Unmodified controls were also performed. Graft survival was assessed by corneal clarity and rejection was confirmed histologically. Results In organ-cultured corneas, expression of anti-CD4scFv was detected at 2 days post-transduction with the adenoviral vector, compared with 5 days post-transduction with the lentivector, and was 10-fold higher from the former. More inflammation was observed in Ad-CD4scFv-modified allografts than in Lv-CD4scFv-modified grafts at 15 days postsurgery (p=0.01). The median time to rejection for unmodified, LV-eYFP and Ad-CD4scFv grafts was day 17, compared with day 22 for Lv-CD4scFv grafts (p≤0.018). Conclusion Donor corneas transduced with a lentiviral vector carrying anti-CD4scFv cDNA showed a modest but significant prolongation in graft survival compared with unmodified, Lv-eYFP and Ad-CD4scFv grafts. However, rejection still occurred in all Lv-CD4scFv grafts, indicating that sensitization may have been delayed but was not prevented.