Figure 4. Effects of viral RNA and viral/bacterial DNA on gene expression and the secretion of angiogenic growth factors. The mRNA levels (B, C, E) 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 fold of unstimulated controls. The levels of VEGF-A₁₆₅ and bFGF proteins (D) were determined with ELISA in the cultured media of cells stimulated for 6 and 24 h, and are expressed in percent of unstimulated controls (100%). A: Expression of growth factor 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: Near-confluent cultures were stimulated with poly(I:C; 500 µg/ml). C. Dose-dependent effect of poly(I:C). Confluent cultures were stimulated with poly(I:C; 100 and 500 µg/ml, respectively). E: 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. ●, p<0.05.