Characterization of functional ability and tumor efficacy of immunotherapy expanded CD8⁺ T cells. (A) Granzyme B expression in CD44^highCD8⁺ T cells on day 12 of anti-CD40 and IL-2 treatment. (B) Lytic ability of whole splenocytes (left) or sorted CD44^high and CD44^low CD8⁺ T cells (right) from anti-CD40 and IL-2 or control treated animals redirected against anti-CD3 labeled P815 targets. (C) NKG2D expression and (D) quantification of CD25 (pos) and (neg) CD8⁺ T cells from mice bearing orthotopic Renca tumors. (E) Tumor growth after immunotherapy concurrent with blockade of NKG2D in sc NKG2D ligand expressing Renca tumors. Data are representative of at least 3 independent experiments (*P < .05, **P < .01, ***P < .001).