[Intragraft mRNA expression in small intestinal allograft rejection].

OBJECTIVE

To investigate the changes of intragraft mRNA expression of IL-2, IFN-gamma, perforin, granzyme B during small intestinal allograft rejection in rats.

METHODS

Heterotopic small intestinal transplantation was performed with inbred rat F344/N(RT1(1)) and inbred rat Wistar/A (RT1-Ak, RT1-Ed). All recipients were divided into four groups; group I, Wistar; group II, Wistar-->Wistar; group III, F344-->Wistar; and group IV, F344-->Wistar + cyclosporine A(6 mg/kg.d-1). The grafts were harvested on POD 3, 5 and 7, All graft samples were examined histologically. The intragraft mRNA expression of IL-2, IFN-gamma, perforin and granzyme B was determined.

RESULTS

1. The histological examination showed that mild acute rejection occurred on POD 3 in group III, moderate acute rejection on POD 5, severe acute rejection on POD 7, while none of group II had histologic evidence of acute rejection. The histologic evidence of group IV indicated that cyclosporine A could effectively controll acute allograft rejection. 2. The gene expression was almost negative in group I. Only on POD 5 was the IL-2 mRNA expression of group III significantly higher than that of group II (P < 0.05). The IFN-gamma mRNA expression of group III was significantly higher than that of group II and group IV (P < 0.01) on POD 3, 5 and 7. The level of perforin and granzyme B mRNA expression was significant higher in group III than in the other two control groups only on POD 5 and POD 7.

CONCLUSIONS

IL-2, IFN-gamma, perforin and granzyme B play important roles in small intestinal allograft rejection. Detection of these molecules gene expression with RT-PCR, especially the gene expression of IFN-gamma, perforin and granzyme can become an early, specific, sensitive and clinically valuable diagnostic tool for small intestinal allograft rejection. Furthermore, anti-rejection therapy or induction of immune tolerance could be achieved by breaking down these molecules gene transcription.