The influence of tissue culture on corneal immunogenicity

In this study we examined whether immunization with heterotopic corneal graft can be suppressed by usage of cultured corneal tissue. Starting from the hypothesis that the corneal antigenicity might change during long-time storage, we compared, in a mouse model, the immunization obtained with fresh and> stored corneas. Heterotopic (chest wall) mice corneal allografts were exchanged between donors and hosts: (1) mismatched at multiple minor H loci and (2) only H-Y mismatched animals. Median survival time (MST) of primary and secondary skin grafts exchanged between mentioned donors and hosts was recorded. 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 placed 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 by 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 secondary skin graft (P<0.05). MST of secondary skin graft following immunization by both fresh and stored corneas was 10 days. These data suggest that stored 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 non-privileged site, have same immunizing capacity as skin (MST of 10 and 9 days, 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 11 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 significantly longer as compared to skin (P<0.05). However, no significant difference 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 mismatched, as well as only H-Y mismatched host, was not influenced by storage in a tissue culture.