The proportion of IL-2Rα in lipid rafts is increased in cells cultured in the presence of immobilized anti–Thy-1.

(A) CTLL-2 cells were cultured in the presence of immobilized anti–Thy-1 or an isotype-matched control (ctrl) mAb before lysis and sucrose density gradient ultracentrifugation. The localization of IL-2Rα and IL-2Rβ chains was assessed by immunoblotting the fractions of the sucrose gradients corresponding to lipid rafts and soluble membranes. (B) The proportion of IL-2Rα and IL-2Rβ in lipid rafts and soluble membranes was quantified by scanning densitometry. Data shown are represented as the percentages of the total IL-2Rα or IL-2Rβ localized in lipid rafts and are the averages from 3 independent experiments.