Skip to main content
Kathrin Leppek

News categories: Honors & Funding

Tuning brain cells with light

Human Frontier Science Program funds transatlantic research project

An international research team, including ImmunoSensation2 member Prof. Kathrin Leppek of the University Hospital Bonn and scientists from the German Center for Neurodegenerative Diseases (DZNE), the Netherlands, and the US has been awarded a US$ 1.3 million grant by the “Human Frontier Science Program” to investigate brain immune cells and manipulate them via light irradiation. This will involve using gene transcripts (mRNAs) as molecular mediators. From these laboratory studies, the scientists aim to gain new insights into how these cells change their shape in response to hazards and the role they play in neurodegenerative diseases such as Alzheimer’s.

The brain houses a special class of immune cells called “microglia” that eliminate toxins, remove cellular debris, and fight pathogens, helping to keep the brain healthy. “These immune cells move through the tissue, surveying the local environment with little processes. When the microglia sense a danger, they are activated, which is associated with changes in their morphology. First, the dimensions and branching of their projections change and eventually, the microglia take on a blob-like shape,” said Dr. Dragomir Milovanovic, a biochemist and research group leader at DZNE’s Berlin site. “This transformation is essential for the immunological function of microglia. However, how this dynamic behavior is achieved is unclear. With our studies, we hope to learn more about the mechanisms involved in this. It is known that in Alzheimer’s microglia become overactive and that their initially beneficial effect escalates into a chronic inflammatory response. Thus, a better understanding of microglia could help in devising new therapies.”

A Switch for Microglia Behavior


For this endeavor, Milovanovic is cooperating with three colleagues, including Prof. Kathrin Leppek in Germany, as well as fellow researchers from University of Utrecht in the Netherlands, and from University of California, Berkeley. “We are an interdisciplinary team, with each member bringing their specific expertise to the table. This includes cell biology, RNA and protein biochemistry, synthetic chemistry and other areas,” the DZNE scientist explained. Supported by an “Early Career Research Grant” of the Human Frontier Science Program (HFSP), the international collaboration aims to study microglia in mouse brains and to manipulate microglia behavior in cell cultures by means of photosensitive molecules and laser light. “We intend to develop compounds that influence the production of proteins. Specifically, proteins significant to changes in microglia morphology. The key point is that the compounds we will synthesize are photoswitchable. Thus, their effect on protein production can be controlled with an appropriate light source. This will allow us to specifically manipulate the morphology of microglia and hence their immunological function with light”, Milovanovic noted. He and his colleagues are looking forward to joining forces for this project. The grant will enable them to recruit PhD students or postdocs who will work highly collaboratively.

Targeting Protein Factories


Recent studies suggest that the morphological transformation of microglia is regulated by proteins that are produced in the cell’s periphery, including its processes. This requires gene transcripts called “mRNAs” as well as molecular machines that “translate” mRNA molecules into proteins. “It seems, and this is something we want to investigate in detail, that the mRNAs relevant for morphological changes are packaged together with protein factories into so-called granules. This happens close to the cell’s nucleus. From there, these granules that resemble tiny droplets suspended in a different liquid, are transported to other sites”, Milovanovic explained.

“Therefore, our collaboration aims to identify mRNAs involved in the morphological changes and develop light-sensitive compounds that can attach to mRNAs to regulate their transport and protein production at specific places in the cell. For this, we need to identify and characterize microglia mRNAs that we can specifically target with light-switchable RNA tools,” said Prof. Kathrin Leppek, an RNA biochemist and research group leader at the Institute of Clinical Chemistry and Clinical Pharmacology of University Hospital Bonn. “With this innovative approach, we want to contribute to a better understanding of the biology of microglia and their role in diseases. Our studies may pave the way to novel therapies.”

A Competitive Selection Procedure


The project is set to run for three years. Acquiring the grant was a highly competitive process, as the success rate for applications was only 6.5 percent. “The winners in this year’s HFSP Research Grant Program are remarkable scientists pioneering life science research that needs international collaboration and basic science in frontier subjects – that is, investigations for which there are no prior studies,” said Pavel Kabat, HFSP Secretary-General. “I was thrilled with the proposals we received and look forward to the ground-breaking discoveries that will be revealed.”

Further Information


The funded project is called “Switchable immunomodulation of mRNA transport and local translation in microglia by bioactive RNAs“, principal investigators (alphabetical order): Prof. Dr. Daniël L.J. Broere (University of Utrecht, NL), Prof. Dr. Meng-Meng Fu (University of California, Berkeley, USA), Prof. Dr. Kathrin Leppek (Institute of Clinical Chemistry and Clinical Pharmacology of University Hospital Bonn, Germany) and Dr. Dragomir Milovanovic (DZNE, Bonn, Germany).

The “Human Frontier Science Program” funds pioneering research in the life sciences. It is run by the “International Human Frontier Science Program Organization”, an international, non-profit entity: https://www.hfsp.org & https://www.hfsp.org/awardees/newly-awarded


Contact

Prof. Kathrin Leppek

Institute of Clinical Chemistry and Clinical Pharmacology

University Hospital Bonn

Venusberg Campus 1

53127 Bonn

kleppek@uni-bonn.de

Related news

Gruppenbild Preistrager Lisec Artz Preisverleihung

News categories: Honors & Funding

Niklas Klümper and Varun Venkataramani receive Lisec-Artz Prize

Dr. Varun Venkataramani of the Faculty of Medicine at Heidelberg University and ImmunoSensation² member Dr. Niklas Klümper of the University Hospital Bonn have been awarded the Lisec Artz Prize for their outstanding cancer research. The University of Bonn Foundation and the University of Bonn Faculty of Medicine presented the awards to the two researchers on Tuesday, November 18, 2025 at the University Hospital Bonn (UKB) as part of the Cluster Science Days event held by the ImmunoSensation² Cluster of Excellence. The prize is worth a total of 15,000 euros.
View entry
20251103 PM Prof Wihelm

News categories: Honors & Funding

Prof. Christoph Wilhelm receives €1.25 million DFG funding for Reinhart-Koselleck project

The German Research Foundation (DFG) is funding a Reinhart-Koselleck project at the University Hospital Bonn (UKB) within the Cluster of Excellence ImmunoSensation² at the University of Bonn with €1.25 million. The research team led by Prof. Christoph Wilhelm, Chair of Immunopathology at the Institute of Clinical Chemistry and Clinical Pharmacology, aims to investigate how the body maintains the balance of the gut microbiome during periods of illness and food scarcity.
View entry
Aschenbrenner_Anna_Award_22102025

News categories: Honors & Funding

Tobias-Welte Prize for Anna Aschenbrenner

Dr. Anna Aschenbrenner, a researcher at the German Center for Neurodegenerative Diseases (DZNE) in Bonn, has received the Tobias-Welte Prize from the German Sepsis Society, endowed with 3,000 Euros. She was honored for her pioneering work published in Cell, in which she and her team uncovered the molecular mechanisms underlying the life-saving effects of dexamethasone in severe COVID-19.
View entry

Back to the news overview