1
|
Timmermans S, Wallaeys C, Garcia-Gonzalez N, Pollaris L, Saeys Y, Libert C. Identification and Characterization of Multiple Paneth Cell Types in the Mouse Small Intestine. Cells 2024; 13:1435. [PMID: 39273007 PMCID: PMC11394207 DOI: 10.3390/cells13171435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/09/2024] [Accepted: 08/23/2024] [Indexed: 09/15/2024] Open
Abstract
The small intestinal crypts harbor secretory Paneth cells (PCs) which express bactericidal peptides that are crucial for maintaining intestinal homeostasis. Considering the diverse environmental conditions throughout the course of the small intestine, multiple subtypes of PCs are expected to exist. We applied single-cell RNA-sequencing of PCs combined with deep bulk RNA-sequencing on PC populations of different small intestinal locations and discovered several expression-based PC clusters. Some of these are discrete and resemble tuft cell-like PCs, goblet cell (GC)-like PCs, PCs expressing stem cell markers, and atypical PCs. Other clusters are less discrete but appear to be derived from different locations along the intestinal tract and have environment-dictated functions such as food digestion and antimicrobial peptide production. A comprehensive spatial analysis using Resolve Bioscience was conducted, leading to the identification of different PC's transcriptomic identities along the different compartments of the intestine, but not between PCs in the crypts themselves.
Collapse
Affiliation(s)
- Steven Timmermans
- VIB Center for Inflammation Research, 9052 Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium
| | - Charlotte Wallaeys
- VIB Center for Inflammation Research, 9052 Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium
| | - Natalia Garcia-Gonzalez
- VIB Center for Inflammation Research, 9052 Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium
| | - Lotte Pollaris
- VIB Center for Inflammation Research, 9052 Ghent, Belgium
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, 9000 Ghent, Belgium
| | - Yvan Saeys
- VIB Center for Inflammation Research, 9052 Ghent, Belgium
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, 9000 Ghent, Belgium
| | - Claude Libert
- VIB Center for Inflammation Research, 9052 Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium
| |
Collapse
|
2
|
Klimovich A, Bosch TCG. Novel technologies uncover novel 'anti'-microbial peptides in Hydra shaping the species-specific microbiome. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230058. [PMID: 38497265 PMCID: PMC10945409 DOI: 10.1098/rstb.2023.0058] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/16/2023] [Indexed: 03/19/2024] Open
Abstract
The freshwater polyp Hydra uses an elaborate innate immune machinery to maintain its specific microbiome. Major components of this toolkit are conserved Toll-like receptor (TLR)-mediated immune pathways and species-specific antimicrobial peptides (AMPs). Our study harnesses advanced technologies, such as high-throughput sequencing and machine learning, to uncover a high complexity of the Hydra's AMPs repertoire. Functional analysis reveals that these AMPs are specific against diverse members of the Hydra microbiome and expressed in a spatially controlled pattern. Notably, in the outer epithelial layer, AMPs are produced mainly in the neurons. The neuron-derived AMPs are secreted directly into the glycocalyx, the habitat for symbiotic bacteria, and display high selectivity and spatial restriction of expression. In the endodermal layer, in contrast, endodermal epithelial cells produce an abundance of different AMPs including members of the arminin and hydramacin families, while gland cells secrete kazal-type protease inhibitors. Since the endodermal layer lines the gastric cavity devoid of symbiotic bacteria, we assume that endodermally secreted AMPs protect the gastric cavity from intruding pathogens. In conclusion, Hydra employs a complex set of AMPs expressed in distinct tissue layers and cell types to combat pathogens and to maintain a stable spatially organized microbiome. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.
Collapse
Affiliation(s)
- Alexander Klimovich
- Zoological Institute, Christian-Albrechts University of Kiel, Am Botanischen Garten 1-9, Kiel 24118, Germany
| | - Thomas C. G. Bosch
- Zoological Institute, Christian-Albrechts University of Kiel, Am Botanischen Garten 1-9, Kiel 24118, Germany
| |
Collapse
|
3
|
Larsen MC, Rondelli CM, Almeldin A, Song YS, N’Jai A, Alexander DL, Forsberg EC, Sheibani N, Jefcoate CR. AhR and CYP1B1 Control Oxygen Effects on Bone Marrow Progenitor Cells: The Enrichment of Multiple Olfactory Receptors as Potential Microbiome Sensors. Int J Mol Sci 2023; 24:16884. [PMID: 38069208 PMCID: PMC10706615 DOI: 10.3390/ijms242316884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
Polycyclic aromatic hydrocarbon (PAH) pollutants and microbiome products converge on the aryl hydrocarbon receptor (AhR) to redirect selective rapid adherence of isolated bone marrow (BM) cells. In young adult mice, Cyp1b1-deficiency and AhR activation by PAH, particularly when prolonged by Cyp1a1 deletion, produce matching gene stimulations in these BM cells. Vascular expression of Cyp1b1 lowers reactive oxygen species (ROS), suppressing NF-κB/RelA signaling. PAH and allelic selectivity support a non-canonical AhR participation, possibly through RelA. Genes stimulated by Cyp1b1 deficiency were further resolved according to the effects of Cyp1b1 and Cyp1a1 dual deletions (DKO). The adherent BM cells show a cluster of novel stimulations, including select developmental markers; multiple re-purposed olfactory receptors (OLFR); and α-Defensin, a microbial disruptor. Each one connects to an enhanced specific expression of the catalytic RNA Pol2 A subunit, among 12 different subunits. Mesenchymal progenitor BMS2 cells retain these features. Cyp1b1-deficiency removes lymphocytes from adherent assemblies as BM-derived mesenchymal stromal cells (BM-MSC) expand. Cyp1b1 effects were cell-type specific. In vivo, BM-MSC Cyp1b1 expression mediated PAH suppression of lymphocyte progenitors. In vitro, OP9-MSC sustained these progenitors, while Csf1 induced monocyte progenitor expansion to macrophages. Targeted Cyp1b1 deletion (Cdh5-Cre; Cyp1b1fl/fl) established endothelium control of ROS that directs AhR-mediated suppression of B cell progenitors. Monocyte Cyp1b1 deletion (Lyz2-Cre; Cyp1b1fl/fl) selectively attenuated M1 polarization of expanded macrophages, but did not enhance effects on basal M2 polarization. Thus, specific sources of Cyp1b1 link to AhR and to an OLFR network to provide BM inflammatory modulation via diverse microbiome products.
Collapse
Affiliation(s)
- Michele C. Larsen
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; (M.C.L.); (A.A.)
| | | | - Ahmed Almeldin
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; (M.C.L.); (A.A.)
| | - Yong-Seok Song
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA;
| | - Alhaji N’Jai
- Department of Pathobiological Sciences, University of Wisconsin, Madison, WI 53706, USA;
| | - David L. Alexander
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA; (D.L.A.); (E.C.F.)
| | - E. Camilla Forsberg
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA; (D.L.A.); (E.C.F.)
| | - Nader Sheibani
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; (M.C.L.); (A.A.)
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA;
| | - Colin R. Jefcoate
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; (M.C.L.); (A.A.)
| |
Collapse
|
4
|
Kiyozumi D. Lumicrine signaling: Extracellular regulation of sperm maturation in the male reproductive tract lumen. Genes Cells 2023; 28:757-763. [PMID: 37696504 DOI: 10.1111/gtc.13066] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/24/2023] [Accepted: 08/27/2023] [Indexed: 09/13/2023]
Abstract
The behaviors of cells, tissues, and organs are controlled by the extracellular environment in addition to their autonomous regulatory system. Dysfunction of extracellular regulatory mechanisms affects not only the development and survival of organisms but also successful reproduction. In this review article, a novel extracellular regulatory mechanism regulating the mammalian male reproductive ability will be briefly summarized. In terrestrial vertebrates, spermatozoa generated in the testis are transported through the lumen of the male reproductive tract and become functionally mature during the transport. Recent studies with gene-modified animals are unveiling the luminal extracellular environment of the reproductive tract to function not only as the pathway of sperm transport and the site of sperm maturation but also as the channel for cellular communication to regulate sperm maturation. Of special interest is the molecular mechanism of lumicrine signaling, a transluminal secreted signal transduction in the male reproductive tract lumen as a master regulator of sperm maturation and male reproductive ability. The general significance of such transluminal signaling in the context of cell biology will also be discussed.
Collapse
Affiliation(s)
- Daiji Kiyozumi
- Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- PRESTO, Japan Science and Technology Agency, Tokyo, Japan
| |
Collapse
|
5
|
Fu J, Zong X, Jin M, Min J, Wang F, Wang Y. Mechanisms and regulation of defensins in host defense. Signal Transduct Target Ther 2023; 8:300. [PMID: 37574471 PMCID: PMC10423725 DOI: 10.1038/s41392-023-01553-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/11/2023] [Accepted: 06/26/2023] [Indexed: 08/15/2023] Open
Abstract
As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.
Collapse
Affiliation(s)
- Jie Fu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Xin Zong
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Mingliang Jin
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Junxia Min
- The First Affiliated Hospital, Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Fudi Wang
- The Second Affiliated Hospital, School of Public Health, State Key Laboratory of Experimental Hematology, Zhejiang University School of Medicine, Hangzhou, China.
- The First Affiliated Hospital, Basic Medical Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, China.
| | - Yizhen Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China.
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China.
| |
Collapse
|
6
|
Dong X, Limjunyawong N, Sypek EI, Wang G, Ortines RV, Youn C, Alphonse MP, Dikeman D, Wang Y, Lay M, Kothari R, Vasavda C, Pundir P, Goff L, Miller LS, Lu W, Garza LA, Kim BS, Archer NK, Dong X. Keratinocyte-derived defensins activate neutrophil-specific receptors Mrgpra2a/b to prevent skin dysbiosis and bacterial infection. Immunity 2022; 55:1645-1662.e7. [PMID: 35882236 PMCID: PMC9474599 DOI: 10.1016/j.immuni.2022.06.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 04/19/2022] [Accepted: 06/24/2022] [Indexed: 11/20/2022]
Abstract
Healthy skin maintains a diverse microbiome and a potent immune system to fight off infections. Here, we discovered that the epithelial-cell-derived antimicrobial peptides defensins activated orphan G-protein-coupled receptors (GPCRs) Mrgpra2a/b on neutrophils. This signaling axis was required for effective neutrophil-mediated skin immunity and microbiome homeostasis. We generated mutant mouse lines lacking the entire Defensin (Def) gene cluster in keratinocytes or Mrgpra2a/b. Def and Mrgpra2 mutant animals both exhibited skin dysbiosis, with reduced microbial diversity and expansion of Staphylococcus species. Defensins and Mrgpra2 were critical for combating S. aureus infections and the formation of neutrophil abscesses, a hallmark of antibacterial immunity. Activation of Mrgpra2 by defensin triggered neutrophil release of IL-1β and CXCL2 which are vital for proper amplification and propagation of the antibacterial immune response. This study demonstrated the importance of epithelial-neutrophil signaling via the defensin-Mrgpra2 axis in maintaining healthy skin ecology and promoting antibacterial host defense.
Collapse
Affiliation(s)
- Xintong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nathachit Limjunyawong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Elizabeth I Sypek
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gaofeng Wang
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Roger V Ortines
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Christine Youn
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin P Alphonse
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dustin Dikeman
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yu Wang
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mark Lay
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ruchita Kothari
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chirag Vasavda
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Priyanka Pundir
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Loyal Goff
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lloyd S Miller
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Wuyuan Lu
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Luis A Garza
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Brian S Kim
- Kimberly and Eric J. Waldman Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Nathan K Archer
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
7
|
Kiyozumi D. The molecular mechanisms of mammalian sperm maturation regulated by NELL2-ROS1 lumicrine signaling. J Biochem 2022; 172:341-346. [PMID: 36071564 DOI: 10.1093/jb/mvac071] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
In terrestrial vertebrates, spermatozoa generated in the testis are transported through the reproductive tract toward outside the body. In addition to as the pathway of sperm transport, the male reproductive tract also functions as the site of post-testicular sperm maturation and the epididymis, which constitutes the majority of male reproductive tract, plays central roles in such a sperm maturation. Recent studies with gene-modified animals have been unveiling not only the molecular mechanisms of sperm maturation in the epididymis but the regulatory system by which the epididymis acquires and executes sperm maturing functions. In this review, the mechanisms of mammalian sperm maturation will be summarized, based on recent findings including the lumicrine regulation of sperm maturation.
Collapse
Affiliation(s)
- Daiji Kiyozumi
- Research Institute for Microbial Diseases, Osaka University, Japan.,Japan Science and Technology Agency (JST), Japan
| |
Collapse
|
8
|
Muchhala KH, Jacob JC, Kang M, Dewey WL, Akbarali HI. The Guts of the Opioid Crisis. Physiology (Bethesda) 2021; 36:315-323. [PMID: 34431418 PMCID: PMC8813205 DOI: 10.1152/physiol.00014.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/10/2021] [Accepted: 06/10/2021] [Indexed: 01/09/2023] Open
Abstract
Bidirectional interactions of the gut epithelium with commensal bacteria are critical for maintaining homeostasis within the gut. Chronic opioid exposure perturbs gut homeostasis through a multitude of neuro-immune-epithelial mechanisms, resulting in the development of analgesic tolerance, a major underpinning of the current opioid crisis. Differences in molecular mechanisms of opioid tolerance between the enteric and central pain pathways pose a significant challenge for managing chronic pain without untoward gastrointestinal effects.
Collapse
Affiliation(s)
- Karan H Muchhala
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Joanna C Jacob
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Minho Kang
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - William L Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| | - Hamid I Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
| |
Collapse
|
9
|
An Experimental Approach to Rigorously Assess Paneth Cell α-Defensin (Defa) mRNA Expression in C57BL/6 Mice. Sci Rep 2019; 9:13115. [PMID: 31511628 PMCID: PMC6739474 DOI: 10.1038/s41598-019-49471-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/24/2019] [Indexed: 12/17/2022] Open
Abstract
Abundant evidence from many laboratories supports the premise that α-defensin peptides secreted from Paneth cells are key mediators of host-microbe interactions in the small intestine that contribute to host defense and homeostasis. α-defensins are among the most highly expressed antimicrobial peptides at this mucosal surface in many mammals, including humans and mice; however, there is striking variation among species in the number and primary structure of α-defensin paralogs. Studies of these biomolecules in vivo are further complicated by striking variations between laboratory mouse strains. Herein, we report an experimental approach to determine with precision and specificity expression levels of α-defensin (Defa) mRNA in the small intestine of C57BL/6 mice through an optimized set of oligonucleotide primers for qRT-PCR assays and cloned cDNA plasmids corresponding to the Defa paralogs. This approach demonstrated marked differences in α-defensin expression in C57BL/6 mice with respect to proximal/distal anatomical location and developmental stage, which have not been described previously. These data underscore the importance of careful attention to method (primer choice, proximal vs. distal location, and developmental stage) in analysis of antimicrobial peptide expression and their impact.
Collapse
|
10
|
β-Defensins Coordinate In Vivo to Inhibit Bacterial Infections of the Trachea. Vaccines (Basel) 2018; 6:vaccines6030057. [PMID: 30154362 PMCID: PMC6161282 DOI: 10.3390/vaccines6030057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 08/21/2018] [Accepted: 08/25/2018] [Indexed: 12/20/2022] Open
Abstract
β-defensins are predicted to play an important role in innate immunity against bacterial infections in the airway. We previously observed that a type III-secretion product of Bordetella bronchiseptica inhibits the NF-κB-mediated induction of a β-defensin in airway epithelial cells in vitro. To confirm this in vivo and to examine the relative roles of other β-defensins in the airway, we infected wild-type C57BL/6 mice and mice with a deletion of the mBD-1 gene with B. bronchiseptica wild-type strain, RB50 and its mutant strain lacking the type III-secretion system, WD3. The bacteria were quantified in the trachea and the nasal tissue and mRNA levels of mouse β-defensin-3 (mBD-3) were assessed after 24 h. Infection with the wild-type bacterial strain resulted in lower mBD-3 mRNA levels in the trachea than in mice infected with the type III-deficient strain. Furthermore, we observed an increase in bacterial numbers of RB50 only in the tracheas of mBD-1-deficient mice. Neutrophils were also more abundant on the trachea in RB50 infected WT mice but not in the bronchiolar lavage fluid (BAL), compared with WD3 infected WT and mBD-1−/− mice, indicating that the coordination of β-defensin chemotactic effects may be confined to tracheal epithelial cells (TEC). RB50 decreased the ability of mice to mount an early specific antibody response, seven days after infection in both WT and mBD-1−/− mice but there were no differences in titers between RB50-infected WT and mBD-1−/− mice or between WD3-infected WT and mBD-1−/− mice, indicating mBD-1 was not involved in induction of the humoral immune response to the B. bronchiseptica. Challenge of primary mouse TEC in vitro with RB50 and WD3, along with IL-1β, further corroborated the in vivo studies. The results demonstrate that at least two β-defensins can coordinate early in an infection to limit the growth of bacteria in the trachea.
Collapse
|
11
|
|
12
|
Abstract
α, β, and θ defensins are effectors of the innate immune system with potent antibacterial, antiviral, and antifungal activity. Defensins have direct antiviral activity in cell culture, with varied mechanisms for individual viruses, although some common themes have emerged. In addition, defensins have potent immunomodulatory activity that can alter innate and adaptive immune responses to viral infection. In some cases, there is evidence for paradoxical escape from defensin neutralization or enhancement of viral infection. The direct and indirect activities of defensins have led to their development as therapeutics and vaccine components. The major area of investigation that continues to lag is the connection between the effects of defensins in cell culture models and viral pathogenesis in vivo. Model systems to study defensin biology, including more physiologic models designed to bridge this gap, are also discussed.
Collapse
Affiliation(s)
- Mayumi K Holly
- Department of Microbiology, University of Washington, Seattle, Washington 98195;
| | - Karina Diaz
- Department of Microbiology, University of Washington, Seattle, Washington 98195;
| | - Jason G Smith
- Department of Microbiology, University of Washington, Seattle, Washington 98195;
| |
Collapse
|
13
|
Sugi Y, Takahashi K, Kurihara K, Nakano K, Kobayakawa T, Nakata K, Tsuda M, Hanazawa S, Hosono A, Kaminogawa S. α-Defensin 5 gene expression is regulated by gut microbial metabolites. Biosci Biotechnol Biochem 2016; 81:242-248. [PMID: 27760493 DOI: 10.1080/09168451.2016.1246175] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
α-Defensin 5 is important to both maintenance of a gut microbiota and host immunity. While previous reports have shown that gut bacteria are able to upregulate α-defensin 5 through Toll-like receptor signaling, we demonstrate here that α-defensin 5 expression can also be regulated by microbial metabolites. Among these, lactate appeared to significantly suppress α-defensin 5 gene transcription. Actually, fractions of <3 kD compounds obtained from the ceca of SPF mice were suppressed α-defensin 5 gene transcription at specific concentrations. Our results also suggest that cecal content may include as yet unidentified factors that can enhance α-defensin 5 expression. Our data point to a novel function for the gut microbial metabolites in controlling the expression of antimicrobial peptides in the intestine.
Collapse
Affiliation(s)
- Yutaka Sugi
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Kyoko Takahashi
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan.,b Department of Applied Biological Science , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Kenta Kurihara
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Kou Nakano
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Tetsuro Kobayakawa
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Kazuaki Nakata
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan.,b Department of Applied Biological Science , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Masato Tsuda
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Shigemasa Hanazawa
- b Department of Applied Biological Science , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Akira Hosono
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| | - Shuichi Kaminogawa
- a Department of Food Biochemistry and Biotechnology , College of Bioresource Sciences, Nihon University , Fujisawa , Japan
| |
Collapse
|
14
|
Gounder AP, Myers ND, Treuting PM, Bromme BA, Wilson SS, Wiens ME, Lu W, Ouellette AJ, Spindler KR, Parks WC, Smith JG. Defensins Potentiate a Neutralizing Antibody Response to Enteric Viral Infection. PLoS Pathog 2016; 12:e1005474. [PMID: 26933888 PMCID: PMC4774934 DOI: 10.1371/journal.ppat.1005474] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 02/05/2016] [Indexed: 12/18/2022] Open
Abstract
α-defensins are abundant antimicrobial peptides with broad, potent antibacterial, antifungal, and antiviral activities in vitro. Although their contribution to host defense against bacteria in vivo has been demonstrated, comparable studies of their antiviral activity in vivo are lacking. Using a mouse model deficient in activated α-defensins in the small intestine, we show that Paneth cell α-defensins protect mice from oral infection by a pathogenic virus, mouse adenovirus 1 (MAdV-1). Survival differences between mouse genotypes are lost upon parenteral MAdV-1 infection, strongly implicating a role for intestinal defenses in attenuating pathogenesis. Although differences in α-defensin expression impact the composition of the ileal commensal bacterial population, depletion studies using broad-spectrum antibiotics revealed no effect of the microbiota on α-defensin-dependent viral pathogenesis. Moreover, despite the sensitivity of MAdV-1 infection to α-defensin neutralization in cell culture, we observed no barrier effect due to Paneth cell α-defensin activation on the kinetics and magnitude of MAdV-1 dissemination to the brain. Rather, a protective neutralizing antibody response was delayed in the absence of α-defensins. This effect was specific to oral viral infection, because antibody responses to parenteral or mucosal ovalbumin exposure were not affected by α-defensin deficiency. Thus, α-defensins play an important role as adjuvants in antiviral immunity in vivo that is distinct from their direct antiviral activity observed in cell culture.
Collapse
Affiliation(s)
- Anshu P. Gounder
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Nicolle D. Myers
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Piper M. Treuting
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Beth A. Bromme
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Sarah S. Wilson
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Mayim E. Wiens
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC Norris Cancer Center, Los Angeles, California, United States of America
| | - Katherine R. Spindler
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - William C. Parks
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Jason G. Smith
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| |
Collapse
|
15
|
Barson G, Griffiths E. SeqTools: visual tools for manual analysis of sequence alignments. BMC Res Notes 2016; 9:39. [PMID: 26801397 PMCID: PMC4724122 DOI: 10.1186/s13104-016-1847-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/08/2016] [Indexed: 11/23/2022] Open
Abstract
Background Manual annotation is essential to create high-quality reference alignments and annotation. Annotators need to be able to view sequence alignments in detail. The SeqTools package provides three tools for viewing different types of sequence alignment: Blixem is a many-to-one browser of pairwise alignments, displaying multiple match sequences aligned against a single reference sequence; Dotter provides a graphical dot-plot view of a single pairwise alignment; and Belvu is a multiple sequence alignment viewer, editor, and phylogenetic tool. These tools were originally part of the AceDB genome database system but have been completely rewritten to make them generally available as a standalone package of greatly improved function. Findings Blixem is used by annotators to give a detailed view of the evidence for particular gene models. Blixem displays the gene model positions and the match sequences aligned against the genomic reference sequence. Annotators use this for many reasons, including to check the quality of an alignment, to find missing/misaligned sequence and to identify splice sites and polyA sites and signals. Dotter is used to give a dot-plot representation of a particular pairwise alignment. This is used to identify sequence that is not represented (or is misrepresented) and to quickly compare annotated gene models with transcriptional and protein evidence that putatively supports them. Belvu is used to analyse conservation patterns in multiple sequence alignments and to perform a combination of manual and automatic processing of the alignment. High-quality reference alignments are essential if they are to be used as a starting point for further automatic alignment generation. Conclusions While there are many different alignment tools available, the SeqTools package provides unique functionality that annotators have found to be essential for analysing sequence alignments as part of the manual annotation process. Electronic supplementary material The online version of this article (doi:10.1186/s13104-016-1847-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Gemma Barson
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
| | - Ed Griffiths
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
| |
Collapse
|
16
|
Lee KH, Lim D, Chiu S, Greenhalgh D, Cho K. Genomic landscapes of endogenous retroviruses unveil intricate genetics of conventional and genetically-engineered laboratory mouse strains. Exp Mol Pathol 2016; 100:248-56. [PMID: 26779669 DOI: 10.1016/j.yexmp.2016.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/09/2016] [Indexed: 11/24/2022]
Abstract
Laboratory strains of mice, both conventional and genetically engineered, have been introduced as critical components of a broad range of studies investigating normal and disease biology. Currently, the genetic identity of laboratory mice is primarily confirmed by surveying polymorphisms in selected sets of "conventional" genes and/or microsatellites in the absence of a single completely sequenced mouse genome. First, we examined variations in the genomic landscapes of transposable repetitive elements, named the TREome, in conventional and genetically engineered mouse strains using murine leukemia virus-type endogenous retroviruses (MLV-ERVs) as a probe. A survey of the genomes from 56 conventional strains revealed strain-specific TREome landscapes, and certain families (e.g., C57BL) of strains were discernible with defined patterns. Interestingly, the TREome landscapes of C3H/HeJ (toll-like receptor-4 [TLR4] mutant) inbred mice were different from its control C3H/HeOuJ (TLR4 wild-type) strain. In addition, a CD14 knock-out strain had a distinct TREome landscape compared to its control/backcross C57BL/6J strain. Second, an examination of superantigen (SAg, a "TREome gene") coding sequences of mouse mammary tumor virus-type ERVs in the genomes of the 46 conventional strains revealed a high diversity, suggesting a potential role of SAgs in strain-specific immune phenotypes. The findings from this study indicate that unexplored and intricate genomic variations exist in laboratory mouse strains, both conventional and genetically engineered. The TREome-based high-resolution genetics surveillance system for laboratory mice would contribute to efficient study design with quality control and accurate data interpretation. This genetics system can be easily adapted to other species ranging from plants to humans.
Collapse
Affiliation(s)
- Kang-Hoon Lee
- Department of Surgery, University of California, Davis, and Shriners Hospitals for Children Northern California, Sacramento, CA 95817, United States
| | - Debora Lim
- Department of Surgery, University of California, Davis, and Shriners Hospitals for Children Northern California, Sacramento, CA 95817, United States
| | - Sophia Chiu
- Department of Surgery, University of California, Davis, and Shriners Hospitals for Children Northern California, Sacramento, CA 95817, United States
| | - David Greenhalgh
- Department of Surgery, University of California, Davis, and Shriners Hospitals for Children Northern California, Sacramento, CA 95817, United States
| | - Kiho Cho
- Department of Surgery, University of California, Davis, and Shriners Hospitals for Children Northern California, Sacramento, CA 95817, United States.
| |
Collapse
|
17
|
Dobeš J, Neuwirth A, Dobešová M, Vobořil M, Balounová J, Ballek O, Lebl J, Meloni A, Krohn K, Kluger N, Ranki A, Filipp D. Gastrointestinal Autoimmunity Associated With Loss of Central Tolerance to Enteric α-Defensins. Gastroenterology 2015; 149:139-50. [PMID: 25982289 DOI: 10.1053/j.gastro.2015.05.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is an autoimmune disorder characterized by chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency, but patients also develop intestinal disorders. APECED is an autosomal recessive disorder caused by mutations in the autoimmune regulator (AIRE, which regulates immune tolerance) that allow self-reactive T cells to enter the periphery. Enteric α-defensins are antimicrobial peptides secreted by Paneth cells. Patients with APECED frequently have gastrointestinal symptoms and seroreactivity against secretory granules of Paneth cells. We investigated whether enteric α-defensins are autoantigens in humans and mice with AIRE deficiency. METHODS We analyzed clinical data, along with serum and stool samples and available duodenal biopsies from 50 patients with APECED collected from multiple centers in Europe. Samples were assessed for expression of defensins and other molecules by quantitative reverse transcription polymerase chain reaction and flow cytometry; levels of antibodies and other proteins were measured by immunohistochemical and immunoblot analyses. Histologic analyses were performed on biopsy samples. We used Aire(-/-) mice as a model of APECED, and studied the effects of transferring immune cells from these mice to athymic mice. RESULTS Enteric defensins were detected in extraintestinal tissues of patients with APECED, especially in medullary thymic epithelial cells. Some patients with APECED lacked Paneth cells and were seropositive for defensin-specific autoantibodies; the presence of autoantibodies correlated with frequent diarrhea. Aire(-/-) mice developed defensin-specific T cells. Adoptive transfer of these T cells to athymic mice resulted in T-cell infiltration of the gut, loss of Paneth cells, microbial dysbiosis, and the induction of T-helper 17 cell-mediated autoimmune responses resembling those observed in patients with APECED. CONCLUSIONS In patients with APECED, loss of AIRE appears to cause an autoimmune response against enteric defensins and loss of Paneth cells. Aire(-/-) mice developed defensin-specific T cells that cause intestinal defects similar to those observed in patients with APECED. These findings provide a mechanism by which loss of AIRE-mediated immune tolerance leads to intestinal disorders in patients with APECED.
Collapse
Affiliation(s)
- Jan Dobeš
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic
| | - Aleš Neuwirth
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic
| | - Martina Dobešová
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic
| | - Matouš Vobořil
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic
| | - Jana Balounová
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic
| | - Ondřej Ballek
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic
| | - Jan Lebl
- Department of Pediatrics, 2(nd) Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | - Antonella Meloni
- Pediatric Clinic II, Ospedale Microcitemico and Department of Biomedical and Biotechnological Science, University of Cagliari, Cagliari, Italy
| | - Kai Krohn
- Clinical Research Institute HUCH, Helsinki, Finland; Department of Dermatology and Allergology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - Nicolas Kluger
- Department of Dermatology and Allergology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - Annamari Ranki
- Department of Dermatology and Allergology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - Dominik Filipp
- Laboratory of Immunobiology, Institute of Molecular Genetics of the AS CR, Prague, Czech Republic.
| |
Collapse
|
18
|
Dupont A, Kaconis Y, Yang I, Albers T, Woltemate S, Heinbockel L, Andersson M, Suerbaum S, Brandenburg K, Hornef MW. Intestinal mucus affinity and biological activity of an orally administered antibacterial and anti-inflammatory peptide. Gut 2015; 64:222-32. [PMID: 24811998 DOI: 10.1136/gutjnl-2014-307150] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Antimicrobial peptides (AMP) provide protection from infection by pathogenic microorganisms and restrict bacterial growth at epithelial surfaces to maintain mucosal homeostasis. In addition, they exert a significant anti-inflammatory activity. Here we analysed the anatomical distribution and biological activity of an orally administered AMP in the context of bacterial infection and host-microbial homeostasis. DESIGN The anatomical distribution as well as antibacterial and anti-inflammatory activity of the endogenous AMP cryptdin 2 and the synthetic peptide Pep19-2.5 at the enteric mucosal surface were analysed by immunostaining, functional viability and stimulation assays, an oral Salmonella enterica subsp. enterica sv. Typhimurium (S. Typhimurium) model and comparative microbiota analysis. RESULTS Endogenous cryptdin 2 was found attached to bacteria of the enteric microbiota within the intestinal mucus layer. Similarly, the synthetic peptide Pep19-2.5 attached rapidly to bacterial cells, exhibited a marked affinity for the intestinal mucus layer in vivo, altered the structural organisation of endotoxin in a mucus matrix and demonstrated potent anti-inflammatory and antibacterial activity. Oral Pep19-2.5 administration induced significant changes in the composition of the enteric microbiota as determined by high-throughput 16S rDNA sequencing. This may have contributed to the only transient improvement of the clinical symptoms after oral infection with S. Typhimurium. CONCLUSIONS Our findings demonstrate the anti-inflammatory activity and mucus affinity of the synthetic AMP Pep19-2.5 and characterise the influence on microbiota composition and enteropathogen infection after oral administration.
Collapse
Affiliation(s)
- Aline Dupont
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Yani Kaconis
- Division of Biophysics, Research Center Borstel, Borstel, Germany
| | - Ines Yang
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Thorben Albers
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Sabrina Woltemate
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Lena Heinbockel
- Division of Biophysics, Research Center Borstel, Borstel, Germany
| | - Mats Andersson
- Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden
| | - Sebastian Suerbaum
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | | | - Mathias W Hornef
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| |
Collapse
|
19
|
Fukuda M, Mizutani T, Mochizuki W, Matsumoto T, Nozaki K, Sakamaki Y, Ichinose S, Okada Y, Tanaka T, Watanabe M, Nakamura T. Small intestinal stem cell identity is maintained with functional Paneth cells in heterotopically grafted epithelium onto the colon. Genes Dev 2014; 28:1752-7. [PMID: 25128495 PMCID: PMC4197962 DOI: 10.1101/gad.245233.114] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
To develop stem cell therapy for small intestinal (SI) diseases, it is essential to determine whether SI stem cells in culture retain their tissue regeneration capabilities. By using a heterotopic transplantation approach, we show that cultured murine SI epithelial organoids are able to reconstitute self-renewing epithelia in the colon. When stably integrated, the SI-derived grafts show many features unique only to the SI but distinct from the colonic epithelium. Our study provides evidence that cultured adult SI stem cells could be a source for cell therapy of intestinal diseases, maintaining their identity along the gastrointestinal tract through an epithelium-intrinsic mechanism.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Yukinori Okada
- Department of Human Genetics and Disease Diversity, Bioresource Research Center
| | - Toshihiro Tanaka
- Department of Human Genetics and Disease Diversity, Bioresource Research Center
| | | | - Tetsuya Nakamura
- Department of Advanced Therapeutics for GI Diseases, Tokyo Medical and Dental University, 113-8519 Tokyo, Japan
| |
Collapse
|
20
|
Host defense peptides: front-line immunomodulators. Trends Immunol 2014; 35:443-50. [DOI: 10.1016/j.it.2014.07.004] [Citation(s) in RCA: 349] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 07/10/2014] [Accepted: 07/11/2014] [Indexed: 12/30/2022]
|
21
|
Host defense peptide resistance contributes to colonization and maximal intestinal pathology by Crohn's disease-associated adherent-invasive Escherichia coli. Infect Immun 2014; 82:3383-93. [PMID: 24866805 DOI: 10.1128/iai.01888-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Host defense peptides secreted by colonocytes and Paneth cells play a key role in innate host defenses in the gut. In Crohn's disease, the burden of tissue-associated Escherichia coli commonly increases at epithelial surfaces where host defense peptides concentrate, suggesting that this bacterial population might actively resist this mechanism of bacterial killing. Adherent-invasive E. coli (AIEC) is associated with Crohn's disease; however, the colonization determinants of AIEC in the inflamed gut are undefined. Here, we establish that host defense peptide resistance contributes to host colonization by Crohn's-associated AIEC. We identified a plasmid-encoded genomic island (called PI-6) in AIEC strain NRG857c that confers high-level resistance to α-helical cationic peptides and α- and β-defensins. Deletion of PI-6 sensitized strain NRG857c to these host defense molecules, reduced its competitive fitness in a mouse model of infection, and attenuated its ability to induce cecal pathology. This phenotype is due to two genes in PI-6, arlA, which encodes a Mig-14 family protein implicated in defensin resistance, and arlC, an OmpT family outer membrane protease. Implicit in these findings are new bacterial targets whose inhibition might limit AIEC burden and disease in the gut.
Collapse
|
22
|
Stockinger S, Albers T, Duerr CU, Ménard S, Pütsep K, Andersson M, Hornef MW. Interleukin-13-mediated paneth cell degranulation and antimicrobial peptide release. J Innate Immun 2014; 6:530-41. [PMID: 24556597 DOI: 10.1159/000357644] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 11/30/2013] [Indexed: 12/18/2022] Open
Abstract
Paneth cell-derived enteric antimicrobial peptides significantly contribute to antibacterial host defense and host-microbial homeostasis. Regulation occurs by enzymatic processing and release into the small intestinal lumen, but the stimuli involved are incompletely understood. Here, the capacity of various microbial and immune stimuli to induce antimicrobial peptide release from small intestinal tissue was systematically evaluated using antibacterial activity testing, immunostaining for Paneth cell granules and mass spectrometry. We confirmed the stimulatory activity of the muscarinic receptor agonist carbachol and the nucleotide-binding oligomerization domain ligand muramyl dipeptide. In contrast, no release of antibacterial activity was noted after treatment with the Toll-like receptor ligands poly(I:C), lipopolysaccharide or CpG, and the cytokines interleukin (IL)-15, IL-22, IL-28 and interferon-γ. Rapid Paneth cell degranulation and antimicrobial activity release, however, was observed after stimulation with the endogenous mediators IL-4 and IL-13. This process required phosphatidylinositol 3-kinase and was associated with protein kinase B phosphorylation in Paneth cells. Flow cytometric analysis confirmed expression of the IL-13 receptor α1 on isolated Paneth cells. Our findings identify a novel role of IL-13 as inducer of Paneth cell degranulation and enteric antimicrobial peptide release. IL-13 may thus contribute to mucosal antimicrobial host defense and host microbial homeostasis.
Collapse
Affiliation(s)
- Silvia Stockinger
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Paneth cells are highly specialized epithelial cells of the small intestine, where they coordinate many physiological functions. First identified more than a century ago on the basis of their readily discernible secretory granules by routine histology, these cells are located at the base of the crypts of Lieberkühn, tiny invaginations that line the mucosal surface all along the small intestine. Investigations over the past several decades determined that these cells synthesize and secrete substantial quantities of antimicrobial peptides and proteins. More recent studies have determined that these antimicrobial molecules are key mediators of host-microbe interactions, including homeostatic balance with colonizing microbiota and innate immune protection from enteric pathogens. Perhaps more intriguing, Paneth cells secrete factors that help sustain and modulate the epithelial stem and progenitor cells that cohabitate in the crypts and rejuvenate the small intestinal epithelium. Dysfunction of Paneth cell biology contributes to the pathogenesis of chronic inflammatory bowel disease.
Collapse
Affiliation(s)
- Hans C Clevers
- Hubrecht Institute-KNAW, University Medical Center Utrecht, Uppsalalaan, Utrecht 3584CT, The Netherlands.
| | | |
Collapse
|
24
|
Zhu S, Gao B. Evolutionary origin of β-defensins. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 39:79-84. [PMID: 22369779 DOI: 10.1016/j.dci.2012.02.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Revised: 02/18/2012] [Accepted: 02/18/2012] [Indexed: 05/31/2023]
Abstract
β-Defensins are a group of vertebrate-specific antimicrobial peptides (AMPs) with microbicidal and immune regulatory functions. In spite of their conservation across the vertebrate lineage ranging from bony fish to human, the evolutionary origin of these molecules remains unsolved. We addressed this issue by comparing three-dimensional (3D) structure and genomic organization of β-defensins with those of big defensins, a family of invertebrate-derived β-defensin-related peptides with two distinct structural and functional domains. β-Defensins and the carboxyl-terminal domain of big defensins adopt a conserved β-sheet topology stabilized by three identical disulfide bridges. Genomic organization analysis revealed that the defensin domain of these two classes of molecules is encoded by a single exon with a positionally conserved phase-1 intron in its upstream. The genomic and 3D structural conservation provides convincing evidence for their evolutionary relationship, in which β-defensins emerged from an ancestral big defensin through exon shuffling or intronization of exonic sequences. The phylogenetic distribution of big defensins in Arthropoda, Mollusca and Cephalochordata suggests an early origin of the β-defensin domain, which can be traced to the common ancestor of bilateral metazoans.
Collapse
Affiliation(s)
- Shunyi Zhu
- Group of Animal Innate Immunity, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, 100101 Beijing, China.
| | | |
Collapse
|
25
|
Menendez A, Willing BP, Montero M, Wlodarska M, So CC, Bhinder G, Vallance BA, Finlay BB. Bacterial stimulation of the TLR-MyD88 pathway modulates the homeostatic expression of ileal Paneth cell α-defensins. J Innate Immun 2012; 5:39-49. [PMID: 22986642 DOI: 10.1159/000341630] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 07/06/2012] [Indexed: 12/15/2022] Open
Abstract
Paneth cell α-defensins are antimicrobial peptides involved in the control of the intestinal microbiota and immunological homeostasis. In mice, they are encoded by multiple, highly homologous genes (Defa). The transcriptional activity of ileal Defa genes was studied in response to pharmacological and genetic perturbations of the intestinal environment of C57BL/6 mice. Defa gene transcription was sensitive to oral antibiotic administration suggesting that commensal microbes regulate Defa expression. Ileal microbiota analysis showed that decreased transcription of Defa genes correlated with depletion of Lactobacillus. Defa expression was partially restored in vivo by lactobacillus administration to antibiotic-treated mice. Defa transcripts were less abundant in ex vivo, microbiota-free intestinal explants but recovered after explant exposure to UV-killed bacteria, Toll-like receptor (TLR)-2 or TLR4 agonists. Genetic deficiency of several TLRs or MyD88 led to dramatic drops in Defa transcription in vivo. These results show that Paneth cell Defa genes are regulated by commensal bacteria through TLR-MyD88 signaling and provide a further understanding of the dysregulation of intestinal homeostasis that occurs as a result of imbalances in the populations of commensal bacteria.
Collapse
Affiliation(s)
- A Menendez
- Michael Smith Laboratories, The University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Andersson ML, Karlsson-Sjöberg JMT, Pütsep KLA. CRS-peptides: unique defense peptides of mouse Paneth cells. Mucosal Immunol 2012; 5:367-76. [PMID: 22535181 DOI: 10.1038/mi.2012.22] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The intestine is the most densely colonized site in both mice and man. Recent data suggest that the intestinal flora is, in part, controlled by antimicrobial substances secreted by the intestinal epithelium. The defense system of the small intestine includes a protective mucus layer, a high turnover of epithelial cells, and a regulated secretion of effector molecules, notably antimicrobial peptides. Human and mouse small intestines share many similarities in their intestinal defense micro-organization, including the secretion of the well-known α-defensins. Mice, however, produce an additional unique antimicrobial peptide family, the CRS (cryptdin-related sequences)-peptides, not found in man. This review comprises a detailed presentation of the peptide-based defense of the gut, with specific emphasis on the CRS-peptide family. The first part presents the current knowledge of the CRS-peptide family's biochemical characteristics and nomenclature, and the second part is devoted to the possible role of this family in the homeostasis of the gut.
Collapse
Affiliation(s)
- M L Andersson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
| | | | | |
Collapse
|
27
|
Abstract
Defensins are small, multifunctional cationic peptides. They typically contain six conserved cysteines whose three intramolecular disulfides stabilize a largely β-sheet structure. This review of human α-defensins begins by describing their evolution, including their likely relationship to the Big Defensins of invertebrates, and their kinship to the β-defensin peptides of many if not all vertebrates, and the θ-defensins found in certain non-human primates. We provide a short history of the search for leukocyte-derived microbicidal molecules, emphasizing the roles played by luck (good), preconceived notions (mostly bad), and proper timing (essential). The antimicrobial, antiviral, antitoxic, and binding properties of human α-defensins are summarized. The structural features of α-defensins are described extensively and their functional contributions are assessed. The properties of HD6, an enigmatic Paneth cell α-defensin, are contrasted with those of the four myeloid α-defensins (HNP1-4) and of HD5, the other α-defensin of human Paneth cells. The review ends with a decalogue that may assist researchers or students interested in α-defensins and related aspects of neutrophil function.
Collapse
Affiliation(s)
- Robert I Lehrer
- Department of Medicine and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1688, USA.
| | | |
Collapse
|
28
|
Nikitina IG, Bukurova YA, Krasnov GS, Grineva EN, Karpov VL, Lisitsyn NA, Beresten SF. Structure and function of enteric α-defensins in norm and pathology. Mol Biol 2012. [DOI: 10.1134/s0026893311060094] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
29
|
Mastroianni JR, Costales JK, Zaksheske J, Selsted ME, Salzman NH, Ouellette AJ. Alternative luminal activation mechanisms for paneth cell α-defensins. J Biol Chem 2012; 287:11205-12. [PMID: 22334698 DOI: 10.1074/jbc.m111.333559] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Paneth cell α-defensins mediate host defense and homeostasis at the intestinal mucosal surface. In mice, matrix metalloproteinase-7 (MMP7) converts inactive pro-α-defensins (proCrps) to bactericidal forms by proteolysis at specific proregion cleavage sites. MMP7(-/-) mice lack mature α-defensins in Paneth cells, accumulating unprocessed precursors for secretion. To test for activation of secreted pro-α-defensins by host and microbial proteinases in the absence of MMP7, we characterized colonic luminal α-defensins. Protein extracts of complete (organ plus luminal contents) ileum, cecum, and colon of MMP7-null and wild-type mice were analyzed by sequential gel permeation chromatography/acid-urea polyacrylamide gel analyses. Mature α-defensins were identified by N-terminal sequencing and mass spectrometry and characterized in bactericidal assays. Abundance of specific bacterial groups was measured by qPCR using group specific 16 S rDNA primers. Intact, native α-defensins, N-terminally truncated α-defensins, and α-defensin variants with novel N termini due to alternative processing were identified in MMP7(-/-) cecum and colon, and proteinases of host and microbial origin catalyzed proCrp4 activation in vitro. Although Paneth cell α-defensin deficiency is associated with ileal microbiota alterations, the cecal and colonic microbiota of MMP7(-/-) and wild-type mice were not significantly different. Thus, despite the absence of MMP7, mature α-defensins are abundant in MMP7(-/-) cecum and colon due to luminal proteolytic activation by alternative host and microbial proteinases. MMP7(-/-) mice only lack processed α-defensins in the small intestine, and the model is not appropriate for studying effects of α-defensin deficiency in cecal or colonic infection or disease.
Collapse
Affiliation(s)
- Jennifer R Mastroianni
- Department of Pathology & Laboratory Medicine and the USC Norris Cancer Center Keck School of Medicine of The University of Southern California, Los Angeles, California 90089-9601, USA
| | | | | | | | | | | |
Collapse
|
30
|
Lisitsyn NA, Bukurova YA, Nikitina IG, Krasnov GS, Sykulev Y, Beresten SF. Enteric alpha defensins in norm and pathology. Ann Clin Microbiol Antimicrob 2012; 11:1. [PMID: 22236533 PMCID: PMC3268740 DOI: 10.1186/1476-0711-11-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 01/11/2012] [Indexed: 12/19/2022] Open
Abstract
Microbes living in the mammalian gut exist in constant contact with immunity system that prevents infection and maintains homeostasis. Enteric alpha defensins play an important role in regulation of bacterial colonization of the gut, as well as in activation of pro- and anti-inflammatory responses of the adaptive immune system cells in lamina propria. This review summarizes currently available data on functions of mammalian enteric alpha defensins in the immune defense and changes in their secretion in intestinal inflammatory diseases and cancer.
Collapse
Affiliation(s)
- Nikolai A Lisitsyn
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova St,, Moscow, Russian Federation.
| | | | | | | | | | | |
Collapse
|
31
|
Yamaguchi Y, Ouchi Y. Antimicrobial peptide defensin: identification of novel isoforms and the characterization of their physiological roles and their significance in the pathogenesis of diseases. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2012; 88:152-66. [PMID: 22498979 PMCID: PMC3406309 DOI: 10.2183/pjab.88.152] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 02/21/2012] [Indexed: 05/31/2023]
Abstract
Defensins comprise a family of cationic antimicrobial peptides containing a specific six-cysteine motif. Their contribution to the host defense against microbial invasion and the control of normal flora have been previously described. Some of the β-defensin isoforms are predominantly expressed in the epididymis and showed a region-specific expression pattern in the epididymis, which thus suggested that these isoforms may possess epididymis-specific functions in addition to antimicrobial activities. A sequence variant of the β-defensin 126 gene has been shown to be associated with reductions in the human sperm function, thus supporting this hypothesis. Furthermore, defensins have the capacity to chemoattract immune cells and induce the secretion of inflammatory cytokines. Mice expressing human neutrophil α-defensin showed more severe lung injuries after the aspiration of acidic contents than did control mice. Recent investigations regarding copy number variations of human defensin genes also suggest the significance of defensin in the pathogenesis or the worsening of chronic obstructive pulmonary diseases, sepsis and psoriasis.
Collapse
Affiliation(s)
- Yasuhiro Yamaguchi
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
| | | |
Collapse
|
32
|
Bruhn O, Grötzinger J, Cascorbi I, Jung S. Antimicrobial peptides and proteins of the horse--insights into a well-armed organism. Vet Res 2011; 42:98. [PMID: 21888650 PMCID: PMC3179947 DOI: 10.1186/1297-9716-42-98] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 09/02/2011] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial peptides play a pivotal role as key effectors of the innate immune system in plants and animals and act as endogenous antibiotics. The molecules exhibit an antimicrobial activity against bacteria, viruses, and eukaryotic pathogens with different specificities and potencies depending on the structure and amino-acid composition of the peptides. Several antimicrobial peptides were comprehensively investigated in the last three decades and some molecules with remarkable antimicrobial properties have reached the third phase of clinical studies. Next to the peptides themselves, numerous organisms were examined and analyzed regarding their repertoire of antimicrobial peptides revealing a huge number of candidates with potencies and properties for future medical applications. One of these organisms is the horse, which possesses numerous peptides that are interesting candidates for therapeutical applications in veterinary medicine. Here we summarize investigations and knowledge on equine antimicrobial peptides, point to interesting candidates, and discuss prospects for therapeutical applications.
Collapse
Affiliation(s)
- Oliver Bruhn
- Institute for Experimental and Clinical Pharmacology, Hospitalstraße 4, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany.
| | | | | | | |
Collapse
|
33
|
Ouellette AJ. Paneth cell α-defensins in enteric innate immunity. Cell Mol Life Sci 2011; 68:2215-29. [PMID: 21560070 PMCID: PMC4073591 DOI: 10.1007/s00018-011-0714-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 04/26/2011] [Accepted: 04/26/2011] [Indexed: 12/18/2022]
Abstract
Paneth cells at the base of small intestinal crypts of Lieberkühn secrete high levels of α-defensins in response to cholinergic and microbial stimuli. Paneth cell α-defensins are broad spectrum microbicides that function in the extracellular environment of the intestinal lumen, and they are responsible for the majority of secreted bactericidal peptide activity. Paneth cell α-defensins confer immunity to oral infection by Salmonella enterica serovar Typhimurium, and they are major determinants of the composition of the small intestinal microbiome. In addition to host defense molecules such as α-defensins, lysozyme, and Pla2g2a, Paneth cells also produce and release proinflammatory mediators as components of secretory granules. Disruption of Paneth cell homeostasis, with subsequent induction of endoplasmic reticulum stress, autophagy, or apoptosis, contributes to inflammation in diverse genetic and experimental mouse models.
Collapse
Affiliation(s)
- André Joseph Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC/Norris Cancer Center, Los Angeles, CA 90089-9601, USA.
| |
Collapse
|
34
|
Brosch M, Saunders GI, Frankish A, Collins MO, Yu L, Wright J, Verstraten R, Adams DJ, Harrow J, Choudhary JS, Hubbard T. Shotgun proteomics aids discovery of novel protein-coding genes, alternative splicing, and "resurrected" pseudogenes in the mouse genome. Genome Res 2011; 21:756-67. [PMID: 21460061 DOI: 10.1101/gr.114272.110] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recent advances in proteomic mass spectrometry (MS) offer the chance to marry high-throughput peptide sequencing to transcript models, allowing the validation, refinement, and identification of new protein-coding loci. We present a novel pipeline that integrates highly sensitive and statistically robust peptide spectrum matching with genome-wide protein-coding predictions to perform large-scale gene validation and discovery in the mouse genome for the first time. In searching an excess of 10 million spectra, we have been able to validate 32%, 17%, and 7% of all protein-coding genes, exons, and splice boundaries, respectively. Moreover, we present strong evidence for the identification of multiple alternatively spliced translations from 53 genes and have uncovered 10 entirely novel protein-coding genes, which are not covered in any mouse annotation data sources. One such novel protein-coding gene is a fusion protein that spans the Ins2 and Igf2 loci to produce a transcript encoding the insulin II and the insulin-like growth factor 2-derived peptides. We also report nine processed pseudogenes that have unique peptide hits, demonstrating, for the first time, that they are not just transcribed but are translated and are therefore resurrected into new coding loci. This work not only highlights an important utility for MS data in genome annotation but also provides unique insights into the gene structure and propagation in the mouse genome. All these data have been subsequently used to improve the publicly available mouse annotation available in both the Vega and Ensembl genome browsers (http://vega.sanger.ac.uk).
Collapse
Affiliation(s)
- Markus Brosch
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Maróti G, Kereszt A, Kondorosi E, Mergaert P. Natural roles of antimicrobial peptides in microbes, plants and animals. Res Microbiol 2011; 162:363-74. [PMID: 21320593 DOI: 10.1016/j.resmic.2011.02.005] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 01/20/2011] [Indexed: 12/18/2022]
Abstract
Antimicrobial peptides (AMPs) are ribosomally synthesized natural antibiotics that are crucial effectors of innate immune systems in all living organisms. AMPs are diverse peptides, differing in their amino acid composition and structure, that generally display rapid killing and broad-spectrum antimicrobial activities. Therefore, AMPs have high potential for therapeutic use in healthcare and agriculture. This review focuses on in vivo studies relating how organisms - bacteria, plants, insects and mammals - employ AMPs in their interactions with microbial competitors, pathogens and symbionts.
Collapse
Affiliation(s)
- Gergely Maróti
- Institute for Plant Genomics, Human Biotechnology and Bioenergy, Bay Zoltán Foundation for Applied Research, Derkovits fasor 2, Szeged 6726, Hungary.
| | | | | | | |
Collapse
|
36
|
Shanahan MT, Tanabe H, Ouellette AJ. Strain-specific polymorphisms in Paneth cell α-defensins of C57BL/6 mice and evidence of vestigial myeloid α-defensin pseudogenes. Infect Immun 2011; 79:459-73. [PMID: 21041494 PMCID: PMC3019906 DOI: 10.1128/iai.00996-10] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 10/12/2010] [Accepted: 10/17/2010] [Indexed: 12/18/2022] Open
Abstract
Paneth cells at the base of small intestinal crypts secrete microbicidal α-defensins, termed cryptdins (Crps) in mice, as mediators of innate immunity. Proteomic studies show that five abundant Paneth cell α-defensins in C57BL/6 mice are strain specific in that they have not been identified in other inbred strains of mice. Two C57BL/6-specific peptides are coded for by the Defcr20 and -21 genes evident in the NIH C57BL/6 genome but absent from the Celera mixed-strain assembly, which excludes C57BL/6 data and differs from the NIH build with respect to the organization of the α-defensin gene locus. Conversely, C57BL/6 mice lack the Crp1, -2, -4, and -6 peptides and their corresponding Defcr1, -2, -4, and -6 genes, which are common to several mouse strains, including those of the Celera assembly. In C57BL/6 mice, α-defensin gene diversification appears to have occurred by tandem duplication of a multigene cassette that was not found in the mixed-strain assembly. Both mouse genome assemblies contain conserved α-defensin pseudogenes that are closely related to functional myeloid α-defensin genes in the rat, suggesting that the neutrophil α-defensin defect in mice resulted from progressive gene loss. Given the role of α-defensins in shaping the composition of the enteric microflora, such polymorphisms may influence outcomes in mouse models of disease or infection.
Collapse
Affiliation(s)
- Michael T. Shanahan
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Hiroki Tanabe
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California
| |
Collapse
|
37
|
Abstract
PURPOSE OF REVIEW Recent evidence shows that disruption of Paneth cell homeostasis by induction of endoplasmic reticulum stress or autophagy, with consequent apoptosis, contributes to inflammation and morbidity in a variety of experimental mouse models. RECENT FINDINGS Recent advances show that proinflammatory mediators in Paneth cell dense core secretory granules mediate tumor necrosis factor-α-induced shock, that Paneth cell α-defensins modulate the composition of the small intestinal microflora, that development of crypt organoid culture systems provides a novel means for investigating the crypt microenvironment, and that varied genetic defects that disrupt Paneth cell homeostasis are emergent as risk factors in inflammatory bowel disease. SUMMARY This recent literature identifies Paneth cells as particularly sensitive targets of endoplasmic reticulum stress responses and implicates this unique small intestinal lineage in inflammatory bowel disease pathogenesis resulting from diverse heritable and environmental causes.
Collapse
Affiliation(s)
- André J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of The University of Southern California, Los Angeles, California 90089-9601, USA.
| |
Collapse
|