Voprosy virusologii最新文献

Introduction: Altai Krai is a region with an unfavorable situation of HIV-1 and HCV infection, as well as HIV-1 and HCV coinfection. Due to this, it is necessary to study the HCV genetic variants and their drug resistance (DR) to direct-acting antivirals (DAAs) in patients with HIV-1 and HCV coinfection.

Aim of the study: The analysis of HCV genome fragments encoding NS5A and NS5B proteins in samples obtained from treatment-naïve residents of Altai Krai with newly diagnosed HIV and HCV co-infection to determine the genetic variant of HCV and genetic features of the virus associated with its sensitivity to NS5A and NS5B inhibitors.

Materials and methods: Blood plasma samples (n = 286) collected in 2022-2023 from HIV-infected individuals were analyzed for HCV markers. The HCV RNA concentration was measured, nucleotide sequences of NS5A and NS5B and Core (for HCV 2k/1b samples) fragments were obtained, the subtype was determined, and DR and polymorphic positions were analyzed.

Results: Antibodies to HCV were detected in 94/286 (32.86%) samples, sequences were obtained from 52 samples. Subtypes 3a, 1b, recombinant form 2k/1b and subtype 1a were found in 28 (53.85%), 17 (32.69%), 5 (9.62%) and one (1.92%) samples, respectively. One sample harbored HCV 1b + 3a mix-infection. Reduced sensitivity (5.66%) and complete resistance (9.43%) to the NS5A inhibitor daclatasvir were most often detected. Certain gene polymorphisms were identified in the sequences.

Conclusion: Our results may indirectly indicate the increasing proportion of the HCV subtype 3a in the hepatitis C epidemic in the Altai Territory. Our data on DR and polymorphisms should be taken into account in antiviral therapy of patients.

Introduction: Norovirus (NoV) is one of the main causes of acute gastroenteritis. Currently, there is no vaccine to prevent norovirus infection. Vaccines under development are based on the capsid protein VP1, which is capable of forming virus-like particles. The aim of the work was to analyze the immunogenic properties of the recombinant VP1 protein of NoV GII.4.

Materials and methods: In the blood serum of animals immunized with the recombinant VP1 protein obtained by the authors, titers and avidity of total antibodies and IgM antibodies against NoV VP1 were determined using enzyme immunoassay. The ability of the obtained antibodies to interact with NoV of different genotypes was assessed using immunoelectron microscopy.

Results: The recombinant VP1 protein induced high titer antibody production in animals. Total antibodies against VP1 had a high avidity, reaching 100%, which suggests that they have viral neutralizing activity. IgM antibodies had low avidity. Immunoelectron microscopy showed that IgG antibodies against VP1 protein of genotype GII.4 interact with wild-type NoV of genotype GII.7 and GII.17.

Conclusion: The obtained recombinant protein induces a sufficiently strong immune response with the formation of high avidity polyclonal cross-reacting antibodies, which allows us to consider it as an antigen component of a NoV vaccine candidate.

Herpes simplex viruses (HSV) are extremely widespread pathogens that cause human infections of varying severity, from mild orofacial ulcerations of the skin and mucous membranes to life-threatening encephalitis and severe generalized forms of infection or recurrent herpetic corneal lesions leading to blindness. Standard treatment with acyclovir, penciclovir, or the corresponding prodrugs valacyclovir and famciclovir is usually sufficient to stop recurrent HSV infections. However, immunocompromised patients are of particular concern and often require long-term antiviral therapy. In such conditions, the risk of developing drug resistance, often cross-resistance increases significantly, since all basic antiherpetic drugs have a similar mechanism of action and affect the same drug target - viral DNA polymerase (DNA-pol). With the development of drug resistance, the effectiveness of treatment decreases, and it becomes necessary to switch to second-line drugs with severe side effects. Thus, it is necessary to develop new alternative treatment options. The creation of drugs aimed at a biotarget different from DNA-pol eliminates the risk of cross-resistance to acyclovir and related drugs, and their use in combination with traditional antiherpetic drugs can prevent or slow down the development of drug resistance in the virus. When combining drugs that affect the pathogen in different ways, it is important to maintain the therapeutic effect with the use of lower doses due to the synergistic nature of the interaction, which reduces the likelihood of developing unwanted side effects of drugs. The review presents current data on the state and possible prospects for the development of combination therapy for HSV infections, obtained as a result of searching the literature related to anti-herpetical therapy using the PubMed, Medline databases, RSCI, the international registry of clinical trials of the US National Institutes of Health.

Introduction: The Vif protein counteracts cellular deaminases, APOBEC3, which prevent viral replication. Vif is used for development of therapeutic agents. Natural polymorphisms in Vif can affect its functionality and may be associated with accelerated progression of HIV-infection to the AIDS. The study of Vif features in HIV-1 variants circulating in Russia has not been conducted previously.

The aim of the study: to study the genetic diversity of Vif in the HIV-1 variants that circulated in the Moscow region in 2019-2020.

Materials and methods: 234 whole blood samples obtained from HIV-infected patients without experience of therapy were analyzed. The study design included the following stages: extraction of proviral DNA, amplification of the vif gene, sequencing, identification of genetic variants, followed by a study of consensus sequences of the most common genetic variants of HIV-1, analysis of the conservation and genetic diversity of Vif-A6 (Vif protein of HIV-1 sub-subtype A6 variants) in patients with different stages of the disease, and assessment of genetic diversity of Vif-A6 in the Moscow region.

Results: A high degree of genetic diversity of vif gene was revealed. Consensus sequences of Vif in B and CRF63_02A6 variants were obtained for the first time. Characteristic substitutions in the consensus sequences were determined for the most common HIV-1 variants.

Conclusion: The limitation of this study is the small sample of B and CRF63_02A6. The results obtained may be of interest and may be taken into account in the development of therapeutic agents based on the Vif protein, as well as in the study of the pathogenicity of HIV-1 sub-subtype A6.

Introduction: In 2014-2016, an epidemic of Ebola virus disease (EVD) was registered in Guinea. In 2021, EVD cases were repeated in the region. The importance of studying the duration of post-infection immunity to the Ebola virus in the body of convalescents is due to the fact that after the end of the epidemic they can be the main sources of infection. One of the indicators of the pathogen circulation in a certain area is the detection of specific IgG antibodies in the blood sera of the inhabitants. The aim of the study is to identify IgG immunoglobulins to Ebola virus in the blood sera of reconvalescents and practically healthy residents of the Republic of Guinea after the end of the epidemic.

Materials and methods: The ELISA method was used to test the blood sera of 9 patients treated at the NKDCEM hospital (Kindia), collected after the end of the disease and up to 72 months after recovery, and 3939 blood serum samples from practically healthy residents of Guinea.

Results: IgG antibodies in the blood sera of reconvalescents a month after recovery were detected in a titer of up to 1 : 800. By 12 months, the antibody level decreased to 1 : 100 and remained at this level for up to 48 months. After 6 years of observation, no antibodies were registered. Among the 3939 blood samples from healthy residents, IgG immunoglobulins to the Ebola virus were detected in 5.6%. Most of the positive samples were collected in Forest Guinea (7.7%), and a smaller part in Upper Guinea (4.5%). The maximum percentage of positive samples was detected in people over 70 years of age (12.3%).

Conclusion: In our case, it was shown that a high level of post-infection immunity in the blood sera of patients with EVD persists for the first 6 months, this corresponds to the data obtained by other authors, and does not exclude the possibility of re-infection. The highest level of the seroprevalence is registered in Forest Guinea. This indicates the active circulation of the pathogen and the constant contact of the inhabitants of the region with it, which leads to epidemiological complications.

Introduction: Enterovirus infection, widespread in the world and in Russia, is characterized by a variety of clinical forms, one of which is serous meningitis. The most common cause of enterovirus meningitis in children is echovirus 30 (E30). Previously, we obtained a chimeric protein consisting of the S domain of norovirus VP1 protein(S_N), fused into one molecule with VP1 protein of E30 (S_N-VP1_E30), which in the future can be used to develop a vaccine for the prevention of enterovirus meningitis caused by the E30 virus. The aim of this work was to study the immunological properties of the S_N-VP1_E30 protein.

Materials and methods: Balb/c mice and a guinea pig were immunized with the S_N-VP1_E30 protein. The production of IgG and IgM antibodies was studied by ELISA. The interaction of antibodies against S_N-VP1_E30 with virions of enteroviruses E30 of different genotypes was studied by electron microscopy. The reaction of neutralization of E30 by antibodies was carried out in vitro in RD cells.

Results: In mice immunized with S_N-VP1_E30 without adjuvant, the average titers of total antibodies against E30 VP1 protein were 1 : 19,000. The use of adjuvant increased the average titer of antibodies by 3 times. The level of IgM antibodies was significantly lower and amounted to, on average, 1 : 1500. Using immunoelectron microscopy, it was shown that guinea pig antibodies against chimeric S_N-VP1_E30 are able to bind virions of E30 genotypes h and eC2. Mouse and guinea pig antibodies were able to neutralize E30 in RD cell line. Neutralizing antibody titers in mice varied from 20 to 40, and were 40 in guinea pigs.

Conclusion: The immunogenicity of S_N-VP1_E30 in two animal species and the ability of antibodies to bind and neutralize enterovirus E30 allows us to propose it as an antigen in a vaccine for the prevention of diseases caused by E30.

Introduction: Tick cell lines are widely used to study the biology of ticks and tick-borne pathogens, especially viruses. Most of the cell cultures currently available have been obtained from tick embryonic cells and can be infected with viruses. The HAE/CTVM8 cell line was obtained from Hyalomma anatolicum ticks and is often used for isolation of novel viruses. The aim of the work is to study the HAE/CTVM8 cell line using high-throughput sequencing in order to search for viruses in it.

Materials and methods: The HAE/CTVM8 cell culture fluid was ultracentrifuged. The resulting pellet was used for high-throughput sequencing after RNA extraction, reverse transcription reaction, and synthesis of the second strand. The resulting reads were filtered by length and quality in the Trimmomatic program, after which the contigs were assembled using the SPAdes program and analyzed for the presence of viral sequences. The final assembly of the virus genome was carried out in the Ugene program. Sequence alignment was performed by the MAFFT program. The phylogenetic trees were constructed using the IQ-TREE program.

Results: We have identified the persistence of one virus, Liman tick virus (LMTV), in HAE/CTVM8 cell culture. Phylogenetically LMTV belongs to the Chuviridae - novel family, that consists of viruses detected by high-throughput sequencing, the virological characteristics of which are currently unknown.

Conclusion: The obtained information is of significant importance when utilizing HAE/CTVM8 cell culture in scientific research and during the process of isolating new viruses. Our study shows that this cell line with persistent LMTV is a ready-to-use system for studying Chuviridae reproduction.

Introduction: Human metapneumovirus (hMPV) holds significant epidemiological importance, being a dominant cause of lower respiratory tract infections in children under two years of age and individuals over 65. Multiple infections with hMPV throughout a person's life are possible due to the antigenic and genetic variability of the virus. However, the genetic variability of hMPV circulating in Russia remains unexplored.

Aim of the study: The aim of this study was to test a protocol for whole-genome sequencing of hMPV to assess the genetic diversity of metapneumoviruses circulating in certain regions of Russia.

Materials and methods: Nasopharyngeal swabs were collected from patients of different ages with acute respiratory viral infections (ARVI) tested positive for hMPV using polymerase chain reaction (PCR). From some of the samples, viral isolates were obtained in cell culture. Whole-genome sequencing was performed on both swabs and isolates using the MiSeq Illumina platform, followed by phylogenetic analysis.

Results: For the first time in Russia, whole-genome sequencing of 44 hMPV strains circulating from 2017 to 2024 was conducted. Their genetic group affiliation was described, with the A2b2 clade shown to dominate. It was confirmed that the greatest variability among genes encoding viral surface proteins was observed in the G gene, while changes in the F gene were minimal during the studied period.

Conclusion: The study provides insights into the genetic diversity of hMPV strains circulating in various regions of the Russian Federation. Understanding the genetic variability of hMPV is crucial for comprehending viral evolution, transmission dynamics, and mechanisms of immune evasion, which influence the development of vaccines and antiviral drugs.

Animal rotaviruses (RV) play a significant role in the formation of new variants of epidemiologically significant human group A rotavirus (RVA) strains.A reassortant variant of genotype G3P[8] which has been shown to originate from RV in horses and cattle currently dominates on the territory of the Russian Federation. In addition, reassortant RV variants of genotypes G3P[3], G3P[9], G6P[9], similar to RV of cats and dogs, have been sporadically identified in the world for a long time. Given the relevance of this topic, a detailed study of the AU-1-like genetic group of RVAs, whose representatives are closely related to animal RVs, particularly those found in cats and dogs, is of scientific and practical interest. The aim of this review is to analyze published scientific data on human, feline and canine RV that belong to the AU-1-like genetic group and have been studied based on their complete genotypes.

Introduction: The prevalence of new coronavirus infection (COVID-19) in 2021-2022 in the pediatric population was 9.5%, and fatal outcomes began to be recorded. In 2022-2023, the proportion of children infected with COVID-19 increased to 18%. Developing a vaccine for the pediatric population is an urgent task. The aim of the study is to explore the effect of the vaccine on the parameters of general and biochemical blood tests in immature rats.

Materials and methods: The study was performed on 112 immature rats (60 females, 52 males) of the Wistar line. Animals were randomized into groups that received the CoviVac vaccine at doses of 0.125, 0.25 and 0.5 mL/animal or placebo (0.5 mL/animal), intramuscularly on days 1, 15, 29 and 43 of the experiment. General and biochemical blood tests were performed twice, on the 57th and 71st days.

Results: Oligocythemia (0.25 and 0.5 mL/animal, p < 0.05), leukocytosis and thrombocytopenia (0.5 mL/animal, p < 0.05) were recorded in males. Monocytopenia (0.5 mL/animal, p < 0.05) and leukopenia (0.25 mL/animal, p < 0.05) were established in females. In males, an increase in the amount of globulins and total protein (0.5 mL/animal), a decrease in the A/G ratio (doses 0.25 and 0.5 mL/animal), a decrease in the cholesterol level (0.125 mL/animal) were detected. In females, an increase in the amount of albumin and total protein (0.5 mL/animal, p < 0.05), a decrease in the level of triglycerides (0.125, 0.25, 0.5 mL/animal, placebo, p < 0.05), a decrease in the level of lactate dehydrogenase, triglycerides and urea (0.25 mL/animal, p < 0.05) were recorded.

Conclusion: The safety of the CociVac vaccine in relation to clinical and biochemical blood parameters has been demonstrated.