EXPRESSION OF FAS AND FAS LIGAND IN RENAL GRAFTS WITH ACUTE AND CHRONIC REJECTION IN THE RAT MODEL

The Fas system-based rejection mechanism has not been studied well in terms of cytotoxic T cell activity in graft rejection, We investigated the Fas and Fas ligand level in renal grafts with acute and chronic r ejection in a rat model using semiquantitative reverse transcription-p olymerase chain reaction (RT-PCR), Fas ligand in renal allografts was detected as early as 1 day after transplantation in an acute rejection model, It was highly expressed at day 4 and began to decline at day 6 after transplantation. In contrast, Fas ligand in normal kidneys was almost undetectable, Fas ligand in isografts was increased, but the ex pression level was much lower than in allografts, Interestingly, when Fas ligand expression began to decline in renal allografts, it increas ed in the spleens of recipients, Fas ligand expression in chronically rejecting allografts was slightly increased,but it was stronger than i n isografts, In contrast to Fas ligand gene expression, Fas was consti tutively expressed in isografts, allografts, and normal kidneys, Howev er, the Fas level in renal allografts was higher than in normal kidney s, Our data demonstrated that the Fas system might play an important r ole in acute and chronic rejection by causing apoptosis, and the splee n may eliminate the lymphocytes strongly expressing Fas ligand after c ompletion of the acute rejection.