The facilitated antigen binding (FAB) assay--a protocol to measure allergen-specific inhibitory antibody activity.
Specific allergen immunotherapy is an effective treatment for IgE-mediated allergic disease and involves T- and B-cell mediated events. IgE receptors on the surface of antigen-presenting cells facilitate the presentation of allergens in the presence of specific IgE antibody resulting in T-cell activation. Interference with these IgE-dependent mechanisms by 'blocking' IgG antibodies may downregulate T-cell responses and manifest as a reduction in allergic responses in vivo. The vigor of proliferative responses by T-cell clones is representative of the binding of allergen-IgE complexes to B cells. Therefore, a simplified assay can be employed that measures the binding of allergen-IgE complexes to B cells instead of a more complex assay involving proliferative assays using antigen-specific T-cell clones. Allergen-IgE complexes can be easily detected by flow cytometry and this simplified technique is called the IgE-facilitated allergen binding (IgE-FAB) assay which is described in this chapter.
Francis
James N
JN
Department of Allergy and Clinical Immunology, National Heart and Lung Institute, Imperial College, South Kensington, London.
D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis*; D000941:Antigens / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018929:Cell Culture Techniques; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology
D000936:Antigen-Antibody Complex; D000941:Antigens; D007073:Immunoglobulin E