1
|
Fu J, Zong X, Jin M, Min J, Wang F, Wang Y. Mechanisms and regulation of defensins in host defense. Signal Transduct Target Ther 2023; 8:300. [PMID: 37574471 PMCID: PMC10423725 DOI: 10.1038/s41392-023-01553-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/11/2023] [Accepted: 06/26/2023] [Indexed: 08/15/2023] Open
Abstract
As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.
Collapse
Affiliation(s)
- Jie Fu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Xin Zong
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Mingliang Jin
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China
| | - Junxia Min
- The First Affiliated Hospital, Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Fudi Wang
- The Second Affiliated Hospital, School of Public Health, State Key Laboratory of Experimental Hematology, Zhejiang University School of Medicine, Hangzhou, China.
- The First Affiliated Hospital, Basic Medical Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, China.
| | - Yizhen Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou, China.
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, Hangzhou, Zhejiang Province, China.
| |
Collapse
|
2
|
Othumpangat S, Noti JD. β-Defensin-1 Regulates Influenza Virus Infection in Human Bronchial Epithelial Cells through the STAT3 Signaling Pathway. Pathogens 2023; 12:pathogens12010123. [PMID: 36678471 PMCID: PMC9865356 DOI: 10.3390/pathogens12010123] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 12/27/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Understanding the host response to influenza A virus (IAV) infection is vital for developing intervention strategies. The primary barriers for invading respiratory pathogens are the respiratory tract epithelial cells and antimicrobial proteins generated by these cells. The antimicrobial peptide, β-defensin-1, has antiviral activity against both enveloped and non-enveloped viruses. Significant downregulation of β-defensin1 gene (DEFB1) expression was observed when human bronchial epithelial cells (HBEpCs) were exposed to IAV. HBEpCs overexpressing DEFB1 caused a significant reduction in IAV, that was confirmed by IAV matrix gene analysis, plaque assay, and confocal microscopy. DEFB1 expression after transfection with two micro RNAs (miRNAs), hsa-miR-186-5p and hsa-miR-340-5p, provided evidence that DEFB1 expression could be modulated by these miRNAs and hsa-miR-186-5p had a higher binding efficiency with DEFB1. Overexpression of DEFB1 in IAV-infected HBEpCs led to increased NF-κB expression. In a PCR array analysis of 84 transcription factors, either overexpressing DEFB1 or siRNA silencing of DEFB1 expression significantly modulated the expression of signal transducer and activator of transcription 3 (STAT3). In addition, Ingenuity Pathway Analysis (IPA) integrated with PCR array data showed that the JAK1/STAT3 pathway was significantly altered in cells overexpressing DEFB1, suggesting this to be one of the pathways by which defensin regulates IAV replication in HBEpCs. In conclusion, the reduction in IAV copy number in DEFB1 overexpressing cells suggests that β-defensin-1 plays a key role in regulating IAV survival through STAT3 and is a potential target for antiviral drug development.
Collapse
|
3
|
Agamennone M, Fantacuzzi M, Vivenzio G, Scala MC, Campiglia P, Superti F, Sala M. Antiviral Peptides as Anti-Influenza Agents. Int J Mol Sci 2022; 23:11433. [PMID: 36232735 PMCID: PMC9569631 DOI: 10.3390/ijms231911433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/16/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Influenza viruses represent a leading cause of high morbidity and mortality worldwide. Approaches for fighting flu are seasonal vaccines and some antiviral drugs. The development of the seasonal flu vaccine requires a great deal of effort, as careful studies are needed to select the strains to be included in each year's vaccine. Antiviral drugs available against Influenza virus infections have certain limitations due to the increased resistance rate and negative side effects. The highly mutative nature of these viruses leads to the emergence of new antigenic variants, against which the urgent development of new approaches for antiviral therapy is needed. Among these approaches, one of the emerging new fields of "peptide-based therapies" against Influenza viruses is being explored and looks promising. This review describes the recent findings on the antiviral activity, mechanism of action and therapeutic capability of antiviral peptides that bind HA, NA, PB1, and M2 as a means of countering Influenza virus infection.
Collapse
Affiliation(s)
- Mariangela Agamennone
- Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, Via dei Vestini 31, 66100 Chieti, Italy
| | - Marialuigia Fantacuzzi
- Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, Via dei Vestini 31, 66100 Chieti, Italy
| | - Giovanni Vivenzio
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
| | - Maria Carmina Scala
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
| | - Pietro Campiglia
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
| | - Fabiana Superti
- National Centre for Innovative Technologies in Public Health, National Institute of Health, Viale Regina Elena 299, 00161 Rome, Italy
| | - Marina Sala
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
| |
Collapse
|
4
|
Zannella C, Chianese A, Greco G, Santella B, Squillaci G, Monti A, Doti N, Sanna G, Manzin A, Morana A, De Filippis A, D’Angelo G, Palmieri F, Franci G, Galdiero M. Design of Three Residues Peptides against SARS-CoV-2 Infection. Viruses 2022; 14:v14102103. [PMID: 36298659 PMCID: PMC9612326 DOI: 10.3390/v14102103] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/11/2022] [Accepted: 09/19/2022] [Indexed: 11/20/2022] Open
Abstract
The continuous and rapid spread of the COVID-19 pandemic has emphasized the need to seek new therapeutic and prophylactic treatments. Peptide inhibitors are a valid alternative approach for the treatment of emerging viral infections, mainly due to their low toxicity and high efficiency. Recently, two small nucleotide signatures were identified in the genome of some members of the Coronaviridae family and many other human pathogens. In this study, we investigated whether the corresponding amino acid sequences of such nucleotide sequences could have effects on the viral infection of two representative human coronaviruses: HCoV-OC43 and SARS-CoV-2. Our results showed that the synthetic peptides analyzed inhibit the infection of both coronaviruses in a dose-dependent manner by binding the RBD of the Spike protein, as suggested by molecular docking and validated by biochemical studies. The peptides tested do not provide toxicity on cultured cells or human erythrocytes and are resistant to human serum proteases, indicating that they may be very promising antiviral peptides.
Collapse
Affiliation(s)
- Carla Zannella
- Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Annalisa Chianese
- Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Giuseppe Greco
- Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Biagio Santella
- Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Giuseppe Squillaci
- Research Institute on Terrestrial Ecosystems, National Research Council (CNR), Via Pietro Castellino 111, 80131 Naples, Italy
| | - Alessandra Monti
- Institute of Biostructures and Bioimaging (IBB), National Research Council (CNR), 80134 Naples, Italy
| | - Nunzianna Doti
- Institute of Biostructures and Bioimaging (IBB), National Research Council (CNR), 80134 Naples, Italy
| | - Giuseppina Sanna
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, 09042 Cagliari, Italy
| | - Aldo Manzin
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, 09042 Cagliari, Italy
| | - Alessandra Morana
- Research Institute on Terrestrial Ecosystems, National Research Council (CNR), Via Pietro Castellino 111, 80131 Naples, Italy
| | - Anna De Filippis
- Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Gianni D’Angelo
- Department of Computer Science, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy
| | - Francesco Palmieri
- Department of Computer Science, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy
| | - Gianluigi Franci
- Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana”, University of Salerno, 84081 Baronissi, Italy
- Correspondence:
| | - Massimiliano Galdiero
- Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, 80138 Naples, Italy
| |
Collapse
|
5
|
Huang J, Liu X, Sun Y, Huang C, Wang A, Xu J, Zhou H, Li L, Zhou R. Porcine β-defensin 2 confers enhanced resistance to swine flu infection in transgenic pigs and alleviates swine influenza virus-induced apoptosis possibly through interacting with host SLC25A4. Antiviral Res 2022; 201:105292. [PMID: 35341807 DOI: 10.1016/j.antiviral.2022.105292] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 11/29/2022]
Abstract
Swine influenza virus (SIV) not only brings about great economic losses on the global pig industry, it also poses a significant threat to the public health for its interspecies transmission capacity. Porcine β-defensin 2 (PBD-2) is a host defense peptide and our previous study has shown that PBD-2 inhibits proliferation of enveloped pseudorabies virus both in vitro and in transgenic (TG) mice. The aim of this study is to investigate the possible anti-SIV ability of PBD-2 in a TG pig model created in our previous study. The in-contact challenge trial demonstrated that overexpression of PBD-2 in pigs could efficiently alleviate SIV-associated clinical signs. The SIV titers quantified by EID50 in lung tissues of infected TG pigs were significantly lower than that of wild-type littermates. In vitro, the cell viability assay revealed that PBD-2 mainly interfered with viral entry and post-infection stages. It was further confirmed that PBD-2 could enter porcine tracheal epithelial cells. The proteins interacting with PBD-2 inside host cells were identified with immunoprecipitation and the pathways involved were analyzed. Results showed that PBD-2 could interact with pro-apoptotic solute carrier family 25 member 4 (SLC25A4), also known as adenine nucleotide translocase 1, and thereby inhibited SIV-induced cell apoptosis. The molecular docking analysis suggested that PBD-2 interacted with porcine SLC25A4 mainly through strong hydrogen binding, with the predicted binding affinity being -13.23 kcal/mol. Altogether, these indicate that PBD-2 protects pigs against SIV infection, which may result from its role as a SLC25A4 blocker to alleviate cell apoptosis, providing a novel therapeutic and prophylactic strategy of using PBD-2 to combat SIV.
Collapse
Affiliation(s)
- Jing Huang
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China; Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, 55108, USA
| | - Xiao Liu
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China
| | - Yufan Sun
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China
| | - Chao Huang
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China
| | - Antian Wang
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China
| | - Jiajia Xu
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China
| | - Hongbo Zhou
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China
| | - Lu Li
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China.
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, Cooperative Innovation Center for Sustainable Pig Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China; International Research Center for Animal Disease, Ministry of Science and Technology of China, Wuhan, 430070, China.
| |
Collapse
|
6
|
Cross-linking peptide and repurposed drugs inhibit both entry pathways of SARS-CoV-2. Nat Commun 2021; 12:1517. [PMID: 33750821 PMCID: PMC7943568 DOI: 10.1038/s41467-021-21825-w] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/04/2021] [Indexed: 01/31/2023] Open
Abstract
Up to date, effective antivirals have not been widely available for treating COVID-19. In this study, we identify a dual-functional cross-linking peptide 8P9R which can inhibit the two entry pathways (endocytic pathway and TMPRSS2-mediated surface pathway) of SARS-CoV-2 in cells. The endosomal acidification inhibitors (8P9R and chloroquine) can synergistically enhance the activity of arbidol, a spike-ACE2 fusion inhibitor, against SARS-CoV-2 and SARS-CoV in cells. In vivo studies indicate that 8P9R or the combination of repurposed drugs (umifenovir also known as arbidol, chloroquine and camostat which is a TMPRSS2 inhibitor), simultaneously interfering with the two entry pathways of coronaviruses, can significantly suppress SARS-CoV-2 replication in hamsters and SARS-CoV in mice. Here, we use drug combination (arbidol, chloroquine, and camostat) and a dual-functional 8P9R to demonstrate that blocking the two entry pathways of coronavirus can be a promising and achievable approach for inhibiting SARS-CoV-2 replication in vivo. Cocktail therapy of these drug combinations should be considered in treatment trials for COVID-19.
Collapse
|
7
|
Fan J, Luo Y, Qin Y, Wu C, Han X, Ouyang H, Zhang L, Cai P, Li N. The expression of β-Defensin-2, IL-22, IL-22R1 and IL-10R2 in rat model of Klebsiella pneumonia and their correlation with histological grades. Exp Lung Res 2020; 46:109-116. [PMID: 32169023 DOI: 10.1080/01902148.2020.1725690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/13/2020] [Accepted: 01/31/2020] [Indexed: 12/18/2022]
Abstract
Backgrounds and Aims:Klebsiella pneumoniae represents the most common opportunistic pathogen contributing to Klebsiella pneumonia in hospital-acquired infections. Klebsiella pneumonia has a rapidly progressive clinical course and multi-drug resistant (MDR). Identification of the effective biochemical markers is crucial for improving early diagnosis and treatment of Klebsiella pneumonia. The aims of our study are to 1) investigate the expression of β-Defensin-2(rβD2), IL-22, IL-22R1 and IL-10R2 in Klebsiella pneumonia-infected rats and 2) their association with the histological grades of Klebsiella pneumonia.Methods and Materials: Fifty specific pathogen free (SPF) male SD rats were randomly divided into two groups: control group (treated with normal saline) and pneumonia group (treated with K. pneumoniae). All animals were sacrificed 1 h, 12 h, 1 d, 3 d, 5 d post infection. The severity and property of pneumonia was evaluated by histopathologic observation and pathogen identification. The mRNA expression of rβD2, IL-22, IL-22R1 and IL-10R2 was measured by RT-qPCR assay. The expression of rβD2 in rat lung tissue was determined by Western blot analysis, and the level of IL-22 in rat serum was determined by ELISA.Results: Histopathologic examination and bacterial counting of lung tissues confirmed the successful establishment of rat pneumonia model. The gene expression of rβD2, IL-22, IL-22R1 and IL-10R2 in pneumonia rats were significantly higher than those in healthy control mice (P < 0.05). The expression of rβD2 was correlated with histological grades of Klebsiella pneumonia and the level of IL-22. RT-qPCR results showed that the peak expression of IL-22R1 appeared earlier than IL-10R2 in rat pneumonia model.Conclusions: The expression of rβD2 and IL-22 was increased significantly at early stage in rat Klebsiella pneumonia model, suggesting that IL-22 and rβD2 might serve as potential biomarkers for the early diagnosis of Klebsiella pneumonia.
Collapse
Affiliation(s)
- Jianyong Fan
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| | - Yuan Luo
- Department of Respiratory Diseases, Hefei Second People's Hospital, Hefei, Anhui Province, China
| | - Yan Qin
- Department of Geriatrics Diseases, Xi'an 521 Hospital, Xi'an, Shanxi Province, China
| | - Changgui Wu
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| | - Xinpeng Han
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| | - Haifeng Ouyang
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| | - Liyuan Zhang
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| | - Pei Cai
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| | - Nie Li
- Department of Respiratory Diseases, Xi'an International Medical Center, Xi'an, Shanxi Province, China
| |
Collapse
|
8
|
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]
|
9
|
Liu C, Jiang L, Liu L, Sun L, Zhao W, Chen Y, Qi T, Han Z, Shao Y, Liu S, Ma D. Induction of Avian β-Defensin 2 Is Possibly Mediated by the p38 MAPK Signal Pathway in Chicken Embryo Fibroblasts After Newcastle Disease Virus Infection. Front Microbiol 2018; 9:751. [PMID: 29725321 PMCID: PMC5916956 DOI: 10.3389/fmicb.2018.00751] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/03/2018] [Indexed: 12/12/2022] Open
Abstract
The study was conducted to evaluate whether avian β-defensins (AvBDs) could be induced by Newcastle disease virus (NDV) infection, and to investigate the potential signaling pathway of AvBD2 induction in response to NDV infection as well. First, mRNA expression of AvBDs (1–14) was evaluated in the chicken embryo fibroblasts (CEFs) infected with NDV strain F48E9 at 6, 12, 24, 36, and 48 h post-inoculation (hpi), respectively. The results demonstrated a significant induction of AvBD2 in CEFs elicited by the NDV strain. Then, we expressed and purified the AvBD2 proteins in both eukaryotic cells and prokaryotic cells. Of the two recombinant AvBD2 proteins, only the protein expressed in eukaryotic cells showed directly antiviral activity against NDV strain F48E9 in vitro. Ligands of toll-like receptors (TLRs) were chosen as alternatives to NDV to further study signaling pathway of AvBD2 induction here, due to insufficient upregulation of AvBD2 expression elicited by NDV. We found that the mRNA expression of AvBD2 was highly upregulated by Pam3CSK4, FLA-ST, and ODN-M362. Then, four inhibitors of signaling pathway, including inhibitors of JNK, ERK1/2, p38 MAPK, and NF-κB, were used in this study. Of the four inhibitors, only inhibition of the p38 MAPK signaling pathway significantly reduced AvBD2 expression after stimulation with Pam3CSK4, FLA-ST and ODN-M362, respectively. Taken together, these results revealed that AvBD2 play a pivotal role in host innate immunity response to NDV infection. The mRNA expression of AvBD2 might be regulated in a p38 MAPK-dependent manner.
Collapse
Affiliation(s)
- Chenggang Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Lei Jiang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Liangliang Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Li Sun
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Wenjun Zhao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuqiu Chen
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Tianming Qi
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.,Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zongxi Han
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuhao Shao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Shengwang Liu
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Deying Ma
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| |
Collapse
|
10
|
Kalenik BM, Góra-Sochacka A, Sirko A. Β-defensins - Underestimated peptides in influenza combat. Virus Res 2018; 247:10-14. [PMID: 29421304 DOI: 10.1016/j.virusres.2018.01.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/15/2018] [Accepted: 01/21/2018] [Indexed: 02/07/2023]
Abstract
Defensins are a family of host defense peptides present in vertebrates, invertebrates and plants. They display broad antimicrobial activity and immunomodulatory functions. Herein, the natural anti-influenzal role of β-defensins, as well as their potential usage as anti-influenza vaccine adjuvants and therapeutic agents, is reviewed. This article summarizes previously published information on β-defensin modes of action, expression changes after influenza infection and vaccination, biotechnological usage and possible boosting of their production by dietary supplementation.
Collapse
Affiliation(s)
- Barbara Małgorzata Kalenik
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106 Warsaw, Poland
| | - Anna Góra-Sochacka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106 Warsaw, Poland
| | - Agnieszka Sirko
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106 Warsaw, Poland.
| |
Collapse
|
11
|
Dan K, Takanashi K, Akiyoshi H, Munakata K, Hasegawa H, Ogawa K, Watanabe K. Mechanism of Action of the Anti-Influenza Virus Active Kampo (Traditional Japanese Herbal) Medicine, Hochuekkito. Pharmacology 2017; 101:148-155. [PMID: 29275416 DOI: 10.1159/000485628] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 11/23/2017] [Indexed: 11/19/2022]
Abstract
When the Kampo medicine, Hochuekkito (Hochu), was administered to normal mice for 2 weeks, influenza virus titer was reduced. The mechanism of action of Hochu was examined using the plaque assay method. It was suggested that Hochu may either obstruct the first stage of the infection process (adsorption and entry) or may directly target viral particles. Using the plaque assay method, these 2 modes of action could not be differentiated. Virus RNA in the infected cell was verified by quantitative real-time polymerase chain reaction. An equal inhibition effect was obtained when Hochu was preprocessed for normal cells and when they were made to act simultaneously with virus adsorption. The viral load at the cell surface following UV irradiation was higher in the Hochu-administered group as compared with that of the control. Moreover, the affinity of Hochu for the influenza virus was hundred times higher than its affinity for the host cell. The effect of entry obstruction by Hochu was observed via image analysis, where the amount of virus nucleocapsid protein (NP) invading the cell was visualized with FITC-labeled NP antibody. Hochu does not seem to have an effect on nucleic acid synthesis, viral release from infected cells, and on the subsequent second round of infection. In conclusion, Hochu binds to viral particles and forms complexes that can obstruct the entry of influenza virus into cells.
Collapse
Affiliation(s)
- Katsuaki Dan
- Division of Research and Development, Research Organization of Bioactivity, Tokyo, Japan
| | - Keita Takanashi
- Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hiroko Akiyoshi
- Center for Kampo Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Kaori Munakata
- East-West Life Science Innovation Laboratory, Keio University, Tokyo, Japan
| | - Hideki Hasegawa
- Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kaoru Ogawa
- Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Kenji Watanabe
- Center for Kampo Medicine, Keio University School of Medicine, Tokyo, Japan.,East-West Life Science Innovation Laboratory, Keio University, Tokyo, Japan.,Faculty of Environmental and Information Study, Keio University, Tokyo, Japan
| |
Collapse
|
12
|
Zhao H, Zhou J, Zhang K, Chu H, Liu D, Poon VKM, Chan CCS, Leung HC, Fai N, Lin YP, Zhang AJX, Jin DY, Yuen KY, Zheng BJ. A novel peptide with potent and broad-spectrum antiviral activities against multiple respiratory viruses. Sci Rep 2016; 6:22008. [PMID: 26911565 PMCID: PMC4766503 DOI: 10.1038/srep22008] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/03/2016] [Indexed: 12/19/2022] Open
Abstract
A safe, potent and broad-spectrum antiviral is urgently needed to combat emerging respiratory viruses. In light of the broad antiviral activity of β-defensins, we tested the antiviral activity of 11 peptides derived from mouse β-defensin-4 and found that a short peptide, P9, exhibited potent and broad-spectrum antiviral effects against multiple respiratory viruses in vitro and in vivo, including influenza A virus H1N1, H3N2, H5N1, H7N7, H7N9, SARS-CoV and MERS-CoV. The antiviral activity of P9 was attributed to its high-affinity binding to viral glycoproteins, as well as the abundance of basic amino acids in its composition. After binding viral particles through viral surface glycoproteins, P9 entered into cells together with the viruses via endocytosis and prevented endosomal acidification, which blocked membrane fusion and subsequent viral RNA release. This study has paved the avenue for developing new prophylactic and therapeutic agents with broad-spectrum antiviral activities.
Collapse
Affiliation(s)
- Hanjun Zhao
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Jie Zhou
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Ke Zhang
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Hin Chu
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Dabin Liu
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | | | | | - Ho-Chuen Leung
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Ng Fai
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Yong-Ping Lin
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Anna Jin-Xia Zhang
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Dong-Yan Jin
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-Yung Yuen
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Bo-Jian Zheng
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| |
Collapse
|
13
|
Aksoy O, Parlak E, Parlak M, Aksoy H. Serum β-Defensin-2 Levels and Their Relationship with the Clinical Course and Prognosis in Patients with Crimean-Congo Hemorrhagic Fever. Med Princ Pract 2016; 25:163-8. [PMID: 26539993 PMCID: PMC5588343 DOI: 10.1159/000442177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 11/04/2015] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate the role of the clinical course and prognosis of serum levels of β-defensin-2 (BD-2) in patients with Crimean-Congo hemorrhagic fever (CCHF). SUBJECTS AND METHODS Patients who were hospitalized in the Department of Infectious Diseases and Clinical Microbiology of the Faculty of Medicine, Ataturk University, were considered for inclusion in this study. The patients had positive real-time reverse transcription polymerase chain reaction and/or enzyme-linked immunosorbent assay results of the CCHF virus. There were 60 patients with CCHF in the study group and 25 healthy participants in the control group. Serum BD-2 levels were measured using ELISA. Data were analyzed using the Student t test or Mann-Whitney U test. RESULTS Of the 60 patients, 6 (10%) died and 54 (90%) were discharged following their recovery. The mean BD-2 level of the patient group was significantly higher (4,180.30 ± 3,944.19 pg/ml) than that of the control group (964.45 ± 266.07 pg/ml; p = 0.001). Serum BD-2 levels of the patients with fatal (1,529.81 ± 1,028.14) and nonfatal disease (4,474.80 ± 4,041.58) differed, but this difference showed only borderline significance (p = 0.055). The mean BD-2 level of the severe group was 5,507.45 ± 4,327.06 pg/ml, while it was 3,611.52 ± 3,676.73 pg/ml in the mild/moderate group, and both were significantly higher than that of the control group (p = 0.001). CONCLUSION In this study, the expression of serum BD-2 was raised in patients with CCHF, and this increase may beneficially affect survival. Studies with larger sample sizes are needed to confirm the association of serum BD-2 with CCHF prognosis.
Collapse
Affiliation(s)
- Osman Aksoy
- Balıklı Göl State Hospital, Urfa, and Departments of, Erzurum, Turkey
| | - Emine Parlak
- Medical Biochemistry, Infectious Diseases and Clinical Microbiology, Erzurum, Turkey
- *Dr. Emine Parlak, Department of Infectious Diseases and Clinical Microbiology, Atatük University School of Medicine, University street 2506, TR-25070 Erzurum (Turkey), E-Mail
| | - Mehmet Parlak
- Medical Biochemistry, Infectious Diseases and Clinical Microbiology, Erzurum, Turkey
| | - Hülya Aksoy
- Medical Biochemistry, Faculty of Medicine, Atatürk University, Erzurum, Turkey
| |
Collapse
|
14
|
Epand RM. Antiviral Host Defence Peptides. HOST DEFENSE PEPTIDES AND THEIR POTENTIAL AS THERAPEUTIC AGENTS 2016. [PMCID: PMC7123656 DOI: 10.1007/978-3-319-32949-9_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The ongoing global mortality and morbidity associated with viral pathogens highlights the need for the continued development of effective, novel antiviral molecules. The antiviral activity of cationic host defence peptides is of significant interest as novel therapeutics for treating viral infection and predominantly due to their broad spectrum antiviral activity. These peptides also display powerful immunomodulatory activity and are key mediators of inflammation. Therefore, they offer a significant opportunity to inform the development of novel therapeutics for treating viral infections by either directly targeting the pathogen or by enhancing the innate immune response. In this chapter, we review the antiviral activity of cathelicidins and defensins, and examine the potential for these peptides to be used as novel antiviral agents.
Collapse
Affiliation(s)
- Richard M. Epand
- Health Sciences Centre, McMaster University, Hamilton, Ontario Canada
| |
Collapse
|
15
|
Percopo CM, Rice TA, Brenner TA, Dyer KD, Luo JL, Kanakabandi K, Sturdevant DE, Porcella SF, Domachowske JB, Keicher JD, Rosenberg HF. Immunobiotic Lactobacillus administered post-exposure averts the lethal sequelae of respiratory virus infection. Antiviral Res 2015; 121:109-19. [PMID: 26145728 PMCID: PMC4536168 DOI: 10.1016/j.antiviral.2015.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/28/2015] [Accepted: 07/01/2015] [Indexed: 01/08/2023]
Abstract
We reported previously that priming of the respiratory tract with immunobiotic Lactobacillus prior to virus challenge protects mice against subsequent lethal infection with pneumonia virus of mice (PVM). We present here the results of gene microarray which document differential expression of proinflammatory mediators in response to PVM infection alone and those suppressed in response to Lactobacillus plantarum. We also demonstrate for the first time that intranasal inoculation with live or heat-inactivated L. plantarum or Lactobacillus reuteri promotes full survival from PVM infection when administered within 24h after virus challenge. Survival in response to L. plantarum administered after virus challenge is associated with suppression of proinflammatory cytokines, limited virus recovery, and diminished neutrophil recruitment to lung tissue and airways. Utilizing this post-virus challenge protocol, we found that protective responses elicited by L. plantarum at the respiratory tract were distinct from those at the gastrointestinal mucosa, as mice devoid of the anti-inflammatory cytokine, interleukin (IL)-10, exhibit survival and inflammatory responses that are indistinguishable from those of their wild-type counterparts. Finally, although L. plantarum interacts specifically with pattern recognition receptors TLR2 and NOD2, the respective gene-deleted mice were fully protected against lethal PVM infection by L. plantarum, as are mice devoid of type I interferon receptors. Taken together, L. plantarum is a versatile and flexible agent that is capable of averting the lethal sequelae of severe respiratory infection both prior to and post-virus challenge via complex and potentially redundant mechanisms.
Collapse
Affiliation(s)
- Caroline M Percopo
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tyler A Rice
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Todd A Brenner
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kimberly D Dyer
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Janice L Luo
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kishore Kanakabandi
- Genomics Unit, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Daniel E Sturdevant
- Genomics Unit, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Stephen F Porcella
- Genomics Unit, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Joseph B Domachowske
- Department of Pediatrics, Upstate Medical University, State University of New York Upstate Medical University, Syracuse, NY, USA
| | - Jesse D Keicher
- Infectious Disease, Drug Discovery, Glaxo Smith Kline, Inc., Research Triangle Park, NC, USA
| | - Helene F Rosenberg
- Inflammation Immunobiology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
16
|
Tripathi S, Wang G, White M, Rynkiewicz M, Seaton B, Hartshorn K. Identifying the Critical Domain of LL-37 Involved in Mediating Neutrophil Activation in the Presence of Influenza Virus: Functional and Structural Analysis. PLoS One 2015; 10:e0133454. [PMID: 26308522 PMCID: PMC4550355 DOI: 10.1371/journal.pone.0133454] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/25/2015] [Indexed: 11/18/2022] Open
Abstract
The human cathelicidin LL-37 has been shown to play a role in host defense against influenza A viruses (IAV) through direct antiviral effects and through modulating inflammatory responses to infection. We recently showed that LL-37 increases neutrophil respiratory burst and neutrophil extracellular trap (NET) responses to IAV through engaging formyl peptide receptor 2 (FPR-2). In this paper we show that a fragment of LL-37, GI-20, which is composed of the central helical segment of the peptide, has similar effects as LL-37 on neutrophil activation. In addition to increasing respiratory burst and NET responses of the cells to IAV through an FPR-2 dependent mechanism, it reduces neutrophil IL-8 production to IAV (also like LL-37). The N-terminal fragment, LL-23, did not have similar effects. Both GI-20 and LL-37 increase neutrophil intracellular calcium levels and their ability to increase neutrophil activation responses was calcium dependent and partially inhibited by pertussis toxin. These studies show that the central helix of LL-37 retains the ability of LL-37 to modulate neutrophil responses through FPR-2. Based on our findings we developed a homology model of FPR-2 and performed docking experiments of LL-37 and GI-20 with the receptor.
Collapse
Affiliation(s)
- Shweta Tripathi
- Boston University School of Medicine, Department of Medicine, Boston, MA, United States of America
| | - Guangshun Wang
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Mitchell White
- Boston University School of Medicine, Department of Medicine, Boston, MA, United States of America
| | - Michael Rynkiewicz
- Boston University School of Medicine, Department of Biophysics, Boston, MA, United States of America
| | - Barbara Seaton
- Boston University School of Medicine, Department of Biophysics, Boston, MA, United States of America
| | - Kevan Hartshorn
- Boston University School of Medicine, Department of Medicine, Boston, MA, United States of America
- * E-mail:
| |
Collapse
|
17
|
Abstract
The airway epithelial cell barrier serves as the main site of replication for most of the common respiratory viruses and is thereby the first line of defense against these viruses. Host epithelial cells are specially enriched for pattern recognition receptors that activate immune response genes to limit viral replication. A prominently expressed set of these genes encodes cytokines that orchestrate key aspects of host defense, such as recruitment of immune cells and repair of epithelial cell damage. Under some circumstances, airway epithelial cells may be programmed to release cytokines (notably IL-33) that activate a type 2 immune response, which in excess might contribute to the development of chronic obstructive lung disease. Moreover, long-term epithelial progenitor cells with this capability may explain an ongoing susceptibility to lung disease in response to acute respiratory infection or other types of inhaled danger signals. The mucosal airway epithelial cell can thereby mediate a beneficial response for host defense and a detrimental response leading to inflammatory disease.
Collapse
|
18
|
Passive broad-spectrum influenza immunoprophylaxis. INFLUENZA RESEARCH AND TREATMENT 2014; 2014:267594. [PMID: 25328697 PMCID: PMC4190013 DOI: 10.1155/2014/267594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/10/2014] [Indexed: 12/14/2022]
Abstract
Influenza is a perennial problem affecting millions of people annually with the everpresent threat of devastating pandemics. Active prophylaxis by vaccination against influenza virus is currently the main countermeasure supplemented with antivirals. However, disadvantages of this strategy include the impact of antigenic drift, necessitating constant updating of vaccine strain composition, and emerging antiviral drug resistance. The development of other options for influenza prophylaxis, particularly with broad acting agents able to provide protection in the period between the onset of a pandemic and the development of a strain specific vaccine, is of great interest. Exploitation of broad-spectrum mediators could provide barricade protection in the early critical phase of influenza virus outbreaks. Passive immunity has the potential to provide immediate antiviral effects, inhibiting virus replication, reducing virus shedding, and thereby protecting vulnerable populations in the event of an impending influenza pandemic. Here, we review passive broad-spectrum influenza prophylaxis options with a focus on harnessing natural host defenses, including interferons and antibodies.
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
In addition to its antiviral and immunomodulatory properties, the zebrafish β-defensin 2 (zfBD2) is a potent viral DNA vaccine molecular adjuvant. Antiviral Res 2014; 101:136-47. [DOI: 10.1016/j.antiviral.2013.11.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/04/2013] [Accepted: 11/18/2013] [Indexed: 11/21/2022]
|
21
|
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.
Collapse
Affiliation(s)
| | | | - Jason G. Smith
- University of Washington School of Medicine, Box 357735, 1705 North East Pacific Street, Seattle, WA 98195, USA
| |
Collapse
|
22
|
Vemula SV, Amen O, Katz JM, Donis R, Sambhara S, Mittal SK. Beta-defensin 2 enhances immunogenicity and protection of an adenovirus-based H5N1 influenza vaccine at an early time. Virus Res 2013; 178:398-403. [PMID: 24051000 DOI: 10.1016/j.virusres.2013.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 08/30/2013] [Accepted: 09/06/2013] [Indexed: 11/16/2022]
Abstract
Reports of human infections with highly pathogenic H5N1 avian influenza viruses in many countries in Asia and Africa with varying case fatality rates highlight the pandemic potential of these viruses. In order to contain a rapidly spreading influenza virus in a pandemic scenario, a vaccine which can induce rapid and robust immune responses, preferably in a single dose, is necessary. Murine beta-defensin 2 (Mbd2), a small molecular weight protein expressed by epithelial cells, has been shown to enhance antigen-specific immune responses by recruiting and activating professional antigen presenting cells to the site of vaccination. This study assessed the potential of Mbd2 to enhance the immunogenicity and protective efficacy of a human adenovirus (HAd)-based vaccine expressing the hemagglutinin (HA) and nucleoprotein (NP) [HAd-HA-NP] of an H5N1 influenza virus. A single inoculation of mice with both HAd-HA-NP and a HAd vector expressing Murine β-defensin 2 (HAd-Mbd2) resulted in significantly higher levels of both humoral and cell-mediated immune responses compared to the groups vaccinated only with HAd-HA-NP. These responses were evident even at day 7 post-immunization. Furthermore, the HAd-HA-NP+HAd-Mbd2-immunized group receiving the lowest vector dose (2 × 10(7)+1 × 10(7)) was completely protected against an rgH5N1 virus challenge on day 7 post-vaccination. These results highlight the potential of Mbd2 as a genetic adjuvant in inducing rapid and robust immune responses to a HAd-based vaccine.
Collapse
Affiliation(s)
- Sai V Vemula
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA; Bindley Bioscience Center, Purdue University, West Lafayette, IN, USA
| | | | | | | | | | | |
Collapse
|
23
|
Dan K, Akiyoshi H, Munakata K, Hasegawa H, Watanabe K. A Kampo (traditional Japanese herbal) medicine, Hochuekkito, pretreatment in mice prevented influenza virus replication accompanied with GM-CSF expression and increase in several defensin mRNA levels. Pharmacology 2013; 91:314-21. [PMID: 23796966 DOI: 10.1159/000350188] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/19/2013] [Indexed: 11/19/2022]
Abstract
A Kampo medicine, Hochuekkito (TJ-41), with an influenza virus-preventing effect had life-extending effectiveness, and immunological responses other than interferon (IFN)-α release were examined. TJ-41 (1 g/kg) was given to C57BL/6 male mice orally once a day for 2 weeks. Mice were then intranasally infected with influenza virus. After infection, virus titers and various parameters, mRNA levels and protein expression, for immunoresponses in the bronchoalveolar lavage fluid or removed lung homogenate, were measured by plaque assay, quantitative RT-PCR and ELISA. IFN-α and -β levels of TJ-41-treated mice were higher than those of the control. Toll-like receptor TLR7 and TLR9 mRNAs were elevated after infection, but retinoic acid-inducible gene (RIG-1) family mRNA levels, RIG-1, melanoma differentiation-associated gene 5 and Leishmania G protein 2 showed no response in either TJ-41 or control groups. Interferon regulatory transcription factor (IRF)-3 mRNA levels to stimulate type I (α/β) IFN were increased, but IRF-7 did not change. Only granulocyte-macrophage colony-stimulating factor (GM-CSF) after Hochuekkito treatment was significantly elevated 2 and 3 days after infection. The mRNA levels of 7 defensins after infection increased compared to preinfection values. The key roles of TJ-41 were not only stimulation of type I IFN release but also GM-CSF-derived anti-inflammation activity. Furthermore, defensin (antimicrobial peptide) mRNA levels increased by infection and were further enhanced by TJ-41 treatment. Defensin might prevent influenza virus replication.
Collapse
Affiliation(s)
- Katsuaki Dan
- Collaborative Research Resources, Core Instrumentation Facility, Keio University School of Medicine, Tokyo, Japan.
| | | | | | | | | |
Collapse
|
24
|
Dai J, Pei D, Wang B, Kuang Y, Ren L, Cao K, Wang H, Zuo B, Shao J, Li S, Li H, Li M. Molecular adjuvant Ag85A enhances protection against influenza A virus in mice following DNA vaccination. Viruses 2012; 4:3606-24. [PMID: 23223215 PMCID: PMC3528282 DOI: 10.3390/v4123606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 11/07/2012] [Accepted: 11/21/2012] [Indexed: 11/16/2022] Open
Abstract
A novel DNA vaccine vector encoding the Mycobacterium tuberculosis secreted antigen Ag85A fused with the influenza A virus (IAV) HA2 protein epitopes, pEGFP/Ag85A-sHA2 (pAg85A-sHA2), was designed to provide protection against influenza. The antigen encoded by the DNA vaccine vector was efficiently expressed in mammalian cells, as determined by reverse transcription polymerase chain reaction (RT-PCR) and fluorescence analyses. Mice were immunized with the vaccine vector by intramuscular injection before challenge with A/Puerto Rico/8/34 virus (PR8 virus). Sera and the splenocyte culture IFN-γ levels were significantly higher in immunized mice compared with the control mice. The novel vaccine group showed a high neutralization antibody titer in vitro. The novel vaccine vector also reduced the viral loads, increased the survival rates in mice after the PR8 virus challenge and reduced the alveolar inflammatory cell numbers. Sera IL-4 concentrations were significantly increased in mice immunized with the novel vaccine vector on Day 12 after challenge with the PR8 virus. These results demonstrated that short HA2 (sHA2) protein epitopes may provide protection against the PR8 virus and that Ag85A could strengthen the immune response to HA2 epitopes, thus, Ag85A may be developed as a new adjuvant for influenza vaccines.
Collapse
MESH Headings
- Acyltransferases/administration & dosage
- Acyltransferases/genetics
- Adjuvants, Immunologic/administration & dosage
- Adjuvants, Immunologic/genetics
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Viral/blood
- Antigens, Bacterial/administration & dosage
- Antigens, Bacterial/genetics
- Cell Line
- Female
- Hemagglutinin Glycoproteins, Influenza Virus/genetics
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Humans
- Influenza A virus/genetics
- Influenza A virus/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/immunology
- Interferon-gamma/blood
- Interferon-gamma/metabolism
- Interleukin-4/blood
- Interleukin-4/metabolism
- Leukocytes, Mononuclear/immunology
- Lung/pathology
- Mice
- Mice, Inbred BALB C
- Spleen/immunology
- Survival Analysis
- Vaccination/methods
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
- Viral Load
Collapse
Affiliation(s)
- Jun Dai
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
- Department of Pathobiology and Immunology, School of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050091, China
| | - Decui Pei
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Baoning Wang
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Yu Kuang
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Laifeng Ren
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Kang Cao
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Huan Wang
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Bin Zuo
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Jingjing Shao
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Sha Li
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
| | - Hong Li
- The Joint Research Center of West China Second University Hospital of Sichuan University and the Faculty of Medicine, University of Hong Kong, Sichuan University, Chengdu, Sichuan 610041, China
| | - Mingyuan Li
- Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan 610041, China
- Author to whom correspondence should be addressed; E-Mail: ; Tel. +86-028-8550-1267
| |
Collapse
|
25
|
Jiang Y, Yang D, Li W, Wang B, Jiang Z, Li M. Antiviral activity of recombinant mouse β-defensin 3 against influenza A virus in vitro and in vivo. Antivir Chem Chemother 2012; 22:255-62. [PMID: 22345365 DOI: 10.3851/imp2077] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2011] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Influenza causes significant morbidity and mortality. Mammalian β-defensins are small peptides of about 4.5-6 kDa in mass and are effectors of the innate immune response with potent antimicrobial activity. In this paper, we focused on the anti-influenza A activity of the recombinant mouse β-defensin 3 (rMBD-3) in vivo and in vitro. METHODS The rMBD-3 peptide was added to Madin-Darby canine kidney (MDCK) cells at different stages of influenza A virus (IAV) A/PR/8/34 (H1N1) infection and its virus inhibitory properties were determined. Mice were infected with IAV and treated with rMBD-3 peptide from 12 h post-infection. The effect of rMBD-3 peptide was determined by pulmonary viral load, pathology and mortality. In addition, the expression of interleukin (IL)-12, interferon (IFN)-γ and tumour necrosis factor (TNF)-α genes in mice with or without rMBD-3 treatment was determined by semi-quantitative reverse transcriptase PCR. RESULTS rMBD-3 was shown to protect MDCK cells against IAV infection and had a major role in inhibition of adsorption and uptake by cells infected with IAV. Following the addition of 100 μg/ml rMBD-3 to MDCK cells medium, approximately 80% of cells were protected from infection in vitro. rMBD-3 given by tail vein injection (10 mg/kg/day) was the most effective method to improve the survival rate of the mice. Treatment with rMBD-3 was found to up-regulate IFN-γ and IL-12 gene expression, but reduced expression of the TNF-α gene. CONCLUSIONS These results demonstrate that rMBD-3 possesses anti-influenza virus activity both in vivo and in vitro that might be of therapeutic use.
Collapse
Affiliation(s)
- Yan Jiang
- Department of Microbiology, Guiyang Medical College, Guiyang, China
| | | | | | | | | | | |
Collapse
|
26
|
Jiang Y, Yi X, Li M, Wang T, Qi T, She X. Antimicrobial activities of recombinant mouse β-defensin 3 and its synergy with antibiotics. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1723-1728. [PMID: 22528077 DOI: 10.1007/s10856-012-4645-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 04/07/2012] [Indexed: 05/31/2023]
Abstract
Mammalian β-defensins are small cationic peptides of approximately 2-6 kDa that have been implicated in mediating innate immune defenses against microbial infection. This present study investigated the activity of mouse β-defensin 3 (MBD3) against bacterial and yeast drug-resistant strains in vitro, and whether this molecule acts in synergy with antibiotics. Minimum inhibitory concentrations (MICs) and minimum bactericidal/fungicidal concentrations (MBC/MFC) of recombinant MBD3 (rMBD3) were determined by microdilution assays against different strains of Staphylococcus aureus and Candida albicans. rMBD3 inhibited the growth of S. aureus (MIC, 25 μg/ml) and C. albicans (MIC, 25 μg/ml), and showed fungicidal activity against this yeast (MFC, 100 μg/ml). The influences of rMBD3 on S. aureus and C. albicans cells were examined using electron microscopy. Cells treated with rMBD3 showed morphological and structural changes, including delamination and perforation of the peripheral cell walls, porosity, and inanition of the cytoplasmic contents. Synergistic activities of rMBD3 with different antibiotics were assessed using checkerboard tests. Interestingly, the anti-methicillin-resistant S. aureus activity of rMBD3 in combination with ampicillin was synergistic; however, this was not the case against S. aureus (ATCC 25923). Combinations of rMBD3 with itraconazole, amphotericin or 5-fluorocytosine were synergistic against the two tested C. albicans strains. These results support the interest devoted to defensins as a novel class of antimicrobial agents, and highlight their abilities to potentiate the activities of conventional antibiotics.
Collapse
Affiliation(s)
- Yan Jiang
- Department of Microbiology, Guiyang Medical College, Guiyang, 550004, China.
| | | | | | | | | | | |
Collapse
|
27
|
Demirkhanyan LH, Marin M, Padilla-Parra S, Zhan C, Miyauchi K, Jean-Baptiste M, Novitskiy G, Lu W, Melikyan GB. Multifaceted mechanisms of HIV-1 entry inhibition by human α-defensin. J Biol Chem 2012; 287:28821-38. [PMID: 22733823 DOI: 10.1074/jbc.m112.375949] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The human neutrophil peptide 1 (HNP-1) is known to block the human immunodeficiency virus type 1 (HIV-1) infection, but the mechanism of inhibition is poorly understood. We examined the effect of HNP-1 on HIV-1 entry and fusion and found that, surprisingly, this α-defensin inhibited multiple steps of virus entry, including: (i) Env binding to CD4 and coreceptors; (ii) refolding of Env into the final 6-helix bundle structure; and (iii) productive HIV-1 uptake but not internalization of endocytic markers. Despite its lectin-like properties, HNP-1 could bind to Env, CD4, and other host proteins in a glycan- and serum-independent manner, whereas the fusion inhibitory activity was greatly attenuated in the presence of human or bovine serum. This demonstrates that binding of α-defensin to molecules involved in HIV-1 fusion is necessary but not sufficient for blocking the virus entry. We therefore propose that oligomeric forms of defensin, which may be disrupted by serum, contribute to the anti-HIV-1 activity perhaps through cross-linking virus and/or host glycoproteins. This notion is supported by the ability of HNP-1 to reduce the mobile fraction of CD4 and coreceptors in the plasma membrane and to precipitate a core subdomain of Env in solution. The ability of HNP-1 to block HIV-1 uptake without interfering with constitutive endocytosis suggests a novel mechanism for broad activity against this and other viruses that enter cells through endocytic pathways.
Collapse
Affiliation(s)
- Lusine H Demirkhanyan
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia 30322, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Underwood M, Bakaletz L. Innate immunity and the role of defensins in otitis media. Curr Allergy Asthma Rep 2012; 11:499-507. [PMID: 21901304 DOI: 10.1007/s11882-011-0223-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Otitis media is the most common pediatric disease in developed countries and a significant cause of morbidity and hearing loss in developing countries. The innate immune system is essential to protecting the middle ear from infection. Defensins, broad-spectrum cationic antimicrobial peptides, have been implicated in prevention of and the early response to acute otitis media; however, the mechanisms by which defensins and other antimicrobial molecules mediate this protection have not been completely elucidated. In both animal otitis media models and human middle ear epithelial cell culture models, β-defensins are highly induced and effectively kill the common pathogens associated with otitis media. We review the importance of innate immunity in protecting the middle ear and recent advances in understanding the roles of defensins and other antimicrobial molecules in the prevention and treatment of otitis media. The extremely high prevalence of otitis media, in spite of sophisticated innate and adaptive immune systems, is a vexing problem for clinicians and scientists. We therefore also review mechanisms by which bacteria evade innate immune defenses.
Collapse
Affiliation(s)
- Mark Underwood
- Department of Pediatrics, University of California, Davis School of Medicine, Sacramento, CA 95817, USA.
| | | |
Collapse
|
29
|
Gong T, Li W, Wang Y, Jiang Y, Zhang Q, Feng W, Jiang Z, Li M. Expression of mouse beta defensin 2 in escherichia coli and its broad-spectrum antimicrobial activity. Braz J Microbiol 2011; 42:1180-7. [PMID: 24031740 PMCID: PMC3768774 DOI: 10.1590/s1517-838220110003000043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 03/14/2011] [Indexed: 12/20/2022] Open
Abstract
Mature mouse beta defensin 2 (mBD2) is a small cationic peptide with antimicrobial activity. Here we established a prokaryotic expression vector containing the cDNA of mature mBD2 fused with thioredoxin (TrxA), pET32a-mBD2. The vector was transformed into Escherichia Coli (E. coli) Rosseta-gami (2) for expression fusion protein. Under the optimization of fermentation parameters: induce with 0.6 mM isopropylthiogalactoside (IPTG) at 34°C in 2×YT medium and harvest at 6 h postinduction, fusion protein TrxA-mBD2 was high expressed in the soluble fraction (>95%). After cleaved fusion protein by enterokinase, soluble mature mBD2 was achieved 6 mg/L with a volumetric productivity. Purified recombinant mBD2 demonstrated clear broad-spectrum antimicrobial activity for fungi, bacteria and virus. The MIC of antibacterial activity of against Staphylococcus aureus was 50 μg/ml. The MIC of against Candida albicans (C. albicans) and Cryptococcus neoformans (C. neoformans) was 12.5μg/ml and 25μg/ml, respectively. Also, the antimicrobial activity of mBD2 was effected by NaCl concentration. Additionally, mBD2 showed antiviral activity against influenza A virus (IAV), the protective rate for Madin-Darby canine kidney cells (MDCK) was 93.86% at the mBD2 concentration of 100 μg/ml. These works might provide a foundation for the following research on the mBD2 as therapeutic agent for medical microbes.
Collapse
Affiliation(s)
- Tianxiang Gong
- Chengdu Blood Centre , 610041 Chengdu , China ; Department of Microbiology, West China School of Preclinical and Forensic Medicine, Sichuan University , 610041 Chengdu , China
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Chrudimská T, Slaninová J, Rudenko N, Růžek D, Grubhoffer L. Functional characterization of two defensin isoforms of the hard tick Ixodes ricinus. Parasit Vectors 2011; 4:63. [PMID: 21504572 PMCID: PMC3102633 DOI: 10.1186/1756-3305-4-63] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 04/19/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The immune system of ticks is stimulated to produce many pharmacologically active molecules during feeding and especially during pathogen invasion. The family of cationic peptides - defensins - represents a specific group of antimicrobial compounds with six conserved cysteine residues in a molecule. RESULTS Two isoforms of the defensin gene (def1 and def2) were identified in the European tick Ixodes ricinus. Expression of both genes was induced in different tick organs by a blood feeding or pathogen injection. We have tested the ability of synthetic peptides def1 and def2 to inhibit the growth or directly kill several pathogens. The antimicrobial activities (expressed as minimal inhibition concentration and minimal bactericidal concentration values) against Gram positive bacteria were confirmed, while Gram negative bacteria, yeast, Tick Borne Encephalitis and West Nile Viruses were shown to be insensitive. In addition to antimicrobial activities, the hemolysis effect of def1 and def2 on human erythrocytes was also established. CONCLUSIONS Although there is nothing known about the realistic concentration of defensins in I. ricinus tick body, these results suggest that defensins play an important role in defence against different pathogens. Moreover this is a first report of a one amino acid substitution in a defensins molecule and its impact on antimicrobial activity.
Collapse
Affiliation(s)
- Tereza Chrudimská
- University of South Bohemia, Faculty of Science, České Buděovice, Czech Republic.
| | | | | | | | | |
Collapse
|