Resistance of established islet allografts to rejection by antibody and complement

Using preliminary in vitro culture in an oxygen-rich atmosphere to facilitate survival of the graft, long term survival (greater than 100 days) of mouse pancreatic islet allografts was obtained subsequently in non-immunosuppressed diabetic animals. When anti-donor alloantiserum was transferred to these animals, the grafts were not rejected despite the fact that circulating cytotoxic antibody was demonstrated up to 7 days after injection of alloantiserum. Similarly, there was no graft rejection following the injection of anti-donor alloantiserum and complement. These results show that cultured islet allografts are not susceptible to antibody and complement.