Quantitative measurement of mast cell degranulation using a novel flow cytometric annexin-V binding assay.
Cytometry
; 36(4): 340-8, 1999 Aug 01.
Article
em En
| MEDLINE
| ID: mdl-10404150
ABSTRACT
BACKGROUND:
Mast cells are primary mediators of allergic inflammation. Antigen-mediated crosslinking of their cell surface immunoglobulin E (IgE) receptors results in degranulation and the release of proinflammatory mediators including histamine, tumor necrosis factor-alpha, and leukotrienes.METHODS:
Mast cells were stimulated to degranulate by using either IgE crosslinking or ionophore treatment. Exogenously added annexin-V was used to stain exocytosing granules, and the extent of binding was measured flow cytometrically. Release of the enzyme beta-hexosaminidase was used for population-based measurements of degranulation. Two known inhibitors of degranulation, the phosphatidylinositol 3 kinase inhibitor wortmannin and overexpression of a mutant rab3d protein, were used as controls to validate the annexin-V binding assay.RESULTS:
Annexin-V specifically bound to mast cell granules exposed after stimulation in proportion to the extent of degranulation. Annexin-V binding was calcium dependent and was blocked by phosphatidylserine containing liposomes, consistent with specific binding to this membrane lipid. Visualization of annexin-V staining showed granular cell surface patches that colocalized with the exocytic granule marker VAMP-green fluorescent protein (GFP). Wortmannin inhibited both annexin-V binding and beta-hexosaminidase release in RBL-2H3 cells, as did the expression of a dominant negative rab3d mutant protein.CONCLUSIONS:
The annexin-V binding assay represents a powerful new flow cytometric method to monitor mast cell degranulation for functional analysis.
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Bases de dados:
MEDLINE
Assunto principal:
Degranulação Celular
/
Anexina A5
/
Citometria de Fluxo
/
Mastócitos
Limite:
Animals
Idioma:
En
Revista:
Cytometry
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos