1
|
Bosch TCG, Blaser MJ, Ruby E, McFall-Ngai M. A new lexicon in the age of microbiome research. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230060. [PMID: 38497258 PMCID: PMC10945402 DOI: 10.1098/rstb.2023.0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 12/04/2023] [Indexed: 03/19/2024] Open
Abstract
At a rapid pace, biologists are learning the many ways in which resident microbes influence, and sometimes even control, their hosts to shape both health and disease. Understanding the biochemistry behind these interactions promises to reveal completely novel and targeted ways of counteracting disease processes. However, in our protocols and publications, we continue to describe these new results using a language that originated in a completely different context. This language developed when microbial interactions with hosts were perceived to be primarily pathogenic, as threats that had to be vanquished. Biomedicine had one dominating thought: winning this war against microorganisms. Today, we know that beyond their defensive roles, host tissues, especially epithelia, are vital to ensuring association with the normal microbiota, the communities of microbes that persistently live with the host. Thus, we need to adopt a language that better encompasses the newly appreciated importance of host-microbiota associations. We also need a language that frames the onset and progression of pathogenic conditions within the context of the normal microbiota. Such a reimagined lexicon should make it clear, from the very nature of its words, that microorganisms are primarily vital to our health, and only more rarely the cause of disease. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.
Collapse
Affiliation(s)
| | - Martin J. Blaser
- Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ 08854, USA
| | - Edward Ruby
- California Institute of Technology, Pasadena, CA 91125, USA
| | | |
Collapse
|
2
|
Skłodowski K, Suprewicz Ł, Chmielewska-Deptuła SJ, Kaliniak S, Okła S, Zakrzewska M, Minarowski Ł, Mróz R, Daniluk T, Savage PB, Fiedoruk K, Bucki R. Ceragenins exhibit bactericidal properties that are independent of the ionic strength in the environment mimicking cystic fibrosis sputum. Front Microbiol 2023; 14:1290952. [PMID: 38045035 PMCID: PMC10693459 DOI: 10.3389/fmicb.2023.1290952] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/02/2023] [Indexed: 12/05/2023] Open
Abstract
The purpose of the work was to investigate the impact of sodium chloride (NaCl) on the antimicrobial efficacy of ceragenins (CSAs) and antimicrobial peptides (AMPs) against bacterial and fungal pathogens associated with cystic fibrosis (CF) lung infections. CF-associated bacterial (Pseudomonas aeruginosa, Ochrobactrum spp., and Staphylococcus aureus), and fungal pathogens (Candida albicans, and Candida tropicalis) were used as target organisms for ceragenins (CSA-13 and CSA-131) and AMPs (LL-37 and omiganan). Susceptibility to the tested compounds was assessed using minimal inhibitory concentrations (MICs) and bactericidal concentrations (MBCs), as well as by colony counting assays in CF sputum samples supplemented with various concentrations of NaCl. Our results demonstrated that ceragenins exhibit potent antimicrobial activity in CF sputum regardless of the NaCl concentration when compared to LL-37 and omiganan. Given the broad-spectrum antimicrobial activity of ceragenins in the microenvironments mimicking the airways of CF patients, ceragenins might be promising agents in managing CF disease.
Collapse
Affiliation(s)
- Karol Skłodowski
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Łukasz Suprewicz
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | | | | | - Sławomir Okła
- Holy Cross Cancer Center, Kielce, Poland
- Institute of Health Science, Collegium Medicum, Jan Kochanowski University of Kielce, Kielce, Poland
| | - Magdalena Zakrzewska
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Łukasz Minarowski
- 2nd Department of Lung Diseases and Tuberculosis, Medical University of Bialystok, Bialystok, Poland
| | - Robert Mróz
- 2nd Department of Lung Diseases and Tuberculosis, Medical University of Bialystok, Bialystok, Poland
| | - Tamara Daniluk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Paul B. Savage
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, United States
| | - Krzysztof Fiedoruk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Robert Bucki
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| |
Collapse
|
3
|
Chatziparasidis G, Kantar A, Grimwood K. Pathogenesis of nontypeable Haemophilus influenzae infections in chronic suppurative lung disease. Pediatr Pulmonol 2023. [PMID: 37133207 DOI: 10.1002/ppul.26446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/09/2023] [Accepted: 04/23/2023] [Indexed: 05/04/2023]
Abstract
The respiratory tract antimicrobial defense system is a multilayered defense mechanism that relies upon mucociliary clearance and components of both the innate and adaptive immune systems to protect the lungs from inhaled or aspirated microorganisms. One of these potential pathogens, nontypeable Haemophilus influenzae (NTHi), adopts several, multifaceted redundant strategies to successfully colonize the lower airways and establish a persistent infection. NTHi can impair mucociliary clearance, express multiple multifunctional adhesins for various cell types within the respiratory tract and evade host defenses by surviving within and between cells, forming biofilms, increasing antigenic drift, secreting proteases and antioxidants, and by host-pathogen cross-talk, impair macrophage and neutrophil function. NTHi is recognized as an important pathogen in several chronic lower respiratory disorders, such as protracted bacterial bronchitis, bronchiectasis, cystic fibrosis, and primary ciliary dyskinesia. The persistence of NTHi in human airways, including its capacity to form biofilms, results in chronic infection and inflammation, which can ultimately injure airway wall structures. The complex nature of the molecular pathogenetic mechanisms employed by NTHi is incompletely understood but improved understanding of its pathobiology will be important for developing effective therapies and vaccines, especially given the marked genetic heterogeneity of NTHi and its possession of phase-variable genes. Currently, no vaccine candidates are ready for large phase III clinical trials.
Collapse
Affiliation(s)
- Grigorios Chatziparasidis
- Paediatric Respiratory Unit, IASO Hospital, Larissa, Thessaly, Greece
- Faculty of Nursing, Thessaly University, Larissa, Greece
| | - Ahmad Kantar
- Pediatric Asthma and Cough Centre, Instituti Ospedalieri Bergamaschi, Bergamo, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Keith Grimwood
- School of Medicine and Dentistry, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
- Departments of Infectious Disease and Paediatrics, Gold Coast Health, Southport, Queensland, Australia
| |
Collapse
|
4
|
Antimicrobial peptides for tackling cystic fibrosis related bacterial infections: a review. Microbiol Res 2022; 263:127152. [DOI: 10.1016/j.micres.2022.127152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022]
|
5
|
Kotlyarov S. Involvement of the Innate Immune System in the Pathogenesis of Chronic Obstructive Pulmonary Disease. Int J Mol Sci 2022; 23:985. [PMID: 35055174 PMCID: PMC8778852 DOI: 10.3390/ijms23020985] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 01/27/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a common, socially significant disease characterized by progressive airflow limitation due to chronic inflammation in the bronchi. Although the causes of COPD are considered to be known, the pathogenesis of the disease continues to be a relevant topic of study. Mechanisms of the innate immune system are involved in various links in the pathogenesis of COPD, leading to persistence of chronic inflammation in the bronchi, their bacterial colonization and disruption of lung structure and function. Bronchial epithelial cells, neutrophils, macrophages and other cells are involved in the development and progression of the disease, demonstrating multiple compromised immune mechanisms.
Collapse
Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
| |
Collapse
|
6
|
Gan BH, Gaynord J, Rowe SM, Deingruber T, Spring DR. The multifaceted nature of antimicrobial peptides: current synthetic chemistry approaches and future directions. Chem Soc Rev 2021; 50:7820-7880. [PMID: 34042120 PMCID: PMC8689412 DOI: 10.1039/d0cs00729c] [Citation(s) in RCA: 175] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Indexed: 12/13/2022]
Abstract
Bacterial infections caused by 'superbugs' are increasing globally, and conventional antibiotics are becoming less effective against these bacteria, such that we risk entering a post-antibiotic era. In recent years, antimicrobial peptides (AMPs) have gained significant attention for their clinical potential as a new class of antibiotics to combat antimicrobial resistance. In this review, we discuss several facets of AMPs including their diversity, physicochemical properties, mechanisms of action, and effects of environmental factors on these features. This review outlines various chemical synthetic strategies that have been applied to develop novel AMPs, including chemical modifications of existing peptides, semi-synthesis, and computer-aided design. We will also highlight novel AMP structures, including hybrids, antimicrobial dendrimers and polypeptides, peptidomimetics, and AMP-drug conjugates and consider recent developments in their chemical synthesis.
Collapse
Affiliation(s)
- Bee Ha Gan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Josephine Gaynord
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Sam M Rowe
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Tomas Deingruber
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - David R Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| |
Collapse
|
7
|
Kuek LE, Lee RJ. First contact: the role of respiratory cilia in host-pathogen interactions in the airways. Am J Physiol Lung Cell Mol Physiol 2020; 319:L603-L619. [PMID: 32783615 PMCID: PMC7516383 DOI: 10.1152/ajplung.00283.2020] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/28/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023] Open
Abstract
Respiratory cilia are the driving force of the mucociliary escalator, working in conjunction with secreted airway mucus to clear inhaled debris and pathogens from the conducting airways. Respiratory cilia are also one of the first contact points between host and inhaled pathogens. Impaired ciliary function is a common pathological feature in patients with chronic airway diseases, increasing susceptibility to respiratory infections. Common respiratory pathogens, including viruses, bacteria, and fungi, have been shown to target cilia and/or ciliated airway epithelial cells, resulting in a disruption of mucociliary clearance that may facilitate host infection. Despite being an integral component of airway innate immunity, the role of respiratory cilia and their clinical significance during airway infections are still poorly understood. This review examines the expression, structure, and function of respiratory cilia during pathogenic infection of the airways. This review also discusses specific known points of interaction of bacteria, fungi, and viruses with respiratory cilia function. The emerging biological functions of motile cilia relating to intracellular signaling and their potential immunoregulatory roles during infection will also be discussed.
Collapse
Affiliation(s)
- Li Eon Kuek
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Robert J Lee
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| |
Collapse
|
8
|
Xia E, Duan R, Shi F, Seigel KE, Grasemann H, Hu J. Overcoming the Undesirable CRISPR-Cas9 Expression in Gene Correction. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 13:699-709. [PMID: 30513454 PMCID: PMC6278715 DOI: 10.1016/j.omtn.2018.10.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 10/25/2018] [Accepted: 10/25/2018] [Indexed: 01/06/2023]
Abstract
The CRISPR-Cas9 system is attractive for gene therapy, as it allows for permanent genetic correction. However, as a new technology, Cas9 gene editing in clinical applications faces major challenges, such as safe delivery and gene targeting efficiency. Cas9 is a foreign protein to recipient cells; thus, its expression may prompt the immune system to eliminate gene-edited cells. To overcome these challenges, we have engineered a novel delivery system based on the helper-dependent adenoviral (HD-Ad) vector, which is capable of delivering genes to airway basal stem cells in vivo. Using this system, we demonstrate the successful co-delivery of both CRISPR-Cas9/single-guide RNA and the LacZ reporter or CFTR gene as donor DNA to cultured cells. HD-Ad vector genome integrity is compromised following donor DNA integration, and because the CRISPR-Cas9/single-guide RNA and donor DNA are carried on the same vector, CRISPR-Cas9 expression is concurrently eliminated. Thus, we show the feasibility of site-specific gene targeting with limited Cas9 expression. In addition, we achieved stable CFTR expression and functional correction in cultured cells following successful gene integration.
Collapse
Affiliation(s)
- Emily Xia
- Translational Medicine, Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Rongqi Duan
- Translational Medicine, Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Fushan Shi
- Translational Medicine, Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Kyle E Seigel
- Translational Medicine, Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Hartmut Grasemann
- Translational Medicine, Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Paediatrics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Jim Hu
- Translational Medicine, Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Paediatrics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
| |
Collapse
|
9
|
Niemirowicz K, Surel U, Wilczewska AZ, Mystkowska J, Piktel E, Gu X, Namiot Z, Kułakowska A, Savage PB, Bucki R. Bactericidal activity and biocompatibility of ceragenin-coated magnetic nanoparticles. J Nanobiotechnology 2015; 13:32. [PMID: 25929281 PMCID: PMC4458011 DOI: 10.1186/s12951-015-0093-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 04/23/2015] [Indexed: 01/04/2023] Open
Abstract
Background Ceragenins, synthetic mimics of endogenous antibacterial peptides, are promising candidate antimicrobial agents. However, in some settings their strong bactericidal activity is associated with toxicity towards host cells. To modulate ceragenin CSA-13 antibacterial activity and biocompatibility, CSA-13-coated magnetic nanoparticles (MNP-CSA-13) were synthesized. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize MNP-CSA-13 physicochemical properties. Bactericidal action and ability of these new compounds to prevent Pseudomonas. aeruginosa biofilm formation were assessed using a bacteria killing assay and crystal violet staining, respectively. Release of hemoglobin from human red blood cells was measured to evaluate MNP-CSA-13 hemolytic activity. In addition, we used surface activity measurements to monitor CSA-13 release from the MNP shell. Zeta potentials of P. aeruginosa cells and MNP-CSA-13 were determined to assess the interactions between the bacteria and nanoparticles. Morphology of P. aeruginosa subjected to MNP-CSA-13 treatment was evaluated using atomic force microscopy (AFM) to determine structural changes indicative of bactericidal activity. Results Our studies revealed that the MNP-CSA-13 nanosystem is stable and may be used as a pH control system to release CSA-13. MNP-CSA-13 exhibits strong antibacterial activity, and the ability to prevent bacteria biofilm formation in different body fluids. Additionally, a significant decrease in CSA-13 hemolytic activity was observed when the molecule was immobilized on the nanoparticle surface. Conclusion Our results demonstrate that CSA-13 retains bactericidal activity when immobilized on a MNP while biocompatibility increases when CSA-13 is covalently attached to the nanoparticle.
Collapse
Affiliation(s)
- Katarzyna Niemirowicz
- Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2c, 15-222, Bialystok, Poland.
| | - Urszula Surel
- Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2c, 15-222, Bialystok, Poland.
| | | | - Joanna Mystkowska
- Department of Materials and Biomedical Engineering, Białystok University of Technology, 15-351, Białystok, Poland.
| | - Ewelina Piktel
- Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2c, 15-222, Bialystok, Poland.
| | - Xiaobo Gu
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA.
| | - Zbigniew Namiot
- Department of Physiology, Medical University of Białystok, 15-230, Białystok, Poland.
| | - Alina Kułakowska
- Department of Neurology, Medical University of Bialystok, 15-230, Bialystok, Poland.
| | - Paul B Savage
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA.
| | - Robert Bucki
- Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2c, 15-222, Bialystok, Poland. .,Department of Physiology, Pathophysiology and Microbiology of Infections, The Faculty of Health Sciences of the Jan Kochanowski University in Kielce, 25-317, Kielce, Poland.
| |
Collapse
|
10
|
Rational design of engineered cationic antimicrobial peptides consisting exclusively of arginine and tryptophan, and their activity against multidrug-resistant pathogens. Antimicrob Agents Chemother 2013; 57:2511-21. [PMID: 23507278 DOI: 10.1128/aac.02218-12] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The emergence of multidrug-resistant (MDR) pathogens underscores the need for new antimicrobial agents to overcome the resistance mechanisms of these organisms. Cationic antimicrobial peptides (CAPs) provide a potential source of new antimicrobial therapeutics. We previously characterized a lytic base unit (LBU) series of engineered CAPs (eCAPs) of 12 to 48 residues demonstrating maximum antibacterial selectivity at 24 residues. Further, Trp substitution in LBU sequences increased activity against both P. aeruginosa and S. aureus under challenging conditions (e.g., saline, divalent cations, and serum). Based on these findings, we hypothesized that the optimal length and, therefore, the cost for maximum eCAP activity under physiologically relevant conditions could be significantly reduced using only Arg and Trp arranged to form idealized amphipathic helices. Hence, we developed a novel peptide series, composed only of Arg and Trp, in a sequence predicted and verified by circular dichroism to fold into optimized amphipathic helices. The most effective antimicrobial activity was achieved at 12 residues in length (WR12) against a panel of both Gram-negative and Gram-positive clinical isolates, including extensively drug-resistant strains, in saline and broth culture and at various pH values. The results demonstrate that the rational design of CAPs can lead to a significant reduction in the length and the number of amino acids used in peptide design to achieve optimal potency and selectivity against specific pathogens.
Collapse
|
11
|
Can the interaction between the antimicrobial peptide LL-37 and alginate be exploited for the formulation of new biomaterials with antimicrobial properties? Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2010.08.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
12
|
Benincasa M, Mattiuzzo M, Herasimenka Y, Cescutti P, Rizzo R, Gennaro R. Activity of antimicrobial peptides in the presence of polysaccharides produced by pulmonary pathogens. J Pept Sci 2009; 15:595-600. [PMID: 19466693 DOI: 10.1002/psc.1142] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Antimicrobial peptides (AMPs) are secreted in the airway and contribute to initial defence against inhaled pathogens. Infections of the respiratory tract are a major cause of morbidity and mortality in preterm newborns and in patients with cystic fibrosis (CF). In this latter group, the state of chronic lung infection is due to the ability of bacteria to grow as mucoid biofilm, a condition characterised by overproduction and release of polysaccharides (PSs). In this study, we investigate the effect of PSs produced by lung pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and members of the Burkholderia cepacia complex on the antibacterial activity of structurally different peptides. The AMPs tested in this study include the cathelicidin LL-37 and the beta-defensin hBD-3 from humans, both released at the alveolar level, as well as peptides from other mammals, i.e. SMAP-29, PG-1 and Bac7(1-35). Susceptibility assays, time killing and membrane permeabilization kinetics experiments were carried out to establish whether PSs produced by lung pathogens may be involved in the poor defence reaction of infected lungs and thus explain infection persistence. All the PSs investigated inhibited, albeit to a different extent, the antibacterial activity of the peptides tested, suggesting that their presence in the lungs of patients with CF may contribute to the decreased defence response of this district upon infection by PS-producing microorganisms. The results also show that inhibition of the antibacterial activity is not simply due to ionic interaction between the negatively charged PSs and the cationic AMPs, but it also involves other structural features of both interactors.
Collapse
Affiliation(s)
- M Benincasa
- Department of Life Sciences, University of Trieste, I-34127 Trieste, Italy
| | | | | | | | | | | |
Collapse
|