Because successful allotransplantation of islets of Langerhans isolated by collagenase digestion has been difficult in many animal species, we asked whether isolated islet preparations might have tissue specific determinants conferring amplified immunogenicity in vitro. Lymphocyte proliferative responses ([3H]thymidine uptake) were studied in beagle dogs in mixed culture combinations of lymphocyte vs. lymphocyte (MLC) and lymphocyte vs. islet (MLIC). In five MLC responder and five nonresponder pairs, peripheral blood lymphocytes of dogs A and B were used as responding cells, and dog B x-irradiated lymphocytes (Bx), x-irradiated (or nonirradiated) islets (BI), or hepatic cells (BH) were used as stimulating cells in primary and secondary reactions. For the secondary reactions, A + Bx, A + BI, or B + BI were incubated for 9 d (A′B, A′BI, B′BI, respectively) before addition of new stimulating cells.
Alexander Rabinovitch, Laphalle Fuller, Daniel Mintz, Walter Severyn, Jack Noel, Cathy Flaa, George Kyriakides, Joshua Miller