Impaired Fas-Fas Ligand Interactions Result in Greater Recurrent Herpetic Stromal Keratitis in Mice
Infection with HSV-1 induces functional Fas ligand. Corneas were infected with HSV-1, KOS strain, for 24 hours at which point [3H]Thymidine labeled L1210-Fas cells (2 × 104) were cultured in contact with the corneal epithelium in vitro for 20 h at 37°C. In some cultures the chimeric protein Fas-Fc (10 μg/mL) or TNFR1-Fc (10 μg/mL) was included for the entire incubation period. The amount of apoptotic cell death was determined by calculating percent of DNA fragmentation. Each value represents the mean of three replicate cultures ± SEM, and each culture condition was performed at least three times. Infected corneas displayed significantly greater cell death than did uninfected corneas (). Addition of Fas-Fc significantly reduced cell death when compared to either HSV alone () or HSV + TNFR1-Fc ().