MiR-155 deficiency in adoptively transferred recipient-type DCs is connected to lower GVHD severity. (A) Lethally irradiated WT C57BL/6 mice were transplanted with 5 × 10⁶ BM cells from a syngeneic miR-155^−/− C57BL/6 donor. After 30 days, the miR-155^−/− BM chimeric mice were irradiated with 5 Gy and injected with 5 × 10⁶ BM cells and 8 × 10⁵ CD4⁺/CD8⁺ T cells from an allogeneic BALB/c donor. Groups additionally received 2 × 10⁶ WT or miR-155^−/− C57BL/6 BM-derived DCs on the day of allo-HCT. Survival data were pooled from 2 independent experiments (n = 11-12/group). (B) Lethally irradiated WT C57BL/6 mice were transplanted with 5 × 10⁶ BM cells from a syngeneic miR-155^−/− C57BL/6 donor. After 30 days, the miR-155^−/− BM chimeric mice were irradiated with 5 Gy and injected with 5 × 10⁶ BM cells and 8 × 10⁵ CD4⁺/CD8⁺ T cells from an allogeneic BALB/c donor. Groups additionally received 2 × 10⁶ WT or miR-155^−/− C57BL/6 BM-derived macrophages on the day of allo-HCT (n = 7-8/group).