Transforming growth factor β decreases the immunogenicity of rat islet xenografts (rat to mouse) and prevents rejection in association with treatment of the recipient with a monoclonal antibody to interferon γ

Culture of rat islets of Langerhans for 1 week at 37°C with recombinant transforming growth factor β prolonged the survival of islet xenografts transplanted into diabetic mouse recipients. Treatment of diabetic recipients with a neutralizing monoclonal antibody to murine interferon γ did not affect the survival of islet xenografts cultured 7 days in control medium. However, treatment of donor islets with transforming growth factor β in combination with treatment of diabetic recipients with interferon γ antibody produced a 75% survival of the islet xenografts at 100 days. Fifty percent of the recipients who had accepted their graft for more than 100 days were immune unresponsive to a transplant of freshly isoalted islets from the same donor strain.