Cluster of Excellence –
University of Freiburg

Dr. David Medgyesi

Dr. David Medgyesi

Project leader
Max Planck Institute of Immunobiology and Epigenetics, Freiburg

+49 761 5108 433

The antigen-specific activation of B cells is mediated by the B cell antigen receptor , and it is regulated by different co-receptors. The downstream signaling of these receptors includes several tyrosine phosphorylation steps, which are under the tight control of protein tyrosine phosphatases (PTPs). Most of the non-receptor PTPs play inhibitory role in the regulation of B cell activation, therefore they are important regulators maintaining immunological tolerance. Our goal is to understand how SHP1 and PTP1B regulate B cell development and the function of mature B cells.

During oncogenic signaling, certain protein tyrosine kinases can be expressed as fusion proteins as a result of chromosomal translocation (such as Tel-Syk and Bcr-Abl). These fusion kinases are hyperactive, and cannot be efficiently inhibited by the PTPs. Our further goal is to study the mechanisms how these kinases escape from the control of the relevant PTPs. Moreover we generate fusion phosphatase constructs (Tel-PTP, Bcr-PTP) in order to counteract oncogenic kinase activity.

10 selected publications

  • The protein tyrosine phosphatase PTP1B is a negative regulator of CD40 and BAFF-R signaling controls B-cell autoimmunity
    Medgyesi D, Hobeika E, Biesen R, Kollert F, Taddeo A, Voll RE, Hiepe F, Reth M.
    J Exp Med. 2014 Mar 10;211(3):427-40.
  • Heme Oxygenase-1 Drives Metaflammation and Insulin Resistance in Mouse and Man
    Jais A, Einwallner E, Sharif O, Gossens K, Lu TT, Soyal SM, Medgyesi D, Neureiter D, Paier-Pourani J, Dalgaard K, Duvigneau JC, Lindroos-Christensen J, Zapf TC, Amann S, Saluzzo S, Jantscher F, Stiedl P, Todoric J, Martins R, Oberkofler H, Müller S, Hauser-Kronberger C, Kenner L, Casanova E, Sutterlüty-Fall H, Bilban M, Miller K, Kozlov AV, Krempler F, Knapp S, Lumeng CN, Patsch W, Wagner O, Pospisilik JA, Esterbauer H.
    Cell. 2014 Jul 3;158(1):25-40.
  • The Role of the Syk/Shp-1 Kinase-Phosphatase Equilibrium in B Cell Development and Signaling
    Alsadeq A, Hobeika E, Medgyesi D, Kläsener K, Reth M.
    J Immunol. 2014 Jul 1;193(1):268-76
  • B cell receptor Induced Ca2+ mobilization mediates actin cytoskeleton rearrangements in B lymphocytes and is indispensible for adhesion and spreading of B cells
    Maus M, Medgyesi D, Kiss E, Schneider AE, Enyedi A, Szilágyi N, Matkó J, Sármay G.
    J Leukoc Biol. 2013 Apr;93(4):537-47.
  • CD16/32 specific biotinylated 2.4G2 single chain Fv complexed with avidin-FITC enhances FITC-specific humoral immune response in vivo in a CD16-dependent manner
    Adrienn Angyal, Zsuzsanna Szekeres, Péter Balogh, Zsuzsa Neer, Eszter Szarka, Viktor Virag, David Medgyesi, Jozsef Prechl and Gabriella Sarmay
    Int. Immunol. 2010 22 (2): 71-80.
  • Grb2 associated binder 2 couples B-cell receptor to cell survival.
    Maus M, Medgyesi D, Kövesdi D, Csuka D, Koncz G, Sármay G.
    Cell Signal. 2009 Feb;21(2):220-7.
  • Functional mapping of the FcgRII binding site on human IgG1 by synthetic peptides
    D. Medgyesi, K. Uray, K. Sallai, F. Hudecz, G. Koncz, J. Abramson, I. Pecht, G. Sármay and J. Gergely
    Eur J Immunol. 2004 Apr;34(4):1127-35.
  • Functional consequences of a MAPK docking site on FcgRIIb of human B cells
    D. Medgyesi, R. Sárközi, G. Koncz, K. Arató, G. Váradi, G. K. Tóth, G. Sármay
    Immunol Lett. 2004 Mar 29; 92(1-2): 83-90.
  • Synthesis and receptor binding of IgG1 peptides derived from the IgG Fc region
    K. Uray, D.Medgyesi, Á Hilbert, G. Sármay, J. Gergely  and F. Hudecz
    J. Mol. Recognit. 2004; 17: 95–105
  • Co-clustering of Fcgamma and B cell receptors induces dephosphorylation of the Grb2-associated binder 1 docking protein.
    Koncz G, Toth GK, Bokonyi G, Keri G, Pecht I, Medgyesi D, Gergely J, Sarmay G.
    Eur J Biochem. 2001 Jul;268(14):3898-906.