title: Characterization of alpha 5-integrin-dependent mast cell adhesion following Fc epsilon RI aggregation.
abstract: BACKGROUND
  Integrin receptors are engaged in the upregulation of mast cell adhesion to extracellular matrix components upon stimulation with cytokines and antigen. Fibronectin receptor containing the alpha 5-integrin subunit is critical for mast cell interaction with the extracellular matrix protein fibronectin (FN).
  
  
  METHODS
  The murine MCP5/L mast cell line was employed to investigate the process of Fc epsilon RI-mediated mast cell adhesion to FN. RT-PCR and cytofluorimetric analysis were used to assess the expression of alpha 5 integrin in MCP5/L mast cells. Radiolabelled mast cells were sensitized with monoclonal IgE and used in adhesion assays. Anti-alpha 5-integrin antibody (Ab), monovalent hapten and metabolic inhibitors were used to characterize antigen-mediated mast cell adhesion to FN.
  
  
  RESULTS
  Addition of antigen to IgE-sensitized cells resulted in transient upregulation of mast cell adhesion to FN with a maximum adhesion following 30 min of incubation. Mast cell adhesion was inhibited with anti-alpha 5-integrin monoclonal antibodies blocking FN receptor or with excess monovalent hapten preventing antigen-mediated IgE cross-linking. The presence of the protein kinase C (PKC) inhibitor staurosporine also inhibited mast cell adhesion in a dose-dependent fashion. The process of Fc epsilon RI-mediated upregulation of mast cell adhesion to FN was not associated with an increase in surface expression of mast cell FN receptors.
  
  
  CONCLUSIONS
  The major FN receptor on MCP5/L mast cell surface, an integrin containing the alpha 5 subunit mediates a transient change in mast cell adhesiveness following IgE cross-linking. Fc epsilon RI-derived signals engage PKC and upregulate mast cell adhesion in a process which might involve changes in integrin avidity rather than integrin expression.
authors: Department of Biogenic Amines, Polish Academy of Sciences, Lodz, Poland. jdastych@iimcb.gov.pl
authors: J
authors: J
authors: Dastych
authors: J
authors: J
authors: Wyczółkowska
authors: D D
authors: DD
authors: Metcalfe
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D015153:Blotting, Western; D002448:Cell Adhesion; D002460:Cell Line; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D007152:Immunologic Capping / Q000187:drug effects; D039482:Integrin alpha5; D008407:Mast Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D017469:Receptors, Fibronectin / Q000737:chemistry / Q000502:physiology*; D017455:Receptors, IgE / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D019311:Staurosporine / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D004791:Enzyme Inhibitors; D005353:Fibronectins; D039482:Integrin alpha5; D017469:Receptors, Fibronectin; D017455:Receptors, IgE; D011493:Protein Kinase C; D019311:Staurosporine