FIGURE 6.

TGF-β1 inhibits the expression of FcεRI subunit proteins. BMMC were cultured in IL-3 and SCF with or without TGF-β1 for 3 days, and down-regulation of surface FcεRI expression was confirmed by flow cytometry. A, Total protein from 30 million cells was immunoprecipitated with anti-FcεRIα or control IgG. Immunoprecipitates were subjected to SDS-PAGE and Western blotting with anti-FcεRI. Data shown are representative of two independent experiments. B, Total protein from ~1 million cells was subjected to SDS-PAGE and Western blotting with anti-FcεRIβ or -γ. The same membranes were stripped and reprobed with anti-actin to demonstrate protein loading. Data shown are representative of three to five independent experiments.