Anti–human CTLA-4 mAb promotes the engraftment of PBLs and the expansion of human T cells at 24 days. CB.17 SCID mice were engrafted with 50 × 106 human PBLs and were treated with 100 μg TMβ1 mAb on days –1, 1, and 3, 100 μL ascites containing anti–human CTLA-4 mAb or 100 μg mouse IgG on days 1, 5, 9, and 13, and 3 μg human GM-CSF every other day. At 24 days after engraftment, mice were killed and spleens were harvested and pooled for staining. (A) Representative dot plot showing expansion of CD8 and CD4 T cells with anti–human CTLA-4 mAb clone L3D10 treatment. (B) Variable expansion of CD8 and CD4 T cells with treatment by different clones of anti–human CTLA-4 mAb. Bars represent cells from pooled spleens from 2 to 3 mice per treatment group.
