Figure 2. Effects of viral RNA and viral/bacterial DNA on the expression of TLR2, TLR3, and TLR9 genes in RPE cells. A: Expression of TLR genes in cells cultured for 2 (1), 6 (2), and 24 h (3), as determined by RT–PCR. Negative controls (0) were done by adding double-distilled water instead of cDNA as a template. B-D: The mRNA levels were determined with real-time RT–PCR analysis after stimulation of the cells for 2, 6, and 24 h (as indicated by the panels of the bars), and are expressed as folds of unstimulated controls. B: Near-confluent cultures were stimulated with poly(I:C; 500 µg/ml). C: Confluent cultures were stimulated with poly(I:C; 100 and 500 µg/ml, respectively). D: Near-confluent cultures were stimulated with CpG-ODN (500 nM). Each bar represents data obtained in 3 to 5 independent RPE cell lines, each from a different human eye donor; experiments with each cell line were carried out in triplicate. Significant difference versus unstimulated controls: *p<0.05.