title: A novel flow-cytometry-based assay for quantification of affinity and avidity changes of integrins.
abstract: Cell adhesion plays an important role in cell-cell contact formation and cell migration. Thus, the assessment of cellular adhesiveness is one important feature when studying cell-mediated immune responses. The interaction of lymphocytes with other cell types such as antigen-presenting cells or vascular-endothelial cells occurs via adhesion molecules including L-selectin, VCAM-1 or ICAM-1. There are principally two mechanisms by which cell adhesion can be enhanced: namely changes in the affinity or avidity of receptor interactions. Conventional plate-based adhesion assays detect both forms. However, they do not permit discrimination between affinity- and avidity-mediated changes in the adhesiveness. Moreover, analysis of cell subpopulations requires cell separation prior to performance of the adhesion assay. Conventional flow-cytometry-based tests make it possible to determine changes in the affinity of integrins at the single cell level. However, they fail to quantify avidity-mediated adhesiveness. Here we describe a novel flow-cytometry-based assay, which allows the detection of both integrin-mediated affinity as well as avidity changes at the single cell level. This opens up the possibility of precisely characterizing the adhesive capacity of subpopulations in heterogeneous cell populations.
authors.affiliation: Institute for Immunology, Ruprecht-Karls-University, Heidelberg, Germany.
authors.forename: M H
authors.initials: MH
authors.lastname: Konstandin
authors.forename: U
authors.initials: U
authors.lastname: Sester
authors.forename: M
authors.initials: M
authors.lastname: Klemke
authors.forename: T
authors.initials: T
authors.lastname: Weschenfelder
authors.forename: G H
authors.initials: GH
authors.lastname: Wabnitz
authors.forename: Y
authors.initials: Y
authors.lastname: Samstag
mesh_terms: D000915:Antibody Affinity / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology*; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007128:Immunoglobulin Fragments / Q000737:chemistry; D018799:Intercellular Adhesion Molecule-1 / Q000737:chemistry*; D013601:T-Lymphocytes / Q000166:cytology*
chemical_list: D007128:Immunoglobulin Fragments; D018799:Intercellular Adhesion Molecule-1