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Aim. The development of the hepatitis E virus (HEV) genotype 1 full-size ORF3 recombinant polypeptide. Materials and methods. Escherichia coli strains, plasmid vectors, serological and clinical samples, ELISA reagent kits, molecular biological, bioinformatic, biotechnological, biochemical and serological methods. Results. HEV genotype 1 RNA had been isolated from clinical samples collected in Kyrgyzstan. DNA copy of subgenomic virus RNA had been cloned and used for further development of E.coli strains producing full-size recombinant protein ORF3 fused to E.coli beta-galactosidase. Codons optimization method was used in aim to increase expression level of recombinant protein. Recombinant protein ORF3 had been isolated from the inclusion bodies of the E.coli biomass and purified by size exclusion chromatography. Antigenic specificity of recombinant polypeptide had been confirmed by enzyme-linked immunosorbent assay and Western blotting with the specific sera. Conclusion. HEVgenotype 1 ORF3 recombinant antigen had been designed, and it’s applicability in diagnostic tests had been experimentally confirmed.

Relationships between viruses and their human host are traditionally described from the point of view taking into consideration hosts as victims of viral aggression, which results in infectious diseases. However, these relations are in fact two-sided and involve modifications of both the virus and host genomes. Mutations that accumulate in the populations of viruses and hosts may provide them advantages such as the ability to overcome defense barriers of host cells or to create more efficient barriers to deal with the attack of the viral agent. One of the most common ways of reinforcing anti-viral barriers is the horizontal transfer of viral genes into the host genome. Within the host genome, these genes may be modified and extensively expressed to compete with viral copies and inhibit the synthesis of their products or modulate their functions in other ways. This review summarizes the available data on the horizontal gene transfer between viral and human genomes and discusses related problems.

An austenitic-martensitic nitrogen steel 0Kh16N4AB has been studied under load using high-resolution neutron diffraction analysis on an FSD neutron diffractometer at an IBR-2 reactor (Dubna) and on a diffractometer with a focusing monochromator on a reactor of the Nuclear Physics Institute (Czech Republic). Young’s moduli calculated from different reflections of the martensite and austenite phases have been obtained. It has been found that the yield strength σ0.2 corresponding to the slip plane (111) of the austenite phase is anomalously low and that with increasing degree of uniaxial tension the width of lines (111)γ strongly grows. In the steel under consideration the plane (111) of the austenite phase appears to be an easy-slip plane that ensures the enhanced properties of the steel, i.e., the combination of a high ultimate strength (1600 MPa) with a high plasticity (δ = 16%).

A comparative study of the hemagglutinin (HA) receptor binding site (RBS) of a number of H13 influenza viruses isolated from Laridae family of birds (gulls) and other influenza viruses obtained from the Anatidae family (ducks) was conducted. The affinity of all viruses to alpha N-acetylneuraminic acid (Neu5Ac alpha), 3'sialyllactose (3'SL), and sialylglycopolymers bearing 3'-sialyl(N-acetyllactosamine) (3'SLN-PAA), [Neu5Ac alpha(2-3)Gal beta(1-4)][-Fuc alpha(1-3)]GlcNAc beta (SLe(x)-PAA), and [Neu5Ac alpha(2-3)Gal beta(1-3)][-Fuc alpha(1-4)]GlcNAc beta (SLe(a)-PAA), was determined. The last three polymer glycoconjugates were synthesized for determining the contribution of carbohydrate chains after the galactose link to the binding with the receptor. The difference in affinity between 3'SL and Neu5Ac alpha in all studied H13 viruses is small, which indicates a less significant role of the galactose moiety in the binding to the receptor. The results of virus binding with polymer sialylglycoconjugates indicates that the method of linking, the third monosaccharide moiety, and the presence of an extra fucose substitute in this moiety may influence the binding considerably. For viruses isolated from ducks, the suitable polymer is SLe(a)-PAA (i.e., a 1-3 linkage between galactose and glucosamine is optimal). This finding is in accord with the data that H13 viruses isolated from the gulls differ based on their ability to interact with polymer sialylglycoconjugates. The affinity to all three polymers is uniform, and the presence of GlcNAc-linked fucose does not prevent the binding. A comparative analysis of six sequenced HA H13 viruses and other subtype viruses showed presence of substantial differences in the composition of amino acids of this region in H13 viruses.

Horizontal transfer of genes between viruses and their hosts played an important role in the evolution of various eukaryotes including contemporary mammals as well as the pathogens themselves. Elements of viruses of various types can be found in the genome of animals. Endogenous retroviral elements composing up to 8% of human genome length not only determine its high flexibility and rapid adaptation potential. Many of virus genes such as Fv1, Lv1, Lv2 being analogues of capsid and other proteins determine effective suppression of viral replication after cell penetration by the causative agent. Introduction of these elements into genome of a wide variety of animals from fish to primates could have taken place against the background of global natural cataclysms of viral origin. Integration of retrovirus genes coding surface glycoproteins with immunosuppressing domains into genetic apparatus of animals served as an impetus to the development of viviparity and spread ofplacental mammals. Their cell analogs syncytins perform a dual function: take direct part in the formation of syncytiotrophoblast layer of placenta and ensure tolerance of immune system of mother to embryo. The acquisition of cell genes by viruses also played an important role in their evolution: various interleukins and other modulators of immune response introduced into viral genome from cell genetic apparatus became one of the most important factors of pathogenicity of a wide variety of causative agents including poxviruses, cytomegalovirus, Epstein-Barr virus and many others. Evolutionary pathways of the virus and host are thus inseparable from each other, and character of one of these directions is largely dictated by the vector of another.

The experiment demonstrated the podibility of obtaining stable suspensions of B. subtilis, a microorganism used as an experimental model, in an electromagnetic apparatus with a bilateral inductor. The optimum conditions of obtaining such suspensions were chosen, these conditions excluding the inactivation of the bacteria used as a model in the course of the process. Suspensions containing 75% of culture fluid were shown to have the highest stability during prolonged storage. Suspensions on the basis of the crystal-forming bacteria B. thuringiensis sp. kurstaki, strain Z-52, used in the production of entomopathogenic preparations and characterized by high stability and good viability in the process of storage were prepared under the selected conditions. The apparatus used in these experiments was recommended for use in the technology of the production of biopreparations of the basis of the above-mentioned bacteria.

Receptor CD4, expressed on the surface of immunocompetent cells, plays the key role in the pathogenesis of HIV infection, facilitating the penetration of the virus into the susceptible tissues of the host body. In this work the nucleotide sequence of the site on the gene of receptor CD4, responsible for the regulation of its transcription, has been determined.

The nucleotide sequence of the long terminal repeat (LTR) of human endogenous retrovirus element (HERV), localized in the first introne of the CD4 gene in the antisense direction, is determined. This new retrotransposon is highly homologous with different LTR HERV and belongs to HERV-K family. A peculiar feature of this element is an insertion of the Alu repeated sequence inside LTR. This Alu repeat has the same orientation as LTR HERV and contains two short open frames with a high level of homology with DAF (decay accelerating factor) proteins and the fifth complement component. In addition, this Alu repeat of LTR HERV contains regulatory elements: enhancer, TATAA box, poly A site, etc. Preservation of putative regulatory elements in the LTR suggests that they can render distinct regulatory properties to CD4 receptor gene.

Two strains of parotitis virus were isolated from patients with clinical symptoms of the disease in epidemiological screening which was carried out during an outbreak of epidemic parotitis in the village of Koltsovo in 1994. The strains were isolated from the saliva of children aged 7 and 8 years vaccinated with live parotitis vaccine at the age of 1.5 years. Primers for the genome site coding for the gene F terminal and the SH gene (a total of 509 n. p.) were estimated and synthesized and the site was amplified. Electron-microscopic examination of purified virus and Vero cells infected with it and serological tests showed a similarity of the newly isolated virus with the Anders strain of parotitis virus. The Dragun-1 and Dragun-2 strains of parotitis virus have been deposited in the collection of viruses at the Vektor State Research Center of Virology and Biotechnology in the village of Koltsovo, Novosibirsk district.

Immunization of BALB/c, C57BL/6, CBA/calac mice with strain XJ44 of Argentine hemorrhagic fever resulted in changes of nonspecific immunity parameters, such as interferon, interleukin-1, tumor necrosis factor, and natural killers. The formation of a specific humoral and cellular immune response in BALB/c mice immunized with this strain has been demonstrated. Immunization of BALB/c mice with strain XJ44 protected the animals from infection with a heterogeneous strain Carvallo of Bolivian hemorrhagic fever.

Large-scale and uneven distribution of hepatitis C and B (HC and HB) among free blood donors of different regions of the Moldova Republic was established. The rate of detection of anti-HCV (South 6.2%, North 3.6%) correlated with that of HBsAg detection (south 12.5%, north 4.5%). A great role of HCV in the etiology of acute (among them posttransfusion) hepatitis and chronic hepatitis was demonstrated. A significant frequency of detection of anti-HCV (15%) in children treated in oncohematology wards and receiving multiple hemotransfusions as well as the detected cases of acute posttransfusion HC attest to active realization of this virus transmission in the transfusions of blood and/or its components. The necessity of urgent introduction into the Blood Transfusion Service of the republic of the examination of blood donors for HBsAg, alongside with their examination for the presence of anti-HCV and vaccination prophylaxis of HB in high risk groups is substantiated.

The authors tried to decode the mechanism of influenza viruses species adaptation in the process of host changing. The functionally important replacement in the surface pocket domains were revealed, particularly in the conservative region 221-241, involving fibronectin-like part. Close replacements were revealed in the region 141-161. The method of construction of heteroduplexes between hemagglutinin RNA of duck, pig, and human viruses was used. The method showed that all heteroduplexes formed recombinogene structures. An unexpected effect of directional recombination was elicited for hemagglutinin RNA heteroduplexes in cases of duck-pig and human-pig viruses. During the directional recombination the following processes took place: the receptor-binding site of animal type was transmitted to the duck virus, while the human receptor-binding site was transmitted to the pig virus. According to the experimental data, a new hypothesis is formulated: the cascade mechanism of directional recombination for duck, animal and human viruses makes it possible for the recombinant viruses to overcome interspecies barriers.

Molecular and cytogenetic characteristics are given of a 2846 bp DNA sequence from the YDm12 clone, previously derived from the long arm of the Drosophila melanogaster Y chromosome. Sequence analysis revealed within it a 1176 bp fragment with 37 bp terminal inverted repeats, flanked by 6 bp direct repeats. This fragment (called "element 1360") appeared to be A-T rich, and was saturated with short direct and inverted repeats of different degrees of homology and consensus sequences for transcription, potential Z-DNA transition and autonomous replication. After in situ hybridization to polytene chromosomes, the element 1360 exhibited variable, strain-specifics location in the euchromatic parts of the chromosome arms, but constant heavy labelling of the X chromosome region 12E1-2, autosomal regions 42B1-3, 52A1-2, 62A1-2, 75B, 82C1-3, chromosome bases, the chromocentre and numerous sites of chromosome 4. The possible role of element 1360 in heterochromatin organization is discussed.