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Pérez Rodríguez F, Valdés-Santiago L, Noé García-Chávez J, Luis Castro-Guillén J, Ruiz-Herrera J. Analysis of gene expression related to polyamine concentration and dimorphism induced in ornithine decarboxylase (odc) and spermidine synthase (spd) Ustilago maydis mutants. Fungal Genet Biol 2023; 166:103792. [PMID: 36996931 DOI: 10.1016/j.fgb.2023.103792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023]
Abstract
Polyamines are ubiquitous small organic cations, and their roles as regulators of several cellular processes are widely recognized. They are implicated in the key stages of the fungal life cycle. Ustilago maydis is a phytopathogenic fungus, the causal agent of common smut of maize and a model system to understand dimorphism and virulence. U. maydis grows in yeast form at pH 7 and it can develop its mycelial form in vitro at pH 3. Δodc mutants that are unable to synthesize polyamines, grew as yeast at pH 3 with a low putrescine concentration, and to complete its dimorphic transition high putrescine concentration was required. Δspd mutants required spermidine to grow and cannot form mycelium at pH 3. In this work, the increased expression of the mating genes, mfa1 and mfa2, on Δodc mutants, was related to high putrescine concentration. Global gene expression analysis comparisons of Δodc and Δspd U. maydis mutants indicated that 2,959 genes were differentially expressed in the presence of exogenous putrescine at pH 7 and 475 genes at pH 3. While, in Δspd mutant, the expression of 1,426 genes was affected by exogenous spermine concentration at pH 7 and 11 genes at pH 3. Additionally, we identified 28 transcriptional modules with correlated expression during seven tested conditions: mutant genotype, morphology (yeast, and mycelium), pH, and putrescine or spermidine concentration. Furthermore, significant differences in transcript levels were noted for genes in modules relating to pH and genotype genes involved in ribosome biogenesis, mitochondrial oxidative phosphorylation, N-glycan synthesis, and Glycosylphosphatidylinositol (GPI)-anchor. In summary, our results offer a valuable tool for the identification of potential factors involved in phenomena related to polyamines and dimorphism.
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Bitencourt TA, Hatanaka O, Pessoni AM, Freitas MS, Trentin G, Santos P, Rossi A, Martinez-Rossi NM, Alves LL, Casadevall A, Rodrigues ML, Almeida F. Fungal Extracellular Vesicles Are Involved in Intraspecies Intracellular Communication. mBio 2022; 13:e0327221. [PMID: 35012355 PMCID: PMC8749427 DOI: 10.1128/mbio.03272-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 12/16/2022] Open
Abstract
Fungal infections are associated with high mortality rates in humans. The risk of fungal diseases creates the urgent need to broaden the knowledge base regarding their pathophysiology. In this sense, the role of extracellular vesicles (EVs) has been described to convey biological information and participate in the fungus-host interaction process. We hypothesized that fungal EVs work as an additional element in the communication routes regulating fungal responses in intraspecies interaction systems. In this respect, the aim of this study was to address the gene regulation profiles prompted by fungal EVs in intraspecies recipient cells. Our data demonstrated the intraspecies uptake of EVs in pathogenic fungi, such as Candida albicans, Aspergillus fumigatus, and Paracoccidioides brasiliensis, and the effects triggered by EVs in fungal cells. In C. albicans, we evaluated the involvement of EVs in the yeast-to-hypha transition, while in P. brasiliensis and A. fumigatus the function of EVs as stress transducers was investigated. P. brasiliensis and A. fumigatus were exposed to an inhibitor of glycosylation or UV light, respectively. The results demonstrated the role of EVs in regulating the expression of target genes and triggering phenotypic changes. The EVs treatment induced cellular proliferation and boosted the yeast to hyphal transition in C. albicans, while they enhanced stress responsiveness in A. fumigatus and P. brasiliensis, establishing a role for EVs in fungal intraspecies communication. Thus, EVs regulate fungal behavior, acting as potent message effectors, and understanding their effects and mechanism(s) of action could be exploited in antifungal therapies. IMPORTANCE Here, we report a study about extracellular vesicles (EVs) as communication mediators in fungi. Our results demonstrated the role of EVs from Candida albicans, Aspergillus fumigatus, and Paracoccidioides brasiliensis regulating the expression of target genes and phenotypic features. We asked whether fungal EVs play a role as message effectors. We show that fungal EVs are involved in fungal interaction systems as potent message effectors, and understanding their effects and mechanisms of action could be exploited in antifungal therapies.
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Affiliation(s)
- Tamires A. Bitencourt
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Otavio Hatanaka
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Andre M. Pessoni
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Mateus S. Freitas
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Gabriel Trentin
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Patrick Santos
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Nilce M. Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Lysangela L. Alves
- Gene Expression Regulation Laboratory, Carlos Chagas Institute, Fiocruz, Curitiba, PR, Brazil
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Marcio L. Rodrigues
- Gene Expression Regulation Laboratory, Carlos Chagas Institute, Fiocruz, Curitiba, PR, Brazil
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
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Gonçales RA, Ricci-Azevedo R, Vieira VCS, Fernandes FF, Thomaz SMDO, Carvalho A, Vendruscolo PE, Cunha C, Roque-Barreira MC, Rodrigues F. Paracoccin Overexpression in Paracoccidioides brasiliensis Enhances Fungal Virulence by Remodeling Chitin Properties of the Cell Wall. J Infect Dis 2020; 224:164-174. [PMID: 33201217 DOI: 10.1093/infdis/jiaa707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 11/12/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The thermodimorphic fungi Paracoccidioides spp. are the etiological agents of paracoccidioidomycosis. Although poorly studied, paracoccin (PCN) from Paracoccidioides brasiliensis has been shown to harbor lectinic, enzymatic, and immunomodulatory properties that affect disease development. METHODS Mutants of P. brasiliensis overexpressing PCN (ov-PCN) were constructed by Agrobacterium tumefaciens-mediated transformation. ov-PCN strains were analyzed and inoculated intranasally or intravenously to mice. Fungal burden, lung pathology, and survival were monitored to evaluate virulence. Electron microscopy was used to evaluate the size of chito-oligomer particles released by ov-PCN or wild-type strains to growth media. RESULTS ov-PCN strains revealed no differences in cell growth and viability, although PCN overexpression favored cell separation, chitin processing that results in the release of smaller chito-oligomer particles, and enhanced virulence. Our data show that PCN triggers a critical effect in the cell wall biogenesis through the chitinase activity resulting from overexpression of PCN. As such, PCN overexpression aggravates the disease caused by P. brasiliensis. CONCLUSIONS Our data are consistent with a model in which PCN modulates the cell wall architecture via its chitinase activity. These findings highlight the potential for exploiting PCN function in future therapeutic approaches.
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Affiliation(s)
- Relber Aguiar Gonçales
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto/São Paulo, Brazil.,Life and Health Sciences Research Institute School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rafael Ricci-Azevedo
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto/São Paulo, Brazil
| | - Vanessa C S Vieira
- Life and Health Sciences Research Institute School of Medicine, University of Minho, Braga, Portugal
| | - Fabrício F Fernandes
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto/São Paulo, Brazil
| | - Sandra M de O Thomaz
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto/São Paulo, Brazil
| | - Agostinho Carvalho
- Life and Health Sciences Research Institute School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrícia E Vendruscolo
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto/São Paulo, Brazil
| | - Cristina Cunha
- Life and Health Sciences Research Institute School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Maria Cristina Roque-Barreira
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto/São Paulo, Brazil
| | - Fernando Rodrigues
- Life and Health Sciences Research Institute School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
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Steenwyk JL, Lind AL, Ries LNA, Dos Reis TF, Silva LP, Almeida F, Bastos RW, Fraga da Silva TFDC, Bonato VLD, Pessoni AM, Rodrigues F, Raja HA, Knowles SL, Oberlies NH, Lagrou K, Goldman GH, Rokas A. Pathogenic Allodiploid Hybrids of Aspergillus Fungi. Curr Biol 2020; 30:2495-2507.e7. [PMID: 32502407 PMCID: PMC7343619 DOI: 10.1016/j.cub.2020.04.071] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 02/25/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Interspecific hybridization substantially alters genotypes and phenotypes and can give rise to new lineages. Hybrid isolates that differ from their parental species in infection-relevant traits have been observed in several human-pathogenic yeasts and plant-pathogenic filamentous fungi but have yet to be found in human-pathogenic filamentous fungi. We discovered 6 clinical isolates from patients with aspergillosis originally identified as Aspergillus nidulans (section Nidulantes) that are actually allodiploid hybrids formed by the fusion of Aspergillus spinulosporus with an unknown close relative of Aspergillus quadrilineatus, both in section Nidulantes. Evolutionary genomic analyses revealed that these isolates belong to Aspergillus latus, an allodiploid hybrid species. Characterization of diverse infection-relevant traits further showed that A. latus hybrid isolates are genomically and phenotypically heterogeneous but also differ from A. nidulans, A. spinulosporus, and A. quadrilineatus. These results suggest that allodiploid hybridization contributes to the genomic and phenotypic diversity of filamentous fungal pathogens of humans.
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Affiliation(s)
- Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN 37235, USA
| | - Abigail L Lind
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, 1211 Medical Center Drive, Nashville, TN 37232, USA; Gladstone Institute of Data Science and Biotechnology, San Francisco, CA 94158, USA
| | - Laure N A Ries
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil; Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Thaila F Dos Reis
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil; Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Lilian P Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Fausto Almeida
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Rafael W Bastos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Thais Fernanda de Campos Fraga da Silva
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Vania L D Bonato
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - André Moreira Pessoni
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Fernando Rodrigues
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4715-495 Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, 4715-495 Braga, Portugal
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 1400 Spring Garden Street, Greensboro, NC 27412, USA
| | - Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 1400 Spring Garden Street, Greensboro, NC 27412, USA
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 1400 Spring Garden Street, Greensboro, NC 27412, USA
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit Leuven, 3000 Leuven, Belgium; Department of Laboratory Medicine and National Reference Centre for Mycosis, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil.
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN 37235, USA; Department of Biomedical Informatics, Vanderbilt University School of Medicine, 1211 Medical Center Drive, Nashville, TN 37232, USA.
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Decyl Gallate as a Possible Inhibitor of N-Glycosylation Process in Paracoccidioides lutzii. Antimicrob Agents Chemother 2019; 63:AAC.01909-18. [PMID: 31451502 DOI: 10.1128/aac.01909-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 07/28/2019] [Indexed: 01/29/2023] Open
Abstract
The available antifungal therapeutic arsenal is limited. The search for alternative drugs with fewer side effects and new targets remains a major challenge. Decyl gallate (G14) is a derivative of gallic acid with a range of biological activities and broad-spectrum antifungal activity. Previously, our group demonstrated the promising anti-Paracoccidioides activity of G14. In this work, to evaluate the antifungal characteristics of G14 for Paracoccidioides lutzii, a chemical-genetic interaction analysis was conducted on a Saccharomyces cerevisiae model. N-glycosylation and/or the unfolded protein response pathway was identified as a high-confidence process for drug target prediction. The overactivation of unfolded protein response (UPR) signaling was confirmed using this model with IRE1/ATF6/PERK genes tagged with green fluorescent protein (GFP). In P. lutzii, this prediction was confirmed by the low activity of glycosylated enzymes [α-(1,3)-glucanase, N-acetyl-β-d-glucosaminidase (NAGase), and α-(1,4)-amylase], by hyperexpression of genes involved with the UPR and glycosylated enzymes, and by the reduction in the amounts of glycosylated proteins and chitin. All of these components are involved in fungal cell wall integrity and are dependent on the N-glycosylation process. This loss of integrity was confirmed by the reduction in mitochondrial activity, impaired budding, enhancement of wall permeability, and a decrease in viability. These events led to a reduction of the ability of fungi to adhere on human lung epithelial cells (A549) in vitro Therefore, G14 may have an important role in balancing the inflammatory reaction caused by fungal infection, without interfering with the microbicidal activity of nitric oxide. This work provides new information on the activity of G14, a potential anti-Paracoccidioides compound.
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Guo Y, Yao S, Yuan T, Wang Y, Zhang D, Tang W. The spatiotemporal control of KatG2 catalase-peroxidase contributes to the invasiveness of Fusarium graminearum in host plants. MOLECULAR PLANT PATHOLOGY 2019; 20:685-700. [PMID: 30919582 PMCID: PMC6637876 DOI: 10.1111/mpp.12785] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Reactive oxygen species (ROS) are involved in the pathogen-host interactions, and play a Janus-faced role in the resistance and susceptibility of plants to biotrophic and necrotrophic pathogens. The ascomycete fungus Fusarium graminearum causes hazardous wheat Fusarium head blight worldwide. Deletion of the putative secreted catalase-peroxidase gene in F. graminearum, KatG2, reduced the virulence in wheat spike infection. However, it remains unclear when and where KatG2 scavenges ROS during the invasion of wheat. In this study, we delineate the change in ROS levels in the transition of the infection phase under microscopic observation. Correspondingly, the pathogen switches its strategy of infection with temporal and spatial regulation of KatG2 to counteract oxidative stress generated by host plant cells. With the native promoter-driven KatG2-mRFP strain, we show that KatG2-mRFP expression was induced in planta and accumulated in the infection front region at the early infection stage. In contrast to its ubiquitous cellular localization in runner hyphae, KatG2-mRFP is exclusively located on the cell wall of invading hyphal cells, especially at the pathogen-host cellular interface. Using posttranslational modification analysis, we found that asparagine residues at the 238 and 391 positions of KatG2 could be modified by N-glycosylation and that these two residues are required for KatG2 accumulation and cell wall localization in planta.
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Affiliation(s)
- Yan Guo
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
- University of the Chinese Academy of SciencesChina
| | - Shenghua Yao
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
- School of Life ScienceEast China Normal UniversityShanghai200062China
- Shanghai High School International DivisionShanghai200231China
| | - Tinglu Yuan
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
| | - Yanzhang Wang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
| | - Dong Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
| | - Weihua Tang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai200032China
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Galectin-3 Inhibits Paracoccidioides brasiliensis Growth and Impacts Paracoccidioidomycosis through Multiple Mechanisms. mSphere 2019; 4:4/2/e00209-19. [PMID: 31019001 PMCID: PMC6483048 DOI: 10.1128/msphere.00209-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The thermodimorphic pathogenic fungi Paracoccidioides brasiliensis and Paracoccidioides lutzii are the etiologic causes of paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in Latin America. Galectin-3 (Gal-3), an animal β-galactoside-binding protein, modulates important roles during microbial infections, such as triggering a Th2-polarized immune response in PCM. Herein, we demonstrate that Gal-3 also plays other important roles in P. brasiliensis infection. We verified that Gal-3 levels are upregulated in human and mice infections and established that Gal-3 inhibited P. brasiliensis growth by inhibiting budding. Furthermore, Gal-3 affected disruption and internalization of extracellular vesicles (EVs) from P. brasiliensis by macrophages. Our results suggest important protective roles for Gal-3 in P. brasiliensis infection, indicating that increased Gal-3 production during P. brasiliensis infection may affect fungal growth and EV stability, thus promoting beneficial effects that could influence the course of PCM. The finding that Gal-3 has effects against P. brasiliensis together with previously reported effects against Cryptococcus neoformans suggests that molecule has a general antifungal role in innate defenses against fungal pathogens.IMPORTANCE Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin America. Although the immune mechanisms to control PCM are still not fully understood, several events of the host innate and adaptive immunity are crucial to determine the progress of the infection. Mammalian β-galactoside-binding protein galectin-3 (Gal-3) plays significant roles during microbial infections and has been studied for its immunomodulatory roles, but it can also have direct antimicrobial effects. We asked whether this protein plays a role in Paracoccidioides brasiliensis We report herein that Gal-3 indeed has direct effects on the fungal pathogen, inhibiting fungal growth and reducing extracellular vesicle stability. Our results suggest a direct role for Gal-3 in P. brasiliensis infection, with beneficial effects for the mammalian host.
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Oliveira AF, Fernandes FF, Mariano VS, Almeida F, Ruas LP, Oliveira LL, Oliver C, Jamur MC, Roque-Barreira MC. Paracoccin distribution supports its role in Paracoccidioides brasiliensis growth and dimorphic transformation. PLoS One 2017; 12:e0184010. [PMID: 28846733 PMCID: PMC5573292 DOI: 10.1371/journal.pone.0184010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/16/2017] [Indexed: 12/30/2022] Open
Abstract
Paracoccidioides brasiliensis yeast was reported to express paracoccin, a GlcNAc-binding protein that displays N-acetyl-β-d-glucosaminidase (NAGase) activity. Highly specific anti-paracoccin antibodies have been previously used to examine the localization of paracoccin in yeast and inhibit its growth in vitro. In the present study, anti-paracoccin antibodies were used to characterize, by scanning confocal microscopy, the distribution of paracoccin in P. brasiliensis hyphae, transition forms from hyphae to yeast, and mature yeast. In the mycelial phase, paracoccin was detected mainly in the hyphae tips, where it demonstrated a punctate distribution, and was associated with the cell wall. During the first 48 hours after a temperature shift from 26°C to 37°C, paracoccin expression in the differentiating hyphae was mainly detected in the budding regions, i.e. lateral protrusions, and inside the new daughter cells. There was an increased number of chlamydoconidia that expressed a high concentration of paracoccin on their surfaces and/or in their interiors 72–96 hours after the temperature shift. After 120 hours, yeast cells were the predominant form and their cytoplasm stained extensively for paracoccin, whereas Wheat Germ Agglutinin (WGA) staining was predominant on their exterior walls. After 10 days at 37°C, the interior of both mother and daughter yeast cells, as well as the budding regions, stained intensely for paracoccin. The comparison of mRNA-expression in the different fungal forms showed that PCN transcripts, although detected in all evaluated morphological forms, were higher in hypha and yeast-to-hypha transition forms. In conclusion, the pattern of paracoccin distribution in all P. brasiliensis morphotypes supports prevalent beliefs that it plays important roles in fungal growth and dimorphic transformation.
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Affiliation(s)
- Aline Ferreira Oliveira
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Fabricio Freitas Fernandes
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Vânia Sammartino Mariano
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Fausto Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Luciana Pereira Ruas
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | | | - Constance Oliver
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Maria Celia Jamur
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Maria Cristina Roque-Barreira
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
- * E-mail:
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9
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Freitas MS, Oliveira AF, da Silva TA, Fernandes FF, Gonçales RA, Almeida F, Roque-Barreira MC. Paracoccin Induces M1 Polarization of Macrophages via Interaction with TLR4. Front Microbiol 2016; 7:1003. [PMID: 27458431 PMCID: PMC4932198 DOI: 10.3389/fmicb.2016.01003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/13/2016] [Indexed: 11/16/2022] Open
Abstract
The fungal human pathogen Paracoccidioides brasiliensis contains paracoccin (PCN), a multi-domain protein that has lectin and N-acetyl-glucosaminidase activities, which account for its effects on the growth and morphogenesis of the fungus and on the activation of host macrophages through its interaction with TLR N-glycans. With the purpose of detailing the knowledge on the effects of PCN on macrophages, we used recombinant PCN expressed in Pichia pastoris (p-rPCN) to stimulate isolated murine peritoneal macrophages. The activation of these cells manifested through the release of high levels of inflammatory mediators, such as nitric oxide, TNF-α, IL-12p40, and IL-6. Furthermore, peritoneal macrophages stimulated with p-rPCN increased the relative expression of STAT1, SOCS3, and iNOS2 mRNA (M1 polarization markers). However, the expression of Arginase-1, Ym-1, and FIZZ1 (M2 polarization markers) remained at basal levels. Interestingly, the observed M1 macrophages’ polarization triggered by p-rPCN was abolished in cells obtained from knockout Toll-like receptor-4 mice. In this case, the p-rPCN-induced production of pro-inflammatory mediators was blocked too. These results demonstrate that the classical activation of macrophages induced by paracoccin depends on TLR4. Taken together, the results of our study indicate that paracoccin acts as a TLR agonist able to modulate immunity and exerts biological activities that favor its applicability as an immunotherapeutic agent to combat systemic fungal infections.
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Affiliation(s)
- Mateus S Freitas
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
| | - Aline F Oliveira
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
| | - Thiago A da Silva
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
| | - Fabrício F Fernandes
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
| | - Relber A Gonçales
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
| | - Fausto Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
| | - Maria C Roque-Barreira
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo Ribeirão Preto, Brazil
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Almeida F, Antoniêto ACC, Pessoni AM, Monteiro VN, Alegre-Maller ACP, Pigosso LL, Pereira M, Soares CMDA, Roque-Barreira MC. Influence of N-glycans on Expression of Cell Wall Remodeling Related Genes in Paracoccidioides brasiliensis Yeast Cells. Curr Genomics 2016; 17:112-8. [PMID: 27226767 PMCID: PMC4864839 DOI: 10.2174/1389202917666151116212705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/30/2015] [Accepted: 07/12/2015] [Indexed: 12/14/2022] Open
Abstract
Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America. It is caused by the temperature-dependent dimorphic fungus Paracoccidioides brasiliensis. The P. brasiliensis cell wall is a dynamic outer structure, composed of a network of glycoproteins and polysaccharides, such as chitin, glucan and N-glycosylated proteins. These glycoproteins can interact with the host to affect infection rates, and are known to perform other functions. We inhibited N-linked glycosylation using tunicamycin (TM), and then evaluated the expression of P. brasiliensis genes related to cell wall remodeling. Our results suggest that cell wall synthesis related genes, such as β-1,3-glucanosyltransferase (PbGEL3), 1,3-β-D-glucan synthase (PbFKS1), and α-1,4-amylase (PbAMY), as well as cell wall degrading related genes, such as N-acetyl-β-D-glucosaminidase (PbNAG1), α-1,3-glucanase (PbAGN), and β-1,3-glucanase (PbBGN1 and PbBGN2), have their expression increased by the N-glycosylation inhibition, as detected by qRT-PCR. The observed increases in gene expression levels reveal possible compensatory mechanisms for diminished enzyme activity due to the lack of glycosylation caused by TM.
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Affiliation(s)
- Fausto Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14049-900, Brazil
| | - Amanda Cristina Campos Antoniêto
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-900, Brazil
| | - André Moreira Pessoni
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14049-900, Brazil
| | - Valdirene Neves Monteiro
- Universidade Estadural de Goiás, UnUCET, BR 153, Km98. Campus Henrique Santillo, Anapolis, GO 75000-000, Brazil
| | - Ana Claudia Paiva Alegre-Maller
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14049-900, Brazil
| | - Laurine Lacerda Pigosso
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Maristela Pereira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Maria Cristina Roque-Barreira
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14049-900, Brazil
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Almeida F, Sardinha-Silva A, da Silva TA, Pessoni AM, Pinzan CF, Alegre-Maller ACP, Cecílio NT, Moretti NS, Damásio ARL, Pedersoli WR, Mineo JR, Silva RN, Roque-Barreira MC. Toxoplasma gondii Chitinase Induces Macrophage Activation. PLoS One 2015; 10:e0144507. [PMID: 26659253 PMCID: PMC4684212 DOI: 10.1371/journal.pone.0144507] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/19/2015] [Indexed: 01/06/2023] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite found worldwide that is able to chronically infect almost all vertebrate species, especially birds and mammalians. Chitinases are essential to various biological processes, and some pathogens rely on chitinases for successful parasitization. Here, we purified and characterized a chitinase from T. gondii. The enzyme, provisionally named Tg_chitinase, has a molecular mass of 13.7 kDa and exhibits a Km of 0.34 mM and a Vmax of 2.64. The optimal environmental conditions for enzymatic function were at pH 4.0 and 50 °C. Tg_chitinase was immunolocalized in the cytoplasm of highly virulent T. gondii RH strain tachyzoites, mainly at the apical extremity. Tg_chitinase induced macrophage activation as manifested by the production of high levels of pro-inflammatory cytokines, a pathogenic hallmark of T. gondii infection. In conclusion, to our knowledge, we describe for the first time a chitinase of T. gondii tachyzoites and provide evidence that this enzyme might influence the pathogenesis of T. gondii infection.
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Affiliation(s)
- Fausto Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - Aline Sardinha-Silva
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - Thiago Aparecido da Silva
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - André Moreira Pessoni
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - Camila Figueiredo Pinzan
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - Ana Claudia Paiva Alegre-Maller
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - Nerry Tatiana Cecílio
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
| | - Nilmar Silvio Moretti
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Sao Paulo, São Paulo, SP, Brasil
| | - André Ricardo Lima Damásio
- Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade de Campinas, Campinas, SP, Brasil
| | - Wellington Ramos Pedersoli
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14040-900, Brasil
| | - José Roberto Mineo
- Laboratorio de Imunoparasitologia, Departamento de Imunologia, Microbiologia e Parasitologia, Universidade Federal de Uberlândia, Av. Pará, 1720, Uberlândia, MG, 38400 902, Brasil
| | - Roberto Nascimento Silva
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14040-900, Brasil
| | - Maria Cristina Roque-Barreira
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
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Abstract
Enzymes play key roles in fungal pathogenesis. Manipulation of enzyme expression or activity can significantly alter the infection process, and enzyme expression profiles can be a hallmark of disease. Hence, enzymes are worthy targets for better understanding pathogenesis and identifying new options for combatting fungal infections. Advances in genomics, proteomics, transcriptomics, and mass spectrometry have enabled the identification and characterization of new fungal enzymes. This review focuses on recent developments in the virulence-associated enzymes from Cryptococcus neoformans. The enzymatic suite of C. neoformans has evolved for environmental survival, but several of these enzymes play a dual role in colonizing the mammalian host. We also discuss new therapeutic and diagnostic strategies that could be based on the underlying enzymology.
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Extracellular vesicles from Paracoccidioides pathogenic species transport polysaccharide and expose ligands for DC-SIGN receptors. Sci Rep 2015; 5:14213. [PMID: 26387503 PMCID: PMC4585699 DOI: 10.1038/srep14213] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 08/20/2015] [Indexed: 01/08/2023] Open
Abstract
Extracellular vesicles (EVs) mediate non-conventional transport of molecules across the fungal cell wall. We aimed at describing the carbohydrate composition and surface carbohydrate epitopes of EVs isolated from the pathogenic fungi Paracoccidioides brasiliensis and P. lutzii using standard procedures. Total EV carbohydrates were ethanol-precipitated from preparations depleted of lipids and proteins, then analyzed by chemical degradation, gas chromatography-mass spectrometry, nuclear magnetic resonance and size-exclusion chromatography. EV glycosyl residues of Glc, Man, and Gal comprised most probably two major components: a high molecular mass 4,6-α-glucan and a galactofuranosylmannan, possibly an oligomer, bearing a 2-α-Manp main chain linked to β-Galf (1,3) and α-Manp (1,6) end units. The results also suggested the presence of small amounts of a (1→6)-Manp polymer, (1→3)-glucan and (1→6)-glucan. Glycan microarrays allowed identification of EV surface lectin(s), while plant lectin microarray profiling revealed terminal Man and GlcNAc residues exposed at the EVs surface. Mammalian lectin microarray profiling showed that DC-SIGN receptors recognized surface carbohydrate in Paracoccidioides EVs. Our results suggest that oligosaccharides, cytoplasmic storage, and cell wall polysaccharides can be exported in fungal EVs, which also expose surface PAMPs and lectins. The role of these newly identified components in the interaction with the host remains to be unraveled.
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Recombinant paracoccin reproduces the biological properties of the native protein and induces protective Th1 immunity against Paracoccidioides brasiliensis infection. PLoS Negl Trop Dis 2014; 8:e2788. [PMID: 24743161 PMCID: PMC3990478 DOI: 10.1371/journal.pntd.0002788] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/02/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Paracoccin is a dual-function protein of the yeast Paracoccidioides brasiliensis that has lectin properties and N-acetylglucosaminidase activities. Proteomic analysis of a paracoccin preparation from P. brasiliensis revealed that the sequence matched that of the hypothetical protein encoded by PADG-3347 of isolate Pb-18, with a polypeptide sequence similar to the family 18 endochitinases. These endochitinases are multi-functional proteins, with distinct lectin and enzymatic domains. METHODOLOGY/PRINCIPAL FINDINGS The multi-exon assembly and the largest exon of the predicted ORF (PADG-3347), was cloned and expressed in Escherichia coli cells, and the features of the recombinant proteins were compared to those of the native paracoccin. The multi-exon protein was also used for protection assays in a mouse model of paracoccidioidomycosis. CONCLUSIONS/SIGNIFICANCE Our results showed that the recombinant protein reproduced the biological properties described for the native protein-including binding to laminin in a manner that is dependent on carbohydrate recognition-showed N-acetylglucosaminidase activity, and stimulated murine peritoneal macrophages to produce high levels of TNF-α and nitric oxide. Considering the immunomodulatory potential of glycan-binding proteins, we also investigated whether prophylactic administration of recombinant paracoccin affected the course of experimental paracoccidioidomycosis in mice. In comparison to animals injected with vehicle (controls), mice treated with recombinant paracoccin displayed lower pulmonary fungal burdens and reduced pulmonary granulomas. These protective effects were associated with augmented pulmonary levels of IL-12 and IFN-γ. We also observed that injection of paracoccin three days before challenge was the most efficient administration protocol, as the induced Th1 immunity was balanced by high levels of pulmonary IL-10, which may prevent the tissue damage caused by exacerbated inflammation. The results indicated that paracoccin is the protein encoded by PADG-3347, and we propose that this gene and homologous proteins in other P. brasiliensis strains be called paracoccin. We also concluded that recombinant paracoccin confers resistance to murine P. brasiliensis infection by exerting immunomodulatory effects.
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Dos Reis Almeida FB, Pigosso LL, de Lima Damásio AR, Monteiro VN, de Almeida Soares CM, Silva RN, Roque-Barreira MC. α-(1,4)-Amylase, but not α- and β-(1,3)-glucanases, may be responsible for the impaired growth and morphogenesis of Paracoccidioides brasiliensis induced by N-glycosylation inhibition. Yeast 2013; 31:1-11. [PMID: 24155051 PMCID: PMC4235422 DOI: 10.1002/yea.2983] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/13/2013] [Accepted: 10/10/2013] [Indexed: 11/12/2022] Open
Abstract
The cell wall of Paracoccidioides brasiliensis, which consists of a network of polysaccharides and glycoproteins, is essential for fungal pathogenesis. We have previously reported that N-glycosylation of proteins such as N-acetyl-β-d-glucosaminidase is required for the growth and morphogenesis of P. brasiliensis. In the present study, we investigated the influence of tunycamicin (TM)-mediated inhibition of N-linked glycosylation on α- and β-(1,3)-glucanases and on α-(1,4)-amylase in P. brasiliensis yeast and mycelium cells. The addition of 15 µg/ml TM to the fungal cultures did not interfere with either α- or β-(1,3)-glucanase production and secretion. Moreover, incubation with TM did not alter α- and β-(1,3)-glucanase activity in yeast and mycelium cell extracts. In contrast, α-(1,4)-amylase activity was significantly reduced in underglycosylated yeast and mycelium extracts after exposure to TM. In spite of its importance for fungal growth and morphogenesis, N-glycosylation was not required for glucanase activities. This is surprising because these activities are directed to wall components that are crucial for fungal morphogenesis. On the other hand, N-glycans were essential for α-(1,4)-amylase activity involved in the production of malto-oligosaccharides that act as primer molecules for the biosynthesis of α-(1,3)-glucan. Our results suggest that reduced fungal α-(1,4)-amylase activity affects cell wall composition and may account for the impaired growth of underglycosylated yeast and mycelium cells. © 2013 The Authors. Yeast published by John Wiley & Sons Ltd.
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Affiliation(s)
- Fausto Bruno Dos Reis Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil
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