Surface and cytoskeletal events regulating leukocyte membrane topography.

The experiments reviewed here establish that surface components and surface functions can assume predictable, asymmetric patterns within the continuous plasma membranes of mammalian leukocytes. Recent biophysical and morphological studies show that receptor redistribution can occur very rapidly and that a unique geometric association is maintained between moving receptors and surface geometry. Based on these experimental data, a new working model for surface topographical control has been proposed. Its essence is the entrainment of certain receptors and receptor complexes on membrane waves that are generated by microfilament-membrane interaction. Several pathological conditions associated directly or indirectly with cytoskeleton and membrane abnormalities have been described. The continued application of modern biochemical, immunologic, and biophysical techniques to probe the underlying defects should provide new insight into the mechanisms of leukocyte response to surface stimulation.