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Abstract
Most infants born to human immunodeficiency virus (HIV)-infected women escape HIV infection. Infants evade infection despite an immature immune system and, in the case of breastfeeding, prolonged repetitive exposure. If infants become infected, the course of their infection and response to treatment differs dramatically depending upon the timing (in utero, intrapartum, or during breastfeeding) and potentially the route of their infection. Perinatally acquired HIV infection occurs during a critical window of immune development. HIV's perturbation of this dynamic process may account for the striking age-dependent differences in HIV disease progression. HIV infection also profoundly disrupts the maternal immune system upon which infants rely for protection and immune instruction. Therefore, it is not surprising that infants who escape HIV infection still suffer adverse effects. In this review, we highlight the unique aspects of pediatric HIV transmission and pathogenesis with a focus on mechanisms by which HIV infection during immune ontogeny may allow discovery of key elements for protection and control from HIV.
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202
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Mirpuri J, Raetz M, Sturge CR, Wilhelm CL, Benson A, Savani RC, Hooper LV, Yarovinsky F. Proteobacteria-specific IgA regulates maturation of the intestinal microbiota. Gut Microbes 2014; 5:28-39. [PMID: 24637807 PMCID: PMC4049932 DOI: 10.4161/gmic.26489] [Citation(s) in RCA: 184] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The intestinal microbiota changes dynamically from birth to adulthood. In this study we identified γ-Proteobacteria as a dominant phylum present in newborn mice that is suppressed in normal adult microbiota. The transition from a neonatal to a mature microbiota was in part regulated by induction of a γ-Proteobacteria-specific IgA response. Neocolonization experiments in germ-free mice further revealed a dominant Proteobacteria-specific IgA response triggered by the immature microbiota. Finally, a role for B cells in the regulation of microbiota maturation was confirmed in IgA-deficient mice. Mice lacking IgA had persistent intestinal colonization with γ-Proteobacteria that resulted in sustained intestinal inflammation and increased susceptibility to neonatal and adult models of intestinal injury. Collectively, these results identify an IgA-dependent mechanism responsible for the maturation of the intestinal microbiota.
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Affiliation(s)
- Julie Mirpuri
- Department of Pediatrics; Division of Neonatal-Perinatal Medicine; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Megan Raetz
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Carolyn R Sturge
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Cara L Wilhelm
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Alicia Benson
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Rashmin C Savani
- Department of Pediatrics; Division of Neonatal-Perinatal Medicine; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Lora V Hooper
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA,Howard Hughes Medical Institute; University of Texas Southwestern Medical Center; Dallas, TX USA
| | - Felix Yarovinsky
- Department of Immunology; University of Texas Southwestern Medical Center; Dallas, TX USA,Correspondence to: Felix Yarovinsky,
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203
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Abstract
Understanding the interplay between metabolic and cellular signaling systems has emerged as a focus in the study of metabolic disorders, cancer, and immune responses. Immune system is active in the regulation of metabolism. Lymphocyte activation initiates a program of cell growth, proliferation, and differentiation that increase metabolic demand. Activated lymphocytes must alter their metabolism to support these increased synthetic activities. In this chapter, we describe how signaling via the immune system integrates with metabolic functions to control immune response and vice versa. It has been explained mainly in the context of T lymphocyte activation and, to a lesser detail, in other immune cell types.
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Affiliation(s)
- Namrata Tomar
- Machine Intelligence Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata, 700108, India,
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204
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Abstract
The gastrointestinal tract is heavily colonized with commensal microbes with the concentration of bacteria increasing longitudinally down the length of the intestine. Bacteria are also spatially distributed transversely from the epithelial surface to the intestinal lumen with the inner mucus layer normally void of bacteria. Maintenance of this equilibrium is extremely important for human health and, as the dominant immunoglobulin at mucosal sites, IgA influences mutualism between the host and its normal microbiota. In this review we focus on the links between immune and microbial geography of the mammalian intestinal tract.
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205
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Brown EM, Sadarangani M, Finlay BB. The role of the immune system in governing host-microbe interactions in the intestine. Nat Immunol 2013; 14:660-7. [PMID: 23778793 DOI: 10.1038/ni.2611] [Citation(s) in RCA: 260] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/11/2013] [Indexed: 02/08/2023]
Abstract
The mammalian intestinal tract harbors a diverse community of trillions of microorganisms, which have co-evolved with the host immune system for millions of years. Many of these microorganisms perform functions critical for host physiology, but the host must remain vigilant to control the microbial community so that the symbiotic nature of the relationship is maintained. To facilitate homeostasis, the immune system ensures that the diverse microbial load is tolerated and anatomically contained, while remaining responsive to microbial breaches and invasion. Although the microbiota is required for intestinal immune development, immune responses also regulate the structure and composition of the intestinal microbiota. Here we discuss recent advances in our understanding of these complex interactions and their implications for human health and disease.
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Affiliation(s)
- Eric M Brown
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
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206
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Cerini C, Aldrovandi GM. Breast milk: proactive immunomodulation and mucosal protection against viruses and other pathogens. Future Virol 2013. [DOI: 10.2217/fvl.13.91] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The majority of microorganisms infecting humans cross through the mucosal barrier. This is particularly true in infants who explore the world with their mouths while their immune system is still developing. Human milk not only supplies the nutritional needs of the newborn and protects the baby against infection by confering trophic protection to the intestinal mucosa, but additionally shapes the infant’s gut microbiota and instructs immunomodulation. Reflecting maternal environmental exposition and in virtue of its multiple mechanism of action, secretory IgA in milk exerts a decisive role in direct and cross-protection against a variety of pathogens. Its active role in priming the infant’s immune system is an intriguing hypothesis. From this perspective, breast milk antibodies produced by means of maternal immunization might represent protective and proactive factors able to shape and enhance the infant’s immune responses. Strategies to optimize the benefits of maternal immunization include novel vaccine formulations and mucosal route of delivery.
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Affiliation(s)
- Chiara Cerini
- Department of Pediatrics & Molecular Microbiology & Immunology, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA, USA
| | - Grace M Aldrovandi
- Department of Pediatrics & Molecular Microbiology & Immunology, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA, USA
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207
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Procházková P, Šustr V, Dvořák J, Roubalová R, Škanta F, Pižl V, Bilej M. Correlation between the activity of digestive enzymes and nonself recognition in the gut of Eisenia andrei earthworms. J Invertebr Pathol 2013; 114:217-21. [DOI: 10.1016/j.jip.2013.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/12/2013] [Accepted: 08/19/2013] [Indexed: 11/26/2022]
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208
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Del Chierico F, Petrucca A, Mortera SL, Vernocchi P, Rosado MM, Pieroni L, Carsetti R, Urbani A, Putignani L. A metaproteomic pipeline to identify newborn mouse gut phylotypes. J Proteomics 2013; 97:17-26. [PMID: 24176786 DOI: 10.1016/j.jprot.2013.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 09/20/2013] [Accepted: 10/18/2013] [Indexed: 12/12/2022]
Abstract
UNLABELLED In order to characterize newborn mouse gut microbiota phylotypes in very early-life stages, an original metaproteomic pipeline, based on LC-MS(2)-spectra and Mascot driven NCBI non-redundant repository database interrogation was developed. An original computational analysis assisted in the generation of a taxonomic gut architecture from protein hits to operational taxonomic units (OTUs) and related functional categories. Regardless of the mouse's genetic background, a prevalence of Firmicutes (Lactobacillaceae) and Proteobacteria (Enterobacteriaceae) was observed among the entire Eubacteria taxonomic node. However, a higher abundance of Firmicutes was retrieved for Balb/c gut microbiota compared to Rag2(ko) mice, the latter was mainly characterized by a Proteobacteria enriched microbiota. The metaproteomic-obtained OTUs were supported, for the identification (ID) of the cultivable bacteria fraction, corroborated by axenic culture-based MALDI-TOF MS IDs. Particularly, functional analysis of Rag2(ko) mice gut microbiota proteins revealed the presence of abundant glutathione, riboflavin metabolism and pentose phosphate pathway components, possibly related to genetic background. The metaproteomic pipeline herein presented may represent a useful tool to investigate the highly debated onset of the human gut microbiota in the first days of life, when the bacterial composition, despite its very low diversity (complexity), is still very far from an exhaustive description and other complex microbial consortia. BIOLOGICAL SIGNIFICANCE The manuscript deals with a "frontier" topic regarding the study of the gut microbiota and the application of a metaproteomic pipeline to unveil the complexity of this fascinating ecosystem at the very early stages of life. Indeed during these phases, its diversity is very low but the bacterial content is highly "instable", and the relative balance between mucosal and fecal bacteria starts its dynamics of "fight" to get homeostasis. However, in the neonatal period, especially immediately after birth, a comprehensive description of this microbial eco-organ is still lacking, while it should be mandatory to highlight its first mechanisms of homeostasis and perturbation, while it co-develops with and within the host species. In order to unravel its low but almost unknown microbial community multiplicity, the newborn mouse gut, characterized by a "very" low complexity, was herein selected as model to design a LC-MS(2)-based shotgun metaproteomic approach, potentially suitable to study onset and shaping in human newborns. A microbiological semi-automatic computational analysis was performed to infer gut phylotypes; such as proof of evidence, related OTUs were compared to axenic-culture-based MALDI-TOF MS IDs showing consistency at family and phyla levels for the bacterial cultivable fraction. This article is part of a Special Issue entitled: Trends in Microbial Proteomics.
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Affiliation(s)
- Federica Del Chierico
- Parasitology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy; Metagenomics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Andrea Petrucca
- Parasitology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy; Metagenomics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy; Department of Diagnostic Science, Sant'Andrea Hospital, Rome, Italy
| | - Stefano Levi Mortera
- Department of Experimental Medicine, University of Rome "Tor Vergata", Rome, Italy; IRCCS-Santa Lucia Foundation, Rome, Italy
| | - Pamela Vernocchi
- Parasitology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy; Metagenomics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy; Interdipartimental Centre for Industrial Research, Alma Mater Studiorum, University of Bologna, Italy
| | - Maria M Rosado
- B-cell development Unit and Immunological Diagnosis Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Luisa Pieroni
- Department of Experimental Medicine, University of Rome "Tor Vergata", Rome, Italy; IRCCS-Santa Lucia Foundation, Rome, Italy
| | - Rita Carsetti
- B-cell development Unit and Immunological Diagnosis Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Andrea Urbani
- Department of Experimental Medicine, University of Rome "Tor Vergata", Rome, Italy; IRCCS-Santa Lucia Foundation, Rome, Italy.
| | - Lorenza Putignani
- Parasitology Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy; Metagenomics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
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209
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Greer RL, Morgun A, Shulzhenko N. Bridging immunity and lipid metabolism by gut microbiota. J Allergy Clin Immunol 2013; 132:253-62; quiz 263. [PMID: 23905915 DOI: 10.1016/j.jaci.2013.06.025] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 06/13/2013] [Accepted: 06/24/2013] [Indexed: 12/13/2022]
Abstract
The human gut is a unique organ in which hundreds of different microbial species find their habitat and in which different host physiologic functions, such as digestion, nutrition, and immunity, coexist. Although all these players were studied separately for decades, recently, there has been an explosion of studies demonstrating the essential role for interactions between these components in gut function. Furthermore, new systems biology methods provide essential tools to study this complex system as a whole and to identify key elements that define the crosstalk between the gut microbiota, immunity, and metabolism. This review is devoted to several human diseases resulting from the disruption in this crosstalk, including immunodeficiency-associated and environmental enteropathies, celiac disease, inflammatory bowel disease, and obesity. We describe findings in experimental models of these diseases and in germ-free animals that help us understand the mechanisms and test new therapeutic strategies. We also discuss current challenges that the field is facing and propose that a new generation of antibiotics, prebiotics, and probiotics coupled with novel, systems biology-driven diagnostics will provide the basis for future personalized therapy.
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Affiliation(s)
- Renee L Greer
- College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
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210
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Communication between B-Cells and Microbiota for the Maintenance of Intestinal Homeostasis. Antibodies (Basel) 2013. [DOI: 10.3390/antib2040535] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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211
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Winer DA, Winer S, Chng MHY, Shen L, Engleman EG. B Lymphocytes in obesity-related adipose tissue inflammation and insulin resistance. Cell Mol Life Sci 2013; 71:1033-43. [PMID: 24127133 DOI: 10.1007/s00018-013-1486-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 09/06/2013] [Accepted: 09/26/2013] [Indexed: 12/11/2022]
Abstract
Obesity-related insulin resistance is a chronic inflammatory condition that often gives rise to type 2 diabetes (T2D). Much evidence supports a role for pro-inflammatory T cells and macrophages in promoting local inflammation in tissues such as visceral adipose tissue (VAT) leading to insulin resistance. More recently, B cells have emerged as an additional critical player in orchestrating these processes. B cells infiltrate VAT and display functional and phenotypic changes in response to diet-induced obesity. B cells contribute to insulin resistance by presenting antigens to T cells, secreting inflammatory cytokines, and producing pathogenic antibodies. B cell manipulation represents a novel approach to the treatment of obesity-related insulin resistance and potentially to the prevention of T2D. This review summarizes the roles of B cells in governing VAT inflammation and the mechanisms by which these cells contribute to altered glucose homeostasis in insulin resistance.
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Affiliation(s)
- Daniel A Winer
- Department of Pathology, Toronto General Hospital, University Health Network, University of Toronto, Eaton Wing, 11E - 424A, 200 Elizabeth Street, Toronto, ON, M5G 2C4, Canada
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212
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Paquin-Proulx D, Santos BAN, Carvalho KI, Toledo-Barros M, Barreto de Oliveira AK, Kokron CM, Kalil J, Moll M, Kallas EG, Sandberg JK. IVIg immune reconstitution treatment alleviates the state of persistent immune activation and suppressed CD4 T cell counts in CVID. PLoS One 2013; 8:e75199. [PMID: 24130688 PMCID: PMC3793979 DOI: 10.1371/journal.pone.0075199] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/10/2013] [Indexed: 01/12/2023] Open
Abstract
Common variable immunodeficiency (CVID) is characterized by defective B cell function, impaired antibody production, and increased susceptibility to bacterial infections. Here, we addressed the hypothesis that poor antibody-mediated immune control of infections may result in substantial perturbations in the T cell compartment. Newly diagnosed CVID patients were sampled before, and 6-12 months after, initiation of intravenous immunoglobulin (IVIg) therapy. Treatment-naïve CVID patients displayed suppressed CD4 T cell counts and myeloid dendritic cell (mDC) levels, as well as high levels of immune activation in CD8 T cells, CD4 T cells, and invariant natural killer T (iNKT) cells. Expression of co-stimulatory receptors CD80 and CD83 was elevated in mDCs and correlated with T cell activation. Levels of both FoxP3+ T regulatory (Treg) cells and iNKT cells were low, whereas soluble CD14 (sCD14), indicative of monocyte activation, was elevated. Importantly, immune reconstitution treatment with IVIg partially restored the CD4 T cell and mDC compartments. Treatment furthermore reduced the levels of CD8 T cell activation and mDC activation, whereas levels of Treg cells and iNKT cells remained low. Thus, primary deficiency in humoral immunity with impaired control of microbial infections is associated with significant pathological changes in cell-mediated immunity. Furthermore, therapeutic enhancement of humoral immunity with IVIg infusions alleviates several of these defects, indicating a relationship between poor antibody-mediated immune control of infections and the occurrence of abnormalities in the T cell and mDC compartments. These findings help our understanding of the immunopathogenesis of primary immunodeficiency, as well as acquired immunodeficiency caused by HIV-1 infection.
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Affiliation(s)
- Dominic Paquin-Proulx
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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213
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Kato LM, Kawamoto S, Maruya M, Fagarasan S. Gut TFH and IgA: key players for regulation of bacterial communities and immune homeostasis. Immunol Cell Biol 2013; 92:49-56. [PMID: 24100385 DOI: 10.1038/icb.2013.54] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 08/27/2013] [Accepted: 08/28/2013] [Indexed: 02/07/2023]
Abstract
The main function of the immune system is to protect the host against pathogens. However, unlike the systemic immune system, the gut immune system does not eliminate, but instead nourishes complex bacterial communities and establishes advanced symbiotic relationships. Immunoglobulin A (IgA) is the most abundant antibody isotype in mammals, produced mainly in the gut. The primary function of IgA is to maintain homeostasis at mucosal surfaces, and studies in mice have demonstrated that IgA diversification has an essential role in the regulation of gut microbiota. Dynamic diversification and constant adaptation of IgA responses to local microbiota require expression of activation-induced cytidine deaminase by B cells and control from T follicular helper and Foxp3(+) T cells in germinal centers (GCs). We discuss the finely tuned regulatory mechanisms for IgA synthesis in GCs of Peyer's patches and emphasize the roles of CD4(+) T cells for IgA selection and the maintenance of appropriate gut microbial communities required for immune homeostasis.
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Affiliation(s)
- Lucia M Kato
- Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences IMS-RCAI, RIKEN Yokohama Institute, Yokohama, Japan
| | - Shimpei Kawamoto
- Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences IMS-RCAI, RIKEN Yokohama Institute, Yokohama, Japan
| | - Mikako Maruya
- Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences IMS-RCAI, RIKEN Yokohama Institute, Yokohama, Japan
| | - Sidonia Fagarasan
- Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences IMS-RCAI, RIKEN Yokohama Institute, Yokohama, Japan
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214
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Brandtzaeg P. Immune aspects of breast milk: an overview. HANDBOOK OF DIETARY AND NUTRITIONAL ASPECTS OF HUMAN BREAST MILK 2013. [DOI: 10.3920/978-90-8686-764-6_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- P. Brandtzaeg
- Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Centre for Immune Regulation (CIR), University of Oslo and Department of Pathology, Oslo University Hospital, Rikshospitalet, Oslo, P.O. Box 4950 Nydalen, 0424 Oslo, Norway
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215
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Brandtzaeg P. Secretory IgA: Designed for Anti-Microbial Defense. Front Immunol 2013; 4:222. [PMID: 23964273 PMCID: PMC3734371 DOI: 10.3389/fimmu.2013.00222] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 07/16/2013] [Indexed: 01/30/2023] Open
Abstract
Prevention of infections by vaccination remains a compelling goal to improve public health. Mucosal vaccines would make immunization procedures easier, be better suited for mass administration, and most efficiently induce immune exclusion - a term coined for non-inflammatory antibody shielding of internal body surfaces, mediated principally by secretory immunoglobulin A (SIgA). The exported antibodies are polymeric, mainly IgA dimers (pIgA), produced by local plasma cells (PCs) stimulated by antigens that target the mucose. SIgA was early shown to be complexed with an epithelial glycoprotein - the secretory component (SC). A common SC-dependent transport mechanism for pIgA and pentameric IgM was then proposed, implying that membrane SC acts as a receptor, now usually called the polymeric Ig receptor (pIgR). From the basolateral surface, pIg-pIgR complexes are taken up by endocytosis and then extruded into the lumen after apical cleavage of the receptor - bound SC having stabilizing and innate functions in the secretory antibodies. Mice deficient for pIgR show that this is the only receptor responsible for epithelial export of IgA and IgM. These knockout mice show a variety of defects in their mucosal defense and changes in their intestinal microbiota. In the gut, induction of B-cells occurs in gut-associated lymphoid tissue, particularly the Peyer's patches and isolated lymphoid follicles, but also in mesenteric lymph nodes. PC differentiation is accomplished in the lamina propria to which the activated memory/effector B-cells home. The airways also receive such cells from nasopharynx-associated lymphoid tissue but by different homing receptors. This compartmentalization is a challenge for mucosal vaccination, as are the mechanisms used by the mucosal immune system to discriminate between commensal symbionts (mutualism), pathobionts, and overt pathogens (elimination).
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Affiliation(s)
- Per Brandtzaeg
- Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Centre for Immune Regulation (CIR), University of Oslo, Oslo, Norway
- Department of Pathology, Oslo University Hospital Rikshospitalet, Oslo, Norway
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216
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Gut Lactobacillales are associated with higher CD4 and less microbial translocation during HIV infection. AIDS 2013; 27:1921-31. [PMID: 24180001 DOI: 10.1097/qad.0b013e3283611816] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Early HIV infection is characterized by a dramatic depletion of CD4 T cells in the gastrointestinal tract and translocation of bacterial products from the gut into the blood. In this study, we evaluated if gut bacterial profiles were associated with immune status before and after starting antiretroviral therapy (ART). DESIGN We evaluated the gut microbiota of men recently infected with HIV (n = 13) who were participating in a randomized, double-blind controlled trial of combination ART and maraviroc versus placebo and who were followed for 48 weeks. METHODS To evaluate the gut microbiota of participants, we pyrosequenced the bacterial populations from anal swabs collected before and longitudinally after the initiation of ART. Associations of the gut flora with clinical variables (lymphocyte profiles and viral loads), activation and proliferation markers in peripheral blood mononuclear cells and gut biopsies (measured by flow cytometry) and markers of microbial translocation (lipopolysaccharide and soluble CD14) were performed by regression analyses using R statistical software. RESULTS Using pyrosequencing, we identified that higher proportions of Lactobacillales in the distal gut of recently HIV-infected individuals were associated with lower markers of microbial translocation, higher CD4% and lower viral loads before ART was started. Similarly, during ART, higher proportions of gut Lactobacillales were associated with higher CD4%, less microbial translocation, less systemic immune activation, less gut T lymphocyte proliferation, and higher CD4% in the gut. CONCLUSION Shaping the gut microbiome, especially proportions of Lactobacillales, could help to preserve immune function during HIV infection.
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217
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Wu Z. Antigen specific immunotherapy generates CD27(+) CD35(+) tolerogenic dendritic cells. Cell Immunol 2013; 283:75-80. [PMID: 23887049 DOI: 10.1016/j.cellimm.2013.06.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/05/2013] [Accepted: 06/24/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIMS The mechanism of antigen specific immunotherapy (ASIT) remains to be further understood. The present study aims to investigate the role of ASIT in the generation of tolerogenic dendritic cells (DC) in patients with food allergy (FA). METHODS Twenty patients with egg FA and 10 healthy subjects were recruited into this study. Blood samples were obtained from each subject before and after the ASIT and analyzed by flow cytometry. RESULTS In FA patients, the frequencies of CD27(+) B cells and TGF-b(+) DCs were significantly lower than that in healthy subjects. More than 90% CD27(+) B cells also express CD35; about 90% CD27(+) CD35(+) B cells expressed TGF-b. Coculture of CD27(+) CD35(+) B cells with immature DCs generated TGF-b-expressing tolerogenic DCs; the latter was able to induce CD4(+) CD25(+) Foxp3(+) regulatory T cells. CONCLUSIONS Treatment with ASIT can induce TGF-b-expressing tolerogenic DCs in patients with FA.
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Affiliation(s)
- Zhiqiang Wu
- Department of Gastroenterology, First Affiliated Hospital, The PLA General Hospital, Beijing 100037, China.
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218
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Macy JD, Paturzo FX, Compton SR. Effect of immunodeficiency on MPV shedding and transmission. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2013; 52:467-74. [PMID: 23849445 PMCID: PMC3725932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 02/22/2013] [Accepted: 03/09/2013] [Indexed: 06/02/2023]
Abstract
C57BL/6 (B6) mice briefly shed low levels of MPV, and transmission is inefficient. To determine whether deficits in B or T cells or in interferon γ on a B6 background increased the duration of MPV shedding or transmission, B-cell-deficient (Igh), interferon-γ-deficient (Ifnγ), B- and T-cell-deficient (Rag), and B6 mice were inoculated with MPV. At 1 and 2 wk postinoculation (wpi), 11% to 94% of mice shed MPV. From 4 to 18 wpi, 80% to 100% of Rag mice and 0% of B6 and Ifnγ mice shed MPV; Igh mice sporadically shed MPV through 20 wpi. MPV was transmitted from B6 mice and Ifnγ mice at 2 to 4 wpi. Rag and Igh mice transmitted MPV to sentinels at all or most time points, respectively, between 2 to 16 wpi. Once transmission ceased from B6, Ifnγ, and Igh mice, breeding trios were setup and showed that MPV was transmitted to offspring in only one cage of Igh mice. In another experiment, MPV shedding ceased from B6, CD8-deficient (CD8), CD4-deficient (CD4), and T-cell-receptor-deficient (TCR) mice by 2, 6, 8, and 8 wpi, respectively. MPV was transmitted to sentinels only at 1 to 4 wpi. Mesenteric lymph nodes collected from 61% to 100% of B6, Ifnγ, TCR, CD4, CD8, and Rag mice were MPV DNA-positive. In conclusion, MPV transmission did not differ between mice deficient in T cell functions or Ifnγ and B6 mice. In contrast, B-cell deficiency posed an increased risk for MPV transmission in mice.
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Key Words
- b6, c57bl/6j mice
- cd4, b6.129s2-cd4tm1mak/j mice
- cd8, b6.129s2-cd8atm1mak/j mice
- igh, b6.129s2-ighmtm1cgn/j mice
- ifnγ , b6.129s7-ifngtm1ts/j mice
- mln, mesenteric lymph nodes
- mpv, mouse parvovirus
- rag, b6.129s7-rag1tm1mom/j mice
- tcr, b6.129p2-tcrbtm1mom/j mice
- wpi, weeks post-inoculation
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Affiliation(s)
- James D Macy
- Section of Comparative Medicine, School of Medicine, Yale University, New Haven, CT, USA.
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Mavrommatis B, Young GR, Kassiotis G. Counterpoise between the microbiome, host immune activation and pathology. Curr Opin Immunol 2013; 25:456-62. [PMID: 23743081 DOI: 10.1016/j.coi.2013.05.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/03/2013] [Accepted: 05/08/2013] [Indexed: 12/13/2022]
Abstract
The role of the mammalian intestinal microbiota in health and disease of the host has long been recognized and extensively studied. Largely, these studies have focused on the bacterial component of the microbiota. However, recent technological advances have shed new light on the microbiome at distinct anatomical locations and uncovered the role of additional microbial symbionts, including the virome and endogenous retroelements. Together, they have revealed interactions more intricate than previously recognized. Here, we review recent advances in our knowledge of this collective microbiome and the interactions with the immune system of their host.
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Affiliation(s)
- Bettina Mavrommatis
- Division of Immunoregulation, MRC National Institute for Medical Research, The Ridgeway, London NW7 1AA, UK
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220
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Abstract
PURPOSE OF REVIEW Sepsis is a serious complication in preterm and term infants, yet our understanding of how neonates respond to infection remains poorly defined. RECENT FINDINGS We describe our current clinical, cellular and molecular understanding of the neonatal host systemic response to infection. We find that host resilience essentially relies on innate immune mechanisms despite there being a complete repertoire of cellular components of the adaptive immune arm. The functional interplay between metabolism, immunity and microbiome further suggests that neonatal vulnerability to infection is not simply due to immaturity of the immune system but how immune homeostasis is regulated. Further research is required for exploring regulatory homeostatic mechanisms between innate and adaptive responses and microbiome colonization at birth, but which can impart an adverse trajectory to infection. SUMMARY The vulnerability and resilience against infection in neonates, including extreme preterm infants, still remains poorly understood. We advance the view that greater consideration should be given to understanding the set point in the regulation of homeostatic control of innate and adaptive immunity and its interplay with metabolism and the newly acquired microbiome.
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Affiliation(s)
- Peter Ghazal
- Division of Pathway Medicine, University of Edinburgh, Edinburgh, UK.
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221
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Faria AMC, Gomes-Santos AC, Gonçalves JL, Moreira TG, Medeiros SR, Dourado LPA, Cara DC. Food components and the immune system: from tonic agents to allergens. Front Immunol 2013; 4:102. [PMID: 23730302 PMCID: PMC3656403 DOI: 10.3389/fimmu.2013.00102] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 04/20/2013] [Indexed: 12/13/2022] Open
Abstract
The intestinal mucosa is the major site of contact with antigens, and it houses the largest lymphoid tissue in the body. In physiological conditions, microbiota and dietary antigens are the natural sources of stimulation for the gut-associated lymphoid tissues (GALT) and for the immune system as a whole. Germ-free models have provided some insights on the immunological role of gut antigens. However, most of the GALT is not located in the large intestine, where gut microbiota is prominent. It is concentrated in the small intestine where protein absorption takes place. In this review, we will address the involvement of food components in the development and the function of the immune system. Studies in mice have already shown that dietary proteins are critical elements for the developmental shift of the immature neonatal immune profile into a fully developed immune system. The immunological effects of other food components (such as vitamins and lipids) will also be addressed. Most of the cells in the GALT are activated and local pro-inflammatory mediators are abundant. Regulatory elements are known to provide a delicate yet robust balance that maintains gut homeostasis. Usually antigenic contact in the gut induces two major immune responses, oral tolerance and production of secretory IgA. However, under pathological conditions mucosal homeostasis is disturbed resulting in inflammatory reactions such as food hypersensitivity. Food allergy development depends on many factors such as genetic predisposition, biochemical features of allergens, and a growing array of environmental elements. Neuroimmune interactions are also implicated in food allergy and they are examples of the high complexity of the phenomenon. Recent findings on the gut circuits triggered by food components will be reviewed to show that, far beyond their role as nutrients, they are critical players in the operation of the immune system in health and disease.
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Affiliation(s)
- Ana Maria Caetano Faria
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Belo Horizonte, Minas Gerais, Brazil ; Instituto de Investigação em Imunologia (iii) São Paulo, Brazil
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222
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Collini PJ, Kuijper E, Dockrell DH. Clostridium Difficile Infection in Patients with HIV/AIDS. Curr HIV/AIDS Rep 2013; 10:273-82. [DOI: 10.1007/s11904-013-0162-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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223
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Capolunghi F, Rosado MM, Sinibaldi M, Aranburu A, Carsetti R. Why do we need IgM memory B cells? Immunol Lett 2013; 152:114-20. [PMID: 23660557 DOI: 10.1016/j.imlet.2013.04.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/24/2013] [Accepted: 04/26/2013] [Indexed: 12/22/2022]
Abstract
Immunological memory is our reservoir of ready-to-use antibodies and memory B cells. Because of immunological memory a secondary infection will be very light or not occur at all. Antibodies and cells, generated in the germinal center in response to the first encounter with antigen, are highly specific, remain in the organism virtually forever and are mostly of IgG isotype. Long lived plasma cells homing to the bone marrow ensure the constant production of protective antibodies, whereas switched memory B cells proliferate and differentiate in response to secondary challenge. IgM memory B cells represent our first-line defense against infections. They are generated by a T-cell independent mechanism probably triggered by Toll-like receptor-9. They produce natural antibodies with anti-bacterial specificity and the spleen is indispensable for their maintenance. We will review the characteristics and functions of IgM memory B cells that explain their importance in the immediate protection from pathogens. IgM memory B cells, similar to mouse B-1a B cells, may be a remnant of a primitive immune system that developed in the spleen of cartilaginous fish and persisted throughout evolution notwithstanding the sophisticated tools of the adaptive immune system.
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Affiliation(s)
- Federica Capolunghi
- Department of Laboratories, Children Hospital Bambino Gesù (IRCCS), Piazza S.Onofrio 4, 00165 Rome, Italy
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224
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Neonatal immune adaptation of the gut and its role during infections. Clin Dev Immunol 2013; 2013:270301. [PMID: 23737810 PMCID: PMC3659470 DOI: 10.1155/2013/270301] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/03/2013] [Indexed: 12/22/2022]
Abstract
The intestinal tract is engaged in a relationship with a dense and complex microbial ecosystem, the microbiota. The establishment of this symbiosis is essential for host physiology, metabolism, and immune homeostasis. Because newborns are essentially sterile, the first exposure to microorganisms and environmental endotoxins during the neonatal period is followed by a crucial sequence of active events leading to immune tolerance and homeostasis. Contact with potent immunostimulatory molecules starts immediately at birth, and the discrimination between commensal bacteria and invading pathogens is essential to avoid an inappropriate immune stimulation and/or host infection. The dysregulation of these tight interactions between host and microbiota can be responsible for important health disorders, including inflammation and sepsis. This review summarizes the molecular events leading to the establishment of postnatal immune tolerance and how pathogens can avoid host immunity and induce neonatal infections and sepsis.
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225
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Kuo SM, Merhige PM, Hagey LR. The effect of dietary prebiotics and probiotics on body weight, large intestine indices, and fecal bile acid profile in wild type and IL10-/- mice. PLoS One 2013; 8:e60270. [PMID: 23555939 PMCID: PMC3605333 DOI: 10.1371/journal.pone.0060270] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 02/26/2013] [Indexed: 12/24/2022] Open
Abstract
Previous studies have suggested roles of probiotics and prebiotics on body weight management and intestinal function. Here, the effects of a dietary prebiotic, inulin (50 mg/g diet), and probiotic, Bfidobacterium animalis subsp. lactis (Bb12) (final dose verified at 105 colony forming unit (cfu)/g diet, comparable to human consumption), were determined separately and in combination in mice using cellulose-based AIN-93G diets under conditions allowed for the growth of commensal bacteria. Continuous consumption of Bb12 and/or inulin did not affect food intake or body, liver, and spleen weights of young and adult mice. Fecal bile acid profiles were determined by nanoESI-MS/MS tandem mass spectrometry. In the presence of inulin, more bacterial deconjugation of taurine from primary bile acids was observed along with an increased cecal weight. Consumption of inulin in the absence or presence of Bb12 also increased the villus cell height in the proximal colon along with a trend of higher bile acid sulfation by intestinal cells. Feeding Bb12 alone at the physiological dose did not affect bile acid deconjugation and had little effect on other intestinal indices. Although interleukin (IL)10-null mice are susceptible to enterocolitis, they maintained the same body weight as the wild type mice under our specific pathogen-free housing condition and showed no signs of inflammation. Nevertheless, they had smaller cecum suggesting a mildly compromised intestinal development even before the disease manifestation. Our results are consistent with the notion that dietary factors such as prebiotics play important roles in the growth of intestinal microbiota and may impact on the intestinal health. In addition, fecal bile acid profiling could potentially be a non-invasive tool in monitoring the intestinal environment.
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Affiliation(s)
- Shiu-Ming Kuo
- Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA.
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226
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Hato T, El-Achkar TM, Dagher PC. Sisters in arms: myeloid and tubular epithelial cells shape renal innate immunity. Am J Physiol Renal Physiol 2013; 304:F1243-51. [PMID: 23515715 DOI: 10.1152/ajprenal.00101.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The importance of innate immunity for survival is underscored by its presence at almost every level of the evolutionary tree of life. The task of "danger" recognition by the innate immune system is carried out by a broad class of pattern recognition receptors. These receptors are expressed in both hematopoietic and nonhematopoietic cells such as renal epithelial cells. Upon activation, pattern recognition receptors induce essentially two types of defensive responses: inflammation and phagocytosis. In this review, we highlight evidence that renal epithelial cells are endowed with such defensive capabilities and as such fully participate in renal innate immune responses.
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Affiliation(s)
- Takashi Hato
- Department of Medicine, Indiana University, Indianapolis, IN, USA
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227
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B cells promote inflammation in obesity and type 2 diabetes through regulation of T-cell function and an inflammatory cytokine profile. Proc Natl Acad Sci U S A 2013; 110:5133-8. [PMID: 23479618 DOI: 10.1073/pnas.1215840110] [Citation(s) in RCA: 353] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Patients with type 2 diabetes (T2D) have disease-associated changes in B-cell function, but the role these changes play in disease pathogenesis is not well established. Data herein show B cells from obese mice produce a proinflammatory cytokine profile compared with B cells from lean mice. Complementary in vivo studies show that obese B cell-null mice have decreased systemic inflammation, inflammatory B- and T-cell cytokines, adipose tissue inflammation, and insulin resistance (IR) compared with obese WT mice. Reduced inflammation in obese/insulin resistant B cell-null mice associates with an increased percentage of anti-inflammatory regulatory T cells (Tregs). This increase contrasts with the sharply decreased percentage of Tregs in obese compared with lean WT mice and suggests that B cells may be critical regulators of T-cell functions previously shown to play important roles in IR. We demonstrate that B cells from T2D (but not non-T2D) subjects support proinflammatory T-cell function in obesity/T2D through contact-dependent mechanisms. In contrast, human monocytes increase proinflammatory T-cell cytokines in both T2D and non-T2D analyses. These data support the conclusion that B cells are critical regulators of inflammation in T2D due to their direct ability to promote proinflammatory T-cell function and secrete a proinflammatory cytokine profile. Thus, B cells are potential therapeutic targets for T2D.
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228
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Plasticity of Th17 cells in Peyer's patches is responsible for the induction of T cell-dependent IgA responses. Nat Immunol 2013; 14:372-9. [PMID: 23475182 PMCID: PMC3672955 DOI: 10.1038/ni.2552] [Citation(s) in RCA: 385] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 01/22/2013] [Indexed: 12/12/2022]
Abstract
Intestinal Peyer’s patches are essential lymphoid organs for the generation of T cell-dependent immunoglobulin (Ig) A production for gut homeostasis. Using IL-17 fate reporter mice we show here that endogenous TH17 cells in lymphoid organs of naïve mice home preferentially to the intestine and are maintained independently of IL-23. In Peyer’s patches such TH17 cells acquire a T follicular helper (TFH) phenotype and induce the development of IgA-producing germinal center B cells. Mice deficient in TH17 cells fail to generate antigen specific IgA responses, providing evidence that TH17 cells are the crucial subset required for high affinity T cell-dependent IgA production.
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229
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Chorny A, Puga I, Cerutti A. Regulation of frontline antibody responses by innate immune signals. Immunol Res 2013; 54:4-13. [PMID: 22477522 DOI: 10.1007/s12026-012-8307-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mature B cells generate protective immunity by undergoing immunoglobulin (Ig) class switching and somatic hypermutation, two Ig gene-diversifying processes that usually require cognate interactions with T cells that express CD40 ligand. This T-cell-dependent pathway provides immunological memory but is relatively slow to occur. Thus, it must be integrated with a faster, T-cell-independent pathway for B-cell activation through CD40 ligand-like molecules that are released by innate immune cells in response to microbial products. Here, we discuss recent advances in our understanding of the interplay between the innate immune system and B cells, particularly "frontline" B cells located in the marginal zone of the spleen and in the intestine.
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Affiliation(s)
- Alejo Chorny
- Department of Medicine, The Immunology Institute, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA
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230
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Abstract
There is currently a major focus on the role of the gut barrier function in balancing mucosal immune responses. Increased epithelial permeability for exogenous antigens is a crucial primary or secondary event in the pathogenesis of several disorders affecting body surfaces and beyond. The epithelial gate-keeper function is determined by the individual's age (e.g. preterm vs. term infant), diet, genetics, mucus composition, interactions between mast cells, nerves and neuropeptides, concurrent infection, the commensal microbiota and the epithelium-shielding effect of secretory IgA (SIgA) antibodies provided by breast milk or produced in the individual's gut. The integrity of the epithelial barrier furthermore depends on homeostatic regulatory mechanisms, including mucosal induction of regulatory T cells, where commensal microbiota-host interactions apparently play decisive roles. Thus, both extrinsic and intrinsic factors have been identified that may have an impact on the dynamics of the epithelial cell-cell junctions in the gut and thereby increase or reduce paracellular permeability. Experiments have shown that SIgA normally cooperates with innate defence factors to protect the epithelium and reinforce its barrier function. In the absence of SIgA commensal gut bacteria overstimulate innate epithelial immunity at the expense of expression of genes that regulate fat and carbohydrate metabolism, resulting in an epithelial gene signature that correlates with the development of lipid malabsorption. This shows that the intestinal epithelial barrier is a cross-road between defence and nutrition, and that SIgA is essential to keep the balance between these two functions.
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Affiliation(s)
- P. Brandtzaeg
- Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Centre for Immune Regulation (CIR), University of Oslo
- Department of Pathology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950, 0424 Oslo, Norway
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231
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Bienenstock J, Gibson G, Klaenhammer TR, Walker WA, Neish AS. New insights into probiotic mechanisms: a harvest from functional and metagenomic studies. Gut Microbes 2013; 4:94-100. [PMID: 23249742 PMCID: PMC3595083 DOI: 10.4161/gmic.23283] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There has been continued and expanding recognition of probiotic approaches for treating gastrointestinal and systemic disease, as well as increased acceptance of probiotic therapies by both the public and the medical community. A parallel development has been the increasing recognition of the diverse roles that the normal gut microbiota plays in the normal biology of the host. This advance has in turn has been fed by implementation of novel investigative technologies and conceptual paradigms focused on understanding the fundamental role of the microbiota and indeed all commensal bacteria, on known and previously unsuspected aspects of host physiology in health and disease. This review discusses current advances in the study of the host-microbiota interaction, especially as it relates to potential mechanisms of probiotics. It is hoped these new approaches will allow more rational selection and validation of probiotic usage in a variety of clinical conditions.
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Affiliation(s)
- John Bienenstock
- Pathology and Molecular Medicine; McMaster University; Hamilton, ON Canada
| | - Glenn Gibson
- School of Food Biosciences; The University of Reading; Reading, UK
| | - Todd R. Klaenhammer
- Department of Food, Bioprocessing and Nutrition Sciences; North Carolina State University; Raleigh, NC USA
| | - W. Allan Walker
- Department of Pediatrics; Mucosal Immunology Laboratory; Massachusetts General Hospital; Harvard Medical School; Boston, MA USA
| | - Andrew S. Neish
- Department of Pathology; Emory University School of Medicine; Atlanta, GA USA,Correspondence to: Andrew S. Neish,
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232
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Schuijt TJ, van der Poll T, de Vos WM, Wiersinga WJ. The intestinal microbiota and host immune interactions in the critically ill. Trends Microbiol 2013; 21:221-9. [PMID: 23454077 DOI: 10.1016/j.tim.2013.02.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 01/28/2013] [Accepted: 02/01/2013] [Indexed: 12/12/2022]
Abstract
The gastrointestinal tract harbors a complex population of microbes that play a fundamental role in the development of the immune system and human health. Besides an important local contribution in the host defense against infections, it has become increasingly clear that intestinal bacteria also modulate immune responses at systemic sites. These new insights can be of profound clinical relevance especially for intensive care medicine where the majority of patients are treated with antibiotics, which have pervasive and long-term effects on the intestinal microbiota. Moreover, considerable progress has been made in defining the role of the intestinal microbiota in both health and disease. In this review, we highlight these aspects and focus on recent key findings addressing the role of intestinal microbiota in antimicrobial defense mechanisms and its impact on intestinal homeostasis in the critically ill.
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Affiliation(s)
- Tim J Schuijt
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands.
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233
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Nikolajczyk BS, Jagannathan-Bogdan M, Denis GV. The outliers become a stampede as immunometabolism reaches a tipping point. Immunol Rev 2013; 249:253-75. [PMID: 22889227 DOI: 10.1111/j.1600-065x.2012.01142.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Obesity and Type 2 diabetes mellitus (T2D) are characterized by pro-inflammatory alterations in the immune system including shifts in leukocyte subset differentiation and in cytokine/chemokine balance. The chronic, low-grade inflammation resulting largely from changes in T-cell, B-cell, and myeloid compartments promotes and/or exacerbates insulin resistance (IR) that, together with pancreatic islet failure, defines T2D. Animal model studies show that interruption of immune cell-mediated inflammation by any one of several methods almost invariably results in the prevention or delay of obesity and/or IR. However, anti-inflammatory therapies have had a modest impact on established T2D in clinical trials. These seemingly contradictory results indicate that a more comprehensive understanding of human IR/T2D-associated immune cell function is needed to leverage animal studies into clinical treatments. Important outstanding analyses include identifying potential immunological checkpoints in disease etiology, detailing immune cell/adipose tissue cross-talk, and defining strengths/weaknesses of model organism studies to determine whether we can harness the promising new field of immunometabolism to curb the global obesity and T2D epidemics.
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234
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235
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Abstract
PURPOSE OF REVIEW Diverse research interests have converged on the gut microbiota because of its contribution to immune development, mucosal homeostasis and to the pathogenesis of a diversity of intestinal and extraintestinal disorders. Recent landmark findings are addressed here. RECENT FINDINGS The impact of lifestyle, including dietary changes and antibiotics, on the microbiota has been mechanistically linked with disease risk. Microbial, immune and metabolic signalling are mutually interactive, with each of these being regulated by diet. Although changes in the microbiota have been found in several disorders and may have important therapeutic implications, some components of the commensal microbiota may behave like pathogens (pathobionts) depending on the context and host susceptibility. SUMMARY Advances in understanding host-microbe interactions in the gut continue apace, they are relevant to a diversity of infectious, inflammatory, neoplastic and metabolic disorders and are poised for clinical translation.
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236
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Abstract
Fiber intake is critical for optimal health. This review covers the anti-inflammatory roles of fibers using results from human epidemiological observations, clinical trials, and animal studies. Fiber has body weight-related anti-inflammatory activity. With its lower energy density, a diet high in fiber has been linked to lower body weight, alleviating obesity-induced chronic inflammation evidenced by reduced amounts of inflammatory markers in human and animal studies. Body weight-unrelated anti-inflammatory activity of fiber has also been extensively studied in animal models in which the type and amount of fiber intake can be closely monitored. Fermentable fructose-, glucose-, and galactose-based fibers as well as mixed fibers have shown systemic and local intestinal anti-inflammatory activities when plasma inflammatory markers and tissue inflammation were examined. Similar anti-inflammatory activities have also been demonstrated in some human studies that controlled total fiber intake. The anti-inflammatory activities of synbiotics (probiotics plus fiber) were reviewed as well, but there was no convincing evidence indicating higher efficacy of synbiotics compared with that of fiber alone. Adverse effects have not been observed with the amount of fiber intake or supplementation used in studies, although patients with Crohn's disease may be more sensitive to inulin intake. Several possible mechanisms that may mediate the body weight-unrelated anti-inflammatory activity of fibers are discussed based on the in vitro and in vivo evidence. Fermentable fibers are known to affect the intestinal microbiome. The immunomodulatory role of the intestinal microbiome and/or microbial metabolites could contribute to the systemic and local anti-inflammatory activities of fibers.
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Affiliation(s)
- Shiu-Ming Kuo
- Department of Exercise and Nutrition Sciences, University at Buffalo, NY, USA.
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237
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Kunisawa J, Kiyono H. Immune regulation and monitoring at the epithelial surface of the intestine. Drug Discov Today 2013; 18:87-92. [DOI: 10.1016/j.drudis.2012.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 07/06/2012] [Accepted: 08/02/2012] [Indexed: 02/08/2023]
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238
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Mine KL, Shulzhenko N, Yambartsev A, Rochman M, Sanson GFO, Lando M, Varma S, Skinner J, Volfovsky N, Deng T, Brenna SMF, Carvalho CRN, Ribalta JCL, Bustin M, Matzinger P, Silva IDCG, Lyng H, Gerbase-DeLima M, Morgun A. Gene network reconstruction reveals cell cycle and antiviral genes as major drivers of cervical cancer. Nat Commun 2013; 4:1806. [PMID: 23651994 PMCID: PMC4237593 DOI: 10.1038/ncomms2693] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 03/04/2013] [Indexed: 01/04/2023] Open
Abstract
Although human papillomavirus was identified as an aetiological factor in cervical cancer, the key human gene drivers of this disease remain unknown. Here we apply an unbiased approach integrating gene expression and chromosomal aberration data. In an independent group of patients, we reconstruct and validate a gene regulatory meta-network, and identify cell cycle and antiviral genes that constitute two major subnetworks upregulated in tumour samples. These genes are located within the same regions as chromosomal amplifications, most frequently on 3q. We propose a model in which selected chromosomal gains drive activation of antiviral genes contributing to episomal virus elimination, which synergizes with cell cycle dysregulation. These findings may help to explain the paradox of episomal human papillomavirus decline in women with invasive cancer who were previously unable to clear the virus.
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Affiliation(s)
- Karina L. Mine
- Instituto de Imunogenética - Associação Fundo de Incentivo à Pesquisa (IGEN-AFIP), São Paulo SP, Brazil
- Universidade Federal de São Paulo, SP, Brazil
| | - Natalia Shulzhenko
- Instituto de Imunogenética - Associação Fundo de Incentivo à Pesquisa (IGEN-AFIP), São Paulo SP, Brazil
- Laboratory of Cellular and Molecular Immunology, NIAID, NIH, Bethesda, MD, United States
- College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Anatoly Yambartsev
- Institute of Mathematics and Statistics, Department of Statistics, University of Sao Paulo, SP, Brazil
| | - Mark Rochman
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, NCI, NIH, Bethesda, MD, United States
| | - Gerdine F. O. Sanson
- Instituto de Imunogenética - Associação Fundo de Incentivo à Pesquisa (IGEN-AFIP), São Paulo SP, Brazil
| | - Malin Lando
- Department of Radiation Biology, Norwegian Radium Hospital, Oslo, Norway
| | - Sudhir Varma
- Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, United States
| | - Jeff Skinner
- Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, United States
| | - Natalia Volfovsky
- Advanced Biomedical Computing Center, SAIC-Frederick, Inc., Frederick, MD, United States
| | - Tao Deng
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, NCI, NIH, Bethesda, MD, United States
| | - Sylvia M. F. Brenna
- Medical School of Universidade Cidade de São Paulo (UNICID), Sao Paulo, Brazil
| | | | | | - Michael Bustin
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, NCI, NIH, Bethesda, MD, United States
| | - Polly Matzinger
- Laboratory of Cellular and Molecular Immunology, NIAID, NIH, Bethesda, MD, United States
| | | | - Heidi Lyng
- Department of Radiation Biology, Norwegian Radium Hospital, Oslo, Norway
| | - Maria Gerbase-DeLima
- Instituto de Imunogenética - Associação Fundo de Incentivo à Pesquisa (IGEN-AFIP), São Paulo SP, Brazil
- Universidade Federal de São Paulo, SP, Brazil
| | - Andrey Morgun
- Instituto de Imunogenética - Associação Fundo de Incentivo à Pesquisa (IGEN-AFIP), São Paulo SP, Brazil
- Laboratory of Cellular and Molecular Immunology, NIAID, NIH, Bethesda, MD, United States
- College of Pharmacy, Oregon State University, Corvallis, OR, United States
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239
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Clark PM, Dawany N, Dampier W, Byers SW, Pestell RG, Tozeren A. Bioinformatics analysis reveals transcriptome and microRNA signatures and drug repositioning targets for IBD and other autoimmune diseases. Inflamm Bowel Dis 2012; 18:2315-33. [PMID: 22488912 DOI: 10.1002/ibd.22958] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 02/27/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND Inflammatory bowel disease (IBD) is a complex disorder involving pathogen infection, host immune response, and altered enterocyte physiology. Incidences of IBD are increasing at an alarming rate in developed countries, warranting a detailed molecular portrait of IBD. METHODS We used large-scale data, bioinformatics tools, and high-throughput computations to obtain gene and microRNA signatures for Crohn's disease (CD) and ulcerative colitis (UC). These signatures were then integrated with systemic literature review to draw a comprehensive portrait of IBD in relation to autoimmune diseases. RESULTS The top upregulated genes in IBD are associated with diabetogenesis (REG1A, REG1B), bacterial signals (TLRs, NLRs), innate immunity (DEFA6, IDO1, EXOSC1), inflammation (CXCLs), and matrix degradation (MMPs). The downregulated genes coded tight junction proteins (CLDN8), solute transporters (SLCs), and adhesion proteins. Genes highly expressed in UC compared to CD included antiinflammatory ANXA1, transporter ABCA12, T-cell activator HSH2D, and immunoglobulin IGHV4-34. Compromised metabolisms for processing of drugs, nitrogen, androgen and estrogen, and lipids in IBD correlated with an increase in specific microRNA. Highly expressed IBD genes constituted targets of drugs used in gastrointestinal cancers, viral infections, and autoimmunity disorders such as rheumatoid arthritis and asthma. CONCLUSIONS This study presents a clinically relevant gene-level portrait of IBD subtypes and their connectivity to autoimmune diseases. The study identified candidates for repositioning of existing drugs to manage IBD. Integration of mice and human data point to an altered B-cell response as a cause for upregulation of genes in IBD involved in other aspects of immune defense such as interferon-inducible responses.
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Affiliation(s)
- Peter M Clark
- Center for Integrated Bioinformatics, Drexel University, Philadelphia, Pennsylvania 19104, USA
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240
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Kremer B, Mariman R, van Erk M, Lagerweij T, Nagelkerken L. Temporal colonic gene expression profiling in the recurrent colitis model identifies early and chronic inflammatory processes. PLoS One 2012; 7:e50388. [PMID: 23226271 PMCID: PMC3511545 DOI: 10.1371/journal.pone.0050388] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 10/18/2012] [Indexed: 12/30/2022] Open
Abstract
The recurrent TNBS-colitis model in BALB/c mice has been proposed as a model of Inflammatory Bowel Disease with a shifting pattern of local cytokines with the expression of Th1 cytokines during the early phase, Th17 cytokines during the intermediate phase and Th2 cytokines during late fibrotic stages. In this study, we evaluated the development of pathology in time–in conjunction with genome-wide gene expression in the colons–in response to three weekly intrarectal instillations of TNBS. During this time-frame mice develop colitis with extensive cellular infiltration of (sub)mucosa and mildly to moderately affected crypt architecture. These pathological processes were sensitive to local treatment with budesonide. Gene expression profiling confirmed an acute phase response after each intrarectal TNBS-challenge. In addition, a chronic inflammatory process developed over time particularly evident from a gradual increase in expression of mast cell related genes. The changes in pathological hallmarks were consistent with a temporal expression of mRNA encoding a selection of chemokines. In conclusion, the early stages of the recurrent TNBS-colitis model reflect several aspects of inflammatory bowel disease which are sensitive to immunomodulation.
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Affiliation(s)
- Bas Kremer
- Department of Metabolic Health Research, TNO, Leiden, The Netherlands.
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241
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Chassin C, Hempel C, Stockinger S, Dupont A, Kübler JF, Wedemeyer J, Vandewalle A, Hornef MW. MicroRNA-146a-mediated downregulation of IRAK1 protects mouse and human small intestine against ischemia/reperfusion injury. EMBO Mol Med 2012; 4:1308-19. [PMID: 23143987 PMCID: PMC3531605 DOI: 10.1002/emmm.201201298] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 09/21/2012] [Accepted: 09/25/2012] [Indexed: 01/28/2023] Open
Abstract
Intestinal ischemia/reperfusion (I/R) injury causes inflammation and tissue damage and is associated with high morbidity and mortality. Uncontrolled activation of the innate immune system through toll-like receptors (Tlr) plays a key role in I/R-mediated tissue damage but the underlying mechanisms have not been fully resolved. Here, we identify post-transcriptional upregulation of the essential Tlr signalling molecule interleukin 1 receptor-associated kinase (Irak) 1 as the causative mechanism for post-ischemic immune hyper-responsiveness of intestinal epithelial cells. Increased Irak1 protein levels enhanced epithelial ligand responsiveness, chemokine secretion, apoptosis and mucosal barrier disruption in an experimental intestinal I/R model using wild-type, Irak1−/− and Tlr4−/− mice and ischemic human intestinal tissue. Irak1 accumulation under hypoxic conditions was associated with reduced K48 ubiquitination and enhanced Senp1-mediated deSUMOylation of Irak1. Importantly, administration of microRNA (miR)-146a or induction of miR-146a by the phytochemical diindolylmethane controlled Irak1 upregulation and prevented immune hyper-responsiveness in mouse and human tissue. These findings indicate that Irak1 accumulation triggers I/R-induced epithelial immune hyper-responsiveness and suggest that the induction of miR-146a offers a promising strategy to prevent I/R tissue injury.
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Affiliation(s)
- Cécilia Chassin
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
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242
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243
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Intestinal GATA4 deficiency protects from diet-induced hepatic steatosis. J Hepatol 2012; 57:1061-8. [PMID: 22750465 PMCID: PMC3477492 DOI: 10.1016/j.jhep.2012.06.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 06/04/2012] [Accepted: 06/22/2012] [Indexed: 01/07/2023]
Abstract
BACKGROUND & AIMS GATA4, a zinc finger domain transcription factor, is critical for jejunal identity. Mice with an intestine-specific GATA4 deficiency (GATA4iKO) are resistant to diet-induced obesity and insulin resistance. Although they have decreased intestinal lipid absorption, hepatic de novo lipogenesis is inhibited. Here, we investigated dietary lipid-dependent and independent effects on the development of steatosis and fibrosis in GATA4iKO mice. METHODS GATA4iKO and control mice were fed a Western-type diet (WTD) or a methionine and choline-deficient diet (MCDD) for 20 and 3 weeks, respectively. Functional effects of GATA4iKO on diet-induced liver steatosis were investigated. RESULTS WTD-but not MCDD-fed GATA4iKO mice showed lower hepatic concentrations of triglycerides, free fatty acids, and thiobarbituric acid reactive species and had reduced expression of lipogenic as well as fibrotic genes compared with controls. Reduced nuclear sterol regulatory element-binding protein-1c protein levels were accompanied by lower lipogenic gene expression. Oil red O and Sirius Red staining of liver sections confirmed the observed reduction in hepatic lipid accumulation and fibrosis. Immunohistochemical staining revealed an increased number of jejunal glucagon-like peptide 1 (GLP-1) positive cells in GATA4iKO mice. Consequently, we found enhanced phosphorylation of hepatic AMP-activated protein kinase and acetyl-CoA carboxylase alpha. CONCLUSIONS Our results provide strong indications for a protective effect of intestinal GATA4 deficiency on the development of hepatic steatosis and fibrosis via GLP-1, thereby blocking hepatic de novo lipogenesis.
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Key Words
- dnl, de novo lipogenesis
- tg, triglycerides
- nafld, non-alcoholic fatty liver disease
- wtd, western-type diet
- acc, acetyl-coa carboxylase alpha
- mcdd, methionine and choline-deficient diet
- glp-1, glucagon-like peptide-1
- iis, ileal interposition surgery
- gata4iko, intestine-specific gata4 deficiency
- alt, alanine aminotransferase
- ast, aspartate transaminase
- ldh, lactate dehydrogenase
- ffa, free fatty acids
- tbars, thiobarbituric acid reactive substances
- ampk, amp-activated protein kinase
- p, phosphorylated
- p38, p38 mitogen-activated protein kinase
- pparg, peroxisome proliferator-activated receptor gamma
- α-sma, alpha-smooth muscle actin
- srebp-1c, sterol regulatory element-binding protein-1c
- hsc, hepatic stellate cells
- gata4
- non-alcoholic fatty liver disease
- glp-1
- ileal interposition surgery
- de novo lipogenesis
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244
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Abstract
The intestinal mucosa contains the largest population of antibody-secreting plasma cells in the body, and in humans several grams of secretory immunoglobulin A (SIgA) are released into the intestine each day. In the gut lumen, SIgA serves as a first-line barrier that protects the epithelium from pathogens and toxins. Recently, next-generation sequencing has revolutionized our understanding of the nature of the intestinal microbiota and has also shed new light on the important roles of SIgA in the regulation of host-commensal homeostasis. Here, I discuss pathways of IgA induction in the context of SIgA specificity and function.
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Affiliation(s)
- Oliver Pabst
- Institute of Immunology, Hannover Medical School, Carl-Neuberg Strae 1, 30625 Hannover, Germany.
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245
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Young GR, Eksmond U, Salcedo R, Alexopoulou L, Stoye JP, Kassiotis G. Resurrection of endogenous retroviruses in antibody-deficient mice. Nature 2012; 491:774-8. [PMID: 23103862 PMCID: PMC3511586 DOI: 10.1038/nature11599] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 09/18/2012] [Indexed: 01/12/2023]
Abstract
The mammalian host has developed a long-standing symbiotic relationship with a considerable number of microbial species. These include the microbiota on environmental surfaces, such as the respiratory and gastrointestinal tracks1, and also endogenous retroviruses (ERVs), comprising a substantial fraction of the mammalian genome2,3. The long-term consequences for the host of interaction with these microbial species can range from mutualism to parasitism and are not always completely understood. The potential impact of one microbial symbiont on another is even less clear. We have studied the control of ERVs in the commonly-used C57BL/6 (B6) mouse strain, which lacks endogenous murine leukaemia viruses (MLVs) able to replicate in murine cells. We demonstrate the spontaneous emergence of fully infectious ecotropic4 MLV (eMLV) in B6 mice with a range of distinct immune deficiencies affecting antibody production. These recombinant retroviruses establish infection of immunodeficient mouse colonies, and ultimately result in retrovirus-induced lymphomas. Notably, ERV activation in immune-deficient mice is prevented in husbandry conditions associated with reduced or absent intestinal microbiota. Our results shed light onto a previously unappreciated role for immunity in the control of ERVs and provide a potential mechanistic link between immune activation by microbial triggers and a range of pathologies associated with ERVs, including cancer.
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Affiliation(s)
- George R Young
- Division of Immunoregulation, MRC National Institute for Medical Research, The Ridgeway, London NW7 1AA, UK
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246
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Blumberg R, Powrie F. Microbiota, disease, and back to health: a metastable journey. Sci Transl Med 2012; 4:137rv7. [PMID: 22674557 PMCID: PMC5020897 DOI: 10.1126/scitranslmed.3004184] [Citation(s) in RCA: 205] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alterations in the composition of the commensal microbiota have been observed in many complex diseases. Understanding the basis for these changes, how they relate to disease risk or activity, and the mechanisms by which the symbiotic state of colonization resistance and host homeostasis is restored is critical for future therapies aimed at manipulating the microbiota.
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Affiliation(s)
- Richard Blumberg
- Gastroenterology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
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Abstract
Once considered obscure and largely ignored by microbiologists, the human microbiota has moved centre-stage in biology. The gut microbiota is now a focus of disparate research disciplines, with its contributions to health and disease ready for translation to clinical medicine. The changing composition of the microbiota is linked with changes in human behaviour and the rising prevalence of immunoallergic and metabolic disorders. The microbiota is both a target for drug therapy and a repository for drug discovery. Its secrets promise the realization of personalized medicine and nutrition, and will change and improve conventional dietary management.
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Affiliation(s)
- Fergus Shanahan
- Department of Medicine and Alimentary Pharmabiotic Centre, University College Cork, National University of Ireland, Cork, Ireland.
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Rol N, Favre L, Benyacoub J, Corthésy B. The role of secretory immunoglobulin A in the natural sensing of commensal bacteria by mouse Peyer's patch dendritic cells. J Biol Chem 2012; 287:40074-82. [PMID: 23027876 DOI: 10.1074/jbc.m112.405001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The mammalian gastrointestinal (GI) tract harbors a diverse population of commensal species collectively known as the microbiota, which interact continuously with the host. From very early in life, secretory IgA (SIgA) is found in association with intestinal bacteria. It is considered that this helps to ensure self-limiting growth of the microbiota and hence participates in symbiosis. However, the importance of this association in contributing to the mechanisms ensuring natural host-microorganism communication is in need of further investigation. In the present work, we examined the possible role of SIgA in the transport of commensal bacteria across the GI epithelium. Using an intestinal loop mouse model and fluorescently labeled bacteria, we found that entry of commensal bacteria in Peyer's patches (PP) via the M cell pathway was mediated by their association with SIgA. Preassociation of bacteria with nonspecific SIgA increased their dynamics of entry and restored the reduced transport observed in germ-free mice known to have a marked reduction in intestinal SIgA production. Selective SIgA-mediated targeting of bacteria is restricted to the tolerogenic CD11c(+)CD11b(+)CD8(-) dendritic cell subset located in the subepithelial dome region of PPs, confirming that the host is not ignorant of its resident commensals. In conclusion, our work supports the concept that SIgA-mediated monitoring of commensal bacteria targeting dendritic cells in the subepithelial dome region of PPs represents a mechanism whereby the host mucosal immune system controls the continuous dialogue between the host and commensal bacteria.
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Affiliation(s)
- Nicolas Rol
- Research and Development Laboratory, Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland
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249
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Matzinger P. The evolution of the danger theory. Interview by Lauren Constable, Commissioning Editor. Expert Rev Clin Immunol 2012; 8:311-7. [PMID: 22607177 DOI: 10.1586/eci.12.21] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Polly Matzinger, now Chief of the Ghost Laboratory and the section on T-cell Tolerance and Memory at the NIH, has previously worked as a bartender, carpenter, jazz musician, Playboy bunny and dog trainer. She completed her PhD at the University of California, San Diego (USA) and was a postdoctoral fellow at the University of Cambridge (UK). She has worried for years that the dominant model of immunity does not explain a wealth of accumulated data and has recently suggested an alternative, the danger model, which suggests that the immune system is far less concerned with things that are foreign than with those that do damage. This model, whose two major tenets Matzinger admits were thought up in a bath and on a field while herding sheep, has very few assumptions and yet "explains most of what the immune system seems to do right, as well as most of what it appears to do wrong", covering such areas as transplantation, autoimmunity and the immunobiology of tumors. The model has been the subject of a BBC Horizon film and has featured in two other films about immunity and countless articles in both the scientific and the lay press. In her spare time, Matzinger trains border collies for competitive shepherding trials and, in her own words, "composes songs that are not really worth listening to, and worries about the next major question in the immune system", namely "once it decides to respond, how does the immune system know what kind of response to make?"
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Affiliation(s)
- Polly Matzinger
- Ghost Laboratory, Laboratory of Cellular & Molecular Immunology, National Institute of Allergy & Infectious Diseases/NIH, Bethesda, MD 20894, USA.
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250
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Reikvam DH, Derrien M, Islam R, Erofeev A, Grcic V, Sandvik A, Gaustad P, Meza-Zepeda LA, Jahnsen FL, Smidt H, Johansen FE. Epithelial-microbial crosstalk in polymeric Ig receptor deficient mice. Eur J Immunol 2012; 42:2959-70. [DOI: 10.1002/eji.201242543] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/19/2012] [Accepted: 07/10/2012] [Indexed: 12/14/2022]
Affiliation(s)
- Dag Henrik Reikvam
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
| | - Muriel Derrien
- Laboratory of Microbiology; Wageningen University; Wageningen The Netherlands
| | - Rejoanoul Islam
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
- Laboratory of Microbiology; Wageningen University; Wageningen The Netherlands
| | - Alexander Erofeev
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
| | - Vedrana Grcic
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
| | - Anders Sandvik
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
| | - Peter Gaustad
- Institute of Microbiology; University of Oslo; Oslo Norway
| | - Leonardo A. Meza-Zepeda
- Department of Tumor Biology; Oslo University Hospital - The Norwegian Radium Hospital; Oslo Norway
- Norwegian Microarray Consortium,; Department of Molecular Biosciences; University of Oslo; Oslo Norway
| | - Frode L. Jahnsen
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
| | - Hauke Smidt
- Laboratory of Microbiology; Wageningen University; Wageningen The Netherlands
| | - Finn-Eirik Johansen
- Department of Pathology and Centre for Immune Regulation; University of Oslo and Oslo University Hospital - Rikshospitalet; Oslo Norway
- Department of Molecular Biosciences; University of Oslo; Oslo Norway
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