Anti–human CTLA-4 mAb L3D10 decreases percentages of engrafted cells expressing EBV LMP-1. Mice were treated as described in the legend to Figure 2 except that TMβ1 mAb was given on days 0, 2, and 4. Spleens were harvested at day 22 after engraftment and were stained for intracellular LMP-1 or isotype IgG2a. (A) Representative FACS plot of LMP-1 staining, depicting cells from the lymphocyte gate. Data shown are LMP-1 and CD19 profiles of gated human CD45⁺ cells. (B) Summary graph showing percentages (top) and numbers (bottom) of LMP-1–staining cells for 3 to 4 individual mice per treatment group. Data are representative of 2 independent experiments. P values were generated using a 2-sample t test.