Fluorescence/patch clamp setup

• Subject Area: Basic Research in Biology and Medicine
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 438033605

We apply for a fluorescence-patch clamp combination, which will be mainly used for infection work with human pathogens of risk group 2. This device ensemble that will be unique at the University of Freiburg is essential for the future research activities of the working group of Winfried Römer in order to be able to continue to conduct top research.The Römer lab explores the molecular mechanisms of the interactions of bacteria with various mammalian cells, e.g. lung, skin and immune cells. Here, the focus is on bacterial lectins, which recognize glycosylated receptors on the host cell plasma membrane and induce diverse signalling pathways that influence the physiology of the cell - in both a positive and a negative sense. The strength of our approach lies in the fact that, on the one hand, coming from complex cell biology, we can identify key molecules, and with this knowledge we can rebuild natural processes in simpler, synthetic systems and thus better understand them. Many important receptors, e.g. growth factor receptors, cell adhesion molecules, glycosphingolipids, and ion channels are targets of these bacterial lectins that massively affect the organization, dynamics, and stability of the plasma membrane.We had to realize that one technique alone, e.g. fluorescence microscopy, is by far not sufficient to adequately describe the complexity of cellular processes. With the help of the fluorescence-patch clamp combination, we would like to make the next big step in the integral understanding of our biological and synthetic systems in the context of three key projects. For each project, patch clamp measurements are carried out in parallel with various fluorescence microscopy techniques, e.g. Ca-imaging, FRET, or colocalization studies.For example, one project will shed light on the atypical activation of B cells by the bacterial lectins BambL from B. ambifaria and LecB from P. aeruginosa. This is induced by the binding of the lectins to glycosylated plasma membrane receptors, especially to the B cell receptor. With the help of the new equipment, we can characterize the whole of the processes in much more detail. The opening of Ca2+-channels in the plasma membrane (recorded by patch clamp) can thus be correlated with the binding to receptors, the uptake of lectins / bacteria (recorded by fluorescence) and the Ca2+-release into the cytosol of the cells (recorded by Ca-imaging).The purchase of this unique combination of devices would enable us to conduct our studies of biological infection processes at a scientifically excellent level using these correlative and complementary measurement methods.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Fluoreszenz/Patch clamp-Gerätekombination
• Instrumentation Group: 5040 Spezielle Mikroskope (außer 500-503)
• Applicant Institution: Albert-Ludwigs-Universität Freiburg
• Leader: Professor Dr. Winfried Römer