Dynamics of adhesion molecule domains on neutrophil membranes: surfing the dynamic cell topography

Abstract

Lateral organization and mobility of adhesion molecules play a significant role in determining the avidity with which cells can bind to target cells or surfaces. Recently, we have shown that the lateral mobility of the principal adhesion molecules on neutrophils is lower for rolling associated adhesion molecules (RAAMs: L-selectin and PSGL-1) than for β2 integrins (LFA-1 and Mac-1). Here we report that all four adhesion molecules exhibit distinct punctate distributions that are mobile on the cell surface. Using uniform illumination image correlation microscopy (UI-ICM), we measure the lateral mobility of these topologically distinct domains. For all four molecules, we find that diffusion coefficients calculated from domain mobility agree with measurements we made previously using fluorescence recovery after photobleaching (FRAP). This agreement indicates that the transport of receptors on the surface of the resting neutrophil is dominated by the lateral movement of domains rather than individual molecules. The diffusion of pre-assembled integrin domains to zones of neutrophil/endothelial contact may provide a mechanism to facilitate high avidity adhesion during the earliest stages of firm arrest.

Deposition of microparticles by neutrophils onto inflamed epithelium: a new mechanism to disrupt epithelial intercellular adhesions and promote transepithelial migration

“…Immunofluorescence staining revealed that MMP-9 exhibited punctate distribution similar to that reported for CD11b (45), but did not colocalize with CD11b, which is typically expressed on membrane ruffles (46). It remains to be determined whether MMP-9 expressed at the PMN surface associates with another protein or nonspecifically coats PMN membranes.…”

Crossing the Vascular Wall: Common and Unique Mechanisms Exploited by Different Leukocyte Subsets during Extravasation

“…Sundd and colleagues have recently made some interesting observations on how these neutrophils maintain contact with EC during rolling [ 32 ]. During the initial contacts with EC through selectins/selectin ligands, the structure of the neutrophil cell membrane is modified by reorganization of both cytoskeleton and surface adhesion molecules leading to the formation of an extended protrusion called sling [ 33 ]. This structure is formed from a membrane tether at the back of the rolling neutrophil like an anchor before it is wrapped around the rolling leukocyte and swings to the front of the cell to recontact the EC.…”

Recent applications of fluorescence correlation spectroscopy in live systems

“…Comparison of diffusion of several proteins can show the selectivity of proteins for certain domains [16,17], while the increase in diffusion coefficient (D) upon cholesterol depletion indicates affinity of the concerned proteins for cholesterol enriched domains [16]. Diffusion of whole domains containing different adhesion molecules was measured by temporal ICS (TICS) and found to correlate with the function of the respective molecules [18]. The selectivity of proteins for certain domains was also demonstrated by Lillemeier et al [19].…”

“…1). Diffusion of whole domains containing different adhesion molecules was measured by temporal ICS (TICS) and found to correlate with the function of the respective molecules [18]. Diffusion of whole domains containing different adhesion molecules was measured by temporal ICS (TICS) and found to correlate with the function of the respective molecules [18].…”

“…For example Ganguly and Chattopadhyay found diffusion of serotonin receptor 5-HT 1A R to be hindered by a meshwork. However, even under cholesterol depletion, the mem- ; aggregation of amyloid peptides on plasma membrane (3); oligomerization state of membrane receptors (4,5); binding of ligands to membrane receptors (6, 7); diffusion of proteins in cytoplasm (8); protein-protein interactions in cytosol and nucleus (9); interaction of proteins with small nucleic acid molecules (10); binding of proteins to chromatin and nuclear DNA (11); influence of chromatin architecture on diffusion of inert tracers (12); passive or active transport of molecules between nucleus and cytoplasm (13); anomalous diffusion of protein complexes in endoplasmic reticulum (14); in embryos 3 days post fertilization: blood flow (15) and protein diffusion in plasma membrane (16) [135] and protein-protein interactions in cytosol (17) of muscle cells; morphogen gradients originating from a single source region (depicted as the green cell) in gastrula stage embryos (18). Other evidence for the role of cholesterol in mediating of diffusion hindering by actin comes from Sankaran et al who studied the influence of cholesterol depletion and actin disruption on diffusion of a sphingolipid binding domain (SBD).…”