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Pearson JA, Hu Y, Peng J, Wong FS, Wen L. TLR5-deficiency controls dendritic cell subset development in an autoimmune diabetes-susceptible model. Front Immunol 2024; 15:1333967. [PMID: 38482010 PMCID: PMC10935730 DOI: 10.3389/fimmu.2024.1333967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/06/2024] [Indexed: 03/17/2024] Open
Abstract
Introduction The incidence of the autoimmune disease, type 1 diabetes (T1D), has been increasing worldwide and recent studies have shown that the gut microbiota are associated with modulating susceptibility to T1D. Toll-like receptor 5 (TLR5) recognizes bacterial flagellin and is widely expressed on many cells, including dendritic cells (DCs), which are potent antigen-presenting cells (APCs). TLR5 modulates susceptibility to obesity and alters metabolism through gut microbiota; however, little is known about the role TLR5 plays in autoimmunity, especially in T1D. Methods To fill this knowledge gap, we generated a TLR5-deficient non-obese diabetic (NOD) mouse, an animal model of human T1D, for study. Results We found that TLR5-deficiency led to a reduction in CD11c+ DC development in utero, prior to microbial colonization, which was maintained into adulthood. This was associated with a bias in the DC populations expressing CD103, with or without CD8α co-expression, and hyper-secretion of different cytokines, both in vitro (after stimulation) and directly ex vivo. We also found that TLR5-deficient DCs were able to promote polyclonal and islet antigen-specific CD4+ T cell proliferation and proinflammatory cytokine secretion. Interestingly, only older TLR5-deficient NOD mice had a greater risk of developing spontaneous T1D compared to wild-type mice. Discussion In summary, our data show that TLR5 modulates DC development and enhances cytokine secretion and diabetogenic CD4+ T cell responses. Further investigation into the role of TLR5 in DC development and autoimmune diabetes may give additional insights into the pathogenesis of Type 1 diabetes.
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Affiliation(s)
- James Alexander Pearson
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT, United States
- Diabetes Research Group, Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Youjia Hu
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT, United States
| | - Jian Peng
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT, United States
| | - F Susan Wong
- Diabetes Research Group, Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Li Wen
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT, United States
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2
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Lim JS, Jeon EJ, Go HS, Kim HJ, Kim KY, Nguyen TQT, Lee DY, Kim KS, Pietrocola F, Hong SH, Lee SE, Kim KS, Park TS, Choi DH, Jeong YJ, Park JH, Kim HS, Min JJ, Kim YS, Park JT, Cho JH, Lee GW, Lee JH, Choy HE, Park SC, Lee CH, Rhee JH, Serrano M, Cho KA. Mucosal TLR5 activation controls healthspan and longevity. Nat Commun 2024; 15:46. [PMID: 38167804 PMCID: PMC10761998 DOI: 10.1038/s41467-023-44263-2] [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: 02/26/2020] [Accepted: 12/06/2023] [Indexed: 01/05/2024] Open
Abstract
Addressing age-related immunological defects through therapeutic interventions is essential for healthy aging, as the immune system plays a crucial role in controlling infections, malignancies, and in supporting tissue homeostasis and repair. In our study, we show that stimulating toll-like receptor 5 (TLR5) via mucosal delivery of a flagellin-containing fusion protein effectively extends the lifespan and enhances the healthspan of mice of both sexes. This enhancement in healthspan is evidenced by diminished hair loss and ocular lens opacity, increased bone mineral density, improved stem cell activity, delayed thymic involution, heightened cognitive capacity, and the prevention of pulmonary lung fibrosis. Additionally, this fusion protein boosts intestinal mucosal integrity by augmenting the surface expression of TLR5 in a certain subset of dendritic cells and increasing interleukin-22 (IL-22) secretion. In this work, we present observations that underscore the benefits of TLR5-dependent stimulation in the mucosal compartment, suggesting a viable strategy for enhancing longevity and healthspan.
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Affiliation(s)
- Jae Sung Lim
- Department of Biochemistry, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Eun Jae Jeon
- MediSpan, Inc, Bundang-gu, Gyeonggi-do, 13486, Republic of Korea
| | - Hye Sun Go
- MediSpan, Inc, Bundang-gu, Gyeonggi-do, 13486, Republic of Korea
| | - Hyung-Jin Kim
- MediSpan, Inc, Bundang-gu, Gyeonggi-do, 13486, Republic of Korea
| | - Kye Young Kim
- MediSpan, Inc, Bundang-gu, Gyeonggi-do, 13486, Republic of Korea
| | - Thi Quynh Trang Nguyen
- Department of Biochemistry, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
- Center for Creative Biomedical Scientists, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Da Young Lee
- Department of Biochemistry, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
- Center for Creative Biomedical Scientists, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Kyu Suk Kim
- Department of Biochemistry, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Federico Pietrocola
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Seol Hee Hong
- Department of Pharmacology and Dental Therapeutics, School of Dentistry, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Shee Eun Lee
- Department of Pharmacology and Dental Therapeutics, School of Dentistry, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Kyoung-Shim Kim
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Tae-Shin Park
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Dong-Hee Choi
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea
| | - Yu-Jin Jeong
- Department of Animal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Jong-Hwan Park
- Department of Animal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Hyeon Sik Kim
- Medical Photonic Research Center, Korea Photonics Technology Institute, Gwangju, 61007, Republic of Korea
| | - Jung-Joon Min
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Yong Sook Kim
- Biomedical Research Institute, Chonnam National University Hospital, Gwangju, 61469, Republic of Korea
| | - Joon Tae Park
- Department of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 22012, Republic of Korea
| | - Jae-Ho Cho
- Combinatorial Tumor Immunotherapy Medical Research Center, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Gil-Woo Lee
- Combinatorial Tumor Immunotherapy Medical Research Center, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Ji Hyeon Lee
- Department of Biological Sciences and Bioengineering, Inha University, Incheon, 22212, Republic of Korea
| | - Hyon E Choy
- Department of Microbiology, Chonnam National University Medical School, 264 Seoyang-ro, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Sang Chul Park
- Future Life and Society Research Center, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea
| | - Chul-Ho Lee
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141, Republic of Korea.
| | - Joon Haeng Rhee
- Center for Creative Biomedical Scientists, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea.
- Combinatorial Tumor Immunotherapy Medical Research Center, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea.
- Department of Microbiology, Chonnam National University Medical School, 264 Seoyang-ro, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea.
| | - Manuel Serrano
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (BIST), Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
- Altos Labs, Cambridge Institute of Science, Cambridge, UK.
| | - Kyung A Cho
- Department of Biochemistry, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea.
- MediSpan, Inc, Bundang-gu, Gyeonggi-do, 13486, Republic of Korea.
- Center for Creative Biomedical Scientists, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea.
- Future Life and Society Research Center, Chonnam National University Medical School, Hwasun-gun, Jeonnam-do, 58128, Republic of Korea.
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3
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Wan T, Wang Y, He K, Zhu S. Microbial sensing in the intestine. Protein Cell 2023; 14:824-860. [PMID: 37191444 PMCID: PMC10636641 DOI: 10.1093/procel/pwad028] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/04/2023] [Indexed: 05/17/2023] Open
Abstract
The gut microbiota plays a key role in host health and disease, particularly through their interactions with the immune system. Intestinal homeostasis is dependent on the symbiotic relationships between the host and the diverse gut microbiota, which is influenced by the highly co-evolved immune-microbiota interactions. The first step of the interaction between the host and the gut microbiota is the sensing of the gut microbes by the host immune system. In this review, we describe the cells of the host immune system and the proteins that sense the components and metabolites of the gut microbes. We further highlight the essential roles of pattern recognition receptors (PRRs), the G protein-coupled receptors (GPCRs), aryl hydrocarbon receptor (AHR) and the nuclear receptors expressed in the intestinal epithelial cells (IECs) and the intestine-resident immune cells. We also discuss the mechanisms by which the disruption of microbial sensing because of genetic or environmental factors causes human diseases such as the inflammatory bowel disease (IBD).
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Affiliation(s)
- Tingting Wan
- Division of Life Sciences and Medicine, The CAS Key Laboratory of Innate Immunity and Chronic Disease, Institute of Immunology, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Yalong Wang
- Division of Life Sciences and Medicine, The CAS Key Laboratory of Innate Immunity and Chronic Disease, Institute of Immunology, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Kaixin He
- Division of Life Sciences and Medicine, The CAS Key Laboratory of Innate Immunity and Chronic Disease, Institute of Immunology, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Shu Zhu
- Division of Life Sciences and Medicine, The CAS Key Laboratory of Innate Immunity and Chronic Disease, Institute of Immunology, School of Basic Medical Sciences, University of Science and Technology of China, Hefei 230027, China
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei 230001, China
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei 230601, China
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4
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Dalby MJ. Questioning the foundations of the gut microbiota and obesity. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220221. [PMID: 37661739 PMCID: PMC10475866 DOI: 10.1098/rstb.2022.0221] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/08/2023] [Indexed: 09/05/2023] Open
Abstract
The role of the gut microbiota in determining body fatness has been a prominent area of research and has received significant public attention. Based largely on animal studies, recent attempts to translate these findings into interventions in humans have not been successful. This review will outline the key mouse research that initiated this area of study, examine whether those results warranted the initial enthusiasm and progress into human studies, and examine whether later follow-up research supported earlier conclusions. It will look at whether the absence of a gut microbiota protects germ-free mice from obesity, whether microbiota can transfer obesity into germ-free mice, the evidence for the role of immune system activation as a causal mechanism linking the gut microbiota to body weight, and consider the evidence for effects of individual bacterial species. Finally, it will examine the outcomes of randomized controlled trials of microbiota transfer in human participants that have not shown effects on body weight. With a more critical reading, early studies did not show as large an effect as first appeared and later research, including human trials, has failed to support a role of the gut microbiota in shaping body weight. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.
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Affiliation(s)
- Matthew J. Dalby
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK
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5
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Glowacki RWP, Engelhart MJ, Ahern PP. Controlled Complexity: Optimized Systems to Study the Role of the Gut Microbiome in Host Physiology. Front Microbiol 2021; 12:735562. [PMID: 34646255 PMCID: PMC8503645 DOI: 10.3389/fmicb.2021.735562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/24/2021] [Indexed: 12/26/2022] Open
Abstract
The profound impact of the gut microbiome on host health has led to a revolution in biomedical research, motivating researchers from disparate fields to define the specific molecular mechanisms that mediate host-beneficial effects. The advent of genomic technologies allied to the use of model microbiomes in gnotobiotic mouse models has transformed our understanding of intestinal microbial ecology and the impact of the microbiome on the host. However, despite incredible advances, our understanding of the host-microbiome dialogue that shapes host physiology is still in its infancy. Progress has been limited by challenges associated with developing model systems that are both tractable enough to provide key mechanistic insights while also reflecting the enormous complexity of the gut ecosystem. Simplified model microbiomes have facilitated detailed interrogation of transcriptional and metabolic functions of the microbiome but do not recapitulate the interactions seen in complex communities. Conversely, intact complex communities from mice or humans provide a more physiologically relevant community type, but can limit our ability to uncover high-resolution insights into microbiome function. Moreover, complex microbiomes from lab-derived mice or humans often do not readily imprint human-like phenotypes. Therefore, improved model microbiomes that are highly defined and tractable, but that more accurately recapitulate human microbiome-induced phenotypic variation are required to improve understanding of fundamental processes governing host-microbiome mutualism. This improved understanding will enhance the translational relevance of studies that address how the microbiome promotes host health and influences disease states. Microbial exposures in wild mice, both symbiotic and infectious in nature, have recently been established to more readily recapitulate human-like phenotypes. The development of synthetic model communities from such "wild mice" therefore represents an attractive strategy to overcome the limitations of current approaches. Advances in microbial culturing approaches that allow for the generation of large and diverse libraries of isolates, coupled to ever more affordable large-scale genomic sequencing, mean that we are now ideally positioned to develop such systems. Furthermore, the development of sophisticated in vitro systems is allowing for detailed insights into host-microbiome interactions to be obtained. Here we discuss the need to leverage such approaches and highlight key challenges that remain to be addressed.
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Affiliation(s)
- Robert W. P. Glowacki
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Morgan J. Engelhart
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Philip P. Ahern
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Center for Microbiome and Human Health, Cleveland Clinic, Cleveland, OH, United States
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6
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Young RB, Marcelino VR, Chonwerawong M, Gulliver EL, Forster SC. Key Technologies for Progressing Discovery of Microbiome-Based Medicines. Front Microbiol 2021; 12:685935. [PMID: 34239510 PMCID: PMC8258393 DOI: 10.3389/fmicb.2021.685935] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/25/2021] [Indexed: 12/22/2022] Open
Abstract
A growing number of experimental and computational approaches are illuminating the “microbial dark matter” and uncovering the integral role of commensal microbes in human health. Through this work, it is now clear that the human microbiome presents great potential as a therapeutic target for a plethora of diseases, including inflammatory bowel disease, diabetes and obesity. The development of more efficacious and targeted treatments relies on identification of causal links between the microbiome and disease; with future progress dependent on effective links between state-of-the-art sequencing approaches, computational analyses and experimental assays. We argue determining causation is essential, which can be attained by generating hypotheses using multi-omic functional analyses and validating these hypotheses in complex, biologically relevant experimental models. In this review we discuss existing analysis and validation methods, and propose best-practice approaches required to enable the next phase of microbiome research.
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Affiliation(s)
- Remy B Young
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Vanessa R Marcelino
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, Australia
| | - Michelle Chonwerawong
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, Australia
| | - Emily L Gulliver
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia.,Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, Australia
| | - Samuel C Forster
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia.,Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, Australia
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7
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Hamieh AM, Mallaret G, Meleine M, Lashermes A, Roumeau S, Boudieu L, Barbier J, Aissouni Y, Ardid D, Gewirtz AT, Carvalho FA, Marchand F. Toll-like receptor 5 knock-out mice exhibit a specific low level of anxiety. Brain Behav Immun 2021; 93:226-237. [PMID: 33516921 DOI: 10.1016/j.bbi.2021.01.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 12/14/2022] Open
Abstract
While toll-like receptors (TLRs), which mediate innate immunity, are known to play an important role in host defense, recent work suggest their involvement in some integrated behaviors, including anxiety, depressive and cognitive functions. Here, we investigated the potential involvement of the flagellin receptor, TLR5, in anxiety, depression and cognitive behaviors using male TLR5 knock-out (KO) mice. We aobserved a specific low level of basal anxiety in TLR5 KO mice with an alteration of the hypothalamo-pituitary axis (HPA) response to acute restraint stress, illustrated by a decrease of both plasma corticosterone level and c-fos expression in the hypothalamic paraventricular nucleus where TLR5 was expressed, compared to WT littermates. However, depression and cognitive-related behaviors were not different between TLR5 KO and WT mice. Nor there were significant changes in the expression of some cytokines (IL-6, IL-10 and TNF-α) and other TLRs (TLR2, TLR3 and TLR4) in the prefrontal cortex, amygdala and hippocampus of TLR5 KO mice compared to WT mice. Moreover, mRNA expression of BDNF and glucocorticoid receptors in the hippocampus and amygdala, respectively, was not different. Finally, acute intracerebroventricular administration of flagellin, a specific TLR5 agonist, or chronic neomycin treatment did not exhibit a significant main effect, only a significant main effect of genotype was observed between TLR5 KO and WT mice. Together, those findings suggest a previously undescribed and specific role of TLR5 in anxiety and open original prospects in our understanding of the brain-gut axis function.
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Affiliation(s)
- A M Hamieh
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France; Porsolt SAS, Glatigné, 53940 Le Genest-Saint-Isle, France
| | - G Mallaret
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - M Meleine
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - A Lashermes
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - S Roumeau
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - L Boudieu
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - J Barbier
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - Y Aissouni
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - D Ardid
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - A T Gewirtz
- Center for Inflammation, Immunity and Infection, Georgia State University, Atlanta, GA 30303, United States
| | - F A Carvalho
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France
| | - F Marchand
- Université Clermont Auvergne, Inserm U1107 NEURO-DOL, Pharmacologie fondamentale et clinique de la douleur, F-63000 Clermont-Ferrand, France.
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8
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Modifying bacterial flagellin to evade Nod-like Receptor CARD 4 recognition enhances protective immunity against Salmonella. Nat Microbiol 2020; 5:1588-1597. [PMID: 33106673 DOI: 10.1038/s41564-020-00801-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/17/2020] [Indexed: 02/06/2023]
Abstract
Pattern recognition receptors (PRRs) expressed in antigen-presenting cells are thought to shape pathogen-specific immunity by inducing secretion of costimulatory cytokines during T-cell activation, yet data to support this notion in vivo are scarce. Here, we show that the cytosolic PRR Nod-like Receptor CARD 4 (NLRC4) suppresses, rather than facilitates, effector and memory CD4+ T-cell responses against Salmonella in mice. NLRC4 negatively regulates immunological memory by preventing delayed activation of the cytosolic PRR NLR pyrin domain 3 (NLRP3) that would otherwise amplify the production of cytokines important for the generation of Th1 immunity such as intereukin-18. Consistent with a role for NLRC4 in memory immunity, primary challenge with Salmonella expressing flagellin modified to largely evade NLRC4 recognition notably increases protection against lethal rechallenge. This finding suggests flagellin modification to reduce NLRC4 activation enhances protective immunity, which could have important implications for vaccine development against flagellated microbial pathogens.
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9
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Jang YO, Lee SH, Choi JJ, Kim DH, Choi JM, Kang MJ, Oh YM, Park YJ, Shin Y, Lee SW. Fecal microbial transplantation and a high fiber diet attenuates emphysema development by suppressing inflammation and apoptosis. Exp Mol Med 2020; 52:1128-1139. [PMID: 32681029 PMCID: PMC8080776 DOI: 10.1038/s12276-020-0469-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/24/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022] Open
Abstract
Recent work has suggested a microbial dysbiosis association between the lung and gut in respiratory diseases. Here, we demonstrated that gut microbiome modulation attenuated emphysema development. To modulate the gut microbiome, fecal microbiota transplantation (FMT) and diet modification were adopted in mice exposed to smoking and poly I:C for the emphysema model. We analyzed the severity of emphysema by the mean linear intercept (MLI) and apoptosis by the fluorescent TUNEL assay. Microbiome analysis was also performed in feces and fecal extracellular vesicles (EVs). The MLI was significantly increased with smoking exposure. FMT or a high-fiber diet (HFD) attenuated the increase. Weight loss, combined with smoking exposure, was not noted in mice with FMT. HFD significantly decreased macrophages and lymphocytes in bronchoalveolar lavage fluid. Furthermore, IL-6 and IFN-γ were decreased in the bronchoalveolar lavage fluid and serum. The TUNEL score was significantly lower in mice with FMT or HFD, suggesting decreased cell apoptosis. In the microbiome analysis, Bacteroidaceae and Lachnospiraceae, which are alleged to metabolize fiber into short-chain fatty acids (SCFAs), increased at the family level with FMT and HFD. FMT and HFD attenuated emphysema development via local and systemic inhibition of inflammation and changes in gut microbiota composition, which could provide a new paradigm in COPD treatment.
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Affiliation(s)
- Yoon Ok Jang
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
- Department of Convergence Medicine, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Se Hee Lee
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
- Department of Pulmonology, Allergy and Critical Care Medicine, CHA Bundang Medical Center, CHA University, Seongnam-si, 13496, Republic of Korea
| | - Jong Jin Choi
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Do-Hyun Kim
- Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Research Institute for Convergence of Basic Sciences, Hanyang University, Seoul, 04763, Republic of Korea
| | - Je-Min Choi
- Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Research Institute for Convergence of Basic Sciences, Hanyang University, Seoul, 04763, Republic of Korea
| | - Min-Jong Kang
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, 06520-8057, Connecticut, USA
| | - Yeon-Mok Oh
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea
| | - Young-Jun Park
- Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Yong Shin
- Department of Convergence Medicine, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.
| | - Sei Won Lee
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, 05505, Republic of Korea.
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10
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Burgueño JF, Abreu MT. Epithelial Toll-like receptors and their role in gut homeostasis and disease. Nat Rev Gastroenterol Hepatol 2020; 17:263-278. [PMID: 32103203 DOI: 10.1038/s41575-019-0261-4] [Citation(s) in RCA: 203] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/20/2019] [Indexed: 02/07/2023]
Abstract
The human gastrointestinal tract is colonized by trillions of microorganisms that interact with the host to maintain structural and functional homeostasis. Acting as the interface between the site of the highest microbial burden in the human body and the richest immune compartment, a single layer of intestinal epithelial cells specializes in nutrient absorption, stratifies microorganisms to limit colonization of tissues and shapes the responses of the subepithelial immune cells. In this Review, we focus on the expression, regulation and functions of Toll-like receptors (TLRs) in the different intestinal epithelial lineages to analyse how epithelial recognition of bacteria participates in establishing homeostasis in the gut. In particular, we elaborate on the involvement of epithelial TLR signalling in controlling crypt dynamics, enhancing epithelial barrier integrity and promoting immune tolerance towards the gut microbiota. Furthermore, we comment on the regulatory mechanisms that fine-tune TLR-driven immune responses towards pathogens and revisit the role of TLRs in epithelial repair after injury. Finally, we discuss how dysregulation of epithelial TLRs can lead to the generation of dysbiosis, thereby increasing susceptibility to colitis and tumorigenesis.
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Affiliation(s)
- Juan F Burgueño
- Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Maria T Abreu
- Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.
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11
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Microbial Alterations and Risk Factors of Breast Cancer: Connections and Mechanistic Insights. Cells 2020; 9:cells9051091. [PMID: 32354130 PMCID: PMC7290701 DOI: 10.3390/cells9051091] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 12/12/2022] Open
Abstract
Breast cancer-related mortality remains high worldwide, despite tremendous advances in diagnostics and therapeutics; hence, the quest for better strategies for disease management, as well as the identification of modifiable risk factors, continues. With recent leaps in genomic technologies, microbiota have emerged as major players in most cancers, including breast cancer. Interestingly, microbial alterations have been observed with some of the established risk factors of breast cancer, such as obesity, aging and periodontal disease. Higher levels of estrogen, a risk factor for breast cancer that cross-talks with other risk factors such as alcohol intake, obesity, parity, breastfeeding, early menarche and late menopause, are also modulated by microbial dysbiosis. In this review, we discuss the association between known breast cancer risk factors and altered microbiota. An important question related to microbial dysbiosis and cancer is the underlying mechanisms by which alterations in microbiota can support cancer progression. To this end, we review the involvement of microbial metabolites as effector molecules, the modulation of the metabolism of xenobiotics, the induction of systemic immune modulation, and altered responses to therapy owing to microbial dysbiosis. Given the association of breast cancer risk factors with microbial dysbiosis and the multitude of mechanisms altered by dysbiotic microbiota, an impaired microbiome is, in itself, an important risk factor.
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12
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Ahern PP, Maloy KJ. Understanding immune-microbiota interactions in the intestine. Immunology 2020; 159:4-14. [PMID: 31777071 PMCID: PMC6904641 DOI: 10.1111/imm.13150] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/01/2019] [Accepted: 10/07/2019] [Indexed: 12/13/2022] Open
Abstract
The past two decades have seen an explosion in research that aims to understand how the dynamic interplay with the gut microbiota impacts host health and disease, establishing a role for the gut microbiota in a plethora of pathologies. Understanding how health-promoting microbiota are established and how beneficial host-microbiota interactions are maintained is of immense biomedical importance. Despite the enormous progress that has been made, our knowledge of the specific microbiota members that mediate these effects and the mechanisms underlying these interactions is rudimentary. The dearth of information regarding the nature of advantageous host-microbiota interactions, and the factors that cause these relationships to go awry, has hampered our ability to realize the therapeutic potential of the microbiota. Here we discuss key issues that limit current knowledge and describe a path forwards to improving our understanding of the contributions of the microbiota to host health.
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Affiliation(s)
- Philip P. Ahern
- Department of Cardiovascular and Metabolic SciencesCleveland Clinic Lerner Research InstituteClevelandOHUSA
| | - Kevin J. Maloy
- Institute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
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13
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Møhlenberg M, Terczynska-Dyla E, Thomsen KL, George J, Eslam M, Grønbæk H, Hartmann R. The role of IFN in the development of NAFLD and NASH. Cytokine 2019; 124:154519. [DOI: 10.1016/j.cyto.2018.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/10/2018] [Accepted: 08/11/2018] [Indexed: 02/07/2023]
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14
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Singh V, Yeoh BS, Chassaing B, Xiao X, Saha P, Aguilera Olvera R, Lapek JD, Zhang L, Wang WB, Hao S, Flythe MD, Gonzalez DJ, Cani PD, Conejo-Garcia JR, Xiong N, Kennett MJ, Joe B, Patterson AD, Gewirtz AT, Vijay-Kumar M. Dysregulated Microbial Fermentation of Soluble Fiber Induces Cholestatic Liver Cancer. Cell 2019; 175:679-694.e22. [PMID: 30340040 DOI: 10.1016/j.cell.2018.09.004] [Citation(s) in RCA: 296] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 06/03/2018] [Accepted: 09/06/2018] [Indexed: 12/25/2022]
Abstract
Dietary soluble fibers are fermented by gut bacteria into short-chain fatty acids (SCFA), which are considered broadly health-promoting. Accordingly, consumption of such fibers ameliorates metabolic syndrome. However, incorporating soluble fiber inulin, but not insoluble fiber, into a compositionally defined diet, induced icteric hepatocellular carcinoma (HCC). Such HCC was microbiota-dependent and observed in multiple strains of dysbiotic mice but not in germ-free nor antibiotics-treated mice. Furthermore, consumption of an inulin-enriched high-fat diet induced both dysbiosis and HCC in wild-type (WT) mice. Inulin-induced HCC progressed via early onset of cholestasis, hepatocyte death, followed by neutrophilic inflammation in liver. Pharmacologic inhibition of fermentation or depletion of fermenting bacteria markedly reduced intestinal SCFA and prevented HCC. Intervening with cholestyramine to prevent reabsorption of bile acids also conferred protection against such HCC. Thus, its benefits notwithstanding, enrichment of foods with fermentable fiber should be approached with great caution as it may increase risk of HCC.
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Affiliation(s)
- Vishal Singh
- UT-Microbiome Consortium, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Beng San Yeoh
- Graduate Program in Immunology and Infectious Diseases, Pennsylvania State University, State College, PA 16802, USA
| | - Benoit Chassaing
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA; Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Xia Xiao
- Department of Nutritional Sciences, Pennsylvania State University, State College, PA 16802, USA
| | - Piu Saha
- UT-Microbiome Consortium, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Rodrigo Aguilera Olvera
- Department of Nutritional Sciences, Pennsylvania State University, State College, PA 16802, USA
| | - John D Lapek
- Department of Pharmacology, University of California, San Diego, CA 92093, USA
| | - Limin Zhang
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, State College, PA 16802, USA; CAS and State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan, China
| | - Wei-Bei Wang
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, State College, PA 16802, USA
| | - Sijie Hao
- Department of Biomedical Engineering, Pennsylvania State University, State College, PA 16802, USA
| | - Michael D Flythe
- USDA-Agriculture Research Service, University of Kentucky, Lexington, KY 40546, USA
| | - David J Gonzalez
- Department of Pharmacology, University of California, San Diego, CA 92093, USA
| | - Patrice D Cani
- WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | | | - Na Xiong
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, State College, PA 16802, USA
| | - Mary J Kennett
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, State College, PA 16802, USA
| | - Bina Joe
- UT-Microbiome Consortium, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, State College, PA 16802, USA
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Matam Vijay-Kumar
- UT-Microbiome Consortium, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA; Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH 43614, USA.
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15
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Role of Toll-Like Receptor 5 (TLR5) in Experimental Melioidosis. Infect Immun 2019; 87:IAI.00409-18. [PMID: 31109950 DOI: 10.1128/iai.00409-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 04/26/2019] [Indexed: 12/26/2022] Open
Abstract
The Gram-negative intracellular pathogen Burkholderia pseudomallei is the causative agent of melioidosis, an important cause of sepsis in Southeast Asia. Recognition of pathogen-associated molecular patterns by Toll-like receptors (TLRs) is essential for an appropriate immune response during pathogen invasion. In patients with melioidosis, TLR5 is the most abundantly expressed TLR, and a hypofunctional TLR5 variant has been associated with improved survival. Here, we studied the functional role of TLR5 and its ligand flagellin in experimental melioidosis. First, we observed differential TLR5 expression in the pulmonary and hepatic compartments upon infection with B. pseudomallei Next, we found that B. pseudomallei-challenged TLR5-deficient (Tlr5-/- ) mice were more susceptible to infection than wild-type (WT) mice, as demonstrated by higher systemic bacterial loads, increased organ injury, and impaired survival. Lung bacterial loads were not different between the two groups. The phenotype was flagellin independent; no difference in in vivo virulence was observed for the flagellin-lacking mutant MM36 compared to the wild-type B. pseudomallei strain 1026b. Tlr5-/- mice showed a similar impaired antibacterial defense when infected with MM36 or 1026b. Ex vivo experiments showed that TLR5-deficient macrophages display markedly impaired phagocytosis of B. pseudomallei In conclusion, these data suggest that TLR5 deficiency has a detrimental flagellin-independent effect on the host response against pulmonary B. pseudomallei infection.
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16
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Polymorphism in Toll-Like Receptors and Helicobacter Pylori Motility in Autoimmune Atrophic Gastritis and Gastric Cancer. Cancers (Basel) 2019; 11:cancers11050648. [PMID: 31083432 PMCID: PMC6562993 DOI: 10.3390/cancers11050648] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/03/2019] [Accepted: 05/07/2019] [Indexed: 12/17/2022] Open
Abstract
Autoimmune atrophic gastritis (AAG) is associated with an increased risk of certain types of gastric cancer (GC). Helicobacter pylori (H. pylori) infection may have a role in the induction and/or maintenance of AAG and GC. Toll-like receptors (TLR) are essential for H. pylori recognition and subsequent innate and adaptive immunity responses. This study therefore aimed to characterize TLR polymorphisms, and features of bacterial flagellin A in samples from patients with AAG (n = 67), GC (n = 114) and healthy donors (HD; n = 97). TLR5 rs5744174 C/C genotype was associated with GC, lower IgG anti H. pylori response and a higher H. pylori flagellin A abundance and motility. In a subset of patients with AAG, H. pylori strains showed a reduction of the flagellin A abundance and a moderate motility compared with strains from GC patients, a prerequisite for active colonization of the deeper layers of the mucosa, host immune response and inflammation. TLR9 rs5743836 T allele showed an association with serum gastrin G17. In conclusion, our study suggests that alterations of flaA protein, moderate motility in H. pylori and two polymorphisms in TLR5 and TLR9 may favor the onset of AAG and GC, at least in a subset of patients. These findings corroborate the function of pathogen–host cell interactions and responses, likely influencing the pathogenetic process.
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17
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Coleman OI, Haller D. Bacterial Signaling at the Intestinal Epithelial Interface in Inflammation and Cancer. Front Immunol 2018; 8:1927. [PMID: 29354132 PMCID: PMC5760496 DOI: 10.3389/fimmu.2017.01927] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 12/15/2017] [Indexed: 12/11/2022] Open
Abstract
The gastrointestinal (GI) tract provides a compartmentalized interface with an enormous repertoire of immune and metabolic activities, where the multicellular structure of the mucosa has acquired mechanisms to sense luminal factors, such as nutrients, microbes, and a variety of host-derived and microbial metabolites. The GI tract is colonized by a complex ecosystem of microorganisms, which have developed a highly coevolved relationship with the host’s cellular and immune system. Intestinal epithelial pattern recognition receptors (PRRs) substantially contribute to tissue homeostasis and immune surveillance. The role of bacteria-derived signals in intestinal epithelial homeostasis and repair has been addressed in mouse models deficient in PRRs and signaling adaptors. While critical for host physiology and the fortification of barrier function, the intestinal microbiota poses a considerable health challenge. Accumulating evidence indicates that dysbiosis is associated with the pathogenesis of numerous GI tract diseases, including inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Aberrant signal integration at the epithelial cell level contributes to such diseases. An increased understanding of bacterial-specific structure recognition and signaling mechanisms at the intestinal epithelial interface is of great importance in the translation to future treatment strategies. In this review, we summarize the growing understanding of the regulation and function of the intestinal epithelial barrier, and discuss microbial signaling in the dynamic host–microbe mutualism in both health and disease.
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Affiliation(s)
| | - Dirk Haller
- Technical University of Munich, Munich, Germany.,ZIEL-Institute for Food & Health, Technical University of Munich, Munich, Germany
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18
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Spiljar M, Merkler D, Trajkovski M. The Immune System Bridges the Gut Microbiota with Systemic Energy Homeostasis: Focus on TLRs, Mucosal Barrier, and SCFAs. Front Immunol 2017; 8:1353. [PMID: 29163467 PMCID: PMC5670327 DOI: 10.3389/fimmu.2017.01353] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/03/2017] [Indexed: 12/17/2022] Open
Abstract
The gut microbiota is essential for the development and regulation of the immune system and the metabolism of the host. Germ-free animals have altered immunity with increased susceptibility to immunologic diseases and show metabolic alterations. Here, we focus on two of the major immune-mediated microbiota-influenced components that signal far beyond their local environment. First, the activation or suppression of the toll-like receptors (TLRs) by microbial signals can dictate the tone of the immune response, and they are implicated in regulation of the energy homeostasis. Second, we discuss the intestinal mucosal surface is an immunologic component that protects the host from pathogenic invasion, is tightly regulated with regard to its permeability and can influence the systemic energy balance. The short chain fatty acids are a group of molecules that can both modulate the intestinal barrier and escape the gut to influence systemic health. As modulators of the immune response, the microbiota-derived signals influence functions of distant organs and can change susceptibility to metabolic diseases.
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Affiliation(s)
- Martina Spiljar
- Faculty of Medicine, Department of Cell Physiology and Metabolism, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland.,Diabetes Center, Faculty of Medicine, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Doron Merkler
- Faculty of Medicine, Department of Pathology and Immunology, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland
| | - Mirko Trajkovski
- Faculty of Medicine, Department of Cell Physiology and Metabolism, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland.,Diabetes Center, Faculty of Medicine, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
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19
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Lee SJ, Benoun J, Sheridan BS, Fogassy Z, Pham O, Pham QM, Puddington L, McSorley SJ. Dual Immunization with SseB/Flagellin Provides Enhanced Protection against Salmonella Infection Mediated by Circulating Memory Cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2017; 199:1353-1361. [PMID: 28710253 PMCID: PMC5548602 DOI: 10.4049/jimmunol.1601357] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 06/19/2017] [Indexed: 01/09/2023]
Abstract
The development of a subunit Salmonella vaccine has been hindered by the absence of detailed information about antigenic targets of protective Salmonella-specific T and B cells. Recent studies have identified SseB as a modestly protective Ag in susceptible C57BL/6 mice, but the mechanism of protective immunity remains undefined. In this article, we report that simply combining Salmonella SseB with flagellin substantially enhances protective immunity, allowing immunized C57BL/6 mice to survive for up to 30 d following challenge with virulent bacteria. Surprisingly, the enhancing effect of flagellin did not require flagellin Ag targeting during secondary responses or recognition of flagellin by TLR5. Although coimmunization with flagellin did not affect SseB-specific Ab responses, it modestly boosted CD4 responses. In addition, protective immunity was effectively transferred in circulation to parabionts of immunized mice, demonstrating that tissue-resident memory is not required for vaccine-induced protection. Finally, protective immunity required host expression of IFN-γR but was independent of induced NO synthase expression. Taken together, these data indicate that Salmonella flagellin has unique adjuvant properties that improve SseB-mediated protective immunity provided by circulating memory.
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Affiliation(s)
- Seung-Joo Lee
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Joseph Benoun
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Brian S Sheridan
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | - Zachary Fogassy
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Oanh Pham
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
| | - Quynh-Mai Pham
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | - Lynn Puddington
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | - Stephen J McSorley
- Center for Comparative Medicine, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616;
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616; and
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20
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Dahiya DK, Renuka, Puniya M, Shandilya UK, Dhewa T, Kumar N, Kumar S, Puniya AK, Shukla P. Gut Microbiota Modulation and Its Relationship with Obesity Using Prebiotic Fibers and Probiotics: A Review. Front Microbiol 2017; 8:563. [PMID: 28421057 PMCID: PMC5378938 DOI: 10.3389/fmicb.2017.00563] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/20/2017] [Indexed: 12/12/2022] Open
Abstract
In the present world scenario, obesity has almost attained the level of a pandemic and is progressing at a rapid rate. This disease is the mother of all other metabolic disorders, which apart from placing an added financial burden on the concerned patient also has a negative impact on his/her well-being and health in the society. Among the various plausible factors for the development of obesity, the role of gut microbiota is very crucial. In general, the gut of an individual is inhabited by trillions of microbes that play a significant role in host energy homeostasis by their symbiotic interactions. Dysbiosis in gut microbiota causes disequilibrium in energy homeostasis that ultimately leads to obesity. Numerous mechanisms have been reported by which gut microbiota induces obesity in experimental models. However, which microbial community is directly linked to obesity is still unknown due to the complex nature of gut microbiota. Prebiotics and probiotics are the safer and effective dietary substances available, which can therapeutically alter the gut microbiota of the host. In this review, an effort was made to discuss the current mechanisms through which gut microbiota interacts with host energy metabolism in the context of obesity. Further, the therapeutic approaches (prebiotics/probiotics) that helped in positively altering the gut microbiota were discussed by taking experimental evidence from animal and human studies. In the closing statement, the challenges and future tasks within the field were discussed.
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Affiliation(s)
- Dinesh K Dahiya
- Advanced Milk Testing Research Laboratory, Post Graduate Institute of Veterinary Education and Research - Rajasthan University of Veterinary and Animal Sciences at BikanerJaipur, India
| | - Renuka
- Department of Biochemistry, Basic Medical Science, South Campus, Panjab UniversityChandigarh, India
| | - Monica Puniya
- Food Safety Management System Division, Food Safety and Standards Authority of IndiaNew Delhi, India
| | - Umesh K Shandilya
- Animal Biotechnology Division, National Bureau of Animal Genetic ResourcesKarnal, India
| | - Tejpal Dhewa
- Department of Nutrition Biology, Central University of HaryanaMahendergarh, India
| | - Nikhil Kumar
- Department of Life Sciences, Shri Venkateshwara UniversityJP Nagar, India
| | - Sanjeev Kumar
- Department of Life Science, Central Assam UniversitySilchar, India
| | - Anil K Puniya
- College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences UniversityLudhiana, India.,Dairy Microbiology Division, ICAR-National Dairy Research InstituteKarnal, India
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand UniversityRohtak, India
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21
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Zhou Z, Chen P, Peng H. Are healthy smokers really healthy? Tob Induc Dis 2016; 14:35. [PMID: 27891067 PMCID: PMC5111288 DOI: 10.1186/s12971-016-0101-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/10/2016] [Indexed: 12/21/2022] Open
Abstract
Cigarette smoke contains more than 4500 chemicals which have toxic, mutagenic and carcinogenic effects. Strong evidences have shown that current smokers take a significantly higher risk of cardiovascular diseases, chronic obstructive pulmonary disease (COPD) and lung cancer than nonsmokers. However, less attention has been paid to the smoking induced abnormalities in the individuals defined as healthy smokers who are normal with spirometry, radiographic images, routine physical exam and categorized as healthy control group in many researches. Actually, ‘healthy smokers’ are not healthy. This narrative review focuses on the smoking related pathophysiologic changes mainly in the respiratory system of healthy smokers, including inflammation and immune changes, genetic alterations, structural changes and pulmonary dysfunction.
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Affiliation(s)
- Zijing Zhou
- Department of Respiratory Medicine, the Second Xiangya Hospital, Central South University, 139 Renmin Middle Road, Changsha, Hunan 410011 People's Republic of China
| | - Ping Chen
- Department of Respiratory Medicine, the Second Xiangya Hospital, Central South University, 139 Renmin Middle Road, Changsha, Hunan 410011 People's Republic of China
| | - Hong Peng
- Department of Respiratory Medicine, the Second Xiangya Hospital, Central South University, 139 Renmin Middle Road, Changsha, Hunan 410011 People's Republic of China
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22
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Hedhli D, Moiré N, Akbar H, Laurent F, Héraut B, Dimier-Poisson I, Mévélec MN. The antigen-specific response to Toxoplasma gondii profilin, a TLR11/12 ligand, depends on its intrinsic adjuvant properties. Med Microbiol Immunol 2016; 205:345-52. [DOI: 10.1007/s00430-016-0452-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/18/2016] [Indexed: 10/22/2022]
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23
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Hashizume-Takizawa T, Yamamoto M. Toll-like receptor 5 is not essential for the promotion of secretory immunoglobulin A antibody responses to flagellated bacteria. Microbiol Immunol 2015; 59:716-23. [PMID: 26564803 DOI: 10.1111/1348-0421.12336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/13/2015] [Accepted: 11/04/2015] [Indexed: 11/26/2022]
Abstract
Toll-like receptor 5 recognizes bacterial flagellin, plays a critical role in innate immunity, and contributes to flagellin-specific humoral immunity. Further, TLR5-expressing dendritic cells play an important role in IgA synthesis in the intestine; however, the contribution of TLR5 to antigen (Ag)-specific mucosal immunity remains unclear. Thus, whether TLR5 is essential for the induction of intestinal secretory (S)IgA antibody (Ab) responses against flagellin and bacterial Ags attached to the bacterial surface in response to an oral flagellated bacterium, Salmonella, was explored in this study. Our results indicate that when TLR5 knockout (TLR5(-/-)) mice are orally immunized with recombinant Salmonella expressing fragment C of tetanus toxin (rSalmonella-Tox C), tetanus toxoid (TT)- and flagellin (FliC)-specific systemic IgG and intestinal SIgA Abs are elicited. The numbers of TT-specific IgG Ab-forming cells (AFCs) in the spleen and IgA AFCs in the lamina propria (LP) of TLR5(-/-) mice were comparable to those in wild-type mice. rSalmonella-Tox C was equally disseminated in TLR5(-/-) mice, TLR5(-/-) mice lacking Peyer's patches (PPs), and wild-type mice. In contrast, TLR5(-/-) PP-null mice failed to induce TT- and FliC-specific SIgA Abs in the intestine and showed significantly reduced numbers of TT-specific IgA AFCs in the LP. These results suggest that TLR5 is dispensable for the induction of flagellin and surface Ag-specific systemic and mucosal immunity against oral flagellated bacteria. Rather, pathogen recognition, which occurs in PPs, is a prerequisite for the induction of mucosal immunity against flagellated bacteria.
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Affiliation(s)
- Tomomi Hashizume-Takizawa
- Department of Microbiology and Immunology, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan
| | - Masafumi Yamamoto
- Department of Microbiology and Immunology, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan
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Singh V, Yeoh BS, Carvalho F, Gewirtz AT, Vijay-Kumar M. Proneness of TLR5 deficient mice to develop colitis is microbiota dependent. Gut Microbes 2015; 6:279-83. [PMID: 26067589 PMCID: PMC4615783 DOI: 10.1080/19490976.2015.1060390] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Alterations in the gut microbiota have been implicated to play a role in potentiating inflammatory bowel diseases in both humans and mice. Mice lacking the flagellin receptor, toll-like receptor 5 (TLR5), are prone to develop spontaneous gut inflammation, but are significantly protected when treated with antibiotics or maintained in germ-free conditions. However, given that the incidence of spontaneous inflammation in TLR5KO mice is quite variable in conventional conditions (typically ∼10% show clear colitis), this result is far from definitive and does not rule out that TLR5KO mice might be prone to develop inflammation even in the absence of a microbiota. Herein, we demonstrate that neutralization of IL10 signaling induces colitis in 100% of TLR5KO mice which provide a more rigorous approach to evaluate the role of microbiota in gut inflammation. Mice treated with antibiotics or maintained in germ-free condition are substantially protected against IL-10R neutralization-induced colitis, underscoring that gut inflammation in TLR5KO mice is dependent upon the presence of a gut microbiota.
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Affiliation(s)
- Vishal Singh
- Department of Nutritional Sciences; The Pennsylvania State University; University Park, PA USA
| | - Beng San Yeoh
- Department of Nutritional Sciences; The Pennsylvania State University; University Park, PA USA
| | | | - Andrew T Gewirtz
- Institute of Biomedical Sciences; Georgia State University; Atlanta, GA USA
| | - Matam Vijay-Kumar
- Department of Nutritional Sciences; The Pennsylvania State University; University Park, PA USA,Department of Medicine; The Pennsylvania State University Medical Center; Hershey, PA USA,Correspondence to: Matam Vijay-Kumar;
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25
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Rutkowski MR, Conejo-Garcia JR. TLR5 signaling, commensal microbiota and systemic tumor promoting inflammation: the three parcae of malignant progression. Oncoimmunology 2015; 4:e1021542. [PMID: 26405577 DOI: 10.1080/2162402x.2015.1021542] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 02/14/2015] [Indexed: 02/01/2023] Open
Abstract
We have reported that TLR5-mediated recognition of commensal microbiota modulates systemic tumor-promoting inflammation and malignant progression of tumors at distal locations. Approximately 7-10% of the general population harbors a deleterious single nucleotide polymorphism in TLR5, implicating a novel role for genetic variation during the initiation and progression of cancer.
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Affiliation(s)
- Melanie R Rutkowski
- Tumor Microenvironment and Metastasis Program; The Wistar Institute ; Philadelphia, PA USA
| | - Jose R Conejo-Garcia
- Tumor Microenvironment and Metastasis Program; The Wistar Institute ; Philadelphia, PA USA
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26
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Li W, Yang J, Zhang E, Zhong M, Xiao Y, Yu J, Zhou D, Cao Y, Yang Y, Li Y, Yan H. Activation of NLRC4 downregulates TLR5-mediated antibody immune responses against flagellin. Cell Mol Immunol 2015. [DOI: 10.1038/cmi.2015.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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27
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Activation of NLRC4 downregulates TLR5-mediated antibody immune responses against flagellin. Cell Mol Immunol 2015; 13:514-23. [PMID: 25914934 DOI: 10.1038/cmi.2015.33] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 03/18/2015] [Accepted: 03/18/2015] [Indexed: 12/29/2022] Open
Abstract
Bacterial flagellin is a unique pathogen-associated molecular pattern (PAMP), which can be recognized by surface localized Toll-like receptor 5 (TLR5) and the cytosolic NOD-like receptor (NLR) protein 4 (NLRC4) receptors. Activation of the TLR5 and/or NLRC4 signaling pathways by flagellin and the resulting immune responses play important roles in anti-bacterial immunity. However, it remains unclear how the dual activities of flagellin that activate the TLR5 and/or NLRC4 signaling pathways orchestrate the immune responses. In this study, we assessed the effects of flagellin and its mutants lacking the ability to activate TLR5 and NLRC4 alone or in combination on the adaptive immune responses against flagellin. Flagellin that was unable to activate NLRC4 induced a significantly higher antibody response than did wild-type flagellin. The increased antibody response could be eliminated when macrophages were depleted in vivo. The activation of NLRC4 by flagellin downregulated the flagellin-induced and TLR5-mediated immune responses against flagellin.
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28
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Rutkowski MR, Conejo-Garcia JR. Size does not matter: commensal microorganisms forge tumor-promoting inflammation and anti-tumor immunity. Oncoscience 2015; 2:239-46. [PMID: 25897427 PMCID: PMC4394129 DOI: 10.18632/oncoscience.145] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/16/2015] [Indexed: 12/22/2022] Open
Abstract
Recent studies have demonstrated that the commensal microbiota are indispensable for the maintenance of immune homeostasis, orchestration of immune responses against pathogens and most recently during cancer immunotherapy and malignant progression of extraintestinal tumors. Here we discuss the recent findings that a common genetic variation in TLR5 influences the progression and outcome of ovarian, sarcoma, and luminal breast tumors and the implications of these findings in light of recent publications describing the role of the commensal microbiota in control of the systemic immune system.
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Affiliation(s)
- Melanie R Rutkowski
- Tumor Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, USA
| | - Jose R Conejo-Garcia
- Tumor Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, USA
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29
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Vertically transmitted faecal IgA levels determine extra-chromosomal phenotypic variation. Nature 2015; 521:90-93. [PMID: 25686606 PMCID: PMC4425643 DOI: 10.1038/nature14139] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 12/03/2014] [Indexed: 12/22/2022]
Abstract
The proliferation of genetically modified mouse models has exposed phenotypic variation between investigators and institutions that has been challenging to control. In many cases, the microbiota is the presumed cause of the variation. Current solutions to account for phenotypic variability include littermate and maternal controls or defined microbial consortia in gnotobiotic mice. In conventionally raised mice, the microbiome is transmitted from the dam. Here we show that microbially driven dichotomous faecal immunoglobulin-A (IgA) levels in wild-type mice within the same facility mimic the effects of chromosomal mutations. We observe in multiple facilities that vertically transmissible bacteria in IgA-low mice dominantly lower faecal IgA levels in IgA-high mice after co-housing or faecal transplantation. In response to injury, IgA-low mice show increased damage that is transferable by faecal transplantation and driven by faecal IgA differences. We find that bacteria from IgA-low mice degrade the secretory component of secretory IgA as well as IgA itself. These data indicate that phenotypic comparisons between mice must take into account the non-chromosomal hereditary variation between different breeders. We propose faecal IgA as one marker of microbial variability and conclude that co-housing and/or faecal transplantation enables analysis of progeny from different dams.
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Abstract
Salmonella are a common source of food- or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of host immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T- and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection, but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens.
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Affiliation(s)
- Stephen J McSorley
- Center for Comparative Medicine, Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
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31
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Caballero S, Pamer EG. Microbiota-mediated inflammation and antimicrobial defense in the intestine. Annu Rev Immunol 2015; 33:227-56. [PMID: 25581310 DOI: 10.1146/annurev-immunol-032713-120238] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The diverse microbial populations constituting the intestinal microbiota promote immune development and differentiation, but because of their complex metabolic requirements and the consequent difficulty culturing them, they remained, until recently, largely uncharacterized and mysterious. In the last decade, deep nucleic acid sequencing platforms, new computational and bioinformatics tools, and full-genome characterization of several hundred commensal bacterial species facilitated studies of the microbiota and revealed that differences in microbiota composition can be associated with inflammatory, metabolic, and infectious diseases, that each human is colonized by a distinct bacterial flora, and that the microbiota can be manipulated to reduce and even cure some diseases. Different bacterial species induce distinct immune cell populations that can play pro- and anti-inflammatory roles, and thus the composition of the microbiota determines, in part, the level of resistance to infection and susceptibility to inflammatory diseases. This review summarizes recent work characterizing commensal microbes that contribute to the antimicrobial defense/inflammation axis.
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Affiliation(s)
- Silvia Caballero
- Immunology Program, Sloan Kettering Institute, Infectious Diseases Service, Memorial Sloan Kettering Cancer Center, New York, NY 10065;
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32
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Leifer CA, McConkey C, Li S, Chassaing B, Gewirtz AT, Ley RE. Linking genetic variation in human Toll-like receptor 5 genes to the gut microbiome's potential to cause inflammation. Immunol Lett 2014; 162:3-9. [PMID: 25284610 DOI: 10.1016/j.imlet.2014.07.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/14/2014] [Accepted: 07/28/2014] [Indexed: 01/19/2023]
Abstract
Immunodeficiencies can lead to alterations of the gut microbiome that render it pathogenic and capable of transmitting disease to naïve hosts. Here, we review the role of Toll-like receptor (TLR) 5, the innate receptor for bacterial flagellin, in immune responses to the normal gut microbiota with a focus its role on adaptive immunity. Loss of TLR5 has profound effects on the microbiota that include greater temporal instability of major lineages and upregulation of flagellar motility genes that may be linked to the reduced levels of anti-flagellin antibodies in the TLR5(-/-) host. A variety of human TLR5 gene alleles exist that also associated with inflammatory conditions and may do so via effects on the gut microbiome and altered host-microbial crosstalk.
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Affiliation(s)
- Cynthia A Leifer
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, United States.
| | - Cameron McConkey
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States
| | - Sha Li
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States
| | - Benoit Chassaing
- Center for Inflammation, Immunity and Infection, Georgia State University, Atlanta, GA 30303, United States
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity and Infection, Georgia State University, Atlanta, GA 30303, United States
| | - Ruth E Ley
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, United States.
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33
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Oh JZ, Ravindran R, Chassaing B, Carvalho FA, Maddur MS, Bower M, Hakimpour P, Gill KP, Nakaya HI, Yarovinsky F, Sartor RB, Gewirtz AT, Pulendran B. TLR5-mediated sensing of gut microbiota is necessary for antibody responses to seasonal influenza vaccination. Immunity 2014; 41:478-492. [PMID: 25220212 DOI: 10.1016/j.immuni.2014.08.009] [Citation(s) in RCA: 367] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/06/2014] [Indexed: 11/16/2022]
Abstract
Systems biological analysis of immunity to the trivalent inactivated influenza vaccine (TIV) in humans revealed a correlation between early expression of TLR5 and the magnitude of the antibody response. Vaccination of Trl5(-/-) mice resulted in reduced antibody titers and lower frequencies of plasma cells, demonstrating a role for TLR5 in immunity to TIV. This was due to a failure to sense host microbiota. Thus, antibody responses in germ-free or antibiotic-treated mice were impaired, but restored by oral reconstitution with a flagellated, but not aflagellated, strain of E. coli. TLR5-mediated sensing of flagellin promoted plasma cell differentiation directly and by stimulating lymph node macrophages to produce plasma cell growth factors. Finally, TLR5-mediated sensing of the microbiota also impacted antibody responses to the inactivated polio vaccine, but not to adjuvanted vaccines or the live-attenuated yellow fever vaccine. These results reveal an unappreciated role for gut microbiota in promoting immunity to vaccination.
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Affiliation(s)
- Jason Z Oh
- Emory Vaccine Center, Emory University, Atlanta, GA 30329, USA; Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA
| | - Rajesh Ravindran
- Emory Vaccine Center, Emory University, Atlanta, GA 30329, USA; Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA
| | - Benoit Chassaing
- Center for Inflammation, Immunity, and Infection, Georgia State University, Atlanta, GA 30302, USA
| | - Frederic A Carvalho
- Center for Inflammation, Immunity, and Infection, Georgia State University, Atlanta, GA 30302, USA; INSERM U1107, Universite d'Auvergne, 63001 Clermont-Ferrand Cedex 1, France
| | - Mohan S Maddur
- Emory Vaccine Center, Emory University, Atlanta, GA 30329, USA; Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA
| | - Maureen Bower
- National Gnotobiotic Rodent Resource Center, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Paul Hakimpour
- Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA
| | - Kiran P Gill
- Emory Vaccine Center, Emory University, Atlanta, GA 30329, USA; Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA
| | - Helder I Nakaya
- Department of Pathology, School of Medicine, Emory University, Atlanta, GA 30329, USA; Department of Clinical and Toxicological Analyses, Institute of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil
| | - Felix Yarovinsky
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - R Balfour Sartor
- National Gnotobiotic Rodent Resource Center, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity, and Infection, Georgia State University, Atlanta, GA 30302, USA
| | - Bali Pulendran
- Emory Vaccine Center, Emory University, Atlanta, GA 30329, USA; Yerkes National Primate Center, Emory University, Atlanta, GA 30329, USA; Department of Pathology, School of Medicine, Emory University, Atlanta, GA 30329, USA.
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34
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Miura K, Ohnishi H. Role of gut microbiota and Toll-like receptors in nonalcoholic fatty liver disease. World J Gastroenterol 2014; 20:7381-7391. [PMID: 24966608 PMCID: PMC4064083 DOI: 10.3748/wjg.v20.i23.7381] [Citation(s) in RCA: 245] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/07/2014] [Accepted: 01/20/2014] [Indexed: 02/06/2023] Open
Abstract
Emerging data have shown a close association between compositional changes in gut microbiota and the development of nonalcoholic fatty liver disease (NAFLD). The change in gut microbiota may alter nutritional absorption and storage. In addition, gut microbiota are a source of Toll-like receptor (TLR) ligands, and their compositional change can also increase the amount of TLR ligands delivered to the liver. TLR ligands can stimulate liver cells to produce proinflammatory cytokines. Therefore, the gut-liver axis has attracted much interest, particularly regarding the pathogenesis of NAFLD. The abundance of the major gut microbiota, including Firmicutes and Bacteroidetes, has been considered a potential underlying mechanism of obesity and NAFLD, but the role of these microbiota in NAFLD remains unknown. Several reports have demonstrated that certain gut microbiota are associated with the development of obesity and NAFLD. For instance, a decrease in Akkermansia muciniphila causes a thinner intestinal mucus layer and promotes gut permeability, which allows the leakage of bacterial components. Interventions to increase Akkermansia muciniphila improve the metabolic parameters in obesity and NAFLD. In children, the levels of Escherichia were significantly increased in nonalcoholic steatohepatitis (NASH) compared with those in obese control. Escherichia can produce ethanol, which promotes gut permeability. Thus, normalization of gut microbiota using probiotics or prebiotics is a promising treatment option for NAFLD. In addition, TLR signaling in the liver is activated, and its downstream molecules, such as proinflammatory cytokines, are increased in NAFLD. To data, TLR2, TLR4, TLR5, and TLR9 have been shown to be associated with the pathogenesis of NAFLD. Therefore, gut microbiota and TLRs are targets for NAFLD treatment.
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35
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Takaki A, Kawai D, Yamamoto K. Molecular mechanisms and new treatment strategies for non-alcoholic steatohepatitis (NASH). Int J Mol Sci 2014; 15:7352-79. [PMID: 24786095 PMCID: PMC4057677 DOI: 10.3390/ijms15057352] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 03/28/2014] [Accepted: 04/10/2014] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD), in which most patients exhibit non-progressive, non-alcoholic fatty liver (NAFL) attributable to simple steatosis. Multiple hits, including genetic differences, fat accumulation, insulin resistance and intestinal microbiota changes, account for the progression of NASH. NAFLD is strongly associated with obesity, which induces adipokine secretion, endoplasmic reticulum (ER) and oxidative stress at the cellular level, which in turn induces hepatic steatosis, inflammation and fibrosis. Among these factors, gut microbiota are acknowledged as having an important role in initiating this multifactorial disease. Oxidative stress is considered to be a key contributor in the progression from NAFL to NASH. Macrophage infiltration is apparent in NAFL and NASH, while T-cell infiltration is apparent in NASH. Although several clinical trials have shown that antioxidative therapy with vitamin E can effectively control hepatitis pathology in the short term, the long-term effects remain obscure and have often proved to be ineffective in many other diseases. Several long-term antioxidant protocols have failed to reduce mortality. New treatment modalities that incorporate current understanding of NAFLD molecular pathogenesis must be considered.
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Affiliation(s)
- Akinobu Takaki
- Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
| | - Daisuke Kawai
- Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
| | - Kazuhide Yamamoto
- Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
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36
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Fecal microbiota transplantation: effectiveness, complexities, and lingering concerns. Mucosal Immunol 2014; 7:210-4. [PMID: 24399149 DOI: 10.1038/mi.2013.117] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mammalian colon is home to a microbial ecosystem that enhances resistance to infection, stimulates mucosal immune defenses, synthesizes essential vitamins, and promotes caloric uptake by hydrolyzing complex carbohydrates. The bacterial populations inhabiting the gut are complex and vary between different individuals. Clinical and experimental studies reveal that the colonic microbiota can enhance or ameliorate intestinal and systemic inflammatory diseases. Because of its potential to enhance resistance to infection and to reduce inflammatory diseases, targeted manipulation of microbial populations is a growing focus of investigation. The most dramatic manipulation of the intestinal microbiota involves fecal microbiota transplantation (FMT) from healthy donors to individuals with specific diseases. Remarkable clinical effectiveness of FMT has been demonstrated for recurrent Clostridium difficile infection and ongoing studies are investigating FMT for other diseases. Transplantation of complex microbial populations to recipients likely triggers mucosal immune responses that, depending on the microbiota composition and the recipient's genotype, could range from pro- to anti-inflammatory. The impact of FMT on the recipient immune system is complex and unpredictable. Ongoing discovery of commensal microbes and investigations of their impact on the host will lead to the development of new probiotic agents and microbial consortia that will eventually replace FMT.
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37
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Atif SM, Uematsu S, Akira S, McSorley SJ. CD103-CD11b+ dendritic cells regulate the sensitivity of CD4 T-cell responses to bacterial flagellin. Mucosal Immunol 2014; 7:68-77. [PMID: 23632327 PMCID: PMC4032068 DOI: 10.1038/mi.2013.25] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 03/22/2013] [Indexed: 02/04/2023]
Abstract
Toll-like receptor 5 (TLR5) has been widely studied in an inflammatory context, but the effect of TLR5 on the adaptive response to bacterial flagellin has received considerably less attention. Here, we demonstrate that TLR5 expression by dendritic cells (DCs) allows a 1,000-fold enhancement of T-cell sensitivity to flagellin, and this enhancement did not require the expression of NLRC4 or Myd88. The effect of TLR5 on CD4 T-cell sensitivity was independent of the adjuvant effect of flagellin and TLR5 ligation did not alter the sensitivity of ovalbumin (OVA)-specific T cells to OVA. In the spleen, the exquisite T-cell sensitivity to flagellin was regulated by CD4-CD8α- DCs and was blocked by a monoclonal antibody to TLR5. In the mesenteric lymph nodes, flagellin-specific T-cell activation was regulated by a population of CD103-CD11b+ DCs. Thus, TLR5 expression by mucosal and systemic DC subsets controls the sensitivity of the adaptive immune response to flagellated pathogens.
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Affiliation(s)
- Shaikh M. Atif
- Center for Comparative Medicine, Department of Anatomy, Physiology, and Cell Biology, UC Davis, Davis, CA 95616.,Correspondence should be addressed to: Shaikh M. Atif, Tel: (530) 752 5032, Fax: (530) 752 7914 and Stephen McSorley, Tel: (530) 752 3414, Fax: (530) 752 7914,
| | - Satoshi Uematsu
- Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka University Suita Osaka, 565-0871, Japan
| | - Shizuo Akira
- Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka University Suita Osaka, 565-0871, Japan
| | - Stephen J. McSorley
- Center for Comparative Medicine, Department of Anatomy, Physiology, and Cell Biology, UC Davis, Davis, CA 95616.,Correspondence should be addressed to: Shaikh M. Atif, Tel: (530) 752 5032, Fax: (530) 752 7914 and Stephen McSorley, Tel: (530) 752 3414, Fax: (530) 752 7914,
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38
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Greer RL, Morgun A, Shulzhenko N. Bridging immunity and lipid metabolism by gut microbiota. J Allergy Clin Immunol 2013; 132:253-62; quiz 263. [PMID: 23905915 DOI: 10.1016/j.jaci.2013.06.025] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 06/13/2013] [Accepted: 06/24/2013] [Indexed: 12/13/2022]
Abstract
The human gut is a unique organ in which hundreds of different microbial species find their habitat and in which different host physiologic functions, such as digestion, nutrition, and immunity, coexist. Although all these players were studied separately for decades, recently, there has been an explosion of studies demonstrating the essential role for interactions between these components in gut function. Furthermore, new systems biology methods provide essential tools to study this complex system as a whole and to identify key elements that define the crosstalk between the gut microbiota, immunity, and metabolism. This review is devoted to several human diseases resulting from the disruption in this crosstalk, including immunodeficiency-associated and environmental enteropathies, celiac disease, inflammatory bowel disease, and obesity. We describe findings in experimental models of these diseases and in germ-free animals that help us understand the mechanisms and test new therapeutic strategies. We also discuss current challenges that the field is facing and propose that a new generation of antibiotics, prebiotics, and probiotics coupled with novel, systems biology-driven diagnostics will provide the basis for future personalized therapy.
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Affiliation(s)
- Renee L Greer
- College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
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39
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Takaki A, Kawai D, Yamamoto K. Multiple hits, including oxidative stress, as pathogenesis and treatment target in non-alcoholic steatohepatitis (NASH). Int J Mol Sci 2013; 14:20704-28. [PMID: 24132155 PMCID: PMC3821639 DOI: 10.3390/ijms141020704] [Citation(s) in RCA: 287] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 09/18/2013] [Accepted: 09/29/2013] [Indexed: 12/12/2022] Open
Abstract
Multiple parallel hits, including genetic differences, insulin resistance and intestinal microbiota, account for the progression of non-alcoholic steatohepatitis (NASH). Multiple hits induce adipokine secretion, endoplasmic reticulum (ER) and oxidative stress at the cellular level that subsequently induce hepatic steatosis, inflammation and fibrosis, among which oxidative stress is considered a key contributor to progression from simple fatty liver to NASH. Although several clinical trials have shown that anti-oxidative therapy can effectively control hepatitis activities in the short term, the long-term effect remains obscure. Several trials of long-term anti-oxidant protocols aimed at treating cerebrovascular diseases or cancer development have failed to produce a benefit. This might be explained by the non-selective anti-oxidative properties of these drugs. Molecular hydrogen is an effective antioxidant that reduces only cytotoxic reactive oxygen species (ROS) and several diseases associated with oxidative stress are sensitive to hydrogen. The progress of NASH to hepatocellular carcinoma can be controlled using hydrogen-rich water. Thus, targeting mitochondrial oxidative stress might be a good candidate for NASH treatment. Long term clinical intervention is needed to control this complex lifestyle-related disease.
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Affiliation(s)
- Akinobu Takaki
- Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama City, Okayama 700-8558, Japan.
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40
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Paik J, Fierce Y, Treuting PM, Brabb T, Maggio-Price L. High-fat diet-induced obesity exacerbates inflammatory bowel disease in genetically susceptible Mdr1a-/- male mice. J Nutr 2013; 143:1240-7. [PMID: 23761644 DOI: 10.3945/jn.113.174615] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Obesity is a chronic inflammatory disease and a risk factor for disorders such as heart disease, diabetes, and cancer. A high-fat diet (HFD), a risk factor for obesity, has also been associated with inflammatory bowel disease (IBD). A proinflammatory state characterized by systemic and local increases in cytokine and chemokine levels are noted in both obesity and IBD, but it is unclear whether obesity is a risk factor for IBD. To examine any association between obesity and IBD, we chose FVB.129P2- Abcb1a(tm1Bor)N7 (Mdr1a(-/-)) mice, because this strain develops IBD spontaneously with age without a chemical or bacterial "trigger." In addition, its background strain, FVB, has been used for diet-induced obesity studies. Mdr1a(-/-) mice and wild-type (WT) mice were fed a HFD (∼60% calories from fat) or a low-fat diet (LFD; ∼11% calories from fat) for 12 wk. Obesity phenotypes examined included body weight measurements, glucose metabolism changes, and adiposity at termination of the study. IBD was determined by clinical signs, necropsy, and histopathology. We found that compared with those fed the LFD, both the Mdr1a(-/-) and WT mice fed the HFD had greater weight gains and elevated plasma leptin concentrations (P < 0.0001). When all mice were analyzed, weight gain was also associated with inflammation in mesenteric fat (R(2) = 0.5; P < 0.0001) and mesenteric lymph nodes (R(2) = 0.4; P < 0.0001). In contrast, the HFD was not associated with IBD in WT mice, whereas it exacerbated spontaneous IBD in Mdr1a(-/-) mice (P = 0.012; Fisher's exact test). Although a HFD and obesity were not associated with IBD in WT mice, our studies suggest that they are likely risk factors for IBD in a genetically susceptible host, such as Mdr1a(-/-) mice.
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Affiliation(s)
- Jisun Paik
- Department of Comparative Medicine, and Nutritional Sciences Program, University of Washington, Seattle, WA, USA.
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41
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Cox LM, Blaser MJ. Pathways in microbe-induced obesity. Cell Metab 2013; 17:883-894. [PMID: 23747247 PMCID: PMC3727904 DOI: 10.1016/j.cmet.2013.05.004] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/29/2013] [Accepted: 05/03/2013] [Indexed: 12/12/2022]
Abstract
Diet, host gene composition, and alterations in the intestinal microbiota can contribute to obesity. In microbe-induced obesity, metabolic changes stem from primary perturbation of the microbiota, consequent to modern changes in human biology. Microbiota disruption during early development can result in syndromes of metabolic dysfunction. We focus on the pathways involved in these interactions, particularly related to energy extraction and the role of inflammation in the metabolic phenotypes. Model physiologic systems and perturbations including gastric bypass surgery, pregnancy, and hibernation provide insight into the respective roles of the critical participants.
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Affiliation(s)
- Laura M Cox
- Department of Microbiology, New York University Sackler Institute of Graduate Biomedical Sciences, New York, NY 10016, USA
| | - Martin J Blaser
- Department of Microbiology, New York University Sackler Institute of Graduate Biomedical Sciences, New York, NY 10016, USA; Department of Medicine, New York University School of Medicine, New York, NY 10016, USA; Medical Service, VA New York Harbor Healthcare System, New York, NY 10010, USA.
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42
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Differential colonization with segmented filamentous bacteria and Lactobacillus murinus do not drive divergent development of diet-induced obesity in C57BL/6 mice. Mol Metab 2013; 2:171-83. [PMID: 24049732 DOI: 10.1016/j.molmet.2013.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 04/29/2013] [Indexed: 12/26/2022] Open
Abstract
Alterations in the gut microbiota have been proposed to modify the development and maintenance of obesity and its sequelae. Definition of underlying mechanisms has lagged, although the ability of commensal gut microbes to drive pathways involved in inflammation and metabolism has generated compelling, testable hypotheses. We studied C57BL/6 mice from two vendors that differ in their obesogenic response and in their colonization by specific members of the gut microbiota having well-described roles in regulating gut immune responses. We confirmed the presence of robust differences in weight gain in mice from these different vendors during high fat diet stress. However, neither specific, highly divergent members of the gut microbiota (Lactobacillus murinus, segmented filamentous bacteria) nor the horizontally transmissible gut microbiota were found to be responsible. Constitutive differences in locomotor activity were observed, however. These data underscore the importance of selecting appropriate controls in this widely used model of human obesity.
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43
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Xu X, Xu P, Ma C, Tang J, Zhang X. Gut microbiota, host health, and polysaccharides. Biotechnol Adv 2012; 31:318-37. [PMID: 23280014 DOI: 10.1016/j.biotechadv.2012.12.009] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Revised: 12/20/2012] [Accepted: 12/21/2012] [Indexed: 02/07/2023]
Abstract
The intestinal microbiota is a complicated ecosystem that influences many aspects of host physiology (i.e. diet, disease development, drug metabolism, and regulation of the immune system). It also exhibits spatial patterning and temporal dynamics. In this review, the effects of internal and external (environmental) factors on intestinal microbiota are discussed. We describe the roles of the gut microbiota in maintaining intestinal and immune system homeostasis and the relationship between gut microbiota and diseases. In particular, the contributions of polysaccharides, as the most abundant diet components in intestinal microbiota and host health are presented. Finally, perspectives for research avenues relating to gut microbiota are also discussed.
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Affiliation(s)
- Xiaofei Xu
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China
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44
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Flores-Langarica A, Marshall JL, Hitchcock J, Cook C, Jobanputra J, Bobat S, Ross EA, Coughlan RE, Henderson IR, Uematsu S, Akira S, Cunningham AF. Systemic flagellin immunization stimulates mucosal CD103+ dendritic cells and drives Foxp3+ regulatory T cell and IgA responses in the mesenteric lymph node. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2012; 189:5745-54. [PMID: 23152564 DOI: 10.4049/jimmunol.1202283] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Mucosal immunity is poorly activated after systemic immunization with protein Ags. Nevertheless, induction of mucosal immunity in such a manner would be an attractive and simple way to overcome the intrinsic difficulties in delivering Ag to such sites. Flagellin from Salmonella enterica serovar Typhimurium (FliC) can impact markedly on host immunity, in part via its recognition by TLR5. In this study, we show that systemic immunization with soluble FliC (sFliC) drives distinct immune responses concurrently in the mesenteric lymph nodes (MLN) and the spleen after i.p. and s.c. immunization. In the MLN, but not the spleen, sFliC drives a TLR5-dependent recruitment of CD103(+) dendritic cells (DCs), which correlates with a diminution in CD103(+) DC numbers in the lamina propria. In the MLN, CD103(+) DCs carry Ag and are the major primers of endogenous and transgenic T cell priming. A key consequence of these interactions with CD103(+) DCs in the MLN is an increase in local regulatory T cell differentiation. In parallel, systemic sFliC immunization results in a pronounced switching of FliC-specific B cells to IgA in the MLN but not elsewhere. Loss of TLR5 has more impact on MLN than splenic Ab responses, reflected in an ablation of IgA, but not IgG, serum Ab titers. Therefore, systemic sFliC immunization targets CD103(+) DCs and drives distinct mucosal T and B cell responses. This offers a potential "Trojan horse" approach to modulate mucosal immunity by systemically immunizing with sFliC.
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Affiliation(s)
- Adriana Flores-Langarica
- Medical Research Council Centre for Immune Regulation, Division of Immunity and Infection, Institute of Biomedical Research, University of Birmingham, Birmingham B15 2TT, United Kingdom
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45
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Choi YJ, Jung J, Chung HK, Im E, Rhee SH. PTEN regulates TLR5-induced intestinal inflammation by controlling Mal/TIRAP recruitment. FASEB J 2012; 27:243-54. [PMID: 23038756 DOI: 10.1096/fj.12-217596] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Defective IL-10 allele is a risk factor for intestinal inflammation. Indeed, IL-10(-/-) mice are predisposed to spontaneous colitis in the presence of intestinal microbiota, indicating that microbial factors contribute to developing intestinal inflammation. By recognizing flagellin, TLR5 plays a quintessential role in microbial recognition in intestinal epithelial cells. Here, we treated flagellin (1.0 μg/mouse/d) in mouse colon and found that it elicited colonic inflammation in IL-10(-/-) mice, characterized with tissue hypertrophy, inflamed epithelium, and enhanced cytokine production in the colon (MPO, KC, IL-6; ≥2-fold; P < 0.05). These inflammatory effects were dramatically inhibited in TLR5(-/-);IL-10(-/-) mice. Intestinal epithelium specific PTEN deletion significantly attenuated flagellin-promoted colonic inflammation in IL-10(-/-) mice. As a molecular mechanism that PTEN deletion inhibited TLR5-elicited responses, we hypothesized that PTEN regulated TLR5-induced responses by controlling the involvement of Mal in TLR5 engagement. Mal interacted with TLR5 on flagellin, and Mal deficiency inhibited flagellin-induced responses in intestinal epithelial cells. Similarly, Mal(-/-);IL-10(-/-) mice showed reduced flagellin-promoted responses. Furthermore, PTEN deletion disrupted Mal-TLR5 interaction, resulting in diminished TLR5-induced responses. PTEN deletion impeded Mal localization at the plasma membrane and suppressed Mal-TLR5 interaction. These results suggest that, by controlling Mal recruitment, PTEN regulates TLR5-induced inflammatory responses.
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Affiliation(s)
- Yoon Jeong Choi
- Division of Digestive Diseases, David Geffen School of Medicine, University of California–Los Angeles, Los Angeles, California 90095, USA
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46
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Im E, Jung J, Rhee SH. Toll-like receptor 5 engagement induces interleukin-17C expression in intestinal epithelial cells. J Interferon Cytokine Res 2012; 32:583-91. [PMID: 22994872 DOI: 10.1089/jir.2012.0053] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The family of interleukin-17 (IL-17) cytokine is the essential inflammatory mediator that influences the pathophysiology of various inflammatory diseases. Many studies focused on investigating the expression, signaling, and biological impacts of IL-17A and IL-17F, and the neutralization of these cytokines exhibited some promising results in clinical trials. In contrast, the expression resources and physiological relevance of IL-17C remained to be studied. In this study, through a microarray approach conducted with nontransformed human colonic epithelial cells (NCM460), we found that bacterial flagellin stimulation elicited potent IL-17C mRNA expression. We also confirmed that IL-17C protein production was strongly induced by flagellin in these cells. Flagellin-induced IL-17C expression was also observed in human colon adenocarcinoma cells such as DLD-1 and HT-29, indicating that IL-17C could be a signature inflammatory cytokine from intestinal epithelial cells in response to flagellin. Since inhibited in TLR5-, or MyD88- or TRIF-silenced cells, flagellin-induced IL-17C expression was specifically mediated by TLR5 and, subsequently, MyD88 and TRIF adaptor molecules. Furthermore, in line with inflammatory nature of IL-17, we found that IL-17C expression was substantially enhanced in the intestinal tissues from Ulcerative colitis patients. Given the facts that TLR5 is a key pattern recognition receptor which mediates microbial recognition in the intestinal epithelium and IL-17C turned out to be a unique member of the IL-17 family expressed in intestinal epithelial cells on TLR5 activation, our study may provide an important clue on understanding how intestinal microbes would contribute to an inflammatory program in the gut.
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Affiliation(s)
- Eunok Im
- School of Pharmacy, Pusan National University, Busan, Korea
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47
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Harley ITW, Karp CL. Obesity and the gut microbiome: Striving for causality. Mol Metab 2012; 1:21-31. [PMID: 24024115 DOI: 10.1016/j.molmet.2012.07.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Revised: 07/09/2012] [Accepted: 07/09/2012] [Indexed: 12/15/2022] Open
Abstract
The gut microbiome has been proposed to play a causal role in obesity. Here, we review the historical context for this hypothesis, highlight recent key findings, and critically discuss issues central to further progress in the field, including the central epistemological problem for the field: how to define causality in the relationship between microbiota and obesity phenotypes. Definition of such will be critical for the field to move forward.
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Affiliation(s)
- Isaac T W Harley
- Division of Molecular Immunology, Cincinnati Children's Hospital Research Foundation, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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48
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Wang R, Ahmed J, Wang G, Hassan I, Strulovici-Barel Y, Salit J, Mezey JG, Crystal RG. Airway epithelial expression of TLR5 is downregulated in healthy smokers and smokers with chronic obstructive pulmonary disease. THE JOURNAL OF IMMUNOLOGY 2012; 189:2217-25. [PMID: 22855713 DOI: 10.4049/jimmunol.1101895] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The TLRs are important components of the respiratory epithelium host innate defense, enabling the airway surface to recognize and respond to a variety of insults in inhaled air. On the basis of the knowledge that smokers are more susceptible to pulmonary infection and that the airway epithelium of smokers with chronic obstructive pulmonary disease (COPD) is characterized by bacterial colonization and acute exacerbation of airway infections, we assessed whether smoking alters expression of TLRs in human small airway epithelium, the primary site of smoking-induced disease. Microarrays were used to survey the TLR family gene expression in small airway (10th to 12th order) epithelium from healthy nonsmokers (n = 60), healthy smokers (n = 73), and smokers with COPD (n = 36). Using the criteria of detection call of present (P call) ≥ 50%, 6 of 10 TLRs (TLRs 1-5 and 8) were expressed. Compared with nonsmokers, the most striking change was for TLR5, which was downregulated in healthy smokers (1.4-fold, p < 10⁻¹⁰) and smokers with COPD (1.6-fold, p < 10⁻¹¹). TaqMan RT-PCR confirmed these observations. Bronchial biopsy immunofluorescence studies showed that TLR5 was expressed mainly on the apical side of the epithelium and was decreased in healthy smokers and smokers with COPD. In vitro, the level of TLR5 downstream genes, IL-6 and IL-8, was highly induced by flagellin in TLR5 high-expressing cells compared with TLR5 low-expressing cells. In the context that TLR5 functions to recognize pathogens and activate innate immune responses, the smoking-induced downregulation of TLR5 may contribute to smoking-related susceptibility to airway infection, at least for flagellated bacteria.
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Affiliation(s)
- Rui Wang
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA
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49
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Shibata T, Takemura N, Motoi Y, Goto Y, Karuppuchamy T, Izawa K, Li X, Akashi-Takamura S, Tanimura N, Kunisawa J, Kiyono H, Akira S, Kitamura T, Kitaura J, Uematsu S, Miyake K. PRAT4A-dependent expression of cell surface TLR5 on neutrophils, classical monocytes and dendritic cells. Int Immunol 2012; 24:613-23. [PMID: 22836022 DOI: 10.1093/intimm/dxs068] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
AbstractToll-like receptor 5 (TLR5), a sensor for bacterial flagellin, mounts innate and adaptive immune responses, and has been implicated in infectious diseases, colitis and metabolic syndromes. Although TLR5 is believed to belong to cell surface TLRs, cell surface expression has never been verified. Moreover, it has remained unclear which types of immune cells express TLR5 and contribute to flagellin-dependent responses. In this study we established an anti-mouse TLR5 monoclonal antibody and studied the cell surface expression of TLR5 on immune cells. The macrophage cell line J774 expressed endogenous TLR5 on the cell surface and produced IL-6 and G-CSF in response to flagellin. Cell surface expression of TLR5 and flagellin-induced responses were completely abolished by silencing a TLR-specific chaperone protein associated with TLR4 A (PRAT4A), demonstrating that TLR5 is another client of PRAT4A. In the in vivo immune cells, cell surface TLR5 was mainly found on neutrophils and CD11b (hi) Ly6C (hi) classical monocytes in the bone marrow, circulation, spleen and inflammatory lesions. Ly6C (hi) classical monocytes, but not neutrophils, produced cytokines in response to flagellin. Splenic CD8 (-) CD4 (+) conventional dendritic cells and CD11c (hi) CD11b (hi) lamina propria DCs, also clearly expressed cell surface TLR5. Collectively, cell surface expression of TLR5 is dependent on PRAT4A and restricted to neutrophils, classical monocytes and specific DC subsets.
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Affiliation(s)
- Takuma Shibata
- Division of Infectious Genetics, Department of Microbiology and Immunology, University of Tokyo, Minatoku, Tokyo108-8639, Japan
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50
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Neville BA, Forde BM, Claesson MJ, Darby T, Coghlan A, Nally K, Ross RP, O’Toole PW. Characterization of pro-inflammatory flagellin proteins produced by Lactobacillus ruminis and related motile Lactobacilli. PLoS One 2012; 7:e40592. [PMID: 22808200 PMCID: PMC3393694 DOI: 10.1371/journal.pone.0040592] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 06/11/2012] [Indexed: 11/18/2022] Open
Abstract
Lactobacillus ruminis is one of at least twelve motile but poorly characterized species found in the genus Lactobacillus. Of these, only L. ruminis has been isolated from mammals, and this species may be considered as an autochthonous member of the gastrointestinal microbiota of humans, pigs and cows. Nine L. ruminis strains were investigated here to elucidate the biochemistry and genetics of Lactobacillus motility. Six strains isolated from humans were non-motile while three bovine isolates were motile. A complete set of flagellum biogenesis genes was annotated in the sequenced genomes of two strains, ATCC25644 (human isolate) and ATCC27782 (bovine isolate), but only the latter strain produced flagella. Comparison of the L. ruminis and L. mali DSM20444(T) motility loci showed that their genetic content and gene-order were broadly similar, although the L. mali motility locus was interrupted by an 11.8 Kb region encoding rhamnose utilization genes that is absent from the L. ruminis motility locus. Phylogenetic analysis of 39 motile bacteria indicated that Lactobacillus motility genes were most closely related to those of motile carnobacteria and enterococci. Transcriptome analysis revealed that motility genes were transcribed at a significantly higher level in motile L. ruminis ATCC27782 than in non-motile ATCC25644. Flagellin proteins were isolated from L. ruminis ATCC27782 and from three other Lactobacillus species, while recombinant flagellin of aflagellate L. ruminis ATCC25644 was expressed and purified from E. coli. These native and recombinant Lactobacillus flagellins, and also flagellate L. ruminis cells, triggered interleukin-8 production in cultured human intestinal epithelial cells in a manner suppressed by short interfering RNA directed against Toll-Like Receptor 5. This study provides genetic, transcriptomic, phylogenetic and immunological insights into the trait of flagellum-mediated motility in the lactobacilli.
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Affiliation(s)
- B. Anne Neville
- Department of Microbiology, University College Cork, Cork, Ireland
| | - Brian M. Forde
- Department of Microbiology, University College Cork, Cork, Ireland
| | | | - Trevor Darby
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Avril Coghlan
- Department of Microbiology, University College Cork, Cork, Ireland
| | - Kenneth Nally
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - R. Paul Ross
- Teagasc, Moorepark Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | - Paul W. O’Toole
- Department of Microbiology, University College Cork, Cork, Ireland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
- * E-mail:
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