FIG 8.

DHX9 overexpression negatively regulates viral RNA synthesis independently of type I IFN expression. DHX9^+/– cells and the parental HEK293T cells infected with the CHIKV-LR-5′GFP reporter virus for the indicated times were processed for qRT-PCR amplification of CHIKV (–)RNA (A) or (+)RNA (B). Noninfected cells (NI) are shown as a control. RNA levels were normalized according to GAPDH mRNA levels in the samples. Values were then normalized against an internal control, and results are expressed as arbitrary units. Analyses were performed in triplicate, and the error bars represent the standard deviations. (C) IFN-β mRNA was quantified from the same samples, as previously reported (74). GAPDH was used as an mRNA housekeeping control. Values are means of duplicates, and the error bars represent the standard deviations.