A Comparative Study of the FcεRI Molecule on Human Mast Cell and Basophil Cell Lines

• Published in: International Archives of Allergy and Immunology 2005-06, Vol.137 (2), p.93-103
• Main Authors: Jensen, B.M., Dissing, S., Skov, P.S., Poulsen, L.K.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Immunopathology; Medical sciences; Original Paper
• ISSN: 1018-2438; 1423-0097; 1365-2567
• DOI: 10.1159/000085464

Background: Mast cells and basophils express the high-affinity IgE receptor FcΕRI. We have analysed the human mast cell line LAD2 and four subclones of the basophil cell line KU812 in order to reveal possible differences concerning the FcΕRI surface regulation, anti-IgE-triggered activation, FcΕRIα protein stability and the mRNA level of FcΕRIα-, β- and the truncated β-chain (β T ), and thereby determine the utility of these cell lines in investigations of the FcΕRI biology. Methods: The surface expression of FcΕRI was assessed by flow cytometry, using the monoclonal antibody CRA1. The FcΕRI-induced cellular activation (i.e. cross-linking of FcΕRI) was determined by changes in the intracellular level of Ca 2+ , which was measured by fluorescence of Fura-2. The level of the FcΕRIα protein was determined by a Western blot technique and by a radioimmunoassay. The mRNA level of FcΕRIα, β- and β T -chain was analysed using real-time PCR. Results: Two KU812 subclones and especially LAD2 had FcΕRI surface expression which was capable of inducing cellular activation. Both the FcΕRI expression and stability of the FcΕRIα protein were increased when IgE was present. All the cell lines expressed mRNA of FcΕRIα-, β- and β T , with LAD2 tending to have the highest expression. However, a determination of the β/β T ratio demonstrated no difference between any of the cell clones. Conclusion: These cell lines are important tools in the investigation of both the FcΕRI molecule and the effects induced by its activation.