[Co-transplantation of islet and allogeneic testicular cell induced immune privilege]

To induce islet allograft long-term survival through co-transplantation islet with sertoli cell.

Testicular sertoli cell was prepared by digestion of collagenase, trypsin and Dnase, and cultured for 48 hours. Purified donor (Wistar rat) islet was co-transplanted with allergic sertoli cell, in the absence of systemic immunosuppression. TUNEL (terminal deoxynucleotidyl transferase-mediated X-dUTP nick end labeling) was used to label the apoptosis of lymphocytes surrounding the islet graft. The SABC method was used to label the expression of Fas ligand in co-transplantation.

Islet co-transplantation with 1 x 10(7) sertoli cell reversed the diabetic state for more than 60 days in 100% (6/6) of the chemically diabetic SD recipients. Similar grafts consisting of islet alone or islet plus 1 x 10(5)-sertoli cell survived only for 5 - 6 days. Apoptosis of the lymphocytes surrounding the islet was quite clear.

Co-transplantation islet with FasL(+) sertoli cell induces local immune privilege and allows long-term graft survival without systemic immunosuppression.