Suppressed cellular cytotoxic response in rats bearing skin implants in the anterior chamber of the eye.

The ability of allogeneic skin implants placed into the anterior chamber of the eye to elicit splenic cell cytotoxicity was studied in Le rats. No cellular cytotoxicity was detected in the rats bearing either small (0.5 mm2) or massive (greater than 5 mm2) skin implants, but the injection of allogeneic splenocytes into the anterior chamber readily induced cytotoxic spleen cells. Since the presence of an allogeneic skin implant in the anterior chamber appeared to suppress the production of host cytotoxic cells, studies were performed to determine whether the host's cellular cytotoxic response to an orthotopic allogeneic skin graft could be suppressed by the presence of the implant. It was found that the production of splenic cell cytotoxicity was severely suppressed in rats that were implanted 8-21 days before receiving an orthotopic skin graft from the implant donor strain. No suppression occurred if the implant and the skin graft were performed on the same day. The suppression was specific for the alloantigens present on the implant in the anterior chamber because third party implants did not suppress cytotoxicity. It appears that alloantigen presentation via the anterior chamber of the eye can modulate the host's cellular immune response to systemically administered alloantigens.