Expression of the CD19-IE transgene leads to I-E expression on thymic B cells but not on thymic dendritic cells.

(A) B cells. Thymi of B6 and B6 CD19-IE mice were teased, and cell suspensions were stained with mAbs specific for the pan B-cell antigen CD19 (FITC) (data not shown) and further analyzed for expression of I-E or I-A (PE), respectively (upper panels). (B) Dendritic cells. Thymi of B6 and B6 CD19-IE mice were collagenase digested, and DC were analyzed according to their FSC/SSC criteria (data not shown). Cells were stained with mAbs specific for CD11c (FITC) (data not shown), and CD11c-positive cells were further analyzed for I-E or I-A (PE) expression (lower panels).