Figure 5.

Conversion of the trigger mIFN-β to hIFN-β protects human cells from infection. (A) Schematic representation of Conv-hIFN and ConvAmp-hIFN cells and induced protection against viral infection in presence of antagonistic viral proteins. Coloured boxes indicate constantly induced genes, white boxes indicate the situation upon viral counteraction. (B) Conv-hIFN and Conv-Amp-hIFN cells were cultured in the absence or presence of doxycycline and stimulated for 6h with 500 U/ml mIFN-β. The supernatant was harvested 24h after treatment. Human A549 cells were pre-incubated for 16 h with the different supernatants and then infected with eGFP tagged VSV for one hour (MOI 1). Viral eGFP expression was analysed 24h post infection by flow cytometry. The experiment was performed once in triplicates. (C) ConvAmp-hIFN cells were co-cultured with BFP-tagged A549 cells in a 1:5 ratio in the presence or absence of doxycycline. Cells were stimulated for 6 h with 500 U/ml mIFN-β. 16 h later these cells were infected with VSV (MOI 1) and analysed by time-lapse microscopy. Representative pictures are shown from one experiment performed in triplicates. (D) ConvAmp-hIFN cells were co-cultured with BFP-tagged A549 cells in a 1:5 ratio in the presence or absence of doxycycline. Cells were stimulated with 500 U/ml or 50 U/ml mIFN-β for 6 h. 16 h later, these cells were infected with eGFP-tagged VSV (MOI 1). Virus mediated eGFP expression was analysed 24h post infection by flow cytometry. The experiment was performed once in triplicates. (E) The Conv-hIFN and ConvAmp-hIFN cells were cultured in the presence or absence of doxycycline. Cells were infected with mCMV (MOI 1). The supernatant was harvested 24 h after infection. A549 cells were pre-incubated with the supernatants for 16 h and then infected with VSV (1 h, MOI1). Viral eGFP expression was analysed 24 h post infection by flow cytometry. The experiment was performed once in triplicates.