Figure 1. Viperin differentially regulates ISG expression in BMDMs and MEFs treated with type I IFN. (A-D) The effect of viperin on expression of ISGs in BMDMs and MEFs upon type I IFN treatment. The bone marrow cells isolated from WT and viperin KO C57BL/6 mice were differentiated into BMDMs in M-CSF conditioned media for 7 days. The BMDMs were washed and plated in media without M-CSF for 24 h (A, B). MEFs were isolated from these mice and immortalized (C, D). The cells were treated with or without type I IFN (1,000 U/ml) for 24 h. The mRNA expression levels of ISGs in the cells were measured by qRT-PCR and normalized to β-actin mRNA (A, C). Data are presented as mean ± SEM of triplicate samples and are representative of three individual experiments. Expression of viperin and ISG15 proteins in the cells was detected by immunoblot using anti-viperin (MaP.VIP) or anti-ISG15 antibody (B, D). GRP94 served as a protein-loading control. Quantitation of ISG15 protein level was normalized to GRP94.

^*p<0.05; ^**p<0.01; ^***p<0.001.