For cell surface staining of AR, PBMC were stimulated with medium alone or 1 mg/ml SEB in the presence or absence of 50 mM TAPI-1, an ADAM17 protease inhibitor [32] , for 6, 12, and 24 hours. After stimulation, the cells were stained with antibodies against AR, CD3, CD4, CD8, CD14, CD123, CD69 and 7-AAD. Data were acquired using an LSR II flow cytometer (BD Bioscience), and analyzed with FlowJo software (Tree Star Inc., Ashland, OR).