A new epithelial cell type in the human cornea

• Published in: Investigative ophthalmology & visual science Vol. 34; no. 6; pp. 1983 - 1990
• Main Authors: Lauweryns, B, van den Oord, JJ, De Vos, R, Missotten, L
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.05.1993; Association for Research in Vision and Ophtalmology
• Subjects: Aged; Aged, 80 and over; Antibodies, Monoclonal; Biological and medical sciences; Cornea - cytology; Cornea - metabolism; Cornea - ultrastructure; Epithelial Cells; Epithelium - metabolism; Epithelium - ultrastructure; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Humans; Immunoenzyme Techniques; Intermediate Filaments - metabolism; Intermediate Filaments - ultrastructure; Keratins - metabolism; Middle Aged; Phenotype; Vertebrates: nervous system and sense organs; Vimentin - metabolism; Immunohistochemistry; Human; Eye; Vimentin; Visual system; Cornea; Intermediary filament; Stem cell; Epithelial cell; Histology; Electron microscopy
• ISSN: 0146-0404; 1552-5783

To study the expression of intermediate filaments in the human cornea. Light and electron microscopic and immunohistochemical studies were performed on 20 corneas from subjects of various ages. A hitherto unrecognized epithelial cell population emerged from the immunohistochemical studies. Epithelial cells were invariably present in the superior cornea, whereas the nasal, temporal, and inferior segments almost lacked these cells. They were situated at the transition between peripheral cornea and limbus, and occurred as small groups in the basal epithelium. On electron microscopy, they were recognized by their marginated nuclear chromatin, large nucleoli, prominent bundles of intermediate filaments, and numerous hemidesmosomes and desmosomes. Immunohistochemistry on frozen sections revealed a unique intermediate filament make-up: ie, strong co-expression of vimentin and cytokeratin 19; other intermediate filaments, including cytokeratins 3, 4, 6, 7, 8, 10, 13, and 18 were negative. Finally, the cells lacked ultrastructural and immunohistochemical features of melanocytes, neuroendocrine cells, Langerhans' cells, and leukocytes. A new epithelial cell type in the human cornea is described with characteristic morphologic and immunohistochemical features. According to their particular segmental distribution, restricted localization at the junction between cornea and limbus, and expression of an "early" intermediate filament profile, it is tempting to speculate that they represent stem cells of the human cornea. Further studies are aimed to characterize their phenotype and function more extensively.