Regensburg 2019 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 14: Cell mechanics I

BP 14.5: Hauptvortrag

Mittwoch, 3. April 2019, 10:30–11:00, H10

Physical determinants of phagocytic uptake and transport — •Holger Kress — Biological Physics Group, Department of Physics, University of Bayreuth, Germany

Phagocytosis is an essential part of the human immune system and an evolutionary highly conserved fundamental cellular process. Although a large number of molecules that are involved in phagocytosis are known already, a quantitative physical understanding of this intrinsically mechanical process is still lacking. Therefore we investigate physical determinants of phagocytic uptake and transport. We examine the cellular resolution limit for particle uptake by using holographic optical tweezers in combination with correlative light and electron microscopy to measure the ability of cells to discriminate between two spatially separated objects. These studies provide insights into the spreading of cell signaling during particle uptake. In addition, we investigate the influence of basic spatial factors for the transport of intracellular organelles and we show that not all phagosomes are transported directly from the cell periphery to the perinuclear region, but that they exhibit more complex transport characteristics which depend strongly on the size of the phagosomes. This transport behavior might be the foundation for a size-dependent cellular sorting mechanism for organelles. In addition, we quantify how the intracellular transport forces scale with the organelle size by using magnetic tweezers, which can provide cues for the number of motors involved in the transport of different-sized organelles.