Successful Allotransplantation of Mouse Pancreatic Islets to Nonimmunosuppressed Recipients

Pancreatic islets from BALB/c (H-2^d) mice are rejected within 14 days of transplantation to the kidney capsule of allogeneic, CBA/H (H-2^k) recipients. Cyclophosphamide pretreatment of the islet donor reduced the intensity of the allograft response, and these islets undergo a more chronic rejection process. Islets from cyclophosphamide-pretreated donors can be cultured in a gas phase of 95% O₂ and 5% CO², provided the islets are aggregated into clusters of about 50 islets. After a culture period of 7–12 days, the islet tissue was transplanted to normal allogeneic recipients, where the tissue elicited little or no allograft response over a 3-mo observation period.