The detection of immunologically competent cells in corneas showing an immune reaction - a simplified technique -

We wished to devise a simple in vitro test for identifying the presence of antigen sensitive lymphocytes in corneal tissue having an immunological inflammatory reaction. A number of rabbits were immunized by subcutaneous injections of human serum albumin (HSA). A final injection of the same antigen was given in the centre of the cornea to produce an immunological corneal inflammation. Other rabbits were immunized by an antigen unrelated to HSA. A non-immunological corneal inflammation was produced in another group of animals by applying sodium hydroxide. Five days after the immunogenic and non-immunogenic corneal insults, when the limbus showed vascularization, the eyes of the different groups of animals were enucleated. From each eye, small corneal discs containing a portion of the limbus were cut with a trephine. The discs (explants) were then incubated for 20-24 hours at 37 degrees C in the presence or absence of HSA or in the presence of an antigen unrelated to HSA. At the end of incubation, the extent of leucocyte migration from each explant was measured. Only in the presence of the specific antigen did leucocytes from explants of the immunized animals show marked inhibition of migration.