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Media type:
E-Article
Title:
Cultured Human Mast Cells Are Heterogeneous for Expression of the High-Affinity IgE Receptor FcεRI
Contributor:
Hoffmann, Hans Jürgen;
Frandsen, Pernille Munk;
Christensen, Lars Harder;
Schiøtz, Peter Oluf;
Dahl, Ronald
Published:
S. Karger AG, 2012
Published in:
International Archives of Allergy and Immunology, 157 (2012) 3, Seite 246-250
Language:
English
DOI:
10.1159/000328756
ISSN:
1423-0097;
1018-2438
Origination:
Footnote:
Description:
<i>Objective:</i> We determined the density of Fc&#917;RI on mast cells cultured from cord (CBMC) and peripheral blood (PBMC) and studied the kinetics of the response through Fc&#917;RI. <i>Methods:</i> Mast cells were cultured from CD133+ progenitors from peripheral or cord blood. Fc&#917;RI was stabilized by culture with 2 µg/ml IgE. Cells were activated by addition of anti-Fc&#917;RI antibody (1 ng/ml–10 µg/ml). Maximal activation, sensitivity, and cooperativity were determined. <i>Results:</i> All cultures were homogeneous for tryptase and metachromasy. All cells expressing Fc&#917;RI could be activated by cross-linking Fc&#917;RI to upregulate CD63. PBMC bind 203,000 molecules of IgE/cell. Stabilization of Fc&#917;RI with IgE doubled the number of CD63+ cells (p = 0.0001) and increased the sensitivity (from 0.083 to 0.013 µg/ml anti-Fc&#917;RI) and the slope factor (from 10.8 to 68) of PBMC but not of CBMC. Anti-IgE reversed these effects (p = 0.0002) but did not reduce activation levels below that of cell lines not stabilized with IgE. <i>Conclusion:</i> Baseline expression of Fc&#917;RI is independent of anti-IgE. The fraction of PBMC that binds high levels of IgE can be activated through Fc&#917;RI.