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Nagib M, Sayed AM, Korany AH, Abdelkader K, Shari FH, Mackay WG, Rateb ME. Human Defensins: Structure, Function, and Potential as Therapeutic Antimicrobial Agents with Highlights Against SARS CoV-2. Probiotics Antimicrob Proteins 2025; 17:1563-1583. [PMID: 39693007 PMCID: PMC12055905 DOI: 10.1007/s12602-024-10436-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2024] [Indexed: 12/19/2024]
Abstract
The human defensins are a group of cationic antimicrobial peptides that range in size from 2 to 5 kDa and share a common structural motif of six disulphide-linked cysteines. Several naturally occurring human α- and β-defensins have been identified over the past two decades. They have a wide variety of antimicrobial effects, and their potential to avoid the development of resistance to antimicrobial treatment makes them attractive as therapeutic agents. Human defensins have recently been the focus of medical and molecular biology studies due to their promising application in medicine and the pharmaceutical industry. This work aims to provide a comprehensive summary of the current developments of human defensins, including their identification, categorization, molecular features, expression, modes of action, and potential application in medical settings. Current obstacles and future opportunities for using human defensins are also covered. Furthermore, we shed light on the potential of this class as an antiviral agent, particularly against SARS CoV-2, by providing an in silico-based investigation of their plausible mechanisms of action.
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Affiliation(s)
- Maryam Nagib
- School of Computing Engineering and Physical Sciences, University of the West of Scotland, Paisley, Scotland, PA12BE, UK
| | - Ahmed M Sayed
- Department of Pharmacognosy, College of Pharmacy, Almaaqal University, Basrah, 61014, Iraq
| | - Ahmed H Korany
- Department of Microbiology and Immunology, Faculty of Pharmacy, Nahda University, Beni Suef, 62513, Egypt
| | - Karim Abdelkader
- Department of Microbiology and Immunology, Faculty of Pharmacy, Beni-Suef University, Beni Suef, 62511, Egypt
| | - Falah H Shari
- Department of Clinical Biochemistry, College of Pharmacy, Almaaqal University, Basrah, 61014, Iraq
| | - William G Mackay
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, Glasgow, G72 0LH, UK
| | - Mostafa E Rateb
- School of Computing Engineering and Physical Sciences, University of the West of Scotland, Paisley, Scotland, PA12BE, UK.
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Thangaiyan R, Sakwe AM, Hawkins AT, Washington MK, Ballard BR, Izban MG, Chirwa SS, Hildreth JEK, Shanker A, Blum DL, M'Koma AE. Functional characterization of novel anti-DEFA5 monoclonal antibody clones 1A8 and 4F5 in inflammatory bowel disease colitis tissues. Inflamm Res 2025; 74:30. [PMID: 39883179 PMCID: PMC11782311 DOI: 10.1007/s00011-024-01970-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2024] [Revised: 11/28/2024] [Accepted: 11/30/2024] [Indexed: 01/31/2025] Open
Abstract
BACKGROUND The aberrant expression of α defensin 5 (DEFA5) protein in colonic inflammatory bowel diseases (IBDs) underlies the distinct pathogenesis of Crohn's colitis (CC). It can serve as a biomarker for differentiating CC from Ulcerative colitis (UC), particularly in Indeterminate colitis (IC) cases into UC and CC. We evaluated the specificity of commercially available anti-DEFA5 antibodies, emphasizing the need to further validate their appropriateness for a given application and highlighting the necessity for novel antibodies. METHODS We established two mice monoclonal DEFA5 antibody clones, 1A8 and 4F5, by immunizing mice with purified recombinant protein. We validated the specificity, sensitivity, and cross-reactivity of these antibodies in recognizing both endogenous and recombinant DEFA5 protein, especially for use in Immunohistochemistry (IHC), Western blot (WB), Immunoprecipitation (IP), and enzyme-linked immunosorbent assay (ELISA). RESULTS Clones 1A8 and 4F5 effectively recognized the endogenous DEFA5 in active human colon tissue from patients with diverticulitis (DV), UC, CC, and IC disease samples, as well as in transiently transfected HEK293T cells expressing DEFA5 with minimal non-confounding cross reactivity. CONCLUSIONS The 1A8 and 4F5 clones are useful for a wide variety of immunoassays, including WB, IHC, IP/WB, and ELISA. Their specificity enhances their potential as valuable tools for research applications in IBD colitis.
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Affiliation(s)
- Rabi Thangaiyan
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, 1005 D.B. Todd Jr. Blvd, Nashville, TN, USA
| | - Amos M Sakwe
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, 1005 D.B. Todd Jr. Blvd, Nashville, TN, USA
| | - Alexander T Hawkins
- Section of Colon and Rectal Surgery, Division of General Surgery, School of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mary K Washington
- Department of Pathology, Microbiology, and Immunology, School of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Billy R Ballard
- Department of Pathology, Anatomy and Cell Biology, School of Medicine, Meharry Medical College, Nashville, TN, USA
| | - Michael G Izban
- Department of Pathology, Anatomy and Cell Biology, School of Medicine, Meharry Medical College, Nashville, TN, USA
| | - Sanika S Chirwa
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, 1005 D.B. Todd Jr. Blvd, Nashville, TN, USA
| | - James E K Hildreth
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN, USA
| | - Anil Shanker
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, 1005 D.B. Todd Jr. Blvd, Nashville, TN, USA
| | - David L Blum
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Amosy E M'Koma
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, 1005 D.B. Todd Jr. Blvd, Nashville, TN, USA.
- Section of Colon and Rectal Surgery, Division of General Surgery, School of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Pathology, Anatomy and Cell Biology, School of Medicine, Meharry Medical College, Nashville, TN, USA.
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Jandl B, Dighe S, Gasche C, Makristathis A, Muttenthaler M. Intestinal biofilms: pathophysiological relevance, host defense, and therapeutic opportunities. Clin Microbiol Rev 2024; 37:e0013323. [PMID: 38995034 PMCID: PMC11391705 DOI: 10.1128/cmr.00133-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
SUMMARYThe human intestinal tract harbors a profound variety of microorganisms that live in symbiosis with the host and each other. It is a complex and highly dynamic environment whose homeostasis directly relates to human health. Dysbiosis of the gut microbiota and polymicrobial biofilms have been associated with gastrointestinal diseases, including irritable bowel syndrome, inflammatory bowel diseases, and colorectal cancers. This review covers the molecular composition and organization of intestinal biofilms, mechanistic aspects of biofilm signaling networks for bacterial communication and behavior, and synergistic effects in polymicrobial biofilms. It further describes the clinical relevance and diseases associated with gut biofilms, the role of biofilms in antimicrobial resistance, and the intestinal host defense system and therapeutic strategies counteracting biofilms. Taken together, this review summarizes the latest knowledge and research on intestinal biofilms and their role in gut disorders and provides directions toward the development of biofilm-specific treatments.
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Affiliation(s)
- Bernhard Jandl
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Vienna, Austria
- Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna, Austria
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Satish Dighe
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Christoph Gasche
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Vienna, Vienna, Austria
- Loha for Life, Center for Gastroenterology and Iron Deficiency, Vienna, Austria
| | - Athanasios Makristathis
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Markus Muttenthaler
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Vienna, Austria
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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Gleeson PJ, Monteiro RC. The Role of Mucosal Immunity: What Can We Learn From Animal and Human Studies? Semin Nephrol 2024; 44:151566. [PMID: 40082160 DOI: 10.1016/j.semnephrol.2025.151566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2025]
Abstract
Immunoglobulin A (IgA) is a key actor in the mucosal immune system, which moderates interactions between the host and environmental factors such as food antigens and commensal microorganisms. The pathogenesis of IgA nephropathy (IgAN) involves a multistep process starting with deglycosylation of mucosally derived, polymeric IgA1 (dg-IgA1) that reaches the circulation. Modified O-glycans on dg-IgA1 are targeted by IgG-autoantibodies, leading to the formation of circulating immune complexes that deposit in the glomerular mesangium. Infections of mucosal surfaces trigger flares of primary IgAN, while inflammatory bowel disease and liver cirrhosis are important causes of secondary IgAN, supporting a mucosal source of nephritogenic IgA1. In the presence of microbial pathogens or food antigens, activated dendritic cells in the gut mucosa induce T-cell-dependent or T-cell-independent B-cell differentiation into IgA-secreting plasma cells. Herein we review the literature concerning mucosal immune function and how it is altered in this disease. We discuss recent evidence supporting a causal role of gut microbiota dysbiosis in IgAN pathogenesis.
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Affiliation(s)
- Patrick J Gleeson
- Paris Cité University, Center for Research on Inflammation, Paris, France; Inserm, UMR1149; CNRS EMR8252; Inflamex Laboratory of Excellence; Nephrology Department.
| | - Renato C Monteiro
- Paris Cité University, Center for Research on Inflammation, Paris, France; Inserm, UMR1149; CNRS EMR8252; Inflamex Laboratory of Excellence; Immunology laboratory of Bichat hospital, Paris, France
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Thangaiyan R, Sakwe AM, Hawkins AT, Washington MK, Ballard BR, Izban MG, Chirwa SS, Hildreth JEK, Shanker A, Blum DL, M'Koma AE. Anti-DEFA5 Monoclonal Antibody Clones 1A8 and 4F5 Immunoreactive Bioassay for Diagnosing Inflammatory Bowel Disease. RESEARCH SQUARE 2024:rs.3.rs-4843765. [PMID: 39257990 PMCID: PMC11384025 DOI: 10.21203/rs.3.rs-4843765/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Background Robust evidence suggests that the aberrant expression of α defensin 5 protein (DEFA5) in colon inflammatory bowel diseases (IBDs) underlies the distinct pathogenesis of Crohn's colitis, can be exploited as a reliable diagnostic biomarker to differential diagnosis of Crohn's colitis (CC) from Ulcerative colitis (UC) in otherwise indeterminate colitis (IC). We evaluated the specificity of the commercially available anti-DEFA5 antibodies and showed further validation of their appropriateness for a given application is required. Methods We established two mouse monoclonal DEFA5 antibody clones 1A8 and 4F5 by immunizing the mice with purified recombinant protein and validated the specificity, selectivity and cross reactivity in recognizing the endogenous and recombinant DEFA5 protein, especially for Immunohistochemistry, Western blot, Immunoprecipitation, or enzyme-linked immunosorbent assay. Results Clones 1A8 and 4F5 recognized effectively the endogenous DEFA5 in active human diverticulitis (DV), UC, CC or IC disease samples, including transiently transfected HEK293T cells expressing DEFA5 with high degree of specificity and minimal non-confounding cross reactivity. Conclusions 1A8 and 4F5 clones are worth studying in larger IBD cohorts to fully address whether DEFA5 expression may be used as a diagnostic biomarker to discrimination of the diagnosis of UC from CC or IC into authentic CC or UC or a colitis with different pathological characteristics.
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Ra YE, Bang YJ. Balancing Act of the Intestinal Antimicrobial Proteins on Gut Microbiota and Health. J Microbiol 2024; 62:167-179. [PMID: 38630349 DOI: 10.1007/s12275-024-00122-3] [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: 12/18/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 05/15/2024]
Abstract
The human gut houses a diverse and dynamic microbiome critical for digestion, metabolism, and immune development, exerting profound effects on human health. However, these microorganisms pose a potential threat by breaching the gut barrier, entering host tissues, and triggering infections, uncontrolled inflammation, and even sepsis. The intestinal epithelial cells form the primary defense, acting as a frontline barrier against microbial invasion. Antimicrobial proteins (AMPs), produced by these cells, serve as innate immune effectors that regulate the gut microbiome by directly killing or inhibiting microbes. Abnormal AMP production, whether insufficient or excessive, can disturb the microbiome equilibrium, contributing to various intestinal diseases. This review delves into the complex interactions between AMPs and the gut microbiota and sheds light on the role of AMPs in governing host-microbiota interactions. We discuss the function and mechanisms of action of AMPs, their regulation by the gut microbiota, microbial evasion strategies, and the consequences of AMP dysregulation in disease. Understanding these complex interactions between AMPs and the gut microbiota is crucial for developing strategies to enhance immune responses and combat infections within the gut microbiota. Ongoing research continues to uncover novel aspects of this intricate relationship, deepening our understanding of the factors shaping gut health. This knowledge has the potential to revolutionize therapeutic interventions, offering enhanced treatments for a wide range of gut-related diseases.
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Affiliation(s)
- Ye Eun Ra
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Ye-Ji Bang
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
- Institute of Infectious Diseases, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
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Velázquez J, Rodríguez-Cornejo T, Rodríguez-Ramos T, Pérez-Rodríguez G, Rivera L, Campbell JH, Al-Hussinee L, Carpio Y, Estrada MP, Dixon B. New Evidence for the Role of Pituitary Adenylate Cyclase-Activating Polypeptide as an Antimicrobial Peptide in Teleost Fish. Antibiotics (Basel) 2023; 12:1484. [PMID: 37887185 PMCID: PMC10604671 DOI: 10.3390/antibiotics12101484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/28/2023] Open
Abstract
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is a multifunctional neuropeptide that is widely distributed and conserved across species. We have previously shown that in teleost fish, PACAP not only possesses direct antimicrobial properties but also immunomodulatory effects against the bacterial pathogens Flavobacterium psychrophilum and Pseudomonas aeruginosa using in vitro and in vivo experiments. These previous results suggest PACAP can be used as an alternative to antibiotics to prevent and/or treat bacterial infections in the aquaculture industry. To accomplish this goal, more studies are needed to better understand the effect of PACAP on pathogens affecting fish in live infections. In the present study, the transcripts PACAP, PRP/PACAP, and VPAC2 receptor were examined in rainbow trout (Oncorhynchus mykiss) naturally infected with Yersinia ruckeri, which exhibited an increase in their expression in the spleen when compared to healthy fish. Synthetic Clarias gariepinus PACAP-38 has direct antimicrobial activity on Y. ruckeri and inhibits up to 60% of the bacterial growth when the peptide is at concentrations between 50 and 100 µM in TSB. The growth inhibition increased up to 90% in the presence of 12.5 µM of PACAP-38 when salt-free LB broth was used instead of TSB. It was also found to inhibit Y. ruckeri growth in a dose-dependent manner when the rainbow trout monocyte/macrophage-like cell line (RTS11) was pre-treated with lower concentrations of the peptide (0.02 and 0.1 µM) before going through infection. Differential gene expression was analyzed in this in vitro model. Overall, the results revealed new evidence to support the role of PACAP as an antimicrobial and immunomodulatory peptide treatment in teleosts.
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Affiliation(s)
- Janet Velázquez
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Tania Rodríguez-Cornejo
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Geysi Pérez-Rodríguez
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Laura Rivera
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - James Hugh Campbell
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Lowia Al-Hussinee
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Yamila Carpio
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Mario Pablo Estrada
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
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8
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Xie K, Su G, Chen D, Yu B, Huang Z, Yu J, Zheng P, Luo Y, Yan H, Li H, He J. The immunomodulatory function of the porcine β-defensin 129: Alleviate inflammatory response induced by LPS in IPEC-J2 cells. Int J Biol Macromol 2021; 188:473-481. [PMID: 34352320 DOI: 10.1016/j.ijbiomac.2021.07.194] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 12/24/2022]
Abstract
β-defensin family plays a critical role in host defense against infections. In this study, we found that pBD129 are widely expressed in porcine tissues such as the intestine, liver, and spleen. Interestingly, the expression level of pBD129 in most tissues was higher in Tibetan pigs than in DLY (Duroc × Landrace × Yorkshire) pigs (P < 0.05), and was significantly upregulated upon E. coli K88 infection (P < 0.05). The pBD129 protein was successfully expressed in E. coli and the molecule weight was estimated by SDS-PAGE to be 37.2 kDa. Mass spectrometry verified the protein as a pBD129. The protein showed antibacterial activities against Streptococcus and E. coli DH5α with a minimal inhibitory concentration (MIC) of 32 μg/mL. Hemolytic and cytotoxicity assays indicated that pBD129 had no detrimental effect on cell viability. Importantly, pBD129 significantly reduced the apoptosis of porcine intestinal epithelial cells exposure to bacterial endotoxins, which was associated with down-regulation of inflammatory cytokines such as the IL-1β, IL-6 and TNFα (P < 0.05), and down-regulation of apoptosis-related genes such as the caspase-3, caspase-8, and caspase-9 (P < 0.05). These results suggested that pBD129 is a novel modulator of innate immunity involved in mammalian inflammatory responses.
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Affiliation(s)
- Kunhong Xie
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Guoqi Su
- ChongQing Academy of Animal Sciences, Chongqing 402460, China
| | - Daiwen Chen
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Zhiqing Huang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Jie Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Ping Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Yuheng Luo
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China.
| | - Hui Yan
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Hua Li
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China
| | - Jun He
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, Chengdu 611130, PR China.
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9
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Skeate JG, Segerink WH, Garcia MD, Fernandez DJ, Prins R, Lühen KP, Voss FO, Da Silva DM, Kast WM. Theta-Defensins Inhibit High-Risk Human Papillomavirus Infection Through Charge-Driven Capsid Clustering. Front Immunol 2020; 11:561843. [PMID: 33154746 PMCID: PMC7586039 DOI: 10.3389/fimmu.2020.561843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/24/2020] [Indexed: 11/26/2022] Open
Abstract
Persistent infection with high-risk human papillomavirus (hrHPV) genotypes results in a large number of anogenital and head and neck cancers worldwide. Although prophylactic vaccination coverage has improved, there remains a need to develop methods that inhibit viral transmission toward preventing the spread of HPV-driven disease. Defensins are a class of innate immune effector peptides that function to protect hosts from infection by pathogens such as viruses and bacteria. Previous work utilizing α and β defensins from humans has demonstrated that the α-defensin HD5 is effective at inhibiting the most common high-risk genotype, HPV16. A third class of defensin that has yet to be explored are θ-defensins: small, 18-amino acid cyclic peptides found in old-world monkeys whose unique structure makes them both highly cationic and resistant to degradation. Here we show that the prototype θ-defensin, rhesus theta defensin 1, inhibits hrHPV infection through a mechanism involving capsid clustering that inhibits virions from binding to cell surface receptor complexes.
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Affiliation(s)
- Joseph G Skeate
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Wouter H Segerink
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Mauricio D Garcia
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Daniel J Fernandez
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Ruben Prins
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Kim P Lühen
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, United States
| | - Féline O Voss
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Diane M Da Silva
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, United States.,Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - W Martin Kast
- Department of Molecular Microbiology & Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, United States.,Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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10
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11
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Watanabe K, Itoh K, Park SH, Kaku M, Ishii K, Sasano H, Naitoh T, Unno M, Fukushima K. Resistin-like molecule beta, a colonic epithelial protein, exhibits antimicrobial activity against Staphylococcus aureus including methicillin-resistant strains. Surg Today 2020; 50:920-930. [PMID: 32062787 DOI: 10.1007/s00595-020-01974-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/10/2020] [Indexed: 01/20/2023]
Abstract
PURPOSE Resistin-like molecule beta (RELMβ) is a small cysteine-rich protein secreted by colonic epithelial cells. RELMβ mRNA and protein expressions are dramatically induced by bacterial exposure in germ-free mice. We hypothesized that RELMβ has antimicrobial activity. METHODS The antimicrobial activity of RELMβ was screened by an agar spot test and confirmed by a liquid broth test. The amount of RELMβ in human stools was semi-quantified by Western blot analysis. The induction of RELMβ mRNA and protein expression by bacteria was measured by quantitative RT-PCR using LS174T cells. Electron microscopic immunohistochemistry was performed using polyclonal anti-RELMβ antibody. RESULTS RELMβ showed antimicrobial activity against S. aureus and all MRSAs examined in a dose- and pH-dependent fashion. Western blot study showed that the amount of RELMβ in healthy human stools was comparable to that exhibiting antimicrobial activity in vitro. Both RELMβ mRNA and protein expression were induced by heat-inactivated S. aureus, but not by E. coli in LS174T cells. Electron microscopic immunohistochemistry showed that RELMβ bound to the cell surface of S. aureus, followed by destruction of the bacterial cytoplasm. CONCLUSIONS RELMβ is a colonic antimicrobial protein and its antibacterial activity is species selective. Because RELMβ is abundant in healthy human stool, RELMβ may modulate gut flora.
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Affiliation(s)
- Kazuhiro Watanabe
- Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan.
| | - Kikuji Itoh
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Sang-Hee Park
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Clinical Research Center, Masan National Tuberculosis Hospital, Changwon, South Korea
| | - Mitsuo Kaku
- Department of Infection Control and Laboratory Diagnostics, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Keiko Ishii
- Department of Medical Microbiology, Mycology and Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hironobu Sasano
- Department of Pathology, Tohoku University Hospital, Sendai, Japan
| | - Takeshi Naitoh
- Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan
| | - Michiaki Unno
- Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan
| | - Kouhei Fukushima
- Laboratory of GI Tract Reconstruction, Tohoku University Graduate School of Biomedical Engineering, Sendai, Japan.,Department of Molecular and Surgical Pathophysiology, Tohoku University Graduate School of Medicine, Sendai, Japan
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12
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Umnyakova ES, Zharkova MS, Berlov MN, Shamova OV, Kokryakov VN. Human antimicrobial peptides in autoimmunity. Autoimmunity 2020; 53:137-147. [PMID: 31914804 DOI: 10.1080/08916934.2020.1711517] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Antimicrobial peptides (AMPs) were firstly discovered as cytotoxic substances that killed bacteria. Later they were described as biologically active peptides that are able not only to kill invaders but also to modulate host immunity. In particular, it is shown that human antimicrobial peptides are able to influence the activity of different innate and adaptive immunity components, thus, obviously, they also participate in autoimmune processes. In this review we discuss the nature of human AMPs and analyze their role in such autoimmune disorders like type 1 diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus, psoriasis, Crohn's disease and sarcoidosis. These peptides were shown to have a "double-sided" influence on the autoimmune disease pathogenesis. Thus, described facts should be taken into account for the development of new pharmaceutical agents to cure patients with autoimmune disorders. These agents could derive from natural antimicrobial peptides that in some cases modulate immune response. For example, it was shown that human AMPs are able to modulate complement system dysregulation of which is known to be one of the most dangerous pathogenic factors during autoimmune processes.
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Affiliation(s)
- Ekaterina S Umnyakova
- Department of General Pathology and Pathophysiology, Institute of Experimental Medicine, Saint Petersburg, Russia
| | - Maria S Zharkova
- Department of General Pathology and Pathophysiology, Institute of Experimental Medicine, Saint Petersburg, Russia
| | - Mikhail N Berlov
- Department of General Pathology and Pathophysiology, Institute of Experimental Medicine, Saint Petersburg, Russia
| | - Olga V Shamova
- Department of General Pathology and Pathophysiology, Institute of Experimental Medicine, Saint Petersburg, Russia
| | - Vladimir N Kokryakov
- Department of General Pathology and Pathophysiology, Institute of Experimental Medicine, Saint Petersburg, Russia.,Faculty of Biology, Department of Biochemistry, Saint Petersburg State University, Saint Petersburg, Russia
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13
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Srivastava M, Chandra A, Agarwal J, Rahul R, Nigam J, Parmar D, Satyam LK. Antibacterial spectrum of human omentum and differential expression of beta defensins. Indian J Gastroenterol 2019; 38:303-309. [PMID: 31643029 DOI: 10.1007/s12664-019-00981-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 07/23/2019] [Indexed: 02/04/2023]
Abstract
BACKGROUND Human β defensins (hBD1 and hBD2) are cationic, cysteine-rich peptides and form an integral part of the mammalian innate immune system. hBD1 is constitutively expressed in epithelial cells, whereas hBD2 increases in response to bacterial infection. Human omentum is known for its anti-inflammatory properties and also possesses an antibacterial activity of its own. We hypothesized that antimicrobial peptides, β defensins, may govern host defense mechanism in the microbe-rich environment of the peritoneal cavity. Therefore, we analyzed the expression of hBD1 and hBD2 in omentum tissue in vivo and also studied the antibacterial activity of omentum against common pathogens. METHODOLOGY Omentum tissues were obtained from 30 patients (15 cases and 15 controls). Real-time polymerase chain reaction (PCR) was used to evaluate the mRNA expression of hBD1 and hBD2. Protein quantification was done using Western blotting technique. Antibacterial susceptibility was performed to check the antibacterial activity of omentum. RESULT Significantly higher expression of hBD2 was observed in cases compared to controls at both the transcriptional and translational levels. In comparison with an array of antibiotics, activated omentum also showed antibacterial property even at lower concentration of its extract. CONCLUSION Omentum directly responds to bacterial infection, which may be due to differential expression of hBD1 and hBD2 in human omental tissue. These peptides (hBD1 and hBD2) may be an ideal candidate for novel antibiotic class with a broad-spectrum activity.
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Affiliation(s)
- Meenu Srivastava
- Department of Surgical Gastroenterology, King George's Medical University, Lucknow, 226 003, India
| | - Abhijit Chandra
- Department of Surgical Gastroenterology, King George's Medical University, Lucknow, 226 003, India.
| | - Jyotsna Agarwal
- Department of Microbiology, King George's Medical University, Lucknow, 226 003, India
| | - Rahul Rahul
- Department of Surgical Gastroenterology, King George's Medical University, Lucknow, 226 003, India
| | - Jaya Nigam
- Department of Surgical Gastroenterology, King George's Medical University, Lucknow, 226 003, India
| | - Devendra Parmar
- Developmental Toxicology Division, Indian Institute of Toxicology Research, Lucknow, 226 001, India
| | - Leena Khare Satyam
- Cell and Molecular Biology Department, Aurigene Discovery Technologies Limited, Bangalore, 560 100, India
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14
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Chung LK, Raffatellu M. G.I. pros: Antimicrobial defense in the gastrointestinal tract. Semin Cell Dev Biol 2019; 88:129-137. [PMID: 29432952 PMCID: PMC6087682 DOI: 10.1016/j.semcdb.2018.02.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/06/2018] [Accepted: 02/06/2018] [Indexed: 01/11/2023]
Abstract
The gastrointestinal tract is a complex environment in which the host immune system interacts with a diverse array of microorganisms, both symbiotic and pathogenic. As such, mobilizing a rapid and appropriate antimicrobial response depending on the nature of each stimulus is crucial for maintaining the balance between homeostasis and inflammation in the gut. Here we focus on the mechanisms by which intestinal antimicrobial peptides regulate microbial communities during dysbiosis and infection. We also discuss classes of bacterial peptides that contribute to reducing enteric pathogen outgrowth. This review aims to provide a comprehensive overview on the interplay of diverse antimicrobial responses with enteric pathogens and the gut microbiota.
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Affiliation(s)
- Lawton K Chung
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California, San Diego, La Jolla, CA, 92093-0704, United States
| | - Manuela Raffatellu
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California, San Diego, La Jolla, CA, 92093-0704, United States; Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccines (CU-UCSD cMAV), La Jolla CA, United States.
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15
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Colonic epithelial cell diversity in health and inflammatory bowel disease. Nature 2019; 567:49-55. [PMID: 30814735 DOI: 10.1038/s41586-019-0992-y] [Citation(s) in RCA: 536] [Impact Index Per Article: 89.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 01/28/2019] [Indexed: 02/07/2023]
Abstract
The colonic epithelium facilitates host-microorganism interactions to control mucosal immunity, coordinate nutrient recycling and form a mucus barrier. Breakdown of the epithelial barrier underpins inflammatory bowel disease (IBD). However, the specific contributions of each epithelial-cell subtype to this process are unknown. Here we profile single colonic epithelial cells from patients with IBD and unaffected controls. We identify previously unknown cellular subtypes, including gradients of progenitor cells, colonocytes and goblet cells within intestinal crypts. At the top of the crypts, we find a previously unknown absorptive cell, expressing the proton channel OTOP2 and the satiety peptide uroguanylin, that senses pH and is dysregulated in inflammation and cancer. In IBD, we observe a positional remodelling of goblet cells that coincides with downregulation of WFDC2-an antiprotease molecule that we find to be expressed by goblet cells and that inhibits bacterial growth. In vivo, WFDC2 preserves the integrity of tight junctions between epithelial cells and prevents invasion by commensal bacteria and mucosal inflammation. We delineate markers and transcriptional states, identify a colonic epithelial cell and uncover fundamental determinants of barrier breakdown in IBD.
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16
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Paneth cell α-defensins HD-5 and HD-6 display differential degradation into active antimicrobial fragments. Proc Natl Acad Sci U S A 2019; 116:3746-3751. [PMID: 30808760 PMCID: PMC6397583 DOI: 10.1073/pnas.1817376116] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Paneth cells provide intestinal host defense against pathogens and control the healthy microbiota by secreting antimicrobial peptides. We show that the most abundant secreted Paneth cell products, human defensin HD-5 and HD-6, show a distinct susceptibility to proteolytic digestion by human duodenal fluid. While HD-5 is digested in many fragments, HD-6 is stable and still able to form nanonets. The occurring fragments of HD-5 were antimicrobially active against microorganisms. We provide proof of concept about microbiome modulating capacities in vivo, which includes an increase of Akkermansia sp. Our results indicate that fragmentation of defensins increases antimicrobial diversity and further adds to the complexity of host microbial interaction at interfaces. Fragmentation could lead to new antimicrobial peptides with possible therapeutic usage. Antimicrobial peptides, in particular α-defensins expressed by Paneth cells, control microbiota composition and play a key role in intestinal barrier function and homeostasis. Dynamic conditions in the local microenvironment, such as pH and redox potential, significantly affect the antimicrobial spectrum. In contrast to oxidized peptides, some reduced defensins exhibit increased vulnerability to proteolytic degradation. In this report, we investigated the susceptibility of Paneth-cell–specific human α-defensin 5 (HD-5) and -6 (HD-6) to intestinal proteases using natural human duodenal fluid. We systematically assessed proteolytic degradation using liquid chromatography–mass spectrometry and identified several active defensin fragments capable of impacting bacterial growth of both commensal and pathogenic origins. Of note, incubation of mucus with HD-5 resulted in 255–8,000 new antimicrobial combinations. In contrast, HD-6 remained stable with consistent preserved nanonet formation. In vivo studies demonstrated proof of concept that a HD-5 fragment shifted microbiota composition (e.g., increases of Akkermansia sp.) without decreasing diversity. Our data support the concept that secretion of host peptides results in an environmentally dependent increase of antimicrobial defense by clustering in active peptide fragments. This complex clustering mechanism dramatically increases the host’s ability to control pathogens and commensals. These findings broaden our understanding of host modulation of the microbiome as well as the complexity of human mucosal defense mechanisms, thus providing promising avenues to explore for drug development.
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17
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Shen B. Pathogenesis of Pouchitis. POUCHITIS AND ILEAL POUCH DISORDERS 2019:129-146. [DOI: 10.1016/b978-0-12-809402-0.00011-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2025]
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18
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Lei R, Hou J, Chen Q, Yuan W, Cheng B, Sun Y, Jin Y, Ge L, Ben-Sasson SA, Chen J, Wang H, Lu W, Fang X. Self-Assembling Myristoylated Human α-Defensin 5 as a Next-Generation Nanobiotics Potentiates Therapeutic Efficacy in Bacterial Infection. ACS NANO 2018; 12:5284-5296. [PMID: 29856606 DOI: 10.1021/acsnano.7b09109] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The increasing prevalence of antibacterial resistance globally underscores the urgent need to the update of antibiotics. Here, we describe a strategy for inducing the self-assembly of a host-defense antimicrobial peptide (AMP) into nanoparticle antibiotics (termed nanobiotics) with significantly improved pharmacological properties. Our strategy involves the myristoylation of human α-defensin 5 (HD5) as a therapeutic target and subsequent self-assembly in aqueous media in the absence of exogenous excipients. Compared with its parent HD5, the C-terminally myristoylated HD5 (HD5-myr)-assembled nanobiotic exhibited significantly enhanced broad-spectrum bactericidal activity in vitro. Mechanistically, it selectively killed Escherichia coli ( E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) through disruption of the cell wall and/or membrane structure. The in vivo results further demonstrated that the HD5-myr nanobiotic protected against skin infection by MRSA and rescued mice from E. coli-induced sepsis by lowering the systemic bacterial burden and alleviating organ damage. The self-assembled HD5-myr nanobiotic also showed negligible hemolytic activity and substantially low toxicity in animals. Our findings validate this design rationale as a simple yet versatile strategy for generating AMP-derived nanobiotics with excellent in vivo tolerability. This advancement will likely have a broad impact on antibiotic discovery and development efforts aimed at combating antibacterial resistance.
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Affiliation(s)
- Ruyi Lei
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Jinchao Hou
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Qixing Chen
- The Children's Hospital, School of Medicine , Zhejiang University , Hangzhou 310052 , China
| | - Weirong Yuan
- Institute of Human Virology and Department of Biochemistry and Molecular Biology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - Baoli Cheng
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Yaqi Sun
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Yue Jin
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Lujie Ge
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Shmuel A Ben-Sasson
- Department of Developmental Biology, Institute for Medical Research Israel-Canada , The Hebrew University-Hadassah Medical School , Jerusalem 91120 , Israel
| | - Jiong Chen
- Laboratory of Biochemistry and Molecular Biology , Ningbo University , Ningbo 315211 , China
| | - Hangxiang Wang
- Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology , University of Maryland School of Medicine , Baltimore , Maryland 21201 , United States
| | - Xiangming Fang
- Department of Anesthesiology and Intensive Care, The First Affiliated Hospital, School of Medicine , Zhejiang University , Hangzhou 310003 , China
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19
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Mishra AA, Koh AY. Adaptation of Candida albicans during gastrointestinal tract colonization. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018; 5:165-172. [PMID: 30560045 DOI: 10.1007/s40588-018-0096-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose of Review Colonization of the gastrointestinal (GI) tract with Candida albicans (CA), the most common human fungal pathogen, is the first step towards the development of invasive infection. Yet the fungal virulence factors and host factors that modulate CA GI colonization are still poorly understood. In this review, we will review emerging evidence of the importance of select CA genetic determinants and CA's interaction with the host that contribute to its successful adaptation as a pathobiont in the human GI tract. Recent Findings Recent data reveal the importance of 1) CA genetic determinants; 2) host factors; and 3) environmental factors in modulating CA GI colonization in humans. Summary As evidence continues to grow supporting the notion that the GI tract and its resident microbiota are an integral part of the host immune system, it will be critical for studies to interrogate the interaction of CA with the host (including both the host innate and adaptive immune system as well as the endogenous gut microbiota) in order to dissect the mechanisms of CA pathogenesis and thus lay the foundation for novel therapeutic approaches to prevent and/or treat invasive fungal infections.
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Affiliation(s)
- Animesh A Mishra
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andrew Y Koh
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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20
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Cazorla SI, Maldonado-Galdeano C, Weill R, De Paula J, Perdigón GDV. Oral Administration of Probiotics Increases Paneth Cells and Intestinal Antimicrobial Activity. Front Microbiol 2018; 9:736. [PMID: 29713315 PMCID: PMC5911494 DOI: 10.3389/fmicb.2018.00736] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 03/28/2018] [Indexed: 12/12/2022] Open
Abstract
The huge amount of intestinal bacteria represents a continuing threat to the intestinal barrier. To meet this challenge, gut epithelial cells produce antimicrobial peptides (AMP) that act at the forefront of innate immunity. We explore whether this antimicrobial activity and Paneth cells, the main intestinal cell responsible of AMP production, are influenced by probiotics administration, to avoid the imbalance of intestinal microbiota and preserve intestinal barrier. Administration of Lactobacillus casei CRL 431 (Lc 431) and L. paracasei CNCM I-1518 (Lp 1518) to 42 days old mice, increases the number of Paneth cells on small intestine, and the antimicrobial activity against the pathogens Staphylococcus aureus and Salmonella Typhimurium in the intestinal fluids. Specifically, strong damage of the bacterial cell with leakage of cytoplasmic content, and cellular fragmentation were observed in S. Typhimurium and S. aureus. Even more important, probiotics increase the antimicrobial activity of the intestinal fluids at the different ages, from weaning (21 days old) to old age (180 days old). Intestinal antimicrobial activity stimulated by oral probiotics, do not influence significantly the composition of total anaerobic bacteria, lactobacilli and enterobacteria in the large intestine, at any age analyzed. This result, together with the antimicrobial activity observed against the same probiotic bacteria; endorse the regular consumption of probiotics without adverse effect on the intestinal homeostasis in healthy individuals. We demonstrate that oral probiotics increase intestinal antimicrobial activity and Paneth cells in order to strengthen epithelial barrier against pathogens. This effect would be another important mechanism by which probiotics protect the host mainly against infectious diseases.
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Affiliation(s)
- Silvia I Cazorla
- Laboratorio de Inmunología, Centro de Referencia para Lactobacilos (CERELA-CONICET), San Miguel de Tucumán, Argentina.,Cátedra de Inmunología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
| | - Carolina Maldonado-Galdeano
- Laboratorio de Inmunología, Centro de Referencia para Lactobacilos (CERELA-CONICET), San Miguel de Tucumán, Argentina.,Cátedra de Inmunología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
| | - Ricardo Weill
- Departamento de Investigación y Desarrollo, DANONE, Buenos Aires, Argentina
| | - Juan De Paula
- Servicio de Gastroenterología, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Gabriela D V Perdigón
- Laboratorio de Inmunología, Centro de Referencia para Lactobacilos (CERELA-CONICET), San Miguel de Tucumán, Argentina.,Cátedra de Inmunología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
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21
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Propheter DC, Chara AL, Harris TA, Ruhn KA, Hooper LV. Resistin-like molecule β is a bactericidal protein that promotes spatial segregation of the microbiota and the colonic epithelium. Proc Natl Acad Sci U S A 2017; 114:11027-11033. [PMID: 28973871 PMCID: PMC5651776 DOI: 10.1073/pnas.1711395114] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The mammalian intestine is colonized by trillions of bacteria that perform essential metabolic functions for their hosts. The mutualistic nature of this relationship depends on maintaining spatial segregation between these bacteria and the intestinal epithelial surface. This segregation is achieved in part by the presence of a dense mucus layer at the epithelial surface and by the production of antimicrobial proteins that are secreted by epithelial cells into the mucus layer. Here, we show that resistin-like molecule β (RELMβ) is a bactericidal protein that limits contact between Gram-negative bacteria and the colonic epithelial surface. Mouse and human RELMβ selectively killed Gram-negative bacteria by forming size-selective pores that permeabilized bacterial membranes. In mice lacking RELMβ, Proteobacteria were present in the inner mucus layer and invaded mucosal tissues. Another RELM family member, human resistin, was also bactericidal, suggesting that bactericidal activity is a conserved function of the RELM family. Our findings thus identify the RELM family as a unique family of bactericidal proteins and show that RELMβ promotes host-bacterial mutualism by regulating the spatial segregation between the microbiota and the intestinal epithelium.
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Affiliation(s)
- Daniel C Propheter
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Andrew L Chara
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Tamia A Harris
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Dermatology, The University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Kelly A Ruhn
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lora V Hooper
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX 75390;
- Howard Hughes Medical Institute, The University of Texas Southwestern Medical Center, Dallas, TX 75390
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22
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Shafee TMA, Lay FT, Phan TK, Anderson MA, Hulett MD. Convergent evolution of defensin sequence, structure and function. Cell Mol Life Sci 2017; 74:663-682. [PMID: 27557668 PMCID: PMC11107677 DOI: 10.1007/s00018-016-2344-5] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/27/2016] [Accepted: 08/15/2016] [Indexed: 02/06/2023]
Abstract
Defensins are a well-characterised group of small, disulphide-rich, cationic peptides that are produced by essentially all eukaryotes and are highly diverse in their sequences and structures. Most display broad range antimicrobial activity at low micromolar concentrations, whereas others have other diverse roles, including cell signalling (e.g. immune cell recruitment, self/non-self-recognition), ion channel perturbation, toxic functions, and enzyme inhibition. The defensins consist of two superfamilies, each derived from an independent evolutionary origin, which have subsequently undergone extensive divergent evolution in their sequence, structure and function. Referred to as the cis- and trans-defensin superfamilies, they are classified based on their secondary structure orientation, cysteine motifs and disulphide bond connectivities, tertiary structure similarities and precursor gene sequence. The utility of displaying loops on a stable, compact, disulphide-rich core has been exploited by evolution on multiple occasions. The defensin superfamilies represent a case where the ensuing convergent evolution of sequence, structure and function has been particularly extreme. Here, we discuss the extent, causes and significance of these convergent features, drawing examples from across the eukaryotes.
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Affiliation(s)
- Thomas M A Shafee
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Fung T Lay
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Thanh Kha Phan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Marilyn A Anderson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| | - Mark D Hulett
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
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23
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Chairatana P, Nolan EM. Defensins, lectins, mucins, and secretory immunoglobulin A: microbe-binding biomolecules that contribute to mucosal immunity in the human gut. Crit Rev Biochem Mol Biol 2017; 52:45-56. [PMID: 27841019 PMCID: PMC5233583 DOI: 10.1080/10409238.2016.1243654] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/19/2016] [Accepted: 09/28/2016] [Indexed: 02/08/2023]
Abstract
In the intestine, the mucosal immune system plays essential roles in maintaining homeostasis between the host and microorganisms, and protecting the host from pathogenic invaders. Epithelial cells produce and release a variety of biomolecules into the mucosa and lumen that contribute to immunity. In this review, we focus on a subset of these remarkable host-defense factors - enteric α-defensins, select lectins, mucins, and secretory immunoglobulin A - that have the capacity to bind microbes and thereby contribute to barrier function in the human gut. We provide an overview of the intestinal epithelium, describe specialized secretory cells named Paneth cells, and summarize our current understanding of the biophysical and functional properties of these select microbe-binding biomolecules. We intend for this compilation to complement prior reviews on intestinal host-defense factors, highlight recent advances in the field, and motivate investigations that further illuminate molecular mechanisms as well as the interplay between these molecules and microbes.
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Affiliation(s)
- Phoom Chairatana
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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24
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Chairatana P, Nolan EM. Defensins, lectins, mucins, and secretory immunoglobulin A: microbe-binding biomolecules that contribute to mucosal immunity in the human gut. Crit Rev Biochem Mol Biol 2016. [PMID: 27841019 DOI: 10,1080/10409238.2016.124365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the intestine, the mucosal immune system plays essential roles in maintaining homeostasis between the host and microorganisms, and protecting the host from pathogenic invaders. Epithelial cells produce and release a variety of biomolecules into the mucosa and lumen that contribute to immunity. In this review, we focus on a subset of these remarkable host-defense factors - enteric α-defensins, select lectins, mucins, and secretory immunoglobulin A - that have the capacity to bind microbes and thereby contribute to barrier function in the human gut. We provide an overview of the intestinal epithelium, describe specialized secretory cells named Paneth cells, and summarize our current understanding of the biophysical and functional properties of these select microbe-binding biomolecules. We intend for this compilation to complement prior reviews on intestinal host-defense factors, highlight recent advances in the field, and motivate investigations that further illuminate molecular mechanisms as well as the interplay between these molecules and microbes.
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Affiliation(s)
- Phoom Chairatana
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Elizabeth M Nolan
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA
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25
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Goto Y, Uematsu S, Kiyono H. Epithelial glycosylation in gut homeostasis and inflammation. Nat Immunol 2016; 17:1244-1251. [PMID: 27760104 DOI: 10.1038/ni.3587] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intestinal epithelial cells apically express glycans, especially α1,2-fucosyl linkages, which work as a biological interface for the host-microbe interaction. Emerging studies have shown that epithelial α1,2-fucosylation is regulated by microbes and by group 3 innate lymphoid cells (ILC3s). Dysregulation of the gene (FUT2) encoding fucosyltransferase 2, an enzyme governing epithelial α1,2-fucosylation, is associated with various human disorders, including infection and chronic inflammatory diseases. This suggests a critical role for an interaction between microbes, epithelial cells and ILC3s mediated via glycan residues. In this Review, using α1,2-fucose and Fut2 gene expression as an example, we describe how epithelial glycosylation is controlled by immune cells and luminal microbes. We also address the pathophysiological contribution of epithelial α1,2-fucosylation to pathogenic and commensal microbes as well as the potential of α1,2-fucose and its regulatory pathway as previously unexploited targets in the development of new therapeutic approaches for human diseases.
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Affiliation(s)
- Yoshiyuki Goto
- Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, Japan
- International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Satoshi Uematsu
- International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Department of Mucosal Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hiroshi Kiyono
- International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Department of Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Division of Mucosal Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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Murakami M, Kameda K, Tsumoto H, Tsuda T, Masuda K, Utsunomiya R, Mori H, Miura Y, Sayama K. TLN-58, an Additional hCAP18 Processing Form, Found in the Lesion Vesicle of Palmoplantar Pustulosis in the Skin. J Invest Dermatol 2016; 137:322-331. [PMID: 27771329 DOI: 10.1016/j.jid.2016.07.044] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 06/27/2016] [Accepted: 07/20/2016] [Indexed: 10/20/2022]
Abstract
We previously reported that the early vesicle of the palmoplantar pustulosis (PPP) vesicle originated from eccrine sweat in the acrosyringium and that the PPP vesicle contains the antimicrobial peptide human cathelicidin-18/LL-37. The concentration of LL-37 was sufficient to induce the subsequent inflammation in lesions and human keratinocytes, and the PPP vesicles contained additional small fragments of human cathelicidin-18, of approximately 7 kDa, which have not been identified. The aim of the present study was to clarify the additional processed forms found in PPP vesicles and their physiological effects on normal keratinocytes and sweat gland cells. Lesional PPP vesicles were collected from PPP patients, and endogenous human cathelicidin-18/LL-37 was depleted using a LL-37 antibody affinity column. A designed recombinant human cathelicidin-18 peptide was prepared and incubated with the depleted PPP vesicle fluid to confirm the additional processed form. In-gel digestion analysis and protein sequencing confirmed the additional form as TLN-58. TLN-58 up-regulated IL-17C, IL-8, IL-23, IL-1α, and IL-1β mRNA and protein expression in normal human keratinocytes and also showed antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and group A Streptococcus species, similar to LL-37. This additional form could be involved in the continued inflammation in PPP lesions.
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Affiliation(s)
- Masamoto Murakami
- Department of Dermatology, Ehime University Graduate School of Medicine, Ehime, Japan.
| | - Kenji Kameda
- Advanced Research Support Center, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Hiroki Tsumoto
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Teruko Tsuda
- Department of Dermatology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Kana Masuda
- Department of Dermatology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Ryo Utsunomiya
- Department of Dermatology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Hideki Mori
- Department of Dermatology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Yuri Miura
- Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Koji Sayama
- Department of Dermatology, Ehime University Graduate School of Medicine, Ehime, Japan
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27
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Defensins: The Case for Their Use against Mycobacterial Infections. J Immunol Res 2016; 2016:7515687. [PMID: 27725944 PMCID: PMC5048032 DOI: 10.1155/2016/7515687] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 08/30/2016] [Indexed: 12/20/2022] Open
Abstract
Human tuberculosis remains a huge global public health problem with an estimated 1/3rd of the population being infected. Defensins are antibacterial cationic peptides produced by a number of cell types, most notably neutrophil granulocytes and epithelial cells. All three defensin types (α-, β-, and θ-defensins) have antibacterial activities, mainly through bacterial membrane permeabilization. Defensins are effective against Gram-negative and Gram-positive bacteria including mycobacteria and are active both intra- and extracellularly. Mycobacterial resistance has never been demonstrated although the mprF gene encoding resistance in Staphylococcus aureus is present in the Mycobacterium tuberculosis genome. In addition to their antibacterial effect, defensins are chemoattractants for macrophages and neutrophils. There are many cases for their use for therapy or prophylaxis in tuberculosis as well. In conclusion, we propose that there is considerable scope and potential for exploring their use as therapeutic/prophylactic agents and more comprehensive survey of defensins from different species and their bioactivity is timely.
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Abstract
Amyloid formation has been most studied in the context of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, as well as in amyloidosis. However, it is becoming increasingly clear that amyloid is also present in the healthy setting; for example nontoxic amyloid formation is important for melanin synthesis and in innate immunity. Furthermore, bacteria have mechanisms to produce functional amyloid structures with important roles in bacterial physiology and interaction with host cells. Here, we will discuss some novel aspects of fibril-forming proteins in humans and bacteria. First, the amyloid-forming properties of the antimicrobial peptide human defensin 6 (HD6) will be considered. Intriguingly, unlike other antimicrobial peptides, HD6 does not kill bacteria. However, recent data show that HD6 can form amyloid structures at the gut mucosa with strong affinity for bacterial surfaces. These so-called nanonets block bacterial invasion by entangling the bacteria in net-like structures. Next, the role of functional amyloid fibrils in human semen will be discussed. These fibrils were discovered through their property to enhance HIV infection but they may also have other yet unknown functions. Finally, the role of amyloid formation in bacteria will be reviewed. The recent finding that bacteria can make amyloid in a controlled fashion without toxic effects is of particular interest and may have implications for human disease. The role of amyloid in health and disease is beginning to be unravelled, and here, we will review some of the most recent findings in this exciting area.
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Affiliation(s)
- P Bergman
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - N R Roan
- Department of Urology, University of California, San Francisco, CA, USA.,The J. David Gladstone Institutes, San Francisco, CA, USA
| | - U Römling
- Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - C L Bevins
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, CA, USA
| | - J Münch
- Institute of Molecular Virology, Ulm University Medical Centre, Ulm, Germany.,Ulm Peptide Pharmaceuticals, Ulm University, Ulm, Germany
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Teoh F, Pavelka N. How Chemotherapy Increases the Risk of Systemic Candidiasis in Cancer Patients: Current Paradigm and Future Directions. Pathogens 2016; 5:pathogens5010006. [PMID: 26784236 PMCID: PMC4810127 DOI: 10.3390/pathogens5010006] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 01/08/2016] [Accepted: 01/11/2016] [Indexed: 02/07/2023] Open
Abstract
Candida albicans is a fungal commensal and a major colonizer of the human skin, as well as of the gastrointestinal and genitourinary tracts. It is also one of the leading causes of opportunistic microbial infections in cancer patients, often presenting in a life-threatening, systemic form. Increased susceptibility to such infections in cancer patients is attributed primarily to chemotherapy-induced depression of innate immune cells and weakened epithelial barriers, which are the body’s first-line defenses against fungal infections. Moreover, classical chemotherapeutic agents also have a detrimental effect on components of the adaptive immune system, which further play important roles in the antifungal response. In this review, we discuss the current paradigm regarding the mechanisms behind the increased risk of systemic candidiasis in cancer patients. We also highlight some recent findings, which suggest that chemotherapy may have more extensive effects beyond the human host, in particular towards C. albicans itself and the bacterial microbiota. The extent to which these additional effects contribute towards the development of candidiasis in chemotherapy-treated patients remains to be investigated.
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Affiliation(s)
- Flora Teoh
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Singapore 138648, Singapore.
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - Norman Pavelka
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos Building, Singapore 138648, Singapore.
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
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Yacoub HA, El-Hamidy SM, Mahmoud MM, Baeshen MN, Almehdar HA, Uversky VN, Redwan EM, Al-Maghrabi OA, Elazzazy AM. Biocidal activity of chicken defensin-9 against microbial pathogens. Biochem Cell Biol 2015; 94:176-87. [PMID: 26914652 DOI: 10.1139/bcb-2015-0121] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In this study we identified the expression patterns of β-defensin-9 in chickens from Saudi Arabia, evaluated the antimicrobial activities of synthetic chicken β-defensin-9 (sAvBD-9) against pathogenic bacteria and fungi, and investigated the mode of action of sAvBD-9 on bacterial cells. The AvBD-9 gene of Saudi chickens encodes a polypeptide of 67 amino acids, which is highly similar to the polypeptide in duck, quail, and goose (97%, 86%, and 87%, respectively) and shares a low sequence similarity with the mammalian defensins. AvBD-9 is expressed in various organs and tissues of Saudi chickens and inhibits the growth of both Gram-negative and Gram-positive bacteria, as well as showing activity against unicellular and multicellular fungi (Aspergillus flavus, A. niger, and Candida albicans). sAvBD-9 completely inhibited the growth of both Gram-positive and Gram-negative bacterial strains as well as Candida albicans. The haemolytic effects of sAvBD-9 were limited. Morphological analysis by TEM revealed that sAvBD-9 induces shortening and swelling of Staphylococcus aureus and Shigella sonni cells, opens holes and deep craters in their envelopes, and leads to the release of their cytoplasmic content. Our data shed light on the potential applications of sAvBD-9 in the pharmaceutical industry.
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Affiliation(s)
- Haitham A Yacoub
- a Biological Sciences Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia.,b Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,c National Research Centre, Dokki, Gizza, P.O. Box 12622, Egypt
| | - Salem M El-Hamidy
- b Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Maged M Mahmoud
- d King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia.,i Department of Molecular Genetics and Enzymology, Devision of Human Genetocs and Genome Research, National Research Centre, Dokki, Gizza, P.O. Box 12622, Egypt
| | - Mohamed Nabih Baeshen
- a Biological Sciences Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia.,b Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hussein A Almehdar
- b Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Vladimir N Uversky
- b Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,e Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia.,g Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Elrashdy M Redwan
- b Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.,f Therapeutic and Protective Proteins Laboratory, Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City for Scientific Research and Technology Applications, New Borg EL-Arab 21934, Alexandria, Egypt
| | - Omar A Al-Maghrabi
- a Biological Sciences Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Ahmed M Elazzazy
- a Biological Sciences Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia.,h Department of Chemistry of Natural and Microbial Products, Division of Pharmaceutical and Drug Industries, National Research Centre, Dokki, Gizza, P.O. Box 12622, Egypt
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Mathew B, Nagaraj R. Antimicrobial activity of human α-defensin 6 analogs: insights into the physico-chemical reasons behind weak bactericidal activity of HD6 in vitro. J Pept Sci 2015; 21:811-8. [PMID: 26400692 DOI: 10.1002/psc.2821] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/29/2015] [Accepted: 08/19/2015] [Indexed: 01/07/2023]
Abstract
Human α-defensin 6 (HD6), unlike other mammalian defensins, does not exhibit bactericidal activity, particularly against aerobic bacteria. Monomeric HD6 has a tertiary structure similar to other α-defensins in the crystalline state. However, the physico-chemical reasons behind the lack of antibacterial activity of HD6 are yet to be established unequivocally. In this study, we have investigated the antimicrobial activity of HD6 analogs. A linear analog of HD6, in which the distribution of arginine residues was similar to active α-defensins, shows broad-spectrum antimicrobial activity, indicating that atypical distribution of arginine residues contributes to the inactivity of HD6. Peptides spanning the N-terminal cationic segment were active against a wide range of organisms. Antimicrobial potency of these shorter analogs was further enhanced when myristic acid was conjugated at the N-terminus. Cytoplasmic localization of the analogs without fatty acylation was observed to be necessary for bacterial killing, while they exhibited fungicidal activity by permeabilizing Candida albicans membranes. Myristoylated analogs and the linear full-length arginine analog exhibited activity by permeabilizing bacterial and fungal membranes. Our study provides insights into the lack of bactericidal activity of HD6 against aerobic bacteria.
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Affiliation(s)
- Basil Mathew
- CSIR - Centre for Cellular and Molecular Biology, Hyderabad, 500 007, India
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Mathew B, Nagaraj R. Antimicrobial activity of human α-defensin 5 and its linear analogs: N-terminal fatty acylation results in enhanced antimicrobial activity of the linear analogs. Peptides 2015. [PMID: 26206286 DOI: 10.1016/j.peptides.2015.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human α-defensin 5 (HD5) exhibits broad spectrum antimicrobial activity and plays an important role in mucosal immunity of the small intestine. Although there have been several studies, the structural requirements for activity and mechanism of bacterial killing is yet to be established unequivocally. In this study, we have investigated the antimicrobial activity of HD5 and linear analogs. Cysteine deletions attenuated the antibacterial activity considerably. Candidacidal activity was affected to a lesser extent. Fatty acid conjugated linear analogs showed antimicrobial activity comparable activity to HD5. Effective surface charge neutralization of bacteria was observed for HD5 as compared to the non-fatty acylated linear analogs. Our results show that HD5 and non-fatty acylated linear analogs enter the bacterial cytoplasm without causing damage to the bacterial inner membrane. Although fatty acylated peptides exhibited antimicrobial activity comparable to HD5, their mechanism of action involved permeabilization of the Escherichia coli inner membrane. HD5 and analogs had the ability to bind plasmid DNA. HD5 had greater binding affinity to plasmid DNA as compared to the analogs. The three dimensional structure of HD5 favors greater interaction with the bacterial cell surface and also with DNA. Antibacterial activity of HD5 involves entry into bacterial cytoplasm and binding to DNA which would result in shut down of the bacterial metabolism leading to cell death. We show how a moderately active linear peptide derived from the α-defensin HD5 can be engineered to enhance antimicrobial activity almost comparable to the native peptide.
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Affiliation(s)
- Basil Mathew
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Ramakrishnan Nagaraj
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
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33
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Peptides and Peptidomimetics for Antimicrobial Drug Design. Pharmaceuticals (Basel) 2015; 8:366-415. [PMID: 26184232 PMCID: PMC4588174 DOI: 10.3390/ph8030366] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/27/2015] [Accepted: 06/17/2015] [Indexed: 12/21/2022] Open
Abstract
The purpose of this paper is to introduce and highlight a few classes of traditional antimicrobial peptides with a focus on structure-activity relationship studies. After first dissecting the important physiochemical properties that influence the antimicrobial and toxic properties of antimicrobial peptides, the contributions of individual amino acids with respect to the peptides antibacterial properties are presented. A brief discussion of the mechanisms of action of different antimicrobials as well as the development of bacterial resistance towards antimicrobial peptides follows. Finally, current efforts on novel design strategies and peptidomimetics are introduced to illustrate the importance of antimicrobial peptide research in the development of future antibiotics.
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34
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Schroeder BO, Ehmann D, Precht JC, Castillo PA, Küchler R, Berger J, Schaller M, Stange EF, Wehkamp J. Paneth cell α-defensin 6 (HD-6) is an antimicrobial peptide. Mucosal Immunol 2015; 8:661-71. [PMID: 25354318 PMCID: PMC4424388 DOI: 10.1038/mi.2014.100] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 09/21/2014] [Indexed: 02/04/2023]
Abstract
Defensins protect human barriers from commensal and pathogenic microorganisms. Human α-defensin 6 (HD-6) is produced exclusively by small intestinal Paneth cells but, in contrast to other antimicrobial peptides (AMPs) for HD-6, no direct antibacterial killing activity has been detected so far. Herein, we systematically tested how environmental factors, like pH and reducing conditions, affect antimicrobial activity of different defensins against anaerobic bacteria of the human intestinal microbiota. Remarkably, by mimicking the intestinal milieu we detected for the first time antibacterial activity of HD-6. Activity was observed against anaerobic gut commensals but not against some pathogenic strains. Antibiotic activity was attributable to the reduced peptide and independent of free cysteines or a conserved histidine residue. Furthermore, the oxidoreductase thioredoxin, which is also expressed in Paneth cells, is able to reduce a truncated physiological variant of HD-6. Ultrastructural analyses revealed that reduced HD-6 causes disintegration of cytoplasmic structures and alterations in the bacterial cell envelope, while maintaining extracellular net-like structures. We conclude that HD-6 is an antimicrobial peptide. Our data suggest two distinct antimicrobial mechanisms by one peptide: HD-6 kills specific microbes depending on the local environmental conditions, whereas known microbial trapping by extracellular net structures is independent of the reducing milieu.
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Affiliation(s)
- B O Schroeder
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany,University of Tuebingen, Tuebingen, Germany,Department of Microbiology and Immunology, School of Medicine, University of California, Davis, California, USA
| | - D Ehmann
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany,University of Tuebingen, Tuebingen, Germany
| | - J C Precht
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany,University of Tuebingen, Tuebingen, Germany
| | - P A Castillo
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, California, USA
| | - R Küchler
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany,University of Tuebingen, Tuebingen, Germany
| | - J Berger
- Max-Planck-Institute for Developmental Biology, Electron Microscopy Unit, Tuebingen, Germany
| | - M Schaller
- Department of Dermatology, University Hospital Tuebingen, Tuebingen, Germany
| | - E F Stange
- Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany
| | - J Wehkamp
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany,University of Tuebingen, Tuebingen, Germany,Department of Internal Medicine I, Robert Bosch Hospital, Stuttgart, Germany,Department of Internal Medicine I, University Hospital Tuebingen, Tuebingen, Germany,()
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35
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Yacoub HA, Elazzazy AM, Abuzinadah OAH, Al-Hejin AM, Mahmoud MM, Harakeh SM. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi. Front Cell Infect Microbiol 2015; 5:36. [PMID: 25941665 PMCID: PMC4400880 DOI: 10.3389/fcimb.2015.00036] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 03/29/2015] [Indexed: 01/03/2023] Open
Abstract
Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic.
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Affiliation(s)
- Haitham A Yacoub
- Biological Sciences Department, Faculty of Sciences, King Abdulaziz University Jeddah, Saudi Arabia ; Genetic Engineering and Biotechnology Division, Cell Biology Department, National Research Centre Gizza, Egypt
| | - Ahmed M Elazzazy
- Biological Sciences Department, Faculty of Science, University of Jeddah Jeddah, Saudi Arabia ; Division of Pharmaceutical and Drug Industries, Department of Chemistry of Natural and Microbial Products, National Research Centre Gizza, Egypt
| | - Osama A H Abuzinadah
- Biological Sciences Department, Faculty of Sciences, King Abdulaziz University Jeddah, Saudi Arabia
| | - Ahmed M Al-Hejin
- Biological Sciences Department, Faculty of Sciences, King Abdulaziz University Jeddah, Saudi Arabia
| | - Maged M Mahmoud
- King Fahd Medical Research Center, King Abdulaziz University Jeddah, Saudi Arabia ; Division of Human Genetics and Genome Research, Department of Molecular Genetics and Enzymology, National Research Centre Gizza, Egypt
| | - Steve M Harakeh
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University Jeddah, Saudi Arabia
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Chileveru HR, Lim SA, Chairatana P, Wommack AJ, Chiang IL, Nolan EM. Visualizing attack of Escherichia coli by the antimicrobial peptide human defensin 5. Biochemistry 2015; 54:1767-77. [PMID: 25664683 DOI: 10.1021/bi501483q] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Human α-defensin 5 (HD5) is a 32-residue cysteine-rich host-defense peptide that exhibits broad-spectrum antimicrobial activity and contributes to innate immunity in the human gut and other organ systems. Despite many years of investigation, its antimicrobial mechanism of action remains unclear. In this work, we report that HD5ox, the oxidized form of this peptide that exhibits three regiospecific disulfide bonds, causes distinct morphological changes to Escherichia coli and other Gram-negative microbes. These morphologies include bleb formation, cellular elongation, and clumping. The blebs are up to ∼1 μm wide and typically form at the site of cell division or cell poles. Studies with E. coli expressing cytoplasmic GFP reveal that HD5ox treatment causes GFP emission to localize in the bleb. To probe the cellular uptake of HD5ox and subsequent localization, we describe the design and characterization of a fluorophore-HD5 conjugate family. By employing these peptides, we demonstrate that fluorophore-HD5ox conjugates harboring the rhodamine and coumarin fluorophores enter the E. coli cytoplasm. On the basis of the fluorescence profiles, each of these fluorophore-HD5ox conjugates localizes to the site of cell division and cell poles. These studies support the notion that HD5ox, at least in part, exerts its antibacterial activity against E. coli and other Gram-negative microbes in the cytoplasm.
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Affiliation(s)
- Haritha R Chileveru
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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Trend S, Strunk T, Hibbert J, Kok CH, Zhang G, Doherty DA, Richmond P, Burgner D, Simmer K, Davidson DJ, Currie AJ. Antimicrobial protein and Peptide concentrations and activity in human breast milk consumed by preterm infants at risk of late-onset neonatal sepsis. PLoS One 2015; 10:e0117038. [PMID: 25643281 PMCID: PMC4314069 DOI: 10.1371/journal.pone.0117038] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 12/17/2014] [Indexed: 12/13/2022] Open
Abstract
Objective We investigated the levels and antimicrobial activity of antimicrobial proteins and peptides (AMPs) in breast milk consumed by preterm infants, and whether deficiencies of these factors were associated with late-onset neonatal sepsis (LOS), a bacterial infection that frequently occurs in preterm infants in the neonatal period. Study design Breast milk from mothers of preterm infants (≤32 weeks gestation) was collected on days 7 (n = 88) and 21 (n = 77) postpartum. Concentrations of lactoferrin, LL-37, beta-defensins 1 and 2, and alpha-defensin 5 were measured by enzyme-linked immunosorbent assay. The antimicrobial activity of breast milk samples against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae was compared to the activity of infant formula, alone or supplemented with physiological levels of AMPs. Samples of breast milk fed to infants with and without subsequent LOS were compared for levels of AMPs and inhibition of bacterial growth. Results Levels of most AMPs and antibacterial activity in preterm breast milk were higher at day 7 than at day 21. Lactoferrin was the only AMP that limited pathogen growth >50% when added to formula at a concentration equivalent to that present in breast milk. Levels of AMPs were similar in the breast milk fed to infants with and without LOS, however, infants who developed LOS consumed significantly less breast milk and lower doses of milk AMPs than those who were free from LOS. Conclusions The concentrations of lactoferrin and defensins in preterm breast milk have antimicrobial activity against common neonatal pathogens.
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Affiliation(s)
- Stephanie Trend
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Tobias Strunk
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia
| | - Julie Hibbert
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Chooi Heen Kok
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia
| | - Guicheng Zhang
- School of Public Health, Curtin University, Perth, Australia
| | - Dorota A. Doherty
- School of Women’s and Infants’ Health, University of Western Australia, Perth, Australia
| | - Peter Richmond
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - David Burgner
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- University of Melbourne, Melbourne, Victoria, Australia
| | - Karen Simmer
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia
| | - Donald J. Davidson
- The University of Edinburgh/MRC Centre for Inflammation Research, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Andrew J. Currie
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
- * E-mail:
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Klatte JM, Newland JG, Jackson MA. Incidence, Classification, and Risk Stratification forCandidaCentral Line–Associated Bloodstream Infections in Pediatric Patients at a Tertiary Care Children's Hospital, 2000–2010. Infect Control Hosp Epidemiol 2015; 34:1266-71. [DOI: 10.1086/673988] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Objective.To identify risk factors for pediatricCandidacentral line-associated bloodstream infections (CLABSIs).Design.Retrospective case-control study.Setting.Freestanding tertiary care children's hospital.Patients.Patients withCandidaCLABSI from January 31, 2000, through December 31, 2010, compared with age- and year-matched controls.Methods.Demographics, comorbidities, presence of indwelling foreign bodies, exposure to antibiotics or corticosteroids, total parenteral nutrition (TPN) or blood transfusions, complications, and outcome were evaluated. Bivariate and then logistic regression were used to compare temporal trends and risk factors.Results.A total of 160CandidaCLABSI patients (median age, 1.96 years) were compared with 457 controls. Those withCandidaCLABSIs were more likely to have intestinal failure (adjusted odds ratio [aOR], 6.777 [95% confidence interval (CI), 2.315–19.839];P< .001), to have a gastrostomy tube in place (aOR, 4.156 [95% CI, 2.317–7.456];P< .001), and to receive TPN (aOR, 3.897 [95% CI, 2.403–6.319];P< .001) or blood transfusions (aOR, 2.990 [95% CI, 1.841–4.856];P< .001), and they had a 3-fold increase in mortality (aOR, 3.543 [95% CI, 1.501–8.364];P= .004).Candida albicanswas most common, butnon-albicansstrains resistant to amphotericin (C. lusitaniae) and fluconazole (C. glabrataandC. krusei) were also found.Conclusions.Those patients with intestinal failure, gastrostomy tube presence, and/or receipt of TPN and blood transfusions are at increased risk for development ofCandidaCLABSI.
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New role for human α-defensin 5 in the fight against hypervirulent Clostridium difficile strains. Infect Immun 2014; 83:986-95. [PMID: 25547793 DOI: 10.1128/iai.02955-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clostridium difficile infection (CDI), one of the most common hospital-acquired infections, is increasing in incidence and severity with the emergence and diffusion of hypervirulent strains. CDI is precipitated by antibiotic treatment that destroys the equilibrium of the gut microbiota. Human α-defensin 5 (HD5), the most abundant enteric antimicrobial peptide, is a key regulator of gut microbiota homeostasis, yet it is still unknown if C. difficile, which successfully evades killing by other host microbicidal peptides, is susceptible to HD5. We evaluated, by means of viability assay, fluorescence-activated cell sorter (FACS) analysis, and electron microscopy, the antimicrobial activities of α-defensins 1 and 5 against a panel of C. difficile strains encompassing the most prevalent epidemic and hypervirulent PCR ribotypes in Europe (012, 014/020, 106, 018, 027, and 078). Here we show that (i) concentrations of HD5 within the intestinal physiological range produced massive C. difficile cell killing; (ii) HD5 bactericidal activity was mediated by membrane depolarization and bacterial fragmentation with a pattern of damage peculiar to C. difficile bacilli, compared to commensals like Escherichia coli and Enterococcus faecalis; and (iii) unexpectedly, hypervirulent ribotypes were among the most susceptible to both defensins. These results support the notion that HD5, naturally present at very high concentrations in the mucosa of the small intestine, could indeed control the very early steps of CDI by killing C. difficile bacilli at their germination site. As a consequence, HD5 can be regarded as a good candidate for the containment of hypervirulent C. difficile strains, and it could be exploited in the therapy of CDI and relapsing C. difficile-associated disease.
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Chairatana P, Nolan EM. Molecular basis for self-assembly of a human host-defense peptide that entraps bacterial pathogens. J Am Chem Soc 2014; 136:13267-76. [PMID: 25158166 PMCID: PMC4183631 DOI: 10.1021/ja5057906] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Indexed: 02/07/2023]
Abstract
Human α-defensin 6 (HD6) is a 32-aa cysteine-rich peptide of the innate immune system. Although HD6 is a member of an antimicrobial peptide family, it exhibits negligible antibacterial activity in vitro. Rather, HD6 possesses a unique innate immune mechanism whereby it self-assembles into oligomers that capture pathogens to prevent microbial invasion of the intestinal epithelium and subsequent dissemination. Molecular-level understanding for why HD6 functions differently from other human defensins remains unclear. To further elucidate the HD6 self-assembly process and its biological activity, we developed robust protocols for obtaining native and mutant HD6 in high purity from overexpression in Escherichia coli. We combined biophysical characterization with biological assays to probe HD6 structure and function. We report that native HD6 readily self-assembles into elongated fibrils observable by transmission electron microscopy, agglutinates both Gram-negative and -positive bacteria, and prevents the human gastrointestinal pathogen Listeria monocytogenes from invading cultured mammalian cells. Mutation of hydrophobic residues (F2A, I22T, V25T, F29A) perturbs self-assembly and results in attenuated biological activity. In particular, the F2A and F29A mutants do not form fibrils under our experimental conditions and neither agglutinate bacteria nor prevent L. monocytogenes invasion. In total, our results demonstrate that the hydrophobic effect is essential for promoting HD6 self-assembly and innate immune function, and indicate that HD6 may provide host defense against Listeria in the gut. This investigation provides a timely description of how variations in amino acid sequence confer diverse physiological functions to members of the defensin family.
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Affiliation(s)
- Phoom Chairatana
- Department of Chemistry, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
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Wommack AJ, Ziarek JJ, Tomaras J, Chileveru HR, Zhang Y, Wagner G, Nolan EM. Discovery and characterization of a disulfide-locked C(2)-symmetric defensin peptide. J Am Chem Soc 2014; 136:13494-7. [PMID: 25181039 PMCID: PMC4183617 DOI: 10.1021/ja505957w] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We report the discovery of HD5-CD, an unprecedented C2-symmetric β-barrel-like covalent dimer of the cysteine-rich host-defense peptide human defensin 5 (HD5). Dimerization results from intermonomer disulfide exchange between the canonical α-defensin Cys(II)-Cys(IV) (Cys(5)-Cys(20)) bonds located at the hydrophobic interface. This disulfide-locked dimeric assembly provides a new element of structural diversity for cysteine-rich peptides as well as increased protease resistance, broad-spectrum antimicrobial activity, and enhanced potency against the opportunistic human pathogen Acinetobacter baumannii.
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Affiliation(s)
- Andrew J Wommack
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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Silva PM, Gonçalves S, Santos NC. Defensins: antifungal lessons from eukaryotes. Front Microbiol 2014; 5:97. [PMID: 24688483 PMCID: PMC3960590 DOI: 10.3389/fmicb.2014.00097] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 02/21/2014] [Indexed: 01/07/2023] Open
Abstract
Over the last years, antimicrobial peptides (AMPs) have been the focus of intense research toward the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several of these cysteine-stabilized peptides present a relevant effect against fungi. Defensins are the AMPs with the broader distribution across all eukaryotic kingdoms, namely, Fungi, Plantae, and Animalia, and were recently shown to have an ancestor in a bacterial organism. As a part of the host defense, defensins act as an important vehicle of information between innate and adaptive immune system and have a role in immunomodulation. This multidimensionality represents a powerful host shield, hard for microorganisms to overcome using single approach resistance strategies. Pathogenic fungi resistance to conventional antimycotic drugs is becoming a major problem. Defensins, as other AMPs, have shown to be an effective alternative to the current antimycotic therapies, demonstrating potential as novel therapeutic agents or drug leads. In this review, we summarize the current knowledge on some eukaryotic defensins with antifungal action. An overview of the main targets in the fungal cell and the mechanism of action of these AMPs (namely, the selectivity for some fungal membrane components) are presented. Additionally, recent works on antifungal defensins structure, activity, and cytotoxicity are also reviewed.
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Affiliation(s)
- Patrícia M Silva
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa Lisbon, Portugal
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa Lisbon, Portugal
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Pouchitis: what every gastroenterologist needs to know. Clin Gastroenterol Hepatol 2013; 11:1538-49. [PMID: 23602818 DOI: 10.1016/j.cgh.2013.03.033] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/12/2013] [Accepted: 03/28/2013] [Indexed: 02/07/2023]
Abstract
Pouchitis is the most common complication among patients with ulcerative colitis who have undergone restorative proctocolectomy with ileal pouch-anal anastomosis. Pouchitis is actually a spectrum of diseases that vary in etiology, pathogenesis, phenotype, and clinical course. Although initial acute episodes typically respond to antibiotic therapy, patients can become dependent on antibiotics or develop refractory disease. Many factors contribute to the course of refractory pouchitis, such as the use of nonsteroidal anti-inflammatory drugs, infection with Clostridium difficile, pouch ischemia, or concurrent immune-mediated disorders. Identification of these secondary factors can help direct therapy.
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Wommack AJ, Robson SA, Wanniarachchi YA, Wan A, Turner CJ, Wagner G, Nolan EM. NMR solution structure and condition-dependent oligomerization of the antimicrobial peptide human defensin 5. Biochemistry 2012; 51:9624-37. [PMID: 23163963 DOI: 10.1021/bi301255u] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Human defensin 5 (HD5) is a 32-residue host-defense peptide expressed in the gastrointestinal, reproductive, and urinary tracts that has antimicrobial activity. It exhibits six cysteine residues that are regiospecifically oxidized to form three disulfide bonds (Cys(3)-Cys(31), Cys(5)-Cys(20), and Cys(10)-Cys(30)) in the oxidized form (HD5(ox)). To probe the solution structure and oligomerization properties of HD5(ox), and select mutant peptides lacking one or more disulfide bonds, NMR solution studies and analytical ultracentrifugation experiments are reported in addition to in vitro peptide stability assays. The NMR solution structure of HD5(ox), solved at pH 4.0 in 90:10 H(2)O/D(2)O, is presented (PDB: 2LXZ ). Relaxation T(1)/T(2) measurements and the rotational correlation time (τ(c)) estimated from a (15)N-TRACT experiment demonstrate that HD5(ox) is dimeric under these experimental conditions. Exchange broadening of the Hα signals in the NMR spectra suggests that residues 19-21 (Val(19)-Cys(20)-Glu(21)) contribute to the dimer interface in solution. Exchange broadening is also observed for residues 7-14 comprising the loop. Sedimentation velocity and equilibrium studies conducted in buffered aqueous solution reveal that the oligomerization state of HD5(ox) is pH-dependent. Sedimentation coefficients of ca. 1.8 S and a molecular weight of 14 363 Da were determined for HD5(ox) at pH 7.0, supporting a tetrameric form ([HD5(ox)] ≥ 30 μM). At pH 2.0, a sedimentation coefficient of ca. 1.0 S and a molecular weight of 7079 Da, corresponding to a HD5(ox) dimer, were obtained. Millimolar concentrations of NaCl, CaCl(2), and MgCl(2) have a negligible effect on the HD5(ox) sedimentation coefficients in buffered aqueous solution at neutral pH. Removal of a single disulfide bond results in a loss of peptide fold and quaternary structure. These biophysical investigations highlight the dynamic and environmentally sensitive behavior of HD5(ox) in solution, and provide important insights into HD5(ox) structure/activity relationships and the requirements for antimicrobial action.
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Affiliation(s)
- Andrew J Wommack
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Furci L, Tolazzi M, Sironi F, Vassena L, Lusso P. Inhibition of HIV-1 infection by human α-defensin-5, a natural antimicrobial peptide expressed in the genital and intestinal mucosae. PLoS One 2012; 7:e45208. [PMID: 23028850 PMCID: PMC3459904 DOI: 10.1371/journal.pone.0045208] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 08/17/2012] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND α-defensin-5 (HD5) is a key effector of the innate immune system with broad anti-bacterial and anti-viral activities. Specialized epithelial cells secrete HD5 in the genital and gastrointestinal mucosae, two anatomical sites that are critically involved in HIV-1 transmission and pathogenesis. We previously found that human neutrophil defensins (HNP)-1 and -2 inhibit HIV-1 entry by specific bilateral interaction both with the viral envelope and with its primary cellular receptor, CD4. Despite low amino acid identity, human defensin-5 (HD5) shares with HNPs a high degree of structural homology. METHODOLOGY/PRINCIPAL FINDINGS Here, we demonstrate that HD5 inhibits HIV-1 infection of primary CD4(+) T lymphocytes at low micromolar concentration under serum-free and low-ionic-strength conditions similar to those occurring in mucosal fluids. Blockade of HIV-1 infection was observed with both primary and laboratory-adapted strains and was independent of the viral coreceptor-usage phenotype. Similar to HNPs, HD5 inhibits HIV-1 entry into the target cell by interfering with the reciprocal interaction between the external envelope glycoprotein, gp120, and CD4. At high concentrations, HD5 was also found to downmodulate expression of the CXCR4 coreceptor, but not of CCR5. Consistent with its broad spectrum of activity, antibody competition studies showed that HD5 binds to a region overlapping with the CD4- and coreceptor-binding sites of gp120, but not to the V3 loop region, which contains the major determinants of coreceptor-usage specificity. CONCLUSION/SIGNIFICANCE These findings provide new insights into the first line of immune defense against HIV-1 at the mucosal level and open new perspectives for the development of preventive and therapeutic strategies.
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Affiliation(s)
- Lucinda Furci
- Unit of Human Virology, Department of Biological and Technological Research, San Raffaele Scientific Institute, Milan, Italy.
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Chu H, Pazgier M, Jung G, Nuccio SP, Castillo PA, de Jong MF, Winter MG, Winter SE, Wehkamp J, Shen B, Salzman NH, Underwood MA, Tsolis RM, Young GM, Lu W, Lehrer RI, Bäumler AJ, Bevins CL. Human α-defensin 6 promotes mucosal innate immunity through self-assembled peptide nanonets. Science 2012; 337:477-81. [PMID: 22722251 DOI: 10.1126/science.1218831] [Citation(s) in RCA: 311] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Defensins are antimicrobial peptides that contribute broadly to innate immunity, including protection of mucosal tissues. Human α-defensin (HD) 6 is highly expressed by secretory Paneth cells of the small intestine. However, in contrast to the other defensins, it lacks appreciable bactericidal activity. Nevertheless, we report here that HD6 affords protection against invasion by enteric bacterial pathogens in vitro and in vivo. After stochastic binding to bacterial surface proteins, HD6 undergoes ordered self-assembly to form fibrils and nanonets that surround and entangle bacteria. This self-assembly mechanism occurs in vivo, requires histidine-27, and is consistent with x-ray crystallography data. These findings support a key role for HD6 in protecting the small intestine against invasion by diverse enteric pathogens and may explain the conservation of HD6 throughout Hominidae evolution.
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Affiliation(s)
- Hiutung Chu
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, CA 95616, USA
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Abstract
Restorative proctocolectomy with ileal pouch-anal anastomosis has become the procedure of choice for the majority of patients with ulcerative colitis who require surgical treatment. Pouchitis, the most common long-term complication of the procedure, involves a spectrum of disease processes with heterogeneous risk factors, clinical features, disease courses and prognoses. In addition, clinical symptoms of pouchitis are not specific and often overlap with those of other inflammatory and functional pouch disorders, such as Crohn's disease of the pouch and irritable pouch syndrome. Pouchoscopy and biopsy, along with laboratory and radiographic evaluations, are often required for accurate diagnosis in patients with symptoms indicative of pouchitis. Dysbiosis has been implicated as a triggering factor for pouchitis, and concurrent infection with pathogens, such as Clostridium difficile, might contribute to disease relapse and exacerbation. Antibiotic therapy is the main treatment modality. However, the management of antibiotic-dependent and antibiotic-refractory pouchitis remains challenging. Secondary causes of pouchitis, such as ischaemia, NSAID use, the presence of concurrent primary sclerosing cholangitis and other systemic immune-mediated disorders, should be evaluated and properly managed.
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Expression and Structure/Function Relationships of Human Defensin 5. Appl Biochem Biotechnol 2012; 166:1703-10. [DOI: 10.1007/s12010-012-9571-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Accepted: 01/18/2012] [Indexed: 12/22/2022]
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Spencer JD, Hains DS, Porter E, Bevins CL, DiRosario J, Becknell B, Wang H, Schwaderer AL. Human alpha defensin 5 expression in the human kidney and urinary tract. PLoS One 2012; 7:e31712. [PMID: 22359618 PMCID: PMC3281003 DOI: 10.1371/journal.pone.0031712] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 01/11/2012] [Indexed: 11/18/2022] Open
Abstract
Background The mechanisms that maintain sterility in the urinary tract are incompletely understood. Recent studies have implicated the importance of antimicrobial peptides (AMP) in protecting the urinary tract from infection. Here, we characterize the expression and relevance of the AMP human alpha-defensin 5 (HD5) in the human kidney and urinary tract in normal and infected subjects. Methodology/Principal Findings Using RNA isolated from human kidney, ureter, and bladder tissue, we performed quantitative real-time PCR to show that DEFA5, the gene encoding HD5, is constitutively expressed throughout the urinary tract. With pyelonephritis, DEFA5 expression significantly increased in the kidney. Using immunoblot analysis, HD5 production also increased with pyelonephritis. Immunostaining localized HD5 to the urothelium of the bladder and ureter. In the kidney, HD5 was primarily produced in the distal nephron and collecting tubules. Using immunoblot and ELISA assays, HD5 was not routinely detected in non-infected human urine samples while mean urinary HD5 production increased with E.coli urinary tract infection. Conclusions/Significance DEFA5 is expressed throughout the urinary tract in non-infected subjects. Specifically, HD5 is expressed throughout the urothelium of the lower urinary tract and in the collecting tubules of the kidney. With infection, HD5 expression increases in the kidney and levels become detectable in the urine. To our knowledge, our findings represent the first to quantitate HD5 expression and production in the human kidney. Moreover, this is the first report to detect the presence of HD5 in infected urine samples. Our results suggest that HD5 may have an important role in maintaining urinary tract sterility.
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Affiliation(s)
- John David Spencer
- Pediatric Nephrology Fellowship Program, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - David S. Hains
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Edith Porter
- Department of Biological Sciences, California State University Los Angeles, Los Angeles, California, United States of America
| | - Charles L. Bevins
- Department of Microbiology and Immunology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Julianne DiRosario
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Brian Becknell
- Pediatric Nephrology Fellowship Program, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Huanyu Wang
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Andrew L. Schwaderer
- Division of Nephrology, Department of Pediatrics, Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- * E-mail:
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Tsimogiannis KE, Tellis CC, Tselepis AD, Pappas-Gogos G, Bakola MS, Tsimoyiannis EC, Simopoulos CE, Pitiakoudis M. α-Defensins and hsCRP levels in inflammatory response of standard and laparoendoscopic single-site cholecystectomy. Surg Endosc 2011; 26:627-31. [PMID: 21993933 DOI: 10.1007/s00464-011-1921-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 08/22/2011] [Indexed: 01/02/2023]
Abstract
BACKGROUND Laparoendoscopic single-site (LESS) surgery is an evolution of laparoscopic surgery aiming at decreasing the patient's parietal trauma associated with abdominal operations. LESS has been found so far to be efficient and have the same good results as the standard four-port laparoscopic cholecystectomy. α-Defensins are antimicrobial peptides of the organism. They are the first cell components against pathogens. Cytokines are also mediators in the response to trauma. The aim of this study was to compare the inflammatory reaction in LESS and four-port laparoscopic cholecystectomy. METHODS Forty patients with noncomplicated cholelithiasis were randomly assigned into one of two groups. Group A included the patients who would undergo four-port laparoscopic cholecystectomy and group B included the patients who would undergo LESS cholecystectomy. These patients had a BMI < 30, were ASA I or II, and had no previous upper-GI surgery. Blood was taken preoperatively and 6 and 24 h postoperatively. hsCRP (with automated analyzer) and α-defensins (using ELISA) were calculated for each sample. The same postoperative protocol was followed for both groups. Mann-Whitney U test was used to analyze the results. Pain was calculated with a visual analog scale (VAS) for shoulder and abdomen at 6 and 24 h. Hospital stay, nausea, and pain medication needed was noted. RESULTS The α-defensins value was statistically significantly higher in the 24-h samples (P < 0.001) for LESS cholecystectomy. No statistically significant difference was shown for hsCRP, even though P = 0.05 for the 24-h samples with the values of LESS higher. No LESS was converted to a classical laparoscopic cholecystectomy, and none of the patients of either group needed conversion to open cholecystectomy. Pain was statistically significantly less for the LESS group at the 24-h interval (P < 0.0001). Less medication was needed for LESS patients after the 6th postoperative hour (P = 0.007). CONCLUSION Higher inflammatory reaction in LESS cholecystectomy could be the result of greater tension on the tissues. More studies are needed to conclude if this has a significant clinical expression.
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Affiliation(s)
- Konstantinos E Tsimogiannis
- Department of Surgery, G. Hatzikosta General Hospital of Ioannina, Hippocratus 3, Stavraki, 45332, Ioannina, Greece.
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