TY  - JOUR
A1  - Grafen, Anika
A1  - Schumacher, Fabian
A1  - Chithelen, Janice
A1  - Kleuser, Burkhard
A1  - Beyersdorf, Niklas
A1  - Schneider-Schaulies, Jürgen
T1  - Use of acid ceramidase and sphingosine kinase inhibitors as antiviral compounds against measles virus infection of lymphocytes in vitro
JF  - Frontiers in Cell and Developmental Biology
N2  - As structural membrane components and signaling effector molecules sphingolipids influence a plethora of host cell functions, and by doing so also the replication of viruses. Investigating the effects of various inhibitors of sphingolipid metabolism in primary human peripheral blood lymphocytes (PBL) and the human B cell line BJAB we found that not only the sphingosine kinase (SphK) inhibitor SKI-II, but also the acid ceramidase inhibitor ceranib-2 efficiently inhibited measles virus (MV) replication. Virus uptake into the target cells was not grossly altered by the two inhibitors, while titers of newly synthesized MV were reduced by approximately 1 log (90%) in PBL and 70–80% in BJAB cells. Lipidomic analyses revealed that in PBL SKI-II led to increased ceramide levels, whereas in BJAB cells ceranib-2 increased ceramides. SKI-II treatment decreased sphingosine-1-phosphate (S1P) levels in PBL and BJAB cells. Furthermore, we found that MV infection of lymphocytes induced a transient (0.5–6 h) increase in S1P, which was prevented by SKI-II. Investigating the effect of the inhibitors on the metabolic (mTORC1) activity we found that ceranib-2 reduced the phosphorylation of p70 S6K in PBL, and that both inhibitors, ceranib-2 and SKI-II, reduced the phosphorylation of p70 S6K in BJAB cells. As mTORC1 activity is required for efficient MV replication, this effect of the inhibitors is one possible antiviral mechanism. In addition, reduced intracellular S1P levels affect a number of signaling pathways and functions including Hsp90 activity, which was reported to be required for MV replication. Accordingly, we found that pharmacological inhibition of Hsp90 with the inhibitor 17-AAG strongly impaired MV replication in primary PBL. Thus, our data suggest that treatment of lymphocytes with both, acid ceramidase and SphK inhibitors, impair MV replication by affecting a number of cellular activities including mTORC1 and Hsp90, which alter the metabolic state of the cells causing a hostile environment for the virus.
KW  - measles virus
KW  - sphingolipids
KW  - acid ceramidase
KW  - acid ceramidase inhibitor ceranib-2
KW  - sphingosine kinase
KW  - sphingosine kinase inhibitor SKI-II
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196099
SN  - 2296-634X
VL  - 7
IS  - 218
ER  - 
TY  - JOUR
A1  - Chithelen, Janice
A1  - Franke, Hannah
A1  - Länder, Nora
A1  - Grafen, Anika
A1  - Schneider-Schaulies, Jürgen
T1  - The sphingolipid inhibitors ceranib-2 and SKI-II reduce measles virus replication in primary human lymphocytes: effects on mTORC1 downstream signaling
JF  - Frontiers in Physiology
N2  - The bioactive sphingolipids ceramide and sphingosine-1-phosphate (S1P) are involved in the regulation of cell homeostasis and activity ranging from apoptosis to proliferation. We recently described that the two compounds ceranib-2 (inhibiting acid ceramidase) and SKI-II [inhibiting the sphingosine kinases 1 and − 2 (SphK1/2)] reduce mTORC1 activity and measles virus (MV) replication in human primary peripheral blood lymphocytes (PBL) by about one log step. We now further investigated whether mTORC1 downstream signaling and viral protein expression may be affected by ceranib-2 and/or SKI-II. Western blot analyses showed that in uninfected cells the phosphorylation of the eukaryotic initiation factor 4E (eIF4E) was reduced by both inhibitors. Interestingly, MV infection led to an increase of rpS6 protein levels and phosphorylation of eIF4E. Treatment with both inhibitors reduced the rpS6 protein expression, and in addition, SKI-II reduced rpS6 phosphorylation. The phosphorylation of eIF4E was slightly reduced by both inhibitors. In addition, SKI-II led to reduced levels of IKK in MV-infected cells. Both inhibitors reduced the expression of viral proteins and the titers of newly synthesized MV by approximately one log step. As expected, SKI-II and rapamycin reduced also the virally encoded GFP expression; however, ceranib-2 astonishingly led to increased levels of GFP fluorescence. Our findings suggest that the inhibitors ceranib-2 and SKI-II act via differential mechanisms on MV replication. The observed effects on mTORC1 downstream signaling, predominantly the reduction of rpS6 levels by both inhibitors, may affect the translational capacity of the cells and contribute to the antiviral effect in human primary PBL.
KW  - acid ceramidase inhibitor ceranib-2
KW  - sphingosine kinase inhibitor SKI-II
KW  - mTORC1
KW  - translation
KW  - measles virus
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265988
SN  - 1664-042X
VL  - 13
ER  - 
TY  - JOUR
A1  - Avota, Elita
A1  - Bodem, Jochen
A1  - Chithelen, Janice
A1  - Mandasari, Putri
A1  - Beyersdorf, Niklas
A1  - Schneider-Schaulies, Jürgen
T1  - The Manifold Roles of Sphingolipids in Viral Infections
JF  - Frontiers in Physiology
N2  - Sphingolipids are essential components of eukaryotic cells. In this review, we want to exemplarily illustrate what is known about the interactions of sphingolipids with various viruses at different steps of their replication cycles. This includes structural interactions during entry at the plasma membrane or endosomal membranes, early interactions leading to sphingolipid-mediated signal transduction, interactions with internal membranes and lipids during replication, and interactions during virus assembly and budding. Targeted interventions in sphingolipid metabolism – as far as they can be tolerated by cells and organisms – may open novel possibilities to support antiviral therapies. Human immunodeficiency virus type 1 (HIV-1) infections have intensively been studied, but for other viral infections, such as influenza A virus (IAV), measles virus (MV), hepatitis C virus (HCV), dengue virus, Ebola virus, and severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), investigations are still in their beginnings. As many inhibitors of sphingolipid metabolism are already in clinical use against other diseases, repurposing studies for applications in some viral infections appear to be a promising approach.
KW  - sphingolipid
KW  - ceramide
KW  - sphingosine-1-phosphate
KW  - plasma membrane
KW  - virus entry
KW  - virus replication
KW  - virus budding
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246975
SN  - 1664-042X
VL  - 12
ER  - 
TY  - THES
A1  - Chithelen, Janice
T1  - Targeting viral and host factors to optimize anti-measles virus therapy
T1  - Zielgerichtete Hemmung von Virus- und Wirtsfaktoren zur Optimierung der Anti-Masern-Virus-Therapie
N2  - Measles is an ancient disease with historical records as early as the 9th century.
Extensive study as well as advances in scientific knowledge of virology have led to
identification of the viral pathogen and subsequent development of an effective vaccine
leading to global efforts towards measles elimination. In 2018, around 140,000 deaths were
reported due to measles with incomplete vaccine coverage being one of the leading causes
of resurgence. Measles is highly contagious and often regarded as a childhood illness.
However, measles is associated with a number of complications and persistent infections
like subacute sclerosing panencephalitis (SSPE), which have brought into focus the need
for specific anti-viral therapies.
The aim of this study was to target host and viral factors to optimize anti-measles virus
therapy. Our approach was to test a panel of compounds known to inhibit host cell
functions or viral factors for their antiviral effect on measles replication. Primary human
lymphocytes, persistently infected NT2 cells and post-mitotic neurons were used as in vitro
model systems of acute, persistent and neuronal infection respectively to test the inhibitors.
Using the inhibitors Ceranib-2 and SKI-II to target the sphingolipid metabolism enzymes
acid ceramidase and sphingosine kinase in infected human primary lymphocytes, we
observed a decreased protein translational capacity mediated by mTORC1, EIF4E and
ribosomal protein S6 phosphorylation that probably contributes to the antiviral effect. In
the persistently infected neural NT2 cells and post-mitotic neurons derived from LUHMES
cells, we observed effective infection inhibition and viral clearance upon treatment with a
small non-nucleoside inhibitor (ERDRP-0519) specifically targeting the Morbillivirus
large polymerase. Other inhibitors such as Ribavirin and Favipiravir were less effective. To
conclude, 1) we identified a mTOR associated protein translation axis associated with the
sphingolipid metabolism, which affects measles virus replication and 2) In vitro
persistently infected neuronal and post-mitotic neuron models were successfully used as a
rapid method to test antivirals against measles virus.
N2  - Masern sind eine uralte Krankheit, die bereits im 9. Jahrhundert historisch belegt ist. Umfangreiche Studien und Fortschritte in der Virologie haben die Identifizierung des viralen Erregers und anschließende Entwicklung eines wirksamen Impfstoffs ermöglicht, was zu weltweiten Bemühungen um die Eliminierung der Masern geführt hat. Im Jahr 2018 wurden rund 140.000 Todesfälle aufgrund von Masern gemeldet, wobei die unvollständige Durchimpfungsrate eine der Hauptursachen für das Wiederauftreten der Krankheit ist. Masern sind hoch ansteckend und werden oft als Kinderkrankheit betrachtet. Die Erkrankung ist jedoch assoziiert mit einer Reihe Komplikationen und persistierenden Infektionen wie die subakute sklerosierende Panenzephalitis (SSPE), was den Bedarf nach spezifischen antiviralen Therapien in den Focus gebracht hat.
Ziel dieser Studie war es, zelluläre und virale Faktoren ins Visier zu nehmen, um die Therapie gegen das Masernvirus zu optimieren. Unser Ansatz bestand darin, eine Reihe von Substanzen, die bekanntermaßen Wirtsfunktionen oder virale Faktoren hemmen, auf ihre antivirale Wirkung auf die Masernreplikation zu testen. Primäre menschliche Lymphozyten, persistierend infizierte NT2-Zellen und post-mitotische Neuronen wurden als in-vitro-Modellsysteme für akute, persistierende und neuronale Infektionen verwendet, um die Inhibitoren zu testen. Durch den Einsatz der Inhibitoren Ceranib-2 und SKI-II, die auf die Enzyme saure Ceramidase und Sphingosinkinase des Sphingolipid-Stoffwechsels abzielen, konnten wir in infizierten menschlichen primären Lymphozyten eine verringerte Protein-Translationskapazität vermittelt durch mTORC1, EIF4E und ribosomales Protein S6-Phosphorylierung beobachten, die wahrscheinlich zur antiviralen Wirkung beiträgt. In den persistierend infizierten neuronalen NT2-Zellen und aus LUHMES-Zellen differenzierten post-mitotischen Neuronen beobachteten wir eine effektive Elimination des Virus oder Infektionshemmung bei Behandlung mit einem nicht-nukleosidischen Inhibitor (ERDRP-0519), der spezifisch auf die Polymerase des Morbillivirus abzielt. Andere Inhibitoren wie Ribavirin und Favipiravir waren weniger effektiv. Zusammenfassend lässt sich sagen, dass wir 1) wir eine mTOR-assoziierte Protein-Translationsachse identifiziert haben, die mit dem Sphingolipid-Stoffwechsel in Verbindung steht und die Masernvirus-Replikation beeinflusst, und 2) In-vitro-Modelle für persistierend infizierte neuronale und post-mitotische Neuronen erfolgreich als schnelle Methode zum Testen von Virostatika gegen Masernvirus angewandt haben.
KW  - measles virus
KW  - sphingolipid
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-293059
ER  -