The influence of tissue culture on corneal immunogenicity

In this study we examined whether immunization with heterotopic corneal gra ft can be suppressed by usage of cultured corneal tissue. Starting from the hypothesis that the corneal antigenicity might change during long-time sto rage, we compared, in a mouse model, the immunization obtained with fresh a nd stored corneas. Heterotopic (chest wall) mice corneal allografts were ex changed between donors and hosts: (1) mismatched at multiple minor H loci a nd (2) only H-Y mismatched animals. Median survival time (MST) of primary a nd secondary skin grafts exchanged between mentioned donors and hosts was r ecorded. Recipient mice were immunized with either: (a) tail-skin graft, (b ) fresh cornea graft or (c) corneal graft stored for three weeks in tissue culture. Three weeks later, recipients were challenged with skin graft plac ed at the opposite side of the chest wall and MST of these skin grafts was recorded. MST of secondary skin grafts in animals that had been immunized b y skin served as a control. In case of multiple minor H disparity, MST of a first-set skin graft was 12 days, as compared to 9 days in case of seconda ry skin graft (P < 0.05). MST of secondary skin graft following immunizatio n by both fresh and stored corneas was 10 days. These data suggest that sto red corneas don't loose ability to sensitize the multiple minor H disparate host. It also show that both cultured and fresh corneas, when placed in no n-privileged site, have same immunizing capacity as skin (MST of 10 and 9 d ays, respectively; P > 0.1). When only H-Y disparate animals were used, MST of a first-set skin grafts was 26 days and of secondary skin graft II days (P < 0.01). In case of H-Y disparity, MST obtained after immunization with fresh and stored corneal tissue (19 and 18 days, respectively) was signifi cantly longer as compared to skin (P < 0.05). However, no significant diffe rence in MST of secondary skin grafts between recipients of fresh (19 days) and stored corneal grafts (18 days) was recorded. According to our results , the ability of corneal tissue to immunize both multiple minor H mismatche d, as well as only H-Y mismatched host, was not influenced by storage in a tissue culture. (C) 1999 Academic Press.