Phenotyping of Lymphocytes Following Transplantation of Allogeneic Rat Pancreatic Islets into Streptozotocin-Diabetic Recipients*

We investigated the phenotypes of peripheral and cervical lymphocytes in allografted pancreatic islet recipients during graft rejection. Grafting 2000 pancreatic islets, obtained from LEW. 1A rats, into streptozotocin-diabetic non-immunosuppressed LEW.1W rats acute rejection occurred within 7.0 ± 0.6 days. Neither the T-cells (W3/13+), nor the T helper (W3/25+) or T-suppressor (OX-8+) lymphocytes were markedly altered during rejection crisis in peripheral or cervical lymphocytes. When using monoclonal antibodies detecting activation markers (OX-17 for class II antigens; ART-18 for interleukin-2 receptor) a significant increase of OX-17+ cells and OX-17+ T-lymphocytes could be observed in lymph node lymphocytes from 24 h after transplantation until 7 days, whereas the peripheral lymphocytes behaved inconspicuously. The results underline the uselessness of peripheral lymphocytes to monitor allogeneic destruction of minimal amounts of grafted tissue by using presently known differentiation and activation markers of lymphocytes.