[Allotransplantation of islet endocrine aggregates]

Dissociated pancreatic islets form aggregates from single cell suspension by rotation culture. Islet cell aggregates, or neoislets, newly formed from Lewis islet cells were transplanted into diabetic ACI rats intraportally and prolongation of neoislet grafts was observed (mean survival time greater than 45.8 +/- 6.4 days). Five out of seven recipients were still normoglycemic at 60 days after transplantation. Transplantation of neoislets combined with 3 day cyclosporine therapy for recipients resulted in 100% survival at 60 days after transplantation. These findings indicate that neoislets can provide endocrine constitution for streptozotocin diabetic rats and enjoy prolonged survival. As predicted by cell-cell recognition in rotation mediated aggregation, neoislets can exclude mesenchymal cells which bear Ia antigen. Therefore reduced immunogenicity is accomplished.