Amelioration of hyperglycemia in streptozotocin-induced diabetic mice with fetal pancreatic allografts: prevention of rejection by donor specific transfusion in conjunction with CTLA4Ig.

Introduction: Fetal pancreas has been considered as an alternative donor source for islet transplantation since it has potent capacity for beta cell differentiation and proliferation. However, prevention of fetal pancreatic allograft rejection can be hardly achieved compared with adult islet allografts.

Aims: The aim of the study is to determine whether donor specific transfusion (DST) in conjunction with CTLA4Ig has any favorable effect on prevention of fetal pancreatic allograft rejection in mice.

Methods: BALB/c splenocytes (SPC, 1 x 10) were injected iv into C57BL/6 mice in conjunction with CTLA4Ig (ip, 50 microgram, day 0, 2, and 4). Fourteen days later, the mice were made diabetic with streptozotocin (STZ, iv) and donor specific or third party pancreatic allografts were transplanted beneath the kidney capsule.

Results: Morphologically, it was found that rejection of fetal pancreatic allografts can be prevented at 30 days after transplantation only when donor specific allografts were grafted into the mice treated with DST in conjunction with CTLA4Ig. Functionally, 3 out of 9 diabetic mice became normoglycemic by 120 days after transplantation of fetal pancreatic allografts.

Conclusion: DST in conjunction with CTLA4Ig can have a favorable effect on prevention of fetal pancreatic allograft rejection resulting in amelioration of STZ-induced diabetes in mice.