title: Mapping cell surface adhesion by rotation tracking and adhesion footprinting.
abstract: 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 and membrane tethers are critical in understanding cell rolling behavior. Locally, adhesion molecules are distributed at the tips of membrane tethers. However, how functional adhesion properties are globally distributed on the individual cell's surface is unknown. Here, we developed a label-free technique to determine the spatial distribution of adhesive properties on rolling cell surfaces. Using dark-field imaging and particle tracking, we extract the rotational motion of individual rolling cells. The rotational information allows us to construct an adhesion map along the contact circumference of a single cell. To complement this approach, we also developed a fluorescent adhesion footprint assay to record the molecular adhesion events from cell rolling. Applying the combination of the two methods on human promyelocytic leukemia cells, our results surprisingly reveal that adhesion is non-uniformly distributed in patches on the cell surfaces. Our label-free adhesion mapping methods are applicable to the variety of cell types that undergo rolling adhesion and provide a quantitative picture of cell surface adhesion at the functional and molecular level.
authors.affiliation: Department of Physics and Center for Physics of Living Cells, University of Illinois at Urbana-Champaign, 1110 W Green St., Urbana, IL, 61801, USA.
authors.forename: Isaac T S
authors.initials: IT
authors.lastname: Li
authors.affiliation: Department of Physics and Center for Physics of Living Cells, University of Illinois at Urbana-Champaign, 1110 W Green St., Urbana, IL, 61801, USA.|Howard Hughes Medical Institute, Department of Biophysics and Biophysical Chemistry, Department of Biophysics and Department of Biomedical Engineering, Johns Hopkins University, 725 N. Wolfe Street, Baltimore, MD, 21205, USA.
authors.forename: Taekjip
authors.initials: T
authors.lastname: Ha
authors.affiliation: Department of Physics and Center for Physics of Living Cells, University of Illinois at Urbana-Champaign, 1110 W Green St., Urbana, IL, 61801, USA.
authors.forename: Yann R
authors.initials: YR
authors.lastname: Chemla
mesh_terms: D002448:Cell Adhesion / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000235:genetics; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000737:chemistry / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D006801:Humans; D036904:Leukocyte Rolling / Q000235:genetics*; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D015815:Cell Adhesion Molecules