@article{IrmerTarazonaSasseetal.2015, author = {Irmer, Henriette and Tarazona, Sonia and Sasse, Christoph and Olbermann, Patrick and Loeffler, J{\"u}rgen and Krappmann, Sven and Conesa, Ana and Braus, Gerhard H.}, title = {RNAseq analysis of Aspergillus fumigatus in blood reveals a just wait and see resting stage behavior}, series = {BMC Genomics}, volume = {16}, journal = {BMC Genomics}, number = {640}, doi = {10.1186/s12864-015-1853-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151390}, year = {2015}, abstract = {Background: Invasive aspergillosis is started after germination of Aspergillus fumigatus conidia that are inhaled by susceptible individuals. Fungal hyphae can grow in the lung through the epithelial tissue and disseminate hematogenously to invade into other organs. Low fungaemia indicates that fungal elements do not reside in the bloodstream for long. Results: We analyzed whether blood represents a hostile environment to which the physiology of A. fumigatus has to adapt. An in vitro model of A. fumigatus infection was established by incubating mycelium in blood. Our model allowed to discern the changes of the gene expression profile of A. fumigatus at various stages of the infection. The majority of described virulence factors that are connected to pulmonary infections appeared not to be activated during the blood phase. Three active processes were identified that presumably help the fungus to survive the blood environment in an advanced phase of the infection: iron homeostasis, secondary metabolism, and the formation of detoxifying enzymes. Conclusions: We propose that A. fumigatus is hardly able to propagate in blood. After an early stage of sensing the environment, virtually all uptake mechanisms and energy-consuming metabolic pathways are shut-down. The fungus appears to adapt by trans-differentiation into a resting mycelial stage. This might reflect the harsh conditions in blood where A. fumigatus cannot take up sufficient nutrients to establish self-defense mechanisms combined with significant growth.}, language = {en} } @article{HellmannLotherWursteretal.2017, author = {Hellmann, Anna-Maria and Lother, Jasmin and Wurster, Sebastian and Lutz, Manfred B. and Schmitt, Anna Lena and Morton, Charles Oliver and Eyrich, Matthias and Czakai, Kristin and Einsele, Hermann and Loeffler, Juergen}, title = {Human and Murine Innate Immune Cell Populations Display Common and Distinct Response Patterns during Their In Vitro Interaction with the Pathogenic Mold Aspergillus fumigatus}, series = {Frontiers in Immunology}, volume = {8}, journal = {Frontiers in Immunology}, number = {1716}, doi = {10.3389/fimmu.2017.01716}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169926}, year = {2017}, abstract = {Aspergillus fumigatus is the main cause of invasive fungal infections occurring almost exclusively in immunocompromised patients. An improved understanding of the initial innate immune response is key to the development of better diagnostic tools and new treatment options. Mice are commonly used to study immune defense mechanisms during the infection of the mammalian host with A. fumigatus. However, little is known about functional differences between the human and murine immune response against this fungal pathogen. Thus, we performed a comparative functional analysis of human and murine dendritic cells (DCs), macrophages, and polymorphonuclear cells (PMNs) using standardized and reproducible working conditions, laboratory protocols, and readout assays. A. fumigatus did not provoke identical responses in murine and human immune cells but rather initiated relatively specific responses. While human DCs showed a significantly stronger upregulation of their maturation markers and major histocompatibility complex molecules and phagocytosed A. fumigatus more efficiently compared to their murine counterparts, murine PMNs and macrophages exhibited a significantly stronger release of reactive oxygen species after exposure to A. fumigatus. For all studied cell types, human and murine samples differed in their cytokine response to conidia or germ tubes of A. fumigatus. Furthermore, Dectin-1 showed inverse expression patterns on human and murine DCs after fungal stimulation. These specific differences should be carefully considered and highlight potential limitations in the transferability of murine host-pathogen interaction studies.}, language = {en} }