ORIGINAL RESEARCH

Comparison of the oncolytic activity of recombinant vaccinia virus strains LIVP-RFP and MVA-RFP against solid tumors

About authors

1 Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia

2 Moscow Institute of Physics and Technology, Dolgoprudny, Russia

3 Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia

Correspondence should be addressed: Anastasia V. Lipatova
Vavilova, 32, Moscow, 119991, Russia; moc.liamg@vnaavotapil

About paper

Funding: the development of oncolytic viruses and in vitro experiments were supported by the Russian Science Foundation (Russian Science Foundation grant № 20-75-10157); in vivo experiments were also supported by the Russian Science Foundation (Russian Science Foundation grant № 22-64-00057).

Author contribution: Ya Shakiba — literature analysis, pre-analytical work, in vitro and in vivo experiments, analysis and interpretation of data, preparation of figures and graphs; ER Naberezhnaya — in vitro experiments, data analysis and interpretation; D. V. Kochetkov — animal care, data interpretation; GM Yusubaleva — data visualization, manuscript editing; PO Vorobyev — production of preparative quantities of the virus for in vivo studies; VP Baklaushev — study planning, preanalytical stage of work, data analysis; AV Lipatova — research management, design development of recombinant strains, data interpretation, editing the manuscript.

Compliance with ethical standards: the study was approved by the ethics committee of the EIMB RAS (protocol № 3 dated October 27, 2022). Experiments carried out in accordance with Directive 2010/63/EU of the European Parliament and of the Council of Europe on the protection of animals used for research.

Received: 2023-02-20 Accepted: 2023-04-02 Published online: 2023-04-28
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Fig. 1. Characterization of recombinant LIVP-RFP and MVA-RFP strains in vitro. A. Schematic of the plasmid vector used in the development of the LIVP-RFP and MVA-RFP strains. B, C. Fluorescence microscopy of HEK293T cells infected with the recombinant LIVP-RFP strain. D, E. Fluorescence microscopy of HEK293T infected with MVA-RFP (×100 magnification)
Fig. 2. Cytotoxicity of recombinant LIVP-RFP and MVA-RFP strains in various tumor cell cultures. BHK-21, B16, CT26 and 4T1 cells were infected with MOI 1 and 10 of LIVP-RFP and MVA-RFP viruses and cell viability was assessed using the MTT assay at 24, 48 and 72 hours post-infection. Statistical analysis was performed using a t-test; * — p < 0.05 and * * — p < 0.01 indicate significance.
Fig. 3. Replication efficiency of viral strains in cell lines BHK-21, B16, CT26, 4T1 infected with MOI 1 and 10 LIVP-RFP and MVA-RFP based on the results of flow cytofluorometry after 24 and 48 h. The y-axis shows the number of cells in percent expressing RFP. Statistical analysis was performed using a t-test; * — p < 0.05 indicate significant
Fig. 4. Dynamics of changes in tumor volume in mice with allografts of colon carcinoma CT26, breast carcinoma 4T1, and melanoma B16 after treatment with recombinant strains of LIVP-RFP or MVA-RFP. Tumor measurements were taken every two days after treatment. The symbol † indicates the euthanasia of the animal. Statistical analysis was performed using a t-test; * — p < 0.05; ns — no statistically significant differences
Fig. 5. Kaplan-Meier survival curves in experimental subgroups of mice with allografts of adenocarcinoma CT26, 4T1, and melanoma B16 after two intratumoral injections of recombinant LIVP-RFP or MVA-RFP viruses