Expression of HLA-A/B/C and -DR Locus Antigens on Epithelial, Stromal, and Endothelial Cells of the Human Cornea

Abstract

ABSTRACT We studied class I (A/B/C) and class II (DR) HLA antigens on human corneal cells with monoclonal antibodies using immunofluorescence and immunoperoxidase techniques. Cryostat sections of freshly harvested human corneas expressed class I HLA antigens on the corneal epithelium. Class II antigens were not detected on these corneal specimens, except for occasional, scattered positive cells in the peripheral corneal epithelium and stroma near the corneoscleral limbus. Corneal endothelial whole flat mounts from freshly excised human corneas were negative for class I and class II HLA antigens. In tissue culture, however, growing human corneal endothelial cells expressed class I HLA antigens. Crowing human corneal fibroblasts in tissue culture similarly were shown, through immunofluorescent techniques using monoclonal antibodies, to express class I HLA antigens. Fibroblasts and endothelial cells in tissue culture were negative for class II HLA antigens. We believe the low-to-nondetectable HLA antigen expression on central corneal stroma and endothelium may partly explain the immunological tolerance enjoyed by most corneal allografts.