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  - 
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  -