Fig. 6: Conditionally replicating vaccinia virus as a safe alternative for vaccine development.
From: Synthetic virology approaches to improve the safety and efficacy of oncolytic virus therapies
a–e Evaluation of the safety of the conditionally replicating virus. Mice were injected intravenously with either control vaccinia virus at 1E6 pfu or VV-TetR-iD13 at 1E7 pfu. Formation of pox lesions on mice feet and tails was monitored (a) and quantified (d) 5 days post i.v. injection. IVIS imaging was performed on days 5 and 7 post virus injection (b) and body weight were measured at consistent intervals (c). Organs were harvested at day 10 and tissues processed for quantifying viral titer (e). f, g Mice were intraperitoneally injected with 1E6 pfu of control and vaccine viruses with serum collected at days 7, 14, and 21. Subsequently, a RBD ELISA assay was performed and endpoint titer for all the samples and days were quantified (f). A SARS-CoV-2 pseudotyped neutralization assay was performed on day 14 samples (g). h, i Mice were intraperitoneally injected with 1E6 pfu of the VV-S-Hexapro-TetR-iD13 in the presence or absence of 625 mg/kg Dox in the diet for two days. Serum was collected at day 14 and was used for an RBD ELISA to quantify the normalized ELISA absorbance versus dilution factor in different conditions (h). Serum was also used for a SARS-CoV-2 pseudotyped neutralization assay. j, k Mice were intraperitoneally injected with 1E6 pfu of the VV-S-HexaPro-TetR-iD13 or MVA-S-HexaPro. Serum was collected at day 14 and was used for a RBD ELISA to quantify the normalized ELISA absorbance versus dilution factor in different conditions (j). Serum was also used for a SARS-CoV-2 pseudotyped neutralization assay (k). S and S-HexaPro represent SARS-CoV-2 wild-type spike protein and proline stabilized version of the SARS-CoV-2 spike respectively. Data indicate means ± SD of five (d, f–j) or ten (e) biological replicates. Data indicate means ± SEM of five (c) biological replicates. ns P > 0.05, *P < 0.05 **P < 0.003841, ***P < 0.000125, ****P < 0.001 in unpaired two-samples t-test. Source data are provided as a Source Data file.
