Veronika Sexl, Head of the Institute for Pharmacology and Toxicology at Vetmeduni Vienna, and Florian Grebien, Head of the Institute for Medical Biochemistry at Vetmeduni Vienna, are working on survival rates of leukemia patients. They are financially supported by the European Research Council (ERC). They have talked about teamwork, crazy concepts and their intersections with veterinary medicine in the VETMED conversation.

The protein CDK6 is at the centre of Veronika Sexl's scientific work at the Institute of Pharmacology and Toxicology. "Starting with this tiny molecule, we're doing broad research," explains the scientist. It has long been known that CDK6 plays a role in many cancers because it drives cell division. It is particularly present in higher amounts in the case of leukemia. "This is why many cancer researchers are working on targeting this protein in the cells by developing special inhibitors against CDK6", says Veronika Sexl. "For the first time we were able to show that CDK6 can and does much more than previously thought."

With the same general goal, but with a different research approach, Florian Grebien is also interested in developing new treatments for cancer. His focus is on the molecular mechanisms behind the development of leukemia. “Our focus is on the so-called fusion proteins”, says Florian Grebien. “They arise when chromosomes break and are incorrectly reassembled. Cancer is very often driven by these fusion proteins. If you study them functionally, you can learn a lot about what processes a cell needs to become a cancer cell”.

Both researchers and their projects are currently funded by European Research Council (ERC) grants. In 2016 Sexl received an “Advanced Grant” worth 2.5 million euros. Florian Grebien was awarded a “Starting Grant” worth 1.5 million euros in 2015.

The full interview can be found here.

Langerhans cell histiocytosis (LCH) is a rare disease that mainly affects small children. It occupies a hybrid position between cancers and inflammatory diseases, which makes it an attractive model for studying cancer development. While LCH can heal itself in some patients, other cases require intensive chemotherapy with long-term consequences for the children. The reasons for these differences are hardly known. In a new study published in the journal Cancer Discovery, researchers from St. Anna Children's Cancer Research Institute (CCRI) and the Center for Molecular Medicine of the Austrian Academy of Sciences (CeMM) uncovered important insights into the cellular heterogeneity and molecular mechanisms of LCH.

Caroline Hutter, pediatric oncologist at St. Anna Children's Hospital, observed a remarkable heterogeneity between LCH cells when examining LCH lesions under the microscope. In order to investigate this diversity in detail, she assembled an interdisciplinary team of experimental and computer researchers from CCRI and CeMM, as well as physicians from St. Anna Children's Hospital and General Hospital in Vienna. Caroline Hutter's aim is to answer two fundamental questions: What are the mechanisms behind LCH and how can we improve the treatment of children affected by this disease?

LCH lesions were analysed in the laboratory of Christoph Bock (CeMM), by Florian Halbritter (now at CCRI) and Matthias Farlik (now at the MedUni Vienna), with sufficient resolution to identify the molecular patterns of individual cells in detail and to develop a comprehensive "map" of cellular heterogeneity in LCH. On this molecular map, the team identified several subtypes of LCH cells. Among them was a group of actively dividing cells that are believed to be the precursors of other LCH cells. The team deciphered the molecular signalling pathways that are active in different branches of this unexpected developmental hierarchy, highlighting an interplay of developmental, immunological and oncogenic mechanisms in LCH. In the future, these findings could help to better differentiate between severe and less severe cases of the disease and even open up new treatment options.

Published in Cancer Discovery
Florian Halbritter, Matthias Farlik, Raphaela Schwentner, Gunhild Jug, Nikolaus Fortelny,
Thomas Schnoller, Hanja Pisa, LindaChristina Schuster, Andrea Reinprecht, Thomas Czech,
Johannes Gojo, Wolfgang Holter, Milen Minkov, Wolfgang M Bauer, Ingrid Simonitsch Klupp, Christoph Bock and Caroline Hutter

Doi:10.1158/2159-8290.CD-19-0138

New insights into the development of an unusual childhood disease

The interferons initiate a signaling process that causes the cell to activate the protein complex ISGF3 for driving antimicrobial gene expression. Scientists led by Thomas Decker at the Max Perutz Labs now found out that two of the three proteins forming this complex are permanently present at these genes, independently of the activating cascade caused by interferons. STAT2-IRF9 forms this ‘light’ version of ISGF3 and allows for homeostatic low expression of antimicrobial genes. Upon pathogen recognition interferons are produced and activate the complete version of ISGF3 composed of STAT1-STAT2-IRF9.  This trimeric ISGF3 switches to a full-fledged antimicrobial transcriptional program. The homeostatic presence of STAT2-IRF9 at antimicrobial genes governs cellular alertness and the rapid exchange to the interferon induced complete ISGF3 explains how the innate immune system activates in such a quick manner.

 

 

Publication in Nature Communications

Ekaterini Platanitis, Duygu Demiroz, Anja Schneller, Katrin Fischer, Christophe Capelle, Markus Hartl, Thomas Gossenreiter, Mathias Müller, Maria Novatchkova and Thomas Decker

A molecular switch from STAT2-IRF9 to ISGF3 underlies interferon-induced gene transcription (2019);

Doi: https://doi.org/10.1038/s41467-019-10970-y

As part of the 3rd International Conference on Cytokine Signaling in Cancer in Rhodes, Greece, the Travel Awards were again awarded this year. Two of the awards went to Sebastian Kollmann from the Institute of Pharmacology and Toxicology and Anna Orlova from the Department of Functional Cancer Genomics at Vetmeduni Vienna.

In the project "STAT5A and STAT5B in Hematopoietic and Leukemic Stem Cells - Between Death and Immortality", Sebastian Kollmann addresses the question of why mutations in lymphoma and leukemia patients are mainly found in STAT5B and hardly in the related protein STAT5A. It describes an important role for STAT5B in the self-renewal of hematopoietic and leukemic stem cells and thereby contributes with basic information to understand this question.

In the study “The ERBB-STAT3 Axis Drives Tasmanian Devil Facial Tumor Disease”, Anna Orlova shows that the overactivation of ERBB receptors, and consequently also of STAT3, leads to the transferability of facial tumours among Tasmanian devils. The study also unravels that the cancer cells can be specifically targeted by drug inhibition of the ERBB receptor.

Tobias Suske is a PhD student in the group of Richard Moriggl at the Institute of Animal Breeding and Genetics, Vetmeduni Vienna. He was honored with the Young Investigator Award at the Annual Meeting of the OeGHO & AHOP in Linz AT for his excellent talk on “The gain-of-function STAT5BN642H mutation as a driver of T-cell lymphoma and leukemia”.

The Austrian Society for Haematology and Clinical Oncology (OeGHO, www.oegho.at) and the Working Group for Haematological and Oncological Nursing (AHOP, www.ahop.at) have been awarding outstanding research of young investigators since 2010. The award is € 1.000 and is donated by Janssen Cilag Pharma GmbH.


©OeGHO


©OeGHO

In a triple-effort between international research groups from the University of Veterinary Medicine Vienna, Harvard University and the University of Toronto, important new information was discovered about the protein STAT5B, which is mutated in patients with T-cell cancers. STAT5B, like all proteins, is made up of building blocks called amino acids. A single amino acid change in STAT5B makes it hyperactive and leads to T-cell cancer development. We have tackled the difficult task to visualize the structure and shape of STAT5B in order to facilitate the discovery of new drugs that specifically target the mutant cancer-causing form of the protein, whilst sparing the important normal-functioning STAT5B.

We have used a technique similar to medical X-rays to reveal for the first time the three-dimensional structures of normal and mutant STAT5B down to the atomic level. We also developed a new cancer mouse model driven by mutant STAT5B, which allows the study of one of the most aggressive T-cell cancers seen in patients. Importantly, the structural information and the disease model can now be used to test new drugs that target only the cancer-causing form of STAT5B, which will significantly reduce the side-effects and increase the effectiveness of the treatment.

Publication in Nature Communications

Elvin D. de Araujo*, Fettah Erdogan*, Heidi A. Neubauer*, Deniz Meneksedag-Erol, Pimyupa Manaswiyoungkul, Mohammad S. Eram, Hyuk-Soo Seo, Abdul K. Qadree, Johan Israelian, Anna Orlova, Tobias Suske, Ha T. T. Pham, Auke Boersma, Simone Tangermann, Lukas Kenner, Thomas Rülicke, Aiping Dong, Manimekalai Ravichandran, Peter J. Brown, Gerald F. Audette, Sarah Rauscher, Sirano Dhe-Paganon†, Richard Moriggl† and Patrick T. Gunning†

*equal author contribution; †corresponding authorship

Structural and functional consequences of the STAT5BN642H driver mutation (2019); Doi: https://doi.org/10.1038/s41467-019-10422-7

Tobias Suske, PhD student at the Institute for Animal Breeding and Genetics at Vetmeduni Vienna, was awarded at the Annual Meeting of the Austrian Society for Hematology and Medical Oncology (OeGHO) and the Working Group for Hematological and Oncological Nurses (AHOP) spring conference 2019 for his outstanding presentation “The gain-of-function STAT5BN642H mutation as a driver of T-cell lymphoma and leukemia”. With his work, he won the Young Investigator Award.

Tobias Suske from the Functional Cancer Genomics Department at the Institute of Animal Breeding and Genetics received one of the young talent awards. The Young Investigator Awards are endowed with 1000€ each and are awarded by Janssen Cilag Pharma GmbH. In his PhD project, Tobias Suske studied the STAT5BN642H mutation. This genetic change has been found frequently in recent years in patients with T-cell lymphomas and leukemias, who are usually extremely aggressive and difficult to treat. The research focuses on understanding the mutation at the molecular level in order to create therapeutic approaches for targeted active substances.

An international research team led by Veronika Sexl from Vetmeduni Vienna and supported by other members of SFB ‚JakStat Monarchies‘ have made an important discovery that could lead to a better understanding of lymphocytic leukemia: the STAT5B protein – but not the highly related STAT5A isoform – is crucial for disease development by suppressing interferon signals during leukemic transformation. Our findings will enable novel therapeutic approaches in precision medicine.

Publication in Leukemia:

Sebastian Kollmann, Eva Grundschober, Barbara Maurer, Wolfgang Warsch, Reinhard Grausenburger, Leo Edlinger, Jani Huuhtanen, Sabine Lagger, Lothar Hennighausen, Peter Valent, Thomas Decker, Birgit Strobl, Mathias Mueller, Satu Mustjoki, Andrea Hoelbl-Kovacic and Veronika Sexl

Twins with different personalities: STAT5B—but not STAT5A—has a key role in BCR/ABL-induced leukemia (2019), https://doi.org/10.1038/s41375-018-0369-5

We used conditional ablation of STAT1 in macrophages, monocytes and granulocytes of mice and showed that myeloid STAT1 protects from early murine cytomegalovirus replication and pathology in spleen. Unexpectedly, we found that myeloid STAT1 drives extramedullary haematopoiesis (EMH). STAT1 promotes EMH not only after virus infection but also upon sterile inflammation induced by CpG oligodeoxynucleotides. Using additional genetically engineered mice we analysed the impact of upstream signals known to activate STAT1 and observed that virus-induced EMH does not rely on type I or type II IFN signaling in myeloid cells or IL-27 signaling in all cell types. Our studies provide the first genetic evidence that STAT1-dependent signaling in myeloid cells restricts MCMV at early time points post infection and induces compensatory (stress-induced) haematopoiesis in the spleen.

Publication in Cell Reports

Riem Gawish*, Tanja Bulat*, Mario Biaggio*, Caroline Lassnig, Zsuzsanna Bago-Horvath, Sabine Macho-Maschler, Andrea Poelzl, Natalija Simonović, Michaela Prchal-Murphy, Rita Rom, Lena Amenitsch, Luca Ferrarese, Juliana Kornhoff, Therese Lederer, Jasmin Svinka, Robert Eferl, Markus Bosmann, Ulrich Kalinke, Dagmar Stoiber, Veronika Sexl, Astrid Krmpotić, Stipan Jonjić, Mathias Müller, and Birgit Strobl

*equal author contribution

Myeloid Cells Restrict MCMV and Drive Stress-Induced Extramedullary Hematopoiesis through STAT1 (2019); Doi: https://doi.org/10.1016/j.celrep.2019.02.017

We used conditional ablation of TYK2 in mice and showed that TYK2 promotes NK cell activity in tumour surveillance and the defence against Listeria monocytogenes infection through cell-extrinsic and -intrinsic mechanisms. The key discoveries are as follows: NK cell-extrinsic TYK2 drives peripheral NK cell maturation, demethylation of the Ifng locus, activating receptor-induced IFNg production, cytotoxicity and anti-tumour activity; the NK cell defects observed in Tyk2-/- mice can be restored by recombinant IL-15/IL-15Rα treatment; NK cell-intrinsic TYK2 signalling mediates infection-induced IFNg production and acts protective during Listeria monocytogenes infection.

Collectively, our study disclosed TYK2 functions that remained unrecognized in mice with complete TYK2 deficiency. Our findings that cytotoxic defects of Tyk2-/- NK cells can be rescued by IL-15/IL-15Rα treatment suggest that unwanted effects of TYK2 inhibitors in tumour therapy may be overcome by boosting NK cell activity.

Publication in Journal of Immunology

Natalija Simonović * , Agnieszka Witalisz-Siepracka *, Katrin Meissl, Caroline Lassnig, Ursula Reichart,  Thomas Kolbe,  Matthias Farlik, Christoph Bock, Veronika Sexl, Mathias Müller, and Birgit Strobl

*equal author contribution

NK Cells Require Cell-Extrinsic and -Intrinsic TYK2 for Full Functionality in Tumor Surveillance and Antibacterial Immunity (2019); Doi:

https://doi.org/10.4049/jimmunol.1701649