Anti–third-party Tcm eradicate lymphoma cells while sparing normal B cells in vivo. Lethally irradiated BALB/c mice (H-2^d) received an intravenous transplant of 3 × 10⁶ syngeneic BALB/c nude BM in the absence (BM control) or presence of 5 × 10³A20-luc lymphoma cells (day 0). After 1 day, the mice were treated intravenously with 2 × 10⁷ (C57BL/6xBALB/c) F1-derived anti–third-party Tcm (A20+Tcm). (A) On day 21, the mice were monitored for disease burden by BLI and mice responding beneficially to the Tcm treatment were chosen for further analysis (right panel, A20+ Tcm, n = 3). This is in comparison with mice that did not receive either A20 or Tcm (left panel, BM control, n = 3). (B) B-cell abundance. Mice were sacrificed and mononuclear cells were purified from the spleens and analyzed by FACS. (C) Tcm persistence. On day 21, peripheral blood levels of Tcm were analyzed by FACS to measure H2K^b H2D^d double-positive cells in the CD8⁺ T-cell subpopulation. For panels B and C, representative plots are displayed.