ERC FUNDED PROJECTS

Dysregulation of capillary permeability is a severe problem in critically ill patients, but the mechanisms involved are poorly understood. Further, there are no targeted therapies to stabilize leaky vessels in various common, potentially fatal diseases, such as systemic inflammation and sepsis, which affect millions of people annually. Although a multitude of signals that stimulate opening of endothelial cell-cell junctions leading to permeability have been characterized using cellular and in vivo models, approaches to reverse the harmful process of capillary leakage in disease conditions are yet to be identified. I propose to explore a novel autocrine endothelial permeability regulatory system as a potentially universal mechanism that antagonizes vascular stabilizing ques and sustains vascular leakage in inflammation. My group has identified inflammation-induced mechanisms that switch vascular stabilizing factors into molecules that destabilize vascular barriers, and identified tools to prevent the barrier disruption. Building on these discoveries, my group will use mouse genetics, structural biology and innovative, systematic antibody development coupled with gene editing and gene silencing technology, in order to elucidate mechanisms of vascular barrier breakdown and repair in systemic inflammation. The expected outcomes include insights into endothelial cell signaling and permeability regulation, and preclinical proof-of-concept antibodies to control endothelial activation and vascular leakage in systemic inflammation and sepsis models. Ultimately, the new knowledge and preclinical tools developed in this project may facilitate future development of targeted approaches against vascular leakage.

1 999 770 €

Start date: 2018-05-01, End date: 2023-04-30

I propose to study how eukaryotic cells generate autophagosomes, organelles bounded by a double membrane. These are formed during autophagy and mediate the degradation of cytoplasmic substances within the lysosomal compartment. Autophagy thereby protects the organism from pathological conditions such as neurodegeneration, cancer and infections. Many core factors required for autophagosome formation have been identified but the order in which they act and their mode of action is still unclear. We will use a combination of biochemical and cell biological approaches to elucidate the choreography and mechanism of these core factors. In particular, we will focus on selective autophagy and determine how the autophagic machinery generates an autophagosome that selectively contains the cargo. To this end we will focus on the cytoplasm-to-vacuole-targeting pathway in S. cerevisiae that mediates the constitutive delivery of the prApe1 enzyme into the vacuole. We will use cargo mimetics or prApe1 complexes in combination with purified autophagy proteins and vesicles to reconstitute the process and so determine which factors are both necessary and sufficient for autophagosome formation, as well as elucidating their mechanism of action. In parallel we will study selective autophagosome formation in human cells. This will reveal common principles and special adaptations. In particular, we will use cell lysates from genome-edited cells in combination with purified autophagy proteins to reconstitute selective autophagosome formation around ubiquitin-positive cargo material. The insights and hypotheses obtained from these reconstituted systems will be validated using cell biological approaches. Taken together, our experiments will allow us to delineate the major steps of autophagosome formation during selective autophagy. Our results will yield detailed insights into how cells form and shape organelles in a de novo manner, which is major question in cell- and developmental biology.

1 999 640 €

Start date: 2016-03-01, End date: 2021-02-28

We aim to understand host cell entry of enveloped viruses at molecular level. A crucial step in this process is when the viral membrane fuses with the cell membrane. Similarly to cell–cell fusion, this step is mediated by fusion proteins (classes I–III). Several medically important viruses, notably dengue and many bunyaviruses, harbour a class II fusion protein. Class II fusion protein structures have been solved in pre- and post-fusion conformation and in some cases different factors promoting fusion have been determined. However, questions about the most important steps of this key process remain unanswered. I will focus on the entry mechanism of bunyaviruses by using cutting-edge, high spatial and temporal resolution bio-imaging techniques. These viruses have been chosen as a model system to maximise the significance of the project: they form an emerging viral threat to humans and animals, no approved vaccines or antivirals exist for human use and they are less studied than other class II fusion protein systems. Cryo-electron microscopy and tomography will be used to solve high-resolution structures (up to ~3 Å) of viruses, in addition to virus–receptor and virus–membrane complexes. Advanced fluorescence microscopy techniques will be used to probe the dynamics of virus entry and fusion in vivo and in vitro. Deciphering key steps in virus entry is expected to contribute to rational vaccine and drug design. During this project I aim to establish a world-class laboratory in structural and cellular biology of emerging viruses. The project greatly benefits from our unique biosafety level 3 laboratory offering advanced bio-imaging techniques. Furthermore it will also pave way for similar projects on other infectious viruses. Finally the novel computational image processing methods developed in this project will be broadly applicable for the analysis of flexible biological structures, which often pose the most challenging yet interesting questions in structural biology.

1 998 375 €

Start date: 2015-04-01, End date: 2020-03-31

"Large bodies usually follow the classical equations of motion. Deviations from this can be called macroscopic quantum behavior. These phenomena have been experimentally verified with cavity Quantum Electro Dynamics (QED), trapped ions, and superconducting Josephson junction systems. Recently, evidence was obtained that also moving objects can display such behavior. These objects are micromechanical resonators (MR), which can measure tens of microns in size and are hence quite macroscopic. The degree of freedom is their vibrations: phonons. I propose experimental research in order to push quantum mechanics closer to the classical world than ever before. I will try find quantum behavior in the most classical objects, that is, slowly moving bodies. I will use MR's, accessed via electrical resonators. Part of it will be in analogy to the previously studied macroscopic systems, but with photons replaced by phonons. The experiments are done in a cryogenic temperature mostly in dilution refrigerator. The work will open up new perspectives on how nature works, and can have technological implications. The first basic setup is the coupling of MR to microwave cavity resonators. This is a direct analogy to optomechanics, and can be called circuit optomechanics. The goals will be phonon state transfer via a cavity bus, construction of squeezed states and of phonon-cavity entanglement. The second setup is to boost the optomechanical coupling with a Josephson junction system, and reach the single-phonon strong-coupling for the first time. The third setup is the coupling of MR to a Josephson junction artificial atom. Here we will access the MR same way as the motion of a trapped ions is coupled to their internal transitions. In this setup, I am proposing to construct exotic quantum states of motion, and finally entangle and transfer phonons over mm-distance via cavity-coupled qubits. I believe within the project it is possible to perform rudimentary Bell measurement with phonons."

2 004 283 €

Start date: 2015-01-01, End date: 2019-12-31