Structural elucidation of nameless viruses and insights into immunological overreactions

Dr Kristina Meier and Dr Michaela Raacke receive doctoral prizes from the BNITM Sponsors' Association

This year's doctoral prizes from the Association of Friends of the Tropical Institute Hamburg e.V. (VdF) go to Dr Kristina Meier (Natural Sciences) and Dr Michaela Raacke (Medicine). They are endowed with 2,500 euros each and honour particularly outstanding dissertations at the Bernhard Nocht Institute for Tropical Medicine.

The photo shows, from left to right, one of the two award winners Dr Michaela Raacke, VdF Chairman Manfred Schüller and BNITM Chair Prof. Jürgen May.
©BNITM | Julia Rauner

Dr Kristina Meier dealt with the Sin Nombre virus (virus without a name). This hantavirus can be transmitted from deer mice to humans and cause severe cardiopulmonary syndrome. The young scientist analysed the multifunctional L protein of the virus. It plays an important role in its replication in the host cell and is therefore an ideal starting point for future antiviral strategies. In order to develop these in a targeted manner, as much as possible must be known about the structure and function of the L protein.

Dr Kristina Meier has carried out very successful research in the Structural Virology research group led by Dr Maria Rosenthal. Using cryo-electron microscopy, she was able to elucidate the structure of the L protein - it was the first high-resolution structure of an L protein of a so-called new-world hantavirus. Further biochemical experiments shed light on the various enzymatic functions of the L protein and its ability to interact with viral RNA. The results were published in the journal PLOS Pathogens in 2023.

Dr Kristina Meier: The young scientist has long brown hair, wears a black T-shirt and looks into the camera with a friendly smile.
Dr Kristina Meier   ©Kristina Meier
Coloured cryo-EM images: Putative cap-binding domain in the C-terminus of SNV L
Putative cap-binding domain in the C-terminus of SNV L   ©Meier et al. | PLOS Pathogens 2023
Portrait photo of Michaela Raacke, a researcher with her hair tied back, light-coloured shirt and dark blazer and an open smile
Dr Michaela Raacke   ©Michaela Raacke

Dr Michaela Raacke was interested in the immune response to infections with the most dangerous malaria pathogen, Plasmodium falciparum, and more specifically in the cytokine response of human brain endothelial cells. This may be a key to understanding severe courses of malaria. Infants in particular can suffer fatal cerebral oedema, which can be the result of immunological overreaction.

For her medical dissertation, Raacke conducted research in the laboratory of Prof Iris Bruchhaus (Host-Parasite Interaction Group) in cooperation with Prof Steffen Stenger (Institute of Microbiology at the University of Ulm). Among other things, she found that the plasma of malaria patients increases the production of pro-inflammatory signalling substances by the brain endothelial cells. This suggests that malaria can cause inflammatory reactions in the brain through this mechanism. A corresponding paper was published in CELLS in 2021, and the doctor presented her dissertation in 2022.

The red-black bar graph shows the cytokine content in the culture supernatants of endothelial cells (HBEC-5i) stimulated with plasma from malaria patients (M) and healthy controls (H). It was analysed using a droplet-based LEGENDplex assay (n = 6-26).
The cytokine content in the culture supernatants of endothelial cells (HBEC-5i) stimulated with plasma from malaria patients (M) and healthy controls (H) was analysed using a LEGENDplex test (n = 6-26). It binds the cytokines via antibodies to beads, which enable the concentration to be determined in the flow cytometer.   ©Raacke et al. | Cells 2021
The colourful drawing shows the life cycle of the malaria parasite as a circle of different parasite stages and the activation of the endothelial cells.
The life cycle of the malaria parasite and the activation of endothelial cells   ©Michaela Raacke

The Association of Friends of the Bernhard Nocht Institute for Tropical Medicine in Hamburg e.V., the supporting association of BNITM, annually awards two prizes for outstanding dissertations at the institute. One work in medicine and one in natural sciences are each awarded a prize of 1,000 euros. The two award winners are going to be honoured following the annual general meeting of the VdF.

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