Журнал микробиологии, эпидемиологии и иммунобиологии (Dec 2022)

Comparative study of the biological properties of influenza А virus mutants obtained by site-specific mutagenesis and the live influenza reassortant vaccine variant

  • Bogdan S. Cherepovich,
  • Artem A. Rtishchev,
  • Irina I. Akopova,
  • Olga V. Borisova,
  • Vladimir Y. Kost,
  • Nina M. Kutuzova,
  • Stanislav G. Markushin

DOI
https://doi.org/10.36233/0372-9311-239
Journal volume & issue
Vol. 99, no. 5
pp. 557 – 564

Abstract

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The aim of study was to carry out comparative investigation of biological properties of site-specific mutants of Influenza A virus and variant of live cold-adapted (CA) influenza reassortant vaccine. Materials and methods. The genetic stability of site-specific mutants (SSM) of the A/WSN/33 (H1N1) strain with ts (temperature sensitive)-mutations in polymerase genes was studied using a stress-test in MadinDarby Canine Kidney (MDCK) culture. A comparative study of immunogenicity of U2 and M26 mutants with the high genetic stability and the CA-reassortant with similar surface proteins was carried out. The increase in the antibody titer was investigated using enzyme-linked immunosorbent assay and the reaction of delayed hemagglutination. Ability of the studied viruses to induce type 1 interferon in A549 cells was determined using real-time polymerase chain reaction (real-time PCR). Results. It was shown that U2 and M26 mutants, which have 3 ts-mutations or more in polymerase genes have high genetic stability. It was found that U2 and M26 mutants induced a higher antibody titers than the CA reassortant in mice following the intranasal immunization. The ability of site-specific mutants and CA reassortant to induce type 1 interferon was also investigated. Mutants U2 and M26 increased the level of interferon to a greater extent than the CA-reassortant. Conclusion. The data obtained indicate that SSM U2 and M26 with 3 ts-mutations or more in the genome have a significant level of genetic stability. Mutants U2 and M26 have a higher immunogenicity and a higher ability to induce interferon in comparison with the CA reassortant. These facts allow us to conclude that SSM of the influenza virus with a set of mutations in polymerase genes can be considered as promising candidates for live influenza vaccines.

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