Induction of lymphocyte apoptosis in rat liver allograft by adenoviral gene transfection of human interleukin-10.

BACKGROUND/AIMS: Gene therapy can provide a possible avenue in organ transplantation to treat acute allograft rejection. This study was designed to investigate the effect of adenovirus-mediated human IL-10 (hIL-10) gene transfer on the apoptosis of infiltrating lymphocytes and examine the efficacy of hIL-10 gene transfer in combination with subtherapeutic doses of cyclosporine A (CsA) in a rat liver transplantation model.

METHODS

Inbred male DA and LEW rats were used for liver donors and recipients, respectively. The rats were divided into saline, Ad-lacZ, CsA, Ad-hIL-10 and Ad-hIL-10 + CsA groups. Graft survival, histopathological, enzyme-linked immunosorbent assay, reverse transcriptase-polymerase chain reaction and flow cytometry were performed in liver specimens obtained from different time points after transplantation in the 5 groups.

RESULTS

Ad-hIL-10 pretreatment inhibited allograft rejection, prolonged the survival of hepatic allografts, and downregulated the expression of IFN-gamma and IL-2 mRNA, with simultaneous upregulation of IL-4 mRNA. In addition, Ad-hIL-10 pretreatment upregulated the expression of Fas mRNA in the isolated graft-infiltrating lymphocytes and induced graft-infiltrating lymphocyte apoptosis. A single subtherapeutic dose of CsA acted synergistically with it.

CONCLUSION

hIL-10 gene therapy induced alloreactive lymphocyte apoptosis via Fas/FasL pathway. hIL-10 gene transfection in combination with subtherapeutic doses of CsA facilitates the long-term survival of liver grafts.