TY  - JOUR
A1  - Solger, Franziska
A1  - Kunz, Tobias C.
A1  - Fink, Julian
A1  - Paprotka, Kerstin
A1  - Pfister, Pauline
A1  - Hagen, Franziska
A1  - Schumacher, Fabian
A1  - Kleuser, Burkhard
A1  - Seibel, Jürgen
A1  - Rudel, Thomas
T1  - A Role of Sphingosine in the Intracellular Survival of Neisseria gonorrhoeae
JF  - Frontiers in Cellular and Infection Microbiology
N2  - Obligate human pathogenic Neisseria gonorrhoeae are the second most frequent bacterial cause of sexually transmitted diseases. These bacteria invade different mucosal tissues and occasionally disseminate into the bloodstream. Invasion into epithelial cells requires the activation of host cell receptors by the formation of ceramide-rich platforms. Here, we investigated the role of sphingosine in the invasion and intracellular survival of gonococci. Sphingosine exhibited an anti-gonococcal activity in vitro. We used specific sphingosine analogs and click chemistry to visualize sphingosine in infected cells. Sphingosine localized to the membrane of intracellular gonococci. Inhibitor studies and the application of a sphingosine derivative indicated that increased sphingosine levels reduced the intracellular survival of gonococci. We demonstrate here, that sphingosine can target intracellular bacteria and may therefore exert a direct bactericidal effect inside cells.
KW  - sphingosine
KW  - sphingolipids
KW  - sphingosine kinases
KW  - invasion
KW  - survival
KW  - click chemistry
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204111
SN  - 2235-2988
VL  - 10
ER  - 
TY  - JOUR
A1  - Götz, Ralph
A1  - Kunz, Tobias C.
A1  - Fink, Julian
A1  - Solger, Franziska
A1  - Schlegel, Jan
A1  - Seibel, Jürgen
A1  - Kozjak-Pavlovic, Vera
A1  - Rudel, Thomas
A1  - Sauer, Markus
T1  - Nanoscale imaging of bacterial infections by sphingolipid expansion microscopy
JF  - Nature Communications
N2  - Expansion microscopy (ExM) enables super-resolution imaging of proteins and nucleic acids on conventional microscopes. However, imaging of details of the organization of lipid bilayers by light microscopy remains challenging. We introduce an unnatural short-chain azide- and amino-modified sphingolipid ceramide, which upon incorporation into membranes can be labeled by click chemistry and linked into hydrogels, followed by 4x to 10x expansion. Confocal and structured illumination microscopy (SIM) enable imaging of sphingolipids and their interactions with proteins in the plasma membrane and membrane of intracellular organelles with a spatial resolution of 10-20nm. As our functionalized sphingolipids accumulate efficiently in pathogens, we use sphingolipid ExM to investigate bacterial infections of human HeLa229 cells by Neisseria gonorrhoeae, Chlamydia trachomatis and Simkania negevensis with a resolution so far only provided by electron microscopy. In particular, sphingolipid ExM allows us to visualize the inner and outer membrane of intracellular bacteria and determine their distance to 27.6 +/- 7.7nm. Imaging of lipid bilayers using light microscopy is challenging. Here the authors label cells using a short chain click-compatible ceramide to visualize mammalian and bacterial membranes with expansion microscopy.
KW  - nanoscale imaging
KW  - bacterial infection
KW  - sphingolipid expansion microscopy
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231248
VL  - 11
ER  -