African swine fever (ASF) is a highly contagious viral disease affecting pigs, with mortality rates a primary focus as they can reach up to 100%. The widespread and colossal economic losses from ASF have impacts on the development of animal husbandry practices in most countries within Africa, Asia, and Europe. Currently, a variety of approaches toward the development of vaccines against ASF are being employed. A promising new concept centered around more economical and time-consuming vaccine production is based on the use of viral vectors to deliver selected immunogens. This review discusses the results obtained from testing various viral vectors as carriers of targeted ASF virus genes. The safety and prospects of viral vectors, the possibilities around modulating cellular and humoral immune responses by choosing genes expressing immunodominant antigens, and the degree of protection in experimental animals from infection with a lethal dose of virulent ASF virus strains have been shown and discussed.

Relevance. Prevention and control of ASF is significantly hampered by the lack of available vaccines and effective therapeutic measures. The ASF virus is capable of interfering with various cellular signaling pathways, leading to immunomodulation, which makes the development of an effective vaccine extremely difficult. Given the various limitations of known strategies for the development of ASF vaccines, the search for promising platforms for the development of safe and effective drugs to combat the virus is ongoing. The basis for the design of candidate vaccines is the choice of immunogenic peptides that provide stable humoral and cellular immune responses and the identification of potential targets for immune responses.Methods. In this study, 31 candidate amino acid sequences of more than 100 strains and epizootic isolates of the African swine fever virus was analyzed using standard bioinformatic methods.Results. Based on the number of T- and B-cell epitopes identified during the initial analysis, the type and severity of the immune response in target animals, it was found that the proteins p72 (B646L), p30 (CP204L), p54 (E183L), pp62 (CP530R), pp220 (CP2475L) have the greatest immunogenic potential. For the analyzed proteins, the N- and O-glycosylation sites, the localization of signal peptides and transmembrane domains were determined in silico, and their main physicochemical properties were predicted. The application of the proposed approaches made it possible to select potentially immunogenic epitopes of ASFV proteins, which in the future will be used to design new candidate vector vaccines. Given the number of antigenic determinants, the considered proteins, in our opinion, have a significant vaccine potential, however, real data on their immunogenicity will be established during practical testing of the developed vector constructs.

Abstract— Drug delivery systems are developed to provide a necessary concentration and prolonged effect of the active substance in the organism. Orally administered protein preparations require a protection from the proteolysis in the gastrointestinal tract. Biocompatible hydrophilic polysaccharides in the composition of the matrix are especially promising, since they do not irritate the intestine and are gradually cleaved by specific glycosidases, releasing a therapeutic agent. The introduction of an insoluble porous mineral matrix into the composition of the carrier allows us to increase the concentration of the therapeutic agent in the matrix without a significant increase in the volume of the drug tablet form. In this work, a new original organomineral carrier was created based on heat-treated crushed clinoptilolite zeolite in combination with natural polysaccharides of red algae (agar–agar, agarose, and carrageenan). Granular and finely dispersed clinoptilolites in the composition of the matrix are loaded with a promising therapeutic agent (Bacillus pumilus ribonuclease (binase)), which shows a selective cytotoxicity to tumor cells. It was established that both granular and finely dispersed zeolites in a complex with polysaccharides retain the protein better as compared with pure zeolites and provide a gradual complete release of the enzyme in 18 h; at the same time, binase retains a catalytic activity and causes apoptosis in up to 23.8% of the population of HuTu80 human duodenal adenocarcinoma cells. Data obtained substantiate the prospects of designing dosage forms based on the studied organomineral carriers.

Background. The regulation of the central dopaminergic system under the influence of chronic stress is disturbed, however, the dynamics of changes in the dopamine receptors expression in the periphery remains poorly understood. Aim. Evaluation of the different models of chronic stress influence on changes in the relative level of dopamine receptor gene expression in peripheral blood cells of rats during immobilization and intense physical activity. Material and methods. For 270 days on 88 Wistar rats, the study on the effect of different models of chronic stress on the change in the relative level of Drd15 genes expression was performed in four groups: the first control group; the second group was subjected to intensive physical activity in the Forced swimming with a load test (7-minute swimming with a load of 8% of body weight 2 times a week); the third group experienced daily 90-minute immobilization for 14 days; the fourth group had combined exposure of physical activity and immobilization. The relative level of dopamine receptor gene expression was determined by real-time polymerase chain reaction after 90, 180, and 270 days of the experiment in peripheral blood cells of the tail vein. The calculation of the relative level of gene expression was carried out based on the Livak method (2Ct); the assessment of the difference significance using a two-sample t-test for independent samples. Results. The analysis of the relative level of genes encoding D1-type dopamine receptors expression showed that a decrease in the Drd1 gene expression level after 90 days of the experiment was detected only in male rats from immobilization stress and control groups [RQ 0.35 (p=0.003) and 0.21 (p=0.002), respectively], while in males from other groups and females, the activity of this gene did not change significantly throughout the course of the experiment. The relative expression level of Drd5 gene changed only in female rats. In females subjected to intense physical activity, the level of this gene expression increased almost 4 times (RQ 3.82, p=0.005) 90 days after the start of the experiment, and in females of the control group, the transcriptional activity of the gene decreased 4 times after 180 days of the experiment (RQ 0.25, p=0.015). When assessing changes in the activity of genes encoding D2-type receptors for the Drd3 and Drd4 genes, a significant increase in the relative expression level was revealed in all experimental groups, both in males and females, on the 180th day of exposure to stress factors. At the same time, activation of both genes was occurred after 90 days in the control group only in females and persisted up to another 90 days, after which it returned to the initial level. Expression of the Drd2 gene wasn't detected in rat blood cells. Conclusion. The relative level of expression of D1- and D2-like receptor genes in rat peripheral blood cells depends on the type of chronic stress and has pronounced sexual dimorphism.

The selection of the optimal line of the transplanted cell culture and the adaptation of the rabies virus to it makes it possible to exclude the use of laboratory animals, fully control the process of obtaining viruscontaining material with high infectious activity in large quantities and with a faster and shorter production cycle. The adaptive potential of various strains of rabies virus varies significantly, in this regard, the aim of the study was to study the sensitivity of the production strain of the rabies virus "Sheep" GNKI to the transplanted cultures of NGUK-1 and ВНК-21/13 cells. The adaptation of the rabies virus to the transplanted cultures of NGUK-1 and VNK-21/13 cells was carried out by sequential passivation. The titer of the virus was calculated by the number of fluorescent foci, the concentration of rabies virus antigen was determined by the ELISA method, the pathogenicity of the virus at the level of 11 passages on different cell lines – on white mice.It was found that the transplanted ВНК-21/13 cell line provided a faster adaptation of the virus and the achievement of maximum titers within 36-48 hours, whereas the NGUK-1 line maintained relatively slow replication and ensured the achievement of maximum titers after 96-120 hours. The optimal multiplicity of infection with NGUK-1 and ВНК-21/13 was 0.1 KKID50/cell, while the titers of the "Sheep" virus strains were 4.11±0.26 and 6.17±0.49 lg KKID50/cm3, respectively. Virus replication in ВНК-21/13 cells was characterized by greater intensity: the antigenic titer of the virus at all passage levels was 1.5-2 times (p<0.05) higher than that in NGUK-1 cells. The positive dynamics of the accumulation of the viral titer persisted until passage 8-9, after which this indicator remained stable until passage 11 inclusive. The results of the assessment of the pathogenicity of the rabies virus at the level of passage 11 on different cell lines showed that the virus adapted to both NGUK-1 and ВНК-21/13 has not lost pathogenicity for white mice. Thus, it was found that the transplanted ВНК-21/13 cell line significantly exceeds the NGUK-1 cell line in terms of replicative capabilities and can be used to develop viral raw materials for the production of diagnostic tools and specific prevention.

The aim of the research was to develop a direct dot-immunoassay on a nitrocellulose membrane (NCM) using a conjugate based on colloidal gold for the qualitative determination of the presence of rabies virus antigen in pathological material. As the test samples, we used brain samples of various animal species, which were positive during the initial study by methods of fluorescent antibodies: foxes and mice. IFA and indirect ELISA carried out using diagnostic kits manufactured at the Federal Center for Toxicological, Radiation and Biological Safety. The materials present the results of primary laboratory tests of the test system for the indication of rabies antigen based on direct dotimmunoassay (DIA) 81 samples of pathological material, the brain of various animal species. It was shown that DIA has 100% specificity, and its optical signals correlate with the results of indirect ELISA. The proposed DIA method, in addition to independent application, can also serve as a basis for the design of test systems based on immunochemical analysis.

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The aim of the work was to develop an approach to isolation of rabies virus glycoprotein applying threephase extraction and to characterize its antigenic properties.Materials and methods. Infectious activity of the rabies virus (production strain, “Ovine” GNKI) after long-term storage was restored on white BALB/c mice. The strain was used for cultivation on BHK-21 cells; the culture liquid was concentrated applying ultracentrifugation followed by separation by buoyant density in a sucrose gradient, selection of visually opalescent zones, phase concentration, chromatographic separation on an ENrich™ SEC650 column (Bio-Rad, USA) and selection of monomeric fractions with high serological activity according to the results of Western blotting.Results and discussion. We have demonstrated that preliminary mechanical destruction of brain suspension, extraction of the virus-containing material from the cell suspension through successive low-speed and high-speed centrifugation, separation of the sediment produced in sucrose gradient with further phase concentration and chromatographic separation of the precipitate allows to obtain monomeric antigenic preparations with high serological activity. This methodology has made it possible to obtain an antigen, which is rabies virus glycoprotein with a molecular weight of 67 kDa, and two of its isoforms, having molecular weights of 60 and 54 kDa. The described approach can be viewed as an option for isolation of the rabies virus specific antigen when improving laboratory diagnostics techniques. The resulting antigen is a monomeric discrete containing one fraction with a molecu lar weight of 67 kDa. The data obtained corroborate the high specificity of the antigen and its suitability for the design of enzyme immunoassay and immunochromatographic tests, production of specific immunoglobulins, the study of the antigen/antibody interaction, as well as for the assessment of the protective immunity intensity after vaccination.