Abstract
Abstract: :
Purpose: During chronic allergic eye disease (CAED) CD4+ T cells and eosinophils are found in the subepithelial conjunctival layer, although the mechanisms involved in this immunolocalization remain unclear. Our previous studies have detected Eotaxin-1, but not Eotaxin-2, in culture medium from conjunctival fibroblasts. The aim of this study was to investigate the role of conjunctival epithelial cells and fibroblasts as producers of chemokines, comparing primary conjunctival epithelial cells from atopic kerato-conjunctivitis (AKC), primary conjunctival fibroblasts and a conjunctival epithelial cell line (ChWK). Methods: The effects of culturing ChWK cells and primary conjunctival fibroblasts, either alone or with IFNγ [500U/ml], TNF-α[10-20ng/ml], IL-4 [10-20ng/ml], IL-13 [10-20ng/ml] or RANTES [500ρg/ml] on Eotaxin-1, Eotaxin-2, IP-10, Mig and MCP-1 mRNA expression were investigated by RT-PCR. CCR3 expression on ChWK cells was assayed by flow cytometry. Production of IL-8 and latent TGF-ß1 was quantitated in ChWK cell culture supernatants by ELISA. Results: ChWK were induced to express CCR3 following RANTES treatment, peaking at 16 hr (unstimulated MFI=169.3±12.2; stimulated MFI=208±19; ρ< 0.05), but not by TNF-α [20ng/ml; 0-24 hours stimulation]. RT-PCR analysis revealed that IP-10, Mig and MCP-1 were constitutively expressed on ChWK. IL-4 decreased IP-10 mRNA expression, but TNF-α increased IP-10 mRNA expression, and IL-13 increased Mig mRNA expression. IL-8 was constitutively produced by ChWK, both normal and AKC conjunctival epithelial cells, and was upregulated in fibroblasts by TNF-α. TGF-ß1 production was significantly upregulated by both IFN-γ (untreated 78.2 ± 7.3 pg/ml; IFN-γ treated 123.2±3.8; ρ=0.003) and TNF-α (TNF-α treated 141.7±4.8; ρ=0.0004). Conclusions: Cytokines were able to regulate chemokines and CCR3 expression by conjunctival epithelial cells and fibroblasts, suggesting a potential role for these cells in recruiting T cells to the subepithelial layer during CAED.
Keywords: conjunctiva • immunomodulation/immunoregulation • cytokines/chemokines