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Araujo TT, Dionizio A, Carvalho TDS, Debortolli ALB, Vertuan M, de Souza BM, Camara JVF, Henrique-Silva F, Chiaratti M, Santos A, Alves L, Ferro M, Magalhães AC, Buzalaf MAR. Acquired pellicle and biofilm engineering with CaneCPI-5: Insights from proteomic and microbiomics analysis. Arch Oral Biol 2024; 166:106025. [PMID: 38943859 DOI: 10.1016/j.archoralbio.2024.106025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/14/2024] [Accepted: 06/03/2024] [Indexed: 07/01/2024]
Abstract
OBJECTIVE In this in vivo proof-of-concept study, acquired pellicle engineering was implemented to promote alterations in the protein composition of the acquired enamel pellicle (AEP) and the bacterial composition of the dental biofilm after treatment with Sugarcane cystatin (CaneCPI-5). DESIGN After prophylaxis, 10 volunteers rinsed (10 mL, 1 min) with the following solutions: 1) deionized water (H2O- negative control or 2) 0.1 mg/mL CaneCPI-5. The AEP and biofilm were formed along 2 or 3 h, respectively. The AEP was collected with electrode filter papers soaked in 3 % citric acid. After protein extraction, samples were analyzed by quantitative shotgun label-free proteomics. The biofilm microbiome was collected with a dental curette. The DNA was extracted, amplified, and analyzed by 16S-rRNA Next Generation Sequencing (NGS). RESULTS Treatment with CaneCPI-5 increased several proteins with antimicrobial, acid-resistance, affinity for hydroxyapatite, structural and calcium binding properties, such as Cysteine-rich-3 (6-fold-p = 0.03), Cystatin-B (5.5-fold-p < 0.01), Neutrophil-defensin 1 (4.7-fold-p < 0.01), Mucin (3.9-fold-p < 0.01), Immunoglobulin-heavy-constant (3.8-fold-p < 0.01) and Lactotransferrin (2.8-fold-p < 0.01). Microbiome revealed that several commensal bacteria had their abundance increased after rinsing with CaneCPI-5, such as Corynebacterium and Neisseria, while Streptococcus and Prevotella nigrescens were decreased. The results indicate the efficiency of CaneCPI-5 in promoting beneficial changes in the AEP and biofilm, making this phytocystatin a potential target for incorporation into dental products. CONCLUSION Cane demonstrated the capability to alter the protein composition of the acquired enamel pellicle (AEP) and the initial colonizers of the biofilm, enhancing the presence of proteins and bacteria crucial for dental protection.
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Affiliation(s)
- Tamara Teodoro Araujo
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | - Aline Dionizio
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | | | | | - Mariele Vertuan
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | - Beatriz Martines de Souza
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | - João Victor Frazão Camara
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital, Saarland University, Building 73, 66421 Homburg, Saarland, Germany
| | - Flavio Henrique-Silva
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos 13565-905, Brazil
| | - Marcos Chiaratti
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos 13565-905, Brazil
| | - Angélica Santos
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos 13565-905, Brazil
| | - Lindomar Alves
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos 13565-905, Brazil
| | - Milene Ferro
- Department of General and Applied Biology, Paulista State University (UNESP), Rio Claro 13500230, Brazil
| | - Ana Carolina Magalhães
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
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He S, Deber CM. Interaction of designed cationic antimicrobial peptides with the outer membrane of gram-negative bacteria. Sci Rep 2024; 14:1894. [PMID: 38253659 PMCID: PMC10803810 DOI: 10.1038/s41598-024-51716-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
The outer membrane (OM) is a hallmark feature of gram-negative bacteria that provides the species with heightened resistance against antibiotic threats while cationic antimicrobial peptides (CAPs) are natural antibiotics broadly recognized for their ability to disrupt bacterial membranes. It has been well-established that lipopolysaccharides present on the OM are among major targets of CAP activity against gram-negative species. Here we investigate how the relative distribution of charged residues along the primary peptide sequence, in conjunction with its overall hydrophobicity, affects such peptide-OM interactions in the natural CAP Ponericin W1. Using a designed peptide library derived from Ponericin W1, we determined that the consecutive placement of Lys residues at the peptide N- or C-terminus (ex. "PonN": KKKKKKWLGSALIGALLPSVVGLFQ) enhances peptide binding affinity to OM lipopolysaccharides compared to constructs where Lys residues are interspersed throughout the primary sequence (ex. "PonAmp": WLKKALKIGAKLLPSVVKLFKGSGQ). Antimicrobial activity against multidrug resistant strains of Pseudomonas aeruginosa was similarly found to be highest among Lys-clustered sequences. Our findings suggest that while native Ponericin W1 exerts its initial activity at the OM, Lys-clustering may be a promising means to enhance potency towards this interface, thereby augmenting peptide entry and activity at the IM, with apparent advantage against multidrug-resistant species.
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Affiliation(s)
- Shelley He
- Program in Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
| | - Charles M Deber
- Program in Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada.
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van Dijk A, Guabiraba R, Bailleul G, Schouler C, Haagsman HP, Lalmanach AC. Evolutionary diversification of defensins and cathelicidins in birds and primates. Mol Immunol 2023; 157:53-69. [PMID: 36996595 DOI: 10.1016/j.molimm.2023.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023]
Abstract
Divergent evolution for more than 310 million years has resulted in an avian immune system that is complex and more compact than that of primates, sharing much of its structure and functions. Not surprisingly, well conserved ancient host defense molecules, such as defensins and cathelicidins, have diversified over time. In this review, we describe how evolution influenced the host defense peptides repertoire, its distribution, and the relationship between structure and biological functions. Marked features of primate and avian HDPs are linked to species-specific characteristics, biological requirements, and environmental challenge.
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Crocodile defensin (CpoBD13) antifungal activity via pH-dependent phospholipid targeting and membrane disruption. Nat Commun 2023; 14:1170. [PMID: 36859344 PMCID: PMC9977887 DOI: 10.1038/s41467-023-36280-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 01/24/2023] [Indexed: 03/03/2023] Open
Abstract
Crocodilians are an order of ancient reptiles that thrive in pathogen-rich environments. The ability to inhabit these harsh environments is indicative of a resilient innate immune system. Defensins, a family of cysteine-rich cationic host defence peptides, are a major component of the innate immune systems of all plant and animal species, however crocodilian defensins are poorly characterised. We now show that the saltwater crocodile defensin CpoBD13 harbors potent antifungal activity that is mediated by a pH-dependent membrane-targeting action. CpoBD13 binds the phospholipid phosphatidic acid (PA) to form a large helical oligomeric complex, with specific histidine residues mediating PA binding. The utilisation of histidine residues for PA engagement allows CpoBD13 to exhibit differential activity at a range of environmental pH values, where CpoBD13 is optimally active in an acidic environment.
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Nielsen JE, Alford MA, Yung DBY, Molchanova N, Fortkort JA, Lin JS, Diamond G, Hancock REW, Jenssen H, Pletzer D, Lund R, Barron AE. Self-Assembly of Antimicrobial Peptoids Impacts Their Biological Effects on ESKAPE Bacterial Pathogens. ACS Infect Dis 2022; 8:533-545. [PMID: 35175731 DOI: 10.1021/acsinfecdis.1c00536] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Antimicrobial peptides (AMPs) are promising pharmaceutical candidates for the prevention and treatment of infections caused by multidrug-resistant ESKAPE pathogens, which are responsible for the majority of hospital-acquired infections. Clinical translation of AMPs has been limited, in part by apparent toxicity on systemic dosing and by instability arising from susceptibility to proteolysis. Peptoids (sequence-specific oligo-N-substituted glycines) resist proteolytic digestion and thus are of value as AMP mimics. Only a few natural AMPs such as LL-37 and polymyxin self-assemble in solution; whether antimicrobial peptoids mimic these properties has been unknown. Here, we examine the antibacterial efficacy and dynamic self-assembly in aqueous media of eight peptoid mimics of cationic AMPs designed to self-assemble and two nonassembling controls. These amphipathic peptoids self-assembled in different ways, as determined by small-angle X-ray scattering; some adopt helical bundles, while others form core-shell ellipsoidal or worm-like micelles. Interestingly, many of these peptoid assemblies show promising antibacterial, antibiofilm activity in vitro in media, under host-mimicking conditions and antiabscess activity in vivo. While self-assembly correlated overall with antibacterial efficacy, this correlation was imperfect. Certain self-assembled morphologies seem better-suited for antibacterial activity. In particular, a peptoid exhibiting a high fraction of long, worm-like micelles showed reduced antibacterial, antibiofilm, and antiabscess activity against ESKAPE pathogens compared with peptoids that form ellipsoidal or bundled assemblies. This is the first report of self-assembling peptoid antibacterials with activity against in vivo biofilm-like infections relevant to clinical medicine.
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Affiliation(s)
- Josefine Eilsø Nielsen
- Department of Bioengineering, School of Medicine, Stanford University, Stanford, California 94305, United States
- Department of Chemistry, University of Oslo, Oslo 0315, Norway
| | - Morgan Ashley Alford
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Deborah Bow Yue Yung
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Natalia Molchanova
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - John A. Fortkort
- Department of Bioengineering, School of Medicine, Stanford University, Stanford, California 94305, United States
| | - Jennifer S. Lin
- Department of Bioengineering, School of Medicine, Stanford University, Stanford, California 94305, United States
| | - Gill Diamond
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, Kentucky 40202, United States
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, Roskilde 4000, Denmark
| | - Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Reidar Lund
- Department of Chemistry, University of Oslo, Oslo 0315, Norway
| | - Annelise E. Barron
- Department of Bioengineering, School of Medicine, Stanford University, Stanford, California 94305, United States
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Hawkins P, Sya J, Hup NK, Murphy MP, McElvaney NG, Reeves EP. Alpha-1 Antitrypsin Augmentation Inhibits Proteolysis of Neutrophil Membrane Voltage-Gated Proton Channel-1 in Alpha-1 Deficient Individuals. ACTA ACUST UNITED AC 2021; 57:medicina57080814. [PMID: 34441020 PMCID: PMC8398194 DOI: 10.3390/medicina57080814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022]
Abstract
Background and Objectives: Alpha-1 antitrypsin is a serine protease inhibitor that demonstrates an array of immunomodulatory functions. Individuals with the genetic condition of alpha-1 antitrypsin deficiency (AATD) are at increased risk of early onset emphysematous lung disease. This lung disease is partly driven by neutrophil mediated lung destruction in an environment of low AAT. As peripheral neutrophil hyper-responsiveness in AATD leads to excessive degranulation and increased migration to the airways, we examined the expression of the membrane voltage-gated proton channel-1 (HVCN1), which is integrally linked to neutrophil function. The objectives of this study were to evaluate altered HVCN1 in AATD neutrophils, serine protease-dependent degradation of HVCN1, and to investigate the ability of serum AAT to control HVCN1 expression. Materials and Methods: Circulating neutrophils were purified from AATD patients (n = 20), AATD patients receiving AAT augmentation therapy (n = 3) and healthy controls (n = 20). HVCN1 neutrophil expression was assessed by flow cytometry and Western blot analysis. Neutrophil membrane bound elastase was measured by fluorescence resonance energy transfer. Results: In this study we demonstrated that HVCN1 protein is under-expressed in AATD neutrophils (p = 0.02), suggesting a link between reduced HVCN1 expression and AAT deficiency. We have demonstrated that HVCN1 undergoes significant proteolytic degradation in activated neutrophils (p < 0.0001), primarily due to neutrophil elastase activity (p = 0.0004). In addition, the treatment of AATD individuals with AAT augmentation therapy increased neutrophil plasma membrane HVCN1 expression (p = 0.01). Conclusions: Our results demonstrate reduced levels of HVCN1 in peripheral blood neutrophils that may influence the neutrophil-dominated immune response in the AATD airways and highlights the role of antiprotease treatment and specifically AAT augmentation therapy in protecting neutrophil membrane expression of HVCN1.
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7
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Hayes E, Murphy MP, Pohl K, Browne N, McQuillan K, Saw LE, Foley C, Gargoum F, McElvaney OJ, Hawkins P, Gunaratnam C, McElvaney NG, Reeves EP. Altered Degranulation and pH of Neutrophil Phagosomes Impacts Antimicrobial Efficiency in Cystic Fibrosis. Front Immunol 2020; 11:600033. [PMID: 33391268 PMCID: PMC7775508 DOI: 10.3389/fimmu.2020.600033] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/16/2020] [Indexed: 12/14/2022] Open
Abstract
Studies have endeavored to understand the cause for impaired antimicrobial killing by neutrophils of people with cystic fibrosis (PWCF). The aim of this study was to focus on the bacterial phagosome. Possible alterations in degranulation of cytoplasmic granules and changes in pH were assessed. Circulating neutrophils were purified from PWCF (n = 28), PWCF receiving ivacaftor therapy (n = 10), and healthy controls (n = 28). Degranulation was assessed by Western blot analysis and flow cytometry. The pH of phagosomes was determined by use of BCECF-AM-labelled Staphylococcus aureus or SNARF labelled Candida albicans. The antibacterial effect of all treatments tested was determined by colony forming units enumeration. Bacterial killing by CF and healthy control neutrophils were found to differ (p = 0.0006). By use of flow cytometry and subcellular fractionation the kinetics of intraphagosomal degranulation were found to be significantly altered in CF phagosomes, as demonstrated by increased primary granule CD63 (p = 0.0001) and myeloperoxidase (MPO) content (p = 0.03). In contrast, decreased secondary and tertiary granule CD66b (p = 0.002) and decreased hCAP-18 and MMP-9 (p = 0.02), were observed. After 8 min phagocytosis the pH in phagosomes of neutrophils of PWCF was significantly elevated (p = 0.0001), and the percentage of viable bacteria was significantly increased compared to HC (p = 0.002). Results demonstrate that the recorded alterations in phagosomal pH generate suboptimal conditions for MPO related peroxidase, and α-defensin and azurocidine enzymatic killing of Staphylococcus aureus and Pseudomonas aeruginosa. The pattern of dysregulated MPO degranulation (p = 0.02) and prolonged phagosomal alkalinization in CF neutrophils were normalized in vivo following treatment with the ion channel potentiator ivacaftor (p = 0.04). Our results confirm that alterations of circulating neutrophils from PWCF are corrected by CFTR modulator therapy, and raise a question related to possible delayed proton channel activity in CF.
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Affiliation(s)
- Elaine Hayes
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Mark P Murphy
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Kerstin Pohl
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Niall Browne
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Karen McQuillan
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Le Er Saw
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Clare Foley
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Fatma Gargoum
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Oliver J McElvaney
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Padraig Hawkins
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Cedric Gunaratnam
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Noel G McElvaney
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Emer P Reeves
- Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
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Activity of Antimicrobial Peptides and Ciprofloxacin against Pseudomonas aeruginosa Biofilms. Molecules 2020; 25:molecules25173843. [PMID: 32847059 PMCID: PMC7503749 DOI: 10.3390/molecules25173843] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/20/2020] [Accepted: 08/20/2020] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas aeruginosa is increasingly resistant to conventional antibiotics, which can be compounded by the formation of biofilms on surfaces conferring additional resistance. P. aeruginosa was grown in sub-inhibitory concentrations of the antimicrobial peptides (AMPs) melimine and Mel4 or ciprofloxacin for 30 consecutive days to induce the development of resistance. Antibiofilm effect of AMPs and ciprofloxacin was evaluated using crystal violet and live/dead staining with confocal microscopy. Effect on the cell membrane of biofilm cells was evaluated using DiSC(3)-5 dye and release of intracellular ATP and DNA/RNA. The minimum inhibitory concentration (MIC) of ciprofloxacin increased 64-fold after 30 passages, but did not increase for melimine or Mel4. Ciprofloxacin could not inhibit biofilm formation of resistant cells at 4× MIC, but both AMPs reduced biofilms by >75% at 1× MIC. At 1× MIC, only the combination of either AMP with ciprofloxacin was able to significantly disrupt pre-formed biofilms (≥61%; p < 0.001). Only AMPs depolarized the cell membranes of biofilm cells at 1× MIC. At 1× MIC either AMP with ciprofloxacin released a significant amount of ATP (p < 0.04), but did not release DNA/RNA. AMPs do not easily induce resistance in P. aeruginosa and can be used in combination with ciprofloxacin to treat biofilm.
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Subh L, Correa W, Pinkvos T, Behrens P, Brandenburg K, Gutsmann T, Stiesch M, Doll K, Winkel A. Synthetic anti‐endotoxin peptides interfere with Gram‐positive and Gram‐negative bacteria, their adhesion and biofilm formation on titanium. J Appl Microbiol 2020; 129:1272-1286. [DOI: 10.1111/jam.14701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/18/2020] [Accepted: 05/06/2020] [Indexed: 12/20/2022]
Affiliation(s)
- L. Subh
- Clinic of Prosthetic Dentistry and Biomedical Materials ScienceHannover Medical School Hannover Germany
| | - W. Correa
- Division of Biophysics Research Center Borstel – Leibniz Lung Center Borstel Germany
| | - T.‐J. Pinkvos
- Institute for Inorganic Chemistry Leibniz University of Hannover Hannover Germany
| | - P. Behrens
- Institute for Inorganic Chemistry Leibniz University of Hannover Hannover Germany
| | | | - T. Gutsmann
- Division of Biophysics Research Center Borstel – Leibniz Lung Center Borstel Germany
| | - M. Stiesch
- Clinic of Prosthetic Dentistry and Biomedical Materials ScienceHannover Medical School Hannover Germany
| | - K. Doll
- Clinic of Prosthetic Dentistry and Biomedical Materials ScienceHannover Medical School Hannover Germany
| | - A. Winkel
- Clinic of Prosthetic Dentistry and Biomedical Materials ScienceHannover Medical School Hannover Germany
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Camargo Moreno M, Lewis JB, Kovacs EJ, Lowery EM. Lung allograft donors with excessive alcohol use have increased levels of human antimicrobial peptide LL-37. Alcohol 2019; 80:109-117. [PMID: 30419299 PMCID: PMC6616019 DOI: 10.1016/j.alcohol.2018.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/08/2018] [Accepted: 11/03/2018] [Indexed: 12/18/2022]
Abstract
The relatively low long-term survival rate of lung transplant recipients as compared to other organ recipients serves as an impetus to identify potential lung dysfunction as early as possible. There is an association between donor heavy alcohol use and acute lung injury in the lung allograft after transplant, known as primary graft dysfunction. Excessive alcohol use (EAU) can induce pulmonary immune dysregulation in response to an infection. Antimicrobial peptides (AMPs) are an important component of the innate immune response to pulmonary infections, but the impact of EAU on AMPs in the allograft lung has not been evaluated. Our hypothesis is that specific lung AMPs, LL-37, α-defensin-1,2,3, and β-defensin-2, are dysregulated in the lungs from organ donors who had EAU. In this prospective observational investigation, we measured AMPs via ELISA and inflammatory cytokines via multiplex bead array, in bronchoalveolar lavage (BAL) fluid of lung allograft donors, comparing results based on their alcohol consumption. LL-37 levels in lung donors with EAU were found to be increased compared to nondrinker (ND) donors [median 7.7 ng/mL (IQR 4.1-37.0) vs. 2.3 ng/mL (IQR 1.1-7.9), p = 0.004], whereas α-defensins-1,2,3 were decreased only in the presence of an infection in donors with EAU compared to ND donors [median 2.2 ng/mL (IQR 1.6-2.4) vs. 3.2 ng/mL (IQR 2.3-3.8), p = 0.049]. There was no difference in β-defensin-2 levels. Gene expression levels of these AMPs were not different. Elevated levels of CXCL8 were noted in bronchial washings of donors with EAU compared to ND donors, [median 4372 pg/mL (IQR 3352-13180) vs. 867.3 pg/mL (IQR 163.6-3675), p = 0.04], suggesting a potentially heightened inflammatory response. At 1 month post-transplant, LL-37 and CXCL8 levels are decreased compared to levels at time of transplant. In lung donors with EAU, LL-37 and α-defensins-1,2,3 dysregulated levels in the presence of an infection may be a harbinger of dysfunction of the lungs through the transplant process.
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Affiliation(s)
- M Camargo Moreno
- Alcohol Research Program, Stritch School of Medicine, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Ave., Maywood, IL, 60153, United States; Burn and Shock Trauma Research Institute, Stritch School of Medicine, Loyola University Health Sciences Campus, 2160 S. 1st Ave., Maywood, IL, 60153, United States
| | - J B Lewis
- Burn and Shock Trauma Research Institute, Stritch School of Medicine, Loyola University Health Sciences Campus, 2160 S. 1st Ave., Maywood, IL, 60153, United States
| | - E J Kovacs
- Department of Surgery, University of Colorado School of Medicine, 12631 E. 17th Avenue, Aurora, CO, 80045, United States; Alcohol Research Program, University of Colorado School of Medicine, 12700 E. 19th Avenue, Aurora, CO, 80045, United States
| | - E M Lowery
- Alcohol Research Program, Stritch School of Medicine, Loyola University Chicago Health Sciences Campus, 2160 S. 1st Ave., Maywood, IL, 60153, United States; Burn and Shock Trauma Research Institute, Stritch School of Medicine, Loyola University Health Sciences Campus, 2160 S. 1st Ave., Maywood, IL, 60153, United States.
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Outer Membrane Interaction Kinetics of New Polymyxin B Analogs in Gram-Negative Bacilli. Antimicrob Agents Chemother 2019; 63:AAC.00935-19. [PMID: 31332075 DOI: 10.1128/aac.00935-19] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/18/2019] [Indexed: 11/20/2022] Open
Abstract
Infections caused by drug-resistant Gram-negative bacilli are a severe global health threat, limiting effective drug choices for treatment. In this study, polymyxin analogs designed to have reduced nephrotoxicity, direct activity, and potentiating activity were assessed for inhibition and outer membrane interaction kinetics against wild-type (WT) and polymyxin or multidrug-resistant (MDR) Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae In MIC assays, two polymyxin B (PMB) analogs (SPR1205 and SPR206) and a polymyxin E analog (SPR946), with shortened peptide side chains and branched aminobutyryl N termini, exhibited promising activity compared with PMB and previously tested control polymyxin analogs SPR741 and polymyxin B nonapeptide (PMBN). Using dansyl-polymyxin (DPX) binding to assess the affinity of interaction with lipopolysaccharide (LPS), purified or in the context of intact cells, SPR206 exhibited similar affinities to PMB but higher affinities than the other SPR analogs. Outer membrane permeabilization measured by the 1-N-phenyl-napthylamine (NPN) assay did not differ significantly between the polymyxin analogs. Moreover, Hill numbers were greater than 1 for most of the compounds tested on E. coli and P. aeruginosa strains which indicates that the disruption of the outer membrane by one molecule of compound cooperatively enhances the subsequent interactions of other molecules against WT and MDR strains. The high activity demonstrated by SPR206 as well as its ability to displace LPS and permeabilize the outer membrane of multiple strains of Gram-negative bacilli while showing cooperative potential with other membrane disrupting compounds supports further research with this polymyxin analog.
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Dwivedi R, Aggarwal P, Bhavesh NS, Kaur KJ. Design of therapeutically improved analogue of the antimicrobial peptide, indolicidin, using a glycosylation strategy. Amino Acids 2019; 51:1443-1460. [PMID: 31485742 DOI: 10.1007/s00726-019-02779-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/27/2019] [Indexed: 02/01/2023]
Abstract
Indolicidin is a member of cathelicidin family which displays broad spectrum antimicrobial activity. Severe toxicity and aggregation propensity associated with indolicidin pose a huge limitation to its probable therapeutic application. We are reporting the use of glycosylation strategy to design an analogue of indolicidin and subsequently explore structural and functional effects of sugar on it. Our study led to the design of a potent antibacterial glycosylated peptide, [βGlc-T9,K7]indolicidin, which showed decreased toxicity against erythrocytes and macrophage cells and thus a higher therapeutic selectivity. The incorporation of sugar also increased the solubility of the peptide. The mode of bacterial killing, functional stability, LPS binding, and cytokine inhibitory potential of the peptide, however, seemed unaffected upon glycosylation. Absence of significant changes in structure upon glycosylation accounts for the possibly retained functions and mode of action of the peptide. Our report thus presents the designing of an indolicidin analogue with improved therapeutic potential by substituting aromatic amino acid with glycosylated amino acid as a promising strategy for the first time.
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Affiliation(s)
- Rohini Dwivedi
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Priyanka Aggarwal
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Neel S Bhavesh
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kanwal J Kaur
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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13
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Wei X, Ran D, Campeau A, Xiao C, Zhou J, Dehaini D, Jiang Y, Kroll AV, Zhang Q, Gao W, Gonzalez DJ, Fang RH, Zhang L. Multiantigenic Nanotoxoids for Antivirulence Vaccination against Antibiotic-Resistant Gram-Negative Bacteria. NANO LETTERS 2019. [PMID: 31184899 DOI: 10.1021/acs.nanolett.9b0184410.1021/acs.nanolett.9b01844.s001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Infections caused by multidrug-resistant Gram-negative bacteria have emerged as a major threat to public health worldwide. The high mortality and prevalence, along with the slow pace of new antibiotic discovery, highlight the necessity for new disease management paradigms. Here, we report on the development of a multiantigenic nanotoxoid vaccine based on macrophage membrane-coated nanoparticles for eliciting potent immunity against pathogenic Pseudomonas aeruginosa. The design of this biomimetic nanovaccine leverages the specific role of macrophages in clearing pathogens and their natural affinity for various virulence factors secreted by the bacteria. It is demonstrated that the macrophage nanotoxoid is able to display a wide range of P. aeruginosa antigens, and the safety of the formulation is confirmed both in vitro and in vivo. When used to vaccinate mice via different administration routes, the nanotoxoid is capable of eliciting strong humoral immune responses that translate into enhanced protection against live bacterial infection in a pneumonia model. Overall, the work presented here provides new insights into the design of safe, multiantigenic antivirulence vaccines using biomimetic nanotechnology and the application of these nanovaccines toward the prevention of difficult-to-treat Gram-negative infections.
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Affiliation(s)
- Xiaoli Wei
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Danni Ran
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Anaamika Campeau
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Crystal Xiao
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Jiarong Zhou
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Diana Dehaini
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Yao Jiang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Ashley V Kroll
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Qiangzhe Zhang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Weiwei Gao
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - David J Gonzalez
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Ronnie H Fang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Liangfang Zhang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
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14
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Wei X, Ran D, Campeau A, Xiao C, Zhou J, Dehaini D, Jiang Y, Kroll AV, Zhang Q, Gao W, Gonzalez DJ, Fang RH, Zhang L. Multiantigenic Nanotoxoids for Antivirulence Vaccination against Antibiotic-Resistant Gram-Negative Bacteria. NANO LETTERS 2019; 19:4760-4769. [PMID: 31184899 PMCID: PMC6711367 DOI: 10.1021/acs.nanolett.9b01844] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Infections caused by multidrug-resistant Gram-negative bacteria have emerged as a major threat to public health worldwide. The high mortality and prevalence, along with the slow pace of new antibiotic discovery, highlight the necessity for new disease management paradigms. Here, we report on the development of a multiantigenic nanotoxoid vaccine based on macrophage membrane-coated nanoparticles for eliciting potent immunity against pathogenic Pseudomonas aeruginosa. The design of this biomimetic nanovaccine leverages the specific role of macrophages in clearing pathogens and their natural affinity for various virulence factors secreted by the bacteria. It is demonstrated that the macrophage nanotoxoid is able to display a wide range of P. aeruginosa antigens, and the safety of the formulation is confirmed both in vitro and in vivo. When used to vaccinate mice via different administration routes, the nanotoxoid is capable of eliciting strong humoral immune responses that translate into enhanced protection against live bacterial infection in a pneumonia model. Overall, the work presented here provides new insights into the design of safe, multiantigenic antivirulence vaccines using biomimetic nanotechnology and the application of these nanovaccines toward the prevention of difficult-to-treat Gram-negative infections.
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Affiliation(s)
- Xiaoli Wei
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Danni Ran
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Anaamika Campeau
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Crystal Xiao
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Jiarong Zhou
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Diana Dehaini
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Yao Jiang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Ashley V. Kroll
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Qiangzhe Zhang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Weiwei Gao
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - David J. Gonzalez
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Ronnie H. Fang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Liangfang Zhang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
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15
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Malik E, Dennison SR, Harris F, Phoenix DA. pH Dependent Antimicrobial Peptides and Proteins, Their Mechanisms of Action and Potential as Therapeutic Agents. Pharmaceuticals (Basel) 2016; 9:ph9040067. [PMID: 27809281 PMCID: PMC5198042 DOI: 10.3390/ph9040067] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022] Open
Abstract
Antimicrobial peptides (AMPs) are potent antibiotics of the innate immune system that have been extensively investigated as a potential solution to the global problem of infectious diseases caused by pathogenic microbes. A group of AMPs that are increasingly being reported are those that utilise pH dependent antimicrobial mechanisms, and here we review research into this area. This review shows that these antimicrobial molecules are produced by a diverse spectrum of creatures, including vertebrates and invertebrates, and are primarily cationic, although a number of anionic examples are known. Some of these molecules exhibit high pH optima for their antimicrobial activity but in most cases, these AMPs show activity against microbes that present low pH optima, which reflects the acidic pH generally found at their sites of action, particularly the skin. The modes of action used by these molecules are based on a number of major structure/function relationships, which include metal ion binding, changes to net charge and conformational plasticity, and primarily involve the protonation of histidine, aspartic acid and glutamic acid residues at low pH. The pH dependent activity of pore forming antimicrobial proteins involves mechanisms that generally differ fundamentally to those used by pH dependent AMPs, which can be described by the carpet, toroidal pore and barrel-stave pore models of membrane interaction. A number of pH dependent AMPs and antimicrobial proteins have been developed for medical purposes and have successfully completed clinical trials, including kappacins, LL-37, histatins and lactoferrin, along with a number of their derivatives. Major examples of the therapeutic application of these antimicrobial molecules include wound healing as well as the treatment of multiple cancers and infections due to viruses, bacteria and fungi. In general, these applications involve topical administration, such as the use of mouth washes, cream formulations and hydrogel delivery systems. Nonetheless, many pH dependent AMPs and antimicrobial proteins have yet to be fully characterized and these molecules, as a whole, represent an untapped source of novel biologically active agents that could aid fulfillment of the urgent need for alternatives to conventional antibiotics, helping to avert a return to the pre-antibiotic era.
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Affiliation(s)
- Erum Malik
- School of Forensic and Applied Sciences, University of Central Lancashire, Preston PR1 2HE, UK.
| | - Sarah R Dennison
- School of Pharmacy and Biological Sciences, University of Central Lancashire, Preston PR1 2HE, UK.
| | - Frederick Harris
- School of Forensic and Applied Sciences, University of Central Lancashire, Preston PR1 2HE, UK.
| | - David A Phoenix
- Office of the Vice Chancellor, London South Bank University, 103 Borough Road, London SE1 0AA, UK.
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16
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Wiese A, Gutsmann T, Seydel U. Review: Towards antibacterial strategies: studies on the mechanisms of interaction between antibacterial peptides and model membranes. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519030090020101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Lipopolysaccharides (LPSs) play a dual role as inflammation-inducing and as membrane-forming molecules. The former role attracts significantly more attention from scientists, possibly because it is more closely related to sepsis and septic shock. This review aims to focus the reader's attention to the other role, the function of LPS as the major constituent of the outer layer of the outer membrane of Gram-negative bacteria, in particular those of enterobacterial strains. In this function, LPS is a necessary component of the cell envelope and guarantees survival of the bacterial organism. At the same time, it represents the first target for attacking molecules which may either be synthesized by the host's innate or adaptive immune system or administered to the human body. The interaction of these molecules with the outer membrane may not only directly cause the death of the bacterial organism, but may also lead to the release of LPS into the circulation. Here, we review membrane model systems and their application for the study of molecular mechanisms of interaction of peptides such as those of the human complement system, the bactericidal/permeability-increasing protein (BPI), cationic antibacterial peptide 18 kDa (CAP18) as an example of cathelicidins, defensins, and polymyxin B (PMB). Emphasis is on electrical measurements with a reconstitution system of the lipid matrix of the outer membrane which was established in the authors' laboratory as a planar asymmetric bilayer with one leaflet being composed solely of LPS and the other of the natural phospholipid mixture. The main conclusion, which can be drawn from these investigations, is that LPS and in general its negative charges are the dominant determinants for specific peptide—membrane interactions. However, the detailed mechanisms of interaction, which finally lead to bacterial killing, may involve further steps and differ for different antibacterial peptides.
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Affiliation(s)
- Andre Wiese
- Division of Biophysics, Research Center Borstel, Borstel, Germany
| | - Thomas Gutsmann
- Division of Biophysics, Research Center Borstel, Borstel, Germany
| | - Ulrich Seydel
- Division of Biophysics, Research Center Borstel, Borstel, Germany,
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17
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Bowdish DM, Hancock RE. Anti-endotoxin properties of cationic host defence peptides and proteins. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519050110040801] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The innate immune system of mammals contains a series of peptides with overall positive charge and an amphipathic structure which have a variety of important properties in host defences. Although these are often termed cationic antimicrobial peptides, they have numerous roles in innate defences in all complex species of life and thus we prefer to refer to them as host defence peptides. These roles include: (i) an ability to kill micro-organisms directly, ranging from bacteria to viruses, fungi, parasites and helminths; (ii) an adjuvant activity in the adaptive response; and (iii) a multiplicity of roles in modulating innate immunity, including an apparent ability to stimulate protective innate immunity while suppressing harmful inflammatory/septic responses. This latter property may be one of the more important activities of these peptides in vivo. Innate immunity is thought to be triggered by the interaction of conserved bacterial components with particular receptors including Toll-like receptors (TLRs) on host cells. However, the initiation of the innate immune response through this route may trigger a pro-inflammatory cascade that is the principle cause of harmful conditions such as sepsis. Since we are exposed to potentially dangerous pathogens on a daily basis, the host response must contain certain checks and balances. We propose that host defence peptides have a role in feed-back modulation of inflammation under normal (low-pathogen exposure) conditions. This review surveys the available information regarding the antiendotoxic/anti-inflammatory properties of host defence peptides, and will address whether this potential might be exploited for therapeutic benefit in sepsis.
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Affiliation(s)
- Dawn M.E. Bowdish
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert E.W. Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia, Canada,
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18
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Dosler S, Karaaslan E, Alev Gerceker A. Antibacterial and anti-biofilm activities of melittin and colistin, alone and in combination with antibiotics against Gram-negative bacteria. J Chemother 2016; 28:95-103. [DOI: 10.1179/1973947815y.0000000004] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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19
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Moghaddam MM, Abolhassani F, Babavalian H, Mirnejad R, Azizi Barjini K, Amani J. Comparison of in vitro antibacterial activities of two cationic peptides CM15 and CM11 against five pathogenic bacteria: Pseudomonas aeruginosa, Staphylococcus aureus, Vibrio cholerae, Acinetobacter baumannii, and Escherichia coli. Probiotics Antimicrob Proteins 2016; 4:133-9. [PMID: 26781855 DOI: 10.1007/s12602-012-9098-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In recent years, the widespread use of antibiotics has caused many bacterial pathogens resistance to conventional antibiotics. Therefore, generation of new antibiotics to control and reduce the effects of these pathogens is urgently needed. Antimicrobial peptides and proteins are important members of the host defense system in eukaryotes. These peptides are potent, broad-spectrum antibiotics that demonstrate potential as novel and alternative therapeutic agents for the treatment of drug-resistant infections. Accordingly, we evaluated two hybrid peptides CM11 (WKLFKKILKVL-NH2) and CM15 (KWKLFKKIGAVLKVL-NH2) on five important pathogenic bacteria. These peptides are short cecropin-melittin hybrid peptides obtained through a sequence combination approach, which are highly effective to inhibit the growth of important pathogenic bacteria. The activity of these two cationic peptides (CM11 and CM15) in different concentrations (2-64 mg/L) was investigated against standard and clinical isolates of important hospital infection bacteria by measuring MIC, MBC, and bactericidal assay. These peptides demonstrated the same ranges of inhibitory values: The organisms in early 24 h were more susceptible to polycationic peptides (MIC: 8 mg/L and MBC 32 mg/L), but after 48 h the MIC and MBC remained constant for the CM11 peptide. Bactericidal assay showed that all bacteria strains did not have any growth in agar plates after 40 min. The result showed that these two peptides are more effective than other peptides.
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Affiliation(s)
- M Moosazadeh Moghaddam
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Vanak Sq. Mollasadra St., P.O. Box: 19395-5487, Tehran, Iran.
| | - F Abolhassani
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Vanak Sq. Mollasadra St., P.O. Box: 19395-5487, Tehran, Iran.
| | - H Babavalian
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Vanak Sq. Mollasadra St., P.O. Box: 19395-5487, Tehran, Iran.
| | - R Mirnejad
- Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
| | - K Azizi Barjini
- Department of Molecular Biology, Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran.
| | - J Amani
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Vanak Sq. Mollasadra St., P.O. Box: 19395-5487, Tehran, Iran.
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20
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Kaneti G, Meir O, Mor A. Controlling bacterial infections by inhibiting proton-dependent processes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:995-1003. [PMID: 26522076 DOI: 10.1016/j.bbamem.2015.10.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/20/2015] [Accepted: 10/27/2015] [Indexed: 12/15/2022]
Abstract
Bacterial resistance to antibiotics is recognized as one of the greatest threats in modern healthcare, taking a staggering toll worldwide. New approaches for controlling bacterial infections must be designed, eventually combining multiple strategies for complimentary therapies. This review explores an old/new paradigm for multi-targeted antibacterial therapy, focused at disturbing bacterial cytoplasmic membrane functions at sub minimal inhibitory concentrations, namely through superficial physical alterations of the bilayer, thereby perturbing transmembrane signals transduction. Such a paradigm may have the advantage of fighting the infection while avoiding many of the known resistance mechanisms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert.
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Affiliation(s)
- Galoz Kaneti
- Department of Biotechnology & Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ohad Meir
- Department of Biotechnology & Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Amram Mor
- Department of Biotechnology & Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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21
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Hansmann B, Schröder JM, Gerstel U. Skin-Derived C-Terminal Filaggrin-2 Fragments Are Pseudomonas aeruginosa-Directed Antimicrobials Targeting Bacterial Replication. PLoS Pathog 2015; 11:e1005159. [PMID: 26371476 PMCID: PMC4570713 DOI: 10.1371/journal.ppat.1005159] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/20/2015] [Indexed: 01/08/2023] Open
Abstract
Soil- and waterborne bacteria such as Pseudomonas aeruginosa are constantly challenging body surfaces. Since infections of healthy skin are unexpectedly rare, we hypothesized that the outermost epidermis, the stratum corneum, and sweat glands directly control the growth of P. aeruginosa by surface-provided antimicrobials. Due to its high abundance in the upper epidermis and eccrine sweat glands, filaggrin-2 (FLG2), a water-insoluble 248 kDa S100 fused-type protein, might possess these innate effector functions. Indeed, recombinant FLG2 C-terminal protein fragments display potent antimicrobial activity against P. aeruginosa and other Pseudomonads. Moreover, upon cultivation on stratum corneum, P. aeruginosa release FLG2 C-terminus-containing FLG2 fragments from insoluble material, indicating liberation of antimicrobially active FLG2 fragments by the bacteria themselves. Analyses of the underlying antimicrobial mechanism reveal that FLG2 C-terminal fragments do not induce pore formation, as known for many other antimicrobial peptides, but membrane blebbing, suggesting an alternative mode of action. The association of the FLG2 fragment with the inner membrane of treated bacteria and its DNA-binding implicated an interference with the bacterial replication that was confirmed by in vitro and in vivo replication assays. Probably through in situ-activation by soil- and waterborne bacteria such as Pseudomonads, FLG2 interferes with the bacterial replication, terminates their growth on skin surface and thus may contributes to the skin's antimicrobial defense shield. The apparent absence of FLG2 at certain body surfaces, as in the lung or of burned skin, would explain their higher susceptibility towards Pseudomonas infections and make FLG2 C-terminal fragments and their derivatives candidates for new Pseudomonas-targeting antimicrobials.
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Affiliation(s)
- Britta Hansmann
- Department of Dermatology, University Hospital Schleswig-Holstein, Kiel, Germany
| | | | - Ulrich Gerstel
- Department of Dermatology, University Hospital Schleswig-Holstein, Kiel, Germany
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22
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Peptides and Peptidomimetics for Antimicrobial Drug Design. Pharmaceuticals (Basel) 2015; 8:366-415. [PMID: 26184232 PMCID: PMC4588174 DOI: 10.3390/ph8030366] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/27/2015] [Accepted: 06/17/2015] [Indexed: 12/21/2022] Open
Abstract
The purpose of this paper is to introduce and highlight a few classes of traditional antimicrobial peptides with a focus on structure-activity relationship studies. After first dissecting the important physiochemical properties that influence the antimicrobial and toxic properties of antimicrobial peptides, the contributions of individual amino acids with respect to the peptides antibacterial properties are presented. A brief discussion of the mechanisms of action of different antimicrobials as well as the development of bacterial resistance towards antimicrobial peptides follows. Finally, current efforts on novel design strategies and peptidomimetics are introduced to illustrate the importance of antimicrobial peptide research in the development of future antibiotics.
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23
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Uppu DSSM, Ghosh C, Haldar J. Surviving sepsis in the era of antibiotic resistance: are there any alternative approaches to antibiotic therapy? Microb Pathog 2015; 80:7-13. [PMID: 25677832 DOI: 10.1016/j.micpath.2015.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/04/2015] [Accepted: 02/06/2015] [Indexed: 01/25/2023]
Abstract
Sepsis, a serious cause of morbidity in humans, has no proper single medication dedicated to it. In this review, we look at the current treatment modalities, the different approaches attempted towards treating it and alternative approaches that could be implemented to counter this neglected disease condition. The use of antibiotics towards treatment of sepsis, use of combinations and strategies derived from natural antimicrobial peptides have been dealt in detail. The social and technical difficulties associated with treating sepsis and the possible ways of combating them have also been discussed.
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Affiliation(s)
- Divakara S S M Uppu
- Chemical Biology and Medicinal Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Chandradhish Ghosh
- Chemical Biology and Medicinal Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Chemical Biology and Medicinal Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India.
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24
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Zhang J, Yu LP, Li MF, Sun L. Turbot (Scophthalmus maximus) hepcidin-1 and hepcidin-2 possess antimicrobial activity and promote resistance against bacterial and viral infection. FISH & SHELLFISH IMMUNOLOGY 2014; 38:127-34. [PMID: 24647314 DOI: 10.1016/j.fsi.2014.03.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 02/26/2014] [Accepted: 03/07/2014] [Indexed: 05/06/2023]
Abstract
Hepcidin is an antimicrobial peptide and a regulator of iron homeostasis. In turbot (Scophthalmus maximus), two types of hepcidins have been identified, which share approximately 50% sequence identity. In this study, we examined the antimicrobial potentials of the two hepcidins in the form of synthesized peptides, SmHep1P and SmHep2P. We found that SmHep1P and SmHep2P exhibited apparent bactericidal activities against both Gram-positive and Gram-negative bacteria in a dose-dependent manner. The bactericidal effect of SmHep1P was stronger against Gram-positive bacteria, while the bactericidal effect of SmHep2P was stronger against Gram-negative bacteria. Fluorescence and electron microscopy showed that both peptides were able to bind to the target bacterial cells and alter the surface structure of the cells. In vitro studies showed that SmHep1P and SmHep2P reduced bacterial invasion into cultured fish cells. In vivo studies showed that turbot administered with SmHep1P and SmHep2P exhibited significantly enhanced resistance against bacterial and viral infection. In both in vivo and in vitro studies, the antimicrobial activities of SmHep2P were in most cases significantly stronger than those of SmHep1P. Together these results indicate that the two hepcidins of turbot most likely possess antimicrobial properties and play a role in the innate immune defense against bacterial and viral pathogens.
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Affiliation(s)
- Jian Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan-Ping Yu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Taian 271018, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mo-Fei Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
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25
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López-Abarrategui C, Del Monte-Martínez A, Reyes-Acosta O, Franco OL, Otero-González AJ. LPS inmobilization on porous and non-porous supports as an approach for the isolation of anti-LPS host-defense peptides. Front Microbiol 2013; 4:389. [PMID: 24409171 PMCID: PMC3865429 DOI: 10.3389/fmicb.2013.00389] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 11/29/2013] [Indexed: 12/20/2022] Open
Abstract
Lipopolysaccharides (LPSs) are the major molecular component of the outer membrane of Gram-negative bacteria. This molecule is recognized as a sign of bacterial infection, responsible for the development of local inflammatory response and, in extreme cases, septic shock. Unfortunately, despite substantial advances in the pathophysiology of sepsis, there is no efficacious therapy against this syndrome yet. As a consequence, septic shock syndrome continues to increase, reaching mortality rates over 50% in some cases. Even though many preclinical studies and clinical trials have been conducted, there is no Food and Drug Administration-approved drug yet that interacts directly against LPS. Cationic host-defense peptides (HDPs) could be an alternative solution since they possess both antimicrobial and antiseptic properties. HDPs are small, positively charged peptides which are evolutionarily conserved components of the innate immune response. In fact, binding to diverse chemotypes of LPS and inhibition of LPS-induced pro-inflammatory cytokines from macrophages have been demonstrated for different HDPs. Curiously, none of them have been isolated by their affinity to LPS. A diversity of supports could be useful for such biological interaction and suitable for isolating HDPs that recognize LPS. This approach could expand the rational search for anti-LPS HDPs.
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Affiliation(s)
| | | | | | - Octavio L Franco
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília Brasília, Brazil
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26
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Tan YN, Matthews KR, Di R, Ayob MK. Comparative antibacterial mode of action of purified alcalase- and tryptic-hydrolyzed palm kernel cake proteins on the food-borne pathogen Bacillus cereus. Food Control 2013. [DOI: 10.1016/j.foodcont.2012.09.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Yoshino N, Endo M, Kanno H, Matsukawa N, Tsutsumi R, Takeshita R, Sato S. Polymyxins as novel and safe mucosal adjuvants to induce humoral immune responses in mice. PLoS One 2013; 8:e61643. [PMID: 23593492 PMCID: PMC3623863 DOI: 10.1371/journal.pone.0061643] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 03/12/2013] [Indexed: 11/21/2022] Open
Abstract
There is currently an urgent need to develop safe and effective adjuvants for enhancing vaccine-induced antigen-specific immune responses. We demonstrate here that intranasal immunization with clinically used polypeptide antibiotics, polymyxin B (PMB) and colistin (CL), along with ovalbumin (OVA), increases OVA-specific humoral immune responses in a dose-dependently manner at both mucosal and systemic compartments. Enhanced immunity by boosting was found to persist during 8 months of observation. Moreover, mice intranasally immunized with OVA plus various doses of PMB or CL showed neither inflammatory responses in the nasal cavity and olfactory bulbs nor renal damages, compared to those given OVA alone. These data suggest that polymyxins may serve as novel and safe mucosal adjuvants to induce humoral immune responses. The polymyxin adjuvanticity was found to be independent of endotoxins liberated by its bactericidal activity, as indicated by similar enhancing effects of PMB in lipopolysaccharide (LPS)-hyporesponsive and LPS-susceptible mice. However, despite the presence of preexisting anti-PMB antibodies, we observed no reduction in the adjuvant function of polymyxins when they were given intranasally. Furthermore, the titers of OVA-specific Abs in mice intranasally immunized with OVA plus PMB or CL were significantly higher than those in mice administered with polymyxin analogues, such as polymyxin B nonapeptide and colistin methanesulfonate. The levels of released β-hexosaminidase and histamine in mast cell culture supernatants stimulated by PMB or CL were also significantly higher than those stimulated by their analogues. These results suggest that both the hydrophobic carbon chain and hydrophilic cationic cyclic peptide contribute to the mucosal adjuvanticity of PMB and CL.
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Affiliation(s)
- Naoto Yoshino
- Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, Iwate, Japan.
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28
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Shang D, Li X, Sun Y, Wang C, Sun L, Wei S, Gou M. Design of potent, non-toxic antimicrobial agents based upon the structure of the frog skin peptide, temporin-1CEb from Chinese brown frog, Rana chensinensis. Chem Biol Drug Des 2012; 79:653-62. [PMID: 22348663 DOI: 10.1111/j.1747-0285.2012.01363.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Temporin-1CEb shows antimicrobial activity against Gram-positive bacteria, but its therapeutic potential is limited by its haemolysis. In this study, eight temporin-1CEb analogues with altered cationicities and hydrophobicities were synthesized. Increasing cationicity and amphipathicity by substituting neutral and non-polar amino acid residues on the hydrophilic face of the α-helix by five or six lysines increased antimicrobial potency approximately 10-fold to 40-fold, although when the number of positive charges was increased from +6 to +7, the antimicrobial potency was not additionally enhanced. The substitution of an l-lysine with a d-lysine, meanwhile maintaining the net charge and the mean hydrophobicity values, had only a minor effect on its antimicrobial activity, whereas significantly led a decrease in its haemolytic activity. Of all the peptides, l-K6 has the best potential as an antimicrobial agent because its antimicrobial activity against both Gram-positive and Gram-negative bacteria is substantial, and its haemolytic activity is negligible. l-K6 adopts an α-helix in 50% trifluoroethanol/water and 30 mm SDS solutions. l-K6 killed 99.9% of E. coli and S. aureus at 4× MIC in 60 min, and its postantibiotic effect was >5 h. l-K6 affects the integrity of E. coli and S. aureus plasma membranes by rapidly inducing membrane depolarization.
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Affiliation(s)
- Dejing Shang
- Faculty of Life Science, Liaoning Normal University, Dalian, China.
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Abstract
Phagocytosis is an evolutionarily ancient, receptor-driven process, by which phagocytic cells recognize invading microbes and destroy them after internalization. The phagocytosis receptor Eater is expressed exclusively on Drosophila phagocytes and is required for the survival of bacterial infections. In a recent study, we explored how Eater can defend fruit flies against different kinds of bacteria. We discovered that Eater bound to certain types of bacteria directly, while for others bacterial binding was dependent on prior disruption of the bacterial envelope. Similar to phagocytes, antimicrobial peptides and lysozymes are ancient components of animal immune systems. Our results suggest that cationic antimicrobial peptides, as well as lysozymes, can facilitate Eater binding to live Gram-negative bacteria. Both types of molecules promote surface-exposure of bacterial ligands that otherwise would remain buried and hidden under an outer membrane. We propose that unmasking ligands for phagocytic receptors may be a conserved mechanism operating in many animals, including humans. Thus, studying a Drosophila phagocytosis receptor may advance our understanding of innate immunity in general.
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Affiliation(s)
- Yoon-Suk Alexander Chung
- Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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30
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The potential of antimicrobial peptides as biocides. Int J Mol Sci 2011; 12:6566-96. [PMID: 22072905 PMCID: PMC3210996 DOI: 10.3390/ijms12106566] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/22/2011] [Accepted: 09/26/2011] [Indexed: 12/12/2022] Open
Abstract
Antimicrobial peptides constitute a diverse class of naturally occurring antimicrobial molecules which have activity against a wide range of pathogenic microorganisms. Antimicrobial peptides are exciting leads in the development of novel biocidal agents at a time when classical antibiotics are under intense pressure from emerging resistance, and the global industry in antibiotic research and development stagnates. This review will examine the potential of antimicrobial peptides, both natural and synthetic, as novel biocidal agents in the battle against multi-drug resistant pathogen infections.
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Song A, Walker SG, Parker KA, Sampson NS. Antibacterial studies of cationic polymers with alternating, random, and uniform backbones. ACS Chem Biol 2011; 6:590-9. [PMID: 21370918 DOI: 10.1021/cb100413w] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Antibacterial polymers have potential as pharmaceuticals and as coatings for implantation devices. The design of these materials will be optimized when we have a complete understanding of the structural features that impart activity toward target organisms and those that are benign with respect to the mammalian host. In this work, four series of polymers in which cationic and hydrophobic groups were distributed along the backbone were tested against six different bacterial species (both Gram-positive and Gram-negative) and for host cytotoxicities (red blood cell lysis). The most effective of the polymers studied are regularly spaced, featuring a 6-8 carbon stretch along the backbone between side chains that present positively charged groups. They cause potassium efflux, disorder the bacterial cytoplasmic membrane, and disrupt the membrane potential. These polymers, available from alternating ring-opening metathesis polymerization (AROMP), offer proof of principle for the importance of regular spacing in antibacterial polymers and for the synthesis of additional functional materials based on regularly spaced scaffolds.
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Affiliation(s)
- Airong Song
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Stephen G. Walker
- Department of Oral Biology and Pathology, Stony Brook University, Stony Brook, New York 11794-8700, United States
| | - Kathlyn A. Parker
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Nicole S. Sampson
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
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32
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Chung YSA, Kocks C. Recognition of pathogenic microbes by the Drosophila phagocytic pattern recognition receptor Eater. J Biol Chem 2011; 286:26524-32. [PMID: 21613218 DOI: 10.1074/jbc.m110.214007] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Non-opsonic phagocytosis is a primordial form of pathogen recognition that is mediated by the direct interaction of phagocytic receptors with microbial surfaces. In the fruit fly Drosophila melanogaster, the EGF-like repeat containing scavenger receptor Eater is expressed by phagocytes and is required to survive infections with gram-positive and gram-negative bacteria. However, the mechanisms by which this receptor recognizes different types of bacteria are poorly understood. To address this problem, we generated a soluble, Fc-tagged receptor variant of Eater comprising the N-terminal 199 amino acids including four EGF-like repeats. We first established that Eater-Fc displayed specific binding to broad yet distinct classes of heat- or ethanol-inactivated microbes and behaved similarly to the membrane-bound, full-length Eater receptor. We then used Eater-Fc as a tool to probe Eater binding to the surface of live bacteria. Eater-Fc bound equally well to naive or inactivated Staphylococcus aureus or Enterococcus faecalis, suggesting that in vivo, Eater directly targets live gram-positive bacteria, enabling their phagocytic clearance and destruction. By contrast, Eater-Fc was unable to interact with live, naive gram-negative bacteria (Escherichia coli, Serratia marcescens, and Pseudomonas aeruginosa). For these bacteria, Eater-Fc binding required membrane-disrupting treatments. Furthermore, we found that cecropin A, a cationic, membrane-disrupting antimicrobial peptide, could promote Eater-Fc binding to live E. coli, even at sublethal concentrations. These results suggest a previously unrecognized mechanism by which antimicrobial peptides cooperate with phagocytic receptors to extend the range of microbes that can be targeted by a single, germline-encoded receptor.
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Affiliation(s)
- Yoon-Suk Alexander Chung
- Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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33
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Arcidiacono S, Soares JW, Meehan AM, Marek P, Kirby R. Membrane permeability and antimicrobial kinetics of cecropin P1 against Escherichia coli. J Pept Sci 2009; 15:398-403. [PMID: 19308920 DOI: 10.1002/psc.1125] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The interaction of cecropin P1 (CP1) with Escherichiacoli was investigated to gain insight into the time-dependent antimicrobial action. Biophysical characterizations of CP1 with whole bacterial cells were performed using both fluorescent and colorimetric assays to investigate the role of membrane permeability and lipopolysaccharide (LPS) binding in lytic behavior. The kinetics of CP1 growth inhibition assays indicated a minimal inhibitory concentration (MIC) of 3 microM. Bactericidal kinetics at the MIC indicated rapid killing of E.coli (<30 min). Membrane permeability studies illustrated permeation as a time-dependent event. Maximum permeability at the MIC occurred within 30 min, which correlates to the bactericidal action. Further investigation showed that the immediate permeabilizing action of CP1 is concentration-dependent, which correlates to the concentration-dependent nature of the inhibition assays. At the MIC and above, the immediate permeability was significant enough that the cells could not recover and exhibit growth. Below the MIC, immediate permeability was evident, but the level was insufficient to inhibit growth. Dansyl polymyxin B displacement studies showed LPS binding is essentially the same at all concentrations investigated. However, it does appear that only the immediate interaction is important, because binding continued to increase over time beyond cell viability. Our studies correlated CP1 bactericidal kinetics to membrane permeability suggesting CP1 concentration-dependent killing is driven by the extent of the immediate permeabilizing action of the peptide.
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Affiliation(s)
- Steven Arcidiacono
- Biological Science and Technology Team, Warfighter Science Technology and Applied Research Directorate, U.S. Army Natick Soldier Research, Development, & Engineering Center, Natick, MA 01760-5020, USA.
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34
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Fjell CD, Jenssen H, Hilpert K, Cheung WA, Panté N, Hancock REW, Cherkasov A. Identification of novel antibacterial peptides by chemoinformatics and machine learning. J Med Chem 2009; 52:2006-15. [PMID: 19296598 DOI: 10.1021/jm8015365] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The rise of antibiotic resistant pathogens is one of the most pressing global health issues. Discovery of new classes of antibiotics has not kept pace; new agents often suffer from cross-resistance to existing agents of similar structure. Short, cationic peptides with antimicrobial activity are essential to the host defenses of many organisms and represent a promising new class of antimicrobials. This paper reports the successful in silico screening for potent antibiotic peptides using a combination of QSAR and machine learning techniques. On the basis of initial high-throughput measurements of activity of over 1400 random peptides, artificial neural network models were built using QSAR descriptors and subsequently used to screen an in silico library of approximately 100,000 peptides. In vitro validation of the modeling showed 94% accuracy in identifying highly active peptides. The best peptides identified through screening were found to have activities comparable or superior to those of four conventional antibiotics and superior to the peptide most advanced in clinical development against a broad array of multiresistant human pathogens.
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Affiliation(s)
- Christopher D Fjell
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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35
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Immobilization reduces the activity of surface-bound cationic antimicrobial peptides with no influence upon the activity spectrum. Antimicrob Agents Chemother 2008; 53:1132-41. [PMID: 19104020 DOI: 10.1128/aac.01254-08] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Early studies of immobilized peptides mainly focused upon the relationship between structural properties and the activity of soluble and surface-tethered sequences. The intention of this study was to analyze the influence of immobilization parameters upon the activity profile of peptides. Resin beads (TentaGel S NH(2), HypoGel 400 NH(2), and HypoGel 200 NH(2)) with polyethylene glycol spacers of different lengths were rendered antimicrobial by linkage of an amphipathic model KLAL peptide and magainin-derived MK5E. Standard solid-phase peptide synthesis, thioalkylation, and ligation strategies were used to immobilize the peptides at the C and N termini and via different side-chain positions. Depending upon the resin capacity and the coupling strategies, peptide loading ranged between 0.1 and 0.25 micromol/mg for C-terminally and around 0.03 micromol/mg for N-terminally and side-chain-immobilized peptides. Tethering conserved the activity spectra of the soluble peptides at reduced concentrations. The resin-bound peptides were antimicrobial toward Escherichia coli and Bacillus subtilis in the millimolar range compared to the results seen with micromolar concentrations of the free peptides. B. subtilis was more susceptible than E. coli. The antimicrobial activity distinctly decreased with reduction of the spacer length. Slight differences in the antimicrobial effect of KLAL and MK5E bound at different chain positions on TentaGel S NH(2) suggest that the activity is less dependent upon the position of immobilization. Soluble KLAL was active toward red blood cells, whereas MK5E was nonhemolytic at up to about 400 microM. Resin-induced hemolysis hampered the determination of the hemolytic effect of the immobilized peptides. TentaGel S NH(2)-bound peptides enhanced the permeability of the POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline) and mixed POPC/1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (POPC/POPG) bilayers used to model the charge properties of the biological targets. The results suggest that surface immobilization of the cationic amphipathic antimicrobial peptides does not influence the membrane-permeabilizing mode of action. Peptide insertion into the target membrane and likely the exchange of membrane-stabilizing bivalent cations contribute to the antimicrobial effect. In conclusion, reasonable antimicrobial activity of surface-bound peptides requires the optimization of the coupling parameters, with the length of the spacer and the amount of target-accessible peptide being the most important factors.
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36
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Hao G, Shi YH, Han JH, Li QH, Tang YL, Le GW. Design and analysis of structure-activity relationship of novel antimicrobial peptides derived from the conserved sequence of cecropin. J Pept Sci 2008; 14:290-8. [PMID: 17929330 DOI: 10.1002/psc.926] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have de novo designed four antimicrobial peptides AMP-A/B/C/D, the 51-residues peptides, which are based on the conserved sequence of cecropin. In the present study, the four peptides were chemically synthesized and their activities assayed. Their secondary structure, amphipathic property, electric field distribution and transmembrane domain were subsequently predicted by bioinformatics tools. Finally, the structure-activity relationship was analyzed from the results of activity experiments and prediction. The results of activity experiments indicated that AMP-B/C/D clearly possessed excellent broad-spectrum activity against bacteria, whereas AMP-A was almost inactive against most of the bacterial strains tested. AMP-B/C/D showed more potent activity against Gram-positive bacteria than against Gram-negative bacteria. By utilizing bioinformatics analysis tools, we found that the secondary structure of the four cation peptides was mainly alpha-helix, and the result of CD spectrum also displayed that all the peptides had considerable alpha-helix in the presence of either 50% TFE or SDS micelles. AMP-C showed much better activity than other peptides against most of the bacteria tested, owing to its remarkable cation property and the amphipathic character of its N-terminal. The study of structure-activity relationship of the designed peptides confirmed that amphipathic structure and high net positive charge were prerequisites for maintaining their activities.
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Affiliation(s)
- Gang Hao
- The State Key Laboratory of Food Science and Technology, JiangNan University, Wuxi, 214122, Jiangsu Province, China
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Cy5 labeled antimicrobial peptides for enhanced detection of Escherichia coli O157:H7. Biosens Bioelectron 2008; 23:1721-7. [PMID: 18378438 DOI: 10.1016/j.bios.2008.02.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 01/26/2008] [Accepted: 02/06/2008] [Indexed: 11/23/2022]
Abstract
Fluorescently labeled antimicrobial peptides were evaluated as a potential replacement of labeled antibodies in a sandwich assay for the detection of Escherichia coli O157:H7. Antimicrobial peptides naturally bind to the lipopolysaccharide component of bacterial cell walls as part of their mode of action. Because of their small size relative to antibodies peptides can bind to cell surfaces with greater density, thereby increasing the optical signal and improving sensitivity. This method combines the specificity of a capture antibody with the increased sensitivity provided by using a labeled peptide as a detection molecule. The antimicrobial peptides cecropin P1, SMAP29, and PGQ were labeled with the fluorescent dye Cy5 via maleimide linker chemistry. Preliminary screening using a whole-cell solution binding assay revealed that Cy5 cecropin P1 enhanced the detection of E. coli O157:H7 relative to a Cy5 labeled anti-E. coli O157:H7 antibody 10-fold. Detection sensitivity of antibody and peptide were also compared with a prototype immuno-magnetic bead biosensor. Detection using Cy5 cecropin P1 resulted in a 10-fold improvement in sensitivity. Correlation of peptide antimicrobial activity with detection of E. coli O157:H7 indicated that activity was not predictive of the sensitivity of the fluorescent assay.
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38
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Eswarappa SM, Panguluri KK, Hensel M, Chakravortty D. The yejABEF operon of Salmonella confers resistance to antimicrobial peptides and contributes to its virulence. MICROBIOLOGY (READING, ENGLAND) 2008; 154:666-678. [PMID: 18227269 DOI: 10.1099/mic.0.2007/011114-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Pathogenic micro-organisms have evolved many strategies to counteract the antimicrobial peptides (AMPs) that they encounter upon entry into host systems. These strategies play vital roles in the virulence of pathogenic micro-organisms. The Salmonella enterica serovar Typhimurium genome has a gene cluster consisting of yejA, yejB, yejE and yejF genes, which encode a putative ATP-binding cassette (ABC) transporter. Our study shows that these genes constitute an operon. We deleted the yejF gene, which encodes the ATPase component of the putative ABC transporter. The DeltayejF strain showed increased sensitivity to protamine, melittin, polymyxin B, human defensin (HBD)-1 and HBD-2, and was compromised in its capacity to proliferate inside activated macrophages and epithelial cells. Inside Intestine 407 cells, Salmonella was found to co-localize with human defensins HD-5 and HBD-1; this suggests that the ability to counteract AMPs in the intracellular milieu is important for Salmonella. In a murine typhoid model, the DeltayejF strain displayed decreased virulence when infected intragastrically. These findings suggest that the putative transporter encoded by the yejABEF operon is involved in counteracting AMPs, and that it contributes to the virulence of Salmonella.
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Affiliation(s)
- Sandeepa M Eswarappa
- Centre for Infectious Disease Research and Biosafety Laboratories, Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Kiran Kumar Panguluri
- Centre for Infectious Disease Research and Biosafety Laboratories, Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Michael Hensel
- Institute of Clinical Microbiology, Immunology and Hygiene, FAU Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Dipshikha Chakravortty
- Centre for Infectious Disease Research and Biosafety Laboratories, Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
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Energetics and partition of two cecropin-melittin hybrid peptides to model membranes of different composition. Biophys J 2007; 94:2128-41. [PMID: 18032555 DOI: 10.1529/biophysj.107.119032] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The energetics and partition of two hybrid peptides of cecropin A and melittin (CA(1-8)M(1-18) and CA(1-7)M(2-9)) with liposomes of different composition were studied by time-resolved fluorescence spectroscopy, isothermal titration calorimetry, and surface plasmon resonance. The study was carried out with large unilamellar vesicles of three different lipid compositions: 1,2-dimyristoil-sn-glycero-3-phosphocholine (DMPC), 1,2-dimyristoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DMPG), and a 3:1 binary mixture of DMPC/DMPG in a wide range of peptide/lipid ratios. The results are compatible with a model involving a strong electrostatic surface interaction between the peptides and the negatively charged liposomes, giving rise to aggregation and precipitation. A correlation is observed in the calorimetric experiments between the observed events and charge neutralization for negatively charged and mixed membranes. In the case of zwitterionic membranes, a very interesting case study was obtained with the smaller peptide, CA(1-7)M(2-9). The calorimetric results obtained for this peptide in a large range of peptide/lipid ratios can be interpreted on the basis of an initial and progressive surface coverage until a threshold concentration, where the orientation changes from parallel to perpendicular to the membrane, followed by pore formation and eventually membrane disruption. The importance of negatively charged lipids on the discrimination between bacterial and eukaryotic membranes is emphasized.
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40
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Krupovic M, Daugelavicius R, Bamford DH. Polymyxin B induces lysis of marine pseudoalteromonads. Antimicrob Agents Chemother 2007; 51:3908-14. [PMID: 17709471 PMCID: PMC2151463 DOI: 10.1128/aac.00449-07] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Polymyxin B (PMB) is a cationic antibiotic that interacts with the envelopes of gram-negative bacterial cells. The therapeutic use of PMB was abandoned for a long time due to its undesirable side effects; however, the spread of resistance to currently used antibiotics has forced the reevaluation of PMB for clinical use. Previous studies have used enteric bacteria to examine the mode of PMB action, resulting in a somewhat limited understanding of this process. This study examined the effects of PMB on marine pseudoalteromonads and demonstrates that the frequently accepted view that "what is true for Escherichia coli is true for all bacteria" does not hold true. We show here that in contrast to the growth inhibition observed for enteric bacteria, PMB induces lysis of pseudoalteromonads, which is not prevented by high concentrations of divalent cations. Furthermore, we demonstrate that a high membrane voltage is required for the interaction of PMB with the cytoplasmic membranes of pseudoalteromonads, further elucidating the mechanisms by which PMB interacts with the cell envelopes of those gram-negative bacteria.
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Affiliation(s)
- Mart Krupovic
- Department of Biological and Environmental Sciences, 00014 University of Helsinki, Finland
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41
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Dassanayake RS, Silva Gunawardene YIN, Tobe SS. Evolutionary selective trends of insect/mosquito antimicrobial defensin peptides containing cysteine-stabilized alpha/beta motifs. Peptides 2007; 28:62-75. [PMID: 17161505 DOI: 10.1016/j.peptides.2006.09.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 09/11/2006] [Accepted: 09/11/2006] [Indexed: 11/20/2022]
Abstract
Insect defensins containing cysteine-stabilized alpha/beta motifs (Cs-alpha/beta defensin) are cationic, inducible antibacterial peptides involved in humoral defence against pathogens. To examine trends in molecular evolution of these antimicrobial peptides, sequences similar to the well-characterized Cs-alpha/beta defensin peptide of Anopheles gambiae, using six cysteine residues as landmarks, were retrieved from genomic and protein databases. These sequences were derived from different orders of insects. Genes of insect Cs-alpha/beta defensin appear to constitute a multigene family in which the copy number varies between insect species. Phylogenetic analysis of these sequences revealed two main lineages, one group comprising mainly lepidopteran insects and a second, comprising Hemiptera, Coleoptera, Diptera and Hymenoptera insects. Moreover, the topology of the phylogram indicated dipteran Cs-alpha/beta defensins are diverse, suggesting diversity in immune mechanisms in this order of insects. Overall evolutionary analysis indicated marked diversification and expansion of mature defensin isoforms within the species of mosquitoes relative to non-mosquito defensins, implying the presence of finely tuned immune responses to counter pathogens. The observed higher synonymous substitution rate relative to the nonsynonymous rate in almost all the regions of Cs-alpha/beta defensin of mosquitoes suggests that these peptides are predominately under purifying selection. The maximum-likelihood models of codon substitution indicated selective pressure at different amino acid sites in mosquito mature Cs-alpha/beta defensins is differ and are undergoing adaptive evolution in comparison to non-mosquito Cs-alpha/beta defensins, for which such selection was inconspicuous; this suggests the acquisition of selective advantage of the Cs-alpha/beta defensins in the former group. Finally, this study represents the most detailed report on the evolutionary strategies of Cs-alpha/beta defensins of mosquitoes in particular and insects in general, and indicates that insect Cs-alpha/beta defensins have evolved by duplication followed by divergence, to produce a diverse set of paralogues.
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Affiliation(s)
- R S Dassanayake
- Department of Chemistry, Faculty of Science, University of Colombo, Sri Lanka.
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42
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Abstract
Host defence peptides are a conserved component of the innate immune response in all complex life forms. In humans, the major classes of host defence peptides include the α- and β-defensins and the cathelicidin, hCAP-18/LL-37. These peptides are expressed in the granules of neutrophils and by a wide variety of tissue types. They have many roles in the immune response including both indirect and direct antimicrobial activity, the ability to act as chemokines as well as induce chemokine production leading to recruitment of leukocytes to the site of infection, the promotion of wound healing and an ability to modulate adaptive immunity. It appears that many of these properties are mediated though direct interaction of peptides with the cells of the innate immune response including monocytes, dendritic cells, T cells and epithelial cells. The importance of these peptides in immune responses has been demonstrated since animals defective in the expression of certain host defence peptides showgreater susceptibility to bacterial infections. In the very few instances in which human patients have been demonstrated to have defective host defence peptide expression, these individuals suffer from frequent infections. Although studies of the immunomodulatory properties of these peptides are in their infancy, there is a growing body of evidence suggesting that the immunomodulatory properties of these small, naturally occurring molecules might be harnessed for development as novel therapeutic agents.
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Affiliation(s)
- William M. Shafer
- Department of Microbiology and Immunology, 3001 Rollins Research Center, Emory University School of Medicine, Atlanta, GA 30322 USA
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43
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Campos MA, Morey P, Bengoechea JA. Quinolones sensitize gram-negative bacteria to antimicrobial peptides. Antimicrob Agents Chemother 2006; 50:2361-7. [PMID: 16801413 PMCID: PMC1489791 DOI: 10.1128/aac.01437-05] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The treatment of infections caused by bacteria resistant to the vast majority of antibiotics is a challenge worldwide. Antimicrobial peptides (APs) make up the front line of defense in those areas exposed to microorganisms, and there is intensive research to explore their use as new antibacterial agents. On the other hand, it is known that subinhibitory concentrations of antibiotics affect the expression of numerous bacterial traits. In this work we evaluated whether treatment of bacteria with subinhibitory concentrations of quinolones may alter the sensitivity to APs. A 1-h treatment of Klebsiella pneumoniae with 0.25 x the MIC of ciprofloxacin rendered bacteria more sensitive to polymyxins B and E, human neutrophil defensin 1, and beta-defensin 1. Levofloxacin and nalidixic acid at 0.25 x the MICs also increased the sensitivity of K. pneumoniae to polymyxin B, whereas gentamicin and ceftazidime at 0.25 x the MICs did not have such an effect. Ciprofloxacin also increased the sensitivities of K. pneumoniae ciprofloxacin-resistant strains to polymyxin B. Two other pathogens, Pseudomonas aeruginosa and Haemophilus influenzae, also became more sensitive to polymyxins B and E after treatment with 0.25 x the MIC of ciprofloxacin. Incubation with ciprofloxacin did not alter the expression of the K. pneumoniae loci involved in resistance to APs. A 1-N-phenyl-naphthylamine assay showed that ciprofloxacin and levofloxacin increased the permeabilities of the K. pneumoniae and P. aeruginosa outer membranes, while divalent cations antagonized this action. Finally, we demonstrated that ciprofloxacin and levofloxacin increased the binding of APs to the outer membrane by using dansylated polymyxin B.
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Affiliation(s)
- Miguel A Campos
- Unidad de Investigación, Hospital Universitario Son Dureta, and Institut Universitari d'Investigacions en Ciències de la Salut (IUNICS), Palma de Mallorca, Spain
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44
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Eckert R, Qi F, Yarbrough DK, He J, Anderson MH, Shi W. Adding selectivity to antimicrobial peptides: rational design of a multidomain peptide against Pseudomonas spp. Antimicrob Agents Chemother 2006; 50:1480-8. [PMID: 16569868 PMCID: PMC1426969 DOI: 10.1128/aac.50.4.1480-1488.2006] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Currently available antimicrobials exhibit broad killing with regard to bacterial genera and species. Indiscriminate killing of microbes by these conventional antibiotics can disrupt the ecological balance of the indigenous microbial flora, often resulting in negative clinical consequences. Species-specific antimicrobials capable of precisely targeting pathogenic bacteria without damaging benign microorganisms provide a means of avoiding this problem. In this communication, we report the successful creation of the first synthetic, target-specific antimicrobial peptide, G10KHc, via addition of a rationally designed Pseudomonas-specific targeting moiety (KH) to a generally killing peptide (novispirin G10). The resulting chimeric peptide showed enhanced bactericidal activity and faster killing kinetics against Pseudomonas spp. than G10 alone. The enhanced killing activities are due to increased binding and penetration of the outer membrane of Pseudomonas sp. cells. These properties were not observed in tests of untargeted bacterial species, and this specificity allowed G10KHc to selectively eliminate Pseudomonas spp. from mixed cultures. This work lays a foundation for generating target-specific "smart" antimicrobials to complement currently available conventional antibiotics.
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Affiliation(s)
- Randal Eckert
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA School of Dentistry, 10833 Le Conte Ave., Los Angeles, CA 90095-1668, USA
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45
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Sato H, Feix JB. Peptide-membrane interactions and mechanisms of membrane destruction by amphipathic alpha-helical antimicrobial peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1245-56. [PMID: 16697975 DOI: 10.1016/j.bbamem.2006.02.021] [Citation(s) in RCA: 378] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 02/15/2006] [Accepted: 02/16/2006] [Indexed: 10/24/2022]
Abstract
Antimicrobial peptides (AMPs) have received considerable interest as a source of new antibiotics with the potential for treatment of multiple-drug resistant infections. An important class of AMPs is composed of linear, cationic peptides that form amphipathic alpha-helices. Among the most potent of these are the cecropins and synthetic peptides that are hybrids of cecropin and the bee venom peptide, mellitin. Both cecropins and cecropin-mellitin hybrids exist in solution as unstructured monomers, folding into predominantly alpha-helical structures upon membrane binding with their long helical axis parallel to the bilayer surface. Studies using model membranes have shown that these peptides intercalate into the lipid bilayer just below the level of the phospholipid glycerol backbone in a location that requires expansion of the outer leaflet of the bilayer, and evidence from a variety of experimental approaches indicates that expansion and thinning of the bilayer are common characteristics during the early stages of antimicrobial peptide-membrane interactions. Subsequent disruption of the membrane permeability barrier may occur by a variety of mechanisms, leading ultimately to loss of cytoplasmic membrane integrity and cell death.
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Affiliation(s)
- Hiromi Sato
- Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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46
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Ferre R, Badosa E, Feliu L, Planas M, Montesinos E, Bardají E. Inhibition of plant-pathogenic bacteria by short synthetic cecropin A-melittin hybrid peptides. Appl Environ Microbiol 2006; 72:3302-8. [PMID: 16672470 PMCID: PMC1472336 DOI: 10.1128/aem.72.5.3302-3308.2006] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 02/26/2006] [Indexed: 11/20/2022] Open
Abstract
Short peptides of 11 residues were synthesized and tested against the economically important plant pathogenic bacteria Erwinia amylovora, Pseudomonas syringae, and Xanthomonas vesicatoria and compared to the previously described peptide Pep3 (WKLFKKILKVL-NH(2)). The antimicrobial activity of Pep3 and 22 analogues was evaluated in terms of the MIC and the 50% effective dose (ED(50)) for growth. Peptide cytotoxicity against human red blood cells and peptide stability toward protease degradation were also determined. Pep3 and several analogues inhibited growth of the three pathogens and had a bactericidal effect at low micromolar concentrations (ED(50) of 1.3 to 7.3 microM). One of the analogues consisting of a replacement of both Trp and Val with Lys and Phe, respectively, resulted in a peptide with improved bactericidal activity and minimized cytotoxicity and susceptibility to protease degradation compared to Pep3. The best analogues can be considered as potential lead compounds for the development of new antimicrobial agents for use in plant protection either as components of pesticides or expressed in transgenic plants.
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Affiliation(s)
- Rafael Ferre
- Laboratori de Patologia Vegetal, Institut de Tecnologia Agroalimentària, CIDSAV-CeRTA, Universitat de Girona, Campus Montilivi, 17071 Girona, Spain
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47
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Shaw JE, Alattia JR, Verity JE, Privé GG, Yip CM. Mechanisms of antimicrobial peptide action: Studies of indolicidin assembly at model membrane interfaces by in situ atomic force microscopy. J Struct Biol 2006; 154:42-58. [PMID: 16459101 DOI: 10.1016/j.jsb.2005.11.016] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Revised: 10/13/2005] [Accepted: 11/09/2005] [Indexed: 11/21/2022]
Abstract
We report here on an in situ atomic force microscopy study of the interaction of indolicidin, a tryptophan-rich antimicrobial peptide, with phase-segregated zwitterionic DOPC/DSPC supported planar bilayers. By varying the peptide concentration and bilayer composition through the inclusion of anionic lipids (DOPG or DSPG), we found that indolicidin interacts with these model membranes in one of two concentration-dependent manners. At low peptide concentrations, indolicidin forms an amorphous layer on the fluid domains when these domains contain anionic lipids. At high peptide concentrations, indolicidin appears to initiate a lowering of the gel-phase domains independent of the presence of an anionic lipid. Similar studies performed using membrane-raft mimetic bilayers comprising 30mol% cholesterol/1:1 DOPC/egg sphingomyelin revealed that indolicidin does not form a carpet-like layer on the zwitterionic DOPC domains at low peptide concentrations and does not induce membrane lowering of the liquid-ordered sphingomyelin/cholesterol-rich domains at high peptide concentration. Simultaneous AFM-confocal microscopy imaging did however reveal that indolicidin preferentially inserts into the fluid-phase DOPC domains. These data suggest that the indolicidin-membrane association is influenced greatly by specific electrostatic interactions, lipid fluidity, and peptide concentration. These insights provide a glimpse into the mechanism of the membrane selectivity of antibacterial peptides and suggest a powerful correlated approach for characterizing peptide-membrane interactions.
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Affiliation(s)
- James E Shaw
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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48
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Klajnert B, Janiszewska J, Urbanczyk-Lipkowska Z, Bryszewska M, Shcharbin D, Labieniec M. Biological properties of low molecular mass peptide dendrimers. Int J Pharm 2006; 309:208-17. [PMID: 16386860 DOI: 10.1016/j.ijpharm.2005.10.039] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 10/16/2005] [Accepted: 10/21/2005] [Indexed: 11/28/2022]
Abstract
A series of new, low molecular mass, lysine-based peptide dendrimers with varying distribution of cationic and aromatic groups in the structure were synthesized. They expressed antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria as well as against fungal pathogens (Candida albicans). Their cytotoxic, haematotoxic, and genotoxic effects were studied. It appears that degree of branching and steric distribution and types of hydrophobic (aromatic) groups and cationic centres are important components of dendrimeric structure and influence both antimicrobial potency and toxicity. Such 3D structure of our dendrimers mimics that of the natural antimicrobial peptides and can be achieved by application of dendrimer chemistry.
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Affiliation(s)
- B Klajnert
- Department of General Biophysics, University of Lodz, 90-237 Lodz, Poland
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49
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Malina A, Shai Y. Conjugation of fatty acids with different lengths modulates the antibacterial and antifungal activity of a cationic biologically inactive peptide. Biochem J 2006; 390:695-702. [PMID: 15907192 PMCID: PMC1199663 DOI: 10.1042/bj20050520] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Many studies have shown that an amphipathic structure and a threshold of hydrophobicity of the peptidic chain are crucial for the biological function of AMPs (antimicrobial peptides). However, the factors that dictate their cell selectivity are not yet clear. In the present study, we show that the attachment of aliphatic acids with different lengths (10, 12, 14 or 16 carbon atoms) to the N-terminus of a biologically inactive cationic peptide is sufficient to endow the resulting lipopeptides with lytic activity against different cells. Mode-of-action studies were performed with model phospholipid membranes mimicking those of bacterial, mammalian and fungal cells. These include determination of the structure in solution and membranes by using CD and ATR-FTIR (attenuated total reflectance Fourier-transform infrared) spectroscopy, membrane leakage experiments and by visualizing bacterial and fungal damage via transmission electron microscopy. The results obtained reveal that: (i) the short lipopeptides (10 and 12 carbons atoms) are non-haemolytic, active towards both bacteria and fungi and monomeric in solution. (ii) The long lipopeptides (14 and 16 carbons atoms) are highly antifungal, haemolytic only at concentrations above their MIC (minimal inhibitory concentration) values and aggregate in solution. (iii) All the lipopeptides adopt a partial alpha-helical structure in 1% lysophosphatidylcholine and bacterial and mammalian model membranes. However, the two short lipopeptides contain a significant fraction of random coil in fungal membranes, in agreement with their reduced antifungal activity. (iv) All the lipopeptides have a membranolytic effect on all types of cells assayed. Overall, the results reveal that the length of the aliphatic chain is sufficient to control the pathogen specificity of the lipopeptides, most probably by controlling both the overall hydrophobicity and the oligomeric state of the lipopeptides in solution. Besides providing us with basic important information, these new lipopeptides are potential candidates that can target bacteria and/or fungi, especially in cases where the bacterial flora should not be harmed.
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Affiliation(s)
- Amir Malina
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Yechiel Shai
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
- To whom correspondence should be addressed (email )
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50
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Bader MW, Sanowar S, Daley ME, Schneider AR, Cho U, Xu W, Klevit RE, Le Moual H, Miller SI. Recognition of antimicrobial peptides by a bacterial sensor kinase. Cell 2005; 122:461-72. [PMID: 16096064 DOI: 10.1016/j.cell.2005.05.030] [Citation(s) in RCA: 448] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 04/08/2005] [Accepted: 05/27/2005] [Indexed: 11/21/2022]
Abstract
PhoQ is a membrane bound sensor kinase important for the pathogenesis of a number of Gram-negative bacterial species. PhoQ and its cognate response regulator PhoP constitute a signal-transduction cascade that controls inducible resistance to host antimicrobial peptides. We show that enzymatic activity of Salmonella typhimurium PhoQ is directly activated by antimicrobial peptides. A highly acidic surface of the PhoQ sensor domain participates in both divalent-cation and antimicrobial-peptide binding as a first step in signal transduction across the bacterial membrane. Identification of PhoQ signaling mutants, binding studies with the PhoQ sensor domain, and structural analysis of this domain can be incorporated into a model in which antimicrobial peptides displace divalent cations from PhoQ metal binding sites to initiate signal transduction. Our findings reveal a molecular mechanism by which bacteria sense small innate immune molecules to initiate a transcriptional program that promotes bacterial virulence.
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Affiliation(s)
- Martin W Bader
- Department of Microbiology, University of Washington Medical School, 1959 NE Pacific Street, Seattle, Washington 98195, USA
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