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Fibronectin-, vitronectin- and laminin-binding proteins at the cell walls of Candida parapsilosis and Candida tropicalis pathogenic yeasts.

Kozik A, Karkowska-Kuleta J, Zajac D, Bochenska O, Kedracka-Krok S, Jankowska U, Rapala-Kozik M - BMC Microbiol. (2015)

Bottom Line: The major individual compounds of the fungal cell wall that bound fibronectin, vitronectin and laminin were found to comprise two groups: (1) true cell wall components similar to C. albicans adhesins from the Als, Hwp and Iff/Hyr families; and (2) atypical (cytoplasm-derived) surface-exposed proteins, including malate synthase, glucose-6-phosphate isomerase, 6-phosphogluconate dehydrogenase, enolase, fructose-1,6-bisphosphatase, transketolase, transaldolase and elongation factor 2.The adhesive abilities of two investigated non-albicans Candida species toward extracellular matrix proteins were comparable to those of C. albicans suggesting an important role of this particular virulence attribute in the pathogenesis of infections caused by C. tropicalis and C. parapsilosis.Our results reveal new insight into host-pathogen interactions during infections by two important, recently emerging, fungal pathogens.

View Article: PubMed Central - PubMed

Affiliation: Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7, 30-387, Krakow, Poland. andrzej.kozik@uj.edu.pl.

ABSTRACT

Background: Candida parapsilosis and C. tropicalis increasingly compete with C. albicans-the most common fungal pathogen in humans-as causative agents of severe candidiasis in immunocompromised patients. In contrast to C. albicans, the pathogenic mechanisms of these two non-albicans Candida species are poorly understood. Adhesion of Candida yeast to host cells and the extracellular matrix is critical for fungal invasion of hosts.

Methods: The fungal proteins involved in interactions with extracellular matrix proteins were isolated from mixtures of β-1,3-glucanase- or β-1,6-glucanase-extractable cell wall-associated proteins by use of affinity chromatography and chemical cross-linking methods, and were further identified by liquid chromatography-coupled tandem mass spectrometry.

Results: In the present study, we characterized the binding of three major extracellular matrix proteins-fibronectin, vitronectin and laminin-to C. parapsilosis and C. tropicalis pseudohyphae. The major individual compounds of the fungal cell wall that bound fibronectin, vitronectin and laminin were found to comprise two groups: (1) true cell wall components similar to C. albicans adhesins from the Als, Hwp and Iff/Hyr families; and (2) atypical (cytoplasm-derived) surface-exposed proteins, including malate synthase, glucose-6-phosphate isomerase, 6-phosphogluconate dehydrogenase, enolase, fructose-1,6-bisphosphatase, transketolase, transaldolase and elongation factor 2.

Discussion: The adhesive abilities of two investigated non-albicans Candida species toward extracellular matrix proteins were comparable to those of C. albicans suggesting an important role of this particular virulence attribute in the pathogenesis of infections caused by C. tropicalis and C. parapsilosis.

Conclusions: Our results reveal new insight into host-pathogen interactions during infections by two important, recently emerging, fungal pathogens.

No MeSH data available.


Related in: MedlinePlus

Binding of extracellular matrix proteins by Candida spp. filamentous forms. a Fibronectin (FN) binding by C. albicans, C. parapsilosis and C. tropicalis; b vitronectin (VTN) and laminin (LAM) binding by C. parapsilosis and C. tropicalis. Filamentous forms obtained from 1 × 106 yeast cells and adsorbed in wells of MaxiSorp microplates were incubated at 37 °C for 1.5 h with 50 μl of biotin-labeled FN, VTN or LAM solutions. Additional wells without adsorbed fungal cells but with BSA-blocked surfaces served as controls. The amounts of bound protein were determined using an SA-HRP/TMB system. The readings from control wells were subtracted from the total binding values. Representative binding plots are presented, in which data points represent means from three determinations (three independent wells) ± standard deviation
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Fig1: Binding of extracellular matrix proteins by Candida spp. filamentous forms. a Fibronectin (FN) binding by C. albicans, C. parapsilosis and C. tropicalis; b vitronectin (VTN) and laminin (LAM) binding by C. parapsilosis and C. tropicalis. Filamentous forms obtained from 1 × 106 yeast cells and adsorbed in wells of MaxiSorp microplates were incubated at 37 °C for 1.5 h with 50 μl of biotin-labeled FN, VTN or LAM solutions. Additional wells without adsorbed fungal cells but with BSA-blocked surfaces served as controls. The amounts of bound protein were determined using an SA-HRP/TMB system. The readings from control wells were subtracted from the total binding values. Representative binding plots are presented, in which data points represent means from three determinations (three independent wells) ± standard deviation

Mentions: Representative plots for saturable binding of biotin-labeled fibronectin by C. albicans hyphae and C. parapsilosis and C. tropicalis pseudohyphae are shown in Fig. 1a. The binding levels were within a range of 8–20 fmoles for hyphae/pseudohyphae generated from 1 × 106 cells, and decreased in the order of C. albicans > C. tropicalis > C. parapsilosis. The binding of vitronectin and laminin by C. parapsilosis and C. tropicalis pseudohyphae is shown in Fig. 1b. For each of the latter species, the binding capacities for fibronectin and laminin were comparable; for vitronectin, they were slightly higher in C. parapsilosis and lower in C. tropicalis. The highest (>2-fold) difference in binding capacity was noted between the two species for vitronectin.Fig. 1


Fibronectin-, vitronectin- and laminin-binding proteins at the cell walls of Candida parapsilosis and Candida tropicalis pathogenic yeasts.

Kozik A, Karkowska-Kuleta J, Zajac D, Bochenska O, Kedracka-Krok S, Jankowska U, Rapala-Kozik M - BMC Microbiol. (2015)

Binding of extracellular matrix proteins by Candida spp. filamentous forms. a Fibronectin (FN) binding by C. albicans, C. parapsilosis and C. tropicalis; b vitronectin (VTN) and laminin (LAM) binding by C. parapsilosis and C. tropicalis. Filamentous forms obtained from 1 × 106 yeast cells and adsorbed in wells of MaxiSorp microplates were incubated at 37 °C for 1.5 h with 50 μl of biotin-labeled FN, VTN or LAM solutions. Additional wells without adsorbed fungal cells but with BSA-blocked surfaces served as controls. The amounts of bound protein were determined using an SA-HRP/TMB system. The readings from control wells were subtracted from the total binding values. Representative binding plots are presented, in which data points represent means from three determinations (three independent wells) ± standard deviation
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4595241&req=5

Fig1: Binding of extracellular matrix proteins by Candida spp. filamentous forms. a Fibronectin (FN) binding by C. albicans, C. parapsilosis and C. tropicalis; b vitronectin (VTN) and laminin (LAM) binding by C. parapsilosis and C. tropicalis. Filamentous forms obtained from 1 × 106 yeast cells and adsorbed in wells of MaxiSorp microplates were incubated at 37 °C for 1.5 h with 50 μl of biotin-labeled FN, VTN or LAM solutions. Additional wells without adsorbed fungal cells but with BSA-blocked surfaces served as controls. The amounts of bound protein were determined using an SA-HRP/TMB system. The readings from control wells were subtracted from the total binding values. Representative binding plots are presented, in which data points represent means from three determinations (three independent wells) ± standard deviation
Mentions: Representative plots for saturable binding of biotin-labeled fibronectin by C. albicans hyphae and C. parapsilosis and C. tropicalis pseudohyphae are shown in Fig. 1a. The binding levels were within a range of 8–20 fmoles for hyphae/pseudohyphae generated from 1 × 106 cells, and decreased in the order of C. albicans > C. tropicalis > C. parapsilosis. The binding of vitronectin and laminin by C. parapsilosis and C. tropicalis pseudohyphae is shown in Fig. 1b. For each of the latter species, the binding capacities for fibronectin and laminin were comparable; for vitronectin, they were slightly higher in C. parapsilosis and lower in C. tropicalis. The highest (>2-fold) difference in binding capacity was noted between the two species for vitronectin.Fig. 1

Bottom Line: The major individual compounds of the fungal cell wall that bound fibronectin, vitronectin and laminin were found to comprise two groups: (1) true cell wall components similar to C. albicans adhesins from the Als, Hwp and Iff/Hyr families; and (2) atypical (cytoplasm-derived) surface-exposed proteins, including malate synthase, glucose-6-phosphate isomerase, 6-phosphogluconate dehydrogenase, enolase, fructose-1,6-bisphosphatase, transketolase, transaldolase and elongation factor 2.The adhesive abilities of two investigated non-albicans Candida species toward extracellular matrix proteins were comparable to those of C. albicans suggesting an important role of this particular virulence attribute in the pathogenesis of infections caused by C. tropicalis and C. parapsilosis.Our results reveal new insight into host-pathogen interactions during infections by two important, recently emerging, fungal pathogens.

View Article: PubMed Central - PubMed

Affiliation: Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7, 30-387, Krakow, Poland. andrzej.kozik@uj.edu.pl.

ABSTRACT

Background: Candida parapsilosis and C. tropicalis increasingly compete with C. albicans-the most common fungal pathogen in humans-as causative agents of severe candidiasis in immunocompromised patients. In contrast to C. albicans, the pathogenic mechanisms of these two non-albicans Candida species are poorly understood. Adhesion of Candida yeast to host cells and the extracellular matrix is critical for fungal invasion of hosts.

Methods: The fungal proteins involved in interactions with extracellular matrix proteins were isolated from mixtures of β-1,3-glucanase- or β-1,6-glucanase-extractable cell wall-associated proteins by use of affinity chromatography and chemical cross-linking methods, and were further identified by liquid chromatography-coupled tandem mass spectrometry.

Results: In the present study, we characterized the binding of three major extracellular matrix proteins-fibronectin, vitronectin and laminin-to C. parapsilosis and C. tropicalis pseudohyphae. The major individual compounds of the fungal cell wall that bound fibronectin, vitronectin and laminin were found to comprise two groups: (1) true cell wall components similar to C. albicans adhesins from the Als, Hwp and Iff/Hyr families; and (2) atypical (cytoplasm-derived) surface-exposed proteins, including malate synthase, glucose-6-phosphate isomerase, 6-phosphogluconate dehydrogenase, enolase, fructose-1,6-bisphosphatase, transketolase, transaldolase and elongation factor 2.

Discussion: The adhesive abilities of two investigated non-albicans Candida species toward extracellular matrix proteins were comparable to those of C. albicans suggesting an important role of this particular virulence attribute in the pathogenesis of infections caused by C. tropicalis and C. parapsilosis.

Conclusions: Our results reveal new insight into host-pathogen interactions during infections by two important, recently emerging, fungal pathogens.

No MeSH data available.


Related in: MedlinePlus