Fungus delays immune response

Extracellular vesicles - small, membrane-enclosed particles secreted by cells - are important components of cell communication and interaction. For example, they transport messenger substances from cell to cell. What role they play in the interaction of the pathogenic yeast fungus Candida albicans with the human immune system has now been described for the first time by FungiNet scientists of Projects C4, C5, C6 and Z2 in cooperation with colleagues from the Medical University of Innsbruck.

Infections with the yeast Candida albicans are associated with a high mortality rate. Thus, new therapeutic approaches are needed, which require a profound understanding of the interaction between the pathogenic fungus and the human immune system. The scientists therefore investigated the reaction of monocytes - white blood cells that are part of the immune system - to contact with Candida albicans. Binding to a specific receptor on the monocytes, which is part of the innate immune system, the yeast fungus induces the release of extracellular vesicles that transport a messenger substance to other immune cells. These vesicles reduce the inflammatory response of macrophages. This delays the inflammatory response, the body can only start fighting the dangerous microorganism later and the fungal infection progresses. The discovery of this new mechanism, where Candida albicans affects the human immune response, reveals new possible approaches for a therapy of the fungal infection.

Original publication:

Halder LD, Jo EAH, Hasan MZ, Ferreira-Gomes M, Krüger T, Westermann M, Palme DI, Rambach G, Beyersdorf N, Speth C, Jacobsen ID, Kniemeyer O, Jungnickel B, Zipfel PF, Skerka C (2020) Immune modulation by complement receptor 3 dependent human monocyte TGF-β1-transporting vesicles. Nat Commun 11: 233

Link to PubMed

Press release of Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Jena