Paracoccin, an N-acetyl-glucosamine-binding lectin of Paracoccidioides brasiliensis, is involved in fungal growth

Ganiko, Luciane; Puccia, Rosana; Mariano, Vânia Sammartino; Sant’Anna, Osvaldo A.; Freymüller, Edna; Roque-Barreira, Maria Cristina; Travassos, Luiz R.

doi:10.1016/j.micinf.2007.02.012

Cited by 27 publications

(36 citation statements)

References 29 publications

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“…Although the mechanisms connecting exposure to enolase with changes in surface carbohydrates are unclear, this observation echoes previous findings showing that animal infection with S. pneumoniae, an enolase-producing pathogen (6), results in an increased surface exposure of N-acetylglucosamine residues by host tissues (29). Since P. brasiliensis uses N-acetylglucosamine as a surface site of adhesion in host cells (12,18,23), we hypothesized that treatment of host cells with enolase could result in increased infectivity.…”

Section: Discussionsupporting

confidence: 77%

“…To evaluate the effects of rPbEno on the interaction of P. brasiliensis with host cells, RAW and A549 lineages were first exposed to the enzyme and then probed with succinylated wheat germ agglutinin (S-WGA). S-WGA has affinity for ␤1,4-Nacetylglucosamine (GlcNAc) oligomers, which are recognized by the P. brasiliensis adhesin paracoccin (23). Mammalian cells were placed in a 24-well plate (10 5 cells/well) and treated with various concentrations of rPbEno (1 and 50 g/ml) for 1 h at 37°C.…”

Section: Vol 78 2010 Functions Of P Brasiliensis Enolase 4041mentioning

confidence: 99%

“…5A, panel a) and murine phagocytes (Fig. 5A, panel b) to rPbEno resulted in an expressive increase in their reactivity with WGA, suggesting that the enzyme modifies the surface of host cells to promote an enhanced exposure of GlcNAc residues, which are recognized by a P. brasiliensis adhesin (23). We therefore asked whether exposure to the enzyme would make mammalian cells more susceptible to infection by P. brasiliensis.…”

Section: Vol 78 2010 Functions Of P Brasiliensis Enolase 4045mentioning

confidence: 99%

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Paracoccidioides brasiliensis Enolase Is a Surface Protein That Binds Plasminogen and Mediates Interaction of Yeast Forms with Host Cells

et al. 2010

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Paracoccidioidomycosis (PCM), caused by the dimorphic fungusParacoccidioides brasiliensis, is a disseminated, systemic disorder that involves the lungs and other organs. The ability of the pathogen to interact with host components, including extracellular matrix (ECM) proteins, is essential to further colonization, invasion, and growth. Previously, enolase (EC 4.2.1.11) was characterized as a fibronectin binding protein in P. brasiliensis. Interaction of surface-bound enolase with plasminogen has been incriminated in tissue invasion for pathogenesis in several pathogens. In this paper, enolase was expressed in Escherichia coli as a recombinant glutathione S-transferase (GST) fusion protein (recombinant P. brasiliensis enolase [rPbEno]). The P. brasiliensis native enolase (PbEno) was detected at the fungus surface and cytoplasm by immunofluorescence with an anti-rPbEno antibody. Immobilized purified rPbEno bound plasminogen in a specific, concentrationdependent fashion. Both native enolase and rPbEno activated conversion of plasminogen to plasmin through tissue plasminogen activator. The association between PbEno and plasminogen was lysine dependent. In competition experiments, purified rPbEno, in its soluble form, inhibited plasminogen binding to fixed P. brasiliensis, suggesting that this interaction required surface-localized PbEno. Plasminogen-coated P. brasiliensis yeast cells were capable of degrading purified fibronectin, providing in vitro evidence for the generation of active plasmin on the fungus surface. Exposure of epithelial cells and phagocytes to enolase was associated with an increased expression of surface sites of adhesion. In fact, the association of P. brasiliensis with epithelial cells and phagocytes was increased in the presence of rPbEno. The expression of PbEno was upregulated in yeast cells derived from mouse-infected tissues. These data indicate that surface-associated PbEno may contribute to the pathogenesis of P. brasiliensis.

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Section: Discussionsupporting

confidence: 77%

Section: Vol 78 2010 Functions Of P Brasiliensis Enolase 4041mentioning

confidence: 99%

Section: Vol 78 2010 Functions Of P Brasiliensis Enolase 4045mentioning

confidence: 99%

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Paracoccidioides brasiliensis Enolase Is a Surface Protein That Binds Plasminogen and Mediates Interaction of Yeast Forms with Host Cells

et al. 2010

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“…ELISA with lipid fractions extracted from vesicles was carried out as described previously (25) For immunoblotting, about 6% of one vesicle preparation batch (500 ml culture) from P. brasiliensis was subjected to electrophoresis in a 10% SDSpolyacrylamide gel (21) and electrotransferred to nitrocellulose membranes. The incubation conditions with antibodies and conjugates were as described above for ELISA and elsewhere (17). For silver staining (8), about half of a vesicle preparation (500 ml culture) was necessary for band visualization.…”

Section: Methodsmentioning

confidence: 99%

The Pathogenic Fungus Paracoccidioides brasiliensis Exports Extracellular Vesicles Containing Highly Immunogenic α-Galactosyl Epitopes

et al. 2011

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Exosome-like vesicles containing virulence factors, enzymes, and antigens have recently been characterized in fungal pathogens, such as Cryptococcus neoformans and Histoplasma capsulatum. Here, we describe extracellular vesicles carrying highly immunogenic ␣-linked galactopyranosyl (␣-Gal) epitopes in Paracoccidioides brasiliensis. P. brasiliensis is a dimorphic fungus that causes human paracoccidioidomycosis (PCM). For vesicle preparations, cell-free supernatant fluids from yeast cells cultivated in Ham's defined medium-glucose were concentrated in an Amicon ultrafiltration system and ultracentrifuged at 100,000 ؋ g. P. brasiliensis antigens were present in preparations from phylogenetically distinct isolates Pb18 and Pb3, as observed in immunoblots revealed with sera from PCM patients. In an enzyme-linked immunosorbent assay (ELISA), vesicle components containing ␣-Gal epitopes reacted strongly with anti-␣-Gal antibodies isolated from both Chagas' disease and PCM patients, with Marasmius oreades agglutinin (MOA) (a lectin that recognizes terminal ␣-Gal), but only faintly with natural anti-␣-Gal. Reactivity was inhibited after treatment with ␣-galactosidase. Vesicle preparations analyzed by electron microscopy showed vesicular structures of 20 to 200 nm that were labeled both on the surface and in the lumen with MOA. In P. brasiliensis cells, components carrying ␣-Gal epitopes were found distributed on the cell wall, following a punctuated confocal pattern, and inside large intracellular vacuoles. Lipid-free vesicle fractions reacted with anti-␣-Gal in ELISA only when not digested with ␣-galactosidase, while reactivity with glycoproteins was reduced after ␤-elimination, which is indicative of partial O-linked chain localization. Our findings open new areas to explore in terms of host-parasite relationships in PCM and the role played in vivo by vesicle components and ␣-galactosyl epitopes.

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“…PCN is a multidomain protein with both lectin and enzymatic activities that can bind N-acetylglucosamine (14) and chitin but can also act as an N-acetylglucosaminidase (15). These biological activities may potentially explain the role of PCN in fungal cell growth (16). PCN is also able to act as an immunomodulatory agent when injected subcutaneously into P. brasiliensis -infected mice.…”

Section: Introductionmentioning

confidence: 99%

Impact of Paracoccin Gene Silencing on Paracoccidioides brasiliensis Virulence

Fernandes

Oliveira

Landgraf

et al. 2017

mBio

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Among the endemic deep mycoses in Latin America, paracoccidioidomycosis (PCM), caused by thermodimorphic fungi of the Paracoccidioides genus, is a major cause of morbidity. Disease development and its manifestations are associated with both host and fungal factors. Concerning the latter, several recent studies have employed the methodology of gene modulation in P. brasiliensis using antisense RNA (AsRNA) and Agrobacterium tumefaciens-mediated transformation (ATMT) to identify proteins that influence fungus virulence. Our previous observations suggested that paracoccin (PCN), a multidomain fungal protein with both lectin and enzymatic activities, may be a potential P. brasiliensis virulence factor. To explore this, we used AsRNA and ATMT methodology to obtain three independent PCN-silenced P. brasiliensis yeast strains (AsPCN1, AsPCN2, and AsPCN3) and characterized them with regard to P. brasiliensis biology and pathogenicity. AsPCN1, AsPCN2, and AsPCN3 showed relative PCN expression levels that were 60%, 40%, and 60% of that of the wild-type (WT) strain, respectively. PCN silencing led to the aggregation of fungal cells, blocked the morphological yeast-to-mycelium transition, and rendered the yeast less resistant to macrophage fungicidal activity. In addition, mice infected with AsPCN1, AsPCN2, and AsPCN3 showed a reduction in fungal burden of approximately 96% compared with those inoculated with the WT strain, which displayed a more extensive destruction of lung tissue. Finally, mice infected with the PCN-silenced yeast strains had lower mortality than those infected with the WT strain. These data demonstrate that PCN acts as a P. brasiliensis contributory virulence factor directly affecting fungal pathogenesis.

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Paracoccin, an N-acetyl-glucosamine-binding lectin of Paracoccidioides brasiliensis, is involved in fungal growth

Cited by 27 publications

References 29 publications

Paracoccidioides brasiliensis Enolase Is a Surface Protein That Binds Plasminogen and Mediates Interaction of Yeast Forms with Host Cells

Paracoccidioides brasiliensis Enolase Is a Surface Protein That Binds Plasminogen and Mediates Interaction of Yeast Forms with Host Cells

The Pathogenic Fungus Paracoccidioides brasiliensis Exports Extracellular Vesicles Containing Highly Immunogenic α-Galactosyl Epitopes

Impact of Paracoccin Gene Silencing on Paracoccidioides brasiliensis Virulence

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