Abstract
Purpose: :
To study IL–6 secretion and TLR–3 and –9 gene expression in corneal cells with HSV DNA transfection and HSV–anti–HSV IgG immune complex (IC) treatment
Methods: :
Human corneal epithelial cells (HCE) and primary human corneal fibroblasts (HCRF) were transfected with HSV DNA or treated with IC. Gene expression of TLR–3 and –9 in these cells were quantitated by real time PCR. Supernatants were assayed for IL–6 by ELISA. HCRF transfected with HSV DNA were treated with the following reagents:TLR–9 inhibitory oligomer(iODN:TTAGGG) or PI3–kinase inhibitor (LY294002). To the selected monolayers treated with iODN, anti–TLR–3 antibody was added. After 24 hours, supernatants were assayed for IL–6.
Results: :
When HCE and HCRF were transfected with HSV DNA or treated with IC, TLR–3 and –9 gene expression were augumented. Transfected or IC treated HCRF released greater amount of IL–6 than HCE. Maximum IL–6 release was obtained when HCRF were transfected with HSV–1 McKrae or MP strain DNA or treated with IC. Treatment of HCRF transfected with McKrae DNA with iODN, inhibited IL–6 release dose dependently. When anti–TLR–3 antibody was combined with iODN, inhibition of IL–6 release enhanced and reached 80%. Further inhibition of IL–6 release was obtained using PI3–kinase inhibitor. These results indicated that IL–6 release from HCRF is at least in part mediated by TLR–3 and –9.
Conclusions: :
HSV DNA and IC enhanced IL–6 release from corneal fibroblasts. These phenomena were mediated via augumented TLR–3 and –9 gene expression.
Keywords: herpes simplex virus • keratitis • cytokines/chemokines