Voprosy virusologii最新文献

Introduction: A vaccine against hepatitis C has not yet been developed. Recombinant proteins and plasmids encoding hepatitis C virus (HCV) proteins, the components of candidate vaccines, induce a weak immune response and require the use of adjuvants. The aim of the work was to study the adjuvant action of an aqueous solution of fullerene C60 during immunization of mice with HCV recombinant protein NS5B (rNS5B) that is an RNA-dependent RNA polymerase, or with NS5B-encoding pcNS5B plasmid.

Materials and methods: An aqueous solution of dispersed fullerene (dnC60) was obtained by ultrafiltration. C57BL/6 mice were immunized with rNS5B subcutaneously, pcNS5B intramuscularly mixed with different doses of dnC60 three times, then the humoral and cellular response to HCV was evaluated.

Results: Mice immunization with rNS5B in a mixture with dnC60 at doses of 250 g/mouse significantly induced humoral response: a dose-dependent increase in IgG1 antibody titers was 720 times higher than in the absence of fullerene. There was no increase in the cellular response to rNS5B when administered with dnC60. The humoral response to DNA immunization was weak in mice of all groups receiving pcNS5B. The cellular response was suppressed when the plasmid was injected in a mixture with dnC60.

Conclusions: Dispersed fullerene dnC60 is a promising adjuvant for increasing the immunostimulating activity of weakly immunogenic proteins including surface and other HCV proteins, important for a protective response. Further research is needed to enhance the ability of dnC60 to boost the cellular immune response to the components of the candidate vaccine.

In No. 5, 2022 of the journal "Questions of Virology" in the section "Editorial concept" the article "130 years of virology" was published (Lvov D.K., Alkhovsky S.V., Zhirnov O.P. 130 years of virology. Questions of virology. 2022; 67(5): 357-384. DAY: https://doi.org/10.36233/0507-4088-140).The review presents the main stages of the formation and development of virology as a science in Russia with an emphasis on the most significant achievements of domestic virologists in the fight against viral infectious diseases of humans and animalsThe editorial office received the following reviews and reviews of the article.

Introduction: In Russia, rotavirus A is the main cause of severe viral gastroenteritis in young children. The molecular features that allow a rotavirus of a particular genotype to gain an evolutionary advantage remain unclear, therefore, the study of the genetic diversity of rotaviruses based on genes encoding nonstructural proteins (NSPs) responsible for the reproduction of the virus in the cell is an urgent task.

Objective: To study the genetic diversity of rotaviruses of genotype G9P[8], which dominated Nizhny Novgorod in 20112020, based on genes encoding nonstructural proteins.

Materials and methods: Rotavirus-positive samples were subjected to PCR-genotyping and sequencing of NSP1 NSP5 genes. Phylogenetic analysis was carried out in the MEGA X program.

Results: In the period 20112020, G9P[8] rotaviruses with four variants of the NSP2 gene were co-circulating in Nizhny Novgorod. New alleles were noted in 2012 (N1-a-III), 2016 (N1-a-IV) and in 2019 (N1-a-II). The appearance of new variants of other genes occurred in 2014 (E1-3, NSP4), 2018 (T1-a3-III, NSP3) and in 2019 (A1-b-II, NSP1). NSP2 gene had the most variable amino acid sequence (16 substitutions), 2 to 7 substitutions were observed in NSP1, NSP3 and NSP4, NSP5 was conservative.

Discussion: The results obtained are consistent with the literature data and indicate the participation of NSP genes in maintaining the heterogeneity of the rotavirus population.

Conclusion: Until 2018, the genetic diversity of rotaviruses in Nizhny Novgorod was determined by the circulation of strains carrying several alleles of the NSP2 gene and conservative genes NSP1, NSP3NSP5. By the end of the study period, new variants of the genotype G9P[8] were formed in the population, carrying previously unknown combinations of alleles of nonstructural genes.

Introduction: Outbreaks of infectious diseases seriously hinder the preservation and increase of the number of small ruminants. Such infections include sheep pox virus (SPPV). According to the OIE data of 2021, SPP outbreaks were registered in countries such as Turkey, Israel, China, Maldives, Mongolia, Thailand, Russia, Algeria, Kenya, and in 2019 in Mangistau and Atyrau regions. In Kazakhstan annually conducts routine immunization of sheep at risk with a live attenuated vaccine produced by RIBSP.

Materials and methods: The object of the study was the vaccine strain of NISHI and the virulent strain A of the sheep pox virus. The virus was propagated in Vero cells. To determine the harmlessness and immunogenicity, sheep of the Kazakh fine-wool breed aged from 6 to 12 months were used. Virological, serological and immunobiological methods were used in the study.

Results: The results of the adaptation of the NISHI strain of SPPV to the Vero cell line are presented. Five passages in Vero cells resulted to the adaptation of the NISHI strain with the manifestation of a cytopathogenic effect specific to SPPV with a titer of 6.50 lg TCD50/ml. Following immunization, the formation of immunity was observed in animals on day 7 with an average protective titer 1.8 log2, which increased by day 21 to 4.33 log2.

Conclusion: It has been established that the NISHI strain of SPPV retains its virological and immunobiological properties during reproduction in a Vero cell line.

Introduction: Convalescent COVID-19 patients have various signs of central nervous system damage, including those directly associated with SARS-CoV-2. Hence, studies of SARS-COV-2 related morphological changes in neocortex are particularly relevant for understanding the mechanisms of their formation and development of approaches to preclinical evaluation of the effectiveness of antiviral drugs. The purpose of the research is a longitudinal study of the ultrastructural alterations in Syrian hamsters neocortex after experimental SARS-CoV-2 infection.

Materials and methods: Male Syrian hamsters weighing 80100 g, aged 4 to 6 weeks, were infected with 26 l SARS-CoV-2 intranasally with 4104 TCD50/ml of viral particles. The animals were euthanized on days 3, 7 or 28 post-infection, the brain was extracted with the cortex excision. The material analysis was performed using transmission electron microscopy.

Results and discussion: On day 3 post-infection, the number of moderately hyperchromic neurons in neocortex increased, while by the day 7 the number of apoptotic cells significantly increased. Simultaneously, an increased signs of neuronophagy and representation of atypical glia were observed. Increased number of altered oligodendrocytes was observed on day 28 post-infection. Viral invasion was accompanied by changes in neocortical cells since day 3 post-infection, such as transformation of their nucleus, the rough endoplasmic reticulum and the Golgi vesicles as well as microvascular spasm with perivascular edema.

Conclusion: As a result of electron microscopic study, the ultrastructural alterations in neocortex were described in an experimental model of SARS-CoV-2 infection. The findings can be used to identify the mechanisms of infection pathogenesis and to search for the new directions in development of medicines.

Introduction: The variability of SARS-CoV-2 appeared to be higher than expected, the emergence of new variants raises concerns. The aim of the work was to compare the pathogenicity of the Wuhan and BA.1.1/Omicron variants in BALB/c mice and Syrian hamsters.

Materials and methods: The study used strains of SARS-CoV-2: Dubrovka phylogenetically close to Wuhan-Hu-1, and LIA phylogenetically close to Omicron, BALB/c mice, transgenic mice B6.Cg-Tg(K18-ACE2)2Prlmn/HEMI Hemizygous for Tg(K18-ACE2)2Prlmn, Syrian golden hamsters. Animals were infected intranasally, pathogenicity was estimated by a complex of clinical, pathomorphological and virological methods.

Results: Comparative studies of SARS-CoV-2 Dubrovka and LIA strains on animal models demonstrated their heterogeneous pathogenicity. In parallel infection of BALB/c mice with Dubrovka and LIA variants, the infection proceeded without serious clinical signs and lung damage. Infection with the LIA strain resulted to a systemic disease with a high concentration of viral RNA in the lungs and brain tissues of animals. The presence of viral RNA in mice infected with the Dubrovka strain was transient and undetectable in the lungs by day 7 post-infection. Unlike the mouse model, in hamsters, the Dubrovka strain had a greater pathogenicity than the LIA strain. In hamsters infected with the Dubrovka strain lung lesions were more significant, and the virus spread through organs, in particular in brain tissue, was observed. In hamsters infected with the LIA strain virus was not detected in brain tissue.

Conclusion: The study of various variants of SARS-CoV-2 in species initially unsusceptible to SARS-CoV-2 infection is important for monitoring zoonotic reservoirs that increase the risk of spread of new variants in humans.

The review provides information on the mechanisms of the emergence of resistance to antiviral drugs in human viruses from the subfamily Betaherpesvirinae. Data on the principles of action of antiviral drugs and their characteristics are given. The occurrence rates of viral resistance in various groups of patients is described and information about the possible consequences of the emergence of resistance to antiviral drugs is given. Information is provided regarding the virus genes in which mutations occur that lead to viral resistance, and a list of such mutations that have described so far is given. The significance of the study of mutations leading to the resistance of the virus to antiviral drugs for medical practice is discussed.

130 years ago, in 1892, our great compatriot Dmitry Iosifovich Ivanovsky (18641920) discovered a new type of pathogen viruses. Viruses have existed since the birth of life on Earth and for more than three billion years, as the biosphere evolved, they are included in interpopulation interactions with representatives of all kingdoms of life: archaea, bacteria, protozoa, algae, fungi, plants, invertebrates, and vertebrates, including the Homo sapiens (Hominidae, Homininae). Discovery of D.I. Ivanovsky laid the foundation for a new science virology. The rapid development of virology in the 20th century was associated with the fight against emerging and reemerging infections, epidemics (epizootics) and pandemics (panzootics) of which posed a threat to national and global biosecurity (tick-borne and other encephalitis, hemorrhagic fevers, influenza, smallpox, poliomyelitis, HIV, parenteral hepatitis, coronaviral and other infections). Fundamental research on viruses created the basis for the development of effective methods of diagnostics, vaccine prophylaxis, and antiviral drugs. Russian virologists continue to occupy leading positions in some priority areas of modern virology in vaccinology, environmental studies oz zoonotic viruses, studies of viral evolution in various ecosystems, and several other areas. A meaningful combination of theoretical approaches to studying the evolution of viruses with innovative methods for studying their molecular genetic properties and the creation of new generations of vaccines and antiviral drugs on this basis will significantly reduce the consequences of future pandemics or panzootics. The review presents the main stages in the formation and development of virology as a science in Russia with an emphasis on the most significant achievements of soviet and Russian virologists in the fight against viral infectious diseases.

Introduction: Parenteral viral hepatitis (B, C, D) and HIV share modes of transmission and risk groups, in which the probability of infection with two or more of these viruses simultaneously is increased. Mutual worsening of the course of viral infections is important issue that occurs when HIV positive patients are coinfected with parenteral viral hepatitis. The aim of the study was to determine the prevalence of HCV, HBV and HDV in HIV positive patients in the Novosibirsk region and to give molecular genetic characteristics of their isolates.

Materials and methods: Total 185 blood samples were tested for the presence of total antibodies to HCV, HCV RNA, HBV DNA and HDV RNA. The identified isolates were genotyped by amplification of the NS5B gene fragment for HCV, the polymerase gene for HBV and whole genome for HDV.

Results: The total antibodies to HCV were detected in 51.9% (95% CI: 44.758.9), HCV RNA was detected in 32.9% (95% CI: 26.639.5) of 185 studied samples. The distribution of HCV RNA positive cases completely repeated the distribution of HCV serological markers in different sex and age groups. The number of HCV infected among HIV positive patients increases with age. HCV subgenotypes distribution was as follows: 1b (52.5%), 3а (34.5%), 1а (11.5%), 2а (1.5%). 84.3% of detected HCV 1b isolates had C316N mutation associated with resistance to sofosbuvir and dasabuvir. The prevalence of HBV DNA in the studied samples was 15.2% (95% CI: 10.721.0). M204I mutation associated with resistance to lamivudine and telbivudine was identified in one HBV isolate. Two HDV isolates that belonged to genotype 1 were detected in HIV/HBV coinfected patients.

Conclusion: The data obtained confirm the higher prevalence of infection with parenteral viral hepatitis among people living with HIV in the Novosibirsk region compared to the general population of that region. The genetic diversity of these viruses among HIV infected individuals is similar to that observed in the general population.

The continuous emergence of new pathogens and the evolution of microbial drug resistance make it absolutely necessary to develop innovative, effective vaccination strategies. Use of nasal vaccination can increase convenience, safety, cause both local and systemic immune reactions. Intranasal administration nevertheless has a number of shortcomings that can be overcome by using the latest achievements of pharmaceutical science. One of the aspects of such solution may be the use of systems for the production of intranasal vaccines in situ polymer compositions that provide a directed sol-gel transition controlled by the physiological conditions of the nasal cavity. At the same time, the gelation of the administered dose in contact with the nasal mucosa involves prolonged exposure of the drug at the injection site, greater mucoadhesion, counteraction to mucociliary clearance, modified and more complete release. A number of both foreign and domestic manufacturers produces polymers such as chitosan, gums, polyoxyethylene and polyoxypropylene block copolymers (poloxamers, proxanols), carbomers. For effective pharmaceutical development of new intranasal IBD delivery systems corresponding to the QbD concept, not only the knowledge of the range of excipients is necessary, but also simple, accessible, and reproducible methods for determining indicators that define the critical parameters of such delivery systems. In accordance with the conducted scientific search, the main indicators of standardization of in situ intranasal systems were identified: temperature and time of gel formation, gel strength, rheological characteristics, mucoadhesion, release, nasal mucociliary clearance time.