FAS LIGAND GENE-TRANSFER TO RENAL-ALLOGRAFTS IN RATS - EFFECTS ON ALLOGRAFT SURVIVAL

Background. Fas ligand (FasL) induces apoptosis of cells bearing its r eceptor Fas, and has been shown to be important in T-cell development and regulation and in immune privilege. We hypothesized that FasL expr ession by renal allografts might provide protection from rejection. Me thods. The murine Fast cDNA was cloned into a replication-defective ad enovirus (AdV-FasL). Protein expression was confirmed by immunostainin g of AdV-FasL-transduced HeLa cells. Allogeneic kidney transplants wer e performed between WF (RT1(u)) donors and Lewis (RT1) recipients. Don or kidneys were perfused in situ with saline alone (control), or 9x10( 9) plaque-forming units of AdV-FasL. One native kidney was removed at the time of transplant and the other at 6 or 7 days. Uremic death was the endpoint, and deaths within 7 days of transplant were excluded. Tr ansduced allografts were stained for Fast expression using a monoclona l antibody and tested for Fast mRNA production by reverse transcriptas e-polymerase chain reaction and Northern blotting. Results. Immunostai ning of AdV-FasL-transduced allografts demonstrated efficient gene tra nsfer lasting approximately 2 weeks, and FasL mRNA production in the A dV-FasL-transduced allografts was confirmed by Northern blotting and r everse transcriptase-polymerase chain reaction. Mean survival of anima ls with AdV-FasL-transduced renal allografts was 27.8 days vs. 11.6 da ys in control animals (P<0.05). Conclusions. (1) Adenoviral vectors ca n successfully transduce rat kidneys with the Fast cDNA. (2) Fast gene transfer prolongs rat renal allograft survival.