Intracellular Expression and Release of FcεRIα by Human Eosinophils

摘要: Although FceR have been detected on human eosinophils, levels varied from moderate to extremely low or undetectable depending the donor and methods used. We attempted resolve conflicting data by measuring of IgE, FceRI, FceRII in eosinophils a variety donors ( n = 26) late-phase bronchoalveolar lavage fluids 5). Our results demonstrated little no cell surface IgE receptors as analyzed immunofluorescence flow cytometry. Culture for up 11 days presence absence and/or IL-4 (conditions that enhance other cells) failed induce any detectable FceR. However, immunoprecipitation Western blot analysis eosinophil lysates using mAb specific FceRIα showed distinct band approximately 50 kDa, similar found basophils. blotting also FcR γ-chain, but FceRIβ. Surface biotinylation followed again detect FceRIα, although FcRγ was easily detected. Since we were able intracellular examined its release eosinophils. Immunoprecipitation into supernatant cultured peaking at 48 h. conclude possess sizable pool is available release, with subjects, including those eosinophilia elevated serum IgE. The biological relevance this soluble form remains be determined.