601
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Johnson CR, Thavarajah D, Combs GF, Thavarajah P. Lentil (Lens culinaris L.): A prebiotic-rich whole food legume. Food Res Int 2013. [DOI: 10.1016/j.foodres.2012.11.025] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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602
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Lawley TD, Walker AW. Intestinal colonization resistance. Immunology 2013; 138:1-11. [PMID: 23240815 DOI: 10.1111/j.1365-2567.2012.03616.x] [Citation(s) in RCA: 368] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 06/12/2012] [Accepted: 06/13/2012] [Indexed: 12/16/2022] Open
Abstract
Dense, complex microbial communities, collectively termed the microbiota, occupy a diverse array of niches along the length of the mammalian intestinal tract. During health and in the absence of antibiotic exposure the microbiota can effectively inhibit colonization and overgrowth by invading microbes such as pathogens. This phenomenon is called 'colonization resistance' and is associated with a stable and diverse microbiota in tandem with a controlled lack of inflammation, and involves specific interactions between the mucosal immune system and the microbiota. Here we overview the microbial ecology of the healthy mammalian intestinal tract and highlight the microbe-microbe and microbe-host interactions that promote colonization resistance. Emerging themes highlight immunological (T helper type 17/regulatory T-cell balance), microbiota (diverse and abundant) and metabolic (short-chain fatty acid) signatures of intestinal health and colonization resistance. Intestinal pathogens use specific virulence factors or exploit antibiotic use to subvert colonization resistance for their own benefit by triggering inflammation to disrupt the harmony of the intestinal ecosystem. A holistic view that incorporates immunological and microbiological facets of the intestinal ecosystem should facilitate the development of immunomodulatory and microbe-modulatory therapies that promote intestinal homeostasis and colonization resistance.
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Affiliation(s)
- Trevor D Lawley
- Bacterial Pathogenesis Laboratory, Wellcome Trust Sanger Institute, Hinxton, UK.
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603
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Smoking cessation induces profound changes in the composition of the intestinal microbiota in humans. PLoS One 2013; 8:e59260. [PMID: 23516617 PMCID: PMC3597605 DOI: 10.1371/journal.pone.0059260] [Citation(s) in RCA: 280] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 02/13/2013] [Indexed: 02/08/2023] Open
Abstract
Background The human intestinal microbiota is a crucial factor in the pathogenesis of various diseases, such as metabolic syndrome or inflammatory bowel disease (IBD). Yet, knowledge about the role of environmental factors such as smoking (which is known to influence theses aforementioned disease states) on the complex microbial composition is sparse. We aimed to investigate the role of smoking cessation on intestinal microbial composition in 10 healthy smoking subjects undergoing controlled smoking cessation. Methods During the observational period of 9 weeks repetitive stool samples were collected. Based on abundance of 16S rRNA genes bacterial composition was analysed and compared to 10 control subjects (5 continuing smokers and 5 non-smokers) by means of Terminal Restriction Fragment Length Polymorphism analysis and high-throughput sequencing. Results Profound shifts in the microbial composition after smoking cessation were observed with an increase of Firmicutes and Actinobacteria and a lower proportion of Bacteroidetes and Proteobacteria on the phylum level. In addition, after smoking cessation there was an increase in microbial diversity. Conclusions These results indicate that smoking is an environmental factor modulating the composition of human gut microbiota. The observed changes after smoking cessation revealed to be similar to the previously reported differences in obese compared to lean humans and mice respectively, suggesting a potential pathogenetic link between weight gain and smoking cessation. In addition they give rise to a potential association of smoking status and the course of IBD.
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604
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Liu X, Zou Q, Zeng B, Fang Y, Wei H. Analysis of fecal Lactobacillus community structure in patients with early rheumatoid arthritis. Curr Microbiol 2013; 67:170-6. [PMID: 23483307 DOI: 10.1007/s00284-013-0338-1] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 02/09/2013] [Indexed: 01/06/2023]
Abstract
The objective of this study was to analyze human fecal Lactobacillus community and its relationship with rheumatoid arthritis. Samples taken from rheumatoid arthritis (RA) patients and healthy individuals were analyzed by quantitative real-time PCR. Bacterial DNA was extracted from feces, and amplicons of the Lactobacillus-specific regions of 16S rRNA were analyzed by denaturing gradient gel electrophoresis. The richness, Shannon-Wiener index, and evenness of gut microbiota of both groups were analyzed to compare fecal Lactobacillus community structures. Results of this study demonstrated that fecal microbiota of RA patients contained significantly more Lactobacillus (10.62 ± 1.72 copies/g) than the control group (8.93 ± 1.60 copies/g). Significant increases were observed in RA patients in terms of the richness, Shannon-Wiener, and evenness measures, indicating more bacterial species, and increased bacterial diversity and abundance. These results suggest a potential relationship between Lactobacillus communities and the development and progression of rheumatoid arthritis.
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Affiliation(s)
- Xiaofei Liu
- Department of Rheumatology, Southwest Hospital, Third Military Medical University, Chongqing, China.
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605
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Berthelot JM, de la Cochetière MF, Potel G, Le Goff B, Maugars Y. Evidence supporting a role for dormant bacteria in the pathogenesis of spondylarthritis. Joint Bone Spine 2013; 80:135-40. [PMID: 23473929 DOI: 10.1016/j.jbspin.2012.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2012] [Indexed: 12/18/2022]
Abstract
Spondylarthritis is still viewed as a reaction to infectious agents, as opposed to an infection by persistent bacteria, for several reasons: (a) an infection is considered proven only when the organism can be cultured; (b) no studies have identified dormant bacteria in the tissues targeted by spondylarthritis; (c) the bacterial persistence hypothesis has no therapeutic implications at the time being, since antibiotics are effective neither on dormant bacteria nor on the manifestations of spondylarthritis; and (d) the high prevalence of borderline disorders combining features of spondylarthritis and of psoriatic arthritis, or even rheumatoid arthritis (RA), would indicate a role for dormant bacteria in these last two diseases. However, recent data on dormant bacteria have rekindled interest in the bacterial persistence hypothesis. Dormant bacteria cannot be cultured, because they express only a small group of genes, known as the regulon, which includes genes for transcription factors that block the expression of the usual bacterial genes. Certain forms of cell stress, such as molecule misfolding, promote the entry of bacteria into a state of dormancy, which induces the low-level release by the host cells of cytokines such as TNF. Whether HLA-B27 misfolding facilitates the persistence of dormant bacteria within spondylarthritis tissue targets remains to be determined. If it does, then treatments that reactivate dormant bacteria might make these organisms susceptible to appropriate antibiotics and might therefore serve as useful adjuncts to nonsteroidal anti-inflammatory drugs and TNFα antagonists. TNFα antagonists rarely reactivate dormant bacteria, with the exception of Mycobacterium tuberculosis, which, together with metastatic cells, is the most extensively studied latency model to date.
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Affiliation(s)
- Jean-Marie Berthelot
- Service de Rhumatologie, Hôtel-Dieu, CHU de Nantes, place Alexis-Ricordeau, 44093 Nantes cedex 01, France.
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606
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El Aidy S, Hooiveld G, Tremaroli V, Bäckhed F, Kleerebezem M. The gut microbiota and mucosal homeostasis: colonized at birth or at adulthood, does it matter? Gut Microbes 2013; 4:118-24. [PMID: 23333858 PMCID: PMC3595071 DOI: 10.4161/gmic.23362] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The intimate interplay between the gut microbiota and the host may contribute to health and disease in the host. Experiments using conventionalized and conventionally raised animal models have illustrated the role of the intestinal microbiota in shaping and maintaining the host immune system. However, it is still unclear whether colonization at birth or at adulthood induces different host responses. Here, we perform comparative transcriptome analyses to elucidate the impact of the gut microbiota on the development and maintenance of the immune system in adult conventionalized (after 16 and 30 days of colonization) and conventionally raised mice, which were obtained in two independent laboratories. Transcriptional profiles of jejunum, ileum and colon were compared between germfree, conventionally raised mice and conventionalized mice. Germfree mice from the two different facilities clustered together, establishing the validity of the comparative analysis. Nevertheless, significant spatial differences were detected along the gut; the jejunum and colon exhibited a transient response (conventionalized mice) that eventually returned to a homeostatic level (conventionally raised). In contrast, the ileal response to microbiota was similar in conventionalized and conventionally raised mice. Overall, this comparative analysis supports the hypothesis that co-development of the gut microbiota and its host initiates at early stage of development and indicates that despite the achieved homeostasis, immune development is substantially different in mice conventionalized in adulthood. These findings imply that colonization during development is required to meet the window of opportunity where the gut microbiota can imprint the host's mucosal immune-homeostasis in a way that cannot be achieved at later stages in life.
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Affiliation(s)
- Sahar El Aidy
- Laboratory of Microbiology; Wageningen University; Wageningen, the Netherlands
| | - Guido Hooiveld
- Nutrition, Metabolism and Genomics Group; Division of Human Nutrition; Wageningen University; Wageningen, The Netherlands
| | | | | | - Michiel Kleerebezem
- Laboratory of Microbiology; Wageningen University; Wageningen, the Netherlands,NIZO Food Research; Health Department; Ede, The Netherlands,Host Microbe Interactomics Group; Wageningen University; Wageningen, The Netherlands,Correspondence to: Michiel Kleerebezem,
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607
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Fleming J. Helminth therapy and multiple sclerosis. Int J Parasitol 2013; 43:259-74. [DOI: 10.1016/j.ijpara.2012.10.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 10/16/2012] [Accepted: 10/17/2012] [Indexed: 12/31/2022]
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608
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Mashoof S, Goodroe A, Du CC, Eubanks JO, Jacobs N, Steiner JM, Tizard I, Suchodolski JS, Criscitiello MF. Ancient T-independence of mucosal IgX/A: gut microbiota unaffected by larval thymectomy in Xenopus laevis. Mucosal Immunol 2013; 6:358-68. [PMID: 22929561 PMCID: PMC3514589 DOI: 10.1038/mi.2012.78] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Many studies address the influence of the gut microbiome on the immune system, but few dissect the effect of T cells on gut microbiota and mucosal responses. We have employed larval thymectomy in Xenopus to study the gut microbiota with and without the influence of T lymphocytes. Pyrosequencing of 16S ribosomal RNA genes was used to assess the relative abundance of bacterial groups present in the stomach, small and large intestine. Clostridiaceae was the most abundant family throughout the gut, while Bacteroidaceae, Enterobacteriaceae, and Flavobacteriaceae also were well represented. Unifrac analysis revealed no differences in microbiota distribution between thymectomized and unoperated frogs. This is consistent with immunization data showing that levels of the mucosal immunoglobulin IgX are not altered significantly by thymectomy. This study in Xenopus represents the oldest organisms that exhibit class switch to a mucosal isotype and is relevant to mammalian immunology, as IgA appears to have evolved from IgX based upon phylogeny, genomic synteny, and function.
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Affiliation(s)
- Sara Mashoof
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Anna Goodroe
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Christina C. Du
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Jeannine O. Eubanks
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Natalie Jacobs
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Jörg M. Steiner
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Ian Tizard
- Schubot Exotic Bird Health Center, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Jan S. Suchodolski
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Michael F. Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843 USA
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609
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van Baarlen P, Wells JM, Kleerebezem M. Regulation of intestinal homeostasis and immunity with probiotic lactobacilli. Trends Immunol 2013; 34:208-15. [PMID: 23485516 DOI: 10.1016/j.it.2013.01.005] [Citation(s) in RCA: 245] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/18/2013] [Accepted: 01/22/2013] [Indexed: 02/07/2023]
Abstract
The gut microbiota provide important stimuli to the human innate and adaptive immune system and co-mediate metabolic and immune homeostasis. Probiotic bacteria can be regarded as part of the natural human microbiota, and have been associated with improving homeostasis, albeit with different levels of success. Composition of microbiota, probiotic strain identity, and host genetic differences may account for differential modulation of immune responses by probiotics. Here, we review the mechanisms of immunomodulating capacities of specific probiotic strains, the responses they can induce in the host, and how microbiota and genetic differences between individuals may co-influence host responses and immune homeostasis.
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Affiliation(s)
- Peter van Baarlen
- Host Microbe Interactomics Group, Wageningen University, De Elst 1, 6708WD Wageningen, The Netherlands
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610
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McFall-Ngai M, Hadfield MG, Bosch TCG, Carey HV, Domazet-Lošo T, Douglas AE, Dubilier N, Eberl G, Fukami T, Gilbert SF, Hentschel U, King N, Kjelleberg S, Knoll AH, Kremer N, Mazmanian SK, Metcalf JL, Nealson K, Pierce NE, Rawls JF, Reid A, Ruby EG, Rumpho M, Sanders JG, Tautz D, Wernegreen JJ. Animals in a bacterial world, a new imperative for the life sciences. Proc Natl Acad Sci U S A 2013; 110:3229-36. [PMID: 23391737 PMCID: PMC3587249 DOI: 10.1073/pnas.1218525110] [Citation(s) in RCA: 1561] [Impact Index Per Article: 141.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the last two decades, the widespread application of genetic and genomic approaches has revealed a bacterial world astonishing in its ubiquity and diversity. This review examines how a growing knowledge of the vast range of animal-bacterial interactions, whether in shared ecosystems or intimate symbioses, is fundamentally altering our understanding of animal biology. Specifically, we highlight recent technological and intellectual advances that have changed our thinking about five questions: how have bacteria facilitated the origin and evolution of animals; how do animals and bacteria affect each other's genomes; how does normal animal development depend on bacterial partners; how is homeostasis maintained between animals and their symbionts; and how can ecological approaches deepen our understanding of the multiple levels of animal-bacterial interaction. As answers to these fundamental questions emerge, all biologists will be challenged to broaden their appreciation of these interactions and to include investigations of the relationships between and among bacteria and their animal partners as we seek a better understanding of the natural world.
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Affiliation(s)
- Margaret McFall-Ngai
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706
| | | | - Thomas C. G. Bosch
- Zoological Institute, Christian-Albrechts-University, D-24098 Kiel, Germany
| | - Hannah V. Carey
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706
| | | | - Angela E. Douglas
- Department of Entomology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Symbiosis Group, D-28359 Bremen, Germany
| | - Gerard Eberl
- Lymphoid Tissue Development Unit, Institut Pasteur, 75724 Paris, France
| | - Tadashi Fukami
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Scott F. Gilbert
- Biotechnology Institute, University of Helsinki, Helsinki 00014, Finland
| | - Ute Hentschel
- Julius-von-Sachs Institute, University of Wuerzburg, D-97082 Wuezburg, Germany
| | - Nicole King
- Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Staffan Kjelleberg
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, and Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia
| | | | - Natacha Kremer
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706
| | | | | | - Kenneth Nealson
- Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089
| | - Naomi E. Pierce
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - John F. Rawls
- Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599
| | - Ann Reid
- American Academy of Microbiology, Washington, DC 20036
| | - Edward G. Ruby
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706
| | - Mary Rumpho
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269
| | - Jon G. Sanders
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - Diethard Tautz
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, D-24306 Plön, Germany; and
| | - Jennifer J. Wernegreen
- Nicholas School and Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708
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611
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Sóki J. Extended role for insertion sequence elements in the antibiotic resistance of Bacteroides. World J Clin Infect Dis 2013; 3:1-12. [DOI: 10.5495/wjcid.v3.i1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 12/04/2012] [Accepted: 12/17/2012] [Indexed: 02/06/2023] Open
Abstract
The Bacteroides species are important micro-organisms, both in the normal physiology of the intestines and as frequent opportunistic anaerobic pathogens, with a deeply-rooted phylogenetic origin endowing them with some interesting biological features. Their prevalence in anaerobic clinical specimens is around 60%-80%, and they display the most numerous and highest rates of antibiotic resistance among all pathogenic anaerobes. In these antibiotic resistance mechanisms there is a noteworthy role for the insertion sequence (IS) elements, which are usually regarded as representatives of ‘selfish’ genes; the IS elements of Bacteroides are usually capable of up-regulating the antibiotic resistance genes. These include the cepA (penicillin and cephalosporin), cfxA (cephamycin), cfiA (carbapenem), nim (metronidazole) and ermF (clindamycin) resistance genes. This is achieved by outward-oriented promoter sequences on the ISs. Although some representatives are well characterized, e.g., the resistance gene-IS element pairs in certain resistant strains, open questions remain in this field concerning a better understanding of the molecular biology of the antibiotic resistance mechanisms of Bacteroides, which will have clinical implications.
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612
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Abstract
All multicellular organisms protect themselves against pathogens using sophisticated immune defenses. Functionally interconnected humoral and cellular facilities maintain immune homeostasis in the absence of overt infection and regulate the initiation and termination of immune responses directed against pathogens. Immune responses of invertebrates, such as flies, are innate and usually stereotyped; those of vertebrates, encompassing species as diverse as jawless fish and humans, are additionally adaptive, enabling more rapid and efficient immune reactivity upon repeated encounters with a pathogen. Many of the attributes historically defining innate and adaptive immunity are in fact common to both, blurring their functional distinction and emphasizing shared ancestry and co-evolution. These findings provide indications of the evolutionary forces underlying the origin of somatic diversification of antigen receptors and contribute to our understanding of the complex phenotypes of human immune disorders. Moreover, informed by phylogenetic considerations and inspired by improved knowledge of functional networks, new avenues emerge for innovative therapeutic strategies.
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613
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Reid JNS, Bisanz JE, Monachese M, Burton JP, Reid G. The Rationale for Probiotics Improving Reproductive Health and Pregnancy Outcome. Am J Reprod Immunol 2013; 69:558-66. [DOI: 10.1111/aji.12086] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 01/07/2013] [Indexed: 12/19/2022] Open
Affiliation(s)
| | | | | | - Jeremy P. Burton
- Human Microbiology and Probiotics; Lawson Health Research Institute; London; ON; Canada
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614
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Gilbert SF, Sapp J, Tauber AI. A symbiotic view of life: we have never been individuals. THE QUARTERLY REVIEW OF BIOLOGY 2013; 87:325-41. [PMID: 23397797 DOI: 10.1086/668166] [Citation(s) in RCA: 347] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The notion of the "biological individual" is crucial to studies of genetics, immunology, evolution, development, anatomy, and physiology. Each of these biological subdisciplines has a specific conception of individuality, which has historically provided conceptual contexts for integrating newly acquired data. During the past decade, nucleic acid analysis, especially genomic sequencing and high-throughput RNA techniques, has challenged each of these disciplinary definitions by finding significant interactions of animals and plants with symbiotic microorganisms that disrupt the boundaries that heretofore had characterized the biological individual. Animals cannot be considered individuals by anatomical or physiological criteria because a diversity of symbionts are both present and functional in completing metabolic pathways and serving other physiological functions. Similarly, these new studies have shown that animal development is incomplete without symbionts. Symbionts also constitute a second mode of genetic inheritance, providing selectable genetic variation for natural selection. The immune system also develops, in part, in dialogue with symbionts and thereby functions as a mechanism for integrating microbes into the animal-cell community. Recognizing the "holobiont"--the multicellular eukaryote plus its colonies of persistent symbionts--as a critically important unit of anatomy, development, physiology, immunology, and evolution opens up new investigative avenues and conceptually challenges the ways in which the biological subdisciplines have heretofore characterized living entities.
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Affiliation(s)
- Scott F Gilbert
- Department of Biology, Swarthmore College Swarthmore, Pennsylvania 19081, USA.
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615
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Rescigno M. Mucosal immunology and bacterial handling in the intestine. Best Pract Res Clin Gastroenterol 2013; 27:17-24. [PMID: 23768549 DOI: 10.1016/j.bpg.2013.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 03/01/2013] [Accepted: 03/14/2013] [Indexed: 01/31/2023]
Abstract
The mucosal immune system has the very difficult task to protect against invaders and to promote tolerance toward food antigens and the microbiota. These activities are achieved via a complex interaction between immune cells and the local microenvironment. Under the unperturbed (steady-state) condition the immune system is set toward the activation of tolerogenic responses. During infection the immune system is prompted to initiate immunity. When these two activities are not coordinated, inflammatory conditions may arise. In this review I will summarize the characteristic features of the mucosal immune system and its interaction with the microbiota.
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Affiliation(s)
- Maria Rescigno
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello, 16, 20139 Milan, Italy.
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616
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Rampelli S, Candela M, Severgnini M, Biagi E, Turroni S, Roselli M, Carnevali P, Donini L, Brigidi P. A probiotics-containing biscuit modulates the intestinal microbiota in the elderly. J Nutr Health Aging 2013; 17:166-72. [PMID: 23364497 DOI: 10.1007/s12603-012-0372-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVES Evaluation of the impact of a biscuit containing the probiotics Bifidobacterium longum Bar33 and Lactobacillus helveticus Bar13 on the intestinal microbiota in the elderly. DESIGN Randomized double-blind placebo-controlled trial. PARTICIPANTS Thirty-two elderly volunteers living in Italy. The group was composed of 19 women and 13 men aged between 71 and 88 years (mean 76). INTERVENTION Subjects were randomized in two groups consuming one dose of the probiotics-containing biscuit or placebo once a day for 30 days. MEASUREMENTS For each subject the intestinal microbiota was characterized using the phylogenetic microarray platform HTF-Microbi.Array before and after intervention. RESULTS Our data demonstrated that one-month consumption of a probiotics-containing biscuit was effective in redressing some of the age-related dysbioses of the intestinal microbiota. In particular, the probiotic treatment reverted the age-related increase of the opportunistic pathogens Clostridium cluster XI, Clostridium difficile, Clostridium perfringens, Enterococcus faecium and the enteropathogenic genus Campylobacter. CONCLUSION The present study opens the way to the development of elderly-tailored probiotic-based functional foods to counteract the age-related dysbioses of the intestinal microbiota.
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Affiliation(s)
- S Rampelli
- Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy
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617
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MyD88 signalling in colonic mononuclear phagocytes drives colitis in IL-10-deficient mice. Nat Commun 2013; 3:1120. [PMID: 23047678 PMCID: PMC3521499 DOI: 10.1038/ncomms2113] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 09/04/2012] [Indexed: 12/23/2022] Open
Abstract
Commensal bacterial sensing by Toll-like receptors (TLRs) is critical for maintaining intestinal homeostasis, but can lead to colitis in the absence of IL-10. While TLRs are expressed in multiple cell types in the colon, the cell type(s) responsible for the development of colitis currently unknown. Here, we generated mice that are selectively deficient in MyD88 in various cellular compartments in an IL-10−/− setting. While epithelial expression of MyD88 was dispensable, MyD88 expression in the mononuclear phagocyte (MNP) compartment was required for colitis development. Specifically, phenotypically distinct populations of colonic MNPs expressed high levels IL-1β, IL-23 and IL-6 and promoted Th17 responses in the absence of IL-10. Thus, gut bacterial sensing through MyD88 in MNPs drives inflammatory bowel disease (IBD) when unopposed by IL-10.
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618
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Haahtela T, Holgate S, Pawankar R, Akdis CA, Benjaponpitak S, Caraballo L, Demain J, Portnoy J, von Hertzen L. The biodiversity hypothesis and allergic disease: world allergy organization position statement. World Allergy Organ J 2013; 6:3. [PMID: 23663440 PMCID: PMC3646540 DOI: 10.1186/1939-4551-6-3] [Citation(s) in RCA: 207] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 01/17/2013] [Indexed: 12/21/2022] Open
Abstract
Biodiversity loss and climate change secondary to human activities are now being associated with various adverse health effects. However, less attention is being paid to the effects of biodiversity loss on environmental and commensal (indigenous) microbiotas. Metagenomic and other studies of healthy and diseased individuals reveal that reduced biodiversity and alterations in the composition of the gut and skin microbiota are associated with various inflammatory conditions, including asthma, allergic and inflammatory bowel diseases (IBD), type1 diabetes, and obesity. Altered indigenous microbiota and the general microbial deprivation characterizing the lifestyle of urban people in affluent countries appear to be risk factors for immune dysregulation and impaired tolerance. The risk is further enhanced by physical inactivity and a western diet poor in fresh fruit and vegetables, which may act in synergy with dysbiosis of the gut flora. Studies of immigrants moving from non-affluent to affluent regions indicate that tolerance mechanisms can rapidly become impaired in microbe-poor environments. The data on microbial deprivation and immune dysfunction as they relate to biodiversity loss are evaluated in this Statement of World Allergy Organization (WAO). We propose that biodiversity, the variability among living organisms from all sources are closely related, at both the macro- and micro-levels. Loss of the macrodiversity is associated with shrinking of the microdiversity, which is associated with alterations of the indigenous microbiota. Data on behavioural means to induce tolerance are outlined and a proposal made for a Global Allergy Plan to prevent and reduce the global allergy burden for affected individuals and the societies in which they live.
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Affiliation(s)
- Tari Haahtela
- Skin and Allergy Hospital, Helsinki University Hospital, PO Box 160, 00029, Helsinki, HUCH, Finland
| | - Stephen Holgate
- School of Medicine, University of Southampton, Southampton, UK
| | | | - Cezmi A Akdis
- Swiss Institute of Allergy and Asthma Research, University of Zurich, Davos, Switzerland
| | - Suwat Benjaponpitak
- Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Luis Caraballo
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
| | - Jeffrey Demain
- Allergy, Asthma & Immunology Center of Alaska, Dept of Pediatrics, University of Washington, Washington, USA
| | - Jay Portnoy
- University of Missouri-Kansas City School of Medicine, Missouri, USA
| | - Leena von Hertzen
- Skin and Allergy Hospital, Helsinki University Hospital, PO Box 160, 00029, Helsinki, HUCH, Finland
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619
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Ellis RJ, Bruce KD, Jenkins C, Stothard JR, Ajarova L, Mugisha L, Viney ME. Comparison of the distal gut microbiota from people and animals in Africa. PLoS One 2013; 8:e54783. [PMID: 23355898 PMCID: PMC3552852 DOI: 10.1371/journal.pone.0054783] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 12/17/2012] [Indexed: 01/20/2023] Open
Abstract
The gut microbiota plays a key role in the maintenance of healthy gut function as well as many other aspects of health. High-throughput sequence analyses have revealed the composition of the gut microbiota, showing that there is a core signature to the human gut microbiota, as well as variation in its composition between people. The gut microbiota of animals is also being investigated. We are interested in the relationship between bacterial taxa of the human gut microbiota and those in the gut microbiota of domestic and semi-wild animals. While it is clear that some human gut bacterial pathogens come from animals (showing that human--animal transmission occurs), the extent to which the usually non-pathogenic commensal taxa are shared between humans and animals has not been explored. To investigate this we compared the distal gut microbiota of humans, cattle and semi-captive chimpanzees in communities that are geographically sympatric in Uganda. The gut microbiotas of these three host species could be distinguished by the different proportions of bacterial taxa present. We defined multiple operational taxonomic units (OTUs) by sequence similarity and found evidence that some OTUs were common between human, cattle and chimpanzees, with the largest number of shared OTUs occurring between chimpanzees and humans, as might be expected with their close physiological similarity. These results show the potential for the sharing of usually commensal bacterial taxa between humans and other animals. This suggests that further investigation of this phenomenon is needed to fully understand how it drives the composition of human and animal gut microbiotas.
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Affiliation(s)
- Richard J Ellis
- Specialist Scientific Support Department, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom.
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620
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Levkovich T, Poutahidis T, Smillie C, Varian BJ, Ibrahim YM, Lakritz JR, Alm EJ, Erdman SE. Probiotic bacteria induce a 'glow of health'. PLoS One 2013; 8:e53867. [PMID: 23342023 PMCID: PMC3547054 DOI: 10.1371/journal.pone.0053867] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 12/05/2012] [Indexed: 02/07/2023] Open
Abstract
Radiant skin and hair are universally recognized as indications of good health. However, this 'glow of health' display remains poorly understood. We found that feeding of probiotic bacteria to aged mice induced integumentary changes mimicking peak health and reproductive fitness characteristic of much younger animals. Eating probiotic yogurt triggered epithelial follicular anagen-phase shift with sebocytogenesis resulting in thick lustrous fur due to a bacteria-triggered interleukin-10-dependent mechanism. Aged male animals eating probiotics exhibited increased subcuticular folliculogenesis, when compared with matched controls, yielding luxuriant fur only in probiotic-fed subjects. Female animals displayed probiotic-induced hyperacidity coinciding with shinier hair, a feature that also aligns with fertility in human females. Together these data provide insights into mammalian evolution and novel strategies for integumentary health.
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Affiliation(s)
- Tatiana Levkovich
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Theofilos Poutahidis
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Laboratory of Pathology, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Christopher Smillie
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Bernard J. Varian
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Yassin M. Ibrahim
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jessica R. Lakritz
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Eric J. Alm
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Biological Engineering, Massachusetts Institute of Technology, Cambridge Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail: (EJA); (SEE)
| | - Susan E. Erdman
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail: (EJA); (SEE)
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621
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Rongvaux A, Takizawa H, Strowig T, Willinger T, Eynon EE, Flavell RA, Manz MG. Human hemato-lymphoid system mice: current use and future potential for medicine. Annu Rev Immunol 2013; 31:635-674. [PMID: 23330956 DOI: 10.1146/annurev-immunol-032712-095921] [Citation(s) in RCA: 253] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To directly study complex human hemato-lymphoid system physiology and respective system-associated diseases in vivo, human-to-mouse xenotransplantation models for human blood and blood-forming cells and organs have been developed over the past three decades. We here review the fundamental requirements and the remarkable progress made over the past few years in improving these systems, the current major achievements reached by use of these models, and the future challenges to more closely model and study human health and disease and to achieve predictive preclinical testing of both prevention measures and potential new therapies.
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Affiliation(s)
- Anthony Rongvaux
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520
| | - Hitoshi Takizawa
- Division of Hematology, University Hospital Zürich, CH-8091 Zürich, Switzerland
| | - Till Strowig
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520
| | - Tim Willinger
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520
| | - Elizabeth E Eynon
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520
| | - Richard A Flavell
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520.,Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520;
| | - Markus G Manz
- Division of Hematology, University Hospital Zürich, CH-8091 Zürich, Switzerland
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622
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Biedermann L, Rogler G. Environmental factors and their impact on the intestinal microbiota: a role for human disease? Dig Dis 2013; 30 Suppl 3:20-7. [PMID: 23295688 DOI: 10.1159/000342590] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The intestinal microbiota and its potential role in human health and disease have come into the focus of interest in recent years. An important prerequisite for the achieved advances with regard to a better characterization of its complex composition and influencing factors is the increasing availability and affordability of culture-independent methods, such as high-throughput sequencing technologies. We discuss some general aspects of the intestinal microbiota. Recent insights into its potential pathogenetic role in the metabolic syndrome and inflammatory bowel disease will also be discussed that imply an impact of smoking status and smoking cessation on intestinal microbial composition.
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Affiliation(s)
- Luc Biedermann
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland. luc.biedermann @ usz.ch
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623
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Cervantes JL, Hong BY. Role of Next-Generation Sequencing in Understanding the Interactions between Human Papillomavirus and the Cervicovaginal Microbiome. Gynecol Obstet Invest 2013; 76:195-202. [DOI: 10.1159/000351309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/13/2013] [Indexed: 11/19/2022]
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624
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Probiotic/synbiotic therapy for treating critically ill patients from a gut microbiota perspective. Dig Dis Sci 2013; 58:23-32. [PMID: 22903218 PMCID: PMC3557374 DOI: 10.1007/s10620-012-2334-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 07/18/2012] [Indexed: 12/13/2022]
Abstract
The gut is an important target organ for stress caused by severe insults such as sepsis, trauma, burn, shock, bleeding and infection. Severe insult to the gut is considered to have an important role in promoting infectious complications and multiple organ dysfunction syndrome. These are sequelae of interactions between deteriorated intestinal epithelium, the immune system and commensal bacteria. The gut is the "motor" of multiple organ failure, and now it is recognized that gut dysfunction is a causative factor in disease progression. The gut flora and environment are significantly altered in critically ill patients, and the number of obligate anaerobes is associated with prognosis. Synbiotic therapy is a combination of probiotics and prebiotics. Probiotic, prebiotic and synbiotic treatment has been shown to be a promising therapy to maintain and repair the gut microbiota and gut environment. In the critically ill, such as major abdominal surgery, trauma and ICU patients, synbiotic therapy has been shown to significantly reduce septic complications. Further basic and clinical research would clarify the underlying mechanisms of the therapeutic effect of probiotic/synbiotic treatment and define the appropriate conditions for use.
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625
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Biedermann L, Zeitz J, Mwinyi J, Sutter-Minder E, Rehman A, Ott SJ, Steurer-Stey C, Frei A, Frei P, Scharl M, Loessner MJ, Vavricka SR, Fried M, Schreiber S, Schuppler M, Rogler G. Smoking cessation induces profound changes in the composition of the intestinal microbiota in humans. PLoS One 2013; 8:e59260. [PMID: 23516617 DOI: 10.1371/journal.pone.0059260.s014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 02/13/2013] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND The human intestinal microbiota is a crucial factor in the pathogenesis of various diseases, such as metabolic syndrome or inflammatory bowel disease (IBD). Yet, knowledge about the role of environmental factors such as smoking (which is known to influence theses aforementioned disease states) on the complex microbial composition is sparse. We aimed to investigate the role of smoking cessation on intestinal microbial composition in 10 healthy smoking subjects undergoing controlled smoking cessation. METHODS During the observational period of 9 weeks repetitive stool samples were collected. Based on abundance of 16S rRNA genes bacterial composition was analysed and compared to 10 control subjects (5 continuing smokers and 5 non-smokers) by means of Terminal Restriction Fragment Length Polymorphism analysis and high-throughput sequencing. RESULTS Profound shifts in the microbial composition after smoking cessation were observed with an increase of Firmicutes and Actinobacteria and a lower proportion of Bacteroidetes and Proteobacteria on the phylum level. In addition, after smoking cessation there was an increase in microbial diversity. CONCLUSIONS These results indicate that smoking is an environmental factor modulating the composition of human gut microbiota. The observed changes after smoking cessation revealed to be similar to the previously reported differences in obese compared to lean humans and mice respectively, suggesting a potential pathogenetic link between weight gain and smoking cessation. In addition they give rise to a potential association of smoking status and the course of IBD.
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Affiliation(s)
- Luc Biedermann
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
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626
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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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627
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Triggle DJ. Nous Sommes Tous des Bacteries: Implications for medicine, pharmacology and public health. Biochem Pharmacol 2012; 84:1543-50. [DOI: 10.1016/j.bcp.2012.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 08/01/2012] [Accepted: 08/06/2012] [Indexed: 02/08/2023]
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628
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Gut bacteria-host metabolic interplay during conventionalisation of the mouse germfree colon. ISME JOURNAL 2012. [PMID: 23178667 DOI: 10.1038/ismej.2012.142] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The interplay between dietary nutrients, gut microbiota and mammalian host tissues of the gastrointestinal tract is recognised as highly relevant for host health. Combined transcriptome, metabonome and microbial profiling tools were employed to analyse the dynamic responses of germfree mouse colonic mucosa to colonisation by normal mouse microbiota (conventionalisation) at different time-points during 16 days. The colonising microbiota showed a shift from early (days 1 and 2) to later colonisers (days 8 and 16). The dynamic changes in the microbial community were rapidly reflected by the urine metabolic profiles (day 1) and at later stages (day 4 onward) by the colon mucosa transcriptome and metabolic profiles. Correlations of host transcriptomes, metabolite patterns and microbiota composition revealed associations between Bacilli and Proteobacteria, and differential expression of host genes involved in energy and anabolic metabolism. Differential gene expression correlated with scyllo- and myo-inositol, glutamine, glycine and alanine levels in colonic tissues during the time span of conventionalisation. Our combined time-resolved analyses may help to expand the understanding of host-microbe molecular interactions during the microbial establishment.
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629
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Abstract
The major strides accomplished in elucidating the pathophysiology of rheumatoid arthritis (RA) have translated into therapeutic breakthroughs in clinical practice. However, currently available treatments work only for as long as they are taken. The development of curative treatments will probably require a better understanding of the earliest phases of RA and perhaps the identification of the etiological factors, which are probably numerous. These objectives are being pursued in studies of preclinical RA. The literature review presented herein indicates that the immunological conflict probably originates outside the joints, at mucous membrane sites and, more specifically, in the upper aerodigestive tract. The preclinical phase of RA can last for many years, and some patients probably never progress to arthritis. An immunological conflict develops then spins out of control, causing increases in autoantibody titers and subsequently in levels of serum markers for inflammation, before the development of the first joint symptoms. Improved knowledge of the preclinical phase, together with information from genetic markers, will allow the identification of profiles associated with susceptibility to RA and perhaps, in the future, the development of preventive strategies.
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630
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Turnbull C, Wilson PD, Hoggard S, Gillings M, Palmer C, Smith S, Beattie D, Hussey S, Stow A, Beattie A. Primordial enemies: fungal pathogens in thrips societies. PLoS One 2012; 7:e49737. [PMID: 23185420 PMCID: PMC3504084 DOI: 10.1371/journal.pone.0049737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 10/12/2012] [Indexed: 11/24/2022] Open
Abstract
Microbial pathogens are ancient selective agents that have driven many aspects of multicellular evolution, including genetic, behavioural, chemical and immune defence systems. It appears that fungi specialised to attack insects were already present in the environments in which social insects first evolved and we hypothesise that if the early stages of social evolution required antifungal defences, then covariance between levels of sociality and antifungal defences might be evident in extant lineages, the defences becoming stronger with group size and increasing social organisation. Thus, we compared the activity of cuticular antifungal compounds in thrips species (Insecta: Thysanoptera) representing a gradient of increasing group size and sociality: solitary, communal, social and eusocial, against the entomopathogen Cordyceps bassiana. Solitary and communal species showed little or no activity. In contrast, the social and eusocial species killed this fungus, suggesting that the evolution of sociality has been accompanied by sharp increases in the effectiveness of antifungal compounds. The antiquity of fungal entomopathogens, demonstrated by fossil finds, coupled with the unequivocal response of thrips colonies to them shown here, suggests two new insights into the evolution of thrips sociality: First, traits that enabled nascent colonies to defend themselves against microbial pathogens should be added to those considered essential for social evolution. Second, limits to the strength of antimicrobials, through resource constraints or self-antibiosis, may have been overcome by increase in the numbers of individuals secreting them, thus driving increases in colony size. If this is the case for social thrips, then we may ask: did antimicrobial traits and microbes such as fungal entomopathogens play an integral part in the evolution of insect sociality in general?
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Affiliation(s)
- Christine Turnbull
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Peter D. Wilson
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Stephen Hoggard
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Michael Gillings
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Chris Palmer
- Department of Natural Resources, Northern Territory Government, Alice Springs, Northern Territory, Australia
| | - Shannon Smith
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Doug Beattie
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Sam Hussey
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Adam Stow
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Andrew Beattie
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
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631
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Carey HV, Walters WA, Knight R. Seasonal restructuring of the ground squirrel gut microbiota over the annual hibernation cycle. Am J Physiol Regul Integr Comp Physiol 2012; 304:R33-42. [PMID: 23152108 DOI: 10.1152/ajpregu.00387.2012] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many hibernating mammals suspend food intake during winter, relying solely on stored lipids to fuel metabolism. Winter fasting in these species eliminates a major source of degradable substrates to support growth of gut microbes, which may affect microbial community structure and host-microbial interactions. We explored the effect of the annual hibernation cycle on gut microbiotas using deep sequencing of 16S rRNA genes from ground squirrel cecal contents. Squirrel microbiotas were dominated by members of the phyla Bacteroidetes, Firmicutes, and Verrucomicrobia. UniFrac analysis showed that microbiotas clustered strongly by season, and maternal influences, diet history, host age, and host body temperature had minimal effects. Phylogenetic diversity and numbers of operational taxonomic units were lowest in late winter and highest in the spring after a 2-wk period of refeeding. Hibernation increased relative abundance of Bacteroidetes and Verrucomicrobia, phyla that contain species capable of surviving on host-derived substrates such as mucins, and reduced relative abundance of Firmicutes, many of which prefer dietary polysaccharides. Hibernation reduced cecal short-chain fatty acid and ammonia concentrations, and increased and decreased concentrations of acetate and butyrate, respectively. These results indicate that the ground squirrel microbiota is restructured each year in a manner that reflects differences in microbial preferences for dietary vs. host-derived substrates, and thus the competitive abilities of different taxa to survive in the altered environment in the hibernator gut.
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Affiliation(s)
- Hannah V Carey
- 1Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, 53706, USA.
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632
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Algül H, Chari ST. Lymphotoxin in the pathogenesis of autoimmune pancreatitis: a new player in the field. Gastroenterology 2012; 143:1147-1150. [PMID: 23000229 DOI: 10.1053/j.gastro.2012.09.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Hana Algül
- II. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
| | - Suresh T Chari
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota
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633
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Olofsson PS, Rosas-Ballina M, Levine YA, Tracey KJ. Rethinking inflammation: neural circuits in the regulation of immunity. Immunol Rev 2012; 248:188-204. [PMID: 22725962 DOI: 10.1111/j.1600-065x.2012.01138.x] [Citation(s) in RCA: 283] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Neural reflex circuits regulate cytokine release to prevent potentially damaging inflammation and maintain homeostasis. In the inflammatory reflex, sensory input elicited by infection or injury travels through the afferent vagus nerve to integrative regions in the brainstem, and efferent nerves carry outbound signals that terminate in the spleen and other tissues. Neurotransmitters from peripheral autonomic nerves subsequently promote acetylcholine-release from a subset of CD4(+) T cells that relay the neural signal to other immune cells, e.g. through activation of α7 nicotinic acetylcholine receptors on macrophages. Here, we review recent progress in the understanding of the inflammatory reflex and discuss potential therapeutic implications of current findings in this evolving field.
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Affiliation(s)
- Peder S Olofsson
- Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, Manhasset, New York 11030, USA
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634
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Shen Y, Giardino Torchia ML, Lawson GW, Karp CL, Ashwell JD, Mazmanian SK. Outer membrane vesicles of a human commensal mediate immune regulation and disease protection. Cell Host Microbe 2012; 12:509-20. [PMID: 22999859 PMCID: PMC3895402 DOI: 10.1016/j.chom.2012.08.004] [Citation(s) in RCA: 450] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2012] [Revised: 06/08/2012] [Accepted: 08/01/2012] [Indexed: 12/19/2022]
Abstract
Commensal bacteria impact host health and immunity through various mechanisms, including the production of immunomodulatory molecules. Bacteroides fragilis produces a capsular polysaccharide (PSA), which induces regulatory T cells and mucosal tolerance. However, unlike pathogens, which employ secretion systems, the mechanisms by which commensal bacteria deliver molecules to the host remain unknown. We reveal that Bacteroides fragilis releases PSA in outer membrane vesicles (OMVs) that induce immunomodulatory effects and prevent experimental colitis. Dendritic cells (DCs) sense OMV-associated PSA through TLR2, resulting in enhanced regulatory T cells and anti-inflammatory cytokine production. OMV-induced signaling in DCs requires growth arrest and DNA-damage-inducible protein (Gadd45α). DCs treated with PSA-containing OMVs prevent experimental colitis, whereas Gadd45α(-/-) DCs are unable to promote regulatory T cell responses or suppress proinflammatory cytokine production and host pathology. These findings demonstrate that OMV-mediated delivery of a commensal molecule prevents disease, uncovering a mechanism of interkingdom communication between the microbiota and mammals.
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Affiliation(s)
- Yue Shen
- Division of Biology, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Maria Letizia Giardino Torchia
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Gregory W. Lawson
- Division of Laboratory Animal Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, 90095, USA
| | - Christopher L. Karp
- Division of Molecular Immunology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio 45229, USA
| | - Jonathan D. Ashwell
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Sarkis K. Mazmanian
- Division of Biology, California Institute of Technology, Pasadena, CA, 91125, USA
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635
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A single-amino-acid change in murine norovirus NS1/2 is sufficient for colonic tropism and persistence. J Virol 2012; 87:327-34. [PMID: 23077309 DOI: 10.1128/jvi.01864-12] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human norovirus (HuNoV) is the major cause of acute nonbacterial gastroenteritis worldwide but has no clear animal reservoir. HuNoV can persist after the resolution of symptoms, and this persistence may be essential for viral maintenance within the population. Many strains of the related murine norovirus (MNV) also persist, providing a tractable animal model for studying norovirus (NoV) persistence. We have used recombinant cDNA clones of representative persistent (CR6) and nonpersistent (CW3) strains to identify a domain within the nonstructural gene NS1/2 that is necessary and sufficient for persistence. Furthermore, we found that a single change of aspartic acid to glutamic acid in CW3 NS1/2 was sufficient for persistence. This same conservative change also caused increased growth of CW3 in the proximal colon, which we found to be a major tissue reservoir of MNV persistence, suggesting that NS1/2 determines viral tropism that is necessary for persistence. These findings represent the first identified function for NoV NS1/2 during infection and establish a novel model system for the study of enteric viral persistence.
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636
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Abstract
Given the importance of the microbiome for human health, both the stability and the response to disturbance of this microbial ecosystem are crucial issues. Yet, the current understanding of these factors is insufficient. Early data suggest there is relative stability in the microbiome of adults in the absence of gross perturbation, and that long-term stability of the human indigenous microbial communities is maintained not by inertia but by the action of restorative forces within a dynamic system. After brief exposures to some antibiotics, there is an immediate and substantial perturbation and at least a partial recovery of taxonomic composition. Responses to antibiotics are individualized and are influenced by prior experience with the same antibiotic. These findings suggest that the human microbiome has properties of resilience. Besides serving to reveal critical underlying functional attributes, microbial interactions, and keystone species within the indigenous microbiota, the response to disturbance may have value in predicting future instability and disease and in managing the human microbial ecosystem.
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Affiliation(s)
- David A Relman
- Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.
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637
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Charoenphandhu N, Suntornsaratoon P, Jongwattanapisan P, Wongdee K, Krishnamra N. Enhanced trabecular bone resorption and microstructural bone changes in rats after removal of the cecum. Am J Physiol Endocrinol Metab 2012; 303:E1069-75. [PMID: 22912366 DOI: 10.1152/ajpendo.00242.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cecum, the proximal part of the large intestine, has the highest rate of calcium absorption compared with other intestinal segments. Previously, we showed that rats with the cecum surgically removed (cecectomized rats) had severe negative calcium balance, low bone mineral density (BMD), and a compensatory increase in colonic calcium absorption. Herein, we used the computer-assisted bone histomorphometric technique and microcomputed tomography (μCT) to analyze bone microstructural defects in cecectomized rats at 1 and 3 mo postsurgery compared with age-matched sham-operated control rats. Relatively low BMD as determined by dual energy X-ray absorptiometry was observed in the femora, tibiae, and lumbar vertebrae of the 3-mo cecectomized rats. μCT analysis revealed decreases in the tibial cortical thickness, periosteal and endosteal perimeters, and moment of inertia in cecectomized rats. The histomorphometric results further showed that trabecular bone volume and number were markedly decreased, whereas trabecular separation was increased in the proximal tibial metaphysis of cecectomized rats, thus leading to a decrease in trabecular volumetric BMD. Since osteoclast surface and eroded surface were increased after cecectomy, such bone loss in cecectomized rats appeared to result from an enhanced bone resorption. Moreover, decreases in bone formation rate and osteoblast surface indicated a suppression of osteoblast-mediated bone formation. In conclusion, cecectomy induced widespread osteopenia in rats presumably by enhancing the osteoclast-mediated bone resorption and suppressing bone formation. The present results underline the important role of cecum in the body calcium homeostasis.
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Affiliation(s)
- Narattaphol Charoenphandhu
- Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand. Rama VI Rd., Bangkok, 10400, Thailand.
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638
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Alegado RA, Brown LW, Cao S, Dermenjian RK, Zuzow R, Fairclough SR, Clardy J, King N. A bacterial sulfonolipid triggers multicellular development in the closest living relatives of animals. eLife 2012; 1:e00013. [PMID: 23066504 PMCID: PMC3463246 DOI: 10.7554/elife.00013] [Citation(s) in RCA: 179] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/18/2012] [Indexed: 12/15/2022] Open
Abstract
Bacterially-produced small molecules exert profound influences on animal health, morphogenesis, and evolution through poorly understood mechanisms. In one of the closest living relatives of animals, the choanoflagellate Salpingoeca rosetta, we find that rosette colony development is induced by the prey bacterium Algoriphagus machipongonensis and its close relatives in the Bacteroidetes phylum. Here we show that a rosette inducing factor (RIF-1) produced by A. machipongonensis belongs to the small class of sulfonolipids, obscure relatives of the better known sphingolipids that play important roles in signal transmission in plants, animals, and fungi. RIF-1 has extraordinary potency (femtomolar, or 10(-15) M) and S. rosetta can respond to it over a broad dynamic range-nine orders of magnitude. This study provides a prototypical example of bacterial sulfonolipids triggering eukaryotic morphogenesis and suggests molecular mechanisms through which bacteria may have contributed to the evolution of animals.DOI:http://dx.doi.org/10.7554/eLife.00013.001.
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Affiliation(s)
- Rosanna A Alegado
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Laura W Brown
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Shugeng Cao
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Renee K Dermenjian
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Richard Zuzow
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States
| | - Stephen R Fairclough
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Nicole King
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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639
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Morin S, Fischer R, Przybylski-Nicaise L, Bernard H, Corthier G, Rabot S, Wal JM, Hazebrouck S. Delayed bacterial colonization of the gut alters the host immune response to oral sensitization against cow's milk proteins. Mol Nutr Food Res 2012; 56:1838-47. [PMID: 23065810 DOI: 10.1002/mnfr.201200412] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/03/2012] [Accepted: 09/07/2012] [Indexed: 11/07/2022]
Abstract
SCOPE Cow's milk allergy is the most prevalent food allergy in infants whose immune system development is critically stimulated during postnatal gut colonization by commensal bacteria. Allergenic potential of cow's milk β-lactoglobulin (BLG) and caseins (CAS) was investigated in germ-free (GF) BALB/c mice and in GF mice conventionalized (CVd) at 6 weeks of age. METHODS AND RESULTS Oral sensitization to cow's milk in the presence of cholera toxin led to higher BLG-specific IgE, IgG1, and IgG2a responses in GF mice than in conventional (CV) mice. No significant difference was observed for CAS-specific IgE responses although IgG1 responses to αS1- and κ-caseins were higher in GF mice than in CV mice. CVd mice, orally inoculated with fecal preparations from CV mice, also displayed biased antibody responses compared to CV mice. Secretion of Th2 cytokines by BLG- and CAS-reactivated splenocytes of CVd mice was similar to that of GF mice whereas cytokine production by reactivated cells from mesenteric lymph nodes of CVd mice was equivalent to that of CV mice. CONCLUSION Oral sensitization to BLG and CAS was differentially affected by the absence of gut microbiota and delayed bacterial colonization altered persistently the host immune response to oral sensitization against food antigens.
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Affiliation(s)
- Stéphanie Morin
- INRA, UR 496 - Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, CEA de Saclay, Gif-sur-Yvette, France
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640
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Alcock J, Franklin ML, Kuzawa CW. Nutrient signaling: evolutionary origins of the immune-modulating effects of dietary fat. QUARTERLY REVIEW OF BIOLOGY 2012; 87:187-223. [PMID: 22970557 DOI: 10.1086/666828] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Many dietary fatty acids (FA) have potent effects on inflammation, which is not only energetically costly, but also contributes to a range of chronic diseases. This presents an evolutionary paradox: Why should the host initiate a costly and damaging response to commonly encountered nutrients? We propose that the immune system has evolved a capacity to modify expenditure on inflammation to compensate for the effects of dietary FA on gut microorganisms. In a comprehensive literature review, we show that the body preferentially upregulates inflammation in response to saturated FA that promote harmful microbes. In contrast, the host opften reduces inflammation in response to the many unsaturated FA with antimicrobial properties. Our model is supported by contrasts involving shorter-chain FA and omega-3 FA, but with less consistent evidence for trans fats, which are a recent addition to the human diet. Our findings support the idea that the vertebrate immune system has evolved a capacity to detect diet-driven shipfts in the composition of gut microbiota from the profile of FA consumed and to calibrate the costs of inflammation in response to these cues. We conclude by extending the nutrient signaling model to other nutrients, and consider implications for drug discovery and public health.
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Affiliation(s)
- Joe Alcock
- Department of Emergency Medicine, University of New Mexico Albuquerque, New Mexico 87131, USA.
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641
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Iebba V, Nicoletti M, Schippa S. Gut Microbiota and the Immune System: An Intimate Partnership in Health and Disease. Int J Immunopathol Pharmacol 2012; 25:823-33. [DOI: 10.1177/039463201202500401] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In recent years there have been increased rates of autoimmune diseases, possibly associated to altered intestinal microflora. In this brief review article, after a description of the structure and function of the gut microbiota organ and its cross-talk with the human host, we give a report on findings indicating how the host immune system responds to bacterial colonization of the gastrointestinal tract. The disturbances in the bacterial microbiota will result in the deregulation of adaptive immune cells, which may underlie autoimmune disorders. The mammalian immune system, which seems to be designed to control microorganisms, could be instead influenced by microorganisms, as suggested in recent literature. Alterations in both the structure and function of intestinal microbiota could be one of the ‘common causative triggers’ of autoimmune and/or autoinflammatory disorders.
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Affiliation(s)
- V. Iebba
- Public Health and Infectious Diseases Department, ‘Sapienza’ University of Rome, Rome, Italy
| | - M. Nicoletti
- Department of Biomedical Sciences, University of Chieti, Chieti, Italy
| | - S. Schippa
- Public Health and Infectious Diseases Department, ‘Sapienza’ University of Rome, Rome, Italy
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642
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Banchereau J, Pascual V, O'Garra A. From IL-2 to IL-37: the expanding spectrum of anti-inflammatory cytokines. Nat Immunol 2012; 13:925-31. [PMID: 22990890 PMCID: PMC3609707 DOI: 10.1038/ni.2406] [Citation(s) in RCA: 296] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Feedback regulatory circuits provided by regulatory T cells (T(reg) cells) and suppressive cytokines are an intrinsic part of the immune system, along with effector functions. Here we discuss some of the regulatory cytokines that have evolved to permit tolerance to components of self as well as the eradication of pathogens with minimal collateral damage to the host. Interleukin 2 (IL-2), IL-10 and transforming growth factor-β (TGF-β) are well characterized, whereas IL-27, IL-35 and IL-37 represent newcomers to the spectrum of anti-inflammatory cytokines. We also emphasize how information accumulated through in vitro as well as in vivo studies of genetically engineered mice can help in the understanding and treatment of human diseases.
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643
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Lang ML, Zhu L, Kreth J. Keeping the bad bacteria in check: interactions of the host immune system with oral cavity biofilms. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/j.1601-1546.2012.00278.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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644
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The human gastrointestinal microbiota--an unexplored frontier for pharmaceutical discovery. Pharmacol Res 2012; 66:443-7. [PMID: 23000437 DOI: 10.1016/j.phrs.2012.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 09/11/2012] [Indexed: 02/07/2023]
Abstract
The mammalian gastrointestinal tract (GIT) harbors microorganisms (the microbiota) of vast phylogentic, genomic, and metabolic diversity, and recent years have seen a rapid development in the techniques for studying these complex microbial ecosystems. It is increasingly apparent that the GIT microbiota plays an intricate role in host health and disease. Targeted strategies for modulating human health through the modification of the GIT microbiota, however, are developing and in their infancy. This perspective article discusses the rationale, benefits and limitations of using the GIT microbiota as a pharmacological and nutritional target in the treatment of various diseases and disorders linked to imbalances in our microbiota.
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645
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Kayama H, Takeda K. Regulation of intestinal homeostasis by innate and adaptive immunity. Int Immunol 2012; 24:673-80. [PMID: 22962437 DOI: 10.1093/intimm/dxs094] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The intestine is a unique tissue where an elaborate balance is maintained between tolerance and immune responses against a variety of environmental factors such as food and the microflora. In a healthy individual, the microflora stimulates innate and adaptive immune systems to maintain gut homeostasis. However, the interaction of environmental factors with particular genetic backgrounds can lead to dramatic changes in the composition of the microflora (i.e. dysbiosis). Many of the specific commensal-bacterial products and the signaling pathways they trigger have been characterized. The role of T(h)1, T(h)2 and T(h)17 cells in inflammatory bowel disease has been widely investigated, as has the contribution of epithelial cells and subsets of dendritic cells and macrophages. To date, multiple regulatory cells in adaptive immunity, such as regulatory T cells and regulatory B cells, have been shown to maintain gut homeostasis by preventing inappropriate innate and adaptive immune responses to commensal bacteria. Additionally, regulatory myeloid cells have recently been identified that prevent intestinal inflammation by inhibiting T-cell proliferation. An increasing body of evidence has shown that multiple regulatory mechanisms contribute to the maintenance of gut homeostasis.
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Affiliation(s)
- Hisako Kayama
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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646
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El Aidy S, van Baarlen P, Derrien M, Lindenbergh-Kortleve DJ, Hooiveld G, Levenez F, Doré J, Dekker J, Samsom JN, Nieuwenhuis EES, Kleerebezem M. Temporal and spatial interplay of microbiota and intestinal mucosa drive establishment of immune homeostasis in conventionalized mice. Mucosal Immunol 2012; 5:567-79. [PMID: 22617837 DOI: 10.1038/mi.2012.32] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
During colonization of germfree mice with the total fecal microbial community of their conventionally born and raised siblings (conventionalization), the intestinal mucosal immune system initiates and maintains a balanced immune response. However, the genetic regulation of these balanced, appropriate responses to the microbiota is obscure. Here, combined analysis of germfree and conventionalized mice revealed that the major molecular responses could be detected initiating at day 4 post conventionalization, with a strong induction of innate immune functions followed by stimulation of adaptive immune responses and development and expansion of adaptive immune cells at later stages of conventionalization. This study provides a comprehensive overview of mouse developmental and immune-related cellular pathways and processes that were co-mediated by the commensal microbiota and suggests which mechanisms were involved in this reprogramming. The dynamic, region-dependent mucosal responses to the colonizing microbiota revealed potential transcriptional signatures for the control of intestinal homeostasis in healthy mice, which may help to decipher the genetic basis of pathway dysregulation in human intestinal inflammatory diseases.
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Affiliation(s)
- Sahar El Aidy
- Top Institute Food and Nutrition, Wageningen, The Netherlands
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647
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Feehley T, Stefka AT, Cao S, Nagler CR. Microbial regulation of allergic responses to food. Semin Immunopathol 2012; 34:671-88. [PMID: 22941410 PMCID: PMC3874145 DOI: 10.1007/s00281-012-0337-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 08/17/2012] [Indexed: 02/07/2023]
Abstract
The incidence of food allergy in developed countries is rising at a rate that cannot be attributed to genetic variation alone. In this review, we discuss the environmental factors that may contribute to the increasing prevalence of potentially fatal anaphylactic responses to food. Decreased exposure to enteric infections due to advances in vaccination and sanitation, along with the adoption of high-fat (Western) diets, antibiotic use, Cesarean birth, and formula feeding of infants, have all been implicated in altering the enteric microbiome away from its ancestral state. This collection of resident commensal microbes performs many important physiological functions and plays a central role in the development of the immune system. We hypothesize that alterations in the microbiome interfere with immune system maturation, resulting in impairment of IgA production, reduced abundance of regulatory T cells, and Th2-skewing of baseline immune responses which drive aberrant responses to innocuous (food) antigens.
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Affiliation(s)
- Taylor Feehley
- Committee on Immunology and Department of Pathology, University of Chicago, Chicago, IL, USA
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648
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Size and dynamics of mucosal and peripheral IL-17A+ T-cell pools in pediatric age, and their disturbance in celiac disease. Mucosal Immunol 2012; 5:513-23. [PMID: 22569303 DOI: 10.1038/mi.2012.26] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mucosal interleukin (IL)-17A-producing T cells contribute to protective antimicrobial responses and to epithelial barrier integrity; their role in celiac disease (CD) is debated. We analyzed the frequency and developmental dynamics of mucosal (intraepithelial lymphocytes (IEL)) and circulating (peripheral blood (PB)) IL-17A (T17) and/or interferon (IFN)-γ-producing (T1, T1/T17) T-cell populations in 86 pediatric controls and 116 age-matched CD patients upon phorbol myristate acetate/ionomycin or CD3/CD28 stimulation. T17 and T1/17 are physiologically present among IEL and PB populations, and their frequency is selectively and significantly reduced in CD IEL. The physiological age-dependent increase of Th17 IEL is also absent in CD, while IFN-γ-producing PB-T cells significantly accumulate with patient's age. Finally, the amplitude of IL-17A+ and IFN-γ+ T-cell pools are significantly correlated in different individuals; this relationship only applies to CD4+ T cells in controls, while it involves also the CD4- counterpart in CD patients. In conclusion, both size and dynamics of mucosa-associated and circulating IL-17A+ T-cell pools are finely regulated in human pediatric subjects, and severely disturbed in CD. The impaired IL-17A+ IEL-T pool may negatively impact on epithelial barrier efficiency, and contribute to CD mucosa damage; the disturbed dynamics of circulating IL-17A+ and IFN-γ+ T-cell pools may be involved in the extraintestinal autoimmune manifestations associated with CD.
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649
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Naik S, Bouladoux N, Wilhelm C, Molloy MJ, Salcedo R, Kastenmuller W, Deming C, Quinones M, Koo L, Conlan S, Spencer S, Hall JA, Dzutsev A, Kong H, Campbell DJ, Trinchieri G, Segre JA, Belkaid Y. Compartmentalized control of skin immunity by resident commensals. Science 2012; 337:1115-9. [PMID: 22837383 PMCID: PMC3513834 DOI: 10.1126/science.1225152] [Citation(s) in RCA: 761] [Impact Index Per Article: 63.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Intestinal commensal bacteria induce protective and regulatory responses that maintain host-microbial mutualism. However, the contribution of tissue-resident commensals to immunity and inflammation at other barrier sites has not been addressed. We found that in mice, the skin microbiota have an autonomous role in controlling the local inflammatory milieu and tuning resident T lymphocyte function. Protective immunity to a cutaneous pathogen was found to be critically dependent on the skin microbiota but not the gut microbiota. Furthermore, skin commensals tuned the function of local T cells in a manner dependent on signaling downstream of the interleukin-1 receptor. These findings underscore the importance of the microbiota as a distinctive feature of tissue compartmentalization, and provide insight into mechanisms of immune system regulation by resident commensal niches in health and disease.
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Affiliation(s)
- Shruti Naik
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
- Immunology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicolas Bouladoux
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | - Christoph Wilhelm
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | - Michael J. Molloy
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | - Rosalba Salcedo
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
- SAIC-Frederick Inc., National Cancer Institute, Frederick, MD 21701, USA
| | - Wolfgang Kastenmuller
- Lymphocyte Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | - Clayton Deming
- Genetics and Molecular Biology Branch, National Human Genome Research Institute, Bethesda, MD 20892, USA
| | - Mariam Quinones
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | - Lily Koo
- Research Technology Branch, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
| | - Sean Conlan
- Genetics and Molecular Biology Branch, National Human Genome Research Institute, Bethesda, MD 20892, USA
| | - Sean Spencer
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
- Immunology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jason A. Hall
- Molecular Pathogenesis Program, Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Amiran Dzutsev
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
- SAIC-Frederick Inc., National Cancer Institute, Frederick, MD 21701, USA
| | - Heidi Kong
- Dermatology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Daniel J. Campbell
- Benaroya Research Institute, Seattle, WA 98101, USA
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Giorgio Trinchieri
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Julia A. Segre
- Genetics and Molecular Biology Branch, National Human Genome Research Institute, Bethesda, MD 20892, USA
| | - Yasmine Belkaid
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA
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650
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Himmel ME, Yao Y, Orban PC, Steiner TS, Levings MK. Regulatory T-cell therapy for inflammatory bowel disease: more questions than answers. Immunology 2012; 136:115-22. [PMID: 22348589 DOI: 10.1111/j.1365-2567.2012.03572.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
T regulatory (Treg) cells are critical for maintaining immune homeostasis and establishing tolerance to foreign, non-pathogenic antigens including those found in commensal bacteria and food. Because of their multiple suppressive mechanisms, Tregs represent a promising strategy for engineering tolerance to self and non-self antigens in chronic inflammatory diseases. Already in clinical trials in the transplantation setting, the question remains whether this therapy would be effective for the treatment of mucosal inflammatory diseases that do not pose an immediate threat to life. In this review we will discuss evidence from both animal models and patients suggesting that Treg therapy would be beneficial in the context of inflammatory bowel disease (IBD). We will examine the role of T-cell versus Treg dysfunction in IBD and discuss the putative antigens that could be potential targets of antigen-directed Treg therapy. Finally, the challenges of using Treg therapy in IBD will be discussed, with a specific emphasis on the role that the microbiota may play in the outcome of this treatment. As Treg therapy becomes a bedside reality in the field of transplantation, there is great hope that it will soon also be deployed in the setting of IBD and ultimately prove more effective than the current non-specific immunosuppressive therapies.
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Affiliation(s)
- Megan E Himmel
- Department of Surgery, University of British Columbia & Child and Family Research Centre, Vancouver, BC, Canada
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