Figure 7. In vitro growth properties of rescued WT and ΔNS4 viruses during interferon treatment.

CPT-Tert cells were treated (solid line) or mock treated (dashed line) with 1000 AVU/ml of interferon (Tau, IFNT or Universal, UIFN) for 20 h prior and 2 h after being infected by BTV-8 (dark red, square), BTV8-ΔNS4 (red, triangle), BTV-1 (blue, square) and BTV1-ΔNS4 (light blue, triangle) viruses. Cells were infected at a MOI of 0.01. Supernatants were collected at 24, 48 and 72 h after infection, and then titrated on BSR cells by limiting dilution analysis and virus titers expressed as log₁₀ (TCID₅₀/ml). In parallel, each virus preparation was also re-titrated by limiting dilution analysis to control that equal amounts of input virus was used in each experiment. This experiment was performed three times, each time in duplicate.