Skip to Content
Merck
  • The Fungal Exopolysaccharide Galactosaminogalactan Mediates Virulence by Enhancing Resistance to Neutrophil Extracellular Traps.

The Fungal Exopolysaccharide Galactosaminogalactan Mediates Virulence by Enhancing Resistance to Neutrophil Extracellular Traps.

PLoS pathogens (2015-10-23)
Mark J Lee, Hong Liu, Bridget M Barker, Brendan D Snarr, Fabrice N Gravelat, Qusai Al Abdallah, Christina Gavino, Shane R Baistrocchi, Hanna Ostapska, Tianli Xiao, Benjamin Ralph, Norma V Solis, Mélanie Lehoux, Stefanie D Baptista, Arsa Thammahong, Robert P Cerone, Susan G W Kaminskyj, Marie-Christine Guiot, Jean-Paul Latgé, Thierry Fontaine, Donald C Vinh, Scott G Filler, Donald C Sheppard
ABSTRACT

Of the over 250 Aspergillus species, Aspergillus fumigatus accounts for up to 80% of invasive human infections. A. fumigatus produces galactosaminogalactan (GAG), an exopolysaccharide composed of galactose and N-acetyl-galactosamine (GalNAc) that mediates adherence and is required for full virulence. Less pathogenic Aspergillus species were found to produce GAG with a lower GalNAc content than A. fumigatus and expressed minimal amounts of cell wall-bound GAG. Increasing the GalNAc content of GAG of the minimally pathogenic A. nidulans, either through overexpression of the A. nidulans epimerase UgeB or by heterologous expression of the A. fumigatus epimerase Uge3 increased the amount of cell wall bound GAG, augmented adherence in vitro and enhanced virulence in corticosteroid-treated mice to levels similar to A. fumigatus. The enhanced virulence of the overexpression strain of A. nidulans was associated with increased resistance to NADPH oxidase-dependent neutrophil extracellular traps (NETs) in vitro, and was not observed in neutropenic mice or mice deficient in NADPH-oxidase that are unable to form NETs. Collectively, these data suggest that cell wall-bound GAG enhances virulence through mediating resistance to NETs.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Propidium iodide, ≥94.0% (HPLC)
Sigma-Aldrich
Cortisone 21-acetate, ≥99%
Sigma-Aldrich
Phenol, JIS special grade, ≥99.0%
Sigma-Aldrich
2,3-Dimercapto-1-propanol, ≥98% (iodometric)
Sigma-Aldrich
Phenol, unstabilized, purified by redistillation, ≥99%
Sigma-Aldrich
Phenol, unstabilized, ReagentPlus®, ≥99%
Sigma-Aldrich
Luperox® DI, tert-Butyl peroxide, 98%
Sigma-Aldrich
Fluorescein, for fluorescence, free acid
Sigma-Aldrich
Phenol, ≥99%
Sigma-Aldrich
Phenol, puriss., meets analytical specification of Ph. Eur., BP, USP, ≥99.5% (GC), crystalline (detached)
Sigma-Aldrich
Phenol, ≥96.0% (calc. on dry substance, T)
Supelco
Phenol solution, certified reference material, 500 μg/mL in methanol
Supelco
Phenol solution, 5000 μg/mL in methanol, certified reference material
Sigma-Aldrich
Phenol, puriss., meets analytical specification of Ph. Eur., BP, USP, 99.5-100.5% (GC)
Sigma-Aldrich
Phenol, contains hypophosphorous as stabilizer, loose crystals, ACS reagent, ≥99.0%
Sigma-Aldrich
Phenol, for molecular biology
Sigma-Aldrich
Phenol solution, BioReagent, Saturated with 0.01 M citrate buffer, pH 4.3 ± 0.2, for molecular biology
Sigma-Aldrich
Liquified Phenol, ≥89.0%
Sigma-Aldrich
Dexamethasone, powder, γ-irradiated, BioXtra, suitable for cell culture, ≥80% (HPLC)
Sigma-Aldrich
Dexamethasone, meets USP testing specifications
Sigma-Aldrich
Dexamethasone, ≥98% (HPLC), powder
Sigma-Aldrich
Dexamethasone, powder, BioReagent, suitable for cell culture, ≥97%
Sigma-Aldrich
Propidium iodide solution
Sigma-Aldrich
Phenol solution, Equilibrated with 10 mM Tris HCl, pH 8.0, 1 mM EDTA, BioReagent, for molecular biology
Sigma-Aldrich
Phenol, BioXtra, ≥99.5% (GC)
Sigma-Aldrich
Phenol, ≥99.0%
Sigma-Aldrich
Phenol, ≥99.0%
Sigma-Aldrich
Phenol, SAJ first grade, ≥98.0%
Sigma-Aldrich
Phenol, BioUltra, for molecular biology, TE-saturated, ~73% (T)
Sigma-Aldrich
Phenol, puriss. p.a., ACS reagent, reag. Ph. Eur., 99.0-100.5%