Fig. 2.

Splenocytes from ERAP1^−/− mice express lower cell-surface MHC class I than those from ERAP1^+/+ mice. Splenocytes from ERAP1^+/+ mice (WT, black bars) or ERAP1^−/− mice (KO, gray bars) were stained with mAb to H-2K^b or H-2D^b or, as a control, to I-A^b and various antibodies to distinguish splenocyte subsets (CD11c, predominantly dendritic cells; CD8⁺and CD4, predominantly T lymphocyte subsets; B220, predominantly B cells) as indicated on the x axis. Shown are mean fluorescence intensities with background staining by an irrelevant antibody subtracted (averages of three mice; error bars represent 1 SD; representative of five experiments). Asterisks indicate statistically significant differences (P < 0.05, Student t test) between ERAP1^+/+ and ERAP1^−/− splenocytes.