title: Proteinase 3 contributes to transendothelial migration of NB1-positive neutrophils.
abstract: Neutrophil transmigration requires the localization of neutrophils to endothelial cell junctions, in which receptor-ligand interactions and the action of serine proteases promote leukocyte diapedesis. NB1 (CD177) is a neutrophil-expressed surface molecule that has been reported to bind proteinase 3 (PR3), a serine protease released from activated neutrophils. PR3 has demonstrated proteolytic activity on a number of substrates, including extracellular matrix proteins, although its role in neutrophil transmigration is unknown. Recently, NB1 has been shown to be a heterophilic binding partner for the endothelial cell junctional protein, PECAM-1. Disrupting the interaction between NB1 and PECAM-1 significantly inhibits neutrophil transendothelial cell migration on endothelial cell monolayers. Because NB1 interacts with endothelial cell PECAM-1 at cell junctions where transmigration occurs, we considered that NB1-PR3 interactions may play a role in aiding neutrophil diapedesis. Blocking Abs targeting the heterophilic binding domain of PECAM-1 significantly inhibited transmigration of NB1-positive neutrophils through IL-1β-stimulated endothelial cell monolayers. PR3 expression and activity were significantly increased on NB1-positive neutrophils following transmigration, whereas neutrophils lacking NB1 demonstrated no increase in PR3. Finally, using selective serine protease inhibitors, we determined that PR3 activity facilitated transmigration of NB1-positive neutrophils under both static and flow conditions. These data demonstrate that PR3 contributes in the selective recruitment of the NB1-positive neutrophil population.
authors.affiliation: Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53201, USA. Christopher.Kuckleburg@bcw.edu
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kuckleburg
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Tilkens
authors.forename: Sentot
authors.initials: S
authors.lastname: Santoso
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Newman
mesh_terms: D004789:Enzyme Activation / Q000235:genetics / Q000276:immunology; D058851:GPI-Linked Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D005786:Gene Expression Regulation / Q000276:immunology; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007519:Isoantigens / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D053146:Myeloblastin / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology* / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D057705:Transendothelial and Transepithelial Migration / Q000276:immunology*
chemical_list: C407242:CD177 protein, human; D058851:GPI-Linked Proteins; D007519:Isoantigens; D011956:Receptors, Cell Surface; D053146:Myeloblastin