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Namvar S, Labram B, Rowley J, Herrick S. Aspergillus fumigatus-Host Interactions Mediating Airway Wall Remodelling in Asthma. J Fungi (Basel) 2022; 8:jof8020159. [PMID: 35205913 PMCID: PMC8879933 DOI: 10.3390/jof8020159] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/29/2022] [Accepted: 02/01/2022] [Indexed: 12/03/2022] Open
Abstract
Asthma is a chronic heterogeneous respiratory condition that is mainly associated with sensitivity to airborne agents such as pollen, dust mite products and fungi. Key pathological features include increased airway inflammation and airway wall remodelling. In particular, goblet cell hyperplasia, combined with excess mucus secretion, impairs clearance of the inhaled foreign material. Furthermore, structural changes such as subepithelial fibrosis and increased smooth muscle hypertrophy collectively contribute to deteriorating airway function and possibility of exacerbations. Current pharmacological therapies focused on airway wall remodelling are limited, and as such, are an area of unmet clinical need. Sensitisation to the fungus, Aspergillus fumigatus, is associated with enhanced asthma severity, bronchiectasis, and hospitalisation. How Aspergillus fumigatus may drive airway structural changes is unclear, although recent evidence points to a central role of the airway epithelium. This review provides an overview of the airway pathology in patients with asthma and fungal sensitisation, summarises proposed airway epithelial cell-fungal interactions and discusses the initiation of a tissue remodelling response. Related findings from in vivo animal models are included given the limited analysis of airway pathology in patients. Lastly, an important role for Aspergillus fumigatus-derived proteases in triggering a cascade of damage-repair events through upregulation of airway epithelial-derived factors is proposed.
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Affiliation(s)
- Sara Namvar
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (B.L.); (J.R.)
- School of Science, Engineering and Environment, University of Salford, Salford M5 4WT, UK
- Correspondence: (S.N.); (S.H.)
| | - Briony Labram
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (B.L.); (J.R.)
| | - Jessica Rowley
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (B.L.); (J.R.)
| | - Sarah Herrick
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (B.L.); (J.R.)
- Correspondence: (S.N.); (S.H.)
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Hexosomal Dispersion: A Nano-Based Approach to Boost the Antifungal Potential of Citrus Essential Oils against Plant Fungal Pathogens. Molecules 2021; 26:molecules26206284. [PMID: 34684865 PMCID: PMC8539576 DOI: 10.3390/molecules26206284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 01/08/2023] Open
Abstract
The demand for natural fungicides to replace synthetic ones has surged since toxic residues persist in soils, causing environmental contamination and posing a serious threat to worldwide public health. In the context of crop protection and enhancing the efficiency and safety of fungicides, nanotechnology is an eco-friendly strategy in managing fungal pathogens. In the present study, essential oils were isolated from the peels of four citrus fruits (Citrus lemon, Citrus aurantifolia, Citrus maxima, and Citrus sinensis) and were investigated using gas chromatography-mass spectrometric analysis. Monoterpene hydrocarbon was the most predominant group and limonene was the most abundant in the four oils. The antifungal potential of the oils was investigated, and the most active oil (Citrus lemon) was loaded into hexosomal dispersion, and its antifungal potential was retested against the same fungi. The structurally unique nano-based formulation showed great potency for fungal control. To the best of our knowledge, it is the first time the oil of Citrus lemon in nano-hexosomes has been formulated and its fungicidal activity examined. The data collected suggest that citrus essential oils (CEOs), especially when nano-formulated, could be successfully used in integrated fungus management programs.
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Schiefermeier-Mach N, Perkhofer S, Heinrich L, Haller T. Stimulation of surfactant exocytosis in primary alveolar type II cells by A. fumigatus. Med Mycol 2021; 59:168-179. [PMID: 32459847 DOI: 10.1093/mmy/myaa042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/06/2020] [Accepted: 04/30/2020] [Indexed: 02/06/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen with small airborne spores (conidia) that may escape clearance by upper airways and directly impact the alveolar epithelium. Consequently, innate alveolar defense mechanisms are being activated, including professional phagocytosis by alveolar macrophages, recruitment of circulating neutrophils and probably enhanced secretion of pulmonary surfactant by the alveolar type II (AT II) cells. However, no data are available in support of the latter hypothesis. We therefore used a coculture model of GFP-Aspergillus conidia with primary rat AT II cells and studied fungal growth, cellular Ca2+ homeostasis, and pulmonary surfactant exocytosis by live cell video microscopy. We observed all stages of fungal development, including reversible attachment, binding and internalization of conidia as well as conidial swelling, formation of germ tubes and outgrowth of hyphae. In contrast to resting conidia, which did not provoke immediate cellular effects, metabolically active conidia, fungal cellular extracts (CE) and fungal culture filtrates (CF) prepared from swollen conidia caused a Ca2+-independent exocytosis. Ca2+ signals of greatly varying delays, durations and amplitudes were observed by applying CE or CF obtained from hyphae of A. fumigatus, suggesting compounds secreted by filamentous A. fumigatus that severely interfere with AT II cell Ca2+ homeostasis. The mechanisms underlying the stimulatory effects, with respect to exocytosis and Ca2+ signaling, are unclear and need to be identified.
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Affiliation(s)
| | - Susanne Perkhofer
- FH Gesundheit, Health University of Applied Sciences Tyrol, Innrain 98, A-6020 Innsbruck, Austria
| | - Lea Heinrich
- FH Gesundheit, Health University of Applied Sciences Tyrol, Innrain 98, A-6020 Innsbruck, Austria.,Department of Physiology and Medical Physics, Institute of Physiology, Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck, Austria
| | - Thomas Haller
- Department of Physiology and Medical Physics, Institute of Physiology, Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck, Austria
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Strickland AB, Shi M. Mechanisms of fungal dissemination. Cell Mol Life Sci 2021; 78:3219-3238. [PMID: 33449153 PMCID: PMC8044058 DOI: 10.1007/s00018-020-03736-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/23/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022]
Abstract
Fungal infections are an increasing threat to global public health. There are more than six million fungal species worldwide, but less than 1% are known to infect humans. Most of these fungal infections are superficial, affecting the hair, skin and nails, but some species are capable of causing life-threatening diseases. The most common of these include Cryptococcus neoformans, Aspergillus fumigatus and Candida albicans. These fungi are typically innocuous and even constitute a part of the human microbiome, but if these pathogens disseminate throughout the body, they can cause fatal infections which account for more than one million deaths worldwide each year. Thus, systemic dissemination of fungi is a critical step in the development of these deadly infections. In this review, we discuss our current understanding of how fungi disseminate from the initial infection sites to the bloodstream, how immune cells eliminate fungi from circulation and how fungi leave the blood and enter distant organs, highlighting some recent advances and offering some perspectives on future directions.
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Affiliation(s)
- Ashley B Strickland
- Division of Immunology, Virginia-Maryland College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA.
| | - Meiqing Shi
- Division of Immunology, Virginia-Maryland College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA.
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Workman AD, Cohen NA. The effect of drugs and other compounds on the ciliary beat frequency of human respiratory epithelium. Am J Rhinol Allergy 2015; 28:454-64. [PMID: 25514481 DOI: 10.2500/ajra.2014.28.4092] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Cilia in the human respiratory tract play a critical role in clearing mucus and debris from the airways. Their function can be affected by a number of drugs or other substances, many of which alter ciliary beat frequency (CBF). This has implications for diseases of the respiratory tract and nasal drug delivery. This article is a systematic review of the literature that examines 229 substances and their effect on CBF. METHODS MEDLINE was the primary database used for data collection. Eligibility criteria based on experimental design were established, and 152 studies were ultimately selected. Each individual trial for the substances tested was noted whenever possible, including concentration, time course, specific effect on CBF, and source of tissue. RESULTS There was a high degree of heterogeneity between the various experiments examined in this article. Substances and their general effects (increase, no effect, decrease) were grouped into six categories: antimicrobials and antivirals, pharmacologics, human biological products, organisms and toxins, drug excipients, and natural compounds/other manipulations. CONCLUSION Organisms, toxins, and drug excipients tend to show a cilioinhibitory effect, whereas substances in all other categories had mixed effects. All studies examined were in vitro experiments, and application of the results in vivo is confounded by several factors. The data presented in this article should be useful in future respiratory research and examination of compounds for therapeutic and drug delivery purposes.
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Affiliation(s)
- Alan D Workman
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Green BJ, Tovey ER, Beezhold DH, Perzanowski MS, Acosta LM, Divjan AI, Chew GL. Surveillance of Fungal Allergic Sensitization Using the Fluorescent Halogen Immunoassay. J Mycol Med 2009; 19:253-261. [PMID: 20495612 PMCID: PMC2872482 DOI: 10.1016/j.mycmed.2009.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVE: Conidia derived from a small number of common fungal genera are widely accepted as the etiological agents responsible for fungal allergic sensitization. The contribution of fungal conidia, spores, airborne hyphae, and subcellular fragments from other uncharacterized fungal genera remains unclear. In this proof-of-concept study, we examined the composition of mycoaerosols that atopic women were exposed and sensitized to in their own indoor environment using the fluorescent halogen immunoassay (fHIA). PATIENTS AND METHODS: Mycoaerosols were collected onto mixed cellulose ester protein binding membranes (PBMs) for 30 minutes with volumetric air sampling pumps. The PBMs were laminated with an adhesive cover slip and indirectly immunostained with individual patient serum IgE using the fHIA. Samples were examined using confocal laser scanning microscopy and immunostained particles were expressed as a percentage of total particles. RESULTS: All air samples contained a broad spectrum of fungal spores, conidia, hyphae, and other fungal particulates. Airborne concentrations varied between individual study participant environments. Positively immunostained conidia belonging to moniliaceous amerospores, Cladosporium, Alternaria, and many unknown species were observed in the majority of air samples. Other fungal genera including Bipolaris, Curvularia, Pithomyces, and Stachybotrys, in addition to, ascospore genera and dematiaceous hyphal fragments released detectable allergen. Twelve percent of all fHIA haloes quantified in the analysis were directed towards fungal particles. No immunostaining was detected to conidia belonging to Epicoccum, Fusarium, and Spegazzinia species. CONCLUSION: In addition to characterized fungal aeroallergens, we observed a wider composition of fungi that bound human IgE. Field surveillance studies that utilize immunodiagnostic techniques such as the fHIA will provide further insight into the diversity of fungi that function as aeroallergen sources in individual study participant environments.
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Affiliation(s)
- Brett J. Green
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, U.S.A
| | - Euan R. Tovey
- Woolcock Institute of Medical Research, Sydney, NSW, Australia
| | - Donald H. Beezhold
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, U.S.A
| | | | - Luis M. Acosta
- Mailman School of Public Health, Columbia University, New York, NY, U.S.A
| | - Adnan I. Divjan
- Mailman School of Public Health, Columbia University, New York, NY, U.S.A
| | - Ginger L. Chew
- Mailman School of Public Health, Columbia University, New York, NY, U.S.A
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Pathogenesis of Aspergillus fumigatus in Invasive Aspergillosis. Clin Microbiol Rev 2009; 22:447-65. [PMID: 19597008 DOI: 10.1128/cmr.00055-08] [Citation(s) in RCA: 652] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Aspergillus species are globally ubiquitous saprophytes found in a variety of ecological niches. Almost 200 species of aspergilli have been identified, less than 20 of which are known to cause human disease. Among them, Aspergillus fumigatus is the most prevalent and is largely responsible for the increased incidence of invasive aspergillosis (IA) in the immunocompromised patient population. IA is a devastating illness, with mortality rates in some patient groups reaching as high as 90%. Studies identifying and assessing the roles of specific factors of A. fumigatus that contribute to the pathogenesis of IA have traditionally focused on single-gene deletion and mutant characterization. In combination with recent large-scale approaches analyzing global fungal responses to distinct environmental or host conditions, these studies have identified many factors that contribute to the overall pathogenic potential of A. fumigatus. Here, we provide an overview of the significant findings regarding A. fumigatus pathogenesis as it pertains to invasive disease.
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Green BJ, Mitakakis TZ, Tovey ER. Allergen detection from 11 fungal species before and after germination. J Allergy Clin Immunol 2003; 111:285-9. [PMID: 12589346 DOI: 10.1067/mai.2003.57] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Allergens dispersed by airborne fungal spores play an important but poorly understood role in the underlying cause and exacerbation of asthma. Previous studies suggest that spores of Alternaria and Aspergillus release greater quantities of allergen after germination than before germination. It is unknown whether this is true of other allergenic fungi. OBJECTIVE Our purpose was to investigate the release of allergen from a range of individual fungal spores before and after germination. METHODS Allergen expression from spores of Alternaria alternata, Cladosporium herbarum, Aspergillus fumigatus, Botrytis cinerea, Epicoccum nigrum, Exserohilum rostratum, Penicillium chrysogenum, Stemphylium botryosum, Curvularia lunata, Trichoderma viride, and Bipolaris spicifera was examined by halogen immunoassays through the use of pooled serum IgE from patients allergic to fungus. Spores were deposited onto protein-binding membranes direct from culture. To germinate spores, samples were incubated in high humidity at room temperature for 48 hours. Ungerminated and germinated samples were then laminated with an adhesive film and immunostained by the halogen assay. The samples were examined by light microscopy, and positive counts (haloed particles) were expressed as percentages of total spores. RESULTS For 9 of 11 species, between 5.7% and 92% of spores released allergen before germination. Spores of Penicillium and Trichoderma did not release detectable allergen. After germination, all spores that germinated had allergen elution from their hyphae. Eight of 11 species showed a significant increase (P <.05) in the percentage of spores eluting detectable allergen. Localization of allergen along the hyphae varied with species, such that some eluted allergen mainly from hyphal tips and septal junctions whereas others eluted allergen along the entire length. CONCLUSIONS Increased elution of allergen after germination might be a common feature of many species of allergenic fungi. Although allergens from both spores and hyphae were recognized by human IgE, the extent to which human exposure occurs to allergens eluted from inhaled spores or from hyphae that germinate after deposition in the respiratory tract remains to be explored. The patterns of allergen expression might affect the clinical response to such exposure.
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Affiliation(s)
- Brett James Green
- Faculty of Medicine, Woolcock Allergen Unit, Room 461, Blackburn Building D06, University of Sydney, NSW, Australia 2006
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Abstract
Aspergillus fumigatus is one of the most ubiquitous of the airborne saprophytic fungi. Humans and animals constantly inhale numerous conidia of this fungus. The conidia are normally eliminated in the immunocompetent host by innate immune mechanisms, and aspergilloma and allergic bronchopulmonary aspergillosis, uncommon clinical syndromes, are the only infections observed in such hosts. Thus, A. fumigatus was considered for years to be a weak pathogen. With increases in the number of immunosuppressed patients, however, there has been a dramatic increase in severe and usually fatal invasive aspergillosis, now the most common mold infection worldwide. In this review, the focus is on the biology of A. fumigatus and the diseases it causes. Included are discussions of (i) genomic and molecular characterization of the organism, (ii) clinical and laboratory methods available for the diagnosis of aspergillosis in immunocompetent and immunocompromised hosts, (iii) identification of host and fungal factors that play a role in the establishment of the fungus in vivo, and (iv) problems associated with antifungal therapy.
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Affiliation(s)
- J P Latgé
- Laboratoire des Aspergillus, Institut Pasteur, 75015 Paris, France.
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