FLT3L treatment prevents mice dying from by acute GVHD. (A-E) (C57BL/6 × DBA/2)F₁ mice were treated with FLT3L (20 μg intraperitonal injection every second day from days −7 to 0) or left untreated. At day 0, mice were injected with 50 × 10⁶ pooled lymph node/spleen from C57BL/6 mice. (F-J) (C57BL/6 × DBA/2)F₁ mice were treated with FLT3L (20 μg intraperitoneal injection every second day from days −7 to 7) or left untreated. At day 0, mice were irradiated (600 rad) and injected with 50 × 10⁶ pooled lymph node/spleen plus 8 × 10⁶ bone marrow cells from C57BL/6. (B,G) Survival curves of control and treated mice. (C,H) Percentages of C57BL/6 CD4 and CD8 T cells in the spleen of control or treated mice at day 7. (D,I) Percentage of Foxp3⁺ cells within host or donor CD4 T cells in the spleen of control or treated mice at day 7. (E,J) Percentage of CD11c^highMHCII^high cells within host or donor cells in the spleen of control or treated mice at day 7.