Establishment of a cultivated human conjunctival epithelium as an alternative tissue source for autologous corneal epithelial transplantation

PURPOSE. The corneal epithelium is essential for maintaining corneal transparency, and efforts have been made to develop improved techniques for corneal epithelial transplantation in patients with total limbal failure. We evaluated the suitability of transplanted cultivated human conjunctival epithelium ( HCjE) as a corneal epithelium replacement in rabbits with total corneal and limbal deficiency. METHODS. HCjE cells, cultivated on human amniotic membrane ( AM) to confluence and exposed to an air-liquid interface ( air-lifted), were transplanted onto denuded rabbit corneas and monitored for 2 weeks. The cultivated HCjE sheet and the engrafted epithelium were analyzed by immunohistochemistry and transmission electron microscopy ( TEM). RESULTS. The transplanted HCjE remained transparent, smooth, and without epithelial defects during the follow-up period. Both the cultivated HCjE cells and the engrafted epithelium manifested five to six layers of stratified squamous epithelium similar in morphology to normal corneal epithelium. The basal cells expressed the putative stem cell markers ( ABCG2 and P63) and hemidesmosome and desmosome component proteins. The cytokeratins ( CK4, CK13, CK3, and CK12) and MUC4 were found in the engrafted epithelium. However, MUC5AC was not expressed. The results indicate that HCjE cultivated on AM has the potential to be used as an alternative corneal epithelium. CONCLUSIONS. The transplantation of cultivated HCjE sheets is a promising technique for the treatment of eyes with limbal failure.