TNF Receptor Secretion After Ex Vivo Adenoviral Gene Transfer to Cornea and Effect on in Vivo Graft Survival

Purpose: To explore the potential for adenovirus-mediated ex vivo gene transfer of a soluble tumor necrosis factor (TNF) receptor and evaluate the effect of transplanting the adenovirally transplanted corneas in vivo.

Methods: Rabbit corneal segments were transfected with replication-deficient adenovirus (AdTNFR) encoding a soluble TNF receptor fusion protein (TNFR-Ig). Production of TNFR-Ig was measured by using ELISA and bioassay. Corneas were transfected ex vivo with AdTNFR and then transplanted in vivo. Survival of AdTNFR-transfected corneas was compared with that of those treated either with a null vector control adenovirus (Ad0) or nontransfected control corneas.

Results: Ex vivo production of a molecule with TNF blocking bioactivity from AdTNFR-transfected corneas was demonstrated over a period of 4 weeks. Transplanted AdTNFR-transfected corneas showed a marginally increased survival time in vivo over nontransfected control corneas, but a significantly increased survival time over Ad0-treated control corneas. Ad0 treatment of corneal allografts before transplantation had a proinflammatory effect and accelerated the onset of corneal endothelial rejection.

Conclusions: Adenoviral gene transfer is an effective means of transferring a gene encoding soluble TNFR-Ig to corneal endothelium, and ex vivo production of a biologically active secreted molecule was demonstrated for 4 weeks. However, in vivo, only a marginally increased survival was seen compared with control corneas. The introduction of this transgene using a less immunogenic vector may demonstrate prolongation of corneal allograft survival.