Hannes Stockinger

Early signalling events in T cell activation

Keywords
adaptive immunity, T cell activation, signal transduction, protein kinase, imaging

Research interest of the Faculty Member
Dr. Stockinger is interested in the structure and function of surface receptors on T cells and accessory/dendritic cells to identify novel targets for influencing abnormal and unwanted immune reactions in immunological disorders and diseases. Internationally well recognized are the investigations, which contribute to the understanding of how glycosylphosphatidylinositol (GPI)-anchored receptor proteins transduce signals across the plasma membrane. These studies were fundamental for the identification and characterization of special membrane microdomains, called lipid rafts, which are more and more characterized to control initiation of signal transduction across the plasma membrane of cells. Currently, Dr. Stockinger puts special emphasis on the signal transduction mechanism of the T cell antigen receptor (TCR), in particular how Lck, the key signalling kinase, is regulated as well as how positive and negative regulating transmembrane accessory molecules control TCR signalling.

Collaborating research groups where PhD Students can perform their research stay

• Dr. Giuseppina Caligiuri, INSERM UMRS 681, Université Pierre et Marie Curie Paris 6, 15, rue de l'Ecole de Mèdecine, F-75006 Paris, France
• Prof. Dr. Vaclav Horejsi, Director, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague 4, Czech Republic
• Prof. Dr. Watchara Kasinrerk, Clinical Immunology Branch, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand.
• Prof. Dr. Gerhard Schütz, Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, 1040 Wien, Austria
• Prof. Dr. Michael Stürzl, Division of Molecular and Experimental Surgery, Department of Surgery, University of Erlangen-Nuremberg, Schwabachanlage 10, 91054 Erlangen, Germany.

Know-how and infrastructure of the research group
The research group has outstanding expertise in immune cell biology with major interest towards negative regulating receptors and signalling pathways in T cells to correct pathological and unwanted immune reactions occurring in autoimmunity, allergy, transplantation. Recent advances are: In vivo confirmation of glycoprotein CD31 as negative regulator of T cells by curing atherosclerosis in mice (Groyer et al., 2007); design and molecular and functional characterization of a peptide derived from the mannose-6-phosphate insulin-like growth factor II receptor (CD222) that inhibits in vitro and in vivo angiogenesis and tumour cell growth (Leksa et al., 2011, Leksa et al., 2012), this potential therapeutic peptide is the result of a number of studies describing the CD222 molecule as negative regulator of fibrinolysis and cell migration (Godar et al., 1999; Leksa et al., 2002; Prager et al., 2004; Leksa et al, 2005, Schiller et al., 2008, Probst et al., 2009); large scale production of cytotoxic T cells for adoptive immunotherapy (Jursik et al., 2009). As tools for these experiments, we generated a large panel of monoclonal antibodies to structurally and functionally characterize the target molecules by molecular biological, cellular and biochemical assays. For the latter approaches we established a number of “gain of function” and “loss of function” assays by using recombinant and tagged forms as well as siRNA sequences of the target molecules.

A recent research topic of the research group is the development of advanced microscopy techniques to analyse the function of signalling molecules directly in living cells. For this purpose we mastered construction of fluorescent protein (FP) tagged receptors and signalling molecules. For instance, we have available a number of FP variants of Lck (the major Src protein tyrosine kinase of T cells). These biological tools were the prerequisite for the ultra-sensitive microscopy techniques that we developed during the past years together with Gerhard Schütz to analyse the function of signalling molecules directly in living T cells (Moertelmaier et al., 2005; Madl et al., 2006; Drbal et al., 2007; Wieser et al., 2007a; Wieser et al., 2007b; Omasits et al., 2008; Paar et al., 2008; Schwarzenbacher et al., 2008; Brameshuber et al., 2009; Muhammad et al., 2009; Paster et al., 2009; Wieser et al., 2009; Brameshuber et al., 2010; Weghuber et al., 2010; Zimmermann et al., 2010). Recently, Johannes Huppa, an outstanding expert in single molecule imaging of immune cell functions opened his own research group in the Institute of this Faculty Member.

Together, these two research groups have unique expertise in these novel super-resolution imaging techniques and can use this experience to supervise state-of-the-art PhD projects to identify and characterize antigen presenting cell intrinsic parameters and study their influence on T cell receptor-peptideMHC binding and signalling. Members of these research groups have access to several advanced microscopes, two 18-parameters flow cytometers, two sorters, a top-equipped tissue culture area, immunobiochemistry systems including affinity chromatography and immunoblotting with high sensitive Fuji- and LiCor Odyssey detection.