Thomas Boehm receives third ERC Grant for groundbreaking study on anglerfish immunity

How the bizarre mating behaviour of deep-sea anglerfish could help us with pregnancy, transplants and immune deficiency

Freiburg/Tübingen/Brussels – Thomas Boehm, emeritus Director of the Max Planck Institute of Immunobiology and Epigenetics in Freiburg and currently research group leader at the Max Planck Institute for Biology in Tübingen, has been awarded the third ERC Advanced Grant of his career. The funding from the European Research Council (ERC), worth up to 2.5 million euros, will support the project “ImmunoPlast”. Over the next five years, Thomas Boehm and his team will study the unique immune systems of deep-sea anglerfish to decode the remarkable adaptability of their immune defence: these fish are able to switch off key components of their adaptive immunity enabling their bizarre mating behaviour. The resulting insights promise not only a fundamentally new perspective on the immunological adaptability of vertebrates, but could also advance treatments in which immune tolerance is crucial – for example in organ transplantation, during pregnancy, or in autoimmune diseases.

To the point

• Third ERC Advanced Grant for immunologist Thomas Boehm: up to 2.5 million euros for the project “ImmunoPlast”.

• Central to the project is the unique immune system of deep-sea anglerfish, the unique immune system of deep-sea anglerfish, which switch off key components of their adaptive immune defence to enable their bizarre mating behaviour.

• The findings could advance treatments in which immune tolerance is crucial – for example in transplantation, during pregnancy, or in autoimmune diseases.

In the eternal darkness of the deep sea, an extraordinary love story unfolds – one of considerable immunological significance. When the tiny male of the deep-sea anglerfish finds a female, it bites down and holds fast. In some species, the two bodies fuse permanently, until even their bloodstreams become one. The male is thus reduced to a sperm-providing parasite of the female.

What may sound like a curious oddity of the animal kingdom poses a fundamental puzzle for immunobiology. Under normal circumstances, the vertebrate immune system recognises and attacks foreign tissue. It is precisely this mechanism that prevents donor organs from simply being accepted in transplant medicine. The anglerfish, however, tolerates permanent fusion with a foreign individual by abolishing central functions of the immune response and triggering no corresponding defence reaction.

An abrupt end to the co-evolution of innate and adaptive immunity

In some species, this tolerance goes even further. In these species the activity of the killer T cells of the adaptive immune response is severely restricted, if not shut down altogether. “These fish have achieved something that should be impossible: they operate in a »post-adaptive« state, lacking the very heart of the classical vertebrate immune system. And yet they remain effective against the pathogens that lurk everywhere in the deep sea,” explains Thomas Boehm.

It is precisely this paradox that the “ImmunoPlast” project addresses – work that has now been recognised by the European Research Council. Boehm and his team aim to understand just how malleable the immune system really is, and how nature repeatedly recalibrates the balance between tolerance and defence over the course of evolution. “The anglerfish shows us how radically an immune system can be remodelled in the course of evolution and still function – and what fundamental design principles lie behind this,” says Boehm.

Exploring the design principles of the immune system

For the immunologist, this is already the third ERC Advanced Grant of his career. “I am especially pleased to have prevailed with our evolutionary comparative approach in this highly competitive arena of European top research,” says Boehm, who has studied the immune systems of organisms as diverse as mice, zebrafish, sharks and lampreys. Using genomic, transcriptomic, histological and mechanistic analyses, he now intends to decode how this perhaps most unusual immune system of his career reconciles the seemingly irreconcilable: the fusion of foreign tissue without rejection – and, at the same time, lasting, effective protection against infection.

Outstanding publications of Thomas Boehm

The findings have implications that extend far beyond the puzzling mating behaviour of these deep-sea fish. The tension between tolerance and defence is also familiar to humans. For example, during pregnancy, the maternal body must accept the foetus's genetically foreign tissue rather than attacking it. The anglerfish model could help us better understand these natural tolerance mechanisms. Most importantly, it provides a framework for understanding disturbances in the human immune system that is based on evolution. This framework can be used to understand conditions such as congenital and acquired immunodeficiencies, as well as therapeutic interventions that are designed to restore balance to the body's immune system.

About Thomas Boehm

Thomas Boehm studied human medicine at the Johann Wolfgang Goethe University in Frankfurt am Main, and received additional training at Columbia University in New York (USA) and the Royal Marsden Hospital in London (England). Thomas Boehm graduated in Frankfurt in 1982, where he also qualified as a university lecturer in 1988. After clinical training in pediatrics and human genetics, and research at the MRC Laboratory of Molecular Biology in Cambridge (England), he took up professorships for Medical Molecular Biology at the Albert-Ludwigs University Freiburg and Experimental Therapy at the German Cancer Research Center in Heidelberg. Since January 1998, Thomas Boehm is director at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg and an Honorary Professor at the Medical Faculty of the University of Freiburg. Thomas Boehm is a member of several learned societies, including the European Molecular Biology Organization, the German Academy of Sciences, the Heidelberg Academy of Sciences and Humanities as well as the American Academy of Arts and Sciences. In 2018, he has been appointed Chairman of Scientific Council of the Paul Ehrlich-Foundation and in 2025 he became Vice-President of German National Academy of Sciences Leopoldina. Thomas Boehm has been honoured with numerous awards for his research, including the Gottfried Wilhelm Leibniz Prize (1997), the Ernst Jung Prize for Medicine (2014), the German Immunology Prize from the German Society for Immunology e. V. (2020), the Heinrich Wieland Prize (2021) and the Mendel Medal from the Leopoldina (2024). His research has been recognised with three Advanced Grants (2013, 2019, 2026) from the European Research Council (ERC).

About the ERC

The European Research Council (ERC), established by the European Union in 2007, is Europe’s leading funding organisation for excellent cutting-edge research. It supports creative researchers of all nationalities and ages in carrying out projects across Europe. To this end, the ERC offers four key funding programmes: Starting Grants, Consolidator Grants, Advanced Grants and Synergy Grants. The Advanced Grant supports established and independent top-level scientists who are leaders in their respective fields of research, and is endowed with a sum of up to 2.5 million euros. This award for Thomas Boehm confirms the status of the MPI-IE in Freiburg as a leading hub for cutting-edge European research. Since the ERC was founded, researchers at the MPI in Freiburg have received a total of 17 ERC grants across various programme areas. For Thomas Boehm, this is already his third ERC Advanced Grant.

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