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Dabholkar A, Pandit S, Devkota R, Dhingra S, Lorber S, Puel O, Calvo AM. Role of the osaA Gene in Aspergillus fumigatus Development, Secondary Metabolism and Virulence. J Fungi (Basel) 2024; 10:103. [PMID: 38392775 PMCID: PMC10890407 DOI: 10.3390/jof10020103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/24/2024] Open
Abstract
Aspergillus fumigatus is the leading cause of aspergillosis, associated with high mortality rates, particularly in immunocompromised individuals. In search of novel genetic targets against aspergillosis, we studied the WOPR transcription factor OsaA. The deletion of the osaA gene resulted in colony growth reduction. Conidiation is also influenced by osaA; both osaA deletion and overexpression resulted in a decrease in spore production. Wild-type expression levels of osaA are necessary for the expression of the conidiation regulatory genes brlA, abaA, and wetA. In addition, osaA is necessary for normal cell wall integrity. Furthermore, the deletion of osaA resulted in a reduction in the ability of A. fumigatus to adhere to surfaces, decreased thermotolerance, as well as increased sensitivity to oxidative stress. Metabolomics analysis indicated that osaA deletion or overexpression led to alterations in the production of multiple secondary metabolites, including gliotoxin. This was accompanied by changes in the expression of genes in the corresponding secondary metabolite gene clusters. These effects could be, at least in part, due to the observed reduction in the expression levels of the veA and laeA global regulators when the osaA locus was altered. Importantly, our study shows that osaA is indispensable for virulence in both neutropenic and corticosteroid-immunosuppressed mouse models.
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Affiliation(s)
- Apoorva Dabholkar
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA
| | - Sandesh Pandit
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA
| | - Ritu Devkota
- Department of Biological Sciences and Eukaryotic Pathogen Innovation Center, Clemson University, Clemson, SC 29634, USA
| | - Sourabh Dhingra
- Department of Biological Sciences and Eukaryotic Pathogen Innovation Center, Clemson University, Clemson, SC 29634, USA
| | - Sophie Lorber
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France
| | - Ana M Calvo
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA
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Prasad SK, Bhat SS, Koskowska O, Sangta J, Ahmad SF, Nadeem A, Sommano SR. Naringin from Coffee Inhibits Foodborne Aspergillus fumigatus via the NDK Pathway: Evidence from an In Silico Study. Molecules 2023; 28:5189. [PMID: 37446851 DOI: 10.3390/molecules28135189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
In the tropics, coffee has been one of the most extensively cultivated economic crops, especially Arabica coffee (Coffea arabica L.). The coffee pulp, which includes phytochemicals with a proven antifungal action, is one of the most insufficiently utilized and neglected byproducts of coffee refining. In the current experiment, we carried out in silico screening of the isolated Arabica coffee phytochemicals for antifungal activity against Aspergillus fumigatus: a foodborne fungus of great public health importance. As determined by the molecular docking interactions of the library compounds indicated, the best interactions were found to occur between the nucleoside-diphosphate kinase protein 6XP7 and the test molecules Naringin (-6.771 kcal/mol), followed by Epigallocatechin gallate (-5.687 kcal/mol). Therefore, Naringin was opted for further validation with molecular dynamic simulations. The ligand-protein complex RMSD indicated a fairly stable Naringin-NDK ligand-protein complex throughout the simulation period (2-16 Å). In ADME and gastrointestinal absorbability testing, Naringin was observed to be orally bioavailable, with very low intestinal absorption and a bioavailability score of 0.17. This was further supported by the boiled egg analysis data, which clearly indicated that the GI absorption of the Naringin molecule was obscure. We found that naringin could be harmful only when swallowed at a median lethal dose between 2000 and 5000 mg/kg. In accordance with these findings, the toxicity prediction reports suggested that Naringin, found especially in citrus fruits and tomatoes, is safe for human consumption after further investigation. Overall, Naringin may be an ideal candidate for developing anti-A. fumigatus treatments and food packaging materials. Thus, this study addresses the simultaneous problems of discarded coffee waste management and antifungal resistance to available medications.
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Affiliation(s)
- Shashanka K Prasad
- Department of Biotechnology and Bioinformatics, JSS Academy of Higher Education and Research, Mysuru 570 015, India
- Plant Bioactive Compound Laboratory, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50100, Thailand
| | - Smitha S Bhat
- Department of Biotechnology and Bioinformatics, JSS Academy of Higher Education and Research, Mysuru 570 015, India
| | - Olga Koskowska
- Department of Vegetable and Medicinal Plants, Institute of Horticulture Sciences, Warsaw University of Life Sciences-SGGW, 16602-787 Warsaw, Poland
| | - Jiraporn Sangta
- Plant Bioactive Compound Laboratory, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50100, Thailand
- Interdisciplinary Program in Biotechnology, Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Sheikh F Ahmad
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Ahmed Nadeem
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Sarana Rose Sommano
- Plant Bioactive Compound Laboratory, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50100, Thailand
- Department of Plant and Soil Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand
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3
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Seo H, Kang S, Lee D, Yun CW. Regulation of pseurotin A biosynthesis by GliZ and zinc in Aspergillus fumigatus. Sci Rep 2023; 13:2431. [PMID: 36765124 PMCID: PMC9918513 DOI: 10.1038/s41598-023-29753-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/09/2023] [Indexed: 02/12/2023] Open
Abstract
Recently, we reported that zinc regulates gliotoxin biosynthesis via ZafA, which is a zinc-responsive transcriptional activator. From an HPLC analysis of culture media of Aspergillus fumigatus, we found a trend of decreasing gliotoxin production but increasing pseurotin A and fumagillin production in proportion to the zinc concentration. The expression of the genes involved in pseurotin A biosynthesis was upregulated under high zinc concentrations. Furthermore, upregulated expression of pseurotin A biosynthetic genes and higher production of pseurotin A were observed in the zafA deletion strain. Interestingly, the deletion of gliZ, a transcriptional activator of gliotoxin biosynthesis genes, resulted in upregulated expression of pseurotin A biosynthetic genes and increased production of pseurotin A. We detected upregulation of fumR expression in the gliZ and zafA deletion mutants. The overexpression of gliZ observed in the zafA deletion mutant resulted in the failure of the mutant to increase pseurotin A production, which is a phenotype of the zafA deletion mutant. These results suggest that ZafA sequentially regulates pseurotin A biosynthesis through GliZ. Finally, we found through a murine virulence test that the gliZ and fumR double-deletion mutants showed a delayed death rate compared with the single-deletion mutants of either gliZ or fumR. Taken together, these results suggested that the biosynthesis of gliotoxin and pseurotin A are regulated in opposite ways by zinc utilization and that each secondary metabolite is synthesized when the synthesis of another secondary metabolite fails to protect it against the defense system of the host.
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Affiliation(s)
- Hyewon Seo
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea
| | - Suzie Kang
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea
| | - Dongho Lee
- Department of Plant Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Cheol-Won Yun
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
- NeuroEsgel Co., Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
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Woodring T, Deepe GS, Levitz SM, Wuethrich M, Klein BS. They shall not grow mold: Soldiers of innate and adaptive immunity to fungi. Semin Immunol 2023; 65:101673. [PMID: 36459927 PMCID: PMC10311222 DOI: 10.1016/j.smim.2022.101673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Indexed: 11/30/2022]
Abstract
Fungi are ubiquitous commensals, seasoned predators, and important agents of emerging infectious diseases [1 ]. The immune system assumes the essential responsibility for responding intelligently to the presence of known and novel fungi to maintain host health. In this Review, we describe the immune responses to pathogenic fungi and the varied array of fungal agents confronting the vertebrate host within the broader context of fungal and animal evolution. We provide an overview of the mechanistic details of innate and adaptive antifungal immune responses, as well as ways in which these basic mechanisms support the development of vaccines and immunotherapies.
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Affiliation(s)
- Therese Woodring
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA
| | - George S Deepe
- Department of Medicine, Division of Infectious Diseases, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Stuart M Levitz
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Marcel Wuethrich
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA
| | - Bruce S Klein
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA; Departments of Internal Medicine, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA; Departments of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA.
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Alonso VA, Velasco Manini MA, Pena GA, Cavaglieri LR. Fist report on fumagillin production by Aspergillus fumigatus sensu stricto gliotoxigenic strains recovered from raw cow milk and clinical samples in Argentina. Rev Argent Microbiol 2022; 54:243-246. [PMID: 35654655 DOI: 10.1016/j.ram.2022.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 12/07/2021] [Accepted: 03/04/2022] [Indexed: 10/18/2022] Open
Abstract
In Argentina there are no reports on Aspergillus fumigatus fumagillin-producing strains. In this study we describe the isolation and mycotoxin production capacity of ten A. fumigatus strains isolated from farm and clinical samples. Farm strains were isolated from milk samples taken from dairy cows in Córdoba province, some of which were associated with subclinical mastitis. A culture medium was defined to optimize fumagillin production and a detection method was developed by HPLC chromatography. It is known that in addition to the host immune status, strain virulence is a fundamental characteristic that will determine its pathogenicity and, in this sense, fumagillin is considered to be among the virulence factors. In the present work, all the strains tested for the production of fumagillin were able to synthesize it, highlighting that the strain A. fumigatus RC2243, from a milk sample from a cow with clinical mastitis, was the most productive. The existence of fumagillin-producing strains represents a potential risk of mycotoxins being transferred to raw milk, constituting a public health risk.
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Affiliation(s)
- Verónica A Alonso
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina; Member of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | | | - Gabriela A Pena
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina; Member of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Lilia R Cavaglieri
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina; Member of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Curtis A, Binder U, Kavanagh K. Galleria mellonella Larvae as a Model for Investigating Fungal-Host Interactions. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:893494. [PMID: 37746216 PMCID: PMC10512315 DOI: 10.3389/ffunb.2022.893494] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/01/2022] [Indexed: 09/26/2023]
Abstract
Galleria mellonella larvae have become a widely accepted and utilised infection model due to the functional homology displayed between their immune response to infection and that observed in the mammalian innate immune response. Due to these similarities, comparable results to murine studies can be obtained using G. mellonella larvae in assessing the virulence of fungal pathogens and the in vivo toxicity or efficacy of anti-fungal agents. This coupled with their low cost, rapid generation of results, and lack of ethical/legal considerations make this model very attractive for analysis of host-pathogen interactions. The larvae of G. mellonella have successfully been utilised to analyse various fungal virulence factors including toxin and enzyme production in vivo providing in depth analysis of the processes involved in the establishment and progression of fungal pathogens (e.g., Candida spps, Aspergillus spp., Madurella mycetomatis, Mucormycetes, and Cryptococcus neoformans). A variety of experimental endpoints can be employed including analysis of fungal burdens, alterations in haemocyte density or sub-populations, melanisation, and characterisation of infection progression using proteomic, histological or imaging techniques. Proteomic analysis can provide insights into both sides of the host-pathogen interaction with each respective proteome being analysed independently following infection and extraction of haemolymph from the larvae. G. mellonella can also be employed for assessing the efficacy and toxicity of antifungal strategies at concentrations comparable to those used in mammals allowing for early stage investigation of novel compounds and combinations of established therapeutic agents. These numerous applications validate the model for examination of fungal infection and development of therapeutic approaches in vivo in compliance with the need to reduce animal models in biological research.
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Affiliation(s)
- Aaron Curtis
- Department of Biology, Maynooth University, Maynooth, Ireland
| | - Ulrike Binder
- Institute of Hygiene and Medical Microbiology, Medical University Innsbruck, Innsbruck, Austria
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Maynooth, Ireland
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Kortei NK, Tetteh RA, Wiafe-Kwagyan M, Amon DNK, Odamtten GT. Mycobiota profile, phenology, and potential toxicogenic and pathogenic species associated with stored groundnuts ( Arachis hypogaea L.) from the Volta Region, Ghana. Food Sci Nutr 2022; 10:888-902. [PMID: 35311164 PMCID: PMC8907750 DOI: 10.1002/fsn3.2719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 11/02/2021] [Accepted: 12/13/2021] [Indexed: 11/12/2022] Open
Abstract
This study updates the mycobiota resident in groundnut seeds, their phenology during storage with the view to ascertain their occurrence, potential toxigenic species, and pathologically important species in the stored samples. The moisture content of the seeds ranged from 5.7% to 6.5% within the stipulated safe moisture content of 8% for extension of shelf life. Culturing the seeds on mycological media (Sabouraud's Dextrose Agar SDA; Oxytetracycline Glucose Yeast Extract OGYE, Potato Dextrose Agar, PDA) caused a de novo growth of the quiescent spores at 28-30°C for 7-14 days. Fungal population counts on the three media ranged from 2.01 to 2.16 log10 CFU/g samples to a final 6-month count of 1.67-2.60 log10 CFU/g. Eighteen different fungal species belonging to ten genera were encountered on the media, namely Aspergillus, Cladosporium, Curvularia, Fusarium, Penicillium, Trichoderma, Rhizopus, Rhodotorula, Sporendonema, and Paecilomyces. Aspergillus spp. (A. niger, A. flavus, A. fumigatus, and A. terreus) were the most frequently isolated, followed by Fusarium species (F. oxysporum, F. solani, and F. verticillioides), Trichoderma (T. harzianum and T. viride), Rhizopus spp (R. oligosporus and R. stolonifer), and Penicillium verrucosum. The species which were seed borne (A. niger, A. flavus, A. terreus, A. fumigatus, F. solani, F. verticillioides, T. viride, C. herbarum, and Curvularia lunata) were isolated on both surface sterilized and non-surface sterilized seeds. The phenology of the encountered fungal species generally followed five patterns. The most frequently isolated Aspergillus niger, A. flavus, and A. fumigatus predominated throughout the 6 months sampling period, while A. ustus and A. terreus appeared sporadically and disappeared. The early colonizers (R. oligosporus, R. stolonifer, and Paecilomyces) could not be isolated after 2-3 months owing presumably to stronger antibiosis competition from the Aspergillus species. The most predominant Aspergillus species initially constituted 36%-48% of the total population but declined to 10%-36% in 6 months. Mycobiota encountered with mycotoxigenic potential and human health importance were A. niger, A. flavus, A. fumigatus, F. verticillioides, and Penicillium verrucosum. Other species of pathological importance to plants were Curvularia lunata and Fusarium oxysporum. The practical implications of these findings are discussed.
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Affiliation(s)
- Nii Korley Kortei
- Department of Nutrition and Dietetics School of Allied Health Sciences University of Health and Allied Sciences Ho Ghana
| | - Rachel Adinorkie Tetteh
- Department of Nutrition and Dietetics School of Allied Health Sciences University of Health and Allied Sciences Ho Ghana
| | - Michael Wiafe-Kwagyan
- Department of Plant and Environmental Biology College of Basic and Applied Sciences University of Ghana Legon Ghana
| | - Denick Nii Kotey Amon
- Department of Plant and Environmental Biology College of Basic and Applied Sciences University of Ghana Legon Ghana
| | - George Tawia Odamtten
- Department of Plant and Environmental Biology College of Basic and Applied Sciences University of Ghana Legon Ghana
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Margalit A, Sheehan D, Carolan JC, Kavanagh K. Exposure to the Pseudomonas aeruginosa secretome alters the proteome and secondary metabolite production of Aspergillus fumigatus. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001164. [PMID: 35333152 PMCID: PMC9558348 DOI: 10.1099/mic.0.001164] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/16/2022] [Indexed: 01/09/2023]
Abstract
The fungal pathogen Aspergillus fumigatus is frequently cultured from the sputum of cystic fibrosis (CF) patients along with the bacterium Pseudomonas aeruginosa. A. fumigatus secretes a range of secondary metabolites, and one of these, gliotoxin, has inhibitory effects on the host immune response. The effect of P. aeruginosa culture filtrate (CuF) on fungal growth and gliotoxin production was investigated. Exposure of A. fumigatus hyphae to P. aeruginosa cells induced increased production of gliotoxin and a decrease in fungal growth. In contrast, exposure of A. fumigatus hyphae to P. aeruginosa CuF led to increased growth and decreased gliotoxin production. Quantitative proteomic analysis was used to characterize the proteomic response of A. fumigatus upon exposure to P. aeruginosa CuF. Changes in the profile of proteins involved in secondary metabolite biosynthesis (e.g. gliotoxin, fumagillin, pseurotin A), and changes to the abundance of proteins involved in oxidative stress (e.g. formate dehydrogenase) and detoxification (e.g. thioredoxin reductase) were observed, indicating that the bacterial secretome had a profound effect on the fungal proteome. Alterations in the abundance of proteins involved in detoxification and oxidative stress highlight the ability of A. fumigatus to differentially regulate protein synthesis in response to environmental stresses imposed by competitors such as P. aeruginosa. Such responses may ultimately have serious detrimental effects on the host.
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Affiliation(s)
- Anatte Margalit
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - David Sheehan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - James C. Carolan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Co. Kildare, Ireland
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Fungi—A Component of the Oral Microbiome Involved in Periodontal Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1373:113-138. [DOI: 10.1007/978-3-030-96881-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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10
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Lim JY, Kim YJ, Woo SA, Jeong JW, Lee YR, Kim CH, Park HM. The LAMMER Kinase, LkhA, Affects Aspergillus fumigatus Pathogenicity by Modulating Reproduction and Biosynthesis of Cell Wall PAMPs. Front Cell Infect Microbiol 2021; 11:756206. [PMID: 34722342 PMCID: PMC8548842 DOI: 10.3389/fcimb.2021.756206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/27/2021] [Indexed: 02/01/2023] Open
Abstract
The LAMMER kinase in eukaryotes is a well-conserved dual-specificity kinase. Aspergillus species cause a wide spectrum of diseases called aspergillosis in humans, depending on the underlying immune status of the host, such as allergy, aspergilloma, and invasive aspergillosis. Aspergillus fumigatus is the most common opportunistic fungal pathogen that causes invasive aspergillosis. Although LAMMER kinase has various functions in morphology, development, and cell cycle regulation in yeast and filamentous fungi, its function in A. fumigatus is not known. We performed molecular studies on the function of the A. fumigatus LAMMER kinase, AfLkhA, and reported its involvement in multiple cellular processes, including development and virulence. Deletion of AflkhA resulted in defects in colonial growth, production of conidia, and sexual development. Transcription and genetic analyses indicated that AfLkhA modulates the expression of key developmental regulatory genes. The AflkhA-deletion strain showed increased production of gliotoxins and protease activity. When conidia were challenged with alveolar macrophages, enodocytosis of conidia by macrophages was increased in the AflkhA-deletion strain, resulting from changes in expression of the cell wall genes and thus content of cell wall pathogen-associated molecular patterns, including β-1,3-glucan and GM. While T cell-deficient zebrafish larvae were significantly susceptible to wild-type A. fumigatus infection, AflkhA-deletion conidia infection reduced host mortality. A. fumigatus AfLkhA is required for the establishment of virulence factors, including conidial production, mycotoxin synthesis, protease activity, and interaction with macrophages, which ultimately affect pathogenicity at the organismal level.
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Affiliation(s)
- Joo-Yeon Lim
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea.,Institute of Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Yeon Ju Kim
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Seul Ah Woo
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Jae Wan Jeong
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Yu-Ri Lee
- Laboratory of Developmental Genetics, Department of Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Cheol-Hee Kim
- Laboratory of Developmental Genetics, Department of Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea
| | - Hee-Moon Park
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, South Korea
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Steenwyk JL, Mead ME, de Castro PA, Valero C, Damasio A, dos Santos RAC, Labella AL, Li Y, Knowles SL, Raja HA, Oberlies NH, Zhou X, Cornely OA, Fuchs F, Koehler P, Goldman GH, Rokas A. Genomic and Phenotypic Analysis of COVID-19-Associated Pulmonary Aspergillosis Isolates of Aspergillus fumigatus. Microbiol Spectr 2021; 9:e0001021. [PMID: 34106569 PMCID: PMC8552514 DOI: 10.1128/spectrum.00010-21] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
The ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19), first described in Wuhan, China. A subset of COVID-19 patients has been reported to have acquired secondary infections by microbial pathogens, such as opportunistic fungal pathogens from the genus Aspergillus. To gain insight into COVID-19-associated pulmonary aspergillosis (CAPA), we analyzed the genomes and characterized the phenotypic profiles of four CAPA isolates of Aspergillus fumigatus obtained from patients treated in the area of North Rhine-Westphalia, Germany. By examining the mutational spectrum of single nucleotide polymorphisms, insertion-deletion polymorphisms, and copy number variants among 206 genes known to modulate A. fumigatus virulence, we found that CAPA isolate genomes do not exhibit significant differences from the genome of the Af293 reference strain. By examining a number of factors, including virulence in an invertebrate moth model, growth in the presence of osmotic, cell wall, and oxidative stressors, secondary metabolite biosynthesis, and the MIC of antifungal drugs, we found that CAPA isolates were generally, but not always, similar to A. fumigatus reference strains Af293 and CEA17. Notably, CAPA isolate D had more putative loss-of-function mutations in genes known to increase virulence when deleted. Moreover, CAPA isolate D was significantly more virulent than the other three CAPA isolates and the A. fumigatus reference strains Af293 and CEA17, but similarly virulent to two other clinical strains of A. fumigatus. These findings expand our understanding of the genomic and phenotypic characteristics of isolates that cause CAPA. IMPORTANCE The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), has already killed millions of people. COVID-19 patient outcome can be further complicated by secondary infections, such as COVID-19-associated pulmonary aspergillosis (CAPA). CAPA is caused by Aspergillus fungal pathogens, but there is little information about the genomic and phenotypic characteristics of CAPA isolates. We conducted genome sequencing and extensive phenotyping of four CAPA isolates of Aspergillus fumigatus from Germany. We found that CAPA isolates were often, but not always, similar to other reference strains of A. fumigatus across 206 genetic determinants of infection-relevant phenotypes, including virulence. For example, CAPA isolate D was more virulent than other CAPA isolates and reference strains in an invertebrate model of fungal disease, but similarly virulent to two other clinical strains. These results expand our understanding of COVID-19-associated pulmonary aspergillosis.
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Affiliation(s)
- Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew E. Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), Campinas-SP, Brazil
- Experimental Medicine Research Cluster (EMRC), University of Campinas (UNICAMP), Campinas-SP, Brazil
| | - Renato A. C. dos Santos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Abigail L. Labella
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Yuanning Li
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Xiaofan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Oliver A. Cornely
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- ZKS Köln, Clinical Trials Centre Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn‐Cologne, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Frieder Fuchs
- Faculty of Medicine, Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany
| | - Philipp Koehler
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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12
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Boysen JM, Saeed N, Hillmann F. Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus. Beilstein J Org Chem 2021; 17:1814-1827. [PMID: 34394757 PMCID: PMC8336654 DOI: 10.3762/bjoc.17.124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/14/2021] [Indexed: 11/30/2022] Open
Abstract
The kingdom of fungi comprises a large and highly diverse group of organisms that thrive in diverse natural environments. One factor to successfully confront challenges in their natural habitats is the capability to synthesize defensive secondary metabolites. The genetic potential for the production of secondary metabolites in fungi is high and numerous potential secondary metabolite gene clusters have been identified in sequenced fungal genomes. Their production may well be regulated by specific ecological conditions, such as the presence of microbial competitors, symbionts or predators. Here we exemplarily summarize our current knowledge on identified secondary metabolites of the pathogenic fungus Aspergillus fumigatus and their defensive function against (microbial) predators.
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Affiliation(s)
- Jana M Boysen
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Nauman Saeed
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Falk Hillmann
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
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13
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Liu H, Xu W, Bruno VM, Phan QT, Solis NV, Woolford CA, Ehrlich RL, Shetty AC, McCraken C, Lin J, Bromley MJ, Mitchell AP, Filler SG. Determining Aspergillus fumigatus transcription factor expression and function during invasion of the mammalian lung. PLoS Pathog 2021; 17:e1009235. [PMID: 33780518 PMCID: PMC8031882 DOI: 10.1371/journal.ppat.1009235] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/08/2021] [Accepted: 03/20/2021] [Indexed: 12/14/2022] Open
Abstract
To gain a better understanding of the transcriptional response of Aspergillus fumigatus during invasive pulmonary infection, we used a NanoString nCounter to assess the transcript levels of 467 A. fumigatus genes during growth in the lungs of immunosuppressed mice. These genes included ones known to respond to diverse environmental conditions and those encoding most transcription factors in the A. fumigatus genome. We found that invasive growth in vivo induces a unique transcriptional profile as the organism responds to nutrient limitation and attack by host phagocytes. This in vivo transcriptional response is largely mimicked by in vitro growth in Aspergillus minimal medium that is deficient in nitrogen, iron, and/or zinc. From the transcriptional profiling data, we selected 9 transcription factor genes that were either highly expressed or strongly up-regulated during in vivo growth. Deletion mutants were constructed for each of these genes and assessed for virulence in mice. Two transcription factor genes were found to be required for maximal virulence. One was rlmA, which is required for the organism to achieve maximal fungal burden in the lung. The other was sltA, which regulates of the expression of multiple secondary metabolite gene clusters and mycotoxin genes independently of laeA. Using deletion and overexpression mutants, we determined that the attenuated virulence of the ΔsltA mutant is due in part to decreased expression aspf1, which specifies a ribotoxin, but is not mediated by reduced expression of the fumigaclavine gene cluster or the fumagillin-pseruotin supercluster. Thus, in vivo transcriptional profiling focused on transcription factors genes provides a facile approach to identifying novel virulence regulators. Although A. fumigatus causes the majority of cases of invasive aspergillosis, the function of most genes in its genome remains unknown. To identify genes encoding transcription factors that may be important for virulence, we used a NanoString nCounter to measure the mRNA levels of A. fumigatus transcription factor genes in the lungs of mice with invasive aspergillosis. The transcriptional profiling data indicate that the organism is exposed to nutrient limitation and stress during growth in the lungs, and that it responds by up-regulating genes that encode mycotoxins and secondary metabolites. In vitro, this response was most closely mimicked by growth in medium that was deficient in nitrogen, iron and/or zinc. Using the transcriptional profiling data, we identified two transcription factors that govern A. fumigatus virulence. These were RlmA, which is governs factors that enables the organism to proliferate maximally in the lung and SltA, which controls the production of mycotoxins and secondary metabolites.
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Affiliation(s)
- Hong Liu
- Division of Infectious Diseases, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | - Wenjie Xu
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Vincent M. Bruno
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, United States of America
| | - Quynh T. Phan
- Division of Infectious Diseases, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | - Norma V. Solis
- Division of Infectious Diseases, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | - Carol A. Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Rachel L. Ehrlich
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States of America
| | - Amol C. Shetty
- Institute for Genome Sciences, University of Maryland, Baltimore, MD, United States of America
| | - Carrie McCraken
- Institute for Genome Sciences, University of Maryland, Baltimore, MD, United States of America
| | - Jianfeng Lin
- Division of Infectious Diseases, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, and Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, MA, United Kingdom
| | - Aaron P. Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States of America
- Department of Microbiology, University of Georgia, Athens, GA, United States of America
- * E-mail: (APM); (SGF)
| | - Scott G. Filler
- Division of Infectious Diseases, Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States of America
- David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
- * E-mail: (APM); (SGF)
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14
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F. Q. Smith D, Casadevall A. Fungal immunity and pathogenesis in mammals versus the invertebrate model organism Galleria mellonella. Pathog Dis 2021; 79:ftab013. [PMID: 33544836 PMCID: PMC7981337 DOI: 10.1093/femspd/ftab013] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
In recent decades, Galleria mellonella (Lepidoptera: Pyralidae) have emerged as a model system to explore experimental aspects of fungal pathogenesis. The benefits of the G. mellonella model include being faster, cheaper, higher throughput and easier compared with vertebrate models. Additionally, as invertebrates, their use is subject to fewer ethical and regulatory issues. However, for G. mellonella models to provide meaningful insight into fungal pathogenesis, the G. mellonella-fungal interactions must be comparable to mammalian-fungal interactions. Indeed, as discussed in the review, studies suggest that G. mellonella and mammalian immune systems share many similarities, and fungal virulence factors show conserved functions in both hosts. While the moth model has opened novel research areas, many comparisons are superficial and leave large gaps of knowledge that need to be addressed concerning specific mechanisms underlying G. mellonella-fungal interactions. Closing these gaps in understanding will strengthen G. mellonella as a model for fungal virulence in the upcoming years. In this review, we provide comprehensive comparisons between fungal pathogenesis in mammals and G. mellonella from immunological and virulence perspectives. When information on an antifungal immune component is unknown in G. mellonella, we include findings from other well-studied Lepidoptera. We hope that by outlining this information available in related species, we highlight areas of needed research and provide a framework for understanding G. mellonella immunity and fungal interactions.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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15
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Kitisin T, Ampawong S, Muangkaew W, Sukphopetch P. Phenomic profiling of a novel sibling species within the Scedosporium complex in Thailand. BMC Microbiol 2021; 21:42. [PMID: 33563219 PMCID: PMC7874643 DOI: 10.1186/s12866-021-02105-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
Background Scedosporium species are a group of pathogenic fungi, which can be found worldwide around high human-impacted areas. Infections of Scedosporium have been reported in several immunocompromised and immunocompetent patients with a high mortality rate. Recently, we have isolated and identified several Scedosporium strains during an environmental survey in Thailand. Results We describe the isolate, TMMI-012, possibly a new species isolated from soils in the Chatuchak public park, Bangkok, Thailand. TMMI-012 is phylogenetically related to the Scedosporium genus and is a sibling to S. boydii but shows distinct morphological and pathological characteristics. It is fast growing and highly resistant to antifungal drugs and abiotic stresses. Pathological studies of in vitro and in vivo models confirm its high virulence and pathogenicity. Conclusion TMMI-012 is considered a putative novel Scedosporium species. The high antifungal resistance of TMMI-012 compared with its sibling, Scedosporium species is likely related to its clinical impact on human health.
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Affiliation(s)
- T Kitisin
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - S Ampawong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - W Muangkaew
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - P Sukphopetch
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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16
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Steenwyk JL, Mead ME, de Castro PA, Valero C, Damasio A, dos Santos RAC, Labella AL, Li Y, Knowles SL, Raja HA, Oberlies NH, Zhou X, Cornely OA, Fuchs F, Koehler P, Goldman GH, Rokas A. Genomic and phenotypic analysis of COVID-19-associated pulmonary aspergillosis isolates of Aspergillus fumigatus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.11.06.371971. [PMID: 33173866 PMCID: PMC7654854 DOI: 10.1101/2020.11.06.371971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) first described from Wuhan, China. A subset of COVID-19 patients has been reported to have acquired secondary infections by microbial pathogens, such as fungal opportunistic pathogens from the genus Aspergillus . To gain insight into COVID-19 associated pulmonary aspergillosis (CAPA), we analyzed the genomes and characterized the phenotypic profiles of four CAPA isolates of Aspergillus fumigatus obtained from patients treated in the area of North Rhine-Westphalia, Germany. By examining the mutational spectrum of single nucleotide polymorphisms, insertion-deletion polymorphisms, and copy number variants among 206 genes known to modulate A. fumigatus virulence, we found that CAPA isolate genomes do not exhibit major differences from the genome of the Af293 reference strain. By examining virulence in an invertebrate moth model, growth in the presence of osmotic, cell wall, and oxidative stressors, and the minimum inhibitory concentration of antifungal drugs, we found that CAPA isolates were generally, but not always, similar to A. fumigatus reference strains Af293 and CEA17. Notably, CAPA isolate D had more putative loss of function mutations in genes known to increase virulence when deleted (e.g., in the FLEA gene, which encodes a lectin recognized by macrophages). Moreover, CAPA isolate D was significantly more virulent than the other three CAPA isolates and the A. fumigatus reference strains tested. These findings expand our understanding of the genomic and phenotypic characteristics of isolates that cause CAPA.
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Affiliation(s)
- Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew E. Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), Campinas-SP, Brazil
- Experimental Medicine Research Cluster (EMRC), University of Campinas (UNICAMP), Campinas-SP, Brazil
| | - Renato A. C. dos Santos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Abigail L. Labella
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Yuanning Li
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Xiaofan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Oliver A. Cornely
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- ZKS Köln, Clinical Trials Centre Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn Cologne, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Frieder Fuchs
- Faculty of Medicine, Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany
| | - Philipp Koehler
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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17
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Steenwyk JL, Mead ME, Knowles SL, Raja HA, Roberts CD, Bader O, Houbraken J, Goldman GH, Oberlies NH, Rokas A. Variation Among Biosynthetic Gene Clusters, Secondary Metabolite Profiles, and Cards of Virulence Across Aspergillus Species. Genetics 2020; 216:481-497. [PMID: 32817009 PMCID: PMC7536862 DOI: 10.1534/genetics.120.303549] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/01/2020] [Indexed: 02/07/2023] Open
Abstract
Aspergillus fumigatus is a major human pathogen. In contrast, Aspergillus fischeri and the recently described Aspergillus oerlinghausenensis, the two species most closely related to A. fumigatus, are not known to be pathogenic. Some of the genetic determinants of virulence (or "cards of virulence") that A. fumigatus possesses are secondary metabolites that impair the host immune system, protect from host immune cell attacks, or acquire key nutrients. To examine whether secondary metabolism-associated cards of virulence vary between these species, we conducted extensive genomic and secondary metabolite profiling analyses of multiple A. fumigatus, one A. oerlinghausenensis, and multiple A. fischeri strains. We identified two cards of virulence (gliotoxin and fumitremorgin) shared by all three species and three cards of virulence (trypacidin, pseurotin, and fumagillin) that are variable. For example, we found that all species and strains examined biosynthesized gliotoxin, which is known to contribute to virulence, consistent with the conservation of the gliotoxin biosynthetic gene cluster (BGC) across genomes. For other secondary metabolites, such as fumitremorgin, a modulator of host biology, we found that all species produced the metabolite but that there was strain heterogeneity in its production within species. Finally, species differed in their biosynthesis of fumagillin and pseurotin, both contributors to host tissue damage during invasive aspergillosis. A. fumigatus biosynthesized fumagillin and pseurotin, while A. oerlinghausenensis biosynthesized fumagillin and A. fischeri biosynthesized neither. These biochemical differences were reflected in sequence divergence of the intertwined fumagillin/pseurotin BGCs across genomes. These results delineate the similarities and differences in secondary metabolism-associated cards of virulence between a major fungal pathogen and its nonpathogenic closest relatives, shedding light onto the genetic and phenotypic changes associated with the evolution of fungal pathogenicity.
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Affiliation(s)
- Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
| | - Matthew E Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
| | - Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Christopher D Roberts
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Oliver Bader
- Institute for Medical Microbiology, University Medical Center Göttingen, 37075, Germany
| | - Jos Houbraken
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-900 Brazil
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
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18
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Gayathri L, Akbarsha MA, Ruckmani K. In vitro study on aspects of molecular mechanisms underlying invasive aspergillosis caused by gliotoxin and fumagillin, alone and in combination. Sci Rep 2020; 10:14473. [PMID: 32879392 PMCID: PMC7467938 DOI: 10.1038/s41598-020-71367-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 08/06/2020] [Indexed: 12/19/2022] Open
Abstract
Gliotoxin (GT) and fumagillin (FUM) are mycotoxins most abundantly produced by Aspergillus fumigatus during the early stages of infection to cause invasive aspergillosis (IA). Therefore, we hypothesized that GT and FUM could be the possible source of virulence factors, which we put to test adopting in vitro monoculture and the novel integrated multiple organ co-culture (IdMOC) of A549 and L132 cell. We found that (i) GT is more cytotoxic to lung epithelial cells than FUM, and (ii) GT and FUM act synergistically to inflict pathology to the lung epithelial cell. Reactive oxygen species (ROS) is the master regulator of the cytotoxicity of GT, FUM and GT + FUM. ROS may be produced as a sequel to mitochondrial damage and, thus, mitochondria are both the source of ROS and the target to ROS. GT-, FUM- and GT + FUM-induced DNA damage is mediated either by ROS-dependent mechanism or directly by the fungal toxins. In addition, GT, FUM and GT + FUM may induce protein accumulation. Further, it is speculated that GT and FUM inflict epithelial damage by neutrophil-mediated inflammation. With respect to multiple organ cytotoxicity, GT was found to be cytotoxic at IC50 concentration in the following order: renal epithelial cells < type II epithelial cells < hepatocytes < normal lung epithelial cells. Taken together, GT and FUM alone and in combination contribute to exacerbate the damage of lung epithelial cells and, thus, are involved in the progression of IA.
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Affiliation(s)
- Loganathan Gayathri
- Department of Pharmaceutical Technology, University College of Engineering, Anna University-BIT Campus, Tiruchchirappalli, Tamil Nadu, 620024, India
- Centre for Excellence in Nanobio Translational Research (Autonomous), University College of Engineering, Anna University-BIT Campus, Tiruchchirappalli, Tamil Nadu, 620024, India
- Department of Biotechnology and Bioinformatics, Holy Cross College (Autonomous), Tiruchchirappalli, Tamil Nadu, 620002, India
| | - Mohammad A Akbarsha
- National College (Autonomous), Tiruchchirappalli, Tamil Nadu, 620001, India
- Mahatma Gandhi-Doerenkamp Centre for Alternatives, Bharathidasan University, Tiruchchirappalli, Tamil Nadu, 620 024, India
| | - Kandasamy Ruckmani
- Department of Pharmaceutical Technology, University College of Engineering, Anna University-BIT Campus, Tiruchchirappalli, Tamil Nadu, 620024, India.
- Centre for Excellence in Nanobio Translational Research (Autonomous), University College of Engineering, Anna University-BIT Campus, Tiruchchirappalli, Tamil Nadu, 620024, India.
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19
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Ajdidi A, Sheehan G, Kavanagh K. Exposure of Aspergillus fumigatus to Atorvastatin Leads to Altered Membrane Permeability and Induction of an Oxidative Stress Response. J Fungi (Basel) 2020; 6:jof6020042. [PMID: 32225059 PMCID: PMC7344724 DOI: 10.3390/jof6020042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/18/2020] [Accepted: 03/23/2020] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus is a serious cause of disease in immune-deficient patients and in those with pulmonary malfunction (e.g., cystic fibrosis (CF), asthma). Atorvastatin is a member of the statin drug family, which are the main therapeutic agents used to decrease high serum cholesterol levels by inhibiting (HMG-CoA) reductase enzyme. The aim of the work presented here was to analyse the antifungal activity of atorvastatin and assess its effect on the virulence of A. fumigatus. Atorvastatin demonstrated strong antifungal activity and reduced the growth and viability of A. fumigatus. Exposure of A. fumigatus to atorvastatin led to a reduction in ergosterol content and increased membrane permeability, as evidenced by the release of protein, amino acids and gliotoxin. Proteomic analysis revealed an increased abundance of proteins associated with an oxidative stress response, such as the glutathione s-transferase family protein (+8.43-fold), heat shock protein Hsp30/Hsp42 (+2.02-fold) and 5-demethoxyubiquinone hydroxylase, mitochondrial (+1.73-fold), as well as secondary metabolites such as isocyanide synthase A icsA (+8.52-fold) and non-ribosomal peptide synthetase fmpE (+3.06-fold). The results presented here indicate that atorvastatin has strong antifungal properties and may have potential application in the treatment of A. fumigatus infections alone or in combination with existing antifungal agents.
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20
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Gandra RM, McCarron P, Viganor L, Fernandes MF, Kavanagh K, McCann M, Branquinha MH, Santos ALS, Howe O, Devereux M. In vivo Activity of Copper(II), Manganese(II), and Silver(I) 1,10-Phenanthroline Chelates Against Candida haemulonii Using the Galleria mellonella Model. Front Microbiol 2020; 11:470. [PMID: 32265890 PMCID: PMC7105610 DOI: 10.3389/fmicb.2020.00470] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/04/2020] [Indexed: 12/19/2022] Open
Abstract
Candida haemulonii is an emerging opportunistic pathogen resistant to most antifungal drugs currently used in clinical arena. Metal complexes containing 1,10-phenanthroline (phen) chelating ligands have well-established anti-Candida activity against different medically relevant species. This study utilized larvae of Galleria mellonella, a widely used model of in vivo infection, to examine C. haemulonii infection characteristics in response to different copper(II), manganese(II), and silver(I) chelates containing phen, which had demonstrated potent anti-C. haemulonii activity in a previous study. The results showed that C. haemulonii virulence was influenced by inoculum size and incubation temperature, and the host G. mellonella immune response was triggered in an inoculum-dependent manner reflected by the number of circulating immune cells (hemocytes) and observance of larval melanization process. All test chelates were non-toxic to the host in concentrations up to 10 μg/larva. The complexes also affected the G. mellonella immune system, affecting the hemocyte number and the expression of genes encoding antifungal and immune-related peptides (e.g., inducible metalloproteinase inhibitor protein, transferrin, galiomycin, and gallerimycin). Except for [Ag2(3,6,9-tdda)(phen)4].EtOH (3,6,9-tddaH2 = 3,6,9-trioxoundecanedioic acid), all chelates were capable of affecting the fungal burden of infected larvae and the virulence of C. haemulonii in a dose-dependent manner. This work shows that copper(II), manganese(II), and silver(I) chelates containing phen with anti-C. haemulonii activity are capable of (i) inhibiting fungal proliferation during in vivo infection, (ii) priming an immune response in the G. mellonella host and (iii) affecting C. haemulonii virulence.
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Affiliation(s)
- Rafael M Gandra
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto de Química, Programa de Pós-Graduação em Bioquímica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centre for Biomimetic and Therapeutic Research, Focas Research Institute, Technological University Dublin, Dublin, Ireland
| | - Pauraic McCarron
- Centre for Biomimetic and Therapeutic Research, Focas Research Institute, Technological University Dublin, Dublin, Ireland
| | - Livia Viganor
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centre for Biomimetic and Therapeutic Research, Focas Research Institute, Technological University Dublin, Dublin, Ireland
| | - Mariana Farias Fernandes
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
| | - Malachy McCann
- Department of Chemistry, Maynooth University, National University of Ireland, Maynooth, Ireland
| | - Marta H Branquinha
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - André L S Santos
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto de Química, Programa de Pós-Graduação em Bioquímica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Orla Howe
- Centre for Biomimetic and Therapeutic Research, Focas Research Institute, Technological University Dublin, Dublin, Ireland.,School of Biological & Health Sciences, Technological University Dublin, Dublin, Ireland
| | - Michael Devereux
- Centre for Biomimetic and Therapeutic Research, Focas Research Institute, Technological University Dublin, Dublin, Ireland
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21
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Fungal Infections and ABPA. Respir Med 2020. [DOI: 10.1007/978-3-030-42382-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Guruceaga X, Perez-Cuesta U, Abad-Diaz de Cerio A, Gonzalez O, Alonso RM, Hernando FL, Ramirez-Garcia A, Rementeria A. Fumagillin, a Mycotoxin of Aspergillus fumigatus: Biosynthesis, Biological Activities, Detection, and Applications. Toxins (Basel) 2019; 12:E7. [PMID: 31861936 PMCID: PMC7020470 DOI: 10.3390/toxins12010007] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 12/26/2022] Open
Abstract
Fumagillin is a mycotoxin produced, above all, by the saprophytic filamentous fungus Aspergillus fumigatus. This mold is an opportunistic pathogen that can cause invasive aspergillosis, a disease that has high mortality rates linked to it. Its ability to adapt to environmental stresses through the production of secondary metabolites, including several mycotoxins (gliotoxin, fumagillin, pseurotin A, etc.) also seem to play an important role in causing these infections. Since the discovery of the A. fumigatus fumagillin in 1949, many studies have focused on this toxin and in this review we gather all the information currently available. First of all, the structural characteristics of this mycotoxin and the different methods developed for its determination are given in detail. Then, the biosynthetic gene cluster and the metabolic pathway involved in its production and regulation are explained. The activity of fumagillin on its target, the methionine aminopeptidase type 2 (MetAP2) enzyme, and the effects of blocking this enzyme in the host are also described. Finally, the applications that this toxin and its derivatives have in different fields, such as the treatment of cancer and its microsporicidal activity in the treatment of honeybee hive infections with Nosema spp., are reviewed. Therefore, this work offers a complete review of all the information currently related to the fumagillin mycotoxin secreted by A. fumigatus, important because of its role in the fungal infection process but also because it has many other applications, notably in beekeeping, the treatment of infectious diseases, and in oncology.
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Affiliation(s)
- Xabier Guruceaga
- Fungal and Bacterial Biomics Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (X.G.); (U.P.-C.); (A.A.-D.d.C.); (F.L.H.)
| | - Uxue Perez-Cuesta
- Fungal and Bacterial Biomics Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (X.G.); (U.P.-C.); (A.A.-D.d.C.); (F.L.H.)
| | - Ana Abad-Diaz de Cerio
- Fungal and Bacterial Biomics Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (X.G.); (U.P.-C.); (A.A.-D.d.C.); (F.L.H.)
| | - Oskar Gonzalez
- FARMARTEM Group, Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (O.G.); (R.M.A.)
| | - Rosa M. Alonso
- FARMARTEM Group, Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (O.G.); (R.M.A.)
| | - Fernando Luis Hernando
- Fungal and Bacterial Biomics Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (X.G.); (U.P.-C.); (A.A.-D.d.C.); (F.L.H.)
| | - Andoni Ramirez-Garcia
- Fungal and Bacterial Biomics Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (X.G.); (U.P.-C.); (A.A.-D.d.C.); (F.L.H.)
| | - Aitor Rementeria
- Fungal and Bacterial Biomics Research Group, Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; (X.G.); (U.P.-C.); (A.A.-D.d.C.); (F.L.H.)
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Raffa N, Keller NP. A call to arms: Mustering secondary metabolites for success and survival of an opportunistic pathogen. PLoS Pathog 2019; 15:e1007606. [PMID: 30947302 PMCID: PMC6448812 DOI: 10.1371/journal.ppat.1007606] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Affiliation(s)
- Nicholas Raffa
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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24
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Sheehan G, Nagl M, Kavanagh K. Exposure to N-chlorotaurine induces oxidative stress responses in Aspergillus fumigatus. J Med Microbiol 2018; 68:279-288. [PMID: 30543319 DOI: 10.1099/jmm.0.000900] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PURPOSE The neutrophil-derived oxidant N-chlorotaurine (NCT) displays remarkable in vivo tolerability and efficacy against a range of pathogens. The aim of this study was to characterize the response of the pulmonary pathogen Aspergillus fumigatus to NCT. METHODOLOGY The effect of NCT on the growth and viability of A. fumigatus was characterized. NCT-induced alteration of amino acids and gliotoxin from A. fumigatus mycelium was assessed. Label-free shotgun quantitative proteomic analysis was performed on A. fumigatus exposed to NCT for 24 h. RESULTS Incubation of A. fumigatus with NCT at concentrations ranging from 6.8 to 55 mM decreased conidial growth and viability, and mycelium biomass relative to the controls. Exposure to NCT (13.77 mM) resulted in increased amino acids and gliotoxin levels from A. fumigatus mycelium. Exposure of A. fumigatus mycelium to NCT (6.8 mM) revealed an enrichment in proteins associated with the ribosome, transcription and translation and non-ribosomal peptide biosynthesis (e.g. Pes1, Pes3), which play an essential role in oxidative stress resistance in A. fumigatus. A decrease in the abundance of proteins associated with fumagillin and pseurotin biosynthesis highlighted the anti-virulence activity of NCT. CONCLUSION These results indicate that NCT induces an oxidative stress response in A. fumigatus as evidenced by alterations in the proteome and inhibits conidial and mycelial growth. Clinical investigations of topical application of NCT to treat Aspergillus infections are encouraged.
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Affiliation(s)
- Gerard Sheehan
- 1Medical Mycology Laboratory, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Markus Nagl
- 2Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Kevin Kavanagh
- 1Medical Mycology Laboratory, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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Arias M, Santiago L, Vidal-García M, Redrado S, Lanuza P, Comas L, Domingo MP, Rezusta A, Gálvez EM. Preparations for Invasion: Modulation of Host Lung Immunity During Pulmonary Aspergillosis by Gliotoxin and Other Fungal Secondary Metabolites. Front Immunol 2018; 9:2549. [PMID: 30459771 PMCID: PMC6232612 DOI: 10.3389/fimmu.2018.02549] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/17/2018] [Indexed: 12/12/2022] Open
Abstract
Pulmonary aspergillosis is a severe infectious disease caused by some members of the Aspergillus genus, that affects immunocompetent as well as immunocompromised patients. Among the different disease forms, Invasive Aspergillosis is the one causing the highest mortality, mainly, although not exclusively, affecting neutropenic patients. This genus is very well known by humans, since different sectors like pharmaceutical or food industry have taken advantage of the biological activity of some molecules synthetized by the fungus, known as secondary metabolites, including statins, antibiotics, fermentative compounds or colorants among others. However, during infection, in response to a hostile host environment, the fungal secondary metabolism is activated, producing different virulence factors to increase its survival chances. Some of these factors also contribute to fungal dissemination and invasion of adjacent and distant organs. Among the different secondary metabolites produced by Aspergillus spp. Gliotoxin (GT) is the best known and better characterized virulence factor. It is able to generate reactive oxygen species (ROS) due to the disulfide bridge present in its structure. It also presents immunosuppressive activity related with its ability to kill mammalian cells and/or inactivate critical immune signaling pathways like NFkB. In this comprehensive review, we will briefly give an overview of the lung immune response against Aspergillus as a preface to analyse the effect of different secondary metabolites on the host immune response, with a special attention to GT. We will discuss the results reported in the literature on the context of the animal models employed to analyse the role of GT as virulence factor, which is expected to greatly depend on the immune status of the host: why should you hide when nobody is seeking for you? Finally, GT immunosuppressive activity will be related with different human diseases predisposing to invasive aspergillosis in order to have a global view on the potential of GT to be used as a target to treat IA.
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Affiliation(s)
- Maykel Arias
- Instituto de Carboquímica ICB-CSIC, Zaragoza, Spain
- Immune Effector Cells Group, Aragón Health Research Institute (IIS Aragón), Biomedical Research Centre of Aragón (CIBA), Zaragoza, Spain
| | - Llipsy Santiago
- Immune Effector Cells Group, Aragón Health Research Institute (IIS Aragón), Biomedical Research Centre of Aragón (CIBA), Zaragoza, Spain
- Department of Biochemistry and Molecular and Cell Biology, Fac. Ciencias, University of Zaragoza, Zaragoza, Spain
| | - Matxalen Vidal-García
- Immune Effector Cells Group, Aragón Health Research Institute (IIS Aragón), Biomedical Research Centre of Aragón (CIBA), Zaragoza, Spain
- Servicio de Microbiología - Hospital Universitario Miguel Servet, Zaragoza, Spain
| | | | - Pilar Lanuza
- Immune Effector Cells Group, Aragón Health Research Institute (IIS Aragón), Biomedical Research Centre of Aragón (CIBA), Zaragoza, Spain
- Department of Biochemistry and Molecular and Cell Biology, Fac. Ciencias, University of Zaragoza, Zaragoza, Spain
| | - Laura Comas
- Instituto de Carboquímica ICB-CSIC, Zaragoza, Spain
- Immune Effector Cells Group, Aragón Health Research Institute (IIS Aragón), Biomedical Research Centre of Aragón (CIBA), Zaragoza, Spain
- Department of Biochemistry and Molecular and Cell Biology, Fac. Ciencias, University of Zaragoza, Zaragoza, Spain
| | | | - Antonio Rezusta
- Servicio de Microbiología - Hospital Universitario Miguel Servet, Zaragoza, Spain
- Department of Microbiology, Preventive Medicine and Public Health, University of Zaragoza, Zaragoza, Spain
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Yu Y, Blachowicz A, Will C, Szewczyk E, Glenn S, Gensberger-Reigl S, Nowrousian M, Wang CCC, Krappmann S. Mating-type factor-specific regulation of the fumagillin/pseurotin secondary metabolite supercluster in Aspergillus fumigatus. Mol Microbiol 2018; 110:1045-1065. [PMID: 30240513 DOI: 10.1111/mmi.14136] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2018] [Indexed: 12/13/2022]
Abstract
In the human pathogenic mold Aspergillus fumigatus, sexual identity is determined by the mating-type idiomorphs MAT1-1 and MAT1-2 residing at the MAT locus. Upon crossing of compatible partners, a heterothallic mating is executed to eventually form cleistothecia that contain recombinant ascospores. Given that the MAT1 gene products are DNA binding master regulators that govern this complex developmental process, we monitored the MAT1-driven transcriptomes of A. fumigatus by conditional overexpression of either MAT1 gene followed by RNA-seq analyses. Numerous genes related to the process of mating were found to be under transcriptional control, such as pheromone production and recognition. Substantial differences between the MAT1-1- and MAT1-2-driven transcriptomes could be detected by functional categorization of differentially expressed genes. Moreover, a significant and distinct impact on expression of genetic clusters of secondary metabolism became apparent, which could be verified on the product level. Unexpectedly, specific cross-regulation of the fumagillin/pseurotin supercluster was evident, thereby uncoupling its co-regulatory characteristic. These insights imply a tight interconnection of sexual development accompanied by ascosporogenesis with secondary metabolite production of a pathogenic fungus and impose evolutionary constraints that link these two fundamental aspects of the fungal lifestyle.
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Affiliation(s)
- Yidong Yu
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Adriana Blachowicz
- School of Pharmacy, John Staffer Pharmaceutical Sciences Center, University of Southern California, Los Angeles, CA, USA
| | - Cornelia Will
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Edyta Szewczyk
- Research Center for Infectious Diseases, Julius-Maximilians-Universität Würzburg, Germany
| | - Steven Glenn
- School of Pharmacy, John Staffer Pharmaceutical Sciences Center, University of Southern California, Los Angeles, CA, USA
| | - Sabrina Gensberger-Reigl
- Henriette Schmidt-Burkhardt Chair of Food Chemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Minou Nowrousian
- Department of General and Molecular Botany, Ruhr University Bochum, Germany
| | - Clay C C Wang
- School of Pharmacy, John Staffer Pharmaceutical Sciences Center, University of Southern California, Los Angeles, CA, USA
| | - Sven Krappmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
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Characterisation of the cellular and proteomic response of Galleria mellonella larvae to the development of invasive aspergillosis. BMC Microbiol 2018; 18:63. [PMID: 29954319 PMCID: PMC6025711 DOI: 10.1186/s12866-018-1208-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 06/22/2018] [Indexed: 11/17/2022] Open
Abstract
Background Galleria mellonella larvae were infected with conidia of Aspergillus fumigatus and the cellular and humoral immune responses of larvae to the pathogen were characterized as invasive aspergillosis developed. Results At 2 h post-infection there was an increase in hemocyte density to 7.43 ± 0.50 × 106/ml from 0.98 ± 0.08 × 106/ml at 0 h. Hemocytes from larvae immune primed for 6 h with heat killed A. fumigatus conidia displayed superior anti-fungal activity. Examination of the spread of the fungus by Cryo-imaging and fluorescent microscopy revealed dissemination of the fungus through the larvae by 6 h and the formation of distinct nodules in tissue. By 24 h a range of nodules were visible at the site of infection and at sites distant from that indicating invasion of tissue. Proteomic analysis of larvae infected with viable conidia for 6 h demonstrated an increase in the abundance of gustatory receptor candidate 25 (37 fold), gloverin-like protein (14 fold), cecropin-A (11 fold). At 24 h post-infection gustatory receptor candidate 25 (126 fold), moricin-like peptide D (33 fold) and muscle protein 20-like protein (12 fold) were increased in abundance. Proteins decreased in abundance included fibrohexamerin (13 fold) and dimeric dihydrodiol dehydrogenase (8 fold). Conclusion The results presented here indicate that G. mellonella larvae may be a convenient model for studying the stages in the development of invasive aspergillosis and may offer an insight into this process in mammals. Electronic supplementary material The online version of this article (10.1186/s12866-018-1208-6) contains supplementary material, which is available to authorized users.
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The Human Cathelicidin Antimicrobial Peptide LL-37 Promotes the Growth of the Pulmonary Pathogen Aspergillus fumigatus. Infect Immun 2018; 86:IAI.00097-18. [PMID: 29712727 DOI: 10.1128/iai.00097-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022] Open
Abstract
The pulmonary mucus of cystic fibrosis (CF) patients displays elevated levels of the cathelicidin antimicrobial peptide LL-37, and the aim of this work was to assess the effect of LL-37 on the growth of Aspergillus fumigatus, a common pathogen of CF patients. Exposure of A. fumigatus to LL-37 and its derived fragment RK-31 (1.95 μg/ml) for 24 h had a positive effect on growth (199.94% ± 6.172% [P < 0.05] and 218.20% ± 4.63% [P < 0.05], respectively), whereas scrambled LL-37 peptide did not (85.12% ± 2.92%). Exposure of mycelium (preformed for 24 h) to 5 μg/ml intact LL-37 for 48 h increased hyphal wet weight (4.37 ± 0.23 g, P < 0.001) compared to the control (2.67 ± 0.05 g) and scrambled LL-37 (2.23 ± 0.09 g) treatments. Gliotoxin secretion from LL-37 exposed hyphae (169.1 ± 6.36 ng/mg hyphae, P < 0.05) was increased at 24 h compared to the results seen with the control treatment (102 ± 18.81 ng/mg hyphae) and the scrambled LL-37 treatment (96.09 ± 15.15 ng/mg hyphae). Shotgun proteomic analysis of 24-h LL-37-treated hyphae revealed an increase in the abundance of proteins associated with growth (eukaryotic translation initiation factor 5A [eIF-5A] [16.3-fold increased]), tissue degradation (aspartic endopeptidase [4.7-fold increased]), and allergic reactions (Asp F13 [10-fold increased]). By 48 h, there was an increase in protein levels indicative of cellular stress (glutathione peroxidase [9-fold increased]), growth (eIF-5A [6-fold increased]), and virulence (RNase mitogillin [3.7-fold increased]). These results indicate that LL-37 stimulates A. fumigatus growth and that this stimulation can result in increased fungal growth and secretion of toxins in the lungs of CF patients.
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Abstract
The balance between reactive oxygen species and reactive nitrogen species production by the host and stress response by fungi is a key axis of the host-pathogen interaction. This review will describe emerging themes in fungal pathogenesis underpinning this axis.
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Affiliation(s)
- Adilia Warris
- Medical Research Centre for Medical Mycology, Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, UK
| | - Elizabeth R Ballou
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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Sheehan G, Kavanagh K. Analysis of the early cellular and humoral responses of Galleria mellonella larvae to infection by Candida albicans. Virulence 2017; 9:163-172. [PMID: 28872999 PMCID: PMC5955201 DOI: 10.1080/21505594.2017.1370174] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Galleria mellonella larvae were administered an inoculum of Candida albicans and the response to infection over 24 hours was monitored. The yeast cell density in infected larvae declined initially but replication commenced six hours post-infection. The hemocyte density decreased from 5.2 × 106/ml to 2.5 × 106/ml at 2 hours but increased to 4.2 × 106 at 6 hours and decreased subsequently. Administration of β – glucan to larvae also caused a fluctuation in hemocyte density (5.1 ± 0.22 × 106/ml (0 hour) to 6.25 ± 0.25 × 106/ml (6 hour) (p < 0.05) to 5 ± 2.7 × 106 (24 hour)) and the population showed an increase in the density of small, granular cells at 24 hours (p < 0.05). Hemocytes from larvae inoculated with β – glucan for 6 or 24 hours showed faster killing of C. albicans cells (53 ± 4.1% (p < 0.01), 64 ± 3.7%, (p < 0.01), respectively) than hemocytes from control larvae (24 ± 11%) at 60 min. Proteomic analysis indicated increased abundance of immune related proteins cecropin-A (5 fold) and prophenoloxidase-activating proteinase-1 (5 fold) 6 hours post infection but by 24 hours there was elevated abundance of muscle (tropomyosin 2 (141 fold), calponin (66 fold), troponin I (62 fold)) and proteins indicative of cellular stress (glutathione-S-transferase-like protein (114 fold)), fungal dissemination (muscle protein 20-like protein (174 fold)) and tissue breakdown (mitochondrial cytochrome c (10 fold)). Proteins decreased in abundance at 24 hour included β – 1,3 – glucan recognition protein precursor (29 fold) and prophenoloxidase subunit 2 (25 fold).
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Affiliation(s)
- Gerard Sheehan
- a Department of Biology , Maynooth University , Maynooth, Co. Kildare , Ireland
| | - Kevin Kavanagh
- a Department of Biology , Maynooth University , Maynooth, Co. Kildare , Ireland
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Abstract
Aspergillus fumigatus is an environmental filamentous fungus that can cause life-threatening disease in immunocompromised individuals. The interactions between A. fumigatus and the host environment are dynamic and complex. The host immune system needs to recognize the distinct morphological forms of A. fumigatus to control fungal growth and prevent tissue invasion, whereas the fungus requires nutrients and needs to adapt to the hostile environment by escaping immune recognition and counteracting host responses. Understanding these highly dynamic interactions is necessary to fully understand the pathogenesis of aspergillosis and to facilitate the design of new therapeutics to overcome the morbidity and mortality caused by A. fumigatus. In this Review, we describe how A. fumigatus adapts to environmental change, the mechanisms of host defence, and our current knowledge of the interplay between the host immune response and the fungus.
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Characterization of Aspergillus fumigatus Isolates from Air and Surfaces of the International Space Station. mSphere 2016; 1:mSphere00227-16. [PMID: 27830189 PMCID: PMC5082629 DOI: 10.1128/msphere.00227-16] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/01/2016] [Indexed: 01/02/2023] Open
Abstract
One mission of the Microbial Observatory Experiments on the International Space Station (ISS) is to examine the traits and diversity of fungal isolates to gain a better understanding of how fungi may adapt to microgravity environments and how this may affect interactions with humans in a closed habitat. Here, we report an initial characterization of two isolates, ISSFT-021 and IF1SW-F4, of Aspergillus fumigatus collected from the ISS and a comparison to the experimentally established clinical isolates Af293 and CEA10. Whole-genome sequencing of ISSFT-021 and IF1SW-F4 showed 54,960 and 52,129 single nucleotide polymorphisms, respectively, compared to Af293, which is consistent with observed genetic heterogeneity among sequenced A. fumigatus isolates from diverse clinical and environmental sources. Assessment of in vitro growth characteristics, secondary metabolite production, and susceptibility to chemical stresses revealed no outstanding differences between ISS and clinical strains that would suggest special adaptation to life aboard the ISS. Virulence assessment in a neutrophil-deficient larval zebrafish model of invasive aspergillosis revealed that both ISSFT-021 and IF1SW-F4 were significantly more lethal than Af293 and CEA10. Taken together, these genomic, in vitro, and in vivo analyses of two A. fumigatus strains isolated from the ISS provide a benchmark for future investigations of these strains and for continuing research on specific microbial isolates from manned space environments. IMPORTANCE As durations of manned space missions increase, it is imperative to understand the long-term consequence of microbial exposure on human health in a closed human habitat. To date, studies aimed at bacterial and fungal contamination of space vessels have highlighted species compositions biased toward hardy, persistent organisms capable of withstanding harsh conditions. In the current study, we assessed traits of two independent Aspergillus fumigatus strains isolated from the International Space Station. Ubiquitously found in terrestrial soil and atmospheric environments, A. fumigatus is a significant opportunistic fungal threat to human health, particularly among the immunocompromised. Using two well-known clinical isolates of A. fumigatus as comparators, we found that both ISS isolates exhibited normal in vitro growth and chemical stress tolerance yet caused higher lethality in a vertebrate model of invasive disease. These findings substantiate the need for additional studies of physical traits and biological activities of microbes adapted to microgravity and other extreme extraterrestrial conditions.
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Espinosa V, Rivera A. First Line of Defense: Innate Cell-Mediated Control of Pulmonary Aspergillosis. Front Microbiol 2016; 7:272. [PMID: 26973640 PMCID: PMC4776213 DOI: 10.3389/fmicb.2016.00272] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/19/2016] [Indexed: 12/24/2022] Open
Abstract
Mycotic infections and their effect on the human condition have been widely overlooked and poorly surveilled by many health organizations even though mortality rates have increased in recent years. The increased usage of immunosuppressive and myeloablative therapies for the treatment of malignant as well as non-malignant diseases has contributed significantly to the increased incidence of fungal infections. Invasive fungal infections have been found to be responsible for at least 1.5 million deaths worldwide. About 90% of these deaths can be attributed to Cryptococcus, Candida, Aspergillus, and Pneumocystis. A better understanding of how the host immune system contains fungal infection is likely to facilitate the development of much needed novel antifungal therapies. Innate cells are responsible for the rapid recognition and containment of fungal infections and have been found to play essential roles in defense against multiple fungal pathogens. In this review we summarize our current understanding of host-fungi interactions with a focus on mechanisms of innate cell-mediated recognition and control of pulmonary aspergillosis.
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Affiliation(s)
- Vanessa Espinosa
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers-The State University of New JerseyNewark, NJ, USA; Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers-The State University of New JerseyNewark, NJ, USA
| | - Amariliz Rivera
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers-The State University of New JerseyNewark, NJ, USA; Department of Pediatrics, New Jersey Medical School, Rutgers-The State University of New JerseyNewark, NJ, USA
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Barkal LJ, Theberge AB, Guo CJ, Spraker J, Rappert L, Berthier J, Brakke KA, Wang CCC, Beebe DJ, Keller NP, Berthier E. Microbial metabolomics in open microscale platforms. Nat Commun 2016; 7:10610. [PMID: 26842393 PMCID: PMC4742997 DOI: 10.1038/ncomms10610] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 01/04/2016] [Indexed: 01/04/2023] Open
Abstract
The microbial secondary metabolome encompasses great synthetic diversity, empowering microbes to tune their chemical responses to changing microenvironments. Traditional metabolomics methods are ill-equipped to probe a wide variety of environments or environmental dynamics. Here we introduce a class of microscale culture platforms to analyse chemical diversity of fungal and bacterial secondary metabolomes. By leveraging stable biphasic interfaces to integrate microculture with small molecule isolation via liquid–liquid extraction, we enable metabolomics-scale analysis using mass spectrometry. This platform facilitates exploration of culture microenvironments (including rare media typically inaccessible using established methods), unusual organic solvents for metabolite isolation and microbial mutants. Utilizing Aspergillus, a fungal genus known for its rich secondary metabolism, we characterize the effects of culture geometry and growth matrix on secondary metabolism, highlighting the potential use of microscale systems to unlock unknown or cryptic secondary metabolites for natural products discovery. Finally, we demonstrate the potential for this class of microfluidic systems to study interkingdom communication between fungi and bacteria. Traditional methods for microbial culture and subsequent metabolomics are time-consuming and labour-intensive. Here the authors present a microscale culture platform with integrated extraction for efficient, low-volume metabolomics of relevant microenvironments and microbial co-cultures.
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Affiliation(s)
- Layla J Barkal
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.,Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Ashleigh B Theberge
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.,Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.,Department of Urology, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Chun-Jun Guo
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles California 90089, USA
| | - Joe Spraker
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Lucas Rappert
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Jean Berthier
- Department of Biotechnology, CEA-University Grenoble-Alpes, 17 Avenue des Martyrs, 38054 Grenoble, France
| | - Kenneth A Brakke
- Department of Mathematics, Susquehanna University, Selinsgrove, Pennsylvania 17870, USA
| | - Clay C C Wang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles California 90089, USA.,Department of Chemistry, University of Southern California, Los Angeles California 90089, USA
| | - David J Beebe
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.,Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Erwin Berthier
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.,Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
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Frisvad JC, Larsen TO. Extrolites of Aspergillus fumigatus and Other Pathogenic Species in Aspergillus Section Fumigati. Front Microbiol 2016; 6:1485. [PMID: 26779142 PMCID: PMC4703822 DOI: 10.3389/fmicb.2015.01485] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 12/09/2015] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is an important opportunistic human pathogen known for its production of a large array of extrolites. Up to 63 species have been described in Aspergillus section Fumigati, some of which have also been reliably reported to be pathogenic, including A. felis, A. fischeri, A. fumigatiaffinis, A. fumisynnematus, A. hiratsukae, A. laciniosus, A. lentulus, A. novofumigatus, A. parafelis, A. pseudofelis, A. pseudoviridinutans, A. spinosus, A. thermomutatus, and A. udagawae. These species share the production of hydrophobins, melanins, and siderophores and ability to grow well at 37°C, but they only share some small molecule extrolites, that could be important factors in pathogenicity. According to the literature gliotoxin and other exometabolites can be contributing factors to pathogenicity, but these exometabolites are apparently not produced by all pathogenic species. It is our hypothesis that species unable to produce some of these metabolites can produce proxy-exometabolites that may serve the same function. We tabulate all exometabolites reported from species in Aspergillus section Fumigati and by comparing the profile of those extrolites, suggest that those producing many different kinds of exometabolites are potential opportunistic pathogens. The exometabolite data also suggest that the profile of exometabolites are highly specific and can be used for identification of these closely related species.
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Affiliation(s)
- Jens C. Frisvad
- Section of Eukaryotic Biotechnology, Department of Systems Biology, Technical University of DenmarkKongens Lyngby, Denmark
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Margalit A, Kavanagh K. The innate immune response to Aspergillus fumigatus at the alveolar surface. FEMS Microbiol Rev 2015; 39:670-87. [PMID: 25934117 DOI: 10.1093/femsre/fuv018] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2015] [Indexed: 01/22/2023] Open
Abstract
Aspergillus fumigatus is an ubiquitous, saprophytic mould that forms and releases airborne conidia which are inhaled by humans on a daily basis. When the immune system is compromised (e.g. immunosuppressive therapy prior to organ transplantation) or there is pre-existing pulmonary malfunction (e.g. asthma, cystic fibrosis, TB lesions), A. fumigatus exploits weaknesses in the host defenses which can result in the development of saphrophytic, allergic or invasive aspergillosis. If not effectively eliminated by the innate immune response, conidia germinate and form invasive hyphae which can penetrate pulmonary tissues. The innate immune response to A. fumigatus is stage-specific and various components of the host's defenses are recruited to challenge the different cellular forms of the pathogen. In immunocompetent hosts, anatomical barriers (e.g. the mucociliary elevator) and professional phagocytes such as alveolar macrophages (AM) and neutrophils prevent the development of aspergillosis by inhibiting the growth of conidia and hyphae. The recognition of inhaled conidia by AM leads to the intracellular degradation of the spores and the secretion of proinflammatory mediators which recruit neutrophils to assist in fungal clearance. During the later stages of infection, dendritic cells activate a protective A. fumigatus-specific adaptive immune response which is driven by Th1 CD4(+) T cells.
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Affiliation(s)
- Anatte Margalit
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Co. Kildare, Ireland
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Tamiya H, Ochiai E, Kikuchi K, Yahiro M, Toyotome T, Watanabe A, Yaguchi T, Kamei K. Secondary metabolite profiles and antifungal drug susceptibility of Aspergillus fumigatus and closely related species, Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans. J Infect Chemother 2015; 21:385-91. [PMID: 25737146 DOI: 10.1016/j.jiac.2015.01.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 01/05/2015] [Accepted: 01/13/2015] [Indexed: 11/20/2022]
Abstract
The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes.
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Affiliation(s)
- Hiroyuki Tamiya
- Division of Fungal Infection, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan; Department of Respiratory Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Division of Clinical Research, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
| | - Eri Ochiai
- Division of Fungal Infection, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - Kazuyo Kikuchi
- Division of Bio-resources, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Maki Yahiro
- Division of Fungal Infection, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - Takahito Toyotome
- Division of Fungal Infection, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - Akira Watanabe
- Division of Fungal Infection, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan; Division of Clinical Research, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan; Division of Control and Treatment of Infectious Diseases, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan
| | - Takashi Yaguchi
- Division of Bio-resources, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Katsuhiko Kamei
- Division of Fungal Infection, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan; Division of Clinical Research, Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan; Division of Control and Treatment of Infectious Diseases, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan
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Owens RA, Hammel S, Sheridan KJ, Jones GW, Doyle S. A proteomic approach to investigating gene cluster expression and secondary metabolite functionality in Aspergillus fumigatus. PLoS One 2014; 9:e106942. [PMID: 25198175 PMCID: PMC4157829 DOI: 10.1371/journal.pone.0106942] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/11/2014] [Indexed: 11/18/2022] Open
Abstract
A combined proteomics and metabolomics approach was utilised to advance the identification and characterisation of secondary metabolites in Aspergillus fumigatus. Here, implementation of a shotgun proteomic strategy led to the identification of non-redundant mycelial proteins (n = 414) from A. fumigatus including proteins typically under-represented in 2-D proteome maps: proteins with multiple transmembrane regions, hydrophobic proteins and proteins with extremes of molecular mass and pI. Indirect identification of secondary metabolite cluster expression was also achieved, with proteins (n = 18) from LaeA-regulated clusters detected, including GliT encoded within the gliotoxin biosynthetic cluster. Biochemical analysis then revealed that gliotoxin significantly attenuates H2O2-induced oxidative stress in A. fumigatus (p>0.0001), confirming observations from proteomics data. A complementary 2-D/LC-MS/MS approach further elucidated significantly increased abundance (p<0.05) of proliferating cell nuclear antigen (PCNA), NADH-quinone oxidoreductase and the gliotoxin oxidoreductase GliT, along with significantly attenuated abundance (p<0.05) of a heat shock protein, an oxidative stress protein and an autolysis-associated chitinase, when gliotoxin and H2O2 were present, compared to H2O2 alone. Moreover, gliotoxin exposure significantly reduced the abundance of selected proteins (p<0.05) involved in de novo purine biosynthesis. Significantly elevated abundance (p<0.05) of a key enzyme, xanthine-guanine phosphoribosyl transferase Xpt1, utilised in purine salvage, was observed in the presence of H2O2 and gliotoxin. This work provides new insights into the A. fumigatus proteome and experimental strategies, plus mechanistic data pertaining to gliotoxin functionality in the organism.
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Affiliation(s)
- Rebecca A. Owens
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Stephen Hammel
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Kevin J. Sheridan
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Gary W. Jones
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Sean Doyle
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
- * E-mail:
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Robinet P, Baychelier F, Fontaine T, Picard C, Debré P, Vieillard V, Latgé JP, Elbim C. A polysaccharide virulence factor of a human fungal pathogen induces neutrophil apoptosis via NK cells. THE JOURNAL OF IMMUNOLOGY 2014; 192:5332-42. [PMID: 24790151 DOI: 10.4049/jimmunol.1303180] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Aspergillus fumigatus is an opportunistic human fungal pathogen that sheds galactosaminogalactan (GG) into the environment. Polymorphonuclear neutrophils (PMNs) and NK cells are both part of the first line of defense against pathogens. We recently reported that GG induces PMN apoptosis. In this study, we show that PMN apoptosis occurs via a new NK cell-dependent mechanism. Reactive oxygen species, induced by the presence of GG, play an indispensable role in this apoptotic effect by increasing MHC class I chain-related molecule A expression at the PMN surface. This increased expression enables interaction between MHC class I chain-related molecule A and NKG2D, leading to NK cell activation, which in turn generates a Fas-dependent apoptosis-promoting signal in PMNs. Taken together, our results demonstrate that the crosstalk between PMNs and NK cells is essential to GG-induced PMN apoptosis. NK cells might thus play a role in the induction of PMN apoptosis in situations such as unexplained neutropenia or autoimmune diseases.
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Affiliation(s)
- Pauline Robinet
- Université Pierre et Marie Curie Paris 06, Unité Mixte de Recherche-S CR7, Sorbonne Université, F-75005 Paris, France; INSERM, Centre d'Immunologie et des Maladies Infectieuses, Unité Mixte de Recherche-S CR7, INSERM U1135, F-75013 Paris, France
| | - Florence Baychelier
- INSERM, Centre d'Immunologie et des Maladies Infectieuses, Unité Mixte de Recherche-S CR7, INSERM U1135, F-75013 Paris, France
| | | | - Capucine Picard
- Centre D'étude des Déficits Immunitaires, Assistance Publique-Hôpitaux de Paris, L'hôpital Necker - Enfants Malades, 75743 Paris, France; Paris Descartes University, Sorbonne Paris Cité, 75006 Paris, France; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U980, Necker Medical School, 75015 Paris, France; and
| | - Patrice Debré
- Université Pierre et Marie Curie Paris 06, Unité Mixte de Recherche-S CR7, Sorbonne Université, F-75005 Paris, France; INSERM, Centre d'Immunologie et des Maladies Infectieuses, Unité Mixte de Recherche-S CR7, INSERM U1135, F-75013 Paris, France; Département d'Immunologie, Assistance Publique - Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Vincent Vieillard
- INSERM, Centre d'Immunologie et des Maladies Infectieuses, Unité Mixte de Recherche-S CR7, INSERM U1135, F-75013 Paris, France
| | - Jean-Paul Latgé
- Institut Pasteur, Unité des Aspergillus, 75015 Paris, France
| | - Carole Elbim
- Université Pierre et Marie Curie Paris 06, Unité Mixte de Recherche-S CR7, Sorbonne Université, F-75005 Paris, France; INSERM, Centre d'Immunologie et des Maladies Infectieuses, Unité Mixte de Recherche-S CR7, INSERM U1135, F-75013 Paris, France;
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Fumigaclavine C from a marine-derived fungus Aspergillus fumigatus induces apoptosis in MCF-7 breast cancer cells. Mar Drugs 2013; 11:5063-86. [PMID: 24351905 PMCID: PMC3877903 DOI: 10.3390/md11125063] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 11/30/2013] [Accepted: 12/02/2013] [Indexed: 01/03/2023] Open
Abstract
Recently, much attention has been given to discovering natural compounds as potent anti-cancer candidates. In the present study, the anti-cancer effects of fumigaclavine C, isolated from a marine-derived fungus, Aspergillus fumigatus, was evaluated in vitro. In order to investigate the impact of fumigaclavine C on inhibition of proliferation and induction of apoptosis in breast cancer, MCF-7 cells were treated with various concentrations of fumigaclavine C, and fumigaclavine C showed significant cytotoxicity towards MCF-7 cells. Anti-proliferation was analyzed via cell mobility and mitogen-activated protein kinase (MAPK) signaling pathway. In addition, fumigaclavine C showed potent inhibition on the protein and gene level expressions of MMP-2, -9 in MCF-7 cells which were manifested in Western blot and reverse transcription polymerase chain reaction (RT-PCR) results. The apoptosis induction abilities of the fumigaclvine C was studied by analyzing the expression of apoptosis related proteins, cell cycle analysis, DNA fragmentation and molecular docking studies. It was found that fumigaclavine C fragmented the MCF-7 cell DNA and arrested the cell cycle by modulating the apoptotic protein expressions. Moreover, fumigaclavine C significantly down-regulated the NF-kappa-B cell survival pathway. Collectively, data suggest that fumigaclavine C has a potential to be developed as a therapeutic candidate for breast cancer.
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Browne N, Heelan M, Kavanagh K. An analysis of the structural and functional similarities of insect hemocytes and mammalian phagocytes. Virulence 2013; 4:597-603. [PMID: 23921374 PMCID: PMC3906293 DOI: 10.4161/viru.25906] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 11/29/2022] Open
Abstract
The insect immune response demonstrates a number of structural and functional similarities to the innate immune system of mammals. As a result of these conserved features insects have become popular choices for evaluating the virulence of microbial pathogens or for assessing the efficacy of antimicrobial agents and give results which are comparable to those that can be obtained using mammals. Analysis of the cellular component of the insect and mammalian immune systems demonstrates many similarities. Insect hemocytes recognize pathogens and phagocytose material in a similar manner to neutrophils. The killing of ingested microbes is achieved in both cell types by the production of superoxide and by the release of enzymes in the process of degranulation. Insect hemocytes and mammalian neutrophils are sensitive to the same inhibitors. This review highlights the strong similarities between the phagocytic cells of both groups of animals and demonstrates the potential benefits of using selected insects as in vivo screening systems.
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Affiliation(s)
- Niall Browne
- Department of Biology; NUI Maynooth; Maynooth, Co. Kildare Ireland
| | - Michelle Heelan
- Department of Biology; NUI Maynooth; Maynooth, Co. Kildare Ireland
| | - Kevin Kavanagh
- Department of Biology; NUI Maynooth; Maynooth, Co. Kildare Ireland
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Boyle KB, Stephens LR, Hawkins PT. Activation of the neutrophil NADPH oxidase by Aspergillus fumigatus. Ann N Y Acad Sci 2013; 1273:68-73. [PMID: 23230839 DOI: 10.1111/j.1749-6632.2012.06821.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Upon infection of the respiratory system with the fungus Aspergillus fumigatus various leukoctytes, in particular neutrophils, are recruited to the lung to mount an immune response. Neutrophils respond by both phagocytosing conidia and mediating extracellular killing of germinated, invasive hyphae. Of paramount importance to an appropriate immune response is the neutrophil NADPH oxidase enzyme, which mediates the production of various reactive oxygen species (ROS). This is evidenced by the acute sensitivity of both oxidase-deficient humans and mice to invasive aspergillosis. Herein we briefly review the mechanisms and functions of oxidase activation and discuss our recent work identifying at least some of the important players in hyphal-induced oxidase activation and neutrophil function. Among these we define the phosphoinositide 3-kinase enzyme and the regulatory protein Vav to be of critical importance and allude to a kinase-independent role for Syk.
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Affiliation(s)
- Keith B Boyle
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
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Malekinejad H, Fani F, Shafie-Irannejad V, Fink-Gremmel F. Aspergillus fumigatus toxins cause cytotoxic and apoptotic effects on human T lymphocytes (Jurkat cells). WORLD MYCOTOXIN J 2013. [DOI: 10.3920/wmj2012.1481] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Aspergillus fumigatus is a ubiquitous fungus, which plays a prominent role in the incidence of various diseases including invasive aspergillosis. The cytotoxicity and apoptotic effects of the main secondary metabolites of Aspergillus fumigatus including gliotoxin, kojic acid, fumagillin, and verruculogen were studied on human T lymphocytes (Jurkat cells). The calculated IC50 values, which were obtained based on the Alamar Blue reduction assay, indicated that the strongest toxicity was exerted by gliotoxin, followed by kojic acid and equally by fumagillin and verruculogen. Correspondingly, the evaluation of reactive oxygen species (ROS) production by the selected mycotoxins showed that gliotoxin exposure resulted in the highest ROS generation, followed by kojic acid, fumagillin and verruculogen. Each of the four mycotoxins exhibited concentration- and time-dependent apoptotic effects albeit with differences as evidenced by cytochrome C release, caspase-3/7 activity enhancement, and DNA fragmentation. In conclusion, a comparison of gliotoxin and other metabolites of A. fumigatus such as kojic acid, fumagillin and verruculogen identified gliotoxin as the most cytotoxic mycotoxin for Jurkat cells. As Jurkat cells represent human T lymphocytes, A. fumigatus toxins might exert significant immunosuppressive effects.
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Affiliation(s)
- H. Malekinejad
- Department of Veterinary Pharmacology and Toxicology, Faculty of Veterinary Medicine, Urmia University, P.O. Box 1177, Urmia, Iran
| | - F. Fani
- Department of Veterinary Pharmacology and Toxicology, Faculty of Veterinary Medicine, Urmia University, P.O. Box 1177, Urmia, Iran
| | - V. Shafie-Irannejad
- Department of Veterinary Pharmacology and Toxicology, Faculty of Veterinary Medicine, Urmia University, P.O. Box 1177, Urmia, Iran
| | - F. Fink-Gremmel
- Department of Veterinary Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3508 TD Utrecht, the Netherlands
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Heinekamp T, Thywißen A, Macheleidt J, Keller S, Valiante V, Brakhage AA. Aspergillus fumigatus melanins: interference with the host endocytosis pathway and impact on virulence. Front Microbiol 2013; 3:440. [PMID: 23346079 PMCID: PMC3548413 DOI: 10.3389/fmicb.2012.00440] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 12/19/2012] [Indexed: 11/13/2022] Open
Abstract
The opportunistic human pathogenic fungus Aspergillus fumigatus produces at least two types of melanin, namely pyomelanin and dihydroxynaphthalene (DHN) melanin. Pyomelanin is produced during tyrosine catabolism via accumulation of homogentisic acid. Although pyomelanin protects the fungus against reactive oxygen species (ROS) and acts as a defense compound in response to cell wall stress, mutants deficient for pyomelanin biosynthesis do not differ in virulence when tested in a murine infection model for invasive pulmonary aspergillosis. DHN melanin is responsible for the characteristic gray-greenish color of A. fumigatus conidia. Mutants lacking a functional polyketide synthase PksP, the enzyme responsible for the initial step in DHN-melanin formation, i.e., the synthesis of naphthopyrone, produce white spores and are attenuated in virulence. The activity of PksP was found to be essential not only for inhibition of apoptosis of phagocytes by interfering with the host PI3K/Akt signaling cascade but also for effective inhibition of acidification of conidia-containing phagolysosomes. These features allow A. fumigatus to survive in phagocytes and thereby to escape from human immune effector cells and to become a successful pathogen.
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Affiliation(s)
- Thorsten Heinekamp
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
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Morton CO, Bouzani M, Loeffler J, Rogers TR. Direct interaction studies between Aspergillus fumigatus and human immune cells; what have we learned about pathogenicity and host immunity? Front Microbiol 2012; 3:413. [PMID: 23264771 PMCID: PMC3525292 DOI: 10.3389/fmicb.2012.00413] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 11/15/2012] [Indexed: 12/24/2022] Open
Abstract
Invasive aspergillosis is a significant threat to health and is a major cause of mortality in immunocompromised individuals. Understanding the interaction between the fungus and the immune system is important in determining how the immunocompetent host remains disease free. Several studies examining the direct interaction between Aspergillus fumigatus and purified innate immune cells have been conducted to measure the responses of both the host cells and the pathogen. It has been revealed that innate immune cells have different modes of action ranging from effective fungal killing by neutrophils to the less aggressive response of dendritic cells. Natural killer cells do not phagocytose the fungus unlike the other innate immune cells mentioned but appear to mediate their antifungal effect through the release of gamma interferon. Transcriptional analysis of A. fumigatus interacting with these cells has indicated that it can adapt to the harsh microenvironment of the phagosome and produces toxins, ribotoxin and gliotoxin, that can induce cell death in the majority of innate immune cells. These data point toward potential novel antifungal treatments including the use of innate immune cells as antifungal vaccines.
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Affiliation(s)
- Charles O Morton
- School of Science and Health, University of Western Sydney Campbelltown, NSW, Australia
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Leal SM, Vareechon C, Cowden S, Cobb BA, Latgé JP, Momany M, Pearlman E. Fungal antioxidant pathways promote survival against neutrophils during infection. J Clin Invest 2012; 122:2482-98. [PMID: 22706306 DOI: 10.1172/jci63239] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/09/2012] [Indexed: 01/15/2023] Open
Abstract
Filamentous fungi are a common cause of blindness and visual impairment worldwide. Using both murine model systems and in vitro human neutrophils, we found that NADPH oxidase produced by neutrophils was essential to control the growth of Aspergillus and Fusarium fungi in the cornea. We demonstrated that neutrophil oxidant production and antifungal activity are dependent on CD18, but not on the β-glucan receptor dectin-1. We used mutant A. fumigatus strains to show that the reactive oxygen species-sensing transcription factor Yap1, superoxide dismutases, and the Yap1-regulated thioredoxin antioxidant pathway are each required for protection against neutrophil-mediated oxidation of hyphae as well as optimal survival of fungal hyphae in vivo. We also demonstrated that thioredoxin inhibition using the anticancer drug PX-12 increased the sensitivity of fungal hyphae to both H2O2- and neutrophil-mediated killing in vitro. Additionally, topical application of PX-12 significantly enhanced neutrophil-mediated fungal killing in infected mouse corneas. Cumulatively, our data reveal critical host oxidative and fungal anti-oxidative mediators that regulate hyphal survival during infection. Further, these findings also indicate that targeting fungal anti-oxidative defenses via PX-12 may represent an efficacious strategy for treating fungal infections.
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Affiliation(s)
- Sixto M Leal
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
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Fallon JP, Reeves EP, Kavanagh K. The Aspergillus fumigatus toxin fumagillin suppresses the immune response of Galleria mellonella larvae by inhibiting the action of haemocytes. MICROBIOLOGY-SGM 2011; 157:1481-1488. [PMID: 21349977 DOI: 10.1099/mic.0.043786-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Larvae of Galleria mellonella are widely used to evaluate microbial virulence and to assess the in vivo efficacy of antimicrobial agents. The aim of this work was to examine the ability of an Aspergillus fumigatus toxin, fumagillin, to suppress the immune response of larvae. Administration of fumagillin to larvae increased their susceptibility to subsequent infection with A. fumigatus conidia (P = 0.0052). It was demonstrated that a dose of 2 µg fumagillin ml⁻¹ reduced the ability of insect immune cells (haemocytes) to kill opsonized cells of Candida albicans (P = 0.039) and to phagocytose A. fumigatus conidia (P = 0.016). Fumagillin reduced the oxygen uptake of haemocytes and decreased the translocation of a p47 protein which is homologous to p47(phox), a protein essential for the formation of a functional NADPH oxidase complex required for superoxide production. In addition, toxin-treated haemocytes showed reduced levels of degranulation as measured by the release of a protein showing reactivity to an anti-myeloperoxidase antibody (P<0.049) that was subsequently identified by liquid chromatography-MS analysis as prophenoloxidase. This work demonstrates that fumagillin suppresses the immune response of G. mellonella larvae by inhibiting the action of haemocytes and thus renders the larvae susceptible to infection. During growth of the fungus in the larvae, this toxin, along with others, may facilitate growth by suppressing the cellular immune response.
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Affiliation(s)
- John P Fallon
- Medical Mycology Unit, Department of Biology, National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Co. Kildare, Ireland
| | - Emer P Reeves
- Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland
| | - Kevin Kavanagh
- Medical Mycology Unit, Department of Biology, National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Co. Kildare, Ireland
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Brakhage AA, Bruns S, Thywissen A, Zipfel PF, Behnsen J. Interaction of phagocytes with filamentous fungi. Curr Opin Microbiol 2010; 13:409-15. [PMID: 20627805 DOI: 10.1016/j.mib.2010.04.009] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 04/24/2010] [Accepted: 04/27/2010] [Indexed: 12/12/2022]
Abstract
Phagocytosis of conidia by macrophages and destruction of hyphae by neutrophils are key processes in the defense against infections caused by filamentous fungi. Impairment in phagocytic function leads to increased susceptibility for an infection with Aspergillus species. The fact that a Th1-based immune response to an infection with Aspergillus species results in an improved prognosis for survival underlines the importance of the phagocytic response. Recognition of conidia by macrophages occurs after shedding of the hydrophobic rodlet layer during swelling and germination. Whereas Aspergillus conidia are killed by various immune effector cells, hyphae are in particular targeted and killed by neutrophils. Moreover, both conidia and hyphae are trapped in neutrophil extracellular traps (NETs) that form a containment to localize the infection and to prevent systemic spreading of the fungus in the host. In addition, A. fumigatus interferes with the innate immunity, with both the complement system and defense mechanisms of phagocytes, thereby evading at least in part the innate immune system.
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Affiliation(s)
- Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Beutenbergstrasse 11a, 07745 Jena, Germany.
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