TY  - JOUR
A1  - Eder, Sascha
A1  - Hollmann, Claudia
A1  - Mandasari, Putri
A1  - Wittmann, Pia
A1  - Schumacher, Fabian
A1  - Kleuser, Burkhard
A1  - Fink, Julian
A1  - Seibel, Jürgen
A1  - Schneider-Schaulies, Jürgen
A1  - Stigloher, Christian
A1  - Beyersdorf, Niklas
A1  - Dembski, Sofia
T1  - Synthesis and characterization of ceramide-containing liposomes as membrane models for different T cell subpopulations
JF  - Journal of Functional Biomaterials
N2  - A fine balance of regulatory (T\(_{reg}\)) and conventional CD4\(^+\) T cells (T\(_{conv}\)) is required to prevent harmful immune responses, while at the same time ensuring the development of protective immunity against pathogens. As for many cellular processes, sphingolipid metabolism also crucially modulates the T\(_{reg}\)/T\(_{conv}\) balance. However, our understanding of how sphingolipid metabolism is involved in T cell biology is still evolving and a better characterization of the tools at hand is required to advance the field. Therefore, we established a reductionist liposomal membrane model system to imitate the plasma membrane of mouse T\(_{reg}\) and T\(_{conv}\) with regards to their ceramide content. We found that the capacity of membranes to incorporate externally added azide-functionalized ceramide positively correlated with the ceramide content of the liposomes. Moreover, we studied the impact of the different liposomal preparations on primary mouse splenocytes in vitro. The addition of liposomes to resting, but not activated, splenocytes maintained viability with liposomes containing high amounts of C\(_{16}\)-ceramide being most efficient. Our data thus suggest that differences in ceramide post-incorporation into T\(_{reg}\) and T\(_{conv}\) reflect differences in the ceramide content of cellular membranes.
KW  - liposome
KW  - ceramide
KW  - cell membrane model
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286130
SN  - 2079-4983
VL  - 13
IS  - 3
ER  - 
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  - Schneider-Schaulies, Sibylle
A1  - Schumacher, Fabian
A1  - Wigger, Dominik
A1  - Schöl, Marie
A1  - Waghmare, Trushnal
A1  - Schlegel, Jan
A1  - Seibel, Jürgen
A1  - Kleuser, Burkhard
T1  - Sphingolipids: effectors and Achilles heals in viral infections?
JF  - Cells
N2  - As viruses are obligatory intracellular parasites, any step during their life cycle strictly depends on successful interaction with their particular host cells. In particular, their interaction with cellular membranes is of crucial importance for most steps in the viral replication cycle. Such interactions are initiated by uptake of viral particles and subsequent trafficking to intracellular compartments to access their replication compartments which provide a spatially confined environment concentrating viral and cellular components, and subsequently, employ cellular membranes for assembly and exit of viral progeny. The ability of viruses to actively modulate lipid composition such as sphingolipids (SLs) is essential for successful completion of the viral life cycle. In addition to their structural and biophysical properties of cellular membranes, some sphingolipid (SL) species are bioactive and as such, take part in cellular signaling processes involved in regulating viral replication. It is especially due to the progress made in tools to study accumulation and dynamics of SLs, which visualize their compartmentalization and identify interaction partners at a cellular level, as well as the availability of genetic knockout systems, that the role of particular SL species in the viral replication process can be analyzed and, most importantly, be explored as targets for therapeutic intervention.
KW  - glycosphingolipids
KW  - ceramides
KW  - sphingosine 1-phosphate
KW  - sphingomyelinase
KW  - HIV
KW  - SARS-CoV-2
KW  - measles
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-245151
SN  - 2073-4409
VL  - 10
IS  - 9
ER  -