The Expression of TLR3 and Cytokines Induced by Poly I:C in Human Retinal Pigment Epithelial Cells

ABSTRACT

In this study, we examined the expression of Toll-like receptor3 (TLR3) by human retinal pigment epithelial cells (RPE) and determined whether exposure to the TLR3 agonist polyinosinic-polycytidylic acid (poly IC) would induced the expression of cytokines in these cells. RT-PCR revealed that TLR3 was constitutively expressed in human RPE, and its expression was increased by treatment with poly IC. After treatment with poly IC, we determined the expression levels of pro-inflammatory cytokines in human RPE using RT-PCR and ELISA. We demonstrated that poly IC treatment increased the production of TNF-alpha, IL-6, and IL-8 in human RPE. Upon exposure to poly IC, human RPE initiated antiviral response resulting in the induction of IFN-beta mRNA expression and 2',5'-oligoadenylate synthetase mRNA expression. These results suggest that human RPE may participate in ocular defense mechanism against viral infection through TLR3.