1
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Jennings KC, Johnson KE, Hayward MA, Kristich CJ, Salzman NH. CCR2-dependent CX3CR1+ colonic macrophages promote Enterococcus faecalis dissemination. Infect Immun 2024; 92:e0000624. [PMID: 38629806 PMCID: PMC11075457 DOI: 10.1128/iai.00006-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/29/2024] [Indexed: 05/08/2024] Open
Abstract
Enterococci are common commensal bacteria that colonize the gastrointestinal tracts of most mammals, including humans. Importantly, these bacteria are one of the leading causes of nosocomial infections. This study examined the role of colonic macrophages in facilitating Enterococcus faecalis infections in mice. We determined that depletion of colonic phagocytes resulted in the reduction of E. faecalis dissemination to the gut-draining mesenteric lymph nodes. Furthermore, we established that trafficking of monocyte-derived CX3CR1-expressing macrophages contributed to E. faecalis dissemination in a manner that was not reliant on CCR7, the conventional receptor involved in lymphatic migration. Finally, we showed that E. faecalis mutants with impaired intracellular survival exhibited reduced dissemination, suggesting that E. faecalis can exploit host immune cell migration to disseminate systemically and cause disease. Our findings indicate that modulation of macrophage trafficking in the context of antibiotic therapy could serve as a novel approach for preventing or treating opportunistic infections by disseminating enteric pathobionts like E. faecalis.
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Affiliation(s)
- Kevin C. Jennings
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Kaitlin E. Johnson
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Michael A. Hayward
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Center for Microbiome Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Christopher J. Kristich
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Nita H. Salzman
- Department of Pediatrics, Division of Gastroenterology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Center for Microbiome Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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2
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Demirturk M, Cinar MS, Avci FY. The immune interactions of gut glycans and microbiota in health and disease. Mol Microbiol 2024. [PMID: 38703041 DOI: 10.1111/mmi.15267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 05/06/2024]
Abstract
The human digestive system harbors a vast diversity of commensal bacteria and maintains a symbiotic relationship with them. However, imbalances in the gut microbiota accompany various diseases, such as inflammatory bowel diseases (IBDs) and colorectal cancers (CRCs), which significantly impact the well-being of populations globally. Glycosylation of the mucus layer is a crucial factor that plays a critical role in maintaining the homeostatic environment in the gut. This review delves into how the gut microbiota, immune cells, and gut mucus layer work together to establish a balanced gut environment. Specifically, the role of glycosylation in regulating immune cell responses and mucus metabolism in this process is examined.
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Affiliation(s)
- Mahmut Demirturk
- Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Mukaddes Sena Cinar
- Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Fikri Y Avci
- Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
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3
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Han J, Aljahdali N, Zhao S, Tang H, Harbottle H, Hoffmann M, Frye JG, Foley SL. Infection biology of Salmonella enterica. EcoSal Plus 2024:eesp00012023. [PMID: 38415623 DOI: 10.1128/ecosalplus.esp-0001-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 07/31/2023] [Indexed: 02/29/2024]
Abstract
Salmonella enterica is the leading cause of bacterial foodborne illness in the USA, with an estimated 95% of salmonellosis cases due to the consumption of contaminated food products. Salmonella can cause several different disease syndromes, with the most common being gastroenteritis, followed by bacteremia and typhoid fever. Among the over 2,600 currently identified serotypes/serovars, some are mostly host-restricted and host-adapted, while the majority of serotypes can infect a broader range of host species and are associated with causing both livestock and human disease. Salmonella serotypes and strains within serovars can vary considerably in the severity of disease that may result from infection, with some serovars that are more highly associated with invasive disease in humans, while others predominantly cause mild gastroenteritis. These observed clinical differences may be caused by the genetic make-up and diversity of the serovars. Salmonella virulence systems are very complex containing several virulence-associated genes with different functions that contribute to its pathogenicity. The different clinical syndromes are associated with unique groups of virulence genes, and strains often differ in the array of virulence traits they display. On the chromosome, virulence genes are often clustered in regions known as Salmonella pathogenicity islands (SPIs), which are scattered throughout different Salmonella genomes and encode factors essential for adhesion, invasion, survival, and replication within the host. Plasmids can also carry various genes that contribute to Salmonella pathogenicity. For example, strains from several serovars associated with significant human disease, including Choleraesuis, Dublin, Enteritidis, Newport, and Typhimurium, can carry virulence plasmids with genes contributing to attachment, immune system evasion, and other roles. The goal of this comprehensive review is to provide key information on the Salmonella virulence, including the contributions of genes encoded in SPIs and plasmids during Salmonella pathogenesis.
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Affiliation(s)
- Jing Han
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Nesreen Aljahdali
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
- Biological Science Department, College of Science, King Abdul-Aziz University, Jeddah, Saudi Arabia
| | - Shaohua Zhao
- Center for Veterinary Medicine, U.S. Food and Drug Administration, Rockville, Maryland, USA
| | - Hailin Tang
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Heather Harbottle
- Center for Veterinary Medicine, U.S. Food and Drug Administration, Rockville, Maryland, USA
| | - Maria Hoffmann
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
| | - Jonathan G Frye
- Agricutlutral Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
| | - Steven L Foley
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
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4
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Wang Q, Lu Q, Jia S, Zhao M. Gut immune microenvironment and autoimmunity. Int Immunopharmacol 2023; 124:110842. [PMID: 37643491 DOI: 10.1016/j.intimp.2023.110842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/14/2023] [Accepted: 08/19/2023] [Indexed: 08/31/2023]
Abstract
A variety of immune cells or tissues are present in the gut to form the gut immune microenvironment by interacting with gut microbiota, and to maintain the gut immune homeostasis. Accumulating evidence indicated that gut microbiota dysbiosis might break the homeostasis of the gut immune microenvironment, which was associated with many health problems including autoimmune diseases. Moreover, disturbance of the gut immune microenvironment can also induce extra-intestinal autoimmune disorders through the migration of intestinal pro-inflammatory effector cells from the intestine to peripheral inflamed sites. This review discussed the composition of the gut immune microenvironment and its association with autoimmunity. These findings are expected to provide new insights into the pathogenesis of various autoimmune disorders, as well as novel strategies for the prevention and treatment against related diseases.
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Affiliation(s)
- Qiaolin Wang
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing 210042, China
| | - Qianjin Lu
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing 210042, China
| | - Sujie Jia
- Department of Pharmacy, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China.
| | - Ming Zhao
- Hospital for Skin Diseases, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China; Key Laboratory of Basic and Translational Research on Immune-Mediated Skin Diseases, Chinese Academy of Medical Sciences, Nanjing 210042, China.
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5
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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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6
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López-Yglesias AH, Lu CC, Lai MA, Quarles EK, Zhao X, Hajjar AM, Smith KD. FlgM is required to evade NLRC4-mediated host protection against flagellated Salmonella. Infect Immun 2023; 91:e0025523. [PMID: 37638725 PMCID: PMC10501211 DOI: 10.1128/iai.00255-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 08/29/2023] Open
Abstract
Salmonella enterica serovar Typhimurium is a leading cause of gastroenteritis worldwide and a deadly pathogen in children, immunocompromised patients, and the elderly. Salmonella induces innate immune responses through the NLRC4 inflammasome, which has been demonstrated to have distinct roles during systemic and mucosal detections of flagellin and non-flagellin molecules. We hypothesized that NLRC4 recognition of Salmonella flagellin is the dominant protective pathway during infection. To test this hypothesis, we used wild-type, flagellin-deficient, and flagellin-overproducing Salmonella to establish the role of flagellin in mediating NLRC4-dependent host resistance during systemic and mucosal infections in mice. We observed that during the systemic phase of infection, Salmonella efficiently evades NLRC4-mediated innate immunity. During mucosal Salmonella infection, flagellin recognition by the NLRC4 inflammasome pathway is the dominant mediator of protective innate immunity. Deletion of flgM results in constitutive expression of flagellin and severely limits systemic and mucosal Salmonella infections in an NLRC4 inflammasome-dependent manner. These data establish that recognition of Salmonella's flagellin by the NLRC4 inflammasome during mucosal infection is the dominant innate protective pathway for host resistance against the enteric pathogen and that FlgM-mediated evasion of the NLRC4 inflammasome enhances virulence and intestinal tissue destruction.
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Affiliation(s)
| | - Chun-Chi Lu
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Marvin A. Lai
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Ellen K. Quarles
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Xiaodan Zhao
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Adeline M. Hajjar
- Department of Comparative Medicine, University of Washington, Seattle, Washington, USA
| | - Kelly D. Smith
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
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7
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Haskins BE, Gullicksrud JA, Wallbank BA, Dumaine JE, Guérin A, Cohn IS, O'Dea KM, Pardy RD, Merolle MI, Shallberg LA, Hunter EN, Byerly JH, Smith EJ, Buenconsejo GY, McLeod BI, Christian DA, Striepen B, Hunter CA. Dendritic cell-mediated responses to secreted Cryptosporidium effectors are required for parasite-specific CD8 + T cell responses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.16.553566. [PMID: 37645924 PMCID: PMC10462095 DOI: 10.1101/2023.08.16.553566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Cryptosporidium causes debilitating diarrheal disease in patients with primary and acquired defects in T cell function. However, it has been a challenge to understand how this infection generates T cell responses and how they mediate parasite control. Here, Cryptosporidium was engineered to express a parasite effector protein (MEDLE-2) that contains the MHC-I restricted SIINFEKL epitope which is recognized by TCR transgenic OT-I CD8 + T cells. These modified parasites induced expansion of endogenous SIINFEKL-specific and OT-I CD8 + T cells that were a source of IFN-γ that could restrict growth of Cryptosporidium . This T cell response was dependent on the translocation of the effector and similar results were observed with another secreted parasite effector (ROP1). Although infection and these translocated effector proteins are restricted to intestinal epithelial cells (IEC), type I dendritic cells (cDC1) were required to generate CD8 + T cell responses to these model antigens. These data sets highlight Cryptosporidium effectors as targets of the immune system and suggest that crosstalk between enterocytes and cDC1s is crucial for CD8 + T cell responses to Cryptosporidium .
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8
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Gül E, Bakkeren E, Salazar G, Steiger Y, Abi Younes A, Clerc M, Christen P, Fattinger SA, Nguyen BD, Kiefer P, Slack E, Ackermann M, Vorholt JA, Sunagawa S, Diard M, Hardt WD. The microbiota conditions a gut milieu that selects for wild-type Salmonella Typhimurium virulence. PLoS Biol 2023; 21:e3002253. [PMID: 37651408 PMCID: PMC10499267 DOI: 10.1371/journal.pbio.3002253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/13/2023] [Accepted: 07/13/2023] [Indexed: 09/02/2023] Open
Abstract
Salmonella Typhimurium elicits gut inflammation by the costly expression of HilD-controlled virulence factors. This inflammation alleviates colonization resistance (CR) mediated by the microbiota and thereby promotes pathogen blooms. However, the inflamed gut-milieu can also select for hilD mutants, which cannot elicit or maintain inflammation, therefore causing a loss of the pathogen's virulence. This raises the question of which conditions support the maintenance of virulence in S. Typhimurium. Indeed, it remains unclear why the wild-type hilD allele is dominant among natural isolates. Here, we show that microbiota transfer from uninfected or recovered hosts leads to rapid clearance of hilD mutants that feature attenuated virulence, and thereby contributes to the preservation of the virulent S. Typhimurium genotype. Using mouse models featuring a range of microbiota compositions and antibiotic- or inflammation-inflicted microbiota disruptions, we found that irreversible disruption of the microbiota leads to the accumulation of hilD mutants. In contrast, in models with a transient microbiota disruption, selection for hilD mutants was prevented by the regrowing microbiota community dominated by Lachnospirales and Oscillospirales. Strikingly, even after an irreversible microbiota disruption, microbiota transfer from uninfected donors prevented the rise of hilD mutants. Our results establish that robust S. Typhimurium gut colonization hinges on optimizing its manipulation of the host: A transient and tempered microbiota perturbation is favorable for the pathogen to both flourish in the inflamed gut and also minimize loss of virulence. Moreover, besides conferring CR, the microbiota may have the additional consequence of maintaining costly enteropathogen virulence mechanisms.
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Affiliation(s)
- Ersin Gül
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Erik Bakkeren
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Department of Biology, University of Oxford, Oxford, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Guillem Salazar
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Institute of Microbiology and Swiss Institute of Bioinformatics, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Yves Steiger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Andrew Abi Younes
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Melanie Clerc
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Philipp Christen
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Stefan A. Fattinger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Bidong D. Nguyen
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Patrick Kiefer
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Emma Slack
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Institute for Food, Nutrition and Health, ETH Zürich, Zürich, Switzerland
| | - Martin Ackermann
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Duebendorf, Switzerland
| | - Julia A. Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Shinichi Sunagawa
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Institute of Microbiology and Swiss Institute of Bioinformatics, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Médéric Diard
- Biozentrum, University of Basel, Basel, Switzerland
- Botnar Research Centre for Child Health, Basel, Switzerland
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
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9
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Hegarty LM, Jones GR, Bain CC. Macrophages in intestinal homeostasis and inflammatory bowel disease. Nat Rev Gastroenterol Hepatol 2023:10.1038/s41575-023-00769-0. [PMID: 37069320 DOI: 10.1038/s41575-023-00769-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/13/2023] [Indexed: 04/19/2023]
Abstract
Macrophages are essential for the maintenance of intestinal homeostasis, yet appear to be drivers of inflammation in the context of inflammatory bowel disease (IBD). How these peacekeepers become powerful aggressors in IBD is still unclear, but technological advances have revolutionized our understanding of many facets of their biology. In this Review, we discuss the progress made in understanding the heterogeneity of intestinal macrophages, the functions they perform in gut health and how the environment and origin can control the differentiation and longevity of these cells. We describe how these processes might change in the context of chronic inflammation and how aberrant macrophage behaviour contributes to IBD pathology, and discuss how therapeutic approaches might target dysregulated macrophages to dampen inflammation and promote mucosal healing. Finally, we set out key areas in the field of intestinal macrophage biology for which further investigation is warranted.
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Affiliation(s)
- Lizi M Hegarty
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, Edinburgh BioQuarter, Queen's Medical Research Institute, Edinburgh, UK
| | - Gareth-Rhys Jones
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, Edinburgh BioQuarter, Queen's Medical Research Institute, Edinburgh, UK
| | - Calum C Bain
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, Edinburgh BioQuarter, Queen's Medical Research Institute, Edinburgh, UK.
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10
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Saez A, Herrero-Fernandez B, Gomez-Bris R, Sánchez-Martinez H, Gonzalez-Granado JM. Pathophysiology of Inflammatory Bowel Disease: Innate Immune System. Int J Mol Sci 2023; 24:ijms24021526. [PMID: 36675038 PMCID: PMC9863490 DOI: 10.3390/ijms24021526] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 12/30/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a heterogeneous state of chronic intestinal inflammation with no exact known cause. Intestinal innate immunity is enacted by neutrophils, monocytes, macrophages, and dendritic cells (DCs), and innate lymphoid cells and NK cells, characterized by their capacity to produce a rapid and nonspecific reaction as a first-line response. Innate immune cells (IIC) defend against pathogens and excessive entry of intestinal microorganisms, while preserving immune tolerance to resident intestinal microbiota. Changes to this equilibrium are linked to intestinal inflammation in the gut and IBD. IICs mediate host defense responses, inflammation, and tissue healing by producing cytokines and chemokines, activating the complement cascade and phagocytosis, or presenting antigens to activate the adaptive immune response. IICs exert important functions that promote or ameliorate the cellular and molecular mechanisms that underlie and sustain IBD. A comprehensive understanding of the mechanisms underlying these clinical manifestations will be important for developing therapies targeting the innate immune system in IBD patients. This review examines the complex roles of and interactions among IICs, and their interactions with other immune and non-immune cells in homeostasis and pathological conditions.
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Affiliation(s)
- Angela Saez
- LamImSys Lab, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
- Facultad de Ciencias Experimentales, Universidad Francisco de Vitoria (UFV), 28223 Pozuelo de Alarcón, Spain
| | - Beatriz Herrero-Fernandez
- LamImSys Lab, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain
| | - Raquel Gomez-Bris
- LamImSys Lab, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
- Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain
| | - Hector Sánchez-Martinez
- LamImSys Lab, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
| | - Jose M. Gonzalez-Granado
- LamImSys Lab, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, School of Medicine, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- Correspondence: ; Tel.: +34-913908766
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11
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Hebbandi Nanjundappa R, Sokke Umeshappa C, Geuking MB. The impact of the gut microbiota on T cell ontogeny in the thymus. Cell Mol Life Sci 2022; 79:221. [PMID: 35377005 PMCID: PMC11072498 DOI: 10.1007/s00018-022-04252-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/10/2022] [Accepted: 03/16/2022] [Indexed: 12/12/2022]
Abstract
The intestinal microbiota is critical for the development of gut-associated lymphoid tissues, including Peyer's patches and mesenteric lymph nodes, and is instrumental in educating the local as well as systemic immune system. In addition, it also impacts the development and function of peripheral organs, such as liver, lung, and the brain, in health and disease. However, whether and how the intestinal microbiota has an impact on T cell ontogeny in the hymus remains largely unclear. Recently, the impact of molecules and metabolites derived from the intestinal microbiota on T cell ontogeny in the thymus has been investigated in more detail. In this review, we will discuss the recent findings in the emerging field of the gut-thymus axis and we will highlight the current questions and challenges in the field.
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Affiliation(s)
- Roopa Hebbandi Nanjundappa
- Department of Microbiology, Immunology, and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
- Department of Pediatrics, IWK Research Center, Halifax, NS, Canada
| | - Channakeshava Sokke Umeshappa
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
- Department of Pediatrics, IWK Research Center, Halifax, NS, Canada
| | - Markus B Geuking
- Department of Microbiology, Immunology, and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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12
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Dou D, Liang J, Zhai X, Li G, Wang H, Han L, Lin L, Ren Y, Liu S, Liu C, Guo W, Li J. Oxytocin signalling in dendritic cells regulates immune tolerance in the intestine and alleviates DSS-induced colitis. Clin Sci (Lond) 2021; 135:597-611. [PMID: 33564880 DOI: 10.1042/cs20201438] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that is associated with immune dysfunction. Recent studies have indicated that the neurosecretory hormone oxytocin (OXT) has been proven to alleviate experimental colitis. METHODS We investigated the role of OXT/OXT receptor (OXTR) signalling in dendritic cells (DCs) using mice with specific OXTR deletion in CD11c+ cells (OXTRflox/flox×CD11c-cre mice) and a dextran sulfate sodium (DSS)-induced colitis model. RESULTS The level of OXT was abnormal in the serum or colon tissue of DSS-induced colitis mice or the plasma of UC patients. Both bone marrow-derived DCs (BMDCs) and lamina propria DCs (LPDCs) express OXTR. Knocking out OXTR in DCs exacerbated DSS-induced acute and chronic colitis in mice. In contrast, the injection of OXT-pretreated DCs significantly ameliorated colitis. Mechanistically, OXT prevented DC maturation through the phosphatidylinositol 4,5-bisphosphate 3-kinase (Pi3K)/AKT pathway and promoted phagocytosis, adhesion and cytokine modulation in DCs. Furthermore, OXT pre-treated DCs prevent CD4+ T cells differentiation to T helper 1 (Th1) and Th17. CONCLUSIONS Our results suggest that OXT-induced tolerogenic DCs efficiently protect against experimental colitis via Pi3K/AKT pathway. Our work provides evidence that the nervous system participates in the immune regulation of colitis by modulating DCs. Our findings suggest that generating ex vivo DCs pretreated with OXT opens new therapeutic perspectives for the treatment of UC in humans.
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Affiliation(s)
- Dandan Dou
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Jinghui Liang
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Xiangyu Zhai
- Department of General Surgery, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Guosheng Li
- Department of Hematology, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Hongjuan Wang
- Department of Gastroenterology, Second Hospital, Shandong University, Jinan 250000, China
| | - Liying Han
- College of Life Science, Shandong Normal University, Jinan 250014, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266000, China
| | - Lin Lin
- Department of Gastroenterology, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Yifei Ren
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Shilian Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Chuanyong Liu
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Wei Guo
- Department of Colorectal Surgery, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Jingxin Li
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
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13
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Zhou H, Wang L, Liu F. Immunological Impact of Intestinal T Cells on Metabolic Diseases. Front Immunol 2021; 12:639902. [PMID: 33679800 PMCID: PMC7930072 DOI: 10.3389/fimmu.2021.639902] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence accumulated over the past several years has uncovered intestinal CD4+ T cells as an essential mediator in modulating intestinal immunity in health and diseases. It has also been increasingly recognized that dietary and microbiota-derived factors play key roles in shaping the intestinal CD4+ T-cell compartment. This review aims to discuss the current understanding on how the intestinal T cell immune responses are disturbed by obesity and metabolic stress. In addition, we review how these changes influence systemic metabolic homeostasis and the T-cell-mediated crosstalk between gut and liver or brain in the progression of obesity and its related diseases. Lastly, we highlight the potential roles of some drugs that target intestinal T cells as a therapeutic treatment for metabolic diseases. A better understanding of the interaction among metabolites, bacterial signals, and T cell immune responses in the gut and their roles in systemic inflammation in metabolic tissues should shed new light on the development of effective treatment of obesity and related disorders.
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Affiliation(s)
- Haiyan Zhou
- Department of Metabolism and Endocrinology, National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Liwen Wang
- Department of Metabolism and Endocrinology, National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Feng Liu
- Department of Metabolism and Endocrinology, National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, The Second Xiangya Hospital of Central South University, Changsha, China.,Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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14
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Koscsó B, Kurapati S, Rodrigues RR, Nedjic J, Gowda K, Shin C, Soni C, Ashraf AZ, Purushothaman I, Palisoc M, Xu S, Sun H, Chodisetti SB, Lin E, Mack M, Kawasawa YI, He P, Rahman ZSM, Aifantis I, Shulzhenko N, Morgun A, Bogunovic M. Gut-resident CX3CR1 hi macrophages induce tertiary lymphoid structures and IgA response in situ. Sci Immunol 2020; 5:5/46/eaax0062. [PMID: 32276965 DOI: 10.1126/sciimmunol.aax0062] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 12/27/2019] [Accepted: 02/28/2020] [Indexed: 12/12/2022]
Abstract
Intestinal mononuclear phagocytes (MPs) are composed of heterogeneous dendritic cell (DC) and macrophage subsets necessary for the initiation of immune response and control of inflammation. Although MPs in the normal intestine have been extensively studied, the heterogeneity and function of inflammatory MPs remain poorly defined. We performed phenotypical, transcriptional, and functional analyses of inflammatory MPs in infectious Salmonella colitis and identified CX3CR1+ MPs as the most prevalent inflammatory cell type. CX3CR1+ MPs were further divided into three distinct populations, namely, Nos2 +CX3CR1lo, Ccr7 +CX3CR1int (lymph migratory), and Cxcl13 +CX3CR1hi (mucosa resident), all of which were transcriptionally aligned with macrophages and derived from monocytes. In follow-up experiments in vivo, intestinal CX3CR1+ macrophages were superior to conventional DC1 (cDC1) and cDC2 in inducing Salmonella-specific mucosal IgA. We next examined spatial organization of the immune response induced by CX3CR1+ macrophage subsets and identified mucosa-resident Cxcl13 +CX3CR1hi macrophages as the antigen-presenting cells responsible for recruitment and activation of CD4+ T and B cells to the sites of Salmonella invasion, followed by tertiary lymphoid structure formation and the local pathogen-specific IgA response. Using mice we developed with a floxed Ccr7 allele, we showed that this local IgA response developed independently of migration of the Ccr7 +CX3CR1int population to the mesenteric lymph nodes and contributed to the total mucosal IgA response to infection. The differential activity of intestinal macrophage subsets in promoting mucosal IgA responses should be considered in the development of vaccines to prevent Salmonella infection and in the design of anti-inflammatory therapies aimed at modulating macrophage function in inflammatory bowel disease.
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Affiliation(s)
- Balázs Koscsó
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Sravya Kurapati
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA.,Biomedical Sciences PhD Program, Penn State University College of Medicine, Hershey, PA, USA
| | | | - Jelena Nedjic
- Department of Pathology and Laura and Isaac Perlmutter Cancer Center, NYU School of Medicine, New York, NY, USA
| | - Kavitha Gowda
- Department of Microbiology and Immunology, Penn State University College of Medicine, Hershey, PA, USA
| | - Changsik Shin
- Department of Microbiology and Immunology, Penn State University College of Medicine, Hershey, PA, USA
| | - Chetna Soni
- Department of Microbiology and Immunology, Penn State University College of Medicine, Hershey, PA, USA
| | - Azree Zaffran Ashraf
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Indira Purushothaman
- PhD Program in Anatomy at Penn State College of Medicine, Penn State University College of Medicine, Hershey, PA, USA
| | - Maryknoll Palisoc
- MD/PhD Medical Scientist Training Program, Penn State University College of Medicine, Hershey, PA, USA
| | - Sulei Xu
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Haoyu Sun
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Sathi Babu Chodisetti
- Department of Microbiology and Immunology, Penn State University College of Medicine, Hershey, PA, USA
| | - Eugene Lin
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Matthias Mack
- Department of Internal Medicine/Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - Yuka Imamura Kawasawa
- Department of Pharmacology and Biochemistry and Molecular Biology, Institute of Personalized Medicine, Penn State University College of Medicine, Hershey, PA, USA
| | - Pingnian He
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Ziaur S M Rahman
- Department of Microbiology and Immunology, Penn State University College of Medicine, Hershey, PA, USA
| | - Iannis Aifantis
- Department of Pathology and Laura and Isaac Perlmutter Cancer Center, NYU School of Medicine, New York, NY, USA
| | - Natalia Shulzhenko
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Andrey Morgun
- College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Milena Bogunovic
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA. .,Department of Microbiology and Immunology, Penn State University College of Medicine, Hershey, PA, USA.,Inflammatory Bowel Disease Center, Milton S. Hershey Medical Center, Hershey, PA, USA
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15
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Das S, Ray S, Arunima A, Sahu B, Suar M. A ROD9 island encoded gene in Salmonella Enteritidis plays an important role in acid tolerance response and helps in systemic infection in mice. Virulence 2020; 11:247-259. [PMID: 32116124 PMCID: PMC7051147 DOI: 10.1080/21505594.2020.1733203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 10/31/2022] Open
Abstract
Salmonella, like other pathogenic bacteria has undergone multiple genomic alterations to adapt itself into specific host environments executing varied degrees of virulence through evolution. Such variations in genome content have been assumed to lead the closely related non-typhoidal serovars, S. Enteritidis, and S. Typhimurium to exhibit Type Three Secretion System -2 (T3SS-2) based diverse colonization and inflammation kinetics. Mutually exclusive genes present in either of the serovars are recently being studied and in our currentwork, we focused on a particular island ROD9, present in S. Enteritidis but not in S. Typhimurium. Earlier reports have identified a few genes from this island to be responsible for virulence in vitro as well as in vivo. In this study, we have identified another gene, SEN1008 from the same island encoding a hypothetical protein to be a potential virulence determinant showing systemic attenuation upon mutation in C57BL/6 mice infection model. The isogenic mutant strain displayed reduced adhesion to epithelial cells in vitro as well as was highly immotile. It was also deficient in intracellular replication in vitro, with a highly suppressed SPI-2and failed to cause acute colitis at 72-h p.i.in vivo. Moreover, on acid exposure, SEN1008 showed 17 folds and 2 fold up-regulations during adaptation and challenge phases,respectively and ΔSEN1008 failed to survive during ATR assay, indicating its role under acid stress. Together, our findings suggested ΔSEN1008 to be significantly attenuated and we propose this gene to be a potent factor responsible for S. Enteritidis pathogenesis.
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Affiliation(s)
- Susmita Das
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | - Shilpa Ray
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | | | - Bikash Sahu
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | - Mrutyunjay Suar
- School of Biotechnology, KIIT University, Bhubaneswar, India
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16
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Fattinger SA, Sellin ME, Hardt WD. Epithelial inflammasomes in the defense against Salmonella gut infection. Curr Opin Microbiol 2020; 59:86-94. [PMID: 33128958 DOI: 10.1016/j.mib.2020.09.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 02/06/2023]
Abstract
The gut epithelium prevents bacterial access to the host's tissues and coordinates a number of mucosal defenses. Here, we review the function of epithelial inflammasomes in the infected host and focus on their role in defense against Salmonella Typhimurium. This pathogen employs flagella to swim towards the epithelium and a type III secretion system (TTSS) to dock and invade intestinal epithelial cells. Flagella and TTSS components are recognized by the canonical NAIP/NLRC4 inflammasome, while LPS activates the non-canonical Caspase-4/11 inflammasome. The relative contributions of these inflammasomes, the activated cell death pathways and the elicited mucosal defenses are subject to environmental control and appear to change along the infection trajectory. It will be an important future task to explain how this may enable defense against the challenges imposed by diverse bacterial enteropathogens.
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Affiliation(s)
- Stefan A Fattinger
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland; Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - 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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17
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Ruder B, Becker C. At the Forefront of the Mucosal Barrier: The Role of Macrophages in the Intestine. Cells 2020; 9:cells9102162. [PMID: 32987848 PMCID: PMC7601053 DOI: 10.3390/cells9102162] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/17/2020] [Accepted: 09/22/2020] [Indexed: 12/14/2022] Open
Abstract
Macrophages are part of the innate immunity and are key players for the maintenance of intestinal homeostasis. They belong to the group of mononuclear phagocytes, which exert bactericidal functions and help to clear apoptotic cells. Moreover, they play essential roles for the maintenance of epithelial integrity and tissue remodeling during wound healing processes and might be implicated in intestinal tumor development. Macrophages are antigen-presenting cells and secrete immune-modulatory factors, like chemokines and cytokines, which are necessary to activate other intestinal immune cells and therefore to shape immune responses in the gut. However, overwhelming activation or increased secretion of pro-inflammatory cytokines might also contribute to the pathogenesis of inflammatory bowel disease. Presently, intestinal macrophages are in the center of intense studies, which might help to develop new therapeutic strategies to counteract the development or treat already existing inflammatory diseases in the gut. In this review, we focus on the origin of intestinal macrophages and, based on current knowledge, discuss their role in the gut during homeostasis and inflammation, as well as during intestinal wound healing and tumor development.
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18
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Kreuzer M, Hardt WD. How Food Affects Colonization Resistance Against Enteropathogenic Bacteria. Annu Rev Microbiol 2020; 74:787-813. [DOI: 10.1146/annurev-micro-020420-013457] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Food has a major impact on all aspects of health. Recent data suggest that food composition can also affect susceptibility to infections by enteropathogenic bacteria. Here, we discuss how food may alter the microbiota as well as mucosal defenses and how this can affect infection. Salmonella Typhimurium diarrhea serves as a paradigm, and complementary evidence comes from other pathogens. We discuss the effects of food composition on colonization resistance, host defenses, and the infection process as well as the merits and limitations of mouse models and experimental foods, which are available to decipher the underlying mechanisms.
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Affiliation(s)
- Markus Kreuzer
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, CH-8093 Zurich, Switzerland
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19
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Hao S, Fan Q, Bai Y, Fang H, Zhou J, Fukuda T, Gu J, Li M, Li W. Core Fucosylation of Intestinal Epithelial Cells Protects Against Salmonella Typhi Infection via Up-Regulating the Biological Antagonism of Intestinal Microbiota. Front Microbiol 2020; 11:1097. [PMID: 32528455 PMCID: PMC7266941 DOI: 10.3389/fmicb.2020.01097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/04/2020] [Indexed: 12/15/2022] Open
Abstract
The fucosylated carbohydrate moieties on intestinal epithelial cells (IECs) are involved in the creation of an environmental niche for commensal and pathogenic bacteria. Core fucosylation catalyzed by fucosyltransferase 8 (Fut8) is the major fucosylation pattern on the N-glycans of the surface glycoproteins on IECs, however, the role of IECs core fucosylation during infection remains unclear. This study was conducted to investigate the interaction between IECs core fucosylation and gut microbiota, and the effects of this interaction on protecting Salmonella enterica subsp. enterica serovar Typhi (S. Typhi) infection. Firstly, the Fut8+/+ and Fut8+/– mice were infected with S. Typhi. The level of IECs core fucosylation and protein expression of intestinal mucosa were then detected by LCA blot and Western blot, respectively. The gut microbiota of Fut8+/+ and Fut8+/– mice before and after S. Typhi infection was assessed by 16S rRNA sequencing. Our results showed that core fucosylation was ubiquitous expressed on the intestinal mucosa of mice and had significant effects on their gut microbiota. Fut8+/– mice was more susceptive to S. Typhi infection than Fut8+/+ mice. Interestingly, infection of S. Typhi upregulated the core fucosylation level of IECs and increased the abundances of beneficial microorganisms such as Lactobacillus and Akkermansia spp. Further in vitro and in vivo studies demonstrated that Wnt/β-catenin signaling pathway mediated the elevation of IECs core fucosylation level upon infection of S. Typhi. Taken together, our data in this study revealed that the IECs core fucosylation plays an important role in protecting against S. Typhi infection via up-regulating the biological antagonism of intestinal microbiota.
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Affiliation(s)
- Sijia Hao
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Qingjie Fan
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yaqiang Bai
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Hui Fang
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Jiaorui Zhou
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Tomohiko Fukuda
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Jianguo Gu
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Ming Li
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Wenzhe Li
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
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20
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Uncoupling of invasive bacterial mucosal immunogenicity from pathogenicity. Nat Commun 2020; 11:1978. [PMID: 32332737 PMCID: PMC7181798 DOI: 10.1038/s41467-020-15891-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 03/30/2020] [Indexed: 11/17/2022] Open
Abstract
There is the notion that infection with a virulent intestinal pathogen induces generally stronger mucosal adaptive immunity than the exposure to an avirulent strain. Whether the associated mucosal inflammation is important or redundant for effective induction of immunity is, however, still unclear. Here we use a model of auxotrophic Salmonella infection in germ-free mice to show that live bacterial virulence factor-driven immunogenicity can be uncoupled from inflammatory pathogenicity. Although live auxotrophic Salmonella no longer causes inflammation, its mucosal virulence factors remain the main drivers of protective mucosal immunity; virulence factor-deficient, like killed, bacteria show reduced efficacy. Assessing the involvement of innate pathogen sensing mechanisms, we show MYD88/TRIF, Caspase-1/Caspase-11 inflammasome, and NOD1/NOD2 nodosome signaling to be individually redundant. In colonized animals we show that microbiota metabolite cross-feeding may recover intestinal luminal colonization but not pathogenicity. Consequent immunoglobulin A immunity and microbial niche competition synergistically protect against Salmonella wild-type infection. Virulent pathogens generally induce a stronger mucosal immunity than avirulent strains, but whether the associated inflammation is necessary for this is unclear. Here, using auxotrophic Salmonella enterica, the authors show that virulence factor function determines induction of protective IgA.
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21
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Kulkarni DH, Gustafsson JK, Knoop KA, McDonald KG, Bidani SS, Davis JE, Floyd AN, Hogan SP, Hsieh CS, Newberry RD. Goblet cell associated antigen passages support the induction and maintenance of oral tolerance. Mucosal Immunol 2020; 13:271-282. [PMID: 31819172 PMCID: PMC7044050 DOI: 10.1038/s41385-019-0240-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 10/31/2019] [Accepted: 11/18/2019] [Indexed: 02/07/2023]
Abstract
Tolerance to innocuous antigens from the diet and the commensal microbiota is a fundamental process essential to health. Why tolerance is efficiently induced to substances arising from the hostile environment of the gut lumen is incompletely understood but may be related to how these antigens are encountered by the immune system. We observed that goblet cell associated antigen passages (GAPs), but not other pathways of luminal antigen capture, correlated with the acquisition of luminal substances by lamina propria (LP) antigen presenting cells (APCs) and with the sites of tolerance induction to luminal antigens. Strikingly this role extended beyond antigen delivery. The GAP function of goblet cells facilitated maintenance of pre-existing LP T regulatory cells (Tregs), imprinting LP-dendritic cells with tolerogenic properties, and facilitating LP macrophages to produce the immunomodulatory cytokine IL-10. Moreover, tolerance to dietary antigen was impaired in the absence of GAPs. Thus, by delivering luminal antigens, maintaining pre-existing LP Tregs, and imprinting tolerogenic properties on LP-APCs GAPs support tolerance to substances encountered in the hostile environment of the gut lumen.
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Affiliation(s)
- Devesha H Kulkarni
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Jenny K Gustafsson
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Kathryn A Knoop
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Keely G McDonald
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Shay S Bidani
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Jazmyne E Davis
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Alexandria N Floyd
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Simon P Hogan
- Mary H. Weiser Food Allergy Center, University of Michigan School of Medicine, Ann Arbor, MI, 48109, USA
| | - Chyi-Song Hsieh
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Rodney D Newberry
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO, 63110, USA.
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22
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Intestinal epithelial NAIP/NLRC4 restricts systemic dissemination of the adapted pathogen Salmonella Typhimurium due to site-specific bacterial PAMP expression. Mucosal Immunol 2020; 13:530-544. [PMID: 31953493 PMCID: PMC7181392 DOI: 10.1038/s41385-019-0247-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/18/2019] [Accepted: 12/10/2019] [Indexed: 02/07/2023]
Abstract
Inflammasomes can prevent systemic dissemination of enteropathogenic bacteria. As adapted pathogens including Salmonella Typhimurium (S. Tm) have evolved evasion strategies, it has remained unclear when and where inflammasomes restrict their dissemination. Bacterial population dynamics establish that the NAIP/NLRC4 inflammasome specifically restricts S. Tm migration from the gut to draining lymph nodes. This is solely attributable to NAIP/NLRC4 within intestinal epithelial cells (IECs), while S. Tm evades restriction by phagocyte NAIP/NLRC4. NLRP3 and Caspase-11 also fail to restrict S. Tm mucosa traversal, migration to lymph nodes, and systemic pathogen growth. The ability of IECs (not phagocytes) to mount a NAIP/NLRC4 defense in vivo is explained by particularly high NAIP/NLRC4 expression in IECs and the necessity for epithelium-invading S. Tm to express the NAIP1-6 ligands-flagella and type-III-secretion-system-1. Imaging reveals both ligands to be promptly downregulated following IEC-traversal. These results highlight the importance of intestinal epithelial NAIP/NLRC4 in blocking bacterial dissemination in vivo, and explain why this constitutes a uniquely evasion-proof defense against the adapted enteropathogen S. Tm.
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23
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Salmonella enterica Effectors SifA, SpvB, SseF, SseJ, and SteA Contribute to Type III Secretion System 1-Independent Inflammation in a Streptomycin-Pretreated Mouse Model of Colitis. Infect Immun 2019; 87:IAI.00872-18. [PMID: 31235639 DOI: 10.1128/iai.00872-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 06/11/2019] [Indexed: 01/13/2023] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) induces inflammatory changes in the ceca of streptomycin-pretreated mice. In this mouse model of colitis, the type III secretion system 1 (T3SS-1) has been shown to induce rapid inflammatory change in the cecum at early points, 10 to 24 h after infection. Five proteins, SipA, SopA, SopB, SopD, and SopE2, have been identified as effectors involved in eliciting intestinal inflammation within this time range. In contrast, a T3SS-1-deficient strain was shown to exhibit inflammatory changes in the cecum at 72 to 120 h postinfection. However, the effectors eliciting T3SS-1-independent inflammation remain to be clarified. In this study, we focused on two T3SS-2 phenotypes, macrophage proliferation and cytotoxicity, to identify the T3SS-2 effectors involved in T3SS-1-independent inflammation. We identified a mutant strain that could not induce cytotoxicity in a macrophage-like cell line and that reduced intestinal inflammation in streptomycin-pretreated mice. We also identified five T3SS-2 effectors, SifA, SpvB, SseF, SseJ, and SteA, associated with T3SS-1-independent macrophage cytotoxicity. We then constructed a strain lacking T3SS-1 and all the five T3SS-2 effectors, termed T1S5. The S. Typhimurium T1S5 strain significantly reduced cytotoxicity in macrophages in the same manner as a mutant invA spiB strain (T1T2). Finally, the T1S5 strain elicited no inflammatory changes in the ceca of streptomycin-pretreated mice. We conclude that these five T3SS-2 effectors contribute to T3SS-1-independent inflammation.
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The Interplay between Salmonella enterica Serovar Typhimurium and the Intestinal Mucosa during Oral Infection. Microbiol Spectr 2019; 7. [PMID: 30953432 DOI: 10.1128/microbiolspec.bai-0004-2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bacterial infection results in a dynamic interplay between the pathogen and its host. The underlying interactions are multilayered, and the cellular responses are modulated by the local environment. The intestine is a particularly interesting tissue regarding host-pathogen interaction. It is densely colonized by commensal microbes and a portal of entry for ingested pathogens. This necessitates constant monitoring of microbial stimuli in order to maintain homeostasis during encounters with benign microbiota and to trigger immune defenses in response to bacterial pathogens. Homeostasis is maintained by physical barriers (the mucus layer and epithelium), chemical defenses (antimicrobial peptides), and innate immune responses (NLRC4 inflammasome), which keep the bacteria from reaching the sterile lamina propria. Intestinal pathogens represent potent experimental tools to probe these barriers and decipher how pathogens can circumvent them. The streptomycin mouse model of oral Salmonella enterica serovar Typhimurium infection provides a well-characterized, robust experimental system for such studies. Strikingly, each stage of the gut tissue infection poses a different set of challenges to the pathogen and requires tight control of virulence factor expression, host response modulation, and cooperation between phenotypic subpopulations. Therefore, successful infection of the intestinal tissue relies on a delicate and dynamic balance between responses of the pathogen and its host. These mechanisms can be deciphered to their full extent only in realistic in vivo infection models.
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Ibáñez L, Pontier-Bres R, Larbret F, Rekima A, Verhasselt V, Blin-Wakkach C, Czerucka D. Saccharomyces boulardii Strain CNCM I-745 Modifies the Mononuclear Phagocytes Response in the Small Intestine of Mice Following Salmonella Typhimurium Infection. Front Immunol 2019; 10:643. [PMID: 31001263 PMCID: PMC6455222 DOI: 10.3389/fimmu.2019.00643] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 03/08/2019] [Indexed: 12/23/2022] Open
Abstract
Intestinal mononuclear phagocytes (MPs) comprise dendritic cells (DCs) and macrophages (Mφs) that play different roles in response to Salmonella infection. After phagocytosis, DCs expressing CD103 transport Salmonella from the intestinal tract to the mesenteric lymph nodes (MLN) and induce adaptive immune responses whereas resident Mφs expressing CX3CR1 capture bacteria in the lumen and reside in the lamina propria (LP) where they induce a local immune response. CX3CR1+ Mφs are generated from Ly6Chi monocytes that enter the colonic mucosa and differentiate locally. We previously demonstrated that the probiotic yeast Saccharomyces boulardii CNCM I-745 (S.b) prevents infection by Salmonella enterica serovar Typhimurium (ST), decreases ST translocation to the peripheral organs and modifies the pro-and anti-inflammatory cytokine profiles in the gut. In the present study, we investigated the effect of S.b on the migratory CD103+ DCs and the resident CX3CR1+ Mφs. MPs were isolated from the LP of streptomycin-treated mice infected by ST with or without S.b treatment before or during the infection. In S.b-pretreated mice, we observed a decrease of the CD103+ DCs in the LP that was associated with the drop of ST recovery from MLN. Interestingly, S.b induced an infiltration of LP by classical Ly6Chi monocytes, and S.b modified the monocyte-Mφ maturation process in ST-infected mice. Our results showed that S.b treatment induced the expansion of Ly6Chi monocytes in the blood as well as in the bone marrow (BM) of mice, thus contributing to the Mφ replenishment in LP from blood monocytes. In vitro experiments conducted on BM cells confirmed that S.b induced the expansion of CX3CR1+ Mφs and concomitantly ST phagocytosis. Altogether, these data demonstrate that Saccharomyces boulardii CNCM I-745 modulates the innate immune response. Although here, we cannot explicitly delineate direct effects on ST from innate immunity, S. b-amplified innate immunity correlated with partial protection from ST infection. This study shows that S.b can induce the expansion of classical monocytes that are precursors of resident Mφs in the LP.
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Affiliation(s)
- Lidia Ibáñez
- CNRS, UMR 7370, LP2M, Faculté de Médecine, University Nice Sophia Antipolis, Nice, France.,University Nice Sophia Antipolis, Nice, France
| | | | - Frederic Larbret
- University Nice Sophia Antipolis, Nice, France.,EA6303, University Nice Sophia Antipolis, Hopital de l'Archet, Nice, France
| | - Akila Rekima
- EA6303, University Nice Sophia Antipolis, Hopital de l'Archet, Nice, France
| | - Valérie Verhasselt
- EA6303, University Nice Sophia Antipolis, Hopital de l'Archet, Nice, France
| | - Claudine Blin-Wakkach
- CNRS, UMR 7370, LP2M, Faculté de Médecine, University Nice Sophia Antipolis, Nice, France.,University Nice Sophia Antipolis, Nice, France
| | - Dorota Czerucka
- Ecosystems and Immunity team, Centre Scientifique de Monaco, Monaco, Monaco
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26
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Pang DJ, Huang C, Chen ML, Chen YL, Fu YP, Paulsen BS, Rise F, Zhang BZ, Chen ZL, Jia RY, Li LX, Song X, Feng B, Ni XQ, Yin ZQ, Zou YF. Characterization of Inulin-Type Fructan from Platycodon grandiflorus and Study on Its Prebiotic and Immunomodulating Activity. Molecules 2019; 24:molecules24071199. [PMID: 30934739 PMCID: PMC6479354 DOI: 10.3390/molecules24071199] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/17/2019] [Accepted: 03/25/2019] [Indexed: 01/12/2023] Open
Abstract
Platycodon grandiflorus is a plant widely used in traditional Chinese medicine, of which polysaccharides are reported to be the main components responsible for its bio-functions. In this work, the inulin-type fructan (PGF) was obtained by DEAE anion exchange chromatography from the water extracted from P. grandifloras. Characterization was performed with methanolysis, methylation, and NMR and the results showed that PGF is a β-(2-1) linked fructan, with terminal glucose and with a degree of polymerization of 2–10. In order to study its biofunctions, the prebiotic and immunomodulation properties were assayed. We found that PGF exhibited good prebiotic activity, as shown by a promotion on six strains of lactobacillus proliferation. Additionally, the PGF also displayed direct immunomodulation on intestinal epithelial cells and stimulated the expressions of anti-inflammatory factors. These results indicated that the inulin from P. grandiflorus is a potential natural source of prebiotics as well as a potential intestinal immunomodulator, which will be valuable for further studies and new applications.
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Affiliation(s)
- De-Jiang Pang
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Chao Huang
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Mei-Ling Chen
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Yu-Long Chen
- Sichuan Academy of Forestry, Chengdu 610081, China.
| | - Yu-Ping Fu
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Berit Smestad Paulsen
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P.O. Box 1068, Blindern, 0316 Oslo, Norway.
| | - Frode Rise
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway.
| | - Bing-Zhao Zhang
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen 518055, China.
| | - Zheng-Li Chen
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Ren-Yong Jia
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Li-Xia Li
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Xu Song
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Bin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
| | - Xue-Qin Ni
- Animal Microecology Institute, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Zhong-Qiong Yin
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
| | - Yuan-Feng Zou
- Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
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27
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The Role of the Host in Driving Phenotypic Heterogeneity in Salmonella. Trends Microbiol 2019; 27:508-523. [PMID: 30755344 DOI: 10.1016/j.tim.2019.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/21/2018] [Accepted: 01/18/2019] [Indexed: 02/07/2023]
Abstract
The complex infection environment within hosts exerts unique stresses across tissues and cell types, selecting for phenotypic heterogeneity in bacterial populations. Pathogens maintain variability during infection as a strategy to cope with fluctuating host immune conditions, leading to diversification of virulence phenotypes. Recent improvements in single-cell analyses have revealed that distinct bacterial subpopulations contribute unique colonization and growth strategies across infection sites. We discuss several examples of host-driven phenotypic heterogeneity in Salmonella populations throughout the course of infection, highlighting how variation in gene expression, growth rate, immune evasion, and metabolic activity contribute to overall bacterial success at the population level. We additionally focus our discussion on the implications of diversity within bacterial communities for antimicrobial efficacy.
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28
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Kulkarni DH, Newberry RD. Intestinal Macromolecular Transport Supporting Adaptive Immunity. Cell Mol Gastroenterol Hepatol 2019; 7:729-737. [PMID: 30710727 PMCID: PMC6463120 DOI: 10.1016/j.jcmgh.2019.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/11/2019] [Accepted: 01/11/2019] [Indexed: 12/13/2022]
Abstract
The gastrointestinal tract performs opposing functions of nutrient absorption, barrier maintenance, and the delivery of luminal substances for the appropriate induction of tolerogenic or protective adaptive immunity. The single-layer epithelium lining the gastrointestinal tract is central to each of these functions by facilitating the uptake and processing of nutrients, providing a physical and chemical barrier to potential pathogens, and delivering macromolecular substances to the immune system to initiate adaptive immune responses. Specific transport mechanisms allow nutrient uptake and the delivery of macromolecules to the immune system while maintaining the epithelial barrier. This review examines historical observations supporting macromolecular transport by the intestinal epithelium, recent insights into the transport of luminal macromolecules to promote adaptive immunity, and how this process is regulated to promote appropriate immune responses. Understanding how luminal macromolecules are delivered to the immune system and how this is regulated may provide insight into the pathophysiology of inflammatory diseases of the gastrointestinal tract and potential preventative or therapeutic strategies.
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Affiliation(s)
- Devesha H Kulkarni
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Rodney D Newberry
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri.
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29
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Knoop KA, Newberry RD. Goblet cells: multifaceted players in immunity at mucosal surfaces. Mucosal Immunol 2018; 11:1551-1557. [PMID: 29867079 PMCID: PMC8767637 DOI: 10.1038/s41385-018-0039-y] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/11/2018] [Accepted: 04/14/2018] [Indexed: 02/07/2023]
Abstract
Goblet cells (GCs) are specialized epithelial cells that line multiple mucosal surfaces and have a well-appreciated role in barrier maintenance through the secretion of mucus. Moreover, GCs secrete anti-microbial proteins, chemokines, and cytokines demonstrating functions in innate immunity beyond barrier maintenance. Recently it was appreciated that GCs can form goblet cell-associated antigen passages (GAPs) and deliver luminal substances to underlying lamina propria (LP) antigen-presenting cells (APCs) in a manner capable of inducing adaptive immune responses. GCs at other mucosal surfaces share characteristics with the GAP forming intestinal GCs, suggesting that GAP formation may not be restricted to the gut, and that GCs may perform this gatekeeper function at other mucosal surfaces. Here we review observations of how GCs contribute to immunity at mucosal surfaces through barrier maintenance, the delivery of luminal substances to APCs, interactions with APCs, and secretion of factors modulating immune responses.
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Affiliation(s)
- Kathryn A. Knoop
- Department of Internal Medicine, Washington University School of Medicine, St. Louis MO 63123,Send correspondence to: , 314-362-2670, Fax 314-362-2609, Correspondence and requests for materials should be addressed to KAK
| | - Rodney D. Newberry
- Department of Internal Medicine, Washington University School of Medicine, St. Louis MO 63123
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30
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Arunima A, Yelamanchi SD, Padhi C, Jaiswal S, Ryan D, Gupta B, Sathe G, Advani J, Gowda H, Prasad TSK, Suar M. "Omics" of Food-Borne Gastroenteritis: Global Proteomic and Mutagenic Analysis of Salmonella enterica Serovar Enteritidis. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2018; 21:571-583. [PMID: 29049011 DOI: 10.1089/omi.2017.0112] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Salmonella Enteritidis causes food-borne gastroenteritis by the two type three secretion systems (TTSS). TTSS-1 mediates invasion through intestinal lining, and TTSS-2 facilitates phagocytic survival. The pathogens' ability to infect effectively under TTSS-1-deficient background in host's phagocytes is poorly understood. Therefore, pathobiological understanding of TTSS-1-defective nontyphoidal Salmonellosis is highly important. We performed a comparative global proteomic analysis of the isogenic TTSS-1 mutant of Salmonella Enteritidis (M1511) and its wild-type isolate P125109. Our results showed 43 proteins were differentially expressed. Functional annotation further revealed that differentially expressed proteins belong to pathogenesis, tRNA and ncRNA metabolic processes. Three proteins, tryptophan subunit alpha chain, citrate lyase subunit alpha, and hypothetical protein 3202, were selected for in vitro analysis based on their functional annotations. Deletion mutants generated for the above proteins in the M1511 strain showed reduced intracellular survival inside macrophages in vitro. In sum, this study provides mass spectrometry-based evidence for seven hypothetical proteins, which will be subject of future investigations. Our study identifies proteins influencing virulence of Salmonella in the host. The study complements and further strengthens previously published research on proteins involved in enteropathogenesis of Salmonella and extends their role in noninvasive Salmonellosis.
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Affiliation(s)
| | - Soujanya D Yelamanchi
- 1 School of Biotechnology, KIIT University , Bhubaneswar, India .,2 Institute of Bioinformatics , International Technology Park, Bangalore, India
| | | | | | - Daniel Ryan
- 1 School of Biotechnology, KIIT University , Bhubaneswar, India
| | - Bhawna Gupta
- 1 School of Biotechnology, KIIT University , Bhubaneswar, India
| | - Gajanan Sathe
- 2 Institute of Bioinformatics , International Technology Park, Bangalore, India
| | - Jayshree Advani
- 2 Institute of Bioinformatics , International Technology Park, Bangalore, India
| | - Harsha Gowda
- 1 School of Biotechnology, KIIT University , Bhubaneswar, India .,2 Institute of Bioinformatics , International Technology Park, Bangalore, India
| | - T S Keshava Prasad
- 2 Institute of Bioinformatics , International Technology Park, Bangalore, India
| | - Mrutyunjay Suar
- 1 School of Biotechnology, KIIT University , Bhubaneswar, India
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31
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Abdel-Gadir A, Massoud AH, Chatila TA. Antigen-specific Treg cells in immunological tolerance: implications for allergic diseases. F1000Res 2018; 7:38. [PMID: 29375821 PMCID: PMC5765398 DOI: 10.12688/f1000research.12650.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/08/2018] [Indexed: 02/06/2023] Open
Abstract
Allergic diseases are chronic inflammatory disorders in which there is failure to mount effective tolerogenic immune responses to inciting allergens. The alarming rise in the prevalence of allergic diseases in recent decades has spurred investigations to elucidate the mechanisms of breakdown in tolerance in these disorders and means of restoring it. Tolerance to allergens is critically dependent on the generation of allergen-specific regulatory T (Treg) cells, which mediate a state of sustained non-responsiveness to the offending allergen. In this review, we summarize recent advances in our understanding of mechanisms governing the generation and function of allergen-specific Treg cells and their subversion in allergic diseases. We will also outline approaches to harness allergen-specific Treg cell responses to restore tolerance in these disorders.
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Affiliation(s)
- Azza Abdel-Gadir
- Division of Immunology, Boston Children's Hospital, Boston, USA.,Department of Pediatrics, Harvard Medical School, Boston, USA
| | - Amir H Massoud
- Division of Immunology, Boston Children's Hospital, Boston, USA.,Department of Pediatrics, Harvard Medical School, Boston, USA
| | - Talal A Chatila
- Division of Immunology, Boston Children's Hospital, Boston, USA.,Department of Pediatrics, Harvard Medical School, Boston, USA
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32
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Consequences of Epithelial Inflammasome Activation by Bacterial Pathogens. J Mol Biol 2018; 430:193-206. [DOI: 10.1016/j.jmb.2017.03.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 01/02/2023]
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33
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Knoop KA, Gustafsson JK, McDonald KG, Kulkarni DH, Coughlin PE, McCrate S, Kim D, Hsieh CS, Hogan SP, Elson CO, Tarr PI, Newberry RD. Microbial antigen encounter during a preweaning interval is critical for tolerance to gut bacteria. Sci Immunol 2017; 2:eaao1314. [PMID: 29246946 PMCID: PMC5759965 DOI: 10.1126/sciimmunol.aao1314] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/06/2017] [Indexed: 12/28/2022]
Abstract
We have a mutually beneficial relationship with the trillions of microorganisms inhabiting our gastrointestinal tract. However, maintaining this relationship requires recognizing these organisms as affable and restraining inflammatory responses to these organisms when encountered in hostile settings. How and when the immune system develops tolerance to our gut microbial members is not well understood. We identify a specific preweaning interval in which gut microbial antigens are encountered by the immune system to induce antigen-specific tolerance to gut bacteria. For some bacterial taxa, physiologic encounters with the immune system are restricted to this interval, despite abundance of these taxa in the gut lumen at later times outside this interval. Antigen-specific tolerance to gut bacteria induced during this preweaning interval is stable and maintained even if these taxa are encountered later in life in an inflammatory setting. However, inhibiting microbial antigen encounter during this interval or extending these encounters beyond the normal interval results in a failure to induce tolerance and robust antigen-specific effector responses to gut bacteria upon reencounter in an inflammatory setting. Thus, we have identified a defined preweaning interval critical for developing tolerance to gut bacteria and maintaining the mutually beneficial relationship with our gut microbiota.
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Affiliation(s)
- Kathryn A Knoop
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jenny K Gustafsson
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Keely G McDonald
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Devesha H Kulkarni
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Paige E Coughlin
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stephanie McCrate
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Dongyeon Kim
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chyi-Song Hsieh
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Simon P Hogan
- Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Charles O Elson
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Phillip I Tarr
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rodney D Newberry
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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34
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Lutz C, Weder B, Hünerwadel A, Fagagnini S, Lang B, Beerenwinkel N, Rossel JB, Rogler G, Misselwitz B, Hausmann M. Myeloid differentiation primary response gene (MyD) 88 signalling is not essential for intestinal fibrosis development. Sci Rep 2017; 7:17678. [PMID: 29247242 PMCID: PMC5732165 DOI: 10.1038/s41598-017-17755-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/29/2017] [Indexed: 01/15/2023] Open
Abstract
Dysregulation of the immune response to microbiota is associated with inflammatory bowel disease (IBD), which can trigger intestinal fibrosis. MyD88 is a key component of microbiota signalling but its influence on intestinal fibrosis has not been clarified. Small bowel resections from donor-mice were transplanted subcutaneously into the neck of recipients C57BL/6 B6-MyD88tm1 Aki (MyD88-/-) and C57BL/6-Tg(UBC-green fluorescence protein (GFP))30Scha/J (GFP-Tg). Grafts were explanted up to 21 days after transplantation. Collagen layer thickness was determined using Sirius Red stained slides. In the mouse model of fibrosis collagen deposition and transforming growth factor-beta 1 (TGF-β1) expression was equal in MyD88+/+ and MyD88-/-, indicating that MyD88 was not essential for fibrogenesis. Matrix metalloproteinase (Mmp)9 expression was significantly decreased in grafts transplanted into MyD88-/- recipients compared to MyD88+/+ recipients (0.2 ± 0.1 vs. 153.0 ± 23.1, respectively, p < 0.05), similarly recruitment of neutrophils was significantly reduced (16.3 ± 4.5 vs. 25.4 ± 3.1, respectively, p < 0.05). Development of intestinal fibrosis appears to be independent of MyD88 signalling indicating a minor role of bacterial wall compounds in the process which is in contrast to published concepts and theories. Development of fibrosis appears to be uncoupled from acute inflammation.
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Affiliation(s)
- C Lutz
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland
| | - B Weder
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland
| | - A Hünerwadel
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland
| | - S Fagagnini
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland
| | - B Lang
- Department of Biosystems Sciences and Engineering, ETH Zurich, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Basel, Switzerland
| | - N Beerenwinkel
- Department of Biosystems Sciences and Engineering, ETH Zurich, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Basel, Switzerland
| | - J B Rossel
- Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland
| | - G Rogler
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland
| | - B Misselwitz
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland
| | - M Hausmann
- Department of Gastroenterology and Hepatology, University Hospital, Zurich, Switzerland.
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35
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Regoli M, Bertelli E, Gulisano M, Nicoletti C. The Multifaceted Personality of Intestinal CX 3 CR1 + Macrophages. Trends Immunol 2017; 38:879-887. [DOI: 10.1016/j.it.2017.07.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 07/20/2017] [Accepted: 07/24/2017] [Indexed: 12/30/2022]
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36
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Knoop KA, Gustafsson JK, McDonald KG, Kulkarni DH, Kassel R, Newberry RD. Antibiotics promote the sampling of luminal antigens and bacteria via colonic goblet cell associated antigen passages. Gut Microbes 2017; 8:400-411. [PMID: 28267403 PMCID: PMC5570560 DOI: 10.1080/19490976.2017.1299846] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/11/2017] [Accepted: 02/21/2017] [Indexed: 02/03/2023] Open
Abstract
Bacterial translocation is defined as the passage of live bacteria from the gut lumen to distant sites. Gut commensal bacteria translocation has been attributed to 'leakiness', or 'barrier breach' of the intestinal epithelium, allowing live bacteria to cross an inappropriately permeable barrier and disseminate to distant sites. Alternatively, studies suggest dendritic cells directly capture luminal commensal bacteria and transport them to distant sites in the steady-state by extending dendrites between epithelial cells into the lumen. Recently we identified translocation of commensal gut bacteria following antibiotics was associated with the formation of goblet cell associated antigen passages (GAPs) in the colon and dependent upon goblet cells (GCs). The translocation of native gut commensal bacteria resulted in low-level inflammatory responses and potentiated mucosal damage in response to concurrent epithelial injury. Here we extend these observations and demonstrate properties of colonic GAPs and observations supporting their priority in the translocation of colonic commensal bacteria.
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Affiliation(s)
- Kathryn A. Knoop
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jenny K. Gustafsson
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Keely G. McDonald
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Devesha H. Kulkarni
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rachel Kassel
- Department of Pediatrics, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Rodney D. Newberry
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
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37
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Kim D, Seo SU, Zeng MY, Kim WU, Kamada N, Inohara N, Núñez G. Mesenchymal Cell-Specific MyD88 Signaling Promotes Systemic Dissemination of Salmonella Typhimurium via Inflammatory Monocytes. THE JOURNAL OF IMMUNOLOGY 2017; 199:1362-1371. [PMID: 28674182 DOI: 10.4049/jimmunol.1601527] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 06/07/2017] [Indexed: 12/24/2022]
Abstract
Enteric pathogens including Salmonella enteric serovar Typhimurium can breach the epithelial barrier of the host and spread to systemic tissues. In response to infection, the host activates innate immune receptors via the signaling molecule MyD88, which induces protective inflammatory and antimicrobial responses. Most of these innate immune responses have been studied in hematopoietic cells, but the role of MyD88 signaling in other cell types remains poorly understood. Surprisingly, we found that Dermo1-Cre;Myd88fl/fl mice with mesenchymal cell-specific deficiency of MyD88 were less susceptible to orogastric and i.p. STyphimurium infection than their Myd88fl/fl littermates. The reduced susceptibility of Dermo1-Cre;Myd88fl/fl mice to infection was associated with lower loads of S. Typhimurium in the liver and spleen. Mutant analyses revealed that S. Typhimurium employs its virulence type III secretion system 2 to promote its growth through MyD88 signaling pathways in mesenchymal cells. Inflammatory monocytes function as a major cell population for systemic dissemination of S. Typhimurium Mechanistically, mesenchymal cell-specific MyD88 signaling promoted CCL2 production in the liver and spleen and recruitment of inflammatory monocytes to systemic organs in response to STyphimurium infection. Consistently, MyD88 signaling in mesenchymal cells enhanced the number of phagocytes including Ly6ChiLy6G- inflammatory monocytes harboring STyphimurium in the liver. These results suggest that S. Typhimurium promotes its systemic growth and dissemination through MyD88 signaling pathways in mesenchymal cells.
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Affiliation(s)
- Donghyun Kim
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109.,Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109.,Center for Integrative Rheumatoid Transcriptomics and Dynamics, Catholic University of Korea, Seoul 06591, Korea
| | - Sang-Uk Seo
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109.,Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109.,Department of Biomedical Sciences, Wide River Institute of Immunology, Seoul National University College of Medicine, Gangwon-do 25159, Korea
| | - Melody Y Zeng
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109.,Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Wan-Uk Kim
- Center for Integrative Rheumatoid Transcriptomics and Dynamics, Catholic University of Korea, Seoul 06591, Korea.,Department of Internal Medicine, College of Medicine, Catholic University of Korea, Seoul 06591, Korea; and
| | - Nobuhiko Kamada
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Naohiro Inohara
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Gabriel Núñez
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109; .,Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109
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38
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Wotzka SY, Nguyen BD, Hardt WD. Salmonella Typhimurium Diarrhea Reveals Basic Principles of Enteropathogen Infection and Disease-Promoted DNA Exchange. Cell Host Microbe 2017; 21:443-454. [PMID: 28407482 DOI: 10.1016/j.chom.2017.03.009] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/17/2017] [Accepted: 03/24/2017] [Indexed: 12/18/2022]
Abstract
Despite decades of research, efficient therapies for most enteropathogenic bacteria are still lacking. In this review, we focus on Salmonella enterica Typhimurium (S. Typhimurium), a frequent cause of acute, self-limiting food-borne diarrhea and a model that has revealed key principles of enteropathogen infection. We review the steps of gut infection and the mucosal innate-immune defenses limiting pathogen burdens, and we discuss how inflammation boosts gut luminal S. Typhimurium growth. We also discuss how S. Typhimurium-induced inflammation accelerates the transfer of plasmids and phages, which may promote the transmission of antibiotic resistance and facilitate emergence of pathobionts and pathogens with enhanced virulence. The targeted manipulation of the microbiota and vaccination might offer strategies to prevent this evolution. As gut luminal microbes impact various aspects of the host's physiology, improved strategies for preventing enteropathogen infection and disease-inflicted DNA exchange may be of broad interest well beyond the acute infection.
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Affiliation(s)
- Sandra Y Wotzka
- Institute of Microbiology, ETH Zurich, 8093 Zurich, Switzerland
| | - Bidong D Nguyen
- Institute of Microbiology, ETH Zurich, 8093 Zurich, Switzerland
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39
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Diard M, Bakkeren E, Cornuault JK, Moor K, Hausmann A, Sellin ME, Loverdo C, Aertsen A, Ackermann M, De Paepe M, Slack E, Hardt WD. Inflammation boosts bacteriophage transfer between Salmonella spp. Science 2017; 355:1211-1215. [PMID: 28302859 DOI: 10.1126/science.aaf8451] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 12/19/2016] [Accepted: 02/22/2017] [Indexed: 12/12/2022]
Abstract
Bacteriophage transfer (lysogenic conversion) promotes bacterial virulence evolution. There is limited understanding of the factors that determine lysogenic conversion dynamics within infected hosts. A murine Salmonella Typhimurium (STm) diarrhea model was used to study the transfer of SopEΦ, a prophage from STm SL1344, to STm ATCC14028S. Gut inflammation and enteric disease triggered >55% lysogenic conversion of ATCC14028S within 3 days. Without inflammation, SopEΦ transfer was reduced by up to 105-fold. This was because inflammation (e.g., reactive oxygen species, reactive nitrogen species, hypochlorite) triggers the bacterial SOS response, boosts expression of the phage antirepressor Tum, and thereby promotes free phage production and subsequent transfer. Mucosal vaccination prevented a dense intestinal STm population from inducing inflammation and consequently abolished SopEΦ transfer. Vaccination may be a general strategy for blocking pathogen evolution that requires disease-driven transfer of temperate bacteriophages.
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Affiliation(s)
| | | | - Jeffrey K Cornuault
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy en Josas, France
| | - Kathrin Moor
- Institute of Microbiology, ETH Zurich, Switzerland
| | | | - Mikael E Sellin
- Institute of Microbiology, ETH Zurich, Switzerland.,Present address: Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden
| | - Claude Loverdo
- Laboratoire Jean Perrin (UMR 8237), CNRS-UPMC, 75005 Paris, France
| | - Abram Aertsen
- Department of Microbial and Molecular Systems, KU Leuven, Belgium
| | - Martin Ackermann
- Department of Environmental Systems Science, ETH Zurich, and Department of Environmental Microbiology, Eawag, Switzerland
| | - Marianne De Paepe
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy en Josas, France
| | - Emma Slack
- Institute of Microbiology, ETH Zurich, Switzerland
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40
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Gut microbiota and hematopoietic stem cell transplantation: where do we stand? Bone Marrow Transplant 2016; 52:7-14. [PMID: 27348539 DOI: 10.1038/bmt.2016.173] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/10/2016] [Accepted: 05/13/2016] [Indexed: 12/26/2022]
Abstract
Advances in biological techniques have potentiated great progresses in understanding the interaction between human beings and the ∼10 to 100 trillion microbes living in their gastrointestinal tract: gut microbiota (GM). In this review, we describe recent emerging data on the role of GM in hematopoietic stem cell transplantation, with a focus on immunomodulatory properties in the immune system recovery and the impact in the development of the main complications, as GvHD and infections.
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41
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Müller AA, Dolowschiak T, Sellin ME, Felmy B, Verbree C, Gadient S, Westermann AJ, Vogel J, LeibundGut-Landmann S, Hardt WD. An NK Cell Perforin Response Elicited via IL-18 Controls Mucosal Inflammation Kinetics during Salmonella Gut Infection. PLoS Pathog 2016; 12:e1005723. [PMID: 27341123 PMCID: PMC4920399 DOI: 10.1371/journal.ppat.1005723] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/03/2016] [Indexed: 01/26/2023] Open
Abstract
Salmonella Typhimurium (S.Tm) is a common cause of self-limiting diarrhea. The mucosal inflammation is thought to arise from a standoff between the pathogen's virulence factors and the host's mucosal innate immune defenses, particularly the mucosal NAIP/NLRC4 inflammasome. However, it had remained unclear how this switches the gut from homeostasis to inflammation. This was studied using the streptomycin mouse model. S.Tm infections in knockout mice, cytokine inhibition and –injection experiments revealed that caspase-1 (not -11) dependent IL-18 is pivotal for inducing acute inflammation. IL-18 boosted NK cell chemoattractants and enhanced the NK cells' migratory capacity, thus promoting mucosal accumulation of mature, activated NK cells. NK cell depletion and Prf-/- ablation (but not granulocyte-depletion or T-cell deficiency) delayed tissue inflammation. Our data suggest an NK cell perforin response as one limiting factor in mounting gut mucosal inflammation. Thus, IL-18-elicited NK cell perforin responses seem to be critical for coordinating mucosal inflammation during early infection, when S.Tm strongly relies on virulence factors detectable by the inflammasome. This may have broad relevance for mucosal defense against microbial pathogens. Salmonella Typhimurium is a common cause of foodborne diarrhea. The disease symptoms arise already a few hours after infection. However, it had remained unclear how the immune system can mount the responses eliciting the disease symptoms so quickly. Earlier work in a mouse model had shown that the gut epithelium expresses a sensor, called NAIP/NLRC4/caspase-1 inflammasome that can detect the pathogen and mount a defense by 12-18h p.i. However, it has remained uncharacterized how inflammasome sensing drives the initial gut inflammation. Here, we found that the caspase-1 inflammasome triggers the production of IL-18, a pro-inflammatory cytokine that appears essential for the early onset of inflammation. IL-18 is driving the accumulation of NK cells into the infected mucosa, via the upregulation of NK cell chemoattractants and by the stimulation of their migratory capacity. Mature NK cells seem to induce mucosal inflammation via a perforin-mediated cytotoxic response. These data suggest that the inflammasome/IL-18/NK cell axis is a driver of early mucosal inflammation via a perforin-dependent cytotoxic NK cell response. Future work will have to address, if this mechanism is equally potent in the human gut and may contribute to ramping up the host's response during the first hours of infection. This may have implications for other gut infections and might provide leads for developing therapies.
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Affiliation(s)
- Anna A. Müller
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | | | - Mikael E. Sellin
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
- Department of Cell and Molecular Biology, Microbiology, Uppsala University, Uppsala, Sweden
| | - Boas Felmy
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | | | - Sandra Gadient
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | | | - Jörg Vogel
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
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42
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Allen F, Tong AA, Huang AY. Unique Transcompartmental Bridge: Antigen-Presenting Cells Sampling across Endothelial and Mucosal Barriers. Front Immunol 2016; 7:231. [PMID: 27375624 PMCID: PMC4901051 DOI: 10.3389/fimmu.2016.00231] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 05/27/2016] [Indexed: 12/13/2022] Open
Abstract
Potentially harmful pathogens can gain access to tissues and organ systems through body sites that are in direct contact with the outside environment, such as the skin, the gut, and the airway mucosa. Antigen-presenting cells (APCs) represent a bridge between the innate and adaptive immunity, and their capacity for constant immune surveillance and rapid sampling of incoming pathogens and other potentially harmful antigens is central for mounting an effective and robust protective host response. The classical view is that APCs perform this task efficiently within the tissue to sense invading agents intra-compartmentally. However, recent data based on high resolution imaging support an additional transcompartmental surveillance behavior by APC by reaching across intact physical barriers. In this review, we summarize intravital microscopic evidences of APC to sample antigens transcompartmentally at the gut mucosa and other body sites.
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Affiliation(s)
- Frederick Allen
- Department of Pathology, Case Western Reserve University School of Medicine , Cleveland, OH , USA
| | - Alexander A Tong
- Department of Pathology, Case Western Reserve University School of Medicine , Cleveland, OH , USA
| | - Alex Y Huang
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, OH, USA; Angie Fowler AYA Cancer Institute, University Hospitals Rainbow Babies & Children's Hospital, Cleveland, OH, USA
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43
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Burcelin R. Gut microbiota and immune crosstalk in metabolic disease. Mol Metab 2016; 5:771-81. [PMID: 27617200 PMCID: PMC5004167 DOI: 10.1016/j.molmet.2016.05.016] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 05/24/2016] [Accepted: 05/31/2016] [Indexed: 12/29/2022] Open
Abstract
Background Gut microbiota is considered as a major regulator of metabolic disease. This reconciles the notion of metabolic inflammation and the epidemic development of the disease. In addition to evidence showing that a specific gut microbiota characterizes patients with obesity, type 2 diabetes, and hepatic steatosis, the mechanisms causal to the disease could be related to the translocation of microbiota from the gut to the tissues, inducing inflammation. The mechanisms regulating such a process are based on the crosstalk between the gut microbiota and the host immune system. The hologenome theory of evolution supports this concept and implies that therapeutic strategies aiming to control glycemia should take into account both the gut microbiota and the host immune system. Scope of review This review discusses the latest evidence regarding the bidirectional impact of the gut microbiota on host immune system crosstalk for the control of metabolic disease, hyperglycemia, and obesity. To avoid redundancies with the literature, we will focus our attention on the intestinal immune system, identifying evidence for the generation of novel therapeutic strategies, which could be based on the control of the translocation of gut bacteria to tissues. Such novel strategies should hamper the role played by gut microbiota dysbiosis on the development of metabolic inflammation. Major conclusions Recent evidence in rodents allows us to conclude that an impaired intestinal immune system characterizes and could be causal in the development of metabolic disease. The fine understanding of the molecular mechanisms should allow for the development of a first line of treatment for metabolic disease and its co-morbidities. This article is part of a special issue on microbiota.
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Affiliation(s)
- Rémy Burcelin
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France
- Université Paul Sabatier (UPS), Unité Mixte de Recherche (UMR) 1048, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), F-31432 Toulouse Cedex 4, France
- Inserm 1048, Hôpital Rangueil, 31400 Toulouse, France. Tel.: +33 561 32 56 14; fax: +33 561 32 56 21.Inserm 1048Hôpital RangueilToulouse31400France
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44
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Fransen F, Zagato E, Mazzini E, Fosso B, Manzari C, El Aidy S, Chiavelli A, D'Erchia AM, Sethi MK, Pabst O, Marzano M, Moretti S, Romani L, Penna G, Pesole G, Rescigno M. BALB/c and C57BL/6 Mice Differ in Polyreactive IgA Abundance, which Impacts the Generation of Antigen-Specific IgA and Microbiota Diversity. Immunity 2015; 43:527-40. [PMID: 26362264 DOI: 10.1016/j.immuni.2015.08.011] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 05/12/2015] [Accepted: 08/10/2015] [Indexed: 12/20/2022]
Abstract
The interrelationship between IgAs and microbiota diversity is still unclear. Here we show that BALB/c mice had higher abundance and diversity of IgAs than C57BL/6 mice and that this correlated with increased microbiota diversity. We show that polyreactive IgAs mediated the entrance of non-invasive bacteria to Peyer's patches, independently of CX3CR1(+) phagocytes. This allowed the induction of bacteria-specific IgA and the establishment of a positive feedback loop of IgA production. Cohousing of mice or fecal transplantation had little or no influence on IgA production and had only partial impact on microbiota composition. Germ-free BALB/c, but not C57BL/6, mice already had polyreactive IgAs that influenced microbiota diversity and selection after colonization. Together, these data suggest that genetic predisposition to produce polyreactive IgAs has a strong impact on the generation of antigen-specific IgAs and the selection and maintenance of microbiota diversity.
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Affiliation(s)
- Floris Fransen
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy
| | - Elena Zagato
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy
| | - Elisa Mazzini
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy
| | - Bruno Fosso
- Institute of Biomembranes and Bioenergetics, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy
| | - Caterina Manzari
- Institute of Biomembranes and Bioenergetics, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy
| | - Sahar El Aidy
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy; Groningen Biomolecular Sciences and Biotechnology, Faculty of Mathematics and Natural Sciences, Nijenborgh 7, 9700 CC Groningen, the Netherlands
| | - Andrea Chiavelli
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy
| | - Anna Maria D'Erchia
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Maya K Sethi
- Institute of Immunology, Hannover Medical School, Carl-Neuberg-Stra. 1, 30625 Hannover, Germany
| | - Oliver Pabst
- Institute of Molecular Medicine, RWTH Aachen University, Carl-Neuberg-Str. 1, 52074 Aachen, Germany
| | - Marinella Marzano
- Institute of Biomembranes and Bioenergetics, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy
| | - Silvia Moretti
- Department of Experimental Medicine, University of Perugia, Polo Unico Sant'Andrea delle Fratte, 06132 Perugia, Italy
| | - Luigina Romani
- Department of Experimental Medicine, University of Perugia, Polo Unico Sant'Andrea delle Fratte, 06132 Perugia, Italy
| | - Giuseppe Penna
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy
| | - Graziano Pesole
- Institute of Biomembranes and Bioenergetics, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy; Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Maria Rescigno
- Department of Experimental Oncology and Immunotherapy Programme, IEO, Via Adamello 16, 20139 Milan, Italy; Dipartimento di Scienze della salute, Universita' di Milano, via Rudini 8, 20142 Milan, Italy.
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45
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Abstract
Macrophages form a heterogeneous group of hematopoietic cells that reside in tissues, where they are required to maintain organ integrity. Tissue macrophages contribute to tissue formation, metabolism, homeostasis, and repair. They have a unique ability to sense and respond to tissue damage. They serve as the first line of defense during infection and help promote immune tolerance in the steady state. Although most tissue macrophages share a high phagocytic and degradative potential, they are heterogeneous in origin, as well as in homeostatic function and response to insults. Here, we will discuss recent developments in our understanding of the origin of tissue macrophages and their functional specialization in tissues.
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Affiliation(s)
- Yonit Lavin
- Authors' Affiliation: Department of Oncological Science, The Tisch Cancer Institute and The Immunology Institute, Mount Sinai School of Medicine, New York, New York
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46
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Jennewein J, Matuszak J, Walter S, Felmy B, Gendera K, Schatz V, Nowottny M, Liebsch G, Hensel M, Hardt WD, Gerlach RG, Jantsch J. Low-oxygen tensions found in Salmonella-infected gut tissue boost Salmonella replication in macrophages by impairing antimicrobial activity and augmenting Salmonella virulence. Cell Microbiol 2015; 17:1833-47. [PMID: 26104016 DOI: 10.1111/cmi.12476] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 05/17/2015] [Accepted: 06/18/2015] [Indexed: 12/28/2022]
Abstract
In Salmonella infection, the Salmonella pathogenicity island-2 (SPI-2)-encoded type three secretion system (T3SS2) is of key importance for systemic disease and survival in host cells. For instance, in the streptomycin-pretreated mouse model SPI-2-dependent Salmonella replication in lamina propria CD11c(-)CXCR1(-) monocytic phagocytes/macrophages (MΦ) is required for the development of colitis. In addition, containment of intracellular Salmonella in the gut critically depends on the antimicrobial effects of the phagocyte NADPH oxidase (PHOX), and possibly type 2 nitric oxide synthase (NOS2). For both antimicrobial enzyme complexes, oxygen is an essential substrate. However, the amount of available oxygen upon enteroinvasive Salmonella infection in the gut tissue and its impact on Salmonella-MΦ interactions was unknown. Therefore, we measured the gut tissue oxygen levels in a model of Salmonella enterocolitis using luminescence two-dimensional in vivo oxygen imaging. We found that gut tissue oxygen levels dropped from ∼78 Torr (∼11% O2) to values of ∼16 Torr (∼2% O2) during infection. Because in vivo virulence of Salmonella depends on the Salmonella survival in MΦ, Salmonella-MΦ interaction was analysed under such low oxygen values. These experiments revealed an increased intracellular replication and survival of wild-type and t3ss2 non-expressing Salmonella. These findings were paralleled by blunted nitric oxide and reactive oxygen species (ROS) production and reduced Salmonella ROS perception. In addition, hypoxia enhanced SPI-2 transcription and translocation of SPI-2-encoded virulence protein. Neither pharmacological blockade of PHOX and NOS2 nor impairment of T3SS2 virulence function alone mimicked the effect of hypoxia on Salmonella replication under normoxic conditions. However, if t3ss2 non-expressing Salmonella were used, hypoxia did not further enhance Salmonella recovery in a PHOX and NOS2-deficient situation. Hence, these data suggest that hypoxia-induced impairment of antimicrobial activity and Salmonella virulence cooperate to allow for enhanced Salmonella replication in MΦ.
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Affiliation(s)
- Jonas Jennewein
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Erlangen und Friedrich-Alexander Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany.,Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Regensburg und Universität Regensburg, Regensburg, Germany
| | - Jasmin Matuszak
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Erlangen und Friedrich-Alexander Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
| | - Steffi Walter
- Robert Koch-Institut, Bereich Wernigerode, Wernigerode, Germany
| | - Boas Felmy
- Institut für Mikrobiologie, ETH Zürich, Zürich, Switzerland
| | - Kathrin Gendera
- Robert Koch-Institut, Bereich Wernigerode, Wernigerode, Germany
| | - Valentin Schatz
- Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Regensburg und Universität Regensburg, Regensburg, Germany
| | - Monika Nowottny
- Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Regensburg und Universität Regensburg, Regensburg, Germany
| | | | - Michael Hensel
- Abteilung Mikrobiologie, Fachbereich Biologie / Chemie, Universität Osnabrück, Osnabrück, Germany
| | | | - Roman G Gerlach
- Robert Koch-Institut, Bereich Wernigerode, Wernigerode, Germany
| | - Jonathan Jantsch
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Erlangen und Friedrich-Alexander Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany.,Institut für Klinische Mikrobiologie und Hygiene, Universitätsklinikum Regensburg und Universität Regensburg, Regensburg, Germany
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47
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Gross M, Salame TM, Jung S. Guardians of the Gut - Murine Intestinal Macrophages and Dendritic Cells. Front Immunol 2015; 6:254. [PMID: 26082775 PMCID: PMC4451680 DOI: 10.3389/fimmu.2015.00254] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/07/2015] [Indexed: 12/14/2022] Open
Abstract
Intestinal mononuclear phagocytes find themselves in a unique environment, most prominently characterized by its constant exposure to commensal microbiota and food antigens. This anatomic setting has resulted in a number of specializations of the intestinal mononuclear phagocyte compartment that collectively contribute the unique steady state immune landscape of the healthy gut, including homeostatic innate lymphoid cells, B, and T cell compartments. As in other organs, macrophages and dendritic cells (DCs) orchestrate in addition the immune defense against pathogens, both in lymph nodes and mucosa-associated lymphoid tissue. Here, we will discuss origins and functions of intestinal DCs and macrophages and their respective subsets, focusing largely on the mouse and cells residing in the lamina propria.
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Affiliation(s)
- Mor Gross
- Department of Immunology, Weizmann Institute of Science , Rehovot , Israel ; Biological Services, Weizmann Institute of Science , Rehovot , Israel
| | - Tomer-Meir Salame
- Department of Immunology, Weizmann Institute of Science , Rehovot , Israel ; Biological Services, Weizmann Institute of Science , Rehovot , Israel
| | - Steffen Jung
- Department of Immunology, Weizmann Institute of Science , Rehovot , Israel ; Biological Services, Weizmann Institute of Science , Rehovot , Israel
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Sellin ME, Müller AA, Felmy B, Dolowschiak T, Diard M, Tardivel A, Maslowski KM, Hardt WD. Epithelium-intrinsic NAIP/NLRC4 inflammasome drives infected enterocyte expulsion to restrict Salmonella replication in the intestinal mucosa. Cell Host Microbe 2015; 16:237-248. [PMID: 25121751 DOI: 10.1016/j.chom.2014.07.001] [Citation(s) in RCA: 283] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/20/2014] [Accepted: 06/30/2014] [Indexed: 01/08/2023]
Abstract
The gut mucosal epithelium separates the host from the microbiota, but enteropathogens such as Salmonella Typhimurium (S.Tm) can invade and breach this barrier. Defenses against such acute insults remain incompletely understood. Using a murine model of Salmonella enterocolitis, we analyzed mechanisms limiting pathogen loads in the epithelium during early infection. Although the epithelium-invading S.Tm replicate initially, this intraepithelial replicative niche is restricted by expulsion of infected enterocytes into the lumen. This mechanism is compromised if inflammasome components (NAIP1-6, NLRC4, caspase-1/-11) are deleted, or ablated specifically in the epithelium, resulting in ∼100-fold higher intraepithelial loads and accelerated lymph node colonization. Interestingly, the cytokines downstream of inflammasome activation, interleukin (IL)-1α/β and IL-18, appear dispensable for epithelial restriction of early infection. These data establish the role of an epithelium-intrinsic inflammasome, which drives expulsion of infected cells to restrict the pathogen's intraepithelial proliferation. This may represent a general defense mechanism against mucosal infections.
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Affiliation(s)
- Mikael E Sellin
- Institute of Microbiology, ETH Zürich, 8093 Zürich, Switzerland.
| | - Anna A Müller
- Institute of Microbiology, ETH Zürich, 8093 Zürich, Switzerland
| | - Boas Felmy
- Institute of Microbiology, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Médéric Diard
- Institute of Microbiology, ETH Zürich, 8093 Zürich, Switzerland
| | - Aubry Tardivel
- Department of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland
| | - Kendle M Maslowski
- Department of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland; Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama 230-0045, Japan
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Now you see me, now you don't: the interaction of Salmonella with innate immune receptors. Nat Rev Microbiol 2015; 13:206-16. [PMID: 25749454 DOI: 10.1038/nrmicro3428] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Salmonella enterica serovars are associated with an estimated 1 million deaths annually and are also useful model organisms for investigating the mechanisms of host-bacterium interactions. The insights gained from studies on non-typhoidal Salmonella (NTS) serovars have provided a fascinating overview of the mechanisms by which the innate immune system detects and responds to bacterial pathogens. However, specific virulence factors and changes in virulence gene regulation in S. enterica subsp. enterica serovar Typhi alter the innate immune responses to this pathogen. In this Review, we compare and contrast the interactions of S. Typhi and NTS serovars with host innate immune receptors and discuss why the disease manifestations associated with S. Typhi infection differ considerably from those associated with the closely related NTS serovars.
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Slack E, Balmer ML, Macpherson AJ. B cells as a critical node in the microbiota-host immune system network. Immunol Rev 2015; 260:50-66. [PMID: 24942681 DOI: 10.1111/imr.12179] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mutualism with our intestinal microbiota is a prerequisite for healthy existence. This requires physical separation of the majority of the microbiota from the host (by secreted antimicrobials, mucus, and the intestinal epithelium) and active immune control of the low numbers of microbes that overcome these physical and chemical barriers, even in healthy individuals. In this review, we address how B-cell responses to members of the intestinal microbiota form a robust network with mucus, epithelial integrity, follicular helper T cells, innate immunity, and gut-associated lymphoid tissues to maintain host-microbiota mutualism.
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Affiliation(s)
- Emma Slack
- Institute for Microbiology, ETH Zürich, Zurich, Switzerland
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