POLYMORPHONUCLEAR LEUKOCYTE MOTILITY - CELLULAR AND STRUCTURAL DYNAMICS

The ability of polymorphonuclear leukocytes (PMNs) to emigrate to area s of infection or tissue damage is an important component of the human immune system, Locomotion requires the coordinated remodeling of the PMN cytoskeleton, which is composed of microfilamentous and microtubul ar cytoskeletons. The microfilamentous cytoskeleton is formed by the p olymerization of monomeric or G-actin to polymeric or filamentous F-ac tin, The microtubular cytoskeleton is a polymer composed of tubulin mo nomers, In the last 10 years, the capability for assaying F-actin cont ent in PMNs has lead to significant new observations about actin dynam ics in cells-specifically the existence of distinct filamentous actin pools, the shifts between these pools with cell activation and the rel ationship of the pools to actin binding/regulatory proteins, Due in pa rt to the limited ability to stain PMN microtubules for immunofluoresc ence, less is known about their role in PMN locomotion, However, evide nce suggests that a coordinated interaction between microtubules and m icrofilaments is necessary for normal cell motility, Finally, this rep ort reviews defects of cytoskeletal structure of PMNs in man, These ra re diseases provide further insight into the normal role of cytoskelet al function and its relationship to PMN motility.