RsTβRII-IFN-γ dose-dependently protects L929 cells from infection of VSV. 1 × 104/well L929 cells were added into a 96-well plate. Serial dilutions of RsTβRII-IFN-γ fusion protein were added into the assay plate except for the normal and viral controls after the cells adhered to wells. 3 hours later, 25 μl of VSV was added into each well except for the normal controls. The cells were incubated for 24 hours totally and 10 μl MTT (5 mg/ml) were added into each well 4 hours before the end of the culture. The cells were lysed in 150 μl DMSO. The absorbance at 540 nm was measured and percent protection of L929 from infection of VSV was calculated. Each assay was carried out in triplicate. 1: original RsTβRIFN-γ fusion protein; 2~10: 2 × serial dilutions of 1; VSV Control: L929 challenged by VSV.