METHOD OF PREPARING IMMUNOGENIC COMPOSITION BASED ON THREE FUSION PROTEINS OF SHELL OF TICK-BORNE ENCEPHALITIS VIRUS DEFINING BELONGING TO SIBERIAN (DBD2-D3S), EUROPEAN (DBD2-D3E) AND FAR EAST (DBD2-D3D) VIRUS SUBTYPES; RECOMBINANT PLASMIDS pDBD2-D3S, pDBD2-D3E AND pDBD2-D3D; PRODUCER STRAINS Escherichia coli M15 [pREP4]; CHIMERIC PROTEINS AND THEIR APPLICATION Russian patent published in 2015 - IPC C12N15/00 

FIELD: biotechnology.

SUBSTANCE: production of synthetic genes D3S, D3E and D3D is described, optimised for heterologous expression in non-pathogenic laboratory strains of Escherichia coli. These genes encode the receptor-binding domains III of protein E of the shell of tick-borne encephalitis virus (TBEV). On the basis of genes D3S, D3E and D3D the recombinant plasmids pDBD2-D3S, pDBD2-D3E and pDBD2-D3D are received, which encode the bifunctional recombinant proteins which differ in amino acid composition in positions 166, 170, 184, 211 and determining belonging to three main genetic types of the virus. The invention also comprises the producer strains of the chimeric proteins of E. coli M15 [pREP4, pDBD2-D3S], E. coli M15 [pREP4, pDBD2-D3E] and E. coli M15 [pREP4, pDBD2-D3D], and also a method of immobilisation, concentration and purification of the proteins obtained on dextran-containing sorbent. The invention relates to recombinant proteins DBD2-D3S, DBD2-D3E and DBD2-D3D, intended for use as antigens immobilised in the wells of 96-well plate or strips, as part of a set of diagnostic markers for detection of antibodies to TBEV in blood serum and human cerebrospinal fluid by EIA, as well as to an immunogenic composition comprising recombinant proteins immobilised on dextran and directed to the specific activation of immunity and the formation of immunological memory against the virus.

EFFECT: invention enables to obtain producer strains providing high level of production of recombinant protein antigens DBD2-D3S, DBD2-D3E and DBD2-D3D, for subsequent use for TBEV immunoprophylaxis, the differential diagnosis of flavivirus infections and assessment of immunity stress.

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