A D^b-SAP tetramer can delete antigen-specific CD8⁺ T cells in vivo. (A) Administration of a gpC9M-SAP tetramer selectively eliminates adoptively-transferred P14.GFP (GFP⁺ Vα2⁺) but not H-Y (T3.70⁺) T cells from the spleen of C57BL/6J recipient mice (n = 3/group) at 72 hours. Representative histograms (top and bottom panels are from the same mouse) show a CD8⁺ T-cell–gated population. An identical number of total events (3.0 × 10⁵) were collected in each sample, and cell viability, measured by 7-AAD exclusion, was equivalent between groups. Numbers indicate cell counts in the region. (B) The loss of P14.GFP T cells with gpC9M-SAP versus gpC9M was significant (**P < .005 by 2-tailed Student t test); differences between H-Y T cells were not significant. Results represent 2 independent experiments.