Induction of class II (Ia) alloantigen expression on corneal endothelium in vivo and in vitro.

Class II (DR or Ia) alloantigens are potent inducers of cell-mediated immune responses. However, the expression of Class II alloantigens on corneal cells, except for Langerhans cells within the limbal epithelium, has not previously been described. We have induced Ia expression on cultured rabbit corneal endothelial cells with human immune interferon, and have demonstrated numerous Ia-positive cells in the endothelium during primary immunogenic uveitis in vivo. Cultured endothelial cells which had been treated with immune interferon in vitro functioned as stimulator cells in a mixed leukocyte reaction. Induction of Class II alloantigen expression by lymphokines may potentiate corneal allograft rejection.