title: GPIIb (CD41) integrin is expressed on mast cells and influences their adhesion properties.
abstract: OBJECTIVE
  GPIIb integrin expression has been found on platelets and megakaryocytes, and more recently on immature hematopoietic progenitors. We set out to investigate expression of GPIIb in other hematopoietic cell lineages and, having detected it on mast cells, aimed to determine what possible role it might perform.
  
  
  METHODS
  We have made use of cultured human and murine bone marrow mast cells (BMMC) in order to characterize the expression of GPIIb. Further, BMMC cultures from wild type and GPIIb deficient (gpIIb-/-) mice were used for comparison of the adhesive properties mediated by this receptor. Finally, peritoneal mast cells were analyzed from both wild type and (gpIIb-/-) mice.
  
  
  RESULTS
  We demonstrate expression of GPIIb on cultured BMMC. Using cells derived from mice homozygous for a null allele of gbIIb we show that the absence of GPIIb has no effect on mast cells with respect to a number of measures of cell growth and differentiation. However, loss of GPIIb on BMMC results in an increase in surface expression of aV integrin, the alternative partner of GPIIIa.
  
  
  CONCLUSIONS
  The results in this study demonstrate that GPIIb is expressed in human and murine mast cells. A function for GPIIb on mast cells is suggested by the altered adhesion of gbIIb-/- BMMC to fibronectin- and vitronectin-coated surfaces. Moreover, comparison of mast cells from the peritoneal cavity of wild type and gbIIb-/- mice indicates that GPIIb could influence the in vivo differentiation or homing of tissue mast cells.
authors.affiliation: Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK.
authors.forename: Oscar
authors.initials: O
authors.lastname: Berlanga
authors.forename: Nikla
authors.initials: N
authors.lastname: Emambokus
authors.forename: Jon
authors.initials: J
authors.lastname: Frampton
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002448:Cell Adhesion; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D039564:Integrin alphaV / Q000032:analysis / Q000235:genetics; D008407:Mast Cells / Q000737:chemistry / Q000166:cytology*; D051379:Mice; D018345:Mice, Knockout; D040201:Platelet Membrane Glycoprotein IIb / Q000032:analysis / Q000235:genetics* / Q000502:physiology*; D019096:Vitronectin / Q000378:metabolism
chemical_list: D005353:Fibronectins; D039564:Integrin alphaV; D040201:Platelet Membrane Glycoprotein IIb; D019096:Vitronectin