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Chen H, Zhao L, You C, Liu J, Chen L, Gu Z, Shi G, Li J, Ding Z. Roles of α-1,3-glucosyltransferase in growth and polysaccharides biosynthesis of Ganoderma lucidum. Int J Biol Macromol 2024; 276:134031. [PMID: 39033891 DOI: 10.1016/j.ijbiomac.2024.134031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/12/2024] [Accepted: 07/18/2024] [Indexed: 07/23/2024]
Abstract
Ganoderma lucidum polysaccharides are valuable natural compounds possessing significant biological activity, with glycosyltransferases playing a crucial role in their biosynthesis. Although the function of β-1,3-glucosyltransferase in polysaccharides production is well understood, the role of α-1,3-glucosyltransferase in edible fungi remains unclear. In this study, over-expression of the α-1,3-glucosyltransferase gene in G. lucidum (glagt) was found to suppress the growth, with the maximum biomass and mycelial growth rate decreasing by 21.78 % and 79.61 %, respectively, a behavior distinct from β-1,3-glucosyltransferase. The fungal pellet diameter decreased by 38 % and the cell-wall thickness by 32.44 %, whereas intracellular and extracellular polysaccharides production increased by 27.58 % and 66.08 %, respectively. In the transcription level, overexpressing the glagt gene i) downregulated the citrate synthase and isocitrate dehydrogenase gene in the TCA cycle, disrupting energy metabolism and fungal growth; ii) upregulated key enzymes involved in UDP-glucose synthesis and glycosyltransferases (gl24465, gl24971, and gl22535); and iii) universally increased the transcriptional level of glucosidases gl21451, gl30087, and gl24581 by 22 %-397 %, contributing to cell-wall thinning to facilitate polysaccharides export. Conversely, the glagt gene downregulation promoted G. lucidum growth and decreased polysaccharides production. The results elucidate the roles of GLAGT and are expected to inspire in-depth exploration of polysaccharides biosynthesis pathways.
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Affiliation(s)
- Haixiu Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China
| | - Liting Zhao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China
| | - Cuiping You
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jingyun Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China
| | - Lei Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China
| | - Zhenghua Gu
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China
| | - Guiyang Shi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China
| | - Junxun Li
- Shandong Taishan Shengliyuan Group Co. Ltd., Shandong 271000, China.
| | - Zhongyang Ding
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, China.
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Gong X, Zhou Y, Qin Q, Wang B, Wang L, Jin C, Fang W. Nitrate assimilation compensates for cell wall biosynthesis in the absence of Aspergillus fumigatus phosphoglucose isomerase. Appl Environ Microbiol 2024:e0113824. [PMID: 39158312 DOI: 10.1128/aem.01138-24] [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: 06/11/2024] [Accepted: 07/20/2024] [Indexed: 08/20/2024] Open
Abstract
Phosphoglucose isomerase (PGI) links glycolysis, the pentose phosphate pathway (PPP), and the synthesis of cell wall precursors in fungi by facilitating the reversible conversion between glucose-6-phosphate (Glc6p) and fructose-6-phosphate (Fru6P). In a previous study, we established the essential role of PGI in cell wall biosynthesis in the opportunistic human fungal pathogen Aspergillus fumigatus, highlighting its potential as a therapeutic target. In this study, we conducted transcriptomic analysis and discovered that the Δpgi mutant exhibited enhanced glycolysis, reduced PPP, and an upregulation of cell wall precursor biosynthesis pathways. Phenotypic analysis revealed defective protein N-glycosylation in the mutant, notably the absence of glycosylated virulence factors DPP V and catalase 1. Interestingly, the cell wall defects in the mutant were not accompanied by activation of the MpkA-dependent cell wall integrity (CWI) signaling pathway. Instead, nitrate assimilation was activated in the Δpgi mutant, stimulating glutamine synthesis and providing amino donors for chitin precursor biosynthesis. Blocking the nitrate assimilation pathway severely impaired the growth of the Δpgi mutant, highlighting the crucial role of nitrate assimilation in rescuing cell wall defects. This study unveils the connection between nitrogen assimilation and cell wall compensation in A. fumigatus.IMPORTANCEAspergillus fumigatus is a common and serious human fungal pathogen that causes a variety of diseases. Given the limited availability of antifungal drugs and increasing drug resistance, it is imperative to understand the fungus' survival mechanisms for effective control of fungal infections. Our previous study highlighted the essential role of A. fumigatus PGI in maintaining cell wall integrity, phosphate sugar homeostasis, and virulence. The present study further illuminates the involvement of PGI in protein N-glycosylation. Furthermore, this research reveals that the nitrogen assimilation pathway, rather than the canonical MpkA-dependent CWI pathway, compensates for cell wall deficiencies in the mutant. These findings offer valuable insights into a novel adaptation mechanism of A. fumigatus to address cell wall defects, which could hold promise for the treatment of infections.
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Affiliation(s)
- Xiufang Gong
- Institute of Biological Sciences and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yao Zhou
- Institute of Biological Sciences and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Qijian Qin
- Institute of Biological Sciences and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Bin Wang
- Institute of Biological Sciences and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Cheng Jin
- Institute of Biological Sciences and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wenxia Fang
- Institute of Biological Sciences and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
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Zhong C, Nidetzky B. Bottom-Up Synthesized Glucan Materials: Opportunities from Applied Biocatalysis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2400436. [PMID: 38514194 DOI: 10.1002/adma.202400436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/05/2024] [Indexed: 03/23/2024]
Abstract
Linear d-glucans are natural polysaccharides of simple chemical structure. They are comprised of d-glucosyl units linked by a single type of glycosidic bond. Noncovalent interactions within, and between, the d-glucan chains give rise to a broad variety of macromolecular nanostructures that can assemble into crystalline-organized materials of tunable morphology. Structure design and functionalization of d-glucans for diverse material applications largely relies on top-down processing and chemical derivatization of naturally derived starting materials. The top-down approach encounters critical limitations in efficiency, selectivity, and flexibility. Bottom-up approaches of d-glucan synthesis offer different, and often more precise, ways of polymer structure control and provide means of functional diversification widely inaccessible to top-down routes of polysaccharide material processing. Here the natural and engineered enzymes (glycosyltransferases, glycoside hydrolases and phosphorylases, glycosynthases) for d-glucan polymerization are described and the use of applied biocatalysis for the bottom-up assembly of specific d-glucan structures is shown. Advanced material applications of the resulting polymeric products are further shown and their important role in the development of sustainable macromolecular materials in a bio-based circular economy is discussed.
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Affiliation(s)
- Chao Zhong
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, Graz, 8010, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, Graz, 8010, Austria
- Austrian Centre of Industrial Biotechnology (acib), Krenngasse 37, Graz, 8010, Austria
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Chen Y, Gao F, Chen X, Tao S, Chen P, Lin W. The basic leucine zipper transcription factor MeaB is critical for biofilm formation, cell wall integrity, and virulence in Aspergillus fumigatus. mSphere 2024; 9:e0061923. [PMID: 38284755 PMCID: PMC10900910 DOI: 10.1128/msphere.00619-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/18/2023] [Indexed: 01/30/2024] Open
Abstract
The regulation of fungal cell wall biosynthesis is crucial for cell wall integrity maintenance and directly impacts fungal pathogen virulence. Although numerous genes are involved in fungal cell wall polysaccharide biosynthesis through multiple pathways, the underlying regulatory mechanism is still not fully understood. In this study, we identified and functionally characterized a direct downstream target of SomA, the basic-region leucine zipper transcription factor MeaB, playing a certain role in Aspergillus fumigatus cell wall integrity. Loss of meaB reduces hyphal growth, causes severe defects in galactosaminogalactan-mediated biofilm formation, and attenuates virulence in a Galleria mellonella infection model. Furthermore, the meaB null mutant strain exhibited hypersensitivity to cell wall-perturbing agents and significantly alters the cell wall structure. Transcriptional profile analysis revealed that MeaB positively regulates the expression of the galactosaminogalactan biosynthesis and β-1,3-glucanosyltransferase genes uge3, agd3, and sph3 and gel1, gel5, and gel7, respectively, as well as genes involved in amino sugar and nucleotide sugar metabolism. Further study demonstrated that MeaB could respond to cell wall stress and contribute to the proper expression of mitogen-activated protein kinase genes mpkA and mpkC in the presence of different concentrations of congo red. In conclusion, A. fumigatus MeaB plays a critical role in cell wall integrity by governing the expression of genes encoding cell wall-related proteins, thus impacting the virulence of this fungus.IMPORTANCEAspergillus fumigatus is a common opportunistic mold that causes life-threatening infections in immunosuppressed patients. The fungal cell wall is a complex and dynamic organelle essential for the development of pathogenic fungi. Genes involved in cell wall polysaccharide biosynthesis and remodeling are crucial for fungal pathogen virulence. However, the potential regulatory mechanism for cell wall integrity remains to be fully defined in A. fumigatus. In the present study, we identify basic-region leucine zipper transcription factor MeaB as an important regulator of cell wall galactosaminogalactan biosynthesis and β-1,3-glucan remodeling that consequently impacts stress response and virulence of fungal pathogens. Thus, we illuminate a mechanism of transcriptional control fungal cell wall polysaccharide biosynthesis and stress response. As these cell wall components are promising therapeutic targets for fungal infections, understanding the regulatory mechanism of such polysaccharides will provide new therapeutic opportunities.
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Affiliation(s)
- Yuan Chen
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Fei Gao
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Xiaojin Chen
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Siyuan Tao
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Peiying Chen
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
| | - Wei Lin
- Nanjing University of Chinese Medicine, Nanjing Drum Tower Hospital, Nanjing, China
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
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Schruefer S, Pschibul A, Wong SSW, Sae-Ong T, Wolf T, Schäuble S, Panagiotou G, Brakhage AA, Aimanianda V, Kniemeyer O, Ebel F. Distinct transcriptional responses to fludioxonil in Aspergillus fumigatus and its ΔtcsC and Δskn7 mutants reveal a crucial role for Skn7 in the cell wall reorganizations triggered by this antifungal. BMC Genomics 2023; 24:684. [PMID: 37964194 PMCID: PMC10647056 DOI: 10.1186/s12864-023-09777-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 10/31/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus is a major fungal pathogen that causes severe problems due to its increasing resistance to many therapeutic agents. Fludioxonil is a compound that triggers a lethal activation of the fungal-specific High Osmolarity Glycerol pathway. Its pronounced antifungal activity against A. fumigatus and other pathogenic molds renders this agent an attractive lead substance for the development of new therapeutics. The group III hydride histidine kinase TcsC and its downstream target Skn7 are key elements of the multistep phosphorelay that represents the initial section of the High Osmolarity Glycerol pathway. Loss of tcsC results in resistance to fludioxonil, whereas a Δskn7 mutant is partially, but not completely resistant. RESULTS In this study, we compared the fludioxonil-induced transcriptional responses in the ΔtcsC and Δskn7 mutant and their parental A. fumigatus strain. The number of differentially expressed genes correlates well with the susceptibility level of the individual strains. The wild type and, to a lesser extend also the Δskn7 mutant, showed a multi-faceted stress response involving genes linked to ribosomal and peroxisomal function, iron homeostasis and oxidative stress. A marked difference between the sensitive wild type and the largely resistant Δskn7 mutant was evident for many cell wall-related genes and in particular those involved in the biosynthesis of chitin. Biochemical data corroborate this differential gene expression that does not occur in response to hyperosmotic stress. CONCLUSIONS Our data reveal that fludioxonil induces a strong and TcsC-dependent stress that affects many aspects of the cellular machinery. The data also demonstrate a link between Skn7 and the cell wall reorganizations that foster the characteristic ballooning and the subsequent lysis of fludioxonil-treated cells.
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Affiliation(s)
- Sebastian Schruefer
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, Germany
| | - Annica Pschibul
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Sarah Sze Wah Wong
- UMR2000, Molecular Mycology Unit, Mycology Department, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
| | - Tongta Sae-Ong
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Thomas Wolf
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Sascha Schäuble
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Gianni Panagiotou
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Axel A Brakhage
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Vishukumar Aimanianda
- UMR2000, Molecular Mycology Unit, Mycology Department, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
- Institut Pasteur, Université Paris Cité, Immunobiology of Aspergillus, Mycology Department, Paris, France
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Frank Ebel
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, Germany.
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Ishiwata A, Tanaka K, Ito Y, Cai H, Ding F. Recent Progress in 1,2- cis glycosylation for Glucan Synthesis. Molecules 2023; 28:5644. [PMID: 37570614 PMCID: PMC10420028 DOI: 10.3390/molecules28155644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/30/2023] [Accepted: 07/02/2023] [Indexed: 08/13/2023] Open
Abstract
Controlling the stereoselectivity of 1,2-cis glycosylation is one of the most challenging tasks in the chemical synthesis of glycans. There are various 1,2-cis glycosides in nature, such as α-glucoside and β-mannoside in glycoproteins, glycolipids, proteoglycans, microbial polysaccharides, and bioactive natural products. In the structure of polysaccharides such as α-glucan, 1,2-cis α-glucosides were found to be the major linkage between the glucopyranosides. Various regioisomeric linkages, 1→3, 1→4, and 1→6 for the backbone structure, and 1→2/3/4/6 for branching in the polysaccharide as well as in the oligosaccharides were identified. To achieve highly stereoselective 1,2-cis glycosylation, including α-glucosylation, a number of strategies using inter- and intra-molecular methodologies have been explored. Recently, Zn salt-mediated cis glycosylation has been developed and applied to the synthesis of various 1,2-cis linkages, such as α-glucoside and β-mannoside, via the 1,2-cis glycosylation pathway and β-galactoside 1,4/6-cis induction. Furthermore, the synthesis of various structures of α-glucans has been achieved using the recent progressive stereoselective 1,2-cis glycosylation reactions. In this review, recent advances in stereoselective 1,2-cis glycosylation, particularly focused on α-glucosylation, and their applications in the construction of linear and branched α-glucans are summarized.
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Affiliation(s)
| | - Katsunori Tanaka
- RIKEN, Cluster for Pioneering Research, Saitama 351-0198, Japan
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8552, Japan
| | - Yukishige Ito
- RIKEN, Cluster for Pioneering Research, Saitama 351-0198, Japan
- Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Hui Cai
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China
| | - Feiqing Ding
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China
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Lim JY, Jung YE, Hwang HE, Kim CH, Basaran-Akgul N, Goli SH, Templeton SP, Park HM. Survival Factor A (SvfA) Contributes to Aspergillus nidulans Pathogenicity. J Fungi (Basel) 2023; 9:143. [PMID: 36836258 PMCID: PMC9962611 DOI: 10.3390/jof9020143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/02/2023] [Accepted: 01/19/2023] [Indexed: 01/25/2023] Open
Abstract
Survival factor A (SvfA) in Aspergillus nidulans plays multiple roles in growth and developmental processes. It is a candidate for a novel VeA-dependent protein involved in sexual development. VeA is a key developmental regulator in Aspergillus species that can interact with other velvet-family proteins and enter into the nucleus to function as a transcription factor. In yeast and fungi, SvfA-homologous proteins are required for survival under oxidative and cold-stress conditions. To assess the role of SvfA in virulence in A. nidulans, cell wall components, biofilm formation, and protease activity were evaluated in a svfA-gene-deletion or an AfsvfA-overexpressing strain. The svfA-deletion strain showed decreased production of β-1,3-glucan in conidia, a cell wall pathogen-associated molecular pattern, with a decrease in gene expression for chitin synthases and β-1,3-glucan synthase. The ability to form biofilms and produce proteases was reduced in the svfA-deletion strain. We hypothesized that the svfA-deletion strain was less virulent than the wild-type strain; therefore, we performed in vitro phagocytosis assays using alveolar macrophages and analyzed in vivo survival using two vertebrate animal models. While phagocytosis was reduced in mouse alveolar macrophages challenged with conidia from the svfA-deletion strain, the killing rate showed a significant increase with increased extracellular signal-regulated kinase ERK activation. The svfA-deletion conidia infection reduced host mortality in both T-cell-deficient zebrafish and chronic granulomatous disease mouse models. Taken together, these results indicate that SvfA plays a significant role in the pathogenicity of A. nidulans.
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Affiliation(s)
- Joo-Yeon Lim
- Department of Microbiology and Immunology, Indiana University School of Medicine-Terre Haute, Terre Haute, IN 47807, USA
| | - Ye-Eun Jung
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hye-Eun Hwang
- Laboratory of Developmental Genetics Department of Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Cheol-Hee Kim
- Laboratory of Developmental Genetics Department of Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Nese Basaran-Akgul
- Department of Microbiology and Immunology, Indiana University School of Medicine-Terre Haute, Terre Haute, IN 47807, USA
| | - Sri Harshini Goli
- Department of Microbiology and Immunology, Indiana University School of Medicine-Terre Haute, Terre Haute, IN 47807, USA
| | - Steven P. Templeton
- Department of Microbiology and Immunology, Indiana University School of Medicine-Terre Haute, Terre Haute, IN 47807, USA
| | - Hee-Moon Park
- Laboratory of Cellular Differentiation, Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea
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Tamimi R, Kyazze G, Keshavarz T. Antifungal effect of triclosan on Aspergillus fumigatus: quorum quenching role as a single agent and synergy with liposomal amphotericin-B. World J Microbiol Biotechnol 2022; 38:142. [PMID: 35718814 PMCID: PMC9206924 DOI: 10.1007/s11274-022-03325-1] [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: 11/01/2021] [Accepted: 05/30/2022] [Indexed: 11/29/2022]
Abstract
The purpose of this research was to determine Aspergillus fumigatus conidial viability and its biofilm formation upon treatment with triclosan and amphotericin-B loaded liposomes. A. fumigatus was treated with the antimicrobials, triclosan and liposomal amphotericin-B (L-AMB), in single and combined supplementation. To quantify the cells’ viability upon treatments, resazurin-based viability assay was performed. Confocal laser scanning microscopy was done by applying FUN-1 stain to screen the role of the agents on extracellular polymeric substances. Total A. fumigatus biomass upon treatments was estimated by using crystal violet-based assay. To study the agents’ effect on the conidial viability, flow cytometry analysis was performed. Expression levels of A. fumigatus genes encoding cell wall proteins, α-(1,3)-glucans and galactosaminogalactan were analysed by real-time polymerase chain reaction assay. A synergistic interaction occurred between triclosan and L-AMB when they were added sequentially (triclosan + L-AMB) at their sub-minimum inhibitory concentrations, the triclosan and L-AMB MICs were dropped to 0.6 and 0.2 mg/L, respectively, from 2 to 1 mg/L. Besides, L-AMB and triclosan contributed to the down-regulation of α-(1,3)-glucan and galactosaminogalactan in A. fumigatus conidia and resulted in less conidia aggregation and mycelia adhesion to the biotic/abiotic surfaces; A. fumigatus conidia-became hydrophilic upon treatment, as a result of rodlet layer being masked by a hydrophilic layer or modified by the ionic strength of the rodlet layer. In A. fumigatus, the potential mechanisms of action for L-AMB might be through killing the cells and for triclosan through interrupting the cells’ development as a consequence of quorum quenching.
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Affiliation(s)
- Roya Tamimi
- School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London, W1W 6UW, UK.
| | - Godfrey Kyazze
- School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London, W1W 6UW, UK
| | - Tajalli Keshavarz
- School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London, W1W 6UW, UK
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Miyazawa K, Umeyama T, Hoshino Y, Abe K, Miyazaki Y. Quantitative Monitoring of Mycelial Growth of Aspergillus fumigatus in Liquid Culture by Optical Density. Microbiol Spectr 2022; 10:e0006321. [PMID: 34985327 PMCID: PMC8729762 DOI: 10.1128/spectrum.00063-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/17/2021] [Indexed: 01/24/2023] Open
Abstract
Filamentous fungi form multicellular hyphae, which generally form pellets in liquid shake cultures, during the vegetative growth stage. Because of these characteristics, growth-monitoring methods commonly used in bacteria and yeast have not been applied to filamentous fungi. We have recently revealed that the cell wall polysaccharide α-1,3-glucan and extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae. Here, we tested whether Aspergillus fumigatus shows dispersed growth in liquid media that can be quantitatively monitored, similar to that of yeasts. We constructed a double disruptant mutant of both the primary α-1,3-glucan synthase gene ags1 and the putative GAG synthase gene gtb3 in A. fumigatus AfS35 and found that the hyphae of this mutant were fully dispersed. Although the mutant lost α-1,3-glucan and GAG, its growth and susceptibility to antifungal agents were not different from those of the parental strain. Mycelial weight of the mutant in shake-flask cultures was proportional to optical density for at least 18 h. We were also able to quantify the dose response of hyphal growth to antifungal agents by measuring optical density. Overall, we established a convenient strategy to monitor A. fumigatus hyphal growth. Our method can be directly used for screening for novel antifungals against Aspergillus species. IMPORTANCE Filamentous fungi generally form hyphal pellets in liquid culture. This property prevents filamentous fungi so that we may apply the methods used for unicellular organisms such as yeast and bacteria. In the present study, by using the fungal pathogen Aspergillus fumigatus strain with modified hyphal surface polysaccharides, we succeeded in monitoring the hyphal growth quantitatively by optical density. The principle of this easy measurement by optical density could lead to a novel standard of hyphal quantification such as those that have been used for yeasts and bacteria. Dose response of hyphal growth by antifungal agents could also be monitored. This method could be useful for screening for novel antifungal reagents against Aspergillus species.
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Affiliation(s)
- Ken Miyazawa
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takashi Umeyama
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasutaka Hoshino
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yoshitsugu Miyazaki
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
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10
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Miyazawa K, Yamashita T, Takeuchi A, Kamachi Y, Yoshimi A, Tashiro Y, Koizumi A, Ogata M, Yano S, Kasahara S, Sano M, Yamagata Y, Nakajima T, Abe K. A Glycosylphosphatidylinositol-Anchored α-Amylase Encoded by amyD Contributes to a Decrease in the Molecular Mass of Cell Wall α-1,3-Glucan in Aspergillus nidulans. FRONTIERS IN FUNGAL BIOLOGY 2022; 2:821946. [PMID: 37744142 PMCID: PMC10512252 DOI: 10.3389/ffunb.2021.821946] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/22/2021] [Indexed: 09/26/2023]
Abstract
α-1,3-Glucan is one of the main polysaccharides in the cell wall of Aspergillus nidulans. We previously revealed that it plays a role in hyphal aggregation in liquid culture, and that its molecular mass (MM) in an agsA-overexpressing (agsAOE) strain was larger than that in an agsB-overexpressing (agsBOE) strain. The mechanism that regulates its MM is poorly understood. Although the gene amyD, which encodes glycosylphosphatidylinositol (GPI)-anchored α-amylase (AmyD), is involved in the biosynthesis of α-1,3-glucan in A. nidulans, how it regulates this biosynthesis remains unclear. Here we constructed strains with disrupted amyD (ΔamyD) or overexpressed amyD (amyDOE) in the genetic background of the ABPU1 (wild-type), agsAOE, or agsBOE strain, and characterized the chemical structure of α-1,3-glucans in the cell wall of each strain, focusing on their MM. The MM of α-1,3-glucan from the agsBOE amyDOE strain was smaller than that in the parental agsBOE strain. In addition, the MM of α-1,3-glucan from the agsAOE ΔamyD strain was greater than that in the agsAOE strain. These results suggest that AmyD is involved in decreasing the MM of α-1,3-glucan. We also found that the C-terminal GPI-anchoring region is important for these functions.
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Affiliation(s)
- Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- Laboratory of Filamentous Mycoses, Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takaaki Yamashita
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ayumu Takeuchi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yuka Kamachi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Yuto Tashiro
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ami Koizumi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Makoto Ogata
- Faculty of Food and Agricultural Sciences, Fukushima University, Fukushima, Japan
| | - Shigekazu Yano
- Department of Biochemical Engineering, Graduate School of Engineering, Yamagata University, Yonezawa, Japan
| | - Shin Kasahara
- Food Microbiology Unit, School of Food and Agricultural Sciences, Miyagi University, Sendai, Japan
| | - Motoaki Sano
- Genome Biotechnology Laboratory, Kanazawa Institute of Technology, Hakusan, Japan
| | - Youhei Yamagata
- Department of Applied Life Science, The United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Tasuku Nakajima
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
- Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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11
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The β-1,3-glucan synthase gene GFGLS2 plays major roles in mycelial growth and polysaccharide synthesis in Grifola frondosa. Appl Microbiol Biotechnol 2021; 106:563-578. [PMID: 34939133 DOI: 10.1007/s00253-021-11734-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 12/02/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022]
Abstract
β-1,3-Glucans are well-known biological and health-promoting compounds in edible fungi. Our previous results characterized a glucan synthase gene (GFGLS) of Grifola frondosa for the first time to understand its role in mycelial growth and glucan biosynthesis. In the present study, we identified and functionally reannotated another glucan synthase gene, GFGLS2, based on our previous results. GFGLS2 had a full sequence of 5944 bp including 11 introns and 12 exons and a coding information for 1713 amino acids of a lower molecular weight (195.2 kDa) protein with different conserved domain sites than GFGLS (5927 bp with also 11 introns and a coding information for 1781 aa). Three dual-promoter RNA-silencing vectors, pAN7-iGFGLS-dual, pAN7-iGFGLS2-dual, and pAN7-CiGFGLS-dual, were constructed to downregulate GFGLS, GFGLS2, and GFGLS/GFGLS2 expression by targeting their unique exon sequence or conserved functional sequences. Silencing GFGLS2 resulted in higher downregulation efficiency than silencing GFGLS. Cosilencing GFGLS and GFGLS2 had a synergistic downregulation effect, with slower mycelial growth and glucan production by G. frondosa. These findings indicated that GFGLS2 plays major roles in mycelial growth and polysaccharide synthesis and provides a reference to understand the biosynthesis pathway of mushroom polysaccharides. KEY POINTS: • The 5944-bp glucan synthase gene GFGLS2 of G. frondosa was cloned and reannotated • GFGLS2 showed identity and significant differences with the previously identified GFGLS • GFGLS2 played a major role in fermentation and glucan biosynthesis.
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12
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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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13
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Carvalho VSD, Gómez-Delgado L, Curto MÁ, Moreno MB, Pérez P, Ribas JC, Cortés JCG. Analysis and application of a suite of recombinant endo-β(1,3)-D-glucanases for studying fungal cell walls. Microb Cell Fact 2021; 20:126. [PMID: 34217291 PMCID: PMC8254974 DOI: 10.1186/s12934-021-01616-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/19/2021] [Indexed: 12/31/2022] Open
Abstract
Background The fungal cell wall is an essential and robust external structure that protects the cell from the environment. It is mainly composed of polysaccharides with different functions, some of which are necessary for cell integrity. Thus, the process of fractionation and analysis of cell wall polysaccharides is useful for studying the function and relevance of each polysaccharide, as well as for developing a variety of practical and commercial applications. This method can be used to study the mechanisms that regulate cell morphogenesis and integrity, giving rise to information that could be applied in the design of new antifungal drugs. Nonetheless, for this method to be reliable, the availability of trustworthy commercial recombinant cell wall degrading enzymes with non-contaminating activities is vital. Results Here we examined the efficiency and reproducibility of 12 recombinant endo-β(1,3)-d-glucanases for specifically degrading the cell wall β(1,3)-d-glucan by using a fast and reliable protocol of fractionation and analysis of the fission yeast cell wall. This protocol combines enzymatic and chemical degradation to fractionate the cell wall into the four main polymers: galactomannoproteins, α-glucan, β(1,3)-d-glucan and β(1,6)-d-glucan. We found that the GH16 endo-β(1,3)-d-glucanase PfLam16A from Pyrococcus furiosus was able to completely and reproducibly degrade β(1,3)-d-glucan without causing the release of other polymers. The cell wall degradation caused by PfLam16A was similar to that of Quantazyme, a recombinant endo-β(1,3)-d-glucanase no longer commercially available. Moreover, other recombinant β(1,3)-d-glucanases caused either incomplete or excessive degradation, suggesting deficient access to the substrate or release of other polysaccharides. Conclusions The discovery of a reliable and efficient recombinant endo-β(1,3)-d-glucanase, capable of replacing the previously mentioned enzyme, will be useful for carrying out studies requiring the digestion of the fungal cell wall β(1,3)-d-glucan. This new commercial endo-β(1,3)-d-glucanase will allow the study of the cell wall composition under different conditions, along the cell cycle, in response to environmental changes or in cell wall mutants. Furthermore, this enzyme will also be greatly valuable for other practical and commercial applications such as genome research, chromosomes extraction, cell transformation, protoplast formation, cell fusion, cell disruption, industrial processes and studies of new antifungals that specifically target cell wall synthesis. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01616-0.
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Affiliation(s)
- Vanessa S D Carvalho
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain
| | - Laura Gómez-Delgado
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain
| | - M Ángeles Curto
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain
| | - M Belén Moreno
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain.
| | - Juan Carlos G Cortés
- Instituto de Biología Funcional y Genómica Zacarías González, 2. CSIC and Universidad de Salamanca, 37007, Salamanca, Spain.
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14
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Understanding the fundamental role of virulence determinants to combat Aspergillus fumigatus infections: exploring beyond cell wall. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01677-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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15
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Tamez-Castrellón AK, Romeo O, García-Carnero LC, Lozoya-Pérez NE, Mora-Montes HM. Virulence Factors in Sporothrix schenckii, One of the Causative Agents of Sporotrichosis. Curr Protein Pept Sci 2021; 21:295-312. [PMID: 31589121 DOI: 10.2174/1389203720666191007103004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/02/2019] [Accepted: 08/08/2019] [Indexed: 11/22/2022]
Abstract
Sporothrix schenckii is one of the etiological agents of sporotrichosis, a fungal infection distributed worldwide. Both, the causative organism and the disease have currently received limited attention by the medical mycology community, most likely because of the low mortality rates associated with it. Nonetheless, morbidity is high in endemic regions and the versatility of S. schenckii to cause zoonosis and sapronosis has attracted attention. Thus far, virulence factors associated with this organism are poorly described. Here, comparing the S. schenckii genome sequence with other medically relevant fungi, genes involved in morphological change, cell wall synthesis, immune evasion, thermotolerance, adhesion, biofilm formation, melanin production, nutrient uptake, response to stress, extracellular vesicle formation, and toxin production are predicted and discussed as putative virulence factors in S. schenckii.
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Affiliation(s)
- Alma K Tamez-Castrellón
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
| | - Orazio Romeo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Laura C García-Carnero
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
| | - Nancy E Lozoya-Pérez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
| | - Héctor M Mora-Montes
- Departamento de Biología, División de Ciencias Naturales y Exactas, Campus Guanajuato, Universidad de Guanajuato, Noria Alta s/n, col. Noria Alta, C.P. 36050, Guanajuato, Gto., Mexico
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16
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Gene Expression Analysis of Non-Clinical Strain of Aspergillus fumigatus (LMB-35Aa): Does Biofilm Affect Virulence? J Fungi (Basel) 2020; 6:jof6040376. [PMID: 33352977 PMCID: PMC7766361 DOI: 10.3390/jof6040376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 12/18/2022] Open
Abstract
Aspergillus fumigatus LMB-35Aa, a saprophytic fungus, was used for cellulase production through biofilms cultures. Since biofilms usually favor virulence in clinical strains, the expression of the related genes of the LMB 35-Aa strain was analyzed by qPCR from the biomass of planktonic cultures and biofilms developed on polyester cloth and polystyrene microplates. For this, virulence-related genes reported for the clinical strain Af293 were searched in A. fumigatus LMB 35-Aa genome, and 15 genes were identified including those for the synthesis of cell wall components, hydrophobins, invasins, efflux transporters, mycotoxins and regulators. When compared with planktonic cultures at 37 °C, invasin gene calA was upregulated in both types of biofilm and efflux transporter genes mdr4 and atrF were predominantly upregulated in biofilms on polystyrene, while aspHs and ftmA were upregulated only in biofilms formed on polyester. Regarding the transcription regulators, laeA was downregulated in biofilms, and medA did not show a significant change. The effect of temperature was also evaluated by comparing the biofilms grown on polyester at 37 vs. 28 °C. Non-significant changes at the expression level were found for most genes evaluated, except for atrF, gliZ and medA, which were significantly downregulated at 37 °C. According to these results, virulence appears to depend on the interaction of several factors in addition to biofilms and growth temperature.
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17
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Wang S, Yuan A, Zeng L, Hou S, Wang M, Li L, Cai Z, Zhong G. The putative polysaccharide synthase AfCps1 regulates Aspergillus fumigatus morphogenesis and conidia immune response in mouse bone marrow-derived macrophages. J Microbiol 2020; 59:64-75. [PMID: 33201436 DOI: 10.1007/s12275-021-0347-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
Aspergillus fumigatus is a well-known opportunistic pathogen that causes invasive aspergillosis (IA) infections with high mortality in immunosuppressed individuals. Morphogenesis, including hyphal growth, conidiation, and cell wall biosynthesis is crucial in A. fumigatus pathogenesis. Based on a previous random insertional mutagenesis library, we identified the putative polysaccharide synthase gene Afcps1 and its para-log Afcps2. Homologs of the cps gene are commonly found in the genomes of most fungal and some bacterial pathogens. Afcps1/cpsA is important in sporulation, cell wall composition, and virulence. However, the precise regulation patterns of cell wall integrity by Afcps1/cpsA and further effects on the immune response are poorly understood. Specifically, our in-depth study revealed that Afcps1 affects cell-wall stability, showing an increased resistance of ΔAfcps1 to the chitinmicrofibril destabilizing compound calcofluor white (CFW) and susceptibility of ΔAfcps1 to the β-(1,3)-glucan synthase inhibitor echinocandin caspofungin (CS). Additionally, deletion of Afcps2 had a normal sporulation phenotype but caused hypersensitivity to Na+ stress, CFW, and Congo red (CR). Specifically, quantitative analysis of cell wall composition using high-performance anion exchange chromatography-pulsed amperometric detector (HPAEC-PAD) analysis revealed that depletion of Afcps1 reduced cell wall glucan and chitin contents, which was consistent with the down-regulation of expression of the corresponding biosynthesis genes. Moreover, an elevated immune response stimulated by conidia of the ΔAfcps1 mutant in marrow-derived macrophages (BMMs) during phagocytosis was observed. Thus, our study provided new insights into the function of polysaccharide synthase Cps1, which is necessary for the maintenance of cell wall stability and the adaptation of conidia to the immune response of macrophages in A. fumigatus.
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Affiliation(s)
- Sha Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou Central Hospital, Huzhou, P. R. China
| | - Anjie Yuan
- Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, P. R. China
| | - Liping Zeng
- Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, P. R. China
| | - Sikai Hou
- Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, P. R. China
| | - Meng Wang
- Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, P. R. China
| | - Lei Li
- Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, P. R. China
| | - Zhendong Cai
- Key Laboratory of Animal Protein Deep Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, 315800, P. R. China.
| | - Guowei Zhong
- Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, P. R. China.
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18
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Qi CY, Jia SL, Wei X, Yang G, Chi Z, Liu GL, Hu Z, Chi ZM. The differences between fungal α-glucan synthase determining pullulan synthesis and that controlling cell wall α-1,3 glucan synthesis. Int J Biol Macromol 2020; 162:436-444. [DOI: 10.1016/j.ijbiomac.2020.06.147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 06/16/2020] [Indexed: 11/30/2022]
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19
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Miyazawa K, Yoshimi A, Abe K. The mechanisms of hyphal pellet formation mediated by polysaccharides, α-1,3-glucan and galactosaminogalactan, in Aspergillus species. Fungal Biol Biotechnol 2020; 7:10. [PMID: 32626592 PMCID: PMC7329490 DOI: 10.1186/s40694-020-00101-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/12/2020] [Indexed: 01/01/2023] Open
Abstract
Filamentous fungi are widely used for production of enzymes and chemicals, and are industrially cultivated both in liquid and solid cultures. Submerged culture is often used as liquid culture for filamentous fungi. In submerged culture, filamentous fungi show diverse macromorphology such as hyphal pellets and dispersed hyphae depending on culture conditions and genetic backgrounds of fungal strains. Although the macromorphology greatly affects the productivity of submerged cultures, the specific cellular components needed for hyphal aggregation after conidial germination have not been characterized. Recently we reported that the primary cell wall polysaccharide α-1,3-glucan and the extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae, and that a strain deficient in both α-1,3-glucan and GAG shows dispersed hyphae in liquid culture. In this review, we summarize our current understanding of the contribution of chemical properties of α-1,3-glucan and GAG to hyphal aggregation. Various ascomycetes and basidiomycetes have α-1,3-glucan synthase gene(s). In addition, some Pezizomycotina fungi, including species used in the fermentation industry, also have GAG biosynthetic genes. We also review here the known mechanisms of biosynthesis of α-1,3-glucan and GAG. Regulation of the biosynthesis of the two polysaccharides could be a potential way of controlling formation of hyphal pellets.
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Affiliation(s)
- Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aoba, Aoba-ku, Sendai, 980-8572 Japan
| | - Akira Yoshimi
- Laboratory of Environmental Interface Technology of Filamentous Fungi, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 Japan.,ABE-project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579 Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aoba, Aoba-ku, Sendai, 980-8572 Japan.,ABE-project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki-Aoba, Aoba-ku, Sendai, 980-8579 Japan.,Laboratory of Microbial Resources, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aoba, Aoba-ku, Sendai, 980-8572 Japan
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20
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Mouyna I, Dellière S, Beauvais A, Gravelat F, Snarr B, Lehoux M, Zacharias C, Sun Y, de Jesus Carrion S, Pearlman E, Sheppard DC, Latgé JP. What Are the Functions of Chitin Deacetylases in Aspergillus fumigatus? Front Cell Infect Microbiol 2020; 10:28. [PMID: 32117802 PMCID: PMC7016196 DOI: 10.3389/fcimb.2020.00028] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/15/2020] [Indexed: 11/13/2022] Open
Abstract
Deacetylation of chitin by chitin deacetylases (Cda) results in the formation of chitosan. Chitosan, a polymer of β1,4 linked glucosamine, plays multiple roles in the function of the fungal cell wall, including virulence and evasion of host immune responses. In this study, the roles of chitosan and putative CDAs in cell wall structure and virulence of Aspergillus fumigatus were investigated. Low levels of chitosan were found in the conidial and cell wall of A. fumigatus. Seven putative CDA genes were identified, disrupted and the phenotype of the single mutants and the septuple mutants were investigated. No alterations in fungal cell wall chitosan levels, changes in fungal growth or alterations in virulence were detected in the single or septuple Δcda1-7 mutant strains. Collectively, these results suggest that chitosan is a minority component of the A. fumigatus cell wall, and that the seven candidate Cda proteins do not play major roles in fungal cell wall synthesis or virulence. However, Cda2 is involved in conidiation, suggesting that this enzyme may play a role in N-acetyl-glucosamine metabolism.
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Affiliation(s)
| | - Sarah Dellière
- Infectious Diseases in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, QC, Canada
| | | | - Fabrice Gravelat
- Infectious Diseases in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, QC, Canada
- Departments of Microbiology and Immunology, Medicine, McGill University, Montréal, QC, Canada
| | - Brendan Snarr
- Infectious Diseases in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, QC, Canada
- Departments of Microbiology and Immunology, Medicine, McGill University, Montréal, QC, Canada
| | - Mélanie Lehoux
- Infectious Diseases in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, QC, Canada
| | - Caitlin Zacharias
- Infectious Diseases in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, QC, Canada
- Departments of Microbiology and Immunology, Medicine, McGill University, Montréal, QC, Canada
| | - Yan Sun
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Steven de Jesus Carrion
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Eric Pearlman
- Department of Ophthalmology, University of California, Irvine, Irvine, CA, United States
| | - Donald C. Sheppard
- Infectious Diseases in Global Health Program, Centre for Translational Biology, McGill University Health Centre, Montréal, QC, Canada
- Departments of Microbiology and Immunology, Medicine, McGill University, Montréal, QC, Canada
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21
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Wagener J, Striegler K, Wagener N. α- and β-1,3-Glucan Synthesis and Remodeling. Curr Top Microbiol Immunol 2020; 425:53-82. [PMID: 32193600 DOI: 10.1007/82_2020_200] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Glucans are characteristic and major constituents of fungal cell walls. Depending on the species, different glucan polysaccharides can be found. These differ in the linkage of the D-glucose monomers which can be either in α- or β-conformation and form 1,3, 1,4 or 1,6 O-glycosidic bonds. The linkages and polymer lengths define the physical properties of the glucan macromolecules, which may form a scaffold for other cell wall structures and influence the rigidity and elasticity of the wall. β-1,3-glucan is essential for the viability of many fungal pathogens. Therefore, the β-1,3-glucan synthase complex represents an excellent and primary target structure for antifungal drugs. Fungal cell wall β-glucan is also an important pathogen-associated molecular pattern (PAMP). To hide from innate immunity, many fungal pathogens depend on the synthesis of cell wall α-glucan, which functions as a stealth molecule to mask the β-glucans itself or links other masking structures to the cell wall. Here, we review the current knowledge about the biosynthetic machineries that synthesize β-1,3-glucan, β-1,6-glucan, and α-1,3-glucan. We summarize the discovery of the synthases, major regulatory traits, and the impact of glucan synthesis deficiencies on the fungal organisms. Despite all efforts, many aspects of glucan synthesis remain yet unresolved, keeping research directed toward cell wall biogenesis an exciting and continuously challenging topic.
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Affiliation(s)
- Johannes Wagener
- Institut Für Hygiene Und Mikrobiologie, University of Würzburg, Würzburg, Germany. .,National Reference Center for Invasive Fungal Infections (NRZMyk), Jena, Germany.
| | - Kristina Striegler
- Institut Für Hygiene Und Mikrobiologie, University of Würzburg, Würzburg, Germany
| | - Nikola Wagener
- Department of Cell Biology, Medical Faculty, University of Munich, Martinsried, Germany
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22
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Złotko K, Wiater A, Waśko A, Pleszczyńska M, Paduch R, Jaroszuk-Ściseł J, Bieganowski A. A Report on Fungal (1→3)-α-d-glucans: Properties, Functions and Application. Molecules 2019; 24:E3972. [PMID: 31684030 PMCID: PMC6864487 DOI: 10.3390/molecules24213972] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 12/13/2022] Open
Abstract
The cell walls of fungi are composed of glycoproteins, chitin, and α- and β-glucans. Although there are many reports on β-glucans, α-glucan polysaccharides are not yet fully understood. This review characterizes the physicochemical properties and functions of (1→3)-α-d-glucans. Particular attention has been paid to practical application and the effect of glucans in various respects, taking into account unfavourable effects and potential use. The role of α-glucans in plant infection has been proven, and collected facts have confirmed the characteristics of Aspergillus fumigatus infection associated with the presence of glucan in fungal cell wall. Like β-glucans, there are now evidence that α-glucans can also stimulate the immune system. Moreover, α-d-glucans have the ability to induce mutanases and can thus decompose plaque.
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Affiliation(s)
- Katarzyna Złotko
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
| | - Adrian Wiater
- Department of Industrial and Environmental Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Adam Waśko
- Department of Biotechnology, Human Nutrition and Food Commodity Science, University of Life Sciences in Lublin, Skromna 8, 20-704 Lublin, Poland.
| | - Małgorzata Pleszczyńska
- Department of Industrial and Environmental Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Roman Paduch
- Department of Virology and Immunology, Maria Curie-Skłodowska University, ul. Akademicka 19, 20-033 Lublin, Poland.
- Department of General Ophthalmology, Medical University, Chmielna 1, 20-079 Lublin, Poland.
| | - Jolanta Jaroszuk-Ściseł
- Department of Industrial and Environmental Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Andrzej Bieganowski
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
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23
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Jeennor S, Anantayanon J, Panchanawaporn S, Chutrakul C, Laoteng K. Morphologically engineered strain of Aspergillus oryzae as a cell chassis for production development of functional lipids. Gene 2019; 718:144073. [DOI: 10.1016/j.gene.2019.144073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/08/2019] [Accepted: 08/21/2019] [Indexed: 01/30/2023]
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24
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Patel PK, Free SJ. The Genetics and Biochemistry of Cell Wall Structure and Synthesis in Neurospora crassa, a Model Filamentous Fungus. Front Microbiol 2019; 10:2294. [PMID: 31649638 PMCID: PMC6796803 DOI: 10.3389/fmicb.2019.02294] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/20/2019] [Indexed: 01/25/2023] Open
Abstract
This review discusses the wealth of information available for the N. crassa cell wall. The basic organization and structure of the cell wall is presented and how the wall changes during the N. crassa life cycle is discussed. Over forty cell wall glycoproteins have been identified by proteomic analyses. Genetic and biochemical studies have identified many of the key enzymes needed for cell wall biogenesis, and the roles these enzymes play in cell wall biogenesis are discussed. The review includes a discussion of how the major cell wall components (chitin, β-1,3-glucan, mixed β-1,3-/ β-1,4- glucans, glycoproteins, and melanin) are synthesized and incorporated into the cell wall. We present a four-step model for how cell wall glycoproteins are covalently incorporated into the cell wall. In N. crassa, the covalent incorporation of cell wall glycoproteins into the wall occurs through a glycosidic linkage between lichenin (a mixed β-1,3-/β-1,4- glucan) and a "processed" galactomannan that has been attached to the glycoprotein N-linked oligosaccharides. The first step is the addition of the galactomannan to the N-linked oligosaccharide. Mutants affected in galactomannan formation are unable to incorporate glycoproteins into their cell walls. The second step is carried out by the enzymes from the GH76 family of α-1,6-mannanases, which cleave the galactomannan to generate a processed galactomannan. The model suggests that the third and fourth steps are carried out by members of the GH72 family of glucanosyltransferases. In the third step the glucanosyltransferases cleave lichenin and generate enzyme/substrate intermediates in which the lichenin is covalently attached to the active site of the glucanosyltransferases. In the final step, the glucanosyltransferases attach the lichenin onto the processed galactomannans, which creates new glycosidic bonds and effectively incorporates the glycoproteins into the cross-linked cell wall glucan/chitin matrix.
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Affiliation(s)
| | - Stephen J. Free
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, NY, United States
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25
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Cortés JCG, Curto MÁ, Carvalho VSD, Pérez P, Ribas JC. The fungal cell wall as a target for the development of new antifungal therapies. Biotechnol Adv 2019; 37:107352. [PMID: 30797093 DOI: 10.1016/j.biotechadv.2019.02.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/23/2019] [Accepted: 02/16/2019] [Indexed: 12/17/2022]
Abstract
In the past three decades invasive mycoses have globally emerged as a persistent source of healthcare-associated infections. The cell wall surrounding the fungal cell opposes the turgor pressure that otherwise could produce cell lysis. Thus, the cell wall is essential for maintaining fungal cell shape and integrity. Given that this structure is absent in host mammalian cells, it stands as an important target when developing selective compounds for the treatment of fungal infections. Consequently, treatment with echinocandins, a family of antifungal agents that specifically inhibits the biosynthesis of cell wall (1-3)β-D-glucan, has been established as an alternative and effective antifungal therapy. However, the existence of many pathogenic fungi resistant to single or multiple antifungal families, together with the limited arsenal of available antifungal compounds, critically affects the effectiveness of treatments against these life-threatening infections. Thus, new antifungal therapies are required. Here we review the fungal cell wall and its relevance in biotechnology as a target for the development of new antifungal compounds, disclosing the most promising cell wall inhibitors that are currently in experimental or clinical development for the treatment of some invasive mycoses.
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Affiliation(s)
- Juan Carlos G Cortés
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
| | - M-Ángeles Curto
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Vanessa S D Carvalho
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
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26
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Miyazawa K, Yoshimi A, Kasahara S, Sugahara A, Koizumi A, Yano S, Kimura S, Iwata T, Sano M, Abe K. Molecular Mass and Localization of α-1,3-Glucan in Cell Wall Control the Degree of Hyphal Aggregation in Liquid Culture of Aspergillus nidulans. Front Microbiol 2018; 9:2623. [PMID: 30459735 PMCID: PMC6232457 DOI: 10.3389/fmicb.2018.02623] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/15/2018] [Indexed: 12/21/2022] Open
Abstract
α-1,3-Glucan is one of the main polysaccharides in the cell wall of filamentous fungi. Aspergillus nidulans has two α-1,3-glucan synthase genes, agsA and agsB. We previously revealed that AgsB is a major α-1,3-glucan synthase in vegetative hyphae, but the function of AgsA remained unknown because of its low expression level and lack of phenotypic alteration upon gene disruption. To clarify the role of α-1,3-glucan in hyphal aggregation, we constructed strains overexpressing agsA (agsAOE) or agsB (agsBOE), in which the other α-1,3-glucan synthase gene was disrupted. In liquid culture, the wild-type and agsBOE strains formed tightly aggregated hyphal pellets, whereas agsAOE hyphae aggregated weakly. We analyzed the chemical properties of cell wall α-1,3-glucan from the agsAOE and agsBOE strains. The peak molecular mass of α-1,3-glucan from the agsAOE strain (1,480 ± 80 kDa) was much larger than that from the wild type (147 ± 52 kDa) and agsBOE (372 ± 47 kDa); however, the peak molecular mass of repeating subunits in α-1,3-glucan was almost the same (after Smith degradation: agsAOE, 41.6 ± 5.8 kDa; agsBOE, 38.3 ± 3.0 kDa). We also analyzed localization of α-1,3-glucan in the cell wall of the two strains by fluorescent labeling with α-1,3-glucan-binding domain–fused GFP (AGBD-GFP). α-1,3-Glucan of the agsBOE cells was clearly located in the outermost layer, whereas weak labeling was detected in the agsAOE cells. However, the agsAOE cells treated with β-1,3-glucanase were clearly labeled with AGBD-GFP. These observations suggest that β-1,3-glucan covered most of α-1,3-glucan synthesized by AgsA, although a small amount of α-1,3-glucan was still present in the outer layer. We also constructed a strain with disruption of the amyG gene, which encodes an intracellular α-amylase that synthesizes α-1,4-glucooligosaccharide as a primer for α-1,3-glucan biosynthesis. In this strain, the hyphal pellets and peak molecular mass of α-1,3-glucan (94.5 ± 1.4 kDa) were smaller than in the wild-type strain, and α-1,3-glucan was still labeled with AGBD-GFP in the outermost layer. Overall, these results suggest that hyphal pellet formation depends on the molecular mass and spatial localization of α-1,3-glucan as well as the amount of α-1,3-glucan in the cell wall of A. nidulans.
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Affiliation(s)
- Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Akira Yoshimi
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Shin Kasahara
- Department of Environmental Sciences, School of Food, Agricultural and Environmental Sciences, Miyagi University, Taiwa, Japan
| | - Asumi Sugahara
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ami Koizumi
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Shigekazu Yano
- Department of Biochemical Engineering, Graduate School of Engineering, Yamagata University, Yonezawa, Japan
| | - Satoshi Kimura
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Department of Plant and Environmental New Resources, College of Life Sciences, Kyung Hee University, Seoul, South Korea
| | - Tadahisa Iwata
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Motoaki Sano
- Genome Biotechnology Laboratory, Kanazawa Institute of Technology, Hakusan, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,ABE-Project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan.,Laboratory of Microbial Resources, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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27
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Komarova BS, Wong SSW, Orekhova MV, Tsvetkov YE, Krylov VB, Beauvais A, Bouchara JP, Kearney JF, Aimanianda V, Latgé JP, Nifantiev NE. Chemical Synthesis and Application of Biotinylated Oligo-α-(1 → 3)-d-Glucosides To Study the Antibody and Cytokine Response against the Cell Wall α-(1 → 3)-d-Glucan of Aspergillus fumigatus. J Org Chem 2018; 83:12965-12976. [PMID: 30277398 DOI: 10.1021/acs.joc.8b01142] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biotinylated hepta-, nona- and undeca-α-(1 → 3)-d-glucosides representing long oligosaccharides of α-(1 → 3)-d-glucan, one of the major components of the cell walls of the fungal pathogen Aspergillus fumigatus, were synthesized for the first time via a blockwise strategy. Convergent assembly of the α-(1 → 3)-d-glucan chains was achieved by glycosylation with oligoglucoside derivatives bearing 6- O-benzoyl groups. Those groups are capable of remote α-stereocontrolling participation, making them efficient α-directing tools even in the case of large glycosyl donors. Synthetic biotinylated oligoglucosides (and biotinylated derivatives of previously synthesized tri- and penta-α-(1 → 3)-d-glucosides) loaded on streptavidin microtiter plates were shown to be better recognized by anti-α-(1 → 3)-glucan human polyclonal antibodies and to induce higher cytokine responses upon stimulation of human peripheral blood mononuclear cells than their natural counterpart, α-(1 → 3)-d-glucan, immobilized on a conventional microtiter plate. Attachment of the synthetic oligosaccharides equipped with a hydrophilic spacer via the streptavidin-biotin pair allows better spatial presentation and control of the loading compared to the random sorption of natural α-(1 → 3)-glucan. Increase of oligoglucoside length results in their better recognition and enhancement of cytokine production. Thus, using synthetic α-(1 → 3)-glucan oligosaccharides, we developed an assay for the host immune response that is more sensitive than the assay based on native α-(1 → 3)-glucan.
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Affiliation(s)
- Bozhena S Komarova
- Laboratory of Glycoconjugate Chemistry , N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47 , 119991 Moscow , Russia
| | - Sarah S W Wong
- Unité des Aspergillus , Institut Pasteur , 25 rue du Docteur Roux , 75724 Paris Cedex 15 , France
| | - Maria V Orekhova
- Laboratory of Glycoconjugate Chemistry , N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47 , 119991 Moscow , Russia
| | - Yury E Tsvetkov
- Laboratory of Glycoconjugate Chemistry , N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47 , 119991 Moscow , Russia
| | - Vadim B Krylov
- Laboratory of Glycoconjugate Chemistry , N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47 , 119991 Moscow , Russia
| | - Anne Beauvais
- Unité des Aspergillus , Institut Pasteur , 25 rue du Docteur Roux , 75724 Paris Cedex 15 , France
| | - Jean-Philippe Bouchara
- Groupe d'Etude des Interactions Hôte-Pathogène (EA 3142) , UNIV Brest , 74521-49045 Angers , France
| | - John F Kearney
- University of Alabama , Birmingham , Alabama 35294-2182 , United States
| | - Vishukumar Aimanianda
- Unité des Aspergillus , Institut Pasteur , 25 rue du Docteur Roux , 75724 Paris Cedex 15 , France
| | - Jean-Paul Latgé
- Unité des Aspergillus , Institut Pasteur , 25 rue du Docteur Roux , 75724 Paris Cedex 15 , France
| | - Nikolay E Nifantiev
- Laboratory of Glycoconjugate Chemistry , N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Leninsky prospect 47 , 119991 Moscow , Russia
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28
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Weiss E, Ziegler S, Fliesser M, Schmitt AL, Hünniger K, Kurzai O, Morton CO, Einsele H, Loeffler J. First Insights in NK-DC Cross-Talk and the Importance of Soluble Factors During Infection With Aspergillus fumigatus. Front Cell Infect Microbiol 2018; 8:288. [PMID: 30177958 PMCID: PMC6110135 DOI: 10.3389/fcimb.2018.00288] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/30/2018] [Indexed: 01/12/2023] Open
Abstract
Invasive aspergillosis (IA) is an infectious disease caused by the fungal pathogen Aspergillus fumigatus that mainly affects immunocompromised hosts. To investigate immune cell cross-talk during infection with A. fumigatus, we co-cultured natural killer (NK) cells and dendritic cells (DC) after stimulation with whole fungal structures, components of the fungal cell wall, fungal lysate or ligands for distinct fungal receptors. Both cell types showed activation after stimulation with fungal components and were able to transfer activation signals to the counterpart not stimulated cell type. Interestingly, DCs recognized a broader spectrum of fungal components and thereby initiated NK cell activation when those did not recognize fungal structures. These experiments highlighted the supportive function of DCs in NK cell activation. Furthermore, we focused on soluble DC mediated NK cell activation and showed that DCs stimulated with the TLR2/Dectin-1 ligand zymosan could maximally stimulate the expression of CD69 on NK cells. Thus, we investigated the influence of both receptors for zymosan, Dectin-1 and TLR2, which are highly expressed on DCs but show only minimal expression on NK cells. Specific focus was laid on the question whether Dectin-1 or TLR2 signaling in DCs is important for the secretion of soluble factors leading to NK cell activation. Our results show that Dectin-1 and TLR2 are negligible for NK cell activation. We conclude that besides Dectin-1 and TLR2 other receptors on DCs are able to compensate for the missing signal.
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Affiliation(s)
- Esther Weiss
- Department of Internal Medicine II, University Hospital Wuerzburg, WÜ4i, Wuerzburg, Germany
| | - Sabrina Ziegler
- Department of Internal Medicine II, University Hospital Wuerzburg, WÜ4i, Wuerzburg, Germany
| | - Mirjam Fliesser
- Department of Internal Medicine II, University Hospital Wuerzburg, WÜ4i, Wuerzburg, Germany
| | - Anna-Lena Schmitt
- Department of Internal Medicine II, University Hospital Wuerzburg, WÜ4i, Wuerzburg, Germany
| | - Kerstin Hünniger
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany.,Department of Microbiology and Mycology, Institute for Hygiene and Microbiology, Julius-Maximilian University, Wuerzburg, Germany
| | - Oliver Kurzai
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany.,Department of Microbiology and Mycology, Institute for Hygiene and Microbiology, Julius-Maximilian University, Wuerzburg, Germany
| | | | - Hermann Einsele
- Department of Internal Medicine II, University Hospital Wuerzburg, WÜ4i, Wuerzburg, Germany
| | - Juergen Loeffler
- Department of Internal Medicine II, University Hospital Wuerzburg, WÜ4i, Wuerzburg, Germany
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29
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Valsecchi I, Dupres V, Stephen-Victor E, Guijarro JI, Gibbons J, Beau R, Bayry J, Coppee JY, Lafont F, Latgé JP, Beauvais A. Role of Hydrophobins in Aspergillus fumigatus. J Fungi (Basel) 2017; 4:jof4010002. [PMID: 29371496 PMCID: PMC5872305 DOI: 10.3390/jof4010002] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/20/2017] [Accepted: 12/22/2017] [Indexed: 01/21/2023] Open
Abstract
Resistance of Aspergillus fumigatus conidia to desiccation and their capacity to reach the alveoli are partly due to the presence of a hydrophobic layer composed of a protein from the hydrophobin family, called RodA, which covers the conidial surface. In A. fumigatus there are seven hydrophobins (RodA-RodG) belonging to class I and III. Most of them have never been studied. We constructed single and multiple hydrophobin-deletion mutants until the generation of a hydrophobin-free mutant. The phenotype, immunogenicity, and virulence of the mutants were studied. RODA is the most expressed hydrophobin in sporulating cultures, whereas RODB is upregulated in biofilm conditions and in vivo Only RodA, however, is responsible for rodlet formation, sporulation, conidial hydrophobicity, resistance to physical insult or anionic dyes, and immunological inertia of the conidia. None of the hydrophobin plays a role in biofilm formation or its hydrophobicity. RodA is the only needed hydrophobin in A. fumigatus, conditioning the structure, permeability, hydrophobicity, and immune-inertia of the cell wall surface in conidia. Moreover, the defect of rodlets on the conidial cell wall surface impacts on the drug sensitivity of the fungus.
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Affiliation(s)
- Isabel Valsecchi
- Aspergillus Unit, Institut Pasteur, 75015 Paris, France.
- Unité de RMN des Biomolécules, Institut Pasteur, 75015 Paris, France.
| | - Vincent Dupres
- Centre for Infection and Immunity, Institut Pasteur de Lille-CNRS UMR8204-INSERM U1019-CHRU Lille-Université Lille, 59655 Lille, France.
| | - Emmanuel Stephen-Victor
- Institut National de la Santé et de la Recherche Médicale, Unité 1138, 75006 Paris, France.
- Centre de Recherche des Cordeliers, Université Pierre et Marie Curie-Paris 6, Université Paris Descartes, 75006 Paris, France.
| | - J Iñaki Guijarro
- Unité de RMN des Biomolécules, Institut Pasteur, 75015 Paris, France.
| | - John Gibbons
- Biology Department, Clark University, Worcester, MA 01610, USA.
| | - Rémi Beau
- Aspergillus Unit, Institut Pasteur, 75015 Paris, France.
| | - Jagadeesh Bayry
- Institut National de la Santé et de la Recherche Médicale, Unité 1138, 75006 Paris, France.
- Centre de Recherche des Cordeliers, Université Pierre et Marie Curie-Paris 6, Université Paris Descartes, 75006 Paris, France.
| | - Jean-Yves Coppee
- Transcriptome et Epigénome, Institut Pasteur, 75015 Paris, France.
| | - Frank Lafont
- Centre for Infection and Immunity, Institut Pasteur de Lille-CNRS UMR8204-INSERM U1019-CHRU Lille-Université Lille, 59655 Lille, France.
| | | | - Anne Beauvais
- Aspergillus Unit, Institut Pasteur, 75015 Paris, France.
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30
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Stephen-Victor E, Karnam A, Fontaine T, Beauvais A, Das M, Hegde P, Prakhar P, Holla S, Balaji KN, Kaveri SV, Latgé JP, Aimanianda V, Bayry J. Aspergillus fumigatus Cell Wall α-(1,3)-Glucan Stimulates Regulatory T-Cell Polarization by Inducing PD-L1 Expression on Human Dendritic Cells. J Infect Dis 2017; 216:1281-1294. [PMID: 28968869 DOI: 10.1093/infdis/jix469] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 09/06/2017] [Indexed: 11/13/2022] Open
Abstract
Background Human dendritic cell (DC) response to α-(1,3)-glucan polysaccharide of Aspergillus fumigatus and ensuing CD4+ T-cell polarization are poorly characterized. Methods α-(1,3)-Glucan was isolated from A. fumigatus conidia and mycelia cell wall. For the analysis of polarization, DCs and autologous naive CD4+ T cells were cocultured. Phenotype of immune cells was analyzed by flow cytometry, and cytokines by enzyme-linked immunosorbent assay (ELISA). Blocking antibodies were used to dissect the role of Toll-like receptor 2 (TLR2) and programmed death-ligand 1 (PD-L1) in regulating α-(1,3)-glucan-mediated DC activation and T-cell responses. DCs from TLR2-deficient mice were additionally used to consolidate the findings. Results α-(1,3)-Glucan induced the maturation of DCs and was dependent in part on TLR2. "α-(1,3)-Glucan-educated" DCs stimulated the activation of naive T cells and polarized a subset of these cells into CD4+CD25+FoxP3+ regulatory T cells (Tregs). Mechanistically, Treg stimulation by α-(1,3)-glucan was dependent on the PD-L1 pathway that negatively regulated interferon-gamma (IFN-γ) secretion. Short α-(1,3)-oligosaccharides lacked the capacity to induce maturation of DCs but significantly blocked α-(1,3)-glucan-induced Treg polarization. Conclusions PD-L1 dictates the balance between Treg and IFN-γ responses induced by α-(1,3)-glucan. Our data provide a rationale for the exploitation of immunotherapeutic approaches that target PD-1-PD-L1 to enhance protective immune responses to A. fumigatus infections.
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Affiliation(s)
- Emmanuel Stephen-Victor
- Institut National de la Santé et de la Recherche Médicale.,Sorbonne Universités-Université Pierre et Marie Curie.,Equipe - Immunopathologie et Immunointervention Thérapeutique, Centre de Recherche des Cordeliers
| | - Anupama Karnam
- Institut National de la Santé et de la Recherche Médicale.,Sorbonne Universités-Université Pierre et Marie Curie.,Equipe - Immunopathologie et Immunointervention Thérapeutique, Centre de Recherche des Cordeliers
| | | | - Anne Beauvais
- Unité des Aspergillus, Institut Pasteur, Paris, France
| | - Mrinmoy Das
- Institut National de la Santé et de la Recherche Médicale.,Sorbonne Universités-Université Pierre et Marie Curie.,Equipe - Immunopathologie et Immunointervention Thérapeutique, Centre de Recherche des Cordeliers
| | - Pushpa Hegde
- Institut National de la Santé et de la Recherche Médicale.,Equipe - Immunopathologie et Immunointervention Thérapeutique, Centre de Recherche des Cordeliers
| | - Praveen Prakhar
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Sahana Holla
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | - Srini V Kaveri
- Institut National de la Santé et de la Recherche Médicale.,Sorbonne Universités-Université Pierre et Marie Curie.,Equipe - Immunopathologie et Immunointervention Thérapeutique, Centre de Recherche des Cordeliers.,Université Paris Descartes, Paris, France
| | | | | | - Jagadeesh Bayry
- Institut National de la Santé et de la Recherche Médicale.,Sorbonne Universités-Université Pierre et Marie Curie.,Equipe - Immunopathologie et Immunointervention Thérapeutique, Centre de Recherche des Cordeliers.,Université Paris Descartes, Paris, France
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Yoshimi A, Miyazawa K, Abe K. Function and Biosynthesis of Cell Wall α-1,3-Glucan in Fungi. J Fungi (Basel) 2017; 3:E63. [PMID: 29371579 PMCID: PMC5753165 DOI: 10.3390/jof3040063] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/10/2017] [Accepted: 11/16/2017] [Indexed: 12/30/2022] Open
Abstract
Although α-1,3-glucan is a major cell wall polysaccharide in filamentous fungi, its biological functions remain unclear, except that it acts as a virulence factor in animal and plant pathogenic fungi: it conceals cell wall β-glucan on the fungal cell surface to circumvent recognition by hosts. However, cell wall α-1,3-glucan is also present in many of non-pathogenic fungi. Recently, the universal function of α-1,3-glucan as an aggregation factor has been demonstrated. Applications of fungi with modified cell wall α-1,3-glucan in the fermentation industry and of in vitro enzymatically-synthesized α-1,3-glucan in bio-plastics have been developed. This review focuses on the recent progress in our understanding of the biological functions and biosynthetic mechanism of cell wall α-1,3-glucan in fungi. We briefly consider the history of studies on α-1,3-glucan, overview its biological functions and biosynthesis, and finally consider the industrial applications of fungi deficient in α-1,3-glucan.
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Affiliation(s)
- Akira Yoshimi
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
| | - Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-0845, Japan.
| | - Keietsu Abe
- ABE-Project, New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-0845, Japan.
- Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-0845, Japan.
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Abstract
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
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33
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Yoshimi A, Hirama M, Tsubota Y, Kawakami K, Zhang S, Gomi K, Abe K. Characterization of Cell Wall α-1,3-Glucan-Deficient Mutants in Aspergillus oryzae Isolated by a Screening Method Based on Their Sensitivities to Congo Red or Lysing Enzymes. J Appl Glycosci (1999) 2017; 64:65-73. [PMID: 34354498 PMCID: PMC8056903 DOI: 10.5458/jag.jag.jag-2017_004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 05/18/2017] [Indexed: 11/16/2022] Open
Abstract
We previously reported that sensitivity to Congo Red (CR) or Lysing Enzymes (LE) is affected by the loss of cell-wall α-1,3-glucan (AG) in Aspergillus nidulans. We found that the amount of CR adsorbed to AG was significantly less than the amount adsorbed to β-1,3-glucan (BG) or chitin, suggesting that loss of cell-wall AG would increase exposure of BG on the cell surface, and thereby increase the sensitivity to CR. Generally, fungal BGs are known as biological response modifiers because of their recognition by Dectin-1 receptors in human immune systems. Therefore, isolation of AG-deficient mutants in Aspergillus oryzae has been used in the Japanese fermentation industry to create strains with increased ability to promote immune responses. Here, we aimed to isolate AG-deficient strains by mutagenizing A. oryzae conidia with chemical mutagens. Based on the increased sensitivity to CR in AG-deficient strains of A. nidulans and A. oryzae, we established a screening method for isolation of AG-deficient strains. Several candidate AG-deficient mutants of A. oryzae were isolated using the screening method; these strains showed increased sensitivity to CR and/or LE. Cytokine production was increased in the dendritic cells co-incubated with germinated conidia of the AG-deficient mutants. Furthermore, according to a Dectin-1 NFAT (nuclear factor of activator T cells)-GFP (green fluorescent protein) reporter assay, Dectin-1 response levels in the AG-deficient mutants were higher than those in wild-type A. oryzae. These results suggest that we successfully isolated AG-deficient mutants of A. oryzae with immunostimulatory effects.
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Affiliation(s)
- Akira Yoshimi
- 1 ABE-project, New Industry Creation Hatchery Center, Tohoku University
| | | | | | - Kazuyoshi Kawakami
- 3 Department of Medical Microbiology, Mycology and Immunology, Tohoku University Graduate School of Medicine
| | - Silai Zhang
- 4 Laboratory of Bioindustrial Genomics, Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Sciences, Tohoku University
| | - Katsuya Gomi
- 4 Laboratory of Bioindustrial Genomics, Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Sciences, Tohoku University
| | - Keietsu Abe
- 1 ABE-project, New Industry Creation Hatchery Center, Tohoku University.,5 Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University.,6 Department of Microbial Resources, Graduate School of Agricultural Science, Tohoku University
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Abstract
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
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Affiliation(s)
- Neil A R Gow
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB252ZD, United Kingdom
| | | | - Carol A Munro
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB252ZD, United Kingdom
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Bouklas T, Alonso-Crisóstomo L, Székely T, Diago-Navarro E, Orner EP, Smith K, Munshi MA, Del Poeta M, Balázsi G, Fries BC. Generational distribution of a Candida glabrata population: Resilient old cells prevail, while younger cells dominate in the vulnerable host. PLoS Pathog 2017; 13:e1006355. [PMID: 28489916 PMCID: PMC5440053 DOI: 10.1371/journal.ppat.1006355] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 05/22/2017] [Accepted: 04/15/2017] [Indexed: 12/15/2022] Open
Abstract
Similar to other yeasts, the human pathogen Candida glabrata ages when it undergoes asymmetric, finite cell divisions, which determines its replicative lifespan. We sought to investigate if and how aging changes resilience of C. glabrata populations in the host environment. Our data demonstrate that old C. glabrata are more resistant to hydrogen peroxide and neutrophil killing, whereas young cells adhere better to epithelial cell layers. Consequently, virulence of old compared to younger C. glabrata cells is enhanced in the Galleria mellonella infection model. Electron microscopy images of old C. glabrata cells indicate a marked increase in cell wall thickness. Comparison of transcriptomes of old and young C. glabrata cells reveals differential regulation of ergosterol and Hog pathway associated genes as well as adhesion proteins, and suggests that aging is accompanied by remodeling of the fungal cell wall. Biochemical analysis supports this conclusion as older cells exhibit a qualitatively different lipid composition, leading to the observed increased emergence of fluconazole resistance when grown in the presence of fluconazole selection pressure. Older C. glabrata cells accumulate during murine and human infection, which is statistically unlikely without very strong selection. Therefore, we tested the hypothesis that neutrophils constitute the predominant selection pressure in vivo. When we altered experimentally the selection pressure by antibody-mediated removal of neutrophils, we observed a significantly younger pathogen population in mice. Mathematical modeling confirmed that differential selection of older cells is sufficient to cause the observed demographic shift in the fungal population. Hence our data support the concept that pathogenesis is affected by the generational age distribution of the infecting C. glabrata population in a host. We conclude that replicative aging constitutes an emerging trait, which is selected by the host and may even play an unanticipated role in the transition from a commensal to a pathogen state.
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Affiliation(s)
- Tejas Bouklas
- Department of Medicine, Division of Infectious Diseases, Stony Brook University, Stony Brook, New York, United States of America
- Department of Biomedical Sciences, Long Island University-Post, Brookville, New York, United States of America
| | | | - Tamás Székely
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, United States of America
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, United States of America
| | - Elizabeth Diago-Navarro
- Department of Medicine, Division of Infectious Diseases, Stony Brook University, Stony Brook, New York, United States of America
| | - Erika P. Orner
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Kalie Smith
- Department of Medicine, Division of Infectious Diseases, Stony Brook University, Stony Brook, New York, United States of America
| | - Mansa A. Munshi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
- Veterans Administration Medical Center, Northport, New York, United States of America
| | - Gábor Balázsi
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, United States of America
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, United States of America
| | - Bettina C. Fries
- Department of Medicine, Division of Infectious Diseases, Stony Brook University, Stony Brook, New York, United States of America
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
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36
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Zhang S, Sato H, Ichinose S, Tanaka M, Miyazawa K, Yoshimi A, Abe K, Shintani T, Gomi K. Cell wall α-1,3-glucan prevents α-amylase adsorption onto fungal cell in submerged culture of Aspergillus oryzae. J Biosci Bioeng 2017; 124:47-53. [PMID: 28356219 DOI: 10.1016/j.jbiosc.2017.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 02/17/2017] [Indexed: 10/19/2022]
Abstract
We have previously reported that α-amylase (Taka-amylase A, TAA) activity disappears in the later stage of submerged Aspergillus oryzae culture as a result of TAA adsorption onto the cell wall. Chitin, one of the major components of the cell wall, was identified as a potential factor that facilitates TAA adsorption. However, TAA adsorption only occurred in the later stage of cultivation, although chitin was assumed to be sufficiently abundant in the cell wall regardless of the submerged culture period. This suggested the presence a factor that inhibits TAA adsorption to the cell wall in the early stage of cultivation. In the current study, we identified α-1,3-glucan as a potential inhibiting factor for TAA adsorption. We constructed single, double, and triple disruption mutants of three α-1,3-glucan synthase genes (agsA, agsB, and agsC) in A. oryzae. Growth characteristics and cell wall component analysis of these disruption strains showed that AgsB plays a major role in α-1,3-glucan synthesis. In the ΔagsB mutant, TAA was adsorbed onto the mycelium in all stages of cultivation (early and later), and the ΔagsB mutant cell walls had a significantly high capacity for TAA adsorption. Moreover, the α-1,3-glucan content of the cell wall prepared from the wild-type strain in the later stage of cultivation was markedly reduced compared with that in the early stage. These results suggest that α-1,3-glucan is a potential inhibiting factor for TAA adsorption onto the cell wall component, chitin, in the early stage of submerged culture in A. oryzae.
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Affiliation(s)
- Silai Zhang
- Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan
| | - Hiroki Sato
- Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan
| | - Sakurako Ichinose
- Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan
| | - Mizuki Tanaka
- Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan
| | - Ken Miyazawa
- Laboratory of Applied Microbiology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan
| | - Akira Yoshimi
- New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan; New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Takahiro Shintani
- Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan
| | - Katsuya Gomi
- Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 468-1 Aoba, Aramaki, Aoba-ku, Sendai 980-0845, Japan.
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Ghazaei C. Molecular Insights into Pathogenesis and Infection with Aspergillus Fumigatus. Malays J Med Sci 2017; 24:10-20. [PMID: 28381925 DOI: 10.21315/mjms2017.24.1.2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 12/13/2016] [Indexed: 01/07/2023] Open
Abstract
The virulence of fungi is dependent on multiple factors, including the immune status of patients and biological features of fungi. In particular, the virulence of Aspergillus fumigatus is due to the complex interaction among various molecules involved in thermotolerance (such as ribosomal biogenesis proteins, α-mannosyltransferase and heat shock proteins), pigment production (DHN-melanin), immune evasion (like melanin and hydrophobin) and nutrient uptake (such as siderophores and zinc transporters). Other molecules also play important roles in the virulence of A. fumigatus, including cell wall components and those which maintain its integrity (for instance β-1-3 glucan, α-1-3 glucan, chitin, galactomannan and mannoproteins) and adhesion (such as hydrophobins), as well as various hydrolytic enzymes (such as serine and aspartic protease, phospholipases, metalloproteinase and dipeptidyl peptidases). Signalling molecules (including G-protein, cAMP, Ras protein and calcineurin) also increase the virulence through altering the metabolic response to stress conditions and toxins (such as gliotoxin, fumitremorgins, fumagatin and helvolic acid).
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Affiliation(s)
- Ciamak Ghazaei
- Department of Microbiology, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, Iran
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Henry C, Fontaine T, Heddergott C, Robinet P, Aimanianda V, Beau R, Beauvais A, Mouyna I, Prevost MC, Fekkar A, Zhao Y, Perlin D, Latgé JP. Biosynthesis of cell wall mannan in the conidium and the mycelium ofAspergillusfumigatus. Cell Microbiol 2016; 18:1881-1891. [DOI: 10.1111/cmi.12665] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 09/06/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Christine Henry
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
| | - Thierry Fontaine
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
| | | | - Pauline Robinet
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
| | | | - Remi Beau
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
| | - Anne Beauvais
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
| | - Isabelle Mouyna
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
| | | | - Arnaud Fekkar
- Service de Parasitologie Mycologie; Hôpital de La Pitié-Salpêtrière; Paris France
| | - Yanan Zhao
- Public Health Research Institute, New Jersey Medical School, Rutgers; The State University of New Jersey; Newark New Jersey USA
| | - David Perlin
- Public Health Research Institute, New Jersey Medical School, Rutgers; The State University of New Jersey; Newark New Jersey USA
| | - Jean-Paul Latgé
- Département de Mycologie; Unité des Aspergillus; Paris Cedex France
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Rodrigues LNDS, Brito WDA, Parente AFA, Weber SS, Bailão AM, Casaletti L, Borges CL, Soares CMDA. Osmotic stress adaptation of Paracoccidioides lutzii, Pb01, monitored by proteomics. Fungal Genet Biol 2016; 95:13-23. [DOI: 10.1016/j.fgb.2016.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/25/2016] [Accepted: 08/01/2016] [Indexed: 12/18/2022]
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40
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Al-Bader N, Sheppard DC. Aspergillosis and stem cell transplantation: An overview of experimental pathogenesis studies. Virulence 2016; 7:950-966. [PMID: 27687755 DOI: 10.1080/21505594.2016.1231278] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Invasive aspergillosis is a life-threatening infection caused by the opportunistic filamentous fungus Aspergillus fumigatus. Patients undergoing haematopoietic stem cell transplant (HSCT) for the treatment of hematological malignancy are at particularly high risk of developing this fatal infection. The susceptibility of HSCT patients to infection with A. fumigatus is a consequence of a complex interplay of both fungal and host factors. Here we review our understanding of the host-pathogen interactions underlying the susceptibility of the immunocompromised host to infection with A. fumigatus with a focus on the experimental validation of fungal and host factors relevant to HSCT patients. These include fungal factors such as secondary metabolites, cell wall constituents, and metabolic adaptations that facilitate immune evasion and survival within the host microenvironment, as well as the innate and adaptive immune responses involved in host defense against A. fumigatus.
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Affiliation(s)
- Nadia Al-Bader
- a Departments of Medicine, Microbiology and Immunology , McGill University , Montréal , Québec , Canada
| | - Donald C Sheppard
- a Departments of Medicine, Microbiology and Immunology , McGill University , Montréal , Québec , Canada.,b Infectious Diseases in Global Health Program, Research Institute of the McGill University Health Center, McGill University , Montréal , Québec , Canada
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41
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Yoshimi A, Miyazawa K, Abe K. Cell wall structure and biogenesis in Aspergillus species. Biosci Biotechnol Biochem 2016; 80:1700-11. [DOI: 10.1080/09168451.2016.1177446] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Abstract
Aspergillus species are among the most important filamentous fungi from the viewpoints of industry, pathogenesis, and mycotoxin production. Fungal cells are exposed to a variety of environmental stimuli, including changes in osmolality, temperature, and pH, which create stresses that primarily act on fungal cell walls. In addition, fungal cell walls are the first interactions with host cells in either human or plants. Thus, understanding cell wall structure and the mechanism of their biogenesis is important for the industrial, medical, and agricultural fields. Here, we provide a systematic review of fungal cell wall structure and recent findings regarding the cell wall integrity signaling pathways in aspergilli. This accumulated knowledge will be useful for understanding and improving the use of industrial aspergilli fermentation processes as well as treatments for some fungal infections.
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Affiliation(s)
- Akira Yoshimi
- ABE-project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Ken Miyazawa
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Japan
| | - Keietsu Abe
- ABE-project, New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Japan
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42
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Sheppard DC, Howell PL. Biofilm Exopolysaccharides of Pathogenic Fungi: Lessons from Bacteria. J Biol Chem 2016; 291:12529-12537. [PMID: 27129222 DOI: 10.1074/jbc.r116.720995] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Exopolysaccharides play an important structural and functional role in the development and maintenance of microbial biofilms. Although the majority of research to date has focused on the exopolysaccharide systems of biofilm-forming bacteria, recent studies have demonstrated that medically relevant fungi such as Candida albicans and Aspergillus fumigatus also form biofilms during infection. These fungal biofilms share many similarities with those of bacteria, including the presence of secreted exopolysaccharides as core components of the extracellular matrix. This review will highlight our current understanding of fungal biofilm exopolysaccharides, as well as the parallels that can be drawn with those of their bacterial counterparts.
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Affiliation(s)
- Donald C Sheppard
- Departments of Medicine, Microbiology and Immunology, Research Institute of the McGill University Health Centre, McGill University, Montréal, Québec H4A 3J1; Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, McGill University, Montréal, Québec H4A 3J1.
| | - P Lynne Howell
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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The transcription factor VpCRZ1 is required for fruiting body formation and pathogenicity in Valsa pyri. Microb Pathog 2016; 95:101-110. [PMID: 26970115 DOI: 10.1016/j.micpath.2016.02.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 02/24/2016] [Accepted: 02/26/2016] [Indexed: 11/20/2022]
Abstract
Valsa pyri is a fatal pathogenic fungus that causes pear and apple canker disease. To date, its cellular development and pathogenicity have been poorly understood. In this study, a V. pyri Ca(2+)/calcineurin-dependent transcription factor CRZ1 (VpCRZ1) is identified and functionally characterized. The △VpCRZ1 mutant exhibits impaired pathogenicity and is no longer able to form fruiting body. Interestingly, this mutant also exhibits enhanced pigment deposition and increased resistance to cell wall perturbing agents including SDS, Congo red and calcofluor white (CFW). The expression levels of Congo red resistance genes (VpRCR1 and VpRCR2) and chitin synthetase genes (VpCHS2 and VpCHS6) are upregulated in the △VpCRZ1 mutant compared to the wild type. Furthermore, We show that a VpCRZ1: eGFP fusion protein localizes to the nucleus in a Ca(2+)-dependent manner similar to its homologs in other fungi, and that the VpFKS1, VpPMC1, VpPMC2, VpPMR1, and VpPMA1 genes are regulated by VpCRZ1 in response to Ca(2+) levels. Together, these results suggest that VpCRZ1 is a Ca(2+)-dependent transcription factor and required for regulating mycelial morphology, fruiting body formation, and virulence of this important pear and apple pathogen.
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Recent advances in the understanding of the Aspergillus fumigatus cell wall. J Microbiol 2016; 54:232-42. [PMID: 26920883 DOI: 10.1007/s12275-016-6045-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 02/02/2016] [Indexed: 10/24/2022]
Abstract
Over the past several decades, research on the synthesis and organization of the cell wall polysaccharides of Aspergillus fumigatus has expanded our knowledge of this important fungal structure. Besides protecting the fungus from environmental stresses and maintaining structural integrity of the organism, the cell wall is also the primary site for interaction with host tissues during infection. Cell wall polysaccharides are important ligands for the recognition of fungi by the innate immune system and they can mediate potent immunomodulatory effects. The synthesis of cell wall polysaccharides is a complicated process that requires coordinated regulation of many biosynthetic and metabolic pathways. Continuous synthesis and remodeling of the polysaccharides of the cell wall is essential for the survival of the fungus during development, reproduction, colonization and invasion. As these polysaccharides are absent from the human host, these biosynthetic pathways are attractive targets for antifungal development. In this review, we present recent advances in our understanding of Aspergillus fumigatus cell wall polysaccharides, including the emerging role of cell wall polysaccharides in the host-pathogen interaction.
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Oka T, Goto M. Biosynthesis of Galactofuranose-containing Glycans in Filamentous Fungi. TRENDS GLYCOSCI GLYC 2016. [DOI: 10.4052/tigg.1428.1j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo, University
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University
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Oka T, Goto M. Biosynthesis of Galactofuranose-containing Glycans in Filamentous Fungi. TRENDS GLYCOSCI GLYC 2016. [DOI: 10.4052/tigg.1428.1e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Takuji Oka
- Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo, University
| | - Masatoshi Goto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University
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Martínez-Núñez L, Riquelme M. Role of BGT-1 and BGT-2, two predicted GPI-anchored glycoside hydrolases/glycosyltransferases, in cell wall remodeling in Neurospora crassa. Fungal Genet Biol 2015; 85:58-70. [PMID: 26541633 DOI: 10.1016/j.fgb.2015.11.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/25/2015] [Accepted: 11/01/2015] [Indexed: 02/07/2023]
Abstract
Neurospora crassa BGT-1 (NCU06381) and BGT-2 (NCU09175) are two putative glycoside hydrolases (GHs) with additional predicted glycosyltransferase activity and binding sites for a glycosyl phosphatidyl inositol (GPI) anchor that would facilitate their attachment to the plasma membrane (PM). To discern their role in key morphogenetic events during vegetative development of N. crassa, BGT-1 and BGT-2 were labeled with the green fluorescent protein (GFP). The gfp was inserted immediately after the signal peptide sequence, within the bgt-1 encoding sequence, or directly before the GPI-binding site in the case of bgt-2. Both BGT-1-GFP and BGT-2-GFP were observed at the PM of the hyphal apical dome, excluding the foremost apical region and the Spitzenkörper (Spk), where chitin and β-1,3-glucan synthases have been previously found. These and previous studies suggest a division of labor of the cell wall synthesizing machinery at the hyphal dome: at the very tip, glucans are synthesized by enzymes that accumulate at the Spk, before getting incorporated into the PM, whereas at the subtending zone below the apex, glucans are presumably hydrolyzed, producing amenable ends for further branching and crosslinking with other cell wall polymers. Additionally, BGT-1-GFP and BGT-2-GFP were observed at the leading edge of new developing septa, at unreleased interconidial junctions, at conidial poles, at germling and hyphal fusion sites, and at sites of branch emergence, all of them processes that seemingly involve cell wall remodeling. Even though single and double mutant strains for the corresponding genes did not show a drastic reduction of growth rate, bgt-2Δ and bgt-1Δ::bgt-2Δ strains exhibited an increased resistance to the cell wall stressors calcofluor white (CW) and congo red (CR) than the reference strain, which suggests they present significant architectural changes in their cell wall. Furthermore, the conidiation defects observed in the mutants indicate a significant role of BGT-1 and BGT-2 on the re-arrangement of glucans needed at the conidiophore cell wall to allow conidial separation.
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Affiliation(s)
- Leonora Martínez-Núñez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada-CICESE, Ensenada, Baja California 22860, Mexico
| | - Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada-CICESE, Ensenada, Baja California 22860, Mexico.
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Rocha MC, de Godoy KF, de Castro PA, Hori JI, Bom VLP, Brown NA, da Cunha AF, Goldman GH, Malavazi I. The Aspergillus fumigatus pkcA G579R Mutant Is Defective in the Activation of the Cell Wall Integrity Pathway but Is Dispensable for Virulence in a Neutropenic Mouse Infection Model. PLoS One 2015; 10:e0135195. [PMID: 26295576 PMCID: PMC4546635 DOI: 10.1371/journal.pone.0135195] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/19/2015] [Indexed: 12/03/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic human pathogen, which causes the life-threatening disease, invasive pulmonary aspergillosis. In fungi, cell wall homeostasis is controlled by the conserved Cell Wall Integrity (CWI) pathway. In A. fumigatus this signaling cascade is partially characterized, but the mechanisms by which it is activated are not fully elucidated. In this study we investigated the role of protein kinase C (PkcA) in this signaling cascade. Our results suggest that pkcA is an essential gene and is activated in response to cell wall stress. Subsequently, we constructed and analyzed a non-essential A. fumigatus pkcAG579R mutant, carrying a Gly579Arg substitution in the PkcA C1B regulatory domain. The pkcAG579R mutation has a reduced activation of the downstream Mitogen-Activated Protein Kinase, MpkA, resulting in the altered expression of genes encoding cell wall-related proteins, markers of endoplasmic reticulum stress and the unfolded protein response. Furthermore, PkcAG579R is involved in the formation of proper conidial architecture and protection to oxidative damage. The pkcAG579R mutant elicits increased production of TNF-α and phagocytosis but it has no impact on virulence in a murine model of invasive pulmonary aspergillosis. These results highlight the importance of PkcA to the CWI pathway but also indicated that additional regulatory circuits may be involved in the biosynthesis and/or reinforcement of the A. fumigatus cell wall during infection.
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Affiliation(s)
- Marina Campos Rocha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Krissia Franco de Godoy
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Patrícia Alves de Castro
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Juliana Issa Hori
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Vinícius Leite Pedro Bom
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Neil Andrew Brown
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts, United Kingdom
| | - Anderson Ferreira da Cunha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Gustavo Henrique Goldman
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol, Campinas, São Paulo, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
- * E-mail:
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Valiante V, Macheleidt J, Föge M, Brakhage AA. The Aspergillus fumigatus cell wall integrity signaling pathway: drug target, compensatory pathways, and virulence. Front Microbiol 2015; 6:325. [PMID: 25932027 PMCID: PMC4399325 DOI: 10.3389/fmicb.2015.00325] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/31/2015] [Indexed: 01/06/2023] Open
Abstract
Aspergillus fumigatus is the most important airborne fungal pathogen, causing severe infections with invasive growth in immunocompromised patients. The fungal cell wall (CW) prevents the cell from lysing and protects the fungus against environmental stress conditions. Because it is absent in humans and because of its essentiality, the fungal CW is a promising target for antifungal drugs. Nowadays, compounds acting on the CW, i.e., echinocandin derivatives, are used to treat A. fumigatus infections. However, studies demonstrating the clinical effectiveness of echinocandins in comparison with antifungals currently recommended for first-line treatment of invasive aspergillosis are still lacking. Therefore, it is important to elucidate CW biosynthesis pathways and their signal transduction cascades, which potentially compensate the inhibition caused by CW- perturbing compounds. Like in other fungi, the central core of the cell wall integrity (CWI) signaling pathway in A. fumigatus is composed of three mitogen activated protein kinases. Deletion of these genes resulted in severely enhanced sensitivity of the mutants against CW-disturbing compounds and in drastic alterations of the fungal morphology. Additionally, several cross-talk interactions between the CWI pathways and other signaling pathways are emerging, raising the question about their role in the CW compensatory mechanisms. In this review we focused on recent advances in understanding the CWI signaling pathway in A. fumigatus and its role during drug stress response and virulence.
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Affiliation(s)
- Vito Valiante
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
| | - Juliane Macheleidt
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
| | - Martin Föge
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany ; Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Germany
| | - Axel A Brakhage
- Molecular Biotechnology of Natural Products, Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany ; Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Germany
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