1
|
Tripathi AK, Singh J, Trivedi R, Ranade P. Shaping the Future of Antimicrobial Therapy: Harnessing the Power of Antimicrobial Peptides in Biomedical Applications. J Funct Biomater 2023; 14:539. [PMID: 37998108 PMCID: PMC10672284 DOI: 10.3390/jfb14110539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 11/25/2023] Open
Abstract
Antimicrobial peptides (AMPs) have emerged as a promising class of bioactive molecules with the potential to combat infections associated with medical implants and biomaterials. This review article aims to provide a comprehensive analysis of the role of antimicrobial peptides in medical implants and biomaterials, along with their diverse clinical applications. The incorporation of AMPs into various medical implants and biomaterials has shown immense potential in mitigating biofilm formation and preventing implant-related infections. We review the latest advancements in biomedical sciences and discuss the AMPs that were immobilized successfully to enhance their efficacy and stability within the implant environment. We also highlight successful examples of AMP coatings for the treatment of surgical site infections (SSIs), contact lenses, dental applications, AMP-incorporated bone grafts, urinary tract infections (UTIs), medical implants, etc. Additionally, we discuss the potential challenges and prospects of AMPs in medical implants, such as effectiveness, instability and implant-related complications. We also discuss strategies that can be employed to overcome the limitations of AMP-coated biomaterials for prolonged longevity in clinical settings.
Collapse
Affiliation(s)
- Amit Kumar Tripathi
- Department of Microbiology, Immunology and Genetics, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; (R.T.); (P.R.)
| | - Jyotsana Singh
- Hematopoietic Biology and Malignancy, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Rucha Trivedi
- Department of Microbiology, Immunology and Genetics, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; (R.T.); (P.R.)
| | - Payal Ranade
- Department of Microbiology, Immunology and Genetics, University of North Texas Health Science Center, Fort Worth, TX 76107, USA; (R.T.); (P.R.)
| |
Collapse
|
2
|
Hrynkiewicz R, Niedźwiedzka-Rystwej P. Etiology of viral induced acute liver failure and defensins as potential therapeutic agents in ALF treatment. Front Immunol 2023; 14:1153528. [PMID: 37153560 PMCID: PMC10160486 DOI: 10.3389/fimmu.2023.1153528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 04/12/2023] [Indexed: 05/09/2023] Open
Abstract
Acute liver failure (ALF) is a rare and severe disease, which, despite continuous advances in medicine, is still characterized by high mortality (65-85%). Very often, a liver transplant is the only effective treatment for ALF. Despite the implementation of prophylactic vaccinations in the world, the viral background of ALF is still a problem and leads to many deaths. Depending on the cause of ALF, it is sometimes possible to reverse this condition with appropriate therapies, which is why the search for effective antiviral agents seems to be a very desirable direction of research. Defensins, which are our natural antimicrobial peptides, have a very high potential to be used as therapeutic agents for infectious liver diseases. Previous studies on the expression of human defensins have shown that increased expression of human α and β-defensins in HCV and HBV infections is associated with a better response to treatment. Unfortunately, conducting clinical trials for ALF is very difficult due to the severity of the disease and the low incidence, therefore animal models are important for the development of new therapeutic strategies. One of the best animal models that has real reference to research on acute liver failure (ALF) is rabbit hemorrhagic disease in rabbits caused by the Lagovirus europaeus virus. So far, there have been no studies on the potential of defensins in rabbits infected with Lagovirus europaeus virus.
Collapse
|
3
|
Sterling KG, Dodd GK, Alhamdi S, Asimenios PG, Dagda RK, De Meirleir KL, Hudig D, Lombardi VC. Mucosal Immunity and the Gut-Microbiota-Brain-Axis in Neuroimmune Disease. Int J Mol Sci 2022; 23:13328. [PMID: 36362150 PMCID: PMC9655506 DOI: 10.3390/ijms232113328] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 07/30/2023] Open
Abstract
Recent advances in next-generation sequencing (NGS) technologies have opened the door to a wellspring of information regarding the composition of the gut microbiota. Leveraging NGS technology, early metagenomic studies revealed that several diseases, such as Alzheimer's disease, Parkinson's disease, autism, and myalgic encephalomyelitis, are characterized by alterations in the diversity of gut-associated microbes. More recently, interest has shifted toward understanding how these microbes impact their host, with a special emphasis on their interactions with the brain. Such interactions typically occur either systemically, through the production of small molecules in the gut that are released into circulation, or through signaling via the vagus nerves which directly connect the enteric nervous system to the central nervous system. Collectively, this system of communication is now commonly referred to as the gut-microbiota-brain axis. While equally important, little attention has focused on the causes of the alterations in the composition of gut microbiota. Although several factors can contribute, mucosal immunity plays a significant role in shaping the microbiota in both healthy individuals and in association with several diseases. The purpose of this review is to provide a brief overview of the components of mucosal immunity that impact the gut microbiota and then discuss how altered immunological conditions may shape the gut microbiota and consequently affect neuroimmune diseases, using a select group of common neuroimmune diseases as examples.
Collapse
Affiliation(s)
| | - Griffin Kutler Dodd
- Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Shatha Alhamdi
- Clinical Immunology and Allergy Division, Department of Pediatrics, King Abdullah Specialist Children’s Hospital, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh 11426, Saudi Arabia
| | | | - Ruben K. Dagda
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | | | - Dorothy Hudig
- Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Vincent C. Lombardi
- Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| |
Collapse
|
4
|
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.
Collapse
|
5
|
Abstract
Defensins are a major family of host defense peptides expressed predominantly in neutrophils and epithelial cells. Their broad antimicrobial activities and multifaceted immunomodulatory functions have been extensively studied, cementing their role in innate immunity as a core host-protective component against bacterial, viral and fungal infections. More recent studies, however, paint defensins in a bad light such that they are "alleged" to promote viral and bacterial infections in certain biological settings. This mini review summarizes the latest findings on the potential pathogenic properties of defensins against the backdrop of their protective roles in antiviral and antibacterial immunity. Further, a succinct description of both tumor-proliferative and -suppressive activities of defensins is also given to highlight their functional and mechanistic complexity in antitumor immunity. We posit that given an enabling environment defensins, widely heralded as the "Swiss army knife," can function as a "double-edged sword" in host immunity.
Collapse
Affiliation(s)
- Dan Xu
- Institute of Mitochondrial Biology and Medicine, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Sciences and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
| |
Collapse
|
6
|
Bakare OO, Fadaka AO, Klein A, Pretorius A. Dietary effects of antimicrobial peptides in therapeutics. ALL LIFE 2020. [DOI: 10.1080/26895293.2020.1726826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Affiliation(s)
- Olalekan Olanrewaju Bakare
- Department of Biotechnology, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa
| | - Adewale Oluwaseun Fadaka
- Department of Biotechnology, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa
| | - Ashwil Klein
- Department of Biotechnology, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa
| | - Ashley Pretorius
- Department of Biotechnology, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa
| |
Collapse
|
7
|
Sabiá Júnior EF, Menezes LFS, de Araújo IFS, Schwartz EF. Natural Occurrence in Venomous Arthropods of Antimicrobial Peptides Active against Protozoan Parasites. Toxins (Basel) 2019; 11:E563. [PMID: 31557900 PMCID: PMC6832604 DOI: 10.3390/toxins11100563] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/31/2019] [Accepted: 09/10/2019] [Indexed: 02/07/2023] Open
Abstract
Arthropoda is a phylum of invertebrates that has undergone remarkable evolutionary radiation, with a wide range of venomous animals. Arthropod venom is a complex mixture of molecules and a source of new compounds, including antimicrobial peptides (AMPs). Most AMPs affect membrane integrity and produce lethal pores in microorganisms, including protozoan pathogens, whereas others act on internal targets or by modulation of the host immune system. Protozoan parasites cause some serious life-threatening diseases among millions of people worldwide, mostly affecting the poorest in developing tropical regions. Humans can be infected with protozoan parasites belonging to the genera Trypanosoma, Leishmania, Plasmodium, and Toxoplasma, responsible for Chagas disease, human African trypanosomiasis, leishmaniasis, malaria, and toxoplasmosis. There is not yet any cure or vaccine for these illnesses, and the current antiprotozoal chemotherapeutic compounds are inefficient and toxic and have been in clinical use for decades, which increases drug resistance. In this review, we will present an overview of AMPs, the diverse modes of action of AMPs on protozoan targets, and the prospection of novel AMPs isolated from venomous arthropods with the potential to become novel clinical agents to treat protozoan-borne diseases.
Collapse
Affiliation(s)
- Elias Ferreira Sabiá Júnior
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Luis Felipe Santos Menezes
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Israel Flor Silva de Araújo
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Elisabeth Ferroni Schwartz
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| |
Collapse
|
8
|
Guha S, Ghimire J, Wu E, Wimley WC. Mechanistic Landscape of Membrane-Permeabilizing Peptides. Chem Rev 2019; 119:6040-6085. [PMID: 30624911 DOI: 10.1021/acs.chemrev.8b00520] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Membrane permeabilizing peptides (MPPs) are as ubiquitous as the lipid bilayer membranes they act upon. Produced by all forms of life, most membrane permeabilizing peptides are used offensively or defensively against the membranes of other organisms. Just as nature has found many uses for them, translational scientists have worked for decades to design or optimize membrane permeabilizing peptides for applications in the laboratory and in the clinic ranging from antibacterial and antiviral therapy and prophylaxis to anticancer therapeutics and drug delivery. Here, we review the field of membrane permeabilizing peptides. We discuss the diversity of their sources and structures, the systems and methods used to measure their activities, and the behaviors that are observed. We discuss the fact that "mechanism" is not a discrete or a static entity for an MPP but rather the result of a heterogeneous and dynamic ensemble of structural states that vary in response to many different experimental conditions. This has led to an almost complete lack of discrete three-dimensional active structures among the thousands of known MPPs and a lack of useful or predictive sequence-structure-function relationship rules. Ultimately, we discuss how it may be more useful to think of membrane permeabilizing peptides mechanisms as broad regions of a mechanistic landscape rather than discrete molecular processes.
Collapse
Affiliation(s)
- Shantanu Guha
- Department of Biochemistry and Molecular Biology Tulane University School of Medicine , New Orleans , Louisiana 70112 , United States
| | - Jenisha Ghimire
- Department of Biochemistry and Molecular Biology Tulane University School of Medicine , New Orleans , Louisiana 70112 , United States
| | - Eric Wu
- Department of Biochemistry and Molecular Biology Tulane University School of Medicine , New Orleans , Louisiana 70112 , United States
| | - William C Wimley
- Department of Biochemistry and Molecular Biology Tulane University School of Medicine , New Orleans , Louisiana 70112 , United States
| |
Collapse
|
9
|
Wimley WC. Application of Synthetic Molecular Evolution to the Discovery of Antimicrobial Peptides. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1117:241-255. [PMID: 30980361 DOI: 10.1007/978-981-13-3588-4_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Despite long-standing promise and many known examples, antimicrobial peptides (AMPs) have failed, with few exceptions, to significantly impact human medicine. Impediments to the systemic activity of AMPs include proteolysis, host cell interactions, and serum protein binding, factors that are not often considered in the early stages of AMP development. Here we discuss how synthetic molecular evolution, iterative cycles of library design, and physiologically relevant screening can be used to evolve AMPs that do not have these impediments.
Collapse
Affiliation(s)
- William C Wimley
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, USA.
| |
Collapse
|
10
|
Neelabh, Singh K, Rani J. Sequential and Structural Aspects of Antifungal Peptides from Animals, Bacteria and Fungi Based on Bioinformatics Tools. Probiotics Antimicrob Proteins 2018; 8:85-101. [PMID: 27060002 DOI: 10.1007/s12602-016-9212-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Emerging drug resistance varieties and hyper-virulent strains of microorganisms have compelled the scientific fraternity to develop more potent and less harmful therapeutics. Antimicrobial peptides could be one of such therapeutics. This review is an attempt to explore antifungal peptides naturally produced by prokaryotes as well as eukaryotes. They are components of innate immune system providing first line of defence against microbial attacks, especially in eukaryotes. The present article concentrates on types, structures, sources and mode of action of gene-encoded antifungal peptides such as mammalian defensins, protegrins, tritrpticins, histatins, lactoferricins, antifungal peptides derived from birds, amphibians, insects, fungi, bacteria and their synthetic analogues such as pexiganan, omiganan, echinocandins and Novexatin. In silico drug designing, a major revolution in the area of therapeutics, facilitates drug development by exploiting different bioinformatics tools. With this view, bioinformatics tools were used to visualize the structural details of antifungal peptides and to predict their level of similarity. Current practices and recent developments in this area have also been discussed briefly.
Collapse
Affiliation(s)
- Neelabh
- Department of Zoology (MMV), Banaras Hindu University, Varanasi, 221005, India
| | - Karuna Singh
- Department of Zoology (MMV), Banaras Hindu University, Varanasi, 221005, India.
| | - Jyoti Rani
- Department of Zoology (MMV), Banaras Hindu University, Varanasi, 221005, India
| |
Collapse
|
11
|
Kumar P, Kizhakkedathu JN, Straus SK. Antimicrobial Peptides: Diversity, Mechanism of Action and Strategies to Improve the Activity and Biocompatibility In Vivo. Biomolecules 2018; 8:E4. [PMID: 29351202 PMCID: PMC5871973 DOI: 10.3390/biom8010004] [Citation(s) in RCA: 651] [Impact Index Per Article: 108.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 01/12/2018] [Accepted: 01/12/2018] [Indexed: 02/06/2023] Open
Abstract
Antibiotic resistance is projected as one of the greatest threats to human health in the future and hence alternatives are being explored to combat resistance. Antimicrobial peptides (AMPs) have shown great promise, because use of AMPs leads bacteria to develop no or low resistance. In this review, we discuss the diversity, history and the various mechanisms of action of AMPs. Although many AMPs have reached clinical trials, to date not many have been approved by the US Food and Drug Administration (FDA) due to issues with toxicity, protease cleavage and short half-life. Some of the recent strategies developed to improve the activity and biocompatibility of AMPs, such as chemical modifications and the use of delivery systems, are also reviewed in this article.
Collapse
Affiliation(s)
- Prashant Kumar
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
- Centre for Blood Research, Department of Pathology and Laboratory Medicine, University of British Columbia, 2350 Health Sciences Mall, Life Sciences Centre, Vancouver, BC V6T 1Z3, Canada.
| | - Jayachandran N Kizhakkedathu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
- Centre for Blood Research, Department of Pathology and Laboratory Medicine, University of British Columbia, 2350 Health Sciences Mall, Life Sciences Centre, Vancouver, BC V6T 1Z3, Canada.
| | - Suzana K Straus
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
| |
Collapse
|
12
|
Chang KY, Lin TP, Shih LY, Wang CK. Analysis and prediction of the critical regions of antimicrobial peptides based on conditional random fields. PLoS One 2015; 10:e0119490. [PMID: 25803302 PMCID: PMC4372350 DOI: 10.1371/journal.pone.0119490] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 01/14/2015] [Indexed: 11/27/2022] Open
Abstract
Antimicrobial peptides (AMPs) are potent drug candidates against microbes such as bacteria, fungi, parasites, and viruses. The size of AMPs ranges from less than ten to hundreds of amino acids. Often only a few amino acids or the critical regions of antimicrobial proteins matter the functionality. Accurately predicting the AMP critical regions could benefit the experimental designs. However, no extensive analyses have been done specifically on the AMP critical regions and computational modeling on them is either non-existent or settled to other problems. With a focus on the AMP critical regions, we thus develop a computational model AMPcore by introducing a state-of-the-art machine learning method, conditional random fields. We generate a comprehensive dataset of 798 AMPs cores and a low similarity dataset of 510 representative AMP cores. AMPcore could reach a maximal accuracy of 90% and 0.79 Matthew’s correlation coefficient on the comprehensive dataset and a maximal accuracy of 83% and 0.66 MCC on the low similarity dataset. Our analyses of AMP cores follow what we know about AMPs: High in glycine and lysine, but low in aspartic acid, glutamic acid, and methionine; the abundance of α-helical structures; the dominance of positive net charges; the peculiarity of amphipathicity. Two amphipathic sequence motifs within the AMP cores, an amphipathic α-helix and an amphipathic π-helix, are revealed. In addition, a short sequence motif at the N-terminal boundary of AMP cores is reported for the first time: arginine at the P(-1) coupling with glycine at the P1 of AMP cores occurs the most, which might link to microbial cell adhesion.
Collapse
Affiliation(s)
- Kuan Y. Chang
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
- * E-mail:
| | - Tung-pei Lin
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Ling-Yi Shih
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Chien-Kuo Wang
- Department of Biotechnology, Asia University, Taichung, Taiwan
| |
Collapse
|
13
|
Peptide entry inhibitors of enveloped viruses: the importance of interfacial hydrophobicity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2180-97. [PMID: 24780375 PMCID: PMC7094693 DOI: 10.1016/j.bbamem.2014.04.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/08/2014] [Accepted: 04/17/2014] [Indexed: 12/16/2022]
Abstract
There are many peptides known that inhibit the entry of enveloped viruses into cells, including one peptide that is successfully being used in the clinic as a drug. In this review, we discuss the discovery, antiviral activity and mechanism of action of such peptides. While peptide entry inhibitors have been discovered by a wide variety of approaches (structure-based, accidental, intentional, rational and brute force) we show here that they share a common physical chemical property: they are at least somewhat hydrophobic and/or amphipathic and have a propensity to interact with membrane interfaces. We propose that this propensity drives a shared mechanism of action for many peptide entry inhibitors, involving direct interactions with viral and cellular membranes, as well as interactions with the complex hydrophobic protein/lipid interfaces that are exposed, at least transiently, during virus-cell fusion. By interacting simultaneously with the membrane interfaces and other critical hydrophobic surfaces, we hypothesize that peptide entry inhibitors can act by changing the physical chemistry of the membranes, and the fusion protein interfaces bridging them, and by doing so interfere with the fusion of cellular and viral membranes. Based on this idea, we propose that an approach that focuses on the interfacial hydrophobicity of putative entry inhibitors could lead to the efficient discovery of novel, broad-spectrum viral entry inhibitors. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.
Collapse
|
14
|
Glinel K, Thebault P, Humblot V, Pradier CM, Jouenne T. Antibacterial surfaces developed from bio-inspired approaches. Acta Biomater 2012; 8:1670-84. [PMID: 22289644 DOI: 10.1016/j.actbio.2012.01.011] [Citation(s) in RCA: 208] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/20/2011] [Accepted: 01/10/2012] [Indexed: 11/16/2022]
Abstract
Prevention of bacterial adhesion and biofilm formation on the surfaces of materials is a topic of major medical and societal importance. Various synthetic approaches based on immobilization or release of bactericidal substances such as metal derivatives, polyammonium salts and antibiotics were extensively explored to produce antibacterial coatings. Although providing encouraging results, these approaches suffer from the use of active agents which may be associated with side-effects such as cytotoxicity, hypersensibility, inflammatory responses or the progressive alarming phenomenon of antibiotic resistance. In addition to these synthetic approaches, living organisms, e.g. animals and plants, have developed fascinating strategies over millions of years to prevent efficiently the colonization of their surfaces by pathogens. These strategies have been recently mimicked to create a new generation of bio-inspired biofilm-resistant surfaces. In this review, we discuss some of these bio-inspired methods devoted to the development of antibiofilm surfaces. We describe the elaboration of antibacterial coatings based on natural bactericidal substances produced by living organisms such as antimicrobial peptides, bacteriolytic enzymes and essential oils. We discuss also the development of layers mimicking algae surfaces and based on anti-quorum-sensing molecules which affect cell-to-cell communication. Finally, we report on very recent strategies directly inspired from marine animal life and based on surface microstructuring.
Collapse
Affiliation(s)
- K Glinel
- Institute of Condensed Matter and Nanosciences (Bio- and Soft Matter), Université catholique de Louvain, Louvain-la-Neuve, Belgium.
| | | | | | | | | |
Collapse
|
15
|
Abstract
Defensins are small, multifunctional cationic peptides. They typically contain six conserved cysteines whose three intramolecular disulfides stabilize a largely β-sheet structure. This review of human α-defensins begins by describing their evolution, including their likely relationship to the Big Defensins of invertebrates, and their kinship to the β-defensin peptides of many if not all vertebrates, and the θ-defensins found in certain non-human primates. We provide a short history of the search for leukocyte-derived microbicidal molecules, emphasizing the roles played by luck (good), preconceived notions (mostly bad), and proper timing (essential). The antimicrobial, antiviral, antitoxic, and binding properties of human α-defensins are summarized. The structural features of α-defensins are described extensively and their functional contributions are assessed. The properties of HD6, an enigmatic Paneth cell α-defensin, are contrasted with those of the four myeloid α-defensins (HNP1-4) and of HD5, the other α-defensin of human Paneth cells. The review ends with a decalogue that may assist researchers or students interested in α-defensins and related aspects of neutrophil function.
Collapse
Affiliation(s)
- Robert I Lehrer
- Department of Medicine and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1688, USA.
| | | |
Collapse
|
16
|
Abstract
Antimicrobial peptides are present in all walks of life, from plants to animals, and they are considered to be endogenous antibiotics. In general, antimicrobial peptides are determinants of the composition of the microbiota and they function to fend off microbes and prevent infections. Antimicrobial peptides eliminate micro-organisms through disruption of their cell membranes. Their importance in human immunity, and in health as well as disease, has only recently been appreciated. The present review provides an introduction to the field of antimicrobial peptides in general and discusses two of the major classes of mammalian antimicrobial peptides: the defensins and the cathelicidins. The review focuses on their structures, their main modes of action and their regulation.
Collapse
Affiliation(s)
- Andreas Cederlund
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | | | | |
Collapse
|
17
|
|
18
|
Wimley WC. Describing the mechanism of antimicrobial peptide action with the interfacial activity model. ACS Chem Biol 2010; 5:905-17. [PMID: 20698568 DOI: 10.1021/cb1001558] [Citation(s) in RCA: 660] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Antimicrobial peptides (AMPs) have been studied for three decades, and yet a molecular understanding of their mechanism of action is still lacking. Here we summarize current knowledge for both synthetic vesicle experiments and microbe experiments, with a focus on comparisons between the two. Microbial experiments are done at peptide to lipid ratios that are at least 4 orders of magnitude higher than vesicle-based experiments. To close the gap between the two concentration regimes, we propose an "interfacial activity model", which is based on an experimentally testable molecular image of AMP-membrane interactions. The interfacial activity model may be useful in driving engineering and design of novel AMPs.
Collapse
Affiliation(s)
- William C. Wimley
- Department of Biochemistry SL43, Tulane University Health Sciences Center, New Orleans, Louisiana 70112-2699
| |
Collapse
|
19
|
|
20
|
|
21
|
Carvalho ADO, Gomes VM. Plant defensins--prospects for the biological functions and biotechnological properties. Peptides 2009; 30:1007-20. [PMID: 19428780 DOI: 10.1016/j.peptides.2009.01.018] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 01/22/2009] [Accepted: 01/26/2009] [Indexed: 01/07/2023]
Abstract
Plant defensins are a prominent family of cationic peptides in the plant kingdom. They are structurally and functionally related to defensins that have been previously characterized in mammals and insects. They present molecular masses between 5 and 7kDa and possess a pattern of eight conserved Cys residues. The three-dimensional structure of plant defensins is small and globular. It has three anti-parallel beta-sheets and one alpha-helix that is stabilized by a structural motif composed of disulfide bridges. This motif is found in other peptides with biological activity and is called the Cys stabilized alphabeta motif (CSalphabeta). Based on the growing knowledge on defensin structure, gene expression and regulation, and also their in vitro biological activity, it has become clear that plant defensins are complex and sophisticated peptides whose function extends beyond their role in defense of plants against microbial infection. This review discusses recent data and will present comprehensive information regarding the study of defensins.
Collapse
Affiliation(s)
- André de Oliveira Carvalho
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense-Darcy Ribeiro, Campos dos Goytacazes-RJ, Brazil.
| | | |
Collapse
|
22
|
Lourenzoni MR, Namba AM, Caseli L, Degrève L, Zaniquelli MED. Study of the Interaction of Human Defensins with Cell Membrane Models: Relationships between Structure and Biological Activity. J Phys Chem B 2007; 111:11318-29. [PMID: 17784741 DOI: 10.1021/jp067127g] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The HNP-1, HNP-2, and HNP-3 defensins are human antimicrobial peptides produced in response to microbial invasion. Their properties are distinct, with a more potent action for HNP-3. In this study, the relationship between their structural dissimilarities and their different microbial actions was evaluated by molecular dynamics simulation. Structural determinants related to their intra- and intermolecular interactions were defined for each HNP using a simplified membrane model consisting of a water/n-hexane interface. The hydrophobic portion of the HNPs promotes their diffusion to the interface with a concomitant, slight change in the structure induced by the intermolecular electrostatic interactions between the HPN molecules and the interface. As a consequence, different orientations are probably adopted by the HNPs at the interface, which may explain their different actions. The interaction of HNP-1 and HNP-2 with the surfaces was also studied using Langmuir monolayers as a biomimetic system. It was found that peptides adsorb rapidly at n-hexane/water interfaces as well as at phospholipid Langmuir monolayers but not at the air/liquid interface. This reveals that the presence of an organic phase is required for the exposure of the hydrophobic groups of the peptides. In addition, adsorption kinetics and surface pressure-area isotherms for Langmuir monolayers suggested that the lipid-peptide interaction is strongly influenced by the monolayer electrical charge and packing, depending also on the HPN structure. This study supports a model in which defensins, acting in a dimeric form, are able to disrupt membranes. The model also shows that the individual structures of the HNPs are responsible for their different actions on microbes.
Collapse
Affiliation(s)
- Marcos R Lourenzoni
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto-S. P., Brazil.
| | | | | | | | | |
Collapse
|
23
|
Sinha S, Cheshenko N, Lehrer RI, Herold BC. NP-1, a rabbit alpha-defensin, prevents the entry and intercellular spread of herpes simplex virus type 2. Antimicrob Agents Chemother 2003; 47:494-500. [PMID: 12543649 PMCID: PMC151743 DOI: 10.1128/aac.47.2.494-500.2003] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rabbit neutrophil peptide-1 (NP-1), a prototypic alpha-defensin, protects cells in vitro from infection by clinical and laboratory isolates of herpes simplex virus type 2 (HSV-2). Incubation of concentrated virus stocks for 1 h with noncytotoxic concentrations of NP-1 reduces subsequent infection by >98%. Pretreating cells with NP-1 for 1 h prior to inoculation with untreated virus also prevents infection. NP-1, a cationic peptide, does not compete with viral envelope glycoproteins for binding to cellular heparan sulfate receptors, but it prevents viral entry. No VP16, a major viral tegument protein, is transported to the cell nucleus in the presence of NP-1. Infectious center assays demonstrate that NP-1 also inhibits cell-to-cell viral spread. Thus, NP-1 prevents virally mediated fusion events, entry, and cell-to-cell spread. This unique mechanism of anti-HSV activity, coupled with established antibacterial and possible anti-human immunodeficiency virus type 1 activities of defensins, render this family of compounds excellent candidates for further development as topical microbicides.
Collapse
Affiliation(s)
- Sara Sinha
- Department of Pediatrics and Microbiology, Mount Sinai School of Medicine, New York, New York, USA
| | | | | | | |
Collapse
|
24
|
Kisich KO, Heifets L, Higgins M, Diamond G. Antimycobacterial agent based on mRNA encoding human beta-defensin 2 enables primary macrophages to restrict growth of Mycobacterium tuberculosis. Infect Immun 2001; 69:2692-9. [PMID: 11254636 PMCID: PMC98208 DOI: 10.1128/iai.69.4.2692-2699.2001] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2000] [Accepted: 12/26/2000] [Indexed: 11/20/2022] Open
Abstract
Human macrophages are hosts for Mycobacterium tuberculosis, the causative agent of tuberculosis, which killed approximately 1.87 million people in 1997. Human alveolar macrophages do not express alpha- or beta-defensins, broad-spectrum antimicrobial peptides which are expressed in macrophages from other species more resistant to infection with M. tuberculosis. It has been previously reported that M. tuberculosis is susceptible to killing by defensins, which may explain the difference in resistance. Defensin peptides have been suggested as a possible therapeutic strategy for a variety of infectious diseases, but development has been hampered by difficulties in their large-scale production. Here we report the cellular synthesis of human beta-defensin 2 via highly efficient mRNA transfection of human macrophages. This enabled mycobactericidal and mycobacteristatic activity by the macrophages. Although human macrophages are difficult to transfect with plasmid vectors, these studies illustrate that primary macrophages are permissive for mRNA transfection, which enabled expression of a potentially therapeutic protein.
Collapse
Affiliation(s)
- K O Kisich
- Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado 80206, USA.
| | | | | | | |
Collapse
|
25
|
Risso A. Leukocyte antimicrobial peptides: multifunctional effector molecules of innate immunity. J Leukoc Biol 2000. [DOI: 10.1189/jlb.68.6.785] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Angela Risso
- Department of Biomedical Science and Biotechnology, University of Udine, Italy
| |
Collapse
|
26
|
Edgerton M, Koshlukova SE, Araujo MW, Patel RC, Dong J, Bruenn JA. Salivary histatin 5 and human neutrophil defensin 1 kill Candida albicans via shared pathways. Antimicrob Agents Chemother 2000; 44:3310-6. [PMID: 11083633 PMCID: PMC90198 DOI: 10.1128/aac.44.12.3310-3316.2000] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salivary histatins are a family of basic histidine-rich proteins in which therapeutic potential as drugs against oral candidiasis is apparent, considering their potent in vitro antifungal activity and lack of toxicity to humans. Histatin 5 (Hst 5) kills the fungal pathogen Candida albicans via a mechanism that involves binding to specific sites on the yeast cell membrane and subsequent release of cellular ATP in the absence of cytolysis. We explored the killing pathway activated by Hst 5 and compared it to those activated by other antifungal agents. The candidacidal activity of human neutrophil defensin 1 (HNP-1) shared very similar features to Hst 5 cytotoxic action with respect to active concentrations and magnitude of induction of nonlytic ATP efflux, depletion of intracellular ATP pools, and inhibitor profile. Hst 5 and HNP-1 are basic proteins of about 3 kDa; however, they have unique primary sequences and solution structures that cannot explain how these two molecules act so similarly on C. albicans to induce cell death. Our finding that HNP-1 prevented Hst 5 binding to the candidal Hst 5 binding protein suggests that the basis for the overlapping actions of these two naturally occurring antimicrobial proteins may involve interactions with shared yeast components.
Collapse
Affiliation(s)
- M Edgerton
- Departments of Oral Biology, State University of New York at Buffalo, Buffalo, New York 14214, USA.
| | | | | | | | | | | |
Collapse
|
27
|
De Lucca AJ. Antifungal peptides: potential candidates for the treatment of fungal infections. Expert Opin Investig Drugs 2000; 9:273-99. [PMID: 11060677 DOI: 10.1517/13543784.9.2.273] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Many diversely produced natural peptides, as well as those produced semisynthetically and synthetically, have been found to inhibit the growth or even be lethal to a wide range of fungi. Some of these have the potential to aid mankind in combating mycoses caused by emerging pathogens or as a result of the increasing number of antibiotic-resistant fungi. Antifungal peptides may also assist in non-medical fields such as agriculture. For example, introduction by transgenic research of antifungal peptides could improve crop production yields by increasing host resistance to fungal invasion. The aim of this review is to provide information on research on these important peptides.
Collapse
Affiliation(s)
- A J De Lucca
- Southern Regional Research Center, USDA, ARS 1100 Robert E. Lee Blvd. New Orleans, LA 70124, USA.
| |
Collapse
|
28
|
De Lucca AJ, Walsh TJ. Antifungal peptides: novel therapeutic compounds against emerging pathogens. Antimicrob Agents Chemother 1999; 43:1-11. [PMID: 9869556 PMCID: PMC89011 DOI: 10.1128/aac.43.1.1] [Citation(s) in RCA: 212] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- A J De Lucca
- Southern Regional Research Center, Agricultural Research Service, U. S. Department of Agriculture, New Orleans, Louisiana 70124, USA.
| | | |
Collapse
|
29
|
Abstract
Candida albicans, an increasingly common opportunistic pathogenic fungus, frequently causes disease in immunodeficient but not immunocompetent hosts. Clarifying the role of the phagocytic cells that participate in resistance to candidiasis not only is basic to understanding how the host copes with this dimorphic pathogen but also will expedite the development of innovative prophylactic and therapeutic approaches for treating the multiple clinical presentations that candidiasis encompasses. In this review, we present evidence that a diverse population of mononuclear phagocytes, in different states of activation and differentiation and from a variety of host species, can phagocytize C. albicans blastoconidia via an array of opsonic and nonopsonic mechanisms and can kill C. albicans blastoconidia and hyphae by means of oxygen-dependent and -independent mechanisms. Reactive nitrogen intermediates should now be added to the well-established candidacidal reactive oxygen intermediates of macrophages. Furthermore, what were thought to be two independent pathways, i.e., nitric oxide and superoxide anion, have now been shown to combine to form a potent macrophage candidacidal molecule, peroxynitrite. In contrast to monocytes and neutrophils, which are important in resistance to early stages of C. albicans infections, more differentiated macrophages activated by cytokines such as gamma interferon participate in the acquired resistance of hosts with C. albicans-specific, cell-mediated immunity. Evidence presented in this review demonstrates that mononuclear phagocytes, in some instances in the absence of other professional phagocytes such as neutrophils, play an import role in resistance to systemic and mucosal candidiasis.
Collapse
Affiliation(s)
- A Vázquez-Torres
- Department of Surgery, University of Wisconsin Medical School, Madison 53706-1532, USA
| | | |
Collapse
|
30
|
Abstract
Defensins comprise a structural class of small cationic peptides that exert broad-spectrum antimicrobial activities through membrane permeabilization. Their predominantly beta-sheet structure, stabilized by three disulfide bonds, distinguishes them from other antimicrobial peptides which typically form amphiphilic helices. Defensins bind to membranes electrostatically and subsequently form apparently multimeric pores. Recent structural and biophysical studies are beginning to provide insights into the process of permeabilization.
Collapse
Affiliation(s)
- S H White
- Department of Physiology and Biophysics, University of California, Irvine 92717-4560, USA
| | | | | |
Collapse
|
31
|
Abstract
Defensins are a family of small cationic, antibiotic peptides that contain six cysteines in disulfide linkage. The peptides are abundant in phagocytes and small intestinal mucosa of humans and other mammals and in the hemolymph of insects. They contribute to host defense against microbes and may participate in tissue inflammation and endocrine regulation during infection. Bioengineered defensins are potentially useful as prophylactic and therapeutic agents in infections.
Collapse
Affiliation(s)
- T Ganz
- Department of Medicine, University of California School of Medicine, Los Angeles 90024-1736, USA
| | | |
Collapse
|
32
|
Abstract
Defensins are antimicrobial and cytotoxic peptides that contain 29-35 amino acid residues, including 6 invariant cysteines that form 3 intramolecular disulfide bonds. They constitute more than 5% of the total cellular protein of human and rabbit neutrophils (PMN), and are also produced by rabbit lung macrophages and by murine and human small intestinal Paneth cells. Defensins exerted antimicrobial effects in vitro against many Gram-positive and Gram-negative bacteria, fungi, mycobacteria and some enveloped viruses, and were cytotoxic to a wide range of normal and malignant targets, including cells resistant to TNF-alpha and NK-cytolytic factor. Human and rabbit defensins formed voltage-sensitive channels in a variety of planar lipid bilayers when a negative voltage of approximately 70-90 mV was applied to the contralateral side. These channels showed modest anion selectivity and their formation was strongly influenced by defensin concentration. Although most other channel-forming peptides have prominent alpha-helical domains, the structure of defensin molecules is primarily composed of antiparallel beta-sheets. Studies with various prokaryotic and eukaryotic cells provided convincing evidence that defensins killed these targets by forming voltage-regulated channels in the susceptible cell's membrane. The broad spectrum of defensin-susceptible targets and the abundance of defensins in specialized host defense cells of the blood, lungs and intestinal tract suggest that defensins could play a significant role in innate immunity to infection and neoplasia.
Collapse
Affiliation(s)
- B L Kagan
- Department of Psychiatry and Biobehavioral Science, BRI UCLA-Center for Health Sciences
| | | | | |
Collapse
|
33
|
|
34
|
Isolation and characterization of a novel class of plant antimicrobial peptides form Mirabilis jalapa L. seeds. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)45866-8] [Citation(s) in RCA: 214] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
35
|
Whitfill C, Presson B, Newberry L, Andrews P, Cox E, Skeeles K, Gyles NR, Thoma JA. Action spectrum of antiviral factor from chicken sera. Poult Sci 1991; 70:2450-9. [PMID: 1664518 DOI: 10.3382/ps.0702450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Rous sarcoma virus infections of regressor line chickens stimulate the transient production of antiviral factors in the serum. Earlier the present authors reported that a viral neutralization factor (VNF) inactivated Rous sarcoma virus during a 3-h incubation. The VNF is likely to have a broad antiviral and antimicrobial spectrum because it is active against several unrelated pathogenic poultry viruses. The present study measured the activity of VNF against Newcastle disease virus, infectious bursal disease virus, and infectious bronchitis virus. The VNF is active in immunologically incompetent systems and must be preincubated with the virus in order to inhibit it. Based upon the current experiments, it is proposed that VNF is not an immunomodulator but directly inactivates the virus. The VNF agent appears to be one of a newly identified class of nonspecific antiviral agents produced in vivo in chickens in response to a viral infection.
Collapse
Affiliation(s)
- C Whitfill
- Department of Animal and Poultry Science, University of Arkansas, Fayetteville 72701
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Borenstein LA, Selsted ME, Lehrer RI, Miller JN. Antimicrobial activity of rabbit leukocyte defensins against Treponema pallidum subsp. pallidum. Infect Immun 1991; 59:1359-67. [PMID: 2004816 PMCID: PMC257851 DOI: 10.1128/iai.59.4.1359-1367.1991] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Defensins, which are peptides with broad antimicrobial activity, are major constituents of rabbit neutrophils and certain macrophages. We tested six rabbit defensins, NP-1, NP-2, NP-3a, NP-3b, NP-4, and NP-5, for activity against Treponema pallidum subsp. pallidum. Mixtures of T. pallidum and defensin in 10% normal rabbit serum (NRS) or heat-inactivated NRS (HI-NRS) were incubated anaerobically for various time periods ranging between 0 and 16 h and then examined by dark-field microscopy for treponemal motility or inoculated intradermally into rabbits to assess treponemal virulence. Immobilization of T. pallidum by NP-1 (400 micrograms/ml) occurred after 4 and 8 h of coincubation in mixtures containing NRS and HI-NRS, respectively. Similarly, neutralization of T. pallidum by NP-1 occurred more rapidly and was complete when incubations were performed in NRS as compared with that in HI-NRS. Endpoint titration confirmed the augmentation of NP-1 antitreponemal activity by heat-labile serum factors; NP-1 showed neutralizing activity at 4 micrograms/ml (about 1 microM) in NRS and at 40 micrograms/ml in HI-NRS. When NP-1 was tested in serum that was deficient in C6, the T. pallidum neutralizing activity of NP-1 was reduced to levels slightly greater than that observed in HI-NRS. NP-1 that had been reduced and alkylated was inactive against T. pallidum. When NP-2, NP-3a, NP-3b, NP-4, and NP-5 were tested at 400 micrograms/ml, all exerted potent treponemicidal activity, manifested by abrogation or delayed development of cutaneous lesions relative to that of controls. These data suggest that defensins may equip certain macrophages and neutrophils to participate in host defense against T. pallidum, that the direct activity of defensins against T. pallidum is enhanced by heat-labile serum factors (presumably complement), and that conformational factors influence the biological activity of the defensin molecule.
Collapse
Affiliation(s)
- L A Borenstein
- Department of Microbiology and Immunology, University of California, School of Medicine, Los Angeles 90024
| | | | | | | |
Collapse
|
37
|
|
38
|
Kagan BL, Selsted ME, Ganz T, Lehrer RI. Antimicrobial defensin peptides form voltage-dependent ion-permeable channels in planar lipid bilayer membranes. Proc Natl Acad Sci U S A 1990; 87:210-4. [PMID: 1688654 PMCID: PMC53231 DOI: 10.1073/pnas.87.1.210] [Citation(s) in RCA: 363] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Defensins are cationic, cysteine-rich peptides (Mr = 3500-4000) found in the cytoplasmic granules of neutrophils and macrophages. These peptides possess broad antimicrobial activity in vitro against bacteria, fungi, tumor cells, and enveloped viruses, and they are believed to contribute to the "oxygen-independent" antimicrobial defenses of neutrophils and macrophages. Pathophysiologic studies in vitro have pointed to the plasma membrane as a possible target for the cytotoxic action of defensins. We report here that defensins form voltage-dependent, weakly anion-selective channels in planar lipid bilayer membranes, and we suggest that this channel-forming ability contributes to their antimicrobial properties observed in vitro.
Collapse
Affiliation(s)
- B L Kagan
- Department of Psychiatry, University of California-Los Angeles School of Medicine 90024-1751
| | | | | | | |
Collapse
|
39
|
Abstract
Defensins are a family of small, variably cationic proteins which are highly abundant in the granules of mammalian phagocytes. Three defensins, HNP-1, 2, and 3, comprise 30-50% of total protein in azurophil granules of human neutrophils. Some defensins are broadly antimicrobial, antiviral and cytotoxic, while others are chemotactic, opsonic, or may modulate hormonal responses. The defensin molecule typically consists of 29-34 amino acids with a conserved pattern of disulfide linkage among its 6 cysteines. The three-dimensional fold of defensins forms a highly amphiphilic molecule. Microbicidal and cytotoxic properties of defensins are most likely a consequence of their ability to insert into biological membranes and to generate pores. Defensins are synthesized by phagocytes or their precursors as a 94-95 amino acid charge-neutralized preprodefensin, an arrangement which may avoid cytotoxic injury to the phagocyte. Although defensins were recognized only recently, the existence of homologs in certain invertebrates suggests that they are ancestral components of the host defense system.
Collapse
Affiliation(s)
- T Ganz
- Will Rogers Pulmonary Research Laboratory, School of Medicine, University of California, Los Angeles 90024-1736
| | | | | |
Collapse
|
40
|
Westerhoff HV, Hendler RW, Zasloff M, Juretić D. Interactions between a new class of eukaryotic antimicrobial agents and isolated rat liver mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 975:361-9. [PMID: 2758042 DOI: 10.1016/s0005-2728(89)80344-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Members of a newly discovered class of eukaryotic antimicrobial peptides are shown to release respiratory control in isolated rat-liver mitochondria. They also dissipate the membrane potential and inhibit respiration. The uncoupling activity of the peptides decreases with time probably due to the presence of proteases in the mitochondrial preparation. Quinine and Mg2+ reduce the activity of the peptides. The nature of the dependence of the respiratory rate on the concentration of added peptides suggests that they are active in a multimeric form, consistent with the formation of a channel across the inner mitochondrial membrane. The channel allows passage of sucrose.
Collapse
Affiliation(s)
- H V Westerhoff
- Section of Molecular Biology, Netherlands Cancer Institute, Amsterdam
| | | | | | | |
Collapse
|
41
|
Takahashi H, Chikakane K, Okuda M, Hatano M, Hoshino M, Kaneko O, Kawa Y. Tissue-bound immunity: a mechanism of candidacidal activity. CURRENT TOPICS IN MEDICAL MYCOLOGY 1989; 3:50-63. [PMID: 2688922 DOI: 10.1007/978-1-4612-3624-5_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
42
|
Romeo D, Skerlavaj B, Bolognesi M, Gennaro R. Structure and bactericidal activity of an antibiotic dodecapeptide purified from bovine neutrophils. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)81553-3] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
43
|
Sawyer JG, Martin NL, Hancock RE. Interaction of macrophage cationic proteins with the outer membrane of Pseudomonas aeruginosa. Infect Immun 1988; 56:693-8. [PMID: 3125111 PMCID: PMC259347 DOI: 10.1128/iai.56.3.693-698.1988] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The interaction of the polycationic rabbit alveolar macrophage cationic proteins MCP-1 and MCP-2 (or their identical neutrophil equivalents NP-1 and NP-2) with the surface of Pseudomonas aeruginosa was investigated. Both proteins bound avidly to purified lipopolysaccharide, as judged by their ability to competitively displace the probe dansyl polymyxin with 50% inhibition (I50) values of 2 to 3 microM. Similar I50 were measured with dansyl polymyxin as a probe for cell surface binding, suggesting that the initial binding site for MCP-1 and MCP-2 on the surface of cells was lipopolysaccharide. Both MCP-1 and MCP-2 permeabilized outer membranes to the hydrophobic fluorescent probe 1-N-phenylnaphthylamine (NPN). The initial rate of NPN uptake plotted against the concentration of MCP-1 or MCP-2 gave sigmoidal curves, suggesting cooperative permeabilization of the outer membrane. Replotting the data as a Hill plot gave an affinity parameter, S0.5, the concentration of MCP giving a half-maximal increase in the rate of NPN uptake, of 5 and 25 microM for MCP-1 and MCP-2, respectively, and thus subsequent studies concentrated on the more active permeabilizer MCP-1. Permeabilization of outer membranes to NPN was a function of buffer pH, with lower pH considerably favoring the permeabilizing effects of MCP-1. Thin-section electron microscopic visualization of MCP-1-treated cells showed production of extended blebs. Further evidence of an altered cell surface after MCP-1 treatment was obtained by demonstrating that treated unopsonized cells were more efficiently phagocytosed by unelicited rabbit alveolar macrophages. The data overall suggest that macrophage cationic proteins interact with the P. aeruginosa outer membrane in a manner typical of other polycations and suggest that one of their major functions may be to permeabilize the outer membrane.
Collapse
Affiliation(s)
- J G Sawyer
- Department of Microbiology, University of British Columbia, Vancouver, Canada
| | | | | |
Collapse
|
44
|
Shadomy HJ, Fromtling RA. Interactions between Macrophages and Fungi. Infection 1988. [DOI: 10.1007/978-1-4899-3748-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
45
|
Ginsburg I. Cationic polyelectrolytes: a new look at their possible roles as opsonins, as stimulators of respiratory burst in leukocytes, in bacteriolysis, and as modulators of immune-complex diseases (a review hypothesis). Inflammation 1987; 11:489-515. [PMID: 2961690 DOI: 10.1007/bf00915991] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- I Ginsburg
- Department of Oral Biology, Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel
| |
Collapse
|
46
|
Csuka I, Antoni F, Gróf J. Cytostatic peptide isolation from culture media of mouse peritoneal exudate cells. Cell Immunol 1987; 108:425-37. [PMID: 3621352 DOI: 10.1016/0008-8749(87)90225-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
It was found that the supernatant of mouse PEC culture medium (MCM) (both resident and casein-elicited cells) has an inhibitory effect in vitro on the incorporation of [3H]TdR into DNA of mouse spleen cells. The inhibitory effect in the MCM appears in the first 24 hr and also reaches its maximum value within this time. The inhibitory effect of this factor could not be demonstrated in the extract of freshly harvested M phi cells. The factors responsible for inhibition proved to be heat stable at 80 degrees C for longer than 30 min. Following heat treatment, the crude extract was separated into four fractions absorbing uv light at 280 nm using Sephadex G-25 column chromatography, and the most potent biologically active inhibitory factor was eluted in the last fraction. This fraction could also be obtained with a more effective permeation volume using Trysacryl GF 05 gel chromatography, and the active B fraction from this chromatography could be separated into four subfractions by isotachophoresis (ITP). The active fraction, which was obtained by Trysacryl GF 05 gel chromatography and further separated by ITP, was found to be highly inhibitory. It contained a peptide-like substance with a molecular mass of approximately 2.0 kDa and had an anionic character at pH 4.0. The inhibitory effect of MCM cannot be influenced either by inhibitory compounds of protein synthesis or by proteolysis blocking agents. Furthermore, the inhibitory effect is shown to be reversible and is more pronounced on B cells than on T lymphocytes.
Collapse
|
47
|
Abstract
Respiratory secretions provide an efficient method for protecting the large surface area of the lower respiratory tract. To determine whether lung secretions contribute to antifungal defenses, we tested bronchoalveolar lavage fluid for fungicidal activity. Candida albicans (blastoconidia) was incubated in unconcentrated cell-free lavage fluid from Swiss Webster mice and then cultured quantitatively to measure residual viability. In control buffer the residual fractions of viable fungi were 1.03 +/- 0.12 at 60 min and 0.84 +/- 0.05 at 120 min, whereas the residual fractions in lavage fluid were 0.64 +/- 0.07 and 0.23 +/- 0.05, respectively (P less than 0.05 by t tests). This activity was trypsin sensitive and heat stable (56 degrees C) and did not require divalent cations. It did not sediment with the surfactant fraction of lung lavage fluid. Unconcentrated lavage fluid reduced the adherence of C. albicans to serum-coated glass tubes to 2.3 +/- 1.5% of that of control Candida suspensions (n = 5, P less than 0.05 by t test). It did not alter Candida ingestion or intracellular processing by alveolar macrophages. Lavage fluid also killed clinical isolates of Candida tropicalis and Torulopsis glabrata but did not kill Candida krusei or Candida parapsilosis. Lavage fluid was concentrated and passed through an acrylamide-agarose gel matrix. The chromatogram indicated that the candidacidal activity eluted in a peak with a molecular weight range of 29,000 to 40,000. After electrophoresis on 15% sodium dodecyl sulfate-polyacrylamide gels, these fractions resolved into three bands. These were transferred to nitrocellulose and then eluted with Triton X-100; this procedure permitted the isolation of a single band of candidacidal activity with a molecular weight of 29,000. In summary, murine lavage fluid contains a heat-stable protein with direct antifungal activity. This soluble factor may contribute to lung defense processes by reducing fungal viability and adherence to tissue surfaces.
Collapse
|
48
|
Decker T, Lohmann-Matthes ML, Baccarini M. Heterogeneous activity of immature and mature cells of the murine monocyte-macrophage lineage derived from different anatomical districts against yeast-phase Candida albicans. Infect Immun 1986; 54:477-86. [PMID: 3533781 PMCID: PMC260186 DOI: 10.1128/iai.54.2.477-486.1986] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Mature mononuclear phagocytes have been receiving much attention as effectors of spontaneous candidacidal activity, although with controversial results due to differences in the effector populations and the methods used in different laboratories. We here systematically compare the fungistatic activity of immature and mature cells of the murine macrophage series. The results show that nonadherent, nonphagocytic precursor cells (isolated either [90% purity] from bone marrow liquid cultures or from the organs of mice in which inflammatory conditions had been elicited in vivo) exerted a strong extracellular candidastatic activity. In contrast, mature macrophages, either obtained from different anatomical areas (spleen, liver, lung, peritoneal cavity) or matured in vitro from the precursor populations, displayed striking heterogeneity in their ability to inhibit the growth of Candida albicans, depending on the anatomical site they were derived from. Lymphokine activation did not alter the fungistatic pattern of the untreated cells. The different macrophage populations behaved very differently also in the production of reactive oxygen intermediates (ROI) in response to phagocytosis of C. albicans. The amounts of ROI generated, however, showed no correlation with candidastatic ability. Low levels of candidastatic activity exerted by resident peritoneal macrophages (good ROI producers) were inhibited by catalase, whereas high levels of growth inhibition by Kupffer cells (poor ROI producers) after 8 h of assay were hardly influenced by the enzyme. Our data suggest the existence of two different effector mechanisms in macrophage-mediated C. albicans growth inhibition, a rather inefficient ROI-dependent one, and a second, very efficient oxygen-independent mechanism. The implications of these findings are discussed.
Collapse
|
49
|
Abstract
A review of the literature (148 references) on the interactions of fungi with polymorphonuclear cells, monocytes and macrophages is presented. The interactions of Aspergillus species, Coccidioides immitis, Blastomyces dermatitidis, Histoplasma capsulatum, Cryptococcus neoformans, Candida albicans, and Candida species with human and experimental animal derived immune cells are examined in this overview. An effort has been made to present the reader with a comprehensive list of references with the intent of encouraging additional reading and research in this important area.
Collapse
|
50
|
Oppenheim FG, Yang YC, Diamond RD, Hyslop D, Offner GD, Troxler RF. The primary structure and functional characterization of the neutral histidine-rich polypeptide from human parotid secretion. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)36072-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|