Neutrophil Sling: a New Cell-Autonomous Adhesive Structure Enabling Rolling at High Shear Stress

Abstract

Neutrophil rolling is mediated by P-selectin on the endothelium binding to P-selectin-glycoprotein-ligand (PSGL)-1constitutively expressed on neutrophils. In post capillary venules in vivo, neutrophils roll at shear stresses of 2-35 dyn/cm2. Recently, quantitative dynamic footprinting (qDF) microscopy revealed that neutrophil rolling on P-selectin at a shear stress of 6-8 dyn/cm2 is facilitated by four-fold larger footprints than expected and three to four long membrane tethers at the rear. When mouse bone marrow neutrophils were stained with an intercalating membrane dye (DiI), allowed to roll on P- selectin in a microfluidic device at a shear stress of 6-10 dyn/cm2 and footprints recorded using dual-color qDF (DqDF), we found that following tether bond failure, tethers did not retract.