title: A transmigratory cup in leukocyte diapedesis both through individual vascular endothelial cells and between them.
abstract: The basic route and mechanisms for leukocyte migration across the endothelium remain poorly defined. We provide definitive evidence for transcellular (i.e., through individual endothelial cells) diapedesis in vitro and demonstrate that virtually all, both para- and transcellular, diapedesis occurs in the context of a novel "cuplike" transmigratory structure. This endothelial structure was comprised of highly intercellular adhesion molecule-1- and vascular cell adhesion molecule-1-enriched vertical microvilli-like projections that surrounded transmigrating leukocytes and drove redistribution of their integrins into linear tracks oriented parallel to the direction of diapedesis. Disruption of projections was highly correlated with inhibition of transmigration. These findings suggest a novel mechanism, the "transmigratory cup", by which the endothelium provides directional guidance to leukocytes for extravasation.
authors.affiliation: The CBR Institute for Biomedical Research, Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Carman
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Springer
mesh_terms: D015703:Antigens, CD; D015820:Cadherins / Q000378:metabolism; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009000:Monocytes / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D013997:Time Factors; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D051242:Caveolin 1; D022461:Caveolins; D018799:Intercellular Adhesion Molecule-1; D019010:Vascular Cell Adhesion Molecule-1; D000099152:Cadherin 5