Dynamic changes of indoleamine 2,3-dioxygenase of Kupffer cells in rat liver transplant rejection and tolerance

Aims

To study the dynamic changes and the immunologic role of indoleamine 2, 3-dioxygenase (IDO) in Kupffer cells (KCs) after rat liver transplantation.

Methods

Animals were randomly divided into two groups: a rejection group (REJ; LEW to BN) and a tolerance group (TOL; BN to LEW). Liver morphological changes were observed optically with hematoxylin/eosin staining. KCs were isolated from recipients. mRNA and protein expressions of IDO were detected by real-time polymerase chain reaction and Western blotting at 1, 3, 5, and 7 days after transplantation.

Results

The levels of IDO mRNA and protein in KCs of TOL groups were similar to those in REJ groups at day 1 posttransplantation. However, the expression of IDO mRNA and protein time-dependently increased to much higher levels in the TOL than the in REJ groups at 3, 5, and 7 days posttransplantation (P < .05). The peak was observed at 7 days.

Conclusions

The IDO level of KCs was closely associated with immune tolerance induction. IDO-mediated immune modulation appears to be an attractive means to assess transplant tolerance induction.