The immunomodulatory role of human conjunctival epithelial cells.

Purpose: To characterize phenotypically the primary epithelial cells obtained from normal bulbar conjunctival biopsy specimens and a human conjunctival epithelial cell line (Wong-Kilbourne derivative of Chang conjunctiva; ChWK) with regard to their immunostimulatory function.

Methods: The effects on expression of HLA-DR and costimulatory molecules (CD80, CD86, ICAM-1, and CD40) on normal conjunctival epithelial cells and ChWK treated with various cytokines (IFN-gamma, TNF-alpha, IL-4, and IL-13) were determined using flow cytometry and confocal microscopy.

Results: Epithelial cells were successfully grown from conjunctival explants and cultures passaged three times, while retaining their cell surface markers. At least 97% of primary epithelial cells (n = 10) and more than 96% of ChWK cells (n = 10) were cytokeratin positive by flow cytometry and immunocytochemistry and demonstrated epithelial cell morphology. Both primary conjunctival epithelial cells and ChWK had a low basal expression of HLA-DR and ICAM-1, and both were upregulated by IFN-gamma. For ChWK cells, CD80 and CD86 were constitutively expressed at low levels. CD80 was significantly upregulated after IFN-gamma treatment (P = 0.043), whereas IL-4 induced a significant upregulation of CD86 (P = 0.039). Treatment with IL-13 and TNF-alpha did not induce significant effects.

Conclusions: The ability of conjunctival epithelial cells to express costimulatory molecules suggests a proinflammatory role for conjunctival epithelial cells.