Obtaining highly selective aptamers to the VV-GMCSF-Lact oncolytic virus. Theoretical and experimental approaches

Dymova, M.A., Kuligina, E.V., Richter, V.A., (...), Kichkailo, A.S., Zamay, T.N.// Siberian Medical Review//


Introduction. Destruction of malignant tumours with oncolytic viruses is one of the most effective and safe methods of antitumor therapy. To gain access to tumour cells, the virus must circulate in the bloodstream for a long time, avoiding the action of the immune system. However, when a virus is introduced into the body, it provokes the production of virus-neutralising antibodies that reduce its antitumor effect. The most effective way to protect a virus from antibodies that neutralise it is to screen it: in particular, using selective DNA aptamers. The aim of the research. Using experimental methods and theoretical calculations, to develop DNA aptamers suitable for creating an antitumor drug based on the VV-GMCSF-Lact oncolytic virus, which effectively screen viruses and can protect them from virus-neutralising antibodies. Material and methods. Modelling of the secondary structures of aptamers was performed using the mFold program for nucleic acid folding, modelling of the corresponding spatial full-atom structures of aptamers was performed using the SimRNA and VMD programs. Molecular dynamics calculations were carried out using the GROMACS 2018.8 software package. Cluster analysis of the obtained molecular dynamic trajectories was performed using the VMD program. Binding of Cy5-modified aptamers to the virus was assessed using flow cytometry on a BD FACSCanto II cytometer (Becton Dickinson, Franklin Lakes, New Jersey, USA).

Results. Modification of aptamers experimentally obtained using the SELEX technology made it possible to obtain five truncated oligonucleotides NV1t_72, NV4t_64, NV4t_53, NV14t_41, and NV14t_57, which screen the oncolytic virus VV-GMCSF-Lact, the most effective of which was the NV14t_57 aptamer. Theoretical calculations have shown that the affinity of aptamers is determined by their three-dimensional structure, which depends on the method of modification.

Conclusion. A highly selective aptamer NV14t_57 has been obtained, which is the most promising candidate for further work on the creation of a drug for antitumor therapy of oncological diseases based on the VV-GMCSF-Lact oncolytic vaccinia virus