In vivo activity of an islet-reactive T-cell clone.

BDC-6.9 is a CD4-positive T-cell clone, specific for NOD islets, which was isolated from the spleen and lymph nodes of a diabetic NOD mouse. The cells were transplanted in a blood clot adjacent to established NOD islet grafts in diabetic (CBA X NOD)F1 recipients. The BDC-6.9 cells initiated extensive damage to the islet grafts, while a non-islet specific clone transplanted adjacent to grafted islets caused no noticeable damage. In addition, the BDC-6.9 cells initiated similar destruction when injected intraperitoneally, suggesting that they may have some migratory capacity. By introducing these islet-reactive cells into the (CBA X NOD)F1, a non-diabetes prone environment, we hope to clarify the role of the islet-specific CD4 cell as related to islet destruction in vivo.