TY - JOUR A1 - Ziegler, Sabrina A1 - Weiss, Esther A1 - Schmitt, Anna-Lena A1 - Schlegel, Jan A1 - Burgert, Anne A1 - Terpitz, Ulrich A1 - Sauer, Markus A1 - Moretta, Lorenzo A1 - Sivori, Simona A1 - Leonhardt, Ines A1 - Kurzai, Oliver A1 - Einsele, Hermann A1 - Loeffler, Juergen T1 - CD56 Is a Pathogen Recognition Receptor on Human Natural Killer Cells JF - Scientific Reports N2 - Aspergillus (A.) fumigatus is an opportunistic fungal mold inducing invasive aspergillosis (IA) in immunocompromised patients. Although antifungal activity of human natural killer (NK) cells was shown in previous studies, the underlying cellular mechanisms and pathogen recognition receptors (PRRs) are still unknown. Using flow cytometry we were able to show that the fluorescence positivity of the surface receptor CD56 significantly decreased upon fungal contact. To visualize the interaction site of NK cells and A. fumigatus we used SEM, CLSM and dSTORM techniques, which clearly demonstrated that NK cells directly interact with A. fumigatus via CD56 and that CD56 is re-organized and accumulated at this interaction site time-dependently. The inhibition of the cytoskeleton showed that the receptor re-organization was an active process dependent on actin re-arrangements. Furthermore, we could show that CD56 plays a role in the fungus mediated NK cell activation, since blocking of CD56 surface receptor reduced fungal mediated NK cell activation and reduced cytokine secretion. These results confirmed the direct interaction of NK cells and A. fumigatus, leading to the conclusion that CD56 is a pathogen recognition receptor. These findings give new insights into the functional role of CD56 in the pathogen recognition during the innate immune response. KW - pattern recognition receptors KW - fungal infection KW - Aspergillus fumigatus KW - natural killer cells Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170637 VL - 7 IS - 6138 ER - TY - JOUR A1 - Hellmann, Anna-Maria A1 - Lother, Jasmin A1 - Wurster, Sebastian A1 - Lutz, Manfred B. A1 - Schmitt, Anna Lena A1 - Morton, Charles Oliver A1 - Eyrich, Matthias A1 - Czakai, Kristin A1 - Einsele, Hermann A1 - Loeffler, Juergen T1 - Human and Murine Innate Immune Cell Populations Display Common and Distinct Response Patterns during Their In Vitro Interaction with the Pathogenic Mold Aspergillus fumigatus JF - Frontiers in Immunology N2 - 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. KW - murine model KW - humans KW - Aspergillus fumigatus KW - innate immune response KW - fungal infection Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169926 VL - 8 IS - 1716 ER - TY - JOUR A1 - White, P. Lewis A1 - Wiederhold, Nathan P. A1 - Loeffler, Juergen A1 - Najvar, Laura K. A1 - Melchers, Willem A1 - Herrera, Monica A1 - Bretagne, Stephane A1 - Wickes, Brian A1 - Kirkpatrick, William R. A1 - Barnes, Rosemary A. A1 - Donnelly, J. Peter A1 - Patterson, Thomas F. T1 - Comparison of nonculture blood-based tests for diagnosing invasive aspergillosis in an animal model JF - Journal of Clinical Microbiology N2 - The European Aspergillus PCR Initiative (EAPCRI) has provided recommendations for the PCR testing of whole blood (WB) and serum/plasma. It is important to test these recommended protocols on nonsimulated "in vivo" specimens before full clinical evaluation. The testing of an animal model of invasive aspergillosis (IA) overcomes the low incidence of disease and provides experimental design and control that is not possible in the clinical setting. Inadequate performance of the recommended protocols at this stage would require reassessment of methods before clinical trials are performed and utility assessed. The manuscript describes the performance of EAPCRI protocols in an animal model of invasive aspergillosis. Blood samples taken from a guinea pig model of IA were used for WB and serum PCR. Galactomannan and beta-D-glucan detection were evaluated, with particular focus on the timing of positivity and on the interpretation of combination testing. The overall sensitivities for WB PCR, serum PCR, galactomannan, and beta-D-glucan were 73%, 65%, 68%, and 46%, respectively. The corresponding specificities were 92%, 79%, 80%, and 100%, respectively. PCR provided the earliest indicator of IA, and increasing galactomannan and beta-D-glucan values were indicators of disease progression. The combination of WB PCR with galactomannan and beta-D-glucan proved optimal (area under the curve AUC], 0.95), and IA was confidently diagnosed or excluded. The EAPRCI-recommended PCR protocols provide performance comparable to commercial antigen tests, and clinical trials are warranted. By combining multiple tests, IA can be excluded or confirmed, highlighting the need for a combined diagnostic strategy. However, this approach must be balanced against the practicality and cost of using multiple tests. KW - high-risk hematology KW - Guinea pig model KW - real-time PCR KW - fungal disease KW - galactomannan KW - pulmonary aspergillosis KW - amphotericin B KW - Aspergillus fumigatus KW - beta-D-glucan Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-189674 VL - 54 IS - 4 ER - TY - JOUR A1 - Marischen, Lothar A1 - Englert, Anne A1 - Schmitt, Anna-Lena A1 - Einsele, Hermann A1 - Loeffler, Juergen T1 - Human NK cells adapt their immune response towards increasing multiplicities of infection of Aspergillus fumigatus JF - BMC Immunology N2 - Background: The saprophytic fungus Aspergillus fumigatus reproduces by generation of conidia, which are spread by airflow throughout nature. Since humans are inhaling certain amounts of spores every day, the (innate) immune system is constantly challenged. Even though macrophages and neutrophils carry the main burden, also NK cells are regarded to contribute to the antifungal immune response. While NK cells reveal a low frequency, expression and release of immunomodulatory molecules seem to be a natural way of their involvement. Results: In this study we show, that NK cells secrete chemokines such as CCL3/MIP-1α, CCL4/MIP-1β and CCL5/RANTES early on after stimulation with Aspergillus fumigatus and, in addition, adjust the concentration of chemokines released to the multiplicity of infection of Aspergillus fumigatus. Conclusions: These results further corroborate the relevance of NK cells within the antifungal immune response, which is regarded to be more and more important in the development and outcome of invasive aspergillosis in immunocompromised patients after hematopoietic stem cell transplantation. Additionally, the correlation between the multiplicity of infection and the expression and release of chemokines shown here may be useful in further studies for the quantification and/or surveillance of the NK cell involvement in antifungal immune responses. KW - Aspergillus fumigatus KW - aspergillosis KW - NK cells KW - chemokines KW - CCL4 KW - multiplicity of infection KW - MIP-1β Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176331 VL - 19 IS - 39 ER -