Journal of microbiology, epidemiology and immunobiologyJournal of microbiology, epidemiology and immunobiology0372-93112686-7613Central Research Institute for Epidemiology49110.36233/0372-9311-2019-6-21-29Research ArticleInclusion of site-specific mutations in the PB1-gene of a virulent A/WSN/33 (H1N1) strain of influenza A virus changes its phenotypic characteristicsKostV. Yu.Moscow,115088, Russiafake@neicon.ruhttps://orcid.org/0000-0003-1703-2685SukhovaO. A.Moscow,115088, Russiafake@neicon.ruhttps://orcid.org/0000-0002-5299-003XAkopovaI. I.Moscow,115088, Russiafake@neicon.ruhttps://orcid.org/0000-0003-1795-4356GorbachevaE. O.Moscow,115088, Russiafake@neicon.ruhttps://orcid.org/0000-0002-4347-1684LisovskayaK. V.Moscow,115088, Russiafake@neicon.ruhttps://orcid.org/0000-0002-5119-877XRtishchevA. A.Moscow,115088, Russiafake@neicon.ruhttps://orcid.org/0000-0002-4212-5093MarkushinS. G.Stanislav G. Markushin, Doctor of Medical Sciences, Senior Researcher, the Head of Laboratory of RNA-viruses genetics, Moscow, 115088, Russias.g.markushin@rambler.ruhttps://orcid.org/0000-0003-0994-5337I.I. Mechnikov Research Institute of Vaccines and Sera1612201996621291312201913122019Copyright © 2019, Kost V.Y., Sukhova O.A., Akopova I.I., Gorbacheva E.O., Lisovskaya K.V., Rtishchev A.A., Markushin S.G.2019<p><strong>Aim. </strong>Study of changes in the phenotypic characteristics of the virulent A/WSN/33 (H1N1) strain of influenza A virus under the influence of the inclusion of site-specific mutations in the PB1-gene of this strain.</p>
<p><strong>Materials and methods</strong>. Using a two-step polymerase reaction in the PB1 gene of A/ WSN/33 (H1N1) strain were included ts mutations taken from the genome of attenuated CA donors-strains: A/Ann Arbor/6/60 (H2N2), A/Leningrad 134/17/57 (H2N2) and A/ Krasnodar/101/35/59. Ts-phenotype, att-phenotype, immunogenicity, as well as weight loss in mice infected with these mutants were studied in the obtained site-specific mutants.</p>
<p><strong>Results. </strong>It was shown that the inclusion of ts mutations from the genome of CA donorsstrains of attenuation in the PB1 gene of the virulent A/WSN/33 (H1N1) strain leads to a change in the phenotypic characteristics of this strain to different degrees.</p>
<p><strong>Discussion. </strong>Analysis of the genome of CA strains- donors of attenuation of influenza virus indicates the crucial importance of the presence of functional defects in the PB1 protein for the formation of the attenuation phenotype of the virus.</p>
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