HDM treatment results in solubilization of IL-13Rα2. A, U937 (U) and FLAG–IL-13Rα2 transfected U937 cells (T) were treated with HDM. Soluble IL-13Rα2 was quantified. B, FLAG–IL-13Rα2 transfected U937 cells were treated with the indicated allergen extracts. Soluble IL-13Rα2 was quantified. C, Media from FLAG–IL-13Rα2 transfected cells treated with HDM for minutes as indicated. D, FLAG–IL-13Rα2 transfectants were treated with HDM, alone or with protease inhibitors (+I). Soluble IL-13Rα2 was quantified by ELISA. Significant differences noted. NT, No treatment. *Significantly different from untreated, P < .05.