Life-threatening fungal infections

Abstract

Invasive fungal infections are associated with mortality rates ranging from 30–90 per cent and kill more than 1.5 million mainly immunosuppressed people every year worldwide. Despite this threat, the diagnosis of these invasive fungal infections is often delayed and therapeutic options are limited. Current research aims at understanding defense strategies of the human host as well as the mechanisms allowing fungi to evade the immune defense. Important immune cells are macrophages and neutrophilic granulocytes. Some pathogenic fungi – like Aspergillus fumigatus – interfere with the maturation of phagosomes in these cells and are able to survive for a certain time in this cell compartment – well protected against the remaining immune system – and then they spread. Thus – in the future – it will be important to specifically target phagosomes and transport substances into them to fight such intracellular pathogens. Neutrophilic granulocytes are essential for defending invasive fungal infections. These cells also produce antifungal extracellular vesicles that kill A. fumigatus. Extracellular vesicles do not only have a great potential as novel therapeutic approach against infections but also for the diagnosis of infectious diseases.