The premise behind the proposal is that hOKT3γ1(Ala-Ala) corrects the imbalance between autoreactive and regulatory T cells and consequently prevents autoimmune destruction of transplanted islets. To prevent allorejection, hOKT3γ1(Ala-Ala)was combined with sirolimus and delayed tacrolimus. Additionally, the safety and efficacy of the maintenance immunosuppressive regimen of sirolimus combined with tacrolimus was monitored.