SUPPRESSION OF GRAFT-REJECTION IN RAT KERATOEPITHELIOPLASTY BY ANTERIOR-CHAMBER INOCULATION OF DONOR LYMPHOCYTES

A newly developed model of keratoepithelioplasty (KEP) in the rat was used to analyze the effect of anterior chamber-associated immune devia tion on the suppression of corneal allograft rejection. The right eyes of Fisher rats received an anterior chamber (AC) injection of lymphoc yte suspension from Dark Agouti (DA) rats (DAL group) or phosphate-buf fered saline (positive control group). Seven days later, DA corneal le nticules were grafted onto both eyes of the recipients. Delayed type h ypersensitivity (DTH) was also assessed in another group of Fisher rat s receiving an AC injection of DA lymphocytes in the right eye. Within 15 days, 88% of the eyes in the positive control group demonstrated v igorous epithelial edema, a large area of epithelial defect, and vascu larization. By contrast, in the DAL group, only 37% of the eyes showed slight epithelial edema, a small area of epithelial defect, and rare vascularization; suppression of graft rejection was observed in both e yes. DTH assay demonstrated significant suppression in the recipients of the AC injection of donor-type lymphocytes. This study indicates th at the AC injection of donor-type lymphocytes prior to corneal graftin g suppresses allograft rejection in the rat KEP model, correlative wit h the suppression of DTH reaction.