'Lymphocyte-defined' antigens on corneal fibroblasts

Human stromal (fibroblast) cultures were established from random, normal corneas obtained from the International Eye Bank in Baltimore. Cultures were assessed for the expression of Class I, Class II, monocyte/granulocyte and T-cell antigens before and after treatment with gamma or alpha interferon (IFN), interleukin 2, and 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA). Class I (B2 microglobulin) and monocyte/granulocyte (Leu M-1) antigens were evident before induction, natural killer cell (Leu 7) antigens were transiently expressed, and Class II (HLA-DR, Leu 10) antigens were not expressed until after induction with gamma IFN. PMA reduced the numbers of cells positive for Leu M-1 while alpha IFN and interleukin 2 had no effect on antigen expression. Kinetic studies of HLA-DR induction indicated that as little as 12 hours exposure to gamma IFN was sufficient to initiate induction and that 30% of the population was still expressing HLA-DR 7 days after removal of gamma IFN. The inducible expression of Class II antigens following lymphokine exposure may play a critical role in rejection of allografted corneas.