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Gül E, Fattinger SA, Sellin ME, Hardt WD. Epithelial inflammasomes, gasdermins, and mucosal inflammation - Lessons from Salmonella and Shigella infected mice. Semin Immunol 2023; 70:101812. [PMID: 37562110 DOI: 10.1016/j.smim.2023.101812] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/05/2023] [Accepted: 07/15/2023] [Indexed: 08/12/2023]
Abstract
Besides its crucial function in nutrient absorbance and as barrier against the microbiota, the gut epithelium is essential for sensing pathogenic insults and mounting of an appropriate early immune response. In mice, the activation of the canonical NAIP/NLRC4 inflammasome is critical for the defense against enterobacterial infections. Activation of the NAIP/NLRC4 inflammasome triggers the extrusion of infected intestinal epithelial cells (IEC) into the gut lumen, concomitant with inflammasome-mediated lytic cell death. The membrane permeabilization, a hallmark of pyroptosis, is caused by the pore-forming proteins called gasdermins (GSDMs). Recent work has revealed that NAIP/NLRC4-dependent extrusion of infected IECs can, however, also be executed in the absence of GSDMD. In fact, several reports highlighted that various cell death pathways (e.g., pyroptosis or apoptosis) and unique mechanisms specific to particular infection models and stages of gut infection are in action during epithelial inflammasome defense against intestinal pathogens. Here, we summarize the current knowledge regarding the underlying mechanisms and speculate on the putative functions of the epithelial inflammasome activation and cell death, with a particular emphasis on mouse infection models for two prominent enterobacterial pathogens, Salmonella Typhimurium and Shigella flexneri.
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Affiliation(s)
- Ersin Gül
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Stefan A Fattinger
- Division of Immunology and Molecular Medicine, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Mikael E Sellin
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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Silva Dos Santos F, Neves RAF, Bernay B, Krepsky N, Teixeira VL, Artigaud S. The first use of LC-MS/MS proteomic approach in the brown mussel Perna perna after bacterial challenge: Searching for key proteins on immune response. FISH & SHELLFISH IMMUNOLOGY 2023; 134:108622. [PMID: 36803779 DOI: 10.1016/j.fsi.2023.108622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
The brown mussel Perna perna is a valuable fishing resource, primarily in tropical and subtropical coastal regions. Because of their filter-feeding habits, mussels are directly exposed to bacteria in the water column. Escherichia coli (EC) and Salmonella enterica (SE) inhabit human guts and reach the marine environment through anthropogenic sources, such as sewage. Vibrio parahaemolyticus (VP) is indigenous to coastal ecosystems but can be harmful to shellfish. In this study, we aimed to assess the protein profile of the hepatopancreas of P. perna mussel challenged by introduced - E. coli and S. enterica - and indigenous marine bacteria - V. parahaemolyticus. Bacterial-challenge groups were compared with non-injected (NC) and injected control (IC) - that consisted in mussels not challenged and mussels injected with sterile PBS-NaCl, respectively. Through LC-MS/MS proteomic analysis, 3805 proteins were found in the hepatopancreas of P. perna. From the total, 597 were significantly different among conditions. Mussels injected with VP presented 343 proteins downregulated compared with all the other conditions, suggesting that VP suppresses their immune response. Particularly, 31 altered proteins - upregulated or downregulated - for one or more challenge groups (EC, SE, and VP) compared with controls (NC and IC) are discussed in detail in the paper. For the three tested bacteria, significantly different proteins were found to perform critical roles in immune response at all levels, namely: recognition and signal transduction; transcription; RNA processing; translation and protein processing; secretion; and humoral effectors. This is the first shotgun proteomic study in P. perna mussel, therefore providing an overview of the protein profile of the mussel hepatopancreas, focused on the immune response against bacteria. Hence, it is possible to understand the immune-bacteria relationship at molecular levels better. This knowledge can support the development of strategies and tools to be applied to coastal marine resource management and contribute to the sustainability of coastal systems.
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Affiliation(s)
- Fernanda Silva Dos Santos
- Graduate Program in Sciences and Biotechnology, Institute of Biology, Fluminense Federal University (UFF), R. Mario Santos Braga, S/n. Centro, Niterói, RJ, CEP 24.020-141, Brazil; Research Group of Experimental and Aquatic Ecology, Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458-307, Urca, Rio de Janeiro, RJ, CEP: 22.290-240, Brazil.
| | - Raquel A F Neves
- Graduate Program in Neotropical Biodiversity (PPGBIO), Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, Rio de Janeiro, RJ, CEP: 22.290-255, Brazil; Research Group of Experimental and Aquatic Ecology, Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458-307, Urca, Rio de Janeiro, RJ, CEP: 22.290-240, Brazil.
| | - Benoît Bernay
- Plateforme Proteogen, SFR ICORE 4206, Université de Caen Basse-Normandie, Esplanade de la paix, 14032, Caen cedex, France.
| | - Natascha Krepsky
- Graduate Program in Neotropical Biodiversity (PPGBIO), Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, Rio de Janeiro, RJ, CEP: 22.290-255, Brazil.
| | - Valéria Laneuville Teixeira
- Graduate Program in Sciences and Biotechnology, Institute of Biology, Fluminense Federal University (UFF), R. Mario Santos Braga, S/n. Centro, Niterói, RJ, CEP 24.020-141, Brazil; Graduate Program in Neotropical Biodiversity (PPGBIO), Institute of Biosciences (IBIO), Federal University of the State of Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, Rio de Janeiro, RJ, CEP: 22.290-255, Brazil.
| | - Sébastien Artigaud
- Université de Brest, CNRS, IRD, Ifremer, UMR 6539 LEMAR, F-29280, Plouzané, France.
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Barisch C, Holthuis JCM, Cosentino K. Membrane damage and repair: a thin line between life and death. Biol Chem 2023; 404:467-490. [PMID: 36810295 DOI: 10.1515/hsz-2022-0321] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/03/2023] [Indexed: 02/24/2023]
Abstract
Bilayered membranes separate cells from their surroundings and form boundaries between intracellular organelles and the cytosol. Gated transport of solutes across membranes enables cells to establish vital ion gradients and a sophisticated metabolic network. However, an advanced compartmentalization of biochemical reactions makes cells also particularly vulnerable to membrane damage inflicted by pathogens, chemicals, inflammatory responses or mechanical stress. To avoid potentially lethal consequences of membrane injuries, cells continuously monitor the structural integrity of their membranes and readily activate appropriate pathways to plug, patch, engulf or shed the damaged membrane area. Here, we review recent insights into the cellular mechanisms that underly an effective maintenance of membrane integrity. We discuss how cells respond to membrane lesions caused by bacterial toxins and endogenous pore-forming proteins, with a primary focus on the intimate crosstalk between membrane proteins and lipids during wound formation, detection and elimination. We also discuss how a delicate balance between membrane damage and repair determines cell fate upon bacterial infection or activation of pro-inflammatory cell death pathways.
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Affiliation(s)
- Caroline Barisch
- Molecular Infection Biology Division, Department of Biology and Center of Cellular Nanoanalytics, Osnabrück University, D-49076 Osnabrück, Germany
| | - Joost C M Holthuis
- Molecular Cell Biology Division, Department of Biology and Center of Cellular Nanoanalytics, Osnabrück University, D-49076 Osnabrück, Germany
| | - Katia Cosentino
- Molecular Cell Biophysics Division, Department of Biology and Center of Cellular Nanoanalytics, Osnabrück University, D-49076 Osnabrück, Germany
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Repurposing the tyrosine kinase inhibitor nilotinib for use against intracellular multidrug-resistant Salmonella Typhimurium. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2023:S1684-1182(23)00005-1. [PMID: 36702646 DOI: 10.1016/j.jmii.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/08/2022] [Accepted: 01/09/2023] [Indexed: 01/18/2023]
Abstract
BACKGROUND/PURPOSE The increasing incidence of infections caused by multidrug-resistant Salmonella enterica has become a serious threat to global public health. Here, we found that the tyrosine kinase inhibitor nilotinib exhibits antibacterial activity against intracellular S. enterica serovar Typhimurium in RAW264.7 macrophages. Thus, we aimed to pharmacologically exploit the anti-intracellular Salmonella activity of nilotinib and to elucidate its mechanism of action. METHODS The antibacterial activity of the compounds was assessed by high-content analysis (HCA) and intracellular CFU, minimum inhibitory concentration (MIC), and bacterial growth assays. The cytotoxicity of the compounds was evaluated by HCA and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell viability assays. The levels of cellular AMPK, phospho-AMPK, Atg7 and β-actin were determined by immunoblotting. RESULTS The screen identified two small molecule compounds (SCT1101 and SCT1104) with potent activity against intracellular S. Typhimurium. Moreover, SCT1101 and SCT1104 enhanced the efficacy of ciprofloxacin and cefixime against intracellular S. Typhimurium. However, only SCT1101 exhibited activity against intracellular MDR and fluoroquinolone-resistant S. Typhimurium isolates. Subsequent mechanistic studies showed that neither of these nilotinib derivatives increased the phospho-AMPK level in RAW264.7 cells. Neither the AMPK inhibitor compound C nor SBI-0206965 reversed the inhibitory effects of SCT1101 and SCT1104 on intracellular Salmonella. Furthermore, neither blockade of autophagy by 3-MA nor shRNA-mediated knockdown of Atg7 protein expression in RAW264.7 cells affected the antibacterial activity of SCT1101 and SCT1104. CONCLUSION The structure of nilotinib could be used to develop novel therapeutics for controlling MDR S. Typhimurium infections.
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Liu B, Zhang X, Ding X, Bin P, Zhu G. The vertical transmission of Salmonella Enteritidis in a One-Health context. One Health 2022; 16:100469. [PMID: 36507074 PMCID: PMC9731862 DOI: 10.1016/j.onehlt.2022.100469] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/07/2022] Open
Abstract
Salmonella enterica serovar Enteritidis (S. Enteritidis, SE) is a foodborne zoonotic pathogen, causing economic losses in animal husbandry and large numbers of human deaths and critically threatening economic development and public health. Human infection with SE has complex transmission routes, involving the environment, animal reservoirs, and water in a One-Health context. Food-producing animals, particularly poultry and livestock, are regarded as the most common sources of SE infection in humans. However, there is little known about the vertical transmission of SE in a One-Health context. In this review, we analyze the ecological significance of SE in a One-Health context. Importantly, we focus on the difference in vertical transmission of SE in poultry, livestock, and humans. We introduce the transmission pathway, describe the immune mechanisms, and discuss the models that could be used for studying the vertical transmission of SE and the strategy that prevention and control for vertical transmission of SE into the future from a One-Health perspective. Together, considering the vertical transmission of SE, it is helpful to provide important insights into the control and decontamination pathways of SE in animal husbandry and enhance knowledge about the prevention of fetal infection in human pregnancy.
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Affiliation(s)
- Baobao Liu
- College of Veterinary Medicine (Institute of comparative medicine), Yangzhou University, Yangzhou 225009, China,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China,Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou 225009, China,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaojie Zhang
- College of Veterinary Medicine (Institute of comparative medicine), Yangzhou University, Yangzhou 225009, China,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China,Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou 225009, China,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Xueyan Ding
- College of Veterinary Medicine (Institute of comparative medicine), Yangzhou University, Yangzhou 225009, China,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China,Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou 225009, China,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Peng Bin
- College of Veterinary Medicine (Institute of comparative medicine), Yangzhou University, Yangzhou 225009, China,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China,Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou 225009, China,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Guoqiang Zhu
- College of Veterinary Medicine (Institute of comparative medicine), Yangzhou University, Yangzhou 225009, China,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China,Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou 225009, China,Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China,Corresponding author at: College of Veterinary Medicine (Institute of comparative medicine), Yangzhou University, Yangzhou 225009, China.
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López‐Escarpa D, Castanheira S, García‐del Portillo F. OmpR and Prc contribute to switch the Salmonella morphogenetic program in response to phagosome cues. Mol Microbiol 2022; 118:477-493. [PMID: 36115022 PMCID: PMC9827838 DOI: 10.1111/mmi.14982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 01/12/2023]
Abstract
Salmonella enterica serovar Typhimurium infects eukaryotic cells residing within membrane-bound phagosomes. In this compartment, the pathogen replaces the morphogenetic penicillin-binding proteins 2 and 3 (PBP2/PBP3) with PBP2SAL /PBP3SAL , two proteins absent in Escherichia coli. The basis for this switch is unknown. Here, we show that PBP3 protein levels drop drastically when S. Typhimurium senses acidity, high osmolarity and nutrient scarcity, cues that activate virulence functions required for intra-phagosomal survival and proliferation. The protease Prc and the transcriptional regulator OmpR contribute to lower PBP3 levels whereas OmpR stimulates PBP2SAL /PBP3SAL production. Surprisingly, despite being essential for division in E. coli, PBP3 levels also drop in non-pathogenic and pathogenic E. coli exposed to phagosome cues. Such exposure alters E. coli morphology resulting in very long bent and twisted filaments indicative of failure in the cell division and elongation machineries. None of these aberrant shapes are detected in S. Typhimurium. Expression of PBP3SAL restores cell division in E. coli exposed to phagosome cues although the cells retain elongation defects in the longitudinal axis. By switching the morphogenetic program, OmpR and Prc allow S. Typhimurium to properly divide and elongate inside acidic phagosomes maintaining its cellular dimensions and the rod shape.
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Affiliation(s)
- David López‐Escarpa
- Laboratory of Intracellular Bacterial PathogensNational Centre for Biotechnology (CNB‐CSIC)MadridSpain
| | - Sónia Castanheira
- Laboratory of Intracellular Bacterial PathogensNational Centre for Biotechnology (CNB‐CSIC)MadridSpain
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Ménard S, Lacroix-Lamandé S, Ehrhardt K, Yan J, Grassl GA, Wiedemann A. Cross-Talk Between the Intestinal Epithelium and Salmonella Typhimurium. Front Microbiol 2022; 13:906238. [PMID: 35733975 PMCID: PMC9207452 DOI: 10.3389/fmicb.2022.906238] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/13/2022] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica serovars are invasive gram-negative bacteria, causing a wide range of diseases from gastroenteritis to typhoid fever, representing a public health threat around the world. Salmonella gains access to the intestinal lumen after oral ingestion of contaminated food or water. The crucial initial step to establish infection is the interaction with the intestinal epithelium. Human-adapted serovars such as S. Typhi or S. Paratyphi disseminate to systemic organs and induce life-threatening disease known as typhoid fever, whereas broad-host serovars such as S. Typhimurium usually are limited to the intestine and responsible for gastroenteritis in humans. To overcome intestinal epithelial barrier, Salmonella developed mechanisms to induce cellular invasion, intracellular replication and to face host defence mechanisms. Depending on the serovar and the respective host organism, disease symptoms differ and are linked to the ability of the bacteria to manipulate the epithelial barrier for its own profit and cross the intestinal epithelium.This review will focus on S. Typhimurium (STm). To better understand STm pathogenesis, it is crucial to characterize the crosstalk between STm and the intestinal epithelium and decipher the mechanisms and epithelial cell types involved. Thus, the purpose of this review is to summarize our current knowledge on the molecular dialogue between STm and the various cell types constituting the intestinal epithelium with a focus on the mechanisms developed by STm to cross the intestinal epithelium and access to subepithelial or systemic sites and survive host defense mechanisms.
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Affiliation(s)
- Sandrine Ménard
- IRSD - Institut de Recherche en Santé Digestive, Université́ de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | | | - Katrin Ehrhardt
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School and German Center for Infection Research (DZIF), Hannover, Germany
| | - Jin Yan
- IRSD - Institut de Recherche en Santé Digestive, Université́ de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China
- Research Center of Digestive Disease, Central South University, Changsha, China
| | - Guntram A. Grassl
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School and German Center for Infection Research (DZIF), Hannover, Germany
| | - Agnès Wiedemann
- IRSD - Institut de Recherche en Santé Digestive, Université́ de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
- *Correspondence: Agnès Wiedemann,
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Jiang C, Huang X, Yao J, Yu L, Wei F, Yang A. The role of membrane contact sites at the bacteria-host interface. Crit Rev Microbiol 2021; 48:270-282. [PMID: 34403642 DOI: 10.1080/1040841x.2021.1961678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Membrane contact sites (MCSs) refer to the areas of close proximity between heterologous membranes. A growing body of evidence indicates that MCSs are involved in important cellular functions, such as cellular material transfer, organelle biogenesis, and cell growth. Importantly, the study of MCSs at the bacteria-host interface is an emerging popular research topic. Intracellular bacterial pathogens have evolved a variety of fascinating strategies to interfere with MCSs by injecting effectors into infected host cells. Bacteria-containing vacuoles establish direct physical contact with organelles within the host, ensuring vacuolar membrane integrity and energy supply from host organelles and protecting the vacuoles from the host endocytic pathway and lysosomal degradation. An increasing number of bacterial effectors from various bacterial pathogens hijack components of host MCSs to form the vacuole-organelle MCSs for material exchange. MCS-related events have been identified as new mechanisms of microbial pathogenesis to greatly improve bacterial survival and replication within host cells. In this review, we will discuss the recent advances in MCSs at the bacteria-host interface, focussing on the roles of MCSs mediated by bacterial effectors in microbial pathogenesis.
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Affiliation(s)
- Chen Jiang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Xue Huang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Jia Yao
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Lihua Yu
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Fujing Wei
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Aimin Yang
- School of Life Sciences, Chongqing University, Chongqing, China
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Schulte M, Olschewski K, Hensel M. Fluorescent protein-based reporters reveal stress response of intracellular Salmonella enterica at level of single bacterial cells. Cell Microbiol 2020; 23:e13293. [PMID: 33222378 DOI: 10.1111/cmi.13293] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022]
Abstract
Intracellular bacteria such as Salmonella enterica are confronted with a broad array of defence mechanisms of their mammalian host cells. The ability to sense host cell-imposed damages, and to mount efficient stress responses are crucial for survival and proliferation of intracellular pathogens. The various combinations of host defence mechanisms acting on intracellular bacteria and their individual response also explain the occurrence of distinct subpopulations of intracellular S. enterica such as dormant or persisting, slowly or rapidly replicating cells. Here we describe a set of fluorescence protein (FP)-based reporter strains that were used to monitor the expression of cytoplasmic or periplasmic stress response systems of single bacterial cells. This is mediated by a fast-maturing FP as reporter for induction of stress response genes. We evaluated slower maturing FPs for a second function, that is, the analysis of the status of intracellular proliferation of pathogens. The combination of two FPs allows, at level of single bacterial cells, the interrogation of stress response and intracellular proliferation. Application of these reporters to S. enterica allowed us to detect and quantify distinct intracellular subpopulations with different levels of stress response and proliferation.
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Affiliation(s)
- Marc Schulte
- Abteilung Mikrobiologie, CellNanOs - Center of Cellular Nanoanalytics Osnabrück, Universität Osnabrück, Osnabrück, Germany
| | - Katharina Olschewski
- Abteilung Mikrobiologie, CellNanOs - Center of Cellular Nanoanalytics Osnabrück, Universität Osnabrück, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, CellNanOs - Center of Cellular Nanoanalytics Osnabrück, Universität Osnabrück, Osnabrück, Germany
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