Alexander B. Ryzhikov

Spread of Venezuelan equine encephalitis virus in mice olfactory tract

SummarySpread of Venezuelan equine encephalitis (VEE) virus and damage of the central nervous system (CNS) in mice infected by respiratory route was studied. Virus concentration in organs and blood, “dose-effect” relationships, and ultrastructural lesions in various tissues were examined in immune and normal mice. We showed, via three independent methods — characteristic curve investigations, tissue virus concentration dynamics, and ultrastructural methods — the spread of VEE virus through the olfactory tract into the brain of immune mice. From these experiments it was concluded that in case of respiratory challenge VEE virus can enter the CNS of normal mice by both vascular and olfactory pathways, while in immune mice the main route is olfactory.

Influenza A(H5N8) virus isolation in Russia, 2014

In this study, we report the isolation of influenza A(H5N8) virus from a Eurasian wigeon (Anas penelope) in Sakha Republic of the Russian Far East. The strain A/wigeon/Sakha/1/2014 (H5N8) has been shown to be pathogenic for mammals. It is similar to the strains that caused outbreaks in wild birds and poultry in Southeast Asia and Europe in 2014.

Reintroduction of highly pathogenic avian influenza A/H5N8 virus of clade 2.3.4.4. in Russia

In the spring of 2016, a loss of wild birds was observed during the monitoring of avian influenza virus activity in the Republic of Tyva. That outbreak was caused by influenza H5N8 virus of clade 2.3.4.4. In the fall, viruses of H5N8 clade 2.3.4.4 were propagated in European countries. This paper presents some results of analysis of the virus strains isolated during the spring and fall seasons in 2016 in the Russian Federation. The investigated strains were highly pathogenic for mice, and some of their antigenic and genetic features differed from those of an H5N8 strain that circulated in 2014 in Russia.

A protective chimeric antibody to tick-borne encephalitis virus

The efficiency of several mouse monoclonal antibodies (mAbs) specific to the tick-borne encephalitis virus (TBEV) glycoprotein E in post-exposure prophylaxis was assessed, and mAb14D5 was shown to be the most active of all those studied. It was proven that the hybridoma cell line 14D5 produced one immunoglobulin H chain and two L chains. They were used to construct chimeric antibodies ch14D5a and ch14D5b, the affinity constants of which were 2.6 × 10(10)M(-1) and 1.0 × 10(7)M(-1), respectively, according to the SPR-based ProteOn biosensor assay. The neutralization index (IC50) of ch14D5a was 0.04 μg/ml in the focus reduction neutralization test. In in vivo experiments, ch14D5a at a dose of 10 μg/mouse resulted in a 100% survival of the mice infected with 240 LD50 of TBEV. This chimeric antibody is promising for further development of prevention and therapeutic drugs against TBEV.

Chimeric antibodies against tick-borne encephalitis virus

Two chimeric antibodies (ch) 13D6 and 10C2 against the glycoprotein E of tick-borne encephalitis virus (TBEV) were constructed by fusing variable regions of murine monoclonal antibodies (Mabs) 13D6 and 10C2 to human constant regions. Monovalent analogues of these antibodies in format of single-chain antibodies (scFv or sc) were developed, as well. The ch13D6, ch10C2, sc13D6 and sc10C2 exhibited binding characteristics similar to parental Mabs. Only the ch13D6 and sc13D6 were able to neutralize TBEV infectivity in vitro. The in vitro neutralization provided by ch13D6 suggests that this antibody can be further developed into a potent prophylaxis and therapy for tick-borne encephalitis (TBE) infection.

Highly pathogenic influenza H5N1 virus of clade 2.3.2.1c in Western Siberia

In the spring of 2015, avian influenza virus surveillance in Western Siberia resulted in isolation of several influenza H5N1 virus strains. The strains were isolated from several wild bird species. Investigation of biological features of those strains demonstrated their high pathogenicity for mammals. Phylogenetic analysis of the HA gene showed that the strains belong to clade 2.3.2.1c.

Artificial polyepitope HIV-1 immunogen containing mimotope of 2F5 epitope

Constructing a vaccine against HIV-1, able to induce production of broadly neutralizing antibodies, is crucial. We report here the selection and characterization of RDWSFDRWSLSEFWL peptide mimotope that binds specifically to bNAbs 2F5. The peptide mimotope was selected from 15-mer phage-displayed peptide library by using Mab 2F5 as the selecting agent. The most abundant RDWSFDRWSLSEFWL peptide was inserted into a carrier, an artificial polyepitope immunogen - TBI (T- and B-cell immunogen). TBI-2F5 polyepitope immunogen that includes the mimotope of 2F5 epitope was constructed. It was shown that sera of mice immunized with TBI-2F5 protein recognized TBI protein as well as RDWSFDRWSLSEFWL peptide. The capacity of sera of immunized mice to neutralize HIV-1 was demonstrated using subtype B env-pseudoviruses of HIV-1 QH0692.42 and PVO.4. Based on these results, we conclude that peptide mimotope of 2F5 epitope RDWSFDRWSLSEFWL can be an essential component for a successful HIV-vaccine.

Herd immunity and fatal cases of influenza among the population exposed to poultry and wild birds in Russian Asia in 2013–2014

In total 1,525 blood serum samples were collected in October, 2013 in Russian Asia from people who reside in territories that are at high risk for emergence of influenza viruses with pandemic potential. Presence of antibodies to influenza viruses in the sera was tested in hemagglutination inhibition test. None of the samples produced positive results with the antigens A/H5 and A/H7. Twelve strains of influenza A(H1N1pdm09) virus were isolated from people who died presumably from influenza during 2013–2014 epidemic season. All strains were similar to vaccine strain A/California/07/09 according to their antigenic properties and sensitivity to anti‐neuraminidase drugs (oseltamivir and zanamivir). Genetic analysis revealed that all strains belong to group 6, subgroup 6B of influenza A(H1N1)pdm09 virus. Substitutions in HA1: S164F add E235K as well as E47G, A86V, K331R, N386K, N397K in NA, and K131E, N29S in NS1, and N29S, R34Q in NEP separate investigated strains into two groups: 1st group—A/Chita/1114/2014, A/Chita/1115/2014, A/Chita/853/2014, A/Barnaul/269/2014 and 2nd group—A/Chita/655/2014, A/Chita/656/2014, A/Chita/709/2014, A/Chita/873/2014. Mutation D222G in HA1, which is often associated with high morbidity of the illness, was present in strain A/Novosibirsk/114/2014. Substitution N386K in NA removes a potential N‐glycosylation site in neuraminidases of A/Chita/1114/2014, A/Chita/1115/2014, A/Chita/853/2014, A/Barnaul/269/2014, A/Novosibirsk/114/2014, and A/Blagoveshensk/252/2014. J. Med. Virol. 88:35–44, 2016.

Overview of the Situation on Highly Pathogenic Avian Influenza Virus H5 in Russia in 2016–2017

30 Problemy Osobo Opasnykh Infektsii [Problems of Particularly Dangerous Infections] вирусы гриппа а (вга) способны инфицировать различные виды млекопитающих и птиц, но основным хозяином и природным резервуаром вга являются дикие, преимущественно водоплавающие птицы [5, 20]. вирусы гриппа подразделяются на субтипы на основании антигенных различий в поверхностных гликопротеинах, на сегодняшний день известно 18 субтипов гемагглютинина и 11 субтипов нейраминидазы вга [17, 18]. тем не менее, среди широкого разнообразия вариантов данного инфекционного агента, лишь определенные субтипы вга показали способность преодолевать межвидовой барь ер и вызывать заболевание человека. это обусловлено тем, что в процессе эволюции вируса гриппа возникают его новые, высокопатогенные для человека и животных, варианты. циркуляция таких вариантов вируса в популяциях восприимчивых хозяев может вызывать заболевание, часто с летальным исходом. подтверждением этому служат масштабные эпизоотии среди сельскохозяйственных животных, наносящие колоссальный экономический ущерб, а также документированные случаи инфицирования человека и домашних животных высокопатогенными вирусами гриппа H5, H7 и H9-субтипов гемагглютинина. на сегодняшний день возможными прародителями будущей пандемии считаются субтипы а(H5N1) и а(H7N9), поскольку существует вероятность, что данные варианты вируса приобретут способность к передаче от человека к человеку. по данным всемирной организации здравоохранения, на 7 декабря 2018 г. зафиксировано 860 случаев заражения человека вирусом гриппа а(H5N1), 454 имели летальный исход. при этом зарегистрировано 1565 случаев заражения людей вирусом гриппа а(H7N9), Пробл. особо опасных инф. 2018; 1:30–35. DOI: 10.21055/0370-1069-2018-1-30-35

Humoral immunity to influenza in an at-risk population and severe influenza cases in Russia in 2016–2017

This work aimed to analyze the herd immunity to influenza among a Russian population living in regions with an increased risk of emergence of viruses with pandemic potential, and to isolate and investigate virus strains from severe influenza cases, including fatal cases, during the 2016–2017 epidemic season. In November 2016 – March 2017 highly pathogenic influenza outbreaks were registered in Russia among wild birds and poultry. No cases of human infection were registered. Analysis of 760 sera from people who had contact with infected or perished birds revealed the presence of antibodies to A(H5N1) virus of clade 2.3.2.1c and A(H5N8) virus of clade 2.3.4.4. The 2016–2017 influenza epidemic season in Russia began in weeks 46–47 of 2016 with predominant circulation of influenza A(H3N2) viruses. Strains isolated from severe influenza cases mainly belonged to 3C.2a.2 and 3C.2a.3 genetic groups. Up to the 8th week of 2017 severe influenza cases were often caused by influenza B viruses which belonged to 1A genetic group with antigenic properties similar to B/Brisbane/60/2008. All influenza A and B virus strains isolated in the 2016–2017 epidemic season were sensitive to oseltamivir and zanamivir.