title: Rolling adhesion of human NK cells to porcine endothelial cells mainly relies on CD49d-CD106 interactions.
abstract: BACKGROUND
  Acute vascular rejection in pig-to-primate xenotransplantation involves recognition and damage of porcine (po) endothelial cells (EC) by human (hu) leukocytes, probably including natural killer (NK) cells. To study such interactions we analyzed rolling and static adhesion of hu NK cells to po EC.
  
  
  METHODS
  The effects of blocking hu and po adhesion molecules on the adhesion hu NK cells to po EC monolayers was analyzed under shear stress (10 min, 37 degrees C, 0.7 dynes/cm2) or under static conditions (10 min, 37 degrees C). All used cell populations were phenotypically characterized by flow cytometry.
  
  
  RESULTS
  Blocking of CD106 on po EC or its ligand CD49d on hu NK cells decreased rolling adhesion of both fresh and activated hu NK cells by more than 75%. Masking of CD62L on fresh but not activated hu NK resulted in a 44% decrease in rolling adhesion, in line with the diminished cell surface expression of CD62L upon activation. Antibodies to CD31, CD54, CD62E, and CD62P on EC or CD11a, CD18, and CD162 on NK cells had only minor effects on rolling adhesion. The adhesion of the FcgammaRIII- hu NK cell line NK92 to po EC was inhibited by 95% after masking po CD106 whereas antibodies to po CD31, CD54, CD62E, or CD62P had no effect, thereby excluding effects of Fc-receptor-dependent binding of hu NK cells to po EC. Static adhesion of activated NK cells was reduced by approximately 60% by blocking either CD49d or CD106, by 47% by blocking CD11a, and by 82% upon simultaneous blocking of CD11a and CD49d.
  
  
  CONCLUSIONS
  Interactions between hu CD49d and po CD106 are crucial for both rolling and firm adhesion of hu NK cells to po EC and thus represent attractive targets for specific therapeutic interventions to prevent NK cell-mediated responses against po xenografts.
authors.affiliation: Laboratory for Transplantation Immunology, University Hospital Zürich, CH-8091 Zürich, Switzerland.
authors.forename: Mårten K J
authors.initials: MK
authors.lastname: Schneider
authors.forename: Marion
authors.initials: M
authors.lastname: Strasser
authors.forename: Urs O
authors.initials: UO
authors.lastname: Gilli
authors.forename: Markus
authors.initials: M
authors.lastname: Kocher
authors.forename: René
authors.initials: R
authors.lastname: Moser
authors.forename: Jörg D
authors.initials: JD
authors.lastname: Seebach
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D018821:CD18 Antigens / Q000502:physiology; D002448:Cell Adhesion; D019040:E-Selectin / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology*; D006801:Humans; D039441:Integrin alpha4; D007694:Killer Cells, Natural / Q000502:physiology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D019007:P-Selectin / Q000502:physiology; D012399:Rotation; D013552:Swine; D019010:Vascular Cell Adhesion Molecule-1 / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D018821:CD18 Antigens; D019040:E-Selectin; D016169:Lymphocyte Function-Associated Antigen-1; D019007:P-Selectin; D019010:Vascular Cell Adhesion Molecule-1; D039441:Integrin alpha4