beta-1,3-glucan-lacking Aspergillus fumigatus mediates an efficient antifungal immune response by activating complement and dendritic cells

Steger, Marion; Bermejo-Jambrina, Marta; Yordanov, Teodor; Wagener, Johannes; Brakhage, Axel A.; Pittl, Verena; Huber, Lukas A.; Haas, Hubertus; Lass-Floerl, Cornelia; Posch, Wilfried und Wilflingseder, Doris (2019): beta-1,3-glucan-lacking Aspergillus fumigatus mediates an efficient antifungal immune response by activating complement and dendritic cells. In: Virulence, Bd. 10, Nr. 1: S. 957-969

Abstract

Complement system and dendritic cells (DCs) form - beside neutrophils and macrophages - the first line of defense to combat fungal infections. Therefore, we here studied interactions of these first immune elements with Aspergillus fumigatus lacking ss-1,3-glucans (fks1(tetOn)(rep) under repressed conditions) to mechanistically explain the mode of action of echinocandins in more detail. Echinocandins are cell wall active agents blocking beta-glucan synthase, making the A. fumigatus fks1(tetOn) mutant a good model to study immune-modulatory actions of these drugs. We now demonstrate herein, that complement was activated to significantly higher levels by the fks1-deficient strain compared to its respective wild type. This enhanced covalent linking of complement fragments to the A. fumigatus fks1(tetOn)(rep) mutant further resulted in enhanced DC binding and internalization of the fungus. Additionally, we found that fks1(tetOn)(rep) induced a Th1-/Th17-polarizing cytokine profile program in DCs. The effect was essentially dependent on massive galactomannan shedding, since blocking of DC-SIGN significantly reduced the fks1(tetOn)(rep)-mediated induction of an inflammatory cytokine profile. Our data demonstrate that lack of ss-1,3-glucan, also found under echinocandin therapy, results in improved recognition of Aspergillus fumigatus by complement and DCs and therefore not only directly affects the fungus by its fungistatic actions, but also is likely to exert indirect antifungal mechanisms by strengthening innate host immune mechanisms.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 2150-5594
• Sprache: Englisch