Abstract
Abstract: :
Purpose: To study the relevance of a human conjunctival cell line as a model of conjunctival epithelium. We investigated and compared the effects of IFNγ and TNFα in a primary culture of human conjunctiva and in a human conjunctival cell line. Methods: A human primary conjunctival epithelium and a human conjunctival cell line (Chang conjunctival cells) were treated for 72h with 20, 200, 400 and 600U/ml IFNγ or with 1100 and 11000U/ml TNFα. Then, the expression of HLA DR, CD40, CD44, CD63, CD80, CD86, Fas receptor, E-cadherin, ICAM1, MUC1, MUC5AC, cytokeratin and vimentin were investigated by flow cytometry. Cell morphology was studied with phalloidin staining. Apoptosis was detected by flow cytometry with Annexin V and via cell cycle analysis. Results: Chang epithelium presented a more dedifferentiated phenotype in comparison to the primary culture of human conjunctival epithelium. In Chang cell line, IFNγ induced a significant level of apoptosis at concentrations of 200, 400 and 600U/ml. HLA DR and CD63 were induced at higher levels in primary epithelium than in the cell line. Other proteins were modified in a similar manner after IFNγ treatment in both systems. In the primary epithelium, TNFα induced an important upregulation of ICAM1, Fas and CD40 whereas CD44 and CD63 were significantly decreased. Conversely, only a very weak alteration of CD63 and ICAM1 were observed in Chang conjunctiva after TNFα treatment. Conclusion:TNFα and IFNγ, two inflammatory cytokines, induced different effects in both models of conjunctival epithelium. Inflammation-related molecules were highly upregulated in the primary culture and to a lesser extent in Chang conjunctiva. Thus, Chang conjunctival cell line could be considered, however with some reserves, as an in vitro model of a human conjunctival epithelium.
Keywords: 365 conjunctiva • 380 cytokines/chemokines • 413 flow cytometry