CHARACTERISTICS OF THE FAR EASTERN POPULATION OF TICK-BORNE ENCEPHALITIS VIRUS AND SOLVING ISSUES OF SPECIFIC PREVENTION

The subdivision of the viral population into subtypes and clusters based on the molecular genetic characteristics of the tick-borne encephalitis virus (TBEV) strains predetermines not only the differences in the biological properties of these strains, but also their different responses to specific antibodies in persons vaccinated against TBE.The aim of the present study is to show the differences in biological properties on the model of two strains of Far Eastern TBEV subtype belonging to different clusters and to substantiate the need for a personalized approach to the vaccine prophylaxis of tick-borne encephalitis.Results. Two strains of TBEV were used in the studies. On the basis of full genome sequencing the Dal’negorsk strain (FJ402886, GenBank) is referred to the typical representative of Sofjin-like, and Primorye-437 (JQ825162, GenBank) – to Oshima-like TBEV strains of the Far Eastern subtype.The experiment shows the levels of specific antibodies capable of neutralizing virulence strains of tick- borne encephalitis virus. Low antibody titers (1:100 and 1:400) can neutralize only a low dose of a non-virulent strain of tick-borne encephalitis virus. Reliable protection against the disease of people infected with virulent strains of the TBEV can provide only a high level of specific antibodies.Conclusion. If the level of specific antibodies of IgG is 1:400 or lower, the vaccination course should be continued, at a titer of antibodies above 1:400, revaccination can be postponed subject to annual monitoring of specific immunity parameters in the pre-epidemic TBE season.

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European subtype of tick-borne encephalitis virus. Literature review

Acta biomedica scientifica ◽

10.29413/abs.2021-6.4.9 ◽

2021 ◽

Vol 6 (4) ◽

pp. 100-113

Author(s):

Yu. S. Savinova

Keyword(s):

Genome Stability ◽

Scientific Literature ◽

Biological Properties ◽

Climatic Conditions ◽

Encephalitis Virus ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus ◽

Subtype A ◽

Far Eastern ◽

European Subtype

This review is devoted to the European subtype of tick-borne encephalitis virus (TBEV). It summarizes and analyzes the information available at the scientific literature on the genetic and biological properties of strains of this virus subtype. A comparative analysis of the complete coding sequences of all currently recognized tick-borne flaviviruses was carried out. It was noted that the differences in TBEV strains included in the European subtype are minimal, which indicates a higher degree of their genetic homogeneity than in strains of the Far Eastern and Siberian subtypes. The level of differences in the genome of strains of the European subtype, depending on the region and the source of isolation, was analyzed. No relationship was found between the level of homology of nucleotide sequences of TBEV strains of the European subtype and the source of isolation. The proposed models for the evolution of TBE are described. The area of TBE of the European subtype in Eurasia is analyzed. The maps of the geographical distribution of the European subtype are presented. It shows the European subtype TBE is found in 14 regions of Russia. TBE of this subtype, as a rule, causes a disease with a milder course in comparison with TBE caused by a virus of the Far Eastern or Siberian subtypes. An analysis of the main vectors and reservoir hosts of the European subtype TBEV in Europe and in Siberia has been carried out. It is emphasized that in Eurasia the European TBEV circulates in territories that differ significantly in climatic conditions, relief, landscape, and characteristics of biotopes. However, analysis of scientific literature data showed that, despite these differences, it has a high degree of genome stability.

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Computational and Rational Design of Single-Chain Antibody against Tick-Borne Encephalitis Virus for Modifying Its Specificity

Viruses ◽

10.3390/v13081494 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1494

Author(s):

Ivan K. Baykov ◽

Pavel Y. Desyukevich ◽

Ekaterina E. Mikhaylova ◽

Olga M. Kurchenko ◽

Nina V. Tikunova

Keyword(s):

Rational Design ◽

Fold Increase ◽

Encephalitis Virus ◽

Chimeric Antibody ◽

Single Chain ◽

Single Chain Antibody ◽

Glycoprotein E ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus ◽

Far Eastern

Tick-borne encephalitis virus (TBEV) causes 5−7 thousand cases of human meningitis and encephalitis annually. The neutralizing and protective antibody ch14D5 is a potential therapeutic agent. This antibody exhibits a high affinity for binding with the D3 domain of the glycoprotein E of the Far Eastern subtype of the virus, but a lower affinity for the D3 domains of the Siberian and European subtypes. In this study, a 2.2-fold increase in the affinity of single-chain antibody sc14D5 to D3 proteins of the Siberian and European subtypes of the virus was achieved using rational design and computational modeling. This improvement can be further enhanced in the case of the bivalent binding of the full-length chimeric antibody containing the identified mutation.

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Ability of inactivated vaccines based on far‐eastern tick‐borne encephalitis virus strains to induce humoral immune response in originally seropositive and seronegative recipients

Journal of Medical Virology ◽

10.1002/jmv.25316 ◽

2018 ◽

Vol 91 (2) ◽

pp. 190-200 ◽

Cited By ~ 8

Author(s):

Galina B. Maikova ◽

Liubov L. Chernokhaeva ◽

Yulia V. Rogova ◽

Liubov I. Kozlovskaya ◽

Ivan S. Kholodilov ◽

...

Keyword(s):

Immune Response ◽

Humoral Immune Response ◽

Encephalitis Virus ◽

Humoral Immune ◽

Tick Borne Encephalitis ◽

Inactivated Vaccines ◽

Tick Borne Encephalitis Virus ◽

Far Eastern ◽

Virus Strains

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Tick-borne encephalitides

10.1093/med/9780198570028.003.0044 ◽

2011 ◽

Author(s):

Patricia A. Nuttall

Keyword(s):

North America ◽

Tick Species ◽

Encephalitis Virus ◽

Virus Family ◽

Wild Mammals ◽

Tick Borne Encephalitis ◽

Powassan Virus ◽

Louping Ill ◽

Tick Borne Encephalitis Virus ◽

Far Eastern

Tick-borne encephalitides are caused by three different viruses transmitted by ticks and belonging to the Flaviviridae virus family: tick-borne encephalitis virus (Far Eastern, Siberian, and European subtypes), louping ill virus, and Powassan virus (including deer tick virus). These viruses cause encephalitis affecting humans in Eurasia and North America. In nature, they are maintained in transmission cycles involving Ixodes tick species and small or medium-sized wild mammals. The tick-borne flavivirus group is one of the most intensely studied groups of tick-borne pathogens.

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Effect of Glycosaminoglycans on Pathogenic Properties Far-Eastern Tick-Borne Encephalitis Virus

Bulletin of Experimental Biology and Medicine ◽

10.1007/s10517-019-04555-4 ◽

2019 ◽

Vol 167 (4) ◽

pp. 482-485 ◽

Cited By ~ 1

Author(s):

G. N. Leonova ◽

S. I. Belikov

Keyword(s):

Encephalitis Virus ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus ◽

Far Eastern

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Evaluation of European tick-borne encephalitis virus vaccine against recent Siberian and far-eastern subtype strains

Vaccine ◽

10.1016/s0264-410x(01)00218-3 ◽

2001 ◽

Vol 19 (32) ◽

pp. 4774-4779 ◽

Cited By ~ 35

Author(s):

Daisuke Hayasaka ◽

Akiko Goto ◽

Kentarou Yoshii ◽

Tetsuya Mizutani ◽

Hiroaki Kariwa ◽

...

Keyword(s):

Virus Vaccine ◽

Encephalitis Virus ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus ◽

Far Eastern

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Comparative analysis of genomes of tick-borne encephalitis virus strains isolated from mosquitoes and ticks

Voprosy Virusologii ◽

10.18821/0507-4088-2017-62-1-30-35 ◽

2017 ◽

Vol 62 (1) ◽

pp. 30-35 ◽

Cited By ~ 1

Author(s):

N. M. Pukhovskaya ◽

O. V. Morozova ◽

N. B. Belozerova ◽

S. V. Bakhmetyeva ◽

N. P. Vysochina ◽

...

Keyword(s):

Vaccine Strain ◽

Far East ◽

Encephalitis Virus ◽

Ixodes Persulcatus ◽

Aedes Vexans ◽

Tick Borne Encephalitis ◽

Tbev Strain ◽

Natural Foci ◽

Tick Borne Encephalitis Virus ◽

Far Eastern

The tick-borne encephalitis virus (TBEV) strain Lazo MP36 was isolated from the pool of mosquitoes Aedes vexans collected in Lazo region of Khabarovsk territory in August 2014. Phylogenetic analysis of the strain Lazo MP36 complete genome (GenBank accession number KT001073) revealed its correspondence to the TBEV Far Eastern subtype and differences from the following strains: 1) from ticks Ixodes persulcatus P. Schulze, 1930 [vaccine strain 205 (JX498939) and strains Khekhtzir 1230 (KF880805), Chichagovka (KP844724), Birobidzhan 1354 (KF880805) isolated in 2012-2013]; 2) from mosquitoes [strain Malyshevo (KJ744034) isolated in 1978 from Aedes vexans nipponii in Khabarovsk territory; strain Sakhalin 6-11 isolated from the pool of mosquitoes in 2011 (KF826916)]; 3) from human brain [vaccine strain Sofjin (JN229223), Glubinnoe/2004(DQ862460). Kavalerovo (DQ862460), Svetlogorie (DQ862460)]. The fusion peptide necessary for flavivirus entry to cells of the three TBEV strains isolated from mosquitoes (Lazo MP36, Malyshevo and Sakhalin 6-11) has the canonical structure 98-DRGWGNHCGLFGKGSI-113 for the tick-borne flaviviruses. Amino acid transition H104G typical for the mosquito-borne flaviviruses was not found. Structures of 5’- and 3’-untranslated (UTR) regions of the TBEV strains from mosquitoes were 85-98% homologous to the TBEV strains of all subtypes without recombination with mosquito-borne flaviviruses found in the Far East of Russia. Secondary structures of 5’- and 3'-UTR as well as cyclization sequences (CS) of types a and B are highly homologous for all TBEV isolates independently of the biological hosts and vectors. similarity of the genomes of the TBEV isolates from mosquitoes, ticks and patients as well as pathogenicity of the isolates for new-borne laboratory mice and tissue cultures might suggest a possible role of mosquitoes in the TBEV circulation in natural foci as an accidental or additional virus carrier.

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