades 5'-TOP mRNAs during RVFV infection and this decay is triggered in response to mTOR attenuation via the translational repressor 4EBP1/2 axis. Translational arrest of 5'-TOPs via 4EBP1/2 restricts RVFV replication, and this increased RNA decay results in the loss of visible RNA granules, including P bodies and stress granules. Because RVFV cap-snatches in RNA granules, the increased level of 5'-TOP mRNAs in this compartment leads to snatching of these targets, which are translationally suppressed during infection. Therefore, translation of RVFV mRNAs is compromised by multiple mechanisms during infection. Together, these data present a previously unknown mechanism for translational shutdown in response to viral infection and identify mTOR attenuation as a potential therapeutic avenue against bunyaviral infection.
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25
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Liu X, Cohen JI. The role of PI3K/Akt in human herpesvirus infection: From the bench to the bedside. Virology 2015; 479-480:568-77. [PMID: 25798530 PMCID: PMC4424147 DOI: 10.1016/j.virol.2015.02.040] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 12/25/2022]
Abstract
The phosphatidylinositol-3-kinase (PI3K)-Akt signaling pathway regulates several key cellular functions including protein synthesis, cell growth, glucose metabolism, and inflammation. Many viruses have evolved mechanisms to manipulate this signaling pathway to ensure successful virus replication. The human herpesviruses undergo both latent and lytic infection, but differ in cell tropism, growth kinetics, and disease manifestations. Herpesviruses express multiple proteins that target the PI3K/Akt cell signaling pathway during the course of their life cycle to facilitate viral infection, replication, latency, and reactivation. Rare human genetic disorders with mutations in either the catalytic or regulatory subunit of PI3K that result in constitutive activation of the protein predispose to severe herpesvirus infections as well as to virus-associated malignancies. Inhibiting the PI3K/Akt pathway or its downstream proteins using drugs already approved for other diseases can block herpesvirus lytic infection and may reduce malignancies associated with latent herpesvirus infections.
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Affiliation(s)
- XueQiao Liu
- Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jeffrey I Cohen
- Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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26
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Muraille E, Leo O, Moser M. TH1/TH2 paradigm extended: macrophage polarization as an unappreciated pathogen-driven escape mechanism? Front Immunol 2014; 5:603. [PMID: 25505468 PMCID: PMC4244692 DOI: 10.3389/fimmu.2014.00603] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/10/2014] [Indexed: 02/04/2023] Open
Abstract
The classical view of the Th1/Th2 paradigm posits that the pathogen nature, infectious cycle, and persistence represent key parameters controlling the choice of effector mechanisms operating during an immune response. Thus, efficient Th1 responses are triggered by replicating intracellular pathogens, while Th2 responses would control helminth infection and promote tissue repair during the resolution phase of an infectious event. However, this vision does not account for a growing body of data describing how pathogens exploit the polarization of the host immune response to their own benefit. Recently, the study of macrophages has illustrated a novel aspect of this arm race between pathogens and the immune system, and the central role of macrophages in homeostasis, repair and defense of all tissues is now fully appreciated. Like T lymphocytes, macrophages differentiate into distinct effectors including classically (M1) and alternatively (M2) activated macrophages. Interestingly, in addition to represent immune effectors, M1/M2 cells have been shown to represent potential reservoir cells to a wide range of intracellular pathogens. Subversion of macrophage cell metabolism by microbes appears as a recently uncovered immune escape strategy. Upon infection, several microbial agents have been shown to activate host metabolic pathways leading to the production of nutrients necessary to their long-term persistence in host. The purpose of this review is to summarize and discuss the strategies employed by pathogens to manipulate macrophage differentiation, and in particular their basic cell metabolism, to favor their own growth while avoiding immune control.
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Affiliation(s)
- Eric Muraille
- Laboratory of Parasitology, Faculty of Medicine, Université Libre de Bruxelles , Brussels , Belgium
| | - Oberdan Leo
- Laboratory of Immunobiology, Faculty of Sciences, Université Libre de Bruxelles , Gosselies , Belgium
| | - Muriel Moser
- Laboratory of Immunobiology, Faculty of Sciences, Université Libre de Bruxelles , Gosselies , Belgium
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27
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The emerging role of mTOR signalling in antibacterial immunity. Immunol Cell Biol 2014; 92:346-53. [PMID: 24518980 DOI: 10.1038/icb.2014.3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 12/14/2022]
Abstract
Mammalian target of rapamycin (mTOR) is a central regulator of cellular metabolic homeostasis that is highly conserved in evolution. Recent evidence has revealed the existence of a complex interplay between mTOR signalling and immunity. We review here the emerging role of mTOR signalling in the regulation of Toll-like receptor-dependent innate responses and in the activation of T cells and antigen-presenting cells. We also highlight the importance of amino-acid starvation-driven mTOR inhibition in the control of autophagy and intracellular bacterial clearance.
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