Fig. 1

Adipose-derived stem cells provide potent amplification of vaccinia virus that can be restricted by the induction of IFN-mediated anti-viral state. a, b Both type I and II interferons protect ADSC against vaccinia virus (VV). 50,000 RM35 ADSC were infected in a 12-well plate with 10,000 pfu L14 VV, in the presence of increasing doses (0.08 to 20 ng/ml) of IFNγ or IFNβ added at the time of infection or 24 h earlier (IFNβ/γ 24 h). Fluorescence imaging (a) and plaque assays (b) at 48 h post infection show that a 24 h-pretreatment with both types of interferon is more effective at conferring protection. c Stability of the IFNγ-induced anti-viral state. 100,000 RM20-eGFP ADSC were infected in a 12-well plate with 100,000 pfu L14 VV and incubated for up to 4 days. The ADSC were either untreated, (−) IFNγ CTRL, or pre-treated with 20 ng/ml of IFNγ for 24 h administered 1, 2, or 3 days prior to virus infection. Plaque analysis shows significant virus amplification by the stem cells versus the dose administered, VIRUS INPUT, or remaining after co-culture in medium with no stem cells, VIRUS ALONE. The ability of the stem cells to amplify the virus was completely abrogated by interferon pretreatment as compared to the no interferon control group, (−) IFNγ CTRL. Bars represent duplicate measurements ± SD. Statistically significant differences (Student T-test, p < 0.05) based on duplicates versus (−) IFN CTRL are marked with asterisks