Characterization of alpha 5-integrin-dependent mast cell adhesion following Fc epsilon RI aggregation.
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. CONCLUSION: 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.[1]References
- Characterization of alpha 5-integrin-dependent mast cell adhesion following Fc epsilon RI aggregation. Dastych, J., Wyczółkowska, J., Metcalfe, D.D. Int. Arch. Allergy Immunol. (2001) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
