Analysis of corneal and conjunctival microenvironments using monoclonal antibodies

Purpose. The authors phenotypically compared epithelial and nonepithelial components of human corneal and conjunctival microenvironments using a panel of monoclonal antibody reagents that included markers of epithelial cell maturation, markers of mesodermal-derived fibrous tissue and vessels, markers of specific keratins, and markers of major histocompatibility complex Class I and II antigens. Methods. Corneoscleral rims obtained after trephination of the donor button for use in penetrating keratoplasty procedures were studied. Results. A comparison of cornea and conjunctiva with antiepithelial and antikeratin antibodies demonstrated that corneal and conjunctival keratinocytes undergo similar antigenically defined pathways of maturation. However, the reactivity of antibody 12/1-2 (antibody against low molecular weight keratins) with conjunctival but not corneal basal cells suggested differences in keratin expression between the two epithelial types. Using antibodies against major histocompatibility complex Class I and II antigens, it was demonstrated the two tissues were similar with Class I determinants found on all epithelial, stromal, and endothelial cells, and Class II determinants found on Langerhan's cells, vessels, and a subset of stromal cells. Conclusions. The availability of tissue-specific markers of epithelial and nonepithelial components of the cornea and conjunctiva should be of use in the study of the roles the ocular microenvironment might play in the pathogenesis of ocular inflammatory diseases.