Expression of a mucin-like glycoprotein produced by ocular surface epithelium in normal and keratinized cells

We previously characterized a monoclonal antibody (H185) to a mucin-like glycoprotein produced by human ocular surface epithelium. In the current study, we used H185 to investigate the pattern of the mucin-like glycoprotein in normal and keratinized apical cells of the ocular surface epithelium.

We compared the cell characteristics and the pattern of H185 binding in cytologically and immunohistochemically stained samples of apical cells of conjunctival surface epithelium from 20 normal subjects and six patients before and after treatment for superior limbic keratoconjunctivitis.

In the superior bulbar conjunctiva of normal subjects, the intensity with which H185 antibody bound to apical surface epithelial cells varied, with areas of high-, medium-, and low-intensity binding occurring in a mosaic pattern. This mosaic pattern, and presumably expression of the mucin-like glycoprotein, was absent or remarkably reduced in keratinized cells obtained from patients with superior limbic keratoconjunctivitis before treatment. However, the pattern of H185 binding was normal in samples obtained 2 months after the start of treatment for superior limbic keratoconjunctivitis, and cells had recovered their normal small, round appearance.

When they are keratinized, apical cells of the ocular surface epithelium are altered in appearance and lack the normal mosaic pattern of expression of a mucin-like glycoprotein.