Galactosaminogalactan secreted from Aspergillus fumigatus and Aspergillus flavus induces platelet activation

Publication date: Available online 18 January 2020Source: Microbes and InfectionAuthor(s): Hemalata Deshmukh, Günter Rambach, Donald C. Sheppard, Mark Lee, Magdalena Hagleitner, Martin Hermann, Reinhard Würzner, Cornelia Lass-Flörl, Cornelia SpethAbstractPlatelets are meanwhile recognized as versatile elements within the immune system and appear to play a key role in the innate immune response to pathogens including fungi. Previous experiments revealed platelet activation by direct contact with the hyphal-associated polysaccharide galactosaminogalactan (GAG). Since secreted fungal products may also be relevant and trigger immune reactions or thrombosis, we screened culture supernatants (SN) of human-pathogenic fungi for their capacity to activate platelets. For that purpose, platelets were incubated with SN from various fungal species; platelet activation and GAG deposition on the surface of platelets were detected by flow cytometry and electron and confocal microscopy, Culture supernatants of A. fumigatus and flavus isolates were potent platelet stimulators in a dose- and time-dependent manner, while SN of other Aspergillus species and all tested mucormycete species did not significantly induce platelet activation. The capacity of culture SN to activate platelets was dependent on fungal production of GAG and deposition of secreted GAG on the platelet surface; supernatants from mucormycetes or mutants of A. fumigatus lacking GAG secretion did not affect platelet activity. ...
Source: Microbes and Infection - Category: Infectious Diseases Source Type: research