Berlin 2012 – wissenschaftliches Programm
DY 12.3: Topical Talk
Dienstag, 27. März 2012, 10:30–11:00, H 1028
Dynamics of directed cell migration — •Albrecht Schwab1, Otto Lindemann1, and Peter Dieterich2 — 1University of Münster, Germany — 2University of Dresden, Germany
Directed migration (chemotaxis) is the prerequisite for an efficient immune defense. The chemical signal is transduced to the cell migration machinery via complex intracellular signaling cascades that also include the activation of plasma membrane Ca2+ channels of the TRPC family. Chemotaxis involves a cellular motor for migration and a steering mechanism. Here, we aim to determine which of these two components are controlled by TRPC channels. Their contribution is assessed with time-lapse video microscopy of single neutrophils from wildtype and TRPC knockout mice exposed to chemoattractants. Since raw velocities or straightness indices calculated from the experimental cell paths provide only a coarse interpretation of the migratory behavior, we analyze all data within the concept of stochastic processes. The cell is regarded as an object driven by internally correlated stochastic forces and external fields generated by chemoattractants. Anomalous properties that we previously identified in cells migrating without external stimuli and described with a fractional Klein-Kramers equation are maintained during chemotaxis. This enables a modeling based quantification of correlations and allows to disentangle the influence of the chemoattractants on the motor strength (thermal velocity) and directed migration (drift) of the cells under different conditions. Our statistical analyses show that TRPC channels are primarily involved in controlling the steering mechanism of chemotacting neutrophils.