Paolieri F, Battifora M, Riccio AM, Pesce G, Canonica GW, Bagnasco M. Intercellular adhesion molecule-1 on cultured human epithelial cell lines: influence of proinflammatory cytokines.
The expression of intercellular adhesion molecule-1 ‘CD54 or ICAM-1’ on epithelial cells during acute or chronic inflammation may favor the interaction between epithelial cells and leukocytes expressing the natural ligands of ICAM-1, LFA-1 ‘CD11a/CD18’, and Mac-1 ‘CD11b/CD18’. We have evaluated in vitro the expression of ICAM-1 by a conjunctival ‘WK’ and an intestinal ‘1407’ human continuous epithelial cell line. Cells were cultured for 24 h in the presence or absence of IFN-γ, TNF-α, IL-1β, IL-4, IL-6, IL-8, IL-10, and TGF-Jβ1. Both epithelial cell lines showed a constitutive expression of ICAM-1. IFN-γ at 500 U/ml and TNF-α at 200 ng/ml upregulated ICAM-1 expression; IL-1β at 100 pg/ml upregulated ICAM-1 on WK cells only. Cells cultured in the presence of both IFN-γ and TNF-α exhibited a mean fluorescence intensity far greater than those cultured with IFN-γ or TNF-α alone. 1407 and WK cells were able to release soluble ICAM-1. IFN-γ and TNF-α enhanced the release of sICAM-1. IL-4, IL-6, IL-8, IL-10, and TGF-β1 did not affect either ICAM-1 expression or sICAM-1 release. In conclusion, continuously cultured human epithelial cells may express ICAM-1 on their surface and release it in culture medium. These phenomena are upregulated by proinflammatory cytokines.