Treatment of rat pancreatic islets with MHC Ia antibody and complement prior to transplantation.

Rat pancreatic islets were treated with MHC Ia antigen monoclonal antibody and complement in order to lyse Ia antigen bearing cells within the islets. Ia antigen expression was significantly reduced after this treatment as shown by indirect immunofluorescence tests. Glucose stimulated insulin secretion and viability of the islets were not impaired. The partial reduction of the Ia antigen expression, however, did not provoke a prolongation of the graft acceptance after islet allotransplantation across a major histocompatibility barrier.