Effect of high-dose irradiation.

High-dose irradiation conditioning abolished the delay of GVHD-induced weight loss and lethality by B6-cdd compared with B6 donor CD4⁺ T cells. Highly enriched CD4⁺ cells were obtained as described in Figure 6. Then, 1 × 10⁶ donor CD4⁺ T cells from B6 (♦), B6-pko (▿), B6-gld (▵), and B6-cdd (⋄) donors were combined with 5 × 10⁶ TCD B6-Ly5.1 bone marrow cells and injected into BALB/c recipients (5 per group) that had been irradiated at 11-Gy TBI 24 hours earlier. Weight loss (A) and lethality (B) were monitored. ∗ indicates BM only.