Voprosy virusologii最新文献

Introduction: The widespread occurrence of enterovirus echovirus 30 (E30) and cases of severe disease indicate the need for vaccine development. Epitopes for neutralizing antibodies and T-cell response have been found in VP3 proteins of some enteroviruses. However, the immunogenic properties of VP3 E30 have not been studied. The aim of this work is to characterize the immunogenic properties of VP3 E30 and testing the virus-neutralizing properties of antibodies against VP3 E30.

Materials and methods: VP3_E30 and the chimeric protein S_N-VP3_E30, consisting of the S region of norovirus VP1 and VP3 E30 were expressed in Escherichia coli. S_N-VP3_E30 was used to form virus-like particles (VLPs). The effect on human dendritic cells (DCs) was assessed by flow cytometry to measure changes in HLA-DR, CCR7, CD80, CD83 and CD86 expression. BALB/c mice and guinea pig were used for immunization with S_N-VP3_E30. Antibody titers and avidity were determined by ELISA. The interaction of antibodies with VP3 E30 was studied by immunoelectron microscopy and virus neutralization in embryonal rhabdomyosarcoma (RD) cell culture.

Results: Recombinant VP3 E30 caused incomplete DCs maturation, characterized by the understimulation of the CCR7 chemokine receptor expression. Inclusion of VP3 in the chimeric VLPs resulted in complete DCs maturation and a strong humoral immune response in laboratory animals. Antibodies against VP3 were characterized by high avidity, the ability to induce agglomeration of viral particles and neutralization of E30 in RD cell culture.

Conclusion: The obtained results indicate that VP3 can be used as an antigen in the composition of a subunit vaccine against enterovirus E30.

Introduction: Hepatitis B and C viruses cause chronic infections leading to liver cirrhosis and hepatocellular carcinoma. This study aimed to determine the seroprevalence of hepatitis B and C viruses and the potential risk factors which might influence the prevalence among health care workers (HCWs) in Brazzaville, Republic of Congo.

Materials and methods: We conducted a cross-sectional study from June to November 2022 among HCWs from the Talangaï and Makélékélé referral hospitals, Brazzaville. 107 HCWs were included and serological screening was carried out using rapid screening tests followed by the ELISA technique, after completing a survey questionnaire.

Results: The mean age was 36.56 ± 11.62 years with a female predominance of 1 : 0.36 sex ratio, laboratory technicians were the most represented socio-professional category. Seroprevalence of HBV was 7.48% and that of HCV was 3.74%. During their service, 40% have already been the victims of blood exposure accidents and have 7 times more risk of contracting HBV (odd ratio [OR] = 7.01 (95% Confidence interval [CI] 1.54-31.96); p = 0.01).

Conclusion: These data show that hepatitis B and C viruses are still endemic among HCWs in Republic of Congo. We can conclude that the health care sector is a high-risk profession due to infection with hepatitis B and C viruses. It is therefore necessary to improve the health and safety conditions of HCWs, implement new strategies to reduce occupational exposure to blood and body fluids, and reduce viral contamination by hepatitis B and C.

For nearly 80 years since the discovery of the first virus by the Russian scientist D.I. Ivanovsky, it has been recognized that all organisms of Earth's biosphere serve as natural hosts for viruses. Viruses, grouped within the informal domain Vira, infect all three domains of cellular life: archaea - Archaea, bacteria - Bacteria, and eukaryotes - Eucarya (algae, fungi, protozoa, plants, invertebrates, and vertebrates). The formation of viral population gene pools through interactions with the gene pools of their hosts has taken place under changing environmental conditions over 3.5 billion years, giving rise to the vast diversity of the virosphere. The accumulation of data on the Earth's virosphere, facilitated by the advent of high-throughput sequencing technologies (NGS), has necessitated a reassessment of approaches to virus classification and, since 2018, has led to a reform of viral taxonomy through the introduction of higher taxonomic ranks (megataxonomy). As of September 2025, the International Committee on Taxonomy of Viruses (ICTV) recognizes 15 taxonomic ranks for viruses, the most significant being: realm - 7, kingdom - 11, phylum - 23, class - 49, order - 93, family - 368, genus - 3769, and species - 16,215. Ongoing advances in metagenomics, metatranscriptomics, and the global ecology of the virosphere will inevitably drive further changes in viral taxonomy and megataxonomy. These developments are of fundamental importance for understanding the evolution of the biosphere and of practical relevance for developing new strategies to strengthen biological security and to mitigate the consequences of epidemic emergencies associated with emerging and reemerging infections.

Introduction: Human cytomegalovirus infection can induce tumor cell resistance to chemotherapeutic agents through modulation of apoptotic pathways. In the search for alternative approaches to overcome virus-associated drug resistance, the application of nanomaterials (aqueous fullerene dC₆₀) represents a promising strategy. The potential to overcome human cytomegalovirus mediated chemoresistance opens new avenues for developing combined therapeutic approaches in oncology. Aim - to evaluate the impact of human cytomegalovirus infection on the resistance of hepatocellular carcinoma and promyelocytic leukemia cells to doxorubicin, as well as the potential of aqueous fullerene dC₆₀ to restore chemosensitivity in monocytic leukemia cells.

Materials and methods: Hepatocellular carcinoma cells (Huh 7.5), promyelocytic leukemia cells (HL-60), monocytic leukemia cells (THP-1), and HCMV AD169 were used. The experimental procedures included standard cell culture techniques, virological methods, immunocytochemistry, Western blotting, Real-Time Polymerase Chain Reaction, Quantitative Reverse Transcription Polymerase Chain Reaction and MTT assay.

Results: Human cytomegalovirus infection reduced doxorubicin cytotoxicity by 30% in both hepatocellular carcinoma and promyelocytic leukemia cells. In monocytic leukemia cells, combined treatment with doxorubicin and dC₆₀ restored chemosensitivity to human cytomegalovirus infected cells, achieving 93% tumor cell death at half the standard doxorubicin concentration.

Conclusion: Human cytomegalovirus infection induces doxorubicin resistance in both hematopoietic (promyelocytic leukemia, monocytic leukemia) and solid (hepatocellular carcinoma) tumor models. Importantly, combined treatment doxorubicin with aqueous fullerene dC₆₀ not only overcomes virus-mediated drug resistance in monocytic leukemia cells but also enhances cytotoxicity at reduced doxorubicin concentrations, offering prospects for developing less toxic combined therapeutic regimens.

Introduction: Hepatitis C is a pressing global public health issue. The high variability of the hepatitis C virus (HCV) complicates its whole-genome sequencing; most studies sequence only specific regions of the genome. There is a need for a simple and reliable method for sequencing the whole genome of HCV.

Objective: Development and validation of NGS panel for whole-genome sequencing of HCV.

Materials and methods: This study presents NGS amplification panel for sequencing the genomes of HCV genotypes 1, 2, and 3. Depending on the genotype, a set of 79, 67, or 89 primers is used. These primers enable amplification of overlapping regions of the HCV genome.

Results: The panel was tested on 153 HCV RNA samples isolated from blood plasma specimens (93/6/54 samples of genotypes 1/2/3, respectively). Shannon entropy analysis showed that genetic heterogeneity within the E2 gene is significantly higher than in other parts of viral genome. The frequency of mutations associated with drug resistance was determined. Specifically, for genotype 1, the following mutation detection rates were observed in NS3: Y56F - 37.6%, V170I - 23.7%; in NS5a: R30Q - 8.6%, P58L/S/T - 6.5%, A92T - 4.3%; in NS5b: L159F - 45.2%, S556G/N - 33.3%.

Conclusion: The current study describes a method for whole-genome sequencing of HCV genotypes 1, 2, and 3. The HCV sequencing panel shows great potential for use in scientific research and epidemiological monitoring.

Introduction: Highly pathogenic for humans orthopoxviruses (OPV) - Variola virus (VARV) and Monkeypox virus (MPXV) can cause systemic diseases characterized by high contagiousness and often leading to death. In previous publications (https://doi.org/10.3390/v14112580), we reported on the development of a sensitive, rapid and easy-to-use immunochemical test potentially suitable for use in the infection foci and in laboratory conditions with a high level of biosecurity. The prototype of the diagnostic kit was tested on non-pathogenic and low-pathogenic for humans OPV and specifically detected them with a sensitivity within the range of 10³ to 10⁴ PFU/mL. The aim of this work was to evaluate the sensitivity of this assay in detecting highly pathogenic for humans MPXV and VARV, as well as the applicability of the assay in a laboratory with a high level of biosafety (BSL-4).

Materials and methods: The efficiency of virus detection in cryolysates of CV-1 cell culture samples infected with VARV and MPXV was assessed using a one-step dot immunoassay method in a laboratory with biosafety level BSL-4.

Results: It was shown that the one-step dot assay allows detection of MPXV at a concentration of 2.5 × 10³ PFU/mL, and VARV at a concentration of 1.0 × 10⁴ PFU/mL. It was noted that vapors from disinfectants (hydrogen peroxide/formaldehyde) applied in biosafety cabinet decontamination may interfere with assay performance and affect result interpretation.

Conclusion: The one-step dot immunoassay can be performed in a BSL-4 laboratory. When limiting the contact of the detecting system with formaldehyde vapors, the sensitivity of the test for detection of VARV and MPXV falls within the previously declared range of 10³-10⁴ PFU/mL.

The review examines issues related to occult hepatitis B virus infection (OBI), which occurs at a late stage of chronic hepatitis B (CHB) after HBsAg clearance. In clinical practice, OBI is detected by the absence of HBsAg and the presence of antibodies to HBcAg in the blood serum and is often referred to as «past» or «resolved» hepatitis B. However, hepatitis B virus (HBV) DNA remains in liver cells, is poorly detected by routine diagnostic methods, and cannot be removed by existing therapies. Data on the prevalence of OBI vary, but it is found in all regions of the world, much more often in regions with a high prevalence of HBV. Data on the association of OBI with fibrosis, cirrhosis and hepatocellular carcinoma (HCC) have been obtained. It has been established that OBI is associated with an increased risk of HBV reactivation in patients with infections with other viruses, as well as in cancer patients whose treatment includes immunosuppressive therapy. HBV reactivation leads to severe consequences and, in the absence of treatment, death of patients. It can be concluded that to achieve the goal set by WHO for the eradication of viral hepatitis by 2030, it is necessary to solve the problem of OBI. In order to make this possible, it is essential to create new, more sensitive and informative diagnostic tests, effective methods of HBV DNA elimination, and to investigate the mechanisms of OBI development in more depth.

Introduction: Mosquito-borne human diseases caused by Zika virus and West Nile virus (WNV) are widespread across multiple continents and cause major outbreaks. Their ranges overlap and the possibility of mixed infections is obvious. The information of such mixed infections is limited. The aim of the study is to investigate the features of mixed infection of WNV and Zika virus in vitro and in vivo in order to assess their possible interference and/or enhancement of viral infection.

Materials and methods: The study used West Nile virus and Zika virus strains Vlg27924 and MR766, respectively. The infectious activity of viruses during mono- and co-infection was determined on Vero E6 cell culture using RT-PCR, as well as on BALB/c mice using various administration schemes.

Results: In vitro studies of co-infection with WNV and Zika virus showed that co-infection leads to interference, with the degree of competitive inhibition of replication being more pronounced for Zika virus, reaching 1000 times or more when compared to mono-infection. During simultaneous infection in mice, Zika virus does not affect the development of lethal infection caused by WNV. However, preliminary (4 and 20 days) infection with a sublethal dose of Zika virus reliably protects animals from subsequent administration of 10 and 100 LD₅₀ WNV, respectively. In pre-infected and co-infected animals with Zika virus, the development of WNV-specific viral neutralizing antibodies was recorded in higher titers than in WNV monoinfected animals.

Conclusion: The presence of in vitro interference between the studied orthoflaviviruses was shown, most pronounced in relation to the Zika virus. No significant effect was observed with simultaneous co-infection in vivo. However, pre-infection of mice with Zika virus provides protection to animals from lethal WNV infection due to the induction of high levels of antibodies that specifically neutralize its infectious activity.

Introduction: Vpr is a multifunctional auxiliary HIV-1 protein. Oligomerisation is a prerequisite for the entry of Vpr into the virion and its subsequent participation in the early stages of HIV-infection. To date, natural amino acid substitutions in Vpr associated with disease progression were identified; the possibility of creating therapeutics based on Vpr is being considered. The aim of the study is to investigate Vpr features in the most common genetic variants of HIV-1 circulating in the Moscow region in 2019-2020.

Materials and methods: HIV-1 samples obtained from 231 patients of the AIDS Prevention and Control Center in the period 2019-2020 were studied according to the scheme: proviral DNA extraction, amplification of the vpr gene, sequencing, and data analysis. Consensus Vpr sequences of the most common genetic variants in Russia and their spatial structures, variability of Vpr variants of HIV-1 sub-subtype A6 in patients with different stages of the disease were studied.

Results: Features of Vpr protein in different genetic variants of HIV-1 could influence the formation of their oligomeric forms. No sites with statistically significant differences in the frequency of amino acid substitutions were identified in patients with different stages of disease.

Conclusion: Vpr protein of HIV-1 genetic variants circulating in Russia may have differences in functional properties. Vpr-A6 variants had low variability in patients with different stages of the disease, and therefore Vpr-A6 can be considered as a target for the development of therapeutic agents.