The effect of interleukin-1 on cytokine gene expression by human corneal epithelial cells

The purpose of this study was to characterize the pattern of cytokine gene expression by human corneal epithelial cells (HCEC) in response to interleukin-1 (IL-1). Primary cultured HCEC (P-HCEC) or SV40 transformed HCEC (SV40-HCEC) were treated for 6 hr with serum-free growth-media alone or with recombinant human IL-1β or IL-1α (10 ng ml−1). 33P labeled cDNA was generated from total RNA, then hybridized to a human cytokine expression array. An autoradiograph was generated for each experimental condition and results analysed semi-quantitatively. Reverse transcription polymerase chain reaction (RT-PCR) was performed to detect mRNA for IL-8, growth related oncogene-β (GRO-β), intercellular adhesion molecule (ICAM)-1 and Ephrin A5. P-HCEC and SV40-HCEC demonstrated comparable cytokine profiles. For P-HCEC (n=2) the expression of 35 genes was upregulated or only detectable following IL-1β treatment whereas the expression of nine genes was downregulated or undetectable after IL-1β treatment. In SV40-HCEC (n=3), the expression of 48 genes was upregulated or only detectable following IL-1β treatment and the expression of 10 genes was downregulated or undetectable after IL-1β treatment. Some genes that demonstrated increased expression included cadherin-5, ICAM-1, GRO-α, GRO-β, GRO-γ, Activin A (bA subunit), tumor necrosis factor-α, IL-6, and IL-8. Genes that showed decreased expression included the chemokine receptor—CXCR-4, ciliary neurotrophic factor (CNTF), c-kit ligand, Ephrin A5, G-protein coupled receptor RDC-1 and FGF family FGFR2. Bayesian analysis of the SV40-HCEC data (n=3) revealed the expression of 15 genes that were significantly (p