title: Expression of elastase on polymorphonuclear neutrophils in vitro and in vivo: identification of CD11b as ligand for the surface-bound elastase.
abstract: Elastase is a major serine protease of polymorphonuclear neutrophils (PMN). On activation of PMN, the preformed protein is mobilized from intracellular stores and, depending on the activating conditions, is either released into the supernatant or is bound to the cell surface. By a variety of methods, including uptake and crosslink studies, as well as confocal laser scan microscopy, we now provide evidence that elastase binds to the beta(2)-integrin CD11b and induces a conformational alteration of CD11b, apparent as expression of a neodeterminant. Similarly to the in vitro data, elastase surface expression and conformational alterations of CD11b were seen on PMN of patients with Staphylococcus aureus-induced localized infection, particularly on PMNs recovered from the infected site. The presence of elastase at the site of inflammation is in keeping with its presumed role in leukocyte trafficking and host defense. On the other hand, because of its potential for degrading extracellular matrix proteins, elastase could participate in localized tissue damage as it occurs in severe S. aureus infection.
authors.affiliation: Institut für Immunologie der Universität Heidelberg, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Zimmermann
authors.forename: Karin
authors.initials: K
authors.lastname: Lautenschläger
authors.forename: Volkmar
authors.initials: V
authors.lastname: Heppert
authors.forename: Andreas
authors.initials: A
authors.lastname: Wentzensen
authors.forename: G Maria
authors.initials: GM
authors.lastname: Hänsch
authors.forename: Christof
authors.initials: C
authors.lastname: Wagner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001665:Binding Sites; D001693:Biological Transport, Active; D039481:CD11b Antigen / Q000737:chemistry / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology / Q000276:immunology; D004730:Endothelium, Vascular / Q000166:cytology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D019272:Leukocyte Elastase / Q000378:metabolism*; D008024:Ligands; D016177:Macrophage-1 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology* / Q000276:immunology*; D011487:Protein Conformation; D013203:Staphylococcal Infections / Q000201:enzymology / Q000276:immunology
chemical_list: D039481:CD11b Antigen; D008024:Ligands; D016177:Macrophage-1 Antigen; D019272:Leukocyte Elastase