401
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402
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Yang JY, Lee SN, Chang SY, Ko HJ, Ryu S, Kweon MN. A mouse model of shigellosis by intraperitoneal infection. J Infect Dis 2013; 209:203-15. [PMID: 23904297 DOI: 10.1093/infdis/jit399] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In human and nonhuman primates, Shigella spp. cause bacillary dysentery by invading colon epithelium and promoting a strong inflammatory response; however, adult mice are resistant to oral Shigella infection. In this study, intraperitoneal challenge with virulent S. flexneri 2a (YSH6000) resulted in diarrhea and severe body weight loss in adult B6 mice. Of note, virulent S. flexneri 2a could invade and colonize not only systemic tissues but also the serosa and lamina propria region of the large intestine. In addition, epithelial shedding, barrier integrity, and goblet cell hyperplasia were found in the large intestine by 24 hours post-intraperitoneal Shigella infection. Of note, predominant expression of proinflammatory cytokines and chemokines were found in the large intestine after intraperitoneal challenge. Monocytes played a critical role in attenuating diarrhea and in providing protective efficacy against intraperitoneal Shigella infection. Most importantly, mice prevaccinated with attenuated S. flexneri 2a (SC602) strain were protected against intraperitoneal challenge with YSH6000. When taken together, these findings show that intraperitoneal challenge with virulent S. flexneri 2a can provoke bacillary dysentery and severe pathogenesis in adult mice. This model may be helpful for understanding the induction mechanism of bacillary dysentery and for evaluating Shigella vaccine candidates.
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Affiliation(s)
- Jin-Young Yang
- Mucosal Immunology Section, International Vaccine Institute, Seoul
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403
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Lecuit M, Eloit M. The human virome: new tools and concepts. Trends Microbiol 2013; 21:510-5. [PMID: 23906500 PMCID: PMC7172527 DOI: 10.1016/j.tim.2013.07.001] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 06/15/2013] [Accepted: 07/01/2013] [Indexed: 02/07/2023]
Abstract
New sequencing technologies increase our knowledge regarding the composition of the human virome. There are beneficial and detrimental viruses. The human virome can impact upon health at body surfaces (skin or gut) and within tissues. Some animal viruses are transmitted via the oral route by consumption of food.
The human virome is the viral component of the microbiome. Its composition, and interindividual and temporal variability are not precisely known. Its impact on human health has received less attention than that of the bacterial microbiome, but is likely to be equally important, both in homeostasis and disease. Here we review the recent advances in this field and the questions that arise in the context of our rapidly increasing knowledge regarding the composition and function of the human virome. With the ever-extending use of next-generation sequencing (NGS) on a variety of clinical samples, rapid progress on the composition of the human virome and its impact upon human health are to be expected in the coming years.
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Affiliation(s)
- Marc Lecuit
- Institut Pasteur, Biology of Infection Unit, 75724 Paris, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1117, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Institut Imagine, Paris, France; Necker-Enfants Malades University Hospital, Division of Infectious Diseases and Tropical Medicine, Paris, France
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404
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Abstract
The human microbiota is a complex assemblage of the microbes inhabiting many sites in the human body. Recent advances in technology have enabled deep sequencing and analysis of the members and structures of these communities. Two sites, the vagina and gastrointestinal tract, are highlighted to exemplify how technological advances have enhanced our knowledge of the host-microbiota system. These examples represent low- and high-complexity communities, respectively. In each example, certain community structures are identified that can be extrapolated to larger collections representing multiple individuals and potential disease or health states. One common feature is the unexpected diversity of the microbiota at any of these locations, which poses a challenge for relating the microbiota to health and disease. However, we anticipate microbiota compositional measurements could become standard clinical practice in the future and may become diagnostic for certain diseases or increased susceptibility to certain disorders. The microbiota of a number of disease states are currently being examined to identify potential correlations. In line with these predictions, it is possible that existing conditions may be resolved by altering the microbiota in a positive way.
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Affiliation(s)
- Emiley A Eloe-Fadrosh
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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405
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Kamada N, Chen GY, Inohara N, Núñez G. Control of pathogens and pathobionts by the gut microbiota. Nat Immunol 2013; 14:685-90. [PMID: 23778796 PMCID: PMC4083503 DOI: 10.1038/ni.2608] [Citation(s) in RCA: 979] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 04/09/2013] [Indexed: 02/07/2023]
Abstract
A dense resident microbial community in the gut, referred as the commensal microbiota, coevolved with the host and is essential for many host physiological processes that include enhancement of the intestinal epithelial barrier, development of the immune system and acquisition of nutrients. A major function of the microbiota is protection against colonization by pathogens and overgrowth of indigenous pathobionts that can result from the disruption of the healthy microbial community. The mechanisms that regulate the ability of the microbiota to restrain pathogen growth are complex and include competitive metabolic interactions, localization to intestinal niches and induction of host immune responses. Pathogens, in turn, have evolved strategies to escape from commensal-mediated resistance to colonization. Thus, the interplay between commensals and pathogens or indigenous pathobionts is critical for controlling infection and disease. Understanding pathogen-commensal interactions may lead to new therapeutic approaches to treating infectious diseases.
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Affiliation(s)
- Nobuhiko Kamada
- Department of Pathology and Comprehensive Cancer Center, University of Michigan, Ann Arbor 48109, USA
| | - Grace Y. Chen
- Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan, Ann Arbor 48109, USA
| | - Naohiro Inohara
- Department of Pathology, University of Michigan, Ann Arbor 48109, USA
| | - Gabriel Núñez
- Department of Pathology and Comprehensive Cancer Center, University of Michigan, Ann Arbor 48109, USA
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406
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Needham BD, Trent MS. Fortifying the barrier: the impact of lipid A remodelling on bacterial pathogenesis. Nat Rev Microbiol 2013; 11:467-81. [PMID: 23748343 PMCID: PMC6913092 DOI: 10.1038/nrmicro3047] [Citation(s) in RCA: 392] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Gram-negative bacteria decorate their outermost surface structure, lipopolysaccharide, with elaborate chemical moieties, which effectively disguises them from immune surveillance and protects them from the onslaught of host defences. Many of these changes occur on the lipid A moiety of lipopolysaccharide, a component that is crucial for host recognition of Gram-negative infection. In this Review, we describe the regulatory mechanisms controlling lipid A modification and discuss the impact of modifications on pathogenesis, bacterial physiology and bacterial interactions with the host immune system.
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Affiliation(s)
- Brittany D Needham
- The Institute of Cellular and Molecular Biology, The University of Texas at Austin, 78712, USA
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407
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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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408
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Increase in gut microbiota after immune suppression in baculovirus-infected larvae. PLoS Pathog 2013; 9:e1003379. [PMID: 23717206 PMCID: PMC3662647 DOI: 10.1371/journal.ppat.1003379] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 04/05/2013] [Indexed: 02/04/2023] Open
Abstract
Spodoptera exigua microarray was used to determine genes differentially expressed in S. exigua cells challenged with the species-specific baculovirus SeMNPV as well as with a generalist baculovirus, AcMNPV. Microarray results revealed that, in contrast to the host transcriptional shut-off that is expected during baculovirus infection, S. exigua cells showed a balanced number of up- and down-regulated genes during the first 36 hours following the infection. Many immune-related genes, including pattern recognition proteins, genes involved in signalling and immune pathways as well as immune effectors and genes coding for proteins involved in the melanization cascade were found to be down-regulated after baculovirus infection. The down-regulation of immune-related genes was confirmed in the larval gut. The expression of immune-related genes in the gut is known to affect the status of gut microorganisms, many of which are responsible for growth and development functions. We therefore asked whether the down-regulation that occurs after baculovirus infection affects the amount of gut microbiota. An increase in the gut bacterial load was observed and we hypothesize this to be as a consequence of viral infection. Subsequent experiments on virus performance in the presence and absence of gut microbiota revealed that gut bacteria enhanced baculovirus virulence, pathogenicity and dispersion. We discuss the host immune response processes and pathways affected by baculoviruses, as well as the role of gut microbiota in viral infection. Baculoviruses are large DNA viruses that infect invertebrates, mainly insects from the order Lepidoptera. They were first discovered to cause insects' epizootics and are now used worldwide as biocontrol agents. Extensive studies on baculovirus biology led to the discovery that they can serve as expression vectors in insect cells; recently they have also been considered as vectors for gene therapy. Baculovirus infection, like many other oral infections, starts with the invasion of the gut by viruses; the gut is a compartment colonized by a community of resident microbiota. In this study, we observed that baculovirus infection leads to the decreased expression of immune-related genes in a Spodoptera exigua cell culture as well as in the larval gut. Gut microbial loads were found to increase after baculovirus infection. A series of bioassays showed that the baculovirus performs better in the presence of microbiota in the gut. Our study shows that baculovirus infection leads to increase of microbiota loads in the gut and that the gut microbiota play a significant role in insect immunity and susceptibility to viral infections. These findings suggest that gut microbiota can be manipulated to improve biocontrol strategies that employ baculoviruses.
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409
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410
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Abstract
The animal and bacterial kingdoms have coevolved and coadapted in response to environmental selective pressures over hundreds of millions of years. The meta'omics revolution in both sequencing and its analytic pipelines is fostering an explosion of interest in how the gut microbiome impacts physiology and propensity to disease. Gut microbiome studies are inherently interdisciplinary, drawing on approaches and technical skill sets from the biomedical sciences, ecology, and computational biology. Central to unraveling the complex biology of environment, genetics, and microbiome interaction in human health and disease is a deeper understanding of the symbiosis between animals and bacteria. Experimental model systems, including mice, fish, insects, and the Hawaiian bobtail squid, continue to provide critical insight into how host-microbiota homeostasis is constructed and maintained. Here we consider how model systems are influencing current understanding of host-microbiota interactions and explore recent human microbiome studies.
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Affiliation(s)
- Aleksandar D. Kostic
- Harvard School of Public Health, Boston, Massachusetts 02115, USA
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
- The Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, Massachusetts 02141, USA
| | - Michael R. Howitt
- Harvard School of Public Health, Boston, Massachusetts 02115, USA
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
| | - Wendy S. Garrett
- Harvard School of Public Health, Boston, Massachusetts 02115, USA
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
- The Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, Massachusetts 02141, USA
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411
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Abstract
Chronic infections with persistent pathogens such as helminths, mycobacteria, Plasmodium, and hepatitis viruses affect more than a third of the human population and are associated with increased susceptibility to other pathogens as well as reduced vaccine efficacy. Although these observations suggest an impact of chronic infections in modulating immunity to unrelated antigens, little is known regarding the underlying mechanisms. Here, we summarize evidence of the most prevalent infections affecting immunity to unrelated pathogens and vaccines, and discuss potential mechanisms of how different bystander chronic infections might impact immune responses. We suggest that bystander chronic infections affect different stages of host responses and may impact transmission and recognition of other pathogens, innate immune responses, priming and differentiation of adaptive effector responses, as well as the development and maintenance of immunological memory. Further understanding of the immunological effects of coinfection should provide opportunities to enhance vaccine efficacy and control of infectious diseases.
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412
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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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413
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Merkling SH, van Rij RP. Beyond RNAi: antiviral defense strategies in Drosophila and mosquito. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:159-170. [PMID: 22824741 DOI: 10.1016/j.jinsphys.2012.07.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/11/2012] [Accepted: 07/12/2012] [Indexed: 06/01/2023]
Abstract
Virus transmission and spread by arthropods is a major economic and public health concern. The ongoing dissemination of arthropod-borne viruses by blood-feeding insects is an important incentive to study antiviral immunity in these animals. RNA interference is a major mechanism for antiviral defense in insects, including the fruit fly Drosophila melanogaster and several vector mosquitoes. However, recent data suggest that the evolutionary conserved Toll, Imd and Jak-Stat signaling pathways also contribute to antiviral immunity. Moreover, symbionts, such as the intracellular bacterium Wolbachia and the gut microflora, influence the course of virus infection in insects. These results add an additional level of complexity to antiviral immunity, but also provide novel opportunities to control the spread of arboviruses. In this review, we provide an overview of the current knowledge and recent developments in antiviral immunity in Dipteran insects, with a focus on non-RNAi mediated inducible responses.
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Affiliation(s)
- Sarah H Merkling
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
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414
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Abt MC, Artis D. The dynamic influence of commensal bacteria on the immune response to pathogens. Curr Opin Microbiol 2013; 16:4-9. [PMID: 23332724 DOI: 10.1016/j.mib.2012.12.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 12/20/2012] [Indexed: 12/17/2022]
Abstract
Alterations in the composition of commensal bacterial communities are associated with enhanced susceptibility to multiple inflammatory, allergic, metabolic and infectious diseases in humans. In the context of infection, commensal bacteria-derived signals can influence the host immune response to invasive pathogens by acting as an adjuvant to boost the immune response to infection or by providing tonic stimulation to induce basal expression of factors required for host defense. Conversely, some pathogens have evolved mechanisms that can utilize commensal bacteria to establish a replicative advantage within the host. Thus, examining the dynamic relationship that exists between the mammalian host, commensal bacteria and invasive pathogens can provide insights into the etiology of pathogenesis from an infection.
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Affiliation(s)
- Michael C Abt
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
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415
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Bosch AATM, Biesbroek G, Trzcinski K, Sanders EAM, Bogaert D. Viral and bacterial interactions in the upper respiratory tract. PLoS Pathog 2013; 9:e1003057. [PMID: 23326226 PMCID: PMC3542149 DOI: 10.1371/journal.ppat.1003057] [Citation(s) in RCA: 400] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Respiratory infectious diseases are mainly caused by viruses or bacteria that often interact with one another. Although their presence is a prerequisite for subsequent infections, viruses and bacteria may be present in the nasopharynx without causing any respiratory symptoms. The upper respiratory tract hosts a vast range of commensals and potential pathogenic bacteria, which form a complex microbial community. This community is assumed to be constantly subject to synergistic and competitive interspecies interactions. Disturbances in the equilibrium, for instance due to the acquisition of new bacteria or viruses, may lead to overgrowth and invasion. A better understanding of the dynamics between commensals and pathogens in the upper respiratory tract may provide better insight into the pathogenesis of respiratory diseases. Here we review the current knowledge regarding specific bacterial–bacterial and viral–bacterial interactions that occur in the upper respiratory niche, and discuss mechanisms by which these interactions might be mediated. Finally, we propose a theoretical model to summarize and illustrate these mechanisms.
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Affiliation(s)
- Astrid A. T. M. Bosch
- Department of Pediatric Immunology and Infectious Diseases, University Medical Center-Wilhelmina Children's Hospital, Utrecht, The Netherlands
| | - Giske Biesbroek
- Department of Pediatric Immunology and Infectious Diseases, University Medical Center-Wilhelmina Children's Hospital, Utrecht, The Netherlands
| | - Krzysztof Trzcinski
- Department of Pediatric Immunology and Infectious Diseases, University Medical Center-Wilhelmina Children's Hospital, Utrecht, The Netherlands
| | - Elisabeth A. M. Sanders
- Department of Pediatric Immunology and Infectious Diseases, University Medical Center-Wilhelmina Children's Hospital, Utrecht, The Netherlands
| | - Debby Bogaert
- Department of Pediatric Immunology and Infectious Diseases, University Medical Center-Wilhelmina Children's Hospital, Utrecht, The Netherlands
- * E-mail:
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416
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Abstract
PURPOSE OF REVIEW This review focuses on recent advances and novel insights into the mechanistic events that may link commensal microbiota and host innate immunity in the pathophysiology of intestinal inflammation and neoplasia. Unanswered questions are discussed and future perspectives in the field are highlighted. RECENT FINDINGS Commensal microbiota, host innate immunity, and genetics form a multidimensional network that controls homeostasis of the mucosal barrier in the intestine. Large-scale sequencing projects have begun to catalog the healthy human microbiome. Converging evidence suggests that alterations in the regulation of the complex host environment [e.g., dysbiosis and overgrowth of select commensal bacterial species, dietary factors, copresence of facultative pathogens (including viruses), and changes in mucus characteristics] may trigger aberrant innate immune signaling, thereby contributing to the development of intestinal inflammation and associated colon cancer in the susceptible individual. Genetically determined innate immune malfunction may create an inflammatory environment that promotes tumor progression (such as the TLR4-D299G mutation). SUMMARY The next challenging steps to be taken are to decipher changes in the human microbiome (and virome) during well defined diseased states, and relate them to intestinal mucosal immune functions and host genotypes.
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417
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Bertók T, Katrlík J, Gemeiner P, Tkac J. Electrochemical lectin based biosensors as a label-free tool in glycomics. Mikrochim Acta 2013; 180:1-13. [PMID: 27239071 PMCID: PMC4883647 DOI: 10.1007/s00604-012-0876-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Glycans and other saccharide moieties attached to proteins and lipids, or present on the surface of a cell, are actively involved in numerous physiological or pathological processes. Their structural flexibility (that is based on the formation of various kinds of linkages between saccharides) is making glycans superb "identity cards". In fact, glycans can form more "words" or "codes" (i.e., unique sequences) from the same number of "letters" (building blocks) than DNA or proteins. Glycans are physicochemically similar and it is not a trivial task to identify their sequence, or - even more challenging - to link a given glycan to a particular physiological or pathological process. Lectins can recognise differences in glycan compositions even in their bound state and therefore are most useful tools in the task to decipher the "glycocode". Thus, lectin-based biosensors working in a label-free mode can effectively complement the current weaponry of analytical tools in glycomics. This review gives an introduction into the area of glycomics and then focuses on the design, analytical performance, and practical utility of lectin-based electrochemical label-free biosensors for the detection of isolated glycoproteins or intact cells.
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Affiliation(s)
- Tomáš Bertók
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38, Bratislava, Slovak Republic
| | - Jaroslav Katrlík
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38, Bratislava, Slovak Republic
| | - Peter Gemeiner
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38, Bratislava, Slovak Republic
| | - Jan Tkac
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38, Bratislava, Slovak Republic
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418
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Warrilow D, Allcock RJN. Massively parallel sequencing for the microbiologist. MICROBIOLOGY AUSTRALIA 2013. [DOI: 10.1071/ma13060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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419
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Morens DM, Fauci AS. Emerging infectious diseases in 2012: 20 years after the institute of medicine report. mBio 2012; 3:e00494-12. [PMID: 23232716 PMCID: PMC3520107 DOI: 10.1128/mbio.00494-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 11/06/2012] [Indexed: 02/07/2023] Open
Abstract
Twenty years ago (1992), a landmark Institute of Medicine report entitled "Emerging Infections: Microbial Threats to Health in the United States" underscored the important but often underappreciated concept of emerging infectious diseases (EIDs). A review of the progress made and setbacks experienced over the past 2 decades suggests that even though many new diseases have emerged, such as SARS (severe acute respiratory syndrome) and the 2009 pandemic influenza, significant advances have occurred in EID control, prevention, and treatment. Among many elements of the increase in the capacity to control EIDs are genomics-associated advances in microbial detection and treatment, improved disease surveillance, and greater awareness of EIDs and the complicated variables that underlie emergence. In looking back over the past 20 years, it is apparent that we are in a time of great change in which both the challenge of EIDs and our responses to them are being transformed. Recent advances support guarded optimism that further breakthroughs lie ahead.
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Affiliation(s)
- David M Morens
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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420
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Hyun J, Kanagavelu S, Fukata M. A unique host defense pathway: TRIF mediates both antiviral and antibacterial immune responses. Microbes Infect 2012; 15:1-10. [PMID: 23116944 DOI: 10.1016/j.micinf.2012.10.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 10/19/2012] [Indexed: 01/07/2023]
Abstract
Both anti-viral and anti-bacterial host defense mechanisms involve TRIF signaling. TRIF provides early clearance of pathogens and coordination of a local inflammatory ensemble through an interferon cascade, while it may trigger organ damage. The multipotentiality of TRIF-mediated immune machinery may direct the fate of our continuous battle with microbes.
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Affiliation(s)
- Jinhee Hyun
- Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33101, USA
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421
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van den Bergh MR, Biesbroek G, Rossen JWA, de Steenhuijsen Piters WAA, Bosch AATM, van Gils EJM, Wang X, Boonacker CWB, Veenhoven RH, Bruin JP, Bogaert D, Sanders EAM. Associations between pathogens in the upper respiratory tract of young children: interplay between viruses and bacteria. PLoS One 2012; 7:e47711. [PMID: 23082199 PMCID: PMC3474735 DOI: 10.1371/journal.pone.0047711] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 09/13/2012] [Indexed: 12/15/2022] Open
Abstract
Background High rates of potentially pathogenic bacteria and respiratory viruses can be detected in the upper respiratory tract of healthy children. Investigating presence of and associations between these pathogens in healthy individuals is still a rather unexplored field of research, but may have implications for interpreting findings during disease. Methodology/Principal Findings We selected 986 nasopharyngeal samples from 433 6- to 24-month-old healthy children that had participated in a randomized controlled trial. We determined the presence of 20 common respiratory viruses using real-time PCR. Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus were identified by conventional culture methods. Information on risk factors was obtained by questionnaires. We performed multivariate logistic regression analyses followed by partial correlation analysis to identify the overall pattern of associations. S. pneumoniae colonization was positively associated with the presence of H. influenzae (adjusted odds ratio 1.60, 95% confidence interval 1.18–2.16), M. catarrhalis (1.78, 1.29–2.47), human rhinoviruses (1.63, 1.19–2.22) and enteroviruses (1.97, 1.26–3.10), and negatively associated with S. aureus presence (0.59, 0.35–0.98). H. influenzae was positively associated with human rhinoviruses (1.63, 1.22–2.18) and respiratory syncytial viruses (2.78, 1.06–7.28). M. catarrhalis colonization was positively associated with coronaviruses (1.99, 1.01–3.93) and adenoviruses (3.69, 1.29–10.56), and negatively with S. aureus carriage (0.42, 0.25–0.69). We observed a strong positive association between S. aureus and influenza viruses (4.87, 1.59–14.89). In addition, human rhinoviruses and enteroviruses were positively correlated (2.40, 1.66–3.47), as were enteroviruses and human bocavirus, WU polyomavirus, parainfluenza viruses, and human parechovirus. A negative association was observed between human rhinoviruses and coronaviruses. Conclusions/Significance Our data revealed high viral and bacterial prevalence rates and distinct bacterial-bacterial, viral-bacterial and viral-viral associations in healthy children, hinting towards the complexity and potential dynamics of microbial communities in the upper respiratory tract. This warrants careful consideration when associating microbial presence with specific respiratory diseases.
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Affiliation(s)
- Menno R. van den Bergh
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
- Research Center Linnaeus Institute, Spaarne Hospital, Hoofddorp, The Netherlands
| | - Giske Biesbroek
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - John W. A. Rossen
- Laboratory of Medical Microbiology and Immunology, St Elisabeth Hospital, Tilburg, The Netherlands
| | - Wouter A. A. de Steenhuijsen Piters
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Astrid A. T. M. Bosch
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Elske J. M. van Gils
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
- Research Center Linnaeus Institute, Spaarne Hospital, Hoofddorp, The Netherlands
| | - Xinhui Wang
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Chantal W. B. Boonacker
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Reinier H. Veenhoven
- Research Center Linnaeus Institute, Spaarne Hospital, Hoofddorp, The Netherlands
| | - Jacob P. Bruin
- Regional Laboratory of Public Health, Haarlem, The Netherlands
| | - Debby Bogaert
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
| | - Elisabeth A. M. Sanders
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
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422
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de Vos WM, de Vos EAJ. Role of the intestinal microbiome in health and disease: from correlation to causation. Nutr Rev 2012; 70 Suppl 1:S45-56. [PMID: 22861807 DOI: 10.1111/j.1753-4887.2012.00505.x] [Citation(s) in RCA: 264] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recorded observations indicating an association between intestinal microbes and health are long-standing in terms of specific diseases, but emerging high-throughput technologies that characterize microbial communities in the intestinal tract are suggesting new roles for the supposedly normal microbiome. This review considers the nature of the evidence supporting a relationship between the microbiota and the predisposition to disease as associative, correlative, or causal. Altogether, indirect or associative support currently dominates the evidence base, which now suggests that the intestinal microbiome can be linked to a growing number of over 25 diseases or syndromes. While only a handful of cause-and-effect studies have been performed, this form of evidence is increasing. The results of such studies are expected to be useful in monitoring disease development, in providing a basis for personalized treatments, and in indicating future therapeutic avenues.
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Affiliation(s)
- Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands.
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423
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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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424
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425
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Hara N, Alkanani AK, Ir D, Robertson CE, Wagner BD, Frank DN, Zipris D. Prevention of virus-induced type 1 diabetes with antibiotic therapy. THE JOURNAL OF IMMUNOLOGY 2012; 189:3805-14. [PMID: 22988033 DOI: 10.4049/jimmunol.1201257] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Microbes were hypothesized to play a key role in the progression of type 1 diabetes (T1D). We used the LEW1.WR1 rat model of Kilham rat virus (KRV)-induced T1D to test the hypothesis that the intestinal microbiota is involved in the mechanism leading to islet destruction. Treating LEW1.WR1 rats with KRV and a combination of trimethoprim and sulfamethoxazole (Sulfatrim) beginning on the day of infection protected the rats from insulitis and T1D. Pyrosequencing of bacterial 16S rRNA and quantitative RT-PCR indicated that KRV infection resulted in a transient increase in the abundance of Bifidobacterium spp. and Clostridium spp. in fecal samples from day 5- but not day 12-infected versus uninfected animals. Similar alterations in the gut microbiome were observed in the jejunum of infected animals on day 5. Treatment with Sulfatrim restored the level of intestinal Bifidobacterium spp. and Clostridium spp. We also observed that virus infection induced the expression of KRV transcripts and the rapid upregulation of innate immune responses in Peyer's patches and pancreatic lymph nodes. However, antibiotic therapy reduced the virus-induced inflammation as reflected by the presence of lower amounts of proinflammatory molecules in both the Peyer's patches and pancreatic lymph nodes. Finally, Sulfatrim treatment reduced the number of B cells in Peyer's patches and downmodulated adaptive immune responses to KRV, but did not interfere with antiviral Ab responses or viral clearance from the spleen, pancreatic lymph nodes, and serum. The data suggest that gut microbiota may be involved in promoting virus-induced T1D in the LEW1.WR1 rat model.
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Affiliation(s)
- Naoko Hara
- Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, CO 80045, USA
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426
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Abstract
Recent studies have highlighted the importance of the human microbiome in health and disease. However, for the most part the mechanisms by which the microbiome mediates disease, or protection from it, remain poorly understood. The keystone-pathogen hypothesis holds that certain low-abundance microbial pathogens can orchestrate inflammatory disease by remodelling a normally benign microbiota into a dysbiotic one. In this Opinion article, we critically assess the available literature that supports this hypothesis, which may provide a novel conceptual basis for the development of targeted diagnostics and treatments for complex dysbiotic diseases.
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Affiliation(s)
- George Hajishengallis
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania 19104, USA.
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427
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Abt MC, Osborne LC, Monticelli LA, Doering TA, Alenghat T, Sonnenberg GF, Paley MA, Antenus M, Williams KL, Erikson J, Wherry EJ, Artis D. Commensal bacteria calibrate the activation threshold of innate antiviral immunity. Immunity 2012; 37:158-70. [PMID: 22705104 PMCID: PMC3679670 DOI: 10.1016/j.immuni.2012.04.011] [Citation(s) in RCA: 730] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 02/22/2012] [Accepted: 04/17/2012] [Indexed: 01/02/2023]
Abstract
Signals from commensal bacteria can influence immune cell development and susceptibility to infectious or inflammatory diseases. However, the mechanisms by which commensal bacteria regulate protective immunity after exposure to systemic pathogens remain poorly understood. Here, we demonstrate that antibiotic-treated (ABX) mice exhibit impaired innate and adaptive antiviral immune responses and substantially delayed viral clearance after exposure to systemic LCMV or mucosal influenza virus. Furthermore, ABX mice exhibited severe bronchiole epithelial degeneration and increased host mortality after influenza virus infection. Genome-wide transcriptional profiling of macrophages isolated from ABX mice revealed decreased expression of genes associated with antiviral immunity. Moreover, macrophages from ABX mice exhibited defective responses to type I and type II IFNs and impaired capacity to limit viral replication. Collectively, these data indicate that commensal-derived signals provide tonic immune stimulation that establishes the activation threshold of the innate immune system required for optimal antiviral immunity.
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Affiliation(s)
- Michael C. Abt
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lisa C. Osborne
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laurel A. Monticelli
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Travis A. Doering
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Theresa Alenghat
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gregory F. Sonnenberg
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael A. Paley
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marcelo Antenus
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Jan Erikson
- The Wistar Institute, Philadelphia, PA 19104, USA
| | - E. John Wherry
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David Artis
- Department of Microbiology and Institute for Immunology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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428
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Upper respiratory tract microbial communities, acute otitis media pathogens, and antibiotic use in healthy and sick children. Appl Environ Microbiol 2012; 78:6262-70. [PMID: 22752171 DOI: 10.1128/aem.01051-12] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The composition of the upper respiratory tract microbial community may influence the risk for colonization by the acute otitis media (AOM) pathogens Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. We used culture-independent methods to describe upper respiratory tract microbial communities in healthy children and children with upper respiratory tract infection with and without concurrent AOM. Nasal swabs and data were collected in a cross-sectional study of 240 children between 6 months and 3 years of age. Swabs were cultured for S. pneumoniae, and real-time PCR was used to identify S. pneumoniae, H. influenzae, and M. catarrhalis. The V1-V2 16S rRNA gene regions were sequenced using 454 pyrosequencing. Microbial communities were described using a taxon-based approach. Colonization by S. pneumoniae, H. influenzae, and M. catarrhalis was associated with lower levels of diversity in upper respiratory tract flora. We identified commensal taxa that were negatively associated with colonization by each AOM bacterial pathogen and with AOM. The balance of these relationships differed according to the colonizing AOM pathogen and history of antibiotic use. Children with antibiotic use in the past 6 months and a greater abundance of taxa, including Lactococcus and Propionibacterium, were less likely to have AOM than healthy children (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.25 to 0.85). Children with no antibiotic use in the past 6 months, a low abundance of Streptococcus and Haemophilus, and a high abundance of Corynebacterium and Dolosigranulum were less likely to have AOM (OR, 0.51; 95% CI, 0.31 to 0.83). An increased understanding of polymicrobial interactions will facilitate the development of effective AOM prevention strategies.
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429
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Boissière A, Tchioffo MT, Bachar D, Abate L, Marie A, Nsango SE, Shahbazkia HR, Awono-Ambene PH, Levashina EA, Christen R, Morlais I. Midgut microbiota of the malaria mosquito vector Anopheles gambiae and interactions with Plasmodium falciparum infection. PLoS Pathog 2012; 8:e1002742. [PMID: 22693451 PMCID: PMC3364955 DOI: 10.1371/journal.ppat.1002742] [Citation(s) in RCA: 332] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/26/2012] [Indexed: 12/16/2022] Open
Abstract
The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission. During their development in the mosquito vector, Plasmodium parasites undergo complex developmental steps and incur severe bottlenecks. The largest parasite losses occur in the mosquito midgut where robust immune responses are activated. Variability in P. falciparum infection levels indicates that parasite transmission is the result of complex interactions between vectors and parasites, which rely on both genetic and environmental factors. However, in contrast to genetically encoded factors, the role of environmental factors in parasite transmission has received little attention. In this study, we characterized the midgut microbiota of mosquitoes derived from diverse breeding sites using pyrosequencing. We show that the composition of the midgut microbiota in adult mosquitoes exhibits great variability, which is likely determined by bacterial richness of the larval habitats. When field mosquitoes were collected at late immature stages in natural breeding sites and the emerging females challenged with Plasmodium falciparum in the laboratory, significant correlation was observed between P. falciparum infection and the presence of Enterobacteriaceae in the mosquito midgut. Greater understanding of these malaria-bacteria interactions may lead to novel malaria control strategies.
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Affiliation(s)
- Anne Boissière
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
| | - Majoline T. Tchioffo
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, IRD-OCEAC, BP288, Yaoundé, Cameroun
| | - Dipankar Bachar
- UMR 7138 Systématique Adaptation Evolution, Université de Nice-Sophia Antipolis, Parc Valrose, France
| | - Luc Abate
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
| | - Alexandra Marie
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
| | - Sandrine E. Nsango
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, IRD-OCEAC, BP288, Yaoundé, Cameroun
- CNRS UPR 9022, Inserm U963, Université de Strasbourg, Strasbourg, France
| | - Hamid R. Shahbazkia
- UMR 7138 Systématique Adaptation Evolution, Université de Nice-Sophia Antipolis, Parc Valrose, France
- Área Departamental de Engenharia Electrónica e Computação, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Faro, Portugal
| | | | - Elena A. Levashina
- CNRS UPR 9022, Inserm U963, Université de Strasbourg, Strasbourg, France
| | - Richard Christen
- UMR 7138 Systématique Adaptation Evolution, Université de Nice-Sophia Antipolis, Parc Valrose, France
| | - Isabelle Morlais
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, IRD-OCEAC, BP288, Yaoundé, Cameroun
- * E-mail:
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430
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Korpe PS, Petri WA. Environmental enteropathy: critical implications of a poorly understood condition. Trends Mol Med 2012; 18:328-36. [PMID: 22633998 DOI: 10.1016/j.molmed.2012.04.007] [Citation(s) in RCA: 319] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 04/12/2012] [Accepted: 04/20/2012] [Indexed: 12/13/2022]
Abstract
Environmental enteropathy (also called tropical enteropathy) is a subclinical condition caused by constant fecal-oral contamination and resulting in blunting of intestinal villi and intestinal inflammation. Although these histological changes were discovered decades ago, the clinical impact of environmental enteropathy is just starting to be recognized. The failure of nutritional interventions and oral vaccines in the developing world may be attributed to environmental enteropathy, as the intestinal absorptive and immunologic functions are significantly deranged. Here we review the existing literature and examine potential mechanisms of pathogenesis for this poorly understood condition.
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Affiliation(s)
- Poonum S Korpe
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908-1337, USA
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431
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Moon C, Stappenbeck TS. Viral interactions with the host and microbiota in the intestine. Curr Opin Immunol 2012; 24:405-10. [PMID: 22626624 PMCID: PMC3423491 DOI: 10.1016/j.coi.2012.05.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 05/01/2012] [Accepted: 05/03/2012] [Indexed: 12/11/2022]
Abstract
This review explores the recent advances that have been made in our understanding of host viral interactions in the intestine. Technical advances have allowed the initial definition of intestinal viromes in a number of species including humans. Important advances in our knowledge of the host response to viral infection have shown that interferon lambda has a role that is unique from type I interferons in the intestine. Lastly, our understanding of virally induced phenotypes has expanded through new studies that show bacteria can play an important role in the outcome of viral infection in the intestine.
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Affiliation(s)
- Clara Moon
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, United States
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432
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Affiliation(s)
| | - Tatyana Golovkina
- Department of Microbiology, University of Chicago, Chicago, Illinois, United States
- * E-mail:
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433
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434
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Ohka S, Nihei CI, Yamazaki M, Nomoto A. Poliovirus trafficking toward central nervous system via human poliovirus receptor-dependent and -independent pathway. Front Microbiol 2012; 3:147. [PMID: 22529845 PMCID: PMC3328850 DOI: 10.3389/fmicb.2012.00147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 03/27/2012] [Indexed: 01/22/2023] Open
Abstract
In humans, paralytic poliomyelitis results from the invasion of the central nervous system (CNS) by circulating poliovirus (PV) via the blood-brain barrier (BBB). After the virus enters the CNS, it replicates in neurons, especially in motor neurons, inducing the cell death that causes paralytic poliomyelitis. Along with this route of dissemination, neural pathway has been reported in humans, monkeys, and PV-sensitive human PV receptor (hPVR/CD155)-transgenic (Tg) mice. We demonstrated that a fast retrograde axonal transport process is required for PV dissemination through the sciatic nerve of hPVR-Tg mice and that intramuscularly inoculated PV causes paralysis in a hPVR-dependent manner. We also showed that hPVR-independent axonal transport of PV exists in hPVR-Tg and non-Tg mice, indicating that several different pathways for PV axonal transport exist in these mice. Circulating PV after intravenous inoculation in mice cross the BBB at a high rate in a hPVR-independent manner. We will implicate an involvement of a new possible receptor for PV to permeate the BBB based on our recent findings.
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Affiliation(s)
- Seii Ohka
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan.
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435
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Chervonsky AV. Intestinal commensals: influence on immune system and tolerance to pathogens. Curr Opin Immunol 2012; 24:255-60. [PMID: 22445718 DOI: 10.1016/j.coi.2012.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 03/04/2012] [Indexed: 11/28/2022]
Abstract
The interactions of commensal microorganisms with the host's immune system are in the spotlight. The intestinal microbiota provides both stimulatory and inhibitory signals to the host ensuring its own survival and contributing to resistance to pathogens. Some microbial lineages do this better than others and are attracting a lot of attention. The microbial influences go beyond the gut and have profound effects on infections and autoimmunity in distant locations. Commensals are also involved in regulation of 'tolerance to pathogens', a fundamental type of response to infections that does not reduce pathogen burden but keeps the host healthy.
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Affiliation(s)
- Alexander V Chervonsky
- Department of Pathology, University of Chicago, 924 57th Street, Chicago, IL 60637, United States.
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436
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Incoming pathogens team up with harmless 'resident' bacteria. Trends Microbiol 2012; 20:160-4. [PMID: 22390987 DOI: 10.1016/j.tim.2012.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 01/31/2012] [Accepted: 02/06/2012] [Indexed: 02/03/2023]
Abstract
Microbial diseases occur as a result of multifarious host-pathogen interactions. However, invading pathogens encounter a large number of different harmless and beneficial bacterial species, which colonize and reside in the host. Surprisingly, there has been little study of the possible interactions between incoming pathogens and the resident bacterial community. Recent studies have revealed that resident bacteria assist different types of incoming pathogens via a wide variety of mechanisms including cell-cell signaling, metabolic interactions, evasion of the immune response and a resident-to-pathogen switch. This calls for serious consideration of pathogen-microbe interactions in the host with respect to disease severity and progression.
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437
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Affiliation(s)
- Anthony S Fauci
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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438
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The dialog between microbiota and the immune system: Shaping the partners through development and evolution. Semin Immunol 2012; 24:1-2. [DOI: 10.1016/j.smim.2011.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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439
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Bancroft AJ, Hayes KS, Grencis RK. Life on the edge: the balance between macrofauna, microflora and host immunity. Trends Parasitol 2012; 28:93-8. [PMID: 22257556 DOI: 10.1016/j.pt.2011.12.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/16/2011] [Accepted: 12/19/2011] [Indexed: 12/26/2022]
Abstract
Mammals, microflora and gut-dwelling macrofauna have co-evolved over many millions of years until relatively recently when the geographical prevalence of macrofauna in humans has become restricted to the developing world. Immune homeostasis relies on a balance in the composition of intestinal microflora; long-lived macrofauna have also been shown to regulate immune function, and their absence in Western lifestyles is suggested to be a factor for the increasing frequency of allergy and autoimmunity. The intestinal nematode Trichuris muris was recently demonstrated to utilise microflora to initiate its life cycle. The interdependence on one another of all three factors is such that when the balance is perturbed it must be realigned or the consequences may be detrimental to the mammalian host.
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Affiliation(s)
- Allison J Bancroft
- Manchester Immunology Group, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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440
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Bochkov YA, Gern JE. Clinical and molecular features of human rhinovirus C. Microbes Infect 2012; 14:485-94. [PMID: 22285901 DOI: 10.1016/j.micinf.2011.12.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 12/23/2011] [Accepted: 12/26/2011] [Indexed: 02/06/2023]
Abstract
A newly discovered group of human rhinoviruses (HRVs) has been classified as the HRV-C species based on distinct genomic features. HRV-Cs circulate worldwide, and are important causes of upper and lower respiratory illnesses. Methods to culture and produce these viruses have recently been developed, and should enable identification of unique features of HRV-C replication and biology.
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Affiliation(s)
- Yury A Bochkov
- Department of Pediatrics, University of Wisconsin, School of Medicine and Public Health, Madison, WI 53792, USA.
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441
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Chassaing B, Aitken JD, Gewirtz AT, Vijay-Kumar M. Gut microbiota drives metabolic disease in immunologically altered mice. Adv Immunol 2012; 116:93-112. [PMID: 23063074 DOI: 10.1016/b978-0-12-394300-2.00003-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The mammalian intestine harbors trillions of microbes collectively known as the microbiota, which can be viewed as an anaerobic metabolic organ that benefits the host in a number of ways. The homeostasis of this large microbial biomass is a prerequisite to maintaining host health by maximizing symbiotic interrelations and minimizing the risk of living in a close relationship. The cooperation between the innate and adaptive immune systems of the host maintains homeostasis of the microbiota. The dysregulation/alteration of microbiota in various immunodeficiency states including both innate and adaptive deficiency results in metabolic disease. This review examines the influence of microbiota on host metabolic health in immunologically altered mice. Accumulated data from a variety of immune-deficient murine models indicate that altered microbiota can play a key role in origination of metabolic diseases through the following potential mechanisms: (i) increasing calorie extraction resulting in adiposity, (ii) inducing low-grade chronic inflammation in the gut directly or increasing systemic loads of microbial ligands via leaky guts, (iii) generating toxic metabolites from dietary components, and (iv) inducing a switch from pro-metabolic to pro-immune phenotype that drives malabsorption of lipids resulting in muscle wastage and weight loss-particularly upon states of adaptive immune deficiency. Further, these murine models demonstrate that altered microbiota is not purely a consequence of metabolic disease but plays a key role in driving this disorder.
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Affiliation(s)
- Benoit Chassaing
- Center for Inflammation, Immunity & Infection, Georgia State University, Atlanta, Georgia, USA
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442
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Abstract
Recent studies have highlighted the fundamental role of commensal microbes in the maintenance of host homeostasis. For instance, commensals can play a major role in the control of host defense, metabolism and tissue development. Over the past few years, abundant experimental data also support their central role in the induction and control of both innate and adaptive responses. It is now clearly established that commensals are not equal in their capacity to trigger control regulatory or effector responses, however, the molecular basis of these differences has only recently begun to be explored. This review will discuss recent findings evaluating how commensals shape both effector and regulatory responses at steady state and during infections and the consequence of this effect on local and systemic protective and inflammatory responses.
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Affiliation(s)
- Michael J Molloy
- Mucosal Immunology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 4 Center Drive, Room 4/243, Bethesda, MD 20892, USA
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443
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Abstract
The gut microbiota can facilitate viral infection and transmission.
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