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  - Weiss, Esther
A1  - Ziegler, Sabrina
A1  - Fliesser, Mirjam
A1  - Schmitt, Anna-Lena
A1  - Hünniger, Kerstin
A1  - Kurzai, Oliver
A1  - Morton, Charles-Oliver
A1  - Einsele, Hermann
A1  - Loeffler, Juergen
T1  - First Insights in NK—DC Cross-Talk and the Importance of Soluble Factors During Infection With Aspergillus fumigatus
JF  - Frontiers in Cellular and Infection Microbiology
N2  - Invasive aspergillosis (IA) is an infectious disease caused by the fungal pathogen Aspergillus fumigatus that mainly affects immunocompromised hosts. To investigate immune cell cross-talk during infection with A. fumigatus, we co-cultured natural killer (NK) cells and dendritic cells (DC) after stimulation with whole fungal structures, components of the fungal cell wall, fungal lysate or ligands for distinct fungal receptors. Both cell types showed activation after stimulation with fungal components and were able to transfer activation signals to the counterpart not stimulated cell type. Interestingly, DCs recognized a broader spectrum of fungal components and thereby initiated NK cell activation when those did not recognize fungal structures. These experiments highlighted the supportive function of DCs in NK cell activation. Furthermore, we focused on soluble DC mediated NK cell activation and showed that DCs stimulated with the TLR2/Dectin-1 ligand zymosan could maximally stimulate the expression of CD69 on NK cells. Thus, we investigated the influence of both receptors for zymosan, Dectin-1 and TLR2, which are highly expressed on DCs but show only minimal expression on NK cells. Specific focus was laid on the question whether Dectin-1 or TLR2 signaling in DCs is important for the secretion of soluble factors leading to NK cell activation. Our results show that Dectin-1 and TLR2 are negligible for NK cell activation. We conclude that besides Dectin-1 and TLR2 other receptors on DCs are able to compensate for the missing signal.
KW  - natural killer cells
KW  - dendritic cells
KW  - NK-DC cross-talk
KW  - Aspergillus fumigatus
KW  - soluble factors
KW  - innate immunity
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233565
VL  - 8
ER  -