obituary Harald von Boehmer 1942–2018

oday, few topics in immunology Notch family of signaling receptors in this receive more attention than efforts malignancy. With colleagues in the lab, Tto detect, induce or reinvigorate the Harald also published important insights immune response to tumors. Although into the mechanisms through which many types of immune cells affect different populations respond to and contribute to anti-tumor immune tumors and destroy pancreatic β​-cells. At responses, the initial clinical findings that the same time, he never stopped pursuing electrified the field focused on the T cell. knowledge of the basic mechanisms that Cancer biologists who grabbed the nearest affect T cell development. While in , immunology textbook in an effort to fully his lab described mechanisms that affect comprehend and build upon those initial the development of regulatory T cells in the clinical successes will have quickly realized and the periphery and continued that at their core, such approaches rely on to publish insights into the structure and understanding how T cells recognize and function of the pre-TCR. respond to antigen. What they may not After closing his Boston lab, Harald have realized is how important Harald returned to his alma mater as a guest von Boehmer’s work was in laying the professor at the Institute for Immunology foundation for this understanding. of the Ludwig Maximilian University in Long before translational research was Munich. In his writings during this period, all the rage, Harald charged a segment of between the TCR and peptide–major Harald expressed optimism about the future his lab with investigating how fundamental histocompatibility complex determined of immunological research. In one of his immunological principles might influence the whether a thymocyte would differentiate final Reviews, he mused that “The curiosity onset of autoimmunity and tumor-specific along the CD4+CD8– T cell lineage or the in T cell development is still very much immune responses. Early on he saw that CD4–CD8+ T cell lineage. A few years later, alive even after retirement but I trust that breaking tolerance could result in an attack on Harald’s lab identified a previously unknown the remaining issues are in good hands of healthy tissue or a tumor, and that suppressing TCR, which he called the ‘pre-TCR’. younger scientific colleagues who identify the former and inducing the latter would In 1996, Harald left the Basel Institute of the outstanding questions and think of require the study of two sides of a single coin. Immunology to join the Institut National clever experiments to address them” (von Over the course of his scientific career de la Santé et de la Recherche Médicale and Boehmer, H. Front. Immunol. 5, 424 (2014)). Harald worked in or ran labs in four Institut Necker (Rene Descartes University) The immunology community would countries on three continents. After earning in . At the Institut Necker, Harald found have enough to thank Harald for if the his M.D. from the Ludwig Maximilian phenomenal immunologists, as well as direct only thing he left was the enormous body University in Munich, Harald moved to exposure to a hospital with a tradition of the of immunological knowledge he revealed. Melbourne, , where he obtained study of immunological conditions, including But he left more than that—he left a global his Ph.D. under the supervision of Ken immunodeficiency and autoimmunity. network of trainees, colleagues and friends Shortman. During these early years he This environment prompted him to expand who benefited from his relentless insistence characterized the functions of the various the focus of his work to include more on rigor, thoroughness, preparedness cell types in the mixed-lymphocyte reaction, translational questions, such as those related and creative thinking. As two of Harald’s an assay essential for the understanding to diabetes, T cell anergy and regulatory doctoral trainees, we can attest that thanks to of donor–recipient compatibility in T cell function. However, during the same his directness, it might not have always felt transplantation. period, Harald continued to add substantial like we were benefiting while he conveyed Shortly after receiving his Ph.D., Harald basic insights to the understanding of early his opinion of our work during Monday was recruited by Niels K. Jerne to the (now- T cell development; these included the morning lab meeting. But we can also say defunct) Basel Institute of Immunology in identification of roles for the pre-TCR in with conviction that at the end of the day, it . There he worked closely with thymocyte survival, allelic exclusion and was always obvious that Harald’s comments superb visiting and resident immunologists. commitment to the αβ​ ​ or γδ​ ​ T cell lineage. were made with our best interests in mind. Aided by the recent identification of genes Always fascinated by the USA, Harald Harald passed away on 24 June 2018 at encoding T cell antigen receptors (TCRs) had many good colleagues and friends there, age of 75. His piercing intelligence, candor and breakthroughs in transgenic technology, and on several occasions he considered and unwavering support will be sorely Harald generated mouse models that laid moving to a US university. In the final missed. ❐ the foundation for understanding of the days of the 20th century he did, and he positive and negative selection of T cells, remained at until Iannis Aifantis1* and Christine Borowski2 as well as T cell lineage commitment in his retirement in 2013. Influenced by his 1Department of Pathology and Perlmutter Cancer the thymus. Through the use of these new environment in the Smith Building of Center, NYU Langone Medical Center, New York, mice, he delineated the effect of major the Dana Farber Cancer Institute, Harald NY, USA. 2Apple Tree Partners, New York, NY, USA. histocompatibility complex molecules and focused his work even more heavily on *e-mail: [email protected] TCR cognate antigen on various stages human disease. His lab made substantial of thymocyte development. For example, contributions to the understanding of T Published online: 13 August 2018 Harald demonstrated that the interaction cell leukemia, in particular the role of the https://doi.org/10.1038/s41590-018-0192-1

Nature Immunology | VOL 19 | SEPTEMBER 2018 | 899 | www.nature.com/natureimmunology 899