Antisense oligonucleotide to SARS-Cov-2 trs gene: antiviral activity on an in vitro model and possibilities of vital and postmortem diagnosis of COVID-19. (preprint)

The data on the relevance of the 5 '-AGC CGA GTG ACA GCC ACA CAG antisense oligonucleotide for binding to the trs-gene of the SARS-CoV-2 virus, which causes the new coronavirus infection COVID-19, are presented. The high stability and conservatism of this section of the SARS-CoV-2 genome is shown, which allows it to be used as an application point for antisense oligonucleotides. By evaluating plaque inhibition, the ability of this antisense oligonucleotide with phosphorothioate and 2'-oxymethyl modification to suppress viral replication was found. The effective dosage reducing the virus titer by 50% is 3.84 mcg/ml. No toxicity was shown up to a dosage of 100 g/mL, which is more than 28.8 chemotherapeutic index. The ability of this oligonucleotide conjugated to the fluorescent dye TAMRA to detect the SARS-CoV-2 virus in the fluorescent hybridization reaction in situ in cytological preparations of nasopharyngeal smears and blood smears, as well as in histological preparations of internal tissues is shown.

Potential Opportunity Of Antisense Therapy Of COVID-19 on an in vitro model (preprint)

Data on potential effectiveness and prospects of treatment of new coronavirus infection of COVID-19 caused by virus SARS-CoV-2 with the help of antisense oligonucleotides acting against RNA of virus on an in vitro model are given. The ability of antisense oligonucleotides to suppress viral replication in diseases caused by coronaviruses using the example of SARS and MERS is shown. The identity of the initial regulatory section of RNA of various coronaviruses was found within 50 - 100 nucleotides from the 5'-end, which allows using antisense suppression of this RNA fragment. A new RNA fragment of the virus present in all samples of coronovirus SARS-CoV-2 has been identified, the suppression of which with the help of an antisense oligonucleotide can be effective in the treatment of COVID-19. The study of the synthesized antisense oligonucleotide 5`-AGCCGAGTGACAGCC ACACAG, complementary to the selected virus RNA sequence, was carried out. The low toxicity of the preparations of this group in the cell culture study and the ability to reduce viral load at high doses according to real time-PCR data are shown. The cytopathogenic dose exceeds 2 mg/ml. At a dosage of 1 mg/ml, viral replication is reduced by 5 - 13 times. Conclusions are made about the prospects of this direction and the feasibility of using the inhalation way of drug administration into the body.