Regensburg 2022 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 12: Poster 2

BP 12.28: Poster

Dienstag, 6. September 2022, 17:30–19:30, P4

Motion-correlated particle transport along filopodia and lamellipodia — •Mario Brehm and Alexander Rohrbach — Laboratory for Bio- and Nanophotonics, Department of Microsystems Engineering - IMTEK, Georges-Köhler-Allee 102, 79110 Freiburg, Germany

Macrophages play an important role in cleaning up the body from cell debris, bacteria and viruses. As a prior step to phagocytosis, extracellular particles can attach to cell protrusions like filopodia and be pulled towards the cell body. Our data points to the idea that particles such as bacteria or viruses get mechanically coupled to the actin fibers within the cell, similarly to focal adhesions. The aim of this study is to improve mechanistic models that describe the mechanical coupling of extracellular particles to proteins connected to the retrograde flow of actin fibers. In addition, we investigate whether and how the transport along filopodia and lamellipodia differ from each other.

The high image contrast combined with the high temporal and spatial resolution of ROCS microscopy enables us to observe directed motion and fluctuations along filopodia at 100 Hz and without fluorescence. By recording, tracking and analyzing the nanoparticle's fluctuations it is possible to derive changes of the particle's viscoelastic properties and their relation to molecular bonds during their transport along the cell's protrusions.