GVHD models.

Recipient mice were lethally irradiated at 700 cGy for BALB/c and 1,200 cGy (2 split doses, 3-hour interval) for B6 or B6D2F1 mice using an X-RAD 320 irradiator (Precision X-Ray). Syngeneic (B6) or allogeneic (BALB/c or B6D2F1) irradiated mice were transplanted with 5.0 × 10⁶/mouse TCD-BM from B6 or B6.Ly5.1 donors with or without T cells (0.5–1.0 × 10⁶/mouse). Recipient survival was followed throughout the experiment. The development of GVHD was monitored twice per week for weight loss and once per week for clinical signs of posture, skin damage, hair loss, ruffled fur, diarrhea, and decreased activity. In some experiments, donor T cells were labeled with 2.5 μM CFSE (Invitrogen) and transplanted into irradiated recipients.