AIM:Through the establishment of penetrating keratoplasty model of rats, to detect the role and its mechanism of immature dendritic cells with IL-10 gene modified.

METHODS:Allogeneic penetrating corneal transplantation in rat model was performed. SD rats were randomly divided into positive control group, GFP-DC group, 8-DC and IL-10-GFP-DC group. At 3d before keratoplasty, the rats were given tail intravenous injection with the same amount of PBS, bone marrow 8-DC(DC had cultured for 8d)from donor Wistar rats, GFP-DC after 48h transfection and IL-10-GFP-DC. Rats were observed under slit-lamp for corneal graft cases every day, and recorded rejection index and corneal graft survival time. At 14d after keratoplasty, pathologic and immunohistochemical examinations were performed.

RESULTS:Compared with GFP-DC group and 8-DC group, corneal graft survival time of IL-10-GFP-DC group was significantly longer(P<0.01); at 14d after keratoplasty, corneal opacity, edema, neovascularization and rejection index of IL-10-GFP-DC group were significantly lower(P<0.01). Pathological examination showed that in the three experimental groups corneal inflammation was lighter than the positive control group without significant central graft neovascularization. Immunohistochemistry showed: compared to the positive control group, GFP-DC group and 8-DC group, CD4⁺, CD8⁺, CD25⁺, IL-2⁺, NK⁺ and NF-κB⁺ positive cells in IL-10-GFP-DC group were lower(P<0.01).

CONCLUSION: After donor-derived immature dendritic cells pretreated, corneal graft survival was significantly prolonged, successfully induced corneal transplantation tolerance. CD4⁺, CD8⁺, CD25⁺, IL-2⁺, NK⁺ and NF-κB⁺ positive cells are involved in corneal allograft rejection regulation, IL-10-GFP-DC may reduce CD4⁺, CD8⁺, CD25⁺, IL-2⁺, NK⁺ and NF-κB⁺ positive cell infiltration, inhibit corneal transplant rejection.