DC-induced CD44^hiCD8⁺ T cells are defective in induction of GVHD. (A) Naive C3H.SW CD8⁺ T cells were cultured with B6 DCs plus IL-2 plus IL-15. Five days after the culture, T cells were collected and sorted into CD44^hiCD8⁺ and CD44^loCD8⁺ T cells using FACS. (B) Survival of lethally irradiated B6 mice injected with C3H.SW T^–BM (7 × 10⁶) mixed with or without C3H.SW CD8⁺ T cells (2 × 10⁶). ♦, T^–BM (n = 8); ▪, T^–BM plus unstimulated naive CD8⁺ (n = 8); ▴, T^–BM plus unseparated B6 DC-stimulated CD8⁺ (n = 13); ×, T^–BM plus B6 DC-induced CD44^hiCD8⁺ (n = 19); ○, T^–BM plus B6 DC-induced CD44^loCD8⁺ (n = 15). P < .01 (▴ or × versus ○). Data shown here are pooled from 3 independent experiments. (C) Survival of lethally irradiated B6 mice injected with C3H.SW T^–BM (7 × 10⁶) mixed with or without sorted CD44^hiCD8⁺ or sorted CD44^loCD8⁺ T cells at the dosages ranging from 0.5 × 10⁶ to 2 × 10⁶. ♦, T^–BM (n = 8); ▪, T^–BM plus CD44^loCD8⁺ T cells (2 × 10⁶, n = 8); ▴, T^–BM plus CD44^loCD8⁺ T cells (1 × 10⁶, n = 8); •, T^–BM plus CD44^loCD8⁺ T cells (0.5 × 10⁶, n = 6); □, T^–BM plus CD44^hiCD8⁺ T cells (2 × 10⁶, n = 8); ▵, T^–BM plus CD44^hiCD8⁺ T cells (1 × 10⁶, n = 8); ○, T^–BM plus CD44^loCD8⁺ T cells (0.5 × 10⁶, n = 6). Data shown here are representative of 2 independent experiments. (D) Livers and skin were harvested from mice at day 35 after allo-BMT and sectioned for histologic staining with hematoxylin and eosin; original magnification × 100.