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Wang S, Yang Y, Jiang X, Zheng X, Wei Q, Dai W, Zhang X. Nurturing gut health: role of m6A RNA methylation in upholding the intestinal barrier. Cell Death Discov 2024; 10:271. [PMID: 38830900 PMCID: PMC11148167 DOI: 10.1038/s41420-024-02043-x] [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: 01/11/2024] [Revised: 05/19/2024] [Accepted: 05/22/2024] [Indexed: 06/05/2024] Open
Abstract
The intestinal lumen acts as a critical interface connecting the external environment with the body's internal state. It's essential to prevent the passage of harmful antigens and bacteria while facilitating nutrient and water absorption. The intestinal barriers encompass microbial, mechanical, immunological, and chemical elements, working together to maintain intestinal balance. Numerous studies have associated m6A modification with intestinal homeostasis. This review comprehensively outlines potential mechanisms through which m6A modification could initiate, exacerbate, or sustain barrier damage from an intestinal perspective. The pivotal role of m6A modification in preserving intestinal equilibrium provides new insights, guiding the exploration of m6A modification as a target for optimizing preventive and therapeutic strategies for intestinal homeostasis.
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Affiliation(s)
| | - Yuzhong Yang
- Department of Pathology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China
| | - Xiaohan Jiang
- Department of Pathology, Liuzhou People's Hospital Affiliated to Guangxi Medical University, Liuzhou, Guangxi, China
| | - Xiang Zheng
- Department of Pathology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China
| | - Qiufang Wei
- Department of Pathology, Liuzhou People's Hospital Affiliated to Guangxi Medical University, Liuzhou, Guangxi, China
| | - Wenbin Dai
- Department of Pathology, Liuzhou People's Hospital Affiliated to Guangxi Medical University, Liuzhou, Guangxi, China.
| | - Xuemei Zhang
- Department of Pathology, Liuzhou People's Hospital Affiliated to Guangxi Medical University, Liuzhou, Guangxi, China.
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Zhao C, Porter JM, Burke PC, Arnberg N, Smith JG. Alpha-defensin binding expands human adenovirus tropism. PLoS Pathog 2024; 20:e1012317. [PMID: 38900833 PMCID: PMC11230588 DOI: 10.1371/journal.ppat.1012317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 07/08/2024] [Accepted: 06/04/2024] [Indexed: 06/22/2024] Open
Abstract
Mammalian α-defensins are a family of abundant effector peptides of the mucosal innate immune system. Although primarily considered to be antimicrobial, α-defensins can increase rather than block infection by certain prominent bacterial and viral pathogens in cell culture and in vivo. We have shown previously that exposure of mouse and human adenoviruses (HAdVs) to α-defensins is able to overcome competitive inhibitors that block cell binding, leading us to hypothesize a defensin-mediated binding mechanism that is independent of known viral receptors. To test this hypothesis, we used genetic approaches to demonstrate that none of several primary receptors nor integrin co-receptors are needed for human α-defensin-mediated binding of HAdV to cells; however, infection remains integrin dependent. Thus, our studies have revealed a novel pathway for HAdV binding to cells that bypasses viral primary receptors. We speculate that this pathway functions in parallel with receptor-mediated entry and contributes to α-defensin-enhanced infection of susceptible cells. Remarkably, we also found that in the presence of α-defensins, HAdV tropism is expanded to non-susceptible cells, even when viruses are exposed to a mixture of both susceptible and non-susceptible cells. Therefore, we propose that in the presence of sufficient concentrations of α-defensins, such as in the lung or gut, integrin expression rather than primary receptor expression will dictate HAdV tropism in vivo. In summary, α-defensins may contribute to tissue tropism not only through the neutralization of susceptible viruses but also by allowing certain defensin-resistant viruses to bind to cells independently of previously described mechanisms.
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Affiliation(s)
- Cheng Zhao
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Jessica M. Porter
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Phillip C. Burke
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
| | - Niklas Arnberg
- Department of Clinical Microbiology, Division of Virology and Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Jason G. Smith
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, United States of America
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Zhao C, Porter JM, Burke PC, Arnberg N, Smith JG. Alpha-defensin binding expands human adenovirus tropism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596681. [PMID: 38854108 PMCID: PMC11160700 DOI: 10.1101/2024.05.30.596681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Mammalian α-defensins are a family of abundant effector peptides of the mucosal innate immune system. Although primarily considered to be antimicrobial, α-defensins can increase rather than block infection by certain prominent bacterial and viral pathogens in cell culture and in vivo . We have shown previously that exposure of mouse and human adenoviruses (HAdVs) to α-defensins is able to overcome competitive inhibitors that block cell binding, leading us to hypothesize a defensin-mediated binding mechanism that is independent of known viral receptors. To test this hypothesis, we used genetic approaches to demonstrate that none of several primary receptors nor integrin co-receptors are needed for human α-defensin-mediated binding of HAdV to cells; however, infection remains integrin dependent. Thus, our studies have revealed a novel pathway for HAdV binding to cells that bypasses viral primary receptors. We speculate that this pathway functions in parallel with receptor-mediated entry and contributes to α-defensin-enhanced infection of susceptible cells. Remarkably, we also found that in the presence of α-defensins, HAdV tropism is expanded to non-susceptible cells, even when viruses are exposed to a mixture of both susceptible and non-susceptible cells. Therefore, we propose that in the presence of sufficient concentrations of α-defensins, such as in the lung or gut, integrin expression rather than primary receptor expression will dictate HAdV tropism in vivo . In summary, α-defensins may contribute to tissue tropism not only through the neutralization of susceptible viruses but also by allowing certain defensin-resistant viruses to bind to cells independently of previously described mechanisms. Author Summary In this study, we demonstrate a novel mechanism for binding of human adenoviruses (HAdVs) to cells that is dependent upon interactions with α-defensin host defense peptides but is independent of known viral receptors and co-receptors. To block normal receptor-mediated HAdV infection, we made genetic changes to both host cells and HAdVs. Under these conditions, α-defensins restored cell binding; however, infection still required the function of HAdV integrin co-receptors. This was true for multiple types of HAdVs that use different primary receptors and for cells that are either naturally devoid of HAdV receptors or were engineered to be receptor deficient. These observations suggest that in the presence of concentrations of α-defensins that would be found naturally in the lung or intestine, there are two parallel pathways for HAdV binding to cells that converge on integrins for productive infection. Moreover, these binding pathways function independently, and both operate in mixed culture. Thus, we have found that viruses can co-opt host defense molecules to expand their tropism.
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Fu J, Zong X, Jin M, Min J, Wang F, Wang Y. Mechanisms and regulation of defensins in host defense. Signal Transduct Target Ther 2023; 8:300. [PMID: 37574471 PMCID: PMC10423725 DOI: 10.1038/s41392-023-01553-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/11/2023] [Accepted: 06/26/2023] [Indexed: 08/15/2023] Open
Abstract
As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.
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Affiliation(s)
- Jie Fu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Xin Zong
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Mingliang Jin
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Junxia Min
- The First Affiliated Hospital, Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Fudi Wang
- The Second Affiliated Hospital, School of Public Health, State Key Laboratory of Experimental Hematology, Zhejiang University School of Medicine, Hangzhou, China.
- The First Affiliated Hospital, Basic Medical Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, China.
| | - Yizhen Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China.
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China.
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Siebert HC, Eckert T, Bhunia A, Klatte N, Mohri M, Siebert S, Kozarova A, Hudson JW, Zhang R, Zhang N, Li L, Gousias K, Kanakis D, Yan M, Jiménez-Barbero J, Kožár T, Nifantiev NE, Vollmer C, Brandenburger T, Kindgen-Milles D, Haak T, Petridis AK. Blood pH Analysis in Combination with Molecular Medical Tools in Relation to COVID-19 Symptoms. Biomedicines 2023; 11:biomedicines11051421. [PMID: 37239092 DOI: 10.3390/biomedicines11051421] [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: 03/06/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/28/2023] Open
Abstract
The global outbreak of SARS-CoV-2/COVID-19 provided the stage to accumulate an enormous biomedical data set and an opportunity as well as a challenge to test new concepts and strategies to combat the pandemic. New research and molecular medical protocols may be deployed in different scientific fields, e.g., glycobiology, nanopharmacology, or nanomedicine. We correlated clinical biomedical data derived from patients in intensive care units with structural biology and biophysical data from NMR and/or CAMM (computer-aided molecular modeling). Consequently, new diagnostic and therapeutic approaches against SARS-CoV-2 were evaluated. Specifically, we tested the suitability of incretin mimetics with one or two pH-sensitive amino acid residues as potential drugs to prevent or cure long-COVID symptoms. Blood pH values in correlation with temperature alterations in patient bodies were of clinical importance. The effects of biophysical parameters such as temperature and pH value variation in relation to physical-chemical membrane properties (e.g., glycosylation state, affinity of certain amino acid sequences to sialic acids as well as other carbohydrate residues and lipid structures) provided helpful hints in identifying a potential Achilles heel against long COVID. In silico CAMM methods and in vitro NMR experiments (including 31P NMR measurements) were applied to analyze the structural behavior of incretin mimetics and SARS-CoV fusion peptides interacting with dodecylphosphocholine (DPC) micelles. These supramolecular complexes were analyzed under physiological conditions by 1H and 31P NMR techniques. We were able to observe characteristic interaction states of incretin mimetics, SARS-CoV fusion peptides and DPC membranes. Novel interaction profiles (indicated, e.g., by 31P NMR signal splitting) were detected. Furthermore, we evaluated GM1 gangliosides and sialic acid-coated silica nanoparticles in complex with DPC micelles in order to create a simple virus host cell membrane model. This is a first step in exploring the structure-function relationship between the SARS-CoV-2 spike protein and incretin mimetics with conserved pH-sensitive histidine residues in their carbohydrate recognition domains as found in galectins. The applied methods were effective in identifying peptide sequences as well as certain carbohydrate moieties with the potential to protect the blood-brain barrier (BBB). These clinically relevant observations on low blood pH values in fatal COVID-19 cases open routes for new therapeutic approaches, especially against long-COVID symptoms.
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Affiliation(s)
- Hans-Christian Siebert
- RI-B-NT-Research Institute of Bioinformatics and Nanotechnology, Schauenburgerstr. 116, 24118 Kiel, Germany
| | - Thomas Eckert
- Department of Chemistry and Biology, University of Applied Sciences Fresenius, Limburger Str. 2, 65510 Idstein, Germany
- RISCC-Research Institute for Scientific Computing and Consulting, Ludwig-Schunk-Str. 15, 35452 Heuchelheim, Germany
- Institut für Veterinärphysiologie und Biochemie, Fachbereich Veterinärmedizin, Justus-Liebig Universität Gießen, Frankfurter Str. 100, 35392 Gießen, Germany
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Nele Klatte
- Department of Chemistry and Biology, University of Applied Sciences Fresenius, Limburger Str. 2, 65510 Idstein, Germany
| | - Marzieh Mohri
- RI-B-NT-Research Institute of Bioinformatics and Nanotechnology, Schauenburgerstr. 116, 24118 Kiel, Germany
| | - Simone Siebert
- RI-B-NT-Research Institute of Bioinformatics and Nanotechnology, Schauenburgerstr. 116, 24118 Kiel, Germany
| | - Anna Kozarova
- Department of Biomedical Sciences, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - John W Hudson
- Department of Biomedical Sciences, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Ruiyan Zhang
- Institute of BioPharmaceutical Research, Liaocheng University, Liaocheng 252059, China
| | - Ning Zhang
- Institute of BioPharmaceutical Research, Liaocheng University, Liaocheng 252059, China
| | - Lan Li
- Klinik für Neurochirurgie, Alfried Krupp Krankenhaus, Rüttenscheid, Alfried-Krupp-Straße 21, 45131 Essen, Germany
| | - Konstantinos Gousias
- Klinik für Neurochirurgie, Klinikum Lünen, St.-Marien-Hospital, Akad. Lehrkrankenhaus der Westfälische Wilhelms-Universität Münster, 44534 Lünen, Germany
| | - Dimitrios Kanakis
- Institute of Pathology, University of Nicosia Medical School, 2408 Egkomi, Cyprus
| | - Mingdi Yan
- Department of Chemistry, University of Massachusetts Lowell, 1 University Avenue, Lowell, MA 01854, USA
| | | | - Tibor Kožár
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Šafárik University, Jesenná 5, 04001 Košice, Slovakia
| | - Nikolay E Nifantiev
- Laboratory of Glycoconjugate Chemistry, N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, 119991 Moscow, Russia
| | - Christian Vollmer
- Department of Anesthesiology, University Hospital Düsseldorf, Heinrich-Heine University Duesseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Timo Brandenburger
- Department of Anesthesiology, University Hospital Düsseldorf, Heinrich-Heine University Duesseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Detlef Kindgen-Milles
- Department of Anesthesiology, University Hospital Düsseldorf, Heinrich-Heine University Duesseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Thomas Haak
- Diabetes Klinik Bad Mergentheim, Theodor-Klotzbücher-Str. 12, 97980 Bad Mergentheim, Germany
| | - Athanasios K Petridis
- Medical School, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
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Porter JM, Oswald MS, Sharma A, Emmanuel S, Kansol A, Bennett A, McKenna R, Smith JG. A Single Surface-Exposed Amino Acid Determines Differential Neutralization of AAV1 and AAV6 by Human Alpha-Defensins. J Virol 2023; 97:e0006023. [PMID: 36916912 PMCID: PMC10062168 DOI: 10.1128/jvi.00060-23] [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] [Received: 01/10/2023] [Accepted: 02/21/2023] [Indexed: 03/16/2023] Open
Abstract
Adeno-associated viruses (AAVs) are being developed as gene therapy vectors due to their low pathogenicity and tissue tropism properties. However, the efficacy of these vectors is impeded by interactions with the host immune system. One potential immune barrier to vector transduction is innate immune host defense peptides, such as alpha-defensins, which are potent antiviral agents against other nonenveloped viruses. To investigate the interaction between AAVs and alpha-defensins, we utilized two closely related AAV serotypes, AAV1 and AAV6. Although their capsids differ by only six residues, these two serotypes exhibit markedly different tissue tropisms and transduction efficiencies. Using two abundant human alpha-defensins, enteric human defensin 5 (HD5) and myeloid human neutrophil peptide 1 (HNP1), we found both serotype-specific and defensin-specific effects on AAV infection. AAV6 infection was uniformly neutralized by both defensins at low micromolar concentrations; however, inhibition of AAV1 infection was profoundly influenced by the timing of defensin exposure to the virus relative to viral attachment to the cell. Remarkably, these differences in the defensin-dependent infection phenotype between the viruses are completely dictated by the identity of a single, surface-exposed amino acid (position 531) that varies between the two serotypes. These findings reveal a determinant for defensin activity against a virus with unprecedented precision. Furthermore, they provide a rationale for the investigation of other AAV serotypes not only to understand the mechanism of neutralization of defensins against AAVs but also to design more efficient vectors. IMPORTANCE The ability of adeno-associated viruses (AAVs) to infect and deliver genetic material to a range of cell types makes them favorable gene therapy vectors. However, AAV vectors encounter a wide variety of host immune factors throughout the body, which can impede efficient gene delivery. One such group of factors is the alpha-defensins, which are a key component of the innate immune system that can directly block viral infection. By studying the impact that alpha-defensins have on AAV infection, we found that two similar AAV serotypes (AAV1 and AAV6) have different sensitivities to inhibition. We also identified a single amino acid (position 531) that differs between the two AAV serotypes and is responsible for mediating their defensin sensitivity. By investigating the effects that host immune factors have on AAV infection, more efficient vectors may be developed to evade intervention by the immune system prior to gene delivery.
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Affiliation(s)
- Jessica M. Porter
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Mackenzi S. Oswald
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Anjali Sharma
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Shanan Emmanuel
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Austin Kansol
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Antonette Bennett
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Jason G. Smith
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
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Defensin Interactions in Relation to Monoclonal and Disease-Related Proteinase 3 Antibodies Binding at the Catalytic Site. Antibodies (Basel) 2023; 12:antib12010023. [PMID: 36975370 PMCID: PMC10044823 DOI: 10.3390/antib12010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/21/2023] [Accepted: 03/08/2023] [Indexed: 03/17/2023] Open
Abstract
Proteinase 3 (PR3) is a neutrophil granulocyte enzyme and an autoantigen found in several forms of vasculitis. Due to the diagnostic and clinical importance of antibodies (Abs) to PR3, it is important to characterize the protein and the nature of its epitopes. Here, we have characterized PR3 monoclonal antibodies (MAbs) and disease-associated Abs and their dependency on the PR3 structure and modifications, especially interactions with α-defensins. Three MAbs (HYB 172-01, 172-04, 172-05), which bind to PR3 in its native and denatured forms and provide the disulphide bridges, were intact. α-1-antitrypsin (AT) binds to purified human neutrophil granulocyte PR3 and inhibits its proteolytic activity, towards a small synthetic peptide substrate and a large protein substrate (casein). AT also inhibited the binding of the three MAbs to PR3, indicating that they bind in a region affected by AT binding. However, the MAbs did not inhibit PR3 proteolytic activity with a small substrate, showing that they bound at the active site without restricting access to the substrate cleft. Patient-derived Abs showed essentially the same characteristics as the MAbs, with important implications for vasculitis diagnostics and pathophysiology. Current findings illustrate that PR3 epitopes depend on the three-dimensional structure of the PR3/defensin complex, and that the epitopes depend to a smaller or larger degree on PR3/defensin associations.
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Peng H, Fan P, Hong Y, He J, Zeng X, Xu F, Zhao Y, Jin T. 3' untranslated region variants in DEFA5 gene associated with susceptibility to IgA nephropathy in the Chinese Han population. Biomark Med 2022; 16:1151-1159. [PMID: 36632813 DOI: 10.2217/bmm-2022-0518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Aim: To evaluate the association between single-nucleotide polymorphisms in the 3' untranslated region of the DEFA5 gene and IgA nephropathy (IgAN) risk, the authors performed an association study in the Chinese Han population. Materials & methods: The authors recruited 426 IgAN patients and 498 controls. The MassARRAY platform (Agena Bioscience, Inc., CA, USA) was used to genotype single-nucleotide polymorphisms in DEFA5. Odds ratios and 95% CIs were calculated through logistic regression analysis. Results: The authors observed that rs12716641 significantly reduced IgAN risk in the allele (odds ratio: 0.77; p = 0.026) and genotype (odds ratio: 0.75; p = 0.039) models. Stratification analysis revealed that several genotypes of rs12716641 played a protective role against IgAN. Conclusion: The authors' results revealed that single-nucleotide polymorphisms in the 3' untranslated region of DEFA5 were associated with IgAN risk.
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Affiliation(s)
- Hongwei Peng
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Pingyun Fan
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Yifen Hong
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Jing He
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Xiangxiu Zeng
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Fengguo Xu
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Yunxia Zhao
- Renal Medicine, Hainan Wanning People's Hospital, Wanning, Hainan Province, 571500, China
| | - Tianbo Jin
- Key Laboratory of Resource Biology & Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi, 710000, China.,Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi'an, China
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Chow DT, Rardin MJ. Identification and Mitigation of Defensins in the Immunopurification of Peptide MHC-I Antigens from Lung Tissue. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1590-1597. [PMID: 34645265 DOI: 10.1021/jasms.1c00024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The class I major histocompatibility (MHC-I) complex is a set of diverse cell surface receptors encoded by the human leukocyte antigen gene complex. These receptors present intracellular antigens to cytotoxic T cells providing information on the state and health of cells. Changes in the immunopeptidome during cancer may provide novel targets for therapeutic intervention. To understand how the tumor immunopeptidome is altered, we developed a mass spectrometry (MS) based platform for isolating and identifying MHC-I peptide antigens in lung tumors. In the course of our work, we encountered several large unknown peptide contaminants which had not been previously reported. To understand the source of these major contaminants, we isolated them using offline fractionation and identified them by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as members of the host defense protein family known as the defensins. To mitigate their detrimental effects, we modified our "Original" data-dependent acquisition (DDA) MS method to narrowly target the MHC-I peptides based on their physical properties including charge state and molecular weight ("z state" DDA), evaluated field asymmetric ion mobility spectrometry to attempt gas-phase separation prior to MS analysis, and developed an immunodepletion approach using defensin specific antibodies. This modified approach improves peptide identification and reduces the impact of defensin contamination in lung tissue samples.
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Affiliation(s)
- David T Chow
- Amgen Research, Discovery Attribute Sciences Amgen, South San Francisco, California 94080, United States
| | - Matthew J Rardin
- Amgen Research, Discovery Attribute Sciences Amgen, South San Francisco, California 94080, United States
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Chumponanomakun P, Niramitranon J, Chairatana P, Pongprayoon P. Molecular insights into the adsorption mechanism of E21R and T7E21R human defensin 5 on a bacterial membrane. MOLECULAR SIMULATION 2022. [DOI: 10.1080/08927022.2022.2086253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Phoom Chumponanomakun
- Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Jitti Niramitranon
- Department of Computer Engineering, Faculty of Engineering, Kasetsart University, Bangkok, Thailand
| | - Phoom Chairatana
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Prapasiri Pongprayoon
- Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, KU Institute for Advanced Studies, Kasetsart University, Bangkok, Thailand
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11
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Li Y, Liu N, Ge Y, Yang Y, Ren F, Wu Z. Tryptophan and the innate intestinal immunity: Crosstalk between metabolites, host innate immune cells and microbiota. Eur J Immunol 2022; 52:856-868. [PMID: 35362153 DOI: 10.1002/eji.202149401] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 12/17/2021] [Accepted: 01/20/2022] [Indexed: 11/11/2022]
Abstract
The intestinal mucosal barrier is critical for the absorption of nutrients and the health of both humans and animals. Recent publications from clinical and experimental studies have shown the importanceof the nutrients-bacteria-host interaction for the intestinal homeostasis. Dysfunction of these interactions has been reported to be associated with metabolic disorders and development of intestinal diseases, such as the irritable bowel syndrome and inflammatory bowel diseases. Tryptophan and its metabolites, including kynurenine, kynurenic acid, and 5-hydroxytrptamine, can influence the proliferation of enterocytes, intestinal integrity and immune response, as well as intestinal microbiota, therefore regulating and contributing to the intestinal health. In this review, we highlight recent findings on the effect of tryptophan and its metabolites on the mucosal barrier and intestinal homeostasis and its regulation of innate immune response. Moreover, we present the signaling pathways related to Trp metabolism, such as mammalian target of rapamycin, aryl hydrocarbon receptor, and pregnane X receptor, that contribute to the intestinal homeostasis and discuss future perspectives on spontaneous interference in host tryptophan metabolism as potential clinical strategies of intestinal diseases. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yunke Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100193, China
| | - Ning Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100193, China
| | - Yao Ge
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100193, China
| | - Ying Yang
- State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193, China
| | - Fazheng Ren
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100193, China
| | - Zhenlong Wu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100193, China.,State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193, China
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12
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Gao X, Ding J, Liao C, Xu J, Liu X, Lu W. Defensins: The natural peptide antibiotic. Adv Drug Deliv Rev 2021; 179:114008. [PMID: 34673132 DOI: 10.1016/j.addr.2021.114008] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/28/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022]
Abstract
Defensins are a family of cationic antimicrobial peptides active against a broad range of infectious microbes including bacteria, viruses and fungi, playing important roles as innate effectors and immune modulators in immunological control of microbial infection. Their antibacterial properties and unique mechanisms of action have garnered considerable interest in developing defensins into a novel class of natural antibiotic peptides to fend off pathogenic infection by bacteria, particularly those resistant to conventional antibiotics. However, serious pharmacological and technical obstacles, some of which are unique to defensins and others are common to peptide drugs in general, have hindered the development and clinical translation of defensins as anti-infective therapeutics. To overcome them, several technologies have been developed, aiming for improved functionality, prolonged circulation time, enhanced proteolytic stability and bioavailability, and efficient and controlled delivery and release of defensins to the site of infection. Additional challenges include the alleviation of potential toxicity of defensins and their cost-effective manufacturing. In this review, we briefly introduce defensin biology, focus on various transforming strategies and practical techniques developed for defensins and their derivatives as antibacterial therapeutics, and conclude with a summation of future challenges and possible solutions.
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13
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Evaluation of the Binding Mechanism of Human Defensin 5 in a Bacterial Membrane: A Simulation Study. Int J Mol Sci 2021; 22:ijms222212401. [PMID: 34830284 PMCID: PMC8619297 DOI: 10.3390/ijms222212401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/11/2021] [Accepted: 11/15/2021] [Indexed: 12/27/2022] Open
Abstract
Human α-defensin 5 (HD5) is a host-defense peptide exhibiting broad-spectrum antimicrobial activity. The lipopolysaccharide (LPS) layer on the Gram-negative bacterial membrane acts as a barrier to HD5 insertion. Therefore, the pore formation and binding mechanism remain unclear. Here, the binding mechanisms at five positions along the bacterial membrane axis were investigated using Molecular Dynamics. (MD) simulations. We found that HD5 initially placed at positions 1 to 3 moved up to the surface, while HD5 positioned at 4 and 5 remained within the membrane interacting with the middle and inner leaflet of the membrane, respectively. The arginines were key components for tighter binding with 3-deoxy-d-manno-octulosonic acid (KDO), phosphates of the outer and inner leaflets. KDO appeared to retard the HD5 penetration.
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14
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Luo X, Wu W, Feng L, Treves H, Ren M. Short Peptides Make a Big Difference: The Role of Botany-Derived AMPs in Disease Control and Protection of Human Health. Int J Mol Sci 2021; 22:11363. [PMID: 34768793 PMCID: PMC8583512 DOI: 10.3390/ijms222111363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/16/2021] [Accepted: 10/19/2021] [Indexed: 11/17/2022] Open
Abstract
Botany-derived antimicrobial peptides (BAMPs), a class of small, cysteine-rich peptides produced in plants, are an important component of the plant immune system. Both in vivo and in vitro experiments have demonstrated their powerful antimicrobial activity. Besides in plants, BAMPs have cross-kingdom applications in human health, with toxic and/or inhibitory effects against a variety of tumor cells and viruses. With their diverse molecular structures, broad-spectrum antimicrobial activity, multiple mechanisms of action, and low cytotoxicity, BAMPs provide ideal backbones for drug design, and are potential candidates for plant protection and disease treatment. Lots of original research has elucidated the properties and antimicrobial mechanisms of BAMPs, and characterized their surface receptors and in vivo targets in pathogens. In this paper, we review and introduce five kinds of representative BAMPs belonging to the pathogenesis-related protein family, dissect their antifungal, antiviral, and anticancer mechanisms, and forecast their prospects in agriculture and global human health. Through the deeper understanding of BAMPs, we provide novel insights for their applications in broad-spectrum and durable plant disease prevention and control, and an outlook on the use of BAMPs in anticancer and antiviral drug design.
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Affiliation(s)
- Xiumei Luo
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu Agricultural Science and Technology Center, Chengdu 610000, China; (X.L.); (W.W.); (L.F.)
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China
| | - Wenxian Wu
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu Agricultural Science and Technology Center, Chengdu 610000, China; (X.L.); (W.W.); (L.F.)
| | - Li Feng
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu Agricultural Science and Technology Center, Chengdu 610000, China; (X.L.); (W.W.); (L.F.)
| | - Haim Treves
- School of Plant Sciences and Food Security, Tel-Aviv University, Tel-Aviv 69978, Israel;
| | - Maozhi Ren
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu Agricultural Science and Technology Center, Chengdu 610000, China; (X.L.); (W.W.); (L.F.)
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
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15
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Awang T, Pongprayoon P. The penetration of human defensin 5 (HD5) through bacterial outer membrane: simulation studies. J Mol Model 2021; 27:291. [PMID: 34546425 DOI: 10.1007/s00894-021-04915-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/13/2021] [Indexed: 11/24/2022]
Abstract
Human α-defensin 5 (HD5) is one of cationic antimicrobial peptides which plays a crucial role in an innate immune system in human body. HD5 shows the killing activity against a broad spectrum of pathogenic bacteria by making a pore in a bacterial membrane and penetrating into a cytosol. Nonetheless, its pore-forming mechanisms remain unclear. Thus, in this work, the constant-velocity steered molecular dynamics (SMD) simulation was used to simulate the permeation of a dimeric HD5 into a gram-negative lipopolysaccharide (LPS) membrane model. Arginine-rich HD5 is found to strongly interact with a LPS surface. Upon arrival, arginines on HD5 interact with lipid A head groups (a top part of LPS) and then drag these charged moieties down into a hydrophobic core resulting in the formation of water-filled pore. Although all arginines are found to interact with a membrane, Arg13 and Arg32 appear to play a dominant role in the HD5 adsorption on a gram-negative membrane. Furthermore, one chain of a dimeric HD5 is required for HD5 adhesion. The interactions of arginine-lipid A head groups play a major role in adhering a cationic HD5 on a membrane surface and retarding a HD5 passage in the meantime.
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Affiliation(s)
- Tadsanee Awang
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
| | - Prapasiri Pongprayoon
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand. .,Center for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, KU Institute for Advanced Studies, Kasetsart University, Bangkok, 10900, Thailand.
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16
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Zong X, Fu J, Xu B, Wang Y, Jin M. Interplay between gut microbiota and antimicrobial peptides. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2020; 6:389-396. [PMID: 33364454 PMCID: PMC7750803 DOI: 10.1016/j.aninu.2020.09.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/09/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022]
Abstract
The gut microbiota is comprised of a diverse array of microorganisms that interact with immune system and exert crucial roles for the health. Changes in the gut microbiota composition and functionality are associated with multiple diseases. 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. Major players in this scenario are antimicrobial peptides (AMP), which belong to an ancient defense system found in all organisms and participate in a preservative co-evolution with a complex microbiome. Particularly increasing interactions between AMP and microbiota have been found in the gut. Here, we focus on the mechanisms by which AMP help to maintain a balanced microbiota and advancing our understanding of the circumstances of such balanced interactions between gut microbiota and host AMP. This review aims to provide a comprehensive overview on the interplay of diverse antimicrobial responses with enteric pathogens and the gut microbiota, which should have therapeutic implications for different intestinal disorders.
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Affiliation(s)
- Xin Zong
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jie Fu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Bocheng Xu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yizhen Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Mingliang Jin
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
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17
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Klein ML, Romero A, Kaltner H, Percec V, Gabius HJ. From examining the relationship between (corona)viral adhesins and galectins to glyco-perspectives. Biophys J 2020; 120:1031-1039. [PMID: 33248129 DOI: 10.1016/j.bpj.2020.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/23/2020] [Accepted: 11/17/2020] [Indexed: 12/16/2022] Open
Abstract
Glycan-lectin recognition is vital to processes that impact human health, including viral infections. Proceeding from crystallographical evidence of case studies on adeno-, corona-, and rotaviral spike proteins, the relationship of these adhesins to mammalian galectins was examined by computational similarity assessments. Intrafamily diversity among human galectins was in the range of that to these viral surface proteins. Our findings are offered to inspire the consideration of lectin-based approaches to thwart infection by present and future viral threats, also mentioning possible implications for vaccine development.
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Affiliation(s)
- Michael L Klein
- Institute of Computational Molecular Science, Temple University, Philadelphia, Pennsylvania.
| | - Antonio Romero
- Department of Structural and Chemical Biology, CIB Margarita Salas, CSIC, Madrid, Spain
| | - Herbert Kaltner
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Virgil Percec
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany.
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18
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Batra V, Dagar K, Nayak S, Kumaresan A, Kumar R, Datta TK. A Higher Abundance of O-Linked Glycans Confers a Selective Advantage to High Fertile Buffalo Spermatozoa for Immune-Evasion From Neutrophils. Front Immunol 2020; 11:1928. [PMID: 32983120 PMCID: PMC7483552 DOI: 10.3389/fimmu.2020.01928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 07/17/2020] [Indexed: 12/26/2022] Open
Abstract
The glycans on the plasma membrane of cells manifest as the glycocalyx, which serves as an information-rich frontier that is directly in contact with its immediate milieu. The glycoconjugates (GCs) that adorn most of the mammalian cells are also abundant in gametes, especially the spermatozoa where they perform unique reproduction-specific functions e.g., inter-cellular recognition and communication. This study aimed to implicate the sperm glycosylation pattern as one of the factors responsible for low conception rates observed in buffalo bulls. We hypothesized that a differential abundance of glycans exists on the spermatozoa from bulls of contrasting fertilizing abilities endowing them with differential immune evasion abilities. Therefore, we investigated the role of glycan abundance in the phagocytosis and NETosis rates exhibited by female neutrophils (PMNs) upon exposure to such spermatozoa. Our results indicated that the spermatozoa from high fertile (HF) bulls possessed a higher abundance of O-linked glycans e.g., galactosyl (β-1,3)N-acetylgalactosamine and N-linked glycans like [GlcNAc]1-3, N-acetylglucosamine than the low fertile (LF) bull spermatozoa. This differential glycomic endowment appeared to affect the spermiophagy and NETosis rates exhibited by the female neutrophil cells (PMNs). The mean percentage of phagocytizing PMNs was significantly different (P < 0.0001) for HF and LF bulls, 28.44 and 59.59%, respectively. Furthermore, any introduced perturbations in the inherent sperm glycan arrangements promoted phagocytosis by PMNs. For example, after in vitro capacitation the mean phagocytosis rate (MPR) rate in spermatozoa from HF bulls significantly increased to 66.49% (P < 0.01). Likewise, the MPR increased to 70.63% (p < 0.01) after O-glycosidase & α2-3,6,8,9 Neuraminidase A treatment of spermatozoa from HF bulls. Moreover, the percentage of PMNs forming neutrophil extracellular traps (NETs) was significantly higher, 41.47% when exposed to spermatozoa from LF bulls vis-à-vis the spermatozoa from HF bulls, 15.46% (P < 0.0001). This is a pioneer report specifically demonstrating the role of O-linked glycans in the immune responses mounted against spermatozoa. Nevertheless, further studies are warranted to provide the measures to diagnose the sub-fertile phenotype thus preventing the losses incurred by incorrect selection of morphologically normal sperm in the AI/IVF reproduction techniques.
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Affiliation(s)
- Vipul Batra
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India
| | - Komal Dagar
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India
| | - Samiksha Nayak
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India
| | - Arumugam Kumaresan
- Theriogenelogy Laboratory, SRS of National Dairy Research Institute, Bengaluru, India
| | - Rakesh Kumar
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India
| | - Tirtha K Datta
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, India
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19
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Böffert R, Businger R, Preiß H, Ehmann D, Truffault V, Simon C, Ruetalo N, Hamprecht K, Müller P, Wehkamp J, Schindler M. The human α-defensin-derived peptide HD5(1-9) inhibits cellular attachment and entry of human cytomegalovirus. Antiviral Res 2020; 177:104779. [PMID: 32209394 DOI: 10.1016/j.antiviral.2020.104779] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 10/24/2022]
Abstract
Human cytomegalovirus (HCMV) infection causes severe illness in newborns and immunocompromised patients. Since treatment options are limited there is an unmet need for new therapeutic approaches. Defensins are cationic peptides, produced by various human tissues, which serve as antimicrobial effectors of the immune system. Furthermore, some defensins are proteolytically cleaved, resulting in the generation of smaller fragments with increased activity. Together, this led us to hypothesize that defensin-derived peptides are natural human inhibitors of virus infection with low toxicity. We screened several human defensin HNP4- and HD5-derived peptides and found HD5(1-9) to be antiviral without toxicity at high concentrations. HD5(1-9) inhibited HCMV cellular attachment and thereby entry and was active against primary as well as a multiresistant HCMV isolate. Moreover, cysteine and arginine residues were identified to mediate the antiviral activity of HD5(1-9). Altogether, defensin-derived peptides, in particular HD5(1-9), qualify as promising candidates for further development as a novel class of HCMV entry inhibitors.
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Affiliation(s)
- Rebecca Böffert
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Ramona Businger
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Hannes Preiß
- Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany
| | - Dirk Ehmann
- Department for Internal Medicine I, University Hospital Tübingen, Tübingen, Germany
| | | | - Claudia Simon
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Natalia Ruetalo
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Klaus Hamprecht
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Patrick Müller
- Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany; Translational Oncology Division, University Hospital Tübingen, Tübingen, Germany
| | - Jan Wehkamp
- Department for Internal Medicine I, University Hospital Tübingen, Tübingen, Germany
| | - Michael Schindler
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany.
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20
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Mookherjee N, Anderson MA, Haagsman HP, Davidson DJ. Antimicrobial host defence peptides: functions and clinical potential. Nat Rev Drug Discov 2020; 19:311-332. [DOI: 10.1038/s41573-019-0058-8] [Citation(s) in RCA: 425] [Impact Index Per Article: 106.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2019] [Indexed: 12/18/2022]
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21
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Huang J, Qi Y, Wang A, Huang C, Liu X, Yang X, Li L, Zhou R. Porcine β-defensin 2 inhibits proliferation of pseudorabies virus in vitro and in transgenic mice. Virol J 2020; 17:18. [PMID: 32014007 PMCID: PMC6998849 DOI: 10.1186/s12985-020-1288-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/20/2020] [Indexed: 12/31/2022] Open
Abstract
Background Porcine β-defensin 2 (PBD-2), produced by host cells, is an antimicrobial cysteine-rich cationic peptide with multi-functions. Previous studies have demonstrated that PBD-2 can kill various bacteria, regulate host immune responses and promote growth of piglets. However, the antiviral role of PBD-2 is rarely investigated. This study aimed to reveal the antiviral ability of PBD-2 against pseudorabies virus (PRV), the causative pathogen of Aujeszky’s disease, in PK-15 cells and in a PBD-2 expressing transgenic (TG) mouse model. Methods In this study, the cytotoxicity of PBD-2 on PK-15 cells was measured by CCK-8 assay. PK-15 cells were incubated with PRV pre-treated with different concentrations of PBD-2 and PRV titers in cell culture supernatants were determined by real-time quantitative PCR (RT-qPCR). TG mice and wild-type (WT) mice were intraperitoneally injected with PRV and the survival rate was recorded for 10 days. Meanwhile, tissue lesions in brain, spleen and liver of infected mice were observed and the viral loads of PRV in brain, liver and lung were analyzed by RT-qPCR. Results PBD-2 at a maximum concentration of 80 μg/mL displayed no significant cytotoxicity on PK-15 cells. A threshold concentration of PBD-2 at 40 μg/mL was required to inhibit PRV proliferation in PK-15 cells. The survival rate in PBD-2 TG mice was 50% higher than that of WT mice. In addition, TG mice showed alleviated tissue lesions in brain, spleen and liver compared with their WT littermates after PRV challenge, while viral loads of PRV in brain, liver and lung of TG mice were significantly lower than that of WT mice. Conclusions PBD-2 could inhibit PRV proliferation in PK-15 cells and protect mice from PRV infection, which confirmed the antiviral ability of PBD-2 both in vitro and in vivo. The application of PBD-2 in developing anti-viral drugs or disease-resistant animals can be further investigated.
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Affiliation(s)
- Jing Huang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China
| | - Yanhua Qi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China
| | - Antian Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China
| | - Chao Huang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China
| | - Xiao Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China
| | - Xi Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Lu Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China. .,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China. .,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Wuhan, 430070, China. .,International Research Center for Animal Disease, Ministry of Science and Technology of the People's Republic of China, Wuhan, 430070, China.
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China. .,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, 430070, China. .,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Wuhan, 430070, China. .,International Research Center for Animal Disease, Ministry of Science and Technology of the People's Republic of China, Wuhan, 430070, China.
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22
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Zhao G, Chen Y, He Y, Chen F, Gong Y, Chen S, Xu Y, Su Y, Wang C, Wang J. Succinylated casein-coated peptide-mesoporous silica nanoparticles as an antibiotic against intestinal bacterial infection. Biomater Sci 2019; 7:2440-2451. [PMID: 30939184 DOI: 10.1039/c9bm00003h] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Increasing drug resistance necessitates the discovery of novel bactericides. Human defensin (HD) peptides can eliminate resistant bacteria and are promising candidates for next-generation antibiotics. T7E21R-HD5 is a potent bactericide designed by site mutations at enteric HD5. To facilitate the development of T7E21R-HD5 into an intestinal antibiotic, we employed a mesoporous silica nanoparticle (MSN) as the peptide carrier. Despite its ineffectiveness at killing bacteria, the MSN intensified the outer membrane penetration and inner membrane permeabilization abilities of T7E21R-HD5 and thus enhanced its antibacterial action against multidrug resistant (MDR) E. coli, which broadened the role of MSNs in drug delivery. For the reduction in T7E21R-HD5 losses in the stomach, we further modified MSN@T7E21R-HD5 with succinylated casein (SCN), a milk protein that can be specifically degraded by intestinal protease. SCN coating decreased T7E21R-HD5 release from the MSNs, especially in a highly acidic environment. The controlled release of MSN@T7E21R-HD5 from SCN encapsulation was confirmed in the presence of trypsin. MSN@T7E21R-HD5@SCN was nontoxic to host cells, and it was capable of inactivating MDR E. coli in vivo and alleviating intestinal inflammation by suppressing the production of inflammatory factors TNF-α, IL-1β, and MMP-9. This study provides a peptide-based nanobiotic with efficacy to combat intestinal infection, especially against drug-resistant bacteria. The biocompatible and readily prepared MSN/SCN delivery system may benefit further intestinal antibiotic design and promote the drug transformation of additional enterogenic functional molecules.
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Affiliation(s)
- Gaomei Zhao
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.
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23
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Chen F, Tang Y, Zheng H, Xu Y, Wang J, Wang C. Roles of the Conserved Amino Acid Residues in Reduced Human Defensin 5: Cysteine and Arginine Are Indispensable for Its Antibacterial Action and LPS Neutralization. ChemMedChem 2019; 14:1457-1465. [DOI: 10.1002/cmdc.201900282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/21/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Fang Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive MedicineThird Military Medical University Chongqing 400038 China
| | - Yong Tang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive MedicineThird Military Medical University Chongqing 400038 China
| | - Hong Zheng
- Department of Thoracic Surgery, Xinqiao HospitalThird Military Medical University Chongqing 400037 China
| | - Yang Xu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive MedicineThird Military Medical University Chongqing 400038 China
| | - Junping Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive MedicineThird Military Medical University Chongqing 400038 China
| | - Cheng Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive MedicineThird Military Medical University Chongqing 400038 China
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Murphy AG, Maloy KJ. Defens-IN! Human α-Defensin 5 Acts as an Unwitting Double Agent to Promote Shigella Infection. Immunity 2019; 48:1070-1072. [PMID: 29924970 DOI: 10.1016/j.immuni.2018.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Shigella pathogenesis has confounded researchers for years because of its narrow host selectivity and extraordinary infectious capability. In this issue of Immunity, Xu et al. (2018) identify a cunning mechanism whereby Shigella hijacks human α-defensin 5 to enhance its adhesion and subsequent invasion.
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Affiliation(s)
- Alison G Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Kevin J Maloy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
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25
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Hu H, Di B, Tolbert WD, Gohain N, Yuan W, Gao P, Ma B, He Q, Pazgier M, Zhao L, Lu W. Systematic mutational analysis of human neutrophil α-defensin HNP4. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:835-844. [PMID: 30658057 DOI: 10.1016/j.bbamem.2019.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 12/19/2018] [Accepted: 01/13/2019] [Indexed: 12/28/2022]
Abstract
Defensins are a family of cationic antimicrobial peptides of innate immunity with immunomodulatory properties. The prototypic human α-defensins, also known as human neutrophil peptides 1-3 or HNP1-3, are extensively studied for their structure, function and mechanisms of action, yet little is known about HNP4 - the much less abundant "distant cousin" of HNP1-3. Here we report a systematic mutational analysis of HNP4 with respect to its antibacterial activity against E. coli and S. aureus, inhibitory activity against anthrax lethal factor (LF), and binding activity for LF and HIV-1 gp120. Except for nine conserved and structurally important residues (6xCys, 1xArg, 1xGlu and 1xGly), the remaining 24 residues of HNP4 were each individually mutated to Ala. The crystal structures of G23A-HNP4 and T27A-HNP4 were determined, both exhibiting a disulfide-stabilized canonical α-defensin dimer identical to wild-type HNP4. Unlike HNP1-3, HNP4 preferentially killed the Gram-negative bacterium, a property largely attributable to three clustered cationic residues Arg10, Arg11 and Arg15. The cationic cluster was also important for HNP4 killing of S. aureus, inhibition of LF and binding to LF and gp120. However, F26A, while functionally inconsequential for E. coli killing, was far more deleterious than any other mutations. Similarly, N-methylation of Leu20 to destabilize the HNP4 dimer had little effect on E. coli killing, but significantly reduced the ability of HNP4 to kill S. aureus, inhibit LF, and bind to LF and gp120. Our findings unveil the molecular determinants of HNP4 function, completing the atlas of structure and function relationships for all human neutrophil α-defensins.
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Affiliation(s)
- Han Hu
- Key Laboratory of Fermentation Engineering, Ministry of Education, College of Bioengineering, Hubei University of Technology, Wuhan, China; Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - Bin Di
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - William D Tolbert
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - Neelakshi Gohain
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - Weirong Yuan
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - Pan Gao
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - Bohan Ma
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
| | - Qigai He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Marzena Pazgier
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA.
| | - Le Zhao
- Center for Translational Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
| | - Wuyuan Lu
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA
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26
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The adsorption of human defensin 5 on bacterial membranes: simulation studies. J Mol Model 2018; 24:273. [PMID: 30187138 DOI: 10.1007/s00894-018-3812-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/27/2018] [Indexed: 01/16/2023]
Abstract
Human α-defensin 5 (HD5) is one of the important antimicrobial peptides (AMPs) used against a broad-spectrum of pathogens, especially Gram-negative bacteria. HD5 kills by disrupting and making a pore in the bacterial membrane. The presence of lipopolysaccharide (LPS), located on a membrane surface, is found to have an impact on HD5's activity, where such binding mechanism in microscopic detail remains unclear. In this work, we therefore employed molecular dynamics (MD) simulations to investigate the binding mechanisms of HD5 on LPS in comparison to a bare DMPC lipid membrane. Two oligomers, dimer and tetramer, are studied here. Apparently, the membrane structure influences the protein binding affinity. HD5 binds tighter to a lipid membrane than LPS. Both dimeric and tetrameric HD5 can penetrate deeply into a phosphate layer in a lipid membrane, whereas only facial contacts are observed for LPS systems. The proteins appear to stay in the polar area instead of diving into a hydrophobic region. Furthermore, it happens in all cases that residues in the active region (A1, T2, R6, R13, R32) contribute to the membrane adsorption. The breakdown of tetramer into two dimers is also found. This implies that the dimer is more favorable for membrane binding. Moreover, both dimeric and tetrameric HD5 can significantly disrupt a LPS layer, whilst no serious distortion of lipid membrane is obtained. This emphasizes the importance of LPS on HD5 activity.
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27
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Xu D, Liao C, Zhang B, Tolbert WD, He W, Dai Z, Zhang W, Yuan W, Pazgier M, Liu J, Yu J, Sansonetti PJ, Bevins CL, Shao Y, Lu W. Human Enteric α-Defensin 5 Promotes Shigella Infection by Enhancing Bacterial Adhesion and Invasion. Immunity 2018; 48:1233-1244.e6. [PMID: 29858013 PMCID: PMC6051418 DOI: 10.1016/j.immuni.2018.04.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 02/18/2018] [Accepted: 04/13/2018] [Indexed: 01/07/2023]
Abstract
Shigella is a Gram-negative bacterium that causes bacillary dysentery worldwide. It invades the intestinal epithelium to elicit intense inflammation and tissue damage, yet the underlying mechanisms of its host selectivity and low infectious inoculum remain perplexing. Here, we report that Shigella co-opts human α-defensin 5 (HD5), a host defense peptide important for intestinal homeostasis and innate immunity, to enhance its adhesion to and invasion of mucosal tissues. HD5 promoted Shigella infection in vitro in a structure-dependent manner. Shigella, commonly devoid of an effective host-adhesion apparatus, preferentially targeted HD5 to augment its ability to colonize the intestinal epithelium through interactions with multiple bacterial membrane proteins. HD5 exacerbated infectivity and Shigella-induced pathology in a culture of human colorectal tissues and three animal models. Our findings illuminate how Shigella exploits innate immunity by turning HD5 into a virulence factor for infection, unveiling a mechanism of action for this highly proficient human pathogen.
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Affiliation(s)
- Dan Xu
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China,Center for Translational Medicine, Frontier Institute of Science and Technology, Xi’an Jiaotong University,Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Chongbing Liao
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China,Center for Translational Medicine, Frontier Institute of Science and Technology, Xi’an Jiaotong University
| | - Bing Zhang
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China
| | - W. David Tolbert
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Wangxiao He
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China,Center for Translational Medicine, Frontier Institute of Science and Technology, Xi’an Jiaotong University,Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Zhijun Dai
- The Second Affiliated Hospital, Xi’an Jiaotong University School of Medicine
| | - Wei Zhang
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Weirong Yuan
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Marzena Pazgier
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jiankang Liu
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Jun Yu
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK
| | | | - Charles L. Bevins
- Department of Microbiology and Immunology, University of California, School of Medicine, Davis, California, USA
| | - Yongping Shao
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China,Center for Translational Medicine, Frontier Institute of Science and Technology, Xi’an Jiaotong University,Correspondence to: (lead contact) or
| | - Wuyuan Lu
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China,Center for Translational Medicine, Frontier Institute of Science and Technology, Xi’an Jiaotong University,Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA,Correspondence to: (lead contact) or
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Park MS, Kim JI, Lee I, Park S, Bae JY, Park MS. Towards the Application of Human Defensins as Antivirals. Biomol Ther (Seoul) 2018; 26:242-254. [PMID: 29310427 PMCID: PMC5933891 DOI: 10.4062/biomolther.2017.172] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/29/2017] [Accepted: 10/12/2017] [Indexed: 12/14/2022] Open
Abstract
Defensins are antimicrobial peptides that participate in the innate immunity of hosts. Humans constitutively and/or inducibly express α- and β-defensins, which are known for their antiviral and antibacterial activities. This review describes the application of human defensins. We discuss the extant experimental results, limited though they are, to consider the potential applicability of human defensins as antiviral agents. Given their antiviral effects, we propose that basic research be conducted on human defensins that focuses on RNA viruses, such as human immunodeficiency virus (HIV), influenza A virus (IAV), respiratory syncytial virus (RSV), and dengue virus (DENV), which are considered serious human pathogens but have posed huge challenges for vaccine development for different reasons. Concerning the prophylactic and therapeutic applications of defensins, we then discuss the applicability of human defensins as antivirals that has been demonstrated in reports using animal models. Finally, we discuss the potential adjuvant-like activity of human defensins and propose an exploration of the ‘defensin vaccine’ concept to prime the body with a controlled supply of human defensins. In sum, we suggest a conceptual framework to achieve the practical application of human defensins to combat viral infections.
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Affiliation(s)
- Mee Sook Park
- Department of Microbiology, Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Jin Il Kim
- Department of Microbiology, Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Ilseob Lee
- Department of Microbiology, Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Sehee Park
- Department of Microbiology, Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Joon-Yong Bae
- Department of Microbiology, Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea
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A Simplified Derivative of Human Defensin 5 with Potent and Efficient Activity against Multidrug-Resistant Acinetobacter baumannii. Antimicrob Agents Chemother 2018; 62:AAC.01504-17. [PMID: 29158275 DOI: 10.1128/aac.01504-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/04/2017] [Indexed: 02/08/2023] Open
Abstract
The increasing incidence of multidrug-resistant Acinetobacter baumannii (MDRAb) infections worldwide has necessitated the development of novel antibiotics. Human defensin 5 (HD5) is an endogenous peptide with a complex architecture and antibacterial activity against MDRAb In the present study, we attempted to simplify the structure of HD5 by removing disulfide bonds. We found that the Cys2-4 bond was most indispensable for HD5 to inactivate MDRAb, although the antibacterial activity of the derivative was significantly attenuated. We then replaced the noncationic and nonhydrophobic residues with electropositive Arg to increase the antibacterial activity of HD5 derivative that contains a Cys2-4 bond, obtaining another derivative termed HD5d5. The in vitro antibacterial assay and irradiation-wound-infection animal experiment both showed that HD5d5 was much more effective than HD5 at eliminating MDRAb Further investigations revealed that HD5d5 efficiently bound to outer membrane lipid A and penetrated membranes, leading to bacterial collapse and peptide translocation. Compared to HD5, more HD5d5 molecules were located in the cytoplasm of MDRAb, and HD5d5 was more efficient at reducing the activities of superoxide dismutase and catalase, causing the accumulation of reactive oxygen species that are detrimental to microbes. In addition, HD5 failed to suppress the pathogenic outer membrane protein A of Acinetobacter baumannii (AbOmpA) at concentrations up to 50 μg/ml, whereas HD5d5 strongly bound to AbOmpA and exhibited a dramatic toxin-neutralizing ability, thus expanding the repertoire of drugs that is available to treat MDRAb infections.
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30
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Liu X, Chen Q, Luo Y, Hu Y, Lai D, Zhang X, Zhang X, Yu J, Fang X, Shu Q. Plasma levels of alarmin HNPs 1-3 associate with lung dysfunction after cardiac surgery in children. BMC Pulm Med 2017; 17:218. [PMID: 29282039 PMCID: PMC5745992 DOI: 10.1186/s12890-017-0558-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 12/07/2017] [Indexed: 11/10/2022] Open
Abstract
Background Early onset of lung injury is considerable common after cardiac surgery and is associated with increasing in morbidity and mortality, but current clinical predictors for the occurrence of this complication always have limited positive warning value. This study aimed to evaluate whether elevated plasma levels of human neutrophil peptides (HNPs) 1–3 herald impaired lung function in infants and young children after cardiac surgery necessitating cardiopulmonary bypass (CPB). Methods Consecutive children younger than 3 years old who underwent cardiac surgery were prospectively enrolled. Plasma concentrations of HNPs 1–3 and inflammatory cytokines were measured before, and immediately after CPB, as well as at 1 h, 12 h, and 24 h after CPB. Results Thirty patients were enrolled, 18 (60%) of whom were infants. Plasma levels of HNPs 1–3 and the pro-inflammatory cytokine interleukin-6 (IL-6) significantly increased immediately after CPB (P < 0.001), while IL-8 increased 1 h after the CPB operation (P = 0.002). The anti-inflammatory cytokine IL-10 levels were also significantly elevated immediately after CPB compared with the baseline (P < 0.001). The stepwise multiple linear regression analysis showed that the plasma HNPs 1–3 levels immediately after CPB was independent correlated with the declined lung function, as reflected by the PaO2/FiO2 ratio on the first 2 days after operation (for the first day: OR, −1.067, 95% CI, −0.548 to −1.574; P < 0.001; for the second day: OR, −0.667, 95% CI, −0.183 to −1.148; P = 0.009) and prolonged mechanical ventilation time (OR, 0.039, 95% CI, 0.005 to 0.056; P = 0.011). Plasma levels of HNPs 1–3 and IL-10 returned to the baseline values, while IL-6 and IL-8 levels remained significantly higher than baseline 24 h after CPB (P ≤ 0.01). Conclusions Elevated HNPs 1–3 levels immediately after CPB correlate with impaired lung function, and HNPs 1–3 could serve as a quantifiable early alarmin biomarker for onset of lung injury in infants and young children undergoing cardiac surgery with CPB. Electronic supplementary material The online version of this article (10.1186/s12890-017-0558-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- XiWang Liu
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - QiXing Chen
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - YuJia Luo
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - YaoQin Hu
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - DengMing Lai
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - XiaoLe Zhang
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - XiangHong Zhang
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - JianGen Yu
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China
| | - XiangMing Fang
- Department of Anesthesiology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
| | - Qiang Shu
- Department of Thoracic & Cardiovascular Surgery, Children's Hospital, Zhejiang University School of Medicine and Zhejiang Key Laboratory for Diagnosis and Therapy of Neonatal Diseases, 3333 Binsheng Road, Hangzhou, 310003, China.
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31
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Valere K, Lu W, Chang TL. Key Determinants of Human α-Defensin 5 and 6 for Enhancement of HIV Infectivity. Viruses 2017; 9:E244. [PMID: 28850095 PMCID: PMC5618010 DOI: 10.3390/v9090244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/13/2017] [Accepted: 08/24/2017] [Indexed: 12/22/2022] Open
Abstract
Defensins are antimicrobial peptides important for mucosal innate immunity. They exhibit a broad spectrum of activity against bacteria, viruses, and fungi. Levels of α-defensins are elevated at the genital mucosa of individuals with sexually transmitted infections (STIs). Somewhat paradoxically, human α-defensin 5 and 6 (HD5 and HD6) promote human immunodeficiency virus (HIV) infectivity, and contribute to STI-mediated enhancement of HIV infection in vitro. Specific amino acid residues of HD5 and HD6 that are crucial for antimicrobial activities have been characterized previously; however, the key determinants of defensins responsible for enhancement of HIV infectivity are not known. Here, we have identified residues of HD5 and HD6 that are required for enhancement of HIV attachment and infection. Most of these residues are involved in hydrophobicity and self-association of defensins. Specifically, we found that mutant defensins L16A-HD5, E21me-HD5, L26A-HD5, Y27A-HD5, F2A-HD6, H27W-HD6, and F29A-HD6 significantly lost their ability to promote HIV attachment and infection. L29A mutation also reduced HIV infection-enhancing activity of HD5. Additionally, a number of mutations in charged residues variably affected the profile of HIV attachment and infectivity. One HD5 charged mutation, R28A, notably resulted in a 34-48% loss of enhanced HIV infectivity and attachment. These results indicate that defensin determinants that maintain high-ordered amphipathic structure are crucial for HIV enhancing activity. In a comparative analysis of the mutant defensins, we found that for some defensin mutants enhancement of HIV infectivity was associated with the reverse transcription step, suggesting a novel, HIV attachment-independent, mechanism of defensin-mediated HIV enhancement.
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Affiliation(s)
- Kimyata Valere
- Department of Microbiology and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, NJ 07103, USA.
| | - Wuyuan Lu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21250, USA.
| | - Theresa L Chang
- Department of Microbiology and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, NJ 07103, USA.
- Public Health Research Institute, Rutgers University, New Jersey Medical School, 225 Warren Street, Newark, NJ 07103, USA.
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Abstract
α, β, and θ defensins are effectors of the innate immune system with potent antibacterial, antiviral, and antifungal activity. Defensins have direct antiviral activity in cell culture, with varied mechanisms for individual viruses, although some common themes have emerged. In addition, defensins have potent immunomodulatory activity that can alter innate and adaptive immune responses to viral infection. In some cases, there is evidence for paradoxical escape from defensin neutralization or enhancement of viral infection. The direct and indirect activities of defensins have led to their development as therapeutics and vaccine components. The major area of investigation that continues to lag is the connection between the effects of defensins in cell culture models and viral pathogenesis in vivo. Model systems to study defensin biology, including more physiologic models designed to bridge this gap, are also discussed.
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Affiliation(s)
- Mayumi K Holly
- Department of Microbiology, University of Washington, Seattle, Washington 98195;
| | - Karina Diaz
- Department of Microbiology, University of Washington, Seattle, Washington 98195;
| | - Jason G Smith
- Department of Microbiology, University of Washington, Seattle, Washington 98195;
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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: 61] [Impact Index Per Article: 8.7] [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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α-Defensin HD5 Inhibits Human Papillomavirus 16 Infection via Capsid Stabilization and Redirection to the Lysosome. mBio 2017; 8:mBio.02304-16. [PMID: 28119475 PMCID: PMC5263252 DOI: 10.1128/mbio.02304-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
α-Defensins are an important class of abundant innate immune effectors that are potently antiviral against a number of nonenveloped viral pathogens; however, a common mechanism to explain their ability to block infection by these unrelated viruses is lacking. We previously found that human defensin 5 (HD5) blocks a critical host-mediated proteolytic processing step required for human papillomavirus (HPV) infection. Here, we show that bypassing the requirement for this cleavage failed to abrogate HD5 inhibition. Instead, HD5 altered HPV trafficking in the cell. In the presence of an inhibitory concentration of HD5, HPV was internalized and reached the early endosome. The internalized capsid became permeable to antibodies and proteases; however, HD5 prevented dissociation of the viral capsid from the genome, reduced viral trafficking to the trans-Golgi network, redirected the incoming viral particle to the lysosome, and accelerated the degradation of internalized capsid proteins. This mechanism is equivalent to the mechanism by which HD5 inhibits human adenovirus. Thus, our data support capsid stabilization and redirection to the lysosome during infection as a general antiviral mechanism of α-defensins against nonenveloped viruses. IMPORTANCE Although the antiviral activity of α-defensins against enveloped viruses can be largely explained by interference with receptor binding and fusion, a common mechanism for inhibition of nonenveloped viruses remains elusive. In studies of a prominent human α-defensin that is expressed in the gut and in the male and female genitourinary tract, we discovered striking parallels between the mechanisms of inhibition of HPV and human adenovirus infection. Thus, detailed studies of the impact of α-defensins on the intracellular trafficking of two disparate viruses support a general mechanism of α-defensin antiviral activity against nonenveloped viruses.
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35
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Jung SW, Lee J, Cho AE. Elucidating the Bacterial Membrane Disruption Mechanism of Human α-Defensin 5: A Theoretical Study. J Phys Chem B 2017; 121:741-748. [PMID: 28067516 DOI: 10.1021/acs.jpcb.6b11806] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Human α-defensin 5 (HD5) is a broad-spectrum antibacterial peptide produced by small intestinal Paneth cells. Despite considerable experimental evidence for the correlation between bacterial membrane destruction and the antibacterial activity of HD5, its membrane disruption mechanism remains unclear. Using all-atom molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area analysis, we demonstrate the membrane disruption mechanism of HD5 based on the intrinsic binding of HD5 to Gram-negative (GN) bacterial inner membrane. It was found that both monomer and dimer forms of HD5 bind to the surface of the GN membrane rather than embedding in the hydrophobic core region of the bilayer. Regardless of the form of HD5, the peptide orientated itself similarly on the membrane surface with an inward-pointing electric dipole moment and an outward-pointing hydrophobic dipole moment. We investigated its possible membrane disruption mechanisms and determined that anionic lipid clustering is a plausible mode of action for HD5. Relative binding free energy analysis revealed that electrostatic interactions play a major role in this mechanism. Our findings shed light on the biophysical phenomena of HD5-GN membrane binding and suggest a possible membrane disruption mechanism for HD5. This analysis of the fundamental binding properties of the monomeric HD5-GN membrane complex provides a useful guide for defensin-derived antibiotic design.
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Affiliation(s)
- Sang Won Jung
- Department of Bioinformatics, Korea University , 2511 Sejong-ro, Sejong 30019, Republic of Korea
| | - Juho Lee
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology , 291 Deahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Art E Cho
- Department of Bioinformatics, Korea University , 2511 Sejong-ro, Sejong 30019, Republic of Korea
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36
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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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Elevated Plasma α-Defensins (HNP1-3) Levels Correlated with IgA1 Glycosylation and Susceptibility to IgA Nephropathy. DISEASE MARKERS 2016; 2016:8123138. [PMID: 27563166 PMCID: PMC4985581 DOI: 10.1155/2016/8123138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/11/2016] [Accepted: 06/22/2016] [Indexed: 11/27/2022]
Abstract
Aim. IgA nephropathy (IgAN) is the most common form of glomerulonephritis. Recent genome-wide association study (GWAS) suggested that DEFA locus (which encodes α-defensins) may play a key role in IgAN. Methods. The levels of α-defensins in 169 IgAN patients and 83 healthy controls were tested by ELISA. Results. We observed that α-defensins human neutrophil peptides 1–3 (HNP1–3) in IgAN patients were elevated compared with healthy controls. The mean levels of α-defensins of 83 healthy controls and 169 IgAN patients were 50 ng/mL and 78.42 ng/mL. When the results were adjusted to the mean levels of α-defensins of IgAN patients, the percentage of individuals with high levels of α-defensins increased in IgAN patients (22.5%) compared to healthy controls (9.6%) (p = 0.013). The elevation of α-defensins in IgAN patients was independent of renal function or neutrophil count, which were major sources of α-defensins in circulation. More importantly, negative correlation was observed between galactose-deficient IgA1and α-defensins. Conclusion. As α-defensin is a lectin-like peptide, we speculated that it might be involved in IgA galactose deficiency. The data implied that patients with IgAN had higher plasma α-defensins levels and high α-defensins correlated with IgA galactose deficiency, further suggesting a pathogenic role of α-defensins in IgAN.
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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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Zhang R, Loers G, Schachner M, Boelens R, Wienk H, Siebert S, Eckert T, Kraan S, Rojas-Macias MA, Lütteke T, Galuska SP, Scheidig A, Petridis AK, Liang S, Billeter M, Schauer R, Steinmeyer J, Schröder JM, Siebert HC. Molecular Basis of the Receptor Interactions of Polysialic Acid (polySia), polySia Mimetics, and Sulfated Polysaccharides. ChemMedChem 2016; 11:990-1002. [PMID: 27136597 DOI: 10.1002/cmdc.201500609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/01/2016] [Indexed: 02/05/2023]
Abstract
Polysialic acid (polySia) and polySia glycomimetic molecules support nerve cell regeneration, differentiation, and neuronal plasticity. With a combination of biophysical and biochemical methods, as well as data mining and molecular modeling techniques, it is possible to correlate specific ligand-receptor interactions with biochemical processes and in vivo studies that focus on the potential therapeutic impact of polySia, polySia glycomimetics, and sulfated polysaccharides in neuronal diseases. With this strategy, the receptor interactions of polySia and polySia mimetics can be understood on a submolecular level. As the HNK-1 glycan also enhances neuronal functions, we tested whether similar sulfated oligo- and polysaccharides from seaweed could be suitable, in addition to polySia, for finding potential new routes into patient care focusing on an improved cure for various neuronal diseases. The knowledge obtained here on the structural interplay between polySia or sulfated polysaccharides and their receptors can be exploited to develop new drugs and application routes for the treatment of neurological diseases and dysfunctions.
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Affiliation(s)
- Ruiyan Zhang
- RI-B-NT: Research Institute of Bioinformatics and Nanotechnology, Franziusallee 177, 24148, Kiel, Germany
- Zoological Institute, Department of Structural Biology, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Gabriele Loers
- Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, University of Hamburg, Falkenried 94, 20251, Hamburg, Germany
| | - Melitta Schachner
- Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, University of Hamburg, Falkenried 94, 20251, Hamburg, Germany
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Shantou, Guangdong, 515041, China
| | - Rolf Boelens
- Bijvoet Center for Biomolecular Research, NMR Spectroscopy, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Hans Wienk
- Bijvoet Center for Biomolecular Research, NMR Spectroscopy, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Simone Siebert
- RI-B-NT: Research Institute of Bioinformatics and Nanotechnology, Franziusallee 177, 24148, Kiel, Germany
| | - Thomas Eckert
- Institute of Veterinary Physiology and Biochemistry, Fachbereich Veterinärmedizin, Justus-Liebig-Universität Gießen, Frankfurter Str. 100, 35392, Gießen, Germany
- Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals, Justus-Liebig-Universität Gießen, Frankfurter Str. 106, 35392, Gießen, Germany
| | - Stefan Kraan
- Ocean Harvest Technology Ltd., N17 Business Park, Milltown, County Galway, Ireland
| | - Miguel A Rojas-Macias
- Institute of Veterinary Physiology and Biochemistry, Fachbereich Veterinärmedizin, Justus-Liebig-Universität Gießen, Frankfurter Str. 100, 35392, Gießen, Germany
| | - Thomas Lütteke
- Institute of Veterinary Physiology and Biochemistry, Fachbereich Veterinärmedizin, Justus-Liebig-Universität Gießen, Frankfurter Str. 100, 35392, Gießen, Germany
| | - Sebastian P Galuska
- Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-Universität Gießen, Friedrichstr. 24, 35392, Gießen, Germany
| | - Axel Scheidig
- Zoological Institute, Department of Structural Biology, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Athanasios K Petridis
- Neurosurgery Clinic, University Düsseldorf, Moorenstraße 5, 40255, Düsseldorf, Germany
| | - Songping Liang
- College of Life Sciences, Hunan Normal University, 410081, Changsha, China
| | - Martin Billeter
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 100, 40530, Gothenburg, Sweden
| | - Roland Schauer
- Institute of Biochemistry, Kiel University, Olshausenstr. 40, 24098, Kiel, Germany
| | - Jürgen Steinmeyer
- Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, University Hospital Giessen and Marburg GmbH, Paul-Meimberg-Str. 3, 35392, Gießen, Germany
| | - Jens-Michael Schröder
- Department of Dermatology, University Hospital Schleswig-Holstein, Campus Kiel, 24105, Kiel, Germany
| | - Hans-Christian Siebert
- RI-B-NT: Research Institute of Bioinformatics and Nanotechnology, Franziusallee 177, 24148, Kiel, Germany.
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40
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Synthesis and affinities of C3-symmetric thioglycoside-containing trimannosides. Carbohydr Res 2015; 412:56-65. [DOI: 10.1016/j.carres.2015.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 12/20/2022]
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41
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for 2009-2010. MASS SPECTROMETRY REVIEWS 2015; 34:268-422. [PMID: 24863367 PMCID: PMC7168572 DOI: 10.1002/mas.21411] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 07/16/2013] [Accepted: 07/16/2013] [Indexed: 05/07/2023]
Abstract
This review is the sixth update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2010. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, arrays and fragmentation are covered in the first part of the review and applications to various structural typed constitutes the remainder. The main groups of compound that are discussed in this section are oligo and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Many of these applications are presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis.
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Affiliation(s)
- David J. Harvey
- Department of BiochemistryOxford Glycobiology InstituteUniversity of OxfordOxfordOX1 3QUUK
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42
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Wang C, Shen M, Gohain N, Tolbert WD, Chen F, Zhang N, Yang K, Wang A, Su Y, Cheng T, Zhao J, Pazgier M, Wang J. Design of a potent antibiotic peptide based on the active region of human defensin 5. J Med Chem 2015; 58:3083-93. [PMID: 25782105 DOI: 10.1021/jm501824a] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Human defensin 5 (HD5) is a broad-spectrum antibacterial peptide with a C-terminal active region. To promote the development of this peptide into an antibiotic, we initially substituted Glu21 with Arg because it is an electronegative residue located around the active region. Although detrimental to dimer formation, the E21R substitution markedly enhanced the antibacterial activity of HD5 and increased its ability to penetrate cell membranes, demonstrating that increasing the electropositive charge compensated for the effect of dimer disruption. Subsequently, a partial Arg scanning mutagenesis was performed, and Thr7 was selected for replacement with Arg to further strengthen the antibacterial activity. The newly designed peptide, T7E21R-HD5, exhibited potent antibacterial activity, even in saline and serum solutions. In contrast to monomeric E21R-HD5, T7E21R-HD5 assembled into an atypical dimer with parallel β strands, thus expanding the role of increasing electropositive charge in bactericidal activity and providing a useful guide for further defensin-derived antibiotic design.
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Affiliation(s)
- Cheng Wang
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Mingqiang Shen
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Neelakshi Gohain
- ‡Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - William D Tolbert
- ‡Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Fang Chen
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Naixin Zhang
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Ke Yang
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.,§Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, China
| | - Aiping Wang
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Yongping Su
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Tianmin Cheng
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
| | - Jinghong Zhao
- §Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, China
| | - Marzena Pazgier
- ‡Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Junping Wang
- †State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China
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Maverakis E, Kim K, Shimoda M, Gershwin ME, Patel F, Wilken R, Raychaudhuri S, Ruhaak LR, Lebrilla CB. Glycans in the immune system and The Altered Glycan Theory of Autoimmunity: a critical review. J Autoimmun 2015; 57:1-13. [PMID: 25578468 DOI: 10.1016/j.jaut.2014.12.002] [Citation(s) in RCA: 298] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/03/2014] [Indexed: 12/24/2022]
Abstract
Herein we will review the role of glycans in the immune system. Specific topics covered include: the glycosylation sites of IgE, IgM, IgD, IgE, IgA, and IgG; how glycans can encode "self" identity by functioning as either danger associated molecular patterns (DAMPs) or self-associated molecular patterns (SAMPs); the role of glycans as markers of protein integrity and age; how the glycocalyx can dictate the migration pattern of immune cells; and how the combination of Fc N-glycans and Ig isotype dictate the effector function of immunoglobulins. We speculate that the latter may be responsible for the well-documented association between alterations of the serum glycome and autoimmunity. Due to technological limitations, the extent of these autoimmune-associated glycan alterations and their role in disease pathophysiology has not been fully elucidated. Thus, we also review the current technologies available for glycan analysis, placing an emphasis on Multiple Reaction Monitoring (MRM), a rapid high-throughput technology that has great potential for glycan biomarker research. Finally, we put forth The Altered Glycan Theory of Autoimmunity, which states that each autoimmune disease will have a unique glycan signature characterized by the site-specific relative abundances of individual glycan structures on immune cells and extracellular proteins, especially the site-specific glycosylation patterns of the different immunoglobulin(Ig) classes and subclasses.
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Affiliation(s)
- Emanual Maverakis
- Department of Dermatology, University of California, Davis School of Medicine, 3301 C Street, Suite 1400, Sacramento, CA 95816, USA.
| | - Kyoungmi Kim
- Department of Public Health Sciences, Division of Biostatistics, University of California, Davis Medical Center, Sacramento, CA 95816, USA
| | - Michiko Shimoda
- Department of Dermatology, University of California, Davis School of Medicine, 3301 C Street, Suite 1400, Sacramento, CA 95816, USA
| | - M Eric Gershwin
- Department of Internal Medicine, Division of Rheumatology, University of California, Davis School of Medicine, Sacramento, CA 95817, USA
| | - Forum Patel
- Department of Dermatology, University of California, Davis School of Medicine, 3301 C Street, Suite 1400, Sacramento, CA 95816, USA
| | - Reason Wilken
- Department of Dermatology, University of California, Davis School of Medicine, 3301 C Street, Suite 1400, Sacramento, CA 95816, USA
| | - Siba Raychaudhuri
- Department of Internal Medicine, Division of Rheumatology, University of California, Davis School of Medicine, Sacramento, CA 95817, USA
| | - L Renee Ruhaak
- Department of Public Health Sciences, Division of Biostatistics, University of California, Davis Medical Center, Sacramento, CA 95816, USA
| | - Carlito B Lebrilla
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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44
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Moser S, Chileveru HR, Tomaras J, Nolan EM. A bacterial mutant library as a tool to study the attack of a defensin peptide. Chembiochem 2014; 15:2684-8. [PMID: 25430675 DOI: 10.1002/cbic.201402354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Indexed: 01/06/2023]
Abstract
Defensin attack! Here we report the screening of human defensin 5 against the Keio Collection of E. coli strains. The results of this screen further our understanding of how this important hostdefense peptide kills bacteria and how bacteria protect themselves against the attack from the human host.
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Affiliation(s)
- Simone Moser
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
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45
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Delineation of interfaces on human alpha-defensins critical for human adenovirus and human papillomavirus inhibition. PLoS Pathog 2014; 10:e1004360. [PMID: 25188351 PMCID: PMC4154873 DOI: 10.1371/journal.ppat.1004360] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 07/26/2014] [Indexed: 12/18/2022] Open
Abstract
Human α-defensins are potent anti-microbial peptides with the ability to neutralize bacterial and viral targets. Single alanine mutagenesis has been used to identify determinants of anti-bacterial activity and binding to bacterial proteins such as anthrax lethal factor. Similar analyses of α-defensin interactions with non-enveloped viruses are limited. We used a comprehensive set of human α-defensin 5 (HD5) and human neutrophil peptide 1 (HNP1) alanine scan mutants in a combination of binding and neutralization assays with human adenovirus (AdV) and human papillomavirus (HPV). We have identified a core of critical hydrophobic residues that are common determinants for all of the virus-defensin interactions that were analyzed, while specificity in viral recognition is conferred by specific surface-exposed charged residues. The hydrophobic residues serve multiple roles in maintaining the tertiary and quaternary structure of the defensins as well as forming an interface for virus binding. Many of the important solvent-exposed residues of HD5 group together to form a critical surface. However, a single discrete binding face was not identified for HNP1. In lieu of whole AdV, we used a recombinant capsid subunit comprised of penton base and fiber in quantitative binding studies and determined that the anti-viral potency of HD5 was a function of stoichiometry rather than affinity. Our studies support a mechanism in which α-defensins depend on hydrophobic and charge-charge interactions to bind at high copy number to these non-enveloped viruses to neutralize infection and provide insight into properties that guide α-defensin anti-viral activity. Human α-defensins are an important component of the innate immune response and provide an initial block against a broad number of infectious agents, including viruses and bacteria. Characteristics of α-defensins that are necessary for their anti-bacterial activity have been identified, but our understanding of determinants required for activity against non-enveloped viruses is limited. In this work, we utilized alanine scan mutagenesis to systematically and comprehensively investigate the role of hydrophobic and charged residues of two α-defensins in binding to and/or neutralization of human adenovirus and human papillomavirus. Our results implicate common core hydrophobic residues as critical for inhibition of these non-enveloped viruses by the two α-defensins, with specificity provided by charged residues unique to each interaction. We also found that the number of α-defensin molecules bound to the virus was a stronger correlate of the anti-viral potency of the α-defensin mutants than their absolute affinity for the viral capsid. Understanding common characteristics of α-defensins important for non-enveloped virus binding will inform rules that govern the function of these abundant and multifaceted peptides in host defense.
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Abstract
There is a pressing need to develop new antiviral treatments; of the 60 drugs currently available, half are aimed at HIV-1 and the remainder target only a further six viruses. This demand has led to the emergence of possible peptide therapies, with 15 currently in clinical trials. Advancements in understanding the antiviral potential of naturally occurring host defence peptides highlights the potential of a whole new class of molecules to be considered as antiviral therapeutics. Cationic host defence peptides, such as defensins and cathelicidins, are important components of innate immunity with antimicrobial and immunomodulatory capabilities. In recent years they have also been shown to be natural, broad-spectrum antivirals against both enveloped and non-enveloped viruses, including HIV-1, influenza virus, respiratory syncytial virus and herpes simplex virus. Here we review the antiviral properties of several families of these host peptides and their potential to inform the design of novel therapeutics.
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Affiliation(s)
- Emily Gwyer Findlay
- MRC Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ Scotland, UK
| | - Silke M. Currie
- MRC Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ Scotland, UK
| | - Donald J. Davidson
- MRC Centre for Inflammation Research, Queen’s Medical Research Institute, The University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ Scotland, UK
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47
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Solís D, Bovin NV, Davis AP, Jiménez-Barbero J, Romero A, Roy R, Smetana K, Gabius HJ. A guide into glycosciences: How chemistry, biochemistry and biology cooperate to crack the sugar code. Biochim Biophys Acta Gen Subj 2014; 1850:186-235. [PMID: 24685397 DOI: 10.1016/j.bbagen.2014.03.016] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 03/13/2014] [Accepted: 03/18/2014] [Indexed: 01/17/2023]
Abstract
BACKGROUND The most demanding challenge in research on molecular aspects within the flow of biological information is posed by the complex carbohydrates (glycan part of cellular glycoconjugates). How the 'message' encoded in carbohydrate 'letters' is 'read' and 'translated' can only be unraveled by interdisciplinary efforts. SCOPE OF REVIEW This review provides a didactic step-by-step survey of the concept of the sugar code and the way strategic combination of experimental approaches characterizes structure-function relationships, with resources for teaching. MAJOR CONCLUSIONS The unsurpassed coding capacity of glycans is an ideal platform for generating a broad range of molecular 'messages'. Structural and functional analyses of complex carbohydrates have been made possible by advances in chemical synthesis, rendering production of oligosaccharides, glycoclusters and neoglycoconjugates possible. This availability facilitates to test the glycans as ligands for natural sugar receptors (lectins). Their interaction is a means to turn sugar-encoded information into cellular effects. Glycan/lectin structures and their spatial modes of presentation underlie the exquisite specificity of the endogenous lectins in counterreceptor selection, that is, to home in on certain cellular glycoproteins or glycolipids. GENERAL SIGNIFICANCE Understanding how sugar-encoded 'messages' are 'read' and 'translated' by lectins provides insights into fundamental mechanisms of life, with potential for medical applications.
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Affiliation(s)
- Dolores Solís
- Instituto de Química Física "Rocasolano", CSIC, Serrano 119, 28006 Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), 07110 Bunyola, Mallorca, Illes Baleares, Spain.
| | - Nicolai V Bovin
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul Miklukho-Maklaya 16/10, 117871 GSP-7, V-437, Moscow, Russian Federation.
| | - Anthony P Davis
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
| | - Jesús Jiménez-Barbero
- Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
| | - Antonio Romero
- Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
| | - René Roy
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville, Montréal, Québec H3C 3P8, Canada.
| | - Karel Smetana
- Charles University, 1st Faculty of Medicine, Institute of Anatomy, U nemocnice 3, 128 00 Prague 2, Czech Republic.
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Veterinärstr. 13, 80539 München, Germany.
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48
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Wilson SS, Wiens ME, Smith JG. Antiviral mechanisms of human defensins. J Mol Biol 2013; 425:4965-80. [PMID: 24095897 PMCID: PMC3842434 DOI: 10.1016/j.jmb.2013.09.038] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 09/25/2013] [Accepted: 09/26/2013] [Indexed: 12/21/2022]
Abstract
Defensins are an effector component of the innate immune system with broad antimicrobial activity. Humans express two types of defensins, α- and β-defensins, which have antiviral activity against both enveloped and non-enveloped viruses. The diversity of defensin-sensitive viral species reflects a multitude of antiviral mechanisms. These include direct defensin targeting of viral envelopes, glycoproteins, and capsids in addition to inhibition of viral fusion and post-entry neutralization. Binding and modulation of host cell surface receptors and disruption of intracellular signaling by defensins can also inhibit viral replication. In addition, defensins can function as chemokines to augment and alter adaptive immune responses, revealing an indirect antiviral mechanism. Nonetheless, many questions regarding the antiviral activities of defensins remain. Although significant mechanistic data are known for α-defensins, molecular details for β-defensin inhibition are mostly lacking. Importantly, the role of defensin antiviral activity in vivo has not been addressed due to the lack of a complete defensin knockout model. Overall, the antiviral activity of defensins is well established as are the variety of mechanisms by which defensins achieve this inhibition; however, additional research is needed to fully understand the role of defensins in viral pathogenesis.
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Affiliation(s)
| | | | - Jason G. Smith
- University of Washington School of Medicine, Box 357735, 1705 North East Pacific Street, Seattle, WA 98195, USA
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Thomassin JL, Lee MJ, Brannon JR, Sheppard DC, Gruenheid S, Le Moual H. Both group 4 capsule and lipopolysaccharide O-antigen contribute to enteropathogenic Escherichia coli resistance to human α-defensin 5. PLoS One 2013; 8:e82475. [PMID: 24324796 PMCID: PMC3853201 DOI: 10.1371/journal.pone.0082475] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 11/02/2013] [Indexed: 12/18/2022] Open
Abstract
Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) are food-borne pathogens that colonize the small intestine and colon, respectively. To cause disease, these pathogens must overcome the action of different host antimicrobial peptides (AMPs) secreted into these distinct niches. We have shown previously that EHEC expresses high levels of the OmpT protease to inactivate the human cathelicidin LL-37, an AMP present in the colon. In this study, we investigate the mechanisms used by EPEC to resist human α-defensin 5 (HD-5), the most abundant AMP in the small intestine. Quantitative PCR was used to measure transcript levels of various EPEC surface structures. High transcript levels of gfcA, a gene required for group 4 capsule (G4C) production, were observed in EPEC, but not in EHEC. The unencapsulated EPEC ∆gfcA and EHEC wild-type strains were more susceptible to HD-5 than EPEC wild-type. Since the G4C is composed of the same sugar repeats as the lipopolysaccharide O-antigen, an -antigen ligase (waaL) deletion mutant was generated in EPEC to assess its role in HD-5 resistance. The ∆waaL EPEC strain was more susceptible to HD-5 than both the wild-type and ∆gfcA strains. The ∆gfcA∆waaL EPEC strain was not significantly more susceptible to HD-5 than the ∆waaL strain, suggesting that the absence of -antigen influences G4C formation. To determine whether the G4C and -antigen interact with HD-5, total polysaccharide was purified from wild-type EPEC and added to the ∆gfcA∆waaL strain in the presence of HD-5. The addition of exogenous polysaccharide protected the susceptible strain against HD-5 killing in a dose-dependent manner, suggesting that HD-5 binds to the polysaccharides present on the surface of EPEC. Altogether, these findings indicate that EPEC relies on both the G4C and the -antigen to resist the bactericidal activity of HD-5.
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Affiliation(s)
- Jenny-Lee Thomassin
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - Mark J. Lee
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - John R. Brannon
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - Donald C. Sheppard
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
- Microbiome and Disease Tolerance Centre, McGill University, Montreal, Quebec, Canada
| | - Samantha Gruenheid
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
- Microbiome and Disease Tolerance Centre, McGill University, Montreal, Quebec, Canada
| | - Hervé Le Moual
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
- Microbiome and Disease Tolerance Centre, McGill University, Montreal, Quebec, Canada
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
- * E-mail:
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Zhao L, Tolbert WD, Ericksen B, Zhan C, Wu X, Yuan W, Li X, Pazgier M, Lu W. Single, double and quadruple alanine substitutions at oligomeric interfaces identify hydrophobicity as the key determinant of human neutrophil alpha defensin HNP1 function. PLoS One 2013; 8:e78937. [PMID: 24236072 PMCID: PMC3827289 DOI: 10.1371/journal.pone.0078937] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/25/2013] [Indexed: 12/03/2022] Open
Abstract
HNP1 is a human alpha defensin that forms dimers and multimers governed by hydrophobic residues, including Tyr16, Ile20, Leu25, and Phe28. Previously, alanine scanning mutagenesis identified each of these residues and other hydrophobic residues as important for function. Here we report further structural and functional studies of residues shown to interact with one another across oligomeric interfaces: I20A-HNP1 and L25A-HNP1, plus the double alanine mutants I20A/L25A-HNP1 and Y16A/F28A-HNP1, and the quadruple alanine mutant Y16A/I20A/L25A/F28A-HNP1. We tested binding to HIV-1 gp120 and HNP1 by surface plasmon resonance, binding to HIV-1 gp41 and HNP1 by fluorescence polarization, inhibition of anthrax lethal factor, and antibacterial activity using the virtual colony count assay. Similar to the previously described single mutant W26A-HNP1, the quadruple mutant displayed the least activity in all functional assays, followed by the double mutant Y16A/F28A-HNP1. The effects of the L25A and I20A single mutations were milder than the double mutant I20A/L25A-HNP1. Crystallographic studies confirmed the correct folding and disulfide pairing, and depicted an array of dimeric and tetrameric structures. These results indicate that side chain hydrophobicity is the critical factor that determines activity at these positions.
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Affiliation(s)
- Le Zhao
- Translational Medicine Center, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China ; Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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