WNV differentially modulates the expressions of pro-inflammatory cytokines in human neuroblastoma cell line, SK-N-SH. (A) cDNA templates from mock- and WNV-infected SK-N-SH cells from days 1 to 3 after infection were used to determine the fold-change of IL-1β, -6, -8, and TNF-α by qRT-PCR. Changes in the levels of pro-inflammatory cytokines were first normalized to the GAPDH gene and the fold-change in infected cells as compared to corresponding controls was calculated. Data represents mean ± SD of five independent experiments conducted in duplicate. (B) Levels of IL-1β, -6, -8, and TNF-α in culture supernatants were determined by ELISA. WNV (MOI-1) infection significantly increased the production of pro-inflammatory cytokines. The data expressed are the mean concentration (pg/ml) ± SD of the amount of IL-1β, -6, -8 or TNF-α, secreted in the supernatant and is representative of three independent experiments. *p < 0.05. **p < 0.001.