Amoeboid leukocyte crawling through extracellular matrix: lessons from theDictyostelium paradigm of cell movement

Cell movement within three-dimensional tissues is a cycling multistep proce ss that requires the integration of complex biochemical and biophysical cel l functions. Different cells solve this challenge differently, which leads to differences in migration strategies. Migration principles established fo r leukocytes share many characteristics with those described for ameba of t he lower eukaryote Dictyostelium discoideum. The hallmarks of amoeboid move ment include a simple polarized shape, dynamic pseudopod protrusion and ret raction, flexible oscillatory shape changes, and rapid low-affinity crawlin g. Amoeboid crawling includes haptokinetic adhesion-dependent as well as bi ophysical migration mechanisms on or within many structurally and functiona lly different substrates. We describe central aspects of amoeboid movement in leukocytes and the implications for leukocyte crawling and positioning s trategies within interstitial tissues.