Andreas Radbruch

Andreas Radbruch did his PhD at the Genetics Institute of the Cologne University, Germany, with Klaus Rajewsky. He later became Associate Professor there and was a visiting scientist with Max Cooper and John Kearney at the University of Alabama, Brmingham. In 1996, he became Director of the German Rheumatism Research Centre Berlin, a Leibniz Institute, and in 1998, Professor of Rheumatology at the Charité, the Medical Faculty of the Humboldt University of Berlin.

A biologist by education, Andreas Radbruch early on worked on somatic variants in myeloma and hybridoma cells lines, modeling antibody class switching and somatic hypermutation. In this context, his lab originally developed the MACS technology. Andreas Radbruch then showed that recombination is the physiological mechanism of class switching in vivo, in plasmablasts isolated ex vivo. Moreover, he could show that in vivo, class switch recombination is targeted to the same Ig class on both IgH loci of a cell, reflecting a tight control of targeting of recombination. An essential element of this control is transcription of recombinogenic sequences, and the processing of these switch (germline) transcripts, as became evident from targeted deletion of the control regions involved. The switch transcripts are induced by cytokines of T helper cells, e.g. interleukin-4. The Radbruch lab contributed essentially to our current understanding of the polarization and imprinting of T helper cells expressing interleukin-4 (Th2) versus those expressing interferon-? (Th1).

The lab then addressed the organization of immunological memory as such. First they identified longlived (memory) plasma cells, mostly residing in bone marrow but also in secondary lymphoid organs and in inflamed tissues. They could show that these cells individually persist in dedicated survival niches, organized by CXCL12-expressing mesenchymal stroma cells. They identified different, dedicated niches for CD4+ and CD8+ memory T cells in the bone marrow, too, and could show that, at least in immune responses to vaccines, memory T cells are mostly maintained in bone marrow, resting in terms of proliferation and gene expression. Thus memory niches organize and maintain memory, and bone provides a privileged environment for resting memory cells. In chronic antibody-mediated diseases, Andreas Radbruch´s lab identified pathogenic antibody-secreting memory plasma cells as critical mediators of chronicity, refractory to conventional immunosuppression, and thus representing a novel therapeutic target. Similarly, in chronic T cell-mediated diseases, the pathogenic T cells induce and adapt to chronicity. Recently, the Radbruch group has identified Twist1, HopX and the microRNAs miR-182 and miR148a as molecular adaptations of proinflammatory T cells to chronicity, and innovative therapeutic targets.

Andreas Radbruch´s work has been recognized by the Carol Nachman Prize for Rheumatology (2011), an Advanced Grant of the European Research Council (ERC, 2010), the Federal Cross of Merit (2008) and the Aronson Award (2000). He is a member of the Berlin-Brandenburg Academy of Sciences and Humanities (BBAW), the European Molecular Biology Organization (EMBO) and the German National Academy of Sciences Leopoldina.