Rotation tracking and footprinting reveal asymmetric rolling adhesion mechanism

Rolling adhesion, in which cells passively roll along surfaces under shear flow, is a critical process involved in inflammatory responses and cancer metastasis. Surface adhesion properties regulated by adhesion receptors are critical in understanding cell rolling behavior. However, how functional adhesion properties are globally distributed on the individual cell’s surface is unknown. Here, CPLC postdoc Isaac Li in the Ha and Chemla labs developed a label-free technique to determine the spatial distribution of adhesive properties on rolling cell surfaces. By tracking the rotational motion of individual rolling cells using dark-field imaging, the team constructed an adhesion map along the cell’s contact circumference. To complement this approach, they also developed a DNA-based fluorescent adhesion footprint assay to record the molecular adhesion events from cell rolling. Applying the combination of the two methods on surprisingly reveals that adhesion is non-uniformly distributed in patches on the cell surfaces. The label-free adhesion mapping methods are applicable to cell types that undergo rolling adhesion and provide a quantitative picture of cell surface adhesion at the functional and molecular level. Refer to: Mapping cell surface adhesion by rotation tracking and adhesion footprinting