SHORT COMMUNICATION: Induction of donor-specific ACAID can prolong orthotopic corneal allograft survival in "high-risk" eyes

PURPOSE: To examine the effect of donor-specific anterior chamber-associated immune deviation (ACAID) induction on the survival of orthotopic corneal allografts in neovascularized graft beds. METHODS: To induce donor-specific ACAID in recipients, peritoneal exudate cells (PEC) from C57BL/6 mice were incubated overnight with transforming growth factor (TGF)-beta. Cultured PEC were injected intravenously (i.v.) into BALB/c mice, and, 1 week later, these animals received orthotopic corneal allografts from C57BL/6 donors into neovascularized graft beds. Control mice received i.v. injection of syngeneic (BALB/c) PEC, cultured overnight with TGF-beta, and then received orthotopic corneal allografts from C57BL/6 donors. RESULTS: All corneal allografts (15 out of 15) were rejected within 2 weeks after grafting in the neovascularized graft beds of control animals. However, only 6 out of 16 (37.5%) of corneal allografts were rejected in recipients in which donor-specific ACAID had been induced by injection of allogeneic PEC cultured with TGF-beta. CONCLUSION: Previous studies revealed that rejection of orthotopic corneal allografts in neovascularized graft beds in mice correlated with acquisition of donor-specific delayed hypersensitivity (DH). The results of this study suggest that induction of donor-specific ACAID, which selectively impairs DH responses to donor antigens, effectively prolongs corneal allograft survival in "high-risk" eyes.