title: Cutting edge: Endothelial-specific gene ablation of CD99L2 impairs leukocyte extravasation in vivo.
abstract: CD99-like 2 (CD99L2) is a membrane protein with moderate sequence homology to CD99, which initiates cell aggregation of transfected cells and that is strongly expressed on endothelial cells, neutrophils, and lymphocytes. We showed recently that Abs against CD99L2 inhibit neutrophil, but not T lymphocyte, recruitment into inflamed tissues. In this study, we have generated conditional gene-deficient mice for CD99L2 and show by analyzing them in various inflammation models several results. First, gene ablation of CD99L2 impairs neutrophil recruitment into inflamed cremaster and peritoneum. Second, despite the strong expression of CD99L2 on peripheral neutrophils, only gene ablation on endothelial cells but not on myeloid cells affects neutrophil extravasation. Third, in contrast to our previous Ab-based results, recruitment of activated T cells into inflamed skin was impaired in mice lacking CD99L2 on endothelial cells. We conclude that CD99L2 is an essential endothelial Ag for leukocyte extravasation, which does not require homophilic interactions with CD99L2 on leukocytes.
authors.affiliation: Max Planck Institute for Molecular Biomedicine, D48149 Münster, Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Seelige
authors.forename: Christiane
authors.initials: C
authors.lastname: Natsch
authors.forename: Sigrid
authors.initials: S
authors.lastname: März
authors.forename: Ding
authors.initials: D
authors.lastname: Jing
authors.forename: Maike
authors.initials: M
authors.lastname: Frye
authors.forename: Stefan
authors.initials: S
authors.lastname: Butz
authors.forename: Dietmar
authors.initials: D
authors.lastname: Vestweber
mesh_terms: D000071443:12E7 Antigen; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000276:immunology / Q000473:pathology; D055785:Gene Knockdown Techniques; D007249:Inflammation / Q000276:immunology; D008168:Lung / Q000098:blood supply; D008297:Male; D051379:Mice; D008833:Microcirculation; D022423:Myeloid Cells / Q000276:immunology; D009220:Myositis / Q000276:immunology; D009504:Neutrophils / Q000502:physiology; D010047:Ovalbumin / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology; D010538:Peritonitis / Q000139:chemically induced / Q000276:immunology; D011828:Radiation Chimera; D013601:T-Lymphocytes / Q000276:immunology; D057705:Transendothelial and Transepithelial Migration / Q000502:physiology*
chemical_list: D000071443:12E7 Antigen; D000906:Antibodies; D015703:Antigens, CD; C522605:Cd99 protein, mouse; C111390:OVA 323-339; D010446:Peptide Fragments; D010047:Ovalbumin