The broad, long-term goal of this proposal is to improve the results and applicability of islet allotransplantation early in the course of type 1 diabetes through the administration of selective and short-term immunotherapy. More specifically, the objectives of these studies is to conduct an open-labeled, one-year follow-up Phase I/II study in patients with surgical and type 1 diabetes to determine the safety, tolerability, immune activity, and pharmacokinetics of hOKT3gamma1 (Ala-ala) administration for the prevention of autoimmune destruction and rejection of allogeneic islet transplants.