Russian Journal of Infection and ImmunityRussian Journal of Infection and Immunity2220-76192313-7398SPb RAACI77210.15789/2220-7619-2019-5-6-655-664Features 2016–2018 current human influenza A(H3N2) viruses circulating in RussiaPetrovaP. A.<p>Polina A. Petrova, Junior Researcher, Department of Evolutionary Variability of Influenza Viruses</p><p>197376, St. Petersburg, Professor Popov str., 15/17</p><p>Phone: +7 952 233-36-21 (mobile)</p>suddenkovapolina@gmail.comhttps://orcid.org/0000-0001-8527-7946KonovalovaN. I.<p>PhD, Leading Researcher Assistant of the Laboratory of Evolutionary Variability of Influenza Viruses</p>St. Petersburgkonovalova_nadya@mail.ruhttps://orcid.org/0000-0002-7213-9306VassilievaA. D.<p>Research Assistant of the Laboratory of Evolutionary Variability of Influenza Viruses</p>St. Petersburgnastasya_vasileva_94@mail.ruhttps://orcid.org/0000-0001-6818-5548EropkinaE. M.<p>PhD, Senior Researcher, Laboratory of Evolutionary Variability of Influenza Viruses</p>St. Petersburgelena.eropkina@gmail.comIvanovaA. A.<p>Junior Researcher, Laboratory of Molecular Virology</p>St. Petersburganna_e_svobodniy@mail.ruKomissarovA. B.<p>Head of the Laboratory of Molecular Virology</p>St. Petersburga.b.komissarov@gmail.comEropkinM. Yu.<p>PhD, Head of the Laboratory of Evolutionary Variability of Influenza Viruses</p>St. Petersburgmikhail.eropkin@influenza.spb.ruhttps://orcid.org/0000-0002-3306-847XDanilenkoD. M.<p>PhD, Deputy Director on Science, Head of Etiology and Epidemiology of Influenza and ARI Department</p>St. Petersburgdaria.baibus@gmail.comhttps://orcid.org/0000-0001-6174-0836Smorodintsev Research Institute of Influenza0102202095-66556643110201814032019Copyright © 2020, Petrova P.A., Konovalova N.I., Vassilieva A.D., Eropkina E.M., Ivanova A.A., Komissarov A.B., Eropkin M.Y., Danilenko D.M.2020<p>Influenza A(H3N2) viruses demonstrate the highest level of evolutionary variability compared to other influenza viruses circulating in human population. The strains of this subtype affect a large number of people belonging to highrisk groups: children under three years of age, pregnant women, people over 65 years, medical professionals, and persons with chronic nervous, cardiovascular and respiratory diseases. Influenza A(H3N2) viruses result in high mortality rate in subjects over 65 years causing the most severe course, accompanied by serious complications. Here, we present the data on analyzing antigenic and biological properties of human influenza A(H3N2) viruses which circulated in 2016–2018 epidemic seasons in Russia. The data on the neuraminidase activity (MUNANA test) of recent influenza A(H3N2) viruses isolated on MDCK and MDCK-Siat1 cell cultures are presented to compare with NA sequencing data in order to assess possible influence of the isolation system on NA activity. Due to changes in virus receptor properties, a choice of optimal isolation conditions is of high importance. The WHO recommended cell cultures differing in receptor properties were used. Efficiency of virus isolation on MDCK and MDCK-Siat1 cell lines was also analyzed. It has been established that the efficiency of influenza A(H3N2) virus isolation in MDCK-Siat1 cell culture was 77.3%, whereas in MDCK — 71.3%. It was shown that the majority of isolated strains (68.6% in 2016–2017 and 44.6% in 2017–2018) exhibited a NA-induced erythrocyte agglutination. It was found that current A(H3N2) strains isolated in Russia displayed no significant antigenic differences regardless of cell cultures used; however, adaptive substitutions in neuraminidase may emerge. While studying antigenic properties of influenza A(H3N2) viruses by using the HI assay and the microneutralization assay (cell-ELISA), it was noted that the majority of strains isolated in the 2017–2018 epidemic season was antigenically related and interacted with antiserum against the reference strain A/Singapore/INFIMH-16–0019/2016 (MDCK-Siat1) at a homologous titer. According to the sequencing data, it was established that during the 2017–2018 epidemic season, viruses of subclade 3C.2a2, as well as 3C.2a3 and 3C.2a1b were detected in Russia. Thus, an increasing genetic heterogeneity of A(H3N2) viruses was revealed in Russia.</p>influenza A(H3N2) viruseshemagglutination inhibition testmicroneutralizationantigenic propertiesgenetic propertiesMUNANA-assayвирусы гриппа А(H3N2)реакция торможения гемагглютинацииреакция микронейтрализацииантигенные свойствагенетические свойстваMUNANA-тест[1. Даниленко Д.М., Коновалова Н.И., Прокопец А.В., Бильданова Е.Р., Еропкин М.Ю., Соминина А.А. Возможности использования поликлональных крысиных антисывороток в антигенном анализе вирусов гриппа человека // Эпидемиология и вакцинопрофилактика. 2013. № 1 (68). С. 73–79.][2. Australian Influenza Surveillance Report and Activity Updates – 2017.][3. CDC: Influenza Activity in the United States During the 2017–18 Season and Composition of the 2018–19 Influenza Vaccine.][4. Gulati S., Smith D.F., Cummings R.D., Couch R.B., Griesemer S.B., George K.S., Webster R.G., Air G.M. Human H3N2 influenza viruses isolated from 1968 to 2012 show varying reference for receptor substructures with no apparent consequences for disease or spread. PLoS One, 2013, vol. 8: 6. doi: 10.1371/journal.pone.0066325][5. Koel B.F., Burke D.F., Bestebroer T.M., van der Vliet S., Zondag G.C., Vervaet G., Skepner E., Lewis N.S., Spronken M.I., Russell C.A., Eropkin M.Y., Hurt A.C., Barr I.G., de Jong J.C., Rimmelzwaan G.F., Osterhaus A.D., Fouchier R.A., Smith D.J. Substitutions near the receptor binding site determine major antigenic change during influenza virus evolution. Science, 2013, vol. 342, pp. 976–979. doi: 10.1126/science.1244730][6. Lin Y., Gregory V., Collins P., Kloess J., Wharton S., Cattle N., Lackenby A., Daniels R., Hay A. Neuraminidase receptor binding variants of human influenza A (H3N2) viruses resulting from substitution of aspartic acid 151 in the catalytic site: a role in virus attachment? J. Virol., 2010, vol. 84, no. 13, pp. 6769–6781. doi: 10.1128/JVI.00458-10][7. Lin Y., Wharton S.A., Whittaker L., Dai M., Ermetal B., Lo J., Pontoriero A., Baumeister E., Daniels R.S., McCauley J.W. The characteristics and antigenic properties of recently emerged subclade 3C.3a and 3C.2a human influenza A(H3N2) viruses passaged in MDCK cells. Influenza Other Respir. Viruses, 2017, vol. 11, no. 3, pp. 263–274. doi: 10.1111/irv.12447][8. Lin Y., Xiong X., Wharton S.A., Martin S.R., Coombs P.J. Evolution of the receptor binding properties of the influenza A(H3N2) hemagglutinin. Proc. Natl. Acad. Sci. USA, 2012, vol. 109, no. 52, pp. 21474–21479. doi: 10.1073/pnas.1218841110][9. Manual for the laboratory diagnosis and virological surveillance of influenza. WHO Press, 2011.][10. Matrosovich M., Matrosovich T., Carr J., Roberts N.A., Klenk H. Overexpression of the α-2,6-sialyltransferase in MDCK cells increases influenza virus sensitivity to neuraminidase inhibitors. J. Virol., 2003, vol. 77, no. 15, pp. 8418–8425. doi: 10.1128/JVI.77.15.8418-8425.2003][11. Mohr P.G., Deng Y.M., McKimm-Breschkin J.L. The neuraminidases of MDCK grown human influenza A(H3N2) viruses isolated since 1994 can demonstrate receptor binding. Virology J., 2015, no. 12: 67. doi: 10.1186/s12985-015-0295-3][12. Namura D, Nguyen H.T., Sleeman K., Levine M., Mishin V.P., Yang H., Guo Z., Okomo-Adhiambo M., Xu X., Stevens J., Gubareva L.V. Cell culture-selected substitutions in influenza A(H3N2) neuraminidase affect drug susceptibility assessment. Antimicrob. Agents Chemother., 2013, vol. 57, no. 12, pp. 6141–6146. doi: 10.1128/AAC.01364-13][13. Nicholls J.M., Bourne A.J., Chen H., Guan Y., Peiris J.S. Sialic acid receptor detection in the human respiratory tract: evidence for widespread distribution of potential binding sites for human and avian influenza viruses. Respir. Res., 2007, vol. 8: 73. doi: 10.1186/1465-9921-8-73][14. Skowronski D.M., Sabaiduc S., Chambers C., Eshaghi A., Gubbay J.B. Krajden M., Drews S.J., Martineau C., De Serres G., Dickinson J.A., Winter A.L., Bastien N., Li Y. Mutations acquired during cell culture isolation may affect antigenic characterization of influenza A(H3N2) clade 3C.2a viruses. Eurosurveillance, 2016, vol. 21, no. 3: 30112. doi: 10.2807/1560-7917.ES.2016.21.3.30112][15. Smith D.J., Lapedes A.S., de Jong J.C., Bestebroer T.M., Rimmelzwaan G.F., Osterhaus A.D., Fouchier R.A. Mapping the antigenic and genetic evolution of influenza virus. Science, 2004, vol. 305, pp. 371–376. doi:10.1126/science.1097211][16. Xiong X., McCauley J.W., Steinhauer D.A. Receptor binding properties of the influenza virus hemagglutinin as a determinant of host range. Curr. Top. Microbiol. Immunol., 2014, vol. 385, pp. 63–91. doi: 10.1007/82_2014_423][17. Xue K.S, Greninger A.L., Pérez-Osorio A., Bloom J.D. Cooperating H3N2 influenza virus variants are not detectable in primary clinical samples. mSphere, 2018, vol. 3, no. 1: e00552-17. doi: 10.1128/mSphereDirect.00552-17][18. Xue K.S., Hooper K.A., Ollodart A.R., Dingens A.S., Bloom J.D. Cooperation between distinct viral variants promotes growth of H3N2 influenza in cell culture. Microbiol. Infec. Dis., 2016, no. 5: e13974. doi: 10.7554/eLife.13974][19. WHO Recommended composition of influenza virus vaccines for use in the 2019 southern hemisphere influenza season.][20. Worldwide influenza centre WHO CC for Reference & Research on Influenza Annual report. The Francis Crick Institute. February, 2017.][21. Worldwide influenza centre WHO CC for Reference & Research on Influenza Annual report. The Francis Crick Institute. February, 2018.][22. Worldwide influenza centre WHO CC for Reference & Research on Influenza Annual report. The Francis Crick Institute. September, 2018.]